JPH0963213A - Optical disk device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable a stable tracking servo against disturbance due to vibration and impact by abutting a rack having an elastic deformation part against an intermediate gear at a prestage to bring their tooth surfaces always in mutual contact and absorbing backlash accordingly. SOLUTION: An optical pickup 1 is moved in the radial direction of an optical disk for the purpose of reading out information from the optical disk under rotation. The optical disk is rotated by a turntable 3 fitted to a spindle motor 2. A slide of the optical pickup 1 in the radial direction is performed by its movement along a feed shaft 4 fixed to a chassis 5. An intermediate gear 8 at a prestage, meshed with a motor gear 7 fixed to a shaft of a feed motor 6 is further engaged with the intermediate gear 9 at the prestage, and is subsequently meshed with the rack 12. The rack 12 at the final stage of a driving system is formed in a V-shape to be always opened to the outside by working of spring force, thus pressing the tooth parts of the intermediate gears.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk device such as a CD / CD-ROM equipped with an optical pickup.

[0002]

2. Description of the Related Art Conventionally, an optical disk device has been developed by technical development with an optical pickup and by being miniaturized and stable performance even under a wide range of environments.

A conventional optical disk device will be described below. FIG. 3 is a plan view showing the configuration of a conventional optical disk device. FIG. 4 is an enlarged side sectional view showing an engaging portion between the rack and the intermediate gear of this conventional optical disk device.

In FIG. 3, 1 is an optical pickup for reading information from an optical disc, 2 is a spindle motor for rotating the optical disc, 3 is a turntable attached to the spindle motor 2, and 4 is an optical pickup 1 which is a radial ( A feed shaft for sliding in the (radius) direction, 5 is a chassis fixing the shaft 4, 6
Is a feed motor attached to the chassis 5, 7 is a motor gear fixed to the shaft of the feed motor 6, and 8 is an intermediate gear in the latter stage engaging with the motor gear 7.

The rack 10 is attached to the optical pickup 1 and engages with the intermediate gear 9 in the preceding stage. The backlash between the rack 10 and the intermediate gear 9 at the front stage always occurs, and the configuration for removing the backlash is as follows.

Two racks having the same tooth specifications, that is, a first rack 10 and a second rack 11 are overlapped with each other and pulled (repulsed) by a spring 13 so that the meshing with the intermediate gear 9 at the preceding stage is two. The tooth surfaces on one side of the first and second racks 10 and 11 are always in contact with the spur gear, and the backlash is absorbed [hereinafter, referred to as "conventional example"].

The operation of the conventional optical disk device having the above drive system will be described.

The optical pickup 1 is adapted to align a light spot in a focus direction and a tracking direction with respect to an optical disc (not shown) for reading information. The optical pickup drive device is an optical pickup 1
High accuracy such as mounting position and inclination (skew) is required to maximize the performance of the.

An optical disk is mounted on the turntable 3,
The rotation of the spindle motor 2 is controlled so that the linear velocity is always constant. The information on the optical disk has spiral pits from the inner circumference to the outer circumference, and the information is read by always controlling the light spot position.

For focusing, servo is applied to the optical disk by the actuator of the optical pickup 1. Since the tracking can only follow a few millimeters with the actuator alone, it is necessary to move the optical pickup 1 itself to some extent, and a two-stage control of the servo by the actuator and the servo for sliding the optical pickup 1 by the feed motor 6 and the intermediate gear 8 is performed. ing.

In order to move the optical pickup 1, a motor gear 7 is attached to a feed motor 6 and is decelerated by an intermediate gear 8 to finally move the optical pickup 1 meshing with a rack 10.

When the application is portable or vehicle-mounted, vibration or impact is always applied, so if there is looseness in the tracking direction,
The accuracy of the tracking servo may be deteriorated and sound skipping may occur.

[0013]

However, in this conventional example, in order to eliminate the backlash (backlash) of the gears generated in the meshing of the rack and the gear in the preceding stage, the racks are doubly overlapped and displaced by the spring force. Based on this, the backlash is removed by adopting a structure that eliminates the backlash or, on the contrary, by using a double structure of gears that mesh with the rack. The above configuration has a problem that the number of parts is increased and the number of assembling steps is also increased.

Here, the present invention solves the problems of the above-mentioned conventional example, and the backlash generated between the rack and the front gear can be removed by only one rack component, thereby reducing the number of drive system components. It is an object of the present invention to provide an optical disk device for driving an optical pickup which is stable and highly reliable against vibration and shock while being easy to assemble.

[0015]

In order to achieve this object, the optical disk device of the present invention utilizes an elastically deformable portion of a rack of a drive system component of an optical pickup to provide a spring force so that the rack teeth are always provided. Has a personality of pressing against the teeth of the intermediate gear. That is, an optical pickup for reading information on the optical disc, a shaft for the optical pickup to slide in the radial direction of the optical disc, a chassis for fixing the shaft, a feed motor attached to the chassis,
An optical disk device includes a gear driven by a motor and a rack supported by an optical pickup and having an elastically deformable portion for pressingly engaging with the gear. Further, preferably, the outer shape of the rack at the final stage of the drive system is formed in a substantially V shape, and one side outside thereof has a tooth portion facing the intermediate gear at the front stage of the gear driven by the motor and meshing with it. The optical disk device has a substantially V-shaped shape and is provided with an elastically deformable portion in which a spring force acts in a direction in which both outer sides always open outward.

[0016]

With the above-described structure of the present invention, the backlash between the rack and the intermediate gear at the front stage can be completely and easily absorbed.

[0017]

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

FIG. 1 is a plan view showing the overall structure of an optical disk device according to an embodiment of the present invention.

FIG. 2 is a side sectional view showing the engaged state of the rack and the intermediate gear in one embodiment of the present invention. here,
The same components as those in the conventional example are designated by the same reference numerals.

In FIG. 1, 1 is an optical pickup for reading information from an optical disk, 2 is a spindle motor for rotating the optical disk, 3 is a turntable mounted on the spindle motor 2 for rotating the optical disk, 4
Is a feed shaft for sliding the optical pickup 1 in the radial direction of the disc board, 5 is a chassis fixing the shaft 4, 6 is a feed motor attached to the chassis 5, and 7 is a shaft of the feed motor 6. The motor gear 8 is a rear intermediate gear meshing with the motor gear 7. The rack 12 is fixed to a part of the chassis 5 of the optical pickup 1 and meshes with the intermediate gear 9 in the preceding stage.

The optical pickup 1 applies a tracking servo so as to follow the tracking at an interval of, for example, 1.6 μm adjacent to the optical disk. However, when the application is in-vehicle or portable, the optical pickup drive device itself is subject to vibration or shock. If there is play in the feed drive system, a dead zone will occur when the servo is applied, making it impossible to follow tracking, resulting in sound skipping and the like.

Particularly, the backlash between the rack 12 at the final stage of the drive system and the intermediate gear 9 at the previous stage adversely affects the tracking servo of the intermediate gear 9 at the previous stage. Rack 12 is "
The teeth are formed in a substantially V shape, and the teeth formed on one side of the outside press the teeth of the intermediate gear 9 of the preceding stage by the adjusted spring force that expands outward. At the time of assembling the intermediate gear 9, the elastically deformable portion is provided with a spring property so that the intermediate gear 9 is always pressed against the preceding intermediate gear 9.
In the engaged state of the teeth, the tooth surface of the rack 12 and the tooth surface of the intermediate gear 9 in the preceding stage come into contact with each other, and the backlash can be removed at all times.

[0023]

As is apparent from the above description, according to the present invention, the tooth flanks are always in contact with each other by the elastic deformation portion of the rack being pressed against the intermediate gear of the preceding stage to absorb the backlash. By doing so, it is possible to eliminate rattling of the drive system, the drive system can be configured with a small number of parts and assembly man-hours, and a particular effect that stable tracking servo is possible even if disturbance due to vibration, shock, etc. is applied be able to.

[Brief description of drawings]

FIG. 1 is a plan view showing the overall configuration of an optical disk device according to an embodiment of the present invention.

FIG. 2 is an enlarged side sectional view showing an engaged state of a rack and an intermediate gear in one embodiment of the present invention.

FIG. 3 is a plan view showing a configuration of a conventional optical disc device.

FIG. 4 is an enlarged side sectional view showing an engaging portion between a rack and an intermediate gear of the conventional optical disc device.

[Explanation of symbols]

1 Optical Pickup 2 Spindle Motor 3 Turntable 4 Feed Shaft 5 Chassis 6 Feed Motor 7 Motor Gear 8 Rear Stage Intermediate Gear 9 Front Stage Intermediate Gear 10 First Rack 11 Second Rack 12 Elastic Deformation Part "V-shaped" Rack having [invention] 13 spring

Claims (2)

[Claims] 1. An optical pickup for reading information on an optical disc, a shaft for the optical pickup to slide in the radial direction of the optical disc, a chassis for fixing the shaft, a feed motor attached to the chassis, and the motor. An optical disk device comprising: a gear driven by the optical pickup; and a rack supported by the optical pickup and having an elastically deformable portion for pressingly engaging the gear. 2. A rack at the final stage of the drive system is formed into a substantially V-shaped outer shape, and a tooth portion is formed on one side outside the rack so as to face the intermediate gear at the front stage of the gear driven by the motor and mesh with it. 2. The optical disk device according to claim 1, wherein the rack is provided with the substantially V-shaped shape and an elastically deforming portion in which spring force acts in a direction in which both outer sides always open outward.