JPH05113530A - Driving device for rotary reflection mirror - Google Patents

Abstract

PURPOSE:To obtain a device for driving a rotary reflection mirror in which the optical distortion of a reflecting surface caused at the time of attaching a reflection mirror is reduced and the positional deviation of the reflection mirror by centrifugal force is prevented. CONSTITUTION:A groove is formed on the reflection mirror attaching surface of a rotary boss 9, so that the adhesive area of the reflection mirror 10 is made small and the back face out of the effective range of the reflection mirror 10 is stuck. By providing a wall surface which is in parallel with the rotary center axis 1 and in contact with the reflection mirror 10 without gap, the adhesive area is reduced and the entire optical distortion of the reflection mirror 10 is reduced. The adhesive surface of the reflection mirror is positioned out of the effective range of a light beam, so that the effect of the distortion given to the effective range is decreased even when the distortion occurs in the adhesive part. Furthermore, even though the centrifugal force acts, the reflection mirror 10 does not rise and the deviation of the reflected light of the light beam is prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary mirror driving device used for scanning a light beam.

[0002]

2. Description of the Related Art Conventionally, as a mirror surface used for scanning a light beam, a surface of a metal such as aluminum has been mirror-finished and a surface protection treatment such as silicon dioxide has been carried out. Special equipment such as vapor deposition is required.
Therefore, a method of fixing a reflecting mirror made of inexpensive glass or the like by adhesion or the like has attracted attention.

A conventional rotary reflecting mirror driving device will be described below. FIG. 3 shows an example of a conventional rotary mirror driving device.

In FIG. 3, 1 is a rotary shaft, 2 and 3 are ball bearings, 4 is a bracket, 5 is a printed circuit board, and 6 is a coil which is fixed to the printed circuit board. Reference numeral 7 is a magnet, and 8 is a rotating yoke which fixes the magnet 7. Reference numeral 39 denotes a rotary boss which is fitted and fixed to the rotary shaft 1 and also fixes the rotary yoke 8. Reference numeral 10 is a reflecting mirror, 11 is a spring, 12 is a washer, and 13 is a retaining ring, and preload is applied to the ball bearings 2 and 3.

The operation of the rotary reflecting mirror driving device constructed as described above will be described below. First, when a current flows through the coil 6, a magnetic field is generated, a driving force is applied to the opposing magnet 7 to rotate the rotating boss 39 and the reflecting mirror 10, and the light beam emitted from above is reflected in the lateral direction for scanning. .. The reflecting mirror 10 is surface-bonded and fixed to the inclined surface of the rotary boss 39.

[0006]

However, in the above-mentioned conventional structure, the reflecting mirror made of a material such as glass, which is an adhesive, is generally subjected to thermal expansion of the rotary boss made of a material, such as metal or resin, which is an adherend. Since the ratio is smaller than the ratio, the adhesive is hardened in a state in which the adherend is significantly expanded due to heating and temperature rise at the time of adhesion. It caused optical distortion in the reflector. In addition, when the adhesive changes, the reflecting mirror itself slightly rises due to centrifugal force and causes a position shift, and there is a problem that the reflected light of the light beam does not reach the point where it is originally reflected. ..

An object of the present invention is to solve the above-mentioned problems of the prior art, and to provide a rotary reflecting mirror driving device in which the optical distortion of the reflecting mirror due to adhesion is reduced and the fixed position of the reflecting mirror does not change.

[0008]

In order to achieve this object, a rotary reflecting mirror driving device of the present invention is provided with a groove on the reflecting mirror mounting surface to reduce the bonding area of the reflecting mirror, and at the same time the outer surface of the effective range of the reflecting mirror. The back surface of the is adhered, and a wall surface that is parallel to the central axis of rotation and is in contact with the reflecting mirror is provided.

[0009]

With this configuration, the entire surface of the reflecting mirror is changed from partial bonding to partial bonding, and the bonding area is reduced, so that the overall optical distortion of the reflecting mirror is reduced, and the bonding surface of the reflecting mirror is out of the effective range of the light beam. Even if the adhesive is distorted, the effect on the effective range can be reduced by locating it at, and even if centrifugal force acts, the reflecting mirror does not rise and the deviation of the reflected light of the light beam is eliminated. be able to.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a structural diagram of a rotary reflecting mirror driving device according to an embodiment of the present invention. The same components as those in the conventional example are designated by the same reference numerals and the description thereof will be omitted. 2 is an exploded perspective view and a partial cross-sectional view of the rotary boss 9 and the reflecting mirror 10.

In FIGS. 1 and 2, 14 and 16 are convex portions on the inclined surface of the rotary boss 9, and 15 are concave portions (grooves) on the inclined surface of the rotary boss 9, and 14, 15 and 16 are geta-like irregularities. Make up. Reference numeral 17 is a reflecting mirror positioning convex portion of the rotary boss 9, and has a wall surface 19 parallel to the central axis of rotation. Reference numeral 18 denotes an effective range where the optical beam of the reflecting mirror 10 hits.

The function of the rotary reflecting mirror driving device configured as described above will be described with reference to FIGS. 1 and 2.

First, the reflecting mirror 10 is fixed by applying an adhesive only to the convex portions 14 on the inclined surface of the rotary boss 9. Centrifugal force acts in the direction in which the reflecting mirror 10 itself rises during rotation, but a force that presses the reflecting mirror 10 is applied to the convex portion 16, so that centrifugal force is applied even if no adhesive is applied to the convex portion 16. On the other hand, the reflecting mirror 10 is difficult to move. Also, the convex portion 1
Since only 4 partial surfaces are bonded, heating during bonding,
The optical distortion caused by the temperature rise can be reduced. Further, even if a slight distortion occurs due to a temperature change or the like, it is possible to reduce the influence on the effective range 18 hit by the optical beam, and the degree of security is high. Furthermore, wall surface 1
Since 9 and the reflecting mirror 10 are in close contact with each other, the reflecting mirror 10 does not rise even if centrifugal force acts when the adhesive changes, and the reflected light of the light beam is displaced. It doesn't end up.

[0015]

As described above, according to the present invention, the slopes on which the reflecting mirrors are mounted are provided with the grooves forming the geta-like irregularities, and the adhesive is applied only to the convex surface below the slopes, and the reflection on the coated surface is achieved. Make sure that the mirror surface is located outside the effective range for light beam irradiation,
Further, by providing a positioning convex portion having a wall surface parallel to the central axis of rotation further below the adhesive convex portion surface below the slope, and by adopting a structure in which the reflecting mirror and the parallel wall surface of the positioning convex portion are in close contact with each other. As a result, it is possible to realize an excellent rotary reflecting mirror driving device that can reduce the optical distortion of the reflecting mirror surface and suppress the displacement of the reflected light surface due to the centrifugal force.

[Brief description of drawings]

FIG. 1 is a structural diagram of a rotary reflecting mirror driving device according to an embodiment of the present invention.

FIG. 2A is a partially exploded perspective view of a rotary reflecting mirror driving device according to an embodiment of the present invention, and FIG. 2B is a partial sectional view of a rotary reflecting mirror driving device according to an embodiment of the present invention.

FIG. 3 is a structural diagram of a conventional rotary reflector driving device.

[Explanation of symbols]

 1 rotating shaft 2,3 ball bearing 4 bracket 5 printed circuit board 6 coil 7 magnet 8 rotating yoke 9,39 rotating boss 10 reflecting mirror 11 spring 12 washer 13 retaining ring 14,16 convex portion 15 concave portion (groove) 17 reflecting mirror positioning convex Part 18 Effective range where the optical beam of the reflecting mirror 10 hits 19 Parallel wall surfaces

Claims (4)

[Claims] 1. A rotary reflecting mirror driving device in which an inclined portion is provided on a top surface of a cylindrical or prismatic rotating member fastened to a rotary shaft and a reflecting mirror is provided on the inclined portion, and a groove is provided in the inclined portion. A rotary reflecting mirror drive device having a limited bonding area with the reflecting mirror. 2. The rotating member comprises a convex portion, a concave portion, and
2. The rotary reflecting mirror driving device according to claim 1, wherein the convex-concave-shaped unevenness is formed in the order of the convex portions, and the reflecting mirror is adhered and fixed only on the convex surface below the slope. 3. The rotary reflecting mirror driving device according to claim 1, wherein the rear surface of the outer surface of the reflecting mirror, which is outside the effective range of light beam irradiation, is bonded and fixed. 4. The rotary reflecting mirror drive according to claim 1, wherein the rotating member has a wall surface parallel to the central axis of rotation below the inclined portion, and the parallel wall and the reflecting mirror are in contact with each other without a gap. apparatus.