JPH08147889A - Method for converting recorded data and data recording device using the method - Google Patents

Abstract

PURPOSE: To reduce jitter at the time of recording and reproducing in writing data on a magnetooptic disk, for example. CONSTITUTION: A coding modulation processing circuit 11 conducts coding modulation of the data to be recorded, and thus processed data is supplied to a data conversion and processing circuit 12. The circuit 12 divides each channel bit after coding modulation in n (n is an integer of two or more) based on the dividing parameter supplied from a dividing parameter memory setting circuit 14, and, at the same time, applies data conversion to the above n-divided channel bit in compliance with a specified conversion pattern supplied from a conversion pattern storing circuit 15. And the output of the data conversion circuit 12 is supplied to a data recording circuit 16 to write data on the magnetooptic disk D used for a recording medium.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording data conversion method suitable for use as recording means for, for example, a magneto-optical disk and a recording apparatus using the same, and more particularly to recording and reproducing signals recorded on a recording medium. The present invention relates to a data conversion method and a recording device capable of reducing time jitter.

[0002]

2. Description of the Related Art For example, in a mark edge recording method for a magneto-optical disk, a recording waveform (domain) on a recording medium of a disk formed by a light spot by a square wave pulse causes heat to accumulate when a long mark is recorded, It is known that the recording magnetic domain has a so-called "tear-shaped" phenomenon in which its width increases in the recording direction. That is, the mark width at the trailing edge of the square wave pulse is increased by the accumulated heat, and the crosstalk to the adjacent track is increased. Further, since the rise of the temperature rise of the front edge portion is gentle, the position of the front edge easily changes.

Further, the "tear-shaped" length and width change depending on the length of the recording mark, and a jitter phenomenon occurs in which the position of the edge detected from the reproduced signal changes depending on the pattern.

In order to suppress the occurrence of such a jitter phenomenon, for example, when a mark up to 5.33T having a mark length of 2T (T is a distance on the disc surface corresponding to the bit time) or more is recorded on the disc recording surface. , A so-called multi-pulse recording method in which the reference mark is added one by one by continuing the minimum mark length of 1.33T determined by the modulation code (IEICE, November 1992 p.
p13-18 recording / reproducing characteristics of a magneto-optical disk) have been proposed.

[0005]

When the above-mentioned multi-pulse recording method is used, the width of the magnetic domain on the recording surface becomes constant, and a magnetic domain having a length substantially corresponding to the mark length is formed to reduce the jitter during reproduction. It becomes possible.

However, the means for continuously adding the reference pulse one by one in accordance with the mark length has a problem that the control circuit becomes complicated because the minimum mark length determined by the modulation code is continued.

The present invention has been made in view of the above problems, and the structure is simplified by converting data recorded on a disc itself so as to reduce jitter during reproduction. It is an object of the present invention to provide a simplified recording device.

[0008]

According to a first aspect of the present invention, there is provided a recording data conversion method, wherein the data to be recorded is coded and modulated, and each coded and modulated data is recorded. Each channel bit is divided into n (n is an integer of 2 or more), and each n-divided channel bit is converted in accordance with a predetermined conversion pattern to form recording data on a recording medium.

Further, the data recording apparatus according to the second aspect of the present invention is supplied with the data to be recorded, and performs coding modulation processing means (for example, the coding modulation processing circuit 11 in FIG. 1) for coding and modulating the data. ) And each channel bit after coded modulation obtained by the coded modulation processing circuit 11 based on the division parameters supplied from the division parameter storage setting means (for example, the division parameter storage setting circuit 16 in FIG. 1). Data conversion for dividing n (where n is an integer of 2 or more) and converting each of the n divided channel bits in accordance with a predetermined conversion pattern supplied from the conversion pattern storage means (for example, the conversion pattern storage circuit 13 in FIG. 1). Processing means (for example, the data conversion processing circuit 1 in FIG. 1)
2) and the recording data obtained by the data conversion processing circuit 12 and writing the data to the recording medium (for example, the data recording circuit 1 in FIG. 1).
7) and are provided.

Further, in the data recording apparatus according to claim 3 of the present invention, a plurality of types of conversion patterns are stored in the conversion pattern storage circuit 13, and the conversion pattern to be supplied to the data conversion processing circuit 12 is selected. It is characterized by being made possible.

Further, a data recording apparatus according to a fourth aspect of the present invention is configured to record a signal on a magneto-optical disk as a recording medium.

[0012]

According to the first aspect of the present invention, in the recording data conversion method, each channel bit after coded modulation of the data to be recorded is divided into n and each n-divided channel bit is converted according to a predetermined conversion pattern. As a result, the data recorded on the disc itself can be converted so that the jitter during reproduction can be reduced.

Further, in the data recording apparatus having the structure of the second aspect, each channel bit after coded modulation obtained by the coded modulation processing circuit 11 becomes a division parameter supplied from the division parameter storage setting circuit 16. Based on the predetermined conversion pattern supplied from the conversion pattern storage circuit 13, each channel bit is further divided into n based on the conversion pattern storage circuit 13.

With this structure, the data recorded on the disk is converted so that the jitter during reproduction is reduced, and the structure of the recording apparatus can be simplified.

Further, in the data recording apparatus having the structure of claim 3, a plurality of types of conversion patterns are stored in the conversion pattern storage circuit 13, and the conversion pattern to be supplied to the data conversion processing circuit 12 can be selected. Since it is configured, it is possible to easily generate a recording data string that is suitable for encoding systems having different characteristics or recording media.

Further, in the data recording apparatus having the structure of the fourth aspect, the signal can be recorded on the magneto-optical disk as the recording medium.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A recording data conversion method of the present invention and a data recording apparatus using the same will be described below with reference to the embodiments shown in the drawings. First, FIG. 1 illustrates the recording data conversion method of the present invention. The example shown in the figure shows an example of a data conversion method for the purpose of reducing jitter in mark edge recording of magneto-optical recording.

What is required as the data conversion unit is the number of divisions (n) and the conversion pattern. For example, with the division number n: 3,
When the conversion pattern is “100” and the code string after code modulation is as follows, for example, 1 0 0 1 1 0 0 1 0 0 0 1 1 0 0 ...... (1) Code after NRZI conversion A sequence, that is, a channel bit sequence is represented as follows. 1 1 1 0 0 0 1 1 1 1 1 0 0 0 (2) And, if the number of divisions is n = 3 and the conversion pattern is "100" as described above, the code string after data conversion is expressed as follows. Be done. 100 100 100 000 000 000 100 100 100 100 000 000 000 …… (3)

The one shown as (1) above is a code string after coded modulation, which is NRZ (Non Return to Zero).
). In this specific example, an RLL code having a parameter of d = 2 is used, and examples thereof include a 2-7 RLL recording code and an EFM modulation method. The 2-7RLL code is a code that is converted so that “0” s are arranged in a line of at least two and at most seven or less, and one of the EFM modulation methods is “0”.
Is a code that is converted so that a minimum of 2 and a maximum of 10 are arranged.

The one shown in (2) above is NRZI (No
n Return to Zero Inverted) The code string after being converted. According to the conversion method of the present invention, one channel bit is divided by the number of divisions n = 3, and when the code string given in (2) is in the “1” state, the conversion pattern (that is, “1”) is obtained.
00 "), and when the code string given in (2) is" 0 ", all the divided n times are" 0 "(that is," 00 ").
0 "is given. The data string thus converted is shown in (3).

Further, the channel clock at the time of recording may be increased in speed by the number of divisions, and when the number of divisions is n, the channel clock given in (1) may be multiplied by n. In the case of this example, the channel clock is tripled.

The code string data-converted by this method can obtain reproduction data similar to the code string (1) after the first code modulation by giving an appropriate recording power. Therefore, the reproducing unit does not require a special device (processing circuit). For the channel clock, the same one as in (1) is used.

When the code trains shown in (1) to (3) above are represented by recording pulses, they are shown in (1) to (3) in FIG. The recording power is determined by the size of the recording pulse area, for example.

In this case, the apparent parameters (d, k) after the data conversion are (2,26) for the (2,7) RLL code and (2,35) for the EFM modulation method. Here, d is the minimum run and k is the maximum run.

In the above conversion method, the number of divisions of one channel bit is "3" and the conversion pattern is "10".
The case where the number of divisions of one channel bit is “3” as described above is shown as an example, but the conversion pattern is “010”, “001”, “1” in addition to “100”.
10 ”,“ 011 ”, and“ 101 ”can be selected.
It can be appropriately selected depending on the combination of the encoding system and the recording medium.

FIG. 2 is a block diagram showing an embodiment of a data recording apparatus using the recording data conversion method shown in FIG. The data to be recorded, that is, the input data string is supplied to the code modulation processing circuit 11 as the code modulation processing means. This input data string is coded and modulated in the coding and modulation processing circuit 11 and converted into, for example, the code string shown by (1) in FIG. Further, the coding and modulation processing circuit 11 performs NRZI conversion,
In FIG. 1, the code string is converted into the code string indicated by (2), and the code string is the data conversion processing circuit 1 as the data conversion processing means.
2 is supplied. In addition, the channel clock generation circuit 13 generates a channel clock based on the conversion efficiency of the coded modulation in the coded modulation processing circuit 11.

On the other hand, the data conversion processing circuit 12 is supplied with the division parameter (n) from the division parameter storage setting circuit 14 as the division parameter storage setting means.
Furthermore, the data conversion processing circuit 12 is supplied with the conversion pattern from the conversion pattern storage circuit 15 as the conversion pattern storage means.

The conversion pattern storage circuit 15 is supplied with the division parameter (n) from the division parameter storage setting circuit 14, and the division parameter storage setting circuit 14 is determined by this division parameter (n). A plurality of types of conversion patterns are made selectable, and the selected conversion pattern is supplied to the data conversion processing circuit 12.

In the data conversion processing circuit 12, each channel bit after coded modulation is divided into n based on the division parameter (n) supplied from the division parameter storage setting circuit 14, and the above-mentioned n division is performed. Each channel bit is converted according to a predetermined conversion pattern supplied from the conversion pattern storage circuit 15. Specifically, when the division parameter n is “3”, the parameters that can be generated by the division parameter storage setting circuit 14 are “100” “010” “001” “110” “0.
11 "and" 101 ", for example," 1 "as a parameter
When it is set to select "00", the code string output from the data conversion processing circuit 12 is as shown in (3) in FIG. 1, and this code string is the data recording circuit 16 as the data recording means. Is supplied to.

The channel clock generated by the channel clock generation circuit 13 is supplied to the channel clock division circuit 17, receives the division parameter (n = 3) supplied from the division parameter storage setting circuit 14, and receives the channel clock. A recording channel clock that is three times the channel clock generated by the generation circuit 13 is generated, and this recording channel clock is supplied to the data recording circuit 16.

The data recording circuit 16 is also supplied with the division parameter from the division parameter storage setting circuit 14, and the data recording circuit 16 uses the division parameter and the recording channel clock from the data conversion processing circuit 12. The supplied recording data is recorded on the magneto-optical disk D as a recording medium.

FIG. 3 is a known reproducing apparatus for decoding the data read from the magneto-optical disk D recorded by the recording data conversion method shown in FIG. 1 and the data recording apparatus shown in FIG. 2 using the same. Shows an example of.

That is, a magneto-optical disk D as a recording medium
The information recorded in is supplied to the data reproducing circuit 21. The data reproduction circuit 21 is supplied with a channel clock from the channel clock generation circuit 13 shown in FIG. 2, and reproduces a data string using this channel clock as an operation clock. The data string reproduced by the data reproducing circuit 21 is supplied to the decoding circuit 22, and the data string reproduced by the data reproducing circuit 21 is decoded by the decoding circuit 22 to obtain the original data string. You can

In the above description, a magneto-optical disk is used as an example of the recording medium, but the scope of application of the present invention is not limited to a specific magneto-optical disk.
For example, other video discs, compact discs (C
D, CD-ROM, CD-I), or a write-once type optical disc. Also,
In this case, the division parameter and the conversion pattern can be appropriately selected according to the combination of the encoding method and the recording medium.

[0035]

As is apparent from the above description, claim 1
According to the recording data conversion method described in (3), each channel bit after the coded modulation of the data to be recorded is divided into n (n is an integer of 2 or more), and each n divided channel bit is converted into a predetermined conversion pattern. Since the conversion is performed in accordance with the above, it is possible to perform the data conversion on the recording data itself on the recording medium so that the jitter at the time of reproduction is reduced.

Further, according to the data recording apparatus of the second aspect, each channel bit after the coded modulation obtained by the coded modulation processing means is based on the division parameter supplied from the division parameter storage setting means. It is configured such that each of them is divided into n and each of the divided n-bits is converted according to a predetermined conversion pattern supplied from the conversion pattern storage means.

With this structure, the data recorded on the recording medium is converted so that the jitter during reproduction is reduced, and therefore the structure of the recording apparatus can be simplified.

According to the data recording apparatus of the third aspect, the conversion pattern storage means stores a plurality of types of conversion patterns, and the conversion pattern to be supplied to the data conversion processing means 12 can be selected. Is made,
It is possible to easily generate a recording data string suitable for an encoding method having different characteristics other than the magneto-optical disk or a recording medium.

Further, according to the data recording apparatus of the fourth aspect, it is possible to use the magneto-optical disk as a recording medium, and it is possible to reduce the occurrence of jitter during reproduction of the magneto-optical disk.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of data conversion according to a recording data conversion method of the present invention.

FIG. 2 is a block diagram showing a configuration of an embodiment of a data recording device of the present invention.

3 is a block diagram showing an example of a reproducing apparatus for a recording medium recorded by the data recording apparatus of FIG.

[Explanation of symbols]

11 coded modulation processing circuit (coded modulation processing means) 12 data conversion processing circuit (data conversion processing means) 13 channel clock generation circuit 14 division parameter memory setting circuit (division parameter memory setting means) 15 conversion pattern memory circuit (conversion pattern) Storage means 16 Data recording circuit (data recording means) 17 Channel clock dividing circuit 21 Data reproducing circuit 22 Decoding processing circuit

Claims (4)

[Claims] 1. Data to be recorded is coded and modulated, and each coded and modulated channel bit is divided into n (n is an integer of 2 or more), and each n-divided channel bit is subjected to a predetermined conversion pattern. By converting according to
A recording data conversion method, wherein the recording data is recorded on a recording medium. 2. A coding parameter processing unit for receiving coded data to be recorded and coding-modulating the data, and storing each channel bit after coded modulation obtained by the coding modulation processing unit as a division parameter. Based on the division parameter supplied from the setting means, each is divided into n (n is an integer of 2 or more), and each of the n divided channel bits is converted according to a predetermined conversion pattern supplied from the conversion pattern storage means. A data recording device comprising: a data conversion processing means; and a data recording means for receiving the recording data obtained by the data conversion processing means and writing the data to a recording medium. 3. The conversion pattern storage means stores a plurality of types of conversion patterns, and the conversion pattern to be supplied to the data conversion processing means is selectable. 2. The data recording device according to 2. 4. The data recording device according to claim 2, wherein the recording medium is a magneto-optical disk.