# US 7,411,879 B2 · Optical disk device

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- Number: US 7,411,879 B2
- Document ID: US7411879B2
- Status: Granted
- Kind: B2
- Application number: 11/177,137
- Filed: 2005-07-08
- Published: 2006-01-12
- Granted: 2008-08-12
- Earliest claimed: 2004-07-12
- Assignees: TEAC Corporation
- Inventors: Akira Mashimo
- Web page: https://patentgrep.com/patent/US7411879B2

## CPC

- G11B 27/24: by sensing features on the record carrier other than the transducing track {; sensing signals or marks recorded by another method than the main recording}
- G11B 20/1803: {by redundancy in data representation}
- G11B 2020/1843: {using a cyclic redundancy check [CRC]}
- G11B 2220/2579: HD-DVDs [high definition DVDs]; AODs [advanced optical discs]
- G11B: INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER (recording measured values in a way that does not require playback through a transducer G01D9/00; recording or playback apparatus using mechanically marked tape, e.g. punched paper tape, or using unit records, e.g. punched or magnetically marked cards G06K; transferring data from one type of record carrier to another G06K1/18; circuits for coupling output of reproducer to radio receiver H04B1/20; gramophone pick-ups or like acoustic electromechanical transducers or circuits therefor H04R)

## Abstract

An optical disk device which drives an HD-DVD or the like. When recording or reproducing data with respect to an optical disk of HD-DVD, the address information is demodulated by an address decoding circuit and is supplied to a system controller. The system controller performs error checking using the CRC technique. When a resulting CRC value does not correspond to CRC bits, the system controller regards a bit in which the number of waves in wobbles having the same phase is not four, which is a predetermined value, as an error bit, and performs bit data replacement with respect to the error bit. Specifically, the system controller searches for a combination of bit values by which a resulting CRC value matches the CRC bits, thereby performing error correction. At this time, the system controller tries the data value replacement preferentially using a combination of bit values by which the address is advanced by one address from the immediately previous address which is fixed among all the possible combinations with respect to the error bits.

## Claims

### Claim 1

An optical disk device for recording or reproducing data with respect to grooves of an optical disk in which address information is embedded by forming the grooves in wobbles,
in which the wobbles form data of a single bit using N waves with the same phase, and a predetermined check bit for CRC is added to the address information,
the optical disk device comprising:
means for reproducing the wobbles and extracting the address information; and
address determining means for determining a bit in which the number of waves with the same phase in the wobbles is N/2 to be a reading error bit and replacing bit data of the reading error bit such that a resulting CRC value matches the check bit for CRC, when a resulting CRC value with regard to the address information which is extracted does not match the check bit for CRC.

### Claim 2

An optical disk device for recording or reproducing data with respect to grooves of an optical disk in which address information is embedded by forming the grooves in wobbles,
in which the wobbles form data of a single bit using N waves with the same phase, and a predetermined check bit for CRC is added to the address information,
the optical disk device comprising:
means for reproducing the wobbles and extracting the address information; and
address determining means for determining a bit in which the number of waves with the same phase in the wobbles is N−1 or smaller to be a reading error bit and replacing bit data of the reading error bit such that a resulting CRC value matches the check bit for CRC, when a resulting CRC value with regard to the address information which is extracted does not match the check bit for CRC.

### Claim 3

An optical disk device for recording or reproducing data with respect to grooves of an optical disk in which address information is embedded by forming the grooves in wobbles,
in which the wobbles form data of a single bit using N waves with the same phase, and a predetermined check bit for CRC is added to the address information,
the optical disk device comprising:
means for reproducing the wobbles and extracting the address information; and
address determining means for determining a bit in which the number of waves with the same phase in the wobbles is N/2 to be a reading error bit and replacing bit data of the reading error bit such that a resulting CRC value matches the check bit for CRC when a resulting CRC value with regard to the address information which is extracted does not match the check bit for CRC, and for further determining a bit in which the number of waves with the same phase in the wobbles is N−1 or smaller to be a reading error bit and replacing bit data of the reading error bit such that a resulting CRC value matches the check bit for CRC when the resulting CRC value with regard to the address information which is extracted does not match the check bit for CRC even by the bit data replacement which is performed.

### Claim 4 (depends on 1)

An optical disk device according to claim 1, wherein
when a plurality of bits are determined to be the reading error bit, the address determining means selects, among possible combinations of bit values, a combination of bit values by which a resulting CRC value matches the check bit for CRC, and performs the bit data replacement using the combination which is selected.

### Claim 5 (depends on 2)

An optical disk device according to claim 2, wherein
when a plurality of bits are determined to be the reading error bit, the address determining means selects, among possible combinations of bit values, a combination of bit values by which a resulting CRC value matches the check bit for CRC, and performs the bit data replacement using the combination which is selected.

### Claim 6 (depends on 3)

An optical disk device according to claim 3, wherein
when a plurality of bits are determined to be the reading error bit, the address determining means selects, among possible combinations of bit values, a combination of bit values by which a resulting CRC value matches the check bit for CRC, and performs the bit data replacement using the combination which is selected.

### Claim 7 (depends on 1)

An optical disk device according to claim 1, wherein
when a plurality of bits are determined to be the reading error bit, the address determining means selects, among possible combinations of bit values, a combination of bit values by which the address is advanced by one address from an immediately previous address which is already fixed and determines whether or not a resulting CRC value matches the check bit for CRC, and, if the resulting CRC value matches the CRC bit, the address determining means performs the bit data replacement using the combination which is selected.

### Claim 8 (depends on 2)

An optical disk device according to claim 2, wherein
when a plurality of bits are determined to be the reading error bit, the address determining means selects, among possible combinations of bit values, a combination of bit values by which the address is advanced by one address from an immediately previous address which is already fixed and determines whether or not a resulting CRC value matches the check bit for CRC, and, if the resulting CRC value matches the CRC bit, the address determining means performs the bit data replacement using the combination which is selected.

### Claim 9 (depends on 3)

An optical disk device according to claim 3, wherein
when a plurality of bits are determined to be the reading error bit, the address determining means selects, among possible combinations of bit values, a combination of bit values by which the address is advanced by one address from an immediately previous address which is already fixed and determines whether or not a resulting CRC value matches the check bit for CRC, and, if the resulting CRC value matches the CRC bit, the address determining means performs the bit data replacement using the combination which is selected.