JPH0346165A - Alternative processing method for optical disk - Google Patents

Abstract

PURPOSE:To prevent data from defectively read in a guaranteed period and to shorten time for writing by changing an alternative processing condition according to the passage of time after the date of manufacture, which is recorded to a disk as data, and the position of the optical disk in a radial direction. CONSTITUTION:The date to manufacture the optical disk is recorded to a certain area in the optical disk. When this optical disk is used by a drive, the date to manufacture the optical disk is read by the drive and the guaranteed limit is calculated from the date. Then, the alternative processing is executed by using the alternative condition considering only a margin to the guaranteed limit. In the case of a fixed rotating speed system, the size of a recorded bit is made different in the inner and outer circumference parts of the optical disk and jitter is adverse in the inner circumference part rather than the outer circumference part. Then, error is easily generated. Thus, by changing the alternative processing condition corresponding to the position in the radial direction, this trouble can be excluded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an optical disk replacement processing method for replacing defective sectors with other sectors.

[Conventional technology]

If there are defects, dust, etc. on the recording surface of an optical disc, it may not be possible to play the disc correctly. For this reason, generally, after writing data, the data is read immediately to determine whether the data has been written correctly. This judgment operation is generally called verify. The determination of whether the data is written correctly is based on whether or not the user data, synchronization data, ECC (error detection and correction), etc. in the data area contain errors exceeding a certain threshold. There is. This threshold is called the "replacement processing condition," and a sector that exceeds the replacement processing condition during verification is considered a bad sector.

The same data is written to the alternate processing sector again. Conventionally, the replacement processing conditions have been constant values regardless of the manufacturing date of the media or the radial position of the media.

[Problems to be Solved by the Invention] Generally, the above replacement processing conditions are determined as follows.

"Alternative processing condition" = "Number of errors that cannot be corrected" - "Margin" In other words, even if the number of errors in the alternating processing condition occurs, it is actually still possible to correct errors; If an error with a margin of 1 minute occurs after verification, the error cannot be corrected and the data cannot be read. Therefore, the "margin" is the point at which the user attempts to read the data some time after verification. Deterioration of the media recording film is considered to be the main cause of this increasing error, which must be determined by taking into account the number of errors that will occur up to that point. In other words, if you take into account the increase in errors until the user attempts to read the data some time after verification, the possibility that the data will become unreadable will be reduced. However, if we take into account the ``6r margin'', the ``replacement processing conditions'' become stricter (the number of allowable errors decreases), and the probability of replacement processing increases. Point defects occur.

■Write time (data transfer rate) becomes longer (replacement processing takes time).

■A large capacity of the sector for replacement processing is required, which reduces the area used by the user.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an optical disk system that can take sufficient "margin" into account and that does not cause the above-mentioned problems (1) and (2).

[Means to solve the problem]

In order to achieve the above object, according to the present invention, an optical disc in which the date of manufacture is recorded as data in a predetermined area is used, and an optical disc is replaced according to the elapsed time from the date of manufacture indicated by the data read from the optical disc. An optical disc replacement processing method is provided, which is characterized by changing processing conditions.

Further, according to the present invention, there is provided an optical disc replacement processing method characterized in that replacement processing conditions are changed depending on the radial position of the optical disc.

[Effect]

During recording, the number of unnecessary replacement processes can be reduced by reading the manufacturing date recorded on the optical disc and changing the replacement processing conditions taking into account the elapsed time.

In addition, by changing the replacement processing conditions by taking into account the radial position of the optical disk, replacement processing conditions can be set that match the difference in the likelihood of errors occurring at the inner and outer circumferences of the optical disk. Similarly, the number of times unnecessary replacement processing is performed is reduced.

【Example) The present invention will be explained in more detail below with reference to Examples.

First, let's think again about the ``margin'' mentioned above. The "margin" can be thought of as the difference between the error during verification and the error after time passes. Therefore, it is naturally necessary to change the margin amount depending on the warranty period of the media. In other words, for an optical disc with a 10-year warranty, a 10-year margin must be expected, and for an optical disc with a 20-year warranty, 20 years' worth of margin must be expected.Therefore, ``Margin J must be taken into great consideration.

However, sectors written after 5 years on an optical disc with a 10-year warranty only need to be guaranteed for the remaining 5 years.
You only need to consider the margin for the year.

Therefore, the present invention records the manufacturing date of an optical disc in a certain area of the optical disc, and when this optical disc is used in a drive, the drive reads the manufacturing date of the optical disc and starts the warranty period from that date. is calculated, and replacement processing is performed using replacement processing conditions that take into account only the margin up to the warranty expiration date. To record the date of manufacture on an optical disc, 1) Record it in advance on the control track section where various information on the optical disc is written (record the information as uneven pits on the standby), 2) Record the manufacturing date on the area where the optical disc is located (e.g. Data representing the date of manufacture is recorded in an area outside the user area (where the address number is negative) according to the modulation/demodulation method of the data section.■ IC memory with the date of manufacture recorded in the cartridge case of the optical disk. This can be done by attaching (RAM) or the like.It is preferable that the optical disc not only record the manufacturing date but also the warranty period.

In addition, in the case of the CAV method (constant rotation speed method), the size of the recording pits differs between the inner and outer circumferences of the optical disc (
(inner circumference pit, outer circumference pit), therefore, the jitter is worse on the inner circumference than on the outer circumference, and errors are more likely to occur. Therefore, by focusing on this difference between the inner and outer peripheries, changing the ``margin'' depending on the radial position, and changing the ``alternative processing condition j'', the above-mentioned inconvenience can be eliminated.

The radial position is calculated from the address number and track number.

Note that changing the replacement processing conditions based on the radial position may be performed alone, or may be performed in conjunction with changing the replacement processing conditions based on the elapsed time from the manufacturing date described above.

FIG. 1 is a flowchart showing the procedure of an optical disk replacement processing method according to an embodiment of the present invention.

First, in step S1, the elapsed time and radial position of the optical disc are determined, and a threshold value N for replacement processing is calculated. Here, the elapsed time of the optical disc is determined by reading the manufacturing date recorded on the optical disc as data using the method described above on the drive side, and also checking the current year and month from the host computer's clock or a clock installed in the drive. The system detects the day and calculates the difference between the two using the drive.

Further, the radial position of the optical disc is calculated based on the address number and track number. When the elapsed time and radial position are determined in this way, the drive refers to a table like Table 1 prepared in advance in the control ROM G in the drive and sets the threshold according to the radial position and elapsed time. Calculate the value N.

Next, in step S2, the written data section is read, and in step S3, the ECC error words are counted to determine the number A of error words. Next, in step S4,
It is determined whether the number of error words is equal to or greater than a threshold value N, and if it is equal to or greater than N, replacement processing is performed (step S5), and if it is less than N, write verification is terminated (step S6).

Next, a specific example in which replacement processing is performed according to the above procedure will be described. In this example, as shown in FIG.
1287 sectors).

It is assumed that the number of ECC words for which error correction becomes impossible is j=8. In the comparative example using the conventional method, considering the margin,
Assuming that three "replacement processing conditions" are set, the replacement processing conditions are as shown in Table 1 in a specific example according to the present invention.

Table 1 According to the example of the present invention shown in Table 1, for example, at the innermost circumference after 10 years, the replacement processing condition in the present invention will be 5 pieces, which is an extra 2 pieces compared to 3 pieces in the conventional example. This reduces the number of times unnecessary replacement processing is performed.

〔Effect of the invention〕

As described in detail above, according to the present invention, the replacement processing conditions are changed depending on the elapsed time from the manufacturing date recorded as data on the optical disc, so that the following effects can be obtained.

■Data reading failures can be prevented within the media warranty period.

■Writing time can be shortened by reducing unnecessary replacement processing. Furthermore, since the number of sectors for replacement processing can be reduced, the user area can be increased, and the user capacity of the medium can be increased.

[Brief explanation of drawings]

FIG. 1 is a flowchart showing the procedure of an optical disk replacement processing method according to an embodiment of the present invention, and FIG. 2 is a diagram showing an example of arrangement of each data within one sector.

Claims (2)

[Claims] (1) A feature is that an optical disk in which the date of manufacture is recorded as data in a predetermined area is used, and the replacement processing conditions are changed depending on the elapsed time from the date of manufacture indicated by the data read from the optical disk. A replacement processing method for optical discs. (2) An optical disc replacement processing method characterized by changing replacement processing conditions depending on the radial position of the optical disc.