OPTICAL DISC DEVICE

• US 20190189154A1
• Filed: 12/18/2018
• Published: 06/20/2019
• Est. Priority Date: 12/19/2017
• Status: Active Grant

• Current Assignee: Panasonic Intellectual Property Management Co., Ltd. (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Intellectual Property Management Co., Ltd. (Panasonic Holdings Corporation)
• Inventors: NAKATA, Kohei, NAKASENDO, Tsuyoshi
• Granted Patent: US 10,453,490 B2
• Time in Patent Office: Days
• CPC Class Codes: G11B 20/1037 based on hard decisions, e.g. by evaluating bit error rates before or after ECC decoding
• CPC Class Codes: G11B 20/1833 by adding special lists or symbols to the coded information G11B20/1806, G11B20/1866 take precedence
• CPC Class Codes: G11B 7/0045 Recording G11B7/006, G11B7/0065 take precedence

Abstract

An optical disc device includes a first error correction coding circuit that codes the recording data according to a first error correction coding format, a second error correction coding circuit that codes the recording data according to a second error correction coding format, and a recorder that converts the recording data into a recording signal and records it on an optical disc. The second error correction coding format is different in an arrangement of the recording data from the first error correction coding format. The second error correction coding format is configured to generate a second parity code with a higher degree of redundancy. The recorder records the recording data coded by the first error correction coding circuit and only the second parity code in the recording data coded by the second error correction coding circuit.

Claims

1. An optical disc device which records and reproduces recording data on or from tracks on an optical disc in units of a prescribed block, the optical disc device comprising:

a first error correction coding circuit that codes the recording data according to a first error correction coding format;

a second error correction coding circuit that codes the recording data according to a second error correction coding format; and

a recorder that converts the recording data coded by the first error correction coding circuit or the recording data coded by the second error correction coding circuit into a recording signal and records the recording signal on the optical disc,

wherein the second error correction coding format is different in an arrangement of the recording data from the first error correction coding format, and the second error correction coding format is configured to generate a second parity code with a higher degree of redundancy than in a case that the recording data is coded according to the first error correction coding format; and

wherein the recorder records the recording data coded by the first error correction coding circuit and only the second parity code in the recording data coded by the second error correction coding circuit.

2. The optical disc device according to claim 1, wherein when continuous errors have occurred in a number that is larger than a first threshold value in a coding according to the first error correction coding format, the recorder records the second parity code generated by the second error correction coding circuit on a different track being different from a track on which the recording data coded by the first error correction coding circuit is recorded.

3. The optical disc device according to claim 2, wherein when continuous errors have occurred in a number that is larger than a second threshold value that is larger than the first threshold value in the coding according to the first error correction coding format, the recorder records the recording data coded by the first error correction coding circuit again, separately on a different track being different from a track on which the recording data coded by the first error correction coding circuit have been recorded previously.

4. The optical disc device according to claim 2, wherein the recorder records, on the optical disc, management information indicating that the second parity code generated by the second error correction coding circuit is recorded on the different track.

5. The optical disc device according to claim 1, further comprising:

a first error correction decoding circuit that performs an error correction according to the first error correction coding format; and

a second error correction decoding circuit that performs an error correction according to the second error correction coding format,

wherein the recording data is recovered by performing the error correction by the first error correction decoding circuit and the error correction by the second error correction decoding circuit alternately and repeatedly.

6. The optical disc device according to claim 1, wherein when continuous errors have occurred in a number that is larger than a first threshold value in a coding according to the first error correction coding format, the recorder records the second parity code generated by the second error correction coding circuit on a second block at a position that follows a position where the recording data coded by the first error correction coding circuit is recorded as a first block.

7. The optical disc device according to claim 6, wherein the recorder records the first block and the second block in such a manner that the first block and the second block include a runin region indicating a block head, a data frame region including coded recording data, and a runout region indicating a block end;

and

wherein the runin region includes format discrimination information which has either a first particular pattern if the coded recording data included in the data frame region is recording data coded according to the first error correction coding format or a second particular pattern if the coded recording data included in the data frame region is a second parity code coded according to the second error correction coding format.

8. The optical disc device according to claim 7, further comprising:

a first error correction decoding circuit that performs an error correction according to the first error correction coding format; and

a second error correction decoding circuit that performs an error correction according to the second error correction coding format,

wherein at least one of the error correction by the first error correction decoding circuit and the error correction by the second error correction decoding circuit is performed in response to a result of reproduction of the format discrimination information included in the runin region.