U.S. patent application number 12/186305 was filed with the patent office on 2008-12-25 for multi-layered information recording medium, reproduction apparatus, recording apparatus, reproduction method, and recording method.
This patent application is currently assigned to Matsushita Electric Industrial Co., Ltd.. Invention is credited to Takashi Ishida, Motoshi Ito, Mamoru Shoji, Hiroshi UEDA, Yoshikazu Yamamoto.
Application Number | 20080316884 12/186305 |
Document ID | / |
Family ID | 26625604 |
Filed Date | 2008-12-25 |
United States Patent
Application |
20080316884 |
Kind Code |
A1 |
UEDA; Hiroshi ; et
al. |
December 25, 2008 |
MULTI-LAYERED INFORMATION RECORDING MEDIUM, REPRODUCTION APPARATUS,
RECORDING APPARATUS, REPRODUCTION METHOD, AND RECORDING METHOD
Abstract
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.
Inventors: |
UEDA; Hiroshi; (Nara,
JP) ; Ito; Motoshi; (Osaka, JP) ; Ishida;
Takashi; (Kyoto, JP) ; Yamamoto; Yoshikazu;
(Osaka, JP) ; Shoji; Mamoru; (Osaka, JP) |
Correspondence
Address: |
MARK D. SARALINO (PAN);RENNER, OTTO, BOISSELLE & SKLAR, LLP
1621 EUCLID AVENUE, 19TH FLOOR
CLEVELAND
OH
44115
US
|
Assignee: |
Matsushita Electric Industrial Co.,
Ltd.
|
Family ID: |
26625604 |
Appl. No.: |
12/186305 |
Filed: |
August 5, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11382517 |
May 10, 2006 |
7423941 |
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12186305 |
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|
10339630 |
Jan 9, 2003 |
7123556 |
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11382517 |
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Current U.S.
Class: |
369/53.17 ;
369/94; G9B/20.059; G9B/27.05; G9B/3.108; G9B/5.202 |
Current CPC
Class: |
G11B 27/329 20130101;
G11B 2220/2575 20130101; G11B 2020/1826 20130101; G11B 2220/216
20130101; G11B 2220/2537 20130101; G11B 2220/20 20130101; G11B
20/1883 20130101; G11B 2020/1893 20130101; G11B 2220/235 20130101;
G11B 2220/237 20130101 |
Class at
Publication: |
369/53.17 ;
369/94; G9B/5.202; G9B/3.108 |
International
Class: |
G11B 5/58 20060101
G11B005/58; G11B 3/74 20060101 G11B003/74 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 22, 2002 |
JP |
2002-013491 |
Mar 1, 2002 |
JP |
2002-056635 |
Claims
1-7. (canceled)
8. 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
that is information for managing a defective area detected in the
user data area, wherein the defect list storing area is provided in
a prescribed layer of the plurality of recording layers, the defect
list is information for managing a defective area detected in the
prescribed layer and a defective area detected in a recording layer
other than the prescribed layer, and at least one of the plurality
of recording layers other than the prescribed layer comprises a
spare defect list storing area that is used to record the defect
list when the defect list storing area is not usable.
9. An apparatus for recording information in a multi-layered
information recording medium according to claim 8, the apparatus
comprises: a defect list recording section for recording the defect
list, wherein the defect list recording section records the defect
list in the spare defect list storing area when the defect list
storing area is not usable.
10. An apparatus for reproducing information recorded on a
multi-layered information recording medium according to claim 8,
the apparatus comprising: a defect list reproducing section for
reproducing the defect list, wherein the defect list reproducing
section reproduces the defect list from the spare defect list
storing area when the defect list storing area is not usable.
Description
[0001] This application is a continuation application of U.S.
patent application Ser. No. 11/382,517 filed on May 10, 2006, which
is a divisional of U.S. application Ser. No. 10/339,630 filed Jan.
9, 2003, now U.S. Pat. No. 7,123,556, the entire disclosures of
which are incorporated herein by reference, and is related to
co-pending sibling U.S. application Ser. Nos. 11/382,519,
11/382,520, and 11/382,522 all filed on May 10, 2006, and U.S.
Application Nos. ______ (Docket No. OKUDP0182USE), ______ (Docket
No. OKUDP0182USG) and ______ (Docket No. OKUDP0182USH), all filed
concurrently herewith.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a multi-layered information
recording medium comprising at least two recording layers, a
reproduction apparatus, a recording apparatus for use with the
multi-layered information recording medium, a reproduction method
for reproducing information from the multi-layered information
recording medium, and a recording method for recording information
in the multi-layered information recording medium.
[0004] 2. Description of the Related Art
[0005] A typical information recording medium which has a sector
structure is an optical disc. In recent years, AV 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.
[0006] Providing a plurality of recording layers is useful in
increasing 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.
[0007] FIG. 1 shows a structure of a typical optical disc medium 1
including a track 2 and sectors 3. On the optical 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 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
(herein after, abbreviated as "PSN(s)") are assigned to the sectors
3 in order to identify the respective sectors 3. Further,
consecutive logical sector numbers (herein after, 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.
[0008] FIG. 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 FIG. 2 is briefly
described. Grooves are formed on transparent 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,
thereby obtaining a single read-only optical disc 30. In this
specification, for convenience of description, in FIG. 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 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.
[0009] FIGS. 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. FIG. 3A shows a
spiral groove pattern of the second recording layer 42. FIG. 3B
shows a spiral groove pattern of the first recording layer 41. FIG.
3C shows the reproduction direction in user data areas 8 provided
on the recording layers 41 and 42. FIG. 3D shows sector numbers
assigned to the recording layers 41 and 42.
[0010] 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 back side of the sheets of FIGS. 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 FIG. 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 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 FIG. 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 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 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.
[0011] FIGS. 4A, 4B, 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.
FIG. 4A shows a spiral groove pattern of the second recording layer
44. FIG. 4B shows a spiral groove pattern of the first recording
layer 43. FIG. 4C shows the reproduction direction in user data
areas 8 provided on the recording layers 43 and 44. FIG. 4D shows
sector numbers assigned to the recording layers 43 and 44.
[0012] 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 back side of the sheets of FIGS. 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
FIG. 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
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 FIG. 4D, the PSNs and LSNs of each of the recording layers 43
and 44 are incrementally assigned along the reproduction 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 LSN in the
user data area 8 of the first recording layer 43, and increments by
ones toward the innermost perimeter.
[0013] 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.
[0014] FIG. 5A shows an area layout of a typical rewritable disc
45. The rewritable disc 45 includes only one 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 11,
and a defect management area 12. The lead-out area 6 includes
another defect management 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.
[0015] A disc information area 10 stores disc information regarding
a parameter(s) or a format necessary for recording/reproduction of
data of the optical disc. The disc information area 10 is also
included in a read-only optical disc, 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 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.)
[0016] 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 incorporated 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.
[0017] 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, defect management is generally performed.
[0018] 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 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 FIG. 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.
[0019] 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 13 is placed; a defect management
sector (DMS) storing area 21 storing data for managing the defect
of the defect management area 12 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 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.
[0020] FIG. 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 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.
[0021] FIG. 5C shows data stored in a DL storing area 22. The data
stored in the DL storing area 22 area DL identifier 32 which is a
unique identifier for identifying a defect list, and the number of
defective sectors 33 registered 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.
[0022] 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 single defective sector. The
replacement status 40 is a flag indicating whether or not
replacement is applied to a defective 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 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
address 41. The n defect entry areas are arranged in ascending
order of the address of a defective sector.
[0023] 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.
[0024] 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 directed to
management of only one recording layer.
[0025] 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 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 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.
[0026] As used herein, the term "initial process" for an optical
disc refers to a process in which defect management 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
[0027] 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.
[0028] 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.
[0029] In one embodiment of this invention, the reference layer may
be one of the plurality of recording layers which is located at a
predetermined distance from the data read-out surface of the
multi-layered information recording medium.
[0030] 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.
[0031] In one embodiment of this invention, the reference layer may
be 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.
[0032] 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.
[0033] In one embodiment of this invention, the defect list storing
area may be provided in one of the plurality of 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.
[0034] 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 area, the at least one
replacement area may be used in place of the at least one defective
area.
[0035] 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.
[0036] 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.
[0037] In one embodiment of this invention, the multi-layered
information recording medium may further comprise 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
indicating the location of the additional defect list storing area.
The first defect list location information 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 which the additional defect list storing area is
provided.
[0038] 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 information 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 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 be adjacent to the area to which the greatest
logical address is assigned.
[0039] According to another 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; 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. 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 list storing areas when none of the plurality of first
defect list storing areas is usable.
[0040] 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.
[0041] 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 list among
the plurality of first defect list storing areas and the plurality
of second spare defect list storing areas.
[0042] 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 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 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 the reproduced defect list.
[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 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 the location of the defect list storing area
by reproducing the defect list location information stored in the
defect list location information storing area.
[0044] 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 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.
[0045] 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 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 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.
[0046] 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 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.
[0047] 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 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.
[0048] 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 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.
[0049] 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.
[0050] 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.
[0051] 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 management may further comprise replacing the
defective area present in the user data area with the replacement
area contained in the spare area.
[0052] According to another aspect of the present invention, a
method 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 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 in
the user data area based on the reproduced defect list.
[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 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 of the defect list storing area by
reproducing the defect list location information stored in the
defect list location information storing area.
[0054] 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 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.
[0055] 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 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 is present in the
user data area.
[0056] 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 list storing area is unusable.
[0057] 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 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.
[0058] 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 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.
[0059] 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.
[0060] 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.
[0061] 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 may further comprise replacing the defective area
present in the user data area with the replacement area contained
in the spare area.
[0062] Thus, the invention described herein makes possible the
advantages of providing a defect management method capable of
shortening the time required to read a defect management area in an
initial process for a disc and efficiently managing defective
areas.
[0063] 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
[0064] FIG. 1 is a diagram showing a track and sectors in an
optical disc.
[0065] FIG. 2 is a diagram showing a principle of reproduction of
an optical disc comprising two recording layers.
[0066] FIG. 3A is a diagram showing a groove pattern of a second
recording layer in a parallel path DVD.
[0067] FIG. 3B is a diagram showing a groove pattern of a first
recording layer in a parallel path DVD.
[0068] FIG. 3C is a diagram showing a reproduction direction of a
parallel path DVD.
[0069] FIG. 3D is a diagram showing assignment of sector numbers in
a parallel path DVD.
[0070] FIG. 4A is a diagram showing a groove pattern of a second
recording layer in an opposite path DVD.
[0071] FIG. 4B is a diagram showing a groove pattern of a first
recording layer in an opposite path DVD.
[0072] FIG. 4C is a diagram showing a reproduction direction of an
opposite path DVD.
[0073] FIG. 4D is a diagram showing assignment of sector numbers in
an opposite path DVD.
[0074] FIG. 5A is a diagram showing locations of areas in a
DVD-RAM.
[0075] FIG. 5B is a diagram showing a data structure of a DMS shown
in FIG. 5A.
[0076] FIG. 5C is a diagram showing a data structure of a DL shown
in FIG. 5A.
[0077] FIG. 6 is a diagram showing locations of areas in a
multi-layered information recording medium according to Embodiment
1 of the present invention.
[0078] FIG. 7 is a diagram showing a data structure of a first
defect management area in Embodiment 1 of the present
invention.
[0079] FIG. 8 is a diagram showing a data structure of a first
spare DL storing area in Embodiment 1 of the present invention.
[0080] FIG. 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.
[0081] FIG. 10A 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.
[0082] FIG. 10B 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.
[0083] FIG. 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.
[0084] FIG. 11 is a diagram showing locations of areas in a
multi-layered information recording medium according to Embodiment
2 of the present invention.
[0085] FIG. 12 is a diagram showing a data structure of a first
defect management area in Embodiment 2 of the present
invention.
[0086] FIG. 13 is a diagram showing a recording/reproduction
apparatus according to Embodiment 3 of the present invention.
[0087] FIG. 14 is a flowchart for illustrating a procedure of
obtaining defect management information in Embodiment 3 of the
present invention.
[0088] FIG. 15 is a flowchart for illustrating a reproduction
procedure of sectors according to Embodiment 3 of the present
invention, wherein replacement is considered.
[0089] FIG. 16 is a flowchart for illustrating conversion of LSN to
PSN in Embodiment 3 of the present invention.
[0090] FIG. 17 is a flowchart for illustrating a procedure of
updating defect management information in Embodiment 3 of the
present invention.
[0091] FIG. 18 is a flowchart for illustrating a recording
procedure according to Embodiment 3 of the present invention,
wherein replacement is considered.
[0092] FIG. 19 is a diagram showing locations of areas in a
multi-layered information recording medium according to Embodiment
4 of the present invention.
[0093] FIG. 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.
[0094] FIG. 21 is a diagram showing locations of areas in a
multi-layered information recording medium according to Embodiment
5 of the present invention.
[0095] FIG. 22 is a diagram showing locations of areas in a
multi-layered information recording medium according to Embodiment
6 of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Embodiment 1
[0096] Hereinafter, a multi-layered information recording medium
according to Embodiment 1 of the present invention 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.
[0097] FIG. 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 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 FIG. 6
is referred to as a first recording layer, and the lower recording
layer (52) is referred to as a second recording layer.
[0098] The first recording layer 51 is located at a predetermined
distance from a surface of the multi-layered information 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.
[0099] 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, and a
lead-out area 604.
[0100] 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 management area 611 (DMA1) and a
second defect management area 612 (DMA2) for recording defect
management information relating to a defective area (defect
management information contains disc definition structure data, a
defect list, and the like). The middle area 603 of the first
recording layer 51 contains a third defect management area 613
(DMA3) and a fourth defect management area 614 (DMA4). The first
defect management area 611, the second defect management area 612,
the third defect management area 613, and the fourth defect
management area 614 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 medium 600, the reliability of the defect management
information is improved. A defective area is herein a defective
sector.
[0101] 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 (DMA3) of the
first recording layer 51 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 or the 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 management area 611 (DMA1) of the first recording
layer 51 when DMA1 is no longer appropriately recordable (unusable)
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 or the like.
[0102] It is now assumed that as shown in FIG. 6, a defective area
A 630 is present in the first user data area 15, 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 (FIG. 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.
[0103] Referring to FIG. 7, a data structure of the first defect
management area 611 (DMA1) will be described below. Note that the
first defect management area 611 (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.
[0104] The first defect management area 611 (DMA1) 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 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 FIG. 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 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 FIG. 7). The DDS area 700 also stores information indicating a
defect verification status or the like. If the second DL storing
area 702 becomes defective due to repetition of write operations or
the like, the third DL storing area 703 is used.
[0105] 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 sector number 712 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 711 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
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.
[0106] 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 DLheader 720. In the
example shown in FIG. 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.
[0107] 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 area is
replaced with a spare area (normal area) and indicates a value 1
when no replacement is performed. In Embodiment 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.
[0108] 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 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 (FIG. 6). The defect
entry B 722 is used to manage the defective area B 631 (FIG. 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 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.
[0109] 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 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 0000000h to 0FFFFFFh
("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 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.
[0110] 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 layer numbers 737 and 742, while 00000000h
is set in each of the replacement sector numbers 738 and 743.
[0111] 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 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.
[0112] 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 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
1000 sectors. This is because it is necessary to handle an
unbalanced situation such that 950 defective sectors are present in
the first recording layer 51 while no defective area is present in
the second 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 1000
sectors, and therefore, the total size of all DL storing areas can
be reduced.
[0113] Next, the first spare DL storing area 620 (spare DL1)
included in the second recording layer 52 will be described with
reference to FIG. 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 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).
[0114] 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 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.
[0115] In the above-described case, when the first defect
management area 611 (DMA1) is unusable, the first spare 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.
[0116] FIG. 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 FIG. 9, four DL storing areas in the first defect
management area 611 (DMA1) are determined to be defective. In this
case, a defect list is recorded in a DL storing area of the first
spare DL storing area 620 (spare DL1) contained in the second
recording layer 52. As shown in FIG. 9, when the fifth DL storing
area 705 is also defective, the defect list 709 (FIG. 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 711 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.
[0117] 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 recording media which are likely to be degraded
due to repetition of write operations. Note that in Embodiment 1
the fifth 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.
[0118] Next, with reference to FIGS. 10A and 10B, a description
will be given of the relationship between the radial 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. FIG. 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 by the DL start
sector number 712 of the DDS area 700. The first spare DL storing
area 620 (spare DL1) and the first defect management area 611
(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
FIG. 10A, the first DL storing area 701 in the first defect
management area 611 (DMA1) 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 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 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 611 (DMA1) at the same
radial position. As a result, as shown in FIG. 10B, the first
recording layer 51 is slightly shifted from the second recording
layer 52. In FIG. 10B, the first defect management area 611 (DMA1)
in the first recording layer 51 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.
[0119] 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 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 FIG. 10B.
[0120] 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 DL storing area is preferable in view
of an access time. For example, as shown in FIG. 10C compared to
FIG. 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.
[0121] 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 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).
[0122] The multi-layered information recording medium 600 according
to Embodiment 1 of the present invention has been heretofore
described.
[0123] As described above, in the multi-layered information
recording medium 600 according to Embodiment 1 of 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.
[0124] 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, 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.
[0125] 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 significantly improve
the reliability of defect management information of defects due to
degradation of medium material.
[0126] 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.
[0127] Note that Embodiment 1 shows an opposite path disc in which
recording and reproduction are performed 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 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 closer to the inner periphery than a
defect management area provided on the inner periphery.
[0128] Note that in the case of a multi-layered information
recording medium having at least three recording layers, the
multi-layered information recording medium may store DL storing
area management information in order to 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.
[0129] 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
distance from the data read-out surface of a multi-layered
information recording medium, or a recording layer which is located
at the longest distance from the data read-out surface.
[0130] 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 while a spare DL storing area is provided in other
recording layers.
Embodiment 2
[0131] Next, a multi-layered information recording medium according
to Embodiment 2 of the present invention will be described with
reference to the accompanying drawings.
[0132] FIG. 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 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 1102, and the second recording
layer 54 contains an intermediate spare area 1102' 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 that
all spare areas have the same size (the size is indicated by the
spare area size 713 (FIG. 12)). A data area 1100 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.
[0133] The head spare area 1101, the intermediate spare area 1102,
the intermediate spare area 1102', and the 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 1110 a defective area B 1112 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 replacement area A 1111.
Similarly, in a read operation, user data is read from the
replacement area A 1110 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 1113 containing the head
spare area 1101 in the first recording layer 53.
[0134] Next, the contents of defect management information in
Embodiment 2 will be described with reference to FIG. 12. FIG. 12
shows locations of areas in a first defect management area 611
(DMA1). Hereinafter, only features 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 1202. The defect entry A 1201 is information
indicating that the defective area A 1110 of FIG. 11 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 FIG. 11 is replaced with the replacement area B 1113.
Therefore, a replacement 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 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 1113 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 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.
[0135] In Embodiment 2, the defective area B 1112 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 be present in two recording
layers. If defect management was performed separately for each
recording layer, a spare area(s) corresponding to at least 1000
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
Embodiment 2, a defect list for all recording layers is stored in a
unified manner while a defective area in a certain recording 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.
[0136] The multi-layered information recording medium 800 according
to Embodiment 2 of the present invention has been heretofore
described.
[0137] 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 described in Embodiment 1.
[0138] Defect management information relating to all recording
layers contained in a multi-layered information recording 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
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.
[0139] 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 to the inner periphery of the
second recording layer 54. Similarly, in a parallel path disc in
which recording and reproduction are performed from the inner
periphery to the outer periphery in all recording layers, defective
areas can be similarly managed.
Embodiment 3
[0140] 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 apparatus 500 performs recording
and reproduction using the multi-layered information recording
mediums 600 and 800 described in Embodiments 1 and 2,
respectively.
[0141] FIG. 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 512, a buffer
513, 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 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. 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. Reference numeral 532
denotes an encoded data signal. Reference numeral 533 denotes a
modulated data signal.
[0142] 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 described 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.
[0143] In response to the laser emission permission signal 522
output from the CPU 514, the laser driving circuit 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
binarization circuit 510 to the binarized data signal 528. The
binarized data signal 528 is demodulated by the
modulation/demodulation circuit 511 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 signal 524, thereby feeding a
servo error back to the actuator 504 for focusing control or
tracking control of the lens 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 511 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.
[0144] 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 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.
[0145] 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 information and a process of
reproducing sectors while considering replacement, in order to
reproduce information recorded in the multi-layered information
recording medium 800 comprising two recording layers to which
defect management of the present invention is applied.
[0146] In a recording operation of the information
recording/reproducing apparatus 500 according to Embodiment 3 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, 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.
[0147] 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, FIGS. 11 and 12. A high level
apparatus, such 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.
[0148] FIG. 14 shows a flowchart 1400 for illustrating a procedure
of obtaining defect management information in Embodiment 3 of the
present invention.
[0149] 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.
[0150] At step 1402, the optical head section 535 reproduces a
sector which stores disc information, and the CPU 514 confirms
parameters and a format which are necessary for
recording/reproduction of the multi-layered information recording
medium 800.
[0151] 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.
[0152] At step 1404, the CPU 514 determines whether or not a DL
starting layer is present in a reference layer, by referencing a DL
start sector layer number 711 in the DDS data within the buffer
513. 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.
[0153] At step 1405, the CPU 514 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.
[0154] 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 712. The read defect list is retained
at a predetermined place in the buffer 513.
[0155] FIG. 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 management information including DDS
data and a defect list have already been retained in the buffer
513.
[0156] At the first step of this reproduction process, i.e., at
step 1501, the CPU 514 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 FIG.
16).
[0157] At step 1502, the CPU 514 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 to be reproduced. If
identical, the process proceeds to step 1504; if not, the process
proceeds to step 1503.
[0158] At step 1503, 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 to be reproduced.
[0159] At step 1504, the optical head section 535 reproduces
information recorded in a sector indicated by the PSN obtained at
conversion step 1501.
[0160] FIG. 16 is a flowchart 1600 for illustrating a procedure of
converting LSNs to PSNs (i.e., step 1501 of FIG. 15) according to
Embodiment 3 of the present invention.
[0161] At the first step 1601 of this conversion process, LSN is
converted to PSN without considering the presence or absence of
replacement, i.e., in a manner similar to when no defective sector
is present. Referring to FIG. 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,
PSN=(Smallest PSN in the first user data area 15)+LSN.
[0162] 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,
PSN=(Smallest PSN in the second user data area 16)+LSN-(the total
number of sectors in the first user data area 15).
[0163] Note that since the multi-layered information recording
medium 800 of FIG. 11 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').
[0164] At step 1602, 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 in the defect list. If registered,
the process proceeds to step 1603; if not (i.e., no replacement),
the process ends.
[0165] 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.
[0166] Note that when data is reproduced from the multi-layered
information recording medium 600 (FIG. 6) having no spare area, the
process indicated by step 1603 is omitted or the processes
indicated by steps 1602 and 1603 are omitted.
[0167] As described above, the information recording/reproduction
apparatus 500 according to Embodiment 3 of the present invention
can reproduce data from a multi-layered information recording
medium containing a defect management area. The reproduction
operation of user data which is performed after the focal point of
the laser light 536 has 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.
[0168] FIG. 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 information recording
medium, initialization and updating of defect management
information will be described.
[0169] At the first step 1701 of the updating process, the CPU 514
produces DDS data having predetermined definition 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 711
and a DL start sector number 712 in a DDS 700 before a formatting
process (FIG. 12) are set in a newly produced DDS.
[0170] 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 1704; if not, the process proceeds to step 1703.
[0171] 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 711.
[0172] At step 1704, the CPU 514 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 (FIG. 12)), the previously recorded defect list is updated to
a newly produced defect list.
[0173] At step 1705, the CPU 514 determines whether or not data is
correctly recorded in a DL storing area. If correctly recorded, the
process proceeds to step 1707. If not (the area is not usable), the
process proceeds to step 1706. 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.
[0174] At step 1706, the CPU 514 selects another usable DL storing
area. Initially, the CPU 514 determines whether 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 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.
[0175] At step 1707, the CPU 514 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 1709; if
not, the process proceeds to step 1708.
[0176] At step 1708, 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 reference layer.
[0177] 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.
[0178] At step 1710, the CPU 514 records the DDS data produced in
the buffer memory 513 in a DDS area of a multi-layered information
recording medium using the optical head section 535.
[0179] Note that in Embodiment 3, at step 1704, 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.
[0180] FIG. 18 is a flowchart 1800 for illustrating a recording
procedure according to Embodiment 3 of the present invention,
wherein replacement is considered.
[0181] 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 FIG. 21).
[0182] 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 recorded. If identical,
the process proceeds to step 1804; if not, the process proceeds to
step 1803.
[0183] 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.
[0184] 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.
[0185] 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 1807; 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.
[0186] 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 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 (FIG. 11), a replacement area is
allocated from the first intermediate spare area 1102 provided in
the recording layer 53. If the intermediate spare area 1102 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 recording 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.
[0187] 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 1808.
[0188] At step 1808, 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.
[0189] When data is recorded in the multi-layered information
recording medium 600 (FIG. 6) containing no spare 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.
[0190] 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 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 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.
[0191] Although in the above descriptions of the present invention,
reproduction/recording of information and defect 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 those skilled
in the art, falls within the scope of the claims of the present
invention.
Embodiment 4
[0192] Next, a multi-layered information recording medium according
to Embodiment 4 of the present invention will be described with
reference to the accompanying drawings.
[0193] FIG. 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 FIG. 19 is referred to as a
first recording layer, and the lower recording layer (56) is
referred to as a second recording layer.
[0194] The first recording layer 55 is located at a predetermined
distance from a surface of the multi-layered information 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 a plurality of recording layers.
[0195] 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 1900, a
lead-in area 1901, 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 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.
[0196] 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 management area 1913 (DMA2) for
recording defect management information relating to a defective
area. The head spare 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 (DMA3) 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 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.
[0197] The user data area 1903 contains a first user data area 1931
and a second user data area 1932. 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 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.
[0198] 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 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.
[0199] A data structure of the first defect management area 1912
will be described with reference to FIG. 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
other defect management areas is omitted.
[0200] FIG. 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 FIG. 7, and a 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.
[0201] The defect entry A 2021 contains defect management
information relating to a defective area A 1915 (FIG. 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 A 1915 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 recording layer 55.
[0202] The defect entry B 2022 contains defect management
information relating to a defective area B 1924 (FIG. 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 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.
[0203] 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.
[0204] 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 reproduction are performed from the inner
periphery to the outer periphery in all recording layers, defective
areas can be managed.
[0205] 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.
[0206] Note that in Embodiment 4, for the sake of simplicity, the
multi-layered information recording medium 1900 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.
[0207] In the case of a multi-layered information recording medium
having at least three recording layers, a defect management area
may be provided on the inner peripherys of all recording layers
other than the reference layer.
Embodiment 5
[0208] Next, a multi-layered information recording medium according
to Embodiment 5 of the present invention will be described with
reference to the accompanying drawings.
[0209] FIG. 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 of the present invention, the upper recording layer
(57) shown in FIG. 21 is referred to as a first recording layer,
and the lower recording layer (58) is referred to as a second
recording layer.
[0210] The first recording layer 57 is located at a predetermined
distance from a surface of the multi-layered information 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 an optical disc comprising only one recording
layer to the recording layer. A reference layer is predetermined
among a plurality of recording layers.
[0211] 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 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.
[0212] 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 management 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 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 information is improved.
[0213] 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.
[0214] 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 management 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; and
making it possible to obtain the reliability of defect management
information. Defect management areas are provided 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.
[0215] A data structure of the defect management area in Example 5
is the same as that of Example 4 described with reference to FIG.
20, and a description thereof is omitted.
[0216] 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.
[0217] 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 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.
[0218] 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 manage information relating to a defective area
with no replacement area allocated.
[0219] 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 layer.
Embodiment 6
[0220] Next, a multi-layered information recording medium according
to Embodiment 6 of the present invention will be described with
reference to the accompanying drawings.
[0221] FIG. 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 of the present invention, the upper recording layer
(59) shown in FIG. 21 is referred to as a first recording layer,
and the lower recording layer (60) is referred to as a second
recording layer.
[0222] The first recording layer 59 is located at a predetermined
distance from a surface of the multi-layered information recording
medium 2200 through which data is read out (data read-out surface).
The first recording layer 59 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.
[0223] The first recording layer 59 contains, from the inner
periphery to the outer periphery along the recording/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 area 2203, an
end spare area 2208, and a second lead-out area 2209.
[0224] 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
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
(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 management
area 2216 (DMA3), the fourth defect management area 2217 (DMA4),
the fifth defect management area 2221 (DMA5), the sixth defect
management area 2222 (DMA6), the seventh defect management area
2223 (DMA7), and the eighth defect management area 2224 (DMA8) 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.
[0225] The user data area 2203 contains a first user data area 2231
and a second user data area 2232. A defective 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.
[0226] 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 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 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.
[0227] A data structure of the defect management area in Example 6
is the same as that of Example 4 described with reference to FIG.
20, and a description thereof is omitted.
[0228] 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.
[0229] 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 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.
[0230] 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 information 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.
[0231] Note that in Embodiment 6, for the sake of simplicity, the
multi-layered information recording medium 2200 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.
[0232] 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.
[0233] According to the multi-layered information recording medium
of the present invention, all defect management information for all
recording layers is stored in a single recording layer, thereby
making it possible to access defect management information at high
speed.
[0234] According to the multi-layered information recording medium
of the present invention, a spare defect list storing 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.
[0235] According to the multi-layered information recording medium
of the present invention, a disc definition structure 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.
[0236] According to the multi-layered information recording medium
of the present invention, all defect lists in all 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.
[0237] 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.
[0238] 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.
[0239] 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 management information relating
to a plurality of recording layer.
[0240] According to the information recording method and the
information recording apparatus of the present invention, it is
possible to record information in a multi-layered information
recording medium containing defect management information relating
to a plurality of recording layer.
[0241] Various other modifications will be apparent to and can be
readily made by those skilled in the art without 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.
* * * * *