JP2003075738A - Optical switch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem that it is difficult to tilt a mirror by using only a bimorph type actuator although it is possible to transfer the mirror up and down. SOLUTION: A reflector is configured to cause rotational movement by connecting a microactuator which bends in two opposite directions and by connecting the reflector to a connecting part. Rotational movement having two rotational shafts orthogonal to each other is caused by arranging two sets of actuator orthogonal to each other in a cruciform by superposing each connecting part. The effective area of the mirror is increased by connecting the actuator, the mirror and a balance weight with a connecting member while maintaining a predetermined distance with each other, and making a center of rotation coincide with the center of gravity of a movable part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical switch equipped with a micromirror used for optical communication and the like.

[0002]

2. Description of the Related Art A conventional optical switch for switching a light reflecting direction to one of two directions by vertically driving a micro-optical element by using a monomorph type actuator having both ends fixed or a bimorph type actuator. Is disclosed in, for example, Japanese Patent Laid-Open No. 2000-66122.

[0003]

In the above-mentioned prior art, the movement of the driven micro-optical element is vertical movement. The direction of the light beam reflected by the micro-optical element is limited to two, and no description is given regarding the configuration of reflecting in any direction. When there are three or more light inputs or outputs, switching in two directions cannot be dealt with, and a structure capable of reflecting a light beam in any direction by tilting an optical element such as a mirror is required.

An object of the present invention is to provide an optical switch capable of reflecting light in any direction.

[0005]

The above object is to provide two actuators that are flexibly deformed in the longitudinal direction and a frame that supports the end portions of these actuators, and fix a mirror to the central portion of the actuators. Achieved by

Further, the above-mentioned object is provided with two actuators which cause a flexural deformation in the longitudinal direction and a frame which supports the end portions of these actuators, said actuators are connected in a cross shape, and a mirror is connected to this connection portion. Achieved by fixing.

Further, the above object is achieved by fixing a connecting member having a predetermined length from the connecting portion of the actuator and fixing a balance weight to the connecting member.

[0008] Further, the above-mentioned object is to connect electrode films provided on both surfaces of a piezoelectric element, electrodes connected to both ends of the electrode film, a mirror fixed to the central portion of the piezoelectric element, and the electrodes. And a driving power supply, the mirror is operated by deformation of the piezoelectric element.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a perspective view illustrating the outline of a micromirror according to the present invention. In FIG. 1, 101 is four mirrors. These mirrors 10
1 are connected by a mirror connecting portion 101a.
102, 103, 104 and 105 are actuators. Reference numeral 106 is a frame, and the actuators 102, 1
03, 104 and 105 are fixed.

The four mirrors 101 are formed by one plate, and only the central portion is the connecting portion 1 of each mirror 101.
It is left behind as 01a. Actuator 10
2, 103, 104 and 105 are mounted so as to bridge the frame 106, and these actuators are
The connecting portion 101a is connected to a portion where 2, 103, 104 and 105 intersect.

For example, the actuator 102 operates to give a downward displacement to the mirror connecting portion 101a, and the actuator 104 operates to give an upward displacement to the mirror connecting portion 101a. As a result, the mirror connecting portion 10
1a includes an actuator 102 and an actuator 10.
4 is orthogonal to the longitudinal direction and tilts about the rotation axis parallel to the substrate surface.

Similarly, due to the operation of the actuator 103 and the actuator 105, the mirror connecting portion 101a is tilted about the rotation axis which is orthogonal to the longitudinal direction of the actuator 103 and the actuator 105 and is parallel to the substrate surface. By combining the rotations in these two directions, it is possible to cause the mirror connecting portion 101a and the mirror 101 to tilt in any direction.

FIG. 2 is a view showing a sectional structure of a micro mirror including a set of actuators, which will be described in more detail. In FIG. 2, 201 is a reflective film, and 202, 20.
3, 206 and 207 are piezoelectric elements, 204 is a reflective film support plate, 205 is a substrate, 208, 209, 210, 211,
Reference numerals 212 and 213 are electrodes, and 214 is a driving power source.

That is, electrode films are formed on both surfaces of the piezoelectric elements 202 and 203, and electrodes 208, 209 and 2 are formed.
It is connected to the drive power supply 214 via 10 and can be independently applied with a voltage. Similarly, electrode films are formed on both surfaces of the piezoelectric elements 206 and 207.
The driving power source 214 is connected via 1, 212 and 213. These piezoelectric elements are mechanically connected to each other via a mirror connecting portion 101a, and the other end is connected to the frame 106.
Since it is connected to, the mirror composed of the reflection film support plate 204 and the reflection film 201 can be driven.

For example, in this embodiment, the electrodes 208 and 21 are
Since a voltage is applied to the piezoelectric element 3, the piezoelectric elements 202 and 207 are
Deforms in the direction of elongation. Since the piezoelectric elements 202 and 203 are attached to each other and the piezoelectric elements 206 and 207 are also attached to each other, these piezoelectric elements bend as shown in the drawing, and the mirror tilts to the right. Electrodes 208 and 213
Since the deflection amount of the piezoelectric element also changes depending on the applied voltage to the mirror, the tilt of the mirror can be adjusted by adjusting the applied voltage.

FIG. 3 shows an embodiment of a micromirror having one rotation axis. In FIG. 3, 301, 302,
Reference numerals 303 and 304 are actuators. When there is only one rotation axis, it is not necessary to make the actuators array orthogonal. Although a pair of actuators may be used to support the mirror central portion, supporting the mirror at both ends can further stabilize the posture of the mirror.

FIG. 4 is a top view of FIG. 3 showing an electrode structure of a micromirror actuator having one rotation axis. In FIG. 4, 401 and 402 are connection electrodes. The electrode 210 formed on the actuator is connected to the electrode on the back side of the opposing actuator by the connection electrode 401 via the through hole formed in the mirror connecting portion 101a. Similarly, the electrode 213 is connected to the opposite electrode of the actuator by the connection electrode 402 through the through hole formed in the mirror connecting portion 101a. Electrodes 208, 209 and 2
A connection pad having a large area is formed on the portion of the frame 10 mounted on the frame 106, so that a drive power source can be easily connected.

FIG. 5 is a sectional view of FIG. 3 showing the electrode connection structure of the actuator of the micromirror having one rotation axis. In FIG. 5, 501, 502 and 503 are electrode wires, 504, 505 and 506 are electrode films and 50
7 is a through hole. For example, the electrode film 504 is connected to the electrode film 510 via the connection electrode 401 formed in the through hole 507. Similarly, the electrode film 508
Is connected to the electrode film 506 via the connection electrode.

According to this structure, the piezoelectric elements 207 and 2
Of the electrodes on the 06 side, only the electrode film 509 needs to be connected to the driving power supply, and the wiring structure can be simplified.

FIG. 6 is a sectional view showing a sectional structure of a micromirror including a set of actuators. In FIG. 6, 601 is a connecting member and 602 is a balance weight. A balance weight 602 is coupled to the mirror including the reflective film 201 and the reflective film support plate 204 by a connecting member 601. The center of gravity of these movable parts is the connecting member 601.
Piezoelectric element 202, 203, 206
And 207 are connected. Although the substrate 205 has a recess for the purpose of preventing interference with the balance weight 602, the frame 106 may be raised to omit the recess. By adopting these configurations, the piezoelectric element 202,
Since the interference between 203, 206 and 207 and the reflection film support plate 204 can be prevented, it is not necessary to provide a notch in the reflection film support plate 204, and the reflection ability of the mirror can be further enhanced.

Further, since the center of rotation and the center of gravity of the movable part coincide with each other due to the action of the balance weight 602, the mirror posture can be stably maintained even when an external force such as vibration or impact is applied.

As described above, the present invention provides a micromirror capable of reflecting a light beam in an arbitrary direction by combining four bimorph type actuators in a cross shape.

[0023]

According to the present invention, an optical switch capable of reflecting light in any direction can be provided.

[Brief description of drawings]

FIG. 1 is a perspective view of a micromirror equipped with the present invention.

FIG. 2 is a cross-sectional view of a micromirror including a set of actuators.

FIG. 3 is a perspective view showing an embodiment of a micromirror having one rotation axis.

FIG. 4 is a top view showing an electrode structure of an actuator of a micromirror having one rotation axis.

FIG. 5 is a cross-sectional view showing an electrode connection structure of a micromirror actuator having one rotation axis.

FIG. 6 is a sectional view showing a sectional structure of a micromirror including a set of actuators.

[Explanation of symbols]

101 ... Mirror, 101a ... Mirror connection part, 102, 1
03, 104 and 105 ... Actuator, 106 ... Substrate. 201 ... Reflective film, 202, 203, 206 and 207 ... Piezoelectric element, 204 ... Reflective film support plate, 205 ...
Substrate, 208, 209, 210, 211, 212 and 2
13 ... Electrode, 214 ... Driving power source, 301, 302, 30
3 and 304 ... Actuator, 401 and 402 ... Connection electrode, 501, 502 and 503 ... Electrode wire, 50
4, 505 and 506 ... Electrode film, 507 ... Through hole, 601 ... Connecting member, 602 ... Balance weight.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Tadaaki Ishikawa             502 Kintatemachi, Tsuchiura City, Ibaraki Japan             Tate Seisakusho Mechanical Research Center F term (reference) 2H041 AA12 AB14 AC08 AZ02 AZ08

Claims (4)

[Claims] 1. An optical switch comprising: two actuators that are flexibly deformed in a longitudinal direction; and a frame that supports end portions of these actuators, and a mirror is fixed to a central portion of the actuators. 2. An actuator comprising: two actuators that are flexibly deformed in the longitudinal direction; and a frame that supports the end portions of these actuators. The actuators are connected in a cross shape, and a mirror is fixed to the connection portions. Characteristic optical switch. 3. The optical switch according to claim 2, wherein a connecting member having a predetermined length is fixed from the connecting portion of the actuator, and a balance weight is fixed to the connecting member. 4. An electrode film provided on both surfaces of a piezoelectric element, electrodes connected to both ends of the electrode film, a mirror fixed to the central portion of the piezoelectric element, and a driving power source connected to the electrode. And an optical switch, wherein the mirror operates by deformation of the piezoelectric element.