Digital signal forming method, disc recording media using the same, and reproducing method thereof
There are provided a digital signal forming method, a disc recording medium for high density recording and a method of reproducing a digital signal for encoding of the error correction code of the related art and improving the error correction capability without any requirement in change of the number of codes. A plurality of correction blocks are formed by forming, a plurality of sector data adding the address information indicating the position on the recording disc to the main data of a plurality of lines in every constant amount of recording information, sharing the main data of each sector data into a plurality of sector data blocks and adding the first correction code to correct the error in the line direction of data and the second correction code to correct the error in the vertical direction of data to each of the divided sector data blocks. Moreover, a plurality of lines of the first correction codes corresponding to the main data of each line of each sector data interleaved to a plurality of correction blocks are allocated with continuation to a plurality of main data of each sector data and each line of a plurality of second correction codes is sequentially allocated among a plurality of sector data.
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The present invention relates to a digital signal forming method, disc recording media using the same and reproducing method thereof and particularly to a digital signal forming method suitable for information recording media, disc recording media having recorded the digital signal formed with this method as the recording pits (marks) and the reproducing method thereof.
As an example of disc recording media for converting a recording information to a digital signal suitable for recording media and then recording such digital signal as the recording pits (marks) on the media, a DVD (Digital Versatile Disc) may be listed. A method of forming such digital signal is described in the article “Data Compression and Digital Modulation”, NIKKEI ELECTRONICS BOOKS, 1998, pp. 119 to 123. In this reference, 2064 bytes where an addition information pieces such as sector ID number are added to the recording information amount in unit of 2048 bytes (number of bytes up to main data 12 from the main data 1) after scramble process are defined as one sector data, these sector data are in the form of 172 bytes×12 lines. In the allocation in unit of 172 bytes×12 lines×16 sectors for 16 sector data, the PO correction code of 16 bytes are added in the vertical direction as the external code, and the PI correction code of 10 bytes are also added in the lateral direction including the PO correction code as the internal code, and the correction block of (172+10) bytes×(12 lines×16 sectors+16 lines) is formed. Moreover, the interleave allocation is formed by interleaving in unit of one line the line data of the correction block. After modulation and framing process (to add a synchronization signal) from the heading line of the interleave allocation, generated digital signal is recorded as the recording pits (marks) along the tracks on the disc. At the time of reproducing, the original recording information can be reproduced by reproducing the recording pits (marks) using an optical head, then conducting detection of the frame synchronizing signal, demodulation process, recovery of the interleave allocation and then conducting the correction process for the error generated in the correction block with the PI, PO correction code. The PI correction code is used for correction of the random error included in unit of line from, while the PO correction code is used for correction of the burst error included in a plurality of line data.
The correction code, allocation format, modulation system, framing process are used in common for the recording signals to the DVD disc such as read-only disc (DVD-ROM), WORM (Write Once Recording Media) disc (DVD-R), re-writable disc (DVD-RW, DVD-RAM or the like) and the compatibility of digital signal process for recording and reproducing is assured.
A digital signal forming method of the related art will be explained with reference to
FIGS. 2 illustrate allocation of data and codes for explaining the digital signal forming method on the occasion of recording information to a disc of the related art.
In these figures, the reference numeral 1 indicates a series of recording information (divided in unit of 2048 bytes) to be recorded to a recording medium; 2, a format of the sector data which is one of the recording unit to the recording medium The sector data 2 divides a series of recording information 1 in unit of 2048 bytes. The sector data 2 is formed of an additional information of 12 bytes for RSV (reservation) including the sector ID (Identification Data) indicating the physical recording position on the disc, IED (ID Error Detection Code) for correction of one byte to the sector ID and a copy inhibit flag information or the like and the EDC (Error Detecting Code) checking existence of error to the main data 1 to 12 of 2048 bytes recording information. Moreover, the allocation in total of 172 bytes×12 lines×16 sectors is formed by collecting 16 sector data 2. In this allocation of 172 bytes×12 lines×16 sectors, the correction block 3 is formed with addition of the error correction code to each series of vertical and lateral series in order to cover the burst error and random error resulting from scratch or dust on the disc during the reproducing of disc. Namely, the correction block 3 of 182 bytes×208 lines is formed by generating and adding the PI (outer-code parity) correction code of 16 bytes to the codes 12×16 bytes in the vertical direction and then the PI (inner-code parity) correction code of 10 bytes to the code of 172 bytes in the lateral direction. Moreover, in the correction block 3, the interleave allocation 4 can be obtained by conducting the interleave process in every line from the heading line in the allocation of the PO correction code in unit of allocation of the data of sector 15 from the data of sector 0 by 182 bytes×12 lines. In the interleave allocation 4, the PO correction code of one byte is allocated sequentially between sectors and the sector ID is allocated at the heading position of each sector. Each line of the sectors 0 to 15 is provided with a line of the data and PI correction code.
The ID number included in each sector after the interleave is given a series of continuous number and also continuous even at the adjacent sectors. Finally, the modulation process and framing process are performed to generate the adequate digital signal for recording as the recording pits (marks) on the disc
In the case of reproducing of the recording information from a disc, the recording pits (marks) are read with an optical head and are then converted to a digital signal. Thereafter, after the frame synchronizing process and demodulating process are conducted in the inverse sequence of generation of the digital signal explained with reference to
A disc recording medium represented by the DVD is assumed in future to show more improvement of recording density of a recording medium and higher transfer rate for the purpose of longer-term recording and reproduction of video information and recording of higher definition video information in the higher transmission rate. As an example of the method to realize improvement in recording density and transfer rate, it is possible to form a track pitch to 1/m (m is a decimal number larger than 1) and a recording pit (mark) to 1/n (n is a decimal number larger than 1) on the disc of the related art or introduce the modulation system having higher encoding efficiency for generation of the digital signal. However, with improvement in the recording density, generation of burst error resulting from scratch or dust generated on the disc during the reproducing increases, and thereby readability of disc is lowered. Therefore, on the high density recording, it is essential to assure sufficient readability resistive to actual operation for scratch and dust, namely to improve the error correction capability for the digital signal to be recorded.
However, when only the number of correction codes is increased, the number of symbols that can be corrected is increased and the number of codes as the correction object and the number of correction codes to be generated are increased for improvement of error correcting capability, here rises problems that the correction code to realize error correction capability cannot be generated and redundant data having no relation to the recording information increases. Moreover, there rises also a problem that compatibility of signal process between the generation and reproduction processes of the recording signal for the current DVD is remarkably lowered.
SUMMARY OF THE INVENTIONTherefore, it is an object of the present invention to provide a digital signal forming method, disc recording media using the same and recording method thereof for solving the problems explained above, assuring the error correction capability required for high density recording and maintaining high level compatibility for generation and reproduction processes of the recording signal.
In order to achieve the object explained above, in the digital signal recording method, the data of every constant information amount unit is interleaved in a plurality of correction block allocations for completing the error correction process for a series of recording information. In each correction block allocation, the PO correction code for the vertical direction series and PI correction code for the lateral direction series are generated and added to form the correction block in order to correct an error generated in the reproducing. After forming the correction block, the data line including the PI correction code is alternately allocated from the beginning of the correction block and the line including the PO correction code is allocated in the equal interval for every constant line data. Thereby, the interleave allocation can be formed. Moreover, the digital signal is generated by executing at least modulation process from the heading line of the interleave allocation and it is then recorded on the disc as the recording marks (pits). At the time of recording the digital signal, the digital signal generated with the modulation process where less amount of redundant data is generated with the highly efficient encoding and with reduction of recording mark (pit) size.
Moreover, at the time of reproducing the digital signal recorded on a disc in the higher recording density, the demodulation process is executed to the reproducing signal obtained, this signal is then temporarily stored to recover the interleave allocation and the error correction process due to the decoding of the PI, PO correction codes is performed respectively for a plurality of correction blocks. Moreover, the recording information interleaved in the correction block can be reproduced by outputting such information to maintain the permutation of recording information.
BRIEF DESCRIPTION OF THE DRAWINGSFIGS. 1(A) to 1(D) illustrate the allocation of data and code for explaining a first embodiment of the digital signal forming method of the present invention.
FIGS. 2(A) to 2(D) illustrate the allocation of data and code for explaining the digital signal forming method at the time of recording the information to the disc of the related art.
FIGS. 3(A) to 3(D) illustrate the allocation of data and code for explaining a second embodiment of the digital signal forming method of the present invention.
FIGS. 4(A) to 4(D) illustrate the allocation of data and code for explaining the second embodiment of the digital signal forming method of the present invention.
DESCRIPTION OF THE REFERRED EMBODIMENTSThe preferred embodiments of the present invention will be explained with reference to the accompanying drawings.
In these figures, the reference numeral 1 designates a series of recording information to be recorded to a recording medium; 2, a format of the sector data which is one of recording unit to the recording medium, including a part of the recording information 1; 5, 6, formats of the first and second correction block that are the unit for completing the PO correction code as the external code and the PI correction code as the internal code including a plurality of sector data 2; 4a, an interleave format respectively for the sector data included in the first and second correction blocks 5, 6 and the line data including the PO correction code.
Details of the digital signal forming method in the first embodiment will be explained below.
The structural elements of the sector data 2 in
Therefore, in this embodiment, the sector data 2 is divided into two blocks as the first sector data block 2a and the second sector data block 2b. In the first sector block 2a, the sector ID, IED code, RSV code and main data 1, 3, . . . , 11 of the odd number are allocated, in the second sector block 2b, the main data 2, 4, . . . , 12 of the even number and EDC are allocated. At the forming the correction block, the sector ID and additional information, and the main data 1, 3, . . . , 11 of the odd number are allocated in the first correction block 5, while the main data 2, 4, . . . , 12 of the even number and EDC are allocated in the second correction block 6. The required number of sectors is identical to the 32 sector data up to the sector 31 from the sector 0 in order to perform the interleave to the two correction blocks in unit of 172 bytes. Therefore, each sector data of the sector 0 to sector 31 is divided into the two sector data blocks that are respectively allocated in the first and the second correction block 5, 6.
After the main data of sector 0 to sector 31 are interleaved to the first and second correction block 5, 6, the PI, PO correction codes are encoded independently as in the case of
Moreover, the interleave allocation 4a is a result of the interleave process for the line data included of the first and second correction blocks 5, 6 conducted to avoid the burst error to the PO correction code. In the interleave allocation 4a, each line of the PO correction coeds 16, 19 of the first and second correction blocks 5, 6 is alternately allocated in such a manner that 21a, 21b, . . . , 21z, 21aa, . . . , 21af are allocated in the first line of the PO correction code 16 of the first correction block 5, first line of the PO correction code 19 of the second correction block, second line of the PO correction code 16 of the first correction block 5, second line of the PO correction code 19 of the second correction block 6, . . . . On the other hand, 22a, 22b, . . . , 22z, 22aa, . . . , 22af are identical to a lines of the data of sector 0 to sector 31 and PI correction codes 15, 16.
In the interleave allocation 4a, sector data in unit of 182 bytes including the PI correction codes 15, 19 is allocated in the sequence of the line data for the main data 1 to 12 and the sector data is allocated to result in the continuous line data including the main data 1 to 12. Namely, reallocation is performed maintaining continuity of the recording information 1. Moreover, the line data including the PO correction codes 16, 19 included in the first and second correction blocks 5, 6 are alternately interleaved between the sector data.
In the case of FIGS. 1(A) to 1(D), the heading line of the line data including the PO correction code 16 is allocated, for example, between the data 22a and 22b, while the heading line of the line data including the PO correction code 19 is allocated between the data 22b and 22c. Hereinafter, the line data including the PO correction codes 16, 19 are alternately interleaved. After interleaving, the higher efficiency modulation process and framing process due to addition of the synchronizing signal are performed, and high density recording by the short wavelength laser is conducted along the tracks on the disc and thereby the data is recorded as the recording marks or pits.
In the first embodiment explained above, the data amount same as the correction block and correction code of
Improvement effect of correction capability due to the interleaving of burst error in the first embodiment will be explained. For example, the digital signal generated depending on the first embodiment is recorded on the disc in the doubled recording density of that in the related art with reduction in length of the recording marks (pits) and highly efficient modulation. In this case, if a scratch or dust occurs on the disc to generate the burst error, for example, of 16 lines in the disc of related art having the equal recording density, the burst error occurs in the 32 lines. However, since the burst error of 32 lines is interleaved in every 16-line for the allocation of the first and second correction block 5, 6, if the limit of the PO correction capability is set to 16 lines, reproducing is possible because the number of burst error line included each correction block 5, 6 is within such limit. Namely, while the allocation of the correction code and correction block of
The digital signal forming method in the first embodiment can be described as follow as the processing steps.
The digital signal forming method comprises a step to form, in every constant recording information amount, a plurality of sector data in which an address information indicating the position on the recording medium is added to the main data, a step to share the address information of each sector data and main data of the odd number to the first sector data block and share the main data of the even number of each sector data to the second sector data block, and a step to form the first and the second correction block by adding the first correction code and the second correction code to correct the error in the line direction to each of the first sector data block and second sector data block, and adding the third correction code and fourth correction code to correct the error in the vertical direction to plurality of the first and second sector data block.
Moreover, the digital signal forming method of the first embodiment also comprises a step to sequentially allocate a plurality of sector data giving continuity to the main data by alternately allocating the line data forming the first, second correction block and a step to sequentially allocate the line of the third, fourth correction code between the sector data sequentially allocated. Namely, the correction codes added in the line and vertical directions in the respective first and second correction blocks are not limited only to the codes of the same kind and the number of codes.
On a recording medium, the digital signal that is generated by at least the modulation process to the digital signal generated with the process including the steps explained above is recorded.
With reference to
In
In the first correction block 31 illustrated in
As explained above, in the sector data including the elements similar to that of
In addition, the line data including the PO correction codes 36, 39, 43 are alternately interleaved. In the case of
As explained above, the interleave allocation 4c can be obtained. In
In the second embodiment, the data amount identical to the correction blocks of
Effect of improvement in the correction capability due to the interleaving of the burst error in the second embodiment will then be explained. For example, the digital signal generated depending on the second embodiment is recorded to a disc in the recording density of three times. In this case, if a scratch or dust which generates the burst error of 16 lines is generated in the disc of a certain recording density in the related art, the burst error of 48 lines (three times of 16 lines) is generated. However, since the burst error of 48 lines is interleaved in every 16-line in the allocation of the first, second and third correction block 31, 32, 33, if the limit of the PO correction capability is 16 lines, reproduction becomes possible because the number of burst error line included each correction block 31 to 33 is within such limit. Namely, while the correction code and correction block allocation in
Therefore, in the case where 16×n sectors are required when the line data in unit of 172 bytes in the sector is interleaved and allocated in the correction blocks from the 1st to nth blocks (n is a divisor for the number of lines of line data included in the sector data) in the recording sequence of the main data, the correction capability of the generated digital signal can be improved up to n times in comparison with that of
Next, the third embodiment of the digital signal forming method of the present invention will be explained with reference to
As illustrated in
In the first correction block 49 illustrated in
As explained above, in the third embodiment, the sector data in unit of the 172 bytes×2 lines are allocated to be interleaved to the first and second correction block 49, 50. Since the sector data is interleaved to the first and second correction blocks 49, 50, the 32 sector data (16 sectors×2) are required. Two correction blocks, each block is formed of 182 bytes×(6 lines×32 sectors+16 lines), namely 182 bytes×208 lines, are formed.
In regard to the interleave method of the line data including the PO correction codes 54, 65 after generation of the first and second correction blocks 49, 50, the sector data in unit of 182 bytes including the PI correction codes 53, 64 is allocated in the sequence of line data to the main data 1 to 12 like
With formation of the format as explained above, the interleave allocation 4d of
As explained above, in the third embodiment, the data amount same as the correction block and the correction code of
Effect of improvement in the correction capability by dispersion of burst error in the third embodiment explained above will then be explained. For example, the digital signal generated depending on the third embodiment is recorded in the recording density two times the density of the related art. In this case, if a scratch or dust for generating the burst error of 16 lines is generated in the disc having a certain recording density, the burst error occurs in the 32 lines which are two times of 16 lines. However, since the burst error of 32 lines is interleaved to the allocation of the first and second correction block 49, 50 and thereby the error correction capability of the generated digital signal can be improved.
The steps to provide the digital signal forming method corresponding to the second and third embodiments explained above will be explained below.
The digital signal forming method comprises a step to form a plurality of sector data adding the address information indicating the position on the recording medium to a plurality of lines of main data in every constant recording information amount for the series of recording information, a step to divide the main data into a plurality of sector data blocks and a step to form a plurality of correction blocks adding the first correction code for the error in the line direction and the second correction code for the error in the vertical direction to each of the divided sector data blocks.
Moreover, the digital signal forming method further comprises a step to allocate the main data forming each sector data interleaved in a plurality of correction blocks by giving continuity thereto and a step to sequentially allocate each line of the second correction code among a plurality of sector data.
On a recording medium, the digital signal generated by executing at least the modulation process to the digital signal generated through the process including the above step is recorded.
Moreover, the amount of data in each process in the first, second and third embodiments will be expressed with the following ordinary formula.
In the digital signal forming method, the first to the nth correction blocks of the (i+q) bytes×(j×k/n+P) lines can be formed by forming a plurality of sector data, dividing such sector data to (i bytes×n lines)×j lines (i, j, n are positive integers and n is a divisor of j) for the continuous k (k is a positive integer) of sector data, generating the first correction code of p bytes (p is a positive integer) to each code length of (j×k/n) bytes and then generating the second correction code of q bytes (q is a positive integer) to each code length of i bytes series including the first correction code. Moreover, the allocation of (i+q) bytes×(j×k+p×n) lines maintaining continuity of the line data for the k sector data interleaved in at least the first to nth correction blocks is formed. In this invention, after forming the first to nth correction block of the (i+q) bytes×(j×k/n+p) lines on the occasion of forming the allocation of the (i+q) bytes×(j×k+P×n) lines due to the k sector data interleaved to the at least first to nth correction blocks the line data including the address information is allocated in the interval of (j×k+p×n)/k lines from the heading line of its allocation and the address information is continuous. And the line data including the first correction code is allocated in the interval of (j×k+p×n)/k lines following the line data for sector data and the line data including the first correction code for the first to nth correction blocks are alternately allocated.
At the forming the first to nth correction blocks, it is also possible that the line data is allocated in the n lines with the line data of continuous r lines defined as a unit (r is a positive integer and a divisor of j) of line data in unit of the i bytes (i is a positive integer) which is included in the sector data and is the additional unit of the second correction code. This is covered with the third embodiment.
Moreover, in the above ordinary formula, n=2 corresponds to the first embodiment.
Thereafter, on the occasion of recording the information to a recording medium, at least the modulation process and addition of the synchronous signal are executed to the digital signal generated through the above processes and is recorded on the recording medium.
Moreover, on the occasion of recording the digital signal generated with the method of the first, second and third embodiments explained above to a recording medium, the recording marks or pits are recorded in the recording density of y times (y is a decimal number equal to or larger than 1 (≧1)), or with the higher efficient modulation system or with combination of the higher efficient modulation system and reduction of the recording marks or pits.
In regard to the recording to the tracks existing on the recording medium, the recording marks or pits are continuously or non-continuously recorded in every constant amount of data along with the tracks.
Next, a method for reproducing from the disc with the digital signals generated by the first, second and third embodiments will be explained below.
The digital signal is reproduced with the demodulation process to the modulation system for the signal read out from the tracks on the disc. The interleave allocation can be reproduced by storing the reproduced digital signal to a buffer memory. Moreover, a interleaving method of sector data executed in the recording, format of correction block and the number of blocks and the interleave method to form the interleave allocation from a plurality of correction blocks are determined depending on determination of the kind of disc. From the determination result, error correction process due to the decoding of the PI, PO correction codes for a plurality of correction blocks are performed with the random access to the buffer memory for the interleave allocation stored. Moreover, after the error correction process, the recording information can be reproduced by outputting the data of the main data 1 to 12 continuously from the buffer memory
In this case, at the storing of the reproduced digital signal on the buffer memory, it is also possible to reproduce the digital signal with reproducing a plurality of correction blocks on the buffer memory and then executing the PI, PO correction processes.
Moreover, when further improvement of correction capability for the error is required due to the maintaining of readability and employment of the high efficient modulation system in the first, second and third embodiments explained above, it is also possible to introduce the method wherein encoding of the correction code having the higher correction capability with the same number of the correction code and the same length of the vertical and lateral series in the correction block. And the number of correction codes is increased without increase of the length of the vertical and lateral series. In this case, amount of data of correction block will be changed but the digital signal having improved the burst error correction capability can be generated through combination with the method to interleave the data in a plurality of correction blocks as in the case of embodiments.
In addition, the method of interleave the sector data to a plurality of correction blocks is not limited only to the methods of the first, second and third embodiments, it is enough that the line data included in the sector data is interleaved to a plurality of correction blocks. Therefore, the allocation sequence of sector data and the allocation sequence of line data including the main data interleaved a plurality of correction blocks are not required to be persisted in the continuity of the recording information.
Moreover, the interleave allocation is also not required to be persisted in continuity of the recording information in the sector data. The line data including the sector ID is allocated regularly in order to detect the position on the disc in reproducing, but the other line data may be allocated freely within the sector data or within the range in a plurality of correction block.
In addition, the digital signal generated depending on the first, second and third embodiments is recorded to a disk in the higher recording density with reduction of the recording marks (pits) or highly efficient modulation system in which generation of redundant signal is suppressed or with combination of these reduction and modulation system.
As explained above, according to the present invention, generation of the digital signal having improved the correction capability for the burst error can be realized by interleaving the line data of the sector data to a plurality of correction blocks with generation of the correction code.
Moreover, since the same correction code and correction block allocation can be used and there is no increase in amount of redundant data, the compatibility of the digital signal process can be maintained in the higher level.
In addition, since the burst error can be interleaved efficiently to a plurality of correction blocks at the time of reproducing a disc by recording the digital signal generated with the method of the present invention to a disc in the higher recording density, readability in the disc reproducing can be attained easily.
Claims
1. A method for recording a digital signal on a recording medium comprising:
- a step to form a plurality of main data by dividing a stream of recording information;
- a step to form a plurality of data sectors, each data sector comprising address information indicating its position on a recording medium and the main data;
- a step to divide the data sectors to produce a first sector data block with the address information and a second sector data block without the address information;
- a step to form a first correction block comprising a plurality of the first sector data blocks and first correction codes for correcting errors in the vertical direction of data in the first sector data blocks;
- a step to form a second correction block comprising a plurality of the second sector data blocks and second correction codes for correcting errors in the vertical direction of data in the second sector data blocks; and
- a step to record the first correction block and the second correction block on the recording medium.
2. A method for recording a digital signal on a recording medium as recited in claim 1, wherein the step to record comprises:
- a step to position the first correction on an nth line of the first correction block; and
- a step to position the second correction codes on an mth line of the second correction block.
3. A method for recording a digital signal on a recording medium comprising:
- a step to form a plurality of main data by dividing a stream of recording information;
- a step to form a plurality of data sectors, each comprising address information indicating its position on a recording medium and the main data;
- a step to divide the data sectors to produce a plurality of units;
- a step to form a first sector data block comprising odd-numbered units in the data sectors;
- a step to form a second sector data block comprising even-numbered units in the data sectors;
- a step to form a first correction block comprising a plurality of the first sector data blocks and first correction codes for correcting errors in the vertical direction of data in the first sector data blocks;
- a step to form a second correction block comprising a plurality of the second sector data blocks and second correction codes for correcting errors in the vertical direction of data in the second sector data blocks; and
- a step to record the first correction block and the second correction block on the recording medium.
4. A method for recording a digital signal on a recording medium as recited in claim 3, wherein the step to record comprises:
- a step to position the first correction on an nth line of the first correction block; and
- a step to position the second correction codes on an mth line of the second correction block.
5. A recording medium on which a plurality of data sectors are recorded, wherein each data sector has address information indicating its position on a recording medium and main data obtained from a stream of recording information, each data sector formed by:
- forming a first correction block comprising a plurality of first sector data blocks and first correction codes for correcting errors in the vertical direction of data in the first sector data blocks, wherein each first sector data block comprises a part of the data sector with the address information; and
- forming a second correction block comprising a plurality of second sector data blocks and second correction codes for correcting errors in the vertical direction of data in the second sector data blocks, wherein the second sector data block comprises a part of the data sector without the address information.
6. The recording medium of claim 5, wherein the first correction codes are positioned on an nth line of the first correction block and the second correction codes are positioned on an mth line of the second correction block.
7. A recording medium on which a plurality of data sectors are recorded wherein each data sector includes address information indicating its position on a recording medium and main data obtained from a stream of recording information, each data sector formed by:
- forming a first correction block comprising a plurality of first sector data blocks and first correction codes for correcting errors in the vertical direction of data in the first sector data blocks, wherein the first sector data block comprises odd-numbered units in the data sector; and
- forming a second correction block comprising a plurality of second sector data blocks and second correction codes for correcting errors in the vertical direction of data in the second sector data blocks, wherein the second sector data block comprises even-numbered units in the data sector.
8. The recording medium of claim 7, wherein the first correction codes are positioned on an nth line of the first correction block and the second correction codes are positioned on an mth line of the second correction block.
9. A method for reproducing a stream of recording information from a digital signal recorded on a recording medium, the digital signal being recorded on the recording medium in accordance with the method of claim 1, the method for reproducing comprising:
- a step to output a plurality of the first correction blocks and a plurality of the second correction blocks from the recording medium;
- a step to correct errors in the vertical direction of data in the first correction blocks using the first correction codes;
- a step to correct errors in the vertical direction of data in the second correction blocks using the second correction codes; and
- a step to produce the stream of recording information from the first correction block and the second correction block.
10. A method for reproducing a stream of recording information from a digital signal recorded on a recording medium, the digital signal being recorded on the recording medium in accordance with the method of claim 3, the method for reproducing comprising:
- a step to output a plurality of the first correction blocks and a plurality of the second correction blocks from the recording medium;
- a step to correct errors in the vertical direction of data in the first correction blocks using the first correction codes;
- a step to correct errors in the vertical direction of data in the second correction blocks using the second correction codes; and
- a step to produce the stream of recording information from the first correction block and the second correction block.
Type: Application
Filed: Jan 21, 2005
Publication Date: Jul 7, 2005
Applicant: Hitachi, Ltd. (Tokyo)
Inventor: Hiroshi Hirayama (Tokyo)
Application Number: 11/041,119