JPS63157361A - Optical disk driving device - Google Patents

Abstract

PURPOSE:To normally reproduce a sector by reproducing an inter-sector code stored in a different sector even when an error occurs over an entire sector and the correction of this sector is impossible. CONSTITUTION:The address 8 of a sector of an optical disk 1 is sent to a reproduction part 2 by a control circuit 6. The part 2 sends a reproduction signal 12 to a demodulation circuit 3 and a demodulation signal 13 to a decoding circuit 4. The circuit 4 corrects errors and stores the decoding data in a buffer 5 to output the reproduction data after the data on a single sector is decoded. If an error occurs over an entire sector, the circuit 4 sends an error detecting signal to the circuit 6. The circuit 6 reads out those sectors forming an inter- sector code and instructs the address of each sector where the data forming the inter-sector code and the check data are recorded via the address 8. Then the data on each sector is read out and stored in a parity buffer 7 and the data is normally reproduced.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an optical disc drive device for reproducing data from a read-only optical disc on which data has been recorded in advance, and in particular for the reproduction of code data such as computer programs. The present invention relates to an optical disc drive device for an optical disc having a sector structure suitable for recording.

Conventional technology records data in the form of bits with submicron-order irregularities on the plastic base material of the disk, and laser light is irradiated with one.
A read-only optical disc (hereinafter referred to as an R10 disc), which reproduces data by focusing the radiation on the order of μm, is attracting attention.

As a conventional R10 disk, a compact disk (hereinafter referred to as a CD) on which music data is recorded has already been put into practical use.

On the other hand, optical discs capable of recording code data are currently being developed as external storage devices for personal computers and the like. In general, external storage devices for computers, such as magnetic disks, are used to record, play, and record data.
In order to facilitate erasing and speed up access to data, a sector structure is adopted in which data is divided and recorded into sectors of 512 bytes to 2 bytes. Similarly, optical discs that are recordable (hereinafter referred to as W10 discs) or rewritable (hereinafter referred to as W/E discs) generally have a sector structure. Even in the case of an R10 disk on which code data such as programs and word processor dictionaries are prerecorded, it is desirable to have a sector structure because of the need for compatibility with W10 disks and W/E disks.

Problems to be Solved by the Invention With optical discs, recording and playback is performed by irradiating laser light focused to about 1 μm, so problems such as dust on the disc surface, foreign matter in the disc base material, or defects on the recording surface may be the cause. Various errors occur. For this reason, in an optical disc having a sector structure, data is encoded for error detection and correction on a sector-by-sector basis so that data in each sector can be reproduced correctly. However, since the error detection and correction code is based on sectors of 512 to 2 bytes, it is difficult to obtain a sufficient interleave length as with CDs that do not have a sector structure, and large errors that cover the entire sector can occur. If this occurs, correction may become impossible and normal reproduction of data may become difficult. Therefore, W10 disk - 9W
/E disks, play the data again immediately after recording to confirm that the recorded data is played back correctly.
It has become common to perform a so-called read verify operation, and this was also essential in the case of R10 disks, which have the same sector structure as W10 disks and W/E disks.

However, read verification operations cannot be performed on R10 disks, which are produced and duplicated in large quantities at dedicated factories.
That is, rereading and inspecting all of the produced disks leads to an increase in the number of manufacturing steps, which poses a problem of increasing manufacturing costs.

In view of the above, an object of the present invention is to provide an optical disk drive device that can sufficiently ensure reliability in data reproduction without performing a read verify operation.

Means for Solving the Problems The present invention provides at least one
A means for decoding an inter-sector code encoded with error detection and correction between sectors by adding test data of more than one sector; means for decoding the encoded intra-sector code, and when reproducing data, each sector is decoded by the means for decoding the intra-sector code, and if the decoding of the sector is uncorrectable, the above-mentioned This optical disc drive circuit is characterized in that a corresponding sector is decoded by means for decoding an inter-sector code.

Effect of the Invention With the above-described configuration, the present invention can decode inter-sector codes recorded in different sectors even if a large error occurs throughout the sector and the sector error correction using the intra-sector code becomes impossible. By doing so, the corresponding sector can be reproduced normally.

Embodiment FIG. 2 shows an example of a configuration diagram of an inter-sector code of an optical disc used in an optical disc drive device in an embodiment of the present invention. In FIG. 2, 17 is an information sector, 18 is a test sector, 19 is an information track, and 21 is a test track, and one track is composed of n sectors.

In the optical disc of this embodiment, data of one track, that is, n sectors, is first subjected to overall parity of data of each sector for error detection and correction, and test data of one sector is generated.

Next, the data of n sectors and the test data of one sector are error detection encoded for each sector by an intra-sector code for error detection and correction, and are recorded in the information sector 17 and the test sector 18, respectively. Here, the information sector 17 and the inspection sector 18 are respectively numbered 0.
The inspection sector 18 for the data of the first track is allocated to the first track and the mth track.
+(l/n)th (1-n *[l/n) track
'] ') is recorded in the sector. Here, * means multiplication, and [X] means an integer t that does not exceed X.

FIG. 1 shows a block diagram of an optical disc drive device according to an embodiment of the present invention, which reproduces data from the optical disc shown in FIG.

In FIG. 1, 1 is an optical disk, 2 is a reproducing unit that irradiates the optical disk with a laser beam such as a semiconductor laser to reproduce recorded signals, 3 is a demodulation circuit, and 4 is an intra-sector code decoder that decodes intra-sector codes. 5 is a data buffer, 6 is a control circuit composed of a microprocessor, etc., and 7 is a parity buffer.

The operation of the optical disc drive circuit in this embodiment configured as described above will be described below.

When reproducing data recorded on an optical disc having a sector structure, first, the control circuit 6 sends the address 8 of the sector in which the data is recorded to the reproducing unit 2. In the following description, it is assumed that the j-th sector of the first track in FIG. 2 is read out. At this time, the control circuit 6 sets A as the address 8 of the sector 22 to be reproduced.
(1,j) is sent to the reproduction section 2. Here, A(1,j) indicates the address of the j-th sector of the first track. The reproducing unit 2 searches for the corresponding sector 22 indicated by the given address 8, and irradiates the recording bits recorded in the form of uneven bits with a laser beam such as a semiconductor laser.
The signal obtained from the reflected light is binarized and sent to the demodulation circuit 3 as a reproduced signal 12. The demodulation circuit 3 demodulates the reproduced signal 12 that has been modulated into a signal suitable for recording in advance during recording, and sends it as a demodulated signal 13 to the intra-sector code decoding circuit 4.
Send to. The intra-sector code decoding circuit 4 decodes the intra-sector code encoded within the sector for error detection and correction, and performs error correction for random errors that occur due to small defects on ordinary disks. After error correction, the data is stored in the data buffer 5 as decoded data 14. Then, after all the data of one sector has been decoded, reproduced data 15 is sent out from the data buffer 5. However, if a large error occurs throughout the sector, decoding of the intra-sector code may become uncorrectable. At this time, the intra-sector code decoding circuit u4 detects that error correction cannot be performed, and sends the error detection signal 9 to the control circuit i86.
I'll send it to you. Here, if the sector 22 indicated by the address A (i Hj) is uncorrectable, the control circuit 6 receiving the error detection signal 9 from the address A (1, j) of the corresponding sector 22 corrects the corresponding sector. The addresses of the information sector 17 and the test sector 18 in which the data of multiple sectors constituting the intersector code including the data recorded in the 22 and the test data are recorded are A(1,0) to A(1, n-1) and A (m + [
i/n], I-n*[l/ngo)
Each sector making up the inter-sector code is read out using the following. In this embodiment, since the inter-sector code is the overall parity of a plurality of sectors, the overall parity of each sector constituting the inter-sector code other than the sector 22 is the data of the sector 22. Therefore, the control circuit 6 uses the address 8 to indicate the address of each sector in which the data constituting the inter-sector code and the test data other than the sector 22 are recorded, and reads out each sector. The sector data is stored in the parity buffer 7 again by exclusive ORing with the parity stored in the parity buffer 7 whose initial value is 0 by the control circuit 6. By repeating the above operations, the corresponding sector 22
It is possible to take overall parity for other sectors.

Then, the overall parity itself becomes the data of the corresponding sector 22, and the data is reproduced normally.

As described above, according to the optical disk drive circuit of the embodiment of the present invention, by decoding an inter-sector code in which one sector of overall parity is added to one track of data, a large error over the entire sector can be avoided. Even if this occurs and the corresponding sector becomes uncorrectable, the data can be reproduced normally.

In the embodiment of the present invention, the inter-sector code is an overall parity code, but a code with stronger correction ability such as a Reed-Solomon code may be used.

As described in detail, according to the present invention, even if an error occurs over the entire sector and the sector becomes uncorrectable, the inspection data of one or more sectors can be corrected for the data of multiple sectors. By decoding the intersector code encoded by adding , the data can be reproduced normally, which has a great practical effect.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an optical disk drive circuit according to an embodiment of the present invention, and FIG. 2 is a block diagram of an inter-sector code of an optical disk used in the optical disk drive circuit according to an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Optical disc, 4... Intra-sector code decoding circuit, 5... Data buffer, 6... Control circuit, 7...
...Parity buffer, 9...Information sector, 17
...Information sector, 18...Inspection sector.

Claims (3)

[Claims] (1) A device for reproducing data from an optical disk having a track divided into multiple sectors, which detects and corrects errors between sectors by adding inspection data of at least one sector to the data of multiple sectors. A means for decoding the encoded inter-sector code, and decoding the intra-sector code encoded for error detection and correction within each sector when recording the data and test data of the plurality of sectors in the information sector and the test sector, respectively. and address generating means for generating each address of the plurality of information sectors and inspection sectors in which the inter-sector code including data recorded in a certain sector is recorded, and when reproducing data, The information sector is decoded by means for decoding the intra-sector code, and if the error cannot be corrected, each address of the information sector and the test sector in which the inter-sector code including the data of the corresponding sector is recorded is set to the address. An optical disc characterized in that each sector generated by a generating means and in which the inter-sector code is recorded is decoded by the means for decoding the intra-sector code, and the corresponding sector is decoded by the means for decoding the inter-sector code. Drive device. (2) The optical disc drive device according to claim 1, wherein the means for decoding the inter-sector code is erasure correction using erasure information that the corresponding sector is uncorrectable. (3) The address generating means for generating each address of a plurality of information sectors and inspection sectors in which inter-sector codes including the applicable sector are recorded is generated from the address of the applicable sector. 2
The optical disc drive device described in .