JPH0695398B2 - Optical disk defect position recording device - Google Patents

Description

TECHNICAL FIELD The present invention relates to an apparatus for recording a defect position of an optical disc on the optical disc.

(Prior Art) It is desired that the defect occurrence rate, which is one of the important performances of optical disks, be as low as possible. Therefore, in order to reduce the defect occurrence rate, it is necessary to know the cause of the defect occurrence, and observing the defective portion with a microscope (optical microscope, electron microscope, etc.) is one of the important means.

The defective portion of the optical disc is determined by processing a reproduced signal using a reproducing optical system and determining whether or not an error has occurred. Conventionally, the defect occurrence position at this time is observed as follows. When the track address information and the sector address information are already recorded on the optical disc, each address information is read at the time of observing a defect. If there is no address information on the optical disk, a read radius position reading mechanism of the read optical system and a rotation angle reading mechanism on the optical disk rotation axis are attached to read the read radius and the disk rotation angle when a defect is observed. When observing the defective portion of the disk whose defect generation position has been read as described above using a microscope, the defective portion is searched by observing the vicinity of the above-mentioned disk radial position and rotation angle position read at the time of defect observation.

(Problems to be Solved by the Invention) When a defect is searched and a defect is observed by the above method,
When the size of the observable symmetry defect is about 1 μm, there are the following problems. Even if the defect area is searched by observing the disk radial position and the rotation angle position read at the time of defect observation, if the microscope magnification is increased, the observation field becomes narrower, making it difficult to find the defect area. When the magnification is reduced, the defect itself becomes invisible. For this reason, it is difficult to search for the defective portion. Further, even if a position which is expected to be a defective portion is found, it is impossible to judge whether or not the portion is judged to be defective by the reproducing optical system.

It is an object of the present invention to provide an optical disk defect position recording apparatus for solving the above problems and efficiently searching for the defect position of an optical disk.

(Means for Solving Problems) The gist of the present invention is that in an apparatus having a recording / reproducing function for an optical disc, first means for detecting a defect in the optical disc and recording on the optical disc from the time of detecting the defect. An optical disk defect position recording apparatus comprising: a second means; and a third means for not detecting a defect during the recording by the second means.

(Operation) The present invention will be described in detail below with reference to the drawings.

Further, in the following description, recording on the optical disc from the time when a defect of the optical disc is detected is referred to as marking, and the marked region on the optical disc is referred to as marking region.

FIG. 1 shows a device configuration according to the present invention.

In the signal reproduced from the optical disc 4, the defect detection circuit 2 detects a defect. When a defect is detected, the defect detection circuit 2
Causes the defect position recording circuit 3 that performs recording for a certain period of time and the gate circuit 1 that does not detect a defect during the period when recording is performed by the defect position recording circuit 3. The marking is performed by the above operation. By performing such marking, even if the size of the defect is about 1 μm, if the marking region is made large, the defect position can be immediately searched when observing the defect.

With the device configuration excluding the above-described functions, the optical disc 4 is set on the disc spindle 5 and rotated, and the optical head 6 directs the recording / reproducing laser focused beam onto the optical disc 4, similar to a general optical disc recording / reproducing device. To focus
It is controlled by the optical head drive system 7.

FIG. 2 shows a schematic view of the arrangement of the defective portion 8 and the marking area 9. In this way, since the marking area 9 is in the immediate vicinity of the defective portion 8, the defect can be easily found,
The efficiency of defect observation can be improved.

(Embodiment 1) FIGS. 3 and 4 are schematic diagrams of micrographs in which a defective portion where a recording bit is missing is searched using the defect position searching device of the present invention.
Shown in the figure. FIG. 3 is a schematic view of the marking area observed with an optical microscope at a magnification of 100 times. Although there is a defective portion at the tip of the marking area, the defective portion cannot be seen at this magnification. FIG. 4 is a schematic diagram when the tip portion of the marking area in FIG. 3 is enlarged and the magnification is 2000 times. At this magnification, the defective portion can be observed.

(Example 2) FIG. 5 shows a schematic diagram of a micrograph of an extra defect portion retrieved by using the defect position retrieval apparatus of the present invention. FIG. 5 is a schematic diagram in which the tip of the marking area is enlarged (magnification: 1000 times) as in FIG. At this magnification, the defective portion can be observed.

(Effects of the Invention) As described in detail above, by using the optical disk defect locator search device according to the present invention, it is possible to search for defects at a low magnification, speed up defect observation of an optical disc, and perform defect observation. The efficiency can be improved.

[Brief description of drawings]

FIG. 1 is a diagram showing the structure of an optical disc defect position recording apparatus, FIG. 2 is a diagram showing the arrangement of defective portions and marking areas, and FIGS. 3, 4 and 5 are schematic micrographs of defective portions and marking areas. FIG. In the figure, 1 is a gate circuit, 2 is a defect detection circuit, 3 is a defect position recording circuit, 4 is an optical disk, 5 is a disk spindle, 6 is an optical head, 7 is an optical head drive system, 8 is a defective portion, and 9 is marking. Area.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP 63-152038 (JP, A) JP 63-152039 (JP, A) JP 63-152041 (JP, A) JP 63- 117245 (JP, A)

Claims (1)

[Claims] 1. An apparatus having a recording / reproducing function for an optical disc, comprising: first means for detecting a defect in the optical disc; second means for recording on the optical disc after the defect is detected; and recording by the second means. An optical disk defect position recording apparatus comprising a third means for not detecting a defect during a period during which the optical disc defect position is recorded.