JP3332099B2 - Disk unit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk device for recording and reproducing information from a disk-shaped information recording medium (disk).

[0002]

2. Description of the Related Art Disk devices are used as storage devices for various computers and document file devices. In the disk, a track to be recorded is predetermined, and the track is divided into a plurality of sectors, and a sector number corresponding to each sector is recorded in advance. Recording position information for specifying in which sector of the disk the recorded information is recorded is required. The recording position information is recorded in a management area on the disc. In the management area, in addition to the position information, the attributes of the recorded information, the usage status of the disc, and the like are recorded. In recording information, the information is recorded, and the position information where the information is recorded is recorded in the management area. Based on the management information, a sector position where desired information is recorded is specified and the information is reproduced. An example in which an optical disk device is used as a disk device will be described below. Now, it is assumed that the optical disk is composed of five tracks and four sectors. The storage capacity per sector is 4 bytes. It is assumed that physical sectors 1 to 20 are allocated to all these sectors in ascending order. That is, the physical sector is (track number-1) * 1
It can be expressed by the number of sectors per track + sector number. For example, the sector having the track number 1 and the sector number 1 is the physical sector 1, and the physical sector of the sector having the track number 3 and the sector number 4 is 12. FIG. 8 is a management table showing a file name of information to be recorded and a first physical sector in which the information is recorded. The first sector number (entry sector) in which the file name and its information are recorded is represented by one byte. This management table is recorded in physical sectors 1 and 2. Next, FIG. 9 is a management table for managing recorded sectors and non-recorded sectors, and corresponds one-to-one with physical sectors on the optical disk. If the information continues to record another physical sector, and if there is no subsequent physical sector number at the position of the table corresponding to the recorded physical sector, an end-of-file symbol is written. This management table is recorded in physical sectors 3 to 7. Therefore, the management area is the physical sector 1 in which FIGS. 8 and 9 are recorded.
~ 7.

Next, management of recorded information using FIGS. 8 and 9 will be described. Information A includes physical sectors 8, 9, 13,
It is assumed that the data is divided into 17 and recorded. First, information A is
From the table in FIG. 8, the first physical sector in which information A is recorded is 8
It turns out that it is. Next, it can be seen from the correspondence to the physical sector 8 in FIG. 9 that the information A is still written in the physical sector 9. Subsequently, looking at the next recording sector number corresponding to the physical sector 9, it can be seen that the information A is continuously written in the physical sector 13. Subsequently, looking at the next recording sector number corresponding to the physical sector 13, the information A continues to be the physical sector 1
7 is written. Next, when looking at the next recording sector number corresponding to the physical sector 17, it is found that the information A is not written in the other physical sectors because the end of file symbol is written. Therefore, information A is obtained from the management tables shown in FIGS.
Are obtained in the physical sectors 8, 9, 13, and 17. In recording information, the file name and physical sector of the recorded information are written in the management tables of FIGS. 8 and 9 according to the rules.

FIG. 10 shows a processing procedure of the optical disk apparatus when reproducing the information A. In order to reproduce information recorded on an optical disk, an access operation for moving an optical head over a sector to be reproduced is required. First, physical sector 1 is accessed to obtain physical sector number 8 in which information A is recorded (ST71). Next, physical sector 8
To reproduce the contents of the information A (ST72). Subsequently, the physical sector 4 is accessed to obtain a physical sector number 9 to be reproduced next (ST73). Next, the physical sector 9 is accessed to read the content of the next information A (ST74). Subsequently, the physical sector 5 is accessed and the physical sector number 13 to be reproduced next is obtained (ST75). Next, the physical sector 13 is accessed to read the contents of the next information A (ST76). Subsequently, the physical sector 6 is accessed to obtain the physical sector number 17 to be reproduced next (ST77). Next, the physical sector 17 is accessed to read the contents of the remaining information A (ST78). Subsequently, the physical sector 17 is accessed to obtain an end-of-file symbol,
The reproduction of the information A ends (ST79). As described above, the information A is reproduced while repeatedly accessing the sector in the management area and the sector in which the information A is recorded.

[0005] Here, since the number of accesses is nine, the reproduction time of the information A occupies a lot of access time.
For example, the optical disc rotates 3000 revolutions per minute, and the average seek time (time for moving the optical head to the target track) is 30
msec, the average access time is the average seek time + ／ rotation time = 40 ms, and the capacity of information A is 4 sectors. Therefore, the net time for reproducing information A from the optical disk is the reproduction time for each sector. 5msec so 20
msec. Therefore, the time required to reproduce the information A is the access time 40 msec * 9 = 360 msec.
Sum 380 of net time 20msec to read information A
msec. The ratio of access time is as high as 95%. Therefore, the time required for reproducing the information is long.

Further, when a disk device is connected to an unspecified host computer, a disk operation system for performing disk recording management and the like by the host computer differs, and an area where the management information is recorded may be different. However, the disk device can copy only predetermined management information of a specific disk operation system to the semiconductor memory in the disk device. Further, the disk device cannot determine the area where the management information is recorded because it cannot determine the difference between the disk operation systems. As a result, the management information cannot be copied to the semiconductor memory in the disk device.

At this time, in the method of storing the management information in the memory, each time the disk operation system uses a different disk, an operator (user) specifies an area in which the management information is recorded, and the semiconductor memory in the disk device is used. Must be instructed to copy this management information to the disk device. However, such operations are complicated because they cannot be performed automatically. By the way, the disk device
It is used as a large-capacity storage device such as various computers and image file devices. Recently, a disk device capable of recording and reproducing information such as a digital moving image with a large capacity and a high data transfer speed has been desired. For example, in an optical disc device,
An optical disk drive 8 having two optical heads 81 and 83 as shown in FIG.
Nine are considered. On the optical disc, a track to be recorded is predetermined, and this track is divided into a plurality of sectors. Tracks and sectors of the same number on the upper surface and the lower surface of the optical disk are arranged facing each other at the same radial position so that recording and reproduction can be performed simultaneously. Furthermore, when a spiral track is used, the spiral direction of the optical disk differs between the upper surface and the lower surface so that the two optical heads 81 and 83 move in the same radial direction by the rotation of the optical disk 82. Since recording and reproduction are performed simultaneously on both sides of the optical disk, the information transfer speed is twice as fast as that of an optical disk device having one optical head. Each sector of the optical disk includes a corresponding track number, an area in which the sector number is recorded in advance, a data area for recording information, and an error correction area. The error rate of the optical disk is 10 ⁻⁵ to 10 ⁻⁶ , which is larger than the error rate (10 ⁻¹¹ to 10 ⁻¹² ) required for the information storage device. Therefore, the required error rate is satisfied using the error correction code. FIG. 19 is a diagram showing a configuration of a general optical disk device. At the time of recording information, information is fetched from an external device such as a computer via a data input / output unit 91, an error correction code is added by an error correction processor 92, and a modem 93
Modulates the digital data (information, error correction code) into an electric signal, converts the electric signal into light by the optical head 94, and writes it on the optical disk 95. When reproducing information, the optical disk 95
The information recorded above is read by an optical pickup 94 and converted into an electric signal, and the modem 93 outputs digital data (information,
The error is demodulated to an error correction code, and an error is detected by an error correction processor 92. If there is an error, the error is corrected. Subsequently, the reproduced information is output from the data input / output device 91 to an external device such as a computer. The optical disk must be separated from the protective layer where dirt and scratches are attached and the information recording surface, and data must be recorded with interleaved (rearranged) data to disperse continuous errors (burst errors). Smaller scratches, dirt, and stains are less affected. Therefore, in normal recording and reproduction, there is no problem in the recording and reproduction method using the error correction code. However, frequent recording and reproduction of the same sector, deterioration of the recording medium due to long-term storage, large optical disk stains, large scratches, etc. may cause errors exceeding the capability of the error correction code during reproduction, resulting in incorrect information. It may not play. Usually, a method of an alternative sector is used in which a sector in which the number of errors is increased within a range not exceeding the capability of the correction code is stopped, a sector in an alternative area is allocated, and information is transferred. The alternative area is often located on a track separated from the information recording area, and when information is reproduced, the number of times of access (the number of times the optical head moves to the target track or sector) increases and it takes a long time to reproduce. For example, it is assumed that the information A is recorded in the sectors 1 to 4 of the track 1 and the replacement area is on the track 10. When reproducing the information A, first, the optical head of the optical disk device is moved on the track 1 and the information A is reproduced by reading the information recorded in the sectors 1 to 4. Therefore, the number of accesses when the replacement sector is not required is one. Then track 1
It is assumed that the sector 3 has an increased number of errors due to dirt or scratches on the optical disk and an alternative sector is assigned, and the information of the sector 3 has moved to the sector 1 of the track 10 in the alternative area. When reproducing the information A, first, the optical head of the optical disk device is moved on the track 1 and the information recorded in the sectors 1 and 2 is read. Next, the optical head is moved onto the track 10 in the substitute area, and the information recorded in the sector 1 is read. Subsequently, the optical head is moved onto the track 1 and the information recorded in the sector 4 is read. The information A is reproduced by the above operation. Therefore, the number of accesses is three, and the time for reproducing the information A increases. Therefore, as the number of replacements of information in the replacement sector increases, the time for recording and reproducing information increases. Therefore, in the optical disc apparatus 89 for simultaneously recording and reproducing the same numbered tracks on both sides of two optical head optical discs, when a replacement occurs on either side of the optical disc, an access is made to the replacement area, and information cannot be reproduced simultaneously on both sides. The result information cannot be continuously reproduced, and the information transfer speed decreases.
Therefore, when a moving image is recorded as information, the image is interrupted during reproduction. For example, when reproducing information without substitution, two optical heads can simultaneously reproduce tracks of the same number on both sides of an optical disk. Next, when the information on the upper surface of the optical disk is replaced, the information on the lower surface of the optical disk where no replacement occurs is reproduced. Subsequently, an access is made to the substitute area on the upper surface of the optical disk, and the substituted information is reproduced. Therefore, information recorded on both sides of the optical disk cannot be reproduced simultaneously. For this reason, the information transfer speed is 1 /
2 or less. That is, when there is a substitute, the information reproduction time when there is no substitute and the access time to the substitute area,
The reproduction time of the substituted information is required for reproducing the information.

[0008]

As described above, in a disk device provided with two or more recording / reproducing heads and simultaneously recording / reproducing on tracks of the same number on both surfaces of the disk, if a conventional disk device is used, deterioration of the recording medium will occur. If replacement by a substitute sector occurs due to contamination of the disk, an access occurs at the time of reproduction, so that there is a problem that it cannot be reproduced simultaneously with other information on the disk surface where no substitution occurs. As a result, the information transfer speed is greatly reduced. Therefore, an object of the present invention is to reproduce information at the same time as a disk surface on which no other replacement occurs even if replacement by a replacement sector occurs due to deterioration of a recording medium or contamination of the disk.

Further, since the recording area of the management information in which the recording position information, the use status of the disk and the like are recorded differs depending on the disk operation system of the computer used, the management information is stored in a storage means (for example, a semiconductor memory) in the disk device. ) Cannot be copied. For this reason, it is troublesome for the user to specify the area where the management information is recorded every time the disk operation system uses a different disk, and to issue an instruction to the disk device to copy the management information to the memory in the disk device. There was a problem.

According to the present invention, in reproducing information from a disk, the number of accesses to the disk for reproducing management information can be reduced, and the speed of information reproduction can be increased.
It is another object of the present invention to provide a disk device that allows a user to start a disk operation at high speed.

[0011]

SUMMARY OF THE INVENTION According to the present invention, it is possible to use a disk using an error correction code for recording and reproducing information, and to simultaneously perform recording and reproduction on both sides of the disk using a plurality of recording and reproducing heads. In the disk device, an alternate area is provided for each track having the same track number on both sides of the disk, a sector having an increased error is detected using the error correction code, and information of this sector is included in a track including the sector, or Means for substituting a substitute area of a track having the same track number on a surface different from the surface including the track, and when reproducing information, recording information reproduced from the disc in a track buffer for each track,
Means for outputting the information from the track buffer in accordance with the order of the sectors before replacing the information when there is the replaced information.

[0012]

[0013]

[0014]

According to the present invention, since the replacement area is located on the track having the same track number as the track on which the information to be replaced is recorded, even if the replacement occurs, no access occurs.
Since the information read from the track buffer is output according to the order of the sectors before the replacement, even if the replacement occurs, the information can be continuously reproduced without lowering the information transfer speed.

[0015]

【Example】

(First Embodiment) FIG. 1 is a diagram showing a configuration in which the disk device of the present invention is applied to an optical disk device. A host computer 11 via an interface 12
Send recording data from The recording data is modulated into an electric signal by the modulator / demodulator 14, the electric signal is converted into light by the optical head 15, and is recorded on the optical disk 16. At the time of reproducing the information, the information recorded on the optical disk 16 is read by the optical head 15 and converted into an electric signal, and the modem 14 demodulates the data into data.
The demodulated data is sent to the host computer 11 via the interface 12.

The memory 13 is a memory for recording management information such as recording position information and disk use status described in the conventional example. The memory 13 has a two-dimensional array configuration corresponding to sectors of the optical disk. For example, as shown in FIG. 2, a two-dimensional array F (i, j) is configured on the memory 13 so that i corresponds to a physical sector number and j corresponds to each data in the sector. For example, the fourth data of the physical sector 4 can be represented by F (4,4), and in the table of FIG. 2, it can be seen that the numeral 9 is stored at a location corresponding to F (4,4). . The management information recorded on the optical disk has seven sectors in total, based on the management tables shown in FIGS. 8 and 9, so that a storage capacity of seven sectors * 4 bytes = 28 bytes is sufficient. First, the management tables in FIGS. 8 and 9 are reproduced from the optical disk and stored in the memory 13. Next, the sector number where the information is recorded is searched from the management table in the memory, and the information recorded in the corresponding sector is reproduced. In recording information, the information is recorded on an optical disk, and the position information of the sector corresponding to the management table in the memory is stored. Subsequently, the same contents are written in the management areas (physical sectors 1 to 7) on the optical disk. This is to maintain consistency between the management area on the optical disc and the newly recorded information.

FIG. 3 shows a processing procedure of the optical disk apparatus when reproducing the information A. It is assumed that the sector position where the information A is recorded is the same physical sector 8, 9, 13, 17 as the conventional example for comparison. FIG. 8, which is recorded on the optical disk when the optical disk is mounted on the optical disk device,
It is assumed that the management information of the management table No. 9 is reproduced and stored in the memory 13 as shown in FIG.

In order to reproduce information recorded on an optical disk, an access operation for moving an optical head to a sector to be reproduced is required. First, data F (1,1) and F (1,2) in the array corresponding to physical sector 1 on the memory are read, and a physical sector number 8 in which information A is recorded is obtained (ST31). Next, the physical sector 8 is accessed to reproduce the contents of the information A (ST32). Subsequently, the data F (4, 4) in the array corresponding to the physical sector 4 on the memory is read, and the physical sector number 9 to be reproduced next is obtained (ST33). Next, the physical sector 9 is accessed to read the next content of the information A (ST34). Subsequently, the data F (5, 1) in the array corresponding to the physical sector 5 on the memory is read, and the physical sector number 13 to be reproduced next is obtained (ST35). Next, the physical sector 13 is accessed to read the next content of the information A (ST
36). Subsequently, the data F (6, 1) in the array corresponding to the physical sector 6 on the memory is read, and the physical sector number 17 to be reproduced next is obtained (ST37). Next, the physical sector 17 is accessed to read the contents of the next information A (ST38).
Subsequently, the data F (7, 1) in the array corresponding to the physical sector 6 on the memory is read out to obtain a file end symbol, and the reproduction ends (ST39). As described above, the information A is reproduced by repeating the reading of the management information stored in the memory and the access of the sector in which the information A is recorded.

Since the number of accesses to the optical disc is different from that of the conventional example, only the sector in which the information A is actually recorded is 4 times.
Only once. Therefore, assuming that the optical disc rotates 3000 revolutions per minute and the average seek time (time for moving the optical head to the target track) is 30 msec, the average access time is the average seek time + ／ rotation time = 40 ms, and the capacity of the information A is Since the number of sectors is 4, the net time for reproducing the information A from the optical disk is 5 m for each sector.
sec, it is 20 msec. Therefore, the time required to reproduce the information A is the access time of 40 msec * 4.
= 160 msec, net time to read information A 20 m
sec is 180 msec. Also, the access time to the management table of the semiconductor memory is less than μsec and is 10,000 times or more faster than the access time of the optical disk, so that the time required for reproducing the information A has almost no effect.

Since access to the management area on the optical disk is eliminated as compared with the embodiment described above, 380
The time required for reproducing information A from ms to 180 ms has been greatly reduced.

When the management of the recording information is performed by the optical disk device itself, or when a specific fixed host computer is connected to the optical disk device, the sector position where the management information is recorded is specified in advance. As shown in the example, it is more efficient to read the management information from the optical disk and store it in the memory when the optical disk device is used. However, when the present optical disc apparatus is mounted on an unspecified host computer, a disc operation system for performing recording management and the like of the optical disc differs depending on the host computer, and a management method and an area where management information is recorded may be different. In this case, if the sector position where the management information is recorded is designated by the host computer and read from the optical disc and recorded in the memory, then the management information can be read not from the optical disc but from the memory. Therefore, it is possible to reduce the information reproduction time according to the present invention. By instructing the present optical disc apparatus to copy the management information from the optical disc to the semiconductor memory from the host computer, the present invention can be applied to a host computer having a different management method and management information (different disc operation system). (Second Embodiment) FIG. 4 is a diagram showing a configuration in which the disk device of the present invention is applied to an optical disk device. The host computer 21 via the interface 22
Send recording data from The recording data is modulated into an electric signal by a modulator / demodulator 24, the electric signal is converted into light by an optical head 25, and is recorded on an optical disk 26. At the time of reproducing the information, the information recorded on the optical disk 26 is read by the optical head 25 and converted into an electric signal, and the modem 24 demodulates the data into data.
The demodulated data is sent to the host computer 21 via the interface 22. The memory 23 is a memory for recording management information such as recording position information and disk use status described in the conventional example. The memory 27
This is a memory for recording disk format information such as the start position of management information and the type of management information that differs for each disk operation system. Note that the memory 27 can also be used as the memory 23.

Now, consider three types of disk operation systems A, B, and C. FIG. 5 shows an example of the configuration of the disk operation system management information. The management information of the disk operation system A includes physical sectors 0 to
20 is recorded. Physical sector 0 has an identification code AOS indicating that it is a disk operation system A.
And 1 and 20 indicating the physical sector range in which the management table is recorded as the recording area information of the management information are recorded. The management information of the disk operation system B is recorded in physical sectors 50 to 70. In the physical sector 50, an identification symbol BOS indicating that the disk operation system is B, and 51 and 70 indicating a physical sector range in which a management table is recorded as management information recording area information are recorded. Similarly, the management information of the disk operation system C is recorded in the physical sectors 100 to 110. In the physical sector 100, an identification code COS indicating that the disk operation system is C, and 101 and 110 indicating a physical sector range in which a management table is recorded as management information recording area information are recorded. The disk format information shown in FIG. 6 is registered in the memory 27 in the optical disk device in advance. This disk format information represents the start physical sector number of the management information of each disk operation system, and is 0 in the disk operation system A, 50 in the disk operation system B, and 100 in the disk operation system C.

Next, a recording area in which the management information is written is specified from the disk format information and the recording area information of the management information recorded on the disk, and the management information is read out and copied to a semiconductor memory in the disk device. FIG.

First, it is known from the disk format information that the start physical sector number of the management information of the disk operation system A is 0 sector.
Is reproduced from the optical disk (ST11). Subsequently, it is determined whether the identification symbol of the reproduced information of the physical sector 0 is AOS (ST12). If the identification symbol is not AOS, it is known from the disk format information that the start physical sector number of the management information of the disk operation system B is 50 sectors, so the information of the physical sector 50 is reproduced from the optical disk (ST13). Subsequently, it is determined whether the identification symbol of the reproduced information of the physical sector 50 is BOS (ST14). If the identification symbol is not BOS, the starting physical sector number of the management information of the disk operation system C is 1 based on the disk format information.
Since it is determined that the sector is 00, information of the physical sector 100 is reproduced from the optical disk (ST15). Subsequently, it is determined whether or not the identification symbol of the reproduced information of the physical sector 100 is COS (ST16). After determining the type of the disk operation system in this way, the recording area information of the management information following the identification code is read (ST1).
7). Since the physical sector range where the management information is written can be determined from the recording area information of the management information, the management information of the optical disk is copied to the memory 23 in the disk device according to the range (ST18).

For example, the procedure for using a disk on which management information has been written by the disk operation system B in the present optical disk apparatus is as follows. First, start physical sector 0 of management information of disk operation system A
Is reproduced from the optical disk (ST11). Subsequently, it is determined whether the identification symbol of the reproduced information of the physical sector 0 is AOS (ST12). Since it is not AOS, the information of the start physical sector 50 of the management information of the disk operation system B is reproduced from the optical disk (ST13). Subsequently, the identification symbol of the information of the reproduced physical sector 50 is BOS.
Is determined (ST14). Since it is a BOS, the management recording area information following the identification symbol is read (ST1).
7). From FIG. 5, it can be seen that 51 and 70 indicating the physical sector range in which the management table is recorded are recorded in the management recording area information, and accordingly, the management information is reproduced from the optical disk and stored in the memory 23 in the disk device. Copy (S
T18). It is clear that the disc operation systems A and C can copy the management information of the optical disc to the memory 23 in the disc device according to the procedure of FIG.

As described above, even if a disk having a different disk operation system and a different area in which management information is recorded is used, the present disk apparatus can store the disk format information registered in the disk apparatus and the disk without discarding the operator's hand. Judge the type of disc operation system from the recording area information of the recorded management information,
The recording area in which the management information is written can be specified, and this management information can be read out and copied to the semiconductor memory in the disk device. Therefore, it is possible to apply a management information cache that significantly reduces the information reproduction time.

In this embodiment, for the sake of simplicity, an identification symbol and a management table are recorded in each disk operation system in which only the start physical sector number of the management information of each disk operation system is used as disk format information. If the physical sector range information is written at a different position, the present invention can be applied by adding the position information to the disk format information. When using a disk operation system other than the disk operation system registered in the disk format information, the host computer connected to the optical disk apparatus adds and stores the disk format information of the disk operation system in the memory 27. Copying of the management information of the present invention to a semiconductor memory in a disk device can be applied.

[0028]

[0029]

(Third Embodiment) The disk device of this embodiment uses a disk that uses an error correction code for recording and reproducing information, and uses a plurality of recording and reproducing heads to simultaneously record and reproduce data on both sides of the disk. In a disk device capable of performing the above, an alternative area is provided for each track having the same track number on both sides of the disk, a sector having an increased error is detected using the error correction code, and information of this sector is written to the sector. Means for substituting a track included in the track, or a substitute area of a track having the same track number on a surface different from the surface including the track, and information reproduced from the disc when reproducing information is stored in a track buffer for each track. Recording the information and, if there is the replaced information, outputting the information from the track buffer in accordance with the order of the sectors before replacing the information. It is characterized in that it has and. More specifically, in a disk device that uses a disk that uses an error correction code for recording and reproducing information and that simultaneously records and reproduces information on both sides of the disk using two or more recording and reproducing heads, Means for providing an alternate area for each track, for each track on one of the surfaces, or for a track having the same track number, and for detecting a sector with an increased error using an error correction code. Means for replacing the information of the sector having the increased error with a replacement area of a track having the same track number on the same surface or a different surface, information replacing the replacement area with an identification symbol and a sector of the replacement disk surface Number recording means, and information obtained by recording reproduced information in a track buffer of one track capacity or more for each track. Constituted by the means for outputting the information in the order of the previous sector to replace.

In this embodiment, a disk using an error correction code for recording and reproducing information is used, and a disk device for simultaneously recording and reproducing information on the same number of tracks on both sides of the disk using two or more recording and reproducing heads. For each track on both sides of this disc, or for each track on one side, or for each track with the same track number, an alternate area is provided in a track on one side, and an error correction code is used to increase the error. The sector described above is detected, and the information of this sector is replaced with a replacement area of a track having the same track number on the same surface or a different surface. Since the replacement area is on the track having the same track number as the track on which the information to be replaced is recorded, no access occurs even if the replacement occurs. The information read from the track buffer is output according to the order of the sectors before replacement. Thus, even if substitution occurs, the information transfer speed can be continuously reproduced without decreasing the information transfer speed.

Hereinafter, an example in which the present embodiment is applied to an optical disk device will be described in detail. FIG. 11 is a diagram illustrating an example of the configuration of the optical disc device according to the present embodiment. Two optical heads 11 facing both sides of the optical disc 112
Tracks with the same track number are recorded and reproduced simultaneously on both sides. Inside the optical disk drive 12
In the optical disk 112 of No. 0, tracks and sectors of the same number on the upper surface (A surface) and the lower surface (B surface) of the optical disk are arranged facing each other at the same radius so that recording and reproduction can be performed simultaneously. Further, when a spiral track is used, two optical heads 111 and 113 are rotated by rotation of the optical disk 112.
Are moved in the same radial direction, and the spiral direction of the optical disk is different between the upper surface and the lower surface. Also, the optical disk 11
2 is composed of three tracks and four sectors as shown in FIG. Information is recorded in sectors 1 to 3. Sector 4
Is an alternative area. The track buffer 114 corresponds to FIG.
As shown by 3, it is composed of 8 data * 2 rows and can hold information of 2 tracks. Data 1 to 4 hold information corresponding to sectors 1 to 4 on the optical disk A surface, and data 5 to 8 hold information corresponding to sectors 1 to 4 on the optical disk B surface.

In order to show that the information can be continuously reproduced without lowering the information transfer speed even when the replacement which is the object of the present embodiment occurs, the description will be given below by taking the recording and reproduction of moving image information as an example. In recording the moving image information, the moving image information is sent from the host computer 119 to the optical disk device via the interface 118. The moving picture information is divided into two parts by the track buffer 117 and is simultaneously recorded on the same numbered tracks on the A and B sides of the optical disk 112 in the optical disk device 120. For example, the moving image information of frame 1 is divided into A1 and B1 and recorded on the optical disk A and B surfaces as shown in FIG. Similarly, frame 2,
3. . . The image information of the nine frames is (A2,
B2), (A3, B3). . . (A9, B9) are recorded on the optical disk A and B surfaces. In reproducing moving image information, moving image information divided and recorded on both surfaces of the optical disk is simultaneously read out by using two optical heads 111 and 113 and held in a track buffer 117 in track units. The track buffer 11 under the control of the controller 116
The moving image information obtained by synchronizing the moving image information of No. 7 is restored. For example, the moving image information A1 and B1 simultaneously reproduced from the optical discs A and B shown in FIG. 12 are stored in the track buffer 17 in track units as shown in FIG. After that, data 1 and data 5 in the first row of the track buffer in FIG. 14 are simultaneously read out and combined as moving picture information of frame 1, and then the moving picture information is sent to the host computer 19 via the interface 18. Similarly, moving image information (A2, B2) reproduced from the optical disk A surface and the optical disk B surface,
(A3, B3). . . (A9, B9) are stored in the track buffer 17 in track units,
3. . . 9 are combined as image information. When there is no substitute, the reproduction of the moving image information is performed in this way.

Next, the reproduction when the substitution occurs will be described.
As shown in FIG. 14, an error exceeding the capability of the error correction code occurs in track 1 and sector 2 on the optical disk A surface, and as a result, moving image information of A2 is recorded in a substitute area of track 1 and sector 4. In this alternative area, the replaced moving image information A2 and the replaced sector number for specifying the replaced sector are recorded. In the reproduction, the moving image information reproduced from the optical discs A and B at the same time is recorded in the track buffer in track units as shown in FIG. The moving image information A1 and B1 of the frame 1 are reproduced from the data 1 and the data 5 in the first row of the track buffer in FIG. The image information A2 of the frame 2 is not the data 2 in the first line of the track buffer but the data 4
Is held in. Therefore, image information A2 of frame 2,
B2 is reproduced from data 4 and data 6 in the first row of the track buffer in FIG. Since the replacement sector and the replacement area are on the same track, there is no need to perform an access (moving the optical head to a target track) operation.
Therefore, the substitute processing is not affected by the access time at all. Also, the moving picture information A2 substituted by changing the reading order of the track buffer in FIG. 15 and the moving picture information B2 not substituted are synchronized to reproduce the moving picture information of the frame 2. That is, by outputting the replaced information in the order of the sectors before the replacement, the moving image information A2 and the moving image information B2 are synchronized, and the moving image information can be correctly reproduced. Even if no access is made and the replaced information is output in accordance with the order of the sectors before the replacement, the replacement can be performed, so that the moving image can be reproduced without interruption in the reproduction. Therefore, even if substitution occurs, information can be continuously reproduced without lowering the transfer speed of information.

Next, reproduction when two sectors are replaced on the same track will be described. As shown in FIG. 16, when an error exceeding the capacity of the error correction code occurs in the sector 2 and the sector 3 of the track 1 on the optical disk A, the information A2 of the sector 2
Is an alternative area of sector 4, and sector 3 is optical disc B
The data is recorded in the track 1 on the surface and in the alternative area of the sector 4. That is, the information is replaced with the replacement area of the same numbered track on a different surface. In this replacement area, information on the occurrence of the replacement, an identification symbol of the replaced optical disk surface and a sector number for identifying the replaced optical disk surface and sector are recorded.

In the reproduction, the moving picture information simultaneously reproduced from the optical discs A and B is held in a track buffer in track units as shown in FIG. The moving image information A1 and B1 of the frame 1 are reproduced from the data 1 and the data 5 in the first row of the track buffer in FIG. The moving image information A2 of the frame 2 is held in the data 4 instead of the data 2 in the first row of the track buffer because the replacement has occurred. Therefore, the moving image information A2 and B2 of the frame 2 are reproduced from the data 4 and the data 6 in the first row of the track buffer in FIG. Next, the moving image information A3 of the frame 3 is held in the data 8 instead of the data 3 in the first line of the track buffer because the replacement has occurred. Therefore, information A of frame 3
3 and B3 are reproduced from data 8 and data 7 in the first line of the track buffer in FIG. Access is not performed because the replacement sector and the replacement area are on the same track. Therefore, the substitute processing is not affected by the access time at all. Also, the moving picture information A3 substituted by changing the reading order of the track buffer in FIG. 17 and the moving picture information B3 not substituted are synchronized to reproduce the moving picture information of the frame 3. In other words, by using the track buffer, even if the replacement area is on another surface, the replacement information can be reproduced according to the order of the sectors before the replacement, and as a result, the moving image information can be correctly reproduced. Even if the access is not performed and the replacement occurs by outputting the replaced information in the order of the sector before the replacement,
A moving image can be reproduced without a break in the reproduction.

Accordingly, the present optical disk device and the computer
It is possible to realize a moving image recording / reproducing system using an image input / output device or the like. Also, in an information processing system using the present optical disk device and a computer, it is apparent that the information processing speed using the optical disk is improved because a high information transfer speed can be maintained by simultaneous double-sided reproduction using two or more optical heads. is there. Further, it can be easily analogized that the present invention can be applied to a stack type optical disk apparatus in which a plurality of optical disks are coaxially fixed and a plurality of optical heads can simultaneously record and reproduce data. In this embodiment,
Although the optical disk device has been described as an example, the present invention can be applied to a fixed magnetic disk device, a magnetic disk device having a removable disk, a floppy disk device, or the like.

As described above, according to this embodiment, a disk using an error correction code for recording and reproducing information is used.
In a disk device for simultaneously recording and reproducing information on both sides of the disk using two or more recording / reproducing heads, for each track on both sides of the disk, for each track on one of the surfaces, or for each track having the same track number On the other hand, an alternative area is provided in a track on one of the surfaces, an error correction code is used to detect a sector having an increased error, and the information of this sector is replaced with an alternative area having the same track number on the same surface or a different surface. Since the replacement area is located on the track having the same track number as the trick in which the information to be replaced is recorded, no access occurs even if the replacement occurs. The information read from the track buffer is output according to the order of the sectors before replacement. Thus, even if substitution occurs, the information transfer speed can be continuously reproduced without decreasing the information transfer speed. (Fourth Embodiment) An optical disk is a recording medium for recording and reproducing information by irradiating a light beam (generally a laser beam). The information is recorded, for example, as a pit row, and the reproduction detects the amount of reflected light and the degree of polarization. This is done optically. Optical disks include a read-only type, a write-once type, and a rewritable type. Optical discs form a thin film that becomes a recording / reflection film on the pit formation surface of a transparent substrate, and
Many have a structure in which a protective film made of a synthetic resin is formed on a reflective film.

In the conventional optical disc, when two optical discs are pasted together for the purpose of increasing the recording capacity, especially when simultaneous double-sided recording and reproduction are performed using two pickups, it is necessary to distinguish between the A side and the B side. Become. This is because, in the case of a spiral, the recording direction is clockwise or counterclockwise depending on each surface, so that if the spiral direction is wrong, recording and reproduction become impossible. However, the direction of the spiral cannot be distinguished by its appearance, whether clockwise or counterclockwise. In the bonding step, it is necessary that the external appearance can be easily determined and the alignment at the time of bonding is easy. This is because the relative position of the two pickups is usually kept constant in double-sided simultaneous recording / reproducing, so that it is desired that the recording / reproducing positions of the disc also have a constant interval.

The present embodiment has been made in consideration of the above points. In addition to the information recording, the discriminating marks corresponding to the side A and the side B are provided so that the appearance can be easily confirmed and the lamination can be performed. An object of the present invention is to provide an optical disc that can be easily aligned.

In order to solve the above-mentioned problem, the present invention provides a mark for discriminating the A-side and the B-side in an area other than the information recording area of the optical disk, one in which a mark synchronized with the sector is provided, and the other in the other. The disc is characterized by having a discrimination mark different from that of one of the discs and a portion that can be visually discriminated. In particular, by putting a discrimination mark on the outer periphery,
At the time of lamination, the lamination position can be easily checked,
Inspection after bonding is also easy.

The pits or groups recorded on the optical disk appear to the naked eye as interference fringes due to light interference. Therefore, the discrimination of the A side or the B side is performed on the optical disc,
By using a pit or a group, a discrimination mark synchronized with the sector is recorded on one side and a discrimination mark different from that of the other disc is recorded on each side, so that the disc can be easily distinguished from the appearance.

Hereinafter, this embodiment will be described with reference to the drawings. At the time of producing the optical disc master, after recording the format of the information recording area of the optical disc, a group signal for one sector was recorded from the outer periphery to the outermost periphery of the information recording area in synchronization with the sector. In this embodiment, in FIG. 20, the recording direction is synchronized with the sector when the recording direction is clockwise. This corresponds to the side A during simultaneous double-sided recording and reproduction. On the other hand, FIG. 21 corresponds to the surface B and the recording direction is shifted counterclockwise from the sector.

FIG. 20 shows a clockwise optical disc 201 recorded by the above-described method. A group synchronized with 0 sector is recorded on the outermost periphery other than the information recording area 203 to form a discrimination mark 2. FIG. 21 shows a counterclockwise optical disk 214 recorded by the above-described method, in which the discrimination mark 215 is formed by recording a group extending from both sectors to the outermost periphery except for the information recording area 216 by delaying 1/2 sector from 0 sector.

When the optical disks 201 and 214 are bonded, the relative positions are determined so that the two discrimination marks overlap as shown in FIG. It is easy to place a sensor on the outer periphery and automate it, and visual inspection after bonding is also easy.

Although a group signal is used in the above embodiment, a pit signal may be used. In the above-described embodiment, the discrimination mark portion is recorded. On the contrary, the discrimination mark may not be recorded but the discrimination mark portion may be recorded.

As described above, according to the optical disc of the present embodiment, the discrimination marks of the A side and the B side are recorded outside the information recording of the optical disc, so that the A side and the B side can be easily confirmed from the appearance. It is possible to provide an optical disk that can be easily positioned in the bonding step, can be visually checked, and can be prevented from being erroneously inserted at the time of assembling into a cartridge. Further, the optical disk of this embodiment can be applied to all the above-described embodiments.

[0048]

[0049]

According to the present invention, there is provided a disk apparatus capable of simultaneously recording and reproducing both sides of the disk by using a disk using an error correction code for recording and reproducing information and using a plurality of recording and reproducing heads. In the above, since the replacement area is located on the track having the same track number as the track on which the information to be replaced is recorded, no access occurs even when the replacement occurs, and the information read from the track buffer is replaced with the sector before the replacement. Since the output is performed in the order, even if the replacement occurs, the information can be continuously reproduced without reducing the information transfer speed.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of an optical disk device according to a first embodiment of the present invention.

FIG. 2 is a diagram showing an example of an array configuration of a memory for storing management information according to the first embodiment of the present invention.

FIG. 3 is an exemplary view showing a processing procedure of the optical disc apparatus when reproducing information A according to the first embodiment of the present invention.

FIG. 4 is a diagram showing a configuration of an optical disc device according to a second embodiment of the present invention.

FIG. 5 is an example of the configuration of various disk operation system management information according to a second embodiment of the present invention.

FIG. 6 shows an example of disc format information according to the second embodiment of the present invention.

FIG. 7 is a diagram showing a procedure for specifying a recording area in which management information is written according to a second embodiment of the present invention, reading out the management information, and copying the management information to a semiconductor memory in a disk device.

FIG. 8 is a management table showing a file name of information to be recorded and a first physical sector in which the information is recorded.

FIG. 9 is a management table for managing recorded sectors and non-recorded sectors.

FIG. 10 is a diagram showing a processing procedure of the optical disk device when reproducing information A used in the conventional example.

FIG. 11 shows an example of the configuration of an optical disk device according to a third embodiment of the present invention.

FIG. 12 is an example of information recorded on an optical disc device according to a third embodiment of the present invention.

FIG. 13 shows an example of the contents of a track buffer of the optical disk device according to the third embodiment of the present invention.

FIG. 14 shows an example of information when there is an alternative in the optical disc device according to the third embodiment of the present invention.

FIG. 15 shows an example of a track buffer when there is an alternative in the optical disc device according to the third embodiment of the present invention.

FIG. 16 shows an example of information when there is an alternative in the optical disc device according to the third embodiment of the present invention.

FIG. 17 shows an example of a track buffer when there is an alternative to the optical disc device according to the third embodiment of the present invention.

FIG. 18 is a diagram showing an example of the configuration of an optical disk device provided with two optical heads.

FIG. 19 is a diagram showing a configuration of a conventional optical disk device.

FIG. 20 is a plan view of an optical disc substrate corresponding to a surface A of an optical disc according to a fourth embodiment of the present invention.

FIG. 21 is a plan view of an optical disk substrate corresponding to a surface B of an optical disk according to a fourth embodiment of the present invention.

FIG. 22 is an exemplary perspective view of a discrimination mark side of an optical disc according to a fourth embodiment of the present invention;

[Explanation of symbols]

11 Host computer 12 Interface
DESCRIPTION OF SYMBOLS 13 ... Memory 14 ... Modulator / demodulator 15 ... Optical head 16
... Optical disk 23 ... Memory 27 ... Memory

────────────────────────────────────────────────── ─── Continuation of the front page Examiner Tatsutoshi Takenaka (56) References JP-A-4-195878 (JP, A) JP-A-2-187979 (JP, A) JP-A-58-51366 (JP, A) JP-A-1-70969 (JP, A) JP-A-1-4975 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G11B 27/00 G11B 7/00 G11B 7/007 G11B 20/12

Claims (1)

(57) [Claims] 1. A disk device capable of simultaneously recording and reproducing both sides of the disk using a disk using an error correction code for recording and reproducing information and using a plurality of recording and reproducing heads. An alternate area is provided for each track having the same track number, a sector having an increased error is detected by using the error correction code, and information of this sector is defined as a track including the sector or a surface including the track. Means for substituting a substitute area of a track having the same track number on a different surface, and information reproduced from the disc when information is reproduced is recorded in a track buffer for each track, and if there is the substituted information, Means for outputting the data from the track buffer in accordance with the order of the sectors before replacing the data.