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(12) INTERNATIONAL APPLICATION PUBLISHED UNDER THE PATENT COOPERATION TREATY (PCT) 




(19) World Intellectual Property Organization 

International Bureau 

(43) International Publication Date (10) International Publication Number 

5 April 2001 (05.04.2001) PCT WO 01/24179 Al 



(51) International Patent Classification 7 : Gl IB 20/12, 

27/10, 27/034, 27/30 

(21) International Application Number: PCT/JP00/06800 

(22) International Filing Date: 

29 September 2000 (29.09.2000) 

(25) Filing Language: English 

(26) Publication Language: English 

(30) Priority Data: 

1 1/280857 30 September 1999 (30.09.1999) JP 

2000/272263 7 September 2000 (07.09.2000) JP 

(71) Applicant: MATSUSHITA ELECTRIC INDUSTRIAL 
CO., LTD. [JP/JP]; 1006, Oaza Kadoma, Kadoma-shi, Os- 
aka 571-8501 (JP). 



(72) Inventors: GOTOH, Yoshiho; 5-1-3, Higashinakahama, 
Joto-ku, Osaka-shi, Osaka 536-0023 (JP). UEDA, Hi- 
roshi; 4-3426, Gotenyamaminamimachi, Hirakata-shi, 
Osaka 573-1193 (JP). SASAKI, Miyuki; 411, Syouken- 
ryo, 24-11, Saigodori 1-chome, Moriguchi-shi, Osaka 
570-0034 (JP). FUKUSHBV1A, Yoshi.hisa; 14-C-508, 
Sekime 6-chome, Joto-ku, Osaka-shi, Osaka 536-0008 
(JP). 

(74) Agent: YAMAMOTO, Shusaku; Crystal Tower, Fif- 
teenth Floor, 2-27, Shiromi 1-chome, Chuo-ku, Osaka-shi, 
Osaka 540-6015 (JP). 

(81) Designated States (national): CN, ID, KR, MX. 

Published: 

— With international search report. 



[ Continued on next page ] 



= (54) Title: INFORMATION RECORDING MEDIUM AND SYSTEM CONTROLLER 



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101- 
102 
103— 
104— 
105— 
106— 
107- 
RTi- 

108- 1 
RT2 

109- 1 
RT3 

no— t 



RT4- 



120-1 
As- 
121 
RT5- 
122 



Lead-in area 



DMA qreq 



Spare area 



Volume structure area 



RT6- 
123— 
124— 
125— 



File structure area 



Allocated area 



Guard area 



Reel-time extent 



Defective ECC block 



Real-time extent 



Guard area 



Real-time extent 



Allocated area 



Real-time extent 



Allocated area 



Pre-allocated area 



Allocated area 



Real-time extent 



Allocated area 



Real-time extent 



Empty extent 



Unrecorded area 



Allocated area 



126—1 Lead-out area 



-N 



File structure area 



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I 



\ 



I \ 



\ 



Space bit map 



file entry 
(ROOT directory) 



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file identifier 
(F1LEA.DAT) 



file identifier 
(REALTIME) 



file entry 
(F1LEA.DAT) 



File entry 
(REALTIME) 



file identifier 
(VIDE0.VR0) 



file entry 
(VIDE0.VR0) 



.-144 



•141 



-142 



-143 



-145 
H46 

•147 
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(57) Abstract: An information 
recording medium for recording a 
real-time file containing real-time 
data in such a manner that the 
real-time data is continuously 
reproducible by a playback 
reference model, the real-time data 
including at least one of video 
data and audio data. The playback 
reference model includes: a pickup 
for reading the real-time data from 
the information recording medium; 
a buffer memory for temporarily 
storing the real-time data read 
by the pickup; and a decoder 
module for reading the real-time 
data from the buffer memory 
for processing. The information 
recording medium includes a 
volume space for at least recording 
in sectors a file containing data and 
file management information for 
managing the file. The real-time 
data is recorded in at least two 
real-time extents each of which is 
allocated in logically contiguous 
sectors within the volume space. 
An (i+l)* real-time extent among 
the at least two real-time extents is 
positioned at a position satisfying 
a real-time reproduction condition. 



wo oi/24i79 ai imniniiiiiiinMii 



For two-letter codes and other abbreviations, refer to the "Guid- 
ance Notes on Codes and Abbreviations " appearing at the begin- 
ning of each regular issue of the PCT Gazette. 



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DESCRIPTION 

INFORMATION RECORDING MEDIUM AND SYSTEM CONTROLLER 

5 

TECHNICAL FIELD 

The present invention relates to an information 
recording medium for recording general data (e.g., 
programs) and/or real-time data (e.g., video data and/or 

10 audio data) thereon on a sector-by-sector basis; a method 
for recording data on the information recording medium; a 
method for reproducing data on the information recording 
medium; and a system controller, an information recording 
apparatus, and an information reproduction apparatus for 

15 performing such methods. 



BACKGROUND ART 

Optical disks are representative of information 
20 recording media having a sector structure . The recent trend 
for higher density, larger capacity, and multimedia 
technologies has shed light on optical disks as information 
media for use with personal computers and various consumer 
use apparatuses. 

25 

Hereinafter, by referring to the accompanying 
figures, a DVD-RAM disk will be described as an example of 
a conventional rewritable optical disk. Figure 16A 
illustrates the physical layout of a conventional 
30 rewritable optical disk of a ZCLV (zpned constant linear 
velocity ) format . 



As shown in Figure 16A, the rewritable disk includes 



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a lead-in area, a DMA (defect management area) , a data area, 
and a lead-out area, in this order from the inner periphery 
to the outer periphery. The DMA is used for managing 
defective sectors on the disk. Each area has digital data 
5 recorded therein. The digital data is managed in units 
which are commonly referred to as sectors. The data area 
includes a spare area used for replacing a defective sector 
in a replacement process, as well as regions denoted as 
zones 0 to 34. In each zone, data is recorded in physical 
10 sectors which are 2048 bytes long. 

As shown in Figure 16B, information areas on the 
rewritable optical disk have physical sector numbers (PSN) 
assigned thereto . User data may be recorded in a space which 

15 is defined as a volume space including logical sectors to 
which logical sector numbers (LSN) are assigned. Stated 
otherwise, the volume space is the information area minus 
the lead-in area, the DMA, the unused regions within the 
spare area, any number of defective sectors which are 

20 registered in a primary defect list (PDL) within the DMA, 
guard regions in between the respective zones, and the lead 
out region. In order to provide improved data reliability, 
an error correction process is performed on an ECC 
block-by- ECC block basis, where each ECC (error correction 

25 code) block is composed of 16 logical sectors. 

Any defective sectors which have been detected 
through a certify process performed at the time of 
initialization of the disk are registered in the PDL, so 
30 that these defective sectors will not receive any LSNs 
assigned thereto. Therefore, it is possible that sectors 
of consecutive logical addresses may include regions which 
are not in a physically consecutive order. Any defective 



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sectors which are detected during data recording are 
subjected to a linear replacement whereby the entire 
ECC block containing each defective area is replaced by a 
spare region, and are registered in a secondary defect list 
5 (SDL) within the DMA. Thus, a rewritable disk is provided 
with a mechanism for improving data reliability. 

As described above, a DVD-RAM disk, which is 
provided with a defect management mechanism, is subjected 

10 to a defect management process by a drive . On the other hand, 
a CD-RW disk which is not provided with any defect management 
mechanism, is subjected to a defect management process 
--similar to the aforementioned SDL -based defect 
management-- which is performed by a file system based on 

15 a sparing table as defined under the UDF® (universal disk 
format) specification of OSTA. Specifically, in the case 
of CD-RW disks, the entire ECC block including a defective 
sector is replaced by a spare area which is set within the 
volume space, and this replacement information is managed 

20 based on a sparing table as defined under the UDF 
specification. 

Next, as an example of a conventional write -once 
optical disk, a 3 . 95 Gbyte DVD-R as specified under the DVD-R 
25 Standards (Version 1.0) will be described. It is assumed 
that the volume/file structures conform to the data 
structures defined under the ISO/IEC 13346 Standards or the 
UDF specification, unless otherwise specified. 

30 Figure 17 illustrates an exemplary directory 

structure to be recorded on an optical disk. Under a ROOT 
directory 201 is recorded a REALTIME directory 202, which 
is dedicated to video applications. Under the REALTIME 



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directory 202, audio/video data (hereinafter referred to 
as M AV data") which has been compressed in the MPEG format 
is recorded in a file named VIDEO. VRO file 203. A number 
of still picture files which have been recorded by means 
5 of a digital camera or the like are recorded in a file named 
FILEA.DAT 204. 

Figures 18A to 18C are diagrams illustrating extent 
locations in the case where AV data is appended to the 
10 VIDEO. VRO file. As used herein, an "extent" means a region 
containing logically contiguous sectors in which data is 
recorded. 

When AV data is recorded, a linking loss area 561 
15 (32 KB) is first recorded, and thereafter AV data is 
recorded in an extent 562, and furthermore a padding 
area 563, in which OOh data is recorded, is recorded in the 
sectors up to the ECC block boundary. In the case of DVD 
disks, an ECC error correction is performed in units of 
20 16 sectors, so that data recording also occurs in units of 
16 sectors. Next, a file structure concerning this DVD- 
R disk is recorded. After a border-out (not shown) is 
recorded so as to enable reading by a read-only system, a 
recording area will be formed after the padding area 563. 
25 The border-out has a size of 10 to 100 MB. 

In the case of a DVD-R disk in which data is 
sequentially recorded, AV data will be sequentially 
appended, beginning from the inner periphery of an 
30 unrecorded area which is left in the outer periphery of the 
disk. Therefore, in a second append operation, as shown in 
Figure 18B, after a linking loss area 564, AV data is 
recorded in an extent 565 , and a padding area 566 is recorded 



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- 5 - 

in the sectors up to the ECC block boundary • 

Similarly, as shown in Figure 18C, in a third AV data 
append operation, a linking loss area 567, an extent 568, 
5 and a padding area 569 are recorded. Thus, AV data is 
appended in split portions over a number of extents. 

Next, a linking scheme for DVD-R disks will be 
described with reference to Figures 19A to 19D. A so-called 

10 "buffer underrun" occurs due to the difference between the 
data rate of the AV data to be recorded and the data rate 
when the data is recorded on the disk by the pickup. If a 
buffer underrun occurs, the drive temporarily suspends the 
recording, and resumes recording after a predetermined 

15 amount of data is stored within the buffer. At this time, 
the linking scheme forms a linking loss area. 

Figure 19A is a diagram illustrating extent 
locations in the case where two buffer underrun s occur during 
20 AV data recording. Extents 222, 223, and 224 represent 
areas in which AV data has been recorded. A linking loss 
area 220 is an area which is recorded prior to the recording 
of AV data. Linking loss areas 226 and 227 are areas which 
are recorded responsive to the buffer underruns. 

25 

Figures 19B and 19C are sector-by- sector 
illustrations of area structures. The linking loss 
area 220 is recorded by recording OOh data so as to begin 
in the middle of the first sector and reach the end of the 
30 16 th sector. If an ensuing extent 222 is to be recorded, 
the extent 222 is recorded from the beginning of the first 
sector up to the beginning in the next sector adjoining this 
extent, and the recording operation is finished for the time 



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- 6 - 

being. Next, when the linking loss area 226 is to be 
recorded, the recording is resinned in the middle of the first 
sector. Thus, since a data append operation for DVD-R disks 
occurs in the middle of a sector, any sector that contains 
5 areas which are adjoined by the linking scheme is referred 
to as a linking sector 225. 

The specific linking scheme to be performed within 
a linking sector is illustrated in Figure 19D. One sector 
consists of 26 sync frames. Reference numerals 241, 242, 
243, and 244 represent areas which are recorded at an end 
portion when the extent 222 is recorded; 241 and 242 
represent a sync portion and a data portion, respectively, 
of a first sync frame; and 243 and 244 represent a sync 
portion and a data portion, respectively, of a second sync 
frame. The data portions 242 and 244 are sized so as to be 
able to allow 91 bytes and 86 bytes of data, respectively, 
to be recorded therein . An area 245 and the following areas 
represent areas which are formed within the first sector 
of the ECC block in the linking loss area 226 when the 
extent 223 is recorded. Reference numeral 245 represents 
a data portion in the second sync frame. Reference 
numerals 246 and 247 represent sync portions in sync frames . 

25 Data OOh is recorded in a runout area 228 so as not 

be finalized at the time of recording the extent 222. A 
region 229 spanning from the 82nd byte to the 87 bytes in 
the second sync frame is a region which overwrites a 
previously recorded area through appending; this area is 

30 referred to as a linking gap because no valid data can be 
recorded therein. Thus, the linking sector 225 containing 
the linking gap 229 is subject to the physical constraint 
that data cannot be properly recorded therein. Therefore, 



10 



15 



20 



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the 32 KB ECC block containing this linking sector is defined 
as a linking loss area so as to ensure that any data that 
requires reliability is prevented from being recorded 
therein as valid data. 

5 

However, in the case where real-time data is 
reproduced from an optical disk having the aforementioned 
format with the real-time data being recorded thereon, it 
is difficult to continuously reproduce the recorded 
10 real-time data because access may have to occur to physically 
non-contiguous areas which are formed between or within 
extents. 

In particular , in the case where data is recorded 
15 in a conventional file system, the data reproduction may 
be Interrupted due to a data read delay occurring when 
accessing a guard area provided in the vicinity of a zone 
boundary, a read delay arising from any defective sectors 
or defective blocks that are registered in the PDL or SDL, 
20 and/ or a data read delay arising from bouncing from one 
recording area to another to access data recorded in a 
plurality of discrete, empty areas. 

Since it is currently impossible to distinguish 
25 real-time files from general files, once an error occurs 
during the reproduction of real-time data, a delay may occur 
in order to again reproduce a location which was not 
successfully reproduced previously. 

30 Since no identification information is currently 

available to show conditions for reproducing real-time data 
and the fact that given real-time data was in fact recorded 
under such conditions, it is impossible to know whether or 



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not the recorded real-time data can be continuously 
reproduced . 

In the case where a recording apparatus appends 
5 real-time data to an already- recorded real-time file, it 
may not be possible to achieve continuous data reproduction 
between the end portion of the already- recorded data and 
the beginning portion of the appended data. 

10 In the case of real-time data which has been encoded 

by the MPEG method, it may not be possible to achieve 
continuous data reproduction between the end portion of the 
already- recorded data and the beginning portion of the 
appended data due to differing encoding conditions. 

15 

In the case of an optical disk to which data is 
recorded while using a linking scheme, e.g., a DVD-R disk, 
a linking loss area which is 32 KB long is formed every time 
a buffer underrun occurs. This causes each area in which 

20 data is recorded to be split into a plurality of extents, 
resulting in a large amount of address information being 
associated with each extent to-be managed by the file system, 
making it difficult to reproduce the data by means of a 
reproduction -only apparatus with a limited memory size. 

25 Moreover, when AV data having a low data rate is recorded, 
linking loss areas to be recorded will account for a large 
proportion, resulting in a poor recording efficiency. 

30 DISCLOSURE OF THE INVENTION 

According to one aspect of the present invention, 
there is provided an information recording medium for 
recording a real-time file containing real-time data in such 



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- 9 - 

a manner that the real-time data is continuously 
reproducible by a playback reference model, the real-time 
data including at least one of video data and audio data, 
wherein the playback reference model includes: a pickup for 
5 reading the real-time data from the information recording 
medium; a buffer memory for temporarily storing the 
real-time data read by the pickup; and a decoder module for 
reading the real-time data from the buffer memory for 
processing, wherein the information recording medium 

10 includes a volume space for at least recording in sectors 
a file including data and file management information for 
managing the file; the real-time data is recorded in at least 
two real-time extents each of which is allocated in logically 
contiguous sectors within the volume space; and an (1+1)^ 

15 real-time extent among the at least two real-time extents 
is positioned at a position satisfying a real-time 
reproduction condition defined as: T(i) ^ (B(i-l) + 
D(i))/Vout, wherein: T(i) represents a time required for 
the pickup to access from an end of an 1 th real-time extent 

20 among the at least two real-time extents to a beginning of 
the (i+l) th real-time extent; B(i) represents an amount of 
data having been stored in the buffer memory when the pickup 
accesses from the end of the i th real-time extent to the 
beginning of the (i+l)** 1 real-time extent, such that B(i) 

25 = B(l-l) + D(i) - Vout X T(i), assuming that B(0) = 0, D(i) 
represents an increase in the amount of data having been 
stored in the buffer memory responsive to the pickup reading 
the data from the i th real-time extent, such that D(i) = (Vin 
- Vout) X s(i) / Vin, wherein D(i) is corrected at least 

30 to a value equal to or smaller than M - B(i-l) when D(i) 
> M - B(i-l) , where M represents a size of the buffer memory; 
Vout represents a data transfer rate when the data is 
transferred from the buffer memory to the decoder module; 



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- 10 - 

Vin represents a data transfer rate when the data is read 
from each of the at least two real-time extents by the pickup 
and transferred to the buffer memory; and S(i) represents 
a data size of the i th real-time extent. 

5 

In one embodiment of the invention, D(i) is 
corrected so that D(i) = (Vin - Vout) X s(i) / Vin + B(i-l) 
- k X (VoutXTk) when D(i) > M - B(l-l), wherein: Tk 
represents a maximum rotation wait time of the information 
10 recording medium; and k represents an integer portion of 
((D(i) + B(i-l) - M) / (VoutXTk) + 1). 

In another embodiment of the invention, each of the 
at least two real-time extents is allocated in physically 
15 contiguous sectors* 

In still another embodiment of the invention, the 
file management information includes location information 
indicating each of the at least two real-time extents. 

20 

In still another embodiment of the invention, the 
file management information includes first identification 
information for identifying the real-time file including 
real-time data. 

25 

In still another embodiment of the invention, the 
file management information includes second identification 
information for indicating that the at least two real-time 
extents are positioned in accordance with the real-time 
30 reproduction condition. 

In still another embodiment of the invention, the 
file management information includes, as an extended 



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- 11 - 

attribute, information representing a condition under which 
the at least two real-time extents were positioned. 

Alternatively, there is provided an information 
5 recording medium for recording a real-time file containing 
real-time data in such a manner that the real-time data is 
continuously reproducible by a playback reference model, 
the real-time data including at least one of video data and 
audio data, wherein the playback reference model includes: 

10 a pickup for reading the real-time data from the information 
recording medium; a buffer memory for temporarily storing 
the real-time data read by the pickup; and a decoder module 
for reading the real-time data from the buffer memory for 
processing, wherein the information recording medium 

15 includes a volume space for at least recording in sectors 
a file including data and file management information for 
managing the file; the real-time data is recorded in at least 
two real-time extents each of which is allocated in logically 
contiguous sectors within the volume space; and an (i+l) th 

20 real-time extent among the at least two real-time extents 
is positioned at a position satisfying a real-time 
reproduction condition defined as: T(i) ^ (B(i-l) + 
D(i))/Vout, wherein: T(i) represents a time required for 
the pickup to access from an end of an i th real-time extent 

25 among the at least two real-time extents to a beginning of 
the (i+l)** real-time extent; B(i) represents an amount of 
data having been stored in the buffer memory when the pickup 
accesses from the end of the i th real-time extent to the 
beginning of the (i+l)^ real-time extent, such that B(i) 

30 = B(i-l) + D(i) - Vout X T(i), assuming that B(0) = 0, D(i) 
represents an increase in the amount of data having been 
stored in the buffer memory responsive to the pickup reading 
the data from the i th real-time extent, such that D(i) - (Vin 



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- 12 - 

- Vout) X s(i) / Vin, wherein D(i) is corrected at least 
to a value equal to or smaller than M - B(i-l) when D(i) 
> M - B(i-l) , where M represents a size of the buffer memory; 
Vout represents a data transfer rate when the data is 

5 transferred from the buffer memory to the decoder module; 
Vin represents a data transfer rate when the data is read 
from each of the at least two real-time extents by the pickup 
and transferred to the buffer memory; and S(i) represents 
a data size of the i th real-time extent , wherein the real- time 
10 file is a file in which the real-time data is appended; and 
wherein data of an already recorded real-time extent is 
recorded in a newly recorded real-time extent. 

In one embodiment of the invention, D(i) is 
15 corrected so that D(i) = (Vin - Vout) X s(i) / Vin + B(i-l) 

- k X (VoutXTk) when D(i) > M - B(i-l), wherein: Tk 
represents a maximum rotation wait time of the information 
recording medium; and k represents an integer portion of 
((D(i) + B(i-l) - M) / (VoutXTk) + 1). 

20 

In another embodiment of the invention, each of the 
at least two real-time extents is allocated in physically 
contiguous sectors. 

25 In still another embodiment of the invention, the 

file management information includes location information 
indicating each of the at least two real-time extents. 

In still another embodiment of the invention, the 
30 file management information includes first identification 
information for identifying the real-time file including 
real-time data. 



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- 13 - 

In still another embodiment of the invention, the 
file management information includes second identification 
information for indicating that the at least two real-time 
extents are positioned in accordance with the real-time 
5 reproduction condition. 

In still another embodiment of the invention, the 
file management information includes, as an extended 
attribute, information representing a condition under which 
10 the at least two real-time extents were positioned. 

Alternatively, there is provided an information 
recording medium for recording a real-time file containing 
real-time data in such a manner that the real-time data is 

15 continuously reproducible by a playback reference model, 
the real-time data including at least one of video data and 
audio data, wherein the playback reference model includes: 
a pickup for reading the real-time data from the information 
recording medium; a buffer memory for temporarily storing 

20 the real-time data read by the pickup; and a decoder module 
for reading the real-time data from the buffer memory for 
processing, wherein the information recording medium 
includes a volume space for at least recording in sectors 
a file including data and file management information for 

25 managing the file; the real-time data is recorded in at least 
two real-time extents each of which is allocated in logically 
contiguous sectors within the volume space; and an (i+l) th 
real-time extent among the at least two real-time extents 
is positioned at a position satisfying a real-time 

30 reproduction condition defined as: T(i) ^ (B(i-l) + 
D(i))/Vout, wherein: T(i) represents a time required for 
the pickup to access from an end of an 1 th real-time extent 
among the at least two real-time extents to a beginning of 



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- 14 - 

the (i+l) th real-time extent; B(i) represents an amount of 
data having been stored in the buffer memory when the pickup 
accesses from the end of the i fch real-time extent to the 
beginning of the (i+l) th real-time extent, such that B(i) 
5 = B(i-l) + D(i) - Vout X T(i), assuming that B(0) = 0, D(i) 
represents an increase in the amount of data having been 
stored in the buffer memory responsive to the pickup reading 
the data from the i th real-time extent, such that D(i) = (Vin 

- Vout) X s(i) / Vin, wherein D(i) is corrected at least 
10 to a value equal to or smaller than M - B(i-l) when D(i) 

> M - B(i-l) , where M represents a size of the buffer memory; 
Vout represents a data transfer rate when the data is 
transferred from the buffer memory to the decoder module; 
Vin represents a data transfer rate when the data is read 

15 from each of the at least two real-time extents by the pickup 
and transferred to the buffer memory; and S(i) represents 
a data size of the 1 th real-time extent, wherein the real-time 
file is a file in which the real-time data is appended; 
wherein the real-time data is compressed in an MPEG format; 

20 and wherein data including one or more GOPs recorded at an 
end of the real-time file before appending is re -encoded 
and is recorded in a newly recorded real-time extent. 

In one embodiment of the invention, D(i) is 
25 corrected so that D(i) = (Vin - Vout) X s(i) / Vin + B(i-l) 

- k X (VoutXTk) when D(i) > M - B(i-l), wherein: Tk 
represents a maximum rotation wait time of the information 
recording medium; and k represents an integer portion of 
((D(i) + B(i-l) - M) / (VoutXTk) + 1). 

30 

In another embodiment of the invention, each of the 
at least two real-time extents is allocated in physically 
contiguous sectors. 



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- 15 - 

In still another embodiment of the invention, the 
file management information includes location information 
indicating each of the at least two real-time extents . 

5 

In still another embodiment of the invention, the 
file management information includes first identification 
information for identifying the real-time file including 
real-time data, 

10 

In still another embodiment of the invention, the 
file management information includes second identification 
information for indicating that the at least two real-time 
extents are positioned in accordance with the real-time 
15 reproduction condition • 

In still another embodiment of the invention, the 
file management information includes, as an extended 
attribute, information representing a condition under which 
20 the at least two real-time extents were positioned. 

Alternatively, there is provided an information 
recording medium including a volume space for at least 
recording in sectors a file including data and file 

25 management information for managing the file, wherein: the 
data includes real-time data, the real-time data including 
at least one of video data and audio data; the real-time 
data is recorded in at least one real-time extent each of 
which is allocated in logically contiguous sectors within 

30 the volume space; the file includes at least one real-time 
extent; a linking loss extent is positioned before each of 
the at least one real-time extent; and a linking gap is formed 
in the at least one real-time extent. 



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- 16 - 

In one embodiment of the invention, the linking loss 
extent includes one ECC block, 

5 In another embodiment of the invention, the file 

management information includes location information 
indicating each of the at least one real-time extent. 

In still another embodiment of the invention, the 
10 file management information includes identification 
information for identifying the real-time file including 
real-time data. 

In still another embodiment of the invention, a data 
15 type bit is recorded in an area for recording physical 
additional information concerning each sector within the 
linking loss extent, the data type bit being used for 
identifying the linking loss extent; and wherein the data 
type bit for the sector is set to 1 if a next sector is included 
20 within the linking loss extent, unless the sector is a 
linking sector. 

In still another embodiment of the invention, 
wherein a runout area is formed before the linking gap; and 
25 the real-time data is recorded in the runout area within 
the linking loss extent. 

According to another aspect of the present invention, 
there is provided, a method for recording a real-time file 
30 containing real-time data on an information recording 
medium in such a manner that the real-time data is 
continuously reproducible by a playback reference model, 
the real-time data including at least one of video data and 



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audio data, wherein the playback reference model includes: 
a pickup for reading the real-time data from the 
information recording medium; a buffer memory for 
temporarily storing the real-time data read by the pickup; 
5 and a decoder module for reading the real-time data from 
the buffer memory for processing, wherein the information 
recording medium includes a volume space for at least 
recording in sectors a file including data and file 
management information for managing the file, the real- 

10 time data is recorded in at least one real-time extent each 
of which is allocated in logically contiguous sectors within 
the volume space, wherein the method includes the steps of: 
searching for at least two areas satisfying a real-time 
reproduction condition from among a plurality of logically 

15 contiguous unused areas within the volume space, each of 
the at least two areas being designated as a pre -allocated 
area, an (i+l)th pre-allocated area among the at least two 
areas satisfying the real-time reproduction condition being 
defined as: T(i) ^ (B(i-l) + D(i))/Vout, wherein: T(i) 

20 represents a time required for the pickup to access from 
an end of an i th pre-allocated area among the at least two 
pre-allocated areas to a beginning of the (i+l) th pre- 
allocated area; B(i) represents an amount of data having 
been stored in the buffer memory when the pickup accesses 

25 from the end of the 1 th pre-allocated area to the beginning 
of the (i+l) th pre-allocated area, such that B(i) = B(i- 
1) + D(i) - Vout X T(i), assuming that B(0) = 0, D(i) 
represents an increase in the amount of data having been 
stored in the buffer memory responsive to the pickup reading 

30 the data from the i th pre-allocated area, such that D(i) = 
(Vin - Vout) X s(i) / Vin, wherein D(i) is corrected at least 
to a value equal to or smaller than M - B(i-l) when D(i) 
> M - B(i-l) , where M represents a size of the buffer memory; 



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Vout represents a data transfer rate when the data is 
transferred from the buffer memory to the decoder module; 
Vin represents a data transfer rate when the data is read 
from the pre-allocated area by the pickup and transferred 
5 to the buffer memory; and S(i) represents a data size of 
the 1 th pre-allocated area; recording the real-time data in 
the pre-allocated area; designating a set of logically 
contiguous sectors in which real-time data is recorded as 
a real-time extent; and recording the file management 
10 information for managing the real-time data as the real-time 
file. 

In one embodiment of the invention , . D(i) is 
corrected so that D(i) - (Vin - Vout) X s(i) / Vin + B(i-l) 
15 - k X (VoutXTk) when D(i) > M - B(i-l), wherein: Tk 
represents a maximum rotation wait time of the Information 
recording medium; and k represents an integer portion of 
((D(i) + B(i-l) - M) / (VoutXTk) + 1). 

20 In another embodiment of the invention, each of the 

at least one pre-allocated area is allocated in physically 
contiguous sectors on an ECC block-by-ECC block basis. 

In still another embodiment of the invention, the 
25 file management information includes location information 
indicating each of the at least two real-time extents. 

In still another embodiment of the invention, the 
file management information includes first identification 
30 information for identifying the real-time file including 
real-time data. 

In still another embodiment of the invention, the 



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file management information includes second identification 
information for indicating that the at least two real-time 
extents are positioned in accordance with the real-time 
reproduction condition. 

5 

In still another embodiment of the invention, the 
file management information includes, as an extended 
attribute, information representing a condition under which 
the at least two real-time extents were positioned. 

10 

Alternatively, there is provided a method for 
recording a real-time file containing real-time data on an 
information recording medium in such a manner that the 
real-time data is continuously reproducible by a playback 

15 reference model, the real-time data including at least one 
of video data and audio data, wherein the playback reference 
model includes: a pickup for reading the real-time data from 
the information recording medium; a buffer memory for 
temporarily storing the real-time data read by the pickup? 

20 and a decoder module for reading the real-time data from 
the buffer memory for processing, wherein the information 
recording medium includes a volume space for at least 
recording in sectors a file including data and file 
management information for managing the file, the real- 

25 time data is recorded in at least one real-time extent each 
of which is allocated in logically contiguous sectors within 
the volume space, wherein the method includes the steps of: 
calculating whether or not each of the at least one real-time 
extent will cause an overflow in an amount of data stored 

30 in the buffer memory if the real-time extent is reproduced 
by the playback reference model; when it is calculated that 
the real-time extent will cause an overflow, correcting the 
amount of data stored in the buffer memory to equal to or 



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smaller than the size of the buffer memory; calculating 
whether or not an underflow will occur in the amount of data 
stored in the buffer memory if the playback reference model 
accesses from the real-time extent to a newly- allocated 
5 pre-allocated area; when it is calculated that an underflow 
will occur, searching for a real-time extent which will not 
cause an underflow, on accessing from the real-time extent 
to the pre-allocated area; recording in the newly- allocated 
pre-allocated area the real-time data already recorded in 

10 the real-time extent which will cause an underflow; 
recording real-time data to be appended in the newly- 
allocated pre-allocated area; designating a set of 
logically contiguous sectors in which real-time data is 
recorded as a real-time extent; and recording the file 

15 management information. 

In one embodiment of the invention, each of the at 
least one pre-allocated area is allocated in physically 
contiguous sectors on an ECC block-by-ECC block basis. 

20 

In another embodiment of the invention, the file 
management information includes location information 
indicating each of the at least one real-time extent. 

25 In still another embodiment of the invention, the 

file management information includes first identification 
information for identifying the real-time file including 
real-time data. 

30 In still another embodiment of the invention, the 

file management information includes second identification 
information for indicating that the at least two real-time 
extents are positioned in accordance with the real-time 



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reproduction condition. 

In still another embodiment of the invention, the 
file management information includes, as an extended 
5 attribute, information representing a condition under which 
the at least two real-time extent were positioned. 

According to yet another aspect of the present 
invention, there is provided a method for appending a 

10 real-time file containing real-time data on an information 
recording medium in such a manner that the real-time data 
is continuously reproducible by a playback reference model, 
the real-time data including at least one of video data and 
audio data, wherein the playback reference model includes: 

15 a pickup for reading the real-time data from the information 
recording medium; a buffer memory for temporarily storing 
the real-time data read by the pickup; and a decoder module 
for reading the real-time data from the buffer memory for 
processing, wherein the information recording medium 

20 includes a volume space for at least recording in sectors 
a file including data and file management information for 
managing the file, the real-time data is recorded in at least 
one real-time extent each of which is allocated in logically 
contiguous sectors within the volume space, wherein the 

25 real-time file includes data which is compressed in an MPEG 
format, wherein the method includes the steps of: reading 
data recorded at an end of the real-time file before 
appending, the data including one or more GOPs; re-encoding 
the data which has been read; recording the re-encoded data 

30 in a newly allocated pre-allocated area; recording 
real-time data to be appended in the newly- allocated 
pre-allocated area; designating a set of logically 
contiguous sectors in which real-time data is recorded as 



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a real-time extent; and recording the file management 
information. 

In one embodiment of the invention, each of the at 
5 least one pre-allocated area is allocated in physically 
contiguous sectors on an ECC block-by-ECC block basis. 

In another embodiment of the invention, the file 
management information includes location information 
10 indicating each of the at least one real-time extent. 

In still another embodiment of the invention, the 
file management information includes first identification 
information for identifying the real-time file including 
15 real-time data. 

In still another embodiment of the invention, the 
file management information includes second identification 
information for indicating that the at least two real-time 
20 extents are positioned in accordance with the real-time 
reproduction condition. 

In still another embodiment of the invention, the 
file management information includes, as an extended 
25 attribute, information representing a condition under which 
the at least two real-time extents were positioned. 

Alternatively, there is provided a method for 
recording information on an information recording medium 
30 including a volume space for at least recording in sectors 
a file including data and file management information for 
managing the file, including the steps of: determining 
whether or not the file is a real-time file containing 



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real-time data; recording the file management information 
in the volume space; recording the real-time data next to 
a linking loss extent if the file is determined to be a 
real-time file; and responsive to a buffer underrun 
5 occurring during the recording of the real-time data, 
forming a linking gap in a real-time extent in which the 
real-time data is recorded. 

In one embodiment of the invention, the linking loss 
10 extent includes one ECC block. 

In another embodiment of the invention, the file 
management information includes location information 
indicating each real-time extent. 

15 

In still another embodiment of the invention, the 
file management information includes identification 
information for identifying the real-time file including 
real-time data. 

20 

In still another embodiment of the invention, a data 
type bit is recorded in an area for recording physical 
additional information concerning each sector within the 
linking loss extent, the data type bit being used for 
25 identifying the linking loss extent; and wherein the data 
type bit for the sector is set to 1 if a next sector is included 
within the linking loss extent, unless the sector is a 
linking sector. 

30 In still another embodiment of the invention, the 

method further includes a step of recording the real-time 
data in a runout area within the linking loss extent. 



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According to yet another aspect of the present 
invention, there is provided an information recording 
apparatus for recording a real-time file containing 
real-time data on an information recording medium in such 
5 a manner that the real-time data is continuously 
reproducible by a playback reference model, the real-time 
data including at least one of video data and audio data, 
wherein the playback reference model includes : a pickup for 
reading the real-time data from the information recording 

10 medium; a buffer memory for temporarily storing the 
real-time data read by the pickup; and a decoder module for 
reading the real-time data from the buffer memory for 
processing, wherein the information recording medium 
includes a volume space for at least recording in sectors 

15 a file including data and file management information for 
managing the file; wherein the information recording 
apparatus includes a file system processing section for: 
allocating at least two areas satisfying a real-time 
reproduction condition from among a plurality of logically 

20 contiguous unused areas within the volume space, each of 
the at least two areas being designated as a pre-allocated 
area; recording the real-time data and the file management 
information; designating a set of logically contiguous 
sectors in which real-time data is recorded as a real-time 

25 extent; and generating the file management information for 
managing the real-time data as the real-time file, wherein 
an (i+l) th pre-allocated area among the at least two 
pre-allocated areas is positioned at a position satisfying 
a real-time reproduction condition defined as: T(i) ^ 

30 (B(i-l) + D(i))/Vout, wherein: T(i) represents a time 
required for the pickup to access from an end of an i th 
pre-allocated area among the at least two pre-allocated 
areas to a beginning of an (i+l) th pre-allocated area among 



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the at least two pre -allocated areas; B(i) represents an 
amount of data having been stored in the buffer memory when 
the pickup accesses from the end of the i th pre- allocated 
area to the beginning of the (i+l) th pre -allocated area, such 
5 that B(i) = B(i-l) + D(i) - Vout X T(i), assuming that B(0) 
= 0, D(i) represents an increase in the amount of data having 
been stored in the buffer memory responsive to the pickup 
reading the data from the i th pre-allocated area, such that 
D(i) = (Vin - Vout) X s(i) / Vin, wherein D(i) is corrected 

10 at least to a value equal to or smaller than M - B(i-l) when 
D(i) > M - B(i-l), where M represents a size of the buffer 
memory; Vout represents a data transfer rate when the data 
is transferred from the buffer memory to the decoder module; 
Vin represents a data transfer rate when the data is read 

15 from the pre-allocated area by the pickup and transferred 
to the buffer memory; and S(i) represents a data size of 
the i th pre-allocated area. 

In one embodiment of the invention, D(i) is 
20 corrected so that D(i) = (Vin - Vout) X s(i) / Vin + B(i-l) 
- k X (VoutXTk) when D(i) > M - B(i-l), wherein: Tk 
represents a maximum rotation wait time of the information 
recording medium; and k represents an integer portion of 
((D(i) + B(i-l) - M) / (VoutXTk) + 1). 

25 

In another embodiment of the invention, each of the 
at least one pre-allocated area is allocated in physically 
contiguous sectors on an ECC block-by-ECC block basis. 

30 In still another embodiment of the invention # the 

file management information includes location information 
indicating each real-time extent. 



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In still another embodiment of the invention, the 
file management information includes first identification 
information for identifying the real-time file including 
real-time data. 

5 

In still another embodiment of the invention, the 
file management information includes second identification 
information for indicating that the at least two real-time 
extents are positioned in accordance with the real-time 
10 reproduction condition. 

In still another embodiment of the invention, the 
file management Information includes, as an extended 
attribute, information representing a condition under which 
15 the at least two real-time extents were positioned. 

According to yet another aspect of the present 
invention, there is provided an information recording 
apparatus for appending a real-time file containing 

20 real-time data on an information recording medium in such 
a manner that the real-time data is continuously 
reproducible by a playback reference model, the real-time 
data including at least one of video data and audio data, 
wherein the playback reference model includes: a pickup for 

25 reading the real-time data from the information recording 
medium; a buffer memory for temporarily storing the 
real-time data read by the pickup; and a decoder module for 
reading the real-time data from the buffer memory for 
processing, wherein the information recording medium 

30 Includes a volume space for at least recording in sectors 
a file including data and file management information for 
managing the file, the real-time data is recorded in at least 
one real-time extent each of which is allocated in logically 



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contiguous sectors within the volume space, wherein the 
information recording apparatus includes: a data amount 
calculation section for calculating whether or not each of 
the at least one real-time extent will cause an overflow 
5 in an amount of data stored in the buffer memory if the 
real-time extent is reproduced by the playback reference 
model; correcting the amount of data stored in the buffer 
memory to equal to or smaller than the size of the buffer 
memory when it is calculated that the real-time extent will 

10 cause an overflow; calculating whether or not an underflow 
will occur in the amount of data stored in the buffer memory 
if the playback reference model accesses from the real- 
time extent to a newly- allocated pre-allocated area; and 
searching for a real-time extent which will not cause an 

15 underflow, on accessing from the real-time extent to the 
pre-allocated area when it is calculated that an underflow 
will occur; a data recording section for recording in the 
newly allocated pre-allocated area the real-time data 
already recorded in the real-time extent which will cause 

20 an underflow, and recording real-time data to be appended 
in the newly- allocated pre-allocated area; and a file 
structure processing section for designating a set of 
logically contiguous sectors in which real-time data is 
recorded as a real-time extent and for generating and 

25 recording the file management information. 

In one embodiment of the invention, each of the at 
least one pre-allocated area is allocated in physically 
contiguous sectors on an ECC block-by-ECC block basis. 

30 

In another embodiment of the invention, the file 
management information includes location information 
indicating each of the at least one real-time extent. 



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In still another embodiment of the invention, the 
file management information includes first identification 
information for identifying the real-time file including 
5 real-time data. 

In still another embodiment of the invention, the 
file management information includes second identification 
information for indicating that the at least two real-time 
10 extents are positioned in accordance with the real-time 
reproduction condition. 

In still another embodiment of the invention, the 
file management information includes, as an extended 
15 attribute, information representing a condition under which 
the at least two real-time extents were positioned. 

Alternatively, there is provided an information 
recording apparatus for appending a real-time file 

20 containing real-time data on an information recording 
medium in such a manner that the real-time data is 
continuously reproducible by a playback reference model, 
the real-time data including at least one of video data and 
audio data, wherein the playback reference model includes: 

25 a pickup for reading the real-time data from the information 
recording medium; a buffer memory for temporarily storing 
the real-time data read by the pickup; and a decoder module 
for reading the real-time data from the buffer memory for 
processing, wherein the information recording medium 

30 includes a volume space for at least recording in sectors 
a file including data and file management information for 
managing the file, the real-time data is recorded in at least 
one real-time extent each of which is allocated in logically 



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contiguous sectors within the volume space, wherein the 
real-time file includes data which is compressed in an MPEG 
format, wherein the information recording apparatus 
includes: a re-encoding section for reading data recorded 
5 at an end of the real-time file before appending, the data 
including one or more GOPs, re-encoding the data which has 
been read, and recording the re-encoded data in a newly 
allocated pre-allocated area; and a file structure 
processing section for designating a set of logically 
10 contiguous sectors in which real-time data is recorded as 
a real-time extent and for generating and recording the file 
management information. 

In one embodiment of the invention, each of the at 
15 least one pre-allocated area is allocated in physically 
contiguous sectors on an ECC block-by-ECC block basis. 

In another embodiment of the invention, the file 
management information includes location information 
20 indicating each of the at least two real-time extents. 

In still another embodiment of the invention, the 
file management information includes first identification 
information for identifying the real-time file including 
25 real-time data. 

In still another embodiment of the invention, the 
file management information includes second identification 
information for indicating that the at least two real-time 
30 extents are positioned in accordance with the real-time 
reproduction condition. 

In still another embodiment of the invention, the 



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file management information includes, as an extended 
attribute, information representing a condition under which 
the at least two real-time extents were positioned • 

5 Alternatively, there is provided an information 

recording apparatus for recording information on an 
information recording medium including a volume space for 
at least recording in sectors a file including data and file 
management information for managing the file, including: 

10 a recording mode determination section for determining 
whether or not the file is a real-time file containing 
real-time data; a file structure processing section for 
recording the file management information in the volume 
space; a linking setting section for recording the real-time 

15 data next to a linking loss extent if the file is determined 
to be a real-time file; and a linking controller for, 
responsive to a buffer underrun occurring during the 
recording of the real-time data, forming a linking gap in 
a real-time extent in which the real-time data is recorded. 

20 

In one embodiment of the invention, the linking loss 
extent includes one ECC block. 

In another embodiment of the invention, the file 
25 management information includes location information 
indicating each real-time extent. 

In still another embodiment of the invention, the 
file management information includes identification 
30 information for identifying the real-time file including 
real-time data. 

In still another embodiment of the invention, the 



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linking controller records a data type bit in an area for 
recording physical additional information concerning each 
sector within the linking loss extent, the data type bit 
being used for identifying the linking loss extent; and 
5 wherein the data type bit for the sector is set to 1 if a 
next sector is included within the linking loss extent, 
unless the sector is a linking sector. 

In still another embodiment of the invention, the 
10 recording apparatus further includes a runout controller 
for recording the real-time data in a runout area within 
the linking loss extent. 

According to yet another aspect of the present 

15 invention, there is provided a system controller for an 
information recording apparatus for recording a real-time 
file containing real-time data on an information recording 
medium in such a manner that the real-time data is 
continuously reproducible by a playback reference model, 

20 the real-time data including at least one of video data and 
audio data, wherein the playback reference model includes: 
a pickup for reading the real-time data from the information 
recording medium; a buffer memory for temporarily storing 
the real-time data read by the pickup; and a decoder module 

25 for reading the real-time data from the buffer memory for 
processing, wherein the information recording medium 
includes a volume space for at least recording in sectors 
a file including data and file management information for 
managing the file; wherein the system controller includes 

30 a file system processing section for: allocating at least 
two areas satisfying a real-time reproduction condition 
from among a plurality of logically contiguous unused areas 
within the volume space, each of the at least two areas being 



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designated as a pre -allocated area; recording the real- 
time data and the file management information; designating 
a set of logically contiguous sectors in which real-time 
data is recorded as a real-time extent; and generating the 
5 file management information for managing the real-time data 
as the real-time file, wherein an (i+l) th pre-allocated area 
among the at least two pre-allocated areas is positioned 
at a position satisfying a real-time reproduction condition 
defined as: T(i) ^ (B(i-l) +D(i))/Vout # wherein: T(i) 

10 represents a time required for the pickup to access from 
an end of an i th pre-allocated area among the at least two 
pre-allocated areas to a beginning of an (i+l) th pre- 
allocated area among the at least two pre-allocated areas; 
B(i) represents an amount of data having been stored in the 

15 buffer memory when the pickup accesses from the end of the 
1 th pre-allocated area to the beginning of the (i+l) th 
pre-allocated area, such that B(i) = B(i-l) + D(i) - Vout 
X T(i) , assuming that B(0) = 0, D(i) represents an increase 
in the amount of data having been stored in the buffer memory 

20 responsive to the pickup reading the data from the i th 
pre-allocated area, such that D(i) = (Vin - Vout) X s(i) 
/ Vin, wherein D(i) is corrected at least to a value equal 
to or smaller than M - B(i-l) when D(i) > M - B(i-l), where 
M represents a size of the buffer memory; Vout represents 

25 a data transfer rate when the data is transferred from the 
buffer memory to the decoder module; Vin represents a data 
transfer rate when the data is read from the at pre-allocated 
are by the pickup and transferred to the buffer memory; and 
S(i) represents a data size of the i th pre-allocated area. 

30 

Alternatively, there is provided a system 
controller for an information recording apparatus for 
appending a real-time file containing real-time data on an 



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information recording medium in such a manner that the 
real-time data is continuously reproducible by a playback 
reference model , the real-time data including at least one 
of video data and audio data, wherein the playback reference 
5 model includes: a pickup for reading the real-time data from 
the information recording medium; a buffer memory for 
temporarily storing the real-time data read by the pickup; 
and a decoder module for reading the real-time data from 
the buffer memory for processing, wherein the information 

10 recording medium includes a volume space for at least 
recording in sectors a file including data and file 
management information for managing the file, the real- 
time data is recorded in at least one real-time extent each 
of which is allocated in logically contiguous sectors within 

15 the volume space, wherein the system controller includes: 
a data amount calculation section for calculating whether 
or not each of the at least one real-time extent will cause 
an overflow in an amount of data stored in the buffer memory 
if the real-time extent is reproduced by the playback 

20 reference model; correcting the amount of data stored in 
the buffer memory to equal to or smaller than the size of 
the buffer memory when it is calculated that the real-time 
extent will cause an overflow; calculating whether or not 
an underflow will occur in the amount of data stored in the 

25 buffer memory if the playback reference model accesses from 
the real-time extent to a newly- allocated pre-allocated 
area; and searching for a real-time extent which will not 
cause an underflow, on accessing from the real-time extent 
to the pre-allocated area when it is calculated that an 

30 underflow will occur; a data recording section for recording 
in the newly allocated pre-allocated area the real-time data 
already recorded in the real-time extent which will cause 
an underflow, and recording real-time data to be appended 



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in the newly- allocated pre-allocated area; and a file 
structure processing section for designating a set of 
logically contiguous sectors in which real-time data is 
recorded as a real-time extent and for generating and 
5 recording the file management information. 

According to yet another aspect of the present 
invention, there is provided a method for reproducing a 
real-time file containing real-time data on an information 

10 recording medium in such a manner that the real-time data 
is continuously reproducible by a playback reference model, 
the real-time data including at least one of video data and 
audio data, wherein the playback reference model includes: 
a pickup for reading the real-time data from the information 

15 recording medium; a buffer memory for temporarily storing 
the real-time data read by the pickup; and a decoder module 
for reading the real-time data from the buffer memory for 
processing, wherein the information recording medium 
includes a volume space for at least recording in sectors 

20 a file including data and file management information for 
managing the file, wherein the real-time data is recorded 
in at least two real-time extents each of which is allocated 
in logically contiguous sectors within the volume space; 
and an (i+l) th real-time extent among the at least two 

25 real-time extents is positioned at a position satisfying 
a real-time reproduction condition defined as: T(i) ^ 
(B(i-l) + D(i))/Vout, wherein: T(i) represents a time 
required for the pickup to access from an end of an i th 
real-time extent among the at least two real-time extents 

30 to a beginning of the (i+l)^ real-time extent; B(i) 
represents an amount of data having been stored in the buffer 
memory when the pickup accesses from the end of the i th 
real-time extent to the beginning of the (i+l) th real-time 



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extent, such that B(i) = B(i-l) + D(i) - Vout X T(i), 
assuming that B(0) = 0, D(i) represents an increase in the 
amount of data having been stored in the buffer memory 
responsive to the pickup reading the data from the i th 
5 real-time extent, such that D(i) - (Vin - Vout) X s(i) / 
Vin, wherein D(i) is corrected at least to a value equal 
to or smaller than M - B(i-l) when D(i) > M - B(i-l), where 
M represents a size of the buffer memory; Vout represents 
a data transfer rate when the data is transferred from the 

10 buffer memory to the decoder module; Vin represents a data 
transfer rate when the data is read from each of the at least 
two real-time extents by the pickup and transferred to the 
buffer memory; and S(i) represents a data size of the 1 th 
real-time extent, wherein the method includes the steps of: 

15 reproducing the real-time file from the information 
recording medium by means of a disk drive ; acquiring location 
information of each of the at least two real-time extents 
and identification information indicating that the at least 
two real-time extents are positioned in accordance with the 

20 real-time reproduction condition; reading data from the at— 
least two real-time extents at a data transfer rate which 
is equal to or greater than Vin of the playback reference 
model; temporarily storing the real-time data which has been 
read in the buffer memory; reading the data stored in the 

25 buffer memory and decoding the data in a decoder; and 
accessing a next real-time extent within the time T(i) of 
the playback reference model. 

In one embodiment of the invention, the file 
30 management information includes, as an extended attribute, 
information representing a condition under which the at 
least two real-time extents were positioned, the method 
further including a step of: reading the extended attribute 



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from the file management Information, and informing a 
reproduction mode to the disk drive based on the extended 
attribute prior to reproduction. 

5 Alternatively, there is provided a method for 

reproducing real-time data from an information recording 
medium including a volume space for at least recording in 
sectors a file including data and file management 
information for managing the file, wherein: the data 

10 includes real-time data, the real-time data including at 
least one of video data and audio data; the real-time data 
is recorded in at least one real-time extent each of which 
is allocated in logically contiguous sectors within the 
volume space; the file includes at least one real-time 

15 extent; a linking loss extent is positioned before each of 
the at least one real-time extent; and a linking gap is formed 
in the at least one real-time extent, wherein the method 
includes the steps of: determining whether or not the file 
is a real-time file containing real-time data; and 

20 performing a reproduction operation for data recorded in 
a real-time extent, the reproduction operation being 
continuously performed without performing a recovery 
process even if a reproduction error due to invalid data 
recorded in the linking gap occurs. 

25 

According to yet another aspect of the present 
invention, there is provided an information reproduction 
apparatus for reproducing a real-time file containing 
real-time data on an information recording medium in such 
30 a manner that the real-time data is continuously 
reproducible by a playback reference model, the real-time 
data including at least one of video data and audio data, 
wherein the playback reference model includes: a pickup for 



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reading the real-time data from the information recording 
medium; a buffer memory for temporarily storing the 
real-time data read by the pickup; and a decoder module for 
reading the real-time data from the buffer memory for 
5 processing, wherein the information recording medium 
includes a volume space for at least recording in sectors 
a file including data and file management information for 
managing the file, wherein the real-time data is recorded 
in at least two real-time extents each of which is allocated 

10 in logically contiguous sectors within the volume space; 
and an (i+l) 1 * real-time extent among the at least two 
real-time extents is positioned at a position satisfying 
a real-time reproduction condition defined as: T(i) ^ 
(B(i-l) + D(i))/Vout, wherein: T(i) represents a time 

15 required for the pickup to access from an end of an i th 
real-time extent among the at least two real-time extents 
to a beginning of the (i+l)** 1 real-time extent; B(i) 
represents an amount of data having been stored in the buffer 
memory when the pickup accesses from the end of the i th 

20 real-time extent to the beginning of the (i+l) th real-time 
extent, such that B(i) = B(i-l) + D(i) - Vout X T(i), 
assuming that B(0) = 0, D(i) represents an increase in the 
amount of data having been stored in the buffer memory 
responsive to the pickup reading the data from the 1 th 

25 real-time extent, such that D(i) ■ (Vin - Vout) X s(i) / 
Vin, wherein D(i) is corrected at least to a value equal 
to or smaller than M - B(i-l) when D(i) > M - B(i-l), where 
M represents a size of the buffer memory; Vout represents 
a data transfer rate when the data is transferred from the 

30 buffer memory to the decoder module; Vin represents a data 
transfer rate when the data is read from each of the at least 
two real-time extents by the pickup and transferred to the 
buffer memory; and S(i) represents a data size of the i th 



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real-time extent, wherein the information reproduction 
apparatus includes: a disk drive for reproducing the 
real-time file from the information recording medium; a file 
structure processing section for acquiring location 
5 information of each of the at least two real-time extents 
and identification information indicating that the at least 
two real-time extents are positioned in accordance with the 
real-time reproduction condition; a data reproducer for 
reading data from the at least two real-time extents at a 

10 data transfer rate which is equal to or greater than Vin 
of the playback reference model; a buffer memory for 
temporarily storing the real-time data which has been read; 
and a°decoder for reading the data stored in the buffer memory 
and decoding the data, wherein a data reproduction 

15 performance which is determined as a function of an access 
performance and data transfer rate of the data reproducer 
and a size of the buffer memory satisfies a predetermined 
data reproduction performance of the playback reference 
model • 

20 

In one embodiment of the invention, the file 
management information includes, as an extended attribute, 
information representing a condition under which the at 
least two real-time extents were positioned, the 
25 information reproduction apparatus further including: a 
reproduction mode informing section for reading the 
extended attribute from the file management information, 
and informing a reproduction mode to the disk drive based 
on the extended attribute prior to reproduction, 

30 

Alternatively, there is provided an information 
reproduction apparatus for reproducing a real-time file 
containing real-time data on an information recording 



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medium including a volume space for at least recording in 
sectors a file including data and file management 
information for managing the file, wherein: the data 
includes real-time data, the real-time data including at 
5 least one of video data and audio data; the real-time data 
is recorded in at least one real-time extent each of which 
is allocated in logically contiguous sectors within the 
volume space; the file includes at least one real-time 
extent; a linking loss extent is positioned before each of 

10 the at least one real-time extent ; and a linking gap is formed 
in the at least one real-time extent, wherein the information 
reproduction apparatus includes: a file structure 
processing section for determining whether or not the file 
is a real-time file containing real-time data; and a data 

15 reproducer for performing a reproduction operation for data 
recorded in a real-time extent, the reproduction operation 
being continuously performed without performing a recovery 
process even if a reproduction error due to invalid data 
recorded in the linking gap occurs. 

20 

The information recording medium according to the 
present invention, on which real-time extents are 
positioned so as to satisfy a real-time reproduction 
condition, utilizes a playback reference model so as to 
25 enable reproduction apparatuses to continuously reproduce 
real-time data. As a result, various reproduction 
apparatuses can continuously reproduce real-time data from 
the information recording medium according to the present 
invention . 

30 

Since each real-time extent is composed of a 
physically contiguous area, it is possible to calculate 
underflows occurring responsive to accesses. 



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By providing an area for recording information for 
identifying real-time files from general files in a file 
management information area, it is possible to more 
5 effectively perform continuous reproduction even when 
errors occur during the reproduction of a real-time file. 

By providing information indicating that a real- 
time reproduction condition is satisfied by the real-time 
extents in the file management information area, it is 
possible to determine whether or not a reproduction 
apparatus satisfying the prescribed performance of the 
playback reference model can continuously reproduce a 
real-time file from the information recording medium 
according to the present invention. 

Even in the case where real-time data is appended 
to a previously recorded real-time file, it is possible to 
position or arrange real-time extents on the information 
20 recording medium according to the present invention based 
on the real-time reproduction condition, so that a 
reproduction apparatus can continuously reproduce data from 
the beginning of the appended real-time file. 

25 Even in the case where the appended data is real-time 

data which has been encoded in the MPEG format , it is ensured 
that a reproduction apparatus can continuously reproduce 
data by providing an area for recording re -encoded VOBUs 
in a newly allocated unrecorded area. 

30 

In accordance with the information recording medium 
according to the present invention, even in the case where 
it is implemented as an optical disk which records data by 



10 



15 



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using a linking scheme, e.g., a DVD-R disk, it is ensured 
that real-time data is recorded in contiguous areas even 
if a buffer underrun occurs while a recording apparatus 
records real-time data, by providing a real-time extent 
5 after a linking loss extent and forming a linking gap within 
the real-time extent . By providing a real-time extent after 
a linking loss extent, it is possible to improve data 
reliability in the beginning portion of the real-time data. 

10 By sizing each linking loss extent as one ECC block, 

it is possible to further improve data reliability in the 
beginning portion of real-time data. 

By providing an area for recording information for 
15 identifying a linking loss extent in an area for recording 
physical additional information, a reproduction apparatus 
can recognize, upon detection of a linking gap, that the 
sector contains unnecessary data, thereby simplifying the 
designing of reproduction apparatuses. 

20 

By recording valid data in a runout area, it is 
ensured that the only areas in which data cannot be recorded 
will be the linking gaps even if a buffer underrun occurs 
when a recording apparatus records real-time data, so that 
25 the reliability of real-time data can be improved. 

The recording method according to the present 
invention is capable of searching for and allocating 
real-time extents in such a manner as to realize continuous 
30 reproduction of real-time data, by calculating a data amount 
within a buffer memory during reproduction. 

In accordance with the recording method according 



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to the present invention, areas in which the playback 
reference model will not experience overflow or underflow 
can be calculated before recording of real-time data* As 
a result, it is possible to record data in such a manner 
5 that various reproduction apparatuses can continuously 
reproduce real-time data. 

Even in the case where new real-time data is appended 
to an already- recorded real-time file, upon detecting that 

10 the playback reference model will experience a buffer 
underflow, the real-time data recorded in an area which is 
considered responsible for the buffer underflow can be 
copied to an unrecorded area, whereby data can be recorded 
in such a manner that a reproduction apparatus can 

15 continuously reproduce the real-time data. 

In the case where appended data is real-time data 
which has been encoded in the MPEG format, the last VOBU 
in already -recorded AV data can be re-encoded along with 
20 the newly appended data for recording, thereby making it 
possible to attain seamless reproduction of MPEG streams. 

The recording method according to the present 
invention provides an appropriate method of recording data 

25 on an optical disk which utilizes a linking scheme for data 
recording. For example, since information relating to an 
I picture is recorded in the first sector of MPEG data, the 
data quality of the first sector is very influential over 
the reproduced images and sounds. In the case of high- 

30 quality audio data, too, the data quality of the first sector 
will determine the impression of a song at its beginning. 
Therefore, in the case of recording real-time data, every 
first sector is required to have a high reliability. 



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On the other hand, audio /video data which is 
recorded in extents require continuous recording and 
continuous reproduction capabilities because "freezing" of 
5 images and sounds, occurring responsive to an access, will 
be more readily recognized than a deterioration in the 
quality of images and/or sounds due to loss of data. 

In accordance with the recording method according 
to the present invention, the first sector can be recorded 
so as to succeed a linking loss extent, so that linking 
sectors will not be formed, thereby contributing to high 
data reliability. Since a linking loss extent is not formed 
responsive to every instance of buffer underrun, it is 
possible to continuously record real-time data. 

Any data that was not successfully recorded due to 
a linking gap can be easily error-corrected based on ECCs, 
because each linking gap is only several bytes in size. 

Even if a buffer underrun occurs during recording, 
it is ensured that a multitude of linking loss areas will 
not be formed, thereby providing for a high recording 
efficiency. Furthermore, it is possible to reduce the size 
of address information pertaining to each real-time extent, 
which is managed by a file system. 

In accordance with the reproduction method 
according to the present invention, it is possible to switch 
30 between a read command for general data and a read command 
for real-time data, based on file type information, so that 
it is possible to realize continuous reproduction even if 
a defective sector is detected during the reading of 



10 



15 



20 



25 



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real-time data. 

The data reproduction performance of , the 
information reproduction apparatus according to the present 
5 invention # which is determined as a function of the access 
performance and data read performance of a reproduction 
drive and the size of a reproduction buffer memory, is 
selected so as to satisfy a predetermined data reproduction 
performance that is defined by the playback reference model . 
10 As a result, continuous reproduction capabilities are 
provided on any information reproduction apparatuses that 
share the same data reproduction performance. 

Thus , the invention described herein makes possible 
15 the advantages of (1) providing an information recording 
medium in the form of a recordable optical disk which enables 
continuous reproduction of real-time data; (2) providing 
a method for recording data on such an information recording 
medium and a method for reproducing data on such an 
20 information recording medium; and (3) providing an 
information recording apparatus and an information 
reproduction apparatus to be used in conjunction with such 
an information recording medium. 

25 These and other advantages of the present invention 

will become apparent to those skilled in the art upon reading 
and understanding the following detailed description with 
reference to the accompanying figures. 

30 

BRIEF DESCRIPTION OF THE DRAWINGS 

Figure 1 is a data structural diagram illustrating 
area structures on an information recording medium 



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according to Example 1 of the present invention. 

Figures 2A and 2B illustrate the structure of a 
playback reference model and its access performance, 
5 respectively, according to Example 1 of the present 
invention. 

Figure 3 is a block diagram of the information 
recording/reproduction apparatus according to Example 1 of 
10 the present invention. 

Figure 4 is a flowchart illustrating a recording 
method according to Example 1 of the present invention. 

15 Figures 5A to 5C are diagrams illustrating an 

exemplary area arrangement allocated for a real-time file 
in accordance with the recording method according to 
Example 1 of the present invention. 

20 Figure 6 shows a transition in the amount of data 

in a buffer memory as calculated by the recording method 
according to Example 1 of the present invention. 

Figures 7A, 7B, and 7C are data structural diagrams 
25 illustrating the data structure of attribute information 
of a real-time file according to Example 1 of the present 
invention. 

Figure 8 is a flowchart illustrating a reproduction 
30 method according to Example 1 of the present invention. 

Figure 9 is a block diagram of an information 
recording/reproduction apparatus according to the present 



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invention. 

Figures 10A and 10B illustrate the structure of a 
playback reference model and its access performance, 
5 respectively, according to Example 2 of the present 
Invention. 

Figure 11 is a flowchart illustrating a recording 
method according to Example 2 of the present invention. 

10 

Figure 12 shows a transition in the amount of data 
in a buffer memory as calculated by the recording method 
according to Example 2 of the present invention. 

15 Figures 13A to 13D are diagrams illustrating an 

exemplary area arrangement allocated for a real-time file 
in accordance with the recording method according to 
Example 2 of the present invention. 

20 Figures 14A to 14E are data structural diagrams 

illustrating a linking scheme concerning real-time extents 
according to Example 2 of the present invention. 

Figure 15 is a data structural diagram illustrating 
25 area structures on the information recording medium 
according to Example 2 of the present invention. 

Figures 16A and 16B are data structural diagrams 
illustrating area structures on a conventional information 
30 recording medium. 

Figure 17 is schematic representation of a 
directory structure for files to be recorded. 



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Figures 18A to 18C are data diagrams illustrating 
an extent arrangement in the case where AV data is appended 
to a VIDEO. VRO file. 

5 

Figures 19A to 19D are data structural diagrams 
illustrating a linking scheme for a DVD-R disk. 

10 BEST MODES FOR CARRYING OUT THE INVENTION 

Hereinaf ter, the present invention will be 
described by way of illustrative examples , with reference 
to the accompanying figures. 

15 Example 1 is directed to an embodiment in which a 

real-time file is newly recorded on a DVD-RAM disk. 
Example 2 is directed to an embodiment in which real-time 
data is appended to a real-time file which has already been 
recorded on a DVD-R disk. 

20 

(Example 1) 

In the course of our description , the area 
structures in an information recording medium in which files 
that are managed based on a volume file structure as 

25 specified under the ECMA167 Standards (shown in Figure 1) 
and a playback reference model and access performance 
illustrated in Figures 2A and 2B will be first described. 
Then, a method for recording a real-time file on the 
information recording medium shown in Figure 1 will be 

30 described with reference to a block structural diagram shown 
in Figure 3 and a flowchart shown in Figure 4. Finally, a 
method for reproducing a real-time file on the information 
recording medium shown in Figure 1 will be described with 



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reference to the block structural diagram shown in Figure 3 
and a flowchart shown in Figure 8. 

In the following description, it is assumed that 
5 various descriptors, pointers, and the like which are 
recorded in the volume/file structures of an information 
recording medium conform to the data structures defined 
under the ECMA167 Standards, unless otherwise specified • 

10 Figure 1 is a data structural diagram illustrating 

the area structures on an information recording medium in 
the form of a rewritable optical disk according to one 
embodiment of the present invention. As shown in Figure 1, 
information areas, which are composed of physical sectors, 

15 include a lead-in area 101, a DMA area 102, zones 0 to 34 
(not all of which are shown), and a lead- out area 126. In 
the beginning portion of zone 0, a spare area 103 for 
substituting for a defective sector or a defective block 
is provided, followed by a volume space. From the beginning 

20 of the volume space, a volume structure area 104 for 
logically handling the information recording medium, and 
a file structure area 105 in which a file structure is 
recorded, are provided. 

25 Allocated areas 106, 110, 120, 121, 122, and 125 are 

regions in which data have already been recorded. Guard 
areas 107 and 109, in which no user data can be recorded, 
are formed between zone 0 and zone 1, and between zone 1 
and zone 2, respectively. Although not shown, allocated 

30 areas 120, 122, and 125 include guard areas formed at 
respective zone boundaries. In zone 1, real-time 
extents RT 2 and RT a , in which real-time data is recorded, 
are formed so as to interpose a defective block 108 in 



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between, for example. The defective block 108 may be a 
defective block which has been detected during the recording 
of general data, whose data is recorded in the spare area 103 
as a substitution. In zone 2, real-time extents RT 3 and RT 4 
5 are formed. In zone 3, a pre-allocated area A 5 and a 
real-time extent RT 5 are formed. 

In zone 7, a real-time extent RT 6 , an empty 
extent 123, and an unused area 124 are formed „ The 

10 real-time extents RT 2 to RT 6 are positioned in such a manner 
as to satisfy a set of conditions which are defined by a 
playback reference model having a predetermined access 
performance, as described later in more detail. No 
real-time data is recorded in the pre-allocated area A 3 

15 because any real-time data recorded in this area would result 
in an interruption of continuous data reproduction. In the 
file structure area 105, a space bit map 141 for managing 
unallocated areas (which are capable of allowing data to 
be recorded therein) within the volume space and file 

20 management information having a directory structure as 
shown in Figure 17 are recorded. 

A file entry 142 is management information for 
managing the location information and attribute information, 

25 of the ROOT directory 201 . The ROOT directory file includes 
file identifier descriptors 143 and 144. The file 
identifier descriptors 143 and 144 contain location 
information of file entries 145 (FILEA.DAT file 204 under 
the ROOT directory 201) and 146 (the REALTIME 

30 directory 202 under the ROOT directory 201), respectively . 
The file entry 145 includes location information of the 
allocated area 106 in which the data of this file is recorded. 
The file entry 146 includes location information of a 



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REALTIME directory file, i.e., the file identifier 
descriptor 147. A file identifier descriptor 147 includes 
location information of a file entry 148 for the 
VIDEO. VRO file 203. The file entry 148 includes location 
5 information of real-time extents RT 2 to RT 6 , in which 
real-time data is recorded, and the empty extent 123. 

Figures 2A and 2B illustrate a playback reference 
model and its access performance for determining conditions 
for positioning the real-time data according to one 
embodiment of the present invention, respectively. The 
playback reference model shown in Figure 2A includes a 
disk 301, a pickup 302 for reading data from the disk 301, 
a buffer memory 303 for temporarily storing the data that 
has been read, and a decoder module 304 for decoding the 
data which has been transferred from the buffer memory 303 . 
Vin denotes a data transfer rate when transferring data from 
the disk 301 to the buffer memory 303. Vout denotes a data 
transfer rate when transferring data from the buffer 
memory 303 to the decoder module 304 . Vin is set at a value 
which is larger than Vout, which defines the largest data 
transfer rate for any real-time data that is contemplated 
for each given application. 

25 Figure 2B is a graph illustrating a relationship 

between access distances and access times during an access 
made by the pickup 302 in the playback reference model. In 
Figure 2B, ip(x) is a function which extracts an integer 
portion of x. Assuming that n - ip (TI/TS), any access to 

30 an nth sector takes a skip access time, which is an integer 
function of an n multiple of single sector latencies TS. 
For any access that occurs astride a zone boundary, a fixed 
time TZ ("zone boundary crossing time") applies. For any 



10 



15 



20 



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access to a position within the same zone, a fixed time TI 
( "intra-zone access time") applies. For any access to a 
position in a neighboring zone, TN ( "neighboring zone access 
time) = (2TI + TZ) applies. For any access to a position 
5 which is two or more zones away, a fixed time TL ( "long access 
time" ) applies, which is substantially equal to a full stroke 
access time required for the pickup 302 to travel from the 
innermost periphery to the outermost periphery. 

10 This playback reference model is created so as to 

serve as a reference in determining conditions under which 
continuous reproduction is ensured when reproducing 
real-time data on an optical disk is reproduced by any one 
of various types of reproduction apparatuses . Accordingly, 

15 each access time in the access performance profile defined 
in the graph of Figure 2B are to be determined on the basis 
of access times which are realizable on various reproduction 
apparatus which are envisaged to reproduce the optical disk 
according to the present invention . For example , a portable 

20 optical disk player for consumer use, which is required to 
operate under certain power consumption conditions , incurs 
longer access times than does an optical disk drive for use 
with a computer. Under such circumstances, the access 
performance profile defined in the graph of Figure 2B are 

25 to be determined on the basis of the access times incurred 
by the portable optical disk player for consumer use. 

When reading data in accordance with the playback 
reference model , data will be stored in the buffer memory 303 
30 at a rate of Vin -Vout; on the other hand, during an access 
operation of the pickup 302, data within the buffer 
memory 303 will be consumed at a rate of Vout because data 
cannot be read. By applying specific access time values in 



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this operation model , it is possible to quantitatively 
calculate variations in the data amount within the buffer 
memory 303 as the playback reference model reproduces 
real-time data. Accordingly, if data recording areas are 
5 positioned in such a manner that the data within the buffer 
memory 303 does not experience underf lowing as the playback 
reference model reproduces real-time data # then it is 
possible to continuously reproduce real-time data. By 
means of this modeling ,- conditions for positioning the 
10 real-time extents (in which real-time data is recorded) can 
be determined. 

Now, with reference to a block diagram shown in 
Figure 3 and a flowchart shown in Figure 4 of an information 

15 recording/reproduction apparatus according to one 
embodiment of the present invention, a method for recording 
real-time files to the information recording medium shown 
in Figure 1 will be described. The information 
recording/reproduction apparatus includes a system 

20 controller 701, an I/O bus 706, an optical disk drive 707, 
an input section 708 for inputting recording modes, etc., 
a tuner 710 for receiving TV broadcast programs, an 
encoder 709 for encoding video/audio signals into AV data, 
and a decoder 711 for decoding the AV data and outputting 

25 the decoded AV data to a TV set 712. The system 
controller 701 includes: a recording mode determination 
section 702, an allocation parameter memory 703, a file 
system processing section 704, and a file system processing 
memory 705. The file system processing section 704 

30 includes: a reproduction mode informing section 741, a data 
amount calculation section 742, a time information 
calculation section 743, an unallocated area search 
section 744, a physically non- contiguous location 



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acquisition section 745 , a file structure processing 
section 746, a data recording section 747, and a data read 
section 748. The file system processing memory 705 , which 
is utilized by these sections includes: an empty extent 
5 memory 751, a time information memory 752, a pre-allocated 
area memory 753, a physically non-contiguous location 
memory 754, a file structure memory 755, a bit map 
memory 756, a data buffer memory 757. 

10 It is ensured that the access performance and the 

recording rate during data recording of the optical disk 
drive 707 and the size of the data buffer memory 757 are 
chosen so as to provide a data recording performance which 
satisfies a level of recording performance that would be 

15 attained by using the playback reference model for 
recording. 

A recording mode and a recording time are designated 
via the input section 708, which may be Implemented as a 

20 remote control, a mouse, or a keyboard. The recording mode 
determination section 702 first determines whether the data 
to be recorded is AV data or not , and performs the subsequent 
steps if the data to be recorded is AV data. If the data 
to be recorded is AV data, the recording mode determination 

25 section 702 determines Vout, which defines a fixed value 
which is used to ensure successful recording even in the 
case where any data to be recorded is continually provided 
at the maximum data transfer rate; Vin, which defines a read 
rate from the disk; size SR of data to be recorded; a buffer 

30 size Bmax; and various access times, and store these values 
in the allocation parameter memory 703. As for real-time 
data which is recorded on a DVD-RAM disk, predetermined fixed 
values for read rate Vin and buffer size Bmax are already 



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retained in the allocation parameter memory 703 in order 
to clarify the requirements that an apparatus must satisfy 
in order to be able to reproduce that particular real-time. 
More than one set of such fixed values are preset so as to 
5 support read drives which may be relatively faster or slower . 
The read rate Vin depends on the data to be recorded, and 
the maximum data transfer rate for given data that is desired 
to be recorded by a user may be designated for Vin. For 
example, a relatively large value is set for the read 
10 rate Vin in the case of recording in high picture quality 
mode, and a relatively small value is set for the read 
rate Vin in the case of recording in a long-time mode 
(Step S801). 

15 The file structure processing section 746 

instructs the data read section 748 to read the volume 
structure area 104 and the file structure area 105, and the 
data which has been read by the optical disk drive 707 is 
analyzed on the file structure memory 755. A space bit map 

20 which is among the data that has been read is transferred 
to the bit map memory 756. The physically non-contiguous 
location acquisition section 745 instructs the optical disk 
drive 707 to report location information of zone boundaries 
and/or location information of defective blocks registered 

25 in the PDL or SDL, as physically non-contiguous location 
information on the disk. The physically non- contiguous 
location information which has been reported from the 
optical disk drive 707 is retained in the physically 
non-contiguous location memory 754. 

30 

The unallocated area search section 744 searches 
for any unallocated areas which are physically contiguous 
on an ECC block-by-ECC block basis as pre-allocatfed areas, 



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by using the location information of unallocated areas 
retained in the bit map memory 756 and the physically 
non-contiguous location information retained in the 
physically non-contiguous location memory 754. The 
5 location information of the pre-allocated areas found in 
the search is stored in the pre-allocated area memory 753. 
This search operation is performed until the total size of 
the pre-allocated areas well exceeds the size of data to 
be recorded SR as determined at Step S801, so that it will 
10 be unnecessary to again perform this step even if any areas 
which cannot be allocated are found in later steps. 

Figure 5A is a diagram illustrating an exemplary 
arrangement of locations of pre-allocated areas which have 

15 been found as a result of the search in this step. Pre- 
allocated areas h ± to &, are allocated. In order to secure 
the pre-allocated areas, the file structure processing 
section 746 updates corresponding pre-allocated regions in 
the bit map on the bit map memory 756 to an "allocated" 

20 status • 

At this point, all areas that are found to be 
recordable based on the space bit map, except for those 
registered in the SDL, are logically- contiguous recordable 

25 areas because any area that is registered in the SDL would 
actually be recorded in the spare area as a substitution. 
Moreover, logically- contiguous areas can be determined by 
splitting such logically-contiguous areas at the guard 
areas within each zone or at the boundaries between the areas 

30 registered in the PDL. The reason for searching for 
physically-contiguous areas is so that the transition in 
the amount of data within the buffer can be more accurately 
calculated in the subsequent steps. 



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The reason why the search is performed on an ECC 
block-by-ECC block basis is in order to prevent real-time 
data from being subjected to a replacement process , as part 
5 of defect management, in the case where both real-time data 
and general data are recorded in one ECC block (Step S802) . 

The time information calculation section 743 
calculates a read time TR A (where i corresponds to the area 

10 number A t for pre-allocated areas as shown in Figure 5A) 
required for reading each pre-allocated area at a data 
transfer rate of Vin and an access time T 1JU1 between 
pre-allocated areas (i.e., access time between pre- 
allocated areas A t and A i+1 as shown in Figure 5A), by using 

15 the location information of pre-allocated areas retained 
in the pre-allocated area memory 753 and the various access 
times retained in the allocation parameter memory 703 . The 
read time T^ is determined to be S^Vin, where S L represents 
the size of each pre-allocated area A ± . 

20 

In Figure 5A, the read times TR X to TR 7 are times 
required for reading the pre-allocated areas A r to A 7 , 
respectively. The access time T 1#2 is a read delay time 
which is ascribable to a defective ECC block, equal to 16TS. 

25 T 2i3 , T 3j4 , T 4<5 , T 5#6 , and T 6#7 , are a zone boundary crossing 
time TZ, an intra-zone access time TI, a neighboring zone 
access time TN, an intra-zone access time TI, and a long 
access time TL, respectively. These access times can be 
derived from the access performance of the playback 

30 reference model as shown in Figure 2B. In order to 
calculate how the playback reference model would reproduce 
data from pre-allocated areas, the read time for each 
pre-allocated area and the access time for a next pre- 



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allocated area are alternately calculated (Step S803). 

Next # the data amount calculation section 742 
performs calculation processes from Steps S804 to S813 by 
5 using the read times and access times retained in the time 
information memory 752 , and calculates the amount of data 
within the buffer memory at the time when the read for 
pre -allocated areas has completed. Figure 6 shows a 
transition in the amount of data in the buffer memory as 
10 data in the pre-allocated areas is read. At time t 1# which 
is after reading of the pre-allocated area A l# the data 
amount has increased at a rate of (Vin - Vout), over the 
time period TR X (Step S804). 

15 Since the buffer memory of an actual reproduction 

apparatus is finite, it is necessary to consider the 
operation at an upper limit of buffer size. Therefore, it 
is checked whether or not the calculated data amount exceeds 
the buffer size Bmax (Step S805). 

20 

If overflow does not occur, then, it is checked 
whether or not the total calculated size of the pre-allocated 
areas well exceeds the size of data to be recorded SR, which 
was previously set at Step S801. By allocating sufficient 
25 recordable areas as pre-allocated areas, it is ensured that 
there will always be enough recordable areas even if areas 
in which data cannot be recorded due to dust or scratches 
are avoided during actual recording (Step S807). 

30 If the total calculated size of pre-allocated areas 

does not exceed SR, then it is checked whether or not the 
calculated data amount exceeds an allocation level BL (= 
Vout X TL). If the amount of data within the buffer exceeds 



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BL, then underflow will never occur when any area on the 
disk is accessed from the end of this pre-allocated area. 
Therefore, the first pre-allocated area to this pre- 
allocated area are determined as areas which will not cause 
5 underf lowing, and hence these areas are registered as empty 
extents in which real-time data can be recorded. Thus, the 
subsequent steps can be performed in a more efficient manner. 
When conducting a search for areas associated with 
underf lowing, for example, it is possible to exclude the 
10 areas that have been registered as empty extents (Step S809) 
from those which are searched. 

Next, the amount of data within the buffer memory 
at the time of starting a read of pre-allocated areas is 
15 calculated. At time t 2 in Figure 5A, which is before 
reading the pre-allocated area A 2 , the data amount has 
decreased at a rate of Vout, over the time period T 1#2 
(Step S811). 

It is checked whether or not the calculated data 
amount has a negative (-) value. If the calculated data 
amount has a negative (-) value, it means that a buffer 
underflow will occur responsive to this access, so that the 
data reproduction will be interrupted (Step S812). 

If the calculated data amount does not have a 
negative (-) value, the control proceeds to the beginning 
of Step S804. In Figure 6, the pre-allocated areas A 2 to 
A 4 are calculated while repeating Steps 804 to S812. 

With reference to Step S805, the data may overflow 
the buffer at the tail end of the pre-allocated area A 4 , as 
shown in Figure 6. In this case, the optical disk drive 707 



20 



25 



30 



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temporarily suspends the data reproduction operation in 
order to avoid data overflow; therefore, a minimum rotation 
wait time is added to TR 4 . Accordingly, the calculated data 
amount is corrected on the assumption that the data has 
5 decreased at a rate of Vout over a period of kXTK, where 
TK represents a rotation wait time at the outermost periphery 
of the information recording medium, and k = ip ((B(t) - 

Bmax) / (VoutXTK) + 1)), where ip(x) is a function which 
extracts an integer portion of x. B(t) represents a data 
10 amount when overflow occurs. However, in order to simplify 
the data amount correction calculation, Bmax may be regarded 
as the data amount when overflow occurs, although this will 
result in a lower calculation accuracy (Step S806). 

15 Since the data amount exceeds the allocation 

level BL at time t 7 , the pre-allocated areas A x to A 4 are 
allocated as empty extents E x to E 4 , and the location 
information there of is stored in the empty extent memory 751 
(Step S810). 

20 

In Figure 6, the data amount calculation results in 
the case of reading the pre-allocated areas A 3 to A 7 are shown 
by dotted lines. A data underflow occurs at time t 12 . In 
this case, the pre-allocated area which is most responsible 

25 for the underflow is excluded from allocation, and the 
control proceeds to the beginning of Step S811. The 
pre-allocated area which is most responsible for the 
underflow can be determined based on D 1# which represents 
a decrease in the data amount that occurs between accessing 

30 the beginning of an pre-allocated area h L and finishing data 
read from this area. By calculating the decrease for each 
pre-allocated area and finding a pre-allocated area which 
has the largest decrease, the pre-allocated area which is 



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most responsible for the data underflow can be known. 

Specifically, D 5 , D 6 , and D 7 in Figure 6 are 
calculated. Since D 5 is the largest among the three, the 
5 pre-allocated area A 3 is excluded from allocation . In other 
words, in Figure 5B, the area numbers are updated so that 
the old pre-allocated areas A 6 and A 7 become new pre- 
allocated areas A 5 *andA 6 *, respectively. Furthermore, as 
shown in Figures 4 and 5B, an access time T 45 * between the 

10 pre-allocated areas A 4 and A s * is calculated, and the old 
read times TR 6 and TR 7 are renumbered as new read times TR 5 * 
and TR 6 *, respectively, and the access time T 6 7 is renumbered 
as a new access time T 5 6 *. Since this method takes into 
account access times, a higher calculation efficiency is 

15 provided than by methods in which the pre-allocated areas 
are omitted one by one from calculation in an ascending order 
of size (i.e. , smaller areas first) . If an underflow still 
occurs after the area associated with the largest decrease 
in data amount is omitted from the calculation, the area 

20 associated with the second largest decrease in data amount 
is omitted from the calculation, and so on (Step S813). 

Next, the calculation of Step S811 is resumed at 
time T 43 *. After an increase in data amount from the 

25 pre-allocated area A 6 * is calculated, since the total size 
of the pre-allocated areas exceeds the size of data to be 
recorded SR, the pre-allocated areas A 5 * and A 6 * are 
allocated as empty extents E 5 and E 6 , and the location 
information there of is stored in the empty extent memory 751 , 

30 and the control proceeds to Step 814. Through the flow of 
control up to this step, areas in which real-time data can 
be recorded have been determined (Step S808). 



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In order to indicate that the allocated empty 
extents are in fact pre -allocated for recording real-time 
data, the file structure processing section 746 generates 
a file entry for the VIDEO. VRO file containing location 
5 information of the empty extents, and instructs the data 
recording section 747 to record data on the disk, so that 
the file entry is recorded on the disk by the optical disk 
drive 707. In the case where the system controller 
accomplishes recording of a plurality of files in a 

10 multi-task environment, the process from Steps S802 to S813 
may be performed as one process that has precedence over 
other tasks, and the determined empty extents are registered 
on the optical disk during this step. As a result, in a 
multi-task environment, too, the data of general files can 

15 be prevented from being erroneously recorded in any empty 
extents determined through the calculation (Step S814). 

An audio/video signal which is input from the 
tuner 710 is encoded by the encoder 709 into AV data by a 

20 variable length compression method, and transferred to the 
data buffer memory 757. The file structure processing 
section 746 instructs the data recording section 747 to 
record the AV data in an already-allocated empty extent , 
and the AV data is recorded without a replacement process 

25 to a spare area. Since the data recording performance which 
is determined as a function of an access performance and 
data read performance of the optical disk drive 707 and the 
size of the reproduction buffer memory 757 satisfies a 
predetermined data reproduction performance that can be 

3 0 achieved by a playback reference model during data recording , 
the data buffer memory 757 is not overflowed during data 
recording. 



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As shown in Figure 5C, the empty extents E 1 to E 5 
in which real-time data has been recorded become real-time 
extents RT X to RT S , respectively. Since each empty extent 
is allocated by using the fixed data transfer rate Vout, 
5 which supports the optimum sound/image quality, a region 
thereof will be left unused after completion of the recording 
of AV data. Accordingly, a region in the empty extent E 6 
in which data has been recorded becomes a real-time 
extent RT 6 . If a region of an ECC block is left without any 
10 AV data recorded therein, as may happen at the end of any 
given AV data to be recorded, such a region becomes an empty 
extent 123. If one whole ECC block is left without any 
AV data recorded therein, such an ECC block becomes an unused 
area 124 (Step S815). 

15 

In order to reinstate the unused area 124 as a 
recordable area, the file structure processing section 746 
updates the data on the bit map memory 756, and generates 
a file entry for the VIDEO. VRO file (composed of the 

20 real-time extents RT t to RT 6 and the empty extent 123) on 
the file structure memory 755. The data recording 
section 747 instructs the optical disk drive 707 to record 
these space bit map and file entry in predetermined positions . 
As a result, the space bit map 141 and the file entry 148 

25 as shown in Figure 1 are recorded (Step S816). 

Thus, as described above, predetermined parameters 
are set according to user instructions at Step S801; 
information concerning non- contiguous areas on the optical 
30 disk is acquired from the optical disk drive 707 at 
Step S802; and areas from which data can be continuously 
reproduced are finalized as empty extents at Steps S803 to 
S814. As a result, the optical disk drive 707, the control 



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system , and the application can be separately implemented. 
Therefore, the recording method according to the present 
invention can be easily implemented in a computer system 
in which an optical disk drive, a control system (including 
5 the operating system (OS) ) , and applications are separately 
provided. Since steps S803 to S814 and step S816 can be 
realized by using standard file system drivers which are 
provided in each OS, it is possible to handle recording of 
general files and real-time files by using standard file 
10 system drivers which are provided in each OS, thereby 
facilitating the development of application software for 
recording/edition of video data. 

Next, features of the information recording medium 
15 according to the present invention will be described with 
reference to the playback reference model illustrated in 
Figure 2A and the real-time extent arrangement illustrated 
in Figure 5C. Each real-time extent is composed of a 
logically and physically contiguous area so that it is 
20 possible to calculate any decrease in data amount within 
the buffer memory occurring responsive to access by a pickup 
of the optical disk drive. 

An increase (D(i) ) in the amount of data having been 
25 stored in the buffer memory responsive to the playback 
reference model reading the data from an i th real-time extent 
is: 

D(i) = (Vin - Vout) X s(i) / Vin, 
where S(i) represents the data size of an 1 th real-time 
30 extent; and 

T(i) represents a time required for a pickup of the 
playback reference model to access from the end of the i th 
real-time extent to the beginning of an (i+l) th real-time 



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extent . 



The amount of data which is consumed from within the 
buffer memory when the playback reference model accesses 
5 from the end of the i th real-time extent to the beginning 
of the (i+l) th real-time extent is - Vout X T(i). 



Therefore, assuming that B(0) =0, the amount of data 
(B(i)) which has been stored in the buffer memory when the 
10 playback reference model accesses from the end of the i th 
real-time extent to the beginning of the (i+l) th real-time 
extent is: 

B(i) = B(i-l) + D(i) - Vout X T(i). 



15 Since the i th real-time extent which was recorded 

by the above recording method is positioned so that a buffer 
overflow will not occur, D(i) is subjected to the following 
correction concerning overflow conditions. 

20 When D(i) > Bmax - B(i-l), 

D(i) = Bmax - B(i-l), or 

D(i) = (Vin - Vout) X s(i) / Vin + B(i-l) 
- k X (VoutXTk). 



25 In the above equation, k represents an integer portion 

of ((D(i) + B(i-l) - Bmax) / (VoutXTk) + 1). 

In order to prevent a buffer underflow, the (i+l) th 
real-time extent is positioned at a position satisfying a 
30 real-time reproduction condition defined as: 



T(i) ^ (B(i-l) + D(i))/Vout. 



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In other words, since the real-time extents RT t to 
RT 6 in Figure 5C are positioned so as to satisfy the real-time 
reproduction condition defined above, it is possible for 
an actual reproduction apparatus which satisfies the 
5 performance of the playback reference model to continuously 
reproduce video data and audio data from this real-time 
extent. In the determination as to whether the (i+l) th 
pre -allocated area can be allocated as an empty extent in 
Steps S804 to S814, the aforementioned real-time 
10 reproduction condition can be conveniently used to 
facilitate the determination. 

Now, referring to Figures 7A, 7B, and 7C, attribute 
information according to the present invention to be 

15 registered in the file entry for real-time files (which has 
been recorded in Step S816) will be described. Figure 7A 
is a data structure diagram illustrating the file entry for 
a real-time file. In the beginning of the file entry is 
recorded a descriptor tag identifying this descriptor as 

20 a file entry. At byte position (hereinafter referred to as 
"BP") 16 is recorded an ICB tag for recording attribute 
information of a real-time file. At BP 56 is recorded the 
information length of the file body for identifying the file 
body from the file tail. At BP 112 is recorded an extended 

25 attribute ICB for recording location information for 
designating, in the case where the extended attribute 
information (recorded at BP176) becomes too large to be 
recorded within the file entry, where to record the extended 
attribute information. At BP168 is recorded the length of 

30 the extended attribute recorded at BP176 ( = LJSA) . At BP172 
is recorded the entire length of an allocation descriptor 
which is recorded in byte positions following L_EA. At 
BP176 is recorded an extended attribute. In the byte 



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positions following L_EA is recorded an allocation 
descriptor. 

In the byte positions following L_EA, short 
5 allocation descriptors for real-time extents RT X to RT 6 and 
an empty extent 123 are recorded. Real-time extents and 
empty extents are distinguished from one another based on 
the value ( *0 U and "1" , respectively) of the most significant 
2 bits of the extent length recorded at relative byte 
10 position (hereinafter referred to as "RBP") 0 of each short 
allocation descriptor. Furthermore, the real-time 
extents RT l to RT 6 are recorded in the file main body, whereas 
the empty extent 123 is recorded in the file tail. 

15 At RBP1 of the ICB tag which is recorded in the file 

entry for a real-time file, a file type value w 249 a is 
recorded to indicate that the file entry represents a 
real-time file. Based on the file type value, it can be 
determined whether or not real-time data (which requires 

20 continuous reproduction) is recorded in the file. RBP18 of 
the ICB tag is a flag field, in which bit 4 indicates whether 
or not re-allocation is permitted. Bit 4 is set to "1" to 
indicate that the real-time extents are positioned so as 
to satisfy the real-time reproduction condition according 

25 to the present invention so far as this file is concerned. 
Bit 4 is reset to "0" if the real-time files have been copied 
without considering the real-time reproduction condition, 
thereby providing a means for indicating that the 
positioning of real-time extents is no longer appropriate. 

30 This bit can also be utilized to prevent a utility such as 
a defragmentation utility from undesirably changing the 
positioning of real-time files. 



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In an extended attribute for allocation that is 
recorded in the file entry for a real-time file, parameters 
used when allocating the respective extents of the real-time 
file are recorded. That is, a data transfer rate Vin is 
5 recorded at RBPO; a data transfer rate Vout is recorded at 
RBP2; a buffer memory size is recorded at RBP4 ; an access 
type for identifying each access performance type rate is 
recorded at RBP6; and access times are recorded at RBP8 and 
the subsequent relative bit positions. In the case of the 

10 access performance according to the present example, n l n 
is recorded as the access type, and the values of TZ, TI, 
and TL are recorded as access times Ta, Tb, and Tc, 
respectively. In the case of the access performance of a 
DVD-R which is described in Example 2, "2" is recorded as 

15 an access type. 

Next, a method for reproducing real-time data from 
the information recording medium shown in Figure 1 by using 
the information recording/reproduction apparatus according 

20 to one embodiment of the present invention, in accordance 
with the block structure illustrated in Figure 3 and the 
flowchart illustrated in Figure 8, will be described. The 
optical disk drive 707, which satisfies the access 
performance of the playback reference model, is capable of 

25 reading data at a predetermined data transfer rate Vin . The 
data buffer memory 757 has a size which is equal to or greater 
than that of the buffer memory 303 of the playback reference 
model. Thus, the information recording/ reproduction 
apparatus satisfies the predetermined performance of the 

30 playback reference model. 

In the case where the information 
recording/reproduction apparatus has an access performance 



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such that it is capable of faster access than the 
predetermined access performance of the playback reference 
model, it is possible to reduce the size of the data buffer 
memory 757 so as to be smaller than that of the buffer 
5 memory 303 of the playback reference model. 

The file structure processing section 746 
instructs the data read section 748 to read the volume 
structure area 104 and the file structure area 105, and the 
10 data which is read by the optical disk drive 707 is 
transferred to the file structure memory 755 for analysis. 
Among the data which has been read, the location information 
and attribute information of real-time extents are stored 
in the file structure memory 755 (Step S901). 

15 

The file structure processing section 746 
determines whether or not this file is a real-time file based 
on the file type which is recorded in the ICB tag shown in 
Figure 7A, and confirms whether or not the real-time extents 
20 are positioned so as to satisfy the real-time reproduction 
condition based on the non-relocatable bit (Step S902). 

In the case where the file is a real-time file, the 
reproduction mode informing section 741 informs the 
25 allocation parameters which are recorded in the extended 
attribute in the file entry to the optical disk drive 707. 
Then, the optical disk drive 707 determines whether the 
real-time file can be reproduced or not (Step S903). 

30 The data read section 748 issues a reproduction 

command for real-time data to the optical disk drive 707 
(Step S904). 



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In accordance with the issued reproduction command, 
the optical disk drive 707 reads data from the real-time 
extents. During a reproduction operation from real-time 
extents, the location information of any defective sectors 
5 which have been subjected to a replacement process is 
ignored; and even if an error occurs during data reproduction, 
continuous data reproduction is performed without 
performing any recovery process. The data which has been 
read is temporarily transferred to the data buffer 
10 memory 757, so that video data and audio data are reproduced 
on the TV set via the decoder 711, which corresponds to the 
decoder module in the playback reference model (Step S905) . 

In the case where the file is a general file, the 
15 data read section 748 issues a reproduction command for 
general data to the optical disk drive 707 (Step S906). 

In accordance with the issued reproduction command 
for general data, the optical disk drive 707 reads data. 
20 The data which has been read is temporarily transferred to 
the data buffer memory 757, (Step S907). 

Thus, the information recording/reproduction 
apparatus can reproduce the data continuously from 
25 real-time extents which are positioned so as to satisfy the 
real-time reproduction condition, because the information 
recording/reproduction apparatus satisfies the 
predetermined performance of the playback reference model. 

30 Although the present example is directed to an 

optical disk of the ZCLV format, the present invention is 
also applicable to any DVD-RW disk or hard disk whose defect 
management processing is handled by a system controller. 



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In the case of a DVD-RW, defect management is performed based 
on a file system, and the location information of any sectors 
that are replaced by spare areas is managed based on a sparing 
table. Therefore , at Step 802 , it is possible to search for 
5 logically and physically contiguous unallocated areas from 
a space bit map. 

Although the present example illustrates the case 
where the file structure area is a single continuous region , 
10 the respective descriptors may be distributed throughout 
the disk without undermining the effects of the present 
invention . 

(Example 2) 

15 Example 2 illustrates an instance in which new 

real-time data is appended to a real-time file which is 
already recorded on a DVD-R disk. 

In the course of our description , the block 
20 structure of an information recording/reproduction 
apparatus shown in Figure 9, and a playback reference model 
and access performance in accordance with this information 
recording/reproduction apparatus will be first described 
with reference to Figure 10. Then, a method for appending 
25 data to a real-time file will be described with respect to 
an area structure shown in Figure 13 and data amount 
transition within a buffer during reproduction shown in 
Figure 12. Next, a linking scheme for recording AV data 
will be described with reference to Figure 14. Then, the 
30 data structure of the optical disk will be described with 
a focus on file management information. Finally, a 
reproduction method will be described with reference to the 
flowchart shown in Figure 8. 



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Figure 9 is a block diagram illustrating an 
information recording/reproduction apparatus according to 
one embodiment of the present invention. The information 
5 recording/reproduction apparatus includes a system 
controller 801, an I/O bus 806, an optical disk drive 807 , 
an input section 808 for inputting recording modes, etc., 
a tuner 810 for receiving TV broadcast programs, an 
encoder 809 for encoding video/audio signals into AV data, 

10 and a decoder 811 for decoding the AV data and output ting 
the decoded AV data to a TV set 812. In the case of a 
personal computer, the respective sections in the system 
controller 801 as shown in Figure 9 may be implemented by 
a main CPU. Although discrete memories dedicated to 

15 different purposes are described, they may be realized on 
one memory circuit. In the case of a video recorder which 
integrates the system controller 801 and the optical disk 
drive 807, the various sections within the system 
controller 801 and the optical disk drive 807 may be 

20 implemented by a single CPU. 

The system controller 801 includes: a recording 
mode determination section 802, an allocation parameter 
memory 803, a VOBU (video object unit) re-encoding 

25 section 821, a VOBU memory 822 for re-encoding VOBUs, a file 
system processing section 804, and a file system processing 
memory 805. In the case of a PC system, the recording mode 
determination section 802 and the VOBU re-encoding 
section 821 may be implemented by application software, and 

30 the file system processing section 804 may be implemented 
by using standard file system drivers which are provided 
in each OS. 



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The file system processing section 804 includes: an 
unrecorded area check section 841 , which in turn includes 
a linking setting section 842 for designating a linking 
scheme and data recording start locations; a time 
5 information calculation section 843 for calculating time 
information concerning reading of extents and access; a data 
amount calculation section 844 , which in turn includes a 
final access check section 845 for calculating the presence 
or absence of a buffer underflow during access to a data 

10 recordable area which is set within an unrecorded area; a 
file structure processing section 846; a data recording 
section 847 , which in turn includes a data copying 
section 848 for copying already- recorded data to an 
unrecorded area in the case where a buffer underflow occurs; 

15 and a data read section 849, which in turn includes a 
reproduction mode informing section 850 for switching 
between reproduction modes for AV data and non-AV data. 
The file system processing memory 805 , which is utilized 
by these sections includes a file structure memory 851 , and 

20 a data memory 852, which also serves as a buffer memory. 

The optical disk drive 807 includes: a data 
memory 871 for temporarily storing data to be recorded or 
reproduced; a runout controller 872 for controlling data 

25 to be recorded in a runout area; a linking controller 873 
for controlling data append in a linking scheme; a data 
recorder 874 for controlling data recording; and a data 
reproducer 875 for controlling data reproduction.- It is 
ensured that the access performance and the data recording 

30 rate of the optical disk drive 807 and the size of the data 
buffer memory 852 are chosen so as to provide a data 
recording performance which satisfies a level of recording 
performance that would be attained by using the playback 



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reference model for recording. 

Figures 10A and 10B illustrate a playback reference 
model and its access performance for determining conditions 
5 for positioning the real-time data according to one 
embodiment of the present invention, respectively. The 
playback reference model illustrated in Figure 10A is the 
same playback reference model as that described in Example 1 . 
A buffer memory 303 and a decoder module 304 shown in 
10 Figure 10A are implemented as data the data memory 852 and 
the decoder 811, respectively. 

Figure 10B is a graph illustrating a relationship 
between access distances and access times during an access 

15 made to a DVD-R disk by a pickup 302 in the playback reference 
model. It should be noted that, the graph of Figure 10B 
illustrates different access times from those illustrated 
in Example 1 (Figure 2B), which was directed to a DVD -RAM 
disk, because a different access performance is required 

20 of a reproduction apparatus for DVD-R disk due to the 
physical structure of the disk medium. The access times are 
conveniently divided into four access categories, depending 
on the access distance: skip access, short access, middle 
access, and long access, although the actual access 

25 performance will present a non-linear profile. Any access 
occurring at the ECC block level is defined as a skip access . 

Next, in accordance with a flowchart shown in 
Figure 11 , a recording method will be described with respect 
30 to an area structure shown in Figure 13 and data amount 
transition within a buffer during reproduction shown in 
Figure 12. The following example illustrates a method for 
appending AV data to a real-time file which is composed of 



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real-time extents RT X and RT 2 that have already been recorded. 
In order to permit the appended AV data and the 
already- recorded AV data to be reproduced in a seamless 
manner, real-time extents are allocated under the real- 
5 time reproduction condition as described in Example 1. 

A recording mode and a recording time are designated 
via the input section 808, which may be implemented as a 
remote control, a mouse, or a keyboard. The recording mode 

10 determination section 802 first determines whether the data 
to be recorded is AV data or not , and performs the subsequent 
steps if the data to be recorded is AV data. If the data 
to be recorded is AV data, the recording mode determination 
section 802 determines Vout, which defines a maximum data 

15 transfer rate; Vin, which defines a read rate from the disk; 
size SR of data to be recorded; a buffer size Bmax; and 
various access times, and store these values in the 
allocation parameter memory 803 (Step S401: determination 
of recording parameters ) . 

20 

The unrecorded area check section 841 acquires the 
size of an unrecorded area 553 (shown in Figure 13A) from 
the optical disk drive 807 to confirm that this size is 
sufficiently greater than the size of data SR (= Vout X 

25 recording time) to be recorded. After the AV data, a file 
entry for the real-time file to be updated and file 
management information such as VAT ICB and VAT are recorded 
along with a linking loss extent (32 KB) . For example, when 
closing the disk, a border out is further recorded. 

30 Therefore, a sufficient data recordable area is required 
for the AV data to be recorded. 



In order to realize a seamless reproduction between 



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the file tail of a real-time file and the beginning of the 
appended AV data, the VOBU re-encoding section 821 reads 
the last VOBU in the last real-time extent. The last VOBU 
is re-encoded by the encoder 809 so as to be able to be 
5 recorded in the unrecorded area along with the new AV data. 
The re-encoded VOBU is retained in the VOBU memory 822. 

As used herein, a video object unit (VOBU) is 
MPEG data which is composed of a number of GOPs (group of 

10 pictures) within AV data which has been compressed in the 
MPEG format. Since MPEG data includes video information 
and audio information that are recorded with a certain time 
offset, any appended AV data must be recorded while keeping 
this offset intact in order to be able to be reproduced in 

15 a seamless manner. Accordingly, as described above, the 
last VOBU which has been read is re- encoded along with the 
newAV data to be recorded, and re -recorded in the unrecorded 
area. 

20 The file structure processing section 846 

instructs the data read section 849 to read the volume 
structure area and the file structure area (described 
later) , and the data which has been read by the optical disk 
drive 807 is analyzed on the file structure memory 851, 

25 whereby the locations of all real-time extents (i.e., RT X 
and RT 2 in this example) in the real-time file are determined. 
At this time, real-time extents RT i# except for the last 
extent, are allocated as pre-allocated areas A ± (i = 1 to 
n-1; n is 2 in the example shown in Figure 13), and the 

30 portion of the last real-time extent RT n excluding the VOBU 
which has been read is allocated as a pre-allocated area A„. 
Moreover, the linking setting section 842 sets a linking 
loss extent 555 (described later) for the unrecorded area, 



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while allocating the remainder as a pre-allocated area A„ tl . 

In Figure 13A, a linking loss extent 551 and an 
empty extent E x are areas which were formed when the 
5 real-time extent RT X was recorded. Similarly, a linking 
loss extent 552 and an empty extent E 2 are areas which were 
formed when the real-time extent RT 2 was recorded. An empty 
extent is an area spanning between a sector in which data 
is recorded and an ECC block boundary. Reference 

10 numeral 554 represents an area in which the VOBU that has 
been read is recorded. Reference numeral 555 represents a 
linking loss extent which is set within the unrecorded 
area 553. The pre-allocated areas which are allocated 
during this step are denoted as A 1# A 2# and A 3 (Step S402: 

15 check for unrecorded areas). 

The time information- calculation section 843 
calculates a read time TR ± (where i corresponds to the area 
number A t for pre-allocated areas) required for reading each 

20 pre-allocated area at a data transfer rate of Vin (except 
for the last area) and an access time T ii+1 between pre- 
allocated areas (i.e., access time between pre-allocated 
areas A t and A 1+1 ) , by using the location information of the 
pre-allocated areas and the various access times retained 

25 in the allocation parameter memory 803. In Figure 13B, the 
read times TR L and TR 2 are times required for reading the 
pre-allocated areas A 1 and A 2 , respectively. Access times 
T l 2 and T 2 3 are calculated based on the access performance 
shown in Figure 10B, where access time T m#n represents an 

30 access time from the end of a pre-allocated area ^ to the 
beginning of A n (Step S403: calculation of read time 
information and access time information). 



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Next, the data amount calculation section 844 
performs calculation processes from Steps S404 to S414 for 
the pre-allocated area that has been recorded, by using the 
read times and access times obtained at Step S403. 
5 Figure 12 shows a transition in the amount of data in the 
buffer memory responsive to reading of the pre-allocated 
areas and accesses (calculation of data amount in the buffer 
for each recorded area). 

10 First, the data amount (B(t)) in the buffer memory 

for the pre-allocated areas A x to A„ in which AV data has 
already been recorded is calculated in accordance with the 
following steps. It is assumed that t 2i _ 2 and t 21 . x represent 
data read start time and data read end time for an area A 1# 

15 respectively (Step S404). 

The data amount in the buffer memory at the data read 
start time for an area A L is calculated as follows 
(Step S405): 

20 

B(0) = 0 (for AJ 

B (t 2i _ 2 ) =B (t 2i „ 3 ) - (Vout X T t . ul ) (for A 2 and after). 

The data amount in the buffer memory at the data read 
25 end time for an area A^s calculated as follows (Step S406) : 

B (t 21 .J = B (t 2i _ 2 ) + (Vin - Vout) X TR,. 

30 Next, it is checked whether or not the calculated 

data amount exceeds the buffer size Bmax 

If overflow does not occur, the area for which to 



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perform the calculation Is moved to a next area (Step S409) , 
and the control returns to Step S404 (Step S407). 

If the calculation result indicates overflow, the 
5 optical disk drive 807 temporarily suspends the data 
reproduction operation in order to avoid overflow. 
Therefore, a minimum rotation wait time is added. 
Accordingly, the calculated data amount is corrected on the 
assumption that the data has decreased at a rate of Vout 

10 over a period of kXTK, where TK represents a rotation wait 
time at the outermost periphery of the information recording 
medium, and k = ip ((B(t) - Bmax) / (VoutXTK) + 1)). B(t) 
represents a data amount when overflow occurs. Next, the 
area for which to perform the calculation is moved to a next 

15 area (Step S409), and the control returns to Step S404 
(Step S408). 

At time t L shown in Figure 12, the data amount is 
corrected responsive to an overflow. 

20 

Next, by using Steps S410 to S414, the final access 
check section 845 calculates the data amount (B(t 2n ) ) in the 
buffer memory at the data read start time for the pre- 
allocated area A n+1 that has been set in the unrecorded area 
25 (calculation of data amount in the buffer at the beginning 
of the last pre-allocated area). 

First, this data amount (B(t 2n )) is calculated as 
follows (Step S410): 

30 

B(t 2n ) = BU^) - (VoutXT^) 

At this time, data underflow is checked for. If 



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underflow does not occur, the control proceeds to Step S415 
(Step S411). 

If underflow occurs, those pre-allocated areas 
5 which result in a non^zero (i.e. , more than zero) data amount 
even when accessing to the last pre-allocated are searched 
for, while excluding one after another pre-allocated area 
from this calculation from the outer periphery toward the 
inner periphery of the disk, until an area in which underflow 
10 will not occur. This search is performed as follows 
(Steps S412, S413, and S414): 

for i = 1 to n-1 { 

B(t 2n ) = B(t 2n . Wi ) - (VoutXT n . 1>n+1 ). 
If B(t 2n ) ^ 0, 

A„ +1 is updated to A„_ 3 * (where j - i-1); 
T„-i. a+ i is updated to T n . lin . 1+1 *; and 
the control proceeds to Step S415 

}. 

In the example illustrated in Figures 12 and 13C, 
since a data underflow occurs at time t 4 , the pre-allocated 
area A 2 is excluded from the above calculation . Accordingly , 
T l>3 is updated to T lt2 *, and A 3 is updated to A 2 *, and the data 
amount after access from the end of the pre-allocated area A x 
to the beginning of A 2 * is calculated. No underflow occurs 
when the pre-allocated area A 2 is excluded. 

Next, the data copying section 848 copies the data 
30 recorded in the pre-allocated area A 2 , which was excluded 
from the above calculation, to the pre-allocated area A 2 * 
(in a portion denoted as 557 in Figure 13D) so as to succeed 
the linking loss extent 555. The data recording 



15 



20 



25 



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section 847 records the re-encoded VOBU (in a portion 
denoted as 558 in Figure 13D) and the AV data to be appended 
(in a portion denoted as 559 in Figure 13D)so as to succeed 
the data recorded in the pre-allocated area A 2 . The 
5 regions 557. 558, and 559 become real-time extents RT 2 * 
(Step S415: recording of real-time data). 

In the case where data is recorded to a DVD-R disk, 
the files are recorded by using a VAT system which is defined 
10 under the UDF specification. Therefore, a file structure 
associated therewith is recorded in the unrecorded area 556 
(Step S416: update of file structure). 

Thus, the arrangement of the real-time extents 
15 recorded in the aforementioned manner satisfy the real- 
time reproduction condition as described in Example 1 of 
the present invention. 

Next, recording of real-time extents will be 
20 described with respect to the data structure of a linking 
scheme as shown in Figure 14. The linking setting 
section 842 sets a linking loss extent 210 (32 KB), and 
records AV data. The linking loss extent 210 is composed 
of one ECC block with OOh being recorded in all sectors. 
25 The first sector defines a linking sector. Since the 
linking loss extent 210 and the real-time extent 211 are 
recorded so as to adjoin each other, no linking gap is formed 
at the boundary therebetween. As a result, the data 
reliability of the first sector is prevented from 
30 deteriorating. 

Next, a recording method in the case where a buffer 
underrun occurs between regions 212 and 213 will be 



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described* A sector 215 is a linking sector. The specific 
data structure concerning sync frames is shown in Figure 14D. 
Reference numerals 251 , 252 , 253, and 254 represent areas 
which are recorded at an end portion when the area 212 is 
5 recorded; 251 and 252 represent a sync portion and a data 
portion, respectively, of a first sync frame; and 253 and 
254 represent a sync portion and a data portion , respectively, 
of a second sync frame* Reference numerals 255, 256, 257, 
and 258 represent areas which are recorded at a beginning 

10 portion when the area 213 is recorded. Reference 
numeral 255 represents a data portion in the second sync 
frame. Reference numerals 256, 257, and 258 represent sync 
portions in sync frames. The respective areas are sized as 
in the conventional example described earlier. Areas 216 

15 and 217 are a runout area and a linking gap, respectively. 

The runout controller 872 of the optical disk 
drive 807 always retains in the data memory 871 the data 
to be recorded to a next ECC block. Therefore, if a buffer 

20 underrun occurs during data recording, the data to be 
recorded in the runout area 216 is recorded, and the 
recording of the real-time extent 211 is temporarily 
suspended, and recording of the area 212 is completed. At 
this time, the data to be recorded in the ECC block, including 

25 the linking sector, is retained in the data memory 871. 
Next , when predetermined data is transferred from the system 
controller 801 to the data memory 871, the data 
recorder 874 records the remaining linking sector data from 
the linking gap 217, and continues data recording. 

30 

Thus, since AV data (which requires continuity) is 
recorded in contiguous sectors, any waste of recordable 
areas due to linking loss areas can be prevented. Whereas 



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the aforementioned conventional linking scheme only permits 
OOh data to be recorded in the runout area, the linking scheme 
according to the present example of the invention allows 
actual data to be recorded in the runout area even in the 
5 presence of a buffer underrun. The portion in which data 
cannot be properly recorded is reduced to the few bytes which 
form as a linking gap. Therefore, even if a linking gap is 
formed within a real-time extent, an error correction based 
on ECC can be easily performed during data reproduction. 
10 Moreover, identification information is recorded in areas 
as illustrated in Figure 14K, thereby making it possible 
for a reproduction drive apparatus to easily distinguish 
the previously- recorded linking loss extents from real- 
time extents. 

15 

Each sector of a DVD disk includes regions for 
recording physical additional information, i.e., ID 261, 
I ED 262, and CPR 263, in addition to a Main Data region 264 
for recording 2048 bytes of user data. The physical 

20 information concerning the sector is recorded in ID 261. 
An error detection code for the ID section is recorded in 
I ED 262. Copy management information is recorded in 
CPR 263. ID 261 includes a sector format bit 265 and a data 
type bit 266 . The sector format bit 265 indicates whether 

25 the disk is in the CLV format or in the zone format. The 
data type bit 266 is a bit which is set to "1° in the case 
where a next sector is Included within a linking loss extent, 
unless the sector is a linking sector. As shown in 
Figure 14B, the first sector in the linking loss extent has 

30 a "0° data type bit because it is a linking sector. The 
second to the 15th sector have a "1" data type bit because 
they belong in a linking loss extent. 



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Figure 15 shows an exemplary data structure of an 
information recording medium in which files managed based 
on volume/file structures under the UDF specification are 
recorded. The arrangement of areas in each real-time extent 
5 corresponds to that shown in Figure 13 . The upper portions 
in Figure 15 correspond to the inner portions, and the lower 
portions in Figure 15 to the outer portions, of a DVD-R disk, 
A volume space is defined as a region spanning from a volume 
structure area 152 to an unrecorded area 171 , in which files 

10 and volume/file structures are recorded. From the inner 
periphery side, a lead-in area 151, a volume structure 
area 152 and a file structure area 153 (which are recorded 
at the time of formatting), and a linking loss extent 551, 
a real-time extent RT 1# and an empty extent E r (which are 

15 formed at the time of recording AV data) are provided in 
this order. 

Then, a FILEA.DAT file, which contains data of a 
plurality of still images obtained from a digital camera 

20 or the like, is recorded. Since still image data requires 
more reliability than real-time reproducibility, an 
extent 158 is recorded so as to succeed a linking loss 
area 157, as in the case of general data. Furthermore, a 
file structure area 159 for managing the recorded file is 

25 recorded so as to succeed the extent 158. If AV data is to 
be recorded next, a linking loss extent 552, a real-time 
extent RT 2 and an empty extent E 2 are recorded. In order to 
ensure that this disk will be able to be reproduced by a 
read-only apparatus, a linking loss area 163 and a file 

30 structure area 164 are recorded, and a border out (not shown) 
is recorded within a border zone 165. In the case of 
appending AV data as described with reference to 
Figures 13A to 13D, the VOBU 554 is read from the last region 



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of the real-time extent RT 2 , and the data recorded in the 
remaining pre -allocated area A 2 is recorded in the copy 
area 557. The VOBU which has been read is re-encoded and 
recorded in the re-encode area 558, and appended data is 
5 recorded in the added data area 559, which succeeds the 
re- encode area 558. 

When recording the real-time extent RT 2 *, the 
linking loss extent 555 and the empty extent E 3 are recorded . 

10 If a buffer underrun occurs during the recording of the 
real-time extent RT 2 *, a linking gap is formed, although not 
shown in Figure 15. In the case of sequential recording 
media such as DVD-R disks and CD-R disks, the files are 
managed based on a VAT system which is defined under the 

15 UDF specif ication . Therefore, a file structure area 170 is 
recorded at the end of the recorded area on the disk. The 
data recorded as described above has the same structure as 
that described with reference to Figure 17. 

20 In the file structure area 170, a file entry 181 for 

a ROOT directory, a file entry 182 for a REALTIME directory, 
a file entry 183 for a VIDEO. VRO file, a file entry 184 for 
the FILEA.DAT file, the ROOT directory 185, the REALTIME 
directory 186, a VAT 187, and a VAT ICB 188 are recorded. 

25 The file entry 181 is management information for managing 
the attribution information and the location information 
of the ROOT directory 185. As a ROOT directory file, a file 
identifier descriptor is recorded, although not shown in 
Figure 15. The file identifier descriptor includes 

30 location information of the file entries 184 and 182 for 
the FILEA.DAT file and the REALTIME directory, which are 
created under the ROOT directory 185. 



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The file entry 184 includes the location 
information of the extent 158 in which this file is recorded. 
The file entry 182 includes the location information of the 
REALTIME directory file, which is composed of a file 
5 identifier descriptor. The file identifier descriptor 
includes the location information of the file entry 183 for 
the VIDEO. VRO file, which is created under the REALTIME 
directory 186. The file entry 183 includes the location 
information of the real-time extents RT 1 to RT 2 * in which 
10 AV data is recorded. 

The attribute information which is recorded in the 
file entry for a real-time file is the same as that described 
in Example 1 with reference to Figures 7A to 7C. However, 
15 in the case of a DVD-R disk, it is unnecessary to register 
empty extents in real-time files because a DVD-R disk has 
no defective management mechanism associated therewith. 

Next, a method for reproducing AV data from the 
20 information recording medium illustrated in Figure 15 in 
accordance with the block structure illustrated in Figure 9 
and the flowchart illustrated in Figure 8 will be described. 
The reproduction method is the same as that described in 
Example 1. The optical disk drive 807, which satisfies the 
25 access performance of the playback reference model, is 
capable of reading data at a predetermined data transfer 
rate Vin. The data buffer memory 852 has a size which is 
equal to or greater than that of the buffer memory 303 of 
the playback reference model. 

30 

The file structure processing section 846 causes 
the volume structure area 152 and the file structure 
area 170 to be read to the file structure memory 851 for 



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analysis. Among the data which has been read, the location 
information and attribute information of real-time extents 
are stored in the file structure memory 851 (Step S901). 

5 The file structure processing section 846 

determines whether or not this file is a real-time file, 
and confirms whether or not the real-time extents are 
positioned so as to satisfy the real-time reproduction 
condition (Step S902). 

10 

In the case where the file is a real-time file, the 
reproduction mode informing section 850 informs the 
allocation parameters which are stored in the allocation 
parameter memory 803 to the optical disk drive 807 
15 (Step S903). The data read section 849 issues a 
reproduction command for AV data to the optical disk 
drive 807 (Step S904). 

In accordance with the reproduction command issued 
20 at Step S904, the optical disk drive 807 reads AV data from 
the real-time extents RT t and RT 2 *. Even if an error occurs 
during data reproduction due to reproduction from a linking 
gap, continuous data reproduction is performed without 
performing any recovery process. The data which has been 
25 read is subjected to ECC processing, temporarily 
transferred to the data buffer memory 852 # so that video 
data and audio data are reproduced on the TV set 812 via 
the decoder 811 (Step S905). 

30 In the case where the file is a general file, the 

data read section 849 issues a reproduction command for 
general data to the optical disk drive 807 (Step S906). 



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In accordance with the issued reproduction command 
for general data, the optical disk drive 807 reads data. 
The data which has been read is temporarily transferred to 
the data buffer memory 852 (Step S907). 

5 

It will be appreciated that the recording method 
according to the present example of the invention, which 
involves copying a recorded area to an unrecorded area and 
re-encoding VOBUs in order to allocate pre-allocated areas 
10 so that the playback reference model will not experience 
a buffer underflow when reproducing a real-time file, can 
be applied not only to write-once optical disks but also 
rewritable optical disks. 

15 In the case where the recording method according to 

the present invention is applied to a rewritable optical 
disk, a plurality of unallocated areas are searched for at 
Step S402 shown in Figure 11. In that case, the recording 
method described in Example 2 is applied to the last 

20 real-time extent of a previously-recorded real-time file 
and the first real-time extent that is newly- allocated; and 
the recording method described in Example 1 is applied to 
the selection as to which one of the plurality of 
newly- searched areas should be selected. 

25 

Although Figure 10B illustrates an example in which 
the access performance for a DVD-R disk is defined based 
on four categories of access distances, the transition in 
data amount with the buffer can be more accurately calculated 
30 by defining the access performance based on e.g., five or 
six access distance categories. 



Although AV data which has been compressed in the 



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MPEG format is illustrated above, it will be appreciated 
that the effects of the present invention can also be 
attained when applied to non- compressed, high quality audio 
data that has been subjected to high -sampling, or transport 
5 streams which are transferred via digital TV broadcasting . 

Although the above examples illustrated linking 
loss extents which are sized at 32 KB, they may alternatively 
sized at 2 KB. In this case, the first sector of an ECC block 
10 will be a linking loss extent, whereas the other 15 sectors 
can be used for recording data, so that the data recording 
efficiency will be improved by 15 sectors. However, the 
error correction ability for data within each ECC block will 
be correspondingly reduced. 

15 

It will be appreciated that the present invention 
is also applicable to a DVD-RW, in which a linking gap within 
a linking sector is positioned at the 15th byte to the 17th 
byte in a first sync frame, and a runout area is composed 

20 of a sync portion in the first sync frame and 16 bytes of 
a data portion. In particular, by recording a linking loss 
extent prior to the recording of real-time data, it will 
be possible to secure the reliability of the first data of 
each real-time extent, and continuous data 

25 recording/reproduction abilities can be realized by forming 
a linking gap within the real-time extent, while minimizing 
the deterioration in data reliability. 

The above examples illustrates Instances where 
30 real-time data is recorded in a runout area which is 
positioned within a real-time extent. However, it is 
possible to provide a simplified optical disk drive by 
recording OOh data in a runout area without implementing 



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this particular function . Although data reliability within 
each linking loss extent will deteriorate, it is still 
possible to continuously record real-time data, 

5 Although Figure 15 illustrates the case where the 

linking loss extent 555 is positioned outside the border 
zone 165, it will be appreciated that the effects of the 
present invention can also be attained in the case where 
the linking loss extent 555 is recorded in a portion of the 
10 border zone 165 • 



INDUSTRIAL APPLICABILITY 

Thus, according to the present invention, it is 

15 possible to provide an information recording medium which 
permits continuous reproduction of real-time data carried 
on a recordable optical disk; a recording method and a 
reproduction method for such an information recording 
medium; and an information recording apparatus and an 

20 information reproduction apparatus for such an information 
recording medium. 

Various other modifications will be apparent to and 
can be readily made by those skilled in the art without 
25 departing from the scope and spirit of this invention. 
Accordingly, it is not intended that the scope of the claims 
appended hereto be limited to the description as set forth 
herein, but rather that the claims be broadly construed. 



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CLAIMS 

1. An information recording medium for recording a 
real-time file containing real-time data in such a manner 
5 that the real-time data is continuously reproducible by a 
playback reference model, the real-time data comprising at 
least one of video data and audio data, 

wherein the playback reference model includes: 
a pickup for reading the real-time data from the 
10 information recording medium; a buffer memory for 
temporarily storing the real-time data read by the pickup; 
and a decoder module for reading the real-time data from 
the buffer memory for processing, 

wherein the information recording medium comprises a 
15 volume space for at least recording in sectors a file 
comprising data and file management information for 
managing the file; the real-time data is recorded in at least 
two real-time extents each of which is allocated in logically 
contiguous sectors within the volume space; and 
20 an (i+l)* 1 real-time extent among the at least two 

real-time extents is positioned at a position satisfying 
a real-time reproduction condition defined as: 
T(i) ^ (B(i-l) + D(i))/Vout, 
wherein : 

25 T(i) represents a time required for the pickup to 

access from an end of an i th real-time extent among the at 
least two real-time extents to a beginning of the (i+l) th 
real-time extent; 

B(i) represents an amount of data having been stored 

30 in the buffer memory when the pickup accesses from the end 
of the i tb real-time extent to the beginning of the (i+l) th 
real-time extent, such that B(i) = B(i-l) + D(i) - Vout X 
T(i), assuming that B(0) = 0, 



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D(i) represents an increase in the amount of data 
having been stored in the buffer memory responsive to the 
pickup reading the data from the 1 th real-time extent, such 
that D(i) = (Vin - Vout) X s(i) / Vin, wherein D(i) is 
5 corrected at least to a value equal to or smaller than M 
- B(i-l) when D(i) > M - B(i-l), where M represents a size 
of the buffer memory; 

Vout represents a data transfer rate when the data 
is transferred from the buffer memory to the decoder module; 
10 Vin represents a data transfer rate when the data 

is read from each of the at least two real-time extents by 
the pickup and transferred to the buffer memory; and 

S(i) represents a data size of the 1 th real-time 

extent . 

15 

2. An information recording medium according to claim 1, 
wherein D(i) is corrected so that D(l) = (Vin - Vout) X s(i) 
/ Vin + B(i-l) - k X (VoutXTk) when D(i) > M - B(i-l), 
wherein : 

20 Tk represents a maximum rotation wait time of the 

information recording medium; and 

k represents an integer portion of ((D(i) + B(i-l) - 

M) / (VoutXTk) +1). 

25 3. An Information recording medium according to claim 1, 
wherein each of the at least two real-time extents is 
allocated in physically contiguous sectors. 

4. An information recording medium according to claim 1, 
30 wherein the file management information comprises location 
information indicating each of the at least two real-time 
extents. 



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5. An information recording medium according to claim 1, 
wherein the file management information comprises first 
identification information for identifying the real-time 
file including real-time data. 

5 

6. An information recording medium according to claim 1, 
wherein the file management information comprises second 
identification information for indicating that the at least 
two real-time extents are positioned in accordance with the 

10 real-time reproduction condition. 

7. An information recording medium according to claim 1, 
wherein the file management information comprises, as an 
extended attribute, information representing a condition 

15 under which the at least two real-time extents were 
positioned. 

8 . An information recording medium for recording a real-time 
file containing real-time data in such a manner that the 

20 real-time data is continuously reproducible by a playback 
reference model, the real-time data comprising at least one 
of video data and audio data, 

wherein the playback reference model includes: 
a pickup for reading the real-time data from the 
25 information recording medium; a buffer memory for 
temporarily storing the real-time data read by the pickup; 
and a decoder module for reading the real-time data from 
the buffer memory for processing, 

wherein the information recording medium comprises a 
30 volume space for at least recording in sectors a file 
comprising data and file management information for 
managing the file; the real-time data is recorded in at 
least two real-time extents each of which is allocated in 



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logically contiguous sectors within the volume space; and 
an (i+l) th real-time extent among the at least two 
real-time extents is positioned at a position satisfying 
a real-time reproduction condition defined as: 
5 T(i) < (B(i-l) + D(i))/Vout, 

wherein : 

T(i) represents a time required for the pickup to 
access from an end of an i th real-time extent among the at 
least two real-time extents to a beginning of the (i+l) th 
10 real-time extent; 

B(i) represents an amount of data having been stored 
in the buffer memory when the pickup accesses from the end 
of the 1 th real-time extent to the beginning of the (i+l) th 
real-time extent, such that B(i) = B(i-l) + D(i) - Vout X 
15 T(i), assuming that B(0) = 0, 

D(i) represents an increase in the amount of data 
having been stored in the buffer memory responsive to the 
pickup reading the data from the 1 th real-time extent, such 
that D(i) = (Vin - Vout) X S(i) / Vin, wherein D(i) is 
20 corrected at least to a value equal to or smaller than M 
- B(i-l) when D(i) > M - B(i-l), where M represents a size 
of the buffer memory; 

Vout represents a data transfer rate when the data 
is transferred from the buffer memory to the decoder module; 
25 Vin represents a data transfer rate when the data 

is read from each of the at least two real-time extents by 
the pickup and transferred to the buffer memory; and 

S(i) represents a data size of the i th real-time 

extent , 

30 wherein the real-time file is a file in which the 

real-time data is appended; and 

wherein data of an already recorded real-time extent 
is recorded in a newly recorded real-time extent. 



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9. An information recording medium according to claim 8, 
wherein D(i) is corrected so that D(i) = (Vin - Vout) X s(i) 
/ Vin + B(i-l) - k X (VoutXTk) when D(i) > M - B(i-l), 

5 wherein : 

Tk represents a maximum rotation wait time of the 
information recording medium? and 

k represents an integer portion of ((D(i) + B(i-l) - 
M) / (VoutXTk) + 1). 

10 

10. An information recording medium according to claim 8, 
wherein each of the at least two real-time extents is 
allocated in physically contiguous sectors. 

15 11. An information recording medium according to claim 8, 
wherein the file management information comprises location 
information indicating each of the at least two real-time 
extents . 

20 12. An information recording medium according to claim 8, 
wherein the file management information comprises first 
identification information for identifying the real-time 
file including real-time data. 

25 13. An Information recording medium according to claim 8, 
wherein the file management information comprises second 
identification information for indicating that the at least 
two real-time extents are positioned in accordance with the 
real-time reproduction condition. 

30 

14. An information recording medium according to claim 8, 
wherein the file management information comprises, as an 
extended attribute, information representing a condition 



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under which the at least two real-time extents were 
positioned. 

15. An information recording medium for recording a 
5 real-time file containing real-time data in such a manner 
that the real-time data is continuously reproducible by a 
playback reference model . the real-time data comprising at 
least one of video data and audio data, 

wherein the playback reference model includes: 
10 a pickup for reading the real-time data from the 

information recording medium; a buffer memory for 
temporarily storing the real-time data read by the pickup; 
and a decoder module for reading the real-time data from 
the buffer memory for processing, 
15 wherein the information recording medium comprises a 

volume space for at least recording in sectors a file 
comprising data and file management information for 
managing the file; the real-time data is recorded in at 
least two real-time extents each of which is allocated in 
20 logically contiguous sectors within the volume space; and 
an (i+l) th real-time extent among the at least two 
real-time extents is positioned at a position satisfying 
a real-time reproduction condition defined as: 
T(i) < (B(i-l) + D(i))/Vout, 
25 wherein: 

T(i) represents a time required for the pickup to 
access from an end of an 1 th real-time extent among the at 
least two real-time extents to a beginning of the (i+l)* 1 
real-time extent; 
30 B(i) represents an amount of data having been stored 

in the buffer memory when the pickup accesses from the end 
of the i th real-time extent to the beginning of the (i+l)^ 
real-time extent, such that B(i) = B(i-l) + D(i) - Vout X 



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T(i), assuming that B(0) ■ 0, 

D(i) represents an increase in the amount of data 
having been stored in the buffer memory responsive to the 
pickup reading the data from the i th real-time extent, such 
5 that D(i) = (Vin - Vout) X s(i) / Vin, wherein D(i) is 
corrected at least to a value equal to or smaller than M 
- B(i-l) when D(i) > M - B(i-l), where M represents a size 
of the buffer memory; 

Vout represents a data transfer rate when the data 
10 is transferred from the buffer memory to the decoder module; 

Vin represents a data transfer rate when the data 
is read from each of the at least two real-time extents by 
the pickup and transferred to the buffer memory; and 

S(i) represents a data size of the i th real-time 

15 extent , 

wherein the real-time file is a file in which the 
real-time data is appended; 

wherein the real-time data is compressed in an MPEG 
format; and 

20 wherein data comprising one or more GOPs recorded at 

an end of the real-time file before appending is re-encoded 
and is recorded in a newly recorded real-time extent. 

16. An information recording medium according to claim 15, 
25 wherein D(i) is corrected so that D(i) - (Vin - Vout) X s(i) 
/ Vin + B(i-l) - k X (VoutXTk) when D(i) > M - B(i-l), 
wherein ; 

Tk represents a maximum rotation wait time of the 
information recording medium; and 
30 k represents an integer portion of ((D(i) + B(i-l) - 

M) / (VoutXTk) + 1). 



17. An information recording medium according to claim 15 . 



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wherein each of the at least two real-time extents is 
allocated in physically contiguous sectors, 

18. An information recording medium according to claim 15 , 
5 wherein the file management information comprises location 

information indicating each of the at least two real-time 
extents . 

19. An information recording medium according to claim 15, 
10 wherein the file management information comprises first 

identification information for identifying the real-time 
file including real-time data. 

20. An information recording medium according to claim 15, 
15 wherein the file management information comprises second 

identification Information for indicating that the at least 
two real-time extents are positioned in accordance with the 
real-time reproduction condition. 

20 21. An information recording medium according to claim 15 , 
wherein the file management information comprises, as an 
extended attribute, information representing a condition 
under which the at least two real-time extents were 
positioned. 

25 

22. An information recording medium comprising a volume 
space for at least recording in sectors a file comprising 
data and file management information for managing the file, 
wherein : 

30 the data comprises real-time data, the real-time data 

comprising at least one of video data and audio data; 

the real-time data is recorded in at least one real-time 
extent each of which is allocated in logically contiguous 



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sectors within the volume space; 

the file comprises at least one real-time extent; 

a linking loss extent is positioned before each of the 
at least one real-time extent; and 
5 a linking gap is formed in the at least one real-time 

extent . 

23. An information recording medium according to claim 22, 
wherein the linking loss extent comprises one ECC block. 

10 

24. An information recording medium according to claim 22, 
wherein the file management information comprises location 
information indicating each of the at least one real-time 
extent . 

15 

25. An information recording medium according to claim 22, 
wherein the file management information comprises 
identification information for identifying the real-time 
file including real-time data. 

20 

26. An information recording medium according to claim 22, 
wherein a data type bit is recorded in an area for 

recording physical additional information concerning each 
sector within the linking loss extent, the data type bit 
25 being used for identifying the linking loss extent; and 
wherein the data type bit for the sector is set to 1 
if a next sector is included within the linking loss extent, 
unless the sector is a linking sector. 

30 27. An information recording medium according to claim 22, 
wherein a runout area is formed before the linking gap; 

and 

the real-time data is recorded in the runout area within 



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the linking loss extent. 

28. A method for recording a real-time file containing 
real-time data on an information recording medium in such 
5 a manner that the real-time data is continuously 
reproducible by a playback reference model, the real-time 
data comprising at least one of video data and audio data, 
wherein the playback reference model includes: 
a pickup for reading the real-time data from the 
10 information recording medium; a buffer memory for 
temporarily storing the real-time data read by the pickup; 
and a decoder module for reading the real-time data from 
the buffer memory for processing, 

wherein the inf ormation recording medium comprises a 
15 volume space for at least recording in sectors a file 
comprising data and file management information for 
managing the file, 

the real-time data is recorded in at least one real-time 
extent each of which is allocated in logically contiguous 
20 sectors within the volume space, 

wherein the method comprises the steps of: 
searching for at least two areas satisfying a real- 
time reproduction condition from among a plurality of 
logically contiguous unused areas within the volume space, 
25 each of the at least two areas being designated as a 
pre-allocated area, an (i+l)th pre-allocated area among the 
at least two areas satisfying the real-time reproduction 
condition being defined as: 

T(i) ^ (B(i-l) + D(i))/Vout, 
30 wherein: 

T(i) represents a time required for the pickup to 
access from an end of an i th pre-allocated area among the 
at least two pre-allocated areas to a beginning of the ( i+1 ) th 



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pre -allocated area; 

B(i) represents an amount of data having been stored 
in the buffer memory when the pickup accesses from the end 
of the i th pre-allocated area to the beginning of the (i+l) th 
5 pre-allocated area, such that B(i)=B(i-l)+D(i)- Vout 

X T(i), assuming that B(0) = 0, 

D(i) represents an increase in the amount of data 
having been stored in the buffer memory responsive to the 
pickup reading the data from the 1 th pre-allocated area, such 
10 that D(i) = (Vin - Vout) X S(i) / Vin, wherein D(i) is 
corrected at least to a value equal to or smaller than M 

- B(i-l) when D(i) > M - B(i-l), where M represents a size 
of the buffer memory; 

Vout represents a data transfer rate when the data 
15 is transferred from the buffer memory to the decoder module; 

Vin represents a data transfer rate when the data 
is read from the pre-allocated area by the pickup and 
transferred to the buffer memory; and 

S(i) represents a data size of the 1 th pre-allocated 

20 area; 

recording the real-time data in the pre-allocated area; 
designating a set of logically contiguous sectors in 
which real-time data is recorded as a real-time extent; and 
recording the file management information for managing 
25 the real-time data as the real-time file. 

29. A method according to claim 28 , wherein D(i) is 
corrected so that D(i) = (Vin - Vout) X s(i) / Vin + B(i-l) 

- k X (VoutXTk) when D(i) > M - B(i-l), wherein: 

30 Tk represents a maximum rotation wait time of the 

information recording medium; and 

k represents an integer portion of ((D(i) + B(i-l) - 

M) / (VoutXTk) + 1). 



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30. A method according to claim 28, wherein each of the at 
least one pre-allocated area is allocated in physically 
contiguous sectors on an ECC block-by-ECC block basis. 

5 

31. A method according to claim 28, wherein the file 
management information comprises location information 
indicating each of the at least two real-time extents. 

10 32. A method according to claim 28, wherein the file 
management information comprises first identification 
information for identifying the real-time file including 
real-time data. 

15 33. A method according to claim 28, wherein the file 
management information comprises second identification 
information for indicating that the at least two real-time 
extents are positioned in accordance with the real-time 
reproduction condition. 

20 

34. A method according to claim 28, wherein the file 
management information comprises, as an extended attribute, 
information representing a condition under which the at 
least two real-time extents were positioned. 

25 

35. A method for recording a real-time file containing 
real-time data on an information recording medium in such 
a manner that the real-time data is continuously 
reproducible by a playback reference model, the real-time 

30 data comprising at least one of video data and audio data, 
wherein the playback reference model includes: 
a pickup for reading the real-time data from the 
information recording medium; a buffer memory for 



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temporarily storing the real-time data read by the pickup; 
and a decoder module for reading the real-time data from 
the buffer memory for processing, 

wherein the information recording medium comprises a 
5 volume space for at least recording in sectors a file 
comprising data and file management information for 
managing the file, 

the real-time data is recorded in at least one real-time 
extent each of which is allocated in logically contiguous 
10 sectors within the volume space, 

wherein the method comprises the steps of: 

calculating whether or not each of the at least one 
real-time extent will cause an overflow in an amount of data 
stored in the buffer memory if the real-time extent is 
15 reproduced by the playback reference model? 

when it is calculated that the real-time extent will 
cause an overflow, correcting the amount of data stored in 
the buffer memory to equal to or smaller than the size of 
the buffer memory; 
20 calculating whether or not an underflow will occur in 

the amount of data stored in the buffer memory if the playback 
reference model accesses from the real-time extent to a 
newly- allocated pre-allocated area; 

when it is calculated that an underflow will occur, 
25 searching for a real-time extent which will not cause an 
underflow, on accessing from the real-time extent to the 
pre-allocated area; 

recording in the newly-allocated pre-allocated area the 
real-time data already recorded in the real-time extent 
30 which will cause an underflow; 

recording real-time data to be appended in the 
newly-allocated pre-allocated area; 

designating a set of logically contiguous sectors in 



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which real-time data is recorded as a real-time extent? and 
recording the file management information. 

36. A method according to claim 35, wherein each of the at 
5 least one pre-allocated area is allocated in physically 

contiguous sectors on an ECC block-by-ECC block basis. 

37. A method according to claim 35 , wherein the file 
management information comprises location information 

10 indicating each of the at least one real-time extent. 

38. A method according to claim 35, wherein the file 
management information comprises first identification 
information for identifying the real-time file including 

15 real-time data. 

39. A method according to claim 35 , wherein the file 
management information comprises second identification 
information for indicating that the at least two real-time 

20 extents are positioned in accordance with the real-time 
reproduction condition. 

40. A method according to claim 35 , wherein the file 
management information comprises, as an extended attribute, 

25 information representing a condition under which the at 
least two real-time extent were positioned. 

41. A method for appending a real-time file containing 
real-time data on an information recording medium in such 

30 a manner that the real-time data is continuously 
reproducible by a playback reference model, the real-time 
data comprising at least one of video data and audio data, 
wherein the playback reference model includes: 



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a pickup for reading the real-time data from the 
information recording medium; a buffer memory for 
temporarily storing the real-time data read by the pickup; 
and a decoder module for reading the real-time data from 
5 the buffer memory for processing, 

wherein the information recording medium comprises a 
volume space for at least recording in sectors a file 
comprising data and file management information for 
managing the file, 
10 the real-time data is recorded in at least one real-time 

extent each of which is allocated in logically contiguous 
sectors within the volume space, 

wherein the real-time file comprises data which is 
compressed in an MPEG format, 
15 wherein the method comprises the steps of : 

reading data recorded at an end of the real-time file 
before appending, the data comprising one or more GOPs; 

re-encoding the data which has been read; 

recording the re-encoded data in a newly allocated 
20 pre-allocated area; 

recording real-time data to be appended in the 
newly-allocated pre-allocated area; 

designating a set of logically contiguous sectors in 
which real-time data is recorded as a real-time extent; and 
25 recording the file management information. 

42. A method according to claim 41, wherein each of the at 
least one pre-allocated area is allocated in physically 
contiguous sectors on an ECC block-by-ECC block basis. 

30 

43. A method according to claim 41 , wherein the file 
management information comprises location information 
indicating each of the at least one real-time extent. 



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44. A method according to claim 41, wherein the file 
management information comprises first identification 
information for identifying the real-time file including 

5 real-time data. 

45. A method according to claim 41, wherein the file 
management information comprises second identification 
information for indicating that the at least two real-time 

10 extents are positioned in accordance with the real-time 
reproduction condition. 

46. A method according to claim 41, wherein the file 
management information comprises, as an extended attribute , 

15 information representing a condition under which the at 
least two real-time extents were positioned. 

47. A method for recording information on an information 
recording medium comprising a volume space for at least 

20 recording in sectors a file comprising data and file 
management information for managing the file, comprising 
the steps of: 

determining whether or not the file is a real-time file 
containing real-time data; 
25 recording the file management information in the volume 

space ; 

recording the real-time data next to a linking loss 
extent if the file is determined to be a real-time file; 
and 

30 responsive to a buffer underrun occurring during the 

recording of the real-time data, forming a linking gap in 
a real-time extent in which the real-time data is recorded. 



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48 . A method according to claim 47 , wherein the linking loss 
extent comprises one ECC block • 

49. A method according to claim 47, wherein the file 
5 management information comprises location information 

indicating each real-time extent, 

50. A method according to claim 47, wherein the file 
management Information comprises identification 

10 information for identifying the real-time file including 
real-time data. 

51. A method according to claim 47, 

wherein a data type bit is recorded in an area for 
15 recording physical additional information concerning each 
sector within the linking loss extent, the data type bit 
being used for identifying the linking loss extent; and 
wherein the data type bit for the sector is set to 1 
if a next sector is included within the linking loss extent, 
20 unless the sector is a linking sector. 

52. A method according to claim 47, further comprising a 
step of recording the real-time data in a runout area within 
the linking loss extent. 

25 

53. An information recording apparatus for recording a 
real-time file containing real-time data on an information 
recording medium in such a manner that the real-time data 
is continuously reproducible by a playback reference model, 

30 the real-time data comprising at least one of video data 
and audio data, 

wherein the playback reference model includes: 

a pickup for reading the real-time data from the 



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information recording medium; a buffer memory for 
temporarily storing the real-time data read by the pickup; 
and a decoder module for reading the real-time data from 
the buffer memory for processing, 
5 wherein the information recording medium comprises a 

volume space for at least recording in sectors a file 
comprising data and file management information for 
managing the file; 

wherein the information recording apparatus comprises 

10 a file system processing section for: allocating at least 
two areas satisfying a real-time reproduction condition 
from among a plurality of logically contiguous unused areas 
within the volume space , each of the at least two areas being 
designated as a pre-allocated area; recording the real- 

15 time data and the file management information; designating 
a set of logically contiguous sectors in which real-time 
data is recorded as a real-time extent; and generating the 
file management information for managing the real-time data 
as the real-time file, 

20 wherein an (i+l)** pre-allocated area among the at least 

two pre-allocated areas is positioned at a position 
satisfying a real-time reproduction condition defined as: 
T(i) ^ (B(i-l) + D(i))/Vout, 
wherein : 

25 T(i) represents a time required for the pickup to 

access from an end of an i th pre-allocated area among the 
at least two pre-allocated areas to a beginning of an (i+l) th 
pre-allocated area among the at least two pre-allocated 
areas ; 

30 B(i) represents an amount of data having been stored 

in the buffer memory when the pickup accesses from the end 
of the i th pre-allocated area to the beginning of the (i+l)* 1 
pre-allocated area, such that B(i)=B(i-l)+D(i) - Vout 



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X T(i), assuming that B(0) = 0, 

D(i) represents an increase in the amount of data 
having been stored in the buffer memory responsive to the 
pickup reading the data from the 1 th pre -allocated area, such 
5 that D(i) = (Vin - Vout) X s(i) / Vin, wherein D(i) is 
corrected at least to a value equal to or smaller than M 
- B(i-l) when D(i) > M - B(i-l), where M represents a size 
of the buffer memory; 

Vout represents a data transfer rate when the data 
10 is transferred from the buffer memory to the decoder module; 

Vin represents a data transfer rate when the data 
is read from the pre- allocated area by the pickup and 
transferred to the buffer memory; and 

S(i) represents a data size of the i th pre-allocated 

15 area. 

54. An information recording apparatus according to 
claim 53, wherein D(i) is corrected so that D(i) = (Vin - 
Vout) X s(i) / Vin + B(i-l) - k X (VoutXTk) when D(i) > 

20 M - B(i-l), wherein: 

Tk represents a maximum rotation wait time of the 
information recording medium; and 

k represents an integer portion of ((D(i) + B(i-l) - 
M) / (VoutXTk) + 1). 

25 

55. An information recording apparatus according to 
claim 53 f wherein each of the at least one pre-allocated 
area is allocated in physically contiguous sectors on an 
ECC block-by-ECC block basis. 

30 

56. An information recording apparatus according to 
claim 53, wherein the file management information comprises 
location information indicating each real-time extent. 



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57. An information recording apparatus according to 
claim 53 , wherein the file management information comprises 
first identification information for identifying the 

5 real-time file including real-time data. 

58. An information recording apparatus according to 
claim 53 , wherein the file management information comprises 
second identification information for indicating that the 

10 at least two real-time extents are positioned in accordance 
with the real-time reproduction condition. 

59. An information recording apparatus according to 
claim 53 , wherein the file management information comprises , 

15 as an extended attribute, information representing a 
condition under which the at least two real-time extents 
were positioned. 

60. An information recording apparatus for appending a 
20 real-time file containing real-time data on an information 

recording medium in such a manner that the real-time data 
is continuously reproducible by a playback reference model , 
the real-time data comprising at least one of video data 
and audio data, 

25 wherein the playback reference model includes: 

a pickup for reading the real-time data from the 
information recording medium; a buffer memory for 
temporarily storing the real-time data read by the pickup; 
and a decoder module for reading the real-time data from 

30 the buffer memory for processing, 

wherein the information recording medium comprises a 
volume space for at least recording in sectors a file 
comprising data and file management information for 



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managing the file, 

the real-time data is recorded in at least one real-time 
extent each of which is allocated in logically contiguous 
sectors within the volume space, 
5 wherein the information recording apparatus comprises : 

a data amount calculation section for calculating 
whether or not each of the at least one real-time extent 
will cause an overflow in an amount of data stored in the 
buffer memory if the real-time extent is reproduced by the 

10 playback reference model; correcting the amount of data 
stored in the buffer memory to equal to or smaller than the 
size of the buffer memory when it is calculated that the 
real-time extent will cause an overflow; calculating 
whether or not an underflow will occur in the amount of data 

15 stored in the buffer memory if the playback reference model 
accesses from the real-time extent to a newly- allocated 
pre-allocated area; and searching for a real-time extent 
which will not cause an underflow, on accessing from the 
real-time extent to the pre-allocated area when it is 

20 calculated that an underflow will occur; 

a data recording section for recording in the newly 
allocated pre-allocated area the real-time data already 
recorded in the real-time extent which will cause an 
underflow, and recording real-time data to be appended in 

25 the newly- allocated pre-allocated area; and 

a file structure processing section for designating a 
set of logically contiguous sectors in which real-time data 
is recorded as a real-time extent and for generating and 
recording the file management information • 

30 

61. An information recording apparatus according to 
claim 60, wherein each of the at least one pre-allocated 
area is allocated in physically contiguous sectors on an 



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ECC block-by-ECC block basis. 

62. An information recording apparatus according to 
claim 60 , wherein the file management information comprises 

5 location information indicating each of the at least one 
real-time extent. 

63. An information recording apparatus according to 
claim 60 , wherein the file management information comprises 

10 first identification information for identifying the 
real-time file including real-time data. 

64. An information recording apparatus according to 
claim 60, wherein the file management information comprises 

15 second identification information for indicating that the 
at least two real-time extents are positioned in accordance 
with the real-time reproduction condition. 

65. An information recording apparatus according to 
20 claim 60 , wherein the file management information comprises , 

as an extended attribute, information representing a 
condition under which the at least two real-time extents 
were positioned. 

25 66. An information recording apparatus for appending a 
real-time file containing real-time data on an information 
recording medium in such a manner that the real-time data 
is continuously reproducible by a playback reference model, 
the real-time data comprising at least one of video data 
30 and audio data, 

wherein the playback reference model includes: 
a pickup for reading the real-time data from the 
information recording medium; a buffer memory for 



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temporarily storing the real-time data read by the pickup; 
and a decoder module for reading the real-time data from 
the buffer memory for processing, 

wherein the information recording medium comprises a 
5 volume space for at least recording in sectors a file 
comprising data and file management information for 
managing the file, 

the real-time data is recorded in at least one real-time 
extent each of which is allocated in logically contiguous 
10 sectors within the volume space, 

wherein the real-time file comprises data which is 
compressed in an MPEG format, 

wherein the information recording apparatus comprises : 

a re-encoding section for reading data recorded at an 
15 end of the real-time file before appending, the data 
comprising one or more GOPs, re-encoding the data which has 
been read, and recording the re -encoded data in a newly 
allocated pre- allocated area; and 

a file structure processing section for designating a 
20 set of logically contiguous sectors in which real-time data 
is recorded as a real-time extent and for generating and 
recording the file management information. 

67. An information recording apparatus according to 
25 claim 66, wherein each of the at least one pre-allocated 

area is allocated in physically contiguous sectors on an 
ECC block-by-ECC block basis. 

68. An information recording apparatus according to 
30 claim 66, wherein the file management information comprises 

location information indicating each of the at least two 
real-time extents. 



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69. An information recording apparatus according to 
claim 66 , wherein the file management Information comprises 
first identification information for identifying the 
real-time file including real-time data. 

5 

70. An information recording apparatus according to 
claim 66 , wherein the file management information comprises 
second identification information for indicating that the 
at least two real-time extents are positioned in accordance 

10 with the real-time reproduction condition. 

71. An information recording apparatus according to 
claim 66 , wherein the file management information comprises , 
as an extended attribute, information representing a 

15 condition under which the at least two real-time extents 
were positioned. 

72. An information recording apparatus for recording 
information on an information recording medium comprising 

20 a volume space for at least recording in sectors a file 
comprising data and file management information for 
managing the file, comprising: 

a recording mode determination section for determining 
whether or not the file is a real-time file containing 
25 real-time data; 

a file structure processing section for recording the 
file management information in the volume space; 

a linking setting section for recording the real-time 
data next to a linking loss extent if the file is determined 
30 to be a real-time file; and 

a linking controller for, responsive to a buffer 
underrun occurring during the recording of the real-time 
data, forming a linking gap in a real-time extent in which 



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the real-time data is recorded ♦ 

73. An information recording apparatus according to 
claim 72, wherein the linking loss extent comprises one 

5 ECC block. 

74. An information recording apparatus according to 
claim 72 r wherein the file management Information comprises 
location information indicating each real-time extent. 

10 

75. An information recording apparatus according, to 
claim 72, wherein the file management information comprises 
identification information for identifying the real-time 
file including real-time data. 

15 

76. An information recording apparatus according to 
claim 72, 

wherein the linking controller records a data type bit 
in an area for recording physical additional information 
20 concerning each sector within the linking loss extent, the 
data type bit being used for identifying the linking loss 
extent ; and 

wherein the data type bit for the sector is set to 1 
if a next sector is included within the linking loss extent, 
25 unless the sector is a linking sector. 

77. An information recording apparatus according to 
claim 72, further comprising a runout controller for 
recording the real-time data in a runout area within the 

30 linking loss extent. 

78. A system controller for an information recording 
apparatus for recording a real-time file containing 



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real-time data on an information recording medium in such 
a manner that the real-time data is continuously 
reproducible by a playback reference model, the real-time 
data comprising at least one of video data and audio data, 
5 wherein the playback reference model includes: 

a pickup for reading the real-time data from the 
information recording medium; a buffer memory for 
temporarily storing the real-time data read by the pickup; 
and a decoder module for reading the real-time data from 

10 the buffer memory for processing, 

wherein the information recording medium comprises a 
volume space for at least recording in sectors a file 
comprising data and file management information for 
managing the file; 

15 wherein the system controller comprises a file system 

processing section for: allocating at least two areas 
satisfying a real-time reproduction condition from among 
a plurality of logically contiguous unused areas within the 
volume space, each of the at least two areas being designated 

20 as a pre-allocated area; recording the real-time data and 
the file management information; designating a set of 
logically contiguous sectors in which real-time data is 
recorded as a real-time extent; and generating the file 
management information for managing the real-time data as 

25 the real-time file, 

wherein an (i+l)* 1 pre-allocated area among the at least 
two pre-allocated areas is positioned at a position 
satisfying a real-time reproduction condition defined as: 
T(i) ^ (B(i-l) + D(i))/Vout, 

30 wherein: 

T(i) represents a time required for the pickup to 
access from an end of an i th pre-allocated area among the 
at least two pre-allocated areas to a beginning of an (i+l) th 



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pre-allocated area among the at least two pre-allocated 
areas ; 

B(i) represents an amount of data having been stored 
in the buffer memory when the pickup accesses from the end 
5 of the i th pre-allocated area to the beginning of the (i+l) th 
pre-allocated area, such that B(i)=B(i-l)+D(i)- Vout 

X T(i), assuming that B(0) = 0, 

D(i) represents an increase in the amount of data 

having been stored in the buffer memory responsive to the 
10 pickup reading the data from the 1 th pre-allocated area, such 

that D(i) = (Vin - Vout) X S(i) / Vin, wherein D(i) is 

corrected at least to a value equal to or smaller than M 

- B(i-l) when D(i) > M - B(i-l), where M represents a size 

of the buffer memory; 
15 Vout represents a data transfer rate when the data 

is transferred from the buffer memory to the decoder module; 

Vin represents a data transfer rate when the data 

is read from the at pre-allocated are by the pickup and 

transferred to the buffer memory; and 
20 S(i) represents a data size of the i th pre-allocated 

area. 

79. A system controller for an information recording 
apparatus for appending a real-time file containing 

25 real-time data on an information recording medium in such 
a manner that the real-time data is continuously 
reproducible by a playback reference model, the real-time 
data comprising at least one of video data and audio data, 
wherein the playback reference model includes: 

30 a pickup for reading the real-time data from the 

information recording medium; a buffer memory for 
temporarily storing the real-time data read by the pickup; 
and a decoder module for reading the real-time data from 



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the buffer memory for processing, 

wherein the information recording medium comprises a 
volume space for at least recording in sectors a file 
comprising data and file management information for 
5 managing the file, 

the real-time data is recorded in at least one real-time 
extent each of which is allocated in logically contiguous 
sectors within the volume space, 

wherein the system controller comprises: 

10 a data amount calculation section for calculating 

whether or not each of the at least one real-time extent 
will cause an overflow in an amount of data stored in the 
buffer memory if the real-time extent is reproduced by the 
playback reference model; correcting the amount of data 

15 stored in the buffer memory to equal to or smaller than the 
size of the buffer memory when it is calculated that the 
real-time extent will cause an overflow; calculating 
whether or not an underflow will occur in the amount of data 
stored in the buffer memory if the playback reference model 

20 accesses from the real-time extent to a newly-allocated 
pre-allocated area; and searching for a real-time extent 
which will not cause an underflow, on accessing from the 
real-time extent to the pre-allocated area when it is 
calculated that an underflow will occur; 

25 a data recording section for recording in the newly 

allocated pre-allocated area the real-time data already 
recorded in the real-time extent which will cause an 
underflow, and recording real-time data to be appended in 
the newly- allocated pre-allocated area; and 

30 a file structure processing section for designating a 

set of logically contiguous sectors in which real-time data 
is recorded as a real-time extent and for generating and 
recording the file management information. 



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80. A method for reproducing a real-time file containing 
real-time data on an information recording medium in such 
a manner that the real-time data is continuously 
5 reproducible by a playback reference model, the real-time 
data comprising at least one of video data and audio data, 
wherein the playback reference model includes: 
a pickup for reading the real-time data from the 
information recording medium; a buffer memory for 
10 temporarily storing the real-time data read by the pickup; 
and a decoder module for reading the real-time data from 
the buffer memory for processing, 

wherein the information recording medium comprises a 
volume space for at least recording in sectors a file 
15 comprising data and file management information for 
managing the file, 

wherein the real-time data is recorded in at least two 
real-time extents each of which is allocated in logically 
contiguous sectors within the volume space; and 
20 an (1+1 1 th real-time extent among the at least two 

real-time extents is positioned at a position satisfying 
a real-time reproduction condition defined as: 
T(i) ^ (B(i-l) + D(i))/Vout, 
wherein : 

25 T(i) represents a time required for the pickup to 

access from an end of an 1 th real-time extent among the at 
least two real-time extents to a beginning of the (i+l) 1 * 
real-time extent; 

B(i) represents an amount of data having been stored 

30 in the buffer memory when the pickup accesses from the end 
of the i th real-time extent to the beginning of the (i+l) th 
real-time extent, such that B(i) = B(i-l) + D(i) - Vout X 
T(i), assuming that B(0) = 0, 



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D(i) represents an increase in the amount of data 
having been stored in the buffer memory responsive to the 
pickup reading the data from the i th real-time extent, such 
that D(i) = (Vin - Vout) X s(i) / Vin, wherein D(i) is 
5 corrected at least to a value equal to or smaller than M 
- B(i-l) when D(i) > M - B(i-l), where M represents a size 
of the buffer memory; 

Vout represents a data transfer rate when the data 
is transferred from the buffer memory to the decoder module; 
10 Vin represents a data transfer rate when the data 

is read from each of the at least two real-time extents by 
the pickup and transferred to the buffer memory; and 

S(i) represents a data size of the 1 th real-time 

extent , 

15 wherein the method comprises the steps of: 

reproducing the real-time file from the information 
recording medium by means of a disk drive; 

acquiring location information of each of the at least 
two real-time extents and identification information 
20 indicating that the at least two real-time extents are 
positioned in accordance with the real-time reproduction 
condition; 

reading data from the at least two real-time extents 
at a data transfer rate which is equal to or greater than 
25 Vin of the playback reference model; 

temporarily storing the real-time data which has been 
read in the buffer memory; 

reading the data stored in the buffer memory and decoding 
the data in a decoder; and 
30 accessing a next real-time extent within the time T(i) 

of the playback reference model, 

81. A method according to claim 80, wherein the file 



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management inf ormation comprises, as an extended attribute, 
information representing a condition under which the at 
least two real-time extents were positioned, the method 
further comprising a step of: 
5 reading the extended attribute from the file management 

information, and informing a reproduction mode to the disk 
drive based on the extended attribute prior to reproduction. 

82. A method for reproducing real-time data from an 
10 information recording medium comprising a volume space for 

at least recording in sectors a file comprising data and 
file management information for managing the file, wherein: 

the data comprises real-time data, the real-time data 
comprising at least one of video data and audio data; 
15 the real-time data is recorded in at least one real-time 

extent each of which is allocated in logically contiguous 
sectors within the volume space; 

the file comprises at least one real-time extent; 

a linking loss extent is positioned before each of the 
20 at least one real-time extent; and 

a linking gap is formed in the at least one real-time 
extent , 

wherein the method comprises the steps of: 
determining whether or not the file is a real-time file 
25 containing real-time data; and 

performing a reproduction operation for data recorded 
in a real-time extent, the reproduction operation being 
continuously performed without performing a recovery 
process even if a reproduction error due to invalid data 
30 recorded in the linking gap occurs. 

83. An information reproduction apparatus for reproducing 
a real-time file containing real-time data on an information 



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recording medium in such a manner that the real-time data 
is continuously reproducible by a playback reference model, 
the real-time data comprising at least one of video data 
and audio data, 
5 wherein the playback reference model includes: 

a pickup for reading the real-time data from the 
information recording medium; a buffer memory for 
temporarily storing the real-time data read by the pickup; 
and a decoder module for reading the real-time data from 
10 the buffer memory for processing, 

wherein the information recording medium comprises a 
volume space for at least recording in sectors a file 
comprising data and file management information for 
managing the file, 
15 wherein the real-time data is recorded in at least two 

real-time extents each of which is allocated in logically 
contiguous sectors within the volume space; and 

an (i+l) th real-time extent among the at least two 
real-time extents is positioned at a position satisfying 
20 a real-time reproduction condition defined as: 
T(i) ^ (B(i-l) + D(i))/Vout, 
wherein : 

T(i) represents a time required for the pickup to 
access from an end of an 1 th real-time extent among the at 
25 least two real-time extents to a beginning of the (i+l) th 
real-time extent; 

B(i) represents an amount of data having been stored 
in the buffer memory when the pickup accesses from the end 
of the i th real-time extent to the beginning of the (i+lp 
30 real-time extent, such that B(i) = B(i-l) + D(i) - Vout X 
T(i), assuming that B(0) = 0, 

D(i) represents an increase in the amount of data 
having been stored in the buffer memory responsive to the 



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pickup reading the data from the 1 th real-time extent, such 
that D(i) = (Vin - Vout) X s(i) / Vin, wherein D(i) is 
corrected at least to a value equal to or smaller than M 
- B(i-l) when D(i) > M - B(i-l), where M represents a size 
5 of the buffer memory; 

Vout represents a data transfer rate when the data 
is transferred from the buffer memory to the decoder module; 

Vin represents a data transfer rate when the data 
is read from each of the at least two real-time extents by 
10 the pickup and transferred to the buffer memory; and 

S(i) represents a data size of the i th real-time 

extent , 

wherein the information reproduction apparatus 
comprises: 

15 a disk drive for reproducing the real-time file from 

the information recording medium; 

a file structure processing section for acquiring 
location information of each of the at least two real-time 
extents and identification information indicating that the 
20 at least two real-time extents are positioned in accordance 
with the real-time reproduction condition; 

a data reproducer for reading data from the at least 
two real-time extents at a data transfer rate which is equal 
to or greater than Vin of the playback reference model; 
25 a buffer memory for temporarily storing the real-time 

data which has been read; and 

a decoder for reading the data stored in the buffer 
memory and decoding the data, 

wherein a data reproduction performance which is 
30 determined as a function of an access performance and data 
transfer rate of the data reproducer and a size of the buffer 
memory satisfies a predetermined data reproduction 
performance of the playback reference model. 



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84. An information reproduction apparatus according to 
claim 83 , wherein the file management information comprises , 
as an extended attribute, information representing a 

5 condition under which the at least two real-time extents 
were positioned, the information reproduction apparatus 
further comprising: 

a reproduction mode informing section for reading the 
extended attribute from the file management information, 
10 and informing a reproduction mode to the disk drive based 
on the extended attribute prior to reproduction. 

85. An information reproduction apparatus for reproducing 
a real-time file containing real-time data on an information 

15 recording medium comprising a volume space for at least 
recording in sectors a file comprising data and file 
management information for managing the file, 
wherein : 

the data comprises real-time data, the real-time data 
20 comprising at least one of video data and audio data; 

the real-time data is recorded in at least one real-time 
extent each of which is allocated in logically contiguous 
sectors within the volume space; 

the file comprises at least one real-time extent; 
25 a linking loss extent is positioned before each of the 

at least one real-time extent; and 

a linking gap is formed in the at least one real-time 
extent , 

wherein the information reproduction apparatus 
30 comprises: 

a file structure processing section for determining 
whether or not the file is a real-time file containing 
real-time data; and 



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a data reproducer for performing a reproduction 
operation for data recorded in a real-time extent, the 
reproduction operation being continuously performed 
without performing a recovery process even if a reproduction 
5 error due to invalid data recorded in the linking gap occurs . 



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FIG. 1 



1/19 



101- 
102- 
103-— 

105- 
106- 
107- 
RTi- 

ioa-* 

RT2- 

109— t 
RT3- 

110- 1 



RT4- 



12(H 
As- 
121- 
RTs- 
122- 



Leod-in area 



DM A qreq 



Spare area 



Volume structure qreq 



RTe- 
123- 
124- 
125- 



File structure area 



Allocated qreq 



Guard area 



Real-time extent 



Defective ECC block 



Real-time extent 



Guard area 



Real-time extent 



Allocated area 



Real-time extent 



Allocated area 



Pre-allocated area 



Allocated area 



Real-time extent 



Allocated area 



Real-time extent 



Empty extent 



Unrecorded area 



Allocated areq 



126—1 Lead-out areo 



c 
o 

t 4 



d 
O 



V 

I' 



a> 
c 
o 
rvj 



a> 
c 
o 
r>4 



Rle structure area 



Space bit map 



Rle entry 
(ROOT directory) 



Rle identifier 
(FILEA.DAT) 



Rle identifier 
(REALTIME) . 



Rle entry 
(RLEA.DAT) 



Rle entry 
(REALTIME) 



Rle identifier 
(VIDEO.VRO) 



Rle entry 
(VIDEO.VRO) 



-141 
-142 
-143 

-144 
-145 
-146 

-147 
-148 



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2/19 



FIG. 2 A 

Vin 

301 



303 

L- 

Buffer memory 



Vout 



304 

Decoder module 



302 



Vin: Data transfer rate from disk to buffer memory 

Vout: Data transfer rate from buffer memory to decoder module 



FIG.2B 




Access distance 



Skip / Neighboring-zone LoVig 
access , / access access 

Intra-zone 
access 



TZ: Zone boundary access time 
TS: Single sector latency 



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FIG. 3 

System controller 



3/19 



701 



Recording mode 
determination section 



y702 



Allocation parameter 
memory 



-703 



File _system jracessing jectton 704 Rle system processing memory 705 



Reproduction mode 
informing section 



Data amount 
calculation section 



Time information 
calculation section 



Unallocated area 
search section 



v 

lf741 

li-742! 

i 
i 

^743 1 
I 
I 
i 



Empty extent memory 



Time information memory 



lW44i 
i 



Pre— allocated area memory 



Physically non-contiguous Lk*745i 
location acquisition section 



Physically non-contiguous 
location memory 



Rle structure 
processing section 



Data recording section 



4-746 1 

i i 
i i 

>-747| 



File structure memory 



Bit map memory 



Data read section 



Data buffer memory 



i i 



i i 



-751 
-752 
•753 
•754 
-755 
-756 

-757 



I 



706 



I/O bus 



Optical disk 
drive 



708 



Inpu: 
section 



709 



Encoder 



E7 



711 



Decoder 



710 



p 



Tuner 



n 



TV set 



712 



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FIG. 4 



( START ) 



Determine recording parameters 



Search for unallocated areas 

I 



Calculate time information 



I 



Calculate data amount 
(at read completion) 



4/19 
^S801 

^5803 
-S804 




S806 



Correct data amount 



Allocate empty extent 



Allocate empty extent 



S808 



S810 



S811 



1 



Calculate data amount 
(at beginning of read) 




I 



S813 



Exclude from allocation 



Record file structure 

i 



Record real-time data 

i 



Update file structure 
I 



-S814 
-S815 

-S816 



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5/19 



FIG. 5 A 



Defective ECC block 

Zone boundary _ 
Zone 1 i Zone 2 
.,- _ • 



Ai 
(Ei) 



=5 



A2 

(E 2 ) 



A3 
(E3) 



A4 
(E4) 



Zone 3 



t — r — i r 

1A51 iAe i 
I i I I 
i 



Zone 7 
/ — * — \ 



•1 

I A7 I 
I I 



nrrm 



TRi| TR2 ( TR3 ) TR4 \ TRs \ TRe V TR7 
Tu(=16 TS) T2,3(=TZ) T3.4(=H) T4,s(=TN) Ts,6(=TI) Te.7(=TL) 



FIG.5B 

Defective ECC block 



f — -> 

A1 
(Ei) 


A2 

(E2) 


i, 

A3 
(E3) 




, 

A4 
(E4) 




As* 
(Es) 




f A V 

Ae* 
(Ee) 


H 






[ i 


r i 


i i 






TRi 
Tu(= 


r in ii 

TR2 ( TR3 \ 
16 TS) T2,3(=TZ) T 


TR4 

3,4(=TI) 


1 \ 1 

T4,5*(=TN) 


TRs 


[ . \' 

Ts, 


M 

TRs* 
e*(=TL) 



FIG.5C 



Defective ECC block 

Zone boundary 
Zone 1 ) Zone 2 

_A / 



5 



RT1 



F 



RT2 



RT3 



RT4 



Ai A2 A3 
a:ECC block boundary 



f 



A4 



Unrecorded 

Empty extent123 are( | 124 
Zone 3V^ Zone 7/ 



RTs 



RTe 



As* 



Ae* 



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FIG. 7 A 

RIe entry 



7/19 



BP 


Red name 


0 


Descriptor tqg 


16 


ICB tqg 






56 


Information length 






112 


Extended attribute ICB 






168 


Extended attribute length 


172 


Length of allocation 
descriptor 


175 


Extended attribute 


L.EA+176 


Short allocation 
descriptor for RTi 


L.EA+184 


Short allocation 
descriptor for RT2 


L.EA+192 


Short allocation 
descriptor for RT3 


L.EA+200 


Short allocation 
descriptor for RT4 


L.EA+208 


Short allocation 
descriptor for RTs 


I FA+91R 


onon uiiuuuiion 
Hp^rrintnx fnr RTfi 

UCOLrl ipiVl Ivl I\l D 


1 FA4-994 


onon uiiocuuun 

descriDtor for 
empty extent 


FIG. 7, 

Short alloc 


B 

ation descriptor 


RBP 


Reld nqme 


0 


Extent length 


4 


Extent location 



V 



V 



ICB tag 



RBP 


Reld name 






11 


, RIe type 
(=2491 






18 


Hag 

bit4=0NE 

(Non-relocatable bit) 



RBP 


Reld name 


0 


Vin 


2 


Yogt 


4 


Buffer memory size 


6 


Access tvpe 


8 


Ta 


10 


Tb 


> 12 


Tc 



FIG. 7C 

Meanings of 2 most significant bits of extent length 



Value, 



Megnin 



Allocated and recorded (r eal-time exte^T) 



Allocated but unrecorded' (empty extent 



ML 

Extent of subsequent alloc ation descripfhT 



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fig. a 



( START ) 



Process file structure 



S901 




S903 



Inform reproduction mode 



S904 



S906 



Issue real-time 
reproduction command 




Issue general 
reproduction command 




^S905 




Execute real-time 
reproduction command 




Execute general 
reproduction command 



-S907 



( END ) 



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9/19 



FIG. 9 

System controller 

Recording mode 
determination section 



801 



VOBU re-encoding section |/* 8 21 

-fe04 



/*802 | Allocation parameter memory |^-803 

-822 



VOBU memory 



file _system_ £roce_ssing jection 



file jystem £rocessjng jnemory_ 



/ 



-805 



Unrecorded area check sectiortk"841 

842! 



Unking setting section 



Time information 
calculation section 



Data amount calculation 
section 



final access check section 



File structure processing 
section 



Data recording section 



Data copying section 



Data read section 




Reproduction mode 
informing section 



I I 



843 i 

'844! 
-845 1 

846 j 

-847 1 
'848 1 

'849! 
-850 ! 



file structure memory r"851 
(Buffer memory) 



i i 



806 



I/O bus 



Optical disk drive 1 






Data memory 


-871 


Runout controller 


-872 


Linking controller 


--873 


Data recorder 




-874 


Data reproducer 


-875 



A 



808 



Input section 


Encoder 







Decoder 



-810 



Tuner 



5 



n 



812 



TV set 



WO 01/24179 



PCT/JPOO/06800 



10/19 



FIG. 1 0A 

Vin 



301 



303 



Buffer memory 



Vout 



304 

Z_ 

Decoder module 



> 4^-302 

Vin: Data transfer rate from disk to buffer memory 

Vout: Data transfer rate from buffer memory to decoder module 



FIG. 1 0B 




Skip 
access 



Short 
access 



Middle 
access 



Access distance 



TS: Single sector latency 



WO 01/24179 



PCT/JPOO/06800 



FIG. 1 1 



( START ) 



Determine recording param eters 



Check for unallocated areas 



11/19 

^-S401 

S402 
S403 




Recorded area? 
No 



S410 

1 



Calculate data amount 
(at b eginning of read) 

I 



-S405 



Calculate data amount 
(at read completion) 



S406 



S407 



Calculate data amount 
(at beginning of read) 




S408 



Correct data 
amount 



S411 




I 



Re-calculate data amount 
(at beginning of read) 




Exclude from allocation of 
pre—allocated area 

i 



Record real-time data 



I 



Update file structure 

- 1 

C END ) 



•S415 
•S416 



WO 01/24179 



PCT/JP00/06800 




WO 01/24179 



PCT/JP00/06800 



FIG.13A 



13/19 



551 

Jr- 



RTi 
(AO 



FIG.13B 

551 

J, 



Ei 



Ei 

An 



552 E2 

I 



AA 



RT2 



t 
554 



553 
._/- 



Unrecorded area 

4-m- — Jnzl 



555 



552 554 E2 555 
!>, S..I. T 



I 
t 
I 
1 

-J 
I 

-A 



RTi 
(AO 



A2 



l l 
I 
l 
l 

1 i 



3- 



A3 



I 

4 



TR1 



AA 



Tu TR2 T2.3 



FIG.13C 



551 



Ei 
4i 



552 554 E2 555 



RTi 
(AO 



A2 



A2* 



4 



TRi 



T1,2 



FIG. 1 3D 

551 

rl 



RTi 



Ei 
4, 



5 52 554 & 555 



A2 



AA 



RT2 : 



E3 556 



E AA \ ^ \ 

557 558 559 



A 



a:ECC block boundary 



WO 01/24179 



PCT/JPOO/06800 



14/19 



FIG.14A 



210 

Ar 



211 



-V- 

212 



213 



214 



FIG.14B 



Sectors with data type bit = 1 



210 



211 



FIG.14C 



215 





■ • • 








f 






• • • 




1 1 

1 &H &-I 



FIG.14D 



251 



212 

252 253 254 
4—rA k 



213 



(Data) (Data) 



— v — 

216 



255 256 257 
i I / , / ■ » ■ / , *■ 
I [(Dato; 



217 



Linking sector 215(=26 sync frame) 



258 
r-A- 



ECC block (=16 sectors) 



FIG.14E 

261262 263 
A A / 



ID 



ED 



CPR 



264 



265" 



Sector 
format 



Main Data 
2 ; 66 



Data type 



WO 01/24179 



PCT/JPOO/06800 



FIG. 15 



15/19 



CD 
O 
O 
CL 

co 

CD 



152- 
153-1 
551- 

RTi- 



Ei- 
157- 
158- 
159- 
552- 

RT2- 



E2- 
163^ 
164— 
165- 
555- 



RT2* 



E 3 
169- 
170- 

171 



Leod-in area 



Volume structure area 



File structure area 



Linking loss extent 



Real- tin^ e xtent 



Empty extent 



Linking loss area 



Extent (FILEA.DATT 



File structure area 



Linking loss extent 



Real-time jPre-allocated 
extent I area 



• , 



VOBU 



Empty extent 



Linking loss area 



File structure area 



Border zone 



Linking loss extent 



Real-time 
extent 



Copy area 

Re"-encocfe 
__area 

Added data 
area 



Empty extent 



Linking loss area 



File structure area 



Unrecorded area 



kA2 
^554 



557 

•558 
-559/ 



File structure area 



File entry 
(ROOT) 



File entry 
(REALTIME) 



File entry 
(VIDEO.VRO) 



File entry 
(FILEA.DAT) 



ROOT directory 



REALTIME 
Directory 

VAT 
VAT ICB 



-181 
-182 
-183 

-184 
-185 
-186 
-187 
-188 



WO 01/24179 



PCT/JP00/06800 



FIG. 1 6 A 




16/19 

Lead-in area 

DMA area 
Spare area 

Zone 0 
Zone 1 

Zone 34 
Lead-out area 



FIG. 1 6B 



101- 
102- 



CO 

o 

CD 



103- 



o 



151- 



107- 



Lead-in area 



DMA area 



Spare area 



Defective sector (PPL) 



Defective sector (SDL) 



Guard area 



A 



/ 

/ 



<D 
O 
O 
Cl 

co 

CD 



O 
> 



126\ 



Lead-out area 



PCT/JPOO/06800 



17/19 



FIG.17 



201 



ROOT directory 





202 

1 



REALTIME directory]^) 



203 



VIDEO.VRO file 



FILEA.DAT file 



-204 



WO 01/24179 



18/19 



PCT/JPOO/06800 



FIG.18A 



561 562 5 


63 570 

E f , 


rj -J- » 

Extent 

AA 


Unrecorded area I 
J. _ _ t 



FIG.18B 

561 562 




5845^556 6 



Extent 



AA 



570 

/ 

Unrecorded area 



FIG.18C 



564565566 567 568 




Unrecorded areaj 



a:ECC block boundary 



WO 01/24179 



PCT7JPOO/06800 



FIG. 1 9 A 

220 



FIG. 1 9B 



I 

I— 



FIG. 1 9C 



FIG. 1 9D 



19/19 



jC 



221 



111 lie 223 227 



220 



222 



225 



224 



221 



226 



241 242 243 244 
1 J-t4 k 



(OOh) 



(OOh) 



228 



245 246 247 
I — t — » ,/ , «- 



229 



Linking sector 225(=26 sync frames) 



ECC block (=16 sectors) 



PCT/JP 00/06800 



A. CLASSIFICATION OF SUBJECT MATTER 

IPC 7 G11B20/12 G11B27/10 G11B27/034 611B27/30 



According to International Patent Classification (IPC) or to both national classification and IPC 



B. FIELDS SEARCHED 



Minimum documentation searched {classification system followed by classification symbols) 

IPC 7 G11B 



Documentation searched other than minimum documentation to the extent that such documents are included in the fields searched 



Electronic data base consulted during the international search (name of data base and, where practical, search terms used) 

EPO-Internal , WPI Data, PAJ, INSPEC, IBM-TDB 



C. DOCUMENTS CONSIDERED TO BE RELEVANT 



Category 0 Citation of document, with indication, where appropriate, of the relevant passages 



Relevant to claim No. 



EP 0 866 456 A (MATSUSHITA ELECTRONICS 
CORP) 23 September 1998 (1998-09-23) 



abstract 

column 1, line 33 -column 3, line 24 
column 8, line 48 -column 9, line 10 
figures 1,3,9 

_/-- 



1,3,5,8, 

10,12, 

15,17, 

19,22, 

28,32, 

35,37, 

53,56, 

72,75, 

78,80-85 



m 



Further documents are listed in the continuation of box C. 



ID 



Patent family members are listed in annex. 



• Special categories of cited documents : 

'A* document defining the general state of the art which is not 

considered to be of particular relevance 
a E' earlier document but published on or after the international 

filing date 

•|_" document which may throw doubts on priority daim(s)or 
which is cited to establish the publication date of another 
citation or other special reason (as specified) 

'O* document referring to an oral disclosure, use, exhibition or 
other means 

•P" document published prior to the international Tiling date but 
later than the priority dale claimed 



"T later document published after the international filing date 
or priority date and not in conflict with the application but 
cited to understand the principle or theory underlying the 
invention 

"X" document of particular relevance; the claimed invention 
cannot be considered novel or cannot be considered to 
involve an inventive step when the document is taken alone 

"V document of particular relevance; the claimed invention 

cannot be considered to involve an inventive step when the 
document is combined with one or more other such docu- 
ments, such combination being obvious to a person skilled 
in the art. 

"&• document member of the same patent family 



Date of the actual completion of the international search 



20 December 2000 



Date of mailing of the international search report 



15/01/2001 



Name and mailing address of the ISA 

European Patent Office, P.B. 5818 Patentlaan 2 
NL - 2280 HV Rijswijk 
Tel. (+31-70) 340-2040, Tx. 31 651 epo nl, 
Fax (+31-70) 340-3016 



Authorized officer 



Schlwy-Rausch, G 



Form PCT7ISA/210 (second shoot) (July 1992) 



PCT/JP 00/06800 


r* /Pnntiniinti/tnY OflPUMENTS CON^IHFRFn Tf> RF RF1 FVAMT 




f~*itali/in rtf rinnimpnl with inriireitinn wharp annranrtatA of thp rplpvztnt nfrcsaa&s 

\j 11 a i \ji wuiiiiciii, mill ii iuii^oik/i i,m lai c a|spivpi wic, ui iiic iciciain jju.iju y 


Relevant to claim No. 


A,P 


WO 99 65026 A (KONINKL PHILIPS ELECTRONICS 


1,8,15, 


NV ;PHILIPS AB (SE)) 


28,35, 




16 December 1999 (1999-12-16) 


47,53, 






72,78, 






80,82, 






83,85 




page 2, line 15 -page 4, line 3 






page 6, line 26 -page 8, line 19 






figures 4,7 

— 




A 


EP 0 905 699 A (MATSUSHITA ELECTRIC IND CO 


1-3, 




LTD) 31 March 1999 (1999-03-31) 


8-10, 




15-17, 






28-30, 






35,36, 






47,48, 






53-55, 






72,73, 






78,80-85 




abstract 






page 1, line 19 -page 2, line 37 






nane 11 line 24 — Daae 14 line 4 






page 22, line 12 - line 32 






page 25, line 5 -page 27, line 29 






figures 8,9,39 

— 




A 


EP 0 903 742 A (MATSUSHITA ELECTRIC IND CO 


1-3, 




LTD) 24 March 1999 (1999-03-24) 


8-10, 






15-17, 






28-30, 






35-37, 






47,48, 






53-55, 






72,73, 






78,80-85 




column 3, line 7 - line 50 






column 20 line 50 — column 22 line 55 

\*\J | LI 1 11 1 I I— \J , 1 1 llv *J\J w V 1 villi 1 1 i— <~ , 1 1 I IV- *J *J 






column 64, line 54 -column 66, line 51 






column 68, line 1 -column 69, line 45 






figures 4-6,35,36 

— 




A 


EP 0 929 072 A (TOKYO SHIBAURA ELECTRIC 


41,60, 




CO) 14 July 1999 (1999-07-14) 


66,79 




abstract 






column 5, line 13 - line 25 






column 12, line 9 - line 58 






rnlumn PQ linp P6 — line 53 

l*U 1 Willi , 1 1 IIC C \J 1 1 llv *J*J 






column 35, line 7 - line 14 






column 61, line 14 -column 69, line 50 






claims 23-25; figures 33,34,64-70 






UO Q8 44508 A (DAE WOO ELECTRONICS CO LTD) 


41 60 




8 October 1998 (1998-10-08) 


66,79 




page 1, line 18 -page 4, line 22 






page 9, line 2 - line 26 






-/- 





Form PCT/1SA/210 (continuation of second sheet) (July 1992) 



PCT/JP 00/06800 



C.(Continuation) DOCUMENTS CONSIDERED TO BE RELEVANT 


Category • 


Citation of document, with indication.where appropriate, of the relevant passages 


Relevant to claim No. 


A 


0STA (OPTICAL STORAGE TECHNOLOGY 

ASSOCIATION): "Universal Disk Format 

Specification" 

0STA SPECIFICATION UDF, 

no 2 00 -3 Aoril 1998 (1998-04-03) 

pages 1-141, XP002155418 

Santa Barbara, CA 

cited in the application 




A 


ECMA: "Standard ECMA-167 : Volume and 
File Structure for Write-Once and 
Rewritable Media using Non-Sequential 
Recording for Information Interchange" 
ECMA : STANDARDIZING INFORMATION AND 
COMMUNICATION SYSTEMS, 
no. 3, June 1997 (1997-06), pages 1/1-5/8, 
XP002155419 
Geneva, CH 

cited in the application 





Form PCT/ISA/210 (continuation ot second sheet) (July 1092) 



Information on patent family members 


PCT/JP 00/06800 


Patent document 
cited in search report 


Publication 
date 


Patent family 
member(s) 


Publication 
date 



EP 0866456 A 23-09-1998 CN 1209899 A 03-03-1999 

EP 1018734 A 12-07-2000 

EP 1031979 A 30-08-2000 

W0 9814938 A 09-04-1998 

JP 3097918 B 10-10-2000 





A 
H 


1 f\- 


-1 O- 


-1 QQQ 


pp 




i J UZ7 LUUU 


EP 0905699 


A 


31- 


-03- 


-1999 


EP 


1020860 A 


19-07-2000 












EP 


1020861 A 


19-07-2000 












WO 


9914755 A 


25-03-1999 












JP 


3069324 B 


24-07-2000 












JP 


2000013728 A 


14-01-2000 












US 


6118924 A 


12-09-2000 


EP 0903742 


A 


24- 


-03- 


•1999 


WO 


9914757 A 


25-03-1999 












JP 


11155131 A 


08-06-1999 












US 


6148140 A 


14-11-2000 



EP 0929072 


A 


14-07-1999 


JP 


11176096 A 


02-07-1999 








CN 


1219727 A 


16-06-1999 








JP 


2000082276 A 


21-03-2000 


WO 9844508 


A 


08-10-1998 


KR 


250578 B 


01-04-2000 








US 


5914917 A 


22-06-1999 



Form PCT/1SA/210 (patent family annex) (July 1982)