JPH09180217A - Optical head actuator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To follow up the disk rotational speed corresponding to double speed variations by constituting the moving portion employing the irreducible minimum number of parts without using a wire winding bobbin so as to reduce the weight of the portion. SOLUTION: A lens holder 4 is held by four suspension wires 47 in a position variable manner. On the top and the bottom surfaces of the holder 4, protrusions 48 are provided at the locations, which are close to the both side edge sections of the surfaces, so as to fix the wires 47. Moreover, on the both sides of the top and the bottom ends of the front edge side of the surfaces, protrusions 49 are provided to fix the end portions of the respective winding wire. Each end of the wires 47 is fixed to a damper base 70. In other words, protrusions 71 are provided on the upper surface of the base 70 to fix the wires 47. Damper holders 72 which are filled with a damper material made of semiliquid resin to control the vibration of the wires 47 and the wires 47 are extended to the holder 4 side through the member.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical head actuator provided in an optical disk driver, and more particularly to improvement of a lens holder that holds a pickup lens and a suspension wire for movably supporting the lens holder.

[0002]

2. Description of the Related Art An optical head actuator will be briefly described with reference to FIG. In FIG. 3, an optical head actuator 1 includes a lens holder 4 that functions as a holder that holds an objective lens 2, and an actuator base 20 that functions as a fixed base that supports the lens holder 4 so that it can be displaced in the vertical and horizontal directions. And a drive device provided for these.

The lens holder 4 has a hole 4 at the center thereof.
a is provided. At the edge of the hole 4a, the winding bobbin 6
The winding bobbin 6 is provided with a focusing coil (not shown) and a pair of tracking coils 5a and 5b.
Is provided. Further, one end of each of the suspension wires 7 made of elastic wire rods is fixed on both sides of the lens holder 4 by an adhesive agent 8. The suspension wire 7 has a coiling end of the focusing coil and the tracking coils 5a and 5b at one end thereof, and is soldered to act as a lead wire for supplying a current to the focusing coil and the tracking coils 5a and 5b.

On the other hand, the actuator base 20 is fixed to the actuator base 20 by inserting two sets of magnetism generating portions, which are the yoke 11 and the magnet 12 which are superposed on each other, into the hole 4a of the lens holder 4. One magnetism generating portion is adjacent to the tracking coils 5a and 5b, and the other magnetism generating portion is located inside the winding bobbin 6.

The other end of the suspension wire 7 is fixed to the wire support block 18 with an adhesive 9. The driving device for displacing the lens holder 4 includes tracking coils 5 a, 5 formed on the lens holder 4.
b, a focusing coil, and a magnetism generating portion including a yoke 11 and a magnet 12 provided on the actuator base 20. With this driving device, the lens holder 4 is configured to be displaceable with respect to the actuator base 20 in the vertical direction, that is, the focus direction, and the horizontal direction, that is, the tracking direction.

The optical signal received by the objective lens 2 is guided to the opto-electric conversion section via a light path (not shown).

Next, the winding bobbin 6 will be described with reference to FIG. The winding bobbin 6 is a quadrangular frame body made of resin, and the four sides of the winding bobbin 6 are provided with focusing coil receiving portions 60 by concave grooves so as to extend over the entire circumference. Further, a pair of tracking coil winding frame portions 6 is provided on one side surface.
1, 62 are provided. Focusing coil 14
Is wound along the focusing coil receiving portion 60, and the tracking coils 5a and 5b are wound around the pair of tracking coil winding frame portions 61 and 62. Therefore, the pair of winding ends is led out from the focusing coil 14. On the other hand, since the tracking coils 5a and 5b are connected in series, the derived winding ends are also a pair.

[0008]

By the way, in this type of optical head actuator, it is an important subject to reduce the weight of the movable portion, that is, the lens holder. This is because the reading speed, that is, the rotation speed of the disk, tends to increase in the optical disk driver, and high-speed response of the displacement of the lens holder is indispensable to cope with such a tendency. In other words, the quicker the response, the easier the lens holder becomes.

Further, reducing the number of lens holders and the number of parts around them is also an important subject. This is because not only the weight of the lens holder is reduced, but also the assembly work is simplified.

The present invention is intended to achieve the above-mentioned object, and an object of the present invention is to provide an optical head actuator provided with a lens holder which is reduced in weight.

Another object of the present invention is to provide an optical head actuator which can reduce the number of lens holders and the number of parts around them.

[0012]

The present invention provides an optical head actuator in which a lens holder that holds a lens for an optical pickup is displaceably supported by four suspension wires. A focusing coil and a tracking coil are provided on a side surface, and each of the four suspension wires has a mounting piece having a hole for press-fitting into a protrusion provided on the lens holder. To do.

The lens holder has four protrusions in which the pair of winding ends of the focusing coil and the pair of winding ends of the tracking coil are respectively carved, and the suspension wire is It is preferable that the protrusion has a connecting piece for soldering connection with the winding end portion.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the present invention will be described with reference to FIGS. In FIG.
The lens holder 4 according to the present invention does not require the winding bobbin 6 as described with reference to FIG. 3, and the four tracking coils 45 a, 45 b, 45 are provided directly on the side surface of the lens holder 4.
c (one is not shown), the focusing coil 14 is formed. The lens holder 4 is made of resin and has a hole penetrating in the vertical direction at the center thereof, and the objective lens 50 is held in this hole.

A focusing coil receiving portion 40 is formed on the side surface of the lens holder 4 by a concave groove so as to cover the entire circumference, and the focusing coil 14 is wound along the focusing coil receiving portion 40. Lens holder 4
First and second tracking coil winding frame parts 41 and 42 project from one of the side surfaces facing each other in the longitudinal direction, and the other side of the third tracking coil winding frame part 43 and the fourth tracking coil A reel portion (not shown) is provided so as to project. The first, second, and third tracking coil winding frame parts 41, 42, and 43, and the fourth tracking coil winding frame part have first, second, and third tracking coils 45a, 45b, and 45c. And a fourth tracking coil (not shown) is wound.

By using the lens holder 4 as described above, both the tracking coil and the focusing coil can be directly wound around the lens holder. Therefore, a tracking coil separately prepared as in the prior art is attached or adhered to the lens holder. As a result, it is possible to improve workability in manufacturing.

As shown in FIG. 1, the lens holder 4 includes four suspension wires 47 (only two are shown).
Is displaceably supported by. On both upper and lower surfaces of the lens holder 4, projections 48 for fixing the suspension wires 47 at positions near both side edge portions (total 4
Individual pieces) are provided. In addition, protrusions 49 are provided on both sides of the upper end and the lower end on the front edge side for carving the winding end.
(4 in total) are provided. The tracking coil is not shown in FIG.

One end of the suspension wire 47 is fixed to the damper base 70. That is, the protrusion 71 for fixing the suspension wire 47 is provided on the upper surface of the damper base 70. The damper base 70 is also provided with a damper holder 72 filled with a semi-liquid resin damping material for suppressing the vibration of the suspension wire 47, and the suspension wire 47 passes through the damping material to the lens holder 4 side. It is extended.

The suspension wire 47 applied to the lens holder 4 and the damper base 70 as described above is made of a conductive metal and has a mounting piece 47-1 having a hole for press-fitting into the protrusion 71. It has a mounting piece 47-2 having a hole for press-fitting into the protrusion 48, and a connection piece 47-3 for soldering to the winding end portion which is carved by the protrusion 49. The protrusion 71 and the mounting piece 47-1 and the protrusion 48 and the mounting piece 47-2 are bonded with an adhesive after press-fitting.

Two sets of yokes 11 and magnets 12 are provided corresponding to the two sets of tracking coils.

[0021]

Since the optical head actuator according to the present invention does not use the winding bobbin and is constituted by the minimum necessary parts, the weight of the movable portion can be reduced. When the movable portion becomes lighter, it becomes possible to follow the disk rotation speed such as 6 times speed or 8 times speed. Further, since the number of parts can be reduced, cost reduction can be realized and assemblability is improved.

[Brief description of the drawings]

FIG. 1 is a plan view for explaining a lens holder of an optical head actuator used in the present invention and a supporting structure thereof.

FIG. 2 is a schematic perspective view of the lens holder shown in FIG.

3A and 3B are views for explaining a lens holder of a conventional optical head actuator and a supporting structure thereof, FIG. 3A is a plan view, and FIG. 3B is a cross-sectional view taken along the line AA ′ in FIG. 3A. Is.

4 is a schematic perspective view of the winding bobbin shown in FIG.

[Explanation of symbols]

40 Focusing coil receiving parts 41, 42, 43, 44 1st-4th tracking coil winding frame parts 45a, 45b, 45c 1st-3rd tracking coils 50 Objective lens

Claims (2)

[Claims] 1. An optical head actuator in which a lens holder holding a lens for an optical pickup is displaceably supported by four suspension wires, wherein the lens holder has a focusing coil and a tracking coil on its side surface. Is provided, and each of the four suspension wires has an attachment piece having a hole for press-fitting into a protrusion provided on the lens holder. 2. The optical head actuator according to claim 1, wherein the lens holder has four protrusions in which a pair of winding end portions of the focusing coil and a pair of winding end portions of the tracking coil are respectively carved. The optical head actuator according to claim 1, wherein the suspension wire has a connection piece for soldering connection to the winding end portion at the protrusion.