U.S. patent application number 11/563721 was filed with the patent office on 2007-05-17 for data processing method and apparatus, recording medium, reproducing method and apparatus using the same method.
Invention is credited to Tadashi KOJIMA.
Application Number | 20070113153 11/563721 |
Document ID | / |
Family ID | 18744243 |
Filed Date | 2007-05-17 |
United States Patent
Application |
20070113153 |
Kind Code |
A1 |
KOJIMA; Tadashi |
May 17, 2007 |
DATA PROCESSING METHOD AND APPARATUS, RECORDING MEDIUM, REPRODUCING
METHOD AND APPARATUS USING THE SAME METHOD
Abstract
A burst error-correcting capability is largely improved. At
least the even-number row and at least the odd-number row of the
data block which is a set of data sectors are separated. An outer
parity is created for each column and an inner parity is created
for each row. Then, the outer parity is scattered with respect to
each of the sectors of the data block to be interleaved.
Inventors: |
KOJIMA; Tadashi;
(Yokohama-shi, JP) |
Correspondence
Address: |
OBLON, SPIVAK, MCCLELLAND, MAIER & NEUSTADT, P.C.
1940 DUKE STREET
ALEXANDRIA
VA
22314
US
|
Family ID: |
18744243 |
Appl. No.: |
11/563721 |
Filed: |
November 28, 2006 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
10765848 |
Jan 29, 2004 |
7124345 |
|
|
11563721 |
Nov 28, 2006 |
|
|
|
10765848 |
Jan 29, 2004 |
7124345 |
|
|
11563721 |
Nov 28, 2006 |
|
|
|
09804242 |
Mar 13, 2001 |
6718510 |
|
|
10765848 |
Jan 29, 2004 |
|
|
|
Current U.S.
Class: |
714/763 |
Current CPC
Class: |
H04L 1/0071 20130101;
H03M 13/1515 20130101; H03M 13/2909 20130101; G11B 2220/2562
20130101; H03M 13/27 20130101; G11B 2020/10759 20130101; G11B
2020/1853 20130101; H03M 13/2703 20130101; H03M 13/2903 20130101;
G11B 2020/1222 20130101; H03M 13/271 20130101; H04L 1/0065
20130101; H03M 13/151 20130101; G11B 20/1833 20130101; G11B
2020/1836 20130101 |
Class at
Publication: |
714/763 |
International
Class: |
G11C 29/00 20060101
G11C029/00 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 25, 2000 |
JP |
2000-255463 |
Claims
1. (canceled)
2. A data recording medium which is recorded information by
arranging error correction code (ECC) blocks comprising: a
plurality of sectors configured to include information; a first PO
creation block corresponding to one of the ECC blocks, being
configured by rows in the plurality of sectors; and a second PO
creation block corresponding to an other one of the ECC blocks,
being configured by rows in the plurality of sectors, a first PO
created into the first PO creation block; and a second PO created
into the second PO creation block, wherein the each row of the
first PO is disposed immediately in front of the row, except rows
of the second PO, in the second creation block.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is based upon and claims the benefit of
priority from the prior Japanese Patent Application No.
2000-255463, filed Aug. 25, 2000, the entire contents of which are
incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to a data processing method
and apparatus, and a recording medium for an error-correcting
product code favorable for use in the recording and transmission of
digital data.
[0003] More particularly, the present invention relates to a data
processing system using an error-correcting product code which
comprises an error-correcting outer parity and an error-correcting
inner parity which are effective in the case where information data
is recorded on a plurality kinds of recording media particularly
having a largely different recording density. Here, particularly,
in a method for forming the outer parity, a PO series creation by n
sets of data items aggregated by n rows is used. Consequently, even
when the error-correcting product code block is recorded on a
recording medium in an order of data transmission without carrying
out data interleave process; the capability of coping with the
defect is largely improved.
[0004] In a system in which digital data is recorded on an optical
disk by bytes (one byte is equal to eight bits) or digital data is
transmitted to a transmission channel, a Reed-Solomon
error-correcting product code block is constructed to process data.
That is, (M.times.N) bytes of data is arranged in a matrix
containing an M rows.times.N columns. Then, PO bytes
error-correcting word is added to each column of M bytes
information portion. Then, PI bytes of error-correcting words are
added to each row of N bytes information portion. Then, (M+Po)
rows.times.(N+Pi) columns Reed-Solomon error-correcting product
code block is constructed. Then, this Reed-Solomon error-correcting
product code block is either recorded on a recording medium or
transmitted to a transmission channel. The error-correcting
processing portion on the information reproduction side of the
recording medium and the receiving side of the transmission channel
are capable of correcting random errors and burst errors on the
information portion by using the error-correcting words PO and
PI.
[0005] Such Reed-Solomon error-correcting product code block has a
higher data processing efficiency with a decrease in a ratio of a
redundant portion (Pi.times.M+Po.times.N+Po.times.Pi) of the
error-correcting word with respect to the whole word referred to as
redundancy ratio, namely (M+Po).times.(N+Pi). On the other hand,
the error-correcting capability is also heightened with respect to
the random error and the burst error with an increase in the Pi and
Po.
[0006] Here, it is known that the Reed-Solomon error-correcting
code block having small M and N, namely small Pi and Po has a lower
correcting capability because of relatively higher probability of
error in error correction in the case where the Reed-Solomon
error-correcting product code blocks having the same redundancy
ratio are compared with each other.
[0007] On the contrary, it is known that since Pi and Po can be
increased at the same redundancy ratio with an increase in M and N,
a high error-correcting capability can be obtained. However, such
capability cannot be realized unless the constraint conditions
described below are satisfied.
[0008] A first constraint condition is that M+Po and M+Pi must be
equal to or less than 255 bytes as a code length for constructing
the Reed-Solomon error-correcting product code block (in the case
where the length of the code is eight bits). Incidentally, Pi
described above refers to the PI series error-correcting code
length while Po refers to the PO series error-correcting code
length.
[0009] A second constraint condition is a cost constraint resulting
from the scale of the hardware.
[0010] By the way, when considered on the basis of the above
conditions, optical disk standards such as a DVD-ROM, a DVD-RAM, a
DVD-R or the like which are the information recording media in
recent years are made public as a standard in which the improved
Reed-Solomon error-correcting product code block is adopted. Out of
these standards, the DVD-ROM and the DVD-RAM are established as
DIS16448 (DVD-ROM having a diameter of 80 mm) and DIS16449 (DVD-ROM
having a diameter of 120 mm) and DIS16825 (DVD-RAM).
[0011] In this DVD standard, the above idea is adopted with respect
to the error-correcting word processing method so that the
error-correcting capability is remarkably improved with
error-correcting word having a small redundancy ratio as compared
with the method used in the conventional optical disks.
[0012] The concept on the error-correcting method of the DVD is
basically described above, the fundamental problem is to what level
the target of the random error-correcting capability and the burst
error-correcting capability is to be set. In order to set such
level, the recording method of the recording medium and the
generation of defects resulting from the handling thereof must be
considered.
[0013] The recording/reproducing method is determined from the
recording/reproducing beam spot size resulting from the recording
wavelength and the optical system characteristic in the optical
disk system. Here, the recording density constitutes a large factor
in the determination of the error-correcting method. In particular,
in the determination of the burst error correction capability, the
defect length such as scratches or the like generated in the
handling of the discs can be determined from experience. With
respect to the error-correcting capability, the multiplication of
line recording density by the physical defect length constitutes a
burst error length of information data with the result that the
error correcting capability is required to be raised in the
improvement of the recording density.
[0014] The recording density can be described as follows with
particular reference to the reproduction system.
[0015] When, a light source wavelength is denoted by .lamda., and a
numeric aperture of an object lens is denoted by NA, the recording
density stands proportional to (NA/.lamda.).sup.2. The wavelength
adopted in the DVD is 650 nm while NA is 0.6.
[0016] In the error-correcting method, a row side inner parity of
RS (182, 172, 11) and a column side outer parity of RS (208, 192,
17) are adopted by means of PI (inner parity)=10 bytes and PO
(outer parity)=16 respectively with respect to the
(M.times.N)=(192.times.172) bytes information data block in terms
of the Reed-Solomon error-correcting product code (RS is referred
to as Reed-Solomon). The block used in this error-correcting method
is referred to as the error-correcting product code block.
[0017] Here, with respect to the error-correcting product code
block, the error is corrected in the PI series at first, and an
error mark is attached to a row whose error cannot be corrected.
Thereafter, at the time of the error correction on the PO series,
the error mark is treated as an error position. When the so-called
"erasure correction" method for calculating and extracting only
error patterns is used, a maximum of 16 rows of burst errors can be
corrected. In the DVD, since the recording density is data bit
length=0.267 .mu.m, 0.000267.times.8.times.182.times.16=6.2 mm is
given. It is possible to say that about 6 mm burst error-correcting
capability is given.
[0018] However, as a next generation DVD an examination is started
on an optical disk having a large capacity resulting from further
increase in the density. For the increase in capacity exceeding the
DVD, the recording density must be increased. Recently, in order to
meet such request, a blue laser diode having a wavelength of 450 nm
is made public. When such laser diode is used, it is expected that
the recording density can be improved by about 2.6 times in the
optical system similar to the DVD or the like. With the improvement
in the optical system, four to five times higher density can be
realized so that a fine image such as a high definition image such
as a Hi-Vision or the like can be recorded for two or more hours on
one disc.
[0019] In such increase in the density (for example, the line
density is about twice as compared with the conventional one), only
about 3 mm error-correcting capability can be provided with respect
to the burst error when the conventional error-correcting method is
introduced.
[0020] Furthermore, as described above, the error-correcting word
length is 255 bytes at most as long as 1 word=8 bit system
processing system is used. Since the PO series is 208 bytes in the
DVD standard, the burst error correcting capability is close to the
limit in the above error-correcting method so that only little
improvement can be expected.
[0021] In order to expand the error-correcting word length, the
word length may only be lengthened. With respect to the word
length, a multiple of eight can be easily used. As a consequence, 1
word=16 bits can be considered. The scale of the error-correcting
circuit as hardware is extremely large as compared with the
conventional one so that there arises many problems.
[0022] In such a case, there is generally available a technique in
which the burst error-correcting capability is improved while
maintaining the error-correcting code length by adopting a data
interleave to scatter the burst error.
[0023] However, the data interleave is not adopted even in the DVD
standard. The reason goes as follows: in the case where an error is
created which exceeds the error-correcting capability in the
reproduction processing in the case of an image signal in which
information data is compressed, the error data is scattered with
the result that a disadvantage of the reproduced image is generated
at many positions. In the reproduction processing of the image
signal, it is thought that processing of concentrating and
reproducing disadvantageous images as much as possible is favorable
as a processing of generated disadvantage. This is because the
processing can be completed with the reproduction of an instant
disadvantageous image.
[0024] Besides, a structure close to the current DVD system is
favorable for the upper compatibility with respect to the next
generation system.
[0025] Points Noted by the Inventors of the Present Invention
[0026] Generally, in the error-correcting processing method such as
a package medium or the like, the Reed-Solomon product code block
method is introduced in many cases. This is because high
performance and high efficiency can be expected with this method in
the case where defect error data such as defects generated in
package medium or the like is detected and corrected.
[0027] With respect to the unit of processed data, 1 word=1 byte (8
bits) is favorable. When the application development of the system
is considered, it is required to suppress a processing circuit to
an appropriate hardware scale. Besides, this fact is required for
facilitating a connection to the recording medium and the
transmission channel because a front and rear processing circuit is
provided in the recording on the recording medium and data
transmission to the transmission channel in addition to the
error-correcting processing.
[0028] Under these circumstances, use of the Reed-Solomon
error-correcting product code block used in the current DVD is
optimal as an error-correcting method which can corresponds to a
large improvement in the recording density of the recording medium
under the above surrounding situation.
[0029] row side inner parity RS (182, 172, 11)
[0030] column side outer parity RS (208, 192 17)
[0031] Here, the problem is that it is required to settle the
improvement of the burst error correcting capability.
[0032] In order to heighten the burst error correcting capability,
the error may only be scattered in the error detecting and
correcting capability in each of the correction code. However, an
image and an acoustic signal as information data are subject to
compression coding. In a system for recording and reproducing the
compression signal, a data structure or error-correcting processing
system is desirable which is capable of suppressing information
breakdown to a minimal level in the final reproduction of the image
and acoustic signal.
[0033] In particular, as countermeasures for dealing with the burst
error, the number of errors in one error correction block is
decreased by scattering the error signal, so that the
error-correcting capability can be improved. However, in the case
where errors are present in the number exceeding the
error-correcting capability, the dispersion of the error signal
will result in the expansion of the damage done on the whole data.
Consequently, it is difficult to adopt the method using the error
data dispersion, namely, the data interleave, which constitutes the
basic concept of heightening the burst error-correcting
capability.
BRIEF SUMMARY OF THE INVENTION
[0034] (1) Therefore, an object of the present invention is to
provide a data processing method and apparatus and a reproducing
method and apparatus, wherein the creation of an outer parity is
devised which directly affects a burst error-correcting
capability.
[0035] (2) Furthermore, an object of the present invention is to
provide a data processing method and apparatus and a reproducing
method and apparatus which can largely improve a burst
error-correcting capability even in a correction flag redundancy
ratio which is the same as the conventional one in an
error-correcting method based on byte data.
[0036] (3) Furthermore, an object of the present invention is to
provide a data processing method and apparatus and a reproducing
method and apparatus which are capable of realizing an
error-correcting process on a high-density optical disk using a
blue laser having a short wavelength up to a physical
error-correcting length larger than the conventional one.
[0037] (1A)
[0038] That is, in the first method of the present invention, one
matrix block is such that a plurality of M rows.times.N columns
data sectors are aggregated and formed. Furthermore, sub-blocks
each having the same number of Y rows is such that one matrix block
is divided and formed. Furthermore, Y error-correcting word blocks
P0-1 through P0-y are created with respect to the data in the row
(vertical) direction of Y sub-blocks. Then, one error-correcting
code block (ECC block) is such that Y error-correcting word PO-1
through P0-y are scattered and arranged in bytes at the end of each
row. Furthermore, at the end of each row, a configuration is formed
such that an error-correcting word PI in the column (horizontal)
direction is added at the end of each block.
[0039] Then, the present invention provides either a data
processing method or apparatus characterized by constructing the
ECC block, or the present invention provides a recording medium in
which such ECC block is recorded. Furthermore, the present
invention provides a method and an apparatus for reproducing the
matrix block by processing such ECC block.
[0040] Specifically, for example, in the beginning, a main block is
constructed which has larger than the maximum byte numbers (=255
bytes) and has twice as many as rows, the block being constructed
as a code length in the Reed-Solomon code in which 8 bits=1 bytes
are set as data unit.
[0041] Then, for example, an even-number row and an odd-number row
of the main block are separated to construct two sub-blocks. An
outer parity is created for each row separately in each block. The
inner parity is created in each of the rows like the prior art.
[0042] (2A)
[0043] Furthermore, in another method of the present invention, one
error-correcting code block (ECC block) is such that Y
error-correcting word blocks PO-1 to PO-y are scattered and
arranged in bytes at the end row of the data sector. Furthermore,
this error-correcting code block has a configuration such that an
error-correcting word PI in the column (horizontal) direction is
added at the end of each row.
[0044] Then, the present invention provides either a data recording
method or apparatus characterized by constructing the ECC block, or
a recording medium on which such ECC is recorded. Furthermore, the
invention provides a method and apparatus for reproducing the
matrix block by processing such ECC block.
[0045] Specifically, for example, in the beginning, a main block is
constructed which has larger than the maximum byte numbers (=255
bytes) and has twice as many as rows, the block being constructed
as a code length in the Reed-Solomon code in which 8 bits=1 byte
are set as data unit. Then, for example, in a first sub-block
comprising an even-row of the former half area of the main block
and an odd-row of the latter half area of the main block, and a
second sub-block comprising an odd-row of the former half area of
the main block and an even-row of the latter half area of the main
block an outer parity is separately created for each of the rows.
Furthermore, an inner parity of each of the first and the second
sub-block is created in each of the rows in the conventional
manner.
[0046] When a varied error-correcting code block as described above
is adopted, the error data is constructed in a scattered manner as
seen from the error-correcting system of the outer parity. There is
realized a structure in which actual recording and transmission
data observes the actual data order so that no error dispersion is
generated at the decoding time.
[0047] That is, in the error-correcting method using the
conventional error-correcting code block, an outer parity and an
inner parity are created and odd to A rows.times.B columns data
block. However, in the present invention, as the number of rows of
the data block, the number of rows is adopted which is larger than
the number of rows of the maximum code length which can be
subjected to error coding. The error-correcting code series (PO
series) in the row (vertical) direction is divided into two sets.
As a consequence, it becomes possible to deal with a data block
larger than the conventional one as an error-correcting code block.
Furthermore, it also becomes possible to not to scatter the data
transmission order which is important in dealing with a compressed
image signal or the like so that a burst error-correcting
capability can be largely improved.
[0048] As described above, in the error-correcting word comprising
a product code in which, for example, 8 bits=1 byte constitutes a
data unit, it is required that the number of rows and the number of
columns are selected so that the byte number of the block in which
the information data and the error-correcting word are odd becomes
255 bytes.times.255 bytes.
[0049] However, generally the information data basically takes a
sector structure in which the data amount obtained by adding an ID
(Identification Data) and a certain amount of control signal are
odd to the data having 512 bytes, 1024 bytes, 2048 bytes, 4096
bytes or the like. Thus, a plurality of sets of such sectors
constitute an error-correcting block. Furthermore, numeric values
such as 8, 16, and 32 suitable for binary processing is favorable
as the number of sectors in the error-correcting blocks for taking
a good timing with other signal processing. When such condition is
added, the number of rows and the number of columns are limited so
that the number of rows and the number of columns become about 200.
As one of such example, in the structure in which the conventional
DVD standard is adopted, 172 bytes.times.12 bytes configures one
data sector, and 16 sectors are clustered to configure a data
block.
[0050] Here, 16 bytes outer parity is generated with respect to the
data of each column (12.times.16=192 bytes) to scatter and add the
outer parity to each row (16) by one byte. As a consequence, 16
sector data block is configured which is a set of (12+1)
rows.times.172 bytes block (one sector) Here, furthermore, 10 bytes
inner parity is created with respect to (12+1) rows.times.(172+10)
rows error-correcting block. 172.times.12 bytes one data sector is
such that ID, 12 bytes control signal and 4 bytes error sensing
code EDC are inserted into the 2048 bytes main data. Consequently,
a product code block can be realized which has a very small
redundancy ratio and which enable very efficient detection and
error.
[0051] However, increasing the number of rows in the row (vertical)
direction is limited as it is, and it is impossible to improve the
error-correcting capability with burst characteristic without
raising the redundancy ratio.
[0052] Then, according to the present invention, the
error-correcting block in the DVD standard is set to two blocks
unit. The even-number row and the odd-number row are separated and
handled to create an error-creating word PO in each row direction
of the even-number row and the odd-number row. As a consequence,
the burst error-correcting capability can be improved by two times.
The error-correcting block is set to 32 blocks unit. However, the
method of the present invention can be used by somewhat correcting
the data reading order of the conventional DVD error-correcting
method. Furthermore, there is an advantage in that the data
processing in the conventional sector unit can be used so that the
method can bee linked to the application standard used in the DVD
as it is.
[0053] The present invention can be described in the following
manner in terms of the constituent element.
[0054] (1B)
[0055] According one embodiment of the present invention, there is
provided a data processing method characterized in that:
[0056] digital data is processed in bytes to constitute one
information data block in (M.times.N) bytes of M rows.times.N
columns;
[0057] data is arranged in bytes in the information data block, so
that data is arranged in the data transmission order from the 0th
column to the (N-1)-th column for each row while data is arranged
in the data transmission order from the 0th row to the (M-1)-th
row;
[0058] (K.times.M) rows.times.N columns matrix block is further
arranged which is a set of the information data block, and which is
constituted of K information data blocks composed of information
data blocks from the 0-th information data block to the (K-1)-th
information data block which continue in the data transmission
order;
[0059] on each column of (K.times.M) bytes of the matrix block, an
error-correcting word PO-a (K.times.Q) or PO-a ((K/2).times.Q)
bytes is created at least with respect to only even-number data
(K.times.M/2) bytes, and an error-correcting word PO-b (K.times.Q)
or PO-b ((K/2.times.Q) bytes is created at least with respect to
only odd-number data (K.times.M/2) bytes;
[0060] PO-a and PO-b are scattered and arranged into K information
data blocks which is constituted of (M.times.N) bytes of M
rows.times.N columns;
[0061] each column of N columns is formed as (K.times.(M+Q)) or
(K.times.(M+2Q)) bytes of Reed-Solomon code PO (Q is an integer of
1 or more); and
[0062] the error-correcting word P bytes is further added for each
row of N bytes and each row of (K.times.(M+Q)) or (K (M+2Q)) rows
is formed as (N+P) bytes Reed-Solomon code PI;
[0063] whereby as an overall block, an error-correcting product
code block is realized which constitutes
(K.times.(M+Q)).times.(N+P)) or (K.times.(M+2Q)).times.(N+P)) bytes
Reed-Solomon error-correcting word having K information data block
of (K.times.M.times.N) bytes as information portion.
[0064] According to the present invention, an error-correcting code
block is constituted wherein the sum of one information data block
of (M.times.N) bytes and an average word bytes added to the data
block becomes a definite value (M+Q).times.(N+P) or
(M+2Q).times.(N+P).
[0065] (2B)
[0066] According one embodiment of the present invention, there is
provided a data processing method comprising:
[0067] digital data is processed in bytes to constitute one
information data block in (M.times.N) bytes of M rows and N
columns;
[0068] data is arranged in bytes in the information data block, so
that data is arranged in the data transmission order from the 0th
column to the (N-1)th column for each row while data is arranged in
the data transmission order from the 0th row to the (M-1)th
row;
[0069] (K.times.M) rows.times.N columns matrix block is further
constructed which is a set of the information data block, and which
is constituted of K information data blocks composed of information
data blocks from the 0th information data block to the (K-1)th
information data block which continue in the data transmission
order;
[0070] on each row of (K.times.M) bytes of the matrix block, an
error-correcting word PO-a{(K/2).times.Q bytes} is created with
respect to the (k/2).times.(mi+mj) bytes which is constituted by
aggregating the even-number rows and the odd-number rows specified
in the K information data block order, and an error-correcting word
PO-b {(K/2).times.Q bytes} is created with respect to the
(K/2).times.(mj+mi) bytes which is constituted by aggregating the
remaining even-number rows and the odd-number rows specified in the
K information data blocks;
[0071] the PO-a and the PO-b are scattered and arranged into the K
information data blocks composed of (M.times.N) bytes of M
rows.times.N columns;
[0072] each column of N columns is formed as two sets of
Reed-Solomon code PO of (K/2).times.(mi+mj)+Q) bytes and (K/2)33
(mj+mi)+Q) bytes (however, M=mi (the number of even-number rows)+mj
(the number of odd-number rows) and (Q is an integar of 1 or more);
and
[0073] the error-correcting word of P bytes is further added for
each row of N bytes;
[0074] whereby as an overall block an error-correcting product code
block is realized which constitutes (K.times.(M+Q).times.(N+P)) or
(K.times.(M+2Q)).times.(N+P)) bytes Reed-Solomon error-correcting
word having K information data block of (K.times.M.times.N) bytes
as information portion.
[0075] As a consequence, two sets of Reed-Solomon codes P on each
row in the column direction constitute an error-correcting product
code in which rows constituting respective code series are
alternately arranged.
[0076] Additional objects and advantages of the invention will be
set forth in the description which follows, and in part will be
obvious from the description, or may be learned by practice of the
invention. The objects and advantages of the invention may be
realized and obtained by means of the instrumentalities and
combinations particularly pointed out hereinafter.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
[0077] The accompanying drawings, which are incorporated in and
constitute a part of the specification, illustrate presently
preferred embodiments of the invention, and together with the
general description given above and the detailed description of the
preferred embodiments given below, serve to explain the principles
of the invention.
[0078] FIG. 1 is a view showing a (M.times.N) bytes of information
block.
[0079] FIG. 2 is a view showing a structure of
(K.times.(M.times.N)) when k pieces of the (M.times.N) bytes
information blocks are aggregated.
[0080] FIG. 3 is a view showing a structure of a correction block
in which the error-correcting code is added to the
(K.times.(M.times.N)) code in the product code structure.
[0081] FIG. 4 is a structure of the correction block in which the
error-correcting word PO (K.times.Q) is added to each of the
information data block in Q bytes so that the information block
added with a correction flag has the same structure.
[0082] FIG. 5 is a view showing a structure of information data
block added with the error-correcting code of FIG. 4.
[0083] FIG. 6 is a view in which a structure of the information
data block of FIG. 5 is shown in the code length used in the DVD
standard.
[0084] FIG. 7 is a view showing one example of a structure of the
error-correcting block according to the present invention.
[0085] FIG. 8 is a view showing a state in which an
error-correcting word PO is scattered and arranged on the
(M.times.N) bytes information data block.
[0086] FIG. 9 is a view shown for explaining one example of the
error-correcting word PI series according to the present
invention.
[0087] FIG. 10 is a view shown for explaining another example of
the error-correcting word PI series according to the present
invention.
[0088] FIG. 11 is a view shown for explaining another example of
the error-correcting word PO series according to the present
invention.
[0089] FIG. 12 is a view showing another example of a process at
the time of creating an error-correcting block is created according
to the present invention.
[0090] FIG. 13 is a view showing a state in which the
error-correcting word is scattered and arranged on each of the
information data block according to the present invention.
[0091] FIGS. 14A and 14B are views showing an example in which
error-correcting words P0-a and PO-b are arranged on (M.times.N)
bytes of information data block according to the present invention
respectively.
[0092] FIG. 15 is an explanatory view showing a sector link
portion, the view being shown for explaining a problem at the time
when an error-correcting block is structured with the method shown
in FIG. 12.
[0093] FIG. 16 is a view showing one example of a process at the
time of creating the error-correcting block according to the
present invention in the case where the error-correcting capability
is further raised.
[0094] FIG. 17 is an explanatory view showing a block in the midst
of the creation of the error-correcting block in which the
error-correcting capability is improved.
[0095] FIG. 18 is a view showing a state in which the
error-correcting word PO is scattered and arranged on each
information data block of the error-correcting block in which the
error-correcting capability according to the present invention is
improved.
[0096] FIG. 19 is an explanatory view showing a sector link portion
at the time when the error-correcting block is structured in a
method shown in FIGS. 16 and 17.
[0097] FIG. 20 is a view for explaining a sector link portion at
the time when the error-correcting block is structured in a method
shown in FIGS. 16 and 17 and an advantage of the present
invention.
[0098] FIG. 21 is a view for explaining a sector link portion of
the error-correcting block created in another embodiment of the
present invention.
[0099] FIG. 22 is a view for explaining a sector link portion of
the error-correcting block created in still another embodiment of
the present invention.
[0100] FIG. 23 is an explanatory view showing a process of creating
an ECC block and a recording medium according to the present
invention.
[0101] FIG. 24 is an explanatory view showing a structure of a data
sector in the DVD.
[0102] FIG. 25 is an explanatory view showing a state in which the
sector according to the present invention is blocked into ECC
blocks.
[0103] FIG. 26 is an explanatory view showing a state in which the
ECC block is divided into to two divided blocks which observes the
rule of the present invention so that a PO series error-correcting
word is added to each of the divided blocks.
[0104] FIG. 27 is a view showing a state in which the two divided
blocks which observes the rule of the present invention shown in
FIG. 15 are integrated so that PI series error-correcting word is
added to the two divided blocks.
[0105] FIG. 28 is an explanatory view showing a state in which the
PO series code is interleaved in the ECC block.
[0106] FIG. 29 is a view showing a reproduction processing
apparatus of the ECC block according to the present invention.
[0107] FIG. 30 is a view showing another embodiment of a method for
creating a PI series error-correcting word of ECC block according
to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0108] Hereinafter, referring to the accompanying drawings,
embodiments of the present invention will be explained.
[0109] In a structure of an error-correcting information data block
in which an error-correcting code is created and added to the
information data block, the Reed-Solomon error correction is used
many times for heightening the random error and burst error
correction capability. Furthermore, generally, in the digital data
processing, a unit of 8 bits constitutes one byte. In consideration
of other aspects of the development, such concept is favorable in
the data processing efficiency.
[0110] Hereinafter, a detailed explanation will be given by
referring to the drawings and the DVD standard.
[0111] FIG. 1 is an M row.times.N columns information data block.
In the field of computers, 128.times.(multiple of 2) is used as
processed information data block.
[0112] In the DVD standard, 2048 bytes are used an information
block unit. By adding ID and a control code or the like to 2048
bytes main data, 2064 bytes is set to constitute 12 rows.times.172
columns information data block. When an attempt is made to gain an
expected error-correcting capability by directly adding an
error-correcting code to (M.times.N=12.times.172) byte block, the
redundancy ratio of the correction code becomes too high. Then,
(K.times.(M.times.N)) bytes information data block is constructed
by aggregating K information data blocks.
[0113] FIG. 2 is a view showing this (K.times.(M.times.N)) bytes
information data block. In the DVD standard, K=16 is adopted.
[0114] The row (vertical) direction in the information data block
is the (K.times.M) bytes data. In the (K.times.M) byte data in each
of the N rows, (K.times.Q) bytes error-correcting code is created
and added. Next, the row (vertical) direction in the information
data block of FIG. 2 is N bytes data. Furthermore, the row number
is (K.times.M)+(K.times.Q) row because of an increase in the
previous error-correcting code (K.times.Q). In each of the
(K.times.M)+(K.times.Q) row, P bytes which are error-correcting
code is created and odd.
[0115] FIG. 3 is a view showing a state in which (K.times.Q) bytes
error-correcting code and P bytes error-correcting code are added
to (K.times.(M.times.N)) information data blocks.
[0116] In the DVD standard, Q=1 and P=10 are given.
[0117] Next, (K.times.Q) bytes error-correcting code is scattered
by Q bytes and is odd to K (M.times.N) bytes information data
blocks respectively so that each of the information data blocks
assumes the same configuration.
[0118] The processing is significant in that all the K information
data blocks are formed in the same structure. That is, (N.times.M)
bytes information data is odd with ID showing an address of the
information data. However, since the error-correcting code
(K.times.Q.times.172) which is an outer parity PO is all
error-correcting code, the ID cannot be added thereto. Then, this
error-correcting code is scattered and arranged in each of the
information data block so that all the information data blocks
assume the same structure and have the ID.
[0119] Incidentally, the order of scattering and arrangement is
such that (K.times.Q) row is scattered and arranged in each
information data block after creating the error-correcting code in
the row (vertical) direction. Otherwise, after an error-correcting
code in the row (horizontal) direction is created and added to each
row, the error-correcting code in the column (horizontal) direction
is created and added to each row, the error-correcting codes of
(K.times.Q) rows in the row (vertical) direction are scattered and
arranged on each information data block. In any order, the method
of the DVD standard yields the same result.
[0120] FIG. 4 is a view showing a new block structure in which
(K.times.Q) rows of the error-correcting words are scattered and
arranged in each of K information data blocks by Q. In the DVD
standard, (K.times.(M+1).times.(N+P)), namely,
[16.times.(208.times.182)] bytes error word block is
constructed.
[0121] FIG. 5 is a view showing a structure of one information data
block (M+Q).times.(N+P) to which the error-correcting code is
added. On the front row, an ID and a control signal (CNT-sig) which
constitute address information of the information data block is
arranged while the error-correcting word Q in the row (vertical)
direction is arranged at the end row. In the DVD standard, Q=1 is
set, and in this structure, the number of K can be increased until
K.times.(M+Q) becomes 255.
[0122] FIG. 6 is a view showing in detail the information data
block of FIG. 5. At the last of the main data, the EDC is
added.
[0123] FIG. 7 is a view showing one embodiment of the information
data block according to the present invention.
[0124] N columns.times.M rows of K information data blocks as shown
in FIG. 1 are aggregated so that (K.times.M) rows.times.N columns
matrix blocks shown in FIG. 2 are constructed. Here, (K.times.Q)
bytes or (K/2.times.Q) bytes error-correcting code
(error-correcting word) PO-a is created with respect to
(K.times.M/2) bytes data on each column of the even-number row.
[0125] Next, (K.times.Q) bytes or (K/2.times.Q) bytes
error-correcting code (error-correcting word) PO-a is created with
respect to (K.times.M/2) bytes data on each column of the
odd-number row.
[0126] PO-a and PO-b created here are scattered and located on each
of (M.times.N) bytes of K information data blocks are scattered and
arranged.
[0127] Here, in the case of PO-a=PO-b=(K.times.Q), PO-a and PO-b
are respectively scattered and arranged by Q on each of the
(M.times.N) bytes information data blocks while in the case of
PO-a=PO-b=((K/2).times.Q), PO-a is scattered and arranged on the
even-number-th information data blocks or the former half of the
information data block out of K information data blocks and PO-b
are scattered and arranged on the odd-number-th information data
blocks or the latter half of the information data blocks.
[0128] Here, in the case where M=12 and N=172 are set in the same
manner as the DVD standard of FIG. 1 according to the present
invention, setting K=32 (16.times.2), Q=1 and PO-a=PO-b=16 leads to
the creation of the error-correcting word PO-a for the even number
and the error-correcting word PO-b for the odd number with respect
to the 172 columns.times.(12.times.32)=384 rows of the
error-correcting data block. Then, on the even number-th of each of
32 information data blocks, PO-a is scattered and arranged. On the
odd number-th thereof, PO-b is scattered and arranged, so that 32
information data blocks of (12+1) bytes.times.172 bytes are formed.
Furthermore, 10 bytes error-correcting word PI is added so that 32
information data blocks of (12+1) rows.times.(172+10) columns are
formed. This is the error-correcting product code block.
[0129] Each of the information data blocks after the addition of
the error-correcting word has the same structure as the
conventional block shown in FIG. 6. However, the value of K is
different. The information data block of DVD are constituted of
main data 2048 bytes composed of 12 rows and 172 columns, an ID and
a control signal (12 bytes), and an EDC (4 bytes). On the whole,
2064 bytes information data block constitutes a unit.
[0130] The present invention is not restricted to the above
embodiment.
[0131] As another embodiment, an information data block is
considered wherein the ID, the control signal (24 bytes) and the
EDC (8 bytes) are added to (M=24 rows).times.(N=172 columns)=4096
bytes main data (information block). Now when PO-a=PO-b=16 bytes is
established at K=16 and Q=1, one byte is scattered and arranged to
each of the information data blocks from PO-a and PO-b
respectively. One information data block after adding the
error-correcting word in this case assumes a structure shown in
FIG. 8.
[0132] Next, the error-correcting code PI will be explained.
[0133] FIG. 9 is a view showing a formation series of the
error-correcting word (inner parity) which is one example of the
present invention. The inner parity Pi is created with respect to
the data in the column (horizontal) direction which is a data
transmission order.
[0134] FIG. 10 is a view showing a variation for forming an
error-correcting word (inner parity) which is another embodiment of
the present invention.
[0135] With respect to M rows.times.N columns data of the
information data block, the formation of the (N+P) bytes
Reed-Solomon code (inner parity) PI is realized in data from 0-th
column to the ((N+P)-1)-th column and 0-th row to the (M-1)-th row.
In the creation of the PI series error-correcting code with respect
to the information data block to which PO is added, each row and
each column are increased on the basis of the byte data of each
front column to rotate and arrange the row number (M) obtained as a
result of increase to move to the 0th row when the increase result
of the row becomes (M)-th row thereby constituting (M) sets of PI
series error code.
[0136] In the conventional recording density, one to two bytes
error is scattered as a random error. However, in a high-density
recording, the error is increased up to five bytes.
[0137] Then, the recording arrangement is not changed with respect
to the data order by setting the error-correcting series to a data
set series having a jump arrangement different from the recording
order. However, since the error-correcting code series is different
from the recording order, a small concentration error is scattered
in the error-correcting processing so that the random error
capability in the execution can be improved.
[0138] FIG. 11 is a view showing a method for forming a PO series
error-correcting code according to another embodiment of the
present invention.
[0139] In FIG. 11, (K.times.M) rows.times.N columns
error-correcting data block (matrix block) like the conventional
DVD standard is formed in a recording order. The block B2 is a
current block while the block B1 is a block before the block B2. In
the creation of the PO series error-correcting data block Po, an
even-number data of the current error-correcting data block is
aggregated in a set to constitute a data block B22. Next, when the
error-correcting code Po is created, the code is scattered and
arranged in the current error-correcting data block B22 to
constitute the block B23. Thereafter, to this block B23, the PI
series error-correcting code Pi is created to add each row.
[0140] In this error-correcting word data processing method, PO
series is subjected to an overlapping processing. However, this
method has an advantage in that the required reading data scope can
be small in an arbitrary two information data blocks.
[0141] Furthermore, the present invention is not limited
thereto.
[0142] FIG. 12 is a view showing a process of creating the ECC
block shown for explaining a basic concept of the present
invention.
[0143] An object of the present invention is to improve the
error-correcting capability in the case where the burst error is
generated. For this purpose, the error-correcting processing block
by the outer parity is scattered.
[0144] In explanations of FIGS. 1 and 2, the information data
blocks (N.times.K) bytes are clustered into K (here K=16) sets.
Then, an outer parity and an inner parity is added to the set data
blocks to generate the ECC blocks. However, in this invention, two
sets of information data blocks are used to generate the ECC block.
Consequently, the number K of the information data blocks to be
handled is 32 in the present invention.
[0145] FIG. 12 is a view showing a state in which two sets of
information data blocks (A-10 and A11) are prepared. Next, the
even-number data blocks and the odd-number data blocks (A-10 and
A-11) are divided into two blocks respectively. Both the
even-number blocks and the odd-number blocks are given in two
blocks respectively. Hereinafter, the two blocks are referred to as
even-number blocks (B-10), (B-11). With respect to the even-number
block and the odd-number block, an outer parity is created and
added. Hereinafter, the outer parity added to the even-number block
(B-10) is denoted by PO-a while the outer parity added to the
odd-number block (B-11) is denoted by PO-b. The outer parities PO-a
and PO-b are referred to an error-correcting code or
error-correcting word.
[0146] Here, as the byte numbers of the outer parity PO-a,
(K.times.Q) bytes or (K/2.times.Q) bytes are given with respect to
the (K.times.M/2) on each column. As the byte numbers of the outer
parity PO-b, (K.times.Q) bytes or (K/2.times.Q) bytes are given
with respect to the (K.times.M/2) on each column.
[0147] Next, the separated even-number row and the odd-number row
are brought back to the original state. The state is shown as block
C. This means that 32 information data blocks (M rows.times.N
columns) are aggregated as sets. Furthermore, as the outer parity,
PO-a and PO-b are added. Furthermore, an inner parity PI (10 bytes)
is also created and added. Next, the PO-a and PO-b created here are
scattered and arranged into K (=32) information data blocks each
having (M.times.N) bytes.
[0148] FIG. 13 is a view showing a state in which each outer parity
PO is scattered and arranged into each information data blocks.
Here, in the case of PO-a=P-b=(K.times.Q), information data blocks
are scattered and arranged by Q bytes to each of (M.times.N) bytes
information data blocks from PO-a and PO-b respectively. In the
case of PO-a=Po-b=((K/2).times.Q), PO-a is scattered and arranged
into even-number information blocks, or the former half information
data blocks while PO-b is scattered and arranged into the
odd-number information data block, or the latter half information
data blocks.
[0149] FIG. 14A is a view showing the state in which one
information data block after the dispersion and arrangement of the
PO in the case of PO-a=PO-b=(K.times.Q). Furthermore, FIG. 14B is a
view showing the state in which one information data block is taken
out after the dispersion and arrangement of PO in the case of
PO-a=PO-b=((K/2).times.Q).
[0150] The ECC blocks shown in FIG. 13 are recorded on a recording
medium from the front recording sector in order. Furthermore, in
the transmission system, the blocks are recorded from the front
recording sector in order. On the reproducing side or the receiving
side, the ECC blocks are incorporated into a buffer memory from the
front thereof in order. In the case where the ECC blocks having a
unit shown in FIG. 13 is restored to a form as shown in the
even-number block B-10 shown in FIG. 12, the odd-number block B-11
in an error-correcting processing so that PO system
error-correcting processing is carried out. As a consequence, even
when a burst error is present at the step of ECC block, the error
is scattered to the even-number block and the odd-number block, so
that the error-correcting capability is raised.
[0151] Here, in the present invention, the following points are
noted to further raise the error-correcting capability.
[0152] FIG. 15 is A view shown for explaining noted point of the
present invention.
[0153] In the above embodiment, the even-number row and the
odd-number row of two set information data blocks are simply
separated to create the PO series code (PO-a and PO-b)
corresponding to the even-number block and the odd-number block.
Next, the even-number block and the odd-number block are brought
back to the arrangement (the state in which the even-number row and
the odd-number row are alternately arranged), so that the PO series
code as shown in FIG. 14A or FIG. 14B are scattered and arranged.
This creates the ECC block as shown in FIG. 13.
[0154] Here, the PO series code is arranged by Q bytes between
sectors. Here, a linkage between the sector (the even-number
sector) and the sector (the odd-number sector) is noted (in this
example, the sector includes 12 rows of information data block).
Then, on the final row of the first sector, a part of PO-a created
by using the even-number block (Q bytes (N+P)) is located and the
front row of the second sector becomes an even-number row.
Consequently, the front row of the second sector (the even-number
row) is present in the even-number row.
[0155] As a consequence, as seen from the PO series, the PO series
data is consecutively arranged for two row portions. An aim of the
present invention is to create an arrangement of each row as a
repetition of odd-numbers and even-numbers while the
error-correcting word is created corresponding to the odd-numbers
and the even-numbers respectively. As a consequence, when the
errors are corrected, the even-number rows and the odd-number
blocks are separated thereby enabling error correction processing
in respective blocks. Consequently, the present invention is
intended to scatter the error even at the time of the generation of
the burst error to the ECC block to improve the error-correcting
capability.
[0156] However, as has been explained in FIG. 15, when the same PO
series data is arranged consecutively for two rows portion, the
expected result of the error dispersion cannot be obtained at the
time of the generation of the burst error at this portion.
[0157] Therefore, in the present invention which has been further
improved, the previous even-number block and the odd-number block
are not obtained, so that the following PO-a creation blocks and
the PO-b creation blocks are obtained. That is, by referring to
FIG. 16, the two blocks will be explained.
[0158] As shown in FIG. 16, using the two set information data
block (A-10, A-11) which constitutes the data transmission order is
the same as the previous example.
[0159] Here, in the PO-a creation block (E-10), the even-number row
in the even-number sector and the odd-number row in the odd-number
sector are aggregated and created from the two set information data
blocks (A-10 and A-11). And in the PO-b creation block (E-11), the
odd-number row in the even-number sector and the even-number row in
the odd-number sector are aggregated and created from the two set
information data blocks (A-10 and A-11).
[0160] FIG. 17 is a view showing the state in which the even-number
row and the odd-number row of the above separated PO-a creation
block (E-10) and PO-b creation block (E-11) are brought back to the
original state and the even-number block and the odd-number block
are linked in order. This block F is a set in which 32 information
data blocks (N columns.times.N rows) are aggregated. Furthermore,
as the outer parity, PO-a and PO-b are added thereto. Furthermore,
the inner parity PI (10 bytes) is also added thereto. Next, the
PO-a and PO-b created here is scattered and arranged in K (=32)
(M.times.N) bytes information data blocks to information data
blocks each having (M.times.N) bytes. As a consequence, between
respective sectors, PO series code is arranged Q bytes.
[0161] FIG. 18 is a view showing the ECC block at this time. A
method for scattering and arranging the PO series is explained in
FIGS. 13, 14A and 14B.
[0162] FIG. 19 is a view in which a linkage between the sector (the
even-number sector) and the sector (the odd-number sector) are
noted in the ECC block. (In this example, the sector includes the
12 line information data blocks.) Then, at the last row of the
first sector, a part (Q bytes.times.(N+P)) of the PO-a created by
using the block E-10 is located at the last row of the first
sector. The front row of the second sector is the even-number row,
but the front row of the second sector is the PO-b series as
explained in FIG. 16. As a consequence, the row at the linkage
between the odd-number sector and the even-number sector is such
that the row at the PO-a series and the row at the Po-b series are
alternately arranged.
[0163] Consequently, the row at the PO-a series and the row at the
Po-b series intended by the present invention are alternately
arranged to form the ECC block with the result that an object of
improving the error-correcting capability with respect to the burst
error is effectively attained. That is, a burst error-correcting
capability having a twice longer code length than the conventional
method is provided by using the ECC blocks which are constituted in
this manner.
[0164] In the above embodiment, there is shown a case in which the
number of rows of one sector is M=12 (even number). Here, there is
considered a case in which M is an odd number (for example,
11).
[0165] Now, in the same manner as the above embodiment, suppose
that PO-a creation block (E-10), PO-b creation block (E-11) are
created, and PO-a and PO-b are created with respect to the
respective blocks. Then, each row of the PO-a creation block (E-10)
and the PO-b creation block (E-11) are brought back to the original
position. Furthermore, the PO-a and PO-b are scattered and arranged
to create the ECC block.
[0166] FIG. 20 is a view in which the linkage between the sector
(even number sector) and the sector (odd number sector) in this ECC
block is noted. (In this example, the sector includes 12 rows of
information data blocks). Then, at the last row of the first
sector, a part (Q bytes.times.(N+P)) of the PO-a block created by
using the block E-10 created by using the block E-10 is located.
The front row of the second sector becomes an even number block.
The front row of the second sector is an even number block, the
PO-b series row which belongs to the block E-11 is located as
explained in FIG. 16.
[0167] As a consequence, the last row of the first sector and the
row before the last row constitute the PO-a series row. Thus, in
the case where a burst error is generated in this portion, the
error-correcting capability cannot be sufficiently displayed.
However, there is an example in which the effect of the present
invention can be sufficiently obtained even when one of the sectors
is an odd-number row.
[0168] FIG. 21 is a view showing an example in which a method
explained in FIG. 14A is adopted as a method for arranging the
error-correcting code by adopting M=9 rows as a sector. In this
example, on the linkage of the sector, the following row
arrangement appears. In the beginning, look at the linkage at a
portion where the odd-number sector is arranged next to the
even-number sector. The last row as the even-number sector
information data block is an even number, and PO-b series
error-correcting code is added to the last row by one row.
[0169] Further, after this PO-b series error-correcting code, PO-a
series error-correcting code is arranged by one row. Here, the
front row of the odd-number sector is an even-number row. This even
number is used to create PO-b series code as shown in the block
E-11 of FIG. 16. Consequently, at the linkage portion of the
even-number sector and the odd-number sector, PO-b and PO-a are
alternately arranged.
[0170] Next, look at a linkage portion where the even-number sector
is arranged next to the odd-number sector. The last row as the
even-number sector information data block is an even number, and
this row is separated into the block E-11 shown in FIG. 16.
Therefore, the last row belongs to the PO-b series. To the
contrary, PO-a series error-correcting code is added to the last
row by one row. Next, after this PO-series error-correcting word,
PO-b series error-correcting code is added by one row. The front
row of the next even-number sector is an even number. The front row
is separated into the block E-10 shown in FIG. 16. Therefore, the
last row belongs to PO-a series. As a consequence, at the linkage
of the odd-number sector and the even-number sector, rows of PO-b
and PO-a series are alternately arranged.
[0171] That is, in the embodiment shown in FIG. 21, when the
error-correcting words PO-a and PO-b are arranged, the selection
order is devised so that the row of the PO-b, PO-a, PO-b and PO-a
series are alternately arranged.
[0172] The concept of the embodiment of FIG. 21 can be applied to
the case where one sector is the odd-number row (for example,
M=10).
[0173] FIG. 22 is an example in which one sector is an even-number
(for example, M=10), and as a method for arranging the
error-correcting method the method explained in FIG. 14A is
adopted. Furthermore, in this example, the block E-10 of FIG. 16
comprises an even-number row of the even-number sector and an
even-number row of the odd-number sector, and the block E-11
comprises an odd-number row of the even-number sector and an
odd-number row of the odd-number sector.
[0174] In this embodiment, the linkage at the sector assumes the
following row arrangement. The last row as the information data
block of the even-number sector is the odd-number. This row is
separated with the block E-11 of FIG. 16. Consequently, the last
row belongs to the PO-b series. In contrast, the PO-a series
error-correcting code is added by one row to the last row. Next,
after the PO-a series error-correcting code, PO-b series
error-correcting code is arranged by one row. The front row of the
next odd-number sector is an even-number. In this case, the front
row belongs to the PO-a series. As a consequence, at the linkage
portion of the odd-number sector and the even-number sector, rows
of the PO-a, PO-b, and PO-a are alternately arranged.
[0175] FIG. 23 is a view showing a data processing procedure of a
recording apparatus to which the present invention is applied. Data
for recording is input to the data sector portion 42 from the
outside to be sectored. In this embodiment, 2K bytes constitute the
basic unit. An error sensing code (EDC) is added to the data block
having a 2K bytes unit data block. This data block is referred to
as information data block. This processing is carried out at the
EDC coding portion 43. Next, the ID for identifying the information
data block (sector) and other control signal is added to the ID
adding portion 44. Next, at the scramble processing portion 45, the
main information data is scramble processed.
[0176] This scramble processing is carried out for the following
reasons. That is, in the case where the main data is an image
signal or the like, "0" continuously appears in the blank portion.
When such signal is handled as a recording signal, there appears a
tendency that the recording signal becomes a repetition of the same
pattern. When the same pattern of the recording medium is present
on the adjacent track such as an optical disk or the like, the
operation of the servo becomes unstable under the influence of the
cross talk between tracks. In order to prevent this, the scramble
pattern determined by ID is used, so that data scramble is provided
by overlapping the scramble data onto the data.
[0177] The scrambled data (sector) is summarized in 32 sector units
in the transmission order so that the data is ECC blocked in the
ECC block portion 46. This ECC block is input to the
even-number/odd-number block portion 47. Here, the even number and
the odd number are temporarily blocked separately. Then, at the
even-number and odd-number PO coding portion, each block is
subjected to the PO series error-correcting word as explained in
the previous embodiment.
[0178] Next, at the PI coding portion, each row is subjected to PI
series error-correcting coding process. Next, at the ECC blocking
portion 50, the block of the even-number row and the block of the
odd-number are integrated. Furthermore, at the PO parity interleave
portion 51, the PO series parity is scattered to each sector while
the PO series inspection and correcting word is interleaved to each
data sector in the whole block.
[0179] Next, this ECC block is input to the recording sector
portion 52. Furthermore, when a synchronizing signal is added with
the recording sector portion 52 and the next modulation and
synchronizing addition portion 53, and is 8/16 modulated. This
modulation signal is supplied to an optical pickup 55 to drive a
laser diode. As a consequence, the laser light is applied to the
disc to record the signal. The disk 56 is rotated and controlled
with the disk motor 57.
[0180] FIG. 24 is a view showing a structure of a data sector in
the DVD format created in the midst of the above recording
processing. The data sector has 172 columns (172 bytes) and 12
rows. The first row is composed of an ID (4 bytes), an IED (ID
error-detecting code: 2 bytes), a CPR-MAI (copyright management
information: 6 bytes), and a 160 bytes of main data. At the end of
the last row (12th row), main data and four bytes of
error-detecting code are added thereto. The remaining row are all
main data.
[0181] FIG. 25 is a view showing a state in which 32 sectors are
aggregated to form an ECC block as has been described above.
[0182] FIG. 26 is a view showing the state in which the ECC block
is divided with the rule explained in FIG. 12 or FIG. 16 to
constitute an even-number block (or PO-a creation block) and an
odd-number block (or PO-b creation block) so that the PO series
codes PO-a and PO-b are created and added with respect to
respective blocks.
[0183] FIG. 27 is a view showing the state of a single ECC block in
which the even-number block (or the PO-a creation block) and the
odd-number block (or the PO-b creation block) are integrated
together with the code PO-a and PO-b. Furthermore, FIG. 27 shows a
state in which the PO-a code are created and added. The arrangement
order of the PO-a and the PO-b are not limited to what is shown in
the drawings.
[0184] FIG. 28 is a view showing a state in which the PO series
code is scattered to each sector. This is the recording sector. To
each recording sector, a synchronizing signal is added and further
modified to be recorded on the recording medium.
[0185] Incidentally, according to the present invention, the PO
series error-correcting word is created and the PI series
error-correcting word is created in the above explanation. However,
this processing procedure is not limited thereto. This processing
order may be the contrary. That is, after the data sector is ECC
blocked, the PI series error-correcting code is created so that the
ECC blocks to which the PI code is added is separated into a block
in which the even-number row of the ECC block added with the PI
code is aggregated and the block in which the odd-number row is
aggregated. Thereafter, the PO series error-correcting word
including the PI code may be created. Then, after that, the
even-number row and the odd-number row are re-aggregated so that,
after that, the PO code may be distributed in the interleave
processing.
[0186] FIG. 29 is a view showing an example of a structure of a
reproducing apparatus to which the basic concept of the present
invention is applied.
[0187] On the disc 56, data is recorded with a recording method as
previously explained. A modification signal read with the pickup
head 55 is supplied to the channel data reading portion 81 to
provide a channel bit unit. Then at the synchronizing separation
portion 82, the synchronizing signal is separated and divided in
symbol units. Next, at the decoding portion 83, the signal is
decoded from 16-bit data to 8-bit data to be supplied to the sector
ID detection portion 84. Here, the data is identified and
aggregated for each of the sectors to be input into the ECC block
creation portion 85. Here, the sectors are aggregated to provide an
EEC block unit data. The ECC block is input to the PI decoding
portion 86 to carry out the PI series error sensing and correcting.
Next, at the PO-a decoding portion 87, the PO-a error detection and
correction is carried out so that the PO-b series error detection
and correction is carried out at the PO-b series decoding portion
88.
[0188] Next, the de-scrambling of the main data portion is
conducted at the de-scramble processing portion 89. Furthermore, at
the error-detecting portion 90, errors in the main data portion are
detected on the basis of the EDC so that a normal data is taken
out. This main data is transmitted to the processing portion after
that via the interface.
[0189] Incidentally, at the reproduction processing, either the PI
series error detection and correction processing or the PO series
error detection and correction processing may be carried out prior
to the rest of the two. The order is not restricted to what is
shown in the drawings.
[0190] By the way, in the DVD, a video object (VOB) is designated
in cells, and VOB is a format in which a plurality of video object
units (VOBU) are included. The video objects allow the inclusion of
a plurality of video packets (V_PCK), audio packets (A_PCK), and
subsidiary image packets (SP_PCK). Furthermore, in the recording
reproduction format, a control packets (RDI_PCK) including the
real-time data information (RDI) arranged at the front of the VOBU.
On this packet, such information as the reproduction start-time,
intermission information at the recording time, display control
information (aspect ratio information), copy control information or
the like. Furthermore, in this packet, a reservation area is also
secured.
[0191] Furthermore, the video data incorporated in the V_PCK is
subjected to compression by means of MPEG1 or MPEG2 method. Either
in the MPEG 1 or MPEG 2 method, information showing an aspect ratio
or the like is described on a sequence head or the like.
Furthermore, the GOP user data for the line 21 can be inserted into
a part of the compressed data. This part is used at the time of
sending a character code data.
[0192] Furthermore, in the DVD standard which can be recorded and
reproduced, a control data area is also secured for describing
program chain information for determining the reproduction order of
the program recorded on the user data area.
[0193] Consequently, in the case where the ECC block of the present
invention is used, an area of a portion of RDI_CK, or an
arrangement portion of the GOP user data or a portion of the
control data area are used to store ECC block identification
information showing what form the ECC block form assumes.
[0194] When this ECC block identification information is stored, it
is possible to identify which form of the ECC block the recorded
information or the transmitted information is. As a consequence,
the present invention can be added and provided on the conventional
DVD reproducing apparatus so that the present invention can be
widely applied. It goes without saying that a circuit may be
arranged in parallel which processes data in the conventional ECC
block forms on the previous recording and reproducing apparatus
with the result that the user can adopt any process form at the
time of recording data. In this case, in accordance with the ECC
block form selected at the time of recording the above ECC block
identification information is automatically prepared so that the
information is stored and arranged in a predetermined area.
[0195] A method for creating the PI series error-correcting code
(or form) according to the present invention is not limited to the
above embodiment.
[0196] FIG. 30 is a view showing another method for creating the PI
series error-correcting word. In this example, there is shown a
method for creating 10 bytes code using these selected data by
alternately selecting two-rows data every two columns. When the
number of rows is the even number, the PI series correcting
capability can be heightened even when a part of one row data is
damaged.
[0197] Furthermore, although the above explanation is centered upon
the recording of the ECC block structure according to the present
invention on the recording medium, the present invention is not
limited to the processing method and apparatus at the time of
recording data on the recording medium. In the communication
apparatus as well, data is formed into packets so that data sectors
are created. These data sector may be aggregated and subjected to
modulation and is transmitted. In this case, it goes without saying
that the form of the present invention may be adopted as the ECC
block form in which the data sectors are aggregated. Furthermore,
with respect to the modulation process method, the present
invention is not limited to the above explanation. The data of the
ECC block is modulated with the QPSK method, the QAK method or the
like. Furthermore, in the transmission channel, data may be sent by
using the OFDM method.
[0198] Furthermore, in the above embodiment, a predetermined unit
of the sector set block is divided into the even number block and
the odd-number block so that an error-correcting words PO-a and
PO-b are created. The error-correcting word may be is divided into
two or more (Y) to create the error-correcting word thereby
constituting the PO series.
[0199] As has been explained above, when the present invention is
used, the burst error-correcting capability can be largely improved
with the redundant flag ratio which is the same as the conventional
ratio in the error-correcting method based on the byte data. Then,
according to the present invention, the error-correcting process at
an optical disk with a high density using a blue laser the
development of which has just started can be realized to a physical
error length larger than the conventional one.
[0200] Additional advantages and modifications will readily occur
to those skilled in the art. Therefore, the invention in its
broader aspects is not limited to the specific details and
representative embodiments shown and described herein. Accordingly,
various modifications may be made without departing from the spirit
or scope of the general inventive concept as defined by the
appended claims and their equivalents.
* * * * *