JPH0676331A - Objective lens actuator - Google Patents

Abstract

(57) [Summary] (Correction) [Constitution] Made of gel silicone rubber, acrylate resin, or the like between the support members 6a, 6c and the sandwiching piece 11a fixed to the base 7 at one end in parallel with the support member. When the movable body 13 is driven in the focusing direction and the tracking direction by disposing the vibration absorber 12a and the vibration absorber 12b between the support members 6b and 6d and the sandwiching piece 11b, and the entire objective lens actuator moves in the tracking direction. When it is made, the resonance due to the twist of the support members 6a, 6b absorbs the vibration energy of the twist resonance by the vibration absorbers 12a, 12b between the sandwiching pieces 11a, 11b and the support members 6a, 6b, and suppresses the vibration. To do. [Effect] It is possible to enhance the stability of the servo performance that shows the performance of causing the light beam spot focused by the objective lens 3 to follow the surface wobbling and eccentricity of the information recording medium.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an objective lens actuator used in an optical recording / reproducing apparatus for recording / reproducing information by condensing a light beam emitted from a light source such as a semiconductor laser on an information recording medium. is there.

[0002]

2. Description of the Related Art A conventional objective lens actuator of this type is constructed as shown in FIG. That is, in the base 2 made of a magnetic metal plate fixed between the light source section of the optical recording / reproducing apparatus and the information recording medium, a rectangular parallelepiped magnet 1a protruding in a rectangular parallelepiped shape at both ends thereof,
The magnet holding pieces 8a and 8b for holding 1b are provided so as to face each other.
Inside the a and 8b, rectangular parallelepiped magnetic path pieces 9a and 9b are provided at regular intervals.

Outside the magnet holding piece 8b, four parallel plate-like supporting members 6a, 6b, 6c, 6d are provided.
Of the supporting member 6a, 6b, 6c, 6d is attached with a base 7 having one end fixed thereto, and a substantially rectangular objective lens holder 4 using a material such as polyphenylene sulfide resin or epoxy resin. It is fixed.

The objective lens 3 is incorporated in the central portion of the objective lens holder 4. On the other hand, the objective lens holder 4
A focusing control coil 10 is wound around, and four ring-shaped tracking control coils 5 are joined to the end faces of the outer periphery of the focusing control coil 10 which are opposed to each other with the objective lens 3 as the center. Coil is magnet 1
It is arranged in the space between a and 1b and the magnetic path pieces 9a and 9b.

With such a configuration, the focus deviation of the light beam with respect to the surface of the information recording medium and the track groove deviation of the light beam with respect to the track groove of the information recording medium surface are detected, and the detection control signal detects the focusing control coil 10 and the tracking. An electric current is applied to the control coil 5 so that the magnet 1
The objective lens 3 is moved up and down in the focusing direction, which is the optical axis direction of the objective lens, by using the magnetic flux in which a magnetic field is always formed by a and 1b and the magnetic path pieces 9a and 9b, and in the direction perpendicular to the optical axis direction of the objective lens. The position of the objective lens 3 is controlled by driving in parallel with a certain tracking direction.

[0006]

However, in the above configuration, when the movable body is driven in the focusing direction and the tracking direction, and when the entire objective lens actuator is moved in the tracking direction, the supporting members 6a, 6b, 6c. , 6d is liable to have torsional resonance, and as a result, a phase delay occurs at the center position of the objective lens 3 with respect to the phase of the input current, and as a result, the light beam spot condensed by the objective lens 3 becomes There is a problem in that the stability of the servo performance, which is the performance to follow surface wobbling and eccentricity, is poor.

An object of the present invention is to eliminate the above-mentioned conventional drawbacks and to provide an objective lens actuator having a stable servo performance which follows eccentricity.

[0008]

In order to solve the above-mentioned problems, the present invention provides a sandwiching piece arranged in parallel with a support member and a vibration absorber between the sandwiching piece and the support member. It is characterized by.

[0009]

With the above structure, when the movable body is driven in the focusing direction and the tracking direction, and when the entire objective lens actuator is moved in the tracking direction, the resonance caused by the twist of the support member causes a gap between the holding piece and the support member. By disposing the vibration absorber, the vibration energy of torsional resonance is absorbed and the vibration is suppressed.

As a result, it is possible to improve the stability of the servo performance which shows the performance of causing the light beam spot focused by the objective lens to follow the surface wobbling and eccentricity of the information recording medium.

[0011]

【Example】

(Embodiment 1) An embodiment of the present invention will be described below with reference to FIG. FIG. 1 is a schematic external perspective view of the present invention. Although the focusing control coil, the tracking control coil, the magnet, and the base in the conventional example are omitted, they are assumed to be movable in the focusing direction and the tracking direction.

In this case, between the support members 6a and 6c and the holding piece 11a having one end fixed to the base 7, a vibration absorber 12a made of gel silicone rubber or acrylate resin, and the support members 6b and 6d are provided. The vibration absorber 12 is provided at a position corresponding to an antinode of vibration of the support members 6a to 6d between the sandwiching pieces 11b.
Since b is arranged, when the movable body 13 moves in the tracking direction and when the entire objective lens actuator is moved in the tracking direction, the supporting members 6a, 6 are provided.
The resonance due to the twist of b, 6c and 6d is suppressed by this structure and the vibration absorbers 12a and 12b, and the delay of the phase with respect to the phase of the input current at the center of the objective lens 3 at the center of the movable body 13 is suppressed. It

As a result, it is possible to enhance the stability of the servo performance which shows the performance of causing the light beam spot focused by the objective lens 3 to follow the surface wobbling and eccentricity of the information recording medium.

(Embodiment 2) Another embodiment of the present invention will be described below with reference to FIG. FIG. 2 is a schematic external perspective view of the present invention. The same parts as in Example 1 are given the same numbers,
The description will be omitted.

In this case, the vibration absorber 12 made of gel silicone rubber, acrylate resin or the like is provided between the support members 6a, 6c and the holding piece 11a having one end fixed to the movable body 13.
a, 12b and the vibration absorbers 12c, 12d between the support members 6b, 6d and the sandwiching piece 11b are arranged, the movable body 13 moves in the tracking direction and the entire objective lens actuator moves in the tracking direction. When the support members 6a, 6b, 6c and 6d are twisted, the resonance caused by the twisting of the support members 6a, 6b, 6c and 6d causes
The absorption is suppressed by 12c and 12d, and the delay of the phase with respect to the phase of the input current at the center of the objective lens 3 at the center of the movable body 13 is suppressed.

As a result, it is possible to enhance the stability of the servo performance which shows the performance of causing the light beam spot focused by the objective lens 3 to follow the surface wobbling and eccentricity of the information recording medium.

(Embodiment 3) Another embodiment of the present invention will be described below with reference to FIG. FIG. 3 is a schematic external perspective view of the present invention. The same parts as in Example 1 are given the same numbers,
The description will be omitted.

In this case, the vibration absorber 12a is sandwiched between the sandwiching piece 11a having one end fixed perpendicularly to the longitudinal direction of the support member 6a and the sandwiching piece 11b having one end fixed perpendicularly to the longitudinal direction of the support member 6b. Similarly, the holding piece 11c having one end fixed vertically to the longitudinal direction of the support member 6c and the holding piece 11d having one end fixed vertically to the longitudinal direction of the support member 6d.
Since the vibration absorber 12b is sandwiched between the support members 6a, 6b, 6c and 6d when the movable body 13 moves in the tracking direction and when the entire objective lens actuator is moved in the tracking direction. Resonance is suppressed by this structure and the vibration absorbers 12a and 12b, and the objective lens 3 at the center of the movable body 13 is suppressed.
The phase delay with respect to the phase of the input current at the center of is suppressed.

As a result, it is possible to enhance the stability of the servo performance showing the performance of causing the light beam spot focused by the objective lens 3 to follow the surface wobbling and eccentricity of the information recording medium.

(Embodiment 4) Another embodiment of the present invention will be described below with reference to FIG. FIG. 4 is a schematic external perspective view of the present invention. The same parts as in Example 1 are given the same numbers,
The description will be omitted.

In this case, the vibration absorber 12a and the vibration absorber 12a are provided at a position corresponding to the antinode of vibration between the support members 6a and 6b.
Since the vibration absorber 12b is arranged at a position corresponding to an antinode of vibration between the support members 6c and 6d, the movable body 1
When 3 is moved in the tracking direction and when the whole objective lens actuator is moved in the tracking direction, resonance due to the twist of the support members 6a, 6b, 6c, 6d is suppressed by this structure and the vibration absorbers 12a, 12b. Thus, the delay of the phase with respect to the phase of the input current at the center of the objective lens 3 at the center of the movable body 13 is suppressed.

As a result, it is possible to enhance the stability of the servo performance showing the performance of causing the light beam spot focused by the objective lens 3 to follow the surface wobbling and eccentricity of the information recording medium.

(Embodiment 5) Another embodiment of the present invention will be described below with reference to FIG. FIG. 5 is a schematic external perspective view of the present invention. The same parts as those in the first embodiment are designated by the same reference numerals, and the description will be omitted.

In this case, the support members 6a, 6b, 6c, 6
Both ends of d are vibration absorbers 12a, 12b, 12c, 12
The vibration absorbers 12a and 12c fixed to the d
Is the movable body 13, and the vibration absorbers 12b and 12d are the bases 7.
Is fixed to the support members 6a, 6 when the movable body 13 moves in the tracking direction and when the entire objective lens actuator is moved in the tracking direction.
The resonance due to the twist of b, 6c and 6d is suppressed by this structure and the vibration absorbers 12a to 12d, and the delay of the phase with respect to the phase of the input current at the center of the objective lens 3 at the center of the movable body 13 is suppressed. It

As a result, it is possible to enhance the stability of the servo performance which shows the performance of causing the light beam spot focused by the objective lens 3 to follow the surface wobbling and eccentricity of the information recording medium.

(Embodiment 6) Another embodiment of the present invention will be described below with reference to FIG. FIG. 6 is a schematic external perspective view of the present invention. The same parts as those in the first embodiment are designated by the same reference numerals, and the description will be omitted.

In this case, the support member 6a made of an elastic material,
6b is a vibration absorber 12a such as an adhesive or an acrylate resin
Since the both ends are fixed to the movable body 13 and the base 7 by sandwiching, and the same applies to other supporting members, when the movable body 13 moves in the tracking direction and the entire objective lens actuator moves in the tracking direction. When the support members 6a, 6b, 6c, 6d, 6e, 6f,
Resonance due to the twist of 6g and 6h is suppressed by the structure and the vibration absorbers 12a to 12d, and the movable body 13 is suppressed.
The phase delay with respect to the phase of the input current at the center of the objective lens 3 at the center of is suppressed.

As a result, it is possible to enhance the stability of the servo performance showing the performance of causing the light beam spot focused by the objective lens 3 to follow the surface wobbling and eccentricity of the information recording medium.

[0029]

As described above, according to the present invention, an objective lens holder for holding an objective lens and two or more parallel plates having one end fixed to the objective lens holder and the other end fixed to a base. The movable member was driven in the focusing direction and the tracking direction by arranging the supporting member in the shape of a line, the sandwiching piece arranged to be parallel to the supporting member, and the vibration absorber between the sandwiching piece and the supporting member. And the torsional resonance of the supporting member that occurs when the entire objective lens actuator is moved in the tracking direction, the vibration energy between the clamping member and the supporting member is absorbed by the vibration absorber to suppress the vibration. can do.

As a result, it is possible to enhance the stability of the servo performance, which shows the performance of making the light beam spot focused by the objective lens follow the surface wobbling and eccentricity of the information recording medium, and to improve the seismic resistance against disturbance vibration. The objective lens actuator that can be improved and has high reliability can be supplied.

[Brief description of drawings]

FIG. 1 is a schematic external perspective view for explaining the operation of an objective lens actuator according to a first embodiment of the present invention.

FIG. 2 is a schematic external perspective view for explaining the operation of the objective lens actuator according to the second embodiment of the present invention.

FIG. 3 is a schematic external perspective view for explaining the operation of the objective lens actuator according to the third embodiment of the present invention.

FIG. 4 is a schematic external perspective view for explaining the operation of the objective lens actuator according to the fourth embodiment of the present invention.

FIG. 5 is a schematic external perspective view for explaining the operation of the objective lens actuator according to the fifth embodiment of the present invention.

FIG. 6 is a schematic external perspective view for explaining the operation of the objective lens actuator according to the sixth embodiment of the present invention.

FIG. 7 is a perspective view of a conventional objective lens actuator.

[Explanation of symbols]

 1a, 1b Magnet 2 Base 3 Objective lens 4 Objective lens holder 5 Tracking control coil 6a-6h Supporting member 7 Base 8a, 8b Magnet holding piece 9a, 9b Magnetic piece 10 Focusing control coil 11a-11d Holding piece 12a- 12d Vibration absorber 13 Movable body

Claims (10)

[Claims] 1. An objective lens holder for holding an objective lens, two or more parallel plate-like support members having one end fixed to the objective lens holder and the other end fixed to a base, and the support. An objective lens actuator comprising a sandwiching piece arranged to be parallel to a member, and a vibration absorber arranged between the sandwiching piece and a support member. 2. The objective lens actuator according to claim 1, wherein one end of the sandwiching piece is fixed to the base. 3. The objective lens actuator according to claim 1, wherein one end of the sandwiching piece is fixed to the objective lens holder. 4. The objective lens actuator according to claim 1, wherein the vibration absorber and the sandwiching piece are arranged in the vicinity of an antinode of vibration of the supporting member. 5. The objective lens actuator according to claim 1, wherein the vibration absorber is gel silicone rubber. 6. The objective lens actuator according to claim 1, wherein the vibration absorber is an acrylate resin. 7. An objective lens holder for holding an objective lens, two or more plate-shaped supporting members having one end fixed to the objective lens holder and the other end fixed to a base, and two or more members. An objective lens actuator comprising a sandwiching piece having one end fixed to the supporting member in a direction perpendicular to the supporting member, and a vibration absorber disposed between the sandwiching pieces. 8. An objective lens holder for holding an objective lens, two or more parallel plate-like support members having one end fixed to the objective lens holder and the other end fixed to a base, and the support. An objective lens actuator, wherein a vibration absorber is arranged so as to be sandwiched between a member and a support member. 9. An objective lens holder for holding an objective lens, and a parallel one end fixed to the objective lens holder via a vibration absorber and the other end fixed to a base via the vibration absorber. An objective lens actuator including two or more plate-shaped support members. 10. An objective lens holder for holding an objective lens, two or more parallel plate-like support members, one end of which is fixed to the objective lens holder and the other end of which is fixed to a base. An objective lens actuator in which a support member includes a plate-shaped elastic body and a vibration absorber sandwiched between the elastic bodies.