JPH04121027U - Optical pick-up actuator - Google Patents

Abstract

(57) [Summary] [Purpose] To make it possible to visually check the filling state of a viscoelastic material for a damper of an actuator of an optical pickup, and to easily discover abnormalities in the filling. [Structure] A fixing member supporting the wire 5 of the actuator of the optical pickup is composed of a translucent housing member 6 including a box-shaped container 8. An insertion hole 10 into which the wire 5 is inserted is formed in the translucent housing member 6.
After inserting the wire 5 into the holder, the wire 5 is fixed by filling with a viscoelastic material 9. The vicinity of the attachment portion of the wire 5 is surrounded by a viscoelastic material 9. [Effect] Since the housing member is translucent, the filling state of the viscoelastic material can be easily visually observed.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

This invention is suitable for recording on record carriers such as optical video discs and compact discs. Regarding the actuator of an optical pickup that optically reads the signal .

0002

[Conventional technology]

The structure of a conventional optical pickup actuator is shown in FIG. In the figure , 1 is an objective lens, and 2 is a holder for the optical system including the objective lens, which is generally made of resin material. It is made. 3 is for moving holder 2 in the direction of the coordinate axes shown in the same figure. A focus coil 4 is a track for moving the holder 2 in the X direction of the coordinate axis. With King Coil, focus coil 3 and tracking coil 4 are attached to holder 2. I'm being kicked.

0003 The holder 2 moves in the direction of the coordinate axes X and Z relative to the fixed member 12. In order to do this, it is attached to the fixed member 12 via a flexible wire 5 . The fixing member 12 is generally made of an insulator such as a resin material. Wire 5 is a metal material It also serves as a guide for the current flowing through the two types of coils 3 and 4. It penetrates through the fixing member 12 and is electrically connected to the wiring board 7 .

0004 13 and 13' are permanent magnets, and 14 is a yoke, which constitutes a magnetic circuit. The lock 14 is structurally attached to the fixed member 12. Permanent magnets 13 and 13' are shown in the figure. As shown in Figure 3, the focus coils are installed so that the same poles face each other. 3 and the direction that intersects the direction of the current flowing through the tracking coil 4, that is, the direction shown in FIG. A magnetic tail is generated in the direction of the coordinate axis Y of 3.

[0005] Therefore, the force generated by the current flowing through the focus coil 3 is This occurs in the Z direction, and the holder 2 is in the focus direction of the objective lens 1, i.e. That is, it moves in the Z direction.

[0006] Similarly, the current flowing through the tracking coil 4 also causes a change in the X direction of the coordinate axis. The force acts to move the holder 2 in the tracking direction of the objective lens 1.

[0007] The wire 5 is connected to the fixed member 12 so that the holder 2 can move in this manner. This supports the holder 2 flexibly.

[0008]

[Problem that the idea aims to solve]

In the actuator of the optical pickup having the above configuration, there is a resonance frequency f ₀ determined by the mass of the movable part consisting of the objective lens 1, holder 2, focus coil 3, and tracking coil 4 and the stiffness of the wire 5.

Conventionally, the wire 5 was passed through a rubber tube in order to damp the resonance at the resonance frequency f ₀ and other parasitic vibrations. This method has problems in that the mass of the vibration system increases and the damping effect is insufficient. In order to solve this problem, as shown in an example in FIG. A method has also been considered in which the viscoelastic material 16 is filled in the surrounding area.

0010 However, in such a structure, the filled state of the viscoelastic material 16 cannot be visually checked, and the It can be detected even if bubbles are generated or the adhesion of the viscoelastic material 16 around the wire 5 is not sufficient. I couldn't come.

[0011] If air bubbles occur around the wire, the braking effect cannot be achieved, and performance such as current sensitivity etc. becomes worse. Also, if moisture gets into the bubbles, viscoelasticity may occur due to temperature changes or thermal shock. There is a risk that the material may come off.

0012 This invention solves these conventional problems and makes filling operations more accurate. The purpose is to make it a reality.

[0013]

[Means to solve the problem]

In order to achieve the above purpose, our school's proposal uses a transparent container to fill the viscoelastic material. The screen is made of a semi-transparent material.

[0014]

[Effect]

By having the above configuration, the filling state of the viscoelastic material can be visually checked, and Facilitates curing of UV-curable viscoelastic materials.

[0015]

【Example】

(Example 1) A first embodiment of the present invention will be described with reference to FIG. Figure 1 (a) is an external view, (b) is a sectional view taken along the line A-A' in (a).

[0016] 5 is the same wire as the actuator of the conventional optical pickup, and 6 is the same wire as the actuator of the conventional optical pickup. This is a fixing member that has the same purpose as the fixing member 12 in the conventional example, but for example, Translucent housing made of translucent or transparent material such as polycarbonate It is.

[0017] This translucent housing member 6 can be filled with a viscoelastic material in the part where the wire 5 is inserted. A container 8 having a box-like shape is integrally formed to serve as a housing member. Container 8 The space portion is not limited to a rectangular shape, but may be elliptical or cylindrical. viscoelastic The material 9 is made of a material such as silicone gel, and is also transparent.

[0018] As shown in FIG. 1(b), the tip of the wire 5 is attached to the wire attachment hole 1 of the translucent housing member 6. 0, penetrates to the circuit board 7, and is fixed. Next, the viscoelastic material 9 is filled, After being cured, the wire 5 is surrounded by a viscoelastic material 9.

[0019] Movable part consisting of objective lens 1, holder 2 and two coils 3 and 4 The movement of the moving part causes the moving part to change depending on its mass and the stiffness of the wire 5. When attempting to resonate at a frequency determined by The parts are also displaced in the coordinate axes X and Z in FIG.

[0020] This displacement causes distortions such as compression and shearing in the viscoelastic material 9, but the viscoelastic material 9 9 has the effect of absorbing this strain and returning the displacement of the wire 5 to its original state. Said resonance will be suppressed and damped.

[0021] (Example 2) A second embodiment of the invention is shown in FIG. Figure (a) is an external view, (b) is the same as (a). FIG. Compared to the first embodiment, the translucent housing member 6 The shape of the container filled with the viscoelastic material 9 provided in the container is different, and a round hole 11 is provided. The rest is the same as the first embodiment. Also, the shape is the same as the conventional example shown in Figure 4. The difference is that the housing member 6 is translucent.

[0022] In addition, in the above-mentioned Examples 1 and 2, the tip of the wire 5, that is, the fixed member side is sticky. Although the case where the wire 5 is surrounded by an elastic material has been described, the end of the wire 5, that is, the holder side A similar effect can be obtained by surrounding the material with a viscoelastic material.

[0023]

[Effect of the idea]

As mentioned above, the present invention uses a translucent housing member to accommodate viscoelastic materials. The filling status can be clearly visualized, making it easy to detect abnormalities in the filling status such as the formation of air bubbles. This has the effect of increasing the reliability of the filling operation. In addition, viscoelastic material In the case of UV curing type, the UV rays can pass through easily, making the curing process easier and more reliable. It also has the effect of

[Brief explanation of drawings]

FIG. 1 (a) is an external view of an actuator of an optical pickup in the first embodiment of the present invention; (b) is (a)
A cross-sectional view on plane A-A' of

FIG. 2(a) is an external view of the actuator of the optical pickup in the second embodiment of the present invention; FIG. 2(b) is FIG.
A cross-sectional view on plane A-A' of

[Figure 3] External view of the actuator of a conventional optical pickup

[Figure 4] Cross-sectional view of the actuator of another conventional optical pickup

[Explanation of symbols]

1 Objective lens 2 Optical system holder 5 wire 6 Translucent housing member 8 Box-shaped container (transparent housing member) 9 Viscoelastic material

Claims (1)

[Scope of utility model registration request] 1. An end of a wire for supporting a holder to which an optical system including an objective lens is attached to a fixing member is attached to a mounting part of at least one of the holder and the fixing member, and An actuator for an optical pickup having a translucent housing member that forms a space having a shape larger than an outer diameter of a wire, and that surrounds the wire and is filled with a viscoelastic material.