JPH0417129A - Pickup driving device for optical disk - Google Patents

Abstract

PURPOSE:To attain high accuracy with a low cost by bringing a guide means between a slider and a chassis into contact with a roller with the attracting force caused between the vertical part of the chassis and a magnet with the magnet of the slider being a component of a linear motor. CONSTITUTION:The chassis 1 is made of a magnetic material such as a roll steel plate, the attracting force is generated with a magnet 16 and a slider 5 is moved on the chassis 1 by the rolling of a ball 14 without floating the slider 5 by a distance equivalent to a diameter of the ball 14 with the attracting force. When the slider 5 is driven in the radial direction of an optical disk by the torque between the magnet 16 and a coil 17, the roller 20 is in rolling of one side of a rail 19 and guided. Thus, the accuracy of the optical axis of the pickup is increased, the assembling is facilitated and the cost of the driving device is reduced.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an optical disc equipped with a pickup for reading signals of an optical disc on which signals are optically recorded, and for moving the pickup in the radial direction of the optical disc. The present invention relates to a pickup drive device.

[Conventional technology]

A conventional optical disk pickup drive device of this type is shown in FIG.

This optical disc pickup drive device has a chassis 1
Two guide rails 2°3 having a circular cross section are fixed on the top.

The slider 5 on which the pickup 4 is mounted has two grooved bearings 6 that move along the guide rail 2, move along the guide rail 3, and are pressed against the guide rail 3 by the biasing force of the springs 7. ■Grooved bearing 8 is installed.

A coil 10 is fixed to the slider 5, and is loosely fitted into a magnet 9 fixed to the chassis 1, and together with the magnet 9 constitutes a linear motor.

The slider 5 is placed on the turntable 11 by the V-grooved bearing 6.7 rolling on the guide rails 2 and 3 due to the driving force generated between the current flowing through the coil 10 and the magnet 9. The pickup 4 is moved in the radial direction of a fixed optical disk.

[Problem to be solved by the invention]

In such an optical disk pickup drive device, the parallelism and bending of the two guide rails 2 and 3 in the height direction have a large effect on the inclination of the optical axis of the pickup 4, so the assembly accuracy is important. required.

Also, the V-groove of the grooved bearing 6.8 is tilted with respect to the axis, that is, the inclination accuracy of the groove with respect to the axis, the bearing backlash, etc. may cause the pickup optical axis to tilt not only from side to side but also from front to back. Therefore, an expensive and high-precision bearing 6.8 had to be used for the groove.

Furthermore, since the grooved bearing 8 is pressed against the guide rail 3 by the biasing force of the spring 7, there is a risk of resonance with the spring 7, so it is necessary to design with resonance in mind. There was a problem.

[Purpose of the invention]

In order to solve the above-mentioned problems in the conventional optical disc pink-up drive device, the present invention uses magnetically permeable materials, such as rolled steel, which can easily obtain flatness precision, and steel bars, which can easily obtain linear precision. , pickup position,
It is an object of the present invention to provide an optical disk pickup drive device which can obtain high precision at a low cost by making it possible to obtain tilt precision.

[Summary of the invention]

The present invention relates to an optical disc pickup drive device for achieving the above-mentioned object, and includes a chassis having a horizontal part parallel to the optical disc surface and a vertical part perpendicular to the horizontal part, and a chassis movably placed on the chassis. A magnet of the slider constituting a linear motor exerts an attraction force between the slider and the slider, and the guide means between the slider and the chassis is brought into contact with the attraction force generated between the vertical part of the chassis and the magnet;
It guides the slider.

[Embodiments of the invention]

Next, an example of implementation of the present invention will be described with reference to FIGS. 1 to 3.

In the figure, ■ is a chassis, 5 is a slider on which a pickup 4 is mounted, and 11 is a turntable on which an optical disk is placed and attached to a spindle motor 12 that rotates the optical disk.

A ball guide 13 is attached to either the chassis 1 or the slider 5 at three locations, and a ball 14 is interposed between the chassis 1 and the slider 5, and by the rotation of this ball 14,
The slider 5 is movable on the chassis l in the longitudinal direction of the ball guide 13.

The two arms 15 of this slider 5 have magnets 1
6 is fixed to the chassis 1, and a coil 17 fixed to the chassis 1 is loosely fitted through the magnet 16.
A linear motor is constructed between the coil 17 and the magnet 16, and the slider 5 is
is driven in the longitudinal direction of the magnet 16, that is, in the radial direction of the optical disk.

The chassis 1 is made of a magnetically permeable material such as a rolled steel plate, and therefore generates an attractive force between it and the magnet 16, which prevents the slider 5 from floating above the diameter of the ball 14. , the slider 5 moves on the chassis 1 due to the transfer of the ball 14.

A raised part 18 made of the same material as the chassis 1 is formed on one side of the chassis 1 along the arm 5 of the slider 5, and an attractive force is exerted between this raised part 18 and one of the magnets 16. It has become.

A round bar rail 19 is attached to the chassis 1, and two rollers 20 attached to the slider 5 are attached to the chassis 1.
is pressed against the rail 19 by the above-mentioned attraction force.

Therefore, when the slider 5 is driven in the radial direction of the optical disk by the driving force between the magnet 16 and the coil 17, the roller 20 rolls on one side of the rail 19 and is guided. .

In this way, the movement of the slider 5 is guided by the chassis 1 and the rails 19, which are made of rolled steel, etc., and the accuracy of the optical axis of the pickup 4 mounted on this is determined by the accuracy of these components. It will be done.

Note that even if the rails 19 and rollers 20 are installed in a reverse relationship, their functions and effects will not change.

In the above embodiment, the pawl 14 is moved in the longitudinal direction of the pawl guide 13, but a roller may be used instead of the pawl.

Further, although the chassis 1 is shown as having an L-shape, the chassis 1 is not limited to an L-shape, and may have a horizontal portion and a vertical portion formed separately.

〔Effect of the invention〕

As described above, in the present invention, the movement accuracy such as the position and inclination of the optical axis of the pickup mounted on the slider is determined by the flatness accuracy of the chassis that guides the slider with the attraction force of its magnet, and the straightness of the guide means such as the rail. It follows accuracy.

The chassis can be made of a material that can easily achieve flatness accuracy, such as magnetically permeable rolled steel, and the guide means, for example, the rail, can be made of a material that can easily achieve linear accuracy, such as bar steel.
The accuracy of the optical axis of the pickup can be made high.

In addition, this accuracy is determined by the parts accuracy and is not affected by the assembly accuracy, so there is no difficult process that requires accuracy in the assembly process, making the assembly work easier, and
The above-mentioned component accuracy can be obtained at a low cost, so that the cost of the device can be reduced.

Furthermore, unlike conventional methods, the grooved bearing is not pressed against the guide rail by the biasing force of a spring.
This does not cause any resonance phenomenon, and therefore has the effect of resolving the difficulty of designing with resonance in mind.

[Brief explanation of the drawing]

FIG. 1 is a plan view of an embodiment of the present invention, FIG. 2 is a side view thereof, FIG. 3 is a sectional view thereof, and FIG. 4 is a plan view of a conventional device. DESCRIPTION OF SYMBOLS 1...Chassis, 4...Pickup, 5...Slider, 11...Turntable, 13...Ball guide, 14...Pole, 16...Magnet, 1
7... Coil, 18... Standing part, 19... Rail, 20... Roller.

Claims (1)

[Claims] a chassis made of a magnetically permeable material and having a horizontal part parallel to the optical disk surface and a vertical part perpendicular to the horizontal part; placed on the horizontal part of the chassis via a moving means for moving on the chassis; A slider equipped with an optical pickup,
a magnet that is fixed to the slider and generates an attractive force between the horizontal portion and the vertical portion of the chassis; a coil that is fixed to the chassis and forms a linear motor with the magnet; and a coil that is fixed to the chassis and forms a linear motor between the magnet and the vertical portion. 1. A pickup drive device for an optical disc, comprising a guide means for guiding the slider by biasing the slider by an adsorption force generated between the slider and the slider.