JPS61133078A - Disk device - Google Patents

Abstract

PURPOSE: prevent the damages of a disk by stopping a turntable with the aid of information from a discriminating circuit when a difference between rotation al speeds of the turntable and the disk exceeds a set value. CONSTITUTION:An F-V converter 8 outputs a voltage in proportion to the rotational frequency of a motor 4 with the aid of a signal from an optical tachometer 5 during a period from the activation to the stop of the motor 4. Moreover an F-V converter 7 inputs a signal for reading the timing mark for detecting the rotational frequency of an optical disk medium 3 by a phototransistor 6, and outputs a voltage in proportion to the rotational frequency of the optical disk medium 3. The deciding circuit 9 compares the output voltages of the F-V converters 7 and 8. When a difference between the rotational frequencies of the motor 4 and the optical disk medium 3 exceeds the preset value, the deciding circuit 9 outputs an abnormality detecting signal to be transmitted to a motor drive part 10, and stops the motor 4. Thus the damage of the optical disk medium 3 can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a disk device that rotates a disk.
In particular, it relates to a disk device that rotates an optical disk.

(Prior Art) Conventionally, an optical disk device used as a file device for information processing, etc. is rotatable as shown in FIG. Rotation was told to the optical disk medium 3, and the optical disk medium 3 was rotated.

(Problems to be Solved by the Invention) The above-mentioned optical disk device has the disadvantage that the optical disk may be damaged. That is, the optical disk medium 3 has a large diameter and therefore a large inertial mass. Furthermore, the period from when the optical disk medium 3 is inserted into the optical disk device until the rotation of the optical disk medium 3 becomes stable and information can be recorded and read on the optical disk medium 3 is required to be short, within a few seconds. Ru. For this reason, the rotational torque applied to the optical disk medium 3 when the turntable 2 is started or stopped is very large. However, the pushing force of the optical disk medium 3 by the clamper 1 has a certain limit in order to avoid generation of distortion of the optical disk medium 3&C.

Furthermore, since the optical disk medium 3 must be precisely positioned, materials with high friction (such as rubber) cannot be used on the surface of the turntable 2.

Therefore, the frictional force between the optical disk medium 3 and the turntable 2 generated by the clamp mechanism has no margin against the rotational torque, and due to a malfunction of the clamp mechanism or the influence of dust, there is a gap between the optical disk medium 3 and the turntable 2. There is a drawback that the optical disk medium 3 may be damaged due to the occurrence of scratches.

The present invention detects the rotational speed of the turntable and the rotational speed of the disc, and stops the rotation of the turntable when the difference between them becomes greater than a preset value, thereby preventing damage to the disc. The present invention provides a disk device with the following features.

(Means for solving the problem) A disk device of the present invention includes a rotating turntable,
A disk device having a clamper that presses and rotates a disk against the turntable, comprising: a rotational speed measuring means for measuring the rotational speed of the turntable and the rotational speed of the disk; and the rotational speed of the turntable and the rotational speed of the disk. the turntable is configured to stop the turntable when the difference in rotational speed becomes greater than the set value based on information from the determination circuit. Features.

(Example) Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 2 is a block diagram of one embodiment of the present invention.

Referring to FIG. 2', one embodiment of the present invention includes a clamper 1, a turntable 2, an optical disk medium 3, a motor 4 for driving the turntable 2, and a motor 4 for driving the turntable 2. -7
an optical tachometer 5 that monitors the rotation of the wheel 2;
A phototransistor 6 that monitors the rotation of the optical disk medium 3, an F-V converter 7 that outputs a voltage proportional to the number of rotations of the optical disk medium 3 according to the signal from the phototransistor 6, and a turntable according to the signal from the optical tachometer 5. 20 Compare the voltages of F-V converter 8, which outputs a voltage proportional to the number of rotations, and F-V converters 7 and 8, and find out if there is an abnormality.
It consists of a determination circuit 9 that determines the presence or absence, a motor drive section 10, an abnormality display section 11, and an interface circuit section 12 for communicating with a host device.

When the optical disk medium 3 is placed on the turntable 2 and the clamper 1 presses the medium 3 against the turntable 2, a motor rotation command signal 13 is sent to the motor drive unit 10 from a control circuit not shown in FIG. The motor drive section 10 controls the voltage or current applied to the motor 4 based on the signal from the optical tachometer 5, and accelerates the motor 4 at a constant acceleration until it reaches a steady rotation speed. After the motor 4 reaches the steady rotation speed, it is controlled to maintain the steady rotation speed. When the motor rotation command signal 13 is no longer applied, the motor drive unit 10 decelerates the motor 4 at a constant deceleration and stops the motor 4 in the same way as when accelerating.

From the start to the stop of the motor 4, the F-V converter 8 is operated by the signal from the optical tachometer 5.

An electric current 8:t- proportional to the rotation speed of the motor 4 is output. or,
The B'-V converter 7 inputs a signal obtained by reading a timing mark for detecting the rotational speed of the optical disk medium 3 by the phototransistor 6, and outputs a voltage proportional to the rotational speed of the optical disk medium 30. The determination circuit 9 compares the output types 8Et- of the F-V converters 7 and 8, and if the difference in the rotational speed between the motor 4 and the optical disk medium 3 exceeds a preset value, it outputs that an abnormality has been detected. . The output signal of the determination circuit 9 is transmitted to the motor drive unit 10, the display unit 11, and the interface unit 12 with the host device, and the motor 4I- is stopped to prevent damage to the optical disk medium 3, and at the same time is transmitted to the operator and the host device. Notify of abnormality.

(Effects of the Invention) As explained above, the present invention can prevent damage to the disc by comparing the rotational speeds of the disc and the turntable and stopping the turntable when the difference between the two speeds exceeds a set value. There is an effect that can be achieved.

[Brief explanation of drawings]

FIG. 1 is a front view of the peripheral portion of a turntable 2 of a conventional optical disk device, and FIG. 2 is a block diagram of an embodiment of the present invention. 1... Clamper, 2... Turntable, 3... Optical disk medium, 4... Motor, 5... Optical tachometer, 6 ...
...Phototransistor, 7゜8...F-V
Converter, 9... Judgment circuit, 10... Motor drive section, 11... Abnormality display section, 12...
...Interface section. , -1, Agent Patent Attorney Susumu Hara', -1゛”-' ”7
"" and 'yf51 Figure 2-481=

Claims (1)

[Claims] A disk apparatus having a rotating turntable and a clamper that presses a disk against the turntable and rotates the disk, comprising: a rotational speed measuring means for measuring a rotational speed of the turntable and a rotational speed of the disk; and a rotational speed of the turntable. and a determination circuit for detecting that the difference between the rotational speeds of the disc and the disc becomes larger than a set value, and the turntable is stopped when the difference in the rotational speed becomes larger than the set value based on information from the determination circuit. A disk device characterized by: