JPS5862832A - Lens driving mechanism of optical disk player - Google Patents

Abstract

PURPOSE:To make a titled mechanism small-sized, and to simplify its assembly, by fixing a magnet to a lens supporting block which is supported so as to be freely displaceable in the two-dimensional direction, and orthogonally winding a coil winding to its opposed magnetic plate. CONSTITUTION:To both left and right sides of a supporting body 1, one end of tracking elastic plates 2a, 2b is made to adhere and fixed, the plate surfaces are opposed in parallel, and to the other end of these elastic plates 2a, 2b, an almost rectangular parallelepiped-like intermediate block 3 is made to adhere and fixed, and the intermediate block 3 is supported so as to be displaceable to the left and right. Also, to the upper surface and the lower surface of this intermediate block 3, one end of 2 tracking elastic plates 4a, 4b is made to adhere and fixed, and to the other end of these elastic plates 4a, 4b, a lens supporting block 5 is made to adhere and fixed, the lens supporting block 5 is supported so as to be displaceable in the upper and lower directions, too, and on the lens supporting block, a through-hole for passing in advance is formed, a lens tube body 6 into which an objective lens has been inserted is fixed onto the through-hole, a pair of focusing magnets 7, 7 are fixed to both sides of the through-hole, and a tracking magnet 8 is fixed to the right end of the block 5.

Description

DETAILED DESCRIPTION OF THE INVENTION - The present invention relates to a lens drive mechanism for an optical disc player that can be miniaturized.

Optical disc players [, with the development of POM compact disc players, etc., smaller optical systems are becoming a necessity, and along with the adoption of semiconductor lasers as light sources]
Optical systems that eliminate racking mirrors have been developed.

In such an optical system, the objective lens can be freely displaced two-dimensionally in a plane including the optical axis, and the amount of the objective lens can be controlled by control signals. At the same time, the assembly work was also complicated.

Therefore, the present invention provides two winding directions in which the magnetic plate is wound in different directions.
The purpose of this paper is to propose a simple lens drive mechanism of II configuration in which tracking control and focusing control are performed using a set of coils.

Hereinafter, first, the driving principle of the present invention will be explained according to the principle diagram shown in FIG. Figure 1 shows the magnetic pole face (N pole) K of the grinding stone (M).
This is a cross-sectional view of a magnetic plate (P) on which coil windings are woven, with the plate surfaces facing each other. As shown in the figure, most of the magnetic flux emitted from the N pole is changed in direction within the magnetic plate (P), and is directed outward along the plate surface and from the edge of the magnetic plate (P).
It rotates around the pole, and a small amount of magnetic flux penetrates the magnetic plate.

Therefore, if only the current in the coil facing the magnetic pole side receives force and the current direction is as shown in the figure, the magnetic plate (P) will be placed on the right side (
Fo), and the drag force drives the magnet (M) to the left (Fl). Therefore, the magnet (M) is displaced in a direction parallel to the surface of the magnetic plate (P) and orthogonal to the coil winding in accordance with the coil current. Therefore, the present invention uses this principle to make the coil winding perpendicular to the magnetic plate in order to drive the magnet two-dimensionally.

FIG. 2 shows a partially exploded perspective view of an embodiment of the invention. Book? In the example, both the left and right sides of the support (1) <
1Ilfi 12 tracking elastic plates (2a) (2
One end of b) is adhesively fixed so that the plate surfaces are parallel to each other, and a substantially rectangular parallelepiped-shaped intermediate block (3) is adhesively fixed to the other end of the tracking elastic plates (2a, 2b) to form the intermediate block ( 3) is supported so as to be movable left and right (in the tracking direction).Furthermore, one end of two tracking elastic plates (da) and (4b) are adhesively fixed to the upper and lower surfaces of this intermediate perock (3). This tracking elastic plate (4a
) (db) A lens support block (5) is adhesively fixed to the other end of the lens support block (5) to support the lens support block (5) so as to be movable in the vertical direction. The lens support block (5)
The hole for light passage (not shown) is shaped like 1! t (lens cylinder body (6
) is fixed, and a pair of focusing magnets (7) + that form KFi magnetic poles on the front and rear surfaces of both the front and rear sides of the through hole.
71 is fixed, and at the right end of the lens support block (5) there is a tracking magnet (8) forming magnetic poles on the front and rear surfaces.
is fixed.0 In the non-implemented example, such a lens support mechanism is assembled by adhesive. The magnetic plate can be fixed on the same surface of the Therefore, the drive mechanism of the unexamined example includes a pair of magnetic plates (10a) (10b) for focusing, each of which has a coil winding on its opposing surface before fixing the pair of fixed blocks (9a) (9b) facing each other to the magnetic poles. and tracking magnetic plates (11a) (11b) are adhesively fixed to the tracking magnetic plates (+0a) (1).
0b) is wound on the coil winding (c
f) (cf) is the focusing plate (10a) so as to flow a focusing control current in the tracking direction.
(10b) is made to stand upright, and the tracking magnetic plate (11a) l'l 1. b)
Tracking coil winding (Ct) (C
In t), the tracking magnetic plates (11a) (N'b) are adhesively fixed during interpolation so that a control current flows in the focusing direction, and after both magnetic plates are adhesively fixed and fc, the fixed block (9a) ( Assembly is completed by simply fixing 9b) facing the magnetic pole surface.In addition, in this embodiment described above, two pairs of magnetic plates each having a magnet and a winding wire are provided, but 7 It goes without saying that the driving mechanism may be formed as a pair by applying a casing coil winding and a tracking coil winding, and that such a configuration is included in the present invention.As described above, according to the present invention, 2 By fixing a magnet to a lens support block that is supported so as to be freely displaceable in a dimensional direction, and winding the coil winding orthogonally on the opposing magnetic plate, the magnet can be driven parallel to the surface of the magnetic plate. With the simplification of the design, assembly becomes easier, which greatly contributes to miniaturization.

[Brief explanation of drawings]

Fig. 1 is a detailed explanatory diagram of the present invention, and Fig. 2 is a partially exploded perspective view of an actual winding mechanism of the present invention.0 Explanation of main figure numbers +5110. Lens support block, (7a) (7b)・
... (for focusing) magnet, (8) ... (for tracking) magnet, (10a) (10b) ・= (for focusing) magnetic plate, (11a) (11b) = () magnetic plate for racking, (Cf) (Cf)...Focusing coil, (Ct)(Ct)...Tracking coil.

Claims (1)

[Claims] fil A lens support block that supports the objective lens movably in the focusing direction and the tracking direction, a grinding stone that is fixed to the lens support block and forms a magnetic pole on a surface including the focusing direction and the tracking direction, and a plate surface facing the magnetic pole. An optical system consisting of a magnetic plate fixed to the magnetic plate, a tracking coil winding wound around the magnetic plate in the focusing direction, and a focusing coil winding wound around the magnetic plate in the tracking direction. Lens support drive Il structure of type disc player 0