JPS58169354A - Information recording disk - Google Patents

Abstract

PURPOSE:To detect the eccentricity of an optical information recording disk without using a tracking signal, and to execute eccentric matching more stably, by providing an eccentric detecting mark on a part of said disk. CONSTITUTION:An eccentric detecting mark 2 of a prescribed shape is provided on the outside circumferential part of an information recording disk 1, and the size of the mark 2 is detected by an optical system 15. An optical spot from a light source 8 of the optical system 15 is converged onto the disk 1, and the reflected light is made incident to a detector 13. A reproducing signal 100 from the detector 13 is varied depending on which part of the triangular mark the optical spot passes through. Therefore, the signal 100 is compared with prescribed comparison voltage in a processing circuit 14, and an output 101 proportional to eccentricity of minus, zero and plus in case of A, B and C, respectively, is outputted by which a moving base 6 is moved and eccentric correction is executed. Therefore, eccentric matching can be executed more stably without using a tracking signal.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an information recording disk such as an optical disk and an O recording/reproducing device therefor, and particularly to a disk and device suitable for correcting eccentricity.

In conventional optical disk information recording and reproducing devices, the eccentricity of nine tracks recorded on the information recording disk is detected, and the detected signal (tracking signal) drives a mirror installed in the device to perform eccentric alignment. . However, in Jin's method, if the eccentricity becomes large, for example, 200 μm or more, there is a fear that sufficient eccentricity alignment, for example, accuracy of 0.1 μm or less, cannot be obtained. Furthermore, depending on the tracking signal detection method, there is a drawback that even the tracking signal cannot be detected.

An object of the present invention is to detect the eccentricity of an information recording disk without using a racking signal KII, and to achieve stable eccentric alignment t.
To provide an information recording disk and a recording/reproducing device that can perform
Toru.

For the above purpose, the information recording disk of the present invention is provided with an eccentricity detection mark on a part thereof, and the information recording internal device detects the magnitude and direction of eccentricity from the eccentricity detection mark. Equipment is provided to do so.

Hereinafter, the present invention will be explained in detail using 19 examples.

FIG. 1 shows a portion of the information recording disk of the present invention.

l rotates around the disk %3. 2 is a mark for detecting eccentricity, and a triangular mark with length t, fIIJ and d is delayed by one turn. FIG. 2 shows a detailed illustration of one triangular mark. The direction of arrow 30 in FIG. 2 represents the radial direction of the disk. One triangular mark is 21, 22, 2
It consists of elongated holes such as 3, 24, 25° 26.27, etc., whose length becomes shorter toward the inside of the disk. This length is formed by removing the reflective film on the disk or by forming a groove with an appropriate depth. The depth of the groove is
A suitable length is 1/4 of the light ea length for detecting this mark.

Further, it is appropriate that the interval between adjacent long and large portions is 1.5 to z5 μm, and the width of the long and large portions is 0.5 to 1#m. Furthermore, 1 the base and height dμ of the above triangular mark, a1 to 1■, respectively,
and 1 to 5 ■ is suitable.

FIG. 3 shows a recording/reproducing apparatus for an information recording disk according to the present invention. Reference numeral 1 denotes an information recording disk, which is rotated by a motor 4. 5 is a recording/reproducing optical system, which is a 6Fi movable table. The movable table 6 is moved in the radial direction of the information recording disk 10 by the Tanabata 7, and the recording and reproducing optical system 5 records and reproduces information. On the other hand, the triangular mark on the erasable recording disk l is detected by the optical system 15. The optical system 15 includes, for example, a light source 8
and.

Lenses 9, 11 and 12, semi-transparent mirror 11 and photodetector 13
It consists of The light source 8 is, for example, a light emitting diode. The lenses 9, 11 and 12 are designed to have focal lengths and positions K such that the light flux emitted from the light emitting diode is converged onto the information recording disk l, and the reflected light is incident on the photodetector 13. All you have to do is decide. However, at this time, the diameter of the elementary light spot converging on the disk 1 is 20#m! degree is preferred. Reproduction signal 10 obtained by optical detection 1813
0 is converted by the signal processing circuit 14 into a signal 101 or 102 corresponding to the eccentricity of the information recording disk 1, and the motor 7 is supplied to the tracking device in the optical system 5.
The eccentricity is corrected by moving the light spot obtained by the moving table 6 or the optical system 5.

ξHere, the reproduced signal 10G is generated depending on where on the triangular mark 2 on the disk l the light spot created by the optical system 15 passes! It changes as shown in Figure 4 (A) to (C). The horizontal axes of FIG.
This is the output when a light spot passes through the positions of the triangular marks OA, B, and C shown in the figure.

This reproduced signal 10G is supplied to the signal processing circuit 14. The signal processing circuit 14 is, for example, a circuit as shown in FIG. R11Rm *Rs *R4 is a resistor b
cl is a capacitor. 41 is a differential amplifier in which the reproduced signal 100 is compared with the voltage V and amplified. The comparison voltage V is 940 as shown in FIG. R4 and 01 constitute a low-pass filter, and the cutoff frequency is preferably selected to be 10 to 20 times the rotational speed of both plates 1. In this way, the output 101 or 102 of the signal processing circuit 14 is 81
4 In the case of A, it is negative, in the case of B, it is zero, and C
In the case of , a positive output is obtained, and its magnitude is proportional to the eccentricity.

As described above in the embodiments, according to the present invention, it is possible to detect the eccentricity of the information recording disk using a simple optical system, and it becomes possible to easily correct the eccentricity in the recording and reproducing apparatus. .

The light spot narrowed down onto the disk by the optical system for detecting eccentricity has a diameter of 20 μm, so the depth of focus is about 400 mm, and even if focusing is performed, a very simple system is sufficient. It has characteristics.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the eccentricity detection mark of the information recording disk of the present invention, fs2 diagram is the detail #Il of the eccentricity detection mark,
Figure 113 is a block diagram of the recording/reproducing apparatus of the present invention, Figure 4 is a diagram explaining the reproduced signal of the eccentricity detection mark, and Figure S is a diagram of the configuration of the signal processing circuit. Country\J 3 Figure (QO1171 %4IZ

Claims (1)

[Claims] 1. An information recording disk for optically recording information, characterized in that a portion K of the disk has an eccentricity detection mark.