Method and apparatus for optical disk device

• US 6,490,236 B1
• Filed: 09/01/2000
• Issued: 12/03/2002
• Est. Priority Date: 04/04/2000
• Status: Expired due to Fees

• Current Assignee: Solexa Incorporated (Illumina Incorporated)
• Original Assignee: Hitachi, Ltd.
• Inventors: Fukuda, Yasushi, Takeuchi, Toshifumi, Tokushuku, Nobuhiro
• Primary Examiner(s): Tran, Thang V.
• Application Number:
  US09/654,178
• Time in Patent Office: 823 Days
• Field of Search: 369/59.23, 369/59.24, 369/59.25, 369/59.26, 369/124.07, 369/124.08, 369/53.35, 369/53.36, 369/47.18, 369/275.3, 714/764, 714/763, 714/769, 714/752, 714/755, 714/758, 714/774, 714/781
• US Class Current: 369/53.35
• CPC Class Codes: G11B 20/18 Error detection or correction; Testing , e.g. of drop-outs

Abstract

In playing back data in an optical disk device, to perform high-speed data playback with a low number of playback retries even if an error occur when data is being read. In reading data composed of ECC blocks, if a data error occurs during a read operation, the data from sectors for which PI error correction can be performed is left alone. Playback retries using different playback conditions are performed just on the sectors for which PI error correction can be performed. Thus, the playback retry count can be reduced.

Claims

1. A method for playing back data from an optical information recording medium, the data organized into plural groups, the groups organized into plural blocks, each block having an associated first error correction code for correcting errors in the block, each group having an associated second error correction code for correcting errors in the group, the method comprising:

reading out one of the blocks from the optical information recording medium;

performing a first error correction for the block based on its associated first error correction code;

performing a second error correction for each group based on its associated second error correction code;

storing a result code indicating, for each group, whether error correction is possible for that group; and

for each group where error correction is not possible, reading out the group from the optical information recording medium to produce a reread group and performing the second error correction on the reread group.

2. The method of claim 1 further including updating the block by replacing groups therein with the reread groups, and performing the first error correction on the updated block.

3. The method of claim 1 wherein the block is an ECC block, the first error correction is PO correction, and the second error correction is PI correction.

4. The method of claim 1 wherein the step of reading out the group includes altering readout conditions based on the group being read out, the step of altering including one or more of:

changing the focus condition,

changing the tracking condition,

changing the speed condition, and

changing at least one of the sync signal detection condition, playback equalizer setting, and data slice setting.

5. A method for playing back data from an optical information recording medium, the data being organized into a plurality of blocks, each block comprising a plurality of groups, each block having an associated first error correction code for correcting errors in the block by performing a first error correction, each group having an associated second error correction code for correcting errors in the group by performing a second error correction, the method comprising:

reading out one of the blocks from the optical information recording medium;

performing an initial second error correction for each group of the block;

storing a resulting data indicating for each group whether or not the initial second error correction is possible;

performing the first error correction on the block; and

if the first error correction for the block is not possible, then;

storing the data of those groups for which the resulting data indicates that the initial second error correction is possible;

rereading the block from the optical information recording medium;

performing an additional second error correction on those groups for which the resulting data indicates that the initial second error correction is not possible; and

performing the first error correction for the data of the groups for which the additional second error correction is performed and for the data of the groups for which the resulting data indicates that the initial second error correction is possible.

6. A method for playing back data from an optical information recording medium, the data comprising plural blocks of data, each block comprising plural groups of data, each block having an associated first error correction code used for correcting an error of data in the block using a first error correction, each group having an associated second error correction code for correcting an error of the data in the group using a second error correction, the method comprising:

reading out one of the blocks from the optical information recording medium;

performing the second error correction for each group of the block;

storing a resulting data indicating whether or not the second error correction for each group is possible;

performing the first error correction; and

when the first error correction is not possible, then;

storing the data of the group for which the resulting data indicates the second error correction is possible;

rereading the group from the optical information medium for which the resulting data indicates the second error correction is not possible;

performing the additional second error correction for the group for which the resulting data indicates the second error correction is not possible; and

performing the first error correction for the data of the group for which the additional second error correction is performed and the data of the group for which the resulting data indicates the second error correction is possible.

7. An optical device for playing back the data from an optical information recording medium, the data being organized into a plurality of blocks, each block comprising a plurality of groups, each block having an associated first error correction code for correcting errors in the block by performing a first error correction, each group having an associated second error correction code for correcting errors in the group by performing a second error correction, the device comprising:

a motor to rotate the optical information recording medium;

an optical head to produce a signal indicative of the information store on the optical information recording medium;

a decoder circuit coupled to the optical head to decode the signal from the optical head and produce data; and

a system controller coupled to the decoder and configured;

to control the optical head to read out a block from the optical information recording medium,

to control the decoder to produce a decoded signal indicative of the block read out by the optical head,

to perform the second error correction for each group of the block,

to store resulting data indicating for each group whether or not the second error correction is possible, and

to perform the first error correction,

wherein when the first error correction is not possible, the system controller performs an additional second error correction based on the resulting data followed by an additional first error correction.

8. The optical device of claim 7 wherein the additional second error correction includes rereading the group from the optical information medium for which the resulting data indicates the second error correction is not possible.

9. An optical device for playing back the data from an optical information recording medium, the data comprising plural blocks of data, each block comprising plural groups of data, each block having an associated first error correction code used for correcting an error of data in the block using a first error correction, each group having an associated second error correction code for correcting an error of the data in the group using a second error correction, the device comprising:

a motor to rotate the optical information recording medium;

an optical head to read a block from the optical information recording medium thereby producing a signal indicative of the information contained therein;

a demodulator circuit coupled to the optical head and to demodulate the signal from the optical head and produce a data; and

a system controller coupled to the decoder and configured;

to control the optical head to reread the block from the optical information recording medium,

to control the decoder to produce a decoded signal indicative of the block read out by the optical head,

to perform the second error correction for each group of the block,

to store resulting data indicating for each group whether or not the second error correction is possible, and

to perform the first error correction,

wherein when the first error correction is not possible, the system controller is further configured;

to store as first data the data of those groups which the resulting data indicates the second error correction is possible,

to control the optical head to read out the block from the optical information recording medium,

to perform an additional second error correction for those groups which the resulting data indicates the second error correction is not possible to produce second data, and

to perform an additional first error correction for the first data and the second data.

10. The optical device of claim 9 further comprising:

a focus control circuit coupled to the optical head and configured to receive the signal to produce a focus control signal under predetermined focus condition;

a tracking control circuit coupled to the optical head and configured to receive the signal to produce a tacking control signal under predetermined tracking condition; and

a motor control circuit coupled to the motor to control the motor under predetermined speed condition,

wherein the demodulator circuit demodulates the signal under a predetermined sync signal detection condition and a predetermined playback equalizer setting and predetermined data slice setting,

wherein prior to rereading the block, the system controller performs at least one of;

changing the focus condition,

changing the tracking condition,

changing the speed condition, and

changing at least one selected from the sync signal detection condition, playback equalizer setting, and data slice setting.

11. The optical device of claim 9 further comprising:

a focus control circuit coupled to the optical head and configured to receive the signal to control the object lens;

a tracking control circuit coupled to the optical head and configured to receive the signal to control the object lens under predetermined tracking condition; and

a motor control circuit coupled to the motor to control the motor under predetermined speed condition,

wherein the demodulator circuit demodulates the signal under a predetermined sync signal detection condition and a predetermined playback equalizer setting and predetermined data slice setting,

wherein prior to rereading the block, the system controller performs at least one of;

changing the focus condition,

changing the tracking condition,

changing the speed condition, and

changing at least one of the sync signal detection condition, playback equalizer setting, and data slice setting.