JPH0644580A - Optical disk device - Google Patents

Abstract

PURPOSE:To continuously move a carriage with a fine pitch by providing a linear stepping motor composed of a slider fixed on a carriage and a stator fixed on a chassis base and driving the stator by a laminated piezoelectric element. CONSTITUTION:The linear stepping motor 20 consists of the laminated piezoelectric element 21 which has its end part fixed on the chassis base 1, the stator 22 arranged in parallel to a guide shaft 2 and the slider 25 fixed on the carriage 7. Plural rectangular magnetic pole teeth 24 are formed at equal intervals on the surface of the stator 22 facing the slider 25, and each magnetic pole tooth 24 is wound with a coil. Therefore, when the coil of the stator 22 is energized, the magnetic pole teeth of the stator 22 and the magnetic pole teeth of the slider 25 are attracted and the slider 25 and stator 22 are restrained. in such a state, when a DC current is applied to the laminated piezoelectric element 21, the laminated piezoelectric element 21 is extended to move the slider 25 by one pitch of the magnetic pole teeth 24 together with the stator 22.

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,
In particular, the present invention relates to an optical disk device that records or reproduces information by moving a carriage equipped with an optical block in the radial direction of a recording medium.

[0002]

2. Description of the Related Art FIGS. 4A and 4B are views showing an example of a conventional optical disk device, wherein FIG. 4A is a plan view and FIG. 4B is a front view.

A conventional optical disk device for recording or reproducing information by moving a carriage having an optical block in the radial direction of a recording medium, as shown in FIG. 4, has guide shafts 32 and 33 fixed to a chassis base 31.
A carriage 37 is mounted on top of the guide rollers 34 and 35, and the guide rollers 34 and 35 roll on the guide shafts 32 and 33, thereby moving the carriage 37 in the radial direction of the recording medium 6. The optical block 38 mounted on the carriage 37 is configured to record or reproduce information on the recording medium 6.

The optical block 38 is equipped with an objective lens actuator 39 in order to make the objective lens 44 follow the surface wobbling and eccentricity that occur when the recording medium 6 rotates. When reading the information recorded in the position, the positioner coil 57 attached to the lower surface of the carriage 37 is energized to move the chassis base 31.
The carriage 37 is moved in the radial direction of the recording medium 6 by an electromagnetic action with a magnetic circuit 58 fixed at a position facing the positioner coil 57.

[0005]

In the conventional optical disk device as described above, since the braking force for stopping the carriage is weak, the device is tilted or an impact force is applied from the outside to cause the carriage to move in the moving direction. When the acceleration of is applied, the movement of the carriage cannot be suppressed and the control of the track following operation is temporarily lost,
It has a drawback that the information reproducing operation is interrupted.

[0006]

An optical disk apparatus according to the present invention comprises a guide shaft fixed to a chassis base, a carriage that moves in the radial direction of a recording medium along the guide shaft, and an optical block mounted on the carriage. In an optical disc device including: a slider having a plurality of magnetic pole teeth at equal intervals coupled to the carriage in parallel to the guide shaft; and a plurality of magnetic pole teeth at equal intervals provided facing the slider and fixed to the chassis base. And a linear step motor having a drive unit that drives the stator with a minute displacement amount.

[0007]

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

FIG. 1 is a diagram showing a first embodiment of the present invention.
2A is a plan view, FIG. 2B is a front view, and FIG. 2 is a side view showing the operation of the embodiment of FIG.

In the embodiment shown in FIG. 1, two parallel guide shafts 2 and 3 fixed to a chassis base 1, guide rollers 4 and 5 rolling on the guide shafts 2 and 3, respectively, and guides on side surfaces. A carriage 7 having rollers 4 and 5, and the guide rollers 4 and 5 rolling on the guide shafts 2 and 3 to move in the radial direction of the recording medium 6, and a recording medium 6 mounted on the carriage 7 An optical block 8 for recording or reproducing information on and from the recording medium 6 mounted on the carriage 7.
The objective lens actuator 9 is provided for causing the objective lens 14 provided in the optical block 8 to follow the surface wobbling and eccentricity that occur during rotation.

The optical block 8 and the objective lens actuator 9 constitute an optical head section, and the optical block 8
The divergent light emitted from the laser diode 10 mounted on the
2, the light path is bent by the rising mirror 13 and enters the objective lens 14. The objective lens 14 is movably held by the objective lens actuator 9,
The recording medium 6 is controlled so as to follow surface wobbling and eccentricity that occur when the recording medium 6 rotates.

The reading light focused on the recording medium 6 by the objective lens 14 is reflected by the recording medium 6 and enters the objective lens 14 again, where it is made into parallel light and returns along the same optical path as the forward path to the prism. It reaches 12 and is reflected in the prism 12 and guided to the detection system. The detection system is composed of a recording signal detecting section and a servo error signal detecting section. The recording signal detecting section condenses with a convex lens 15 and separates a deflection component of the recording signal with a Wollaston prism 16, and a photodiode is used. The intensity is detected by 17. The servo error signal detector generates a focus error signal and a track error signal in the photodiode 19 according to the intensities and areas of the four light spots divided by the four-division prism 18 and controls them for controlling the position of the objective lens 14. Give feedback to.

When reading information recorded at a remote position on the recording medium 6, the carriage 7 is moved in the radial direction of the recording medium 6. This movement is driven by the linear step motor 20.

As shown in FIG. 2, the linear step motor 20 is connected to a laminated piezoelectric element 21 whose ends are fixed to the chassis base 1 and is arranged in parallel with the guide shaft 2, and a stator 22 and a stator 22. And the slider 25 fixed to the carriage 7. A plurality of rectangular magnetic pole teeth 24 are formed at equal intervals on the surface of the stator 22 facing the slider 25, and a coil 23 is wound around each magnetic pole tooth 24. On the surface of the slider 25 facing the stator 22, a plurality of rectangular magnetic pole teeth are similarly formed at equal intervals.

Therefore, when the coil 23 of the stator 22 is energized, a magnetic attractive force is generated between the magnetic pole teeth 24 of the stator 22 and the magnetic pole teeth of the slider 25, as shown in FIG. The positional relationship between the stator 22 and the stator 22 is restricted. When a direct current is applied to the laminated piezoelectric element 21 in this state, the laminated piezoelectric element 21 expands, goes from the state shown in FIG. 2B to the state shown in FIG.
Is moved by one pitch of the magnetic pole teeth 24 together with the stator 22. When the coil 23 is de-energized in this state, the stator 22 releases the restraint of the slider 25 and returns to the original state together with the laminated piezoelectric element 21, as shown in FIG. From the state of (a), the magnetic pole teeth 24
It is in a state of moving forward by one pitch. By repeating the above operation, the linear step motor 20 can move the carriage 7 from the innermost position to the outermost position of the recording medium 6.

FIG. 3 is a diagram showing a second embodiment of the present invention.
(A) is a plan view and (b) is a front view.

In this embodiment, a linear step motor 26 is added to the embodiment shown in FIG. 1, and the construction and operation of the other parts are the same as the embodiment shown in FIG.

The linear step motor 26 comprises a stator 22a having magnetic pole teeth of the same pitch as the linear step motor 20 and a slider 25a. The magnetic pole teeth 24 of the stator 22 and the magnetic pole teeth 24a of the stator 22a are 1 / The mounting phase is shifted by 2 pitches. By configuring the linear step motor 20 and the linear step motor 26 in this way, the positioning of the carriage 27 can be performed with twice the accuracy of the embodiment of FIG.

[0018]

As described above, the optical disk device of the present invention is provided with the slider fixed to the carriage and the linear step motor composed of the stator fixed to the chassis base, and the stator is driven by the laminated piezoelectric element. This makes it possible to move the carriage continuously at a fine pitch, and when the carriage is not moving, it is possible to restrain the carriage by energizing the coils of the stator, so that the device When acceleration in the moving direction of the carriage is applied due to tilting or impact from the outside, the movement of the carriage is restrained, and the control of the track following operation is temporarily lost and the information reproducing operation is interrupted. Is effective in preventing the occurrence of the phenomenon described above, and therefore, a highly reliable optical disk device is provided. There is an effect that is.

[Brief description of drawings]

FIG. 1 is a diagram showing a first embodiment of the present invention, in which (a) is a plan view and (b) is a front view.

FIG. 2 is a side view showing the operation of the embodiment shown in FIG.

FIG. 3 is a diagram showing a second embodiment of the present invention, (a) is a plan view and (b) is a front view.

FIG. 4 is a diagram showing an example of a conventional optical disc device,
(A) is a plan view and (b) is a front view.

[Explanation of symbols]

 1.31 Chassis base 2.32 Guide shaft 3.33 Guide shaft 4.34 Guide roller 5.35 Guide roller 6 Recording medium 7.27.37 Carriage 8.38 Optical block 9.39 Objective lens actuator 10 Laser diode 12 Prism 13 Erecting Mirror 14/44 Objective Lens 15 Convex Lens 16 Wollaston Prism 17 Photodiode 18 4 Dividing Prism 19 Photodiode 20 Linear Step Motor 21 / 21a Multilayer Piezoelectric Element 22 Stator 23 Coil 24 / 24a Magnetic Pole Teeth 25 / 25a Slider 26 Linear Step motor 57 Positioner coil 58 Magnetic circuit

Claims (2)

[Claims] 1. An optical disc apparatus comprising: a guide shaft fixed to a chassis base; a carriage that moves in a radial direction of a recording medium along the guide shaft; and an optical block mounted on the carriage. A slider having a plurality of equally spaced magnetic pole teeth coupled to the carriage, a stator having a plurality of equally spaced magnetic pole teeth fixed to the chassis base and facing the slider, and a small displacement of the stator. An optical disk device comprising a linear step motor having a drive unit driven by an amount. 2. The optical disk device according to claim 1, wherein two sets of linear step motors are provided, and a phase difference of 1/2 pitch is given between the magnetic pole teeth.