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(19) 



J) 



Europaisches Patentamt 
European Patent Office 
Office europeen des brevets 



(11) 



EP 1 329 888 A1 



(12) 



EUROPEAN PATENT APPLICATION 



(43) Date of publication: 

23.07.2003 Bulletin 2003/30 

(21) Application number: 03000696.9 

(22) Date of filing: 17.01 .2003 


(51) mtci7: G1 1 B 20/1 8, G1 1 B 27/32 


(84) Designated Contracting States: 


• 


Ito, Motoshi 


AT BE BG CH CY CZ DE DK EE ES Fl FR GB GR 




Osaka-shi, Osaka 536-0001 (JP) 


HU IE IT LI LU MC NL PT SE SI SK TR 


• 


Ishida, Takashi 


Designated Extension States: 




Yawata-shi, Kyoto 614-8331 (JP) 


AL LT LV MK RO 


• 


Yamamoto, Yoshikazu 






Osaka-shi, Osaka 532-0022 (JP) 


(30) Priority: 22.01.2002 JP 2002013491 


• 


Shoji, Mamoru 


01.03.2002 JP 2002056635 




Sakai-shi, Osaka 591-8032 (JP) 


(71 ) Applicant: MATSUSHITA ELECTRIC INDUSTRIAL 


(74) 


Representative: Balsters, Robert et al 


CO., LTD. 




Novagraaf International SA 


Kadoma-shi, Osaka 571-8501 (JP) 




25, avenue du Pailly 






1220 Les Avanchets - Geneva (CH) 


(72) Inventors: 






• Ueda, Hiroshi 






Kashiba-shi, Nara 639-0223 (JP) 







(54) Multi-layered information recording medium, reproduction apparatus, recording apparatus, 
reproduction method, and recording method 



(57) A multi-layered information recording medium 
comprising a plurality of recording layers, a user data 
area for recording user data, provided in at least two of 
the plurality of recording layers, and a defect list storing 
area for storing a defect list. When at least one defective 



area is detected in the user data area, the defect list is 
used to manage the at least one defective area. The de- 
fect list storing area is provided in only one of the plu- 
rality recording layers. 



GO 
00 
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CD 
CNJ 
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Printed by Jouve ; 75001 PARIS (FR) 



EP 1 329 888 A1 



Description 

BACKGROUND OF THE INVENTION 

5 1 . FIELD OF THE INVENTION: 

[0001 ] The present invention relates to a multi-layered information recording medium comprising at least two record- 
ing layers, a reproduction apparatus, a recording apparatus for use with the multi-layered information recording medi- 
um, a reproduction method for reproducing information from the multi-layered information recording medium, and a 
10 recording method for recording information in the multi-layered information recording medium. 

2. DESCRIPTION OF THE RELATED ART: 

[0002] A typical information recording medium which has a sector structure is an optical disc. In recent years, AV 
15 data, such as audio data, video data, and the like, has been digitalized, and accordingly, an optical disc having a higher 
recording density and a larger capacity has been demanded. Providing a plurality of recording layers is useful in in- 
creasing the capacity of a disc. For example, the capacity of a read-only DVD has been increased about two times by 
providing two recording layers to the DVD. 

[0003] Figure 1 shows a structure of a typical optical disc medium 1 including a track 2 and sectors 3. On the optical 

20 disc medium 1 , the track 2 is turned multiple times in a spiral arrangement. The track 2 is divided into a large number 
of small sectors 3. Regions formed on the disc medium 1 are roughly classified into a lead-in area 4, a user data area 
8, and a lead-out area 6. Recording or reproduction of user data is performed on the user data area 8. The lead-in 
area 4 and the lead-out area 6 are provided as margins such that an optical head (not shown) can appropriately follow 
a track even if overrunning of the optical head occurs when the optical head approaches an end portion of the user 

25 data area 8. The lead-in area 4 includes a disc information area which stores parameters necessary for accessing the 
disc medium 1. Physical sector numbers (hereinafter, abbreviated as "PSN(s)") are assigned to the sectors 3 in order 
to identify the respective sectors 3. Further, consecutive logical sector numbers (hereinafter, abbreviated as "LSN(s)") 
which start with 0 are assigned to the sectors 3 included in the user data area 8 such that a high level apparatus (not 
shown) such as a host computer identifies the respective sectors 3. 

30 [0004] Figure 2 illustrates a principle of reproduction of data from a read-only optical disc 30 having two recording 
layers. Here, production of the read-only optical disc 30 of Figure 2 is briefly described. Grooves are formed on trans- 
parent substrates 31 and 32 so as to form spiral tracks . Over the grooved surfaces of the substrates 31 and 32, 
recording layers 33 and 34 are attached so as to cover the grooved surfaces, respectively. The substrates 31 and 32 
are attached together so as to sandwich a transparent light-curable resin 35 between the recording layers 33 and 34, 

55 thereby obtaining a single read-only optical disc 30. In this specification, for convenience of description, in Figure 2, a 
recording layer 34 closer to the incoming laser light 38 is referred to as a first recording layer 34; whereas the other 
recording layer 33 is referred to as a second recording layer 33. The thickness and composition of the first recording 
layer 34 are adjusted such that the first recording layer 34 reflects a half of the incoming laser light 38 and transmits 
the other half of the incoming laser light 38. The thickness and composition of the second recording layer 33 are 

40 adjusted such that the second recording layer 33 reflects all of the incoming laser light 38. An objective lens 37 for 
converging the laser light 38 is moved toward or away from the read-only optical disc 30 such that the convergence 
point (beam spot) 36 of the laser light 38 is placed on the first recording layer 34 or the second recording layer 33. 
[0005] Figures 3A, 3B, 3C and 3D show tracks of two recording layers 41 and 42 of a read-only DVD, which are 
called parallel paths, and the reproduction direction and sector numbers. Figure 3A shows a spiral groove pattern of 

45 the second recording layer 42. Figure 3B shows a spiral groove pattern of the first recording layer 41. Figure 3C shows 
the reproduction direction in user data areas 8 provided on the recording layers 41 and 42. Figure 3D shows sector 
numbers assigned to the recording layers 41 and 42. 

[0006] Now, consider the read-only DVD disc is rotated clockwise when it is viewed from the back face side of the 
disc in the direction along which laser light comes onto the disc, i.e., when it is viewed from the backside of the sheets 

50 of Figures 3A and 3B. In this case, the laser light moves along the track 2 from the inner periphery to the outer periphery 
of the recording layers 41 and 42. In the case where user data is sequentially reproduced along the reproduction 
direction shown in Figure 3C, reproduction is first performed from the innermost periphery to the outermost periphery 
of the user data area 8 of the first recording layer 41 . Then, reproduction is performed from the innermost periphery 
to the outermost periphery of the user data area 8 of the second recording layer 42. The user data areas 8 of the first 

55 and second recording layers 41 and 42 are sandwiched by the lead-in area 4 and the lead-out area 6 such that an 
optical head can appropriately follow the track 2 even if overrunning of the optical head occurs. As shown in Figure 
3D, the PSNs and LSNs of each of the recording layers 41 and 42 are incrementally assigned along the reproduction 
direction. The PSNs do not necessarily need to start with 0 in view of convenience of disc formation. Further, the PSNs 



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EP 1 329 888 A1 



do not necessarily need to be continuously assigned between the first and second recording layers 41 and 42 (for 
example, a value corresponding to the layer number may be provided at the first location of each sector number). As 
LSNs, consecutive numbers which start with 0 are assigned to all of the user data areas 8 included in the optical disc. 
That is, in the user data area 8 of the first recording layer 41 , the LSN at the innermost periphery is 0, and increases 
5 by ones toward the outermost perimeter. The LSN at the innermost periphery of the user data area 8 of the second 
recording layer 42 is a number obtained by adding 1 to the maximum LSN of the first recording layer 41 . The LSN of 
the second recording layer 42 also increments by ones toward the outermost perimeter. 

[0007] Figures 4A, 4B 5 4C and 4D show tracks of two recording layers 43 and 44 of a read-only DVD, which is called 
an opposite path arrangement, and the reproduction direction and sector numbers. Figure 4A shows a spiral groove 
10 pattern of the second recording layer 44. Figure 4B shows a spiral groove pattern of the first recording layer 43. Figure 
4C shows the reproduction direction in user data areas 8 provided on the recording layers 43 and 44. Figure 4D shows 
sector numbers assigned to the recording layers 43 and 44. 

[0008] Now, consider the read-only DVD disc is rotated clockwise when it is viewed from the back face side of the 
disc in the direction along which laser light comes onto the disc, i.e., when it is viewed from the backside of the sheets 

15 of Figures 4A and 4B. In this case, the laser light moves along the track 2 from the inner periphery to the outer periphery 
in the first recording layer 43, but from the outer periphery to the inner periphery in the second recording layer 44. In 
the case where user data is sequentially reproduced along the reproduction direction shown in Figure 4C, reproduction 
is first performed from the innermost periphery to the outermost periphery of the user data area 8 of the first recording 
layer 43, and then, reproduction is performed from the outermost periphery to the innermost periphery of the user data 

20 area 8 of the second recording layer 44. The user data area 8 of the first recording layer 43 is sandwiched by the lead- 
in area 4 and a middle area 7 such that an optical head can appropriately follow the track 2 even if overrunning of the 
optical head occurs. The user data area 8 of the second recording layer 44 is sandwiched by the middle area 7 and 
the lead-out area 6. The function of the middle area 7 is the same as that of the lead-out area 6. As shown in Figure 
4D, the PSNs and LSNs of each of the recording layers 43 and 44 are incrementally assigned along the reproduction 

25 direction as in the above-described parallel paths, except that the relationship between the sector numbers and the 
radial direction is changed because the spiral direction of the track 2 of the second recording layer 44 is inverse to the 
spiral direction of the track 2 of the first recording layer 43. In the user data area 8 of the first recording layer 43, the 
LSN is 0 at the innermost periphery, and increments by ones toward the outer periphery. The LSN at the outermost 
periphery in the user data area 8 of the second recording layer 44 is a number obtained by adding 1 to the maximum 

30 LSN in the user data area 8 of the first recording layer 43, and increments by ones toward the innermost perimeter. 
[0009] Above, read-only optical discs have been described. Now ; features specific to a rewritable optical disc are 
described. Such features result from the fact that requirements on a margin for a recording operation are more severe 
than that for a reproduction operation. 

[0010] Figure 5A shows an area layout of a typical rewritable disc 45. The rewritable disc 45 includes only one 
55 recording layer. A lead-in area 4 of the rewritable disc 45 includes a disc information area 10 and an OPC (Optimum 
Power Calibration) area 1 1 , and a defect management area 12. The lead-out area 6 includes another defect manage- 
ment area 12. A user data area 8 and a spare area 13 are provided between a lead-in area 4 and a lead-out area 6. 
[001 1 ] A disc information area 1 0 stores disc information regarding a parameter(s) or a format necessary for record- 
ing/reproduction of data of the optical disc. The disc information area 10 is also included in a read-only optical disc, 
40 but the disc information area 10 of the read-only optical disc includes nothing important other than a format identifier 
used for identifying the optical disc. On the other hand, in a rewritable optical disc, specific recommended values for 
the characteristics of the laser light used for recording, such as laser power, pulse width, and the like, are stored for 
each generated mark width. The disc information area 10 is a read-only area in which information is typically written 
at the time of production of the disc. In the rewritable disc 45, pits are formed in the disc surface as in a DVD-ROM or 
45 a CD-ROM. (There is a recording principle different from such a "pit" recording principle. For example, in a CD-RW, 
information is embedded in a meandering pattern (called "wobble") of a groove.) 

[0012] The OPC area 11 is provided for optimally adjusting the recording power of laser light. A disc manufacturer 
stores recommended laser parameters for a recording operation in the disc information area 10. However, a laser 
element used by the disc manufacturer for obtaining the recommended values is different from a laser element incor- 

50 porated in an optical disc drive apparatus, in respect to laser characteristics, such as the wavelength, the rising time 
of the laser power, and the like. Further, even a laser element of the same optical disc drive, the laser characteristics 
thereof vary because of a variation of the ambient temperature or deterioration which occurs over time. Thus, in an 
actual case, test recording is performed on the OPC area 11 while increasingly and decreasingly changing the laser 
parameters stored in the disc information area 10 so as to obtain an optimum recording power. 

55 [0013] A defect management area 12 and a spare areas 13 are provided for defect management, i.e., provided for 
replacing a sector of the user data area 8 in which recording/reproduction cannot be appropriately performed (referred 
to as a "defective sector") with another well-conditioned (i.e.. sufficiently usable) sector. In a rewritable single-layer 
optical disc, such as a 650 MB phase-change optical disc (called a PD) defined in the ECMA-240 format, or the like, 



3 



EP 1 329 888 A1 



defect management is generally performed. 

[0014] The spare area 13 includes a sector for replacing a defective sector (referred to as a spare sector). A sector 
which is already employed in place of a defective sector is referred to as a replacement sector. In a DVD-RAM, spare 
areas 13 are placed at two positions, one at the inner periphery and the other at the outer periphery of the user data 
5 area 8. In the above-described PD, spare areas 13 are provided at 10 positions, and their arrangement varies depending 
on the medium. In the example of Figure 5, for the sake of simplicity, a spare area 13 is provided at only one portion 
at the outer periphery of the user data area 8. 

[0015] The defect management area 12 includes: a disc definition structure (DDS) storing area 20 storing a format 
designed for defect management, which includes the size of the spare area 13 and the position where the spare area 

10 13 is placed; a defect management sector (DMS) storing area 21 storing data for managing the defect of the defect 
management area 1 2 itself; a defect list (DL) storing area 22 storing a list of defects containing the positions of defective 
sectors and the positions of replacement sectors; and a spare defective list (spare DL) storing area 23 which is used 
to replace the defect list (DL) storing area 22 when it is not usable. In view of robustness, many discs are designed 
based on a specification such that each of the inner perimeter portion and outer perimeter portion of a disc has one 

15 defect management area 12, and each defect management area 12 duplicately stores the same contents, i.e., the 
defect management areas 12 of the disc have the four copies of the same contents in total. 

[0016] Figure 5B shows data stored in a DMS 21. The data stored in the DMS 21 are the number of DL sectors 30 
which indicates the number of sectors storing a defect list, and a list of DL sector addresses 31 each of which indicates 
the address of a sector. For the sake of simplicity, DL storing areas 22 each are herein assumed to include only one 
20 sector. If it is determined that a DL storing area 22 is defective when updating a defect list because of detection of a 
new defective sector, the following spare DL storing area 23 is used to record the defect list. In this case, the DL sector 
address list 31 is updated so as to indicate the sector address of the spare DL storing 23. 

[0017] Figure 5C shows data stored in a DL storing area 22. The data stored in the DL storing area 22 are a DL 
identifier 32 which is a unique identifier for identifying a defect list, and the number of defective sectors 33 registered 

25 on the defect list. The DL storing area 22 further includes a plurality of defect entry areas 34 each including the address 
of a defective sector and the address of a replacement sector. It is now assumed that there are n defects registered 
(n is an integer greater than or equal to 3). In this case, the number of defective sectors 33 indicates n. 
[0018] A first defect entry area 34 stores a replacement status 40, a defective sector address 41 , and a replacement 
sector address 42. In other words, a single defect entry area stores information relating to a process for replacing a 

30 single defective sector. The replacement status 40 is a flag indicating whether or not replacement is applied to a de- 
fective sector. When replacement is performed, a value 0 is set in the replacement status 40. When replacement is 
not applied, a value 1 is set in the replacement status 40. When the value 1 is set in the replacement status 40, an 
optical disc drive apparatus accesses a defective sector. In this case, even if an error occurs in a read out process, 
the error is ignored and the read out process is continued while data contains the error. Such a process may be applied 

55 for recording and reproduction of video and audio data requiring continuous recording or reproduction. This is because 
interruptions in reproduction of video or audio due to replacement of a defective area with a distant spare area appears 
more significant than disturbances in video or audio due to the erroneous data itself. The defective sector address 41 
contains the address of a sector which is determined to be defective. The replacement sector address 42 contains the 
address of a sector in a spare area 13, which sector replaces a defective sector indicated by the defective sector 

40 address 41 . The n defect entry areas are arranged in ascending order of the address of a defective sector. 

[0019] As described above, defect management is essential for rewritable optical discs to obtain substantially the 
same data reliability as that of read-only optical discs. 

[0020] Although there are read-only optical discs having a plurality of recording layers, all existing rewritable optical 
discs have only a single recording layer. The above-described defect management for a rewritable optical disc is di- 

45 rected to management of only one recording layer. 

[0021 ] If defect management as described above was simply applied to an optical disc having a plurality of recording 
layers, a defect management area would be provided for each recording layer. A defect management is separately 
performed for each recording layer. A typical recording/reproduction apparatus for rewritable optical discs transfers a 
defect list into a memory within the apparatus when the apparatus is actuated (initial process). This is because defect 

50 management information can be accessed at high speed, which is constantly referenced in recording and reproduction 
of user data. Therefore, when a recording/reproduction apparatus handles an optical disc having a plurality of recording 
layers, the apparatus needs to read all defect management areas in all recording layers when loading a disk into the 
apparatus. This poses a problem such that it takes a long time before starting actual recording or reproduction of a 
disc. Moreover, defect management is separately performed for each recording layer, and therefore, if a finite defect 

55 list storing area is exhausted in a certain recording layer, any defect list storing areas of other recording layers are not 
available for that exhausted recording layer. This poses a problem such that defect list storing areas cannot be efficiently 
used. 

[0022] As used herein, the term "initial process" for an optical disc refers to a process in which defect management 



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information or the like is read out before recording or reproduction user data or the like on the disc when a recording/ 
reproduction apparatus is actuated. 

SUMMARY OF THE INVENTION 

5 

[0023] According to one aspect of the present invention, a multi-layered information recording medium comprises: 
a plurality of recording layers; a user data area for recording user data, provided in at least two of the plurality of 
recording layers; and a defect list storing area for storing a defect list, wherein when at least one defective area is 
detected in the user data area, the defect list is used to manage the at least one defective area. 
10 [0024] In one embodiment of this invention, the multi-layered information recording medium may further comprise a 
defect list location information storing area for storing defect list location information indicating the location of the defect 
list storing area. The defect list location information storing area may be provided in one of the plurality of recording 
layers which is predetermined as a reference layer. 

[0025] In one embodiment of this invention, the reference layer may be one of the plurality of recording layers which 
15 is located at a predetermined distance from the data read-out surface of the multi-layered information recording me- 
dium. 

[0026] In one embodiment of this invention, the reference layer may be one of the plurality of recording layers which 
is located at the shortest distance from the data read-out surface of the multi-layered information recording medium. 
[0027] In one embodiment of this invention, the reference layer may be one of the plurality of recording layers which 
20 is located at the longest distance from the data read-out surface of the multi-layered information recording medium. 
[0028] In one embodiment of this invention, the defect list may indicate the location of the detected at least one 
defective area by a layer number for distinguishing the plurality of recording layer from each other and an intralayer 
address for indicating a position in each of the plurality of recording layers. 

[0029] In one embodiment of this invention, the defect list storing area may be provided in one of the plurality of 
25 recording layer, and the defect list location information may indicate the location of the defect list storing area by a 
layer number for distinguishing the plurality of recording layer from each other and an intralayer address for indicating 
a position in each of the plurality of recording layers. 

[0030] In one embodiment of this invention, the multi-layered information recording medium may further comprise a 
spare area containing at least one replacement area. When at least one defective area is detected in the user data 

30 area, the at least one replacement area may be used in place of the at least one defective area. 

[0031] In one embodiment of this invention, when the defective area is replaced with the replacement area, the defect 
list may indicate the location of the defective area and the location of the replacement area by respective layer numbers 
for distinguishing the plurality of recording layers from each other and respective intralayer addresses for indicating a 
position in each of the plurality of recording layers. 

35 [0032] In one embodiment of this invention, the defect list storing area may be provided one of the plurality of recording 
layers. The multi-layered information recording medium may further comprise an additional defect list storing area for 
storing a defect list having the same contents as the contents of the defect list stored in the defect list storing area. 
The additional defect list storing area may be provided in another one of the plurality of recording layers. 
[0033] In one embodiment of this invention, the multi-layered information recording medium may further comprise a 

40 first defect list location information storing area for storing first defect list location information indicating the location of 
the defect list storing area, and a second defect list location information storing area for storing a second defect list 
location information indicating the location of the additional defect list storing area. The first defect list location infor- 
mation storing area may be provided in the same recording layer as that in which the defect list storing area is provided, 
and the second defect list location information storing area may be provided in the same recording layer as that in 

45 which the additional defect list storing area is provided. 

[0034] In one embodiment of this invention, the recording layer in which the defect list storing area is provided may 
comprise a first defect management area containing the defect list storing area and the first defect list location infor- 
mation storing area. The recording layer in which the additional defect list storing area may be provided comprises a 
second defect management area containing the additional defect list storing area and the second defect list location 

50 information storing area. Logical addresses may be assigned to the user data area. An area of the user data area to 
which the smallest logical address is assigned is provided in the recording layer in which the defect list storing area 
may be provided. An area of the user data area to which the greatest logical address is assigned may be provided in 
the recording layer in which the additional defect list storing area is provided. The first defect management area may 
be adjacent to the area to which the smallest logical address is assigned. The second defect management area may 

55 be adjacent to the area to which the greatest logical address is assigned. 

[0035] According to another aspect of the present invention, a multi-layered information recording medium compris- 
es: a plurality of recording layers; a user data area for recording user data, provided in at least two of the plurality of 
recording layers; a defect management area provided in at least one of the plurality of recording layers; and a spare 



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EP 1 329 888 A1 



defect list storing area provided in another one of the plurality of recording layers. The defect management area contains 
a plurality of first defect list storing areas for storing a defect list, wherein when at least one defective area is detected 
in the user data area, the defect list is used to manage the at least one defective area. The spare defect list storing 
area contains a plurality of second defect list storing areas capable of being used in place of the plurality of first defect 

5 list storing areas when none of the plurality of first defect list storing areas is usable. 

[0036] In one embodiment of this invention, the defect management area and the spare defect list storing area may 
be located at substantially the same radial positions in the multi-layered information recording medium. 
[0037] In one embodiment of this invention, the defect management area may further comprise a defect list location 
information storing area for storing defect list location information indicating the location of an area storing the defect 

10 list among the plurality of first defect list storing areas and the plurality of second spare defect list storing areas. 

[0038] According to another aspect of the present invention, an apparatus for reproducing information recorded in 
a multi-layered information recording medium is provided. The multi-layered information recording medium comprises: 
a plurality of recording layers; a user data area for recording user data, provided in at least two of the plurality of 
recording layers; and a defect list storing area for storing a defect list, wherein when at least one defective area is 

15 detected in the user data area, the defect list is used to manage the at least one defective area. The apparatus com- 
prises: an optical head section capable of optically reading the information recorded in the multi-layered information 
recording medium from one side of the multi-layered information recording medium; and a control section for controlling 
defect management using the optical head section. The defect management comprises the steps of: reproducing the 
defect list stored in the defect list storing area; and reproducing the user data recorded in the user data area based on 

20 the reproduced defect list. 

[0039] In one embodiment of this invention, the multi-layered information recording medium may further comprise: 
a defect list location information storing area for storing defect list location information indicating the location of the 
defect list storing area, wherein the defect list location information storing area is provided in one of the plurality of 
recording layers which is predetermined as a reference layer, the defect management further comprises identifying 

25 the location of the defect list storing area by reproducing the defect list location information stored in the defect list 
location information storing area. 

[0040] In one embodiment of this invention, the multi-layered information recording medium may further comprise: 
a spare area for containing at least one replacement area ; wherein when at least one defective area is detected in the 
user data area, the at least one replacement area may be used in place of the at least one defective area. The defect 
30 list may indicate that a defective area present in the user data area is replaced with the replacement area contained 
in the spare area. The step of reproducing the user data may comprise reproducing user data from the replacement 
area indicated by the defect list instead of the defective area indicated by the defect list. 

[0041] According to another aspect of the present invention, an apparatus for recording information in a multi-layered 
information recording medium is provided. The multi-layered information recording medium comprises: a plurality of 

55 recording layers; a user data area for recording user data, provided in at least two of the plurality of recording layers; 
and a defect list storing area for storing a defect list, wherein when at least one defective area is detected in the user 
data area, the defect list is used to manage the at least one defective area. The apparatus comprises: an optical head 
section capable of optically recording the information in the multi-layered information recording medium from one side 
of the multi-layered information recording medium; and a control section for controlling defect management using the 

40 optical head section. The defect management comprises the steps of: determining whether or not a defective area is 
present in the user data area during recording of user data in the user data area; and updating the defect list so as to 
manage a defective area when it is determined that the defective area is present in the user data area. 
[0042] In one embodiment of this invention, the multi-layered information recording medium may further comprise 
an additional defect list storing area capable of being used in place of the defect list storing area when the defect list 

45 storing area is unusable. The defect management may further comprise recording a defect list having the same contents 
as the contents of a defect list stored in the defect list storing area to the additional defect list storing area, when the 
defect list storing area is unusable. 

[0043] In one embodiment of this invention/the multi-layered information recording medium may further comprise: a 
defect list location information storing area for storing defect list location information indicating the location of a defect 
50 list. The defect list location information storing area may be provided in one of the plurality of recording layers which 
is predetermined as a reference layer. The defect management may further comprise updating the defect list location 
information so that the defect list location information indicates the additional defect list storing area, when the additional 
defect list storing area is used in place of the defect list storing area. 

[0044] In one embodiment of this invention, the multi-layered information recording medium may further comprise: 
55 a defect management area provided in one of the plurality of recording layers; and a spare defect list storing area 
provided in another one of the plurality of recording layer. The defect management area may comprise a plurality of 
defect list storing areas, the spare defect list storing area comprises a plurality of additional defect list storing areas, 
the defect list storing area is one of the plurality of defect list storing areas, the additional defect list storing area is one 



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EP 1 329 888 A1 



of the plurality of additional defect list storing area, and when none of the plurality of defect list storing areas is usable, 
the additional defect list storing area is used in place of the defect list storing area. 

[0045] In one embodiment of this invention, the defect list storing area may be provided in one of the plurality of 
recording layers, and the additional defect list storing area may be provided in the same recording layer as that in 
5 which the defect list storing area is provided. 

[0046] In one embodiment of this invention, the defect list storing area may be provided in one of the plurality of 
recording layers, and the additional defect list storing area may be provided in another one of the plurality of recording 
layers. 

[0047] In one embodiment of this invention, the multi-layered information recording medium may further comprise: 
10 a spare area for containing at least one replacement area, wherein when at least one defective area is detected in the 
user data area, the at least one replacement area may be used in place of the at least one defective area. The defect 
management may further comprise replacing the defective area present in the user data area with the replacement 
area contained in the spare area. 

[0048] According to another aspect of the present invention, a method for reproducing information recorded in a 
15 multi-layered information recording medium is provided. The multi-layered information recording medium comprises: 
a plurality of recording layers; a user data area for recording user data, provided in at least two of the plurality of 
recording layers; and a defect list storing area for storing a defect list, wherein when at least one defective area is 
detected in the user data area, the defect list is used to manage the at least one defective area. The method comprises 
the steps of: reproducing the defect list stored in the defect list storing area; and reproducing the user data recorded 
20 in the user data area based on the reproduced defect list. 

[0049] In one embodiment of this invention, the multi-layered information recording medium may further comprise: 
a defect list location information storing area for storing defect list location information indicating the location of the 
defect list storing area. The defect list location information storing area may be provided in one of the plurality of 
recording layers which is predetermined as a reference layer. The method may further comprise identifying the location 
25 of the defect list storing area by reproducing the defect list location information stored in the defect list location infor- 
mation storing area. 

[0050] In one embodiment of this invention, the multi-layered information recording medium may further comprise: 
a spare area for containing at least one replacement area ; wherein when at least one defective area is detected in the 
user data area, the at least one replacement area may be used in place of the at least one defective area. The defect 
30 list may indicate that a defective area present in the user data area is replaced with the replacement area contained 
in the spare area. The step of reproducing the user data may comprise reproducing user data from the replacement 
area indicated by the defect list instead of the defective area indicated by the defect list. 

[0051] According to another aspect of the present invention, a method for recording information in a multi-layered 
information recording medium is provided. The multi-layered information recording medium may comprise: a plurality 

55 of recording layers; a user data area for recording user data, provided in at least two of the plurality of recording layers; 
and a defect list storing area for storing a defect list, wherein when at least one defective area is detected in the user 
data area, the defect list is used to manage the at least one defective area. The method comprises the steps of: 
determining whether or not a defective area is present in the user data area during recording of user data in the user 
data area; and updating the defect list so as to manage a defective area when it is determined that the defective area 

40 is present in the user data area. 

[0052] In one embodiment of this invention, the multi-layered information recording medium may further comprise 
an additional defect list storing area capable of being used in place of the defect list storing area when the defect list 
storing area is unusable. The method may further comprise recording a defect list having the same contents as the 
contents of a defect list stored in the defect list storing area to the additional defect list storing area, when the defect 

45 list storing area is unusable. 

[0053] In one embodiment of this invention, the multi-layered information recording medium may further comprise: 
a defect list location information storing area for storing defect list location information indicating the location of a defect 
list. The defect list location information storing area may be provided in one of the plurality of recording layers which 
is predetermined as a reference layer. The method may further comprise updating the defect list location information 

50 so that the defect list location information indicates the additional defect list storing area, when the additional defect 
list storing area is used in place of the defect list storing area. 

[0054] In one embodiment of this invention, the multi-layered information recording medium may further comprise: 
a defect management area provided in one of the plurality of recording layers; and a spare defect list storing area 
provided in another one of the plurality of recording layer. The defect management area may comprise a plurality of 
55 defect list storing areas. The spare defect list storing area may comprise a plurality of additional defect list storing 
areas. The defect list storing area may be one of the plurality of defect list storing areas. The additional defect list 
storing area is one of the plurality of additional defect list storing area. When none of the plurality of defect list storing 
areas is usable, the additional defect list storing area may be used in place of the defect list storing area. 



7 



EP 1 329 888 A1 



[0055] In one embodiment of this invention, the defect list storing area may be provided in one of the plurality of 
recording layers, and the additional defect list storing area may be provided in the same recording layer as that in 
which the defect list storing area is provided. 

[0056] In one embodiment of this invention, the defect list storing area may be provided in one of the plurality of 
5 recording layers, and the additional defect list storing area may be provided in another one of the plurality of recording 
layers. 

[0057] In one embodiment of this invention, the multi-layered information recording medium may further comprise: 
a spare area for containing at least one replacement area, wherein when at least one defective area is detected in the 
user data area, the at least one replacement area may be used in place of the at least one defective area. The method 
10 may further comprise replacing the defective area present in the user data area with the replacement area contained 
in the spare area. 

[0058] Thus, the invention described herein makes possible the advantages of providing a defect management meth- 
od capable of shortening the time required to read a defect management area in an initial process for a disc and 
efficiently managing defective areas. 
15 [0059] 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. 

BRIEF DESCRIPTION OF THE DRAWINGS 

20 [0060] 

Figure 1 is a diagram showing a track and sectors in an optical disc. 

Figure 2 is a diagram showing a principle of reproduction of an optical disc comprising two recording layers. 

25 

Figure 3A is a diagram showing a groove pattern of a second recording layer in a parallel path DVD. 
Figure 3B is a diagram showing a groove pattern of a first recording layer in a parallel path DVD. 
30 Figure 3C is a diagram showing a reproduction direction of a parallel path DVD. 

Figure bis a diagram showing assignment of sector numbers in a parallel path DVD. 

Figure 4A is a diagram showing a groove pattern of a second recording layer in an opposite path DVD. 

35 

Figure 4B is a diagram showing a groove pattern of a first recording layer in an opposite path DVD. 
Figure 4C is a diagram showing a reproduction direction of an opposite path DVD. 
40 Figure bis a diagram showing assignment of sector numbers in an opposite path DVD. 

Figure 5A is a diagram showing locations of areas in a DVD-RAM. 
Figure 5B is a diagram showing a data structure of a DMS shown in Figure 5A. 

45 

Figure 5C is a diagram showing a data structure of a DL shown in Figure 5A. 

Figure 6 is a diagram showing locations of areas in a multi-layered information recording medium according to 
Embodiment 1 of the present invention. 

50 

Figure 7 is a diagram showing a data structure of a first defect management area in Embodiment 1 of the present 
invention. 

Figure 8 is a diagram showing a data structure of a first spare DL storing area in Embodiment 1 of the present 
55 invention. 

Figure 9 is a diagram showing the relationship between a first spare DL storing area and a DDS area in Embodiment 
1 of the present invention. 



8 



EP 1 329 888 A1 



Figure 1 0A is a diagram showing locations of a first defect management area and a first spare DL storing area in 
Embodiment 1 of the present invention. 

Figure 1 0B is a diagram showing locations of a first defect management area and a first spare DL storing area in 
5 Embodiment 1 of the present invention. 

Figure 10C is a diagram showing locations of a first defect management area and a first spare DL storing area in 
Embodiment 1 of the present invention. 

10 Figure 11 is a diagram showing locations of areas in a multi-layered information recording medium according to 

Embodiment 2 of the present invention. 

Figure 12 is a diagram showing a data structure of a first defect management area in Embodiment 2 of the present 
invention. 

15 

Figure 13 is a diagram showing a recording/reproduction apparatus according to Embodiment 3 of the present 
invention. 

Figure 14 is a flowchart for illustrating a procedure of obtaining defect management information in Embodiment 3 
20 of the present invention. 

Figure 15 is a flowchart for illustrating a reproduction procedure of sectors according to Embodiment 3 of the 
present invention, wherein replacement is considered. 

25 Figure 16 is a flowchart for illustrating conversion of LSN to PSN in Embodiment 3 of the present invention. 

Figure 17 is a flowchart for illustrating a procedure of updating defect management information in Embodiment 3 
of the present invention. 

30 Figure 18 is a flowchart for illustrating a recording procedure according to Embodiments of the present invention, 

wherein replacement is considered. 

Figure 19 is a diagram showing locations of areas in a multi-layered information recording medium according to 
Embodiment 4 of the present invention. 

35 

Figure 20 is a diagram showing a data structure of a first defect management area in a multi-layered information 
recording medium according to Embodiment 4 of the present invention. 

Figure 21 is a diagram showing locations of areas in a multi-layered information recording medium according to 
40 Embodiment 5 of the present invention. 

Figure 22 is a diagram showing locations of areas in a multi-layered information recording medium according to 
Embodiment 6 of the present invention. 

45 DESCRIPTION OF THE PREFERRED EMBODIMENTS 

(Embodiment 1) 

[0061] Hereinafter, a multi-layered information recording medium according to Embodiment 1 of the present invention 
50 will be described with reference to the accompanying drawings . A multi-layered information recording medium as used 
herein refers to an information recording medium comprising at least two recording layers. 

[0062] Figure 6 is a diagram showing a multi-layered information recording medium 600 according to Embodiment 
1 of the present invention. The multi-layered information recording medium 600 comprises two recording layers 51 and 
52. The multi-layered information recording medium 600 contains a user data area 602 for recording user data. The 
55 user data area 602 straddles a boundary between the two recording layers 51 and 52. In Embodiment 1 of the present 
invention, the upper recording layer (51) shown in Figure 6 is referred to as a first recording layer, and the lower 
recording layer (52) is referred to as a second recording layer. 

[0063] The first recording layer 51 is located at a predetermined distance from a surface of the multi-layered infor- 



9 



EP 1 329 888 A1 



mation recording medium 600 through which data is read out (data read-out surface). The first recording layer 51 is 
referred to as a reference layer. This predetermined distance is equal to a distance from the data read-out surface of 
an optical disc comprising only one recording layer to the recording layer. A reference layer is predetermined among 
a plurality of recording layers. 

5 [0064] The first recording layer 51 contains , from the inner periphery to the outer periphery along the recording/ 
reproduction direction of the multi-layered information recording medium 600, a lead-in area 601 , a first user data area 
15 which is a portion of the user data area 602, and a middle area 603. The second recording layer 52 contains, from 
the outer periphery to the inner periphery along the recording/reproduction direction of the multi-layered information 
recording medium 600, a middle area 603, a second user data area 16 which is a portion of the user data area 602, 

10 and a lead-out area 604. 

[0065] The lead-in area 601 provided in the first recording layer 51 (reference layer) contains a control data area 
610 for storing control information for the multi-layered information recording medium 600, and a first defect manage- 
ment area 611 (DMA1) and a second defect management area 612 (DMA2) for recording defect management infor- 
mation relating to a defective area (defect management information contains disc definition structure data, a defect 

15 list, and the like). The middle area 603 of the first recording layer 51 contains a third defect management area 613 
(DM A3) and a fourth defect management area 614 (DMA4). The first defect management area 611 , the second defect 
management area 61 2, the third defect management area 61 3, and the fourth defect management area 61 4 each store 
the same defect management information. This is because by duplicately recording the same defect management 
information in a plurality of areas on the inner periphery and outer periphery of the multi-layered information recording 

20 medium 600, the reliability of the defect management information is improved. A defective area is herein a defective 
sector. 

[0066] The middle area 603 of the second recording layer 52 contains a third spare defect list (DL) area 622 (spare 
DL3) and a fourth spare DL storing area 623 (spare DL4) for storing spare a defect list. The third spare DL storing area 
622 (spare DL3) may be used in place of the third defect management area 613 (DM A3) of the first recording layer 51 

25 when DMA3 is no longer appropriately recordable (unusable) due to degradation or the like. The fourth spare DL storing 
area 623 (spare DL4) may be used in place of the fourth defect management area 613 (DMA4) of the first recording 
layer 51 when DMA4 is no longer appropriately recordable (unusable) due to degradation orthe like. The lead-out area 
604 contains a first spare DL storing area 620 (spare DL1) and a second spare DL storing area 621 (spare DL2) for 
storing a spare defect list. The first spare DL storing area 620 (spare DL1) may be used in place of the first defect 

30 management area 611 (DMA1) of the first recording layer 51 when DMA1 is no longer appropriately recordable (un- 
usable) due to degradation or the like. The second spare DL storing area 621 (spare DL2) may be used in place of the 
second defect management area 612 (DMA2) of the first recording layer 51 when DMA2 is no longer appropriately 
recordable (unusable) due to degradation orthe like. 

[0067] It is now assumed that as shown in Figure 6, a defective area A 630 is present in the first user data area 15, 
55 and a defective area B 631 is present in the second user data area 16. Although the optical disc comprising the spare 
area 13 is described in the DESCRIPTION OF THE RELATED ART Section (Figure 5A), the multi-layered information 
recording medium 600 of Embodiment 1 does not contain such a spare area. Therefore, none of the defective area A 
630 and the defective area B 631 is replaced with a spare area. 

[0068] Referring to Figure 7, a data structure of the first defect management area 611 (DMA1) will be described 

40 below. Note that the first defect management area 61 1 (DMA1 ), the second defect management area 612 (DMA2), the 
third defect management area 613 (DMA3) ; and the fourth defect management area 614 (DMA4) each store the same 
defect management information. Here, the first defect management area 611 (DMA1) will be described. 
[0069] The first defect management area 61 1 (DM A1 ) of the first recording layer 51 (reference layer) contains a disc 
definition structure (DDS) area 700 (DDS) and a plurality of defect list (DL) storing areas. In Embodiment 1 , the first 

45 defect management area 611 (DMA1) contains a first DL storing area 701, a second DL storing area 702, a third DL 
storing area 703, and a fourth DL storing area 704. Not all of these DL storing areas are simultaneously used. Any one 
of the DL storing areas is used. In the example shown in Figure 7, the first DL storing area 701 is a defective area, 
and the second DL storing area 702 is used. The third DL storing area 703 and the fourth DL storing area 704 are 
unused. The second DL storing area 702 stores a defect list (DL) 709. When at least one defective area is detected 

50 in the use data area 602, the defect list 709 is used to manage the detected defective area. The defect list 709 contains 
the defective area(s) detected in the user data area 602 and the location information of their replacement area(s). The 
DDS area 700 functions as a defect list location information storing area for storing defect list location information 
indicating the location of a DL storing area storing the defect list 709 (e.g., the second DL storing area 702 in Figure 
7). The DDS area 700 also stores information indicating a defect verification status orthe like. If the second DL storing 

55 area 702 becomes defective due to repetition of write operations or the like, the third DL storing area 703 is used. 
[0070] The DDS area 700 contains a DDS identifier 710 for identifying a DDS, a DL start sector layer number 711 
indicating a recording layer containing a DL storing area currently used among a plurality of recording layers (a layer 
number may be any information which permits to distinguish a plurality of recording layers from each other), a DL start 



10 



EP 1 329 888 A1 



sector number 71 2 indicating the location of a DL storing area currently used in a recording layer using a sector number 
which is uniquely identifiable in the recording layer, and a spare area size area 713 for storing information relating to 
the size of a spare area. The DL start sector layer number 71 1 and the DL start sector number area 712 contain defect 
list location information. Since the multi-layered information recording medium 600 does not contain a spare area, a 
5 value 0 is set in the spare area size area 713. The spare area size area 713 can contain the number of recording 
layers, or a plurality of sizes depending on the location of a spare area. For the sake of simplicity, it is here assumed 
that when the multi-layered information recording medium 600 is provided with spare areas, a spare area having a 
size specified by the spare area size area 713 is provided in both the inner periphery and the outer periphery of each 
recording layer. 

10 [0071] The defect list 709 contains a DL header 720 and two pieces of defect entry data. The DL header area 720 
contains a DL identifier 731 for identifying a defect list, a DL update count 732 for indicating the number of repetitions 
of rewriting the defect list, and a number of DL entries 733 for indicating the number of defect entries stored in areas 
following the DL header 720. In the example shown in Figure 7, two pieces of defect entry data, i.e., a defect entry A 
721 and a defect entry B 722, are registered, and therefore, the number of DL entries 733 indicates two. 

15 [0072] The defect entry A 721 contains a replacement status flag 734, a defective sector layer number 735, a defective 
sector number 736, a replacement sector layer number 737, and a replacement sector number 738. Similarly, the 
defect entry B 722 contains a replacement status flag 739, a defective sector layer number 740, a defective sector 
number 741, a replacement sector layer number 742, and a replacement sector number 743. The data contained in 
the defect entry A 721 will be described. The replacement status flag 734 is a flag indicating whether or not a defective 

20 area is replaced with a spare area (normal area) and indicates a value 1 when no replacement is performed. In Em- 
bodiment 1 , no spare area is allocated in the multi-layered information recording medium 600, and therefore, a value 
1 indicating no replacement is set in the replacement status flag 734. 

[0073] The defective sector layer number 735 indicates the layer number of a recording layer in which a defective 
area is detected. The replacement sector layer number 737 indicates the layer number of a recording layer in which a 

25 replacement area is provided. These layer numbers are any information which permits to distinguish a plurality of 
recording layers from each other. The defect entry A 721 is used to manage the defective area A 630 (Figure 6). The 
defect entry B 722 is used to manage the defective area B 631 (Figure 6). In this case, for example, a value 1 indicating 
the first recording layer 51 is set in the defective sector layer number 735, while a value 2 indicating the second recording 
layer 52 is set in the defective sector layer number 740. The defective sector number 736 indicates an identification 

30 value from which the location of a defective area is uniquely determined in the recording layer in which the defective 
area is detected. The sector number is a value which increments by ones from the inner periphery toward the outer 
periphery of the multi-layered information recording medium 600, for example. 

[0074] Even if the sector number of any sector in the first recording layer 51 is the two's complement of the sector 
number of a corresponding sector in the second recording layer 52 where the sectors are placed at the same radial 

55 position, the above-described conditions are satisfied as in the opposite paths of a DVD-ROM. For example, consider 
that physical sector numbers (PSNs) are represented in the 28-bit format, and the PSNs of the first recording layer 51 
are within the range of OOOOOOOh to OFFFFFFh ("h" means that the value is represented by a hexadecimal number). 
When the PSN of a certain sector in the first recording layer 51 is 0123450h, the PSN of a corresponding sector in the 
second recording layer 52 at the same radial position is FEDCBAFh. In this case, the most significant bit of the PSN 

40 for the first layer is constantly 0 and the most significant bit of the PSN for the second layer is constantly F. Thus, the 
most significant bit can be used to indicate the layer number. 

[0075] Similarly, a value capable of uniquely identifying the location of an area replacing a defective area is set in 
each of the replacement sector layer number 737 and the replacement sector number 738. Note that in Embodiment 
1 , since there is no spare area, no replacement is performed. Therefore, 0 is set in each of the replacement sector 

45 layer numbers 737 and 742, while OOOOOOOOh is set in each of the replacement sector numbers 738 and 743. 

[0076] If a defect management area (DMA) was separately provided in each of the first recording layer 51 and the 
second recording layer 52, it is necessary for the recording/reproduction apparatus to read out defect management 
information from each recording layer as described above. However, as described above, the multi-layered information 
recording medium 600 according to Embodiment 1 of the present invention can obtain defect management information 

50 for all of the recording layers only by reading the defect management information from the reference layer. Therefore, 
it is possible to perform an initial process for the multi-layered information recording medium 600 simply and in a short 
time. 

[0077] In the multi-layered information recording medium 600, the defective areas of all of the recording layers are 
managed in a unified manner. Therefore, DL storing areas can be used more efficiently than when defective areas are 
55 managed for each recording layer. For example, an optical disc is assumed to comprise two recording layers containing 
a maximum total of 1000 sectors for which occurrence of a defective area is managed. In this case, when defect 
management information is separately stored in each recording layer, it is necessary to provide each layer with a DL 
storing area which can contain defect entries of a maximum of 1 000 sectors. This is because it is necessary to handle 



11 



EP 1 329 888 A1 



an unbalanced situation such that 950 defective sectors are present in the first recording layer 51 while no defective 
area is present inthesecond recording layer 52. On the other hand, in the case of the multi-layered information recording 
medium 600 according to Embodiment 1 of the present invention, defective areas in all of the recording layers are 
managed in an unified manner using a DL storing area which can contain defect entries of a maximum of 1 000 sectors, 

5 and therefore, the total size of all DL storing areas can be reduced. 

[0078] Next, the first spare DL storing area 620 (spare DL1) included in the second recording layer 52 will be described 
with reference to Figure 8. The first spare DL storing area 620 (spare DL1 ) contains a plurality of DL storing areas. In 
the multi-layered information recording medium 600 according to Embodiment 1 of the present invention, the first spare 
DL storing area 620 (spare DL1 ) contains four DL storing areas, i.e., a fifth DL storing area 705, a sixth DL storing area 

10 706, a seventh DL storing area 707, and an eighth DL storing area 708, each of which is unused. A DL storing area 
contained in the first spare DL storing area 620 (spare DL1) is used in place of the DL storing areas contained in the 
first defect management area 611 (DMA1) when all of them are determined to be defective and unusable. A defect list 
having the same contents as those of a defect list stored in a DL storing area contained in the first defect management 
area 611 (DMA1) is stored in a DL storing area contained in the first spare DL storing area 620 (spare DL1). 

15 [0079] As does the first spare DL storing area 620 (spare DL1), the second spare DL storing area 621 (spare DL2), 
the third spare DL storing area 622 (spare DL3), and the fourth spare DL storing area 623 (spare DL4) each contain 
a plurality of DL storing areas. A DL storing area contained in the second spare DL storing area 621 (spare DL2) is 
used in place of the DL storing areas contained in the second defect management area 612 (DMA2) when all of them 
are determined to be defective and unusable. A DL storing area contained in the third spare DL storing area 622 (spare 

20 DL3) is used in place of the DL storing areas contained in the third defect management area 613 (DMA3) when all of 
them are determined to be defective and unusable. A DL storing area contained in the fourth spare DL storing area 
623 (spare DL4) is used in place of the DL storing areas contained in the fourth defect management area 614 (DMA4) 
when all of them are determined to be defective and unusable. 

[0080] In the above-described case, when the first defect management area 611 (DMA1) is unusable, the first spare 
25 DL storing area 620 (spare DL1 ) is used. Alternatively, for example, another spare DL storing area, such as the second 
spare DL storing area 621 or the like, may be used. 

[0081 ] Figure 9 shows an example of use of the first spare DL storing area 620 (spare DL1 ) in the second recording 
layer 52. In the example of Figure 9, four DL storing areas in the first defect management area 611 (DMA1) are deter- 
mined to be defective. In this case, a defect list is recorded in a DL storing area of the first spare DL storing area 620 

30 (spare DL1) contained in the second recording layer 52. As shown in Figure 9, when the fifth DL storing area 705 is 
also defective, the defect list 709 (Figure 7) is recorded in the sixth DL storing area 706. In this case, a value 2 which 
indicates the use of a DL storing area contained in the second recording layer 52, is set in the DL start sector layer 
number 71 1 of the DDS area 700. The sector number of the starting position of the sixth DL storing area 706 is stored 
in the DL start sector number 712. 

35 [0082] As described above, in the multi-layered information recording medium 600 according to Embodiment 1 of 
the present invention, the recording layer other than the reference layer contains a spare DL storing area. Therefore, 
even if a DL storing area in the reference layer becomes unusable, the spare DL storing area can be used to keep the 
reliability of defect management information. Particularly, this technique is useful for improvement of reliability of re- 
cording media which are likely to be degraded due to repetition of write operations. Note that in Embodiment 1 the fifth 

40 DL storing area 705, the sixth DL storing area 706, the seventh DL storing area 707, and the eighth DL storing area 
708 are used in this order, however, these areas may be used in descending order from the eighth DL storing area 
708 when data is recorded in the second recording layer 52 from the outer periphery to the inner periphery of the multi- 
layered information recording medium 600. 

[0083] Next, with reference to Figures 10A and 10B, a description will be given of the relationship between the radial 
45 position of a defect management area in the first recording layer 51 (reference layer) and the radial position of a spare 
DL storing area in the second recording layer 52. Figure 10A is an enlarged diagram showing locations of the lead-in 
area 601, the middle area 603, and the lead-out area 604 in the multi-layered information recording medium 600 
according to Embodiment 1 of the present invention. It is now assumed that the first spare DL storing area 620 (spare 
DL1) is used. In this case, a defect list is stored in the first spare DL storing area 620 (spare DL1), which is indicated 
50 by the DL start sector number 71 2 of the DDS area 700. The first spare DL storing area 620 (spare DL1 ) and the first 
defect management area 61 1 (DMA1 ) are desirably located at substantially the same radial positions. If so, a recording/ 
reproduction head needs to be shifted by only a small distance in a radial direction. Thus, as shown in Figure 10A, the 
first DL storing area 701 in the first defect management area 61 1 (DM A1 ) and the fifth DL storing area 705 in the first 
spare DL storing area 620 (spare DL1 ) are desirably located at substantially the same radial positions. This is because 
55 when the contents of the first defect management area 611 (DMA1) are read out in an initial process for the multi- 
layered information recording medium 600 and it is determined according to the DDS area 700 that a defect list is 
stored in the fifth DL storing area 705 of the first spare DL storing area 620 (spare DL1 ), having substantially the same 
radial position makes it possible to access the area quickly. However, an error or the like may occur when the first 



12 



EP 1 329 888 A1 



recording layer 51 and the second recording layer 52 are attached together in a fabrication step, thereby making it 
difficult to arrange the first spare DL storing area 620 (spare DL1 ) and the first defect management area 61 1 (DMA1 ) 
at the same radial position. As a result, as shown in Figure 10B, the first recording layer 51 is slightly shifted from the 
second recording layer 52. In Figure 10B, the first defect management area 611 (DMA1) in the first recording layer 51 
5 is radially shifted from the first spare DL storing area 620 (spare DL1 ) in the second recording layer 52. The magnitude 
of the shift is called an attachment error in a disc fabrication process. 

[0084] Considering the operation of a recording/reproduction apparatus for recording and reproduction of the multi- 
layered information recording medium 600, an error occurs due to the inaccuracy of control of lens positions, the 
eccentricity of a disc, or the like when a focal point is switched between the first recording layer 51 and the second 
10 recording layer 52. Therefore, an error in radial position between the first recording layer 51 and the second recording 
layer 52 may be tolerable within a predetermined range based on the attachment precision of recording layers in a 
disc fabrication process as shown in Figure 10B. 

[0085] Further, for the positional relationship between a defect management area and a spare DL storing area, a 
smaller distance between a DDS area in a defect management area and a DL storing area in a corresponding spare 
15 DL storing area is preferable in view of an access time. For example, as shown in Figure 10C compared to Figure 10A, 
each DL storing area in a spare DL storing area may be shifted toward the inner periphery by a used area in a spare 
DL storing area. 

[0086] As described above, when defect management areas (DMAm [m = 1 , 2, 3, 4]) in a reference layer and spare 
DL storing area (spare DLm) in a recording layer(s) other than the reference layer are located at substantially the same 
20 radial positions, it is possible to access a defect list in a short time even if the defect list is stored in a spare DL storing 
area (spare DLm). 

[0087] The multi-layered information recording medium 600 according to Embodiment 1 of the present invention has 
been heretofore described. 

[0088] As described above, in the multi-layered information recording medium 600 according to Embodiment 1 of 
25 the present invention comprising a plurality of recording layers, defect management information relating to all of the 
recording layers is stored in a single recording layer. Therefore, it is possible to read out the defect management 
information more simply and rapidly. 

[0089] In the multi-layered information recording medium 600 according to Embodiment 1 of the present invention, 
all defect management information relating to a plurality of recording layers is stored in a reference layer. Therefore, 
30 even if a larger number of defective areas are intensively present in one recording layer, it is possible to use a defect 
entry area efficiently. 

[0090] In the multi-layered information recording medium 600 according to Embodiment 1 of the present invention, 
a spare DL storing area is provided in a recording layer other than a reference layer. Therefore, it is possible to signif- 
icantly improve the reliability of defect management information of defects due to degradation of medium material. 
35 [0091] In the multi-layered information recording medium 600 according to Embodiment 1 of the present invention, 
a spare DL storing area is placed within a predetermined error range from the radial position of a defect management 
area in a reference layer. Therefore, it is possible to reduce an access time required to read a spare DL storing area 
after reading a DDS area. 

[0092] Note that Embodiment 1 shows an opposite path disc in which recording and reproduction are performed 
40 from the inner periphery to the outer periphery of the first recording layer 51 and from the outer periphery to the inner 
periphery of the second recording layer 52, though a parallel path disc can be similarly managed in which recording 
and reproduction are performed from the inner periphery to the outer periphery in all recording layers. The arrangement 
of recording layers is not particularly limited as long as a defect management area and a spare DL storing area are 
located near each other. Therefore, the arrangement may be slightly adjusted depending on the difference in a recording 
45 and reproduction direction between an opposite path disc and a parallel path disc. For example, in an opposite path 
disc, a second recording layer is accessed from the outer periphery to the inner periphery. Therefore, a spare DL storing 
area in the second recording layer may be placed closerto the inner periphery than a defect management area provided 
on the inner periphery. 

[0093] Note that in the case of a multi-layered information recording medium having at least three recording layers, 
50 the multi-layered information recording medium may store DL storing area management information in orderto manage 
the statuses of DL storing areas in a defect management area and a spare DL storing area. An example of DL storing 
area management information is such that a value 0 is set when the DL storing area is unused, a value 1 is set when 
the DL storing area is used, and a value 2 is set when the DL storing area is determined to be defective. By storing 
such information for managing each DL storing area in a DDS area, the DL storing areas can be efficiently managed. 
55 [0094] Note that in Embodiment 1 a reference layer is the upper recording layer of a plurality of recording layer in 
the figures, though the reference layer is not so limited and may be any of the recording layers uniquely determined 
under a predetermined rule. For example, a reference layer may be a recording layer of a plurality of recording layers 
which is located at the shortest distancef rom the data read-out surface of a multi-layered information recording medium, 



13 



EP 1 329 888 A1 

or a recording layer which is located at the longest distance from the data read-out surface. 

[0095] Note that in Embodiment 1 the multi-layered information recording medium 600 comprising two recording 
layers is described, though an information recording medium may comprise a larger number (at least 3) of recording 
layers. In either multi-layered recording medium, a defect management area is provided in any one of recording layers 
5 while a spare DL storing area is provided in other recording layers. 

(Embodiment 2) 

[0096] Next, a multi-layered information recording medium according to Embodiment 2 of the present invention will 

10 be described with reference to the accompanying drawings. 

[0097] Figure 11 is a diagram showing a multi-layered information recording medium 800 according to Embodiment 
2 of the present invention. The multi-layered information recording medium 800 of Embodiment 2 comprises a first 
recording layer 53 and a second recording layer 54. In the first recording layer 53 and the second recording layer 54, 
defect management areas and spare DL storing areas are arranged in a manner similar to that in the first recording 

15 layer 51 and the second recording layer 52 shown in Embodiment 1 . The multi-layered information recording medium 
800 is different from the multi-layered information recording medium 600 of Embodiment 1 in that in the multi-layered 
information recording medium 800, the first recording layer 53 contains a head spare area 1101 and an intermediate 
spare area 1 1 02, and the second recording layer 54 contains an intermediate spare area 1 1 02' and an end space area 
1103. The sizes of these spare areas can be separately determined, however, for the sake of simplicity, it is assumed 

20 that all spare areas have the same size (the size is indicated by the spare area size 71 3 (Figure 1 2)). A data area 1 1 00 
is an area which contains a user data area 602 and the above-described spare areas. Hereinafter, features of the multi- 
layered information recording medium 800 different from the multi-layered information recording medium 600 will be 
described. 

[0098] The head spare area 1101, the intermediate spare area 1102, the intermediate spare area 1102', and the 
25 end space area 1103 contain a replacement area. When a defective area is detected in the user data area 602, the 
replacement area may be used in place of the defective area. A defective area is herein a defective sector. A defective 
area A 1 1 1 0 and a defective area B 1 1 1 2 each are a defective area in which user data cannot be appropriately recorded 
and reproduced. The defective area A 1110 is replaced with a replacement area A 1111 containing the intermediate 
spare area 1102. As a result, user data which was to be recorded in the defective area A 1110 is recorded in the 
30 replacement area A 1 1 1 1 . Similarly, in a read operation, user data is read from the replacement area A 1 1 1 1 but not 
from the defective area A 1110. Similarly, a defective area B 1112 in the second recording layer 54 is replaced with a 
replacement area B 1 1 1 3 containing the head spare area 1 1 01 in the first recording layer 53. 

[0099] Next, the contents of defect management information in Embodiment 2 will be described with reference to 
Figure 12. Figure 12 shows locations of areas in a first defect management area 611 (DMA1). Hereinafter, only features 

55 of the first defect management area 611 (DMA1) of Embodiment 2 different from Embodiment 1 will be described. A 
defect list 1209 stored in the second DL storing area 702 contains two defect entries, i.e., a defect entry A 1201 and 
a defect entry B 1 202. The defect entry A 1 201 is information indicating that the defective area A 1 1 1 0 of Figure 1 1 is 
replaced with the replacement area A 1111. On the other hand, the defect entry B 1202 stores information indicating 
that the defective area B 1112 of Figure 11 is replaced with the replacement area B 1113. Therefore, a replacement 

40 status flag contained in the defect entry A 1201 and a replacement status flag contained in the defect entry B 1202 
each are 0. This is because a replacement status flag has a value 0 when a corresponding defective area is replaced 
with a replacement area, and has a value 1 when the defective area is not replaced and is registered. A defective 
sector layer number and a defective sector number indicate a number which permits to identify a recording layer and 
a sector number which permits to uniquely determine the location of a sector in a recording layer, respectively, as in 

45 Embodiment 1. The defective area A 1110 and its replacement area B 1111 are both contained in the first recording 
layer 53, and therefore, a defective sector layer number 735 and a replacement sector layer number 737 contained in 
the defect entry A 1201 both indicate 1 . On the other hand, the defective area B 1112 is contained in the second 
recording layer 54, and the replacement area B 1 1 1 3 is contained in the first recording layer 53. Therefore, a defective 
sector layer number 740 contained in the defect entry B 1202 indicates a value 2 representing the second recording 

50 layer 54, and a replacement sector layer number 742 indicates a value 1 representing the first recording layer 53. Note 
that the replacement sector numbers 737 and 742 represent a sector number which uniquely determines the starting 
position of a replacement area in a recording layer as do the defective sector numbers 735 and 740. 
[0100] In Embodiment 2, the defective area B 11 12 in the second recording layer 54 is replaced with the replacement 
area B 1113 in the first recording layer 53. It is now assumed that, for example, a total of 1000 defective sectors can 

55 be present in two recording layers. If defect management was performed separately for each recording layer, a spare 
area(s) corresponding to at least 1 000 sectors has to be allocated in each recording layer. In other words, a spare area 
(s) corresponding to a total of at least 2000 sectors is required for two recording layers. On the other hand, in Embod- 
iment 2, a defect list for all recording layers is stored in a unified manner while a defective area in a certain recording 



14 



EP 1 329 888 A1 



layer can be replaced with a spare area in another recording layer. Therefore, in the present invention, a spare area 
(s) corresponding to a total of 1000 sectors is required for the two recording layers (e.g., 500 sectors are provided in 
each of the two recording layers). Therefore, the volume of an area allocated as a spare area can be reduced, thereby 
making it possible to increase the volume of the user data area 602. 
5 [0101] The multi-layered information recording medium 800 according to Embodiment 2 of the present invention has 
been heretofore described. 

[0102] As described above, the multi-layered information recording medium 800 according to Embodiment 2 of the 
present invention will be described below in terms of its effects in addition to the effects of the present invention de- 
scribed in Embodiment 1. 

10 [0103] Defect management information relating to all recording layers contained in a multi-layered information re- 
cording medium is managed by a single defect list, thereby making it possible to replace a defective area in a certain 
layer with a replacement area in a different layer. Therefore, even if defective areas occur intensively in a certain 
recording layer and all spare area in this layer are exhausted, spare areas in other recording layers can be used for 
replacement. Therefore, even if defective areas occur intensively in a specific recording layer due to degradation of a 

*5 medium material or the like, spare areas in all recording layers can be efficiently used and the reliability of recorded 
data can be achieved. It is clearly appreciated that a method of using a spare DL in Embodiment 2 is the same as that 
in Embodiment 1 , though a description thereof is omitted. 

[01 04] Note that the disc medium of Embodiment 2 is an opposite path disc in which recording and reproduction are 
performed from the inner periphery to the outer periphery of the first recording layer 53 and from the outer periphery 
20 to the inner periphery of the second recording layer 54. Similarly, in a parallel path disc in which recording and repro- 
duction are performed from the inner periphery to the outer periphery in all recording layers, defective areas can be 
similarly managed. 

(Embodiment 3) 

25 

[01 05] Hereinafter, an information recording/reproduction apparatus 500 according to Embodiment 3 of the present 
invention will be described with reference to the accompanying drawings. The information recording/reproduction ap- 
paratus 500 performs recording and reproduction using the multi-layered information recording mediums 600 and 800 
described in Embodiments 1 and 2, respectively. 

30 [0106] Figure 13 is a block diagram showing the information recording/reproduction apparatus 500 according to 
Embodiment 3 of the present invention. The information recording/reproduction apparatus 500 comprises a disc motor 
502, a preamplifier 508, a servo circuit 509, a binarization circuit 510, a modulation/demodulation circuit 511 , an ECC 
circuit 51 2, a buffer 51 3, a CPU 514, an internal bus 534, and an optical head section 535. In the information recording/ 
reproduction apparatus 500, the multi-layered information recording medium 800 is loaded. The optical head section 

55 535 comprises a lens 503, an actuator 504, a laser driving circuit 505, a photodetector 506, and a transport table 507. 
Reference numeral 520 denotes a rotation detection signal. Reference numeral 521 denotes a disc motor driving signal. 
Reference numeral 522 denotes a laser emission permission signal. Reference numeral 523 denotes a light detection 
signal. Reference numeral 524 denotes a servo error signal. Reference numeral 525 denotes an actuator driving signal. 
Reference numeral 526 denotes a transport table driving signal. Reference numeral 527 denotes an analog data signal. 

40 Reference numeral 528 denotes a binarized data signal. Reference numeral 529 denotes a demodulated data signal. 
Reference numeral 530 denotes a corrected data signal. Reference numeral 531 denotes a stored data signal. Ref- 
erence numeral 532 denotes an encoded data signal. Reference numeral 533 denotes a modulated data signal. 
[0107] The CPU 514 functions as a control section. The CPU 514 controls the entire operation of the information 
recording/reproduction apparatus 500 via the internal bus 534 according to an incorporated control program. As de- 

45 scribed below, the optical head section 535 can optically write information in the multi-layered information recording 
medium 800 from one side of the multi-layered information recording medium 800. The optical head section 535 can 
optically read information from the multi-layered information recording medium 800. The CPU 514 controls execution 
of a defect management process using the optical head section 535 as described below. 

[0108] In response to the laser emission permission signal 522 output from the CPU 514, the laser driving circuit 
so 505 emits laser light 536 onto the multi-layered information recording medium 800. The light reflected by the multi- 
layered information recording medium 800 is converted by the photodetector 506 to the light detection signal 523. The 
light detection signal 523 is subjected to addition/subtraction in the preamplifier 508 so as to generate the servo error 
signal 524 and the analog data signal 527. The analog data signal 527 is A/D (analog/digital) converted by the binari- 
zation circuit 510 to the binarized data signal 528. The binarized data signal 528 is demodulated by the modulation/ 
55 demodulation circuit 51 1 to generate the demodulated data signal 529. The demodulated data signal 529 is converted 
by the ECC circuit 512 to the corrected data signal 530 which does not include any error. The corrected data signal 
530 is stored in a buffer 513. The servo circuit 509 outputs the actuator driving signal 525 based on the servo error 
signal524, thereby feeding a servo error back to the actuator 504 for focusing control or tracking control of the lens 



15 



EP 1 329 888 A1 



503. An error correction code is added by the ECC circuit 512 to the stored data signal 531 which is an output of data 
from the buffer 513, so as to generate the encoded data signal 532. Then, the encoded data signal 532 is modulated 
by the modulation/demodulation circuit 51 1 to generate the modulated data signal 533. The modulated data signal 533 
is input to the laser driving circuit 505 so as to modulate the power of laser light. 

5 [0109] The information recording/reproduction apparatus 500 may be used as a peripheral device for a computer, 
such as a CD-ROM drive or the like, along with the computer. In such a case, a host interface circuit (not shown) is 
additionally provided, and data is transmitted between a host computer (not shown) and the buffer 513 through a host 
interface bus (not shown) such as a SCSI or the like. Alternatively, if the information recording/reproduction apparatus 
500 is used as a consumer device, such as a CD player or the like, along with an AV system, an AV decoder/encoder 

10 circuit (not shown) is additionally provided so as to compress a moving image or sound or decompress a compressed 
moving image or sound and the resultant data is transmitted between the host computer and the buffer 513. 
[0110] In a reproduction operation of the information recording/reproducing apparatus 500 according to Embodiment 
3 of the present invention, it is necessary to provide two processes, a process of obtaining defect management infor- 
mation and a process of reproducing sectors while considering replacement, in order to reproduce information recorded 

15 in the multi-layered information recording medium 800 comprising two recording layers to which defect management 
of the present invention is applied. 

[0111] In a recording operation of the information recording/reproducing apparatus 500 according to Embodiments 
of the present invention, it is necessary to provide, in addition to the above reproduction operation, two processes, a 
process of updating defect management information and a process of recording sectors while considering replacement, 
20 in order to record information in the multi-layered information recording medium 800 comprising two recording layers 
to which defect management of the present invention is applied. 

[0112] Hereinafter, an operation of the recording/reproduction apparatus 500 of Embodiment 3 will be described, in 
which recording and reproduction are performed on the multi-layered information recording medium 800 of Embodiment 
2 using defect management as described with reference to, mainly, Figures 11 and 12. A high level apparatus, such 

25 as a host computer or the like, outputs location information specifying an area which recording and reproduction are 
to be performed, which information is represented by a logical sector number (LSN). Physical location information on 
the recording medium is represented by physical sector numbers (PSNs). It is now assumed that a PSN contains a 
sector layer number indicating a layer in which a sector is present, and a sector number with which it is possible to 
identify the location of a sector in a layer in which the sector is present. 

30 [0113] Figure 14 shows a flowchart 1400 for illustrating a procedure of obtaining defect management information in 
Embodiment 3 of the present invention. 

[0114] At the first step of the process of obtaining defect management information, i.e., at step 1401 , the CPU 514 
instructs the servo circuit 509 to control the focal point of laser light so as to follow a track in a reference layer. 
[0115] At step 1402, the optical head section 535 reproduces a sector which stores disc information, and the CPU 
55 51 4 confirms parameters and a format which are necessary for recording/reproduction of the multi-layered information 
recording medium 800. 

[0116] At step 1403, the optical head section 535 reproduces a DDS area 700 stored in a reference layer. The 
reproduced DDS data is retained in a predetermined place of the buffer 513. 

[0117] At step 1404, the CPU 514 determines whether or not a DL starting layer is present in a reference layer, by 
40 referencing a DL start sector layer number 71 1 in the DDS data within the buffer 51 3. If the DL starting layer is present 
in the reference layer, the process proceeds to step 1406. If the DL starting layer is present in a recording layer other 
than the reference layer, the process proceeds to step 1405. 

[01 1 8] At step 1 405, the CPU 51 4 instructs the servo circuit 509 to control the focal point of laser light so as to follow 
a track in a recording layer indicated by the DL start sector layer number 711 . 

45 [0119] At step 1406, the optical head section 535 reads a predetermined size portion of a defect list from a sector 
indicated by the DL start sector number 71 2. The read defect list is retained at a predetermined place in the buffer 513. 
[0120] Figure 15 is a flowchart 1500 for illustrating a reproduction procedure of sectors according to Embodiment 3 
of the present invention, wherein replacement is considered. In this reproduction process, assume that defect man- 
agement information including DDS data and a defect list have already been retained in the buffer 513. 

50 [0121] At the first step of this reproduction process, i.e., at step 1501 , the CPU 51 4 converts LSNs, which are assigned 
to respective areas to be reproduced, to PSNs (detailed descriptions of this step will be described later with reference 
to Figure 16). 

[01 22] At step 1 502, the CPU 51 4 references to the layer number of the PSN of an area to be reproduced to determine 
whether or not a recording layer in which the focal point of laser light currently exists is identical to a recording layer 
55 to be reproduced. If identical, the process proceeds to step 1504; if not, the process proceeds to step 1503. 

[01 23] At step 1 503, the CPU 51 4 instructs the servo circuit 509 to control the focal point of the laser light 536 so as 
to follow a track in a recording layer to be reproduced. 

[0124] At step 1504, the optical head section 535 reproduces information recorded in a sector indicated by the PSN 



16 



EP 1 329 888 A1 



obtained at conversion step 1501 . 

[0125] Figure 16 is a flowchart 1600 for illustrating a procedure of converting LSNsto PSNs (i.e., step 1501 of Figure 
15) according to Embodiment 3 of the present invention. 

[01 26] At the first step 1 601 of this conversion process, LSN is converted to PSN without considering the presence 
5 or absence of replacement, i.e., in a manner similar to when no defective sector is present. Referring to Figure 11, 
when the value of the ordinal level of a LSN to be converted is smaller than the number of sectors in the first user data 
area 15, 

10 PSN = (Smallest PSN in the first user data area 15)+LSN. 

[0127] When the value of the order of a LSN to be converted is greater than the total number of sectors in the first 
user data area 15, 

15 

PSN = (Smallest PSN in the second user data area 16)+LSN-(the 
total number of sectors in the first user data area 1 5). 

20 [01 28] Note that since the multi-layered information recording medium 800 of Figure 1 1 has an opposite path track, 
a sector in the second user data area 16 to which the smallest PSN is assigned is located at the outermost perimeter 
portion of the second user data area 16 (i.e., being adjacent to the intermediate spare area 1002'). 
[0129] At step 1 602, the CPU 514 references defect entry data in a defect list to determine whether or not the PSN 
obtained in the above-described step matches a defective sector layer number and a defective sector number stored 

25 in the defect list. If registered, the process proceeds to step 1603; if not (i.e., no replacement), the process ends. 

[0130] At step 1603, the CPU 514 selects a replacement sector layer number and a replacement sector number 
indicated by a defect entry (i.e., a defective sector layer number and a defective sector number) indicating the PSN 
from defect entry data registered in the defect list. 

[0131] Note that when data is reproduced from the multi-layered information recording medium 600 (Figure 6) having 
30 no spare area, the process indicated by step 1603 is omitted or the processes indicated by steps 1602 and 1603 are 
omitted. 

[01 32] As described above, the information recording/reproduction apparatus 500 according to Embodiment 3 of the 
present invention can reproduce data fromamulti-layered information recording medium containing a defect manage- 
ment area. The reproduction operation of user data which is performed after the focal point of the laser light 536 has 

35 been moved to a recording layer to be accessed, is basically the same as the reproduction operation of user data 
performed for a single-layered information recording medium. Thus, it is clearly appreciated that any reproduction 
procedure for an information recording/ reproducing apparatus designed for a single-layered disc can be used. 
[0133] Figure 17 is a flowchart for illustrating a procedure of updating defect management information according to 
Embodiment 3 of the present invention. In this embodiment, as an example of a formatting process for a multi-layered 

40 information recording medium, initialization and updating of defect management information will be described. 

[0134] At the first step 1701 of the updating process, the CPU 514 produces DDS data having predetermined defi- 
nition values for a recording/reproduction apparatus and a defect list containing a DL header 720 in which the number 
of DL entries is set to be 0, in the buffer memory 513. In this case, a DL start sector layer number 71 1 and a DL start 
sector number 712 in a DDS 700 before a formatting process (Figure 12) are set in a newly produced DDS. 

45 [0135] At step 1702, it is determined whether or not a recording layer indicated by the DL start sector layer number 
712 is identical to a recording layer currently followed by the focal point of the laser light 536. If identical, the process 
proceeds to step 1 704; if not, the process proceeds to step 1 703. 

[0136] At step 1703, the CPU 514 instructs the servo circuit 509 to control the focal point of the laser light 536 so as 
to follow a track in a recording layer indicated by the DL start sector layer number 71 1 . 
50 [01 37] At step 1 704, the CPU 51 4 records a newly produced defect list in an area having a predetermined size which 
starts with a sector number indicated by the DL start sector number 712. In this case, when a defect list has been 
previously recorded in the area indicated by the DL start sector number 712 (e.g., the defect list 1209 (Figure 12)), the 
previously recorded defect list is updated to a newly produced defect list. 

[0138] At step 1705, the CPU 514 determines whether or not data is correctly recorded in a DL storing area. If 
55 correctly recorded, the process proceeds to step 1707. If not (the area is not usable), the process proceeds to step 
1 706. The determination of the correctness of data recording is carried out by reading data recorded in the DL storing 
area and judging whether or not the read data is identical to data to be recorded. 

[0139] At step 1 706, the CPU 514 selects another usable DL storing area. Initially, the CPU 514 determines whether 



17 



EP 1 329 888 A1 



or not a defect management area (or a spare DL) of a recording layer, in which data is currently recorded, contains a 
usable DL storing area. In the same recording layer, a DL storing area having a radial position close to that of a currently 
used DL storing area is selected. If no DL storing area is usable in the same recording layer, the CPU 514 selects a 
usable DL storing area containing an unused spare DL storing area in an adjacent recording layer. The CPU 514 
5 records a defect list, which has the same contents as those of a defect list stored in a DL storing area which has been 
determined to be unusable, in a newly selected DL storing area. 

[01 40] At step 1 707, the CPU 51 4 determines whether or not a track currently followed by the focal point of the laser 
light 536 is of the reference layer. If so, the process proceeds to step 1 709; if not, the process proceeds to step 1 708. 
[01 41 ] At step 1 708, the CPU 51 4 instructs the servo circuit 509 to control the focal point of the laser light 536 so as 
10 to follow a track in the reference layer. 

[0142] At step 1709, the CPU 514 records the starting PSN of a DL area (containing a DL storing area selected in 
step 1706), in which a defect list is recorded, in DDS data produced in the buffer memory 513. Specifically, a DL start 
sector layer number 712 and a DL start sector number 712 are updated. 

[0143] At step 1710, the CPU 514 records the DDS data produced in the buffer memory 513 in a DDS area of a 
15 multi-layered information recording medium using the optical head section 535. 

[0144] Note that in Embodiment 3, at step 1 704, an area in which a defect list is recorded is not limited to a defect 

list storing area before a formatting process. It is clearly appreciated that, for example, all defect list storing areas 

before a formatting process may be made invalid, and the CPU 514 may record a defect list in a newly designated area. 

[01 45] Figure 1 8 is a flowchart 1 800 for illustrating a recording procedure according to Embodiment 3 of the present 
20 invention, wherein replacement is considered. 

[0146] At the first step 1801 of this recording process, the CPU 514 converts LSNs, which specify sectors in which 

data is to be recorded, to PSNs (see Figure 21). 

[0147] At step 1802, the CPU 514 references to the layer number of a PSN to determine whether or not a recording 
layer currently followed by the focal point of the laser light 536 is identical to a recording layer in which data is to be 
25 recorded. If identical, the process proceeds to step 1 804; if not, the process proceeds to step 1 803. 

[0148] At step 1803, the CPU 514 instructs the servo circuit 509 to control the focal point of the laser light 536 so as 
to follow a track in the recording layer in which data is to be recorded. 

[0149] At step 1804 ; the CPU 514 records data in a sector indicated by the PSN obtained at step 1801 using the 
optical head section 535. 

30 [0150] At step 1805, the CPU 514 determines whether or not the data recording was successful at step 1804. If 
successful, the process proceeds to step 1 807; if not, the CPU 514 determines that the sector in which it is attempted 
to record data is defective, and the process proceeds to step 1806. 

[0151] At step 1806, the CPU 514 allocates a spare sector for the sector which is determined to be defective. The 
CPU 514 replaces the defective area with an unused replacement area which contains a spare area at the shortest 

55 radial distance from the defective area and is present in a recording layer containing the defective area (in this case, 
the replacement area is a spare sector). For example, when the defective area is detected on the outer periphery of 
the first recording layer 53 (Figure 11), a replacement area is allocated from the first intermediate spare area 1102 
provided in the recording layer 53. If the intermediate spare area 11 02 in the first recording layer 53 contains no usable 
replacement area, a usable replacement area is allocated from the intermediate spare area 1102' of the second re- 

40 cording layer 54. If the intermediate spare area 1102' of the second recording layer 54 contains no usable replacement 
area, a usable replacement area is allocated from the head spare area 1101 of the first recording layer 53. In such a 
sequence, any one of spare areas in a multi-layered information recording medium is assigned as a replacement area. 
[0152] At step 1807, in the recording process, the CPU 514 determines whether or not a spare sector has been 
newly allocated at step 1806. If not, the recording process ends; if so, the process proceeds to step 1 808. 

45 [01 53] At step 1 808, the newly allocated replacement sector is registered in the defect list stored in the buffer memory 
513. In this case, if the defective sector is already registered in the defect list, only a replacement sector layer number 
and a replacement sector number are updated. On the other hand, if a new defective sector is detected, the detected 
defective sector is added to the defect list. 

[0154] When data is recorded in the multi-layered information recording medium 600 (Figure 6) containing no spare 
50 area, the process indicated by step 1806 is omitted. In this case, information which is used to manage the detected 
defective sector is registered in the defect list. 

[01 55] As described above, the information recording/reproduction apparatus 500 according to Embodiment 3 of the 
present invention can record data in a multi-layered information recording medium having a defect management area. 
In the present invention, a spare sector can be allocated from a spare area provided in a recording layer different from 
55 a recording layer in which a defective sector is present. The information recording/reproduction apparatus 500 can 
allocate spare sectors in a manner that gives a greater weight to reduction of a seek time or in a manner that gives a 
greater weight to reduction of the time required for setting recording power. The recording operation of user data to 
the user data area which is performed after the focal point of laser light has been moved to a recording layer to be 



18 



EP 1 329 888 A1 



accessed, is basically the same as the recording operation of user data performed for a single-layered information 
recording medium. Thus, it is clearly appreciated that any recording procedure for an information recording/reproducing 
apparatus designed for a single-layered disc can be used. 

[0156] Although in the above descriptions of the present invention, reproduction/recording of information and defect 
5 management are performed on a sector- by-sector basis, it is clearly appreciated that the present invention is applicable 
even when reproduction/recording of information and defect management is performed on a block-by-block basis (a 
block contains a plurality of sectors), or on an ECC block-by-ECC block basis (an ECC block is a unit based on which 
an error correction code of, for example, a DVD disc is calculated). Such a modified embodiment is made within the 
spirit and applicable range of the present invention, and any modified embodiment which is readily appreciated by 
10 those skilled in the art, falls within the scope of the claims of the present invention. 

(Embodiment 4) 

[0157] Next, a multi-layered information recording medium according to Embodiment 4 of the present invention will 

15 be described with reference to the accompanying drawings. 

[0158] Figure 19 is a diagram showing a multi-layered information recording medium 1900 according to Embodiment 
4 of the present invention. The multi-layered information recording medium 1900 comprises two recording layers 55 
and 56. The multi-layered information recording medium 1900 comprises a user data area 1903 for recording user 
data. In Embodiment 4 of the present invention, the upper recording layer (55) shown in Figure 19 is referred to as a 

20 first recording layer, and the lower recording layer (56) is referred to as a second recording layer. 

[0159] The first recording layer 55 is located at a predetermined distance from a surface of the multi-layered infor- 
mation recording medium 1900 through which data is read out (data read-out surface). The first recording layer 55 is 
referred to as a reference layer. This predetermined distance is equal to a distance from the data read-out surface of 
an optical disc comprising only one recording layer to the recording layer. A reference layer is predetermined among 

25 a plurality of recording layers. 

[0160] The first recording layer 55 contains, from the inner periphery to the outer periphery along the recording/ 
reproduction direction of the multi-layered information recording medium 1 900, a lead-in area 1 901 , a head spare area 
1902, and a first user data area 1931 which is a portion of the user data area 1903. The second recording layer 56 
contains, from the outer periphery to the inner periphery along the recording/reproduction direction of the multi-layered 

30 information recording medium 1900, a second user data area 1932 which is a portion of the user data area 1903, an 
end spare area 1904, and a lead-out area 1905. 

[0161] The lead-in area 1901 contains a control data area 1911 for storing control information for the multi-layered 
information recording medium 1900, and a first defect management area 1912 (DMA1) and a second defect manage- 
ment area 1913 (DMA2) for recording defect management information relating to a defective area. The head spare 

55 area 1902 and the end spare area 1904 contain a replacement area which may be used in place of a defective area 
in the user data area 1903. The lead-out area 1905 contains a third defect management area 1921 (DM A3) and a 
fourth defect management area 1922 (DMA4) for recording defect management information relating to a defective 
area. The first defect management area 1912 (DMA1), the second defect management area 1913 (DMA2), the third 
defect management area 1921 (DMA3), and the fourth defect management area 1922 (DMA4) each store the same 

40 defect management information. This is because by duplicately recording the same defect management information 
in a plurality of areas in the multi-layered information recording medium 1900, the reliability of the defect management 
information is improved. 

[01 62] The user data area 1 903 contains a first user data area 1 931 and a second user data area 1 932. A defective 
area A 1915 is present in the first user data area 1931. A defective area B 1924 is present in the second user data 
45 area 1932. The defective area A 1915 is replaced with a replacement area A 1914. The defective area B 1924 is 
replaced with a replacement area B 1923. 

[0163] The multi-layered information recording medium 1900 according to Embodiment 4 of the present invention 
contains four defect management areas having the same contents, thereby making it possible to obtain the reliability 
of defect management information. All of the four defect management areas are provided intensively on the inner 

50 periphery of the multi-layered information recording medium 1900, thereby making it possible to minimize a distance 
over the optical head section is moved. According to this feature, the time required for the initial process of the multi- 
layered information recording medium 1900 can be advantageously reduced. Further, no defect management area is 
provided on the outer periphery, and therefore, the entire outer periphery of the multi-layered information recording 
medium 1900 can be used as a user data area. Therefore, a larger user data capacity can be obtained. 

55 [0164] A data structure of the first defect management area 1912 will be described with reference to Figure 20. As 
described above, the first defect management area 1912 (DMA1), the second direct management area 1913 (DMA2), 
the third defect management area 1921, and the fourth direct management area 1922 each have the same defect 
management information. Here, only the first defect management area 1912 will be described and a description of the 



19 



EP 1 329 888 A1 



other defect management areas is omitted. 

[0165] Figure 20 shows a data structure of the first defect management area 1912. A DDS area 2000, first to fourth 
DL storing areas 2001 to 2004, and a DL header area 2020 have the same data structure as that of the DDS area 700, 
the first to fourth DL storing areas 701 to 704, and the DL header area 720, respectively, shown in Figure 7, and a 
5 description thereof is omitted. Here, a defect entry A 2021 and a defect entry B 2022 contained in a defect list 2009 
will be described. 

[0166] The defect entry A 2021 contains defect management information relating to a defective area A 1915 (Figure 
19). The defective area A 1915 is replaced with a replacement area A 1914. Therefore, a replacement status 734 
contained in the defect entry A 2021 indicates 0 which means the presence of replacement. Since the defective area 

10 A 1 91 5 is present in the first recording layer 55, a defective sector layer number 735 indicates a value 1 which means 
the first recording layer 55. A defective sector number 736 indicates an identification number which permits to uniquely 
identify the defective area A 1915 in the first recording layer 55. Similarly, since the replacement area A 1914 is present 
in the first recording layer 55, a replacement sector layer number 737 indicates a value 1 . A replacement sector number 
738 indicates an identification number which permits to uniquely identify the replacement area A 1914 in the first 

15 recording layer 55. 

[0167] The defect entry B 2022 contains defect management information relating to a defective area B 1924 (Figure 
19). The defective area B 1924 is replaced with a replacement area B 1923. Therefore, a replacement status 739 
contained in the defect entry B 2022 indicates 0 which means the presence of replacement. Since the defective area 
B 1924 is present in the second recording layer 56, a defective sector layer number 741 indicates a value 2 which 

20 means the second recording layer 56. A defective sector number 741 indicates an identification number which permits 
to uniquely identify the defective area B 1924 in the second recording layer 56. Similarly since the replacement area 
B 1923 is present in the second recording layer 56, a replacement sector layer number 742 indicates a value 2. A 
replacement sector number 743 indicates an identification number which permits to uniquely identify the replacement 
area B 1923 in the second recording layer 56. 

25 [0168] As described above, according to the multi-layered information recording medium 1900 of Embodiment 4, a 
larger user data capacity is obtained and the performance of reading defect management information can be improved. 
[01 69] Note that the disc medium of Embodiment 4 is an opposite path disc in which recording and reproduction are 
performed from the inner periphery to the outer periphery of the first recording layer 55 and from the outer periphery 
to the inner periphery of the second recording layer 56. Similarly, in a parallel path disc in which recording and repro- 

30 duction are performed from the inner periphery to the outer periphery in all recording layers, defective areas can be 
managed. 

[0170] Note that in Embodiment 4, two spare areas, i.e., the head spare area 1902 and the end space area 1904 
are provided in the multi-layered information recording medium 1900, however either or both of them may be omitted. 
[0171] Note that in Embodiment 4, for the sake of simplicity, the multi-layered information recording medium 1900 
55 having two recording layers has been described, however, even in the case of a multi-layered information recording 
medium having at least three recording layers, the above-described effect is obtained if a defect management area is 
provided on the inner periphery of a reference layer and the inner periphery of a recording layer other than the reference 
layer. 

[0172] In the case of a multi-layered information recording medium having at least three recording layers, a defect 
40 management area may be provided on the inner peripherys of all recording layers other than the reference layer. 

(Embodiment 5) 

[0173] Next, a multi-layered information recording medium according to Embodiment 5 of the present invention will 

45 be described with reference to the accompanying drawings. 

[0174] Figure 21 is a diagram showing a multi-layered information recording medium 2100 according to Embodiment 
5 of the present invention. The multi-layered information recording medium 2100 comprises two recording layers 57 
and 58. The multi-layered information recording medium 2100 contains a user data area 2103 for recording user data. 
The user data area 2103 straddles a boundary of the first and second recording layers 57 and 58. In Embodiment 5 

50 of the present invention, the upper recording layer (57) shown in Figure 21 is referred to as a first recording layer, and 
the lower recording layer (58) is referred to as a second recording layer. 

[0175] The first recording layer 57 is located at a predetermined distance from a surface of the multi-layered infor- 
mation recording medium 2100 through which data is read out (data read-out surface). The first recording layer 57 is 
referred to as a reference layer. This predetermined distance is equal to a distance from the data read-out surface of 
55 an optical disc comprising only one recording layer to the recording layer. A reference layer is predetermined among 
a plurality of recording layers. 

[0176] The first recording layer 57 contains, from the inner periphery to the outer periphery along the recording/ 
reproduction direction of the multi-layered information recording medium 2100, a lead-in area 2101, a head spare area 



20 



EP 1 329 888 A1 



2102, and a first user data area 2131 which is a portion of the user data area 2103. The second recording layer 58 
contains, from the inner periphery to the outer periphery along the recording/reproduction direction of the multi-layered 
information recording medium 2100, a second user data area 2132 which is a portion of the user data area 2103, an 
end spare area 2104, and a lead-out area 2105. 

5 [0177] The lead-in area 2101 contains a control data area 2111 for storing control information for the multi-layered 
information recording medium 2100, and a first defect management area 2112 (DMA1) and a second defect manage- 
ment area 2113 (DMA2) for recording defect management information relating to a defective area. The head spare 
area 2102 and the end spare area 2104 contain a replacement area which may be used in place of a defective area 
in the user data area 2103. The lead-out area 2105 contains a third defect management area 2121 (DMA3) and a 

10 fourth defect management area 2122 (DMA4) for recording defect management information relating to a defective 
area. The first defect management area 2112 (DMA1), the second defect management area 2113 (DMA2), the third 
defect management area 2121 (DMA3), and the fourth defect management area 2122 (DMA4) each store the same 
defect management information. This is because by duplicately recording the same defect management information 
in a plurality of areas in the multi-layered information recording medium 2100, the reliability of the defect management 

15 information is improved. 

[0178] The user data area 2103 contains a first user data area 2131 and a second user data area 2132. A defective 
area A 2115 is present in the first user data area 2131. A defective area B 2124 is present in the second user data 
area 2132. The defective area A 2115 is replaced with a replacement area A 2114. The defective area B 2124 is 
replaced with a replacement area B 2123. 

20 [0179] The multi-layered information recording medium 2100 according to Embodiment 5 of the present invention 
contains defect management areas on the inner periphery in the first recording layer 57 while containing direct man- 
agement areas on the outer periphery in the second layer 58, thereby dramatically improving the possibility that any 
direct management area on either the inner periphery or the outer periphery can be used for reproduction even if a 
stain (e.g., a fingerprint or the like) or a scratch is present on the multi-layered information recording medium 2100; 

25 and making it possible to obtain the reliability of defect management information. Defect management areas are pro- 
vided on only one of the inner periphery and the outer periphery of each recording layer, thereby obtaining a larger 
usable area as a user data area. Therefore, a larger user data capacity can be obtained. 

[0180] A data structure of the defect management area in Example 5 is the same as that of Example 4 described 

with reference to Figure 20, and a description thereof is omitted. 
30 [0181] As described above, according to the multi-layered information recording medium 2100 of Embodiment 5, 

the reliability of defect management information can be improved while a larger user data capacity is obtained. 

[0182] Note that the disc medium of Embodiment 5 is a parallel path disc in which recording and reproduction are 

performed from the inner periphery to the outer periphery of the first recording layer 57 and from the inner periphery 

to the outer periphery of the second recording layer 58. Similarly, in an opposite path disc in which recording and 
55 reproduction are performed from the inner periphery to the outer periphery in the recording layer 57 and from the outer 

periphery to the inner periphery in the recording layer 58, defective areas can be managed. 

[0183] Note that in Embodiment 5, two spare areas, i.e., the head spare area 2102 and the end space area 2104 
are provided in the multi-layered information recording medium 2100, however either or both of them may be omitted. 
If none of the spare areas are present in the multi-layered information recording medium 2100, a defect list is used to 

40 manage information relating to a defective area with no replacement area allocated. 

[0184] Note that in Embodiment 5, for the sake of simplicity, the multi-layered information recording medium 2100 
having two recording layers has been described, however, even in the case of a multi-layered information recording 
medium having at least three recording layers, the above-described effect is obtained if a defect management area is 
provided on the inner periphery of a reference layer and the inner periphery of a recording layer other than the reference 

45 layer. 

(Embodiment 6) 

[0185] Next, a multi-layered information recording medium according to Embodiment 6 of the present invention will 

50 be described with reference to the accompanying drawings. 

[01 86] Figure 22 is a diagram showing a multi-layered information recording medium 2200 according to Embodiment 
6 of the present invention. The multi-layered information recording medium 2200 comprises two recording layers 59 
and 60. The multi-layered information recording medium 2200 contains a user data area 2203 for recording user data. 
The user data area 2203 straddles a boundary of the first and second recording layers 59 and 60. In Embodiment 6 

55 of the present invention, the upper recording layer (59) shown in Figure 21 is referred to as a first recording layer, and 
the lower recording layer (60) is referred to as a second recording layer. 

[0187] The first recording layer 59 is located at a predetermined distance from a surface of the multi-layered infor- 
mation recording medium 2200 through which data is read out (data read-out surface). The first recording layer 59 is 



21 



EP 1 329 888 A1 



referred to as a reference layer. This predetermined distance is equal to a distance from the data read-out surface of 
an optical disc comprising only one recording layer to the recording layer. A reference layer is predetermined among 
a plurality of recording layers. 

[0188] The first recording layer 59 contains, from the inner periphery to the outer periphery along the recording/ 

5 reproduction direction of the multi-layered information recording medium 2200, a lead-in area 2201 , a head spare area 
2202, a first user data area 2231 which is a portion of the user data area 2203, a first intermediate spare area 2204, 
and a first lead-out area 2205. The second recording layer 60 contains, from the inner periphery to the outer periphery 
along the recording/reproduction direction of the multi-layered information recording medium 2200, a second lead-in 
area 2206, a second intermediate spare area 2207, a second user data area 2232 which is a portion of the user data 

10 area 2203, an end spare area 2208, and a second lead-out area 2209. 

[0189] The first lead-in area 2201 contains a control data area 2211 for storing control information for the multi- 
layered information recording medium 2200, and a first defect management area 2212 (DMA1) and a second defect 
management area 2213 (DMA2) for recording defect management information relating to a defective area. The head 
spare area 2202, the first spare area 2204, the second spare area 2207, and the end spare area 2104 contain a 

15 replacement area which may be used in place of a defective area in the user data area 2203. The first lead-out area 
2205 contains a third defect management area 2216 (DMA3) and a fourth defect management area 2217 (DMA4) for 
recording defect management information relating to a defective area. Similar to the first lead-in area 2201 , the second 
lead-in area 2206 contains a control data area 2211 for storing control information for the multi-layered information 
recording medium 2200, and a fifth defect management area 2221 (DMA5) and a sixth defect management area 2222 

20 (DMA6) for recording defect management information relating to a defective area. Similar to the first lead-out area 
2205, the second lead-out area 2209 contains a seventh defect management area 2223 (DMA7) and an eighth defect 
management area 2224 (DMA8) for recording defect management information relating to a defective area. The first 
defect management area 2212 (DMA1), the second defect management area 2213 (DMA2), the third defect manage- 
ment area 2216 (DM A3), the fourth defect management area 2217 (DMA4), the fifth defect management area 2221 

25 (DMA5), the sixth defect management area 2222 (DMA6), the seventh defect management area 2223 (DMA7), and 
the eighth defect management area 2224 (DM A8) each store the same defect management information . This is because 
by duplicately recording the same defect management information in a plurality of areas in the multi-layered information 
recording medium 2200, the reliability of the defect management information is improved. 

[01 90] The user data area 2203 contains a first user data area 2231 and a second user data area 2232. A defective 
30 area A 2215 is present in the first user data area 2231. A defective area B 2225 is present in the second user data 
area 2232. The defective area A 2215 is replaced with a replacement area A 2214. The defective area B 2225 is 
replaced with a replacement area B 2226. 

[0191] The multi-layered information recording medium 2200 according to Embodiment 6 of the present invention 
contains defect management areas on the inner periphery and the outer periphery in both the first recording layer 59 

55 and the second recording layer 60, thereby making it possible to obtain the reliability of defect management information. 
For example, the possibility that any direct management area on either the inner periphery or the outer periphery can 
be used for reproduction even if a stain (e.g., a fingerprint or the like) or a scratch is present on the multi-layered 
information recording medium 2100, is dramatically improved, thereby enhancing the reliability of defect management 
information. On the other hand, if a control circuit or an optical system is affected by variations in temperature inside 

40 a recording/reproduction apparatus, the degradation of the recording/reproduction apparatus over time, or the like, the 
ability of the apparatus to perform recording and reproduction with respect to a specific recording layer may be lowered. 
In such a situation, by storing a direct management area in all recording layers, it is possible to improve the reliability 
of defect management information. 

[0192] A data structure of the defect management area in Example 6 is the same as that of Example 4 described 
45 with reference to Figure 20, and a description thereof is omitted. 

[0193] As described above, according to the multi-layered information recording medium 2200 of Embodiment 6, 
the reliability of defect management information can be significantly improved. 

[0194] Note that the disc medium of Embodiment 6 is a parallel path disc in which recording and reproduction are 
performed from the inner periphery to the outer periphery of the first recording layer 59 and from the inner periphery 
50 to the outer periphery of the second recording layer 60. Similarly, in an opposite path disc in which recording and 
reproduction are performed from the inner periphery to the outer periphery in the recording layer 59 and from the outer 
periphery to the inner periphery in the recording layer 60, defective areas can be managed. 

[0195] Note that in Embodiment 6, four spare areas, i.e., the head spare area 2202, the first intermediate spare area 
2204, the second intermediate spare area 2207, and the end space area 2208, are provided in the multi-layered infor- 
ms mation recording medium 2200, however, any or all of them may be omitted. If none of the spare areas are present in 
the multi-layered information recording medium 2200, a defect list is used to manage information relating to a defective 
area with no replacement area allocated. 

[0196] Note that in Embodiment 6, for the sake of simplicity, the multi-layered information recording medium 2200 



22 



EP 1 329 888 A1 



having two recording layers has been described, however, even in the case of a multi-layered information recording 
medium having at least three recording layers, the above-described effect is obtained if a defect management area is 
provided on the inner periphery and the outer periphery of a reference layer and the inner periphery and the outer 
periphery of a recording layer other than the reference layer. 
5 [0197] According to the multi-layered information recording medium of the present invention, control information 
areas, such as an area for storing recording and reproduction parameters for the multi-layered information recording 
medium, an area for storing information relating to defect management, or the like, is provided in a single recording 
layer, thereby making it possible to access control information at high speed. 

[0198] According to the multi-layered information recording medium of the present invention, all defect management 
10 information for all recording layers is stored in a single recording layer, thereby making it possible to access defect 
management information at high speed. 

[0199] According to the multi-layered information recording medium of the present invention, a spare defect list stor- 
ing area is provided in a recording layer other than a recording layer storing defect management information, thereby 
making it possible to improve the reliability of defect management information. 
15 [0200] According to the multi-layered information recording medium of the present invention, a disc definition struc- 
ture area containing information indicating the location of a defect list and a spare defect list area which may store the 
defect list are located at substantially the same radial positions, thereby making it possible to access the defect list at 
high speed. 

[0201] According to the multi-layered information recording medium of the present invention, all defect lists in all 
20 recording layers are managed in a unified manner, thereby making it possible to efficiently use a defect list area even 
if the incidence of defective areas varies between each recording layer. 

[0202] According to the multi-layered information recording medium of the present invention, a detected defective 
area is replaced with a spare area in any recording layer, thereby making it possible to effectively use spare areas and 
improve the reliability of data. 

25 [0203] According to the multi-layered information recording medium of the present invention, a defect management 
area is provided on one of the inner periphery and the outer periphery of each recording layer, thereby making it possible 
to obtain a larger user data capacity. 

[0204] According to the information reproduction method and the information reproduction apparatus of the present 
invention, it is possible to reproduce information from a multi-layered information recording medium containing defect 
30 management information relating to a plurality of recording layer. 

[0205] According to the information recording method and the information recording apparatus of the present inven- 
tion, it is possible to record information in a multi-layered information recording medium containing defect management 
information relating to a plurality of recording layer. 

[0206] Various other modifications will be apparent to and can be readily made by those skilled in the art without 
55 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. 



Claims 

40 

1. A multi-layered information recording medium, comprising: 
a plurality of recording layers; 

a user data area for recording user data, provided in at least two of the plurality of recording layers; and 
45 a defect list storing area for storing a defect list, 

wherein when at least one defective area is detected in the user data area, the defect list is used to manage the 
at least one defective area. 

50 2. A multi-layered information recording medium according to claim 1 , further comprising: 

a defect list location information storing area for storing defect list location information indicating the location 
of the defect list storing area, 

55 wherein the defect list location information storing area is provided in one of the plurality of recording layers 

which is predetermined as a reference layer. 

3. A multi-layered information recording medium according to claim 2, wherein the reference layer is one of the 



23 



EP 1 329 888 A1 



plurality of recording layers which is located at a predetermined distance from the data read-out surface of the 
multi-layered information recording medium. 

. A multi-layered information recording medium according to claim 2, wherein the reference layer is one of the 
plurality of recording layers which is located at the shortest distance from the data read-out surface of the multi- 
layered information recording medium. 

. A multi-layered information recording medium according to claim 2, wherein the reference layer is one of the 
plurality of recording layers which is located at the longest distance from the data read-out surface of the multi- 
layered information recording medium. 

. A multi-layered information recording medium according to claim 1 , wherein the defect list indicates the location 
of the detected at least one defective area by a layer number for distinguishing the plurality of recording layer from 
each other and an intralayer address for indicating a position in each of the plurality of recording layers. 

. A multi-layered information recording medium according to claim 2, wherein the defect list storing area is provided 
in one of the plurality of recording layer, and 

the defect list location information indicates the location of the defect list storing area by a layer number for 
distinguishing the plurality of recording layer from each other and an intralayer address for indicating a position in 
each of the plurality of recording layers. 

. A multi-layered information recording medium according to claim 1 , further comprises a spare area containing at 
least one replacement area, wherein when at least one defective area is detected in the user data area, the at 
least one replacement area may be used in place of the at least one defective area. 

. A multi-layered information recording medium according to claim 8, wherein when the defective area is replaced 
with the replacement area, the defect list indicates the location of the defective area and the location of the re- 
placement area by respective layer numbers for distinguishing the plurality of recording layers from each other 
and respective intralayer addresses for indicating a position in each of the plurality of recording layers. 

0. A multi-layered information recording medium according to claim 1 , wherein the defect list storing area is provided 
one of the plurality of recording layers, 

the multi-layered information recording medium further comprises an additional defect list storing area for 
storing a defect list having the same contents as the contents of the defect list stored in the defect list storing area, 
and 

the additional defect list storing area is provided in another one of the plurality of recording layers. 

1. A multi-layered information recording medium according to claim 10, further comprising: 

a first defect list location information storing area for storing first defect list location information indicating the 
location of the defect list storing area; and 

a second defect list location information storing area for storing a second defect list location information indi- 
cating the location of the additional defect list storing area, 

wherein the first defect list location information storing area is provided in the same recording layer as that 
in which the defect list storing area is provided, and 

the second defect list location information storing area is provided in the same recording layer as that in 
which the additional defect list storing area is provided. 

2. A multi-layered information recording medium according to claim 1 1 , wherein the recording layer in which the defect 
list storing area is provided comprises a first defect management area containing the defect list storing area and 
the first defect list location information storing area, 

the recording layer in which the additional defect list storing area is provided comprises a second defect 
management area containing the additional defect list storing area and the second defect list location information 
storing area, 

logical addresses are assigned to the user data area, 

an area of the user data area to which the smallest logical address is assigned is provided in the recording 
layer in which the defect list storing area is provided, 



24 



EP 1 329 888 A1 



an area of the user data area to which the greatest logical address is assigned is provided in the recording 
layer in which the additional defect list storing area is provided, 

the first defect management area is adjacent to the area to which the smallest logical address is assigned, and 
the second defect management area is adjacent to the area to which the greatest logical address is assigned. 

13. A multi-layered information recording medium, comprising: 

a plurality of recording layers; 

a user data area for recording user data, provided in at least two of the plurality of recording layers; 
a defect management area provided in at least one of the plurality of recording layers; and 
a spare defect list storing area provided in another one of the plurality of recording layers, 

wherein the defect management area contains a plurality of first defect list storing areas for storing a defect 
list, wherein when at least one defective area is detected in the user data area, the defect list is used to manage 
the at least one defective area, and 

the spare defect list storing area contains a plurality of second defect list storing areas capable of being used 
in place of the plurality of first defect list storing areas when none of the plurality of first defect list storing areas is 
usable. 

14. A multi-layered information recording medium according to claim 13, wherein the defect management area and 
the spare defect list storing area are located at substantially the same radial positions in the multi-layered infor- 
mation recording medium. 

15. A multi-layered information recording medium according to claim 13, wherein the defect management area further 
comprises a defect list location information storing area for storing defect list location information indicating the 
location of an area storing the defect list among the plurality of first defect list storing areas and the plurality of 
second spare defect list storing areas. 

16. An apparatus for reproducing information recorded in a multi-layered information recording medium, 

wherein the multi-layered information recording medium comprises: 

a plurality of recording layers; 

a user data area for recording user data, provided in at least two of the plurality of recording layers; and 
a defect list storing area for storing a defect list, 

wherein when at least one defective area is detected in the user data area, the defect list is used to manage the 
at least one defective area, 

wherein the apparatus comprises: 

an optical head section capable of optically reading the information recorded in the multi-layered information 
recording medium from one side of the multi-layered information recording medium; and 
a control section for controlling defect management using the optical head section, 

wherein the defect management comprises the steps of: 

reproducing the defect list stored in the defect list storing area; and 

reproducing the user data recorded in the user data area based on the reproduced defect list. 

17. An apparatus according to claim 16, wherein the multi-layered information recording medium further comprises: 

a defect list location information storing area for storing defect list location information indicating the location 
of the defect list storing area, 

wherein the defect list location information storing area is provided in one of the plurality of recording layers 
which is predetermined as a reference layer, and 

the defect management further comprises identifying the location of the defect list storing area by reproducing 
the defect list location information stored in the defect list location information storing area. 



25 



EP 1 329 888 A1 

18. An apparatus according to claim 16, wherein the mu It i- layered information recording medium further comprises: 

a spare area for containing at least one replacement area, wherein when at least one defective area is detected 
in the user data area, the at least one replacement area may be used in place of the at least one defective area, 

wherein the defect list indicates that a defective area present in the user data area is replaced with the 
replacement area contained in the spare area, 

wherein the step of reproducing the user data comprises reproducing user data from the replacement area 
indicated by the defect list instead of the defective area indicated by the defect list. 

19. An apparatus for recording information in a multi-layered information recording medium, 

wherein the multi-layered information recording medium comprises: 

a plurality of recording layers; 

a user data area for recording user data, provided in at least two of the plurality of recording layers; and 
a defect list storing area for storing a defect list, 

wherein when at least one defective area is detected in the user data area, the defect list is used to manage the 
at least one defective area, 

wherein the apparatus comprises: 

an optical head section capable of optically recording the information in the multi-layered information recording 
medium from one side of the multi-layered information recording medium; and 
a control section for controlling defect management using the optical head section, 

wherein the defect management comprises the steps of: 

determining whether or not a defective area is present in the user data area during recording of user data in 
the user data area; and 

updating the defect list so as to manage a defective area when it is determined that the defective area is 
present in the user data area. 

20. An apparatus according to claim 19, wherein the multi-layered information recording medium further comprises 
an additional defect list storing area capable of being used in place of the defect list storing area when the defect 
list storing area is unusable, 

wherein the defect management further comprises recording a defect list having the same contents as the 
contents of a defect list stored in the defect list storing area to the additional defect list storing area, when the 
defect list storing area is unusable. 

21. An apparatus according to claim 20, wherein the multi-layered information recording medium further comprises: 

a defect list location information storing area for storing defect list location information indicating the location 
of a defect list, 

wherein the defect list location information storing area is provided in one of the plurality of recording layers 
which is predetermined as a reference layer, 

wherein the defect management further comprises updating the defect list location information so that the 
defect list location information indicates the additional defect list storing area, when the additional defect list storing 
area is used in place of the defect list storing area. 

22. An apparatus according to claim 20, wherein the multi-layered information recording medium further comprises: 

a defect management area provided in one of the plurality of recording layers; and 

a spare defect list storing area provided in another one of the plurality of recording layer 

wherein the defect management area comprises a plurality of defect list storing areas, 
the spare defect list storing area comprises a plurality of additional defect list storing areas, 
the defect list storing area is one of the plurality of defect list storing areas, 



26 



EP 1 329 888 A1 



the additional defect list storing area is one of the plurality of additional defect list storing area, and 
when none of the plurality of defect list storing areas is usable, the additional defect list storing area is used 
in place of the defect list storing area. 

23. An apparatus according to claim 20, wherein the defect list storing area is provided in one of the plurality of recording 
layers, and 

the additional defect list storing area is provided in the same recording layer as that in which the defect list 
storing area is provided. 

24. An apparatus according to claim 20, wherein the defect list storing area is provided in one of the plurality of recording 
layers, and 

the additional defect list storing area is provided in another one of the plurality of recording layers. 

25. An apparatus according to claim 19, wherein the multi-layered information recording medium further comprises: 

a spare area for containing at least one replacement area, wherein when at least one defective area is detected 
in the user data area, the at least one replacement area may be used in place of the at least one defective area, 

wherein the defect management further comprises replacing the defective area present in the user data area 
with the replacement area contained in the spare area. 

26. A method for reproducing information recorded in a multi-layered information recording medium, 

wherein the multi-layered information recording medium comprises: 

a plurality of recording layers; 

a user data area for recording user data, provided in at least two of the plurality of recording layers; and 
a defect list storing area for storing a defect list, 

wherein when at least one defective area is detected in the user data area, the defect list is used to manage the 
at least one defective area, 

wherein the method comprises the steps of: 

reproducing the defect list stored in the defect list storing area; and 

reproducing the user data recorded in the user data area based on the reproduced defect list. 

27. A method according to claim 26, wherein the multi-layered information recording medium further comprises: 

a defect list location information storing area for storing defect list location information indicating the location 
of the defect list storing area, 

wherein the defect list location information storing area is provided in one of the plurality of recording layers 
which is predetermined as a reference layer, 

the method further comprises identifying the location of the defect list storing area by reproducing the defect 
list location information stored in the defect list location information storing area. 

28. A method according to claim 26, wherein the multi-layered information recording medium further comprises: 

a spare area for containing at least one replacement area, wherein when at least one defective area is detected 
in the user data area, the at least one replacement area may be used in place of the at least one defective area, 

wherein the defect list indicates that a defective area present in the user data area is replaced with the 
replacement area contained in the spare area, 

wherein the step of reproducing the user data comprises reproducing user data from the replacement area 
indicated by the defect list instead of the defective area indicated by the defect list. 

29. A method for recording information in a multi-layered information recording medium, 

wherein the multi-layered information recording medium comprises: 



27 



EP 1 329 888 A1 



a plurality of recording layers; 

a user data area for recording user data, provided in at least two of the plurality of recording layers; and 
a defect list storing area for storing a defect list, 

wherein when at least one defective area is detected in the user data area, the defect list is used to manage the 
at least one defective area, 

wherein the method comprises the steps of: 

determining whether or not a defective area is present in the user data area during recording of user data in 
the user data area; and 

updating the defect list so as to manage a defective area when it is determined that the defective area is 
present in the user data area. 

30. A method according to claim 29, wherein the multi-layered information recording medium further comprises an 
additional defect list storing area capable of being used in place of the defect list storing area when the defect list 
storing area is unusable, 

wherein the method further comprises recording a defect list having the same contents as the contents of a 
defect list stored in the defect list storing area to the additional defect list storing area, when the defect list storing 
area is unusable. 

31. A method according to claim 30, wherein the multi-layered information recording medium further comprises: 

a defect list location information storing area for storing defect list location information indicating the location 
of a defect list, 

wherein the defect list location information storing area is provided in one of the plurality of recording layers 
which is predetermined as a reference layer, 

wherein the method further comprises updating the defect list location information so that the defect list 
location information indicates the additional defect list storing area, when the additional defect list storing area is 
used in place of the defect list storing area. 

32. A method according to claim 30, wherein the multi-layered information recording medium further comprises: 

a defect management area provided in one of the plurality of recording layers; and 

a spare defect list storing area provided in another one of the plurality of recording layer. 

wherein the defect management area comprises a plurality of defect list storing areas, 
the spare defect list storing area comprises a plurality of additional defect list storing areas, 
the defect list storing area is one of the plurality of defect list storing areas, 

the additional defect list storing area is one of the plurality of additional defect list storing area, and 
when none of the plurality of defect list storing areas is usable ; the additional defect list storing area is used 
in place of the defect list storing area. 

33. A method according to claim 30, wherein the defect list storing area is provided in one of the plurality of recording 
layers, and 

the additional defect list storing area is provided in the same recording layer as that in which the defect list 
storing area is provided. 

34. A method according to claim 30, wherein the defect list storing area is provided in one of the plurality of recording 
layers, and 

the additional defect list storing area is provided in another one of the plurality of recording layers. 

35. A method according to claim 29, wherein the multi-layered information recording medium further comprises: 

a spare area for containing at least one replacement area, wherein when at least one defective area is detected 
in the user data area, the at least one replacement area may be used in place of the at least one defective area, 

wherein the method further comprises replacing the defective area present in the user data area with the 



28 



EP 1 329 888 A1 

replacement area contained in the spare area. 

5 
10 
15 
20 
25 
30 
35 
40 
45 
50 



29 



EP 1 329 888 A1 




30 



EP 1 329 888 A1 



f 



Read-only optical disc 30 



FIG. 2 

Photo-curing resin 35 
Substrate 31 / Recording layer 33 



Substrate 32 




— -i^— Focal point 36 



Objective lens 37 
Laser I ight 38 



FIG, 3 A 



Second recording 
layer 42 




31 



EP 1 329 888 A1 



FIG.3B 



First recording 
layer 41 




I 



FIG.3C 

Second recording 

layer 42 — 
First recordings- 
layer 41 



Reproduction direction 

FIG. 3D 








-?=^r > 














i 

i 


/ 

4 


V 




I 

6 ! 

I 
1 
1 



32 



EP 1 329 888 A1 



FIG.4A 



Second recording 
layer 44 




FIG. 4B 

First recording 
layer 43 




FIG AC 

Second recording 
layer 44 
First recording 
layer 43 





I 

6 8 7 

I / / 




1 < — ! 


» 
















4 


8 

/ ' 

Reproductic 


7 
>n 



33 



EP 1 329 888 A1 




FIG. 5 A 

45 

Lead-in area 



8 



User data area 



13 



Spare area 



f— 

Lead-out area 



/ 



Disc 
information 
area 




—12 



Defect 
management 
area 



10^ Vs>^ I 
^ ^ ^ WA ^ 



DDS 



DMS 



DL 



20 21 



Spare DL 



22 



T 



Spare DL 



23 



23 



FIG. 5B 



Number of 
sectors (=1) 



r 



21 



DL sector 
address 



Unused 



30 



31 



34 



EP 1 329 888 A1 



FIG. 5C 



22 



D L 

identifier 

1 1 


Number of 
defective 
sectors 


Defect 
entry 1 

L — r 


Defect 
entry 2 


i 


\ 


Defect 
entry n 


Unused 


32 


1— 9 

33/ 


34 









Replacement 
status 


Defective 
sector 
address 


Replacement 
sector 
address 


I 1 


i \ 



40 



41 



42 



FIG, 6 



Lead-in 
area 601 



600 



User data area 
602 



Middle area 
603 

«3 > 



Control data area 610 
/ 611 612 



First recording 
layer 51 

(reference layer) 
15 



Defective area A 
^Recording/ 630 
reproduction 
direction 



613 

4- 



614 

4- 



DMA1 



DMA2 



X 



DMA3 



DMA4 



Spare 
DL1 
t 

620 



Spare 
DL2 
1 

621 



Second 
recording 
layer 52 



X 



Spare 
DL3 

t 



Spare 
DL4 



Defective area B 
631 



622 623 



Lead-out 
area 604 



lAiddle area 
603 



35 



EP 1 329 888 A1 



FIG. 7 



700 



\ 



DMA1 
DDS 



611 



701 



\ 



First DL 
storing 
area 
(defective) 



702 



\ 



703 



704 



Second DL 
storing 
area 
(used) 



Third DL 
storing 

area 
(unused) 



Fourth DL 
storing 

area 
(unused) 





700 

I 






DDS identifier 


— 710 




DL start sector layer number - 


— 711 


r 


DL start sector number - 


— 712 


\ 


Spare area size 


— 713 



702 



709 



DL header 



Defect entry A- 



Defect entry B 



Unused (FRO 



,722\ 



720 



DL identifier 



DL update count 



Number of DL 
entries (=2) 



-731 
-732 
-733 



721 



Replacement status (=1) 



Defective sector layer 
number (=1) 



Defective sector number 



Replacement sector layer number. 



Replacement sector number 
(=00000000 h ) 



-734 
-735 

-736 
-737 
-738 



Replacement status (=1) 



^-722 
~* ~" -739 



Defective sector layer 
number (=2) 



Defective sector number 



Replacement sector layer number. 



Replacement sector number 
(=00000000 h ) 



-740 

-741 
-742 
-743 



36 



EP 1 329 888 A1 



FIG. 8 



First spare DL1 
storing area H 
620 



Fifth DL 
storing area- 
(unused) 



Sixth DL 
storing area- 
(unused) 



Seventh DL 
storing area- 
(unused) 



Eighth DL 
storing area- 
(unused) 



37 



EP 1 329 888 A1 



FIG. 9 



DMA1 
area < 
611 



First spare DL1 
storing area * 
620 



DDS 



First DL 
storing area 
(defective) . 



Second DL 
storing area 
(defective) 



Third DL 
storing area I 7no 
(defective) ' 



Fourth DL 
storing area 
(defective) 



-700 



-701 N - 



-702 



r 



-704 



Fifth DL 
storing area 
(defective) ' 



Sixth DL 
storing area 
(used) 



Seventh DL 
storing area 
(unused) 



Eighth DL 
storing area 
(unused) 



DDS 

DDS identifier 



700 
_L_ 



— 710 



DL start sector layer number 
(=2) 



-705y 



-706 



—707 



— 708 



-711 

DL start sector number -\ — 712 

-713 



Spare area size 



38 



EP 1 329 888 A1 




39 



EP 1 329 888 A1 




40 



EP 1 329 888 A1 




41 



EP 1 329 888 A1 



FIG. 1 1 



Lead-in area 
601 



800 



Data area 
1100 



Middle area 
603 

«s s 



Head spare area 



User data area 
602 



Intermediate spare area 



Control data area 610 
611 612 



Replacement area B 



1102 



1113 



Defective area A Re P |acement area A 



First recording 
layer 53 

(reference layer) 




Recording and 
reproduction 
direction 
Defective area B 1112 



Second 
recording 
layer 54 



Lead-out area 
604 



Enc 



spare area 
1103 



User data area 
602 



Intermediate spare area 
1102' 



Middle area 
603 



42 



EP 1 329 888 A1 



700 



701 



702 N 
703 N 



704 



FIG.12 

DMA1 | / 



DDS 



First DL 
storing 
area 
(defect i ve) 



Second DL 
storing 
area 
(used) 



Third DL 
storing 

area 
(unused) 



Fourth DL 
storing 

area 
(unused) 



700 
_L_ 



DDS identifier 



DL start sector layer number 



DL start sector number 



Spare area size 



-710 
-711 
-712 
•713 



720 
1201 



1202 



\ 

\ 

\ 

\ 
\ 
\ 
\ 



DL header 



Defect entry A 



Defect entry B 



Unused (FFh) 



720 



702 



1209 



DL identif ider 



DL update count -— 



Number of DL entries (=2) 



731 
732 
4-733 



w 



\ 



I_ 



-1201 



Replacement status flag(=0) 



Defective sector layer 
number (=1) 



Defective sector number 



Replacement sector layer 
number (=1) 



Defective sector number 



1 



1202 



Replacement status flag(=0) 



Defective sector layer 
number (=2) 



Defective sector number 



Replacement sector layer 
number (=1) 



Defective sector number 



-734 

-735 
-736 

-737 
-738 

-739 

-740 
-741 

-742 
-743 



43 



EP 1 329 888 A1 



o 

CO, 

in 



lo 




Buffer h~g 



-CO 
LO 



ECC 
circuit 



csj 

5 



CVI 

-co 

LO 



k Modulation/ 
J demodulation 
v circuit 



LO 



CO 

-co 

LO 



Binarization 
circuit 



LO 



44 



EP 1 329 888 A1 



FIG. 1 4 



r 



1400 



f Start ) 



Control focal point to follow a 
track in the reference layer 



— 1401 



Read disc information 



— 1402 



Read DDS 



1403 



1404 

r> , . Other than 

Determine a^^K eference | ayer 

recording layer ^~ 

containing a DL 



Reference 
layer 



Read the DL 



1405 



Shift to a recording 
layer containing the DL 



— 1406 



45 



EP 1 329 888 A1 



FIG. 1 5 



-1500 



1502 



The same 



— 1501 



No 



<1 recording layer? Z> 


1503 

i 1 




Ypts Shift to a desired recording layer 






«s — 




Read a sector — 1504 



46 



EP 1 329 888 A1 



FIG. 1 6 



1600 



( Start ) 



Convert LSN to PSN 
(without considering replacement) 



— 1601 



YES 



1603 



Select PSN of a 
corresponding replacement area 




( End ) 



47 



EP 1 329 888 A1 



FIG. 1 7 



•1700 



( Start ) 



Produce a new DL 



1701 



Select a 
DL area 




— 1706 





1703 




' I 


Shift to a 


i desired 


recording layer 



Recording on the DL area 



— 1704 




1708 



YES~ 




Shift to the 






reference layer 








I 




«s 






Register the recording location of the DL area in DDS 


— 1709 



Recording on the DDS area | — 1710 



48 



EP 1 329 888 A1 



FIG. 18 



-1800 



C Start ) 



Convert LST to PSN 



1804 
I 



YES 



Writing on a sector 



Update and record DL 



1801 




1803 



Shift to a desired 
recording layer 



1806 




A I locate a 
spare sector 



( Ehd ) 



49 



EP 1 329 888 A1 



FIG. 1 9 



Lead-in 
area 1901 



Head spare 
area 1902 



1911 



1912 

-4- 



DMA1 



1913 
—I— 



DMA2 




•1900 



User data area 
1903 



Replacement area A 1914 
Defective area A 1915 

1cm 7 Recording and 
1 9 j> 1 [( reproduct i on di i ectionj 



First recording 

layer 55 
'(reference layer) 



DMA3 



DMA4 



1921 



1922 



Lead-out 
area 1905 




X 



1 r 



Replacement 
area B 1923 



. Second recording 
Defective | ayer 56 

area B 1924 



End spare 
area 1904 



User data area 
1903 



50 



EP 1 329 888 A1 



FIG. 20 



DMA1 



1912/ 



2000 -\ 



DDS 



2001 



\ 



2002 



2003 



2004 x 



First DL 
storing 
area 
(defect i ve) 



Second DL 
storing 
area 
(used) 



Third DL 
storing 

area 
(unused) 



Fourth DL 
storing 

area 
(unused) 



200^ 
\ 

\ 
\ 
\ 
\ 
\ 
\ 

\ 



2000 



DDS identifier 



DL start sector layer number — 71 1 



DL start sector number -1—712 

-713 



Spare area size 



-710 



2002 



DL header 



Defect entry A 



Defect entry B 



Unused (FFh) 



2020 
_L_ 



DL identifider 



DL update count 



Number of DL entries (=2) 



-731 
•732 
• 733 



^-2021 



Replacement status (=0) - — 734 



Defective sector layer 
number (=1) 



Defective sector number 



Replacement sector layer 
number (=1) 



Replacement sector number 



-735 
-736 

-737 
738 



^2 



-2022 



Replacement status (=0) ■ — 739 



Defective sector layer 
number (=2) 



Defective sector number 



Replacement sector layer 
number (=2) 



Replacement sector number 



■ 740 
•741 

742 
• 743 



51 



EP 1 329 888 A1 



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52 



EP 1 329 888 A1 




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ca eg 
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53 



EP 1 329 888 A1 



J 



European Patent 
Office 



EUROPEAN SEARCH REPORT 



Application Number 

EP 03 00 0696 



DOCUMENTS CONSIDERED TO BE RELEVANT 



Category 



Citation of document with indication, where appropriate, 
of relevant passages 



Relevant 
to claim 



CLASSIFICATION OF THE 
APPLICATION (lnt.C1.7) 



EP 1 056 089 A (TOKYO SHIBAURA ELECTRIC 
CO) 29 November 2000 (2909-11-29) 



* column 1, paragraph 1 * 

* column 16, paragraph 68 



paragraph 103 



column 21, 



INC) 



WO GO 07186 A (LG ELECTRONICS 
10 February 2000 (20O0-02-1O) 

* page 1, line 9 - page 8, line 20; 
figures 1-6 * 

US 5 404 357 A (IT0 MOT0SHI ET AL) 
4 April 1995 (1995-04-04) 

* column 1, line 5 - column 3, line 11; 
figures 1-5 * 



The present search report has been drawn up for all claims 



1-6, 
8-11, 

13-35 
7,12 



1-35 



1-35 



G11B20/18 
G11B27/32 



TECHNICAL FIELDS 
SEARCHED (lnt.CI.7) 



G11B 



Place ot search 

MUNICH 



Date ol completion of the search 

21 February 2003 



D'Attilia, M 



CATEGORY OF CITED DOCUMENTS 

X : particularly relevant if taken alone 

Y : particularly relevant if combined with another 

document of the some category 
A : techno logical background 
O : non-written disclosure 
P : intermediate document 



T : theory or principle underlying the invention 
E : earlier patent document, but published on, or 

after the filing date 
D : document cited in the application 
L : dooument cited for other reasons 

& : member of the same patent family, corresponding 
document 



54 



EP 1 329 888 A1 



ANNEX TO THE EUROPEAN SEARCH REPORT 
ON EUROPEAN PATENT APPLICATION NO. 



EP 03 00 0696 



This annex lists the patent family members relating to the patent documents cited in the above-mentioned European search report. 
The members are as contained in the European Patent Office EDP file on 

The European Patent Office is in no way liable for these particulars which are merely given for the purpose of information. 

21-02-2003 



Patent document 
cited in search report 



Publication 
date 



Patent family 
member(s) 



Publication 
date 



EP 


1056089 


A 


29-11- 


-2000 


JP 


11232836 


A 


27-08-1999 












EP 


1056089 


Al 


29-11-2000 












US 


2002191499 


Al 


19-12-2002 












WO 


9941749 


Al 


19-08-1999 


WO 


0007186 


A 


10-02- 


-2000 


KR 


2000010473 


A 


15-02-2000 












KR 


2000014100 


A 


06-03-2000 












KR 


2000015037 


A 


15-03-2000 












AU 


4657199 


A 


21-02-2000 












BR 


9906652 


A 


29-08-2000 












CN 


1274463 


T 


22-11-2000 












EP 


1027705 


Al 


16-08-2000 












OP 


2002521787 


T 


16-07-2002 












WO 


0007186 


Al 


10-02-2000 


US 


5404357 


A 


04-04- 


-1995 


JP 


2887949 


B2 


10-05-1999 












JP 


5002837 


A 


08-01-1993 



o 

Si For more details about this annex : see Official Journal of the European Patent Office, No. 1 2/82 



55