JP2623538B2 - Data recording method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention will be described in the following order.

A. Industrial application fields B. Summary of the invention C. Conventional technology D. Problems to be solved by the invention E. Means to solve the problems F. Operation G. Example G-1. Data structure of one embodiment (Fig. 1) G-2. Recording format (Fig. 2) G-3. Other embodiments (Figs. 3 to 6) H. Effects of the invention A. Industrial use The present invention relates to a data recording method for storing data on a recording medium such as a magneto-optical disk, and more particularly, to a data signal area of a disk-shaped recording medium in which servo signals and data signals are alternately recorded along tracks. So-called LDC (Long Distan
ce Code) for sequentially recording two-dimensional array data.

B. Summary of the Invention The present invention sequentially records data signals in each data signal area on a recording medium in which servo signal areas and data signal areas are alternately provided along a scanning direction during signal recording and reproduction. In the data signal recording method, the data to be recorded is arranged in a two-dimensional array of m columns and l rows, read / write is performed in the column direction, and an error correction code is added to each row. By providing a relationship between the length m in the data column direction and the length k of the data signal area between the servo signal areas so that one becomes an integral multiple of the other, adverse effects due to the occurrence of errors are suppressed. This improves the error correction capability.

C. Prior Art In recent years, optical recording media such as optical disks and magneto-optical disks utilizing an optical or magneto-optical signal recording / reproducing method have been developed and are being supplied to the market. These optical recording media include digital audio discs such as so-called CDs (compact discs) and video discs.
Similar to a disk, a so-called ROM (read only memory) type recording medium for recording various information signals in advance on a recording medium by a manufacturer in a non-rewritable manner and supplying it to a user, and a so-called DRAW or write-once type A so-called PROM that allows the user to write information signals only once.
There are a (programmable ROM) type recording medium and a so-called RAM (random access memory) type recording medium capable of erasing and rewriting recorded information signals, such as a magneto-optical disk. Is very large.

Each of these types of optical recording media is often used in the form of a disc, but has been developed individually and has different development periods, so that different formats are used. For this reason, compatibility between these types of discs cannot be obtained, and there are many disadvantages on both the user side and the maker side. Here, as one of the technologies for realizing this unified format,
Similar to a so-called sector servo in a hard disk in the field of magnetic disks, servo signals are recorded at predetermined intervals or at predetermined angles on concentric or spiral tracks on the disk. It has been proposed to introduce a so-called sampling servo concept in which continuous servo control is performed by sampling and holding the discrete servo signals of the above. The data signal is sequentially recorded between the servo signals, and the recording area of the servo signal and the data signal recording area are alternately arranged along the track direction which is the scanning direction of the pickup head or the like. Will be placed.

In this case, the number of servo signals for one rotation of the unified format disk is limited to some extent according to conditions such as disk rotation speed and servo control characteristics. It is necessary to record and form about servo signals.

By the way, the recording capacity of such an optical disk or the like is extremely large, for example, about several hundred Mbytes or more, and it is important to take measures against errors such as burst errors. For this reason, it is common practice to add error detection or error correction codes to data to be recorded.

There are various methods of error correction encoding for this purpose. For example, data of one sector of a disk is arranged in a two-dimensional matrix of m rows and n columns, and an error correction code is provided for each data sequence in the row direction. There is known a coding system in which reading and writing of data are performed in the column direction while being added. In such a code system, since the minimum distance of the error correction code is relatively large (for example, 10 bytes or more), LDC (Long Distance) is used.
Code), and the interleave depth is m in the column direction.

D. Problems to be Solved by the Invention By the way, when data is recorded on a recording medium such as a disk, the above-described two-dimensional array data of LDC is read out in the column direction, and data between the servo signals is read. The data is sequentially recorded in the signal area. In this case, the data sequentially read out by m pieces in the column direction is divided and recorded for every length k of the data signal area of the disk or the like, but the data structure of the two-dimensional array data is And the data recording format on the disc are set independently of each other, there is a possibility that various inconveniences may occur.

For example, when a servo signal error occurs at the time of signal reproduction or the like, even if a single servo signal becomes an error and data in one data signal area becomes an error, the two-dimensional array is used. On the data, the error does not fit within a predetermined range of columns, and an error may exist over the next column, resulting in a reduction in the error correction capability in the row direction.

Therefore, the present invention has been made in view of the above-described conventional problems,
An object of the present invention is to provide a data recording method in which data recorded in one data signal area between servo signal areas falls within a fixed number of columns in a two-dimensional array data structure such as the LDC. is there.

E. Means for Solving the Problems The data recording method according to the present invention, in order to achieve the above-mentioned object, a servo signal area where a servo signal is recorded and at least a data signal area where a data signal is written, In a method of sequentially recording data in each data signal area of a recording medium alternately provided along a head scanning method at the time of recording and reproduction, data to be recorded is formed in a two-dimensional array of m rows and l columns, The data read / write direction is set to the column direction, an error correction code is added for each sequence in each row direction, the length m of the two-dimensional array data in the column direction,
The lengths m and k are selected so that one is an integral multiple of the length k of the data signal area between the servo signal areas (m, l, and k are all positive integers). It is.

F. Operation The data length m of one column of the two-dimensional array data structure,
Since the data length k of the data signal area of the recording medium is an integer multiple of the other, the data in one data signal area is always contained within a fixed number of columns, Does not extend beyond the first column to the next column,
Even if data in one data signal area becomes an error due to a servo signal error or the like, the above-mentioned fixed number of error columns is sufficient.

G. Embodiment Hereinafter, an embodiment in which the data recording method of the present invention is applied to the case where data is recorded on a magneto-optical disk will be described with reference to the drawings.

FIG. 1 shows a data structure of one sector (for example, 512 bytes) of a magneto-optical disk when data is recorded according to the first embodiment of the present invention, and FIG. 1 shows a recording format of the magneto-optical disk 1. First, in FIG. 2, between each servo signal area 3 in which servo signals are recorded in a so-called pit form, a data signal area 4 in which a data signal or an address signal is written.
These areas 3 and 4 are provided alternately along the tracks 2 in the circumferential direction of the magneto-optical disk 1.
Here, the length of the servo signal area 3 is, for example, 2 bytes in bytes, and the length k of the data signal area 4 is, for example, 16 bytes. Next, data sequentially recorded in each data signal area 4 has a data structure of a two-dimensional array of m rows and l columns as shown in FIG.
For example, 16 bytes of additional information, an error detection code, and the like are added to 512 bytes of data.
= 4 bytes, 1 = 132 bytes of two-dimensional array data. In this case, between the sequence length m (4 bytes) of the two-dimensional array in the column direction and the length k (16 bytes) of the data signal area 4 between the servo signal areas 3 in FIG. The other integer multiple, that is, in this case, k is 4 times m (k = 4). Accordingly, since the data of one data signal area 4 is arranged without excess or shortage within the range of the four columns of the two-dimensional array data, an error due to a servo signal occurs and the data of one data signal area 4 When an error occurs, the error data does not exceed the four columns of the two-dimensional array data and does not protrude to the next column or the like, and the deterioration of the error correction capability can be suppressed.

G-1. Data Structure of First Embodiment (FIG. 1) Here, in the first embodiment of the present invention, the data structure of one sector to be recorded on the magneto-optical disk will be described with reference to FIG. This will be described in detail. The first
FIG. A schematically shows the entire data structure for one sector, and FIG. 1B shows only a part of FIG. 1A in an enlarged manner.

In a magneto-optical disk, the unit data amount recorded in one sector on a recording track is, for example, 512 bytes in consideration of the fact that the magneto-optical disk is used as an information recording medium for a computer. FIG. 1 shows an example of a data structure when one sector is 512 bytes. That is, although the original valid data is 512 bytes, 16 bytes of additional information are added after the valid data to become 528 bytes, and the 528 bytes of data are divided into 4 bytes each of a fixed value corresponding to one column. Are arranged two-dimensionally as 4 bytes in the column direction and 132 bytes (4 × 132 = 528) in the row direction. Here, as the 16-byte additional information, for example, reserve information such as link information to the next sector or data identification information, or an error detection code EDC generated for this reserve information data and the 512-byte data. Etc. are used.

The error correction code ECC of 16 bytes is added to the data (132 bytes) of each row of the two-dimensional array data of 528 bytes, so that a total of 592 bytes are obtained.
It is configured as a so-called LDC (Long Distance Code) having 4 rows and 148 columns. Here, for example, a C (148,132) Reed-Solomon code may be used as the error correction code.
The two-dimensional array data having such an LDC configuration is written and read one by one in the column direction, and is sequentially recorded in the data signal area 4 of the disk.

G-2. Recording Format (FIG. 2) Next, a recording pattern and a track recording form on the magneto-optical disk on which the two-dimensional array data having the LDC configuration is recorded will be described in more detail.

In FIG. 2, the magneto-optical disk 1 has a so-called 5
In the case of the inch type, the diameter is about 13 cm, and one side has a storage capacity of 300 Mbytes or more. This disc 1
The track 2 is rotated at a constant angular velocity, and as one track per rotation, for example, concentrically or spirally.
And data is recorded. 18 tracks per side
2,000 to 20,000, and each track is
As shown in (1), it is divided into (n + 1) sectors, for example, 32 sectors. Next, the format of the sector is shown in FIG.
As shown in the enlarged view, servo signal areas 3 on which servo pits are recorded and data signal areas 4 on which data signals and address signals are written are alternately arranged. In the data signal area, an address signal such as a sector address is recorded and formed in the form of the pit, for example. Each length of the servo signal area 3 and the data signal area 4 is, for example, 2 bytes and 16 bytes, respectively, when converted into bytes. Therefore, in the case of the present embodiment, since the data amount of the entire two-dimensional array per sector is 592 bytes, 3
One sector of data is recorded over seven data areas, and one data signal area 4 for recording an address signal is added to the data, so that a set of a servo signal area 3 and a data signal area is totaled 38.
One set constitutes one sector.

Here, the length m in the column direction of the two-dimensional array data in FIG. 1 is 4 bytes, and the length k of one data signal area 4 is
Since it is 16 bytes, data of one data signal area 4 is allocated to four columns without excess or deficiency, and data of any one data signal area 4 exceeds the range of the four columns of the two-dimensional array data. It does not extend to the next column. Further, as shown by the broken line in FIG. 1B, one servo signal SV is provided for every four columns of the two-dimensional array data. Therefore, for example, if error information at the time of occurrence of an error due to a servo signal is known, the range of the error on the two-dimensional array data is determined, so that the error correction operation can be simplified and the error range at the time of burst error occurrence can be improved. Is easy to limit.

G-3. Other Embodiments (FIGS. 3 to 6) Next, some other embodiments of the present invention will be described with reference to the drawings. In the following embodiment, for the sake of simplicity, it is assumed that a magneto-optical disk 1 having a recording format similar to that shown in FIG. 2 is used as a recording medium, and a data signal area 4 between servo signal areas 3 is used. Length k
Is 16 bytes.

First, FIG. 3 shows an example of the data structure of one sector of data recorded by the data recording method according to the second embodiment of the present invention. In this case, the data size of one sector is 1024 bytes. I have.

In FIG. 3, 16 bytes of additional information are added after the original valid data (1024 bytes) for one sector.
The two-dimensional matrix array data is made up of 1,040 bytes, divided into eight bytes in the column direction, and 130 bytes in the row direction and eight bytes in the column direction. Here, the 16-byte additional information may be composed of, for example, reserve information and an error detection code EDC, as in the embodiment of FIG. A 16-byte error correction code ECC, for example, a C (146,130) Reed-Solomon code is generated and added to each row (130 bytes) of the two-dimensional array data thus obtained to form so-called LDC data. doing. The two-dimensional array data having such an LDC configuration is read and written one by one in the column direction, and is sequentially recorded in each of the 16-byte data signal areas 4 (see FIG. 2) of the disk.

That is, in the second embodiment of FIG. 3, the sequence length m in the column direction of the two-dimensional array data is 8 bytes,
Since the length k of one data signal area is 16 bytes, m: k = 1: 2, and data of one data signal area within the range of two columns of the two-dimensional array data is excessively or insufficiently. The data in any one data signal area is not arranged beyond the range of the two columns.
The servo signal SV is, as shown by the broken line in FIG.
One piece is distributed for every two columns of the two-dimensional array data.

Next, when the data size of one sector is 2048 bytes, the length m of one column may be set to 16 bytes as in the third embodiment shown in FIG. 4, for example. In the third embodiment, 16-byte additional information is added to 2048-byte data to make a total of 2064 bytes, and two-dimensional array data of 16 rows and 129 columns is formed. A byte error correction code ECC is added. In this case, the length k (16 bytes) of the data signal area is equal to the length in the column direction (16 bytes) (m: k = 1: 1), and the length of one column of the two-dimensional array data is One data of the data signal area is allocated within the range without excess or deficiency. Further, as shown by the broken line in FIG.
One piece is allocated to each column of the dimensional array data.

FIG. 5 shows an example of the data structure when the data size of one sector is 4096 bytes. In the example of FIG. 5, 32 bytes of additional information are added to 4096 bytes of data, so that a total of 4128 bytes of data is 32 rows × 12 bytes.
It is formed into nine-column two-dimensional matrix array data. In this case, the length m in the column direction is 32 (bytes), which is twice (m: k = 2: 1) the length k (16 bytes) of the data signal area 4. The data of the two data signal areas 4 is allocated to one column of the dimensional array data without excess or deficiency. Further, as shown by the broken lines in FIG. 5, two servo signals SV are distributed for each column of the two-dimensional array data.

In the above-described first to fourth embodiments, an example has been described in which one line of the two-dimensional array data before error correction coding is approximately 128 bytes (+ several bytes). In addition, it can be set arbitrarily. For example, in the fifth embodiment shown in FIG.
A total of 528 bytes of data to which 6 bytes of additional information have been added are sequentially arranged in the column direction by dividing them every 8 bytes, and
It forms a two-dimensional array of columns. For each row (66 bytes) of this two-dimensional array data, a 16-byte error correction code EC
C, for example, a C (82,66) Reed-Solomon code is generated and added to form a two-dimensional array having eight rows and 82 columns. Since the length k of one data signal area 4 of the magneto-optical disk (see FIG. 2) as a recording medium is 16 bytes, the length m of the two-dimensional array data in the column direction is 8 bytes, m: k
= 1: 2, so that data for one data signal area can be allocated without excess or deficiency within the range of two columns of the two-dimensional array data. That is, the data of any one data signal area is not arranged beyond the range of the two columns, and the servo signal SV is, as shown by the broken line in FIG. One piece is allocated to two rows.

In addition, various changes can be made without departing from the spirit of the present invention. For example, the present invention can be easily applied to a disk-shaped recording medium outside a magneto-optical disk. Further, the length l in the row direction, the length m in the column direction, the length k of the data signal area, and the like of the two-dimensional array data are not limited to the numerical values in the above embodiment, and m: k is 1 Needless to say, it can be set arbitrarily within a range that satisfies the condition of being a ratio to an integer value.

H. Effects of the Invention According to the data recording method of the present invention, even when an error occurs in a servo signal and data in one data signal area becomes an error, the two-dimensional array data is within a fixed number of columns. , The error correction capability can be improved, and the capability can be maximized even in the case of a burst error. Further, when error information is passed to the ECC when a servo signal error occurs, the error does not exceed the range of the fixed number of columns, so that handling is easy. Furthermore, since the entire two-dimensional array data is not divisible by the length of the data signal area and no odd data is generated, it is not necessary to mix and record the address signal and the data signal in the data signal area. The switching operation between the servo signal and the data signal does not occur in the data signal area between the servo signals.

[Brief description of the drawings]

FIG. 1 is a diagram showing a data structure of one sector to be recorded by a data recording method according to a first embodiment of the present invention, and FIG. 2 is a schematic diagram showing a recording pattern of a magneto-optical disk in the embodiment. 3 to 6 show the data structure of one sector applied to the second to fifth embodiments of the present invention, respectively. 1 ... Magneto-optical disk 2 ... Track 3 ... Servo signal area 4 ... Data signal area

Claims (1)

(57) [Claims] A disc provided with a servo signal area in which servo signals are recorded on concentric or spiral tracks and a data signal area in which at least a data signal is written is provided alternately. In a data recording method for sequentially recording data signals in a signal area, data to be recorded is formed in a two-dimensional array of m rows and l columns (m and l are positive integers), and a data read / write direction is set in a column direction. And an error correction code is added for each row-direction sequence. The length m of the two-dimensional array data in the column direction and the length k of the data signal region between two consecutive servo signal regions are added.
(K is a positive integer) and each length m, k is selected so that one is an integral multiple of the other.