JPH06168455A - Adjusting mechanism for optical axis of optical pickup - Google Patents

Abstract

PURPOSE:To provide an adjusting mechanism for optical axis of an optical pickup which can independently perform radial adjustment, tangential adjustment and adjustment for deviation of an optical axis. CONSTITUTION:A base 1 supports a pickup 6 via a pick-holder 3, and moves linearly in the direction of Y and Z as illustrated. The pick-holder 3 is supported floating on the base by a supporting shaft 2, a compression coil spring 4 and a first screw 5. The pickup 6 is supported floating on the pick-holder 3 by supporting shafts 6a, 6b, the compression coil spring and second screw 10, also pressed to left hand by a the compression coil spring 8 and supported with third screw 9 from the opposite side. Therefore, tangential adjustment by the first screw 5, radial adjustment by the second screw 10, and adjustment for deviation of the optical axis can be performed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical pickup of a recordable / reproducible optical disk device, and particularly to an optical pickup for a disk, in which radial direction adjustment, tangential direction adjustment and positional deviation adjustment of the optical axis of the optical pickup are independently performed. The present invention relates to an optical axis adjusting mechanism of an optical pickup suitable for performing the operation.

[0002]

2. Description of the Related Art Conventionally, an optical axis adjusting mechanism of an optical pickup in an optical disc player has been provided as shown in FIG.

FIG. 3 is an exploded perspective view showing an optical axis adjusting mechanism of a conventional optical pickup. FIG. 4 is a diagram for explaining the details of each optical axis adjustment, (A) adjusting the optical axis position shift, and (B).
FIG. 9A is a left side view of FIG. 9B showing tangential adjustment, and FIG. Conventionally, as shown in FIG. 3, an optical pickup 2 having an objective lens 22 on its upper surface is used.
1 is provided with three holes 21a for adjusting screws 23.
Adjustment screws 23a, 23b, 23 inserted in a, 21a, ...
3 are inserted into the compression coils 24, 24 ... And the adjustment screws 23a, 23b, 23c are provided on the base 25.
The optical pickup is screwed into the screw holes 25a, 25a ... And is mounted on the base 25 in a state of being sandwiched between the compression coil spring 24 and the adjusting screw 23, and three adjusting screws 23a,
23b and 23c are individually turned to tilt the optical pickup to adjust the tangential direction of the optical axis (hereinafter referred to as tangential adjustment) and the radial direction of the optical axis (hereinafter referred to as radial adjustment). It was

The tangential adjustment is shown in FIG.
As shown in (B), the tilt angle (β or −β) of the disc 27 placed on the turntable 26 in the cutting line direction is adjusted to match the optical axis C, and the adjustment shown in FIG. This tangential adjustment is performed by the screw 23b or the adjusting screw 23c. Further, in the radial adjustment, as shown in FIG. 4C, the tilt angle (γ or −γ) in the normal direction, which is a straight line passing through the center of the disk 27 placed on the turntable 26, is applied to the disk 27. The adjustment is made so as to match the desired vertical optical axis C, as shown in FIG.
Radial adjustment was performed by the adjusting screw 23a shown in FIG.

[0005]

However, in the above-mentioned optical axis adjusting mechanism of the optical pickup, the radial adjustment can be made independently by turning the adjusting screw 23a.
In the tangential adjustment, when either the adjusting screw 23b or the adjusting screw 23c is turned for adjustment, the optical pickup 21 tilts with the other two adjusting screws as fulcrums, so that the optical axis B in the radial direction also changes. It was impossible to adjust independently. Therefore, the tangential adjustment takes time and cannot be adjusted with high accuracy.

Further, as shown in FIG. 4A, the positional deviation (Δ) from the actual optical axis B with respect to the desired optical axis movement locus A is shown.
Χ) (hereinafter referred to as optical axis position shift) could not be adjusted.

The present invention has been conceived in view of the above points, and the object thereof is to solve the drawbacks of the conventional example, and perform radial adjustment, tangential adjustment, and optical axis position deviation adjustment independently. It is an object of the present invention to provide an optical axis adjusting mechanism of an optical pickup that can be used.

[0008]

The optical axis adjusting mechanism of an optical pickup according to the present invention supports a pickup having an optical axis locus on a straight line passing through the center of a turntable in an optical disk device capable of recording and reproducing. A linearly moving base and a first screw rotatably supported at one end by a fulcrum shaft substantially parallel to the base and parallel to the direction in which the base linearly moves, and the other end screwed to the base. And a pick holder sandwiched by elastic members arranged on the base, and a fulcrum shaft that is substantially parallel to the pick holder and is projected in a direction perpendicular to the linear movement direction of the base,
One end is rotatably supported by fitting into a hole provided in the pick holder, and the other end is sandwiched by a second screw screwed into the pick holder and an elastic member arranged on the pick holder. And a pickup that is biased by an elastic member toward one of the fulcrum axis directions protruding from the pickup, and the other end that is screwed into a screw hole provided in the pick holder at the other end. A third screw configured to receive the pickup, the tangential direction adjustment of the optical axis by the first screw, the radial direction adjustment of the optical axis by the second screw, and the optical axis locus by the third screw. The position deviation of the optical axis of the pickup is adjusted independently of each other.

[0009]

According to the present invention, by rotating the first screw, the pick holder is slightly rotated so as to incline in the cutting line direction of the disk with the fulcrum shaft provided on the base as a fulcrum, and By turning the second screw, the fulcrum shaft provided on the pickup is used as a fulcrum, the pickup is slightly rotated in the moving direction of the pickup and tilted, and further by turning the third screw, the pickup is moved to the pickup. Since the pickup urged in one direction of the fulcrum axis provided can be slightly moved in the opposite direction against this urging force or in the one direction urged, by rotating the first screw the tangential The adjustment can be made, the radial adjustment can be made by turning the second screw, and the optical axis position deviation can be made by turning the third screw.

These adjustments can be made independently of each other without affecting the other.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an optical axis adjusting mechanism of an optical pickup according to the present invention will be described with reference to FIGS.

FIG. 1 is a perspective view showing the present invention. FIG. 2 shows an adjusting mechanism of each part of the present invention. (A) is the Z of FIG.
FIG. 6 is a partial cross-sectional arrow view from the direction, showing an optical axis position deviation adjusting mechanism. (B) is a view from the X direction in FIG. 1, and is a view showing a radial mechanism. (C) is a view from the Y direction of FIG. 1, and is a view showing a tangential adjustment mechanism.

In the figure, reference numeral 1 is a base, which is provided with a screw hole 1a into which a first screw is screwed, and two left and right shaft support portions 1b which pivotally support a fulcrum shaft 2 which is substantially parallel to the moving direction of the base. ing. As shown in FIG. 1, a pick holder and a pickup are attached to the base 1 so that the optical axis moves along a straight line passing through the center of the turntable (shown in FIG. 4) in the arrow Y direction or the arrow Z direction. Make a straight line reciprocating movement to.

Reference numeral 3 is a pick holder, which is substantially parallel to the base 1 in a state of being floated on the base 1. One end of the pick holder is rotatably supported by a fulcrum shaft 2 inserted in both the left and right bearing portions 3a. The other end of the pick holder 3 is compressed by screwing a hole 3b that opposes the screw hole 1a and a first screw 5 inserted into a compression coil spring 4 arranged under the pick holder 3 into the screw hole 1a of the base 1. It is sandwiched by the coil spring 4 and the first screw 5, and is rotatably supported. 3C is second
It is a screw hole into which a screw is screwed. Reference numeral 3e is a bearing shown in FIG. 2A, which is fixed to the rising portion 3d at the end of the pick holder 3, and the left half of the central hole is the screw hole 3f for the third screw.
The right half is a fulcrum shaft hole 3g provided in the pickup.

Reference numeral 6 denotes a pickup, which records and reproduces signals on and from a disc (not shown) by the laser beam that has passed through the objective lens 7. The pickup 6 floats above the pick holder 3 and is substantially parallel to the pick holder 3. The fulcrum shafts 6a and 6b are provided on the left and right side portions of the pick holder 6 which are located substantially right below the objective lens 7. The fulcrum shaft 6 is provided so as to project in a direction orthogonal to the moving direction.
The a and 6b are rotatably supported by being inserted into a hole 3h of a rising portion provided at one end of the pick holder 3 and a bearing 3e of a rising portion 3d provided at the other end opposite to the hole 3h. . The pickup 6 is urged to the left by a compression coil spring 8 attached to the fulcrum shaft 6b, and the fulcrum shaft 6a on the opposite side contacts the third screw 9 for adjusting the optical axis position deviation inside the bearing 3e. There is.

Reference numeral 10 is a second screw for radial adjustment,
As shown in FIG. 2B, it is inserted into the compression coil spring 11 arranged below the hole 6c provided on the upper surface of the pickup 6 so as to face the screw hole 3c of the pick holder 3,
It is screwed into the screw hole 3c. As a result, the pickup 6 is sandwiched between the compression coil spring 11 and the second screw 10 and is rotatably supported about the fulcrum shafts 6a and 6b.

In FIG. 4, A is a desired optical axis locus, which is a straight line (normal line) passing through the center of the turntable 2b. B is the optical axis of the pickup 21. α1,
α2 is a displacement angle between the optical axis B and the center of the turntable 2b with respect to the optical axis locus A when the pickup 6 moves. C is an optical axis perpendicular to the disk 27. β (-β)
Is the deflection angle of the optical axis in the tangential direction, and γ (−γ) is the deflection angle of the optical axis in the radial direction.

The operation and action of the present invention configured as above will be described. As shown in FIG. 1, the optical pickup 6 is supported by the base 1 via the pick holder 3, and the optical axis locus of the laser beam emitted through the objective lens 7 is the optical axis locus A shown in FIG. 1 to move linearly in the direction of the arrow Z in FIG.

The optical axis of the pickup 6 is Δ in FIG.
If there is a positional deviation corresponding to Χ, the third screw 9 is turned to slightly move the pickup 6 in the direction opposite to the arrow X direction in FIG. 1, and this positional deviation (ΔΧ) is adjusted to the predetermined optical axis. Adjustments are made to match the trajectory A. Of course, when the positional deviation (ΔΧ) is on the opposite side (-ΔΧ) of the optical axis locus A, the pickup 6 is rotated by the urging force of the compression coil spring 8 by rotating the third screw 9 in the opposite direction to the adjustment. It can be adjusted by slightly moving it in the direction of arrow X in FIG.

When the optical axis of the pickup 6 is tilted in the tangential direction corresponding to the tilt β (-β) in FIG. 4B, the pick holder 3 is rotated by turning the first screw 5 to move the pick holder 3 to the fulcrum shaft 2. Rotate slightly with the fulcrum as the fulcrum.

As a result, the pickup 6 also slightly rotates and tilts, and is tangentially adjusted so as to coincide with the optical axis C perpendicular to the disk 27 shown in FIG. 4 (B).

When the optical axis of the pickup 6 is tilted in the radial direction corresponding to the tilt γ (-γ) in FIG. 4C, the pick-up 6 is rotated by turning the second screw 10 to move the fulcrum shafts 6a and 6b. It pivots slightly and tilts.

As a result, the tilt of the optical axis of the pickup 6 is radially adjusted so as to match the optical axis C perpendicular to the disk 27 shown in FIG.

[0024]

Since the optical axis adjusting mechanism of the optical pickup according to the present invention is configured as described above, the radial adjustment and the tangential adjustment can be independently performed without being influenced by each other, and therefore, it is easy. And it can be adjusted with high precision.

For this reason, it is very effective for the optical disc device capable of recording and reproducing, which requires higher precision than reproducing only.

Since the optical axis position deviation can be adjusted, the deviation angle α1 when the pickup 21 is positioned near the turntable 26 and the deviation angle α2 when the pickup 21 is moved away from the turntable 26 as shown in FIG. 4A. A change in playability (R-dependence) due to the difference can be eliminated, and a recordable and reproducible optical disk device having the same playability in both inner and outer circumferences of the disk can be manufactured.

[Brief description of drawings]

FIG. 1 is a perspective view showing an optical axis adjusting mechanism of an optical pickup according to the present invention.

FIG. 2A is a partial cross-sectional side view showing an optical axis position deviation adjusting mechanism portion of the present invention. (B) is a side view showing the radial adjustment mechanism portion of the present invention. (C) is a partial cross-sectional side view showing the tangential adjustment mechanism portion of the present invention.

FIG. 3 is an exploded perspective view showing an optical axis adjusting mechanism of an optical pickup in a conventional example.

FIGS. 4A to 4C are diagrams illustrating optical axis adjustment contents, FIG. 4A is an explanatory diagram of optical axis position deviation adjustment, FIG. 4B is a tangential adjustment, and FIG.

[Explanation of symbols]

 1: Base 1a, 3c, 3f: Screw hole 1b: Shaft support part 2: Support shaft 3: Pick holder 3a: Bearing part 3b, 3g, 3h: Hole 3d: Rise part 3e: Bearing 4, 8, 11: Compression coil spring 5: First screw 6: Pickup 7: Objective lens 9: Third screw 10: Second screw

Claims (1)

[Claims] 1. In an optical disk device capable of recording and reproducing, a base that linearly moves by supporting a pick-up having an optical axis locus on a straight line passing through the center of a turntable, and a base that is substantially parallel to the base, One end is rotatably supported by a fulcrum shaft parallel to the direction in which this base moves linearly,
The other end has a first screw screwed to the base, a pick holder sandwiched by an elastic member arranged on the base, and a direction substantially parallel to the pick holder and perpendicular to the linear movement direction of the base. By fitting a fulcrum shaft projecting on the shaft into a hole provided in the pick holder, one end is rotatably supported, and the other end is a second screw screwed into the pick holder and the pick holder. A pickup sandwiched by an elastic member disposed above, and the pickup is biased by the elastic member toward one of the fulcrum axis directions protruding from the pickup and is provided on the other opposite side of the pick holder. A third screw configured to be screwed into a screw hole and configured to receive the pickup at the tip, the tangential direction adjustment of the optical axis by the first screw,
An optical pickup characterized in that the radial direction adjustment of the optical axis by the second screw and the positional deviation adjustment of the optical axis of the pickup with respect to the optical axis locus by the third screw are independently performed. Optical axis adjustment mechanism.