JPH0877587A - Objective lens driving device - Google Patents

Abstract

PURPOSE: To enhance the accuracy of a supporting wire fitting position in the objective lens driving device. CONSTITUTION: A holder 20 has an inserting hole 12a for inserting a supporting wire 6, and this inserting hole 12a is so provided that its center axial direction is unparallel with the longitudinal direction of the supporting wire 6. At the time of fixing the supporting wire 6 by the holder 20, even when a diameter of the inserting hole 12a is larger than a diameter of the supporting wire 6, the supporting wire 6 is accurately positioned by both end edges of the inserting hole 12a, so that four supporting wires 6 can be paralleled. Consequently, the parallelism of the supporting wires 6 is enhanced, and the inclination of an objective lens is diminished accordingly.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an objective lens driving device of an optical pickup for recording or reproducing information on a disc-shaped recording medium.

[0002]

2. Description of the Related Art Generally, an optical disk recording / reproducing apparatus currently in use rotates a disk at a predetermined rotation speed,
The laser light emitted from the laser diode is focused on the disc by the objective lens to record or reproduce the disc information. At this time, by the objective lens driving device,
The objective lens is moved in two axes of the surface wobbling direction (focusing direction) of the disk and the radial direction (tracking direction) parallel to the disk so as to focus the laser light on the disk.

A conventional objective lens driving device will be described below. FIG. 2 is a perspective view of a conventional objective lens driving device. In FIG. 2, the objective lens 1 is bonded to the holder 2. 3 is a focusing coil wound around the holder 2 and 4 is a tracking coil wound in the shape of a flat disk, which is bonded to the holder 2. The movable part substrates 5 are fixed to both sides of the holder 2. The objective lens 1, the holder 2, the focusing coil 3, the tracking coil 4, and the movable portion substrate 5 form a movable portion. One end of each of the support wires 6 formed of four linear spring members is fixed to the movable portion substrate 5 by soldering after being inserted into the insertion holes 2a provided in the holder 2. The other end is inserted into an insertion hole 9a provided in the fixing member 9 and fixed on the back surface by soldering (not shown). Two magnets 7 magnetized in the Y direction are fixed to the outer columnar portion 8a of the yoke base 8 so that the same poles face each other, and each of them has a magnetic gap and faces the inner columnar portion 8b to form a magnetic circuit. ing. The fixing member 9 to which the holder 2 is connected by the supporting wire 6 is fixed to the yoke base 8 so that the focusing coil 3 and the tracking coil 4 are located in the magnetic gap.

The operation of the objective lens driving device constructed as described above will be described below. When a current is applied to the focusing coil 3 from the outside, the current flows in the X direction in the magnetic gap, and a magnetic field in the Y direction generated by the magnet 7 causes a force in the Z direction on the focusing coil 3 according to Fleming's law, causing the movable part to move. Operates in the Z direction. Similarly, when a current is passed through the tracking coil 4, a force in the X direction is generated, and the movable portion operates in the X direction.

Since the holder 2 is made of resin, it is difficult to reduce the diameter of the insertion hole 2a. Generally, the limit is about 0.2 to 0.3 mm. Further, if the diameter of the support wire 6 is increased, the springiness of the support wire 6 is strengthened, and the amount of movement of the movable portion with respect to the current flowing through the coil is reduced. Therefore, the diameter needs to be reduced.
Generally, the wire diameter is around 0.1 mm. FIG. 3 is an enlarged sectional view and a left side view of the insertion hole 2a. The diameter of the insertion hole 2a is larger than the diameter of the support wire 6.

[0006]

However, in the above-mentioned conventional configuration, since the diameter of the insertion hole 2a is larger than the diameter of the support wire 6, when the support wire 6 is fixed to the holder 2, as shown in FIG. The support wire 6 freely moves in the insertion hole 2a, and the position in the X and Z directions cannot be accurately determined. For this reason, the four support wires 6 may not be parallel. If the support wire 6 is not parallel, when the movable portion is driven in the X and Z directions, the movable portion tilts and the objective lens 1 tilts. When the objective lens 1 is tilted, the light condensed by the objective lens 1 cannot read the signal recorded on the disc accurately, and the signal deteriorates.

The present invention solves the above-mentioned conventional problems, and an object of the present invention is to provide an objective lens driving device in which the position is accurately determined when the support wire is attached and the objective lens does not tilt even when the movable part is driven. And

[0008]

In order to solve the above-mentioned problems, an objective lens driving device of the present invention comprises a holder to which an optical system including the objective lens is attached, a fixing member, and a space between the holder and the fixing member. The holder and / or the fixed member has an insertion hole for movably supporting the holder with respect to the fixed member, and the holder and / or the fixed member has an insertion hole in which the central axis direction of the insertion hole is the longitudinal direction of the support member. An insertion hole was provided so that it was not parallel to.

[0009]

According to the present invention, when the support wire is fixed to the holder even if the diameter of the insertion hole is larger than the diameter of the support wire, the position of the support wires is accurately determined and the four support wires are parallel to each other. Can be

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An objective lens driving device according to an embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a partially enlarged sectional view and a left side view of an objective lens driving device showing an embodiment of the present invention. The outline of the configuration and operation of the present invention is equivalent to that described in the conventional example of FIG. Although FIG. 1 shows the insertion hole 12a provided in the holder 20, the central axis of the insertion hole 12a is not parallel to the central axis direction of the support wire 6 but is inclined at a constant angle (R in the figure). Therefore, the positions of the support wire 6 in the X and Z directions are accurately determined by the edges of both ends of the insertion hole 12a.

Although the insertion hole 12a provided in the holder 20 is tilted in this embodiment, the same effect can be obtained by tilting the insertion hole 9a provided in the fixing member 9 in FIG.

[0013]

As described above, according to the present invention, by making the longitudinal direction of the support wire and the central axis direction of the insertion hole non-parallel, the parallelism of the support wire is improved and the objective lens driving with good tilt characteristics of the objective lens is achieved. The device is ready.

[Brief description of drawings]

FIG. 1 is a partially enlarged sectional view and a left side view of an objective lens driving device according to an embodiment of the present invention.

FIG. 2 is a perspective view of a conventional objective lens driving device.

FIG. 3 is a partially enlarged sectional view and a left side view of a conventional objective lens driving device.

[Explanation of symbols]

 6 Support Wire 12a Insertion Hole 20 Holder

Claims (1)

[Claims] 1. A holder to which an optical system including an objective lens is attached, a fixing member, and a supporting member attached between the holder and the fixing member and movably supporting the holder with respect to the fixing member. And a driving means for driving the holder, wherein the holder and / or the fixing member has an insertion hole into which the support member is inserted, and the central axis direction of the insertion hole is different from the longitudinal direction of the support member. An objective lens driving device, wherein the insertion hole is provided so as to be parallel to each other.