JPH055331B2 - - Google Patents

Description

Detailed Description of the Invention <Industrial Application Field> The present invention is directed to tilting a reflecting mirror in the X-axis or Y-axis direction on a plane in response to the generation of an electric signal to deflect light in a desired direction. The present invention relates to an optical deflection device.

Specifically, the present invention relates to an optical deflection device that can be applied to, for example, cases in which a laser beam is suddenly deflected in another direction to draw an image in the air.

<Prior art> As a light deflection device that tilts a reflecting mirror,
As disclosed in No. 52-40215, there is one using a bimorph type piezoelectric element. This thing is
As shown in FIG. 7, one end of a bimorph piezoelectric element a that curves when a voltage is applied is fixed, and the other end is connected to the lower peripheral end of a reflecting mirror b, thereby supporting the reflecting mirror b. At the same time, the curvature causes the reflecting mirror b to be tilted.

<Problems to be Solved by the Invention> Incidentally, the reflecting mirror b and the piezoelectric element a are supported by such a configuration only by fixing the ends of the elements, and therefore the strength is weak, and the center If a force is applied to the piezoelectric element a, the piezoelectric element a is likely to be damaged, and therefore, the reflector b needs to be made thinner to reduce the load. As a result, the reflector b is also easily damaged and difficult to handle. Further, the tilting of the reflecting mirror b depends on various factors such as the amount of voltage applied to the piezoelectric element a, the distance from the fixed part of the piezoelectric element a to the supporting part of the reflecting mirror b, and the weight of the reflecting mirror b. The determined conditions are complex and it is difficult to achieve a predetermined positional accuracy. Furthermore, a large amount of inclination cannot be achieved due to the load at the center of the reflecting mirror b and the like.
There are various drawbacks.

<Means for Solving the Problems> The present invention includes: a casing in which a bottom plate and an upper plate having a circular hole in the center are connected by a plurality of supports; a support plate having a reflective mirror surface on its upper surface; a flexible support plate whose periphery is supported by struts to swingably support the reflective mirror having a mirror surface on its upper surface; a support means for supporting the reflecting mirror from below; A pair of piezoelectric laminates that come into contact with a support plate at separated positions, and a voltage application means that applies a voltage to these piezoelectric laminates to expand and contract in the vertical direction, and tilts the reflecting mirror surface around a fulcrum by the displacement generated at the upper end. It is characterized by being comprised of the following.

<Function> When the piezoelectric laminates on the X-axis and Y-axis are strained in the Z-axis direction along with the generation of electric signals, their displacement ends move, and the reflecting mirror moves in a predetermined direction around the fulcrum. Produces a three-dimensional tilt movement.

<Example> An example of the present invention will be described with reference to the accompanying drawings.

Referring to FIG. 1, reference numeral 1 denotes a housing, which has a square bottom plate 2 and a top plate 3 of the same shape with a circular hole 4 formed in the center, which are connected by four frame pillars 5 at their four corners. Can be connected and assembled. The frame pillar 5 has a second
As shown in the figure, the ends of the legs 6a protruding from the squares of the metal square flexible support plate 6 are clamped. The support of the flexible carrier plate 6 is tension-free and can be moved up and down. Further, a reflecting mirror 8 is fitted in the circular hole 4, and a fixing boss 9 at the lower part of the reflecting mirror 8 is mounted on the upper surface of the supporting plate 6.
A mirror surface 7 is exposed from the upper surface of the housing 1. A caul plate 10 is in contact with the lower surface of the support plate 6, and the abutment plate 1 is connected to the support plate 1 by a screw 11 screwed from the corresponding plate 10.
0, the support plate 6 and the fixed boss 9 are connected. The caul plate 10 is made of a wear-resistant hard metal material.

Note that the contact plate 10 has contact balls 14, which will be described later.
It is also possible to use a wear-resistant hard metal material only at the portion that contacts the contact point 16.

A support post 13 is held in the vertical direction at the center of the bottom plate 2, and a contact ball 14 made of a wear-resistant hard metal material provided at the upper end of the support post 13 is connected to the contact plate 10.
supports the reflecting mirror 8 by applying it to the lower surface of the center of the mirror,
The mirror surface 7 is substantially flush with the upper surface of the housing 1. At this time, the support plate 6 is lifted up somewhat, and the reflecting mirror 8 becomes raised.

The center of the reflecting mirror 8 is not supported by the support 13, but by a contact ball 14 provided at the center of the intermediate plate 20, which is assembled with the periphery supported by the frame pillar 5, as shown in FIG.
It may also be point supported.

An appropriate number of bending wrinkles 12 can be formed on the leg piece 6a of the flexible support plate 6, as shown in FIGS. The flexible support plate 6, which will be described later, can be easily tilted and its assembly can be simplified.

Two columnar piezoelectric laminates 15a and 15b are held on the bottom plate 2 in the vertical direction so as to be located on the same plane, the X-axis and the Y-axis, which are orthogonal to each other with the support 13 as the center. the piezoelectric laminate 15a,
At the upper end of 15b is a contact ball 16 (displacement end) made of the same wear-resistant hard metal material as the contact ball 14.
are provided and are brought into point contact at positions on the plane of the lower surface of the backing plate 10 that coincide with the X and Y axes.

As shown in FIG. 3, the piezoelectric laminates 15a and 15b include a plurality of piezoelectric elements 17 polarized in the vertical direction.
are stacked one above the other with the same polarity facing each other, and input terminals 18, 18 are connected to the respective electrodes of the same polarity.
By applying a voltage between them, each piezoelectric element 17 is distorted in the vertical direction, and the amounts of the distortions are superimposed to cause expansion and contraction in the vertical direction.

The operation of the above embodiment will be explained with reference to FIGS. 3 and 4.

When no signal voltage is applied to the piezoelectric laminates 15a and 15b, the reflecting mirror 8 has its mirror surface 7 equal to the upper surface of the upper plate 3, as shown in FIG.

In order to deflect the light incident on the reflecting mirror 8 by a predetermined amount, the input ends 18,
A predetermined signal voltage is applied between 18 and 18.

As a result, as shown in FIG. 4, the piezoelectric laminate 1
5a and 15b are expanded.

At this time, the reflecting mirror 8 is moved through the flexible support plate 6,
Its central lower surface is point-supported by a contact ball 14 of a support 13, and the flexible support plate 6 can be tilted by deforming the leg piece 6a. Therefore, the reflecting mirror 8 supports the piezoelectric laminate 15 by using the contact ball 14 as a support.
Due to the expansion of a and 15b, the mirror surface 7 is tilted by an angle proportional to the signal voltage, and the mirror surface 7 is tilted by an angle proportional to the signal voltage.
A predetermined angle of inclination is produced in the X (Y) axis direction where a and 15b are located. Therefore, the incident light is reflected in the desired direction.

When the piezoelectric laminates 15a, 15b are released from stretching, the legs 6a generate a spring action to return to the position shown in FIG. follows and returns to the original position.

By expanding and contracting the piezoelectric laminate 15a, the inclination of the mirror surface 7 in the X-axis direction is controlled, and the piezoelectric laminate 15b
The inclination of the mirror surface 7 in the Y-axis direction is controlled by the expansion and contraction of the mirror surface 7.

By varying the signal voltages applied to the piezoelectric laminates 15a and 15b to give different amounts of expansion and contraction, or timings of expansion and contraction, and by appropriately combining these, the reflecting mirror 8 can be adjusted to various values corresponding to the signal voltages. The mirror surface 7 is given an inclination angle of , causing multidimensional oscillation, and the mirror surface 7 can be deflected in any direction with respect to the incident light. Therefore, the angle can be freely shifted with good responsiveness to high-frequency pulsed light and the like.

In the above embodiment, the reflecting mirror 8 is supported by the flexible support 6, the backing plate 10, and the contact ball 14.
There are no welded parts for supporting the reflector, making it easy to assemble, and also having the advantage that frequent tilting of the reflector 8 will not cause fatigue and insufficient support.

<Effects> As clarified by the above description, the present invention provides point support for a reflecting mirror 8 having a mirror surface 7 on its upper surface,
The X-axis and Y-axis pass through the fulcrum and are orthogonal on the plane.
Piezoelectric laminates 15a and 15b that expand and contract in the vertical direction are arranged at positions spaced apart from the fulcrum on the axis,
Since the mirror surface 7 is tilted about the fulcrum by the expansion and contraction of the laminate, the amount of deviation is not affected by the load on the mirror surface 7, etc., and sufficient strength is guaranteed, and the piezoelectric laminate 15a, By changing the voltage applied to the mirror 15b, there are excellent effects such as the ability to freely change the amount and direction of inclination of the mirror surface 7 with high positional accuracy.

[Brief explanation of the drawing]

The accompanying drawings show an embodiment of the present invention, and FIG. 1 is a perspective view, FIG. 2 is a sectional view taken along the line A-A, FIG. 3 is a sectional view taken along the line B-B of FIG. FIG. 5 is a longitudinal sectional side view showing another means for supporting the center of the reflector 8; FIGS. The side view, FIG. 7, is a longitudinal sectional side view of the conventional device. 1; Housing, 2; Bottom plate, 3; Top plate, 5; Frame pillar,
6; Support plate, 6a; Leg piece, 7; Mirror surface, 8; Reflector, 12; Bending wrinkles, 13; Support column, 14; Contact balls, 15a, 15b; Piezoelectric laminate, 16; Contact ball.

Claims (1)

[Scope of Claims] 1. A casing formed by connecting a bottom plate and an upper plate having a circular hole in the center with a plurality of supports, and a support disposed within the circular hole of the upper plate and having a reflective mirror surface on the upper surface. a flexible support plate whose periphery is supported by struts and swingably supports a reflector having a mirror surface on its upper surface; the reflector is held from below via the flexible support plate; a support means disposed within the casing, the lower end of which is fixed to the bottom plate, and the upper end of which is connected to the support plate at a position spaced apart from the fulcrum on the X-axis and Y-axis, which pass through the fulcrum and are orthogonal on a plane. Consisting of a pair of piezoelectric laminates that are in contact with each other, and voltage application means that applies a voltage to these piezoelectric laminates to cause them to expand and contract in the vertical direction, and to tilt the reflecting mirror surface around a fulcrum by the displacement generated at the upper end. A light deflection device featuring: