JPS6120271A - Information recording and reproducing device - Google Patents

Abstract

PURPOSE:To shorten track access time by substituting a defective sector by a substitutive sector. CONSTITUTION:Every N tracks are made to a block, and a substitutive track that substitutes a defective sector occurred in each block is provided. When a reproduction signal is inputted to a sector address reproducing circuit 1 and a data reproducing circuit 2, a signal D of track address and sector address is outputted to the head of each sector, and a data signal E is written in between. When data are recorded, the data are reproduced by the data reproducing circuit 2. When recording or reproducing, track address and sector address of objective sector to be recorded or reproduced are set to an objective sector address register 3. Coincidence of output of the sector address reproducing circuit 1 and the objective sector address register 3 is detected by a coincidence detecting circuit 4, and the coincidence detecting circuit 4 makes data recording and reproducing based on recording and reproducing command. Thus, the track access time can be shortened, and the performance of direct access function can be enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a disc-shaped recording medium having a sector structure in which a spiral or concentric track is divided into a plurality of parts.
The present invention relates to an information recording and reproducing device that records and reproduces information.

Conventional configuration and its problems In an information recording and reproducing apparatus that records and reproduces information in sector units, it is necessary to record information in a designated sector and reproduce it from that sector.

However, in an information recording and reproducing apparatus that uses a recording medium such as an optical disk that has relatively good error characteristics and a long lifespan, bad sectors may occur. A bad sector is a sector where the address of a preformatted sector cannot be demodulated correctly, or a sector where there is a large dropout in the data recording area and an uncorrectable data read error may occur even if data is recorded. This is a sector in which an uncorrectable data read error occurs when data is actually recorded and subsequently reproduced.

In a method in which the user directly specifies the address of the sector to be recorded, that is, in direct access, it is necessary to be able to record even in the above-mentioned bad sectors. Therefore, an alternative sector is required to record the data that should be recorded in the bad sector. In other words, when recording data in a sector specified by the user, if that sector is a bad sector, it will be recorded in the alternative sector, so that the data will be recorded to the user as if it were written in the specified sector. During playback, if the specified sector is a bad sector, it is necessary to play back the data from an alternative sector to that sector, so that it appears as if the data is being played back from the specified sector. .

For this reason, a difference occurs between the address of the sector to be recorded, that is, the logical address, specified by the user, and the address of the sector that is actually recorded, that is, the physical address. Therefore, in conventional information recording and reproducing devices, logical addresses and physical addresses are associated with each other using a directory. However, in the mono method, every time a bad sector occurs during recording, ξ! It is necessary to update the directory, and during playback, searching is only possible after knowing the physical address from the directory. The directory must also reside on the operating system.

The directory system described above cannot be used with non-rewritable optical discs because the directory cannot be updated. Furthermore, even with a rewritable recording medium, if the number of sectors increases, the directory K that resides in the memory of the operating system is too large.

For these reasons, an information recording/reproducing device (
'%Gan Sho 58-181016) was proposed first.

Recent proposals have made it possible to provide direct access during recording and playback even on non-rewritable optical discs.

However, in recording media such as optical disks, which have a large capacity and a high incidence of bad sectors, the frequency of replacing bad sectors is higher than with conventional magnetic disks, so the time required for sector replacement is has a significant impact on performance.

The time required for sector replacement includes the time to detect that the designated sector is a bad sector, the time to find a replacement sector for the designated sector, the time to search for a track for the replacement sector,
This is the sum of rotational waiting times for accessing alternative sectors.

The time for inspecting the track of the alternative sector varies depending on the distance between the track of the bad sector and the track of its alternative sector. This tendency is particularly noticeable in the case of optical disk devices.

Hereinafter, an explanation will be given taking an optical disk device as an example.

An optical disc has approximately 20,000 tracks cut on one side of a disc with a diameter of 20 cm. The sectors of each track are preformatted with the track address, sector address, error detection or error correction code, etc. of each sector! \ing.

Optical disk devices have two types of well-known inspection mechanisms: a fine search in which track jumping is performed by swinging a light beam using an optical helix, and a coarse search in which an optical head transport mechanism such as a linear motor is used. . When searching for a trunk, whether only a fine search or a coarse search is necessary depends on the distance between the currently accessed trunk and the track to be searched.

This boundary is determined according to the performance of the optical head.

A short-distance search that requires only a detailed search can be performed in about half to one-third of the time required for a short-distance search that requires a coarse search.

The conventional arrangement of alternative sectors will be explained from the three viewpoints of the track access time of the alternative sectors described above, sector utilization efficiency, and tolerance for concentrated occurrence of bad sectors.

In the first example, an alternative sector is provided for each track, and bad sectors that occur within that track are replaced with the alternative sector of that track, and those that cannot be replaced are further replaced with another alternative sector prepared separately. This is a method to do so.

The second example is a method in which alternative tracks are arranged in a concentrated manner on the outer or inner periphery of the optical disc, and generated defective sectors are substituted with alternative sectors within this group of alternative tracks.

In the first conventional example, the track access time of the alternative sector is 0, but the sector utilization efficiency is S-17S=1, assuming that the number of sectors on one track is S and the number of alternative sectors is 1.
-, and if S is set to 20, it becomes too small, and it cannot be said that the trench utilization efficiency is high.

Furthermore, if two or more bad sectors occur within one track, it is necessary to access a separately prepared alternative sector.

On the other hand, in the second conventional example, in the worst case, the track of the bad sector and the track of the alternative sector become the most distant tracks on the disk, and the probability that a coarse search is required when accessing the track of the alternative sector is determined. is high, so the average alternative sector track access time is long. On the contrary, the sector utilization efficiency and the tolerance for the concentrated occurrence of bad sectors are high.

OBJECTS OF THE INVENTION The present invention is an optical disk device, etc., in which a defective sector is replaced by a replacement sector, the track access time of the replacement sector is shortened, and the decrease in sector utilization efficiency due to the provision of the replacement sector is reduced. The purpose of this invention is to improve the performance of the direct access function of an information recording and reproducing device that has a large capacity and a relatively high incidence of bad sectors.

Structure of the Invention The present invention is an information recording and reproducing device that realizes a direct access function by replacing defective sectors with alternative sectors. Means for specifying an alternative track to replace a bad sector that occurs in the block; Means for adding and recording the address of the sector to be recorded in data to be recorded; Means for detecting bad sectors; Marking bad sectors. means for reproducing a sector on an alternative track when the sector to be reproduced is a defective sector, and transmitting data of a sector whose address added to the reproduced data matches the address of the sector to be reproduced; The present invention provides an information recording and reproducing apparatus which reduces the decrease in sector utilization rate and shortens the track access time of alternative sectors.

Description of examples Examples of the present invention will be described in detail below.

First, an alternative track arrangement method according to the present invention will be explained.

Figure fM1 is a diagram of a disk showing an alternative track arrangement method according to the present invention. As shown in FIG. 1, the trunks of the disk are divided into blocks of N trunks.

However, the number N is defined within the range that allows trunk access only by the dense search described above. As mentioned above,
The tracks are divided into N blocks and each block, ie, the first block, the second block,...(M-1
) block, 1st block.

Each of the (M+1)th blocks is provided with an alternative track to replace a bad sector occurring within that block. For example, the last track of each block is an alternative track.

In FIG. 1, A indicates an alternative track, and B indicates a normal track.

Furthermore, when a defective sector cannot be replaced by an alternative track within each block, it is replaced by a second alternative trunk independent of each block as shown in FIG. 1C.

FIG. 2 is a block diagram of an information recording/reproducing apparatus using the alternative track arrangement method. The reproduction signal is input to a sector address reproduction circuit 1 and a data reproduction circuit 2. As shown in FIG. 3, the reproduced signal is such that a sector track address and a sector address signal are output at the beginning of each sector, and a data signal E is written between the address signals.
The sector address reproducing circuit 1 reproduces the track address and sector address of the sector being reproduced. Further, if data is recorded, the data is reproduced by the data reproduction circuit 2. During recording or reproduction, the track address and sector address of the target sector to be recorded or reproduced are set in the target sector address register 3. Then, a -scattering product output circuit 4 detects whether the output of the sector address reproduction circuit 1 and the output of the target sector address register 3 match. Then, the scattering output circuit 4 records data based on the recording/reproducing command.

Perform playback. Reference numeral 5 denotes a data recording gate signal circuit that generates a data recording gate signal based on the output of the coincidence detection circuit 4 during data recording. Reference numeral 6 denotes a data reproduction gate signal circuit that generates a data reproduction gate signal based on the output of the coincidence detection circuit 4 when data 1q is generated. This is a 7-digit defective sector detection circuit. The address signal D of the sector corresponding to the track address and sector address set in the target sector address register 3 [When an error occurs and the coincidence detection output is not output in the scatter output circuit 4 during data recording or reproduction, Alternatively, when attempting to reproduce a recorded sector, the data reproduction circuit 2 detects a data error that exceeds the correction capability, or when it is detected that a delete process, which will be described later, has been performed, the target sector address register 3
A sector with a track address or sector address set to is determined to be a bad sector. Reference numeral 8 designates an alternative track setting circuit which uses the output of the defective sector detection circuit 7 and the output of the target sector address register 3 to determine a block in which a defective sector exists and sets an alternative track.

Based on a delete command, a defective sector is deleted by a sector delete gate signal circuit 9 that generates a sector delete gate signal. As described in the previously proposed Japanese Patent Application No. 59-43415, deleting means writing a special signal to a bad sector so that when the bad sector is later accessed during recording or playback, it will be deleted. The purpose of this is to attach a mark so that it is immediately clear that a sector is a bad sector and has already been replaced by a replacement sector.The procedure for replacing a bad sector in the present invention will be explained separately for recording and playback. .

First, we will explain the recording process.◇As shown in FIG. 6, when the sector in which data is to be recorded is determined to be a bad sector by the bad sector detection circuit 7, the sector delete gate signal is used to delete the previously described data in the bad sector. Perform the delete process as shown below.

Thereafter, the alternative track is accessed based on the output of the alternative track setting circuit 8. This is done quickly. Then, an unrecorded sector is searched for in the alternative track starting from the first sector, and the first sector found is set as the alternative sector.

As shown in FIG. 4, the track address and sector address of the defective sector are added as an address G to the data F that was supposed to be recorded in the defective sector, and the data is recorded in the found alternative sector.

If the alternative sector is a bad sector, delete processing is performed on the alternative sector, and then the next sector is made the alternative sector. When all sectors on the alternate track are already used as alternate sectors, the second alternate trunk mentioned above is accessed and substituted in the same way.

Next, the time of reproduction will be explained. When it is found that the sector in which data is to be reproduced has been deleted by the bad sector detection circuit TE, the alternative track is accessed based on the output of the alternative track setting circuit 8. It is done. Then, the recorded sectors of the alternative trunk are played back in order from the first sector. When the address G shown in Figure 4 among the reproduced information matches the track address and sector address of the defective sector to be reproduced, that sector is determined to be the desired replacement sector, and The data is transmitted using the data F of the sector as the data of the bad sector.

Even if all sectors of the alternative track are reproduced, if the address G does not match the track address or sector address of the defective sector, the already mentioned second alternative track is accessed and an alternative sector is similarly searched for.

A defective sector is replaced by the above-described procedure.

In the present invention, when N is 60, the sector utilization efficiency is 98%, which is suppressed to a 2% decrease.

Effects of the Invention According to the present invention, in a device that realizes direct access by replacing a bad sector with an alternative sector, (1) track access time of the alternative sector is shortened.

(2) Decrease in sector utilization efficiency due to provision of alternative sectors is reduced.

This effect can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a method of arranging alternative tracks according to the present invention;
FIG. 2 is a block diagram showing an embodiment of the present invention, FIG. 3 is a diagram showing the format of a reproduced signal, FIG. 4 is a diagram showing an address added to data in an alternative sector, and FIG.
The figure is an explanatory diagram showing a procedure for replacing a bad sector according to the present invention. 1... Sector address regeneration circuit, 2...
・Data reproduction circuit, 3...Target sector address register, 4...-Scatter product output circuit, 5...
Data recording gate signal circuit, 6... Data reproduction gate signal circuit, 7... Defective connector detection circuit, 8...
. . . Alternative track indexing circuit, 9 . . . Sector delete gate signal circuit. Name of the first agent: Patent attorney Toshio Nakao and one other person
Tokuku no 2nd flash 3rd figure 4th figure F (q To figure 5 υya 7g

Claims (5)

[Claims] (1) Alternative track setting means for forming a block for every N tracks of a disc-shaped recording medium having a sector structure in which a track is divided into a plurality of parts, and setting an alternative track in the block to replace a bad sector for each block; means for recording and reproducing signals on a disk-shaped recording medium; means for detecting a bad sector in the disk-shaped recording medium; bad sector deletion means for attaching a signal to the bad sector indicating that the sector is bad; An information recording and reproducing apparatus having means for adding an address to data at the time of reproduction, and means for extracting the address added to the data at the time of reproduction. (2) The information recording and reproducing apparatus according to claim 1, wherein the block size N is set within a range that allows high-speed track access. (3) When a sector in which a signal is to be recorded is detected as a bad sector, a signal indicating that it is a bad sector is attached to the sector, and the data with the address of the bad sector is added to the bad sector alternative track setting means. 2. The information recording and reproducing apparatus according to claim 1, wherein information is recorded in empty sectors of alternative tracks set by the following. (4) When the sector in which the signal was to be reproduced is detected as a bad sector, the data in the recorded sectors of the alternative track set by the bad sector alternative track setting means is played one after another, and the address added to the data is The first aspect of the present invention is characterized in that a sector that matches the address of the bad sector is determined to be a replacement sector for the bad sector.
The information recording and reproducing device described in Section 1. (5) The information recording and reproducing apparatus according to claim 1, further comprising a second alternative track for replacing a bad sector when all alternative tracks in a block have been replaced.