JP2002260314A - Optical disk chucking mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a chucking mechanism in which a disk chucking part can be thinned without being affected by excessive force such as entanglement. SOLUTION: A tapered part is provided in a centering part, and the centering part is moved up and down in a circumference by even force by the expansion and contraction of the ring-shaped coil spring abutting on the circumference of the tapered part in a diameter direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk holding device of an optical information recording / reproducing apparatus for recording or reproducing information by irradiating an information recording medium with a light beam.

[0002]

2. Description of the Related Art Hitherto, there has been proposed an information signal recording disk on which a desired information signal is recorded, such as an optical disk or a magneto-optical disk. For example, a magneto-optical disc having a diameter of 64 mm has been proposed, and a mini-disc and the like have become widespread in the market for music recording. A high-density recording magneto-optical disk is mounted on a disk rotation drive and is rotated at high speed. Then, while being rotated at a high speed, a fine recording track provided on a signal recording layer formed on one main surface of the magneto-optical disk is irradiated with a light beam emitted from the optical pickup, and Thus, a desired information signal is recorded by applying an external magnetic field.

In order to accurately irradiate such a fine recording track with a light beam, a magneto-optical disk is surely integrated with a turntable of a disk rotation drive unit and positioned with high precision. Need to be installed.

By the way, in order to mount the magneto-optical disk accurately on the turntable and to position and mount the height direction and the centering with high precision, a magnetic attraction plate composed of a metal plate or the like provided on the magneto-optical disk side is used. The magnetic plate is attracted by a magnet disposed on the turntable side, and the above-mentioned magneto-optical disk is mounted on the turntable. For example, there is Japanese Patent Laid-Open No. 4-351726. Hereinafter, a conventional example will be described with reference to the drawings.

FIG. 6 is a cross-sectional view of a conventional disk chucking portion. The magneto-optical disk 1 is constituted by disposing a metal plate 3 as a magnetic plate on one flat surface side of the disk 1 so as to cover a center hole 2 formed concentrically with the information recording track at the center of the disk 1. Have been. On the other hand, a disk rotation drive 4 for rotating the magneto-optical disk 1 includes a spindle motor 5
A turntable 7 is integrally attached to the drive shaft 6, and a magnet 9 is integrally attached to a distal end side of the drive shaft 6 via a magnet holding member 8.
In the center of the turntable 7, a centering member 11 is urged by a coil spring 12 so as to be housed in a housing 10 formed in the center of the turntable 7, so that the shaft of the drive shaft 6 It is slidably mounted in the direction.

The magneto-optical disk 1 has the center hole 2 inserted and engaged with the centering member 11 and the periphery of the center hole 2 is supported and mounted on the turntable 7. At this time, the metal plate 3 is attracted by the magnet 9 because of the magnetic material, and the magneto-optical disk 1 is applied to the turntable 7 by the axial attractive force of the magnet 9.
The centering member 11 is pressed against the turntable 7 by a force different from the biasing force of the coil spring 12 received by the centering member 11.

The pressing force is set to have a sufficient size so that the disk does not come off due to disturbance vibration or centrifugal force when the disk rotates.

Further, when the magneto-optical disk 1 is placed on the turntable 7, when the centering member 11 enters and engages with the center hole 2 while being urged by the coil spring 12 in the axial direction of the drive shaft 6. , Centering member 11
Is partially tapered, a component force of the disc pressing force in the disc radial direction acts, and a force acts to match the rotation center with the axis of the drive shaft 6 over the entire circumference, and the turntable 7 Are performed simultaneously.

As described above, the metal plate 3 disposed on the magneto-optical disk 1 is attracted by the magnet 9, and the magneto-optical disk 1 is placed on the turntable 7 by centering using the centering member 11. Thereby, the positioning and centering of the magneto-optical disk 1 in the height direction on the turntable 7 are performed with high accuracy.
Further, since the chucking member is also integrated with the turntable on the spindle motor, the chucking mechanism is simplified. The magneto-optical disk 1 having a small diameter and high-density recording for which handling is important, such as an MD, is housed in a cartridge 13 and mounted on the disk rotation driving device 4 while being housed in the cartridge 13. You.

[0010]

However, when the turntable portion is thin, the sliding portion of the centering portion is short, so that it is difficult to move the centering portion unless it is held with a uniform force over the entire circumference. Becomes If the end face of the coil spring or the leaf spring is used to push up the centering member, it is difficult to generate a uniform force over the entire circumference due to the inclination of the push-up section, etc. It has been difficult to configure components in the space.

[0011]

A means for solving the above-mentioned problem is to support the other plane of a disk provided with a center hole and having a plate made of a magnetic material covering the center hole on one plane. An annular mounting portion rigidly connected to a tip of a rotating shaft of a power source for rotating the disk at a predetermined rotation speed for positioning the disk at a height position; and an inner peripheral side of the mounting portion. And is coaxial with the rotation axis of the power source, has a substantially cylindrical shape,
The portion is a tapered portion, which engages with the center hole of the disk below the tapered portion so as to be centered, and its inner or outer peripheral side is fitted so as to have a peripheral surface slidable in the axial direction. A centering portion having a space extending over the entire circumference in the circumferential direction between the outer circumference and the inner circumference; a ring-shaped elastic member disposed in the space of the centering portion; The plane of the magnet is arranged on the inner peripheral side of the centering portion and is made of a magnet rigidly coupled to the plane so as to attract a plate made of a magnetic material on the disk in the direction of the rotation axis. A tapered portion is provided on the inner peripheral side of the space so as to expand in the direction of the plate made of a magnetic material on the disk, and the ring-shaped elastic member is provided on both the tapered portion and the annular mounting portion. The centering portion is moved in the direction of the rotation axis. Is obtained without to stretch by the ring-like elastic member is the tapered portion with the.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view showing one embodiment of the present invention. The description of the same parts as in the conventional example is omitted.

In a disk rotation drive device 4 for rotating the magneto-optical disk 1, a turntable 20 is integrally mounted on a drive shaft 6 of a spindle motor 5, and a magnet holding member 8 is attached to a tip end side of the drive shaft 6. The magnet 9 is integrally mounted via the intermediary. Magnet 9
Plate 3 made of magnetic material on magneto-optical disk 1
A space is provided on the side facing the same as in the conventional example.
In the center of the turntable 20, a storage unit 2 is provided.
The centering member 24 is always held coaxially with the rotating shaft 6 so as to be slidable in the axial direction by the outer peripheral wall. The centering member 24 has a hollow portion 28 in which the ring-shaped coil spring 22 is housed.

FIG. 2 is a top view of the ring-shaped coil spring 22. Both ends of a normal tension coil spring are formed in a ring shape as shown in the figure by abutting each other.

As shown in FIG. 1, the edge of the center hole 2 has a centering member 24.
Is supported by the taper section. Further, it is supported and mounted on the turntable 20 around the center hole 2.

FIG. 3 is an enlarged cross-sectional view of the centering portion. A tapered portion 30 is formed on the inner peripheral side of the hollow portion 28 in the centering member 24 so as to be coaxial with the rotating shaft 6 and expand upward in the drawing. The ring-shaped coil spring 22 is housed such that the outer peripheral portion thereof is in contact with the tapered portion 30 and the bottom surface 32 of the housing portion 26. Further, a concave portion 34 is provided on the lower side of the tapered portion 30 in the figure. This allows the ring-shaped coil spring 22 to be easily locked into the turntable 20 by being locked to the concave portion 34 from the tapered portion 30 of the centering member 28 when the centering portion is assembled.

Next, the operation of disk chucking in one embodiment of the present invention will be described.

In FIG. 3, the center hole 2 of the disc 1
Is engaged with the outer peripheral tapered portion of the centering member 24. At this time, the magnetic metal plate 3 on the disk 1 is attracted by the magnet 9 downwardly in the axial direction with a suction force F. Next, when the centering member 24 is pushed downward, the ring-shaped coil spring 22 is expanded in the radial direction by the tapered portion 30. At that time, the ring-shaped coil spring 22
A reaction force fx is generated in the radial direction in the entire circumference of
The axial component fy acts to push the centering member 24 upward in the axial direction.

At this time, by setting the spring strength of the ring-shaped coil spring 22 so that the suction force F> (the resultant force of the component force fy (entire circumference)), the disc 1 can be properly pressed against the turntable 20. It is placed at.

For example, when the present embodiment is applied to an MD, the disc pressing force is set to about 0.9 to 1.2N.

Next, another embodiment of the present invention will be described with reference to the drawings. The description of the same parts is omitted.

FIG. 4 is a top view of a ring-shaped coil spring according to another embodiment of the present invention. The ring-shaped coil spring 42 has coil spring portions 42a and wire portions 42b alternately arranged.

FIG. 5 is a cross-sectional view of another embodiment of the present invention. The left sectional view in the figure is the ring-shaped coil spring 42.
The relation between a and the centering member 40 is shown, which is almost the same as the method described above. The right sectional view of the figure shows the relationship between the strand 42 b of the ring-shaped coil spring 42 and the centering member 40. The strand 42b is the centering member 40
The ring-shaped coil spring 42 is prevented from being detached from the centering member 40 by being hooked on the key-shaped portion 44. In the spring having the shape as shown in FIG. 4, the spring is held at six locations on the entire circumference. Although the inner shape of the centering member 40 becomes complicated, the centering member 40 can be easily formed of resin, and the mass productivity can be improved.

In the above description, the ring-shaped coil spring is used, but it goes without saying that a rubber ring can be used as the ring-shaped elastic body.

[0025]

As described above, according to the present invention, since a ring-shaped elastic member is used, a force can be uniformly applied to the centering member over the entire circumference, thereby forming a thin centering portion. I can do it. Therefore, the spindle motor using the present invention can also be made thinner, which can greatly contribute to a thinner portable disk system. Further, by providing the concave portion or the key-shaped portion by the method of holding the ring-shaped coil spring on the centering member, it becomes easy to assemble the turntable, the centering member and the ring-shaped coil spring. As the size and diameter are reduced, the effect of the application is increased.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an embodiment of the present invention.

FIG. 2 is a top view of a ring-shaped coil spring.

FIG. 3 is an enlarged cross-sectional view of a centering portion.

FIG. 4 is a top view of a ring-shaped coil spring according to another embodiment of the present invention.

FIG. 5 is a cross-sectional view of another embodiment of the present invention.

FIG. 6 is a cross-sectional view of a conventional disk chucking portion.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Disk 3 ... Metal plate (plate material made of a magnetic material) 4 ... Spindle motor 6 ... Rotating shaft 9 ... Magnet 20 ... Turntable (circular mounting part) 22.・ Ring coil spring (ring elastic member) 24 ・ ・ Centering member (centering part) 30 ・ ・ Taper part 34 ・ ・ Recess 44 ・ ・ Key part

Claims (5)

[Claims] 1. A chucking mechanism for a disk having a center hole and an upper side of the center hole covered with a plate made of a magnetic material, comprising a circular receiving portion for holding a lower periphery of the center hole. It has a turntable, and the turntable has a centering member on which a magnet for attracting the magnetic material downward is placed at the upper end of the rotating shaft, and which is slidably provided in the axial direction of the rotating shaft. An outer diameter of the centering member is larger than an outer diameter of the center hole, a first tapered portion is provided on an outer peripheral portion of an upper end, and an outer diameter of an upper end flat portion of the centering member is an outer diameter of the center hole. Smaller, having an annular groove below the centering member, and providing a second tapered portion on at least one of an outer peripheral side wall or an inner peripheral side wall of the annular groove; A ring-shaped elastic member is housed in the groove, and the ring-shaped elastic member is provided. The centering member is biased upward in conjunction with the radial expansion and contraction of the ring-shaped elastic member, wherein the member is held between the second tapered portion and the turntable. Is held in close contact with the receiving portion by the attractive force of the magnet, and the lower end of the center hole and the first
A disc chucking mechanism characterized in that the disc chucking mechanism is centered by contact with a tapered portion of the disc. 2. A disk having a center hole provided thereon and a plate made of a magnetic material covering the center hole mounted on one plane for supporting the other plane of the disk and positioning the disk at a height position. An annular mounting portion rigidly connected to a tip of a rotating shaft of a power source for rotating the disk at a predetermined rotation speed; and an inner mounting side of the mounting portion and coaxial with the rotating shaft of the power source. A part of the outer periphery is a tapered portion which is substantially cylindrical and engages with the center hole of the disk below the tapered portion so that the disk is centered, and the inner or outer periphery thereof can slide in the axial direction. A centering portion which is fitted so as to have a proper peripheral surface and has a space extending over the entire circumference in the circumferential direction between the outer periphery and the inner periphery; and a ring-shaped member arranged in the space of the centering portion. An elastic member and a plane on the tip side of the rotation shaft are aligned with the center. A magnet disposed on the inner peripheral side of the portion and made of a magnetic material on the disk so as to be attracted in the direction of the rotation axis and rigidly coupled to the flat surface; A tapered portion extending in the direction of a plate made of a magnetic material on the disk is provided on the side, and the ring-shaped elastic member is disposed so as to be in contact with both the tapered portion and the annular mounting portion. An optical disk chucking mechanism, wherein the ring-shaped elastic member expands and contracts by the tapered portion as the centering portion moves in the rotation axis direction. 3. The optical disk chucking mechanism according to claim 2, wherein the ring-shaped elastic member uses a ring-shaped coil spring whose central axis is formed in an annular shape. 4. The optical disk chucking mechanism according to claim 2, wherein a concave portion for holding said ring-shaped elastic member is provided in a tapered portion provided inside a space of said centering portion. 5. The optical disk chucking mechanism according to claim 2, wherein a key-shaped portion for holding the ring-shaped elastic member is provided in the tapered portion provided inside the space of the centering portion. .