JPH05146131A - Optical disk rotation drive mechanism - Google Patents

Abstract

(57) [Summary] [Object] A rotary drive mechanism for an optical disc medium in a replaceable optical disc device, in which an axial length is shortened by enlarging an outer shape of a motor while avoiding interference with an optical head, thereby reducing an optical disc. The purpose is to enable thinning of the device. [Structure] A rotatable disk-shaped permanent magnet 12-supporting a small-diameter spindle 12 that does not interfere with an optical head for recording and reading optical information and having magnetic poles of different polarities equally divided in the circumferential direction. On the other hand, an optical disk 11 having a disk-shaped metal plate 11-2 made of a thin magnetic material and having a central hole 11-2a at the center is adsorbed to and held by the disk 3, A plurality of flat coils 13 facing the disk-shaped permanent magnet 12-3 on the side opposite to the permanent magnet 12-3.
-2 is provided, and the flat coil 13-2 is energized to rotate the disk-shaped permanent magnet 12-3 and thus the optical disk 11 so that the rotation speed can be controlled to a constant value.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary drive mechanism for an optical disk medium in a replaceable optical disk device.

Recently, the optical disc apparatus is required to be further miniaturized as the computer is miniaturized and its performance is improved. However, in the conventional rotary drive mechanism for the optical disc, the rotary drive mechanism has a large restriction in the radial direction so that the rotary drive mechanism and the optical head do not interfere with each other when the optical head comes to the innermost side of the optical disc medium. is recieving. For this reason, the motor has a structure that is long in the axial direction in order to obtain the necessary drive torque, which is a major factor that the thickness of the optical disk device cannot be reduced.

Therefore, by rotating the new optical disk, the size of the optical disk device can be reduced by shortening the axial length by increasing the outer shape of the motor while avoiding interference with the optical head. A drive mechanism is required.

[0004]

2. Description of the Related Art As shown in FIG. 4, a rotary drive mechanism for an optical disk, which has been widely used in the past, has a thin outer portion corresponding to the height of an optical head 4 mounted on a moving stage and an outer portion of a lower portion thereof. The centering pin 2-2b of the optical disk medium 1 is attached to the stepped cylindrical housing 2-1 with thick
A rotary shaft 2-2 having a flange-shaped turntable 2-2a on one end side and a flange-shaped disc portion 2-2c formed on the other end side, the disc portion 2-2c being the housing 2-1 It is rotatably attached to the inside of the small diameter through a ball bearing 2-5 so as to be located inside the large diameter part of the.

And, the turntable of the rotary shaft 2-2
A permanent magnet 2-3 for fixing the disk is arranged in the concave portion of 2-2a, and at the end face side of the disc portion 2-2c, magnetic poles having different polarities are equally divided in the circumferential direction. The permanent magnet 2-4 is fixed, and a plurality of flat coils 3-2 are provided on the side facing the permanent magnet 2-4. A motor is formed by closing the large-diameter opening of -1 and by energizing the flat coil 3-2, the permanent magnet 2-4 for the motor and thus the optical disk medium 1 can be controlled at a constant rotational speed. Is configured.

[0006]

A problem with the conventional rotary drive mechanism described above is when the optical head 4 mounted on the moving stage comes to the innermost side of the optical disc medium 1 as shown in FIG. Since it interferes with the large diameter portion of the housing 2-1, the outer shape of the portion corresponding to the height of the optical head 4 is made thin, and the rotary shaft 2-2 is inserted in this portion through the ball bearing 2-5.
Is rotatably attached to form a rotary spindle part, and a permanent magnet 2-4 for rotation and a flat coil 3-2 for obtaining a necessary driving torque of the optical disk medium 1 are internally provided in a large-diameter motor as an optical head. Since it is provided below the moving surface of No. 4, there is a problem that the rotation drive mechanism becomes axially long and the thickness of the optical disk device cannot be reduced.

In view of the above problems, the present invention makes it possible to reduce the axial length by enlarging the outer shape of the motor while avoiding interference with the optical head, thereby making the optical disk device thinner. It is an object of the present invention to provide a new optical disk rotation drive mechanism that can be used.

[0008]

As shown in FIG. 1, the present invention is supported by a small spindle 12 that does not interfere with an optical head for recording and reading optical information, and is equally divided in the circumferential direction. For the rotatable disk-shaped permanent magnet 12-3 having magnetic poles with different polarities, the central hole 11 made of a thin magnetic material is used.
An optical disk 11 having a disk-shaped metal plate 11-2 having -2a at its center is adsorbed and held, and the disk-shaped permanent magnet 12-3 is provided on the side opposite to the disk-shaped permanent magnet 12-3. A plurality of flat coils 13-2 facing the magnet 12-3 are provided, and the flat coil 13-2 is energized to rotate the disc-shaped permanent magnet 12-3 and thus the optical disk 11 to rotate at a constant rotational speed. It is configured so that it can be controlled.

[0009]

In the present invention, as shown in FIG.
A spindle 12 that supports and rotates 11 can be regulated to a size that can avoid interference with the optical head 4, and a permanent magnet 12-3 that serves as a rotation drive source of the optical disk medium 11
Since the flat coil 13-2 and the flat coil 13-2 are formed to have an outer diameter capable of obtaining a required drive torque at a position where they do not interfere with the optical head 4, the axial length of the rotary drive mechanism is shortened and the optical disc device is made thinner. It becomes possible.

[0010]

Embodiments of the present invention will be described in detail below with reference to FIGS. FIG. 1 is a partially cutaway sectional view showing a rotary drive mechanism of an optical disk according to a first embodiment of the present invention, FIG. 2 is a sectional view illustrating the operation of the first embodiment, and FIG. 2 is a view of the operation of the first embodiment. 3 shows a partially cutaway sectional view of the second embodiment, and the same members in the respective drawings are designated by the same reference numerals.

In the first embodiment of the present invention, as shown in FIG. 1, a housing 12 in which a flange-shaped fixing seat 12-1a is formed on one end side of a cylinder having an outer diameter and a height that do not interfere with the movement of the optical head. A rotary shaft 12-2 having a centering pin 12-2b for mounting the optical disk medium 11 through a ball bearing 2-5 and a flange-shaped turntable 12-2a on one end side is rotatably provided in the inner diameter of -1. To form a spindle 12, and the spindle 12 is hung on a non-movable member (not shown) and is equally divided in the circumferential direction into the recess of the turntable 12-2a of the rotating shaft 12-2. The disk-shaped permanent magnets 12-3 are fixed to each other in the direction of magnetic force in the direction of plate thickness, and the magnetization directions of adjacent magnets are different from each other.

With respect to the spindle 12, a plurality of flat coils are formed on a yoke 13-1 formed of a disc-shaped metal having excellent magnetism so as to face the disc-shaped permanent magnet 12-3 at the upper part thereof.
13-2 is fixed, and the stator 13 provided with a magnetic sensor 13-3 such as a Hall element for detecting the magnetic pole position of the disk-shaped permanent magnet 12-3 is fixed to a non-movable member (not shown). By doing so, a motor is constructed.

The centering pin 12-2b of the rotary shaft 12-2
The disk-shaped permanent magnet 12 is provided with a central hole 11-2a for fitting with
-3 is adhered to the inner peripheral portion of the optical disk medium 11 so that the magnetic metal plate 11-2 is formed so that it can be attached to the permanent magnet 12-3 of the rotating shaft 12-2. The permanent magnet 12-3 attracts and holds the optical disk medium 11 by the magnetic force of the permanent magnet 12-3, and the flat coil 13-2 is energized to apply the permanent magnet.
12-3, that is, the rotation shaft 12-2 of the spindle 12 that adsorbs the optical disk medium 11 can be controlled to a constant rotation speed.

As a result, the external dimensions of the spindle 12 for supporting and rotating the optical disk medium 11 as shown in FIG.
The outer diameter of the spindle 12 is large enough to avoid interference with the optical head 4 because it can cover the height of the optical head 4 that is accessed in the radial direction of the optical disk medium 11 and can support the rotation of the optical disk medium 11. Permanent magnet 12 that can be regulated up to now and also serves as a drive source for rotation
-3 and the flat coil 13-2 are provided at positions where they do not interfere with the optical head 4, the outer diameter can be increased, the required drive torque can be obtained, and the axial length is shortened, resulting in a thin optical disc device. Can be changed.

As shown in FIG. 3, the rotary drive mechanism of the second embodiment has a centering pin 12-2b and a flange-shaped turntable 12.
-Rolling shaft 12-2 with 2a on one end side, to the inner diameter of housing 12-1 with fixed seat 12-1a formed on one end side of the cylinder Ball bearing 2-
The spindle 12 rotatably attached via the shaft 5 is constructed in the same manner as in the first embodiment.

Further, the optical disk medium 21 has the rotating shaft 12
-2 is a thin disk made of a non-magnetic material or a magnetic material with the disk-shaped permanent magnet 22-3 having a central hole 22-3a fitted to the centering pin 12-2b A cover plate 25 having a shape of a circle is attached to protect the permanent magnet 22-3.

The central hole 22-3a of the optical disk medium 21 is
A rotating shaft 12 supported by a spindle 12 suspended from a non-movable member.
-2 by being fitted to the centering pin 12-2b, it is attracted to the turntable 12-2a made of a magnetic material formed on the rotating shaft 12-2 by the magnetic force of the permanent magnet 22-3. A plurality of flat coils 13-2 are fixed to the yoke 13-1 having excellent magnetism so as to face the permanent magnet 22-3 of the optical disk medium 21, and the magnetic pole position of the disk-shaped permanent magnet 22-3 is set. By fixing the stator 13 provided with the magnetic sensor 13-3 for detection to the movable member (not shown) concentrically with the spindle 12, the same effect as the first embodiment can be obtained.

[0018]

As is apparent from the above description, according to the present invention, there are advantages that the rotation driving mechanism has a short axial length, and the optical disc device can be made thin, with a very simple structure. Therefore, it is possible to provide a rotation drive mechanism of an optical disc which can be expected to have a remarkable economical effect and an effect of improving reliability.

[Brief description of drawings]

FIG. 1 is a partially cutaway sectional view showing a rotation drive mechanism of an optical disc according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view illustrating the operation of the first embodiment.

FIG. 3 is a partially cutaway sectional view showing the configuration of the second embodiment.

FIG. 4 is a sectional view showing a conventional rotary drive mechanism.

[Explanation of symbols]

2-5 is a ball bearing, 11 and 21 are optical disk media, 11-2 is a magnetic metal plate, 11-2a and 22-3a are central holes, 12
Is a spindle, 12-1 is a housing, 12-1a is a fixed seat, 12-2 is a rotary shaft, 12-2a is a turntable, 12-2b is a centering pin, 12-3 and 22-3 are permanent magnets, 13 Is a stator, 13-1 is a yoke, 13-2
Is a flat coil, 13-3 is a magnetic sensor, 25 is a cover plate,

Claims (5)

[Claims] 1. A rotatable disk shape having magnetic poles of different polarities, which are supported by a small-diameter spindle (12) which does not interfere with an optical head for recording and reading optical information, and which are equally divided in the circumferential direction. The permanent magnet (12-3) is made of a thin magnetic material and the disc-shaped metal plate (11-2) with the central hole (11-2a) is attached to the optical disk (11) at the center to hold it. The disk-shaped permanent magnet with respect to the optical disk (11).
A plurality of flat coils (13-2) facing the disk-shaped permanent magnet (12-3) are provided on the side opposite to (12-3), and the flat coil (1
A rotation drive mechanism for an optical disk, characterized in that the disk-shaped permanent magnet (12-3) and, by extension, the optical disk (11) is rotated by energizing 3-2) to control the rotation speed to a constant value. 2. A replaceable optical disk (21) having a permanent magnet (22-3) having magnetic poles of different polarities, which are equally divided in the circumferential direction, embedded in the central portion, and the optical disk (21) is freely rotatable. The spindle (12) supported on the
A rotation drive mechanism for an optical disk, comprising: (12) and a plurality of flat coils (13-2) arranged to face each other with the optical disk (21) interposed therebetween. 3. The optical disk comprising the permanent magnet (22-3).
The rotation drive mechanism for an optical disk according to claim 2, wherein the spindle (12) is also used for fixing. 4. A thin plate (25) on the surface of the permanent magnet (22-3).
3. The rotation drive mechanism for an optical disc according to claim 2, wherein the permanent magnet (22-3) is covered with a layer to protect the permanent magnet (22-3). 5. The flat coil (13-2) is provided with a yoke (13-1) to improve the rotation efficiency of the optical disk (11, 21). Rotational drive mechanism for optical disks.