JPS6370928A - Optical disk - Google Patents

Abstract

PURPOSE:To eliminate a need for discarding the whole disk even if partial recording-unable areas are present therein by dividing a sector into plural first sector groups and further into second sector groups, and allocating a substitution area to record substitution information in to each sector group. CONSTITUTION:To the tail of respective second sectors,a first substitution area is provided, and in the boundary part to separate the segment (first sector) into optional pieces of groups, a secondary substitution area is provided, and to the tail of such one of the respective segments (first sectors) as placed in the last position of the array, a third substitution area is provided. In case an error is made at the time of writing an information, an error sector number as well as a substitution information is written in the first substitution sector. But if the first substitution area is already used, the same substitution information and substitution sector number are written in the second substitution area in the segment where the error is present. In case the second substitution area also is already used, the same substitution information is written in the third substitution area common for all the segments.

Description

[Detailed description of the invention] (Technical field) The present invention relates to an optical disc.

(Prior Art) A rotating optical disk having a plurality of sectors for recording information is known.

In Fig. 2, which schematically shows an arbitrary sector divided into tracks with the number of sectors m as one unit and shown in a laminated manner, if the sector number is from O to QM, each track is divided into tracks from 1 to P. Indicated by the pseudo track number up to. In this.

The area with (Q+1) sector numbers from 0 to L Oniaki is the normal writing area for information, and the remaining area with sector numbers 12+1 to m-1 is m-(Q
+1) area is a first replacement area for replacing a writing failure in the above-mentioned normal writing area. In this way, a first exchange area is provided at the tail of each normal write area. The last sector number M to Q is set as the second replacement area.

As a process, information is written to the "normal write area". 1. For example, if a write error occurs in a sector, write the same information to the first replacement area of the track where the safeter existed. At this time, if the first replacement area is already fully used, The same information was written into the second replacement area.

However, in this case, if writing is impossible due to scratches etc. in the second replacement area, the replacement process cannot proceed and the entire disk must be discarded as a defective disk. There was a problem that effective utilization was hindered.

(Objective) Accordingly, one object of the present invention is to provide an optical disc having an improved recording area that eliminates the need to discard the entire disc even if there is a partially unrecordable area.

(Structure) In order to achieve the above object, the present invention divides a sector into a plurality of first sector groups, further divides these first sector groups into a plurality of second sector groups, and for each of these second sector groups. Allocating one or more first replacement areas for recording replacement information, and allocating one or more second replacement areas for recording replacement information common to all of the second sector group, and , one or more third replacement areas are allocated to the first sector group for recording common replacement information.

Hereinafter, a detailed explanation will be given based on one embodiment of the present invention.

In FIG. 1, which schematically shows the information recording area of the optical disc according to the present invention, if the sector numbers are 0 to Q, a second sector group consisting of m consecutive second sectors corresponds to one track. However, if this one track is made up of r pieces and is referred to as the first sector (hereinafter referred to as a segment), then any sector number constituting a plurality of sectors on the optical disk can be divided into five segments and (Q
-M+1) first sectors. In other words, a 16th replacement area is provided at the end of each second sector, a 16th replacement area is provided at the boundary where segments (first sectors) are divided into arbitrary groups, and a 16th replacement area is provided at the end of each segment (first sector). ) is provided with a third replacement area at the end of the final line position.

Note that the number of segments S is determined by the number of sectors of the optical disc.

Each segment consists of r tracks, of which P (
For example, pseudo track numbers 1 to P) include a "normal write area", and the remaining (r-P) tracks (for example, pseudo track number r) are used as second replacement areas.

Each of the P tracks consists of (Ω+1) normal write sectors forming a ``normal write area'' and (m-Q-1) first spare sectors forming a first spare area.

Each sector is configured as shown in FIG. 3, for example.

That is, there is an ID section 100 that has a part in which the number of each sector is recorded in advance, and a part in which a code indicating whether the sector is a bad sector can be written.

There is a data section 200 for writing information with a gap from this ID section 100, and this data section 200
adjacent to, if the sector is a replacement sector,
Replacement sector number part 30 indicating which sector is the replacement sector (indicating the sector number where replacement occurred)
There is 0.

Next, the information writing operation will be explained.

First, data is written in the "normal write area" according to the specified sector number. After that, the data is read out and checked to see if any errors have occurred. If an error occurs, the error sector number is written to the first replacement sector of the track where the sector exists, along with replacement information that is the same data as the above data. At this time, a code indicating that the sector is a defective sector is written in the ID section of the sector in which the error has occurred.

, However, if the first replacement area is already used,
Substitution information that is the same data as the above data and a spare sector number are written in the second spare area of the segment where the defective sector exists.

However, if the second replacement area is also already used,
Common to all segments. Substitution information that is the same data as the above data is written in the third substitution area.

Next, the information read operation will be explained.

The designated sector is searched, and if there is no defective code in the ID part of that sector, the data of that sector is read. If a defective code is detected, search the first replacement area of the track where the sector exists, read the data and part of the replacement sector number, and check if it matches the sector number where the defective code was detected. Check it, and if it matches, read the data into that sector.

However, if it is not found in the first replacement sector, the search continues to the second and third replacement sectors, as in the information write operation.

Next, the information writing operation will be further explained.

When the information write controller finds that the second spare area is completely used.

By generating a warning to the higher-level system, the higher-level system discards the segment for which the warning was issued and uses another segment. By doing this, even if a part of the optical disc is damaged due to scratches, etc., in the worst case, only one segment can be discarded, and the second replacement area of the other segment can be utilized, and the unused area of the optical disc can be minimized. or avoid wasting the entire optical disk.

In this case, the seek operation is from the first normal write area to the second spare area, which is different from the second spare area in the prior art, which exists at the end of the sector, so the operating distance is reduced and , it also has the advantage of reducing seek time.

(Effects) According to the present invention, it is possible to effectively utilize optical discs, which is advantageous.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram schematically showing sectors of an optical disc according to the present invention by area, Fig. 2 is an explanatory diagram schematically showing sectors of an optical disc according to the prior art by area, and Fig. 3 is an explanatory diagram showing sectors of an optical disc according to the prior art. It is a detailed explanatory diagram.

Claims (1)

[Claims] In a rotating optical disc having a plurality of sectors for recording information, these sectors are divided into a plurality of first sector groups, and these first sector groups are further divided into a plurality of second sector groups. and allocating one or more first replacement areas for recording replacement information to each of these second sector groups,
Allocating one or more second replacement areas for recording replacement information common to all the second sector groups, and
An optical disc characterized in that information is recorded in order to record common alternative information in the first sector group or by allocating a plurality of third alternative areas.