JPH0677042U - Disc clamp device - Google Patents

Abstract

(57) [Summary] [Purpose] To prevent vibration of the optical disk. [Structure] When an optical disc is mounted on a turntable, when the optical disc is held on the turntable via a clamper and the optical disc that covers one side of the optical disc, a magnetic ring is provided on the other side opposite to the clamper side. Is pressed against the clamper side by the magnetic force of an external magnet to prevent the optical disc from vibrating.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an optical disc device for recording and reproducing on a disc, and more particularly to a disc clamp mechanism in which the disc is a CD or a CD-R.

[0002]

[Prior art]

 Generally, the clamp mechanism of a disk device comprises a turntable 2 which holds and rotates the disk 1 as shown in FIG. 3, and a clamper 3 which holds the disk 1 from the non-recording surface and the non-reproducing surface side.

[0003]

[Problems to be solved by the device]

 By the way, the disk 1 has its own vibration, which has harmonic components as shown in FIG. 5B. The disturbance causes the disk to resonate at those frequencies. The resonance of any one of the frequencies affects the servo system for following the track of the disk 1 and causes a phenomenon such as a track jump.

As shown in FIG. 4, this is because a disc along the recording / reproducing surface side cannot be supported and the force for the disc 1 to attract the clamper 3 cannot be obtained. There was a problem that the vibration could not be removed completely.

[0005]

[Means for Solving the Problems]

 In order to solve the above-mentioned problems, in the present invention, the recording and reproducing surface has a magnetic ring that is rotatable after clamping and a magnet that attracts the ring from the non-recording / non-reproducing surface side. The outer peripheral portion of the disc is sandwiched between the ring and the clamper by the attraction force of the magnet and the ring, and the disc is forcibly pressed against the clamper.

[0006]

【Example】

 An embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a state where the disc is clamped, and FIG. 2 shows a state before the disc is clamped. The magnetic ring 5 according to the present invention is a magnet. From FIG. 2, the magnetic ring 4 before the disc clamp is in the state of being attracted to the magnet 5.

When the disc 1 is set on the magnetic ring 4 and the clamper 3 is lowered in the direction of arrow A to clamp the turntable 2 as shown in FIG. 1, the disc 1 is held on the turntable 2. At the same time, it is pressed against the clamper 3 from around the disk 1 by the magnetic ring 4. At this time, the magnetic ring 4 is separated from the magnet 5, but the magnetic ring 4 exerts an attractive force in the direction of arrow B by the magnet 5 to push up the outer peripheral portion of the disk 1 and bring the disk 1 into close contact with the clamper 3. It

Although the magnet 5 is a permanent magnet, it may be an electromagnet, and in this case, the ring 4 causes an attractive force 6 of the ring 4 by a magnetic field generated by energizing the electromagnetic coil after the disk 1 is clamped. It is possible to adopt a structure in which the outer peripheral portion of 1 can be pushed up and brought into close contact with the clamper 3.

Therefore, since the disc 1 can be forcibly brought into close contact with the clamper 3, a characteristic which is more attenuated than that of the conventional B shown in FIG. 5A is obtained, which is a problem. Not only can the natural vibration of the clamp be sandwiched between the clamper 3 and the magnetic ring 4 and suppressed, but also the one given to the rotating body is a uniform ring 4 and there is no means to attract the ring 4 to the clamper 3 itself. , The dynamic balance of the rotating body is not significantly changed. Further, in the above embodiment, the attraction force of the magnet was mainly described, but the same effect can be obtained by the repulsion force. In that case, it is preferable that the magnet 5 is provided below the magnetic ring 4.

[0010]

[Effect of device]

 According to the present invention, the magnetic ring provided around the disk is attracted by the attracting force of the magnet, and the clamper and the magnetic ring are rotatably formed, so that the disk and the clamper contact the entire surface of the disk and prevent the disk from vibrating. can do.

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part showing an embodiment of the present invention.

FIG. 2 is a sectional view of an essential part showing an embodiment of the present invention.

FIG. 3 is a view showing a conventional clamped state.

FIG. 4 is a diagram showing a problem in a conventional clamped state.

FIG. 5 is a diagram showing a vibration characteristic of a disc.

[Explanation of symbols]

 1 disk 2 turntable 3 clamper 4 magnetic ring 5 magnet

Claims (1)

[Scope of utility model registration request] 1. In an optical disk device, a clamper covering one surface of the optical disk, a turntable for holding and rotating the optical disk, a ring of a magnetic material rotatable on an information recording surface of the other surface of the optical disk, and A disc clamp device, comprising: a magnet for applying a magnetic force to a magnetic body, and a magnet for pressing the peripheral portion of the optical disc with the magnetic ring to the clamper via the disc to clamp the disc.