JPH03134826A - Mirror rotation driving device - Google Patents

Abstract

PURPOSE:To speedily access the required information of an optical disk by composing an elastic member, which supports the holder of a mirror to a base, of a lead spring and setting the surface direction of the leaf spring almost at 45 deg. to the surface of the mirror. CONSTITUTION:A mirror 1 is fixed to a holder 2 and near the both ends of the holder 2, two leaf springs 3 are arranged. Then, the other end is fixed to a base 4. The leaf spring 3 is set so that the surface direction can be almost at 45 deg. to the surface of the mirror 1, namely, so that the surface direction can be equal with the surface direction of an optical disk 10. Thus, When such a mirror rotation driving device is moved in the surface direction of the optical disk at high speed, a resonance frequency to be excited by inertia force can be sufficiently increased so that any trouble can not be generated in control operation, and the required information of the optical disk is exactly and speedily accessed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a mirror rotation drive device used in an optical information recording/reproducing device or the like.

(Prior Art) As is well known, many optical information recording devices, image copying devices, image output devices, etc. incorporate rotatable mirrors. For example, in the reproduction system of an optical information recording device (optical disk device), a laser beam is deflected by a deflection splitter and a phase plate.

The light is irradiated onto the optical disc via a rotatably provided mirror, objective lens, etc. Then, the reflected light from the optical disk is guided through a path opposite to the above-mentioned path, and reproduced signals are separated by a deflection beam splitter. The position of the objective lens is controlled by a focusing control system and a tracking control system.

Then, the playback signal is used to detect the deviation of the center hole of the optical disk and the eccentricity of the disk clamp mechanism, and this detection signal is used to control the rotation angle of the rotatable mirror described above, so that the light beam is accurately Fine tracking control is performed to follow a single track.

A conventional mirror rotation drive device is shown in FIG. As shown in the figure, a holder 102 that holds a mirror 101 for reflecting a light beam, a hinge 1-03 that rotatably supports this holder 102, and a fixing member 104 that fixes this hinge 103. , a coil 105 fixed to the holder 102, and a magnetic circuit 106 that applies a magnetic field to the coil 105. By energizing the coil 105, the holder 1.02 can be rotated about the hinge 103, and the mirror 101 can be rotated by a minute amount to a desired angle.

Generally, it is necessary to narrow down the spot of the light beam to a small spot for the information on the optical disk surface, so the optical axis of the objective lens 202 is set at 90 degrees with respect to the surface of the optical disk 201, as shown in FIG. It is being said. Further, the mirror 101 is set at a direction of 45 degrees with respect to the surface of the optical disk 201, since the reflection of the light beam is generally controlled at angles of 90 degrees. Since the axial center line of the hinge 103 coincides with the normal direction of the mirror 101, the hinge 1
The axis center line of 03 is 45 degrees with respect to the optical disk 201 surface.
It is set in the ° direction.

However, the mirror rotation drive device having such a configuration has the following problems.

Mirrors used in optical disk devices must have their primary natural frequency set to an appropriate value in order to obtain appropriate drive sensitivity (rotational drive amount per unit current force) in the low frequency range. , it is necessary to set the bending rigidity of the hinge low. However, if the configuration described above is adopted, the center line of the hinge forms an angle of 45° with respect to the surface of the optical disc, so when the movable part moves parallel to the surface of the optical disc, it will deform as shown in Figure 7. Therefore, the bending rigidity in this mode becomes low.

When a mirror rotation drive device with such a configuration is moved at high speed in the in-plane direction of the optical disk, vibration in the above mode is excited by the inertia force in the in-plane direction of the optical disk acting on the mirror rotation drive device, and the movement is accurate and quick. This will interfere with the tracking operation.

(Problems to be Solved by the Invention) As described above, in the conventional mirror rotation driving device, there is a limit to the ability to move the mirror at high speed because it is necessary to set the mirror at an angle of 45 degrees with respect to the optical disk surface. The present invention was made to solve these problems, and it is possible to move the mirror at high speed without the influence of harmful resonance, thereby making it possible to accurately and quickly access the necessary information on the optical disk. The object of the present invention is to provide a mirror rotation drive device that has the following features.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the object described above, the present invention includes a mirror that guides a light beam to a predetermined position on an optical disk, a holder that holds this mirror, In a mirror rotation drive device having an elastic member that supports the holder with respect to the base, and a drive means that rotates the mirror around the elastic member, the elastic member is constituted by a plate spring, and the elastic member is composed of a plate spring. The surface direction was set at approximately 45° with respect to the mirror surface.

It also includes a mirror that guides the light beam to a predetermined position on the optical disk, a holder that holds this mirror, an elastic member that supports this holder with respect to a base, and a driving means that rotates the mirror around this elastic member. In the mirror rotation drive device having the above, the elastic member is constituted by a plate spring, and the plane direction of the plate spring is set to be substantially equal to the plane direction of the optical disc.

(Function) With the above configuration, harmful resonance does not occur even if the mirror is moved at high speed in the in-plane direction of the optical disk. Further, even if the rigidity of the elastic member is lowered, it is possible to achieve higher speeds than before.

Therefore, a mirror rotation drive device is provided that allows accurate and quick access to necessary information on an optical disc.

(Example) Hereinafter, the present invention will be explained based on the drawings.

1 to 4 are a perspective view, a side view, and a sectional view showing an embodiment of a mirror rotation drive device according to the present invention. As shown in the figure, in the mirror rotation drive device of this embodiment, a mirror 1 is fixed to a holder 2 (movable body).

Two leaf springs 3 (elastic members) are arranged near both ends of the holding body 2, and the other end is fixed to the base 4. In other words, the holder 2 is elastically supported by the base 4.

Note that the plate spring 3 has a surface direction of 4 with respect to the mirror 1 surface.
It is set to be 5°. In other words, the plate spring 3 is set so that its surface direction is equal to the surface direction of the optical disc 10.

Further, here, the leaf spring 3 is made of metal.

On the other hand, a coil 5 is wound and fixed around the holder 2, and a magnetic field is applied by a permanent magnet 6 fixed to the base 4 with the magnetization direction directed in the direction shown in FIG. ing. In the mirror rotation drive device shown here, a member with high magnetic permeability such as a yoke is not used as a means for guiding the magnetic flux from the permanent magnet 6, and the flow of magnetic flux coming out from the N pole of the permanent magnet 6 is used in the device. A magnetic path is formed that passes through the outside of the pole and returns to the south pole. Further, the arrangement is such that a part of the coil 5 is always included in the magnetic path no matter what position the holder 2 moves around the leaf spring 3.

In the mirror rotation drive device configured as described above, the coil 5
By energizing, a Lorentz force is generated in the holder 2 due to the relationship between the current and magnetic flux, and the holder 2 is minutely rotated around the leaf spring 3, positioning the mirror 1 at a desired angle. . As a result, the light beam irradiated from the laser light source is reflected by the mirror 1 at a predetermined reflection angle,
This light beam can be guided to a predetermined position on the optical disc 10.

Here, as described above, the plate spring 3 is set so that its surface direction is 45 degrees with respect to the surface of the mirror 1, that is, the surface direction is set to be equal to the surface direction of the optical disc 10. In this way, the surface direction of the leaf spring 3 coincides with the moving direction of the movable body.

Generally, a thin structural part such as a leaf spring has extremely high rigidity in the plane direction compared to the rigidity in bending deformation.

Therefore, even if the bending rigidity of the leaf spring 3 is reduced, the deformation in the mode in which the movable body moves in the in-plane direction of the optical disc 10 is in the in-plane direction, so that extremely high rigidity can be obtained compared to bending deformation.

When such a mirror rotation drive device is moved at high speed in the in-plane direction of the optical disk, it is possible to raise the resonance frequency of the above mode excited by inertial force to a sufficiently high level without interfering with the control operation. The speed of movement of the robot can be easily increased.

Thus, a mirror rotation drive device is realized that allows accurate and quick access to the necessary information on the optical disc.

[Effects of the Invention] As described above, the mirror rotation drive device of the present invention can accurately record necessary information on an optical disc more than ever before.
will be able to access quickly.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an embodiment of the mirror rotation drive device of the present invention, FIG. 2 is a side view of the same embodiment, and FIG. 3 is the 1-A) J! 4 is a sectional view taken along line B-B in FIG. 1, FIG. 5 is a sectional view showing a conventional mirror rotation drive device, FIG. 6 is a schematic diagram showing light beam reflection control, and FIG. The figure is a sectional view showing a deformed state of the hinge when a conventional mirror rotation drive device is moved. 1... Mirror 2... Holder 3... Elastic member (plate spring) 4... Base 0 1 0... Optical disc

Claims (2)

[Claims] (1) A mirror that guides a light beam to a predetermined position on an optical disk, a holder that holds the mirror, an elastic member that supports the holder with respect to a base, and a rotational drive of the mirror around the elastic member. A mirror rotation drive device comprising: a drive means; wherein the elastic member is a plate spring, and the plane direction of the plate spring is set at approximately 45° with respect to the mirror surface. . (2) A mirror that guides a light beam to a predetermined position on an optical disc; a holder that holds the mirror; and an elastic member that supports the holder relative to a base; a drive unit that rotates the mirror around the elastic member; A mirror rotation drive device comprising the following: The elastic member is made of a plate spring, and the plane direction of the plate spring is set to be substantially equal to the plane direction of the optical disc.