JPH04137262A - Detecting method for characteristic deterioration of optical disk - Google Patents

Abstract

PURPOSE:To detect the accurate life of each optical disk by recording data, which indicates that a measured characteristic deteriorates exceeding a specific threshold value, on the optical disk in such a case and detecting the characteristics of the optical disk corresponding to its use time. CONSTITUTION:Plural characteristic measurement points P1-Pn are set on a user-used track group 3 in a radial direction of the optical disk 10. The characteristics of the optical disk 10 are measured at specific intervals of use time and if a measured characteristic deteriorates exceeding its specific threshold value, that is recorded on the optical disk, thereby detecting deterioration in characteristic of each optical disk 10 corresponding to the use time. Consequently, the accurate life of each optical disk 10 can be detected.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a characteristic deterioration detection method for detecting whether or not an optical disk can be used due to characteristic deterioration.

2. Description of the Related Art In general, an optical disk is a recording medium in which a recording film is formed on a circular substrate, and data is recorded by irradiating the recording film with a spot light to form small holes or by changing the magnetic direction. Dechiru.

Therefore, since this type of optical disc reads data using reflected light from the recording film, if the reflectance deteriorates or becomes distorted after long-term use, the reflectance characteristics etc. deteriorate and data cannot be written. Reading becomes impossible, so the user needs to know the lifespan of the optical disc in advance.

Conventionally, a method for detecting characteristic deterioration of this type of optical disk has been to place the optical disk in an overloaded state and perform a so-called accelerated test to estimate the lifespan due to natural deterioration.

Problems to be Solved by the Invention However, in the conventional optical disk characteristic deterioration detection method described above, in order to estimate the lifespan due to natural deterioration of an optical disk, it is necessary to detect the deterioration of characteristics due to the frequency of use, usage environment, and differences in the material of each optical disk. However, there is a problem in that it is not possible to accurately detect the lifespan of each optical disk.

SUMMARY OF THE INVENTION In view of the above conventional problems, it is an object of the present invention to provide a method for detecting characteristic deterioration of optical disks that can accurately detect the lifespan of each optical disk. In order to solve this problem, the characteristics of the optical disk are measured every predetermined usage time, and when the measured characteristics deteriorate beyond a predetermined threshold value, this fact is recorded on the optical disk.

According to the above-described structure, the present invention can accurately detect the lifespan of each optical disk due to the deterioration of its characteristics depending on the usage time of each optical disk.

EXAMPLES Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 1 is an explanatory diagram showing an optical disc used in an embodiment of the method for detecting characteristic deterioration of an optical disc according to the present invention, and FIG.
FIG. 1 is an explanatory diagram showing the recorded contents of the optical disc, and FIG. 3 is an explanatory diagram showing the recorded contents in more detail than the recorded contents in FIG. 2.

In FIG. 1, an optical disc 10 has concentric or spiral track groups 11 to 15 that serve as recording areas, and the track groups 11 to 15 are divided into a plurality of (for example, 17) sectors in the radial direction of the optical disc 10. has been done.

The track group 11 records data on the optical disc 10,
In addition, the outer control track group, track group 12, in which information necessary for reproducing recorded data (append/rewrite method, modulation method, recording/reproducing power, number of sectors, sector capacity, etc.) is written in advance at the time of manufacturing, This is a group of outer circumferential test tracks used in the method for detecting characteristic deterioration of an optical disc according to the present invention.

The track group 13 is a user-use track group on which the user records data, and a plurality of characteristic measurement points P1, P2 to Pn are set in the user-use track group 13 in the radial direction of the optical disc 10.

The track groups 14 and 15 are an inner test trunk group and an inner control track group, respectively, which are used in the same way as the outer test track group 12 and the outer control track group 11. is composed of at least n trunks 201-2On depending on the number n of characteristic measurement points P1, P2-Pn.

FIG. 2 shows one trunk 20 (tracks 201 to 2) of the outer test track group 12 and the inner test track group 14.
0n), and track 20 is 17
The area 21 of each sector is divided into sectors "0" to "16", and the area 21 of each sector has an address part 22 in which the address of the sector is recorded, and a flag part 23 in which a warning flag is recorded when the characteristics deteriorate. , a data mark section 24 in which a mark indicating the start of the data section 25 is recorded, and a data section 25 in which measured characteristics are recorded.

Here, when detecting whether or not the optical disc 10 can be used, 1
The characteristics fO-=fl to f16 to be measured include the C/N ratio, reflectance, pre-focus signal level, etc. of the optical disc 10.

Next, a method for detecting characteristic deterioration of the optical disc 10 according to the present invention will be explained with reference to FIGS. Initial values f 10 % f 11 to f 116 of the characteristics at ten measurement points P 1 are measured and recorded at the beginning of the data section 25 of sectors “0” to “16” of the trunk 201 .

Similarly, the initial value f2 of the characteristic at each measurement point P2 to Pn
0s f2z-f216, ~fno-v fnz~fn
z6 is measured and recorded at the beginning of the data portion 25 of sectors rOJ to "16" of the trunks 202 to 20n, respectively.

When the optical disc 10 is used and reaches a predetermined usage time ts, the characteristics f's fl to f16 at the measurement point P1 are measured, and the data is transferred to the next area of the data section 25 in sectors "0" to "16" of the track 201. Record.

Similarly, the characteristic fo”=L(
n = 17) and recorded in the next area of the data section 250 of sectors "O" to l'-16J of tracks 202 to 2On.

Next, each measured characteristic fO%fn and a predetermined threshold value fKS
If the sector has deteriorated more than the threshold value fKS, a warning mark is recorded in the flag section 23 of the sector.

On the other hand, if each characteristic fo-fn has not deteriorated below the predetermined threshold value fXs, the difference between the initial value fK+ and the threshold value fKS (f
xt fxs) and the difference (fKfxs) between the measured value fK and the threshold fKs, (fx - fKs) / (fxt - fxs),
It is recorded in the next area of the data section 25 of the sector.

If the above process is performed every time the predetermined usage time ts elapses,
As the usage time passes, the measured value fK deteriorates below the threshold value fxs and the number of warning marks recorded in the flag section 23 of each sector increases. Therefore, by setting the allowable number of warning marks in advance, the life of the optical disc 10 can be can be learned.

Well, the denominator of the above ratio (fx fKs) / (fxt :hs) is constant, and the numerator becomes "0" as the usage time passes.
” The life can be predicted by the slope.

Effects of the Invention As explained above, the present invention measures the characteristics of an optical disk at each predetermined usage time, records the fact on the optical disk when the measured characteristics deteriorate than a predetermined threshold value, and measures the characteristics of the optical disk for each optical disk. In order to detect the lifespan of an optical disc due to the deterioration of the characteristics of the optical disc depending on the usage time, it is possible to accurately detect the lifespan of each optical disc.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing an optical disc used in an embodiment of the method for detecting characteristic deterioration of an optical disc according to the present invention;
1 is an explanatory diagram showing the recorded contents of the optical disc of FIG. 1, and FIG. 3 is an explanatory diagram showing the recorded contents in more detail of the recorded contents of FIG. 2. 10... Optical disk, 12.14... Test trunk, 23 Warning flag section, 25... Data section. Name of agent: Patent attorney Shigetaka Awano and one other person Procedural amendment (name of system invention) Person who amends the method for detecting characteristic deterioration of optical disks Relationship to the case Patent application Person address: 1006 Kadoma, Kadoma City, Osaka Prefecture Name
(582) Representative of Matsushita Electric Industrial Co., Ltd.
Akira Tanii Yuyo Masato 〒
571 Address: 1006 Kadoma, Kadoma City, Osaka Prefecture [Contact number: Tokyo 3434-9471]
Date of amendment order November 26, 1991 Target of amendment! Figure //'1

Claims (4)

[Claims] (1) Measure the characteristics of the optical disc at each predetermined usage time,
A method for detecting characteristic deterioration of an optical disk, which records the fact on an optical disk when measured characteristics have deteriorated beyond a predetermined threshold value, and detects the life of the optical disk due to the deterioration of the characteristics of the optical disk according to usage time. (2) A method for detecting characteristic deterioration of an optical disk according to claim 1, which comprises measuring a plurality of characteristics of the optical disk. (3) A method for detecting characteristic deterioration of an optical disk according to claim 1 or 2, characterized in that the characteristics are measured at a plurality of positions on the optical disk. (4) A patent claim characterized in that when a measured characteristic deteriorates beyond a predetermined threshold value, that fact is recorded on an optical disc, and when the number of measured characteristics deteriorates beyond a predetermined value, it is determined that the optical disc has reached the end of its lifespan. A method for detecting characteristic deterioration of an optical disc according to item 2 or 3.