JPH10275411A - Disk storage device with balance correction mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To correct mass eccentricity of a disk by providing plural weights on a holding part of the disk and moving the weights from the rotary center in utilizing a force difference given to the weights arranged in a symmetry part in a holding device of the disk, so as to be balanced. SOLUTION: When there is mass eccentricity, mass eccentric force 13 is given to the rotary center 2 to vibrate the whole clamper including holders 3a and 3b, and then to generate a difference in force given to the weights 11a and 11b enclosed in these holders 3a and 3b respectively. Since the holder 3b is linked via fulcrums 7a and 7b and a member 8a with the holder 3a, when the holder 3b is rotated around a pivot 6b, the weight 11b inside the holder 3b overflows in its partial part 16b from a lower side projection part 9b of the holder 3b, and by centrifugal force, the overflowing weight is moved into the upper side projection part 10b of the holder 3b. By moving the part 16b of the weight, the force 17a given to the weight 11a and the force 17b given to the weights 11b and 16b are equalized to each other, and hence the rotary center 2 can coincide with a centroid position.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for rotating a disk and a drive for rotating a disk-shaped recording medium, and more particularly to an optical disk apparatus.

[0002]

2. Description of the Related Art Disc eccentricity correction, in other words, centering of a disk, is performed by mechanically fitting the outer periphery of a hole of the disk with a turntable. Alternatively, centering is performed by striking a disk-shaped recording medium, as in a "rotary drive device for a disk-shaped storage medium" described in JP-A-4-37864.

[0003]

In an optical disk device, especially a CD-ROM device, the rotational speed of the disk is improved to improve the data transfer speed. At this time, the eccentricity of the disk becomes a disturbance to the apparatus, and vibration is generated and increased in proportion to the square of the disk rotation speed. This vibration causes the error rate to increase due to a decrease in the actuator follow-up performance margin during high-speed rotation of the disk, the occurrence of bearing backlash due to the wear of the spindle motor bearing, and the phenomenon that the chassis vibrates and the housing of the computer on which it is mounted resonates. Not only does the actual transfer rate decrease, but also the reliability of the device and the discomfort of the computer user.

SUMMARY OF THE INVENTION It is an object of the present invention to reduce the vibration of a rotating disk by providing a mechanism for correcting the center of gravity in a device having a rotating disk, and to achieve a high-speed rotation of the rotating disk.

[0005]

In order to achieve the above object, according to the present invention, a turntable for supporting a disk is provided on a spindle motor for rotating the disk, and the disk is mounted thereon.
In a device for holding a disk, a plurality of weights are provided on a holding portion. At this time, if a disk having an eccentricity is placed, a force is generated at the center of rotation in the direction of the eccentricity. The weight is moved from the center of rotation by using the difference in the forces applied to the weights arranged at the symmetrical portions in the device holding the disk so that the weights are balanced. This provides a mechanism for correcting the eccentricity of the disk.

Further, a mechanism for correcting the eccentricity is provided on the turntable.

[0007] Liquid or particles may be used for the weight.

The above object can be achieved by the above means.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 is an external view of an optical disk apparatus using one embodiment of the present invention. The basic operation of the optical disk device is as follows. The loading mechanism (not shown) for loading or unloading the disk 18 into or from the device causes the tray 1 to be moved.
9 is projected from the front panel 20, and the operation of sending the disk 18 into the apparatus is performed. The disk 18 is a spindle motor 2
The disk is fixed to the first turntable 22 by the magnetic attraction of the clamper 1 holding the disk. After that, the disk 18
Starts rotating at a predetermined number of revolutions by the spindle motor 21, and writes and reads information on and from the disk 18 by an optical head disposed below the disk 18.
The optical head has an objective lens driving device 23 mounted thereon, and is further supported by a unit holder 24 by a traveling driving device that moves in the radial direction of the disk 18. The unit holder 24 is provided with a mechanical base 2 serving as a drive housing.
5 is attached via a vibration isolating leg (not shown) made of an elastic member. The present invention relates to a structure of a clamper 1 in a device for rotating a disk including such an optical disk device and a rotation driving device for a disk-shaped recording medium. One embodiment of the present invention will be described below.

FIG. 2 is an exploded perspective view of a mechanism for correcting the eccentricity of the rotating disk according to the present embodiment.

Spindle motor 2 for rotating disk 18
6, six holders 3a for placing weights in a clamper 1 holding a disk 18 on a turntable 22 supporting the disk,
3b, 4a, 4b, 5a, and 5b into a set of two
Are arranged symmetrically around. The holder 3a has a rotation center 2 around a support shaft 6a arranged in a tangential direction of the rotation center 2.
Are freely movable in the radial direction, and are linked by symmetrical holders 3b and members 8a and 8b at fulcrums 7a. The holder 3a has a lower protrusion 9a provided radially outside the rotation center 2 below the support shaft 6a, and an upper protrusion 10 provided above the lower protrusion 9a.
a is provided. The upper protrusion 10a is longer than the lower protrusion 9a radially outward of the rotation center 2. A weight 11a is sealed inside the holder 3a. The weight 11a is a non-magnetic material, and may have any shape such as a liquid or a particle. The holders 3b, 4a, 4b, 5a, 5b are configured similarly to the holder 3a. A plurality of holders may be provided, and this mechanism may be provided on the turntable 22 side supporting the disk 18 on the spindle motor 21 other than the clamper 1.

FIGS. 3 to 6 show the principle of correcting the eccentricity.

FIG. 3 shows the state of the holders 3a and 3b in a stationary state. In the stationary state, the weights 11a and 11b sealed inside the holders 3a and 3b include the lower protrusions 9a and 9b of the holder. It is on the lower surface of the holder. FIG. 4 shows a state in which the rotating disk 18 has no eccentricity and no center of gravity, and the rotating disk 18 is rotated in an ideal state in which the center of the rotating disk 18 is attached to the rotation center 2. The weight enclosed in the holders 3 a and 3 b is shown. 11
a and 11b are collected on the lower protrusions 9a and 9b of the holder by centrifugal forces 12a and 12b accompanying the rotation. At this time, the forces (centrifugal force) 12a, 12 applied to the weights 11a, 11b
Since b is equal, it is in an equilibrium state in the illustrated state, and is rotated in an ideal state. On the other hand, FIGS. 5 and 6 show a state where the rotating disk 18 having the eccentricity is rotated.
As shown in FIG. 5, an eccentric force 13 accompanying the eccentricity is applied to the rotation center 2, and the entire clamper including the holders 3a and 3b is vibrated. The holder 3a, 3
b Force 14 applied to weights 11a and 11b enclosed inside
a and 14b are different. Due to the difference between the forces 14a and 14b, a moment force 15 having the support shaft 6a as the center of rotation is generated in the holder 3a. As shown in FIG. 6, this moment 15 causes the holder 3a to rotate counterclockwise about the support shaft 6a. On the other hand, since the holder 3b is linked to the holder 3a via the fulcrums 7a and 7b and the member 8a, it similarly rotates counterclockwise around the support shaft 6b.

At this time, the weight 11a sealed inside the holder 3a does not move significantly from the lower protrusion 9a of the holder 3a, but the weight 11a sealed inside the holder 3b.
b is a part of the weight 16b from the lower projection 9b of the holder 3b.
Overflows and the upper protrusion 10b of the holder 3b is caused by centrifugal force.
Go to Since the upper protruding portion 10b is located outside the lower protruding portion 9b with respect to the rotation center 2, the force 17a applied to the weight 11a and the force 17b applied to the weights 11b and 16b are equal by the movement of a part 16b of the weight. It will become. Therefore, the center of gravity and the position of the center of gravity can be made to coincide with each other, whereby the force of the eccentric center can be reduced when the rotating disk having the eccentric center rotates, thereby reducing the vibration and the reading error. Further, it is possible to configure a device capable of rotating at high speed even on a disk having a large eccentricity without adversely affecting other components.

[0016]

By mounting a mechanism for correcting the eccentricity of the rotating disk on the optical disk device, high-speed rotation can be performed even on a rotating disk having a large amount of eccentricity, thereby increasing the data transfer speed and reducing the speed. Vibration can be realized.

[Brief description of the drawings]

FIG. 1 is an external view of an optical disk device using the present embodiment.

FIG. 2 is an exploded perspective view of a mechanism for correcting the eccentricity of the embodiment.

FIG. 3 is a principle diagram of correcting the eccentricity of the present invention.

FIG. 4 is a principle diagram of correcting the eccentricity of the present invention.

FIG. 5 is a diagram illustrating the principle of correcting the center of gravity according to the present invention.

FIG. 6 is a principle diagram of correcting an eccentricity according to the present invention.

[Explanation of symbols]

1 ... clamper, 2 ... rotation center, 3a, 3b, 4a, 4
b, 5a, 5b: holder, 6a, 6b: support shaft, 7a, 7
b: fulcrum, 8a, 8b: member, 9a, 9b: lower projection, 10a, 10b: upper projection, 11a, 11b, 1
6b ... weight, 12a, 12b, 14a, 14b, 17
a, 17b: force applied to weight, 13: eccentric force, 15:
Moment force, 18: disk, 19: tray, 20: front panel, 21: spindle motor, 22: turntable, 23: objective lens driving device, 24: unit holder, 25: mechanical base.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takashi Kono 502, Kandate-cho, Tsuchiura-shi, Ibaraki Pref. Machinery Research Laboratories, Hitachi, Ltd. Inside the mechanical laboratory

Claims (1)

[Claims] A spindle motor for rotating a disk is provided with a turntable for supporting the disk, and the disk is mounted thereon.
An apparatus for holding a disc, comprising: a plurality of weights in a holding section, and a mechanism for correcting the eccentricity of the disc by using a difference in force applied to the weights arranged in the symmetrical section. Disk storage device comprising: