JPH0485751A - Disk-shaped recording medium and disk clamp mechanism - Google Patents

Abstract

PURPOSE:To attain discrimination for the upper or lower side surface of a disk and to suppress the malfunctions together with the total cost reduction of a device and the simplification of the device structure by providing a permanent magnet in the disk and prescribing the magnetizing direction of the magnet. CONSTITUTION:A disk 6 is provided with a clamp guide hole 7 and a clamp permanent magnet 8 and then set on a turntable 2. Thus the tip part of a spindle motor shaft 17 of a spindle motor 1 is put into the hole 7 and the S pole of the magnet 8 is set opposite to the N pole of a clamp permanent magnet 3. These magnets are attracted to each other with their magnetic forces and the disk 6 is attached onto the turntable 2. If a non-recording surface of the disk 6 is set opposite to an optical head, the N pole of the magnet 8 is erroneously set opposite to the N pole of the magnet 3. Thus the magnetic repulsation is caused and therefore the disk 6 is never attached onto the turntable 2. Thus the disk 6 is never clamped in such a wrong inserting way.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a disk clamp mechanism of an optical disk recording/reproducing device for recording information on a rotating flat plate or reproducing information already recorded. .

[Prior Art] Devices that optically record information on concentric or spiral tracks formed on a rotating flat disk, or optically read and reproduce recorded information, include: , compact discs that record information in the form of convexes and convexities, irradiate them with light beams, and reproduce them using optical interference, optical video discs, and magneto-optical discs that record and reproduce information using the magneto-optical effect. This device has already been put into practical use. Conventional disc clamping mechanisms for compact discs, optical video discs, etc. use a spindle motor with a tapered protrusion to automatically center the hole provided on the disc side to position the device or store the disc. The disc is clamped and fixed by a clamp member provided on the cartridge. However, with this configuration, there were many machining errors in the tapered portion of the disk hole, etc., resulting in a large number of eccentricities during rotation, and errors may occur during reproduction, making it unsuitable for information processing.

On the other hand, in a clamping mechanism for an optical disk device for information processing, the disk has a clamping iron material provided with a guide hole to a spindle motor.

In addition to the turntable, the spindle motor is equipped with a permanent magnet for clamping.
A guide hole provided in the clamp iron material is inserted into the spindle motor shaft and positioned.

In this case, since the materials are made of steel, the machining accuracy is extremely high. Thereafter, the iron material for clamping and the permanent magnet for clamping are attracted to each other and become rotatable.

Therefore, in both the above-mentioned method and the clamping iron material, if the optical disk is incorrectly inserted with the non-recording surface facing the optical head, it becomes impossible to record or reproduce information. was established.

Specifically, as shown in FIG. 3, the permanent magnet 11 for clamping is provided with a clamping iron material 16 in which a guide hole 15 for clamping to the spindle motor 1 is provided in the disk 14. It needs to be thick enough to cause this. When installing the disk 14, the clamp guide hole 1 provided in the clamp iron material 16
5 is inserted into the spindle motor shaft 17, the clamping iron material 16 and the clamping permanent magnet 11 are attracted to each other, and the mounting of the disk 14 on the spindle motor 1 is completed.

FIG. 4 shows a cross-sectional view of the clamping mechanism when the non-recording surface of a single-sided disk faces the optical head, that is, when the disk is inserted incorrectly.

In this case, in the clamping mechanism, the clamping iron material 16 on the disk side 14 and the clamping permanent magnet 11 on the turntable 10 side will be longer than when normally installed, and the clamping force will be reduced, but the clamping force will be reduced. Put it away. Furthermore, since the disk 14 is in contact with the turntable 10, it becomes rotatable and the optical head operates for recording and reproduction, but since the non-recording surface faces the optical head, malfunctions occur. .

Conventionally, this method of distinguishing the front and back sides of a disc was done by mechanically detecting and determining the shape of the cartridge in which the disc was stored, but if the disc was inserted into the cartridge with the front and back reversed, malfunctions would occur as described above. do.

[Problems to be Solved by the Invention] As explained above, the conventional disc clamping mechanism requires a special shape or detection mechanism on the cartridge to distinguish between front and back, and cannot be played with a -degree optical head. Since it was only possible to make a distinction after confirming the situation, the problem was that the clamp mechanism had become larger and more complicated.Although the clamp mechanism is simple, the signal processing circuits such as the playback system have become larger and more complicated. I have a problem to solve.

Furthermore, if an attempt was made to increase the disk clamping force for purposes such as high-speed rotation, it would be necessary to increase the thickness of the magnet on the turntable side, resulting in the problem of an increase in the size of the device.

[Means for Solving the Problems] In order to solve the above problems, the present invention first provides a first invention that provides a disk-shaped recording medium for recording and/or reproducing information, and a clamp provided at the center of the disk. A second invention provides a disk-shaped recording medium characterized in that a first magnetic material is provided around a hole, and a second invention uses the disk-shaped recording medium,
The present invention provides a disk clamp mechanism for clamping the disk-shaped recording medium, characterized in that a second magnetic body is provided around the clamp portion corresponding to the clamping hole of the recording medium.

A third invention is characterized in that the polarity of the first magnetic body on the recording surface side and the polarity of the second magnetic body on the clamping surface side are formed so as to attract each other. A fourth invention provides a disk-shaped recording medium and a disk clamp mechanism, wherein the first magnetic body and/or the second magnetic body are formed of permanent magnets. and a disc clamp mechanism.

[Operation] With the configuration of the present invention described above, due to the relationship between the magnetization directions of the permanent magnets on the turntable side and the disk side, the normal direction (
In an arrangement in which the disk information surface and the optical head face each other), the turntable and the disk are attracted to each other by permanent magnets and are rotatable.

In addition, in the direction of incorrect insertion on the front and back sides of the disk (the disk information surface and the optical head are placed in the same direction), the turntable and the disk repel each other due to the influence of their permanent magnets, making it impossible to chuck the disk. At this point, the device has determined whether the disk is front or back, and is controlled to eject the disk.

Furthermore, it is possible to increase the magnetic force of the disk to the turntable.

[Example] FIG. 1 shows a cross-sectional view of a disk clamp mechanism of the present invention.

The spindle motor 1 includes a turntable 2, a permanent magnet 3 for clamping, a rotor 4, a coil 5, and the like.

The disk 6 is provided with a clamping guide hole 7 and a clamping permanent magnet 8, and the clamping permanent magnet 8 and the turntable section clamping permanent magnet 3 are configured such that their magnetic poles are oriented in the direction in which they will attract each other when the disk is mounted. has been done.

When this disk 6 is mounted on the turntable 2, the tip of the motor shaft 17 of the spindle motor 1 is inserted into the clamp guide hole 7 provided in the disk 6, and the S pole of the clamp permanent magnet 8 and the clamp permanent The N poles of the magnets 3 face each other. Then, the disk 6 is attached to the turntable 2 by attracting each other by the magnetic force of each magnet. At this time, if the size of the mounting magnets is the same as that of the conventional one, the two mounting magnets are arranged so that they face each other, so compared to the conventional technology shown in Fig. 3. The mounting force of the disc is much greater. Furthermore, in cases where the attraction force does not need to be increased as much as before or is required to be as large as before, the magnets for attachment can be made smaller, resulting in a thinner overall device.

FIG. 2 shows a sectional view of the disk clamping mechanism according to the present invention when the disk is inserted incorrectly.

This shows the case of incorrect insertion when the information recording surface of the disk and the optical head face each other in the normal direction, but the non-recording surface faces the optical head. In this case, the clamping mechanism of the present invention includes a permanent clamping magnet 8 on the disk side 16 and a permanent clamping magnet 3 on the turntable side 2.
repel each other, and the disc 6 is not mounted on the turntable 2.

In other words, when the non-recording surface is inserted so as to face the optical head, the N pole of the permanent magnet 8 for clamping is placed on the turntable 2.
The disk 6 faces the N pole of the clamping permanent magnet 3 attached to the turntable 2, and magnetic repulsion occurs, so that the disk 6 is not attached to the turntable 2. Therefore, even if the disc is inserted incorrectly, the disc will not be clamped, so there will be no malfunction in the installation as a whole, and there will be no need for special devices to distinguish between the front and back sides of the disc.

[Effect of the invention] The present invention as described above has the following effects.

(1) By having a permanent magnet in the disk, it is possible to reduce the thickness of the spindle motor while maintaining the clamping force.

(2) If there is no need to make the disk thinner, the disk rotation, speed, and rotational force can be increased by keeping the size of the permanent magnet as before and increasing the clamping force.

(3) By regulating the magnetization direction of the permanent magnet provided on the disk, it is possible to distinguish between front and back, which prevents malfunctions. (4) Devices for distinguishing between front and back are not required, reducing the cost and simplifying the entire device. Leads to.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of the optical disk clamping mechanism of the present invention. FIG. 2 shows a sectional view of the optical disk clamping mechanism of the present invention when it is incorrectly inserted. FIG. 3 is a sectional view of a conventional optical disk clamp mechanism. FIG. 4 shows a cross-sectional view of the conventional optical disk clamping mechanism at the time of incorrect insertion. 1... Spindle motor 2... Turntable 3... Permanent magnet for clamp 6... Disk 7... Guide hole for clamp 8... Permanent magnet for clamp 16 ・ 17 ・

Claims (4)

[Claims] (1) A disk-shaped recording medium for recording and/or reproducing information, characterized in that a first magnetic material is provided around a clamping hole provided in the center of the disk. (2) In the clamping mechanism for clamping the disk-shaped recording medium using the disk-shaped recording medium according to claim 1, a second magnetic body is provided around the clamp portion corresponding to the clamping hole of the recording medium. A disc clamp mechanism featuring: (3) The polarity of the first magnetic material on the recording surface side and the polarity of the second magnetic material.
A disk-shaped recording medium and a disk clamp mechanism, characterized in that the polarity of the clamping surface side of the magnetic material is formed so as to be mutually attracted. (4) Claim 1, wherein the first magnetic body and/or the second magnetic body are formed of permanent magnets.
The disc-shaped recording medium and disc clamp mechanism according to items 3 to 3.