JPH026137B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a lens drive mechanism for an optical disk player that is compact and has excellent productivity.

With the development of PCM compact disk players and the like, optical disc players require smaller optical systems, and optical systems that employ semiconductor lasers as light sources and eliminate tracking mirrors have been developed. Such an optical system supports the objective lens so that it can be displaced two-dimensionally with respect to a plane that includes the optical axis, and the amount of displacement is controlled by a control signal, and the structure of the support mechanism and drive mechanism is complicated. This also made assembly work more complicated.

Therefore, in view of the above-mentioned points, the present invention has developed a compact lens support drive that employs a simple assembly structure in which two types of magnetic plates with coil windings are fixed on the same surface of the block and fixed oppositely to the lens support mechanism. This paper aims to propose a mechanism assembly.

Hereinafter, first, the driving principle of the present invention will be explained according to the principle diagram shown in FIG. FIG. 1 is a sectional view showing a state in which the surface of a magnetic plate P on which a coil winding is applied is opposed to the magnetic pole surface (N pole) of a magnet M. As shown in the figure, most of the magnetic flux emitted from the N pole is changed in direction within the magnetic plate P, facing outward along the plate surface, and is directed toward the S pole from the edge, and a small amount of magnetic flux is directed to the S pole from the edge of the magnetic plate P. Penetrate. Therefore, when only the current in the magnetic pole side coil receives a force and the current direction is as shown, the magnetic plate P receives a force in the right direction F ₀ in the figure, and the drag forces the magnet M in the left direction F ₁
drive to. Therefore, the magnet M is displaced along the longitudinal direction of the magnetic plate P according to the current in the coil. The present invention utilizes this driving principle to perform tracking control and focusing control.
FIG. 2 shows a partially exploded perspective view of an embodiment of the invention. In this embodiment, as shown in the figure, one ends of two tracking elastic plates 2a, 2b are adhesively fixed to both left and right side surfaces of a support body 1, so that the plate surfaces are parallel to each other, and the tracking elastic plates 2a, 2b are made to face each other in parallel. A substantially rectangular parallelepiped-shaped intermediate block 3 is adhesively fixed to the other end to support the intermediate block 3 so as to be movable left and right (tracking direction). Furthermore, two elastic plates 4a and 4b for tracking are provided on the upper and lower surfaces of the intermediate block 3.
One end is fixed with adhesive, and a lens support block 5 is fixed with adhesive on the other end of the tracking elastic plates 4a, 4b, and the lens support block 5 is supported so as to be movable in the vertical direction. A light passage hole (not shown) is formed in the lens support block 5, and a lens barrel 6 in which an objective lens (not shown) is inserted is fixed onto the hole. A pair of focusing magnets 7, 7 having magnetic poles formed on the front and rear surfaces are fixed to the lens supporting block 5, and a tracking magnet 8 having magnetic poles formed on the front and rear surfaces is fixed to the right end of the lens support block 5. In this embodiment, such a lens support mechanism is assembled by adhesive.

This embodiment is characterized by the arrangement of drive mechanisms that drive this lens support. That is, in this embodiment, the direction of magnetization of the focusing magnet and the tracking magnet is perpendicular to the direction of displacement of the objective lens,
The magnetic plate can be fixed on the same surface of the fixed block. Therefore, in the drive mechanism of this embodiment, a pair of fixing blocks 9a and 9b are formed by coil windings on their opposing surfaces before they are fixed oppositely to the magnetic poles, focusing magnetic plates 10a and 10b and tracking magnetic plates 11a and 11b. The focusing coil windings C _f and C _f wound around the focusing magnetic plates 10 a and 10 b connect the focusing magnetic plates 10 a and 10 b so that a focusing control current flows in the tracking direction. The tracking coil windings C t and C t wound around the tracking magnetic plates 11a and 11b are placed upright and bonded together, and the tracking coil windings C _t and C _t are wound around the tracking magnetic plates 11a and 11b so that a control current flows in the focusing direction. is glued and fixed horizontally, and after both magnetic plates are glued and fixed, the fixing block 9a,
Assembly is completed by simply fixing 9b facing the magnetic pole surface. Therefore, according to the present invention, the lens support block is supported by two pairs of elastic plates whose surfaces are orthogonal to each other to constitute the lens support mechanism, and the focusing direction and the tracking direction are orthogonal to each other as the magnetization direction. The lens drive mechanism is constructed by fixing two types of magnets to the lens support block and opposing two types of magnetic plates with different coil winding directions on the opposite sides of the magnetic poles. It is possible to support and drive it, and it is easy to assemble, which has great effects.

[Brief explanation of drawings]

FIG. 1 is a diagram illustrating the driving principle of the present invention, and FIG. 2 is a partially exploded perspective view of a mechanism according to an embodiment of the present invention. Explanation of main drawing numbers 2a, 2b...Elastic plate for tracking, 3...Intermediate block, 4a, 4b...
Focusing elastic plate, 5... Lens support block, 7a, 7b... Focusing magnet, 8
...Tracking magnet, 10a, 10b...Magnetic plate for focusing, 11a, 11b...Magnetic plate for tracking.

Claims (1)

[Claims] 1. An elastic plate for tracking that has one end fixed to a support and forms a surface perpendicular to the tracking direction;
an intermediate block fixed to the other end of the tracking elastic plate; a focusing elastic plate having one end fixed to the intermediate block and forming a surface perpendicular to the focusing direction; and a focusing elastic plate fixed to the other end of the focusing elastic plate. A lens support block that fixes an objective lens; a focusing magnet and a tracking magnet that are fixed to the lens support block and form magnetic pole surfaces in a direction perpendicular to the focusing direction and the tracking direction; and a focusing magnet that faces the lens support block. a fixed block having opposing surfaces parallel to the tracking direction and the tracking direction; a focusing magnetic plate facing the focusing magnet and having a focusing coil wound in the tracking direction and fixed to the opposing surface; A lens support drive mechanism assembly for an optical disc player, comprising a tracking magnetic plate facing a magnet and having a tracking coil wound in the focusing direction and fixed to the opposing surface.