JPH11312322A - Objective lens drive - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a protector for preventing damage to a disk due to collision with the disk, and to prevent damage to the disk when colliding with the disk, and to cause deformation of the protector by turning over. It is an object of the present invention to provide an objective lens driving device that does not generate the image. SOLUTION: A protector 10 has a shape that does not obstruct a portion serving as an optical path without a half-turn around a disc intruding side, is adhered and fixed to an upper portion of a bobbin substrate of a coil bobbin 2, and when a disc collides, the force due to the rotation direction is maximized. Since the fixed portion is received, the objective lens 1 can be driven without deformation.

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 apparatus used in an optical disk reproducing apparatus for recording and reproducing information recorded on a disk by projecting a laser beam onto the disk.

[0002]

2. Description of the Related Art A conventional objective lens driving device will be described below.

FIG. 3 is an exploded perspective view showing the structure of a conventional objective lens driving device. In FIG. 3, reference numeral 31 denotes an objective lens, and reference numeral 32 denotes a rectangular parallelepiped coil bobbin that holds the objective lens 31. The coil bobbin 32 includes a focus coil 33 at a substantially central portion of a side surface around an axis perpendicular to the disk 46, and two tracking coils 34a around an axis parallel to the disk 46 and on both sides of the objective lens 31, 34b is directly wound. Both ends of the four metal wire springs 36a, 36b, 36c, 36d
Two coil substrates 35 fixed to coil bobbin 32
a and 35b and are fixed by soldering to the holder substrate 37 on the fixed side. As a result, the coil bobbin 32 is cantilevered so as to be movable in two directions of a focus direction 51 and a tracking direction 52. Both ends of the focus coil 33 and both ends of the tracking coils 34a, 34b, which are two continuous coil windings, are connected to the coil substrates 35a, 35b by soldering, and four metal wire springs are provided. 3
Current can be supplied to each coil from 6a, 36b, 36c, 36d. Reference numeral 39 denotes a suspension holder, which includes four metal wire springs 36a and 36a.
In order to determine the positions of b, 36c and 36d, they are held. Reference numeral 38 denotes a silicon-based gel, which is filled in a container provided in the suspension holder 39 and then gelled by irradiation of ultraviolet rays, which brakes the movement of the metal wire springs 36a, 36b, 36c, and 36d. It is.

[0004] Reference numeral 40 denotes a protector, which is formed of silicone rubber and prevents the objective lens 31 from damaging the disk 46 when the movable part including the objective lens 31 moves in the focus direction 51 and collides with the disk 46. The protector 40 has an opening in an optical path, and is fixed to the upper part of the coil substrate 35 of the coil bobbin 32 with an adhesive 41 at two places so as to cover the objective lens 31. Reference numeral 42 denotes an ACT base unit,
A base portion 42a having a plane parallel to the base 6; and a plate-shaped back yoke 4 arranged so as to project from the base portion 42a toward the disk 46 and perpendicular to the disk 46.
2b and 42c are integrally formed. Back yoke 4
One magnet 43a, 43b magnetized in the thickness direction of each of 2b, 42c is closely fixed with the N pole facing each other to form a magnetic gap, and a part of the focus coil 33 and one of the tracking coil 34 are formed. By causing the sections to face each other, the movable section including the objective lens 31 is moved to a focus direction 51 perpendicular to the disc 46,
Tracking direction 52 parallel to disk 46
Can be driven in two directions. 44 is a shield yoke,
Blocks the effects of external magnetism. The suspension holder 39 and the fixed-side holder substrate 37 are attached with mounting screws 45.
Thereby, it is fixed to the back yoke 42b.

In the conventional objective lens driving device having the above configuration,
Since the protector 40 is made of silicone rubber, when the movable part including the objective lens 31 moves in the focus direction 51 and collides with the disk 46, the protector 40
6 can be prevented from being damaged.

[0006]

However, the conventional objective lens driving device as described above has a protector 40.
Since the movable part including the objective lens 31 is fixed to the bobbin 32 with the adhesive 41,
When it hits the disc 46, the protector 40
The surface on the entry side of the disk 46 is connected to the two adhesives 41 with the line connecting the two adhesives 41 fixing the
With the fulcrum as a fulcrum, there is a problem that deformation is caused by turning over.

The present invention has been made in view of the above-mentioned conventional problems, and when a movable portion including an objective lens moves in a focus direction and collides with a disk, it is possible to prevent damage to the disk and prevent deformation of the protector caused by turning over. It is an object of the present invention to provide an objective lens driving device that does not generate any light.

[0008]

In order to solve the above-mentioned problems, an objective lens driving device according to the present invention comprises an objective lens, a rectangular parallelepiped coil bobbin holding the objective lens, and the coil bobbin being moved in a focus direction and a tracking direction. A support member that is cantilevered so as to be movable, a focus coil wound substantially at the center of the side surface of the coil bobbin around an axis perpendicular to the disk, and a coil around the axis parallel to the disk. A wound tracking coil, a protector made of silicon rubber for suppressing an objective lens from being damaged at the time of collision with the disk, a magnet for driving the lens holder, and a coil, and a disk of the protector In this configuration, the disk does not have a half circumference on the rush side in the tangential direction.

Thus, when the movable portion including the objective lens moves in the focus direction and collides with the disk, the objective lens can be driven without damaging the disk and without deforming a part of the protector. An enabled objective lens drive is obtained.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention comprises an objective lens, a rectangular parallelepiped coil bobbin for holding the objective lens, and a piece so that the bobbin can be moved in a focus direction and a tracking direction. A support member for holding and supporting, a focus coil wound around a substantially central portion of a side surface of the coil bobbin about an axis perpendicular to the disc,
A tracking coil wound around the coil bobbin about an axis parallel to the disc, a protector made of silicone rubber for suppressing an objective lens from being damaged at the time of collision with the disc, and a magnet for driving the lens holder And a coil, wherein the protector does not have a half-periphery of the disk in the tangential direction of the disk in the tangential direction of the disk. When the collision occurs, the objective lens is driven without damaging the disk and without deforming a part of the protector.

Hereinafter, an embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG. (Embodiment 1) FIG. 1 is an exploded perspective view showing an objective lens driving device according to Embodiment 1 of the present invention, and FIG. 2 is a perspective view showing an objective lens driving device according to Embodiment 1 of the present invention. 1 and 2, reference numeral 1 denotes an objective lens,
Reference numeral 2 denotes a rectangular parallelepiped coil bobbin that holds the objective lens 1. The coil bobbin 2 includes a focus coil 3 at a substantially central portion of a side surface around an axis perpendicular to the disk 16, and two tracking coils 4 a around an axis parallel to the disk 16 and on both sides of the objective lens 1. 4b is directly wound. Four metal wire springs 6a, 6b, 6
Both ends of c and 6d are soldered and fixed to the two coil substrates 5a and 5b fixed to the coil bobbin 2 and the holder substrate 7 on the fixed side. As a result, the coil bobbin 2 is moved in two directions of the focus direction 51 and the tracking direction 52. It is cantilevered so that it can move in the direction.

The coil substrates 5a and 5b are connected by soldering to both ends of the focus coil 3 and both ends of two tracking coils 4a and 4b which are continuous coil windings. Metal wire springs 6a, 6b, 6
Current can be supplied to each coil from c and 6d. 9 is a suspension holder, 4
The metal wire springs 6a, 6b, 6c, and 6d are held to determine the positions of the springs. Reference numeral 8 denotes a silicon-based gel, which is filled in a container provided in the suspension holder 9 and then gelled by irradiation with ultraviolet rays, and serves to brake the movement of the metal wire springs 6a, 6b, 6c and 6d. Accordingly, the primary resonance vibration of the movable portion including the coil bobbin 2 is damped.

Reference numeral 10 denotes a protector, in which the movable portion including the coil bobbin 2 moves in the focus direction 51 and the disk 1
When the object 6 collides, the disk 16 is prevented from being damaged by the objective lens 1. The protector 10 includes a disc 16
There is no half circumference of the disk 16 on the tangential direction of
It is shaped so as not to obstruct the portion serving as an optical path, and is fixed to the upper part of the coil substrate 5 of the coil bobbin 2 with an adhesive 11 so as to cover the objective lens 1.

Reference numeral 12 denotes an ACT base unit, which has a base portion 12a having a surface parallel to the disk 16;
Plate-like back yokes 12b and 12c are formed integrally with the base portion 12a so as to protrude toward the disk 16 and perpendicular to the disk 16. One magnet 13a, 13b magnetized in the thickness direction on each of the back yokes 12b, 12c is closely fixed with the N poles facing each other to form a magnetic gap, and a part of the focus coil 3 and the tracking coil 4 are formed. The movable part including the objective lens 1 is moved in the focus direction 5
1 and a tracking direction 52 parallel to the disk 16. Reference numeral 14 denotes a shield yoke, which blocks the influence of external magnetism. The suspension holder 9 and the fixed-side holder board 7
5 fixes it to the back yoke 12b.

Since the objective lens driving device having the above-described configuration has no inner yoke, unnecessary portions for driving the focus coil 3 and the tracking coil 4 can be reduced. It is possible to reduce the size and weight, and since a part of the focus coil 3 and the tracking coil 4 is opposed to the magnets 13a and 13b to form a narrow magnetic gap, magnetic flux can be easily concentrated, and the above-described method can be performed with high efficiency. The movable portion including the objective lens 1 is configured to be driven in two directions, a focus direction 51 perpendicular to the disk 16 and a tracking direction 52 parallel to the disk 16.

The operation will be described below. Objective lens 1
Move in the focus direction 51 and the disk 16
It is the portion of the protector 10 that is adhesively fixed that receives the greatest force in the direction of rotation by the disk 16 when colliding. In the tangential direction of the disk 16, the protector 10 does not have a half circumference of the disk 16 on the rush side,
Since it is adhesively fixed to the bobbin 2, the objective lens 1 can be driven without being turned up from this portion and deformed.

[0017]

As described above, according to the present invention, when the movable part including the objective lens moves in the focus direction and collides with the disk, the objective is prevented without damaging the disk and without deforming a part of the protector. The effect that the lens can be driven can be obtained.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing an objective lens driving device according to a first embodiment of the present invention.

FIG. 2 is a perspective view showing an objective lens driving device according to the first embodiment of the present invention.

FIG. 3 is an exploded perspective view showing a conventional objective lens driving device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Objective lens 2 Bobbin 3 Focus coil 4 Tracking coil 10 Protector

Claims (1)

[Claims] 1. An objective lens, a rectangular parallelepiped coil bobbin holding the objective lens, a support member for cantilevering the coil bobbin so as to be movable in a focus direction and a tracking direction, and an axis perpendicular to the disk. A focus coil wound around the center of the side surface of the coil bobbin at the center, a tracking coil wound around the bobbin around an axis parallel to the disc, and an objective lens for suppressing damage at the time of collision with the disc. An objective lens driving device, comprising: a protector formed of silicone rubber, a magnet for driving the lens holder, and a coil, wherein the protector does not have a half-periphery of the disk in the tangential direction of the disk.