JPS6120662Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a holding device for a movable detector in an optical video disc player.

In an optical video disc player, a video disc is read by focusing an optical barrel on the surface of the video disc.
For this purpose, the holding device of the movable detection unit in the optical video disc player holds the optical system barrel movably relative to the video disc in the tracking direction, tangential direction, and focus direction, and the optical system barrel is moved in the tracking direction or in the focusing direction. The beam spot can be aligned with the track on the video disk by swinging in the tangential direction, and can be focused by moving the beam spot in the tangential direction and moving up and down in the focus direction (optical axis direction of the optical system barrel). is being used.

In the conventional holding device, the side wall of the optical system tube is held by a protrusion having a semicircular cross section, so that the optical system tube can move up and down and swing. However, in order to accurately move the optical system tube up and down and swing it, the outer diameter of the optical system tube and the inner diameter of the protrusion must match, which requires time and effort to process the holding device and reduces costs. It is also the cause of the increase. Another drawback was that the accuracy deteriorated due to wear of the contact points due to long-term use.

The present invention was developed in view of these points, and by making use of the elastic deformation of the holding member to swing the optical system tube, it is possible to create a highly accurate and durable optical video camera. An object of the present invention is to provide a holding device for a movable detection section in a disc player.

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view showing a holding device for a movable detector according to the present invention. In the figure, reference numeral 11 is a yoke as a support made of a metal material with high magnetic permeability, and a pole portion 13 having a through hole 12 in the axial direction is formed in the center of this yoke 11.
Further, a ring-shaped magnet 14 is placed and fixed on the outer peripheral surface of the yoke 11, and this magnet 1
A ring-shaped play 15 is tightly attached to the upper surface of the ring 4. Reference numeral 16 denotes a cylindrical optical system tube, which is disposed within the through hole 12 with its axial direction aligned. The optical system tube 16 is held in the middle by a holding member 17 whose side wall portion has a special shape. As shown in FIG. 2, this holding member 17 is made by bending a thin plate and has concave portions 18 and convex portions 19 in four directions, and a through hole 2 in the center.
The holding member 21 has a structure in which a plurality of cross-shaped thin holding members 21 each having a cross-shaped cross-section are connected by a thin plate-like member 22 in multiple stages. The thin plate member 22 is vertically provided vertically from a thin wall portion forming the convex portion 19 of the holding member 21, and is formed to have a thin plate shape toward the center of the holding member 21, and has a positional relationship in which they face each other. It is erected in Further, the respective thin plate members 22 are erected in the upper and lower adjacent stages so that the directions in which they are erected toward the center of the holding member 21 are orthogonal to each other. The holding member 21 and the thin plate member 22 at each stage are integrally formed of synthetic resin such as plastic. The optical system tube 16 is held by a through hole 20 of a holding member 21 so as to be slidable in the focus direction. Further, among the holding members 21, the lower end member 21a is fitted and fixed to the inner wall of the through-hole 12 of the pole portion 13, and the outer diameters of the other holding members are arranged with gaps from the through-hole 12. .

A branch piece 23 is connected and fixed to a part of the optical system tube 16 above the part held by the holding member 17, and around the outer periphery of this branch piece 23, the pole part 13 and the plate 15 are connected. A coil bobbin 24 inserted into the gap is connected. Reference numeral 25 indicates a coil wound around this coil bobbin 24.
Further, a tracking control mechanism 26 is disposed above the location where the branch piece 23 of the optical system barrel 16 is connected and fixed. As shown in FIG. 3, the tracking control mechanism 26 includes a coil 28 wound around the outer periphery of a rectangular cylindrical bobbin 27 disposed on the side surface of the optical system tube 16, and a coil 28 arranged to sandwich the coil 28. A U-shaped yoke 29 and a plate 3 disposed between the bobbin 27 and the yoke 29
0 and a magnet 31.

Next, the operation of the holding device according to the present invention will be explained.

First, when moving the optical system barrel 16 up and down in the focus direction F to focus, a control signal is sent to the coil 25 and the coil bobbin 24 is moved up and down in the axial direction. In this case, the optical system tube 16 slides within the holding member 17.

Next, when the optical system barrel 16 is to be swung in the tracking direction T or the tangential direction (direction orthogonal to the tracking direction T), a control signal is sent to the tracking control mechanism 26 or the tangential control mechanism (not shown). To do this. In this case, due to the elastic deformation of the thin plate member 22, the upper three holding members 21, excluding the lower end holding member 21a, swing in the tracking direction T or the tangential direction, and the optical system cylinder 16 swings.

As described above, according to the present invention, since the optical system barrel 16 is oscillated by elastic deformation of the thin plate-like member 22 without any frictional contact, the accuracy does not deteriorate due to long-term use. Also, the thin plate member 22
are erected in directions perpendicular to each other at each stage, so the optical system tube 16 can be swung in two directions: the tracking direction and the tangential direction. Further, since the holding member 17 is formed in a thin wall shape, it is lightweight, the moment of inertia due to rocking is small, and the response is quick. Therefore, an optical video disc player with good followability can be obtained. Furthermore, the weight of the holding device can be reduced.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of the holding device according to the present invention, Fig. 2
This figure is a perspective view of the optical system barrel holding member, and FIG. 3 is a perspective view showing the tracking control mechanism. 16... Optical system tube, 17... Holding member, 20
...through hole, 21, 21a...thin holding member, 2
2...Thin plate member.

Claims (1)

[Scope of utility model registration request] A holding device for a movable detection part in an optical video disc player that holds an optical system cylinder equipped with an optical system movably in the tracking direction, tangential direction, and focus direction with respect to the video disc, is made of a bent thin plate made of an elastic material. a multi-stage cross-shaped thin holding member having unevenness in four directions and a through hole in the center;
The holding members in the plurality of stages are connected to each other via thin plate-like members erected at positions facing each other toward the center thereof, and each of the thin plate-like members is connected to the holding members in the plurality of stages through the thin plate-like members erected at adjacent stages. 1. A holding device for a movable detection section in an optical video disk player, characterized in that the optical system tube is fitted and held in the through hole, and the optical system tube is fitted and held in the through hole.