JPH08306058A - Optical head actuator and optical pickup device provided with same - Google Patents

Abstract

PURPOSE: To provide an optical head actuator and an optical pickup device having a uniform damping characteristic in both the tracking and the focusing directions of an optical head, easy assemblability, a low price and an efficient and stable vibration-proof structure. CONSTITUTION: An optical head actuator is provided with a movable part 10 holding an optical head, a fixed part 20 supporting the movable part 10 in a movable state through a wire-like suspension, a focusing coil 6 and tracking coils 5a, 5b relatively moving the movable part 10 to the fixed part 20 and a driving device having a fixed magnet part composed of a yoke 11 and a magnet 12. A damping member 21 for attenuating the oscillation of the optical head is arranged between the movable part 10 and the fixed part 20.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical pickup device provided in an optical disk drive device.
The present invention relates to a vibration control structure for an optical head actuator of an optical pickup device.

[0002]

2. Description of the Related Art Conventionally, an optical pickup device has been used as an optical disk drive device. As shown in FIG. 10, an optical head actuator is used in this optical pickup device (see Japanese Patent Laid-Open No. 7-37261). The actuator of the optical head shown in FIG. 10 is called a biaxial actuator and includes a movable portion 50 and a fixed portion 60.

The movable part 50 includes an objective lens 52 provided on a lens holder 51 and a pair of tracking coils 5.
3 and a focus coil 54 are provided, and are supported by the fixed portion 60 by a plurality of suspensions 55 composed of leaf springs. Further, the fixed portion 60 is provided with a fixed magnet portion 58 including a magnet 56 and a yoke 57. The fixed magnet part 58 of the fixed part and a pair of the tracking coil 53 and the focus coil 54 of the movable part constitute a driving device, and when the tracking coil 53 and the focus coil 54 are energized, they are moved by the action of the magnetic flux from the fixed magnet part. The unit 50 is driven so as to move relative to the fixed unit, and the focus and tracking are adjusted.

[0004]

However, when the actuator is driven, vibration occurs in each part of the actuator in the tracking direction and the focus direction, and it takes a long time for the vibration to subside. Also,
The vibration in these directions also causes a drawback that the optical disc cannot be read accurately.

Therefore, a technical object of the present invention is to provide an optical head actuator which can obtain uniform vibration isolation characteristics in both the tracking direction and the focusing direction of the optical head.

Further, another technical problem of the present invention is
An object is to provide an optical head actuator that is easy to assemble and inexpensive.

Another technical object of the present invention is to provide an optical head actuator which can have an efficient and stable vibration isolation structure.

Still another technical problem of the present invention is to provide an optical pickup device having an optical head actuator having the above-mentioned advantages.

[0009]

According to the present invention, a movable part for holding an optical head, a fixed part for movably holding the movable part via a wire, and the movable part and the fixed part are provided. In an optical head actuator provided with a drive device for moving the movable part relative to the fixed part, a damping member for damping the vibration of the optical head is provided between the movable part and the fixed part. An optical head actuator characterized by being interposed is obtained.

Further, according to the present invention, in the optical head actuator, the movable portion includes a lens holder for holding a lens of the optical head, and the fixed portion is in surface contact with each other forming a part of the driving device. It is possible to obtain an optical head actuator characterized in that the damping member is provided between the lens holder and the fixed magnet portion, and the fixed magnet portion having the yoke and the magnet is provided.

Further, according to the present invention, in the optical head actuator, the movable part includes a coil fixed to the movable part as a part of the driving device, and the fixed part is different from that of the driving device. A fixed magnet part that is fixed to the fixed part and generates a magnetic field so that the magnetic flux passes through the coil is provided, and the damping member is provided between the coil and the fixed magnet part. An optical head actuator characterized by the above is obtained.

Further, according to the invention, in the optical head actuator, the fixed magnet portion includes a yoke and a magnet that are in surface contact with each other, and the damping member is provided between the yoke and the coil. An optical head actuator is obtained.

According to the present invention, in any one of the optical head actuators described above, the vibration damping member is any one of gel substance, rubber and silicone. To be

In the present invention, the damping member is a silicone rubber having a siloxane bond among rubbers such as styrene butadiene, nitrile, chloroprene, ethylene propylene, butyl rubber, fluororubber and natural rubber. Among silicone rubbers, silicone gels having a low cross-linking density can be used, but the present invention is not limited thereto.

According to the present invention, in any one of the optical head actuators described above, the optical head actuator is obtained in which the vibration damping member is a spring member or a plastic member.

Further, according to the present invention, there is provided an optical pickup device including any one of the above optical head actuators.

[0017]

In the actuator of the present invention, since the vibration damping member is arranged between the movable portion and the fixed portion, the optical head intersects with the first direction (focus adjustment direction) along the optical axis of the lens. The first direction by the drive device that drives in the second direction (tracking adjustment direction)
It is possible to damp vibrations in the direction of and the second direction,
Focus error and tracking error can be prevented.

[0018]

Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1) FIG. 1 is a plan view showing an optical head actuator of an optical pickup device according to Embodiment 1 of the present invention, and FIG. 2 is a side view of the optical head actuator of FIG.

Referring to FIGS. 1 and 2, the optical actuator 1 is movable in the up-down direction (first direction) and the left-right direction (second direction) with the movable portion 10 forming the optical head. As described above, the fixed portion 20 that holds the movable portion 10 and the drive device that is provided on the fixed portion 20 are provided.

The movable part 10 comprises an objective lens 2, a holder 3 for holding the objective lens, and a holding part 4 for fixedly supporting the lens holder.

The holding portion 4 is provided with a hole 4a at the center thereof. A pair of tracking coils 5a and 5b wound in the vertical direction are provided in the hole 4a symmetrically with respect to the central axis of the holding unit 4. A focus coil 6 wound in the horizontal direction is provided in the hole 4a adjacent to the tracking coils 5a and 5b in the central axis direction. Further, two suspensions 7 made of elastic rods or wire rods are provided on both sides of the holding portion 4 respectively. One end of the suspension 7 is fixed to the holding portion 4 with a screw 8.

On the other hand, in the fixed portion 20, a pair of fixed magnet portions 13 composed of a yoke 11 and a magnet 12 which are overlapped with each other are arranged so that the magnet 12 faces each other through one side of the tracking coil and the focus coil 6, and the holding portion 4 is formed. Is inserted into the hole 4a of the fixing unit 20 and one end of the base 17
It is fixedly installed in.

The other end of the suspension 7 is fixed to the support portion 15 of the fixed portion 20 via a damping material 14.

The driving device is composed of the tracking coils 5a and 5b formed in the movable part 10, the focus coil 6, and the fixed magnet part 13 including the yoke 11 and the magnet 12 provided in the fixed part 20. The movable part 10 is configured to be movable in the up-down direction and the left-right direction with respect to the fixed part 20.

In the actuator of the optical head according to the first embodiment of the present invention, the damping member 21 made of silicone rubber is arranged between the base and the lower portion of the fixed portion of the movable optical lens. The vibration damping member 21 prevents excessive vibration of the movable portion 10. Among silicone rubbers, a silicone gel having a low cross-linking density, for example, K, manufactured by Shin-Etsu Chemical Co., Ltd.
E1052 (A / B) is preferred.

(Embodiment 2) FIG. 3 is a plan view showing an optical head actuator according to Embodiment 2 of the present invention, and FIG. 4 is a side view of the optical head actuator of FIG. 3 and 4
Referring to, the optical actuator 1 includes a movable portion 10, a fixed portion 20, and a drive device formed on these. Optical head actuator according to Example 2 and Example 2
The difference from the optical pickup according to the present invention is that the vibration damping member 21 is provided between the lower portion of the holder 3 of the optical lens and the base 17 in the first embodiment. Except that the member 22 is provided so as to cover the suspension 7, it is the same as the first embodiment and has the same effect as the first embodiment.

(Embodiment 3) FIG. 5 is a plan view showing an optical head actuator according to Embodiment 3 of the present invention, and FIG. 6 is a side view of the optical pickup of FIG. With reference to FIGS. 5 and 6, the optical head actuator 1 includes a fixed portion 20 and a movable portion 10. The difference between the optical head actuator according to the third embodiment and the optical head actuators according to the first and second embodiments is that in the first embodiment, the damping member 21 is provided between the lower portion of the holder 3 of the optical lens and the base 17. Regarding the second embodiment, instead of the damping member 22 being provided so as to cover the suspension, the optical head actuator according to the third embodiment is provided with the damping member 23 between the coil and the fixed magnet portion. Other than that, it is the same as the first and second embodiments and has the same effect as the first and second embodiments.

(Embodiment 4) FIGS. 7A and 7B are a schematic plan view and a rear view mainly showing an optical head actuator according to Embodiment 4 of the present invention, and FIGS. 8A and 8B are 9 is a schematic side view showing the operation of the optical head actuator of FIG.
7A and 7B are a schematic plan view and a rear view showing the operation of the optical head actuator of FIG. 7, and the illustration below the half in the vertical direction in FIG. 7 is omitted.

With reference to FIG. 7, the optical head actuator 31 includes a movable portion 10, a fixed portion 20 and a drive unit. The movable portion 10 includes a holder 3 for holding the objective lens and a holding portion 4 for fixedly supporting the lens holder. The holding portion 4 is provided symmetrically with respect to the central axis from one side, and the hole portion 4a provided in the central portion is
A pair of tracking coils 5a wound in the vertical direction,
5b and a focus coil 6 wound in the horizontal direction.

Further, two suspensions 7 made of elastic rods or wires are provided on both sides of the holding portion 4 respectively. One end of the suspension 7 is fixed to the holding portion 4 with a screw 8.

Further, a pair of fixed magnet portions 13 composed of a yoke 11 and a magnet 12 which are overlapped with each other are fixed to the fixed portion 20 so that the magnets 12 face each other via one side of the tracking coils 5a and 5b and the focus coil 6. It is inserted into the hole 4a of the holding portion 4 and is provided with one end fixed to the base 17 of the fixing portion 20.

The other end of the suspension 7 is fixed to the support portion 15 of the fixed portion 20 via a damping material 14.

The driving device is composed of the tracking coils 5a and 5b of the movable part 10, the focus coil 6 and the fixed magnet part 13 as in the first to third embodiments.

The optical pickup device according to the first embodiment of the present invention comprises an optical lens holding portion 4 of a movable portion 10 and a yoke 1.
A damping member 24 made of silicone gel is disposed between the damping member 24 and The vibration damping member 21 prevents excessive vibration of the movable portion 10. This silicone gel is KE1052 (AB) manufactured by Shin-Etsu Chemical Co., Ltd., which is heat-cured at 80 ° C. for 30 minutes.
-B) can also be used.

Referring to FIGS. 8 and 9, the focus coil 6 is moved from the position shown in FIG.
The movable part 10 moves up to the position of (b). Also, when a current flows through the tracking coils 5a and 5b,
It moves from the position of FIG. 7A to the position of FIG. 9A according to the magnitude of the current. By this,
The tracking and focus will be automatically adjusted by the drive.

[0037]

As described above, according to the present invention, it is possible to provide an optical head actuator in which uniform vibration isolation characteristics can be obtained in both the tracking direction and the focus direction of the optical head by connecting with a gel.

Further, according to the present invention, since it is supported by the spring member or the plastic member containing the spring or the plastic, it is possible to provide the vibration damping structure for the actuator of the optical head which is easy to assemble and inexpensive.

Further, according to the present invention, it is possible to provide an optical head actuator capable of providing an efficient and stable vibration-proof structure by filling a place where a force is generated with gel.

[Brief description of drawings]

FIG. 1 is a plan view showing an optical head actuator according to a first embodiment of the invention.

FIG. 2 is a side view showing the optical head actuator of FIG.

FIG. 3 is a plan view showing an optical head actuator according to a second embodiment of the invention.

FIG. 4 is a side view mainly showing the optical head actuator of FIG.

FIG. 5 is a plan view showing an optical head actuator according to a third embodiment of the invention.

6 is a side view showing the optical head actuator of FIG. 4. FIG.

FIG. 7A is a schematic plan view showing an optical head actuator according to a fourth embodiment of the present invention. (B) is a schematic rear view showing an optical head actuator according to a fourth embodiment of the present invention.

8A and 8B are schematic side views showing the operation of the optical head actuator of FIG.

9A is a schematic plan view showing the operation of the optical head actuator of FIG. 7. FIG. FIG. 8B is a rear view showing the operation of the optical head actuator of FIG. 7.

FIG. 10 is a diagram mainly showing an optical head actuator according to a conventional example.

[Explanation of symbols]

 1, 31 Optical head actuator 2 Objective lens 3 Holder 4 Holding part 5a, 5b Tracking coil 6 Focus coil 7 Suspension 10 Moving part 11 Yoke 12 Magnet 13 Fixed magnet part 14 Damping material 15 Supporting part 17 Base 20 Fixed part 21, 22, 23, 24 Damping member

Front page continued (72) Inventor Takashi Uemura 1-1059 Tachikawa, Yamagata City, Yamagata Prefecture 5 Yamagata Mitsumi Co., Ltd. (72) Inventor Masayoshi Sugawara 5-1059, Tachikawa Yamagata City Yamagata Prefecture Mitsumi stock In the company

Claims (7)

[Claims] 1. A movable part for holding an optical head, a fixed part for movably holding the movable part via a wire, and the movable part and the fixed part. The movable part is provided for the fixed part. An optical head actuator including a drive device that relatively moves the optical head, wherein a vibration damping member for damping the vibration of the optical head is interposed between the movable portion and the fixed portion. Actuator. 2. The optical head actuator according to claim 1, wherein the movable portion includes a lens holder that holds a lens of the optical head, and the fixed portion is a yoke that forms a part of the driving device and is in surface contact with each other. An optical head actuator, comprising: a fixed magnet portion including a magnet and a magnet, wherein the damping member is disposed between the lens holder and the fixed magnet portion. 3. The optical head actuator according to claim 1, wherein the movable part includes a coil fixed to the movable part as a part of the drive device, and the fixed part is another part of the drive device. A fixed magnet portion fixed to the fixed portion to generate a magnetic field so that a magnetic flux passes through the coil, and the damping member is provided between the coil and the fixed magnet portion. An optical head actuator. 4. The optical head actuator according to claim 3, wherein the fixed magnet portion includes a yoke and a magnet that are in surface contact with each other, and the damping member is provided between the yoke and the coil. An optical head actuator characterized in that 5. The optical head actuator according to any one of claims 1 to 4, wherein the damping member is any one of a gel substance, rubber, and silicon. Actuator. 6. The optical head actuator according to claim 1, wherein the damping member is a spring member or a plastic member. 7. An optical pickup device comprising the optical head actuator according to any one of claims 1 to 6.