JP2000040280A - Disk unit - Google Patents

Abstract

(57) [Summary] In a disk device, self-vibration due to disk imbalance is stably suppressed during high-speed rotation,
At the time of a sudden change in the rotation speed, unnecessary noise is prevented from being generated, and an error-inducing factor such as a read error is eliminated. SOLUTION: The balance includes a balancer provided rotatably integrally with a mounted disk 1 and having a hollow annular portion accommodating a magnetic body 13, and a magnetic field generating means for attracting and holding the magnetic body 13. , The magnetic field generating means to the magnet 27
The outer periphery of the magnet is set as the inner wall of the hollow annular portion, and the magnet 13 is provided with obstacle means such as a rib 35 for preventing the magnetic body 13 from directly abutting on the magnet 27, or a guide groove is provided on the sphere moving surface. By doing so, it is possible to prevent the generation of unnecessary noise, reduce the impact when the magnetic sphere 13 collides, and also prevent the magnet 27 from magnetizing the magnetic sphere 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk device equipped with a vibration suppressing device for suppressing self-vibration due to unbalance of a disk serving as a recording medium and enabling stable recording and reproduction.

[0002]

2. Description of the Related Art Recently, CD-ROM drives and CD-Rs have been developed.
2. Description of the Related Art Data transfer speeds have been increasing in disk devices for recording and reproducing data, such as drives, and in order to transfer data at high speed, it is necessary to rotate the disk at a high distance. In general, there are many unbalanced disks with uneven mass balance due to uneven thickness, etc.When such a disk is rotated at high speed, the unbalance force of the disk acts and self-vibration occurs,
The vibrations are transmitted to the entire device, making it impossible to reproduce data stably, generating noise due to the vibrations, shortening the life of the motor, and transmitting the vibrations to other peripheral devices when the drive is built into the computer. And have adverse effects. Therefore, in order to speed up data transfer by rotating the disk at high speed, it is necessary to suppress self-vibration due to disk imbalance.
Various measures have been taken to cancel the imbalance.

A conventionally known disk device having a function of canceling imbalance will be described below. FIG. 4 is a perspective view showing a disk device equipped with a balancer for canceling imbalance. Reference numeral 1 denotes a disk which is mounted on a turntable 9 and driven to rotate by a spindle motor 2, and an optical pickup 3 reads data recorded on the disk 1 and writes data on the disk 1. The rotation of the optical pickup drive motor 4 is converted into linear motion by the action of the optical pickup drive system 5, and the optical pickup 3 slides in the radial direction of the disk 1. These mechanical systems are all mounted on the sub base 6, and the sub base 6 is connected to the main base 8 by an insulator 7 of a low rigidity elastic body.
Vibrations transmitted from the outside are attenuated by the insulator 7. The disk 1 is held by a turntable 9 and a clamper 10 which rotate integrally with the spindle motor 2 and rotates. The resonance frequency of the vibration of the sub base 6 due to the deformation of the insulator 7 when the disk 1 rotates at high speed is set lower than the rotation frequency of the disk 1 at high speed.

FIG. 5 is a sectional view of the vicinity of the spindle motor 2 showing details of a balancer integrated with the clamper 10 of the disk device. A magnetic yoke 11 made of a magnetic material is fixed to the turntable 9 and rotates integrally with the spindle motor 2. The clamper 10 has a magnet 27 built therein, and the disk 1 is sandwiched by the magnetic attraction force of the magnetic flux between the magnet 27 and the yoke 11 and rotates integrally. Magnetized surface 2 of normal magnet 27
8 is magnetized in two poles for the sake of simplicity in the manufacturing method and simple application. Reference numeral 15 denotes a back yoke made of a metallic magnetic material, which is attracted and fixed to the non-magnetized surface 29 of the magnet 27 to block magnetic flux leaking from other than the magnetized surface 28, thereby increasing the efficiency of the attractive force to the disk 1. A plurality of magnetic spheres 13 are rollably accommodated in the clamper 10. 13a shows the position of the sphere 13 at the time of high-speed rotation, and 13b shows the position of the sphere 13 at the time of low-speed rotation. These balancer components are mounted on a sub-base 6, and the sub-base 6 is connected to a main base 8 through an insulator 7, and as described above, the sub-base 6 is deformed when the disk 1 rotates at a high speed. The resonance frequency of the vibration 6 is set lower than the rotation frequency of the disk 1 at high speed.

FIG. 6 is a cross-sectional view of the clamper 10 as viewed from above, showing that the imbalance is canceled when the disk rotates at a high speed due to the movement of the sphere 13 accommodated in the clamper 10. The state of the sphere 13 when the unbalanced disk 1 is rotated at a low speed and cancellation of the unbalance of the disk 1 when the disk 1 is rotated at a high speed will be described with reference to FIGS.

In a normal CD-ROM drive, the disk 1 is rotated at a high speed (up to about 4200 rpm in an 8 × speed mode) in order to increase the transfer speed when reading data.
00 rpm). As described above, a high-speed rotation range such as data reading and a low-speed rotation range such as audio play are mixed.

When the unbalanced disk 1 is rotated at high speed, an unbalance force 18 as a centrifugal force acts on the center of gravity 17 of the disk 1, and the acting direction rotates together with the disk 1. The insulator 7 is deformed by the unbalance force 18, and the sub base 6 swings at the rotation frequency of the disk 1. As described above, since the resonance frequency of the vibration of the sub-base 6 is set lower than the rotation frequency of the disk 1, the direction of the displacement of the sub-base 6 and the direction of the unbalance force are always opposite. Therefore, clamper 1
The centrifugal force 19 and the rolling surface 2 on which the sphere 13 is pressed and rolled are applied to the plurality of spheres 13 stored so as to be rollable to zero.
A moving force 22, which is a resultant force of a drag 21 from 0, acts, and the sphere 13 moves in a direction away from the whirling center 23, gathers in a direction exactly opposite to the direction of the unbalance force 18, and finally gathers. The unbalance amount of the disk 1 is canceled by the total mass of the sphere 13a.

On the other hand, the sphere 1
3, the ball 13 is not pressed against the rolling surface 20 due to the shortage of the centrifugal force 19, and the location of the ball 13 becomes unstable.
Unnecessary noises such as a rolling noise of the sphere 13, a sliding noise between the sphere 13 and the inner surface of the clamper 10, and a collision noise between the spheres 13 are generated. In order to prevent this, the sphere 13 is made of a metal magnetic material, and the sphere 13 is formed by using the leakage magnetic flux 24 of the magnet 27 and the magnetic flux 25 from the magnetized surface 28 to the back yoke 15.
The unnecessary noise is prevented by directly adsorbing the outer peripheral surface 26 and the back yoke 15 to stabilize the location of the sphere 13b.

[0009]

However, in the above configuration, the following problem occurs when the rotation of the disk 1 changes rapidly from high speed to low speed. In general, some CD-ROM discs contain both data and audio on a single disc. When such discs are played, data is read at high speed, and the speed is immediately reduced to the standard speed to reproduce the audio. Is performed. That is, while the disc is rotating at high speed, it suddenly switches to low speed, and immediately after that, audio play must be performed.

As described above, at high speed, the sphere 13 rotates integrally with the clamper 10 while being pressed against the rolling surface 20 in order to cancel the imbalance of the disk 1, but the rotation speed falls to a predetermined rotation speed. And the centrifugal force acting on the sphere 13 is insufficient, and the leakage magnetic flux 24
The sphere 13 is attracted to the outer peripheral surface 26 of the magnet 27 and the back yoke 15 by the action of the magnetic flux 25 from the magnetized surface 28 to the back yoke 15. However, as mentioned above, magnet 2
The magnetized surface 28 is magnetized to two poles. In the case of the two-pole magnetized, the leakage magnetic flux 24 is large and the magnetic flux 25 has a small magnetic flux density. Therefore, the sphere 13 is the disk 1
When the speed changes from low-speed rotation to high-speed rotation, the magnet 27
It is difficult to separate from the outer peripheral surface 26 of the magnet 27 unless the centrifugal force 19 acting on the sphere 13 changes considerably from high-speed rotation to low-distant rotation. It becomes difficult to adsorb. As described above, in the case where the operation is shifted to the audio play immediately after the data read at the high speed rotation, the sphere 13 is attracted to the outer peripheral surface 26 of the magnet 19 after the start of the audio data read due to the characteristic that the sphere 13 is difficult to separate and attract. The shock at the time of the suction is transmitted to the disk 1 and causes a read error.

In a low-speed rotation range when the disk device is used in a vertical posture, as shown in FIG. 6, when the weight of the sphere 13 is larger than the centrifugal force 19 acting on the sphere 13, the sphere 13 Since the clamper 10 shown in FIG. 5 rotates while being attracted to the outer peripheral portion, unnecessary noise such as a rolling noise of the spheres 13 and a collision noise between the spheres 13 shown in FIG. 6 is generated, degrading the quality of the product. Would.

The present invention has been made in view of the above problems, and in a disk device having the above-described balancer mechanism, the location of a sphere can be stably maintained even when rotating at a high speed, when the rotational speed changes suddenly, or when the disk device is used in a vertical posture. It is an object of the present invention to provide a disk device that does not easily generate unnecessary noise and errors during spin-up by making the disk device easy to move.

[0013]

According to another aspect of the present invention, there is provided a disk device comprising: a balancer having a hollow annular portion provided rotatably integrally with a mounted disk and containing a magnetic material; And a magnetic field generating means for attracting and holding the magnetic material,
At least one of the following configurations (a) and (b) is provided.

(A) The magnetic field generating means is constituted by a magnet,
The outer periphery of the magnet is used as the inner wall of the hollow annular portion, and an obstacle is provided to prevent the magnetic body from directly contacting the magnet. (b) A guide groove for guiding the movement of the magnetic body is provided on the lower surface of the intermediate annular portion. By providing the above configurations (a) and (b), the impact of the magnetic sphere colliding with the rolling surface or the vicinity of the outer periphery of the magnet during spin-up or a sudden change in the rotation speed of the disk is reduced.

[0015]

[Function] In a disk device using a magnetic sphere as a means for canceling imbalance force due to a disk, when the speed is rapidly shifted from a high-speed rotation to a standard-speed audio play, when the start of reading audio data and the impact due to a sphere collision are overlapped. In addition, since the impact due to the ball collision is reduced by the obstacle means or the guide groove, it is possible to prevent errors such as a read error and to perform stable reproduction.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. In the configuration of the embodiment shown in FIGS. 1 to 3, the same components as those of the conventional apparatus shown in FIGS. 4 to 6 are denoted by the same reference numerals. FIG. 1 is a diagram showing a first embodiment of the present invention. Numeral 13 is a metallic magnetic sphere, and a plurality of magnetic spheres are used to cancel the imbalance of the disk 1.
It is rollably stored inside. 13a shows the position of the sphere 13 at the time of high-speed and low-speed rotation, and 13b shows the position of the sphere 13 at the time of stop. A magnet 27 has a magnetized surface 28 which is magnetized in two poles, forms a magnetic path in the direction of the yoke 11 and attracts the yoke 11 to clamp the disk 1 with the turntable 9. . Reference numeral 35 denotes a rib provided on the outer peripheral portion of the magnet 27, which serves as an obstacle to prevent the magnetic sphere 13 from being directly attracted to the magnet 27. Reference numeral 24 denotes a leakage magnetic flux from the magnet 27.

In the first embodiment of the present invention configured as described above, the case where the disk 1 rotates at a high speed and the case where the number of rotations changes suddenly will be described. When the unbalanced disk 1 is rotated during high-speed rotation such as data reading, as shown in FIG. 6, a centrifugal force 19 from the whirling center acts on the sphere 13 so that the sphere 13 is pressed against the rolling surface 20 and moves while rolling. The unbalance of the disc 1 is canceled by gathering in the direction directly opposite to the unbalance direction of the disc 1 and stopping at a place where the unbalance force is balanced, and rotating together with the clamper 10.

On the other hand, when the rotational speed is rapidly reduced from a high speed, the magnetic sphere 13 collides at a high speed from the rolling surface 20 to the rib 35 provided near the outer peripheral portion of the magnet 27. And unnecessary noise is greatly reduced as compared with the case where the noise is directly attracted to the outer peripheral surface of the magnet. Since the impact is greatly reduced as compared with the case where the magnet 27 is directly attracted to the magnet 27, an error-inducing factor such as servo disconnection can be greatly reduced. Further, the magnetic sphere 13 is attracted at a position separated from the outer peripheral surface of the magnet 27 by the thickness of the rib 35 interposed therebetween, and the magnetic sphere 13 is
7 is less likely to be magnetized than when it is directly attracted to the outer peripheral surface. FIGS. 2 and 3 show a second embodiment of the present invention.

FIG. 2 is a detailed sectional view of the balancer, and FIG.
Is a sectional view of the inside of the clamper 10 as viewed from above. Reference numeral 37 denotes a sphere moving groove which guides the movement of the sphere 13 when the rotation of the disk 1 is rapidly switched from high speed to low speed or from low speed to high speed, and is disposed on the lower surface of the clamper 10. The spherical moving groove 37 extends spirally or spirally from the inner peripheral side to the outer peripheral side.
7 is along the tangential direction of the outer peripheral surface and on the outer peripheral side is along the tangential direction of the inner peripheral surface of the rolling surface 20.

In the second embodiment configured as described above, when the disk 1 rotates at high speed, the sphere 13 floats by the action of the outermost peripheral slope 38 of the sphere moving groove 37 and presses against the rolling surface 20. While being rotated together with the clamper 10 (left side in FIG. 2). When the rotation of the disk 1 is rapidly switched from the high speed to the standard speed, the sphere 13 tries to continue to rotate along the rolling surface 20 due to the inertia of the rotation, but enters the sphere moving groove 37 by its own weight. Then, the sphere 13 is drawn into the sphere moving groove 37, rapidly approaches the inner peripheral side along the groove, and is attracted to the magnet 27 (right side in FIG. 2).

In this case, the sphere 13 can move more rapidly than the flat moving surface in the conventional apparatus shown in FIG. 5, and the collision timing of the sphere 13 with the magnet 27 can be set earlier than the start of reading audio data. Therefore, it is possible to prevent occurrence of an error due to a shock at the time of suction. Also, at the time of spin-up, the sphere 13 moves along the sphere moving groove 37 and collides in the tangential direction of the rolling surface 20, so that the impact can be suppressed much smaller than in the case of colliding in the radial direction as in other cases. It is possible to suppress the occurrence of errors due to the impact at the time of spin-up.

[0022]

As described above, according to the disk drive of the present invention, since the impact due to the collision of the magnetic sphere at the time of sudden change in the rotation speed can be reduced, errors such as read error and spin-up time over can be prevented, and the magnetic sphere can be prevented. Since the magnetic disk has a structure that is hardly magnetized by the magnet, the disk device can be stably moved and cancel the imbalance, thereby realizing a disk device capable of reproducing and recording data stably.

[Brief description of the drawings]

FIG. 1 is a side cross-sectional view showing the vicinity of a spindle motor of a disk drive according to an embodiment of the present invention.

FIG. 2 is a side cross-sectional view showing the vicinity of a spindle motor of a disk device according to another embodiment.

FIG. 3 is a horizontal sectional view showing an arrangement structure of a spherical moving groove.

FIG. 4 is a perspective view showing a conventional disk device.

FIG. 5 is a side sectional view showing the vicinity of a spindle motor of a disk device having a conventional balancer.

FIG. 6 is a plan sectional view showing the operation of a balancer in a conventional disk device.

[Explanation of symbols]

 Reference Signs List 1 disc 2 spindle motor 3 optical pickup 4 optical pickup drive motor 5 optical pickup drive system 6 sub base 7 insulator 8 main base 9 turntable 10 clamper 11 yoke 13 sphere 15 back yoke 17 center of gravity of disc 18 unbalance force 19 centrifugal force 20 Rolling surface 21 Drag 22 Moving force 23 Whirling center 24 Leakage magnetic flux 25 Magnetic flux 26 Outer peripheral surface of magnet 27 Magnet 28 Magnetized surface 29 Non-magnetized surface 35 Rib 37 Spherical groove 38 Outermost slope

Claims (2)

[Claims] 1. A disk comprising: a balancer provided rotatably integrally with a mounted disk and having a hollow annular portion accommodating a magnetic material; and a magnetic field generating means for attracting and holding the magnetic material. In the apparatus, the magnetic field generating means is constituted by a magnet, an outer periphery of the magnet is an inner wall of the hollow annular portion, and an obstacle means for preventing the magnetic body from directly contacting the magnet. 2. A disk provided with a balancer having a hollow annular portion accommodating a magnetic material and rotatably provided integrally with a mounted disk, and a magnetic field generating means for attracting and holding the magnetic material. A disk device, comprising: a guide groove for guiding movement of the magnetic body on a lower surface of the intermediate annular portion.