Objective lens drive apparatus, optical pickup device, and optical disk drive

Abstract

An objective lens drive apparatus includes a stationary member, a movable portion having an objective lens, an objective-lens holding member, and driving coils, and a plurality of rod-like elastic support members each having an axial direction parallel to a third direction perpendicular to a first direction and a second direction, the support members elastically supporting the movable portion so that the movable portion is movable to the stationary member in the first direction and the second direction. The movable portion is supported by the support members on both sides of the movable portion in the third direction, the support members are arranged on different planes perpendicular to the first direction, and the movable portion is arranged to be movable in the third direction with the support members, so that the objective lens is rotatable around an axis of the second direction.

Description

BACKGROUND OF THE INVENTION [0001] 1. Surface of The Invention [0002] The present invention relates to an objective lens drive apparatus provided to focus a light beam from an objective lens onto an optical disk as a light spot in order to perform recording / reproduction of the optical disk, and relates to an optical pickup device incorporating the objective lens drive apparatus, and an optical disk drive incorporating the optical pickup device. [0003] 2. Description of the Related Art [0004] Conventionally, in the optical disk drive, the laser light beam, output from the laser light source, is focused with the objective lens on the optical disk as a light spot, and information is read from the optical disk by carrying out the opto-electric conversion of the reflected light from the optical disk. [0005] The objective lens drive apparatus, which is provided in the optical disk drive, drives the objective lens in the focusing direction and the tracking direction using the control signa...

AI Technical Summary

Benefits of technology

[0035] An object of the present invention is to provide an improved objective lens drive apparatus in which the above-described problems are eliminated.

[0036] Another object of the present invention is to provide an objective lens drive apparatus which can drive the objective lens with sufficient accuracy at high speed.

[0037] Another object of the present invention is to provide an optical pickup device that is appropriate for use with an objective lens drive apparatus so that the objective lens drive apparatus can drive the objective lens with sufficient accuracy at high speed.

[0038] Another object of the present invention is to provide an optical disk drive that is appropriate for use with an optical pickup device and stably carries out accessing of an optical disk with the optical pickup device with sufficient accuracy at high speed.

[0044] According to the objective lens drive apparatus of the present invention, it is possible to correct the inclination error of the optical disk and the objective lens. By making it possible to generate the driving force which can follow the optical disk under high-speed rotation to carry out the independent drive at each shaft orientations, the movability of the tangential tilt direction can be made good, and the sensibility can be made small.

[0045] The optical disk drive of the present invention can perform stable control and it sets to the objective lens drive apparatus dealing with inclination compensation. The cross talk between the drive shafts which are easy to pose the problem can be reduced. Specifically, it is possible to reduce the cross talk including the cross talk of the tangential rotation direction generated by focusing translation drive, the cross talk of the tangential movement direction generated by focusing or tracking translation drive, and the cross talk of the tangential movement direction generated by the tangential rotation drive.

Problems solved by technology

However, if the NA is enlarged or the wavelength of laser is shortened, the perpendicularity of the optical axis of the objective lens to the optical disk is shifted, and the coma aberration will easily be generated and the quality of the light spot will deteriorate.

This causes the quality of recording / reproduction to deteriorate.

When the high-speed rotation of the optical disk with which the surface inclination or the eccentricity exists is carried out, the acceleration becomes very large.

This will easily affect the driving of the objective lens drive apparatus in the other directions.

However, in the conventional technique of Japanese Laid-Open Patent Application No. 10-275354, it is difficult to manage the rotation rigidity in the tangential tilt direction of the attachment section of the rod-like members 108,109 on the side of the lens holder 106 with the composition of the conventional objective lens drive apparatus of FIG. 34.

The acceleration sensibility becomes small, and it is difficult to follow the optical disk which is rotated at high speed.

However, when the moving magnet method is used, it is difficult to make sensibility increase since the mass of the movable portion increases when the magnet is enlarged.

It is difficult to ensure adequate level of the acceleration which can follow the surface inclination or eccentricity of the optical disk.

With the composition of the conventional objective lens drive apparatus of Japanese Laid-Open Patent Application No. 10-275354, the movable portion is configured into a thin structure, and the magnitude of the mechanical components cannot be secured enough and there is the problem that the output acceleration is low.

There is also the problem that the servo control becomes unstable.

However, in the conventional objective lens drive apparatus of FIG. 35, the composition of the elastic arm 129 on the side of the stationary portion is complicated, and the elastic properties are not stabilized.

There is the problem that is the same as that of the composition of FIG. 34.

However, in the composition of Japanese Utility Model No. 2579715 or Japanese Laid-Open Patent Application No. 6-162540, when the movable portion containing the objective lens is driven in one direction, the movement of the objective lens in the other directions becomes unstable or the movement is impossible.

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