JPH08297856A - Optical head device - Google Patents

Abstract

PURPOSE: To enable an optical table and an objective lens actuator to be easily positioned, to unnecessitate the re-adjustment after the assemblage of the optical table and the objective lens actuator allowing them to be attachable/detachable and to attain the easy cleaning of optical components mounted inside the optical table. CONSTITUTION: The device is constituted of a reflecting plate 11 for deflecting a light beam ejected from a radiant light source 16 in the vertical direction, the optical table 10 fixing the reflecting plate, and the objective lens actuator. The optical table 10 is provided with a surface 10a made to be the reference against an optical axis of the light beam, and the objective lens actuator is provided with a surface 8a made to be the reference against the optical table 10 and also is provided with more than two positioning parts 10b, 8b at least.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical head device of an optical disc device for optically recording or reproducing information by projecting a light spot on a disc-shaped recording medium.

[0002]

2. Description of the Related Art In recent years, an apparatus (hereinafter referred to as an optical disk apparatus) for recording and reproducing information using a disc-shaped optical recording / reproducing medium (hereinafter referred to as an optical disk) has advantages of large capacity and high speed. It is recognized and widely used for recording voice, images and data. Among the components incorporated in this optical disk device, the optical head device focuses the laser light at a target position on the optical disk for recording and reproduction, and is positioned as an important device that affects the performance of the optical disk device. Has been done.

An example of the above-mentioned conventional optical head device will be described below with reference to the drawings. FIG. 5 is an external perspective view of a conventional optical head device, and FIG. 6 is a configuration diagram of the optical head device. In FIGS. 5 and 6, the objective lens 1 is adhesively fixed to the lens holder 25, the electromagnetic coil 26 is wound around the arrows X1-X2 and Y1-Y2 as an axis, and the coil end portion is the lens holder. Two
It is soldered to the soldering portion of the printed circuit board 28 that is adhesively fixed to 5. A soldering substrate 30 for fixing one end of the suspension wire 29 by soldering is fixedly adhered to the support holder 27. The soldering substrate 30 faces the electromagnetic coil 26 and is electromagnetically driven so as to be electromagnetically driven. The magnetized magnet 31 is adhesively fixed. The suspension wire 7 is obtained by cutting a spring material on the wire into a predetermined length, four of which are arranged in parallel, pass through small holes at both ends of the lens holder 25, and are soldered to the printed board 28.
The printed pattern on the printed circuit board 28 electrically connects to the electromagnetic coil 26. Suspension wire 29
The other end also penetrates the small hole of the flexible printed circuit board 32 having a reinforcing plate such as glass epoxy, and is soldered at the soldering portion to be connected to an electric circuit (not shown).

A reflection mirror 34 is adhered and fixed to the carriage 33, and a laser unit 35 is further press-fitted therein. The objective lens actuator is attached by a screw 37 from the lower surface of the drawing through a coil spring 36 in a screw hole of a support holder 27. Has been. As shown in FIG. 6, the support holder 27 has a convex spherical surface 27 a, and the carriage 33 has a concave spherical surface 33 a.
a is provided, and the support spring 27 holds the support holder 27.
By tightening or loosening the screws 37 at the two holding positions, the objective lens actuator is tilted so that the optical axis 39 of the laser beam emitted by the laser unit 35 is vertically focused through the objective lens 1 with respect to the optical disc 23. Can be adjusted. After the adjustment, it is necessary to perform adhesive fixing such as a screw lock to the screw hole of the support holder 27 and the screw 37 so that there is no error in loosening the screw 37 with time.

The operation of the conventional optical head device configured as described above will be described below. The objective lens actuator is moved together with the carriage 33 to the target position on the optical disc 23. The suspension wire 29 has both ends fixed, and the lens holder 25 side is cantilevered with respect to the support holder 27.
When a current is applied to the electromagnetic coil 26 wound around the magnets, the electromagnetic force generated between the magnet 31 and the magnet 31 magnetized in the N-S direction so as to be opposed to and separated from the electromagnetic coil 26 causes arrows X1-X to the magnets 31, respectively.
2, the driving force in the Y1-Y2 direction is generated and the lens holder 2
5 and thus the objective lens 1 fixed to it can be translated in the directions of the arrows X1-X2 and Y1-Y2.

This makes it possible to move the focus position of the laser beam focused on the optical disc 27 above the objective lens through the objective lens 1, and follow the surface deflection of the optical disc in the surface direction and the eccentricity in the radial direction. Then, the recording or reproducing operation of the information signal is performed.

[0007]

However, in the above-described structure, the objective lens actuator can be easily adjusted after it is assembled and adjusted by adhering and fixing the objective lens actuator or by removing it without adhering and fixing it. However, there is a problem that it is impossible to remove the optical parts and clean the optical parts inside the optical head device.

In view of the above problems, the present invention provides an optical head device which can be easily positioned and can be attached and detached.

[0009]

In order to solve the above problems, an optical head device of the present invention comprises a radiation light source, a reflector for deflecting a light beam emitted from the radiation light source in a right angle direction, and the reflector. And an objective lens actuator, and the optical stage has a feature that has a surface serving as a reference with respect to the optical axis of the light beam. And a feature having at least two or more positioning portions.

The optical head device of the present invention has a structure in which the optical base and the objective lens actuator can be attached and detached.

[0011]

With the above-described structure, the optical head device of the present invention can be attached to the optical stand without adjusting the objective lens actuator with respect to the optical axis of the light beam.
As a result, the optical table and the objective lens actuator can be attached and detached, so that the objective lens actuator can be removed to easily clean the optical parts attached inside the optical table, and adjustment can be made even if the objective lens actuator is attached again. It acts like nothing.

Further, the optical base and the objective lens actuator are easily positioned by two or more positioning portions, respectively, to prevent accumulation of mounting errors and reduce the number of assembling steps.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An optical head device according to an embodiment of the present invention will be described below with reference to the drawings. 1 is an external perspective view of an optical head device according to an embodiment of the present invention, FIG. 2 is an exploded perspective view of the optical head device, and FIG. 3 is a configuration diagram of the optical head device.
FIG. 4 is a detailed view of an essential part of an objective lens actuator of the optical head device.

First, the objective lens actuator will be described. In FIGS. 1, 2 and 4, an objective lens 1 is attached to a lens holder 2 made of synthetic resin, two magnets 3 and an optical element 4 which are magnetized in the N-S direction as shown in the figure.
Are bonded and fixed, and the tip of the suspension wire 7, which is a linear spring member, is molded and fixed by molding. The other end of the suspension wire 7 is molded and fixed to a frame-shaped housing 8 which is a fixing member made of synthetic resin. The lower surface 8a of the housing 8 is formed in a planar shape so as to always serve as a reference for the inclination of the objective lens 1 adhered to the lens holder 2. Basically, the surface of the lens holder 2 supporting the objective lens and the lower surface 8a are kept substantially parallel to each other. Further, four pins 8b are formed on this plane 8a. An electromagnetic coil 6 has an arrow Y1- on a coil frame 5 formed of synthetic resin.
A winding 6a having Y2 and an arrow X1-X2 as an axis is overlapped and wound. Then, each winding start and winding end is wound around the wire treatment groove several times, and soldered to the outer edge portion 6b of each wound wire to be fixed.
Then, the flexible printed board 9 is brought into contact with this portion, and the printed pattern and the edge portion 6b are soldered to be electrically connected to the printed pattern of the flexible printed board 9 connected to an electric circuit (not shown). A signal current can be applied to the electromagnetic coil 6.

In FIGS. 1, 2 and 3, a reflection mirror 11 is adhesively fixed to an optical stand 10 made of a metal material. The upper surface 10a of the optical bench 10 is formed in a planar shape so as to be in close contact with the lower surface 8a when the objective lens actuator is incorporated. The plane 10a is formed so as to be perpendicular to the optical axis 12 of the laser beam, which will be described later. Then, in order to position the objective lens actuator, the positioning hole 10b is formed on the surface 10 so as to fit the pins 8b protruding at the four corners of the housing 8.
If the objective lens actuator is incorporated, the position is likely to be displaced if it is provided at one location, but if there are two or more locations, it is possible to easily and precisely perform positioning. The objective lens actuator can be fixed to the optical table 10 with a screw 13 from a mounting hole 8c appropriately provided in the housing 8.

The collimating lens 1 is provided in the parallel light holder 14.
5 is bonded and fixed, and a printed circuit board 17 to which a laser unit 16 is soldered is further fixed to the parallel light holder with screws 18. And collimated light holder 1
Reference numeral 4 is fixed to the optical table 10 with screws 19. The optical stand 10 is attached to the carriage 20 with a screw 22 via a coil spring 21.

The operation of the optical head device constructed as above will be described below. Laser unit 16
The laser light 12 emitted by the collimator lens 15
And is deflected in the right angle direction by the reflection mirror 11. Then, it is condensed by the objective lens 1, and the optical disc 2
Irradiate to 3. Here, the mounting surface of the laser unit 16 and the parallel light holder 14, the parallel light holder 14 and the optical stand 1
The surface 10a of the optical table 10 can be made perpendicular to the optical axis 12 of the laser light by increasing the accuracy of the mounting surface of 0, and the mounting surfaces of the optical table 10 and the reflection mirror 11. Therefore, by using the surface 10a of the optical table 10 as a reference, the reference surface 8 to be attached in combination with this surface
Even if the objective lens actuator having a is attached or detached, the positional displacement is small due to the respective positioning portions, and the inclination of the objective lens 1 attached to the objective lens actuator does not change from the initial state.

An optical base incorporating an objective lens actuator is provided by pressing or loosening the optical base 10 by the concave and convex spherical surfaces provided on the optical base 10 and the carriage 20 and the pressing spring 24 to tighten or loosen the screws 22 at two places. You can tilt 10 freely,
It can be adjusted so that the optical axis 12 of the laser light emitted from the laser unit 16 is vertically focused on the optical disc 23 through the objective lens 1.

The objective lens 1 is moved to the vicinity of the target position of the optical disc 23 (not shown) by a screw feeding mechanism (not shown) attached to the carriage 20. Therefore, when a current is supplied to the electromagnetic coil 6 through the flexible printed circuit board 12, the lens holder 2 and the objective lens 1 fixed to the lens holder 2 and the objective lens 1 fixed thereto by the electromagnetic action of the magnet 3 magnetized in the N-S direction are indicated by arrows X1-X2 and Y1. -Move in the Y2 direction. As a result, the focal position of the laser beam 12 focused on the optical disc 26 is moved to a target position, and the recording and reproducing operation of the information signal is performed by following the surface deviation and eccentricity of the disc.

As described above, according to the present embodiment, the optical base and the objective lens actuator can be easily positioned, and even if the objective lens actuator is detached and reattached after the assembly and adjustment, the inclination of the objective lens with respect to the optical axis of the laser beam. Does not change, so readjustment is not required. In addition,
In the embodiment, the objective lens actuator is the pin 8b.
Although the optical table is positioned by the hole 10b to be positioned, the objective lens actuator may be positioned by the hole and the optical table may be positioned by a pin. Further, it is sufficient to form a convex shape and a concave shape that can be engaged with each other without using the pin and the hole.

Further, the objective lens actuator may be electrically connected not only by the flexible printed circuit board but also by a lead wire, a connector or a printed circuit board, but if it is detachable without removing soldering, it is flexible. Anything that has sex is acceptable.

[0022]

As described above, according to the present invention, the optical bench and the objective lens actuator have respective positioning portions, and the positioning is easily performed by the positioning portions, so that the number of assembling steps can be reduced. Also, since the optical table has a reference surface for the optical axis of the laser beam and the objective lens actuator has a reference surface for the optical table, it is possible to attach and detach the optical table and the objective lens actuator without re-adjustment after assembly, It is possible to easily clean the optical components attached to the inside of the optical stand, and thus it is possible to provide an optical head device having excellent assemblability.

[Brief description of drawings]

FIG. 1 is an external perspective view of an optical head device according to an embodiment of the present invention.

FIG. 2 is an exploded perspective view of an optical head device.

FIG. 3 is a configuration diagram of an optical head device.

FIG. 4 is a detailed view of a main part of an objective lens actuator.

FIG. 5 is an external perspective view of a conventional optical head device.

FIG. 6 is a configuration diagram of a conventional optical head device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Objective lens 8 Housing 8a Plane 8b Pin 10 Optical stand 10a Plane 10b Positioned hole 11 Reflecting mirror 12 Optical axis 16 Laser unit 23 Optical disk

Claims (6)

[Claims] 1. A radiation source, a reflector for deflecting a light beam emitted from the radiation source in a direction perpendicular to the radiation source, an optical base for fixing the reflection plate, and an objective lens actuator. An optical head device comprising a surface serving as a reference with respect to an optical axis of a beam, and the objective lens actuator including a surface serving as a reference with respect to the optical stand and a positioning portion. 2. The positioning parts of the optical table and the objective lens actuator are at least two on their respective reference planes.
The optical head device according to claim 1, wherein the optical head device has at least one place. 3. The optical head device according to claim 1, wherein the optical base and the objective lens actuator are configured to be detachable. 4. The optical head device according to claim 1, wherein the positioning portion of the optical bench is concave, and the positioning portion of the objective lens actuator is convex. 5. The optical head device according to claim 1, wherein the positioning portion of the optical bench has a convex shape, and the positioning portion of the objective lens actuator has a concave shape. 6. The optical head device according to claim 1, wherein a reference surface of the optical table, a reference surface of the objective lens actuator, and an objective lens mounting surface on the objective lens actuator are substantially parallel to each other.