JPS6120660Y2 - - 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.
To this end, 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 held movably in the tracking direction, tangential direction, and focus direction. It is possible to align the beam spot with the track on the video disk by swinging it in the tangential direction, and to adjust the focus by moving it in the tangential direction and moving it up and down in the focus direction (optical axis direction of the optical system tube). It is being done.

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 an optical system with good precision and durability. An object of the present invention is to provide a holding device for a movable detector in a video 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 plate 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 disposed within the through hole 12 using a holding member 17 made of synthetic resin such as plastic. As shown in FIG. 2, this holding member 17 includes a plurality of ring-shaped members 19a each having a through hole 18,
19b and 19c are connected in multiple stages via a thin plate member 20. The thin plate members 20 are each formed to have a thin plate shape in the radial direction, and are erected in positions facing each other, and the thin plate members 20 are erected in upper and lower adjacent stages. The radial directions are perpendicular to each other. The optical system tube 16 is
It is held in the through hole 18 of this holding member 17 so as to be slidable in the focus direction. Further, among the ring-shaped members, the lower end member 19c is fitted and fixed to the inner wall of the through hole 12 of the pole portion 13, and the other member 19c
a and 19b have a gap with respect to the inner wall of the through hole 12.

A branch piece 21 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 21, the pole part 13 and the plate 15 are connected. A coil bobbin 22 inserted into the gap is connected. Reference numeral 23 indicates a coil wound around this coil bobbin 22.
Further, a tracking control mechanism 24 is disposed above the location where the branch piece 21 of the optical system barrel 16 is connected and fixed. As shown in FIG. 3, the tracking control mechanism 24 includes a coil 26 wound around the outer periphery of a rectangular cylindrical bobbin 25 disposed on the side surface of the optical system tube 16, and a coil 26 arranged to sandwich the coil 26. A U-shaped yoke 27 and a plate 2 disposed between the bobbin 25 and the yoke 27
8 and a magnet 29.

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 23 and the coil bobbin 22 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 perpendicular to the tracking direction T), a control signal is sent to the tracking control mechanism 24 or the tangential control mechanism (not shown). Do it by doing this. In this case, the ring-shaped members 19a, 19b, 19c swing in the tracking direction T or the tangential direction due to the elastic deformation of the thin plate-shaped member 20, and the optical system cylinder 16 swings.

As described above, according to the present invention, since the optical system barrel 16 swings by elastic deformation of the thin plate-like member 20 without frictional contact, the accuracy does not deteriorate due to long-term use. Also, the thin plate member 2
0 are provided upright in directions perpendicular to each other at each stage, so that the optical system tube 16 can be moved in the tracking direction,
It can be swung in two tangential directions.

In this embodiment, the holding member 17 has three stages, but the number of stages may be further increased.

[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 an external perspective view of the holding member for the optical system barrel, and FIG. 3 is a perspective view showing the tracking control mechanism. 16... Optical system tube, 17... Holding member, 18
...Through holes, 19a, 19b, 19c, 19d...
...Ring-shaped member, 20... Thin plate-like member.

Claims (1)

[Scope of utility model registration request] A holding device for a movable detection unit in an optical video disc player that holds an optical system tube equipped with an optical system movably in the tracking direction, tangential direction, and focus direction with respect to the video disc. The holding member is provided with a ring-shaped member having a plurality of stages of through holes connected through a thin plate-like member having elasticity, and the thin plate-like member has thin plate-like members erected in adjacent stages. 1. A holding device for a movable detection unit in an optical video disk player, characterized in that the holding member is erected in such a manner that its radial directions are orthogonal to each other, and an optical system cylinder is fitted into a through hole of the holding member.