JPH0242674A - Mounting device for optical disk medium - Google Patents

Abstract

PURPOSE:To reduce the deformation of an optical disk medium by offsetting the magnetic flux of a permanent magnet provided to a spindle hub with an electromagnetic solenoid and weakining the attracting force. CONSTITUTION:A ring electromagnetic solenoid 17 is provided outside a spindle shaft 18 between a spindle hub 13 and a spindle motor 19 and fixed to the spindle motor 19. A current is made to flow to the electromagnetic solenoid 17 so that, for the generated magnetic pole, a side faced to a permanent magnet 15 can be made into an S pole and the side faced to the spindle motor 19 can be made into an N pole at the time of removing the attracted optical disk medium. As a result, the magnetic flux of the permanent magnet 15 is offset by the magnetic flux of the electromagnetic solenoid 17, and the attracting force to work between a magnetic force generated by the combination of them, namely, the permanent magnet 15 and a central metal fitted to the optical disk medium is made small. Thus, the deformation cannot be given to the optical disk medium.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an optical disk medium mounting device in an optical disk device that optically records and reproduces information on an optical disk medium of a disc-shaped recording medium, and particularly relates to a mounting device for an optical disk medium in an optical disk device that optically records and reproduces information on a disc-shaped optical disk medium. The present invention relates to a mounting device for an optical disc medium that is adsorbed by a holder.

[Conventional technology]

Optical disk media used in optical disk devices that optically record and reproduce information on disk-shaped optical disk media are free from dust and dirt on the optical disk medium in order to ensure the reliability of recorded information. It is often used housed in a cartridge case to prevent it from sticking. Generally, when an optical disk medium is attached to and removed from a spindle hub of an optical disk device, a driving force is applied to a cartridge case that houses the optical disk medium. In other words, the means for attaching the optical disk medium to the spindle hub is carried out by using the attraction force of the permanent magnet built into the spindle hub. Therefore, a metal plate that is attracted by the permanent magnet is attached to the center of the optical disk medium. ing.

FIG. 3 is a sectional view showing an example of a conventional optical disk medium mounting device, and illustrates the external force acting on the optical disk medium and the state of its deformation when the magnetic adsorption type optical disk medium housed in the cartridge case is removed from the spindle hub. This is a diagram for

As shown in FIG. 3, when the magnetic adsorption type optical disc medium 2 housed in the cartridge case 1 is removed from the spindle hub 3 of the optical disc loading device, the central metal part provided at the center of the optical disc medium 2 is inserted into the center of the spindle hub 3. The lick is attracted by the permanent magnet 5 provided at the top,
The center of the optical disc medium 2 receives a force in the direction of arrow A.

- The outer periphery of the destination disk medium 2 is supported by the optical disk support section 6 in the cartridge 1, so it receives a force in the direction of arrow B. Therefore, as shown in the figure, the optical disc medium 2 is curved, with the central portion being pulled downward and the outer peripheral portion being lifted upward.

[Problem to be solved by the invention]

As mentioned above, the conventional optical disk medium loading device deforms the medium when taking out the optical disk medium 2, and there is a risk that this deformation may cause cracks or distortion in the medium. When distortion occurs, there is a problem in that information recorded on the optical disc medium is damaged. Therefore, in order to ensure the reliability of the information recorded on the optical disc medium, there is a need for an optical disc medium mounting device that does not deform the optical disc medium as described above.

[Means to solve the problem]

The optical disc medium mounting device of the present invention includes a spindle shaft that rotates integrally with a spindle motor, a spindle hub that passes through the spindle shaft and is fixed to the upper part thereof, and a spindle hub that is fixed to the upper part of the spindle hub and that faces the upper and lower surfaces of the spindle shaft. an annular permanent magnet having a magnetic pole; and an optical disk medium disposed outside the spindle shaft between the spindle hub and the spindle motor, fixed to the spindle motor, and having a central metal portion attracted by the permanent magnet. and a ring-shaped electromagnetic solenoid wound so as to generate magnetic flux in a direction that cancels the magnetic flux of the permanent magnet when removed.

〔Example〕

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

FIG. 1 is a sectional view showing one embodiment of the present invention.

In FIG. 1, the spindle hub 13 has a spindle shaft 1 passing through the center on its upper optical disk mounting surface.
It has a ring-shaped permanent magnet 15 embedded coaxially with the magnet 8. The spindle hub 13 is coupled to a spindle motor 19 via a spindle shaft 18, and is driven by the rotation of the spindle motor 19. The ring-shaped electromagnetic solenoid 17 is provided outside the spindle shaft 18 between the spindle hub 13 and the spindle motor 19, and is fixed to one spindle motor.

FIG. 2 is a perspective sectional view showing the permanent magnet 15 and electromagnetic solenoid 17 of the embodiment shown in FIG.

As shown in FIG. 2, the polarity of the permanent magnet 15 is such that the upper surface, which attracts the optical disk medium, is made of Ni, and the lower surface, which is fixed to the spindle hub, is the S pole. On the other hand, when removing the attracted optical disk medium, an electric current is applied to the electromagnetic solenoid 17 so that the generated magnetic pole is Si on the side facing the permanent magnet 15 and N pole on the side facing the spindle motor 19. flow. As a result, the magnetic flux of the permanent magnet 15 is canceled by the magnetic flux of the electromagnetic solenoid 17, and the magnetic force generated by their combination, that is, the attractive force acting between the permanent magnet 15 and the central metal 4 attached to the optical disk medium 2, is small. Become. When removing the optical disk medium 2, the electromagnetic solenoid 17 is activated as described above, and then the loader mechanism is activated to remove the optical disk medium together with the cartridge case from the spindle hub 13.

〔Effect of the invention〕

As explained above, the optical disk medium mounting device of the present invention can cancel the magnetic flux of the permanent magnet provided in the spindle hub using the electromagnetic solenoid and weaken the attraction force, so that the optical disk medium mounting device of the present invention can This has the effect that the attraction force between the central metal part provided at the center and the spindle hub can be significantly reduced.

Therefore, the deformation of the optical disk medium that occurs when the optical disk medium is removed from the spindle hub can be reduced, and cracks and distortions of the optical disk medium can be prevented to ensure the reliability of the information recorded on it. There is an effect. Furthermore, there is also the effect that the force acting on the cartridge case housing the optical disc medium can be reduced.

FIG. 3 is a cross-sectional view showing an example of a conventional optical disk medium mounting device.

DESCRIPTION OF SYMBOLS 1... Cartridge case, 2... Optical disk medium, 3.13... Spindle hub, 4... Central metal part, 5.15... Permanent magnet, 6... Optical disk support part, 8. 18... Spindle shaft, 17... Electromagnetic solenoid, 19... Spindle motor.

Claims (1)

[Claims] A spindle shaft that rotates integrally with a spindle motor, a spindle hub that passes through the spindle shaft and is fixed to the upper part thereof, and an annular permanent magnet that is fixed to the upper part of the spindle hub and has magnetic poles on the upper and lower surfaces. , when removing an optical disk medium that is disposed outside the spindle shaft between the spindle hub and the spindle motor, is fixed to the spindle motor, and has a central metal portion attracted by the permanent magnet, the magnetic flux of the permanent magnet is removed. What is claimed is: 1. An optical disk medium mounting device comprising: an annular electromagnetic solenoid wound so as to generate magnetic flux in a canceling direction;