JPS6312412Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an optical head used in optical information reading devices and the like.

Optical heads for use in various of the above-mentioned devices have been proposed in the past. An example is shown in FIG. A focusing lens 3 for focusing the light beam 2 on the surface of the information medium A is fixed to the hollow lens holding tube 1, and the lens holding tube 1 is a frame provided with a light source (not shown) that emits the light beam 2. The upper and lower parts of the body 4 are supported by elastic thin plates 5a and 5b that are movable in the direction of the optical axis of the focusing lens 3. Further, a solenoid coil 6 is wound around the outer periphery of the lower end of the lens holding tube 1, and a protrusion 7a of an inverted T-shaped electromagnetic yoke 7 is inserted into the inside of the lens holding tube 1 so as to correspond to the solenoid coil 6. In addition, a magnet 8 is arranged outside the lens holding cylinder 1 at a position relative to the solenoid coil 6, thereby providing a control mechanism that keeps the distance between the focusing lens 3 and the information medium A constant. An electromagnetic body 10 consisting of the magnet 8, the electromagnetic yoke 7, a housing 9 for fixing these, etc. is fixed to the lower part of the frame 4.
A long screw 11 is screwed into the protrusion 7a of the electromagnetic yoke 7 from below, and a reflective mirror body 12 is fixed to the upper end of the long screw 11. A light beam 2 emitted from a light source provided on the side of the lens is deflected toward the focusing lens 3. The frame 4 is provided on a support 13 via an elastic column 14 so as to be movable in a track access direction parallel to the surface of the information medium A, and is operated by a drive device (not shown).

In this conventional device, an electromagnetic body 10 including a magnet 8 and a reflective mirror body 12 are fixed to a frame 4,
When the frame 4 is moved in the track access direction to perform tracking control, the electromagnetic body 10 and the reflective mirror body 12 move together with the frame 4.
It was heavy and had problems with responsiveness. In particular, the magnet 8 constituting the electromagnetic body 10 cannot be replaced with a lightweight material unlike other constituent members, which is one problem in reducing the weight of a driven part in tracking control.

In view of the above points, it is an object of the present invention to provide an optical head that improves the responsiveness of tracking control by reducing the weight of the driven part in tracking control.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. In the drawings, members having the same functions as those in FIG. 1 are designated by the same reference numerals. The feature of this embodiment is as follows.

The right end of the frame 4 is provided on the support 13 so as to be movable around the support shaft 15 in the track access direction parallel to the information medium A surface, while the left end is fixed to the end of the support 13. It is supported by elastic columns 17a and 17b provided on the inner wall of the receiving body 16. The frame body 4 is tracked by a drive device (not shown). Further, an electromagnetic body 10 is provided at a position facing the solenoid coil 6 provided in the lens holding cylinder 1.
is fixed to the through hole 18 portion of the support body 13. Therefore, when the reflecting mirror body 12 is fixed on the electromagnetic body 10 as in the conventional device described above, even if the frame body 4 moves during tracking control, the electromagnetic body 1
0 is immovable because it is fixed to the support body 13, so the reflection mirror body 12 of the light beam 2 inside the frame body 4
This causes the inconvenience that the irradiation angle relative to the object changes. Therefore, in this embodiment, the reflective mirror body 1
2 is fixed to the end of a fixed body 19 located between the elastic thin plates 5a and 5b and extending inward from the side of the frame 4. The inconvenience has been resolved. That is,
Since the fixed body 19 moves together with the frame 4 provided with the light source during tracking control, the fixed body 19
The irradiation angle of the light beam 2 emitted from the light source with respect to the reflecting mirror body 12 fixed to the mirror body 12 does not change.

In the above embodiment, the reflecting mirror body 12 is fixed to the fixed body 19, but as shown in FIG.
Opposite wall 1 of receiver 16 fixed to the end of support 13
The left end of the fixed body 19 is inserted between 6a and 16b, and the reflection mirror body 12 is fixed to the right end, so that between the left end of the fixed body 19 and the opposing walls 16a and 16b. , elastic columns 17a, 17
It is also possible to simplify the component parts by interposing b.

The present invention is constructed as described above, and in particular, an electromagnetic body consisting of a magnet and an electromagnetic yoke facing a solenoid coil portion provided in a lens holding tube is fixed to a support body, and an electromagnetic body is fixed to a support body, and is provided in the upper and lower parts of the lens holding tube. A reflective mirror body that deflects the light beam emitted from the light source provided in the frame toward the focusing lens is provided between the elastic bodies on the fixed body extending inward from the side of the frame body. The heaviest electromagnetic body in the head is fixed to a support to drive the frame for tracking, and the reflective mirror body is provided on the side of the frame, so there is no adverse effect on the deflection and reflection of the light beam. It is possible to provide an optical head with a lightweight frame and improved tracking control responsiveness.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view showing an example of a conventional optical head, FIG. 2 is a partial sectional view showing a first embodiment of the present invention, and FIG. 3 is a partial sectional view showing a second embodiment of the present invention. FIG. 1...Lens holding tube, 2...Light beam, 3...
Focusing lens, 4...frame body, 5a, 5b...elastic body,
6... Solenoid coil, 7... Electromagnetic yoke, 8
... Magnet, 10 ... Electromagnetic body, 12 ... Reflection mirror body, 13 ... Support body, 19 ... Fixed body, A ... Information medium.

Claims (1)

[Scope of utility model registration request] The upper and lower parts of a lens holding tube 1 to which a focusing lens 3 for focusing the light beam 2 on the information medium A is fixed are attached to elastic bodies 5a and 5b so that the lens holding tube 1 can move in the optical axis direction of the focusing lens 3. The frame 4 is mounted on a support 13 so as to be movable in a track access direction parallel to the information medium surface A, and the solenoid provided on the lens holding cylinder 1 is mounted on the support 13. Magnet 8 facing coil 6 part
An electromagnetic body 10 consisting of an electromagnetic yoke 7 and the like is fixed, and the light beam 2 emitted from the light source provided on the frame body 4 is focused between elastic bodies 5a and 5b provided on the upper and lower parts of the lens holding cylinder 1. An optical head characterized in that a reflecting mirror body 12 for deflecting in the direction of a lens 3 is provided on a fixed body 19 extending inward from a side portion of the frame body 4.