JPH11191253A - Disk device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a disk device having the disk clamp provided with a balance function capable of suppressing the generation of vibration effectively. SOLUTION: This disk device is constituted so as to have the disk clamper 4 constituted of a clamp main body 8 which fixes the disk 1 mounted on a turntable 3 and revolves integrally with the disk 1, ring shaped weights 12 housed in the clamp main baby 8, plural springs 13 whose one ends are connected to the shaft of the clamp main body 8 and whose other ends are connected to inner surfaces of the weights 12 and which are radially arranged, plural weight side magnets 14 arranged on outer surfaces of the weights 12 and plural main body side magnets 15 provided at the main body 8 by being opposed to the weight side magnets 14 so that they attract each other. Thus, the disk device having the disk clamp provided with the balance function capable of suppressing the generation of vibration effectively is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a CD (Compa)
ct Disc) and DVD (Digital Vers)
More particularly, the present invention relates to a disk device having a disk clamp having an imbalance correction function.

[0002]

2. Description of the Related Art Conventionally, as an apparatus for automatically correcting imbalance of a rotating body, there have been known many auto balancers for performing correction using a liquid or a ball. However, an auto balancer using a liquid or a ball has an unbalanced amount when the installation direction of the device incorporating the auto balancer is limited or when the rotating body is rotating at a low speed while reaching the high speed. Is increasing. In order to solve these problems, expensive auto balancers provided with complicated structures have been used. One example of these auto balancers is Japanese Utility Model Application Laid-open No. Sho 62-15817.
No. 2, JP-A-2-119694, JP-A-2-119694
No. 279198 discloses this.

[0003] Further, there is a disk device which rotates a disk for recording information as a rotator, and such a disk device has a high density of information, that is, a high capacity, and a high speed writing of information. And the demand for high-speed reading is increasing. And 1 of speeding up
As one means, a method of rotating a disk at a high speed has been adopted.

[0004]

When the disk is rotated at a low speed, there is not much problem. However, if the weight balance of the disk is slightly deviated and becomes unbalanced, the disk can be rotated at a high speed. When rotated, the problem caused by imbalance has become apparent. For example, when such an unbalanced disk is rotated at a high speed, vibration occurs, and this vibration adversely affects not only the writing and reading performance of the disk device itself, but also the devices around the device itself. The problem has occurred.

Therefore, in order to prevent the above-mentioned adverse effects, it is conceivable to employ a device for adjusting the balance of a washing machine as disclosed in Japanese Patent Laid-Open No. 2-279198, for example, as a disk device. FIG. 9 is a schematic configuration diagram of a balancer mechanism disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 2-279198, in which a balancer 107 attached to a rotating shaft 105a by a coil spring 108 has a rotating shaft 1
Rotates with 05. Here, when an imbalance occurs, the balancer 107 moves in the direction opposite to the eccentric load due to the centrifugal force, and corrects the balance in a state in which the balance force is balanced with the restoring force of the coil spring 108.

However, this balancer mechanism may not be able to follow the rotating shaft 105a due to the inertia of the balancer 107 itself when the rotation speed of the rotating body fluctuates or when the rotating body is started. Furthermore, even if the rotation speed fluctuates and then becomes constant, the balancer 107 may cause vibration in the rotation direction with respect to the rotation shaft 105a due to its inertial force. In particular, in the disk device, in the case of CLV (constant linear velocity) control, the number of rotations is controlled to be different between when the pickup is located at the inner periphery and at the outer periphery of the disk. Fluctuations occur frequently. At this time, if the balancer cannot follow the change in the number of rotations of the motor, the balancer 107 may vibrate in the rotation direction, and therefore, this balancer mechanism cannot be employed in the disk device. The present invention focuses on the above problems, and has been made to solve the problems effectively. The purpose of the present invention is to provide a disk clamp with a balancer function that can effectively suppress the occurrence of vibration. To provide a disk device having the same.

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a clamp body for fixing a disk placed on a turntable and rotating integrally with the disk, and a clamp body inside the clamp body. A ring-shaped weight housed therein, a plurality of radially arranged springs having one end connected to a shaft of the clamp body and the other end connected to an inner surface of the weight, and an outer surface of the weight. A disk clamp comprising a plurality of weight-side magnets and a plurality of body-side magnets provided on the clamp body so as to be attracted to each other so as to face the weight-side magnets.

As a result, when the rotation of the disk is stopped, the weights are in a state of being balanced by the spring force of the spring, the attraction force between the magnets, or the repulsion force.
When the disk has an unbalanced component, vibration tends to occur when the disk rotates. At this time, the ring-shaped weight connected via a spring radially arranged to the center side of the clamp body moves to the side opposite to the direction of the eccentricity of the disk, and performs balance adjustment. As a result, the imbalance is eliminated and the vibration is suppressed. In addition, when the rotation of the disk is controlled to fluctuate by moving the pickup to the inner circumference or the outer circumference of the disk, the rotation speed of the weight tends to deviate from the rotation speed of the disk itself due to the inertia force of the weight itself. Becomes In this case, by providing auxiliary magnets on both sides of the main body-side magnet and having a repulsive force against the weight-side magnet, it is possible to suppress the occurrence of a rotational deviation, that is, a phase deviation between the two.

In this case, the weight-side magnet is provided, for example, on the upper surface of the weight, and the main body-side magnet and the auxiliary magnet are provided, for example, above the weight-side magnet,
The clamp body may be provided with a stopper member for preventing the weight from moving eccentrically or upward.

The weight-side magnet may be provided on an outer surface of the weight, and the body-side magnet and the auxiliary magnet may be provided above and below the weight-side magnet, respectively.

Further, the clamp body may be partially or entirely made of a magnetic material, and may be suction-fixed to a suction plate made of a magnetic material provided on the turntable via a disk.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a disk drive according to the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a schematic configuration diagram showing a disk device of the present invention, FIG. 2 is a cross-sectional view showing a first embodiment of a disk clamp with a balancer function mounted on the device shown in FIG. 1, and FIG. 3 is a disk shown in FIG. It is a top view of a clamp. Here, only the main mechanism components are shown, and the disk mounting mechanism, electric circuit components, exterior components, and the like are omitted. This disk device M
Is a disk 1 such as an optical disk or a magnetic disk
The information is written into, and the information stored therein is read.

That is, the disk 1 has a turntable 3 fixed to the upper end of the rotating shaft 2A of the spindle motor 2.
And a disk clamp 4 which is detachable from the disk clamp and which is a feature of the present invention, and rotates at high speed around a spindle central axis 5. The pickup 6 can be moved by the pickup moving means 7 in the radial direction of the disk 1 as indicated by an arrow, and can write or read information on or from the disk 1. A balancer mechanism is integrally incorporated in the disk clamp 4 which is a feature of the present invention. If the disk 1 is unbalanced, the disk 1 becomes unbalanced as the rotation speed of the disk 1 increases. The correction mechanism acts in the correction direction, and the generated vibration can be reduced.

As shown in FIGS. 2 and 3, the disk clamp 4 is a disk-shaped clamp body 8 made of a magnetic material having a diameter of about 3 to 4 cm or a part of which is made of a magnetic material.
On the lower surface thereof, an umbrella-shaped fitting concave portion 8a that fits with an umbrella-shaped fitting convex portion 3a provided at the upper end of the turntable 3 for center positioning is formed. The center hole 1a of the disc 1 is fitted into the fitting projection 3a. A shaft 9 is provided upright at the center of the clamp body 8, and a ring-shaped outer peripheral wall 10 is provided upright at the periphery of the clamp body 8. In FIGS. 2 and 3, the structure of the disk clamper 4 is open to facilitate the description of the structure, but the upper part may be covered with a lid (not shown). This is due to the structure shown in FIG.
The same applies to the structure shown in FIG. A ring-shaped weight 12 made of, for example, a magnetic material is accommodated inside the outer peripheral wall 10 so as to be movable only in a direction parallel to the disk 1 around the shaft 9. The ring-shaped weights 12 are attached at equal intervals to the center shaft 9 via a plurality of springs 13, and the weights 12 are evenly pulled toward the center by the resilience thereof, or have a radius from the center. Is biased outward in the direction. A plurality of weight-side magnets 14 made of permanent magnets are attached to the outer peripheral side surface of the weight 12 at equal intervals. The weight 12 and the weight-side magnet 14
Is a state in which the shaft 9 is balanced.

The weight-side magnets 14 are arranged such that the magnetic poles N and S are arranged in the radial direction of the ring-shaped weight 12. In the illustrated example, the number of the springs 13 and the weight-side magnets 14 corresponding to the springs 13 are respectively six, but the number is not limited as long as the number is three or more. A body-side magnet 15 made of, for example, a permanent magnet is provided on the inner peripheral surface 10a of the outer peripheral wall 10 at a position facing the weight-side magnet 12 at equal intervals along the circumferential direction.
In this case, the magnetic poles N and S of the main body side magnet 15 are arranged so as to be arranged in the radial direction of the disk-shaped disc clamp 4, and the polarities N and S are pulled so as to be attracted by the opposing weight side magnet 14. Is set. The balance of the suction force is balanced.

Auxiliary magnets made of, for example, permanent magnets having opposite polarities to the body-side magnets 15 are provided on both sides of each body-side magnet 15 in the clamp circumferential direction at a predetermined distance of, for example, about several mm. 17a and 17b are provided. That is, the auxiliary magnets 17a and 17b generate repulsive forces with respect to the corresponding weight-side magnets 14. The function of the auxiliary magnets 17a and 17b is as follows.
In addition to generating the attraction force of the disk clamp described later, the weights 12 are applied to the ring-shaped outer peripheral wall 10 made of a magnetic material so that the auxiliary magnets 17a and 17b uniformly apply repulsive force to the main body side magnet 15. It also has a function to prevent the relative position from being greatly shifted angularly. Furthermore,
There is also a function of recovering the magnetic flux from the weight side magnet 14 and the main body side magnet 15. The reason why the clamp body 8 itself is made of a magnetic material is to make it act as a yoke, thereby preventing the magnetic flux from leaking to the outside.

Further, the shaft 9 and the clamp body 8 have an integral structure, and the body-side magnet 15 and the auxiliary magnet 17a are attached to a ring-shaped suction plate 20 made of a magnetic material provided on the upper surface of the turntable 3. , 17b. This constitutes a disk clamp. Further, a stopper step 21 is formed on the upper surface of the clamp body inside the weight 12 to prevent the weight 12 from being excessively eccentric. The magnetic force acting at the time of this clamping may be the magnets 14 and 15 described above, or a completely different magnet may be used if space is available.

Next, the operation of the embodiment constructed as described above will be described. The disk clamp 4 having such a configuration is mounted and fixed on the turntable 3 together with the disk 1 having the unbalanced element, and the disk clamp 4 is rotated integrally. When the spindle motor 2 starts, vibration occurs due to the unbalance component of the disk 1. When the rotational speed exceeds the critical speed, the phase of the vibration direction becomes opposite to the direction of the unbalance component as is well known. At this time, the weight 12 moves to the side opposite to the direction of the eccentricity of the disk 1 to adjust the balance, thereby reducing the vibration of the disk 1. At this time, in the stopped state, the weights 12 are used for the resilience of the springs 13 and the weight-side magnets 1.
The balance was lost due to the attraction force (or repulsion force) of the magnet 4 and the body-side magnet 15, but the balance was lost.
The disk 1 moves in a direction opposite to the eccentric direction.

Also, the optical disk 1 controls the linear velocity constant (C
In the case of (LV control), the rotation speed of the spindle motor 2 changes every time the pickup 6 moves to the inner circumference or the outer circumference of the disk 1. That is, the number of rotations of the motor frequently changes. If the rotation speed of the motor suddenly changes, the weight 12 tries to rotate at the rotation speed before the rotation speed changes due to its own inertia. Therefore, the weight 12 tends to be out of phase with the clamp body 8 rotating integrally with the disk 1. However, in the present embodiment, the delay of the weight 12 following the clamp body 8 occurs due to the action of the auxiliary magnets 17a and 17b on the clamp body 8 that rotates integrally with the weight 1 of the weight 12 and the disk 1. Can be prevented. That is, when a rotational displacement is to be caused between both the weight 12 and the clamp body 8, the weight-side magnet 14 and one of the auxiliary magnets 17a or 1
7b is reduced and the repulsive force between the two is increased, which acts to return to the original position, that is, a state where there is no rotational displacement.

In a low speed region where the rotation speed of the spindle motor 2 is equal to or lower than the critical speed, an ordinary balance correction device
According to the present invention, in addition to the restoring force of each spring 13, the attraction force of the weight-side magnet 14 and the body-side magnet 15 and the weight-side Magnet 14 and auxiliary magnets 17a, 17
Since the weight 12 is prevented from moving in the same phase as the direction of the eccentricity due to the repulsive force b, there is no possibility of promoting vibration. The weight 12 slides in the radial direction in the clamp body 8, but it is preferable that at least the sliding portion 8b is made of tetrafluoroethylene or the like having a low frictional resistance. Further, each magnet may be movable so that the weight 12 can be moved at the same time as the disk 1 rotates to correct the balance, and the magnetic force is strong enough that the weight 12 does not cause a delay in following the disk 1. .

In the first embodiment, the weight-side magnet 14 is provided on the outer peripheral side surface of the weight 12, and the main-body-side magnet 15 and the auxiliary magnet 17a are provided on the inner peripheral surface of the outer peripheral wall 10 at a predetermined distance. 17b is provided, as shown in FIGS.
The configuration may be the same as the second embodiment shown in FIG. 6 or the third embodiment shown in FIGS. FIG. 5 is a partial sectional view taken along line AA in FIG. In the second embodiment shown in FIGS. 4 and 5, weight-side magnets 14 are provided on the upper surface of the weight 12 at equal intervals. Further, both ends of the outer peripheral wall 10 of the clamp main body 8 are bent inward in the radial direction to form a ring-shaped bent portion 25, and the main body side magnets 15 are provided on the inner side surface at equal intervals along the circumferential direction. . Thereby, both magnets 14 and 15 are substantially opposed in the up-down direction. At this time, the polarities of the opposing surfaces are, of course, opposite to each other, so that a suction force is generated. Auxiliary magnets 17a and 17b having polarities opposite to those of the main body side magnet 15 are provided on both circumferential sides of the main body side magnet 15. Further, the distal end of the bent portion 25 is configured as a stopper member 26 so that the weight 12 is not pulled by the main body side magnet 15 and rises more than necessary. At this time, preferably, the magnetic force of the auxiliary magnets 17a and 17b on both sides of the main body-side magnet 15 is preferably increased. The reason for this is that the rotational displacement between the weight 12 and the clamp body 8 can be strongly suppressed.

It is preferable to arrange the weight-side magnet 14 such that both ends of the weight-side magnet 14 face the auxiliary magnets 17a and 17b. This prevents the weight-side magnets 14 on the weights 12 from being attracted to the body-side magnets 15 of the clamp body 8, and the weights 12 cause the attractive force of the magnets 14, 15 and the weight-side magnets 14 and the auxiliary magnets This is because it is possible to follow the fluctuation of the rotational speed of the disk by the repulsive force acting between the disk 17a and 17b.

FIG. 7 is a partial sectional view taken along line BB in FIG. 6, and FIG. 8 is a partial sectional view taken along line CC in FIG.
6 to 8, the weight magnets 30 are arranged on the side surfaces of the weights 12, but their polarities N and S are set so as to be in the vertical direction unlike the first embodiment. Then, two pairs of main body side magnets 27 and 28 are arranged above and below. The body-side magnets 27 and 28 apply attractive forces to each other with polarities opposite to the polarities of the surfaces of the weight-side magnets 30 facing each other. In addition, each body-side magnet 27, 28
Auxiliary magnets 31a, 31b, 32a, and 32b having the same polarity as the opposite surface of the weight-side magnet 30 are arranged on both sides of the pair to apply a repulsive force to the opposite weight-side magnet 30. At this time, preferably, the main body side magnets 27, 28
The strength of the magnetic force of the auxiliary magnets 31a, 31b, 32a, 32b should be larger than that of the auxiliary magnets. The reason is that the occurrence of rotational displacement between the weight 12 and the clamp body 8 can be strongly suppressed.

Further, the width of the main body side magnets 27 and 28 may be smaller than that of the weight side magnet 30. This is because the weight-side magnet 30 on the weight 12 and the body-side magnets 27 and 28 on the clamp body 8 are hardly attracted. To enhance this effect, the stopper member 21 similar to that of the second embodiment is used. May be provided. Also, this is the weight 12
Is the attractive force between the weight-side magnet 30 and the main body-side magnets 27 and 28, and the weight-side magnet 30 and the auxiliary magnets 31a and 31
Consideration is given so that the repulsive force between b, 32a, and 32b can follow the fluctuation of the rotation speed of the disk. In the above-described embodiment, the structure in which the upper surface of the disk clamp 4 is opened is provided for ease of explanation. However, the structure is not limited to this, and the disk clamp 4 may have a structure in which the upper surface is also closed.

[0025]

As described above, according to the disk device of the present invention, the following excellent functions and effects can be exhibited. A ring-shaped weight for balance adjustment is connected radially from the center by a plurality of springs, and a magnet is provided so as to attract the weight to the outside of the weight. The movement in the direction opposite to the direction can effectively prevent the generation of vibration. When the rotation speed is equal to or lower than the critical speed, the action of each magnet can prevent the weight from moving in the same phase as the eccentric direction, so that vibration is not promoted. In addition, since auxiliary magnets that repel the weight-side magnets are provided on both sides of the main body-side magnets, even if the rotation speed of the spindle motor fluctuates and the rotation of the weights tends to shift,
Rotational deviation is suppressed by the repulsive force, and the weight can rotate following the disk.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a disk device of the present invention.

FIG. 2 is a sectional view showing a first embodiment of a disk clamp with a balancer function mounted on the apparatus shown in FIG. 1;

FIG. 3 is a top view of the disc clamp shown in FIG. 2;

FIG. 4 is a sectional view showing a second embodiment of the main part of the device of the present invention.

FIG. 5 is a partial sectional view taken along line AA in FIG. 4;

FIG. 6 is a sectional view showing a third embodiment of a main part of the device of the present invention.

FIG. 7 is a partial sectional view taken along line BB in FIG. 6;

FIG. 8 is a partial sectional view taken along line CC in FIG. 6;

FIG. 9 is a schematic configuration diagram illustrating an example of a conventional balancer mechanism.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Disc, 2 ... Spindle motor, 3 ... Turntable, 4 ... Disc clamp, 6 ... Pickup, 7 ...
Pickup moving means, 8: clamp body, 9: shaft, 12: weight, 13: spring, 14, 30, ...
Weight side magnets, 15, 27, 28 ... body side magnets, 17
a, 17b, 31a, 131, 32a, 32b: auxiliary magnet, 20: suction plate, 21, 26: stopper member, M:
Disk device.

Claims (4)

[Claims] 1. A clamp body for fixing a disk placed on a turntable and rotating integrally with the disk, a ring-shaped weight housed in the clamp body, and one end of the clamp body being connected to a shaft of the clamp body. A plurality of springs radially arranged with the other end connected to the inner surface of the weight, a plurality of weight-side magnets arranged on the outer surface of the weight, and the weight-side magnet on the clamp body. A disk device comprising: a disk clamp comprising a plurality of body-side magnets provided so as to face each other and attract each other. 2. The disk drive according to claim 1, wherein auxiliary magnets are provided on both sides of the main body side magnet so as to repel the weight side magnet. 3. The clamp body has the weight,
3. The disk device according to claim 1, further comprising a stopper member for preventing eccentricity or upward movement. 4. The clamp body according to claim 1, wherein a part or the whole of the clamp body is made of a magnetic material, and the clamp body is suction-fixed to a suction plate made of a magnetic material provided on the turntable via a disk. The disk device according to any one of claims 1 to 3.