JPH05159471A - System for recording and reproducing data of optical disk - Google Patents

Abstract

PURPOSE:To prevent the occurence of a correction line being incorrigible with- out adding a hardware and to improve correction ability viewing in sector. CONSTITUTION:The data length of one data group unit is set as (n) by a prescribed format. An interleave length is regarded as (m) and the data is stored so that (m) pieces of error correction lines are formed in a data memory at the time of recording and reproducing the data. Further, the data length (n) and/or the interleave length (m) are set so that the interleave length (m) or the divisor of (m) becomes a value indivisible for the data length (n) in one data group.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk data recording / reproducing system for controlling data arrangement to record data on an optical (magneto-optical) disk or reproduce data from the optical disk.

[0002]

2. Description of the Related Art In recent years, not only a read-only optical disk (ROM disk) but also a recordable and reproducible optical disk has been put into practical use, and has become popular for data storage, music use and the like. As a recordable optical disk, a magneto-optical disk having a recording medium which is a light-sensitive recording medium as a recording surface is overwritable and is considered to be most useful.

An optical disk and an optical disk system capable of recording various data on the optical disk by irradiating a spiral or concentric track on the optical disk with a laser beam and reading the recorded data. There are widely known a continuous type in which a track on which data is arranged is configured by a pre-groove and a sample servo type in which a track in which data is arranged are formed by sample servo pits discretely arranged. ..

FIG. 7 shows an example of a magneto-optical disk format in which a recording track is formed by sample servo pits. S _{1 to} S ₄₂ are, for example, sectors divided into 42 in the circumferential direction. Indicates.

The track of each sector is shown in FIG.
As shown in (a), the area where the address data is recorded and the ALPC area (Automatic Laser Power Control A
area is provided with an address test area AD including a header segment H ₁ having a rea) and a header segment H ₂ used for a trial writing area, and the like, and a data recording area DB in which, for example, 20 bytes of data is recorded. Are divided into ₃₀ segments SG _{1 to} SG ₃₀ and formed.

FIG. 8B shows the header segments H ₁ and H.
₂ and the data segments SG ₁ to SG ₃₀ and further expanded the first servo byte SB is disposed on the subsequently address or a magneto-optical (MO) data area to be recorded which are provided.

At least one pair of wobbling pits P ₁ and P ₂ which are deviated from the center of the track T to the outer peripheral side and the inner peripheral side are arranged on the servo bite SB and on the center line of the track T. The clock pit P ₃ is previously formed by embossing or the like.

A mirror surface M is formed between the wobbling pits P ₁ and P ₂ and the clock pit P ₃ , and the focus servo signal is detected by the laser light reflected from the mirror surface M and the laser power control is performed. -Le can also be done. Furthermore, the pits P ₄ and P whose access code as track information forms a gray code
Recorded by ₅ .

In such a magneto-optical disk, a tracking error signal is usually formed by calculating reflected light when the wobbling pits P ₁ and P ₂ are detected at the sampling points t ₁ and t ₂ , and the clock pit P is formed. _The clock signal is formed by the signal detecting ₃ at sample point t ₃ .

This magneto-optical disk has a data byte DB
When the laser beam is applied to the recording surface of the magneto-optical disk along the track T in the area of (1) and a magnetic field is applied from the other surface of the magneto-optical disk, it is applied when the recording surface reaches the Curie point or higher. Data is recorded by being magnetized in the direction of the existing magnetic field. For example, if 20 bytes of data is recorded in the data byte DB of one data segment (SG _{1 to} SG ₃₀ ) (data length of one data group unit is 20 bytes), recording tracks are formed as shown in FIG. To be done.

D _i (i = 0, 1, 2, ...) Shows 1-byte data. In addition, each segment S
If 20 bytes are recorded in each of G _{1 to} SG ₃₀ , and 600 bytes of data is recorded in one sector in total, for example, 520 bytes of data (including control data) are followed by ECC (ErrorCorrelation).
80 bytes of rection code) is recorded.

When information is read from the magneto-optical disk on which data is recorded as described above, the reflected light of the laser beam is detected by utilizing the magnetic focusing effect, so that the data recorded on the data byte DB is detected. Is read. Then, the data read from the recording track as shown in FIG. 9 is arranged in the data memory with, for example, an interleave factor = 5 as shown in FIG. 10, so that five error corrections are made as an error correction processing unit of one sector. Lines L _{1 to} L ₅ are formed, and error correction processing is performed on each error correction line L _{1 to} L ₅ .
As shown, 520 bytes of data (data D
_{0 to} D ₅₁₁ , control data P _{1 to} P ₄ , CRCC
After the data CRC _{1 to} CRC ₄ ), 16-byte ECCs (E1 _{1 to} E ₅ ) are respectively provided to the error correction lines L _{1 to} L _5.
1 ₁₆ , E2 _{1 to} E2 ₁₆ , E3 _{1 to} E3 ₁₆ , E4 _{1 to} E4 ₁₆ , E
5 _{1 to} E 5 ₁₆ ) are arranged and provided for error correction.

[0013]

By the way, in the above-mentioned magneto-optical disk or the like, due to physical influences such as twisting and birefringence at the time of molding, pits are recorded around the servo bite SB which is formed by, for example, embossing. There is a case that the error rate of the read data is higher than that of the data recorded at a position relatively distant from the servo byte SB.

That is, referring to the example of FIG. 9, the head byte and the last byte of the data byte DB adjacent to the servo byte SB, that is, D ₀ , D ₁₉ , D ₂₀ , D ₃₉ , D ₄₀ ... The probability that a read error will occur is not limited to other data (eg D ₁
Up to D ₁₈ , D _{21 to} D _38, etc.).

Here, considering the case where data is reproduced and arranged with an interleave factor = 5 and error correction processing is performed as shown in FIG. 10, the head data D ₀ , D ₂₀ , D _40. .. are all error correction lines L
Located on _1, also it will be located all last data _{D 19, D 39, D 59} ··· are on an error correction line L ₅ of each segment, therefore, the error correction lines L ₁ and L
No. ₅ has a problem that the processing load is likely to be excessive compared to the other error correction lines L _{2 to} L ₄ , that is, the probability of uncorrectability increases.

For example, assuming that one error correction line has a correction capability of 8 bytes, assuming that a read error occurs in the leading data in each data segment SG _{0 to} SG ₂₉ due to physical influence, the error correction line 30 for L ₁
Byte errors concentrate and the error correction line L ₁ becomes uncorrectable.

When the uncorrectability occurs in one error correction line as described above, a serious situation occurs in which the entire sector is defectively reproduced even if the other error correction lines can be corrected. The existence of error correction lines with a high probability of failure must be prevented.

[0018]

SUMMARY OF THE INVENTION In view of the above problems, the present invention applies an evenly equal processing load to each error correction line during error correction processing, and in particular, error correction with a high probability of being uncorrectable. This is to prevent lines from being generated.

For this purpose, 1 is set in a predetermined format.
As a data recording / reproducing method for an optical disc in which the data length of one data group unit is set to n, an interleave length (interleave factor) is formed so that m error correction lines are formed in the data memory at the time of data recording and reproduction. ) Is stored as m, the data is stored, and the interleave length m or a divisor of m is a value that is not divisible by the data length n and / or the data length n of one data group unit. Interleave length m
Provides a recording / playback method in which is set.

[0020]

In the format of the optical disk or the interleave control so that n / m or (n / (a divisor of m)) is not divisible by the data length n of one data group unit and the interleave length m. By setting the operation or both, for example, in a unit of a predetermined number of consecutive data groups in one sector (that is, a predetermined number of consecutive segments), the data in the data memory used for the error correction operation The array is a data array in which the data recorded at corresponding positions in each data area on the disc are not processed by the same error correction line.

That is, the data array formed on the data memory used for the error correction operation is shifted in units of a predetermined number of data groups, and each first byte or each last byte in each data group is specified. There is no need to concentrate on the error correction line.

[0022]

1 is a schematic diagram of an optical disk system to which an optical disk recording / reproducing system of the present invention is applied. Reference numeral 1 denotes a magneto-optical disk.
Is loaded in the optical head device unit 2 and data recording / reproducing operations are executed.

This magneto-optical disk 1 is shown in FIGS. 2 and 3, for example.
The track format of the sample servo system is made as shown in. That is, one track has sectors S _{1 to} S ₅₆ divided into 56 in the circumferential direction, and each sector S
_As shown in FIG. 3A, _{1 to} S ₅₆ are composed of a header segment HS in which address data and the like are recorded and 23 units of data segments SG _{1 to} SG ₂₃ .

In the header segment HS and the data segments SG _{1 to} SG ₂₃ , as shown in FIG. 3B, a servo byte SB is arranged first, and subsequently, an area where an address and magneto-optical (MO) data are recorded. (Data byte D
B) is provided. Further, the servo bite SB is deviated from the center of the track T toward the outer peripheral side and the inner peripheral side.
A pair of wobbling pits P ₁ and P ₂ and a clock pit P ₃ arranged on the center line of the track T are provided. A mirror surface M is formed between the wobbling pits P ₁ and P ₂ and the clock pit P ₃ . Furthermore, the pits P ₄ and P whose access code forms a gray code
Recorded by ₅ .

Here, 26 bytes of data are set to be recorded in the data byte DB of each of the data segments SG _{1 to} SG ₂₃ of the magneto-optical disk 1. Therefore, the recording capacity in one sector is 598 bytes, for example, 512 bytes of user data, 80 bytes of ECC data, 4 bytes of CRCC data, and 2 bytes of control data are recorded.

In the optical head device section 2, the magneto-optical disk 1 is moved at a constant linear velocity (CLV) or a constant angular velocity (CA).
V) is equipped with a spindle motor 2a that is rotationally driven, and an optical head 2b that irradiates a laser beam when recording or reproducing data to or from the magneto-optical disk 1 is loaded with the magneto-optical disk 1 It is arranged to be on the lower side. Further, a magnetic head portion 2c is provided at a position facing the optical head 3 with respect to the magneto-optical disk 1, and a magnetic field which is inverted by recording data is applied when recording data on the magneto-optical disk 1.

For such a magneto-optical disk 1, as is well known, the optical head 2b mounted in the optical head device section 2 in FIG. 1 has a laser emission source, a collimator lens, a beam splitter, and an objective lens. It is composed of an optical system including a biaxial device for controlling the optical axis, and includes a polarization beam splitter and a detector for detecting the reflected light from the magneto-optical disk. In particular, the reflected light is split into a P-polarized component and an S-polarized component by the polarization beam splitter and detected by the two detectors.

In the optical head device section 2, the outputs of the two detectors are supplied to a differential amplifier, and the difference between the two outputs is taken by this differential amplifier to reproduce the reproduction signal of the magneto-optically recorded data. Extract. Further, various servo signals are formed by utilizing the output signals obtained from the detector when the embossing pits of the header segment HS or the servo byte SB are scanned, and are supplied to a servo circuit to drive the biaxial device, Tracking servo and focus servo are performed, and a master clock signal, address information and the like are formed.

Reference numeral 3 is a data memory for storing data to be recorded and supplying it to the optical head device unit 2 as recording data, and also storing data reproduced by the optical head device unit 2. Reference numeral 4 is recording data and reproduction data. A controller (CPU) 5 for controlling the processing of (1), an ECC circuit unit for performing data correction processing, and a reference numeral 6 for an interface unit for exchanging recording data and reproduction data with a host computer (not shown).

As the data recording operation in such an optical disc system, for example, data to be recorded on the magneto-optical disc 1 from the host computer via the interface unit 6 (for example, 512 bytes per sector) is held in the data memory 3. To be done. Further, the controller 4 generates control data (same 2 bytes) and holds it in the data memory 3, and the ECC circuit section 5 further generates CRCC data (same 4 bytes) and ECC data (same 80 bytes). Written in.

For example, for the data memory 3, a data stream as shown in FIG. 4, that is, data D _{0 to} D ₅₁₁ , control data P ₁ and P ₂ , CRCC data CRC _{1 to} C.
RC _4, the data stream using the ECC data E1 ₁ ~E5 ₁₆ is formed. It should be noted that in FIG. 4, the solid line frame indicates a 26-byte data group corresponding to one data segment on the magneto-optical disk 1. These data will be held in the data memory 3 as shown in FIG. Here, in the data memory 3, for example, for the first 2 bytes, dummy fixed data (such as "00" or "FF") is stored.

The data (D _{0 to} D ₅₁₁ , P ₁ , P ₂ , CRC _{1 to} CRC ₄ , E held in the data memory 3 are
1 _{1 to} E5 ₁₆ ) are read out in the order shown in the data stream of FIG. 4 and supplied to the optical head device unit 2, and each data segment SG ₁ to It is recorded in the data byte DB of SG _{23 by} the magnetic field modulation method. Therefore, as shown in FIG. 6, data is recorded in each of the data segments SG _{1 to} SG ₂₃ on the magneto-optical disk 1. For example, the head data of each data byte DB is D ₀ , D ₂₆ , D _52, ...

Further, when the magneto-optically recorded data is reproduced from the magneto-optical disk 1 by the optical head device section 2 during reproduction, it is again written in the data memory 3 as shown in FIG. Here, each data of 598 bytes is arranged in the data memory 3 with the interleave factor = 5. Therefore, in the ECC circuit unit 5, the error correction line L ₁ is applied to the data written in the data memory 3.
~ 16 bytes of E allocated in units of L ₅
CC data (E1 _{1 to} E1 ₁₆ , E2 _{1 to} E2 ₁₆ , E3 _{1 to} E3
₁₆ , E4 _{1 to} E4 ₁₆ and E5 _{1 to} E5 ₁₆ ) are used to perform error detection and correction processing operations. The error-corrected data D _{0 to} D ₅₁₁ are supplied as reproduced data to the host computer, for example, via the interface unit 6.

Here, focusing attention on the data D ₀ , D ₂₆ , D _52, ... Recorded as the first byte in the data byte DB of each data segment on the magneto-optical disk 1, FIG. As indicated by the diagonal lines, the data D ₀ is arranged on the L ₃ line, the D ₂₆ is arranged on the L ₄ line, the D ₅₂ is arranged on the L ₅ line, ... Become. The same applies to the data D ₂₅ , D ₅₁ , ...), which has been recorded as the last byte of each data byte DB on the magneto-optical disk 1.

That is, in this embodiment, for a magneto-optical disk in which data of 26 bytes is recorded in one data segment, an interleave factor = 5 is set so that error processing is performed by five error correction lines. Then, the first byte or the last byte in the data byte DB having the highest error probability is evenly distributed to the five error correction lines to perform the error correction processing. Especially, the error correction line in which the error processing load becomes large. Can be eliminated.

That is, the storage capacity of the data byte DB (2
Since the interleave factor (= 5) is set to a value that cannot be divided with respect to 6 bytes), the data at the corresponding position between the data bytes on the magneto-optical disk will naturally cause each error during interleaving. It will be distributed to the correction line. Of course, no special hardware is required for this processing, and processing such as controlling the address generator of the read / write operation of the data memory 30 to rearrange the interleave positions is not necessary.

In the present invention, when the storage capacity (n) of one data byte DB and the interleave factor (m) are used, n ÷ m or n ÷ (a divisor of m) is divisible. As described above, it is possible to equalize the error processing load for each error correction line by setting the value to be a non-existent value. There are three possible ways: to realize by setting the format of the optical disc, to realize by setting the interleave factor for a specific optical disc format, and to realize by newly setting the optical disc format and the interleave factor.

The above embodiment has been described with reference to the recording / reproducing operation of the optical disk adopting the recording format of the sample servo system, but the recording / reproducing operation corresponding to the optical disk of the continuous composite servo system is also described. The invention is effectively applied.

In the case of the continuous composite servo system, a resync signal is recorded in the data area, whereby the PLL circuit is resynchronized to prevent the expansion of a data error due to a clock shift. Therefore, the data immediately after the resync signal has a relatively low error occurrence rate, but the closer to the data immediately before the resync, the higher the possibility of error occurrence. Therefore, the data between the resync signal and the resync signal is considered as one data group similarly to the data of each data segment of the above embodiment, and the interleave factor m, or The same effect can be obtained by setting the divisor so that it is not divisible.

The present invention is not limited to the above embodiment, and various settings should be changed within the scope of the gist when carrying out the present invention. Of course, the data length n and the interleave factor m are not limited to the values in the above embodiment.

[0041]

As described above, the data recording / reproducing system of the optical disc of the present invention is 1
For an optical disc in which the data length of one data group unit is set to n, the data length n and / or interleave is set so that the interleaving factor m or a divisor of m is a value that is not divisible by the data length n. Since the length m is set, the data array formed on the data memory used for the error correction operation is shifted in each of the predetermined number of data groups, and is set to the first byte or the last byte in each data segment on the optical disc. The distributed data will be distributed so as not to concentrate on a specific error correction line.

As a result, the number of data having a high error probability does not concentrate on a specific error correction line,
Therefore, the probability that a certain error correction line is overcorrected and cannot be corrected becomes considerably low. That is, it is possible to effectively prevent the occurrence of uncorrectability and improve the correction capability in sector units. Moreover, there is also an advantage that it is not necessary to add special hardware to perform such processing.

[Brief description of drawings]

FIG. 1 is a schematic diagram of an optical disc system to which a recording / reproducing system of the present invention is applied.

FIG. 2 is an explanatory diagram showing a format of a magneto-optical disk according to an embodiment.

FIG. 3 is a detailed explanatory diagram of recording tracks according to the embodiment.

FIG. 4 is an explanatory diagram of a data stream for a data memory according to the embodiment.

FIG. 5 is an explanatory diagram of a data holding state of the data memory according to the embodiment.

FIG. 6 is an explanatory diagram of a data recording state of a recording track of the magneto-optical disk of the example.

FIG. 7 is an explanatory diagram showing a format of a magneto-optical disk.

FIG. 8 is a detailed explanatory diagram of recording tracks.

FIG. 9 is an explanatory diagram of data on a recording track.

FIG. 10 is an explanatory diagram of a data holding state in a data memory of a reproduction signal from a magneto-optical disk.

[Explanation of symbols]

 1 magneto-optical disk 2 optical head device section 3 data memory 4 controller 5 ECC circuit section

Claims (1)

[Claims] 1. A data recording / reproducing method for an optical disc in which a data length of one data group unit is set to n according to a predetermined format is as follows. At the time of data recording and reproducing, m error correction lines are formed in a data memory. The interleave length is set to m so that the data is stored, and the interleave length m or a divisor of m is a value that is indivisible to the data length n of one data group unit. A data recording / reproducing system for an optical disc, wherein a data length n and / or an interleave length m is set.