JPH06214181A - Mirror for optical scanner - Google Patents

Abstract

PURPOSE:To make a mirror light in weight and to attain highspeed and high responsiveness while maintaining the surface accuracy of the mirror as it is by forming plural recessed parts on the rear surface on the opposite side of the light reflection surface of the mirror. CONSTITUTION:By coating a glass surface 1a with aluminum vapor deposition, a light reflection surface 2 is formed and plural recessed parts 3 are formed on the rear surface 1b of a mirror 1 by using a method such as etching so that the surface accuracy is not affected. At this time, a part to be engaged (groove-like recessed part) is simultaneously formed on the mid section of the rear surface 1b of the mirror 1 and, on the other hand, an engaging part (groove-like projected part) capable of engaging with the part to be engaged is formed on the mid section of a flat surface for fixing a rotating shaft 5a. Then, in the state in which the part to be engaged of the mirror 1 is engaged with the engaging part of the rotating shaft 5, the mid section of the rear surface 1b of the mirror 1 is fixed on the flat surface for fixing the rotating shaft 5 by means of an adhesive of high rigidity and the mirror 1 and the rotating shaft 5 are integrated. Consequently, the weight of the mirror 1 is lightened by that of the recessed part 3 and the high-speed and high responsiveness of the mirror 1 are attained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mirror for an optical scanner used for scanning light such as laser light.

[0002]

2. Description of the Related Art The basic structure of an optical scanner including a conventional mirror 10 is shown in FIGS. In the figure, the surface 10
The mirror 10 having the light reflecting surface 11 formed on
The rotary shaft 12 is rotatably supported by the drive unit 13, and the rotary shaft 12 is oscillated by the drive unit 13, so that the mirror 10 is oscillated integrally with the rotary shaft 12 to perform scanning with light such as a laser beam.

[0003]

By the way, the conventional mirror 10 is made by subjecting glass to aluminum vapor deposition or the like. In the case of a large mirror, the weight of the mirror 10 itself becomes large, and accordingly the mirror 10 has a large weight. It is difficult to achieve high responsiveness. Therefore, in order to reduce the weight of the mirror 10 itself, for example, it is conceivable to reduce the thickness of the entire mirror 10. However, if the entire mirror 10 is thinned, another surface accuracy cannot be obtained. For this reason, the conventional mirror 10 cannot achieve both weight reduction and surface accuracy maintenance. Further, the center of the back surface 10b of the mirror 10 opposite to the light reflecting surface 11 is placed and fixed on the rotary shaft 12, but it is difficult to position the mirror 10 with respect to the rotary shaft 12, and the mirror 10 is rotated by the rotary shaft 12. On the other hand, there is also a problem in that it is not fixed accurately and high precision cannot be achieved.

The present invention has been made in view of the above conventional problems, and an object thereof is to make it possible to reduce the weight of the mirror while maintaining the surface accuracy of the mirror, and to provide the mirror with high speed and high response. It is an object of the present invention to provide a mirror for an optical scanner capable of achieving high performance, and further provide a mirror for an optical scanner capable of improving the positioning accuracy of the mirror with respect to the rotation axis.

[0005]

In order to solve the above problems, the present invention provides a mirror 1 having a light reflecting surface 2 formed on a surface 1a, a rotary shaft 5 for rotatably supporting the mirror 1, and a rotary shaft 5. And a drive unit 8 for driving the mirror 1 to swing about the rotation axis 5, and a plurality of recesses 3 are formed in the back surface 1b of the mirror 1 opposite to the light reflection surface 2. And

A fitting portion 7 is provided on a part of the rotary shaft 5, and a fitted portion 4 into which the fitting portion 7 can be fitted is provided on the rear surface 1b of the mirror 1. Is preferred.
Furthermore, it is preferable that the mirror 1 is made of silicon.

[0007]

According to the present invention, the light reflecting surface 2 having a thickness capable of maintaining the surface accuracy of the mirror 1 is formed, and the back surface 1b opposite to the light reflecting surface 2 is etched by a method such as etching. By forming the plurality of concave portions 3 so as not to affect the surface accuracy, a structure in which a large number of crosspieces are included in the mirror 1 is formed, and the mirror 1 itself can be formed without reducing the thickness of the entire mirror 1. The strength can be secured and the rigidity can be made high. Further, the weight of the mirror 1 itself is reduced by the amount of the recessed portion 3, and even a large mirror can be made lightweight while maintaining surface accuracy. Therefore, high speed and high responsiveness of the mirror can be achieved.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. In this embodiment, a structure in which the glass mirror 1 is fixed to the rotary shaft is illustrated. The surface 1a of the glass mirror 1 shown in FIGS. 2 (a) and 2 (b) is vapor-deposited with aluminum to form a light reflection surface 2, and on the other hand, the light reflection surface 2 is provided on the opposite side. A large number of recesses 3 are formed on the back surface 1b by etching. Further, a fitted portion 4 formed of a groove-shaped concave portion is formed in the central portion of the back surface 1b of the mirror 1.

On the upper surface of the rotary shaft 5, as shown in FIG.
A belt-shaped fixing flat surface 6 to which the central portion of the back surface 1b of the mirror 1 is fixed is formed, and a fitting portion 7 is provided in the center of the fixing flat surface 6 so as to project. Has a shape (groove-shaped protrusion) corresponding to the fitted portion 4 of the mirror 1. By fitting the fitted portion 4 of the mirror 1 to the fitting portion 7, the mirror 1 is rotated. It is designed to be accurately positioned with respect to 5. One end of the rotary shaft 5 is connected to the drive unit 8 shown in FIG. 1, and the other end is connected to the bearing box 9. The drive unit 8 includes a mechanism for swinging the rotary shaft 5, and the drive unit 8 drives the rotary shaft 5 to swing.
Is driven, the mirror 1 swings in accordance with the movement of the rotating shaft 5, and scanning of light such as a laser is performed.

In making the mirror 1, first, a glass surface 1a is vapor-deposited with aluminum to form a light-reflecting surface 2.
Then, the back surface 1b of the mirror 1 is formed by a method such as etching so that the surface accuracy is not affected and a plurality of recesses 3 are formed. At this time, the fitted portion 4 (groove-shaped recess) is formed at the same time in the center of the back surface 1b of the mirror 1, while the fitted portion 4 is formed in the center of the fixing flat surface 6 of the rotary shaft 5. The fitting portion 7 (groove-shaped convex portion) that can be fitted to is formed.
After that, with the fitted portion 4 of the mirror 1 fitted in the fitting portion 7 of the rotating shaft 5, the central portion of the rear surface 1b of the mirror 1 is rotated by using a highly rigid adhesive such as epoxy resin. The mirror 1 and the rotating shaft 5 are integrated with each other by being fixed to the fixing flat surface 6 of 5. The evaporation of aluminum or the like on the front surface 1a of the mirror 1 may be performed after the back surface 1b is etched.

As described above, after the light reflecting surface 2 (mirror surface) having a thickness capable of maintaining the surface accuracy of the mirror 1, the back surface 1b of the mirror 1 is etched by a method such as etching. Since the plurality of concave portions 3 are formed so as not to affect the above, the entire thickness of the mirror 1 does not become thin, but a structure in which a large number of crosspieces are included in the mirror 1 is provided, and the strength of the mirror 1 itself In addition, the rigidity can be high. Moreover, the weight of the mirror 1 itself is reduced by the amount of the concave portion 3, and even a large mirror can be made lightweight while maintaining the surface accuracy, and the mirror 1 can be made faster and more responsive. . Moreover, the fitting portion 7 provided in the central portion of the fixing flat surface 6 of the rotary shaft 5 has a shape corresponding to the fitted portion 4 provided on the back surface 1b of the mirror 1,
Positioning when the mirror 1 and the rotary shaft 5 are fixed can be performed easily and reliably, the mounting accuracy of the mirror 1 can be improved, and the mirror 1 can be made even more accurate.

As another embodiment of the present invention, FIG.
As shown in (c), instead of the glass mirror 1, a silicon mirror 1'may be fixed to a rotating shaft (not shown). This silicon mirror 1 '
A large number of recessed portions 3 and fitted portions 4 are formed on the back surface 1b of the mating portion 7 and the fitting portion 7 (FIG. 3) is formed at the center of the fixing flat surface 6 of the rotary shaft.
The point that is formed is the same as the structure of the glass mirror 1 and its rotating shaft in the first embodiment. That is, the mirror 1'is made of a silicon material, and its surface 1a is
Light-reflecting surface 2 is formed by applying aluminum vapor deposition to
The back surface 1b on the opposite side of the mirror 1 is formed with a large number of recesses 3 and fitted portions 4 by etching, and the fitting portions are formed on the rotary shaft. The mirror 1 is made of a highly rigid adhesive such as epoxy resin. ′ Is fixed to the rotary shaft. At this time, if the rotating shaft is made of glass,
For fixing to the silicon mirror 1 ', a method such as anodic bonding is used. Thus, by using the mirror 1'made of silicon, in addition to the structural weight reduction due to the concave portion 3 on the back surface 1b, the weight reduction due to the material itself is achieved,
The weight of the mirror 1 made of glass can be further reduced, and even a large mirror can achieve higher speed and higher responsiveness.

As yet another embodiment of the present invention, FIG.
As shown in (a) to (c), it is also possible to form a mirror 1 ″ with a rotating shaft, which is made of a silicon material and has an integral structure. In this case, in addition to the silicon mirror ′,
The rotary shaft 5 "is also made of silicon, and the rotary shaft 5" is formed by a method such as cutting and the mirror 1 '
The recess 3 of the back surface 1b is processed by a method such as etching so that the surface accuracy is not affected. Since the rotating shaft 5 ″ is also made of silicon in this way, the rotating shaft 5 ″ itself is lightened in addition to the weight reduction of the mirror 1 ′ itself.
It is possible to reduce the weight of the entire drive unit 8 (FIG. 1), and it is not necessary to position the rotary shaft 5 ″ and the mirror 1 ′, which is an advantage that higher accuracy can be achieved. is there.

[0014]

As described above, according to the present invention, a mirror having a light-reflecting surface formed on its surface, a rotary shaft for rotatably supporting the mirror, and a rotary shaft are driven to swing the mirror around the rotary shaft. Since a plurality of recesses are provided on the back surface of the mirror opposite to the light reflecting surface of the mirror, the recess on the back surface of the mirror should not affect the surface accuracy of the mirror. By forming the mirror, it is possible to increase the strength and rigidity of the mirror and to reduce the weight of the mirror while maintaining the surface accuracy of the mirror. As a result, it is possible to obtain a high-speed and high-responsiveness mirror for an optical scanner.

When a fitting portion is provided on a part of the rotary shaft and a fitted portion to which the fitting portion can be fitted is provided on the back surface of the mirror, the fitting of the rotary shaft is performed. By making the shape of the mirror and the fitted part of the mirror correspond to each other, the positioning of the mirror and the rotating shaft can be reliably performed when the mirror is fixed, the mirror mounting accuracy is improved, and the mirror accuracy is improved. You can

Furthermore, when the mirror is made of silicon, the material of the mirror itself can be made lighter, and even a large mirror can achieve higher speed and higher responsiveness.

[Brief description of drawings]

FIG. 1 is a partially cutaway perspective view showing the structure of an optical scanner including a glass mirror used in an embodiment of the present invention.

FIG. 2A is a bottom view of the same mirror as above, and FIG. 2B is a perspective view showing a fixed state of the mirror and the rotation shaft.

FIG. 3 is an exploded perspective view of a mirror and a rotation shaft of the same.

FIG. 4 shows a mirror made of silicon used in another embodiment of the present invention, (a) is a plan view, (b) is a side view,
(C) is a bottom view.

5A and 5B show a mirror with a rotating shaft used in still another embodiment of the present invention, FIG. 5A is a plan view, FIG. 5B is a side view,
(C) is a bottom view.

FIG. 6 is a partially cutaway perspective view of the structure of a conventional optical scanner.

FIG. 7 is an exploded perspective view of a conventional mirror and a rotating shaft.

[Explanation of reference numerals] 1 mirror 1a front surface 1b back surface 2 light reflecting surface 3 concave portion 4 mating portion 5 rotating shaft 7 fitting portion 8 driving portion

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Hiromi Nishimura Inventor Hiromi Nishimura 1048, Kadoma, Kadoma-shi, Osaka Matsushita Electric Works Co., Ltd.

Claims (3)

[Claims] 1. A mirror having a light reflecting surface formed on the surface thereof,
The mirror includes a rotary shaft that rotatably supports the mirror, and a drive unit that drives the rotary shaft to swing the mirror around the rotary shaft. A plurality of recesses are formed on the back surface of the mirror opposite to the light reflecting surface. A mirror for an optical scanner, which is characterized by 2. A fitting portion is provided on a part of the rotating shaft, and a fitted portion into which the fitting portion can be fitted is provided on a back surface of the mirror. Item 1. An optical scanner mirror according to item 1. 3. The mirror for an optical scanner according to claim 1, wherein the mirror is made of silicon.