JPH0520781A - Optical disk device - Google Patents

Abstract

PURPOSE:To omit a clamping magnet for optical disks and to reduce the size of an optical disk device using a brushless motor. CONSTITUTION:An optical disk 1 is made of a soft magnetic material and divided in the direction of the circular circumference with the N and S poles magnetized in the thickness direction. The disk 1 is held at a magnet part 2a. A turntable 2 is set at a center guide part 7 of a non-magnetized material which guides the center of the disk 1 provided at the inner circumferential side of the part 2a. A support shaft 3 is provided to a base member 4 and supports rotatably the turntable 2, and a drive coil 10 is provided to the member 4 opposite to the part 2a of the turntable 2. In such a constitution, a clamping magnet can be omitted for the disk 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk device equipped with a thin brushless motor.

[0002]

2. Description of the Related Art A conventional optical disk device will be described below.

As shown in FIG. 5, 17 is an optical disc board,
Reference numeral 18 denotes a turntable which is press-fitted into a shaft 20a of a drive motor 20 fixed to a base member 19 to rotate, and 13
Is an attraction plate fixed to the turntable 18 and made of a ferromagnetic material, 14 is an attraction magnet, and 15 is an attraction magnet 14
Is a clamp member for holding the optical disc board 17 between the turntables 18, and 16 is a clamp holding member for releasing and holding the suction between the clamp member 15 and the suction plate 13. When the optical disc board 17 is set on the turntable 18, the clamp member 15 held by the clamp holding member 16 is driven by a drive mechanism (not shown) until it comes into contact with the upper surface 17 a of the optical disc board 17.
L in the figure indicates the drive motor 2 from the lower surface of the optical disc board 17.
The height to the lower surface of 0 is shown.

[0004]

However, in the above-mentioned conventional structure, the drive motor 20 is arranged below the base member 19 and the turntable 18 is arranged above the base member 19, so that the height L is large. Therefore, there is a problem in that the optical disk device cannot be made thin and small.

The present invention solves the above-mentioned problems of the prior art by eliminating the need for a magnet for clamping an optical disk.
It is an object to provide a miniaturized optical disk device.

[0006]

In order to achieve this object, the optical disk device of the present invention is a disk-shaped disc made of a soft magnetic material, which is divided in the circumferential direction and magnetized with N and S poles in the thickness direction. , A turntable composed of a magnet section for holding the optical disk board and a center guide section made of non-magnetized material for guiding the center of the optical disk board arranged on the circumferential side of the magnet section, and the turntable set up on the base member. It has a structure including a support shaft that rotatably supports the table and a drive coil that is disposed on the base member so as to face the magnet portion between the turntable and the base member.

[0007]

With this structure, a brushless motor is constituted by the turntable made of a soft magnetic material for holding the optical disk and the drive coil arranged on the base member.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

As shown in FIGS. 1 to 3, 1 is an optical disk made of plastic, 2 is a soft disk in which a bearing 5 is press-fitted inside a support shaft 3 which is erected on a base member 4. The turntable 2a made of a magnetic material is a disc-shaped turntable, and the magnet portion of the turntable magnetized by being divided into four poles in the circumferential direction and having N poles and S poles alternating in the thickness direction is magnetized. A center guide portion made of a non-magnetized material which is disposed on the inner peripheral side of the magnet portion 2a and guides the center of the optical disc board 1, a thrust bearing ball 6 and a turntable 8 for the optical disc board 1 by the attraction force of the magnet portion 2a. A clamp member sandwiched between 2 and 9 is a clamp holding member that releases or holds the clamp member 8. 1 in the figure
Reference numeral a denotes the upper surface of the optical disc board 3, reference numeral 3a denotes the axis of the support shaft 3, and reference numeral 11 denotes magnetic lines of force.

As shown in FIG. 4, on the base member 4,
Three drive coils 10 and a Hall sensor 12 are arranged.

The operation of the optical disk device configured as described above will be described below. When the optical disc board 1 is set on the turntable 2, the clamp member 8 held by the clamp holding member 9 is driven by a drive mechanism (not shown) until it comes into contact with the upper surface 1a of the optical disc board 1. Of course, the clamp holding member 9 which does not use a drive mechanism and the opening / closing lid of the apparatus are integrally configured, and the opening / closing operation of the opening / closing lid can be used. The thrust force of the turntable 2 is received by the thrust bearing balls 6. Since the method of driving the brushless motor configured as described above is a known technique, its description is omitted here.

As described above, according to this embodiment, the turntable 2 can be used as a part of the structure of the brushless motor, and the brushless motor can be constructed with a slight gap between the base member 4 and the turntable 2. It is very effective in thinning the optical disk device.

Further, since the magnet portion 2a also generates the attracting force of the clamp member 8, there is an excellent effect that the clamp magnet which has been conventionally required is not required.

[0014]

As described above, according to the present invention, there is provided a magnet portion for holding a disc-shaped optical disk disc made of a soft magnetic material which is divided in the circumferential direction and magnetized with N poles and S poles in the thickness direction. A turntable composed of a center guide part made of a non-magnetized material for guiding the center of an optical disk disc disposed on the inner peripheral side of the magnet part, a support shaft of the turntable set up on a base member, and a turntable. By providing the drive coil arranged between the base members so as to face the magnet portion and arranged on the base member, it is possible to realize a small and excellent optical disk device that does not require a magnet for clamping the optical disk.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing the concept of a main part of an optical disk device according to an embodiment of the present invention.

FIG. 2 is a plan view showing a magnetized state of a turntable of the optical disk device.

FIG. 3 is a schematic sectional view showing a magnetic circuit of the optical disk device.

FIG. 4 is a plan view showing an arrangement of drive coils of a base member of the optical disc device.

FIG. 5 is a schematic cross-sectional view showing the concept of a main part of a conventional optical disc device.

[Explanation of symbols]

 2 Turntable 2a Magnet part 3 Support shaft 4 Base member 7 Center guide part 8 Clamp member 10 Drive coil

Claims (1)

Claims: 1. An N pole / S in the thickness direction divided in the circumferential direction.
A magnet portion for holding a disc-shaped optical disk disc made of a soft magnetic material with magnetized poles, and a center guide portion made of a non-magnetized material for guiding the center of the optical disc disk arranged on the circumferential side of the magnet portion. And a support shaft that is erected on the base member to rotatably support the turntable, and a drive disposed on the base member facing the magnet portion between the turntable and the base member. An optical disk device equipped with a coil.