U.S. patent application number 10/783173 was filed with the patent office on 2004-08-19 for information recording medium, and method and apparatus for managing defect thereof.
Invention is credited to Fukushima, Yoshihisa, Ito, Motoshi, Sasaki, Shinji, Ueda, Hiroshi.
Application Number | 20040160868 10/783173 |
Document ID | / |
Family ID | 17889298 |
Filed Date | 2004-08-19 |
United States Patent
Application |
20040160868 |
Kind Code |
A1 |
Sasaki, Shinji ; et
al. |
August 19, 2004 |
Information recording medium, and method and apparatus for managing
defect thereof
Abstract
An information recording medium includes a disk information
area; a user area including a plurality of sectors; and a spare
area including at least one sector which, when at least one of the
plurality of sectors included in the user area is a defective
sector, is usable instead of the at least one defective sector. The
spare area is located radially inward from the user area. A
physical sector number of a sector to which a logical sector number
"0" is assigned, among the plurality of sectors included in the
user area and the at least one sector included in the spare area,
is recorded in the disk information area.
Inventors: |
Sasaki, Shinji; (Osaka,
JP) ; Ito, Motoshi; (Osaka, JP) ; Ueda,
Hiroshi; (Osaka, JP) ; Fukushima, Yoshihisa;
(Osaka, JP) |
Correspondence
Address: |
Mark D. Saralino
Renner, Otto, Boisselle & Sklar, LLP
Nineteenth Floor
1621 Euclid Avenue
Cleveland
OH
44115-2191
US
|
Family ID: |
17889298 |
Appl. No.: |
10/783173 |
Filed: |
February 20, 2004 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
10783173 |
Feb 20, 2004 |
|
|
|
09596054 |
Jun 16, 2000 |
|
|
|
6732303 |
|
|
|
|
Current U.S.
Class: |
369/47.14 ;
G9B/20.059 |
Current CPC
Class: |
G11B 2020/1826 20130101;
G11B 2220/20 20130101; G11B 20/1258 20130101; G11B 2020/1222
20130101; G11B 2020/1893 20130101; G11B 20/1883 20130101; G11B
2020/1232 20130101 |
Class at
Publication: |
369/047.14 |
International
Class: |
G11B 007/00 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 22, 1998 |
JP |
10-300803 |
Claims
What is claimed is:
1. An information reproduction method for an information recording
medium including a management information area; and a data
recording area including a plurality of sectors to which physical
sector number are respectively assigned; wherein: the management
information area includes an area for recording a physical sector
number of a sector to which a logical sector number "0" is
assigned, among the plurality of sectors included in the data
recording area, the information reproduction method comprising:
reading the management information from the information recording
medium; and obtaining the physical sector number of the sector to
which a logical sector number "0" is assigned.
2. An information reproduction method for an information recording
medium including a management information area; and a data
recording area including a plurality of sectors to which physical
sector number are respectively assigned; wherein: a physical sector
number of a sector to which a logical sector number "0" is
assigned, among the plurality of sectors included in the data
recording area, is recorded in the management information area, the
information reproduction method comprising: reading the management
information from the information recording medium; and obtaining
the physical sector number of the sector to which a logical sector
number "0" is assigned.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to an information recording
medium, and a method and an apparatus for managing a defect
thereof.
[0003] 2. Description of the Related Art
[0004] A representative information recording medium having a
sector structure is an optical disk. Recently, the density and
capacity of optical disks have been improved. Therefore, it is
important to guarantee the reliability of optical disks.
[0005] FIG. 23 shows a logical structure of a conventional optical
disk.
[0006] As shown in FIG. 23, the optical disk includes two disk
information areas 4 and a data recording area 5. The data recording
area 5 includes a user area 6 and a spare area 8. The spare area 8
is located radially outward from the user area 6 on the optical
disk.
[0007] The user area 6 includes a system reservation area 11, a FAT
(File Allocation Table) area 12, a root directory area 13, and a
file data area 14. The system reservation area 11, the FAT area 12,
and the root directory area 13 are collectively referred to as a
file management area 10. A first sector of the file management area
10 is located as a sector to which logical sector number "0"
(LSN:0) is assigned.
[0008] Methods for managing defects of an optical disk are included
in ISO/IEC10090 standards (hereinafter, referred to as the "ISO
standards") provided by the International Organization of
Standardization regarding 90 mm optical disks.
[0009] Hereinafter, two methods for managing defects included in
the ISO standards are described.
[0010] One of the methods is based on a slipping replacement
algorithm. The other method is based on a linear replacement
algorithm. These algorithms are described in Chapter 19 of the ISO
standards.
[0011] FIG. 24 is a conceptual view of the conventional slipping
replacement algorithm. In FIG. 24, each of the rectangle boxes
represents a sector. Characters in each sector represent a logical
sector number (LSN) assigned to the sector. The rectangle boxes
having an LSN represent normal sectors, and the hatched rectangle
box represents a defective sector.
[0012] Reference numeral 2401 represents a sequence of sectors
including no defective sector in the user area 6, and reference
numeral 2402 represents a sequence of sectors including one
defective sector in the user area 6.
[0013] When a first sector in the user area 6 is a normal sector,
LSN:0 is assigned thereto. LSNs are assigned to a plurality of
sectors included in the user area 6 in an increasing order from the
first sector to which LSN:0 is assigned.
[0014] When the user area 6 includes no defective sector, LSN:0
through LSN:m are assigned to the sectors in the user area 6
sequentially from the first sector to a last sector thereof as
represented by the sequence of sectors 2401.
[0015] If a sector in the sequence of sectors 2401 to which LSN:i
is assigned was a defective sector, the assignment of the LSNs is
changed so that LSN:i is not assigned to the defective sector but
to a sector immediately subsequent to the defective sector. Thus,
the assignment of the LSNs are slipped by one sector in the
direction toward the spare area 8 from the user area 6. As a
result, the last LSN:m is assigned to a first sector in the spare
area 8 as represented by the sequence of sectors 2402.
[0016] FIG. 25 shows the correspondence between the physical sector
numbers and the LSNs after the slipping replacement algorithm
described with reference to FIG. 24 is executed. The horizontal
axis represents the physical sector number, and the vertical axis
represents the LSN. In FIG. 25, chain line 2501 indicates the
correspondence between the physical sector numbers and the LSNs
when the user area 6 includes no defective sector. Solid line 2502
indicates the correspondence between the physical sector numbers
and the LSNs when the user area 6 includes defective sectors I
through IV.
[0017] As shown in FIG. 25, no LSN is assigned to the defective
sectors I through IV. The assignment of the LSNs is slipped in the
direction toward an outer portion from an inner portion of the
optical disk (i.e., in the increasing direction of the physical
sector number). As a result, the LSNs are assigned to a part of the
sectors in the spare area 8 which is located immediately after the
user area 6.
[0018] An advantage of the slipping replacement algorithm is that a
delay in access caused by a defective sector is relatively small.
One defective sector delays the access merely by a part of the
rotation corresponding to one sector. A disadvantage of the
slipping replacement algorithm is that the assignment of all the
LSNs is slipped after one defective sector. An upper level
apparatus such as, for example, a host personal computer identifies
sectors by LSNs assigned thereto. When the assignment of the LSNs
to the sectors is slipped, the host computer cannot manage user
data recorded in the optical disk. Accordingly, the slipping
replacement algorithm is not usable after the user data is recorded
in the optical disk.
[0019] FIG. 26 is a conceptual view of the conventional linear
replacement algorithm. In FIG. 26, each of the rectangle boxes
represents a sector. Characters in each sector represent a logical
sector number (LSN) assigned to the sector. The rectangle boxes
having an LSN represent normal sectors, and the hatched rectangle
box represents a defective sector.
[0020] Reference numeral 2601 represents a sequence of sectors
including no defective sector in the user area 6, and reference
numeral 2602 represents a sequence of sectors including one
defective sector in the user area 6.
[0021] If a sector in the sequence of sectors 2601 to which LSN:i
is assigned was a defective sector, the assignment of the LSNs is
changed so that LSN:i is not assigned to the defective sector.
Instead, LSN:i is assigned to, among a plurality of sectors
included in the spare area 8, a sector which is unused yet and has
a minimum physical sector number (e.g., a first sector of the spare
area 8) as represented by the sequence of sectors 2602. Thus, the
defective sector in the user area 6 is replaced with a sector in
the spare area 8.
[0022] FIG. 27 shows the correspondence between the physical sector
numbers and the LSNs after the linear replacement algorithm
described with reference to FIG. 26 is executed. The horizontal
axis represents the physical sector number, and the vertical axis
represents the LSN. In FIG. 27, the solid line 2701 indicates the
correspondence between the physical sector numbers and the LSNs
when the user area 6 includes two defective sectors. The two
defective sectors in the user area 6 are replaced by replacing
sectors in the spare area 8, respectively.
[0023] An advantage of the linear replacement algorithm is that
replacement of a defective sector does not influence other sectors
since defective sectors and replacing sectors correspond to each
other one to one. A disadvantage of the linear replacement
algorithm is that a delay in access caused by a defective sector is
relatively large. Accessing a replacing sector instead of a
defective sector requires a seek operation over a relatively long
distance.
[0024] As can be appreciated, the advantage and disadvantage of the
linear replacement algorithm are converse to the advantage and
disadvantage of the slipping replacement algorithm.
[0025] FIG. 28 shows an example of assignment of the LSNs to the
sectors. In the example shown in FIG. 28, it is assumed that the
user area 6 has a size of 100000, the spare area 8 has a size of
10000, and the user area 6 includes four defective sectors.
[0026] LSNs are assigned to the sectors in accordance with the
slipping replacement algorithm described above.
[0027] First, LSN:0, which is a first LSN, is assigned to a sector
having a physical sector number:0. Then, LSNs are assigned to the
sectors in an increasing order toward an outer portion from an
inner portion of the optical disk (i.e., toward the spare area 8
from the user area 6). No LSN is assigned to the defective sectors.
The LSN which would be assigned to each defective sector is
assigned to a sector immediately subsequent thereto. As a result,
the assignment of the LSNs is slipped in the direction toward an
outer portion from an inner portion of the optical disk by the
number of the defective sectors.
[0028] In the example shown in FIG. 28, the user area 6 includes
four defective sectors I through IV as described above. LSN:99996
through LSN:99999, which would be assigned to the four sectors I
through IV if the four sectors I through IV were not defective, are
assigned to four sectors in the spare area 8, respectively, having
physical sector numbers of 100000 through 100003. The reason for
this is that the assignment of the LSNs is slipped by the number of
the defective sectors (four in this example).
[0029] In FIG. 28, the sectors in the spare area 8 having the
physical sector numbers of 100004 through 109999 are collectively
referred to as an "LR spare area". The LR spare area is defined as
an area in the spare area 8 to which no LSN is assigned. The LR
spare area is used in the linear replacement algorithm as a
replacing area.
[0030] As shown in FIG. 27, the conventional linear replacement
algorithm has a problem in that, when a sector having a small
physical sector number is defected as a defective sector, a delay
in access caused by the defective sector is relatively large since
the distance between the defective sector and the replacing sector
is relatively long. Since the file management area 10 located in
the vicinity of the sector to which LSN:0 is assigned is accessed
each time a file is recorded, a defective sector in the file
management area 10 may directly cause undesirable reduction in the
access speed to the optical disk. The file management area 10,
which is frequently accessed, is expected to have the highest
possibility of generating a defective sector.
[0031] In order to find the first address of the replacing area
(i.e., LR spare area) used in the linear replacement algorithm, the
number of sectors by which the assignment of the LSNs is slipped in
the slipping replacement algorithm needs to be calculated. The
amount of calculation increases as the disk capacity increases.
SUMMARY OF THE INVENTION
[0032] According to one aspect of the invention, an information
recording medium includes a disk information area; a user area
including a plurality of sectors; and a spare area including at
least one sector which, when at least one of the plurality of
sectors included in the user area is a defective sector, is usable
instead of the at least one defective sector. The spare area is
located radially inward from the user area. A physical sector
number of a sector to which a logical sector number "0" is
assigned, among the plurality of sectors included in the user area
and the at least one sector included in the spare area, is recorded
in the disk information area.
[0033] In one embodiment of the invention, a logical sector number
is assigned to the sectors included in the user area other than the
at least one defective sector in a decreasing order from the sector
to which a last logical sector number is assigned.
[0034] In one embodiment of the invention, a physical sector number
of the at least one defective sector is recorded in the disk
information area.
[0035] In one embodiment of the invention, the combined user area
and spare area is divided into a plurality of zones, and a logical
sector number assigned to a first sector of each of the plurality
of zones is recorded in the disk information area.
[0036] In one embodiment of the invention, the combined user area
and spare area is divided into a plurality of zones. Data recorded
in the information recording medium is managed on an ECC
block-by-ECC block basis. A logical sector number is assigned to
the sectors included in the user area other than the at least one
defective sector so that a first sector of each of the plurality of
zones matches a first sector of a corresponding ECC block.
[0037] According to another aspect of the invention, a method for
managing a defect of an information recording medium including a
disk information area; a user area including a plurality of
sectors; and a spare area including at least one sector which, when
at least one of the plurality of sectors included in the user area
is a defective sector, is usable instead of the at least one
defective sector, the spare area being located radially inward from
the user area. The method includes the steps of (a) assigning a
last logical sector number to one of the plurality of sectors
included in the user area; (b) calculating a location fulfilling a
prescribed capacity, with a location of the sector to which the
last logical sector number is assigned being fixed; (c) assigning a
logical sector number "0" to a sector positioned at the location
calculated by the step (b); and (d) recording a physical sector
number of the sector to which the logical sector number "0" is
assigned in the disk information area.
[0038] In one embodiment of the invention, the step (b) includes
the steps of (b-1) detecting the at least one defective sector
included in the user area; and (b-2) calculating the location
fulfilling the prescribed capacity based on the number of the at
least one defective sector detected in the step (b-1).
[0039] In one embodiment of the invention, the method further
includes the step of (e) recording the at least one defective
sector detected in the step (b-1) in the information recording
medium.
[0040] In one embodiment of the invention, the combined user area
and spare area is divided into a plurality of zones, and the method
further includes the step of (f) recording a logical sector number
assigned to a first sector of each of the plurality of zones in the
disk information area.
[0041] In one embodiment of the invention, the combined user area
and spare area is divided into a plurality of zones. Data recorded
in the information recording medium is managed on an ECC
block-by-ECC block basis. The method further includes the step of
(g) assigning a logical sector number to the sectors included in
the user area other than the at least one defective sector so that
a first sector of each of the plurality of zones matches a first
sector of a corresponding ECC block.
[0042] According to still another aspect of the invention, an
apparatus for managing a defect of an information recording medium
including a disk information area; a user area including a
plurality of sectors; and a spare area including at least one
sector which, when at least one of the plurality of sectors
included in the user area is a defective sector, is usable instead
of the at least one defective sector, the spare area being located
radially inward from the user area. The apparatus executes defect
management processing, which comprises the steps of (a) assigning a
last logical sector number to one of the plurality of sectors
included in the user area; (b) calculating a location fulfilling a
prescribed capacity, with a location of the sector to which the
last logical sector number is assigned being fixed; (c) assigning a
logical sector number "0" to a sector positioned at the location
obtained by the step (b); and (d) recording a physical sector
number of the sector to which the logical sector number "0" is
assigned in the disk information area.
[0043] In one embodiment of the invention, the step (b) includes
the steps of (b-1) detecting the at least one defective sector
included in the user area; and (b-2) calculating the location
fulfilling the prescribed capacity based on the number of the at
least one defective sector detected in the step (b-1).
[0044] In one embodiment of the invention, the defect management
processing further includes the step of (e) recording the at least
one defective sector detected in the step (b-1) in the information
recording medium.
[0045] In one embodiment of the invention, the combined user area
and spare area is divided into a plurality of zones. The defect
management processing further includes the step of (f) recording a
logical sector number assigned to a first sector of each of the
plurality of zones in the disk information area.
[0046] In one embodiment of the invention, wherein the combined
user area and spare area is divided into a plurality of zones, data
recorded in the information recording medium is managed on an ECC
block-by-ECC block basis, and the defect management processing
further includes the step of (g) assigning a logical sector number
to the sectors included in the user area other than the at least
one defective sector so that a first sector of each of the
plurality of zones matches a first sector of a corresponding ECC
block.
[0047] Thus, the invention described herein makes possible the
advantages of providing (1) an information recording medium and a
method and an apparatus for managing a defect thereof for keeping a
delay in access relatively small even when a defective sector is
detected in a file management area located in the vicinity of a
sector to which LSN:0 is assigned; and (2) an information recording
medium, and a method and an apparatus for managing a defect thereof
for allowing the location of an LR spare area to be found with
substantially no calculation.
[0048] 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
[0049] FIG. 1 a block diagram showing a structure of an information
processing system in an example according to the present
invention;
[0050] FIG. 2 is a diagram showing a physical structure of an
optical disk 1;
[0051] FIG. 3 is a diagram showing a logical structure of the
optical disk 1;
[0052] FIG. 4 is a diagram showing a structure of a DMA;
[0053] FIG. 5 is a diagram showing a structure of a DDS;
[0054] FIG. 6A is a diagram showing a structure of a PDL;
[0055] FIG. 6B is a diagram showing a structure of an SDL;
[0056] FIG. 7 is a conceptual view of a slipping replacement
algorithm according to the present invention;
[0057] FIG. 8 is a graph illustrating the correspondence between
physical sector numbers and LSNs after the slipping replacement
algorithm shown in FIG. 7 is executed;
[0058] FIG. 9 is a conceptual view of a linear replacement
algorithm according to the present invention;
[0059] FIG. 10 is a graph illustrating the correspondence between
physical sector numbers and LSNs after the linear replacement
algorithm shown in FIG. 7 is executed;
[0060] FIG. 11 is a flowchart illustrating a process of examination
of a disk;
[0061] FIG. 12 is a flowchart illustrating a process of finding a
physical sector number of a sector to which LSN:0 is assigned;
[0062] FIG. 13 is a flowchart illustrating a process of the
function FUNC (TOP, END) shown in FIG. 12;
[0063] FIG. 14 is a diagram showing an example of LSNs assigned to
the sectors after the examination of the disk;
[0064] FIG. 15 is a flowchart illustrating a process of recording
data to the optical disk 1;
[0065] FIG. 16 is a flowchart illustrating a process of replacement
processing executed in steps 1508 and 1509 shown in FIG. 15;
[0066] FIG. 17 is a graph illustrating the correspondence between
physical sector numbers and LSNs after the slipping replacement
algorithm shown in FIG. 7 and the linear replacement algorithm
shown in FIG. 9 are executed;
[0067] FIG. 18 is a flowchart illustrating a process of recording
an AV file in the optical disk 1;
[0068] FIG. 19 is a diagram showing a structure of a data recording
area having the AV file recorded therein;
[0069] FIG. 20 is a diagram showing a physical structure of an
optical disk having two zones;
[0070] FIG. 21 is a graph illustrating the correspondence between
physical sector numbers and LSNs of the optical disk shown in FIG.
20 after the slipping replacement algorithm shown in FIG. 7 is
executed;
[0071] FIG. 22A is a conceptual view of a slipping replacement
algorithm according to the present invention;
[0072] FIG. 22B is a graph illustrating the correspondence between
physical sector numbers and LSNs after the slipping replacement
algorithm shown in FIG. 22A is executed;
[0073] FIG. 22C is a diagram showing a structure of a DDS of the
optical disk shown in FIG. 20;
[0074] FIG. 23 is a diagram showing a logical structure of a
conventional optical disk;
[0075] FIG. 24 is a conceptual view of a conventional slipping
replacement algorithm;
[0076] FIG. 25 is a graph illustrating the correspondence between
physical sector numbers and LSNs of the conventional optical disk
after the conventional slipping replacement algorithm is
executed;
[0077] FIG. 26 is a conceptual view of a conventional linear
replacement algorithm;
[0078] FIG. 27 is a graph illustrating the correspondence between
physical sector numbers and LSNs of the conventional optical disk
after the conventional linear replacement algorithm is executed;
and
[0079] FIG. 28 is a diagram showing an example of LSNs assigned to
the sectors of the conventional optical disk.
DESCRIPTION OF THE EMBODIMENTS
[0080] Hereinafter, the present invention will be described by way
of illustrative examples with reference to the accompanying
drawings.
EXAMPLE 1
1. Structure of an Information Processing System
[0081] FIG. 1 shows a structure of an information processing system
in a first example according to the present invention. The
information processing system includes an upper level apparatus 200
and a disk recording and reproduction apparatus 100. The disk
recording and reproduction apparatus 100 records information to a
rewritable optical disk 1 or reproduces information recorded in the
optical disk 1 in accordance with a command from the upper level
apparatus 200. The upper level apparatus 200 is, for example, a
personal computer.
[0082] The upper level apparatus 200 includes a CPU 201, a main
memory 204, a bus interface (bus I/F) 203, a processor bus 202, an
I/O bus 205, a hard disk device (HDD) 206, a display processing
section 207, and an input section 208. The upper level apparatus
200 is connected to the disk recording and reproduction apparatus
100 through the I/O bus 205.
[0083] The processor bus 202 is a high speed bus through which the
CPU 201 accesses the main memory 204. The processor bus 202 is
connected to the I/O bus 205 through the bus I/F 203.
[0084] In the example shown in FIG. 1, the I/O bus 205 is a
personal computer extended bus such as, for example, a PCI bus or
an ISA bus. The I/O bus 205 can be an arbitrary multi-purpose bus
of, for example, SCSI (Small Computer System Interface), ATA (At
Attachment), USB (Universal Serial Bus), or IEEE1394.
[0085] The display processing section 207 converts display
information sent through the I/O bus 205 into a signal such as, for
example, an RGB signal, and outputs the resultant signal.
[0086] The input section 208 receives data from an input device
such as, for example, a keyboard or a mouse and sends the data to
the CPU 201 through the I/O bus 205.
[0087] The HDD 206 is a secondary memory device for inputting and
outputting data with the main memory 204 through the I/O bus 205.
The HDD 206 has an operating system such as, for example,
MS-DOS.RTM. or Windows.RTM. and a program file stored therein. The
main memory 204 is loaded with the operating system and the program
file, and the operating system and the program file are operated by
the CPU 201 in accordance with an instruction from the user. The
operation results are displayed on a screen by the display
processing section 207.
[0088] The disk recording and reproduction apparatus 100 includes a
microprocessor 101, a data recording and reproduction control
section 102, a bus control circuit 103 and a memory 104.
[0089] The microprocessor 101 controls the elements in the disk
recording and reproduction apparatus 100 in accordance with a
control program built in the microprocessor 101 to execute various
types of processing. Defect management processing and replacement
processing described below are executed by the microprocessor
101.
[0090] The data recording and reproduction control section 102
controls recording of data to and reproduction of data from the
optical disk 1 in accordance with an instruction from the
microprocessor 101. The data recording and reproduction control
section 102 adds an error correction code to the data during
recording, and executes error detection processing and error
correction processing during reproduction. In general, data coded
by encoding processing such as, for example, CRC or ECC is recorded
in the optical disk 1.
[0091] The bus control circuit 103 receives a command from the
upper level apparatus 200 through the I/O bus 205, and transmits
and receives data with the upper level apparatus 200 through the
I/O bus 205.
[0092] The memory 104 is used for storing data during various types
of processing executed by the disk recording and reproduction
apparatus 100. For example, the memory 104 has an area used as an
intermediate buffer during data recording or reproduction and an
area used by the data recording and reproduction control section
102 for the error correction processing.
[0093] The optical disk 1 is a circular information recording
medium to which data can be recorded and from which data can be
reproduced. Usable as the optical disk 1 is an arbitrary
information recording medium such as, for example, a DVD-RAM disk.
Data recording and reproduction is performed on a sector-by-sector
basis or on a block-by-block basis.
2. Physical Structure of the Optical Disk 1
[0094] FIG. 2 shows a physical structure of the optical disk 1. The
circular optical disk 1 has a plurality of concentric tracks or a
spiral track 2 formed therein. Each of the tracks or track 2 is
divided into a plurality of sectors 3. The optical disk 1 includes
at least one disk information area 4 and a data recording area
5.
[0095] The disk information area 4 has, for example, a parameter
required for accessing the optical disk 1. In the example shown in
FIG. 2, the optical disk 1 has one disk information area 4 in an
innermost part and one disk information area 4 in an outermost part
thereof. The disk information area 4 in the innermost part is also
referred to as a "lead-in area". The disk information area 4 in the
outermost part is also referred to as a "lead-out area".
[0096] The data recording area 5 has data recorded therein. Data is
recorded to and reproduced from the data recording area 5. Each of
all sectors in the data recording area 5 has an absolute address
referred to as a physical sector number pre-assigned thereto.
3. Logical Structure of the Optical Disk 1
[0097] FIG. 3 shows a logical structure of the optical disk 1. The
data recording area 5 includes a user area 6 and a spare area
7.
[0098] The user area 6 is prepared for storing user data. Usually,
the user data is stored in the user area 6. Each of sectors
included in the user area 6 has a logical sector number (LSN)
assigned thereto, by which the sector is accessed. The upper level
apparatus 200 shown in FIG. 1 accesses a sector in the optical disk
1 using the LSN to perform recording and reproduction of data.
[0099] The spare area 7 includes at least one sector which, when a
sector in the user area 6 becomes defective, can be used in place
of the defective sector. A sector in the user area 6 becomes
defective by, for example, scratches, stains or quality decline of
the user area 6 of the optical disk 1. The spare area 7 is located
radially inward from the user area 6. Preferably, the spare area 7
is located immediately radially inward from the user area 6.
[0100] The user area 6 includes a system reservation area 11, a FAT
(File Allocation Table) area 12, a root directory area 13, and a
file data area 14. Such a structure is in conformity to an MS-DOS
file system. The structure shown in FIG. 3 is merely an
example.
[0101] The system reservation area 11 has parameter information and
volume information of the optical disk 1 stored therein as a boot
sector. Such information can be referred to by the upper level
apparatus 200.
[0102] In order for the upper level apparatus 200 to access the
optical disk 1, the upper level apparatus 200 needs to access the
system reservation area 11 with certainty. A logical sector number
"0" (LSN:0) is assigned to a first sector of the system reservation
area 11. Sizes and locations of entries in the system reservation
area 11 are predetermined.
[0103] The FAT area 12 has stored therein location information
indicating locations of files and directories in the file data area
14 and a FAT indicating locations of empty areas.
[0104] The root directory area 13 has entry information on files
and sub-directories stored therein. The entry information includes,
for example, a file name, directory name, file attribute and
updating date information.
[0105] The system reservation area 11, FAT area 12, and root
directory area 13 are collectively referred to as a file management
area 10. The file management area 10 is positioned at a location on
the optical disk 1 corresponding to a fixed LSN.
[0106] The file data area 14 has stored therein data which
represents a directory associated with the root directory and data
which represents a file. As described above, in order that the
upper level apparatus 200 may access data stored in the file data
area 14, the upper level apparatus 200 needs to access the file
management area 10 before accessing the file data area 14.
4. Method for Managing a Defect of the Optical Disk 1
[0107] In order to manage a defective sector in the optical disk 1,
a PDL (Primary Defect List) and an SDL (Secondary Defect List) are
used.
[0108] When initializing the optical disk 1, a defective sector is
detected in accordance with the slipping replacement algorithm. The
detected defective sector is registered in the PDL. When recording
data to the optical disk 1, a defective sector is detected in
accordance with the linear replacement algorithm. The detected
defective sector is registered in the SDL. The reliability of the
optical disk 1 is guaranteed by registering the defective sector in
the PDL or SDL.
[0109] The PDL and SDL are stored in a DMA (Defect Management
Area). A DDS (Disk Definition Structure) is also stored in the
DMA.
[0110] 4.1. Structure of the DMA
[0111] FIG. 4 shows a structure of the DMA. The DMA is a part of
the disk information area 4 shown in FIGS. 2 and 3.
[0112] The DMA is described as DMA1 through DMA4 in Chapter 18 of
ISO standards regarding the layout in an optical disk. Two out of
four DMAs (e.g., DMA1 and DMA2) are located in the disk information
area 4 arranged at the inner portion of the optical disk, and the
remaining two DMAs (e.g., DMA3 and DMA4) are located in the disk
information area 4 arranged at the outer portion of the optical
disk 1 (FIG. 3). In the four DMAs, identical information is
multiplex-recorded in order to compensate for a defective sector in
a DMA which cannot be replaced with a replacing sector.
[0113] FIG. 4 shows an example of the disk information area 4
arranged at the inner portion of the optical disk 1, which includes
DMA1 and DMA2 among the four DMAs.
[0114] The DMA1 has a DDS, a PDL and an SDL stored therein. DMA2
through DMA4 have an identical structure with that of DMA1.
[0115] 4.1.1 Structure of the DDS
[0116] FIG. 5 shows a structure of the DDS.
[0117] The DDS includes a header. The header includes, for example,
an identifier indicating the information is the DDS. The DDS
further includes an entry for storing partition information, an
entry for storing PDL location information, an entry for storing
SDL location information, and an entry for storing a physical
sector number of a sector to which the logical sector number "0"
(LSN:0) is assigned to.
[0118] 4.1.2 Structure of the PDL
[0119] FIG. 6A shows a structure of the PDL.
[0120] The PDL includes a header and a plurality of entries (first
through m'th entries in the example shown in FIG. 6A). The header
includes, for example, an identifier indicating the information is
the PDL and the number of entries of defective sectors registered
in the PDL. Each entry stores a physical sector number of the
defective sector.
[0121] 4.1.3. Structure of the SDL
[0122] FIG. 6B shows a structure of the SDL.
[0123] The SDL includes a header and a plurality of entries (first
through n'th entries in the example shown in FIG. 6B). The header
includes, for example, an identifier indicating the information is
the SDL and the number of entries of defective sectors registered
in the SDL. Each entry includes a physical sector number of the
defective sector and the physical sector number of the replacing
sector in which data is recorded instead of the defective sector.
The SDL is different from the PDL in having the physical sector
number of the replacing sector.
[0124] 4.2 Slipping Replacement Algorithm
[0125] FIG. 7 is a conceptual view of a slipping replacement
algorithm executed by the disk recording and reproduction apparatus
100 (FIG. 1) in the first example according to the present
invention. In FIG. 7, each of the rectangle boxes represents a
sector. Characters in each sector represent an LSN assigned to the
sector. The rectangle boxes having an LSN represent normal sectors,
and the hatched rectangle box represents a defective sector.
[0126] Reference numeral 71 represents a sequence of sectors
including no defective sector registered in the PDL, and reference
numeral 72 represents a sequence of sectors including one defective
sector registered in the PDL.
[0127] When a last sector in the user area 6 is a normal sector,
LSN:m is assigned to the last sector. LSNs are assigned to a
plurality of sectors included in the user area 6 in a decreasing
order from the last sector to which LSN:m is assigned.
[0128] When the PDL includes no defective sector, LSN:m through
LSN:0 are assigned to the sectors in the user area 6 sequentially
from the last sector to a first sector thereof as represented by
the sequence of sectors 71.
[0129] If a sector in the sequence of sectors 71 to which LSN:i is
assigned was a defective sector, the assignment of the LSNs is
changed so that LSN:i is not assigned to the defective sector but
to a sector immediately before the defective sector. Thus, the
assignment of the LSNs is slipped by one sector in the direction
toward the spare area 7 from the user area 6. As a result, the last
sector LSN:0 is assigned to a last sector of the spare area 7 as
represented by the sequence of sectors 72.
[0130] FIG. 8 shows the correspondence between the physical sector
numbers and the LSNs after the slipping replacement algorithm
described with reference to FIG. 7 is executed. The horizontal axis
represents the physical sector number, and the vertical axis
represents the LSN. In FIG. 8, chain line 81 indicates the
correspondence between the physical sector numbers and the LSNs
when the user area 6 includes no defective sector. Solid line 82
indicates the correspondence between the physical sector numbers
and the LSNs when the user area 6 includes defective sectors I
through IV.
[0131] As shown in FIG. 8, no LSN is assigned to the defective
sectors I through IV. The assignment of the LSNs are slipped in the
direction toward an inner portion from an outer portion (i.e., in
the decreasing direction of the physical sector number). As a
result, an LSN is assigned to a part of the spare area 7 located
immediately radially inward from the user area 6.
[0132] As described above, when one or more defective sectors are
registered in the PDL, the assignment of the LSNs is slipped in the
direction toward an inner portion from an outer portion of the
optical disk 1, with the location of the sector to which the last
LSN is assigned being fixed. As a result, LSNs are assigned to one
or more sectors in the spare area 7 located radially inward from
the user area 6 of the optical disk 1. The number of the sectors in
the spare area 7 to which the LSNs are assigned equals the number
of the defective sectors in the user area 6.
[0133] The location of a sector to which the LSN:0 is to be
assigned is calculated so as to fulfill a prescribed capacity
(e.g., 4.7 GB), with the location of the sector to which the last
LSN is assigned being fixed. The calculation is performed based on
the number of the defective sectors detected in the user area 6.
LSN:0 is assigned to the sector positioned at the calculated
location. The prescribed capacity is the capacity which is required
to be secured as an area in which user data can be recorded. As
described above, when the user area 6 includes one or more
defective sectors, a prescribed capacity (e.g., 4.7 GB) can always
be secured by using a part of the spare area 7 instead of the user
area 6.
[0134] When the last sector of the user area 6 is a normal sector,
the last LSN is assigned to the last sector of the user area 6.
When the last sector of the user area 6 is a defective sector, the
last LSN is assigned to a normal sector closest to the last
sector.
[0135] The physical sector number of the sector to which LSN:0 is
assigned is stored in an entry in the DDS (FIG. 5). The entry is
referred to by the upper level apparatus 200 for recording data in
the optical disk 1. By referring to the entry, the upper level
apparatus 200 can obtain the physical sector number corresponding
to LSN:0 without performing a calculation. As a result, a high
speed access to the sector having LSN:0 assigned thereto is
realized.
[0136] For recording data in the optical disk 1, the upper level
apparatus 200 needs to access the sector having LSN:0 assigned
thereto, with certainty. Accordingly, the capability of accessing
the sector to which LSN:0 is assigned at a high speed is very
effective in accessing the optical disk 1 at a high speed.
[0137] 4.3 Linear Replacement Algorithm
[0138] FIG. 9 is a conceptual view of a linear replacement
algorithm executed by the disk recording and reproduction apparatus
100 (FIG. 1). In FIG. 9, the rectangle boxes each represent a
sector. Characters in each sector represent an LSN assigned to the
sector. The rectangle boxes having an LSN represent normal sectors,
and the hatched rectangle box represents a defective sector.
[0139] Reference numeral 91 represents a sequence of sectors
including no defective sector in the SDL, and reference numeral 92
represents a sequence of sectors including one defective sector in
the SDL.
[0140] If a sector in the sequence of sectors 91 to which LSN:i is
assigned was a defective sector, the assignment of the LSNs is
changed so that LSN:i is not assigned to the defective sector.
Instead, LSN:i is assigned to a sector which is unused yet and has
a minimum physical sector number (e.g., a first sector of the LR
spare area; described later with reference to FIG. 14) as
represented by the sequence of sectors 92. Thus, the defective
sector in the user area 6 is replaced with a sector in the LR spare
area.
[0141] LSN:i can be assigned to, among the plurality of sectors
included in the LR spare area, a sector which has not been used yet
and has a maximum physical sector number (e.g., a sector having a
physical sector number which is less by 1 than the physical sector
number of the sector to which LSN:0 is assigned). It is not
important in which order the sectors in the LR spare area are
used.
[0142] FIG. 10 shows the correspondence between the physical sector
numbers and the LSNs after the linear replacement algorithm
described with reference to FIG. 9 is executed. The horizontal axis
represents the physical sector number, and the vertical axis
represents the LSN. In FIG. 10, solid line 1001 indicates the
correspondence between the physical sector numbers and the LSNs
when the user area 6 includes two defective sectors.
[0143] It can be appreciated from FIG. 10 that the distance between
the defective sector and the replacing sector (number of physical
sectors) is significantly reduced compared to that in the
conventional art (FIG. 27).
5. Operations of the Disk Recording and Reproduction Apparatus
100
[0144] The disk recording and reproduction apparatus 100 performs
the operations of 5.1 through 5.3 as initialization of the optical
disk 1. The examination of the disk (5.1) is also referred to as
the physical formatting and usually performed once on one optical
disk 1.
[0145] 5.1: Examination of the disk
[0146] 5.2: LSN assignment
[0147] 5.3: Recording of initial data in the file system
[0148] After performing the initialization, the disk recording and
reproduction apparatus 100 performs the operations of 5.4 and 5.5
each time a file is written or read.
[0149] 5.4 Recording of data (recording of the file system and the
file data)
[0150] 5.5 Reproduction of the data
[0151] Hereinafter, the above-mentioned operations will be
described in detail.
[0152] 5.1 Examination of the Disk
[0153] Examination of the disk is performed at least once before
recording data in the optical disk 1 in order to guarantee the
quality of the optical disk 1. When the number of the defective
sectors per optical disk is reduced to several by the improvement
in production technology of optical disks, it will not be necessary
to examine all optical disks to be shipped. It will be sufficient
to examine sampled optical disks.
[0154] The examination of the disk is performed by writing data on
a specific test pattern in all the sectors of the disk and then
reading the data from all the sectors. Such examination of the disk
is also referred to as "certify processing".
[0155] In the examination of the disk, the slipping replacement
algorithm is executed. As a result, one or more defective sectors
are registered in the PDL.
[0156] FIG. 11 is a flowchart illustrating a process of examination
of the disk.
[0157] In step 1101, the address of a first sector of the user area
6 is set as a writing address. In step 1102, it is determined
whether the sector address has been normally read or not. The
reason why this is determined is that, since the sector address
needs to be read in order to write the data in the sector, the data
cannot be written in the sector if an error occurs in reading the
sector address.
[0158] When it is determined that an error has occurred in reading
the sector address in step 1102, the physical sector number of the
defective sector is stored in a first defect list (step 1111).
[0159] When it is determined that no error has occurred in reading
the sector address in step 1102, specified test data is written in
the sector at the writing address (step 1103).
[0160] In step 1104, it is determined whether the writing address
is a last address or not. When the writing address is determined
not to be a last address, "1" is added in the writing address (step
1105). Then, the processing goes back to step 1102. Such processing
is repeated; and when the writing address reaches the last address,
the processing goes to step 1106.
[0161] In step 1106, the address of the first sector of the user
area 6 is set as a reading address. In step 1107, data on the
reading address is read. In step 1108, it is determined whether the
read data is identical with the written data or not (i.e., whether
the data was successfully written or not).
[0162] When it is determined an error has occurred in writing the
data in step 1108, the physical sector number of the defective
sector is stored in a second defect list (step 1112).
[0163] In step 1109, it is determined whether the reading address
is the last address or not. When the reading address is determined
not to be the last address, "1" is added in the reading address
(step 1110). Then, the processing goes back to step 1107. In step
1108, error determination is performed. Such processing is
repeated; and when the reading address reaches the last address,
the first defect list and the second defect list are put together
into one list (step 1113). The PDL is created by sorting the
sectors in the list in the order of the physical sector number
(step 1114). The PDL is recorded in the disk information area 4
together with the DDS (step 1115).
[0164] 5.2 LSN Assignment
[0165] The LSN assignment is performed as described with reference
to FIGS. 7 and 8. When a defective sector is registered in the PDL,
the assignment of the LSNs is slipped in the direction toward an
inner portion from an outer portion of the optical disk 1, with the
location of the sector to which the last LSN is assigned being
fixed. A sector to which LSN:0 is assigned is determined, and then
the physical sector number of the sector to which LSN:0 is assigned
is stored in the DDS.
[0166] FIG. 12 is a flowchart illustrating a process of finding the
physical sector number of the sector to which LSN:0 is
assigned.
[0167] As initial setting, the physical sector number of the first
sector of the user area 6 is substituted into a variable UTSN (step
1201). The value of the variable UTSN is written in the DDS in a
later step.
[0168] Next, the value of the variable UTSN is substituted into a
variable TOP (step 1202), and the physical sector number of the
last sector of a search area is substituted into a variable END
(step 1203). The search area is an area, the number of the
defective sectors in which needs to be found. During a first loop,
the physical sector number of the first sector of the user area 6
is substituted into the variable TOP, and the physical sector
number of the last sector of the user area 6 is substituted into
the variable END.
[0169] Based on the variable TOP and the variable END, the number
of the defective sectors included in the search area is calculated
(step 1204). For example, the number of the defective sectors
included in the search area is given as a return value SKIP of a
function FUNC (TOP, END).
[0170] The value of the variable UTSN is reduced by the return
value SKIP. That is, UTSN=UTSN-SKIP is executed (step 1205). Thus,
the physical sector number of the sector positioned at a location,
obtained by skipping by the number of the defective sectors
included in the user area 6 from the first sector in the user area
6, can be obtained.
[0171] Steps 1202 through 1205 are repeated until it is determined
that the return value SKIP matches 0 in step 1206, in order to deal
with the case where a sector in the spare area 7 is registered in
the PDL as a defective sector.
[0172] The value of the variable UTSN obtained in this manner
indicates the physical sector number of the sector to which LSN:0
is to be assigned. Accordingly, the value of the variable UTSN is
stored in the DDS as the physical sector number of the first sector
of the user area 6 (step 1207).
[0173] FIG. 13 is a flowchart illustrating a process of the
function FUNC(TOP, END) in step 1204 shown in FIG. 12. The function
FUNC (TOP, END) is realized by finding the number of entries in the
PDL in the search area.
[0174] As initial setting, 0 is substituted into the variable SKIP,
which indicates the number of entries (step 1301), and the total
number of entries read from the PDL is substituted into a variable
n (step 1302).
[0175] In step 1303, it is determined whether the value of the
variable n is equal to 0 or not. When Yes, the value of the
variable SKIP is returned as a return value of the function FUNC
(TOP, END) in step 1308. When the total number of entries in the
PDL is 0, value 0 is returned as the value of the variable SKIP,
and the processing is terminated. When No in step 1303, the
processing advances to step 1304.
[0176] The physical sector number (PDE:n) of the n'th entry is read
from the PDL (step 1304). In step 1305, it is determined whether or
not the PDE:n is equal to or greater than the value of the variable
TOP and also equal to or smaller than the value of the variable
END. When Yes, the search area is considered to include a defective
sector registered in the PDL and "1" is added to the value of the
variable SKIP (step 1306). When No in step 1305, the processing
advances to step 1307.
[0177] In step 1307, "1" is subtracted from the value of the
variable n, and the processing goes back to step 1303. In this
manner, the operations in steps 1303 through 1307 are repeated for
all the entries included in the PDL. Thus, the number of the
defective sectors in the search area can be obtained as the value
of the variable SKIP.
[0178] FIG. 14 shows an example of assignment of the LSNs to the
sectors. In the example shown in FIG. 14, it is assumed that the
user area 6 has a size of 100000, the spare area 7 has a size of
10000, the number of entries registered in the PDL by the
examination of the disk (i.e., the number of the defective sectors
detected by the examination of the disk) is four, and the four
defective sectors were all detected in the user area 6.
[0179] LSNs are assigned to the sectors in accordance with the
slipping replacement algorithm described above.
[0180] First, LSN:99999, which is a last LSN, is assigned to a
sector having a physical sector number:109999. Then, the LSNs are
assigned to the sectors in a decreasing order toward an inner
portion from an outer portion of the optical disk 1 (i.e., toward
the spare area 7 from the user area 6). No LSN is assigned to the
defective sectors. Instead, the LSN which would be assigned to each
defective sector is assigned to a sector immediately before the
defective sector. As a result, the assignment of the LSNs is
slipped in the direction toward an inner portion from an outer
portion of the optical disk 1 by the number of the defective
sectors.
[0181] In the example shown in FIG. 14, the user area 6 includes
four defective sectors I through IV as described above. LSN:0
through LSN:3, which would be assigned to the four sectors I
through IV if the four sectors I through IV were not defective, are
assigned to four sectors in the spare area 7, respectively, having
physical sector numbers of 9996 through 9999. The reason for this
is that the assignment of the LSNs are slipped by the number of the
defective sectors (four in this example).
[0182] The physical sector number:9996 of the sector to which LSN:0
has been assigned is recorded in the DDS as the physical sector
number of the first sector of the extended user area 6.
[0183] In FIG. 14, the sectors in the spare area 7 having the
physical sector numbers of 0 through 9995 are collectively referred
to as an "LR spare area". The LR spare area is defined as an area
in the spare area 7 to which no LSN is assigned. The LR spare area
is used as a replacing area in the linear replacement
algorithm.
[0184] The physical sector number of the first sector of the LR
spare area is fixed to 0. The physical sector number of the last
sector of the LR spare area is obtained by subtracting 1 from the
physical sector number recorded in the DDS. Accordingly,
substantially no amount of calculation is required to access the LR
spare area.
[0185] 5.3 Recording of Initial Data in the File System
[0186] The disk recording and reproduction apparatus 100 records
initial data of the file system to the optical disk 1 in accordance
with a logical format instructed by the upper level apparatus 200.
The logical format is represented using the LSN. The initial data
is, for example, data recorded in the system reservation area 11,
the FAT area 12 and the root directory area 13 (i.e., the file
management area 10) shown in FIG. 3.
[0187] The area in which the initial data is recorded is managed by
the upper level apparatus 200 using the LSN. Especially, a first
sector of the system reservation area 11 needs to be a sector to
which LSN:0 is assigned. Accordingly, the upper level apparatus 200
cannot instruct the disk recording and reproduction apparatus 100
to record the initial data unless the LSN is determined. The
content of the initial data is determined by the upper level
apparatus 200.
[0188] The defect management during the recording of the initial
data is performed in accordance with the linear replacement
algorithm. The processing for recording the initial data is
identical with the processing for recording data in the file
management area 10 described below in section 5.4.2, and thus
detailed description thereof is omitted here.
[0189] 5.4. Recording of Data (Recording of the File System and the
File Data)
[0190] FIG. 15 is a flowchart illustrating a process of recording
data to the optical disk 1. The processing shown in FIG. 15
includes recording of data in the file data area 14 (steps 1501
through 1509) and recording of data in the file management area 10
(steps 1510 through 1517).
[0191] 5.4.1 Recording of Data in the File Data Area 14
[0192] In step 1501, a writing address is set. The writing address
is an LSN of a first sector of the file data area 14 (i.e.,
recording area) in which data is to be written. The LSN is
determined by the upper level apparatus 200, referring to the FAT
which manages locations of files and empty areas, and then is sent
to the disk recording and reproduction apparatus 100.
[0193] The FAT is read from the optical disk 1 by the disk
recording and reproduction apparatus 100 before data is written,
and then is stored in the main memory 204 of the upper level
apparatus 200. The CPU 201 refers to the FAT stored in the main
memory 204 to determine the LSN of the first sector of the
recording area. The resultant LSN is stored in the memory 104 of
the disk recording and reproduction apparatus 100 together with a
recording instruction command. The microprocessor 101 executes the
operations in the following steps based on the LSN stored in the
memory 104.
[0194] In step 1502, it is determined whether the sector address
has been normally read or not. The reason why this is determined is
that, since the sector address needs to be read in order to write
data into the sector, the data cannot be written in the sector when
an error occurs in reading the sector address.
[0195] When it is determined that an error has occurred in step
1502, the defective sector is replaced with a normal sector in the
LR spare area (FIG. 14) in step 1508.
[0196] When it is determined that no error has occurred in reading
the sector address in step 1502, data is written in a sector of the
file data area 14 designated by the LSN. The data is sent from the
I/O bus 205 of the upper level apparatus 200, buffered in the
memory 104, and written in the file data area 14.
[0197] In step 1504, verify processing is performed. The verify
processing refers to reading data from the sector in which the data
was written in step 1503 and comparing the read data with the
written data or performing an operation using an error correction
code to check whether the data was successfully written or not.
[0198] In step 1505, it is determined whether an error has occurred
or not. When it is determined that an error has occurred, the
defective sector is replaced with a normal sector in the LR spare
area (FIG. 14) in step 1509.
[0199] In step 1506, it is determined whether all the data has been
recorded or not. When it is determined that all the data has been
recorded, a writing address is set at the next LSN (step 1507).
Then, the processing goes back to step 1502. Such processing is
repeated. When it is determined that all the data has been
recorded, the recording of the data in the file data area 14 is
completed.
[0200] FIG. 16 is a flowchart illustrating a process of replacement
processing executed in steps 1508 and 1509 shown in FIG. 15.
[0201] In step 1601, a sector in the spare area 7 to which no LSN
is assigned (i.e., a sector in the LR spare area) is used as a
replacing sector.
[0202] In step 1602, data which was to be recorded in the defective
sector is recorded in the replacing sector. Although not shown in
FIG. 16, operations corresponding to those in steps 1502 through
1509 in FIG. 15 are performed in order to write the data in the
replacing sector. When an error is detected when writing the data
in the replacing sector, another sector in the LR spare area is
used as the replacing sector.
[0203] In step 1603, the physical sector number of the defective
sector and the physical sector number of the replacing sector are
registered in the SDL. Thus, the defective sector is associated
with the replacing sector used instead of the defective sector.
[0204] The optical disk 1 is not accessed to update the SDL each
time the operation in step 1603 is executed. In step 1603, the
physical sector number of the defective sector and the physical
sector number of the replacing sector are stored in a defect list
stored in the memory 104. After it is determined that all the data
has been recorded in step 1506 in FIG. 15, the SDL is created and
recorded in the disk information area 4. Processing time is
shortened by minimizing the number of times of accessing the
optical disk 1 in this manner.
[0205] 5.4.2 Recording of Data in the File Management Area 10
[0206] After the recording of the data in the file data area 14 is
completed, the data is recorded in the file management area 10. The
reason for this is that, since management data such as, for
example, FAT is updated by recording the data in the file data area
14, the updated management data needs to be recorded in the file
management area 10.
[0207] The processing of recording the data in the file management
area 10 (steps 1510 through 1517 in FIG. 15) is identical with the
processing of recording the data in the file data area 14 (steps
1501 through 1509 in FIG. 15) except for the content of the data
and the recording area. Therefore, a detailed description of the
recording of the data in the file management area 10 is
omitted.
[0208] FIG. 17 shows the correspondence between the physical sector
numbers and the LSNs after the slipping replacement algorithm and
the linear replacement algorithm are executed. The horizontal axis
represents the physical sector number, and the vertical axis
represents the LSN. In FIG. 17, chain line 1701 indicates the
correspondence between the physical sector numbers and the LSNs
when the user area 6 includes no defective sector. Solid line 1702
indicates the correspondence between the physical sector numbers
and the LSNs when the four defective sectors are registered in the
PDL and two defective sectors are registered in the SDL.
[0209] In the example shown in FIG. 17, two defective sectors are
detected when the data is recorded in the file management area 10.
The two defective sectors are replaced with replacing sectors in
the LR spare area in the spare area 7.
[0210] The file management area 10 is located in an area starting
with LSN:0. It can be appreciated from FIG. 17 that the distance
(number of physical sectors) between the defective sector in the
file management area 10 and the replacing sector in the spare area
7 is significantly shortened compared to that of the conventional
art (FIG. 27). For example, the distance in this example (FIG. 17)
is about 10000 whereas the distance in the conventional art (FIG.
27) is 100000 or more. The shortened distance enhances the access
speed to the optical disk 1.
[0211] 5.5 Reproduction of the Data
[0212] For reproducing the data, the upper level apparatus 200
refers to the management data such as, for example, FAT to search
for the location of a file. The upper level apparatus 200 instructs
the disk recording and reproduction apparatus 100 to access the
file management area 10 to refer to the management data. The disk
recording and reproduction apparatus 100 accesses the sector to
which LSN:0 is assigned, with certainty. The physical sector number
of the sector is recorded in the DDS. Accordingly, the disk
recording and reproduction apparatus 100 can access the sector to
which LSN:0 is assigned at a high speed by referring to the
DDS.
[0213] The upper level apparatus 200 instructs the reading location
in the file data area 14 to the disk recording and reproduction
apparatus 100 using the LSN. The disk recording and reproduction
apparatus 100 refers to the PDL and the SDL to convert the LSN
designated by the upper level apparatus 200 to a physical sector
number and reads the data from the sector having the physical
sector number.
[0214] As described above, in the first example according to the
present invention, the spare area 7 is located radially inward from
the user area 6 of the optical disk 1. The assignment of LSNs is
slipped in the direction toward an inner portion from an outer
portion, with the location of the sector to which the last LSN is
assigned being fixed. The location of the sector to which the first
LSN (LSN:0) is assigned is recorded in the DDS.
[0215] The last LSN is not necessarily assigned to the last sector
of the user area 6. When the last sector of the user area 6 is a
defective sector, the last LSN is assigned to a normal sector in
the user area 6 closest to the last sector.
[0216] In the first example according to the present invention, the
defect management is performed on a sector-by-sector basis.
Alternatively, the defect management can be performed on a
block-by-block basis, each block including a plurality of sectors.
In such a case, block numbers are registered in the PDL and the SDL
instead of the physical sector numbers. The defect management can
be performed by any appropriate unit. The same effect can be
obtained regardless of the unit.
[0217] In the first example according to the present invention, the
upper level apparatus 200 and the disk recording and reproduction
apparatus 100 are connected to each other through the I/O bus 205.
Alternatively, the upper level apparatus 200 and the disk recording
and reproduction apparatus 100 can be connected to each other in
any manner (e.g., with wires or in a wireless manner). The elements
in the disk recording and reproduction apparatus 100 can be
connected to one another in any manner.
EXAMPLE 2
[0218] Methods for managing a defect of an optical disk which are
preferable to AV files (Audio Visual Data Files; i.e.,
time-continuous video and audio data files), for which real-time
recording and reproduction is important have been proposed in, for
example, Goto et al., International Publication WO98/14938.
According to such methods, when AV files are recorded in the
optical disk 1, defect management is performed using a file system
which is managed by the upper level apparatus 200 without
performing replacement processing based on the linear replacement
algorithm.
[0219] Hereinafter, an example of a method for managing a defect of
an optical disk according to the present invention applied to an AV
file system will be described.
[0220] The information processing system has the structure shown in
FIG. 1. The optical disk 1 has the physical structure shown in FIG.
2 and the logical structure shown in FIG. 3. The file system is
different from the MS-DOS file system described in the first
example, but is common therewith in that the file management area
10 is positioned at a location in the user area 6 having a fixed
LSN.
[0221] 6. Operation of the Disk Recording and Reproduction
Apparatus 100
[0222] The disk recording and reproduction apparatus 100 performs
the operations of 6.1 through 6.3 as initialization of the optical
disk 1.
[0223] 6.1: Examination of the disk
[0224] 6.2: LSN assignment
[0225] 6.3: Recording of initial data in the file system
[0226] After performing the initialization, the optical recording
and reproduction apparatus 100 performs the operations of 6.4 and
6.5 each time a file is written or read.
[0227] 6.4 Recording of data (recording of the file system and the
file data)
[0228] 6.5 Reproduction of the data
[0229] The operations of 6.1, 6.2, 6.3 and 6.5 are identical with
those of 5.1, 5.2, 5.3 and 5.5, and will not be described in
detail.
[0230] 6.4 Recording of Data (Recording of the File System and the
File Data)
[0231] FIG. 18 is a flowchart illustrating a process of recording
data in the optical disk 1. The processing shown in FIG. 18
includes recording of an AV file in the file data area 14 (steps
1801 through 1809) and recording of the AV file in the file
management area 10 (steps 1810 through 1817).
[0232] 6.4.1 Recording of the AV File in the File Data Area 14
[0233] The upper level apparatus 200 issues an AV file recording
command to the disk recording and reproduction apparatus 100. The
disk recording and reproduction apparatus 100 receives the AV file
recording command and executes the processing of recording the AV
file in the file data area 14.
[0234] The processing of recording the AV file in the file data
area 14 (FIG. 18) is identical with the processing of recording the
data in the file data area 14 (FIG. 15) except for steps 1808 and
1809.
[0235] In step 1808, an area including a defective sector is
registered in the file management information as a defective
area.
[0236] In step 1809, an empty area continuous to the defective area
is set. Then, the processing goes back to step 1802.
[0237] As can be appreciated from above, the disk recording and
reproduction apparatus 100 does not perform replacement processing
even when a defective sector is detected when an AV file recording
command is received.
[0238] FIG. 19 shows a data recording area 5 after the AV file is
recorded.
[0239] It is assumed that an AV file referred to as "V1.MPG"
(hereinafter, referred to as the "V1.MPG file") is recorded in the
file data area 14 and a defective sector is detected in the AV
file. In FIG. 19, a defective area including the defective sector
is hatched. A1, A2 and A3 represent a first LSN of each area, and
L1, L2 and L3 represent a length of each area. The first LSN of the
defective area is A2, and the length thereof is L2.
[0240] The V1.MPG file is managed by a file management table stored
in the FAT area 12. The file management table is linked with a file
entry of the V1.MPG file stored in the root directory area 13.
[0241] The file management table includes therein the first LSNs
and lengths of the areas in which the AV file is located. The file
management table further includes attribute data for identifying
whether data has been recorded in the area or the area is a
defective area in which no data has been recorded. In step 1808
shown in FIG. 18, attribute data of an area starting from LSN:A2
and having a length of L2 is set to be a defective area in which no
data has been recorded. Thus, at the time of reproduction, this
area is recognized to be defective. As a result, reproduction of
the defective area can be skipped.
[0242] In the example shown in FIG. 19, the file management table
includes information on three areas on the V1.MPG file. The file
management table shown in FIG. 19 indicates that an area starting
from LSN:A1 and having a length of L1 and another area starting
from LSN:A3 and having a length of L3 have data recorded therein
and that the area starting from LSN:A2 and having a length of L2
has no data recorded therein.
[0243] As can be appreciated from the above, the file management
table allows a defective area to be identified based on the LSN.
For reproducing the V1.MPG file, the AV file can be continuously
reproduced while skipping the defective area.
[0244] The recording based on the AV file recording command is
performed on a block-by-block basis, each block including a
plurality of sectors because the size of the AV file is relatively
large. Accordingly, the information stored in the FAT area 12 and
the root directory area 13 has block addresses. The size of the
file system management information is reduced by managing the data
on a block-by-block basis. The block-by-block recording can be
performed by repeating sector-by-sector recording a plurality of
times. Accordingly, the fundamental operation of the disk recording
and reproduction apparatus 100 is similar to the operation
described above.
[0245] 6.4.2 Recording of Data in the File Management Area 10
[0246] The processing of recording the AV file in the file
management area 10 (FIG. 18) is identical with the processing of
recording the data in the file management area 10 (FIG. 15). When a
detective sector is detected when the AV file is recorded in the
file management area 10, replacement processing is performed in
steps 1816 and 1817. The reason for this is that the defective
sector detected in the file management area 10 storing the file
management table cannot be logically managed by the file management
table.
[0247] When data for which real-time recording and reproduction is
not very important, such as, for example, computer data
(hereinafter, referred to as the "PC data") is recorded in the
optical disk 1, the upper level apparatus 200 issues a PC file
recording command to the disk recording and reproduction apparatus
100. The operations of the disk recording and reproduction
apparatus 100 in this case are identical with the operations of 5.1
through 5.5.
[0248] As described above, a method for managing a defect of an
optical disk which is suitable to AV files is provided in the
second example according to the present invention.
EXAMPLE 3
[0249] A ZCLV system information recording medium, in which the
combined spare area and user area is divided into a plurality of
zones which have different disk rotation speeds, such as a DVD-RAM
disk or the like, has a guard area on the border between adjacent
zones.
[0250] FIG. 20 shows a physical structure of an optical disk 1a
having two zones. The optical disk la has zone 0 in an inner part
thereof and zone 1 located radially outward from zone 0. A guard
area 2001 is provided on the border between zones 0 and 1 so as to
cover a part of each zone. A part 2001a of the guard area 2001 in
zone 0 and a part 2001b of the guard area 2001 in zone 1 each
include at least one track.
[0251] The part 2001a and the part 2001b of the guard area 2001
have tracks of different structures. Accordingly, the signal
quality in the guard area 2001 is inferior, and therefore the guard
area 2001 is not suitable for recording. The guard area 2001 is set
as an area in which no data is to be recorded. The locations and
sizes of the zones 0 and 1 and guard area 2001 are fixed based on
the optical disk 1a.
[0252] The structure of the information processing system is as
shown in FIG. 1. The logical structure of the optical disk 1a is
identical with that of the optical disk 1 shown in FIG. 3.
[0253] FIG. 21 shows the correspondence between the physical sector
numbers and the LSNs after the slipping replacement algorithm is
executed. The horizontal axis represents the physical sector
number, and the vertical axis represents the LSN. In FIG. 21, chain
line 2101 indicates the correspondence between the physical sector
numbers and the LSNs when the user area 6 includes no defective
sector. Solid line 2102 indicates the correspondence between the
physical sector numbers and the LSNs when the user area 6 includes
four defective sectors.
[0254] As shown in FIG. 21, no LSN is assigned to the defective
sectors. The assignment of the LSNs are slipped in the direction
toward an inner portion from an outer portion of the optical disk
1a (i.e., in the decreasing direction of the physical sector
number) as in the first and the second examples.
[0255] As also shown in FIG. 21, no LSN is assigned to the guard
area 2001. The assignment of the LSNs is performed so that the LSNs
are continuous between two ends of the guard area 2001.
Accordingly, data is not recorded in the guard area 2001.
[0256] The spare area 7 and the file management area 10 having a
first sector to which LSN:0 is assigned are located in the same
zone. Accordingly, the processing of replacing a defective sector
which is detected when the data is recorded in the file management
area 10 can be performed in a single zone, without requiring a seek
operation across the border between the zones.
[0257] In a DVD-RAM disk, an error correction code is calculated
over a plurality of sectors. Therefore, the plurality of sectors is
defined as one block. For example, an ECC block includes 16
sectors. In such a case, the optical disk is designed so that
multiples of the block size are equal to the size of each zone.
However, when LSNs are assigned in accordance with the slipping
replacement $algorithm, one block can possibly be located over two
zones across the guard area 2001 depending on the number of
detected defective sectors. The reason for this is that the number
of LSNs assigned to each zone varies in accordance with the number
of the defective sectors.
[0258] FIG. 22A is a conceptual view of a slipping replacement
algorithm executed by the disk recording and reproduction apparatus
100 (FIG. 1) on the optical disk 1a. In FIG. 22A, each of the
rectangle boxes represents a sector. Characters in each sector
represent an LSN assigned to the sector. The rectangle boxes having
an LSN represent normal sectors, and the hatched rectangle boxes
represent a defective sector. In the example shown in FIG. 22A, an
ECC block for calculating the error detection code includes 16
continuous sectors. However, the number of the sectors included in
the ECC block is not limited to 16. An ECC block can include any
number of sectors.
[0259] Reference numeral 2201 represents a sequence of sectors
including no defective sector in the user area 6. Reference numeral
2202 represents a sequence of sectors including one defective
sector in the user area 6 (with no block correction). Reference
numeral 2203 represents a sequence of sectors including one
defective sector in the user area 6 (with block correction). Block
correction will be described below.
[0260] When a last sector in zone 1 is a normal sector, the last
LSN:m is assigned to the last sector of zone 1. LSNs are assigned
to the plurality of sectors included in the user area 6 in a
decreasing order from the sector to which the last LSN:m is
assigned.
[0261] When the user area 6 includes no defective sector, LSN:m
through LSN:0 are sequentially assigned from the last sector to the
first sector in the user area 6 as represented by the sequence of
sectors 2202.
[0262] When a sector in the sequence of sectors 2201 to which LSN:i
is assigned was a defective sector, the assignment of the LSNs is
changed so that LSN:i is not assigned to the defective sector but
to a sector immediately before the defective sector. Thus, the
assignment of the LSNs is slipped by one sector in the direction
toward the spare area 7 from the user area 6. As a result, LSN:0 is
assigned to a last sector of the spare area 7 as represented by the
sequence of sectors 2202.
[0263] In the sequence of sectors 2202, an ECC block to which LSN:k
through LSN:k+15 are assigned is located over the zones 0 and 1
across the border. In order to prevent one ECC block from being
located over two or more zones, block correction is performed.
[0264] A sequence of sectors 2203 is obtained as a result of block
correction performed on the sequence of sectors 2201. The sequence
of sectors 2202 includes one defective sector in zone 1. In this
case, the sector 2203 is obtained by slipping the LSN assignment to
the sequence of sectors 2202 by 15(=16-1) sectors in the direction
toward the spare, area 7 from the user area 6.
[0265] As described above, when the user area 6 includes a
defective sector, block correction of the LSN assignment is
performed so that the first sector of each zone matches the first
sector of the ECC block of the zone. Such an operation prevents one
block from being located over a plurality of zones. As a result, an
access to a plurality of zones does not occur when recording and
reproduction is performed to and from one block. This allows the
time period required for recording or reproduction of data to be
shortened. This also allows data in one block to be read
continuously. Therefore, a memory for calculation and an operation
apparatus which are required for preliminary pipeline processing
can be curtailed without disturbing the pipeline processing of
error correction.
[0266] FIG. 22B shows the correspondence between the physical
sector numbers and the LSNs after the slipping replacement
algorithm described with reference to FIG. 22A is executed. The
horizontal axis represents the physical sector number, and the
vertical axis represents the LSN. In FIG. 22B, chain line 2211 is
identical with chain line 2101 in FIG. 21, and dashed line 2212 is
identical with chain line 2102 in FIG. 21.
[0267] It is assumed that, as a result of performing assignment of
the LSNs represented by dashed line 2212, one block is located
across the guard area 2001; i.e., a part of the block is located in
zone 0 and the rest of the block (fraction of the block) is located
in zone 1.
[0268] In this case, the assignment of the LSNs is performed in an
increasing direction by the fraction of the block located in zone
1. Due to such assignment, the block located across the guard area
2001 is entirely located in zone 0, and the first sector of the
next block is located as the sector immediately after the guard
area 2001 of zone 1. Accordingly, the first sector of the block can
be located as each of recordable first sector in each zone with
certainty.
[0269] Solid line 2213 in FIG. 22B shows the results of the
assignment of the LSNs. As can be appreciated, as a result of the
assignment of the LSNs, the LSNs corresponding to the fraction of
the block are assigned to the sectors in zone 0. As can be
appreciated, the assignment of the LSNs represented by solid line
2213 prevents the block from being located across the guard area
2001.
[0270] In the optical disk la, the location of the sector to which
LSN:0 is to be assigned is calculated as a location fulfilling a
prescribed capacity (4.7 GB), with the location of the sector to
which the last LSN is assigned being fixed. The location is
calculated based on the number of the defective sectors detected in
each of the plurality of zones. LSN:0 is assigned to the sector
positioned at the resultant location. The physical sector number of
the sector to which the LSN:0 is assigned is stored in the entry of
the DDS.
[0271] The LSN assigned to the first sector of each zone is stored
in the entry of the DDS. By this operation, a high speed access to
the first sector of each zone is realized without calculation.
[0272] FIG. 22C shows a structure of the DDS. The DDS includes
entries for storing the LSNs assigned to the first sector of each
zone. The number of the entries is equal to the number of zones.
For example, when the optical disk la includes two zones (zone 0
and zone 1), the DDS includes an entry for storing an LSN assigned
to the first sector of zone 0 and an entry for storing an LSN
assigned to the first sector of zone 1.
[0273] As described above, in the third example according to the
present invention, a method for managing a defect of an optical
disk having a plurality of zones is provided. Also provided in the
third example according to the present invention is a method for
managing a defect of such an optical disk for, when block-by-block
recording is performed, preventing a block from being located
across a guard area.
[0274] In the third example, the optical disk 1a has two zones.
Alternatively, the optical disk can have three or more zones. Also,
in such cases, LSNs can be assigned to sectors so that the first
sector of the block is located as the recordable first sector of
each zone.
[0275] As described above, according to an information recording
medium of the present invention, a spare area is located radially
inward from a user area. When a defective sector is detected in a
file management area located in the vicinity of LSN:0, the
defective sector is replaced with a replacing sector in the spare
area in accordance with the linear replacement algorithm. Since the
distance between the defective sector and the replacing sector is
relatively small, a delay in access caused by the defective sector
is relatively small. The file management area, which is accessed
frequently, has a high possibility of including a defective sector.
Accordingly, the above-described reduction in the delay in access
caused by a defective sector detected in the file management area
is significantly effective in shortening the time period required
for recording or reproducing data.
[0276] A physical sector number of the sector to which LSN:0 is
assigned is stored in a disk information area. The physical sector
number of the first sector in the replacement area (LR spare area)
used in the linear replacement algorithm is fixed. The physical
sector number of the last sector in the LR spare area may be
determined by subtracting "1" from the physical sector number
recorded in the disk information area. Accordingly, the location of
the LR spare area can be obtained with substantially no calculation
by referring to the physical sector number recorded in the disk
information area.
[0277] When the information recording medium is divided into a
plurality of zones, the defective sector detected in the file
management area and the replacing sector are located in the same
zone. Accordingly, no access to the file management area is to a
plurality of zones. Thus, the time period required for recording or
reproduction of data can be shortened.
[0278] When block-by-block recording is performed, the first sector
of the block can be located as a recordable first sector in each
zone. Accordingly, an access to a plurality of zones does not occur
when recording to and reproduction from one block. This allows the
time period required for recording or reproduction of data to be
shortened. This also allows data in one block to be read
continuously. Therefore, a memory for calculation and an operation
apparatus which are required for preliminary pipeline processing
can be curtailed without disturbing the pipeline processing of
error correction.
[0279] 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.
* * * * *