JP2000293873A - Optical pickup - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical pickup which has a simple structure and a small number of parts and is easily assembled. SOLUTION: An optical pickup 1 consists of a pickup base 2 which can be moved in the radial direction (the direction of an arrow X) of an optical disk, an actuator base 3, a damper base 4, an actuator 5 having a fixed part 5a and a mobile part 5b, and four suspension wires 7 which support the mobile part 5b on the damper base 4 so that it can be displaced. A pair of projections 31 are integrally formed in the actuator base 3. The actuator base 3 and the damper base 4 are integrally formed into one with resin, and this integrally formed material is supported and fixed in a space 21 formed in the pickup base 2 through a skew adjustment mechanism 6 capable of radial skew adjustment and tangential skew adjustment.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical pickup in an optical disk drive and the like.
The present invention relates to an optical pickup that has a small number of parts and is easy to assemble.

[0002]

2. Description of the Related Art Japanese Patent Application Laid-Open No. Hei 10-31557 discloses that
An optical pickup in an optical disk drive or the like is disclosed. This optical pickup has a pickup base provided reciprocally in the radial direction of the optical disk, an actuator base supported by the pickup base, an actuator supported by the actuator base, and a damper base. . The actuator has a fixed part and a movable part, and the movable part of the actuator is displaceably supported by a damper base via a plurality of suspension wires.

The movable part of the actuator is provided with an objective lens, a lens holder for holding the objective lens, and a coil for driving the actuator.

[0004] The optical pickup is provided with a cover member that can come into contact with the movable portion of the actuator base in order to regulate the upper limit position of the movable portion of the actuator base.

However, in such an optical pickup, the actuator base, the damper base, and the cover member are separately formed from each other, and these members are fixed at a number of places by a method such as screwing and assembled. Therefore, the structure is complicated, the number of parts is large,
There is a problem in that the number of assembly steps is large and the assembly takes time.

[0006] In such a conventional optical pickup, an adjustment for adjusting the attitude of the objective lens installed in the movable portion of the actuator to a predetermined attitude (preferably horizontal), that is, skew adjustment is performed at the time of assembly. .

The skew adjustment includes a radial skew adjustment for adjusting the optical axis in the radial direction of the optical disc and a tangential skew adjustment for adjusting the optical axis in the tangential direction of the optical disc. A mechanism for performing adjustment and a mechanism for performing tangential skew adjustment are separately installed at different positions. Therefore, there is a problem that the structure is complicated, the number of parts is large, and it takes time to adjust the skew.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to provide an optical pickup having a simple structure, a small number of parts, and easy assembling work.

[0009]

This and other objects are achieved by the present invention which is defined below as (1) to (12).

(1) An optical pickup characterized in that an actuator base for supporting a fixed portion of an actuator and a damper base for displaceably supporting a movable portion of the actuator are integrally formed of resin.

(2) The optical pickup according to (1), wherein an engaging portion for regulating an upper limit position of a movable portion of the actuator is integrally formed on the actuator base.

(3) A pickup base provided reciprocally in the radial direction of the optical disk along a guide rod provided in the optical disk drive, and supported by the pickup base and holding a fixed portion of the actuator. Optical disc drive apparatus comprising: an actuator base; and a damper base that displaceably supports, via a suspension wire, a movable portion of an actuator including an objective lens and a coil for driving the objective lens in a focusing direction and a tracking direction. An optical pickup, wherein the actuator base and the damper base are integrally formed of resin.

(4) The optical pickup according to (3), wherein an engaging portion for regulating an upper limit position of a movable portion of the actuator is formed integrally with the actuator base.

(5) The optical pickup according to (3) or (4), wherein a skew adjustment mechanism is provided between the bottom of the actuator base and the bottom of the pickup base facing the bottom.

(6) The optical pickup according to (5), wherein the skew adjustment mechanism is configured to perform a radial skew adjustment and a tangential skew adjustment.

(7) The skew adjusting mechanism includes a convex portion formed on one of the bottom of the actuator base or the bottom of the pickup base and a concave portion formed on the other, and an outer peripheral portion of the convex portion. The optical pickup according to (5) or (6), wherein the convex portion is configured to be displaceable in at least two directions with respect to the concave portion by slidably contacting an outer peripheral portion of the concave portion.

(8) In an optical pickup including an actuator base for supporting a fixed portion of an actuator and a pickup base for supporting the actuator base, a bottom of the actuator base, and a bottom of the pickup base opposed to the bottom. Between,
An optical pickup comprising a skew adjustment mechanism capable of radial skew adjustment and tangential skew adjustment.

(9) The skew adjustment mechanism includes a convex portion formed on one of the bottom of the actuator base or the bottom of the pickup base and a concave portion formed on the other, and an outer peripheral portion of the convex portion. The optical pickup according to (8), wherein the protrusion is configured to be slidably in contact with an outer peripheral portion of the concave portion so that the convex portion can be displaced in at least two directions relative to the concave portion.

(10) In the actuator base,
The optical pickup according to the above (8) or (9), wherein an engaging portion for regulating an upper limit position of the movable portion of the actuator is integrally formed.

(11) The integrated body of the actuator base and the damper base is not located on a straight line with respect to the pickup base in a tracking direction or a direction parallel thereto, and is in a tangential direction or a direction parallel thereto. Not on a straight line 2
The optical pickup according to any one of the above (3) to (10), which is screwed at a location.

(12) The optical pickup according to the above (2), (4) or (10), wherein the engaging portion is constituted by a pair of projections abutting on a movable portion of the actuator.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an optical pickup according to the present invention will be described in detail based on a preferred embodiment shown in the accompanying drawings.

FIGS. 1 and 2 are an overall perspective view and an exploded perspective view, respectively, showing an embodiment of an optical pickup according to the present invention, and FIGS. 3 and 4 respectively show an integrated structure of an actuator base and a damper base. It is the perspective view and bottom view shown.

As shown in these figures, the optical pickup 1 of the present invention mainly comprises a pickup base 2, an actuator base 3, a damper base 4, an actuator 5, and four suspension wires 7. Have been.

The pickup base 2 has a space 21 for accommodating the lower portions of the actuator base 3 and the damper base 4 at the center thereof, and guide rods ( (Not shown) are formed. The pickup base 2 is installed such that the guide portions 22 and 23 are engaged with corresponding guide rods, and are reciprocally movable along the guide rods in the radial direction (tracking direction X) of the optical disk.

In the present invention, the optical disk is
CD, CD-ROM, CD-R, CD-WR, DVD,
The concept includes a magneto-optical disk in addition to a normal optical disk (optical disk in a narrow sense) such as a DVD-ROM, a DVD-R, and a DVD-RAM.

The actuator base 3 and the damper base 4 are formed integrally. These are, for example,
It is formed into a desired shape with a hard resin such as polycarbonate or a liquid crystal polymer, particularly by injection molding.
As described above, in the present invention, by integrating the actuator base 3 and the damper base 4, the number of components is reduced, and the labor of the assembling operation is reduced.

The integrated body of the actuator base 3 and the damper base 4 is supported by the pickup base 2 with its lower part housed in the space 21 of the pickup base 2.

The actuator 5 includes a fixed part 5a and a movable part 5b.

The fixed portion 5a is composed of a yoke 51 and a permanent magnet 52 joined to the yoke 51, and these are fixedly supported by the actuator base 3.

On the other hand, the movable part 5b of the actuator 5
A lens holder 53 also serving as a main body of the movable portion 5b, and an objective lens (condensing lens) 5 supported by the lens holder 53
4, a tracking coil 55, and a focusing coil 56. When the tracking coil 55 is energized, the objective lens 54 mounted on the movable portion 5b
Moves in the radial direction of the optical disc (tracking direction X), and the current flowing through the focusing coil 56 causes the objective lens 54 installed in the movable portion 5b to
In the optical axis direction (focusing direction Z).

The movable part 5b of such an actuator 5
Are four conductive (metal) suspension wires 7
And is displaceably supported by the damper base 4 via the. Each suspension wire 7 is arranged in a direction (tangential direction Y) substantially perpendicular to the radial direction (tracking direction X) of the optical disk.

Each of the suspension wires 7 is a support member for supporting the movable portion 5b, and also functions as an electric wire (conductor) for supplying electricity to the tracking coil 55 and the focusing coil 56.

The damper base 4 has a U-shape, and has hollow portions 41 on both sides thereof filled with a gel-like vibration damping material. At the rear end of the damper base 4, wire fixing portions 42 for fixing two suspension wires 7 on the left and right respectively are formed (see FIG. 2).

Further, on the rear surface of the damper base 4, a printed wiring board 45 for energizing each suspension wire 7 is provided (see FIG. 1). An end of each suspension wire 7 is soldered to a predetermined terminal on the printed wiring board 45.

In the center of the bottom of the actuator base 3, an opening 32 for forming an optical path of a laser beam emitted from a laser diode 10 to be described later and a reflected beam of the laser beam from an optical disk is formed. 3).

The actuator base 3 has a pair of L-shaped projections as an engagement portion for regulating the upper limit position when the movable portion 5b of the actuator 5 moves in the vertical direction (focusing direction Z) in FIG. 31 are formed.
These projections 31 are formed integrally with the actuator base 3. Conventionally, the same regulation was performed by attaching a separately prepared cover member,
As described above, since the projections (engaging portions) 31 are formed integrally with the actuator base 3, the number of components is reduced, and the labor of the assembling operation is reduced.

When the movable portion 5b of the actuator 5 moves upward in FIG. 1 by energizing the focusing coil 56, the lens holder 53 of the movable portion 5b abuts against both projections 31 and prevents further movement upward. . This prevents the objective lens 54 from protruding excessively.

Screw holes 33 and 43 for fixing the integrated body of the actuator base 3 and the damper base 4 to the pickup base 2 by screws are formed in one side of the actuator base 3 and the center of the damper base 4, respectively. Are formed.

In the pickup base 2, similar screw holes 24 and 25 are respectively provided at positions facing the screw holes 33 and 43 when the integrated body of the actuator base 3 and the damper base 4 is stored in the space 21. (See FIG. 2). In this case, the screw hole 24 is formed by a long hole extending in the radial direction of the optical disk (tracking direction X), and the screw hole 25 is formed by a long hole extending in a direction substantially perpendicular to the radial direction of the optical disk (tangential direction Y). It is configured. Due to the play of the elongated holes, the posture (installation angle in two directions) of the integrated body of the actuator base 3 and the damper base 4 with respect to the pickup base 2 can be adjusted and fixed as described below. ing.

The screw holes 33 and 43 and the screw holes 24 and 2
5 are not located on a straight line in the tracking direction X or a direction parallel thereto, and are not located on a straight line in the tangential direction Y or a direction parallel thereto. Thus, the posture of the integrated body of the actuator base 3 and the damper base 4 with respect to the pickup base 2 can be specified by the two screws (fixed at two places) and can be securely fixed.

The optical pickup 1 is provided with a skew adjustment mechanism (actuator attitude adjustment mechanism) 6. The skew adjustment mechanism 6 adjusts the attitude of the integrated body of the actuator base 3 and the damper base 4 with respect to the pickup base 2. The skew adjustment mechanism 6 adjusts the optical axis of the objective lens 54 in the radial direction of the optical disk. The tangential skew adjustment for adjusting the optical axis of the lens 54 in the tangential direction of the optical disk can be performed by one mechanism.

Hereinafter, the configuration and the like of the skew adjusting mechanism 6 will be described in detail with reference to FIGS. 2 and 4 and FIGS. 5 and 6 showing the cross-sectional structure of the skew adjusting mechanism. 5 is a sectional view in the radial direction, and FIG. 6 is a sectional view in the tangential direction.

The skew adjusting mechanism 6 is formed between the bottom of the actuator base 3 (the lower part in FIG. 2) and the bottom of the pickup base 2 facing the bottom (the bottom of the space 21).

That is, the skew adjustment mechanism 6 mainly includes:
Convex part 6 protruding from the bottom of actuator base 3
1 and a dish-shaped recess 63 formed at the bottom of the space 21 of the pickup base 2.

In this embodiment, the protrusion 61 is
The projection 61 is divided into two parts left and right through 2 and one projection 61 has an arc shape (see FIG. 4).

When the integrated product of the actuator base 3 and the damper base 4 is stored in the space 21 of the pickup base 2, the convex portion 61 is inserted into the concave portion 63. 63 outer periphery 64
Slidably in contact with

Here, since the outer peripheral portions 62 and 64 are in line contact with each other along the circumferential direction, when viewed in a cross section in the radial direction (X direction) shown in FIG. 5, for example, the posture shown by a solid line in FIG. From (angle), it can be displaced to the posture shown by the dashed line in FIG. Similarly, when viewed in a cross section in the tangential direction (Y direction orthogonal to the radial direction) shown in FIG. 6, for example, the posture (angle) shown by a solid line in FIG. Can be displaced.

As described above, the attitude (angle) of the integrated body of the actuator base 3 and the damper base 4 with respect to the pickup base 2 can be adjusted in at least two directions, a radial direction and a tangential direction.

The integrated body of the actuator base 3 and the damper base 4 is fixed with two screws (not shown) in a state where the attitude (angle) in the radial direction and the tangential direction with respect to the pickup base 2 is adjusted. . That is, from below the pickup base 2, one screw is screwed into the screw holes 24 and 33, and another screw is screwed into the screw holes 25 and 43.
By tightening them, the integrated body of the actuator base 3 and the damper base 4 is fixed to the pickup base 2 while maintaining the adjusted posture.

Conventionally, a mechanism for performing radial skew adjustment and a mechanism for performing tangential skew adjustment are separately provided at different positions, and it is necessary to perform the adjustment work sequentially. However, in this embodiment, Since the radial skew adjustment and the tangential skew adjustment can be performed by one skew adjustment mechanism 6, the structure is simple, the number of parts can be reduced, and the skew adjustment can be performed more easily, quickly, and accurately. Therefore, the work of skew adjustment work (assembly work) can be reduced.

A hole 26 for inserting a laser diode (light source) 10 and a grating (diffraction grating) 11 at the time of assembling is formed obliquely forward of a lower portion of the pickup base 2. Further, a hole 27 for inserting the beam splitter 13 at the time of assembly is formed in the bottom of the concave portion 63 of the pickup base 2.

In this embodiment, the beam splitter 13 is inserted through the hole 27 and the grading 11 is inserted into the hole 2 during assembly.
6, the laser diode 10, the grating 11, and the beam splitter 13 are pressed into the pickup base 2 and fixed. Therefore, unlike the related art, a spring member (pressing member) for fixing the grading 11 is not required, thereby contributing to a reduction in the number of parts and a reduction in labor for assembly work.

1 and 2 of the pickup base 2 are provided with engagement projections 28a, 28 for supporting the substrate.
b, 28c are formed, and these engagement projections 28a, 28c are formed.
The substrate 12 is supported by b and 28c. On the substrate 12, a photodiode (not shown) for receiving reflected light from the optical disk and performing photoelectric conversion is mounted.

The assembling of the optical pickup 1 is performed, for example, as follows.

The movable part 5b of the actuator 5 is fixed by fixing the objective lens 54 to the lens holder 53 and installing the tracking coil 55 and the focusing coil 56.
Assemble.

On the other hand, the permanent magnet 51 and the yoke 52 are fixed to the actuator base 3. Then, while supporting the actuator base 3 and the movable portion 5b in a predetermined positional relationship using a dedicated jig (not shown), the four suspension wires 7 are inserted from the front openings 34 of the actuator base 3 respectively. The front ends thereof are fixed to the lens holder 53 and connected to the coils 55 and 56, and the rear ends thereof are fixed to the fixing portion 42 of the damper base 4.

Next, a gel-like damping material is injected into the hollow portion 41 of the damper base 4 using a syringe or the like and solidified.

The actuator 5 thus obtained
Is inserted into the space 21 of the pickup base 2. The pickup base 2 has
The grading 11, the beam splitter 13, the laser diode 10 and the like are installed.

Next, the fixing of the substrate 12 by the engagement projections 28a to 28c, the installation of the printed wiring board 45 at the rear end of the damper base 4, and the like are performed.

Thereafter, while performing the above-described radial skew adjustment and tangential skew adjustment by the skew adjustment mechanism 6, one screw is screwed into the screw holes 24 and 33.
And the other screw is screwed into the screw holes 25 and 43 and tightened, so that the integrated body of the actuator base 3 and the damper base 4 is adjusted with respect to the pickup base 2 to a predetermined level. Fix in posture.

The optical pickup 1 as described above is mounted on an optical disk device (optical disk drive). Reproduction of optical disk (reading of data) by optical disk device
Alternatively, when recording (writing data), a laser beam is emitted from the laser diode 10 of the optical pickup 1. After passing through the grading 11, the laser light is reflected by the beam splitter, condensed to a predetermined beam diameter by the objective lens 54, and irradiated on the recording surface of the rotating optical disc. The reflected light from the optical disk due to the irradiation light is condensed by the objective lens 54, passes through the beam splitter 13, is received by a photodiode mounted on the substrate 12, is photoelectrically converted, and corresponds to the amount of received light. A signal is output. A signal from the photodiode is input to a predetermined circuit and processed.

Although the optical pickup of the present invention has been described based on the illustrated embodiment, the present invention is not limited to this.
The configuration of each part can be replaced with any configuration that can exhibit the same function, and any members may be added.

For example, an objective lens cover having a function of regulating the upper limit position of the movable portion of the actuator described above may be provided. In this case, the actuator base 3
It is not necessary to provide the projection 31 on the surface.

[0065]

As described above, according to the optical pickup of the present invention, the structure can be simplified and the number of parts can be reduced.
Further, since the assembling becomes easy, the labor and time of the assembling work are reduced.

Further, the structure of the skew adjustment mechanism is simple, the number of parts can be reduced, and the skew adjustment can be made easier.
Can be done quickly and accurately.

[Brief description of the drawings]

FIG. 1 is an overall perspective view showing an embodiment of an optical pickup of the present invention.

FIG. 2 is an exploded perspective view showing an embodiment of the optical pickup of the present invention.

FIG. 3 is a perspective view showing a configuration of an integrated body of an actuator base and a damper base in the optical pickup of the present invention.

FIG. 4 is a perspective view showing a configuration of an integrated body of an actuator base and a damper base in the optical pickup of the present invention.

FIG. 5 is a sectional view showing a sectional structure of the skew adjustment mechanism in a radial direction.

FIG. 6 is a sectional view showing a sectional structure of the skew adjusting mechanism in a tangential direction.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Optical pickup 2 Pickup base 21 Space 22 Guide part 23 Guide part 24 Screw hole 25 Screw hole 26 Hole 27 holes 28a-28c Engagement projection 3 Actuator base 31 Projection 32 Opening 33 Screw hole 34 Opening 4 Damper base 41 Hollow part 42 Fixed Part 43 Screw hole 45 Printed wiring board 5 Actuator 5a Fixed part 5b Movable part 51 Permanent magnet 52 Yoke 53 Lens holder 54 Objective lens 55 Tracking coil 56 Focusing coil 6 Skew adjustment mechanism 61 Convex part 62 Outer part 63 Recess 64 Outer part 7 Suspension Wire 10 laser diode 11 grading 12 substrate 13 beam splitter

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5D117 AA02 GG00 HH12 JJ13 KK08 5D118 AA06 BA01 BB02 DC03 EA02 EE05 EF09 FA29 FB20 FC08 FC10

Claims (12)

[Claims] 1. An optical pickup, wherein an actuator base supporting a fixed portion of an actuator and a damper base supporting a movable portion of the actuator so as to be displaceable are integrally formed of resin. 2. The optical pickup according to claim 1, wherein an engagement portion for regulating an upper limit position of a movable portion of the actuator is integrally formed on the actuator base. 3. A pickup base provided reciprocally in a radial direction of the optical disk along a guide rod installed in the optical disk drive, and an actuator supported by the pickup base and holding a fixed portion of the actuator. An optical pickup for an optical disk drive, comprising: a base; and a damper base that displaceably supports, via a suspension wire, a movable portion of an actuator including an objective lens and a coil for driving the objective lens in a focusing direction and a tracking direction. In the actuator base and the damper base,
An optical pickup characterized by being integrally molded with resin. 4. The optical pickup according to claim 3, wherein an engagement portion for regulating an upper limit position of a movable portion of the actuator is integrally formed on the actuator base. 5. The optical pickup according to claim 3, wherein a skew adjustment mechanism is provided between a bottom of the actuator base and a bottom of the pickup base facing the bottom. 6. The optical pickup according to claim 5, wherein the skew adjustment mechanism is configured to perform a radial skew adjustment and a tangential skew adjustment. 7. The skew adjustment mechanism includes a convex portion formed on one of a bottom portion of the actuator base or the bottom portion of the pickup base, and a concave portion formed on the other, and an outer peripheral portion of the convex portion is provided. The optical pickup according to claim 5, wherein the protrusion is configured to be displaceable in at least two directions with respect to the recess by slidably contacting an outer peripheral portion of the recess. 8. An optical pickup comprising: an actuator base that supports a fixed portion of an actuator; and a pickup base that supports the actuator base, wherein an optical pickup includes: a bottom of the actuator base; and a bottom of the pickup base opposed to the bottom. An optical pickup characterized by providing a skew adjustment mechanism between the skew adjustment and the radial skew adjustment. 9. The skew adjusting mechanism includes a convex portion formed on one of the bottom of the actuator base or the bottom of the pickup base, and a concave portion formed on the other, and an outer peripheral portion of the convex portion is provided. 9. The optical pickup according to claim 8, wherein the projection is configured to be displaceable in at least two directions with respect to the recess by slidably contacting an outer peripheral portion of the recess. 10. The optical pickup according to claim 8, wherein an engagement portion for regulating an upper limit position of a movable portion of the actuator is integrally formed on the actuator base. 11. The integrated body of the actuator base and the damper base is not located on a straight line with respect to the pickup base in a tracking direction or a direction parallel to the tracking direction and in a tangential direction or a direction parallel thereto. The optical pickup according to any one of claims 3 to 10, wherein the optical pickup is screwed at two positions that are not located on a straight line. 12. The optical pickup according to claim 2, wherein said engaging portion is constituted by a pair of projections abutting on a movable portion of said actuator.