JPH1064203A - Driving device for optical pickup - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve mechanical balance of the entire driving mechanism, and prevent blurring motion by arranging two linear driven type vibration actuators in symmetrical positions with respect to a pickup body. SOLUTION: Guide rails 6a and 6b are limited, therefore linear driven type vibration actuators 7a and 7b are driven with respect to the guide rails 6a and 6b, and a pickup body 2, connected to the linear driven type vibration actuators 7a and 7b, is also driven. By changing driving voltage during driving, the driving speed of the linear driven type vibration actuators 7a and 7b are changed. And by changing the phase difference from (π/2) to (-π/2), or from (-π/2) to (π/2), the moving directions of the linear driven type vibration actuators 7a and 7b are inverted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drive device for an optical pickup used in an optical information recording / reproducing apparatus for optically recording / reproducing information on / from an information recording medium.

[0002]

2. Description of the Related Art Conventionally, when recording or reproducing information on or from an optical information recording medium such as an optical disk, a coarse actuator for driving an optical element largely in a tracking direction to access a track and appropriately irradiating a light spot. For this purpose, a precise actuator for minutely moving the optical element in the focusing direction and the tracking direction is required.

In particular, a fine actuator usually uses two electromagnetic motors to move an optical element in a focus direction and a tracking direction, and each requires a unique magnetic circuit.

However, since two electromagnetic motors are used as fine actuators, the mechanism around the pickup becomes complicated. Therefore, the degree of freedom in designing the optical pickup is hindered, and there is a limit in reducing the size of the optical pickup.

[0005] Accordingly, "Proceedings of the 5th Electromagnetics-Related Dynamics Symposium" (pp. 393-398)
Page) proposes to use a linear drive type ultrasonic actuator as a drive source of the fine actuator.

[0006] As described in detail with reference to FIG. 4 of this collection of lectures, this linear drive type ultrasonic actuator includes a rectangular plate-shaped elastic body and a primary element mounted on one plane of the elastic body. And a piezoelectric element, which is an electromechanical conversion element that generates an elliptical periodic displacement in a driving force extracting portion formed on the other plane by generating the longitudinal vibration and the fourth-order bending vibration in harmony. Prepare.

In this proposal, the linear drive type ultrasonic actuator and the optical pickup are connected by one connecting member, and the ultrasonic actuator is driven to be used as a drive source of the optical pickup.

[0008]

However, in this proposal, since the linear drive type ultrasonic actuator and the optical pickup are connected by one connecting member, there are the following problems.

(1) The mechanical balance of the entire driving mechanism during driving is poor. In particular, the phase difference between the two-phase AC voltages applied to the ultrasonic actuator is changed from (π / 2) to (−π /
2) Or, when the optical pickup is to be inverted from (−π / 2) to (π / 2), an unnecessary blurring operation occurs due to the inertia of the optical pickup immediately before the inversion.

(2) The driving force of the optical pickup tends to be insufficient, and the accuracy at the time of high-speed scanning decreases. (3) Since the stopping force of the optical pickup is mainly due to the sliding resistance between the driving force extracting portion of the ultrasonic actuator and the relative motion member, the stopping force is insufficient.

[0011]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and is characterized in that two linear drive type vibration actuators are arranged at positions symmetrical with respect to a pickup body. It is.

According to a first aspect of the present invention, there is provided a driving apparatus for an optical pickup used in an optical information recording / reproducing apparatus for optically performing one or both of recording and reproduction of an information recording medium, wherein an optical spot is formed on the information recording medium. Two linear drive type vibration actuators for driving a pickup main body holding an optical element to be irradiated are provided, and these linear drive type vibration actuators are arranged at symmetrical positions with respect to the pickup main body.

According to a second aspect of the present invention, in the driving device for an optical pickup according to the first aspect, the two linear drive type vibration actuators are symmetrical with respect to a center line parallel to the drive direction of the pickup main body. It is characterized by the following.

[0014] The invention of claim 3 is claim 1 or claim 2.
In the drive device of the optical pickup described in the above, the two linear drive type vibration actuators may be arranged such that the pressing direction of the relative motion member is parallel to the drive surface of the pickup body and perpendicular to the drive direction of the pickup body. , Is arranged.

According to a fourth aspect of the present invention, in the optical pickup driving device according to the third aspect, the two vibration actuators are fixed to the pickup main body while being separated from each other, and extend in parallel with the driving direction of the pickup main body. The two guide rails provided are brought into pressure contact with each other as a relative movement member.

According to a fifth aspect of the present invention, in the driving device for an optical pickup according to the fourth aspect, the pickup main body is provided with one or more rollers that contact two guide rails. I do.

According to a sixth aspect of the present invention, in the optical pickup driving device according to the first aspect, the pickup main body is fixed to two guide rails extending in parallel with the driving direction. Each of the guide rails is driven in a driving direction by a vibration actuator that is brought into contact with each other under pressure.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment) Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 shows a first embodiment of the present invention.
FIG. 2 is a top view showing the embodiment, and FIG.
It is -A sectional drawing.

In the optical pickup 1 of the present embodiment, a holder 3 having an octagonal horizontal cross section is fixed on the plane of a rectangular parallelepiped pickup main body 2, and the optical element 4 is fixed and held by the holder 3.

The pickup main body 2 is mounted on two plate-shaped linear guides 5a and 5b extending in a direction parallel to the driving direction of the pickup main body 2 (the left-right direction in FIG. 1). The linear guides 5a and 5b guide the pickup main body 2 in the left-right direction on the drawing and also regulate the position of the pickup main body 2 in the focusing direction (perpendicular to the drawing).

On both outer sides of the linear guides 5a and 5b, plate-like guide rails 6a and 6b each having a rectangular cross section extend.
The guide rails 6a and 6b function as relative motion members that perform relative motion with the ultrasonic actuators 7a and 7b described later.

Ultrasonic actuators 7a and 7b are provided on the outer surfaces of the guide rails 6a and 6b, respectively.
Are arranged at positions symmetrical with respect to a center line parallel to the driving direction. The ultrasonic actuators 7a and 7b are attached to a flat elastic body and one flat surface of the elastic body,
A piezoelectric element, which is an electromechanical transducer that generates a first-order longitudinal vibration and a fourth-order bending vibration in an elastic body by inputting a drive signal, and a fourth-order bending vibration on the other plane of the elastic body And a driving force extracting portion formed in a protruding shape at the two antinode positions.

The ultrasonic actuators 7a and 7b come into pressure contact with the guide rails 6a and 6b via the driving force take-out portion. Such ultrasonic actuators 7a and 7b are already publicly known, for example, in the above-mentioned "Fifth Electromagnetics-Related Dynamics Symposium Lecture Paper Collection" or the like, and therefore, further description is omitted.

The leaf springs 8a and 8b, which are pressing members for pressing the elastic body toward the guide rails 6a and 6b, are attached to the side of the elastic body on which the piezoelectric body is attached.
a, 8b and the pickup main body 2 are connected by brackets 9a, 9b, which are connecting members bent in an L-shape. By appropriately changing the lengths of the long sides of the brackets 9a and 9b, the spring force of the leaf springs 8a and 8b is changed.

Thus, the ultrasonic actuator 7
a and 7b are guide rails 6a and 6 which are relative motion members.
It is arranged so that the pressing direction with respect to b is parallel to the driving surface of the pickup main body 2 and perpendicular to the driving direction of the pickup main body 2.

The drive device of the optical pickup 1 in this embodiment includes linear drive type vibration actuators 7a and 7b for driving the pickup main body 2 holding the optical element 4, and these linear drive ultrasonic actuators 7a and 7b. Are arranged at positions symmetrical with respect to the pickup main body 2.

In the driving device for the optical pickup 1 of the present embodiment thus configured, a driving voltage is applied to the piezoelectric bodies of the linear drive type ultrasonic actuators 7a and 7b, and an elliptical periodic portion is applied to the driving force output portion. A large displacement,
Guide rails 6a, 6 which come into pressure contact with the linear drive type ultrasonic actuators 7a, 7b via a drive force extracting portion.
b.

Here, in this embodiment, the guide rail 6
Since a and 6b are fixed, the linear drive type vibration actuators 7a and 7b are driven with respect to the guide rails 6a and 6b, and the linear drive type vibration actuators 7a and 7b are driven.
The pickup body 2 connected to b is also driven.

By changing the drive voltage at the time of drive, the drive speed of the linear drive type vibration actuators 7a and 7b is changed, and the phase difference between the two AC voltages to be applied is changed from (π / 2) to (− By changing from (π / 2) or (−π / 2) to (π / 2), the moving direction of the linear drive type vibration actuators 7a and 7b is reversed.

In the linear drive type ultrasonic actuators 7a and 7b of the present embodiment, the two linear drive type ultrasonic actuators 7a and 7b are arranged at symmetrical positions, so that the following effects can be obtained.

(1) The mechanical balance at the time of driving the entire driving mechanism is improved. In particular, when the optical pickup 1 is inverted,
The blurring operation due to the inertia of the optical pickup 1 is eliminated.

(2) The driving force of the optical pickup 1 is sufficient, and the accuracy at the time of high-speed scanning is improved. (3) The stopping force of the optical pickup 1 is doubled.

(Second Embodiment) FIG. 3 is a top view showing a second embodiment of the present invention, and FIG.
It is B sectional drawing. In the following description of each embodiment, only portions different from the first embodiment will be described, and the same portions will be denoted by the same reference numerals in the drawings.
Duplicate description will be omitted as appropriate.

The present embodiment differs from the first embodiment in that linear drive type ultrasonic actuators 7a and 7b are not arranged on the outer surfaces of the guide rails 6a and 6b.
It is a point arranged on the inner surface.

That is, the support pins 10a and 10b penetrating the leaf springs 8a and 8b are vertically installed on the piezoelectric body mounting surfaces of the linear drive type ultrasonic actuators 7a and 7b, and the leaf springs 8a and 8b are located on the optical pickup 1 side. Fixed plates 11a, 1
1b, the support pins 10a, 10b
Is fixed to the optical pickup 1.

Thus, the linear drive ultrasonic actuators 7a, 7b are actuated by the spring forces of the leaf springs 8a, 8b.
Of the guide rail 6 by the spring force of the leaf springs 8a and 8b.
a and 6b are brought into pressure contact with the inner surfaces.

As compared with the first embodiment, the overall size of the optical pickup driving device can be reduced.

(Third Embodiment) FIG. 5A is a top view showing a third embodiment of the present invention. This embodiment is different from the first embodiment in that linear guides 5a and 5b are not provided to guide and position the optical pickup 1, but two guides are provided on the guide rails 6a and 6b side of the optical pickup 1. And a total of four shaft supports 13 are provided.
Is that the four rollers 12 are pivotally supported by the pivot support pins 13a provided in the above.

FIG. 5B is an explanatory view showing the state of engagement between the guide rail 6a and the roller 12. As shown in FIG. 5B, recesses 14a,
14b is formed, and the roller 12 is configured to engage with the recesses 14a and 14b. With the movement of the optical pickup 1, the rollers 12 move into the concave portions 14a, 14a.
Since the optical pickup 1 moves while being guided by b, guidance and position control of the optical pickup 1 are performed.

As compared with the first embodiment, the size of the apparatus can be reduced, and it is not necessary to provide the guide rails 6a and 6b with high dimensional accuracy for the optical pickup 1, and the manufacturing is simplified.

(Fourth Embodiment) FIG. 6 is a top view showing a fourth embodiment of the present invention, and FIG. 7 is a perspective view showing a supporting form of an ultrasonic actuator according to the fourth embodiment.

The first to third embodiments are of the so-called self-propelled type in which the ultrasonic actuators 7a and 7b move together with the optical pickup 1, but in this embodiment, the ultrasonic actuators 7a and 7b do not move. It is a fixed type.

That is, in FIG.
Reference numerals a and 6b are arranged so as to be reciprocally movable in the horizontal direction on the drawing (the driving direction of the optical pickup). In the present embodiment, the ultrasonic actuators 7a and 7b are fixed to fixed parts (not shown) via fixed support brackets 15a and 15b.
The driving force take-out portion formed on the surface opposite to the fixed surface b is in pressure contact with one side surface of the guide rails 6a and 6b. Further, in the present embodiment, the other side surfaces of the guide rails 6a and 6b are fixed to the optical pickup 2.

The other structure is the same as that of the first embodiment. In the drive device of the optical pickup according to the present embodiment, when a drive signal is applied to the ultrasonic actuators 7a and 7b, a vibration that periodically displaces in an elliptical shape is generated in the drive force take-out portion, and the drive force take-out portion passes through the drive force take-out portion. The guide rails 6a, 6b that come into pressure contact are driven in the left-right direction on the drawing.

In this embodiment, the ultrasonic actuator 7
Since a and 7b are fixed, there is no need to make the length of peripheral devices (conductive wires and the like) for applying a drive voltage to the ultrasonic actuators 7a and 7b variable, and a simple structure can be achieved. .

(Modification) In each of the embodiments described in detail above, the ultrasonic actuator is used as the vibration actuator. However, the drive device of the optical pickup according to the present invention is not limited to such an embodiment. The same applies to a vibration actuator using another vibration region.

Further, in each of the embodiments, as the linear drive type vibration actuator, a rectangular flat plate-shaped ultrasonic actuator which generates primary longitudinal vibration and quaternary bending vibration is used. The driving device is not limited to such an embodiment, but may be applied to any ultrasonic actuator that is driven linearly.

In each of the embodiments, the positioning of the optical pickup in the focusing direction is performed by the linear guide or the roller. However, the driving device of the optical pickup according to the present invention is not limited to such a mode. Alternatively, other means that can perform positioning may be used.

[Brief description of the drawings]

FIG. 1 is a top view showing a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA in FIG.

FIG. 3 is a top view showing a second embodiment of the present invention.

FIG. 4 is a sectional view taken along line BB in FIG. 3;

FIG. 5A is a top view showing a third embodiment of the present invention, and FIG. 5B is an explanatory diagram showing an engagement state between a guide rail and a roller.

FIG. 6 is a top view showing a fourth embodiment of the present invention.

FIG. 7 is a perspective view showing a support form of an ultrasonic actuator according to a fourth embodiment.

[Explanation of symbols]

 Reference Signs List 1 optical pickup 2 pickup main body 3 holder 4 optical element 5a, 5b linear guide 6a, 6b guide rail 7a, 7b ultrasonic actuator 8a, 8b leaf spring 9a, 9b bracket 10a, 10b support pin 11a, 11b fixing plate 12 roller 13 shaft Support 13a Axle support pins 14a, 14b Depressions 15a, 15b Fixed support bracket

Claims (6)

[Claims] 1. An optical pickup drive device for use in an optical information recording / reproducing apparatus for optically recording and / or reproducing information recorded on an information recording medium, comprising: an optical element for irradiating the information recording medium with a light spot. An optical pickup driving device, comprising: two linear drive type vibration actuators for driving a pickup main body, wherein the linear drive type vibration actuators are arranged at symmetrical positions with respect to the pickup main body. 2. The drive device for an optical pickup according to claim 1, wherein the two linear drive type vibration actuators are symmetric with respect to a center line parallel to a drive direction of the pickup main body. Optical pickup driving device. 3. The drive device for an optical pickup according to claim 1, wherein each of the two linear drive type vibration actuators has a pressing direction with respect to a relative motion member on a drive surface of the pickup main body. A driving device for an optical pickup, wherein the driving device is arranged in parallel and in a direction perpendicular to a driving direction of the pickup main body. 4. The drive device for an optical pickup according to claim 3, wherein the two vibration actuators are fixed to the pickup main body while being separated from each other, and extend in parallel with a driving direction of the pickup main body. A driving device for an optical pickup, wherein the two guide rails are pressed against each other as the relative movement member. 5. The optical pickup driving device according to claim 4, wherein the pickup main body is provided with one or two or more rollers that contact two guide rails. Drive. 6. The drive device for an optical pickup according to claim 1, wherein the pickup main body is fixed to two guide rails extending in parallel with a driving direction of the pickup main body. A driving device for an optical pickup, wherein the rails are driven in the driving direction by vibrating actuators that are respectively brought into pressure contact.