JPH0135429B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a disk device that records or reproduces information on, for example, an optical disk on which information is recorded in a spiral or concentric manner.

In recent years, image information such as documents that are generated in large quantities is
Image information storage that performs photoelectric conversion through dimensional optical scanning, stores this photoelectrically converted image information in an image storage device, or searches and reproduces it as necessary, and reproduces and outputs it as a hard copy or soft copy. A search device has been developed. Recently, optical disk devices have been used as image storage devices in such image information storage and retrieval devices.

Conventionally, for such optical disk devices,
An optical disk that records information in a spiral or concentric pattern is used, and information is recorded or reproduced by an optical head that is moved linearly in the radial direction of the optical disk by a linear motor. The above-mentioned optical head is positioned within a millimeter or less by a positioning method using a position detector using a non-contact optical linear scale and an optical mask using the principle of overlapping gratings. However, in such an optical disk device,
Due to a mechanical installation error of the optical scale, its positioning could not be performed accurately. Therefore, when accessing a predetermined track with the optical head, the access is performed once, the accessed track number is detected, and the corresponding track is accessed again. Therefore, it takes time to access, and
There was a problem that the access control became complicated.

This invention was made in view of the above circumstances,
The object is to provide a disk device in which the head can be accurately positioned, the head access time can be shortened, and the access control can be simplified.

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 schematically shows an optical disc device of the present invention. 11 is an optical disk, 12 is a motor for rotating the optical disk 11, and 13 is an optical head for recording and reproducing. This optical head 13
is fixed to the movable part 14 of a DC linear motor 16 which is composed of a movable part 14 and a fixed part 15, so that the linear motor 16 drives the optical disk 1.
1 in the radial direction. Reference numeral 17 denotes an optical scale fixed to the movable part 14 by screws, etc.; 18 is a detector for detecting the position of the optical scale 17; this detects the position of the movable part 14 (that is, optical Head 1
According to the movement of 3), two types of detection signals with different phases are output. A position signal processing circuit 19 obtains a position signal by performing predetermined signal processing on the output signal of the detector. This signal processing circuit 19 includes, for example, the detector 18
The pulse generation circuit 26 generates position pulses in response to two types of detection signals with different phases from the pulse generation circuit 26, and the counter 27 counts up or down in response to the pulses from the pulse generation circuit 26. ing. 20 does not show the scale value from the position signal processing circuit 19
When the track detection signal is supplied from the CPU,
A correction scale register 21 for storing correction scale values is a scale conversion section that converts the track number from the CPU into a scale value corresponding to the scale of the linear scale 17. This scale conversion section 21 obtains a scale value by the calculation of [track number x track pitch (3 .mu.m)/scale pitch (32 .mu.m)]. 22 is a designated scale register that stores the scale value of the scale converter 21; 23 is an adder that adds the scale value of this register 22 and the scale value of the correction scale register 20; 24 is this adder 23;
a comparator that compares whether or not the addition result matches the scale value from the signal processing circuit 19;
For example, if they match, a "0" signal is output, and if they do not match, a "1" signal is output. A linear motor driver 25 drives the linear motor 16 in response to a signal from the comparator 24 to linearly move the optical head 13 in the radial direction (directions A and B in the figure) above the optical disk 11.

Next, the operation of such a configuration will be explained with reference to FIG. 2. First, when the optical disc 11 is set at the optical disc position, scale correction is performed. That is, by driving the linear motor driver 25 according to a designation from a CPU (not shown), the optical head 13 is slowly moved in the direction A from the innermost circumferential portion on the optical disk 11. At this time, the optical disk 11 is rotating at a constant speed. As a result, each time the optical head 13 corresponds to the scale in order from the initial position a of the optical scale 17, a signal is output from the pulse generation circuit 26 in response to a detection signal with a different phase from the detector 18, count up. The optical head 13 irradiates the optical disc 11 with the reproduction beam, converts the reflected light into an electrical signal, and outputs the electrical signal to a CPU (not shown). As a result, the CPU detects the innermost track b based on the electrical signal from the optical head 13, and outputs the detection signal to the correction scale register 20. As a result, the correction scale register 20 stores the contents of the counter 27 when the detection signal is supplied as the correction scale c.

In such a state, it is assumed that the track number to be accessed from the CPU is supplied to the scale conversion section 21. Then, the scale conversion unit 21 converts the supplied track number into a corresponding scale value d.
and stores it in the specified scale register 22. As a result, the scale value d of the designated scale register 22 and the contents of the correction scale register are added by the adder 23, and the result of this addition and the scale value e of the counter 27 are compared by the comparator 24. The comparator 24 operates the linear motor driver 25 by outputting a logic "1" signal until the contents of the adder 23 and the scale value e of the counter 27 match. Thereby, the linear motor driver 25 drives the linear motor 16 to move the optical head 13 in the A direction. Thereafter, when the scale value e of the counter 27 and the addition result of the adder 23 match, the comparator 2
4 stops the linear motor drive 25 by outputting a logic "0" signal. As a result, the linear motor drive 25 is connected to the linear motor 1.
By stopping the optical head 6, the optical head 13 is stopped. Thereafter, by tracking using a galvanometer mirror (not shown) in the optical head 13, the beam light of the optical head 13 is made to correspond to a corresponding track.

Also, when accessing the optical head 13 to another track, the linear motor driver 25 drives the optical head 13 by adding the correction scale in the same manner as described above.
can be accessed accurately.

As described in detail above, according to the present invention, the head for reproducing information on the disk is moved in the radial direction of the disk by a moving mechanism, and the head for reproducing information on the disk is moved in the radial direction of the disk, and the head is scaled by a detection signal from a position detector having a scale corresponding to the position of the disk. The number of corrected scales from the initial position of the scale to the innermost track of the disk is detected, this corrected scale number is stored in the storage means, and when accessing a predetermined position, the corrected scale number is detected. The scale value corresponding to the track number of is corrected by the corrected scale number stored in the storage means, and the moving mechanism is operated until the corrected scale value matches the scale number counted by the counting means. Since I made it to drive,
It is possible to provide a disk device in which the head can be accurately positioned, the access time for the head can be shortened, and the access control can be simplified.

[Brief explanation of drawings]

The drawings show one embodiment of the invention.
The figure is a schematic diagram of the overall configuration, and FIG. 2 is a diagram showing the positional relationship between the optical scale and the innermost track of the optical disk. 11... Optical disk, 13... Optical head, 16...
Linear motor, 17... Optical scale, 18... Detector, 19... Position signal processing circuit, 20... Auxiliary scale register, 21... Scale converter, 22... Specified scale register, 23... Adder, 24... Comparator, 25... Linear motor driver, 26...Pulse generation circuit, 27...Counter.

Claims (1)

[Claims] 1. A head for reproducing information on a disk; a moving mechanism for moving the head in the radial direction of the disk; a position detector having a scale corresponding to the position of the disk; a counting means for counting the number of scales based on a detection signal of the head; a detecting means for detecting the innermost track according to a signal obtained when the head is moved from the innermost circumference of the head; Storage means for storing the number of correction scales until a detection signal is supplied by the detection means; and when accessing a predetermined position, the number of correction scales stored in the storage means stores a scale value corresponding to a predetermined track number. and means for driving the moving mechanism until the corrected scale value and the scale number counted by the counting means match.