JPH1196691A - Recording device and reproducing device for optical disk - Google Patents

Abstract

PROBLEM TO BE SOLVED: To limit the mark or space length of the data of a code word to 1T to 3T to suppress inter-code interference, and to suppress the occurrence of a reproducing error in a high data recording density by preparing recording codes by using codes J (0, 2, 4, 5, 0 and 8). SOLUTION: A recording coding section 2 performs recording coding of the recording data DIa of m bit from a data input section 1, and sends the recording data DIb of n bit after the recording coding via an error correction coding section 3. By setting the minimum run of bit information as d, a maximum run as k, the number of nits for 1 processing unit before coding as m, the number of bits for code data word as n and a detection window width as Tw, the recording coding section performs block coding for d, k, m, n and Tw. Here, by using the conversion table of the block codes (0, 2, 4, 5, 0 and 8), a 5-bit conversion channel bit is generated from 4-bit original data.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk recording and reproducing apparatus.

[0002]

2. Description of the Related Art Generally, a reproduced signal from an optical disk contains a jitter component. If the jitter component becomes large, an error occurs in a data reproducing system, and it is difficult to reproduce recorded data properly. Occurs. The influence of such a jitter component increases as the recording density of a signal (spot, pit) increases.

In order to remove the influence of such a jitter component, a high-density optical disc, DV
In D (Digital Video Disk), an 8/16 code (= (2,10,8,16,
0.5) code, and in the magneto-optical disk (MO), the (1,7) RLL code (= (1,7,2,3,0.
67) code).

[0004]

However, these recording codes have the following disadvantages.

First, in the 8/16 code, the mark length is 3T.
For example, when a short mark (or space) such as 3T or 4T is adjacent to a long space (or mark) such as 10T or 11T, intersymbol interference jitter occurs, and a data reproduction error occurs. May occur.

In the (1,7) RLL code, since the mark length changes from 2T to 8T, the same problem as the above-described 8/16 code may occur.

The present invention has been made in view of such circumstances, and has as its object to provide a recording apparatus and a reproducing apparatus for an optical disk capable of suppressing an error in reproducing data between codes.

[0008]

According to the present invention, there is provided a recording encoding means for recording and encoding recording data in a predetermined recording encoding system, An error correction coding unit for adding an error correction code, and a recording apparatus for an optical disc including a recording modulation unit for modulating data output from the error correction coding unit into a recording signal of a predetermined recording modulation method, The recording encoding means uses an encoding method of (0, 2, 4, 5, 0.8) code. Further, it is preferable that the recording modulation means applies the NRZI modulation method. Further, it is preferable that the recording encoding unit inserts a resync code of a predetermined data pattern at a data interval corresponding to a correction capability of the error correction code applied by the error correction encoding unit. Further, it is preferable that the data pattern of the resync code is set so as to suppress a DC component of data output from the recording encoding unit.

Also, in an optical disk reproducing apparatus for reproducing data from an optical disk on which data encoded and encoded by the (0, 2, 4, 5, 0.8) code is recorded, the recording and encoding from the optical disk is performed. As the recording / decoding means for decoding the reproduction data, means for applying the ML decoding process is used.

[0010] Further, in an optical disk reproducing apparatus for reproducing data from an optical disk on which data encoded and encoded by the (0, 2, 4, 5, 0.8) code is recorded, the data encoded from the optical disk is encoded. As the recording / decoding means for decoding the reproduction data, means for applying a PRML decoding process is used.

[0011]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.
An embodiment of the present invention will be described in detail.

FIG. 1 shows a main part of an optical disk recording apparatus according to an embodiment of the present invention.

In FIG. 1, n-bit recording data DI output from recording data generating means (not shown) is converted into m-bit recording data DIa via a data input section 1, and the recording data DIa is converted to a recording code. 2 has been added.

The recording encoder 2 converts the input m-bit recording data DIa into (0, 2, 4, 5, 0.8)
A recording encoding process for forming a recording code of a code (described later) is applied, and the data after the recording encoding process is
The recording data DIb is added to the error correction encoding unit 3.

The error correction encoding unit 3 applies an appropriate error correction encoding process to the input recording data DIb, and the data after the error correction encoding process is recorded as recording data DIc. Modulation unit 4 applies.

The recording modulation section 4 receives the input recording data DI
For c, a predetermined recording modulation method is applied to form a recording signal, and the recording signal is output to the next-stage recording head system. Here, as a recording modulation method applied by the recording modulation unit 4, NZRI capable of recording data at higher density is applied, and mark length recording is performed on an optical disk.

Here, the recording encoding unit 2 applies (0,
The (2, 4, 5, 0.8) code will be described.

This (0, 2, 4, 5, 0.8) code is
This is one of so-called (d, k, m, n, Tw) codes.
Here, the (d, k, m, n, Tw) code means that the minimum run of 0 of bit information (symbol) is d, the maximum run is k, and one processing unit (data word) of original data before encoding. Is m, the number of bits of the code data word is n, and the detection window width is Tw.
Block code.

The (0, 2, 4, 5, 0.8)
The code generates 5-bit conversion channel bits from the input 4-bit original data using the conversion table as shown in FIG.

At the same time, each time the recording encoding unit 2 generates a predetermined number of data words, the recording encoding unit 2 outputs a 5-bit resync code consisting of a predetermined bit pattern.
Insert

Here, as the resync code, a bit pattern having high autocorrelation or a bit pattern which does not appear in the modulation rule can be used. Furthermore, by using a data pattern that can suppress the DC component of the frequency spectrum of the recording data DIb as the bit pattern of the resync code, the DC component is superimposed on the servo signal of the head mechanism of the optical pickup device (not shown). Can be suppressed.

The interval between data words into which the resync code is inserted may be set according to the error correction capability of the error correction code generated by the error correction encoding unit 3 (generally, a number smaller than the error correction capability). .

As a result, even if a synchronization error occurs during data reproduction, synchronization can be recovered by this resync code, and occurrence of an error during data reproduction can be suppressed.

Thus, in this embodiment, (0,
Since the recording code is generated by the (2, 4, 5, 0.8) code, the conversion efficiency is good. In addition, the value of the detection window width Tw is 0.8, and the value of the detection window width Tw is larger than other codewords, so that an error during data reproduction can be suppressed.

FIG. 3 shows an example of a main part of a reproducing apparatus for reproducing data from an optical disk on which data has been recorded by the recording apparatus shown in FIG.

In FIG. 1, a reproduction signal RF output from an optical pickup device (not shown) is applied to a demodulation unit 11, which performs a predetermined recording / demodulation process to obtain a corresponding reproduction data. DRa is generated, and the reproduced data DRa is added to the error correction processing unit 12.

The error correction processing unit 12 corrects a data error included in the reproduced data DRa by applying an error correction process corresponding to the error correction coding process of the error correction coding unit 3. Is added to the recording / decoding unit 13.

The recording / decoding unit 13 cuts out the reproduced data DRb to be added in units of the code word data length, detects the resync code, synchronizes the code words, and performs the above-described operations (0, 2, 4, 5). , 0.8) code, the output data of which is applied to the data output unit 14 as reproduction data DRc in units of m bits. In the decoding process of the recording / decoding unit 13, a well-known ML decoding process or PRM
L decoding processing can be applied.

The data output unit 14 shapes the m-bit reproduced data DRc into n-bit reproduced data and outputs the data to the next-stage device.

In this manner, (0, 2, 4, 5, 0.
8) In the code, since the number of code data patterns is as small as 16, the ML decoding process or the PRML decoding process can be applied as the process of the recording / decoding unit 13, thereby improving the data recording density. Can be.

The conversion table shown in FIG.
It is an example of a configuration of a (0, 2, 4, 5, 0.8) code,
Conversion tables of other configurations can be applied in a similar manner.

[0032]

As described above, according to the present invention,
Since the recording code is created by applying the (0, 2, 4, 5, 0.8) code, the length of the mark or the space of the code word data is limited to 1T to 3T. As a result, even when the present invention is applied to an optical disc having a high data recording density, an effect that a data reproduction error can be significantly suppressed can be obtained.

Since the (0, 2, 4, 5, 0.8) code is a code for converting 4 bits of the original data into a 5-bit code word, the conversion efficiency can be extremely improved. The effect is also obtained.

In order to record data by the NRZI modulation method, a mark edge recording method can be applied.
The effect that the data recording density can be increased is also obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a main configuration of an optical disk recording apparatus according to an embodiment of the present invention.

FIG. 2 is a schematic diagram showing an example of a conversion table for a (0, 2, 4, 5, 0.8) code.

FIG. 3 is a block diagram showing an example of a main configuration of a reproducing apparatus for reproducing data from an optical disk on which data has been recorded by the recording apparatus shown in FIG. 1;

[Explanation of symbols]

 2 Recording Encoding Unit 3 Error Correction Encoding Unit 4 Recording Modulation Unit 11 Demodulation Unit 12 Error Correction Processing Unit 13 Recording Decoding Unit

Claims (6)

[Claims] 1. A recording encoding means for recording and encoding recording data according to a predetermined recording encoding method, and an error correction means for adding a predetermined error correction code to the recording data output from the recording encoding means. In an optical disc recording apparatus comprising: an encoding unit; and a recording modulation unit that modulates data output from the error correction encoding unit into a recording signal of a predetermined recording modulation method, the recording encoding unit includes: An optical disc recording apparatus to which a coding method of (0, 2, 4, 5, 0.8) code is applied. 2. An optical disk recording apparatus according to claim 1, wherein said recording modulation means applies an NRZI modulation method. 3. The recording encoding unit according to claim 2, wherein a resync code of a predetermined data pattern is inserted at a data interval corresponding to a correction capability of the error correction code applied by the error correction encoding unit. An optical disk recording apparatus according to claim 1 or claim 2. 4. The optical disk recording apparatus according to claim 3, wherein a data pattern of the resync code is set so as to suppress a DC component of data output from the recording encoding unit. 5. An optical disk reproducing apparatus for reproducing data from an optical disk on which data recorded and encoded by a (0, 2, 4, 5, 0.8) code is recorded. An apparatus for reproducing an optical disk, comprising: means for applying ML decoding processing as recording and decoding means for decoding reproduction data. 6. An optical disk reproducing apparatus for reproducing data from an optical disk on which data encoded and encoded by a (0, 2, 4, 5, 0.8) code is recorded. An apparatus for reproducing an optical disk, wherein a means for applying a PRML decoding process is used as a recording / decoding means for decoding reproduction data.