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



(19) World Intellectual Property Organization 

International Bureau 

(43) International Publication Date 
17 May 2001 (17.05.2001) 




PCT 



mi mi iii i ii ii ii iii i in ii iii 

(10) International Publication Number 

WO 01/35408 Al 



(51) International Patent Classification 7 : 



G11B 20/18 



(21) International Application Number: PCT/USOO/30605 

(22) International Filing Date: 

7 November 2000 (07. 1 1 .2000) 



(25) Filing Language: 

(26) Publication Language: 



English 
English 



(30) Priority Data: 

60/164,806 10 November 1999 (10. 1 1 .1999) US 

(71) Applicant (for all designated States except US): THOM- 
SON LICENSING S.A. [FR/FR]; 46, quai Alphonse Le 
Gallo, F-92648 Boulogne Cedex (FR). 



(72) Inventor; and 

(75) Inventor/Applicant (for US only): LIN, Shu [CN/US]; 
9269 D Yale Drive, Indianapolis, IN 46240 (US). 

(74) Agents: TRIPOLI, Josph, S. et al.; Thomson Multimedia 
Licensing Inc., P.O. Box 5312, Princeton, NJ 08540 (US). 

(81) Designated States (national): AE, AG, AL, AM, AT, AU, 
AZ, BA, BB, BG, BR, BY, BZ, CA, CH, CN, CR, CU, CZ, 
DE, DK, DM, DZ, EE, ES, FI, GB, GD, GE, GH, GM, HR, 
HU, ID, IL, IN, IS, JP, KE, KG, KP, KR, KZ, LC, LK, LR, 
LS, LT, LU, LV, MA, MD, MG, MK, MN, MW, MX, NO, 
NZ, PL, PT, RO, RU, SD, SE, SG, SI, SK, SL, TJ, TM, TR, 
TT, TZ, UA, UG, US, UZ, VN, YU, ZA, ZW. 

(84) Designated States (regional): ARIPO patent (GH, GM, 
KE, LS, MW, MZ, SD, SL, SZ, TZ, UG, ZW), Eurasian 
patent (AM, AZ, BY, KG, KZ, MD, RU, TJ, TM), European 
patent (AT, BE, CH, CY, DE, DK, ES, FI, FR, GB, GR, IE, 

[Continued on next page] 



(54) Title: METHOD FOR TRACKING DEFECTIVE SECTORS IN WRITABLE DISK MEDIA 







Begin 










Read 


Next 


Sector 



Begin 



-501 




Load Defect 
List 



503- 



Add Sector to 

Defect 
Candidate List 



Load Defect ^602 
Candidate List 



Discard 
Candidate 
Sectors Already 
in 




^603 



Verify Remaining ^-604 



Add Verified 
Sectors to Defect 



Sort Defect 
List 



^--606 



Write Defect 
List to DVD 



o 



(57) Abstract: A method of updating a defect list in a DVD 
can include processing sectors on the DVD during a playback 
operation; adding references to selected ones of the processed 
sectors to a defect candidate list; identifying defective sectors 
among the selected one of the processed sectors; and, adding 
references to the identified defective sectors to the defect list. 
Additionally, the method can include removing from the defect 
candidate references to each sector for which a corresponding 
reference has been added to the defect list. The step of adding 
references to selected one of the processed sectors to a defect 
candidate list can include detecting an unrecoverable error dur- 
ing the playback operation; identifying a processed sector as- 
sociated with the unrecoverable error; and, adding a reference 
to the identified sector to the defect candidate list. Also, the 
identifying step can include identifying each sector having a 
reference in both the defect list and the defect candidate list; 
removing references to the identified sectors from the defect 
candidate list; and, determining whether each sector remain- 
ing in the defect candidate list is a defective sector. 



WO 01/35408 Al H ■ II HI I III III lllllllllllllllllllllllllllllllll 



IT, LU, MC, NL, FT, SE, TR), OAPI patent (BF, BJ, CF, For two-letter codes and other abbreviations, refer to the "Guid- 
CG, CI, CM, GA, GN, GW, ML, MR, NE, SN, TO, TG). ance Notes on Codes and Abbreviations " appearing at the begin- 
ning of each regular issue of the PCT Gazette. 

Published: 

— With international search report. 



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METHOD FOR TRACKING DEFECTIVE SECTORS IN WRITABLE DISK MEDIA 

BACKGROUND OF THE INVENTION 

Technical Field 

5 The inventive arrangements relate generally to methods and apparatus for 

providing advanced operating features for recording data to recordable DVD 
media, and more particularly to a method and apparatus for trackingdefective 
sectors in recordable DVD media. 

10 Description of the Related Art 

Various devices have been developed to enable consumers to record video 
and/or audio programs for later presentation. Such devices include tape 
recorders, video cassette recorders, recordable compact disks, and most 
recently, recordable digital versatile disks (DVD). Hard drives and magneto 

15 optical disks have also been used. A DVD in which data can be recorded once 
only, and thereafter is essentially a DVD read only memory, is referred to by the 
acronym DVD-R. The acronym DVD-R also has been used generally to refer to 
write-once, or record-once, technology. 

In contrast to DVD-R, several formats exist in which data can be recorded 

20 to a DVD, erased and re-recorded. In sum, such a DVD can be overwritten or 
rewritten. These DVDs typically are referred to by the acronyms DVD-RAM, 
DVD-RW and DVD + RW. Although, as of this time no uniform industry standard 
has been adopted, the acronyms DVD-RAM, DVD-RW and DVD + RW have been 
used generally to refer to the respective re-writable DVD technologies. Still, 

25 reference herein to re-writable DVD technology, devices and methods and 

recordable DVD media is generally intended to encompass all of the standards 
which are now being used, as well as those which may be developed in the 
future. 

Present DVDs can have a logical file structure in which audio-video 
30 content can be stored. Specifically, as shown in Figure 7, at the top of the file 
structure hierarchy of a DVD 700, one or more titles 701 can exist which can 
loosely correlate to program episode titles. Titles 701 can consist of control data 



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702 in addition to one or more Video Object Sets 703 (VOBS). The control data 
702 can contain information for managing the title 701 . Each VOBS 703 can 
include a plurality of Video Objects (VOB) 704. Each VOB 704 preferably 
includes a plurality of Cells 705. Each Cell 705 preferably includes a plurality of 
5 Video Object Units (VOBU) 706. Each VOBU 706 roughly correlates to a group 
of pictures which is the smallest addressable chunk in the DVD 700. 

Notably, each VOBU 706 can contain an integer number of video frames. 
As such, each VOBU 706 can contain 0.4 to 1 .0 seconds of presentation 
material. A typical VOBU 706 in a commercial motion picture can contain 0.5 

10 second of presentation material. Notably, each VOBU 706 can include a 

sequence of packs 707 positioned in recording order. Preferably, each VOBU 
can begin with a navigation pack 708 (NVPCK or NAVPACK) which can be 
followed by audio-visual data packs 709, for example video packs (VPCK), 
audio packs (A_PCK) and sub-picture packs (SP PCK). The NV-PCK 708 can 

15 contain navigation information, which can be useful in implementing trick modes 
of operation. The NV_PCK 708 also can include presentation control information 
(PCI) and data search information (DSI). 

Present DVDs can store data using the Universal Disc Format (UDF) 
specification. As such, present DVDs can include a directory and set of files 

20 within the UDF file format. Figure 8 illustrates the directory structure of a typical 
DVD. According to the DVD-ROM specification, all files in a DVD are stored in 
directories 801, 810, 815 and 820 below the root directory 800. In particular, 
DVD-Video data can be stored a single directory referred to as the VIDEO_TS 
directory 801 . The VIDEO_TS directory 801 can contain a Video Manager and 

25 one or more Titles. As illustrated in Figure 8, the Video Manager can include a 
Video Manager information file 802, a Video Manager menu file 803, and a 
Video Manager backup file 804. Additionally, each Title can include a Video Title 
information file 805A, 805B, a Video Title menu 806A, 806B, one or more video 
object set files 807A, 807B, 808A, 808B and a Video Title Backup file 809A, 

30 809B. 

Aside from DVD-Video, DVD-Audio information can be stored in an 
analogous directory, AUDIO TS 810. Furthermore, an optional, root-level 



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directory JACKET_P 81 5 can contain identifying images for the DVD in three 
sizes including thumbnails for graphical directories of DVD collections. Notably, 
a DVD can include other files stored in one or more user-defined directories 820. 
Such directories and files typically are placed on the DVD following the DVD- 
5 Video data and are ignored by conventional DVD players. 

Recordable DVD media can be used for thousands or even tens of 
thousands of times for recordings. For each recording, defective sectors in the 
recordable DVD media potentially can arise. As a result, recordable DVD media 
can accumulate a substantial number of defective sectors during the operational 

10 lifetime of the recordable DVD media. Yet, defective sectors in recordable DVD 
media can inhibit proper playback of data stored in the recordable DVD media. 
Specifically, defective sectors in the control data area, such as a control data 
VOB for a title set, can invalidate the control data. Moreover, defective sectors 
in video data in a VOBU can cause video freeze or blockiness. Additionally, 

15 defective sectors in audio data in a VOBU can cause audio distortion or noise. 
Finally, defective sectors in a menu area can damage a menu. 

For analog tape recording technology, such as VCR technology, a 
defective portion of the video tape may not affect the quality of the signal 
substantially during playback. In contrast, for digital disc recording technology, a 

20 defective sector can significantly affect playback quality causing a loss of 

navigation information and control data, video freeze, blockiness, loss of audio 
information and menu corruption. As a result, if defective sectors cannot be 
identified prior to recording to a re-writable disc, an entire recording can be 
ruined. Accordingly, defective sector checking can be critical to a successful 

25 digital disc recording. 

Notably, re-writable DVDs each have a defect list that is generated by the 
manufacturer. Those sectors which are determined to be defective are added to 
the defect list so that the defective sectors will be skipped during a recording 
session. 

30 Notwithstanding, in most cases, defect checking cannot be performed in real- 
time during a recording session. Moreover, to inspect a re-writable DVD for 
defective sectors by scanning the entire re-writable DVD can consume several 



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4 

hours depending upon the capacity of the re-writable DVD and the front-end 
speed of the re-writable DVD recorder. Accordingly, it can be impractical to 
delay the user for the time required to perform the inspection prior to permitting 
the user to begin recording. 



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SUMMARY 

A method for updating a defect list in a DVD can include playing back the 
DVD; detecting at least one unrecoverable error associated with at least one 
corresponding sector during the playback; adding a reference to each sector 
5 associated with the unrecoverable error to a defect candidate list; determining 
whether each sector referred to in the defect candidate list is a defective sector; 
and adding a reference to each sector determined to be a defective sector to the 
defect list. Additionally, the method can include removing from the defect 
candidate list a reference to each sector for which a corresponding reference has 

10 been added to the defect list. 

The determining step can include identifying each sector having a 
reference in both the defect list and the defect candidate list; removing the 
identified sectors from the defect candidate list; and, determining whether each 
sector remaining in the defect candidate list is a defective sector. The step of 

15 identifying each sector having a reference in both the defect list and the defect 
candidate list can include sorting the defect candidate list in a structured order; 
sorting the defect list in the structured order; and, subtracting the sorted defect 
candidate list from the sorted defect list. Notably, the subtraction can result in 
the identified sectors. Additionally, the sorting steps can include sorting the 

20 defect candidate list in ascending order; and, sorting the defect list in ascending 
order. Similarly, the sorting steps can include sorting the defect candidate list in 
descending order; and, sorting the defect list in descending order. 

A method for updating a defect list in a DVD can include processing 
sectors on the DVD during a playback operation; adding references to selected 

25 ones of the processed sectors to a defect candidate list; identifying defective 
sectors among the selected ones of the processed sectors; and, adding 
references to the identified defective sectors to the defect list. Additionally, the 
method can include removing from the defect candidate references to each 
sector for which a corresponding reference has been added to the defect list. 

30 The step of adding references to selected ones of the processed sectors to 

a defect candidate list can include detecting an unrecoverable error during the 
playback operation; identifying a processed sector associated with the 



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6 

unrecoverable error; and, adding a reference to the identified sector to the defect 
candidate list. Also, the identifying step can include identifying each sector 
having a reference in both the defect list and the defect candidate list; removing 
references to the identified sectors from the defect candidate list; and, 
5 determining whether each sector remaining in the defect candidate list is a 
defective sector. 

The step of identifying each sector having a reference in both the defect 
list and the defect candidate list can include sorting the defect candidate list in a 
structured order; sorting the defect list in the structured order; and, subtracting 

10 the sorted defect candidate list from the sorted defect list. Notably, the 

subtraction can result in the identified sectors. In one aspect of the method, the 
sorting steps can include sorting the defect candidate list in ascending order; 
and, sorting the defect list in ascending order. Similarly, in another aspect of the 
method, the sorting steps can include sorting the defect candidate list in 

15 descending order; and, sorting the defect list in descending order. 



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7 

BRIEF DESCRIPTION OF THE DRAWINGS 

Figure 1 is a block diagram of a DVD recording device that can be provided 
with one or more advance operating features in accordance with the inventive 
arrangements. 

5 Figure 2 is a schematic diagram of recordable DVD media. 

Figure 3 is a cut-away view of the recordable DVD media of Figure 2. 

Figure 4 is a directory tree illustrating a DVD directory and file structure in 
accordance with the inventive arrangements. 

Figure 5 is a flow chart illustrating a process for identifying defective 
10 sectors during playback of a DVD. 

Figure 6 is a flow chart illustrating a process for verifying the identified 
defective sectors of Figure 5. 

Figure 7 is a block diagram illustrating a convention DVD physical data 
structure. 

15 Figure 8 is a directory tree illustrating a conventional DVD directory and 

file structure. 

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 

Recordable DVD Device 

20 A device 100 for implementing the DVD-ROM backwards-compatible 

defect management method in accordance with the inventive arrangements 
taught herein utilizes a recordable, re-writable disk medium 102 in accordance 
with the inventive arrangements is shown in block diagram form in Figure 1 . The 
re-writable disk medium 102 is embodied as a re-writable DVD in the illustrated 

25 embodiment. In many instances, as will be noted, the re-writable disk medium 
can also be, for example, a hard drive or a magneto optical disk (MOD). An 
example of a MOD is a minidisk. In many instances, the inventive arrangements 
are applicable to video or audio or both video and audio. 

The device 100 is capable of writing onto and reading from recordable 

30 DVD media, in this example, a re-writable DVD 102. The device comprises a 

mechanical assembly 104, a control section 120, a video/audio input processing 
path 140 and a video/audio output processing path 170. The allocation of most 



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8 

of the blocks to different sections or paths is self-evident, whereas the allocation 
of some of the blocks is made for purposes of convenience and is not critical to 
understanding the operation of the device. 

The mechanical assembly 104 comprises a motor 106 for spinning the 
5 disk 102 and a pickup assembly 108 that is adapted to be moved over the 

spinning disk. The pickup 108 and the motor 106 are controlled by a servo 110. 
The servo 110 can receive a playback signal of data which can be read from a 
spiral track of the disk 102 as a first input. The playback signal also can be an 
input to an error correction circuit 130, which can be considered part of the 

10 control section or part of the video/audio output processing path. 

When reading data from the disk 102, a laser on the pickup assembly 108 
can direct laser light at an interior layer surface of the disk 102. Depending upon 
the data stored on the disk 102, the laser light can be mostly reflected or mostly 
absorbed. The pickup assembly 108 can interpret reflected light as one type of 

15 electrical signal while light absorbed by the interior layer surface of the disk 102 
can be interpreted as a second type of electrical signal. In the preferred 
embodiment, transitions between reflectivity and non-reflectivity are mapped to a 
digital signal referred to as the playback signal which corresponds to the data 
stored on the disk 102. 

20 By comparison, during recording, a laser on the pickup assembly burns 

spots onto a spiral track on the disk 102 in order to digitally record video and/or 
audio program material. More particularly, the disk 102, which can include at 
least one interior crystalline recording layer, can exhibit two distinctive states, 
amorphous or crystalline, each having different reflectivity characteristics. Those 

25 different levels of reflectivity can be detected by optical sensors in the pickup 
assembly 108. 

Prior to recording, the interior recording layer of the disk is in a crystalline 
state exhibiting high reflectivity. The light intensity of a laser beam can be 
modulated to write amorphous data marks on the surface of tracks in the interior 
30 crystalline recording layer. Specifically, the energy of a laser pulse can quickly 
raise the surface temperature of the interior crystalline recording layer above the 
layer melting point. Once above the melting point, the interior layer can 



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transition from a crystalline state of high reflectivity to an amorphous state of 
low reflectivity. Subsequently, the rapid cooling of the layer prevents the 
molecular structure of the interior layer from reorganizing into a crystalline state. 
Hence, digital data can be mapped to a series of laser pulses which can write a 
5 digital code to the disk 102 which can correspond to the digital data. 

Notably, depending upon capacity requirements, the disk 102 can have 
either one or two recordable sides. Additionally, the disk 102 can have multiple 
recordable layers per side. However, for purposes of understanding the 
invention, the number of sides and layers is irrelevant. Moreover, in the event of 

10 a double-sided recording, it also is irrelevant whether the recording of both sides 
of the disk 102 occurs from one or both sides of the disk 102. 

Returning now to Figure 1, the control section 120 preferably comprises a 
controller 122 and a navigation data generation circuit 126. The controller 122 
supplies a first input signal to the navigation data generation circuit 126 and the 

15 servo 110 supplies a second input signal to the navigation data generation circuit 
126. The servo can also be considered part of the control section 120. The 
navigation data generation circuit 126 supplies a first input signal to the 
multiplexer (MUX) 154, which forms part of the video/audio input processing 
path 140. The output of the MUX 154 is an input to an error correction coding 

20 circuit 128. The output of the error correction coding circuit 128 is a recordable 
input signal supplied to the pickup 108, which will be "burned" onto the spiral 
track of the disk 102 by the laser. 

The controller 122 also preferably has access to the data contained in the 
track buffer 172 and record buffer 152 as shown in Figure 1. The controller 122 

25 can delete, modify, and reformat video data stored in the track buffer 172 and 
record buffer 1 52 for the purpose of implementing the inventive arrangements. 
Control and data interfaces are also preferably provided for permitting the 
controller 122 to control the operation of packet video encoder 144 and audio 
encoder 148 for implementing the inventive embodiments as described herein. 

30 Suitable software or firmware is provided in memory for the conventional 

operations performed by controller 122. In addition, program routines for the 



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advanced features 134 are provided for controlling the controller 122 in 
accordance with the invention as shall hereinafter be described in greater detail. 

A control buffer 132 for viewer activatable functions indicates those 
functions presently available, namely play, record, reverse, fast forward, 
5 pause/play and stop. The pause is a counterpart to pause operation in a VCR, 
for example manually interrupting the play back of a prerecorded program or 
interrupting the recording of a viewed program to eliminate commercials from the 
recording. A separate pause buffer 136 is provided to receive commands for 
performing the pause during record and playback function. 

10 The video/audio input processing path 1 40 is a signal processing circuit for 

converting a conventional television signal, for example NTSC or PAL, into 
digitized packet data, for example MPEG-1 or MPEG-2, for digital recording by 
the device 100. The input path 140 comprises an NTSC decoder 142 and video 
encoder, for example MPEG-1 or MPEG-2, 144 for video in, and comprises an 

15 audio analog-to-digital converter (A/D) 146 and an audio encoder, for example 
MPEG-1 or MPEG-2, 148. The digitized signals are combined in a multiplexer 
1 50 and stored in a record buffer 1 52 until an entire packet has been 
constructed. As each packet is constructed, each packet is combined with the 
output of the navigation data generation circuit in the MUX 1 54 and sent to the 

20 error correction coding circuit 128. Error correction coding circuit 128 can also 
be deemed to be part of the input path 140. 

The output processing path 170 comprises a track buffer, or output 
buffer, 172, in which data read from the disk is assembled into packets for 
further processing. The packets are processed by conditional access circuit 174 

25 that controls propagation of the packets through demultiplexer 1 76 and into 
respective paths for video and audio processing. The video is decoded by 
decoder 178, for example from MPEG-1 or MPEG-2, and encoded as a 
conventional television signal, for example NTSC or PAL. The audio is decoded 
by circuit 182, for example from MPEG-1 or MPEG-2, and converted to analog 

30 form by audio digital-to-analog (D/A) converter 184. The output processing path 
170 can be deemed to include the error correction circuit 130, as noted. 



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1 1 

Device 100 can represent a machine having, for example, a 1X read and 
1X write capability. Such devices can typically have maximum data rates for 
recording or playing back of approximately 1 1 megabits/second. In order to 
implement some of the inventive arrangements is necessary to play back (read) 
5 and record (write) in a manner that appears to be simultaneous. Apparently 

simultaneous playing back and recording with such a machine would seem to be 
impossible, but even such a minimal capability machine can be advantageously 
operated in accordance with the inventive arrangements to provide apparently 
simultaneous playing back and recording as well as other inventive arrangements. 
10 It will also be appreciated that the inventive arrangements can also be useful for 
devices having higher data rates. 

DVD Media 

For purposes of illustrating the inventive arrangements, program material 
can be recorded onto recordable DVD media, for example the re-writable DVD of 

15 Figure 1, and played back from the re-writable DVD. The re-writable DVD 102, 
as shown in further detail in Figure 2, can consist of two substrates bonded 
together by an adhesive layer forming a 1 .2mm thick disk. A center hole 118 
can be formed in the center of the disk so that a gripping device of the motor 
106 of Figure 1 can securely grip the disk and control the angular motion of the 

20 same in accordance with the inventive arrangements. 

As in conventional DVD-RAM technology, the re-writable DVD 102 of the 
present invention incorporates a land/groove structure and phase change material 
to record data to disk. The land/groove combination forms a continuous spiral 
112, with data recorded alternately on land and groove. Data can be written 

25 onto the re-writable DVD 102 in an outwardly direction along the spiral 112, 

beginning with the smaller radius portion of the spiral to the larger radius portion 
of the spiral 112. The several series of three large dots (_ _) denote portions of 
the spiral not shown in the drawing. Each nearly circular, radially concentric 
section of the spiral 1 1 2 is sometimes referred to as a track. Notably, the spiral 

30 112 can be formed with a side-to-side wobble, not shown in the drawing, to 

accommodate media type indexing. Due to difficulties of scale only portions of 
the spiral 16 are shown, and these are shown in greatly enlarged scale. 



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To maintain constant data density across the surface of the re-writable 
DVD 102, the recording surface is divided into twenty-four (24) annular zones. 
Each zone has 1,888 tracks, including 944 land tracks and 944 grove tracks. 
Each track is divided into sectors 1 14 (only a single sector is shown for 
5 simplicity). The innermost zone has seventeen (17) sectors per track. The 

number of sectors per track increases by one in each succeeding zone. Hence, 
the outermost zone contains forty (40) sectors per track. Each sector 114 
begins with a read-only identification field, embossed onto the disk surface. This 
identification field, known as the header, is used to identify the physical location 

10 of the sector and is kept separate from the user recordable data field, to assure 
that it is permanently readable. The re-writable DVD 102 can further include an 
embossed area 116 containing read-only data which can identify the type of 
media, for example DVD-RAM, DVD-ROM, or DVD-R. 

Figure 3 is a cut-away view of the re-writable DVD 102 of Figure 2. As 

15 shown in Figure 3, a re-writable DVD 102 can include both re-writable data areas 
and embossed data areas. The embossed data for a re-writable DVD 102 can be 
located at the innermost portion of the re-writable DVD 102, referred to as the 
lead-in area 116. The lead-in area 116 contains information which can identify 
the type of media, such as DVD-RAM or DVD-R. The re-writable DVD 102 

20 similarly can include a lead-out area 124. Notably, each zone can have a user 
area and an associated spare area (not shown). The spare area can be used for 
the replacement of any defective sector detected in the user area. Finally, 
defective sector addressing can be handled using defect management areas 122. 
Each defect management area 122 can include a list of defective sectors and 

25 associated replacement sectors. Additionally, each defect management area 122 
can contain the same information as other defect management areas 122, 
providing an additional level of redundancy to improve the reliability of the re- 
writable DVD 102. 

It will be appreciated that the advanced features taught herein are 

30 applicable to other kinds of disk media and disk media players and recorders. 
Additionally, various modifications of the device illustrated in Figure 1 and the 
disk medium illustrated in Figures 2 and 3 can be used together to implement the 



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advanced features taught herein in accordance with the inventive arrangements. 
In particular, a solution for defective sector management in accordance with the 
inventive arrangements can include modifications of and additions to hardware, 
firmware and software in the controller 122 for recording data to recordable DVD 
5 media. 

Checking Defective Sectors For Digital Disc Recorders 
Notably, the present invention can be realized in hardware, software, or a 
combination of hardware and software. Machine readable storage according to 
the present invention can be realized in a centralized fashion in one computer 

10 system, for example the controller 122, or in a distributed fashion where 

different elements are spread across several interconnected computer systems. 
Any kind of computer system or other apparatus adapted for carrying out the 
methods described herein is acceptable. 

Specifically, although the present invention as described herein 

15 contemplates the controller 122 of Figure 1, a typical combination of hardware 
and software could be a general purpose computer system with a computer 
program that, when being loaded and executed, controls the computer system 
and a DVD recording system similar to the control section 120 of Figure 1 such 
that it carries out the methods described herein. The present invention can also 

20 be embedded in a computer program product which comprises all the features 
enabling the implementation of the methods described herein, and which when 
loaded in a computer system is able to carry out these methods. 

A computer program in the present context can mean any expression, in 
any language, code or notation, of a set of instructions intended to cause a 

25 system having an information processing capability to perform a particular 

function either directly or after either or both of the following: (a) conversion to 
another language, code or notation; and (b) reproduction in a different material 
form. The invention disclosed herein can be a method embedded in a computer 
program which can be implemented by a programmer using commercially 

30 available development tools for operating systems compatible with the controller 
122 described above. 



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In accordance with the inventive arrangements, defective sectors on a re- 
writable disc are detected and a reference thereto placed in a defect list in the 
defect management area 122 as shown in Figure 3. In consequence, those 
defective sectors having a reference stored in the defect list are not used for 
5 recording. More particularly, the defective sectors on a re-writable disc are 

checked during each playback of the re-writable disc. If an unrecoverable error is 
detected when playing back a particular sector, the particular sector can be 
branded as a defective sector candidate. As such, the particular sector can be 
placed in a defective sector candidate list. If the particular sector later is verified 

10 as a genuinely defective sector, a reference to the particular sector can be added 
to the defect list in the defect management area 122. 

Notably, additional directories can be added to the DVD directory and file 
structure in order to accommodate the defect list and the defective sector 
candidate list. Specifically, as shown in the directory tree illustrated in Figure 4, a 

15 DVD directory structure in accordance with the inventive arrangements can 

include below the root directory 400, a DVD-Video directory 401, a defect list 
425, a defect candidate list 430 and corresponding defect list and defect 
candidate list backup directories 435, 440. Additionally, as in conventional 
DVD-Video directories, the DVD-Video directory 401 can include a Video 

20 Manager information file 402, a Video Manager menu file 403, and the Video 
Manager backup file 404. Additionally, each Title in the DVD-Video directory 
401 can include a Video Title information file 405A, 405B, a Video Title menu 
406A, 406B, one or more video object set files 407A, 407B, 408A, 408B and a 
Video Title Backup file 409A, 409B. Optionally, the DVD directory structure also 

25 can include a DVD-Audio directory 410, the JACKET P directory 415 and other 
user-definable directories 420. 

A defective sector identification and verification method in accordance 
with the inventive arrangements advantageously uses the playback function as a 
defective sector checking process. In consequence, each sector suspected of a 

30 defect during the playback of the sector can be added to a defective candidate 
list. Subsequently, a verification process can determine whether the sectors in 
the defective candidate list are to be added to the defect list. Figure 5 is a flow 



WO 01/35408 PCI7US00/3O6O5 

15 

chart illustrating a process for detecting and tracking suspected defective sectors 
during the execution of a DVD playback function. In accordance with the 
inventive arrangements, in step 501, first the process can attempt to read a 
sector in a re-writable DVD. If, in decision step 502, an uncorrectable error is 
5 encountered, in step 503 the address of the sector or other suitable reference 
thereto can be added to a defect candidate list. If, in decision step 504 it is 
determined that playback should continue, the process can repeat where in step 
501 , the process can read the next sector in the DVD. 

To reduce redundant verification checks of suspected defective sectors 

10 contained in a defect candidate list, addresses of suspected defective sectors 

can be advantageously stored in a structured order in both the defect list and (for 
verified defective sectors) the defect candidate list. Specifically, where both the 
defect and the defect candidate list are stored in a structured order, each can be 
compared and sectors which are not contained in both lists can be more easily 

15 identified. For example, both the defect list and the defect candidate list can be 
sorted in ascending or descending order. In any event, if in step 504 it is 
determined that playback should not continue, in step 505, the defect candidate 
list can be sorted according to a specified structure, for instance ascending or 
descending order. Subsequently, in step 506 the verification process can 

20 commence. 

Figure 6 is a flow chart illustrating a process for verifying suspected 
defective sectors subsequent to the detecting and tracking process of Figure 5. 
Significantly, in order to minimally inconvenience the user, the verification 
process can be advantageously executed just before ejection of the disc. 

25 Specifically, in step 601, an existing defect list can be loaded. Notably, the 
defect list can be a sorted defect list. Additionally, in step 602 the defect 
candidate list can be loaded. Significantly, the invention is not limited to 
retrieving a previously sorted defect list and defect candidate list. Rather, in an 
alternative aspect of the present invention, the lists can be retrieved and 

30 dynamically sorted in a structured order, for example ascending or descending 
order. 



WO 01/35408 



PCT/USOO/30605 



16 

In any event, in step 603, the lists can be compared and those sectors in 
the defect candidate list which are already in the defect list are discarded from 
the defect candidate list. Notably, where the lists have been sorted in a 
structured order, the defect candidate list need only be subtracted from the 
5 defect list to determine which sectors in the defect candidate list have not yet 
been added to the defect list. The remaining sectors are determined to be a set 
of suspected defective sectors which are to be subsequently verified. 

In step 604, the remaining sectors are individually verified to determine 
whether, in fact, the sectors are defective. If it is determined that a suspected 
10 defective sector is in fact defective, in step 605 the defective sector can be 

added to the defect list and removed from the defect candidate list. Otherwise, 
the defective sector is simply removed from the defect candidate list. Finally, in 
steps 606 and 607, the defect list can be sorted according to the structured 
order and written to the defect list in the re-writable DVD. 



WO 01/35408 



PCT/USOO/30605 



17 

CLAIMS 



1 . A method for updating a defect list in a DVD comprising: 
playing back the DVD; 
5 detecting at least one unrecoverable error associated with at least one 

corresponding sector during said playbacks- 
adding a reference to each sector associated with said unrecoverable error 

to a defect candidate list; 

determining whether each sector referred to in said defect candidate list is 
10 a defective sector; and 

adding a reference to each sector determined to be a defective sector to 

the defect list. 



2. The method of claim 1, wherein said determining step comprises: 

15 identifying each sector having a reference in both the defect list and said 

defect candidate list; 

removing said identified sectors from said defect candidate list; and, 
determining whether each sector remaining in said defect candidate list is 

a defective sector. 

20 

3. The method of claim 1 , further comprising: 

removing from said defect candidate list a reference to each sector for 
which a corresponding reference has been added to the defect list. 



25 4. The method of claim 2, wherein said step of identifying each sector having 
a reference in both the defect list and said defect candidate list comprises: 
sorting said defect candidate list in a structured order; 
sorting the defect list in said structured order; and, 

subtracting said sorted defect candidate list from said sorted defect list, 
30 said subtraction resulting in said identified sectors. 



WO 01/35408 



PCT/USOO/30605 



18 

5. The method of claim 4, wherein said sorting steps comprise: 
sorting said defect candidate list in ascending order; and, 
sorting the defect list in ascending order. 

5 6. The method of claim 4, wherein said sorting steps comprise: 
sorting said defect candidate list in descending order; and, 
sorting the defect list in descending order. 

7. A method for updating a defect list in a DVD comprising: 
10 processing sectors on the DVD during a playback operation; 

adding references to selected ones of said processed sectors to a defect 
candidate list; 

identifying defective sectors among said selected ones of said processed 
sectors; and, 

15 adding references to said identified defective sectors to the defect list. 

8. The method of claim 8, wherein said step of adding references to selected 
ones of said processed sectors to a defect candidate list comprises: 

detecting an unrecoverable error during said playback operation; 
20 identifying a processed sector associated with said unrecoverable error; 

and, 

adding a reference to said identified sector to said defect candidate list. 

9. The method of claim 8, wherein said identifying step comprises: 

25 identifying each sector having a reference in both the defect list and said 

defect candidate list; 

removing references to said identified sectors from said defect candidate 
list; and, 

determining whether each sector remaining in said defect candidate list is 
30 a defective sector. 



WO 01/35408 



PCTYUS00/30605 



19 

10. The method of claim 8, further comprising: 

removing from said defect candidate references to each sector for which a 
corresponding reference has been added to the defect list. 

5 11. The method of claim 9, wherein said step of identifying each sector having 
a reference in both the defect list and said defect candidate list comprises: 
sorting said defect candidate list in a structured order; 
sorting the defect list in said structured order; and, 

subtracting said sorted defect candidate list from said sorted defect list, 
10 said subtraction resulting in said identified sectors. 

12. The method of claim 1 1, wherein said sorting steps comprise: 
sorting said defect candidate list in ascending order; and, 
sorting the defect list in ascending order. 

15 

13. The method of claim 1 1, wherein said sorting steps comprise: 
sorting said defect candidate list in descending order; and, 
sorting the defect list in descending order. 

20 14. A machine readable storage having stored thereon, a computer program 
having a plurality of code sections for updating a defect list in a DVD, said code 
sections executable by a machine for causing the machine to perform the steps 
of: 

playing back the DVD; 
25 detecting at least one unrecoverable error associated with at least one 

corresponding sector during said playback; 

adding a reference to each sector associated with said unrecoverable error 
to a defect candidate list; 

determining whether each sector referred to in said defect candidate list is 
30 a defective sector; and 

adding a reference to each sector determined to be a defective sector to 
the defect list. 



WO 01/35408 PCT/US00/30605 

20 

15. The machine readable storage of claim 14, wherein said determining step 
comprises: 

identifying each sector having a reference in both the defect list and said 

defect candidate list; 

removing said identified sectors from said defect candidate list; and, 
determining whether each sector remaining in said defect candidate list is 

a defective sector. 

16. The machine readable storage of claim 14, further comprising: 
removing from said defect candidate list a reference to each sector for 

which a corresponding reference has been added to the defect list. 

17. The machine readable storage of claim 1 5, wherein said step of identifying 
each sector having a reference in both the defect list and said defect candidate 
list comprises: 

sorting said defect candidate list in a structured order; 
sorting the defect list in said structured order; and, 

subtracting said sorted defect candidate list from said sorted defect list, 
said subtraction resulting in said identified sectors. 

18. The machine readable storage of claim 17, wherein said sorting steps 
comprise: 

sorting said defect candidate list in ascending order; and, 
sorting the defect list in ascending order. 

19. The machine readable storage of claim 17, wherein said sorting steps 
comprise: 

sorting said defect candidate list in descending order; and, 
sorting the defect list in descending order. 



WO 01/35408 



PCT/US00/30605 



21 

20. A machine readable storage having stored thereon, a computer program 
having a plurality of code sections for updating a defect list in a DVD, said code 
sections executable by a machine for causing the machine to perform the steps 
of: 

5 processing sectors on the DVD during a playback operation; 

adding references to selected ones of said processed sectors to a defect 
candidate list; 

identifying defective sectors among said selected ones of said processed 
sectors; and, 

10 adding references to said identified defective sectors to the defect list. 

21 . The machine readable storage of claim 20, wherein said step of adding 
references to selected ones of said processed sectors to a defect candidate list 
comprises: 

15 detecting an unrecoverable error during said playback operation; 

identifying a processed sector associated with said unrecoverable error; 

and, 

adding a reference to said identified sector to said defect candidate list. 

20 22. The machine readable storage of claim 20, wherein said identifying step 
comprises: 

identifying each sector having a reference in both the defect list and said 
defect candidate list; 

removing references to said identified sectors from said defect candidate 
25 list; and, 

determining whether each sector remaining in said defect candidate list is 
a defective sector. 

23. The machine readable storage of claim 20, further comprising: 
30 removing from said defect candidate references to each sector for which a 

corresponding reference has been added to the defect list. 



WO 01/35408 



PCT/USOO/30605 



22 

24. The machine readable storage of claim 21, wherein said step of identifying 
each sector having a reference in both the defect list and said defect candidate 
list comprises: 

sorting said defect candidate list in a structured order; 
sorting the defect list in said structured order; and, 

subtracting said sorted defect candidate list from said sorted defect list, 
said subtraction resulting in said identified sectors. 

25. The machine readable storage of claim 24, wherein said sorting steps 
comprise: 

sorting said defect candidate list in ascending order; and, 
sorting the defect list in ascending order. 

26. The machine readable storage of claim 24, wherein said sorting steps 
comprise: 

sorting said defect candidate list in descending order; and, 
sorting the defect list in descending order. 



WO 01/35408 



PCTVUSOO/30605 




WO 01/35408 



PCT/US00/30605 



2/8 



1 1 




112 



FIG. 2 



WO 01/35408 



PCT/USOO/30605 




FIG. 3 



WO 01/35408 



PCT/USOO/30605 



4/8 



Root 



100 



I I 



DEFECT LIST 



.425 



DEFECT 
CANDIDATE LIST 



430 



VIDEO TS 



AUDIO TS 



JACKET P 



.401 



402" 



VIDEO TS.IFO 



403 



VIDEO TS.VOB 



404 

no 



'415 



-A 



VIDEO TS.BUP 



405A 



40 



6A 



407A 







-ooo 


vrs. 


-01. 


_0.IFO 




VTS 


01_ 


0.VOB 




vrs_ 


01_ 


_1.VOB 




o 






o 






o 




vrs_ 


_01_ 


_9.VOB | 




VTS_ 


01. 


_0.BUP 



409A 



VTS 



_01_0.1FO | 



405B 



I 1 

_[ vrs_oi_o.voB | 

406^r 



- - J VTS_01_1.VOB | 
407B o 

408.B o 

~ | VrS_01_9.VOB | 



VTS 01 0.BUP 



409B 



DEFECT LIST 
BACKUP 



DEFECT 
CANDIDATE LIST 
BACKUP 



135 



'440 



o 
o 
o 



USER 
DEFINED 



420 



FIG. 4 



WO 01/35408 



PCT7US00/30605 



5/8 





r 


A 




Begin 






f 




Read Next 


». 


Sector 


502 




r 




Uncorrectable 
Error? 

\^ 






r 


503--^ 


Add Sector to 

Defect 
Candidate List 






r 


S 


Continue 



-501 



Playback? 



504 





r 


Sort Defect 
Candidate List 




r 


Perform 
Verification 
(Figure 6) 




r 


r a 
End 



-505 



.506 



FIG. 5 



WO 01/35408 



PCT7USOO/30605 



6/8 



Begin 




r 


Load Defect 
List 




r 


Load Defect 
Candidate List 




f 



-601 



-602 



Discard 
Candidate 
Sectors Already 
in Defect List 



-603 



1 


r 


Verify Remaining 
j Sectors 




r 


Add Verified 
Sectors to Defect 
List 




r 


Sort Defect 
List 




f 


Write Defect 
List to DVD 




r 


End 



-604 



-605 



-606 



-607 



FIG. 6 



WO 01/35408 



PCT/US00/30605 



7/8 



700- 



DVD 



PHYSICAL DATA STRUCTURE 



701 


VIDEO 


VIDEO TITLE 


VIDEO TITLE 




VIDEO TITLE 




MANAGER 


SET 1 


SET 2 




SET 99 



701 



702 



CONTROL 


DISC 


CONTROL 

DATA 
BACKUP 




DATA 


MENU 





7- 



703 



/ ^02 



CONTROL 


TITLE MENU 


TITLE 
CONTENT 
(VOBS) 


CONTROL 


DATA 


(VOBS) 


DATA BACKUP 



703 



VOB 


VOB 




VOB 


^-704 









CELL 


CELL 




CELL 



705 



707' 





VQBU 


VOBU 




VOBU 






(0.4 -1.0 s) 


(0.4- 1.0 s) 




(0.4- 1.0 s) 


^""^706 














OTHER PACK 




OTHER PACK 


NV_PCK 


(A PClCv 


_PCX, 




(A PCK, v_poc 




SP_PCK) 






3»_PCK) 



-707 



START 


SYSTEM 


PROGRAM 


STUFFING 


STUFFING 


PACKET 1 




PACKET N 


CODE 


CLOCK 


MUX RATE 


LENGTH 





FIG. 7 



START 


STREAM 


PACKET 


MISC. 


PACKET-DEPENDENT DATA 


CODE 


ID 


LENGTH 


(VIDEO, AUDIO, SUBPIQ 



WO 01/35408 



PCT/US00/30605 



8/8 



Root 



I I 

VIDEO TS 





AUDIOJTS 







i i 



USER 
DEFINED 



^801 



802 



— j VIDEO_TS.lFO | 



803 



VIDEO TS.vce 



804 



VIDEO TS.BUP 



no 





JACKET_P 









'815 



.820 



-ooo- 



805A 



80' 



6A 



807A 



vrs. 


.01 


_0.lFO 




vrs 


01. 


_0.VOB | 




vrs_ 


01. 


_1.VOB 




o 






o 






o 




vrs_ 


01. 


_9.VOB 






01_ 


_0.BUP 



809A 



-a 



vrs 01 o.ifo 



i805B 



] \ vrs_oi_o.voB 

I806B" 



VTS 01 1.VOB 



|807B 
i808B 



o 
o 
o 



VTS 01 9.VOB 



i 



VTS_01_0.BUP 



809B 



o 
o 
o 



FIG. 8 



INTERNATIONAL SEARCH REPORT 



Ir ..^national Application No 

PCT/US 00/30605 



A. CLASSIFICATION OF SUBJECT MATTER 

IPC 7 G11B20/18 



According to International Patent Classification (IPC) or to both national classification and IPC 



B. FIELDS SEARCHED 



Minimum documentation searched (classification system followed by classification symbols) 

IPC 7 G11B 



Documentation searched other than minimum documentation to the extent that such documents are included in the fields searched 



Electronic data base consulted during the international search (name of data base and. where practical, search terms used) 

EPO-Internal , WPI Data, PAJ, IBM-TDB 



C. DOCUMENTS CONSIDERED TO BE RELEVANT 



Category ° Citation of document, with indication, where appropriate, of the relevant passages 



Relevant to claim No. 



US 5 895 438 A (Y0MT0UBIAN RUBEN) 
20 April 1999 (1999-04-20) 



column 2, line 5 - line 42 
column 5, line 17 - line 51 
column 6, line 4 - line 52 



1,3,7,8, 
10,14, 
16,20, 
21,23 



-/-- 



m 



Further documents are listed in the continuation of box C. 



Patent family members are listed in annex. 



° Special categories of cited documents : 

"A" document defining the general state of the art which is not 
considered to be of particular relevance 

'E* earlier document but published on or after the international 
filing date 

"L" document which may throw doubts on priority claim(s) or 
which is cited to establish the publication date of another 
citation or other special reason (as specified) 

"O* document referring to an oral disclosure, use, exhibition or 
other means 

■P" document published prior to the international filing date but 
later than the priority date claimed 



■T later document published after the international filing date 
or priority date and not in conflict with the application but 
cited to understand the principle or theory underlying the 
invention 

'X' document of particular relevance; the claimed invention 
cannot be considered novel or cannot be considered to 
involve an inventive step when the document is taken alone 

"Y" document of particular relevance; the claimed invention 

cannot be considered to involve an inventive step when the 
document is combined with one or more other such docu- 
ments, such combination being obvious to a person i 
in the art. 

document member of the same patent family 



Date of the actual completion of the international search 



2 February 2001 



Date of mailing of the international search report 



13/02/2001 



Name and mailing address of the ISA 

European Patent Office, P.B. 5818 Patentlaan 2 
NL - 2280 HV Rijswijk 
Tel. (+31-70) 340-2040, Tx. 31 651 epo nl, 
Fax: (+31-70) 340-3016 



Authorized officer 



Ogor, M 



Form PCT/ISA/210 (second sheet) (July 1992) 



page 1 of 2 



INTERNATIONAL SEARCH REPORT 



u.^er national Application No 

PCT/US 00/30605 



C.(Continuation) DOCUMENTS CONSIDERED TO BE RELEVANT 



Category G 



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



Relevant to claim No. 



EP 0 889 472 A (MATSUSHITA ELECTRIC IND CO 
LTD) 7 January 1999 (1999-01-07) 



figures 8,14,15 
column 4, line 53 -column 5, line 10 
column 9, line 31 - line 36 
column 13, line 19 - line 29 
column 16, line 28 -column 18, line 17 

US 4 498 146 A (MARTINEZ MARIA N) 
5 February 1985 (1985-02-05) 



figure 3 
column 4, line 27 - line 43 
column 4, line 66 -column 5, line 43 
column 11, line 45 -column 13, line 4 



US 5 235 585 A (BISH JOHN E 
10 August 1993 (1993-08-10) 



ET AL) 



column 2, line 37 - line 62 

column 5, line 65 -column 6, line 30 

column 7, line 7 - line 26 

column 10, line 57 - line 60 



1,2,4,5, 

7-9,11, 

12,14, 

15,17, 

18, 

20-22, 
24,25 



1,3,7,8, 
10,14, 
16,20, 
21,23 



1,2,4-9, 
11-15, 
17-21, 
24-26 



Form PCT/ISA/210 (continuation of second sheet) (July 1992) 



page 2 of 2 



INTERNATIONAL SEARCH REPORT 

Information on patent family members 



4. ^national Application No 

PCT/US 00/30605 



Patent document 
cited in search report 



Publication 
date 



Patent family 
member(s) 



Publication 
date 



US 5895438 



20-04-1999 



NONE 



EP 


0889472 


A 


07-01- 


-1999 


DE 


69703537 


D 


?i -l ?-?non 












US 


6134214 


A 


17-10-2000 












CN 


1214146 


A 


14-04-1999 












DE 


69703558 


D 


21-12-2000 












EP 


0964398 


A 


15-12-1999 












EP 


0964399 


A 


15-12-1999 












WO 


9735309 


A 


25-09-1997 












JP 


3061799 

JUU1 / J ^ 


R 

u 


i o-07-?fion 

±\J VJ / L.UUU 












JP 


2000067525 


A 


03-03-2000 












JP 


3061800 


B 


10-07-2000 












JP 


2000067526 


A 


03-03-2000 


us 


4498146 


A 


05-02- 


-1985 


AU 


554707 


B 


28-08-1986 












AU 


1157583 


A 


23-02-1984 












DE 


3374461 


D 


17-12-1987 












EP 


0116544 


A 


29-08-1984 












JP 


59501383 


T 


02-08-1984 












WO 


8400628 


A 


16-02-1984 


us 


5235585 


A 


10-08- 


-1993 


JP 


1998475 


C 


08-12-1995 












JP 


5204559 


A 


13-08-1993 












JP 


7027440 


B 


29-03-1995 



Form PCT/ISA/210 (patent family annex) (July 1992)