JPH07169203A - Optical disk device - Google Patents

Abstract

PURPOSE:To prevent influence of an error of a vender unique area (VU) of an optional code group upon user data of the same code group and error correction on an error correction code by correcting data of the VU read out at the reproducing time to be the same value at the recording time and correcting the error. CONSTITUTION:At the time of recording data, the vendor unique area (VU) of 4 bytes is added to the user data DT0-DT51l of 512 bytes inputted from the outside of the optical disk device l by an error correction circuit 3. It is assumed that there are neither user data nor information desired to be recorded here in a vendor. A fixed value 00H is prepared as the data of the UV. These data are interleaved together with error detection codes CRC0-CRC3 into five correction groups. Moreover, error correction codes EC0-EC16 of 16 bytes are added by the circuit 3 to be outputted to a recording and reproducing circuit 5 and recorded on a disk 2. The data is read out of the disk 2 by the circuit 5 to be transferred to a VU correction circuit 4, and if a data value is other than 00H, the value is corrected to 00H. The corrected right data is outputted to the outside of the device 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rewritable type, a read-only type, a one-time write type optical disc apparatus.

[0002]

2. Description of the Related Art Conventionally, in an optical disk device, a plurality of tracks are concentrically or spirally formed on the surface of a disk medium, and the tracks are further divided into a plurality of sectors to record or reproduce user data in sector units. I was going.

In an optical disk device which may handle numerical data as user data, it is usually required that the error rate be ^10-12 or less. Optical discs have a bit error rate of 1 compared to magnetic discs and magnetic tapes.
0 for higher and ^-6 to 10 ^-4, it is necessary to use an error correction method of the error 10 ^{over 12} below.

Therefore, the optical disc apparatus employs an error correction system that uses an error correction code such as a Reed-Solomon code or a BCH code, and sets a large number of words as one block to perform error correction of a large number of words included in this block. .

An example of the error correction method in the conventional optical disk device shown in FIG. 2 will be described below with reference to FIG.
This is the ISO 90mm magneto-optical disk standard 512
It is in byte format. First, the optical disk device 20
A case where user data is recorded on the disk medium 201 at 0 will be described.

The error correction circuit 202 adds a 4-byte vendor unique area VU to 512-byte user data DT0 to DT511 input from the outside of the optical disk device 200. The vendor unique area is
This is an area where the manufacturer (vendor) records the information that the manufacturer wants to record together with the user data.

Further, the error correction circuit 2 is used during data reproduction.
The user data corrected in 02 and the vendor unique area are 4-byte error detection codes CRC0, CRC1, CRC2, and CRC3 that are error detection codes for checking whether or not the correct area is truly correct. Five correction sequences (code sequence 0
~ 4), and are arranged vertically as rows of 5 bytes each as shown in FIG.

The error correction circuit 202 adds 16-byte error correction codes EC0, 0 to EC4, 15 generated from the user data of the five code sequences, the data of the vendor unique area, and the error detection code to each code sequence. Then, each column is sequentially output to the recording / reproducing circuit 203 from the first column of the code sequence 0.

The recording / reproducing circuit 203 records the data output from the error correcting circuit 202 in a designated sector on the surface of the disk medium 201 via the head 204. In this way, the user data is divided into several groups in units of bytes or bits, error correction codes are generated in units of groups, and then the order is rearranged and recorded, which is called interleaving.

In interleaving, a large burst error of several tens of bytes or more existing on the surface of the disk medium can be converted into a small random error of about 1 or 2 bits. It becomes possible to correct the burst error.

Since the vendor unique area is necessary also for equalizing the number of bytes of the five code sequences, a fixed value such as 00H or FFH is set when the vendor does not want to record the user data together with the user data. Will be recorded.

Next, the case where the user data is reproduced from the sector of the disk medium 201 in the optical disk device 200 will be described. The recording / reproducing circuit 203 reads data from a designated sector on the surface of the disk medium 201 via the head 204 and transfers it to the error correction circuit 202.

In the error correction circuit 202, the data transferred from the upper recording / reproducing circuit 203 is rearranged once again in the order of the five code sequences shown in FIG. 3 (this is called deinterleaving), and each of the five code sequences is arranged. Use to correct the error. After that, the error detection code is used to check whether the corrected user data and vendor unique area have been corrected correctly.
The reproduction data is output to the outside of the optical disc device 200.

[0014]

However, in the conventional technique as described above, even if the vendor does not have the information to be recorded together with the user data, the vendor unique area must be provided for the sake of convenience of the error correction system. On the medium, fixed value data of this unnecessary vendor unique area is recorded together with user data. Therefore, during data reproduction, this vendor unique area is also subject to error correction for both user data and error correction code.

Further, in the error correction circuit of the prior art, if an error of a predetermined byte or more occurs in each code sequence, for example, an error of 9 bytes or more occurs in the error correction circuit 202 of FIG. 2, error correction becomes impossible.

As described above, according to the conventional technique, when an error occurs in the user data and the error correction code belonging to an arbitrary code sequence, the number of which can be corrected (8 bytes in the error correction circuit 202), the same code is further added. If a 1-byte error occurs in the vendor unique area to which the affiliate belongs, there is a problem that the error cannot be corrected.

The present invention solves the above problems, and when the vendor does not have the information to be recorded together with the user data,
An object of the present invention is to obtain an optical disc device in which an error occurring in a vendor unique area belonging to an arbitrary code sequence does not affect error correction for user data and error correction code belonging to the same code sequence.

[0018]

In order to achieve the above object, in the optical disk device according to the invention of claim 1,
In an optical disc device for reproducing user data recorded together with constant value data in sector units formed by dividing a track on the surface of the medium into a plurality of sectors, user data read from the sectors via a head and constant A reproduction circuit for outputting a reproduction data pattern of value data, and a constant value error correction for outputting the reproduction data pattern after previously performing error correction on constant value data of the reproduction data patterns output from the reproduction circuit. The circuit and the reproduction data pattern output from the constant value error correction circuit are again divided into a plurality of groups divided at the time of recording the error correction code, and the error correction code generated for each group And an error correction circuit for performing error correction.

[0019]

According to the present invention, when reproducing user data, first, of the reproduced data patterns of user data and constant value data read from the sector by the reproducing circuit through the head, the constant value is corrected in the constant value error correction circuit. Error correction is performed on the data in advance, and the error-correction circuit divides the error-corrected reproduction data pattern for constant-value data into a plurality of groups that were divided when the error-correcting code was generated during recording. , Is an optical disc device that performs error correction using an error correction code generated in each group.

If there is no information that the vendor wants to record together with the user data, the data in the vendor unique area is set to a constant value and is used to generate the error correction code together with the user data, and then the vendor unique area together with the user data and the error correction code. Constant value data of is recorded in a sector on the disk medium.

According to the present invention, with the above configuration, when reproducing user data together with constant value data in the vendor unique area, user data read from the sector, data in the vendor unique area, error detection code, Among the error correction codes, the constant value error correction circuit corrects the data in the vendor unique area to the same value as that at the time of recording in advance, and then the error correction circuit performs another error correction, so that it is assumed that an arbitrary An error correction circuit is used even if the user data belonging to the code sequence and the error correction code have an error at the limit of the correctable capacity and an error also occurs in the vendor unique area belonging to the same code sequence. Now, since the error in the vendor unique area has already been corrected, it becomes impossible to correct the error as before. Rukoto is not.

[0022]

EXAMPLES The present invention will be described below with reference to examples. FIG. 1 is a schematic configuration diagram of an interleave correction type optical disc apparatus according to the present embodiment. The error correction method here is the same as that shown in FIG. The error correction method used in the present invention is not limited to this, and is effective for all error correction methods that use both error correction code and interleave.

First, a case where user data is recorded on the disk medium 2 in the optical disk device 1 will be described. The error correction circuit 3 is provided with 512 bytes of user data DT0 to DT input from the outside of the optical disk device 1.
511, 4-byte vendor unique area (VU)
Is added. Here, it is premised that the vendor does not have information to be recorded together with the user data, and a fixed value is prepared as data in the vendor unique area. In this embodiment, this constant value is 00H.

These data, together with the 4-byte error detection codes CRC0, CRC1, CRC2, CRC3), have five correction sequences (code sequences 0 to 0) as shown in FIG.
Interleave to 4).

In the error correction circuit 3, the error correction code E of 16 bytes is added to each of these five code sequences.
C0, 0 to EC4, 15 are added, and each column is sequentially output to the recording / reproducing circuit 5 from the first column of the code sequence 0. The recording / reproducing circuit 5 records the above-mentioned data on a specified sector on the surface of the disk medium 2 via the head 6.

Next, the case where the user data is reproduced from the sector of the disk medium 2 in the optical disk device 1 will be described. The recording / reproducing circuit 5 reads the data from the designated sector on the surface of the disk 2 via the head 6 and transfers it to the vendor unique area correction circuit 4.

In the vendor unique area correction circuit 4,
If the value of the 4-byte vendor unique area data in the input reproduction data is other than 00H, it is corrected to 00H. After correcting the vendor unique area, the reproduction data is output to the error correction circuit 3 in the input order (the same as the input order at the time of recording).

The error correction circuit 3 converts the above data into the data shown in FIG.
Deinterleave the input order at the time of recording as shown in
Error correction is performed for each of the five code sequences. After that, the error detection code is used to check whether or not the corrected user data has been correctly corrected, and if it has been corrected correctly, it is output to the outside of the optical disc device 1.

The constant value error correction circuit of the present invention is provided with a detecting means for detecting whether or not the data in the vendor unique area has a constant value so as to automatically perform the constant value error correction operation. Alternatively, a constant value error correction operation may be performed by a signal input from the outside.

[0030]

As described above, in the optical disc apparatus of the present invention, when the vendor does not have the information to be recorded together with the user data and the data in the vendor unique area is recorded on the disc medium as a constant value, at the time of reproduction,
Since the error correction is performed after the read data in the vendor unique area is corrected to the same value as that at the time of recording, there is no error in the vendor unique area at the time of error correction. Therefore, even if the user data belonging to an arbitrary code sequence and the error correction code have an error at the limit of the correctable capacity, the error can be corrected without fail.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an optical disk device according to an embodiment of the present invention.

FIG. 2 is a schematic configuration diagram of an optical disc device according to a conventional technique.

FIG. 3 is an explanatory diagram showing an interleave error correction method.

[Explanation of symbols]

 1,200: Optical disk device 2,201: Disk 3,202: Error correction circuit 4: Vendor unique area correction circuit 5,203: Recording / reproducing circuit 6,204: Head

Claims (1)

[Claims] 1. An optical disk device for reproducing user data recorded together with constant value data in sector units formed by dividing a track on the surface of the disk medium into a plurality of sectors, and reading from the sectors via a head. A reproduction circuit for outputting a reproduction data pattern of user data and constant value data, and a reproduction data pattern output from the reproduction circuit,
A constant value error correction circuit for outputting the reproduction data pattern after performing error correction on the constant value data in advance, and a reproduction data pattern output from the constant value error correction circuit for generating an error correction code at the time of recording. An optical disc device, comprising: an error correction circuit that divides into a plurality of groups that have been divided at this time and that performs error correction using an error correction code generated for each group.