JPH02297778A - Optical recording system - Google Patents

Abstract

PURPOSE:To assure the smooth operation of an optical recording system even though some of optical disk drivers have defects by recording dispersedly the data to plural optical disks and at the same time recording the check symbols of error correction codes to some optical disks. CONSTITUTION:The data are recorded dispersedly to plural optical disks 4 and at the same time the check symbols of the error correction codes of data to be recorded to each optical disk 4 is recorded to a specific disk 4. If one of optical disk drivers 11 - 20 becomes defect, the information on a fact that the data to be recorded disappeared is stored. When the defective disk driver is restored and the data can be recorded to this driver, the disappeared data is restored based on the stored information, the check symbols and/or the recorded data. The restored data is recorded to the corresponding address of the corresponding disk. As a result, an optical recording system smoothly and continuously is operated despite the defects detected in the drivers 11 - 20.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an optical recording system that uses an optical disk (including a magneto-optical disk) as a recording medium.

[Conventional technology]

Some magnetic disks achieve high transmission rates by rotating multiple disk drives synchronously.

For example, there is a system shown in Nikkei Electronics, December 28, 1987, page 48.

On the other hand, optical discs have been put into practical use as large-capacity information recording media. In order to utilize this characteristic more effectively, an array-type optical recording system has been proposed in which a plurality of disk drives are combined to operate as if they were one large-capacity disk drive.

[Problem to be solved by the invention]

In such a conventional large-scale optical recording system, it is essential to take measures in case some optical disk drive devices become malfunctioning.

The present invention was made in order to solve such problems, and the present invention records data in a distributed manner on a plurality of optical disks, and also records check symbols of error correction codes on some of the optical disks. An object of the present invention is to provide an optical recording system that can be operated without any trouble even if a problem occurs in an optical disk drive.

[Means to solve the problem]

The optical recording system of the present invention is an optical recording system that includes a plurality of optical disk drive devices each loaded with an optical disk and performs recording and reproduction on the optical disk, and records data in a distributed manner over a plurality of optical disks. A check symbol of an error correction code for data to be recorded on each optical disc is recorded on a specific optical disc, and if any optical disc drive becomes defective, information regarding the loss of data to be recorded is recorded. It is configured to be memorized.

[Effect]

If any of the optical disk drives becomes defective, recording cannot be performed on the disk loaded therein.

In such a case, the data to be recorded will be lost. Therefore, remember this fact by appropriate means. When the optical disk drive device is restored and becomes capable of recording, the lost data is restored using the above-mentioned storage information, the test symbol and/or the recorded data, and this is recorded at the corresponding address of the corresponding disk. , it is assumed that complete data recording has been performed.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below based on drawings showing embodiments thereof.

FIG. 1 is a block diagram of an optical recording system according to the present invention.

In the figure 1). Reference numerals 12, . . . , 20 are optical disk drive devices, which record data given from the control device 2 on optical disks, or reproduce data recorded on optical disks. 3 is a host computer, which provides data to be recorded to the control device 2 or instructs the data reproduction.

FIG. 2 shows the main part of the recording format of the optical disc 4, including a file name recording area 4a in which information identifying a data file constituted by recorded data is recorded, a number recording area 4b in which the optical disc number is recorded, and the recording format. It has a specific area 4C.

In the recording format specific area 4C, it is possible to determine whether the entire recording area of the disc is used or a part of the recording area is used. The optical disc can be used as a high-capacity recording medium, or conversely, the optical disc can be used as a low-capacity recording medium by using some specific areas while recording and reproducing at high speed.

In optical disc recording, when data is recorded on the entire surface,
Although the capacity per disk becomes larger, it is necessary to seek all the tracks, and the seek time becomes longer. On the other hand, when only some tracks are used, the distance to seek is shortened, so the storage capacity per disc is small (but the seek time is shortened).The code that identifies these recording modes is used to specify the recording format. It is recorded in area 4C.

In this system, an optical disc on which a specific number, for example 9°10, is recorded in the number recording area 4b records only check data generated from data recorded on other optical discs, that is, check symbols of error correction codes. do.

The normal operation of the system of the present invention as described above is as follows. The operation differs depending on whether or not the file name recording area 4a, number recording area 4b, and recording format specific area 4c are recorded on the optical disc. If these areas 4a to 4c are not recorded, the ID section is recorded during formatting of the optical disc. The 10th copy is information for specifying a set of a plurality of optical discs, and its recording is performed, for example, in the file name recording area 48 or the like. Assuming that the ID section has already been recorded, first, before starting the system, the optical disc 4 is inserted into the optical disc drive device 1). Load into 12... In this case, which optical disc is connected to which optical disc drive device 1). 12... may be loaded. When the system is started, the control device 2 reads the contents of the file name recording area 4a, number recording area 4b, and recording format specifying area 4C.The host computer 3 selects and loads an optical disk that matches the purpose of use based on the contents of the file name recording area 4a. Determine whether or not it has been done.

- The force control device 2 is connected to any optical disk drive device 1) depending on the contents of the number recording area 4b. 12... specifies which number of optical disk 4 is loaded.

As will be described later, each optical disk drive device 1). 12...
It is possible to specify which optical disc is loaded in the disc. If there are 10 optical disk drive devices as in this embodiment, 8 are drive devices for recording and reproducing information,
Two drive devices record and reproduce test symbols.

However, the drive device for recording and reproducing information and test symbols is not fixed, and depending on the loaded optical disc, serves as a drive device for original information recording as well as a drive device for recording test symbols. As an error correction method, for example, as shown in FIG. 3, there is a method using a Reed-Solomon code. That is, the 8 bits of data recorded on the optical discs numbered 1 to 8 are taken as one unit, and this is a, (i=1
~8), and the element on GF (2') is represented as αm, and the following parity P1°P2 is calculated.

These P, , P are recorded on optical disks numbered 9 and 10, respectively. In other words, the check symbols P+, P of this error correction code
g is composed of multiple optical discs,
Its Hamming distance is 3. In other words, two optical disks are provided for recording the test symbols Pt and Pz, respectively.

By using this, it is possible to identify the correspondence between the optical disc and the drive device that is recording or reproducing it by error correction. That is,
At the stage when an optical disk is loaded, it is assumed that each optical disk is loaded into a preset optical disk drive, and error correction is performed by creating an exponent of α based on the assumed optical disk-optical disk drive relationship. (described later). However, if the actual loading state of the optical disc is different from the assumed one, error correction cannot be performed and a syndrome occurs. If a syndrome occurs, error correction is performed again assuming a different loading state. In this way, the assumption of the loaded state is sequentially changed and the same process is repeated until the correct state is encountered. In this way, the correct optical disc loading state can be found.

When recording new data, since there is already a recorded part, play that part, use the same procedure as described above to find the correspondence between the optical disc and the optical disc drive, and record the data on the correct optical disc. be able to. By doing this, the number recording area 4b
It is also possible to specify the number of an optical disc without providing a .

FIG. 4 is a block diagram showing an example of the control device 2. As shown in FIG. The control device 2 has a buffer RAl' for each optical disk drive device.
1 (RAMI, RAM2...RAM10),
Each optical disk drive device 1). The data to be recorded by 1) . 1
2. The data played back in step 2 is temporarily stored here. Encoding and decoding of error correction code is done in other RAM (RAM II)
, central processing unit CPU2, read-only memory ROM2 and Galois logic unit) GLU. Data to be encoded and decoded is once stored in RAMII and then calculated using the Galois logic unit GLU.

The calculations are controlled by the central processing unit CPU2.

Firmware for control and instructions for α are stored in a read-only memory ROM2. host computer 3
Data is exchanged with the interface 5 through the interface 5.

Is the data from host computer 3 sent to another RA? 1(R
AM12) and then RA? 1) Transfer to 1. Conversely, when transferring playback data to the host computer 3, it is stored once and then transferred to the host computer 3. These controls are performed by another central processing module "1cPI1), and the firmware for this is stored in another read-only memory R.
Store it in OMI.

In such a system of the present invention, when recording data given from the host computer 3, the control device 2 sends check data of the data input from the host computer 3 to the central processing unit CPU2. RAMII.

Created using the Galois logical unit GLU, check data is added to the input data, and the optical disk drive device 1).
12... and the optical disk drive device 1)
．． The control signals necessary for controlling 12... are sent out.

At this time, the identification of the optical disk drive device to which the data should be sent is based on the recorded data in the number recording area 4b or the error correction repetition method described above.

Optical disk drive 1). 12... records the thus sent data on the optical disc.

On the other hand, during reproduction, in accordance with instructions from the host computer 3, the control device 2 controls the optical disc drive 1) in which the corresponding optical disc 4 is loaded. 12, etc., and a physical address signal or logical address signal of the position where the data to be reproduced is recorded. This allows the required data to be reproduced.

Next, the data recording method of the system of the present invention will be explained in comparison with the conventional method. In a conventional optical disc, data is recorded in a predetermined sector and then reproduced.

At this time, if the difference between the data to be recorded and the reproduced data is greater than a predetermined standard, the data is re-recorded in a spare sector prepared in advance for each track, that is, a replacement sector.

The recording on this spare sector is also reproduced and inspected, but if there are many errors in this recording, recording is performed again on a pre-prepared spare track, that is, a spare track. The replacement track is also used when recording to the replacement sector occurs again in the l trunk.

On the other hand, in the system of the present invention, the above-mentioned replacement sector,
To always record check data on one or more specific optical disks without providing anything similar to a replacement trunk. FIG. 5 is a conceptual diagram showing an example of the recording method, in which the recording unit is 8 bytes, ten optical disk drives are used, and the optical disks of two of the drives are used for recording check data. . As shown in Figure 5(a), 8 bits (1 byte) of data from MSB to LSB are the first
It is assumed that there are bytes from byte to the 8th byte. and the fifth
As shown in Figure ('b), two parity symbols (a first parity symbol P I and a second parity symbol Pg) are created for each byte. This creation is done in (1) above.
+2) According to the formula. All the MSBs of the first to eighth bytes are sent to the optical disk drive device loaded with the optical disk 4 on which the number ■ is recorded. Also, all the data of the second bit of the first to eighth bytes are simultaneously sent to the optical disk drive device in which the optical disk 4 on which the number ``2'' is recorded is loaded. Thereafter, the data of the first to eighth bytes are similarly sent to the optical disk drive device loaded with the optical disk of each number.

The 8-bit data of the first parity symbol P and the second parity symbol P2 are respectively .

The optical disc with the number [phase] is sent to the optical disc drive device loaded with it. The data sent to each optical disk drive device will be recorded on the optical disks loaded respectively.

FIG. 6 is a flowchart of the processing procedure when recording data. An optical disc is loaded (1) 21) Optical disc drive device 1). 12... is started, first each drive device 1). 10 copies are read by 12... (!
122).

This is transferred to RAMI to RAM10 (123).

The central processing unit CPUI checks this ID part (1)24)
, if they are not the same (for example, when there are multiple sets of optical discs and the optical discs between the sets are mixed), this is reported to the host computer 3 (
125). If they are the same, each optical disk drive device 1)
．． Read the number of the optical disc loaded in 12...,
Or it is determined (lt26).

FIG. 7 is a diagram showing data storage areas of RAM1-RAM10. Separate from the area for storing data, areas (labeled 4a, 4b, and 4c in the figure) are provided for storing identification data read from the file name recording area 4a, number recording area 4b, and recording format specifying area 4c. It is.

When the optical disk is loaded, the optical disk drive reproduces the identification data and transfers it to RAM1-RAM10.

The central processing unit cpui reads the identification data stored in the identification data area in RAMl-RAMl0 to determine which optical disc is loaded into which optical disc drive.

10 optical disk drives 1). Data to be recorded on the optical disks loaded in 12, . R
AMI to RAMl0 are allocated to each of the ten optical disk drives. On the other hand, the accumulation in RAMII is also 10
Addressing is done separately for each optical disc. Therefore, when the optical disk loaded in each optical disk drive device can be determined, the address of RAMII, which stores the data to be transferred to each of RAMI to RAM10, is set (
127). After making this setting, the data to be recorded is then transferred from the host computer 3 to the RAM 12 (1) 28). Furthermore, I want to transfer this to RAMII 1)
29), Galois logic unit GLU and central processing unit C
The error correction code is encoded for the data stored in the RAMII using the PU2 (1) 30). Then, according to the address set earlier, RA? 1) RA the data of 1
The data is transferred to each of M1 to RAM10 (131). Then, from each RAMI to RAMl0, the optical disk drive device 1).
12... and recorded in the data area of the optical disk 4 loaded in each.

FIG. 8 shows an example of another recording method. As shown in FIG. 8(b), the first parity symbol P1 and the second parity symbol P2 are created from all bytes, and then the first byte is The optical disc with the number ■, the second byte is the optical disc with the number ■, the first parity symbol is the optical disc with the number ■, and the second parity symbol is the optical disc with the number [phase]. Of course, data is recorded on each optical disc by each drive device.

Furthermore, during playback, the original data is restored using the reverse procedure to the above-mentioned recording procedure. That is, the data reproduced from each optical disk drive device is correlated with the number of the optical disk loaded in each device, and the data is organized byte by byte using logic opposite to interleaving as shown in FIG. 5 or FIG. 8. Get the data. When restoring this data, that is, decoding, error correction is performed using a Reed-Solomon code on GF(2'').

That is, as shown in FIG. 9, the data reproduced from the optical disks numbered 1, 2, . . . 9, 10 are r I+ r Z .
・If r 9+ r 16, the syndrome S,,S, is calculated using the following formula.

S0=Σr.

S, = Σ ri α5 (α1゜-1) If there is no error, ri”αi, so 50 = 81 = 0, but if there is an error on the i-th optical disc, 5
Instead of o=O, 5o=el. Therefore, S+/So=
When αi is determined, since α1 is a value unique to each optical disc, it is possible to identify the optical disc and correct errors. Note that if α is a value outside the plate assigned to each optical disk, it is assumed that simultaneous errors have occurred on two or more optical disks, and error correction is not performed and only the occurrence of simultaneous errors is detected. Even in this case, if one optical disc can be identified using the error pointer, erasure, etc., it is possible to identify the other optical disc, and therefore, to correct errors in both optical discs.

FIG. 10 is a flowchart showing the processing procedure for reproduction and error correction. The optical disc drive device 1) is loaded with the optical disc 4 (Ill). 12... is driven, first each drive device 1). 12... reads 10 copies (I2). This is transferred to RAMI to RAM10 (I3).

The central processing unit CPUI examines these 10 copies (I4), and if they are not the same, reports this to the host computer 3 (
+15), if the same, each optical disk drive ll
.

12... reads or determines the number of the optical disc 4 loaded in the disc 4 (step 6). 10 optical disk drives 1
). The playback data from 12... are respectively stored in a predetermined RAMI.
~RAMl0, but this RAMI~RAMl
The accumulated data of 0 is transferred and stored in each area of RAM II allocated according to the number of the optical disk. In step #7, address settings for this purpose are performed. After doing this, each optical disk drive device 1). The data reproduced in 12... is temporarily stored in RAM1-RAM10,
From here, it is transferred to the RAM II setting address (I8
). Then, the above-mentioned calculations are performed by the central processing unit CPU2 and the Galois logic unit GLU, and if there is an error, it is corrected (1) 9>, and the corrected or correct data is sent to the RA? 1) Transfer to 2 ($1) 0) and further transfer to host computer 3 via interface 5 (1) 1)). In other words, the host computer 3 is not involved in error correction, and the system operates without interruption.

In the above embodiment, the data in one sector (760 bytes) was distributed and recorded in byte units on eight optical disk drives, but it is also possible to record each sector on a separate optical disk drive. .

Figure 1) is an explanatory diagram thereof. The data from the first sector to the eighth sector shown in [a] are arranged like (bl),
Create a first parity symbol and a second parity symbol. For example, if the error correction code to be used is GF (2"), the first byte of each sector is combined to create the first byte data of the parity symbol sector. Similarly, parity symbols are created for the next byte and subsequent bytes. .1st
Data from sector to 8th sector and data from 1st sector to 8th sector. A second parity symbol is recorded on the optical discs 1 to 10.

Now, is control device 2 an optical disk drive? ! 1). 12・
...Monitors whether or not the recording/playback operations of 20 are being performed normally. As a method of this monitoring, the control device 2
to check whether a normal response signal is returned from the optical disk drive to the optical disk drive;
12. ... Checking the status signal indicating 20 defects, counting the number of sectors with reproduction defects, and checking whether it exceeds a predetermined standard.

If it is detected that the optical disk drive has become defective in this way, data may not be recorded on the optical disk loaded in the optical disk drive, or incorrect data may be recorded. . In the system of the present invention, even in such a case, the recording operation is not stopped and continues as it is.

In this case, while other optical discs will be correctly recorded, in the worst case, no recording will be performed on the optical disc of the defective optical disc drive. In other words, part of the data that should be recorded is lost.

Under such conditions, information regarding the disappearance of recorded data is stored. Specifically, this erasure information is a history of accesses related to recording at the time of failure, and includes the address of an accessed sector and the address of an accessed track. According to the former method, the part related to the data loss itself is recorded, so data restoration by error correction described below can be efficiently performed, but the storage capacity becomes large due to the storage of lost information. According to the latter method, extra time is required to reproduce the data by searching for the sector related to the data loss in the corresponding trunk, but the capacity for storing the loss information can be small.

An even simpler method is to place a pointer on the accessed track. According to this, the capacity for storing lost information is minimal, and the time required for data restoration is almost the same as when storing track addresses. Additionally, in systems with multiple sets of optical discs, it is also necessary to store information identifying the cent containing the optical disc involved in the data loss.

The above-mentioned disappearance information may be recorded on an optical disc or stored in the control device 2. When recording on an optical disc, like the original recorded data, it is recorded across multiple optical discs, and the check data is also recorded on a specific optical disc. The information may be recorded on an optical disk loaded in any normally operating optical disk drive device.

In this way, even if some of the optical disk drive devices are defective, other optical disk drive devices continue to record on the optical disk, and the above-mentioned lost information is stored.

On the other hand, some defective optical disks are removed from the system.
Or repairs are carried out in the same condition. Through such repair or when the cause of the failure disappears by itself, the optical disk drive device is restored to a healthy state.

Therefore, during recovery, the free time for recording and playback is used to
According to the procedure shown in the flowchart in the figure, the data that should have been recorded on the optical disc loaded in the defective optical disc drive is restored by error correction and recorded on the optical disc. In this correction, the sectors accessed when the optical disk drive failed are reproduced for all disks based on the above-mentioned erasure information (1), 2). If the sector address is stored, it can be played back immediately; if the track address is stored, it is necessary to play back all sectors of the trunk to extract the data of the required sector. If only the access track pointer is stored, all sectors of all the trunks where the pointers are located are reproduced to extract the data of the required sectors.

The error correction (1) 3) itself is performed by the process shown in FIG. 10, and all corrected data in RAMII is recorded in the corresponding sector of the optical disk (#4).

In this case, it goes without saying that the same process can be applied to the optical disk in which the disappearance occurs even if the disappearance occurs in phase 1 to phase 2 of the optical disk on which the test symbol is recorded.

In this way, each time data is restored or recorded, the related lost information is erased (15).

Next, during playback, even if there is an accidental defect in the playback data from one of the optical disks, the error is corrected by the process shown in FIG. send.

On the other hand, if one of the optical disk drives malfunctions and the above-mentioned accidental defective playback data is obtained from the optical disk loaded in the other optical disk drive, this embodiment Since the system has a Hamming distance of 3, error correction is possible if the number of the optical disk loaded in the defective optical disk drive is obtained as erasure information. This is a normal optical disk drive 1), 12. ... reports to the control device 2 that a playback defective sector has occurred, and the control device 2 stores the erasure information based on this report, accesses the sector again, and retrieves the playback data and the defective optical disk drive. This can be done using disappearance information (in this case, it is necessary to store information that specifies the optical disc). Here, the erasure information becomes erasure information.

It goes without saying that the present invention can also be applied to a system in which the Hamming distance is greater than 3, in other words, a system in which the number of optical disks for recording test symbols tt is greater than the two in the embodiment.

〔Effect of the invention〕

As described above, according to the present invention, even if a defect occurs in the optical disk drive device, system operation can be performed without any problems and without interruption, and data can be restored and recorded later with extremely high reliability. A system with high performance can be realized.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of the system of the present invention, Fig. 2 is an explanatory diagram of the optical disc format, Fig. 3 is an explanatory diagram of check data, Fig. 4 is a block diagram showing the control device, and Fig. 5.8.
6 is a conceptual diagram showing an example of a recording method in the system of the present invention, FIG. 6 is a flowchart showing the procedure during recording, FIG. 7 is a memory map of RAM1 to RAM10, and FIG. 9 is error detection in reproduced data. An explanatory diagram of correction, Figure 10 is a flowchart showing the procedure during playback, Figure 1) is an explanatory diagram showing another recording method, and Figure 12 is an explanatory diagram showing another recording method.
The figure is a flowchart showing processing procedures related to data restoration and recording in the system of the present invention. 1). 12...Optical disc drive device 2...
Control device 3...Host computer 4...Optical disk In the drawings, the same reference numerals indicate the same or corresponding parts. Agent Oiwa Masu Yuan 1 Diagram 2 Diagram 7 Quality Thieves Bandit Army 2 Baritish Shishibor (a) Strategy 5 Mu Lum (b) Zumetsu Bandit Thief Bandit 2 Barite 4 Shishibor (a) Funeral 8 L L 4
(b) Zuwara 9 Figure (a) Ho 1) Zuyan 12 Figure

Claims (1)

[Claims] (1) In an optical recording system comprising a plurality of optical disk drive devices each loaded with an optical disk, and a control device that controls recording and playback on the optical disks, means for distributing data recording across the plurality of optical disks, and A means for creating a test symbol of an error correction code for data to be recorded on an optical disc, a means for recording the test symbol on a specific optical disc, and a method for erasing data to be recorded when an optical disc drive device becomes defective. 1. An optical recording system comprising: means for storing information.