JPH02162575A - Disk-shaped information recording medium - Google Patents

Abstract

PURPOSE:To improve use efficiency by positioning an alternative track in the central position of a block and executing a track access at a high speed to a distance between the alternative track and the both edges of the block. CONSTITUTION:Recording is executed to an arbitrary sector in an M-th block. When the sector is a defective sector, it is checked whether the alternative sector of the same track as the sector is used or not. Then, when it is already used, even in the case of the sector in any sides, the recording is jumped to a track AM and the track is accessed. When the arbitrary sector is reproduced, the purpose sector is accessed at first and when the sector is defective, the alternative sector in the same track is reproduced. When purpose data are not recorded to the alternative sector, the alternative track is accessed and alternative data are searched and reproduced.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a disc-shaped information recording medium, and in particular, a disc-shaped information recording medium in which one track is one or more sectors, and a disc-shaped information recording medium in which each track is divided into blocks. The present invention relates to a disc-shaped information recording medium having an alternative track for each block to replace a defective sector.

[Conventional technology]

Conventionally, in an information recording and reproducing apparatus that records and reproduces information on a sector-by-sector basis, information must be recorded in a designated sector and reproduced from that sector.

However, recording media with poor characteristics such as
In an information recording/reproducing apparatus using a recording medium such as an optical disk, defective sectors are likely to occur, and such sectors are identified by checking writing before or after recording. In methods such as those in which the user directly specifies the address of the sector to be recorded, there must be no defective sectors as described above. Therefore, an alternative sector is required to record data in place of the defective sector.

In other words, when data is recorded in a sector specified by the user, if that sector is a bad sector, it is recorded in an alternative sector so that the data appears to the user as if it was recorded in the specified sector. During playback, if the sector is a bad one, the data is played back from the alternative sector.

A generally known method of providing alternative sector areas is to have an alternative sector for each track, and to provide alternative tracks for each of a plurality of tracks, in which all sectors are used as substitutes. Alternate sectors are used for bad sectors within the same track, and alternate tracks are used when the alternate sectors on each track have already been used or when multiple alternate sectors are required due to burst defects. be done.

In media with a high incidence of bad sectors, such as optical disks, accesses to alternative tracks are more frequent than in magnetic disks, and the time required for alternative processing becomes a problem.

There are two types of track access in optical disk devices: fine access by moving the objective lens in the optical head and track jumps, and coarse access by moving the optical head itself using an optical head movement mechanism such as a linear motor. When the access distance is short, fine access can be used to achieve high speed and accuracy; when the access distance is long, coarse access is required and the processing time becomes longer. Therefore, in the alternative track method, the alternative processing speed is determined by the distance from the defective sector to the alternative track.

Therefore, Japanese Patent Application Laid-Open No. 61-2071 proposes a method in which blocks are formed into blocks with multiple tracks that can be accessed closely and at high speed, and alternative tracks are provided in each block to increase speed by alternative processing.

A conceptual diagram showing this method is shown in FIG. In the same figure,
Assuming that the number of tracks that can be accessed at high speed is N, all tracks on the medium are divided into blocks each consisting of N tracks, and one alternative track is provided for the last track of each block. Each track also has one alternative sector. In Fig. 4, when data is recorded to any track, bad sector 1,
2 occurs, alternative processing is performed by recording defective sector 1 in an alternative sector within the same track and recording defective sector 2 in an alternative track within the block. Access to the alternative track at this time can be performed at high speed.

[Problem to be solved by the invention]

However, in the above conventional example, one alternative track is required for every N tracks, and in devices where N cannot take a large value, there is a problem that an area for alternative is taken up more than necessary, resulting in poor sector utilization efficiency. .

In view of these problems, it is an object of the present invention to provide a disk-shaped information recording medium that can increase sector utilization efficiency without reducing the time required for alternative processing.

[Means to solve the problem]

In order to achieve the above object, a disc-shaped information recording medium in which one track has one or more sectors is divided into blocks for each of a plurality of tracks, and each block has a disc-shaped information recording medium with an alternative track for replacing a defective sector. In the information recording medium, the alternative track is located at the center of the block, and the distance between the alternative track and both ends of the block is such that the track can be accessed at high speed. provided.

〔Example〕

Hereinafter, one embodiment of the present invention will be described in detail using the drawings.

FIG. 1 is an alternative track arrangement diagram of the optical disc according to the present embodiment, FIG. 2 is a schematic diagram of an alternative processing method in an alternative block, and FIG. 3 is a flowchart showing the order of data recording.

As shown in FIG. 1, the optical disc D according to this embodiment is
Concentric tracks 1 are lined up at predetermined intervals, and the tracks 1 are further divided by boundaries 2 extending radially at the same pitch. Each divided track constitutes a sector Ct. is a unit of information recording.

In this embodiment, all the tracks are divided into blocks, with (2N-1) troughs in l block units. Let N be the maximum number of tracks that can be accessed at high speed. In FIG. 1, the (M-1)th block, the Mth block, and the (M+1)th block are shown.

In each block, the Nth truck from one end of the block (also Nth from the other end of the block) is used as an alternative truck person. In addition, B is an alternative track A
It shows the data tracks etc. sandwiched between the two.

As shown in FIG. 2, within one block (the M-th block is shown as an example, the same applies to the others), there are normal tracks BM1 to B.
The final sector k of M(14-1) and BMN-BM(2N-2) is an alternative sector. Further, one alternative track AM is composed of alternative sectors.

Note that FIG. 2 is a schematic diagram (Ih#), but in reality, the left and right sides in FIG. 2 are connected, and each track draws a concentric circle.

Next, the operation of recording information on the optical disc according to the present invention having the above configuration will be explained using FIG. 2 while referring to the flowchart of FIG. 3.

It is assumed that bad sectors ant and bad sectors tl and v occur in tracks BMF and BM, respectively.

First, access any sector and record data (8
1). Then, it is checked whether the data has been recorded normally (S2), and if YES, the recording process for one sector is completed.

Next, it is assumed that the bad sector 8t of track BM is accessed and data is recorded (81). In this case 5, if you check whether data was recorded normally (82), the answer is NO, so the same track as the recorded sector (Track B
Check whether the alternative sector of M, ) has already been used83), if it is unused, record to that alternative sector87), check whether the alternative data was recorded normally86), if YES This process ends.

If No, jump to alternative track A14 in the same block and access it. 84) 1 Record alternative data S
S), check whether the alternative data was recorded normally. S6) If YES, end this process and N
If O, another sector of the alternative track AM is accessed (S4).

Next, it is assumed that bad sector t of track BM is accessed and data is recorded (Sl). In this case, when checking whether data was recorded normally (82), the answer is No, so the same track as the recorded sector (track B,
Check whether the alternative sector of p) is already in use83), and since the alternative sector is already used when accessing the bad sector 8, the
(84) and record alternative data (SS).

Please check whether the alternative data was recorded successfully1.
96), if YES, this process ends; if NO, another sector of the alternative track AM is accessed (S4).

Next, it is assumed that bad sector U of track BMq is accessed and data is recorded (Sl). In this case, when checking whether the data was recorded normally (82), the result is No, so the same track as the recorded sector (track BM
,) Check whether the alternative sector is already in use83), If it is unused, record it in that alternative sector87), Check whether the alternative data was recorded normally.S6) If YES This process ends. N
If YES, jump to the alternate track AM in the same block and access the unrecorded sector (84), record the alternate data (SS), check whether the alternate data was recorded normally (S6), if YES If the answer is NO, another sector of the alternative track AM is accessed (S4).

Next, it is assumed that the bad sector V of track BMqO is accessed and data is recorded (Sl). In this case, when checking whether data was recorded normally (S2), the answer is No, so the same track as the recorded sector (track BM
Check whether the alternative sector in 9) is already in use.83) Since the alternative sector is already used when accessing the bad sector U, jump to the alternative track AM and access the unrecorded sector. S4) - Please record the alternative data. 55) - Check whether the alternative data has been recorded normally. S6) If YES, terminate this process; if No, access another sector of the alternative track AM. (S4).

As explained above, when recording is performed to an arbitrary sector in the Mth block, and if that sector is a bad sector, it is checked whether an alternative sector on the same track as that sector is already used, and if it is already used, an alternative sector is recorded. In the case of a sector on either side of track AM, access is made by shifting to alternative track AM. The same applies to recording in other blocks.

When reproducing an arbitrary sector, the target sector is first accessed, and if that sector is defective, an alternative sector within the same track is reproduced. If the target data is not recorded in the alternative sector, the alternative track is accessed to search for and reproduce the alternative data.

In this embodiment, when the maximum number of tracks that can be accessed at high speed is N, it is decided that (N-1) normal tracks are arranged on both sides of one alternative track and the alternative processing is performed using these as one book p. , the replacement processing speed remains unchanged, and the number of replacement tracks can be reduced by half, increasing sector utilization efficiency.

Note that the number of normal tracks on both sides of the alternative track is (N-
1) The number may be smaller than 1). In this case, the sector utilization efficiency decreases, but the average replacement processing speed can be improved. Note that the number of normal tracks on both sides of the alternative track may be different.

Note that in the above embodiment, data is recorded and reproduced in sector units, but even when data is recorded and reproduced in track units, the alternative track can be positioned in the center of the alternative processing block. Application of the present invention is possible.

Further, in this embodiment, one alternative sector is provided within one track, but it may also be possible when multiple alternative sectors are provided within one track, or when no alternative sector is provided within a track. It goes without saying that the present invention is applicable.

Further, although the tracks are arranged concentrically in this embodiment, the tracks may be arranged in a circular pattern. In this case, one rotation in the circumferential direction is defined as one track, and this one track can be divided into one sector or a plurality of sectors for recording and reproduction.

Furthermore, although this example is applied to an optical disc,
It is also applicable to magnetic disks, magneto-optical disks, etc.

In addition, the present invention is applicable to disk-shaped information recording media of all types and methods.

〔Effect of the invention〕

In the present invention, the alternative track is located in the center of the block, and the distance between the alternative track and both ends of the block is such that the track can be accessed at high speed. Therefore, the time required for the alternative processing does not change and sector utilization efficiency is improved. can be raised.

[Brief explanation of the drawing]

1 to 3 are explanatory diagrams of the first embodiment of the present invention,
Of these, Fig. 1 is an alternative track arrangement diagram of an optical disc, Fig. 2 is a schematic diagram of an alternative processing method within an alternative block,
Figure 3 is a flowchart showing the order of data recording;
The figure is a schematic diagram of an alternative processing method in an alternative block according to a conventional example. 1... Track, 2... Boundary line between sectors, A...
- Alternative track, B...normal track, C...sector, D...optical disc. Agent Patent Attorney Jo Taira Yamashita

Claims (1)

[Claims] (1) In a disk-shaped information recording medium in which one track is one or more sectors, the disk-shaped information recording medium is divided into blocks for each of a plurality of tracks, and each block has an alternative track for replacing a defective sector, The disk-shaped information recording medium is characterized in that the alternative track is located in the center of the block, and the distance between the alternative track and both ends of the block is such that the track can be accessed at high speed.