WO2007086370A1

WO2007086370A1 - Optical pickup device

Info

Publication number: WO2007086370A1
Application number: PCT/JP2007/050976
Authority: WO
Inventors: Masahiko Miyake
Original assignee: Pioneer Corporation
Priority date: 2006-01-27
Filing date: 2007-01-23
Publication date: 2007-08-02

Abstract

In an optical pickup device, a movable unit (2) of an actuator (10) where an objective lens (1) is mounted is displacably supported by two suspension wires (3) at each of the inner circumferential side and the outer circumferential side of an optical disc so as to sandwich the objective lens (1). A moving body (9) including a damping member movable along the suspension wire (3) is attached to the suspension wire (3) of the inner circumferential side of the optical disc so as to hold the suspension wire (3) at a predetermined position. For this, the suspension wire (3) of the inner circumferential side of the optical disc is harder than the suspension wire (3) of the outer circumferential side of the optical disc and hardly moves with respect to displacement in the focus direction.

Description

Specification

Optical pickup device

Technical field

[oooi] The present invention relates to an optical pickup device that performs recording and reproduction of information on an optical disc.

Background art

[0002] An optical pickup device is generally composed of an objective lens driving device (actuator) having an objective lens and an optical system that transmits and receives light to and from the objective lens. The structure is arranged. In such an actuator, generally, a lens holder for holding an objective lens is supported by a plurality of wires, and the lens holder is driven through a magnetic mechanism such as a coil or a permanent magnet. It has become. As a result, the actuator can correct the relative position of the objective lens with respect to the optical disc by moving the lens holder in the focus direction and the tracking direction.

[0003] By the way, when the optical disc is warped, a relative inclination occurs between the optical disc and the objective lens. Therefore, the adjustment of the focus direction and the tracking direction described above is not sufficient. In other words, since the objective lens is designed in consideration of the thickness of the optical disk, there is a problem that the optical disk is warped and coma occurs when the disk is tilted.

[0004] To deal with such a problem, the hardness (for example, the wire diameter of the wire) of the inner and outer peripheral sides of the wire supporting the lens holder is changed in accordance with the warp of the optical disc, An actuator equipped with a tilt mechanism for tilting the lens holder has been developed (see, for example, Patent Documents 1 and 2).

[0005] Patent Document 1: Japanese Utility Model Publication No. 6-4920

Patent Document 2: Japanese Patent Laid-Open No. 2001-14696

Disclosure of the invention

Problems to be solved by the invention [0006] When changing the hardness of the inner and outer circumferences of the optical disk while reducing the force, the difference is small, so in the actual manufacturing process, the tolerances of parts (for example, variations in wire diameter) Therefore, there is a problem that the tilt amount of the objective lens varies. As a result, there arises a problem that a correction process for reattaching the wire becomes necessary, and the yield in the manufacturing process is lowered.

As described above, an actuator equipped with a conventional tilt mechanism has a problem that it is easy to adjust the tilt amount of the objective lens in the manufacturing process! .

[0008] The present invention has been made to solve the above-mentioned problems. As an example of the problem, even if there is a variation in part tolerance in the manufacturing process, the tilt amount of the objective lens can be easily set. An object of the present invention is to provide an optical pickup device that can be adjusted.

Means for solving the problem

In order to achieve the above object, an optical pickup device according to claim 1 includes an objective lens, a lens holder that holds the objective lens, and a drive unit that drives the lens holder in a focus direction and a tracking direction. A support member that extends in the tangential direction of the optical disc on each of the inner peripheral side and the outer peripheral side of the optical disc across the objective lens, and supports the lens holder in a displaceable manner; and a support member on the inner peripheral side of the optical disc The movement of the support member on the inner periphery side of the optical disc is suppressed at a predetermined position, thereby suppressing the displacement of the support member on the inner periphery side of the optical disc in the focus direction. And a body.

Brief Description of Drawings

FIG. 1 is a plan view showing a configuration of an actuator of an optical pickup device according to an embodiment of the present invention.

FIG. 2 is a side view showing the configuration of the actuator of the optical pickup device according to the embodiment of the present invention.

FIG. 3 is a cross-sectional view taken along line AA in FIG.

4 is a diagram schematically showing the support structure of the movable part shown in FIG. 1.

FIG. 5 is a diagram for explaining the operation when the movable part of FIG. 4 is driven in the direction approaching the optical disc by the focus servo. FIG. 6 is a diagram for explaining the operation when the movable part in FIG. 4 is driven by the focus servo in a direction in which the optical disk force is also moved away.

Explanation of symbols

[0011] 1 Objective lens

2 Lens holder (movable part)

3 Suspension wire

4 York

5 Magnet

6 Magnet attachment surface

7 coils

8 Fixed part

9 Mobile

10 Actuator

11 Damping material

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 and FIG. 2 are diagrams showing the configuration of the actuator 10 of the optical pickup device according to the embodiment of the present invention. FIG. 1 is a plan view, FIG. 2 is a side view, and FIG. FIG.

The objective lens 1 is attached to a lens holder (which becomes a displaceable lens holder as will be described later! / So called a movable part) 2, and the lens holder 2 sandwiches the objective lens 1. The optical disk is supported by two suspension wires 3 provided on the inner and outer peripheral sides of the optical disc. Specifically, the suspension wires 3 on the inner and outer peripheral sides of the optical disc are installed between the movable portion 2 and the fixed portion 8 so as to be parallel to each other with respect to the longitudinal direction of the yoke 4 (optical disc tangential direction). ing. In this embodiment, two suspension wires 3 are provided on each of the inner and outer peripheral sides of the optical disc. However, the present invention is not limited to this, and one suspension wire 3 is provided on each of the inner and outer peripheral sides of the optical disc. Or it is good also as a structure provided with three or more suspension wires 3. FIG. In addition, the suspension wire of this embodiment The force 3 is a force using all beryllium copper of the same material, but is not limited to this, and other materials (metal wire, plastic wire, rod-like elastic body) may be used.

The yoke 4 forms the frame portion of the actuator 10, and the magnet 5 is attached to the yoke 4 via the magnet attaching surface 6. The yoke 4 and the magnet 5 form a magnetic path. In addition, the lens holder 2 cooperates with the yoke 4 and the magnet 5 to provide a coil 7 for driving the lens holder 2 equipped with the objective lens 1 in the focus direction (F o) and the tracking direction (Tr), respectively. Is provided. On the other hand, a fixed portion 8 that supports the other end of the suspension wire 3 that supports the movable portion 2 is fixed to an end portion of the yoke 4 in the longitudinal direction.

Accordingly, the objective lens 1 is supported by the four suspension wires 3 so as to be displaceable in the focus direction (Fo) and the tracking direction (Tr).

In addition, a movable body 9 that is movable along the suspension wire 3 is attached to the suspension wire 3 on the inner peripheral side of the optical disc. As shown in FIG. 3, the moving body 9 is formed with a hollow space extending in the moving direction of the moving body 9 in which the suspension wire 3 is enclosed, and this space is filled with the damping material 11. The suspension wire 3 is fixed by the damping material 11. That is, the damping material 11 has a function of fixing the suspension wire 3 to suppress the movement of the suspension wire 3 and moving the moving body 9 smoothly. As the damping material 11, a gel-like material that can use various materials is preferred, and a silcorn-based or modified tantalate-based gel-like damping material is particularly preferred.

Accordingly, as shown in FIG. 4, the suspension wire 3 on the inner peripheral side of the optical disc is harder than the suspension wire 3 on the outer peripheral side of the optical disc with respect to displacement in the focus direction (Fo). It's getting harder. FIG. 4 is a side view of the lens holder 2 as viewed from the longitudinal direction of the yoke 4 and schematically shows a support structure of the lens holder 2.

As shown in FIG. 5, for example, when the optical disc D is tilted away from the objective lens 1, when the lens holder 2 is driven in the focus direction (upward in FIG. 5), the lens holder 2 ! / Because it is lower in rigidity than the suspension wire 3 on the inner peripheral side of the optical disk, the amount of movement on the suspension wire 3 side on the outer peripheral side of the optical disk is substantially larger. this As a result, the lens holder 2 tilts so as to correct the tilt of the optical disc D. In other words, when the objective lens 1 follows the warp of the optical disc D by the focus servo, the optical axis of the object lens 1 is corrected so as to be perpendicular to the optical disc surface.

On the other hand, as shown in FIG. 6, for example, when the optical disc D is tilted in the direction approaching the objective lens 1, when the lens holder 2 is driven in the focus direction (downward in FIG. 6), the lens holder 2 In addition, the rigidity is lower than the suspension wire 3 side on the inner peripheral side of the optical disc, and the amount of movement on the suspension wire 3 side on the outer peripheral side of the optical disc is substantially increased. As a result, the lens holder 2 tilts so as to correct the tilt of the optical disc D. That is, when the objective lens 1 follows the warp of the optical disc D by the focus servo, the optical axis of the objective lens 1 is corrected so as to be perpendicular to the optical disc surface.

As described above, the actuator 10 of the optical pickup device according to the present embodiment has a tilt correction function and can cope with the warp of the disc, so that good optical characteristics can be obtained.

Here, in the present embodiment, the degree of tilt of the lens holder 2 described above, that is, the tilt amount of the objective lens 1 can be adjusted by the arrangement position of the moving body 9, and the moving body 9 is fixed. The tilt amount decreases (closer to the lens holder 2 when approaching the part 8 side), and the tilt amount increases when the moving body 9 is closer to the movable part 2 side (the tilt of the lens holder 2). Is great). Note that the actual tilt amount is very small (for example, more specifically, a tilt of about 0.3 to 0.5 degrees), so the moving body 9 is installed near the fixed portion 8. Is preferable. Of course, there is an individual difference in the tilt amount of each of the actuators 10 in the assembling process. Therefore, the same tilt amount can be realized for all the actuators 10 by appropriately moving the moving body 9. . In other words, in the past, the tilt amount was adjusted while assembling in the course of the assembling process. In the final process, the tilt amount can be adjusted by attaching the movable body 9 and adjusting the position, so that the variation in the tilt amount of the objective lens can be easily eliminated.

As described above, in the present embodiment, when the moving body 9 is attached to the actuator 10 in the manufacturing process, the tilt amount can be adjusted by adjusting the position of the moving body 9. Therefore, the tilt amount of the objective lens 1 can be easily adjusted even if the tolerances of parts vary. As a result, the actuator 10 having the objective lens 1 having the same tilt amount can be provided without individual differences, and the yield in the manufacturing process can be improved. Also, since the tolerance variation of parts can be absorbed by adjusting the position of the moving body 9, it is not necessary to consider the tolerance variation of parts.As a result, the specifications of the parts can be relaxed compared to the conventional one, and the cost of the parts can be reduced. Can be planned.

The embodiments of the present invention have been described above, but various modifications and changes can be made to the embodiments and examples of the present invention without departing from the spirit of the present invention. For example, in the above embodiment, the four suspension wires 3 are installed in parallel, but the four suspension wires 3 do not necessarily have to be parallel. A slight inclination is acceptable as long as it does not interfere with the movement to).

[0025] In the above embodiment, when the objective lens 1 is tilted! For the purpose, the moving body 9 is attached only to the inner periphery of the optical disc. However, the objective lens 1 is intended to be kept horizontal. For example, the moving body 9 may be attached to each of the inner peripheral side of the optical disc and the outer peripheral side of the optical disc.

As described above, the optical pickup device according to the embodiment of the present invention includes the objective lens 1, the lens holder 2 that holds the objective lens, and the drive unit (yoke 4) that drives the lens holder in the focus direction and the tracking direction. A magnet 5 and a coil 7), and a suspension wire 3 extending in the tangential direction of the optical disc on each of the optical disc inner peripheral side and the optical disc outer peripheral side with the objective lens 1 interposed therebetween, and supporting the lens holder 2 in a displaceable manner. The optical disk can be moved along the suspension wire 3 on the inner peripheral side of the optical disc, and the support member on the inner peripheral side of the optical disc is restrained from moving at a predetermined position, so that the suspension wire 3 on the inner peripheral side of the optical disc can be moved in the focus direction. And a moving body 9 that suppresses displacement, so even if there is a variation in part tolerance in the manufacturing process, You can simply adjust the tilt of the objective lens.

Claims

The scope of the claims

[1] an objective lens;

A lens holder for holding the objective lens;

Drive means for driving the lens holder in a focus direction and a tracking direction, and extending in the optical disc tangential direction on each of the inner and outer peripheral sides of the optical disc with the objective lens interposed therebetween, and supports the lens holder in a displaceable manner. A support member;

The focus of the support member on the inner peripheral side of the optical disc can be moved along the support member on the inner peripheral side of the optical disc, and restrains the movement of the support member at a predetermined position on the support member on the inner peripheral side of the optical disc. A moving body that suppresses displacement in the direction;

An optical pickup device comprising:

2. The optical pickup device according to claim 1, wherein the moving body suppresses the movement of the support member via a damping material.

[3] The optical pickup according to claim 1 or 2, wherein the predetermined position is in the vicinity of the other end of the support member on the inner peripheral side of the optical disc opposite to the one end supporting the lens holder. apparatus.

4. The support member is provided with two each of V on the inner peripheral side of the optical disc and the outer peripheral side of the optical disc, and substantially parallel to the tangential direction of the optical disc. 4. The optical pickup device according to any one of items 1 to 3.