JP5319939B2 - Optical deflector and optical device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical deflector that is capable of obtaining a large angle of deflection and an operation at a large amplitude, and that also facilitates miniaturization, reduced thinness, and reduced mass and weight thereof. <P>SOLUTION: An optical deflector includes a plurality of piezoelectric unimorph oscillating bodies 210a to 210d that cause a reflecting plate 1 to oscillate rotationally, centering upon a pair of flexible support units 2a and 2b. The optical deflector forms a single structure of the oscillating plates 23a to 23d, the reflecting plate 1, the flexible support units 2a and 2b, and a support body 9, by connecting one set of the both terminals of the oscillating plates 23a to 23d of the suite of piezoelectric unimorph oscillating bodies 210a to 210d to the flexible support units 2a and 2b, and connecting the other set of the both terminals to the support body 9. Furthermore, the plurality of piezoelectric unimorph oscillating bodies 210a to 210d each respectively include a plurality of parallel oscillating bodies 23a-1 to 23a-3, 23b-1 to 23b-3, 23c-1 to 23c-3, and 23d-1 to 23d-3, and a suite of parallel actuators 28a-1 to 28a-3, 28b-1 to 28b-3, 28c-1 to 28c-3, and 28d-1 to 28d-3. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to an optical deflector that deflects incident light and performs optical scanning, and more particularly to an optical deflector having a movable plate capable of high-speed and large-amplitude operation and an optical device using the same.

  The present invention relates to general optical equipment that deflects and scans a light beam such as a laser beam, an electrophotographic copying machine, a laser beam printer, a barcode reader, a display device that scans a laser beam and projects an image, and a head-up display. It can be widely applied to raster scan displays for mobile devices (for automobiles and consumer devices), distance measuring sensors, shape measuring sensors, optical space communication units, and the like.

  2. Description of the Related Art Conventionally, an optical deflector that deflects and scans a light beam such as a laser beam is widely used in an optical apparatus such as an electrophotographic copying machine, a laser beam printer, and a barcode reader. It is also used in display devices that project images by scanning laser light.

  As such an optical deflector that mechanically deflects light, a rotating polygon mirror (polygon mirror), a vibrating reflector (galvano mirror), and the like are generally known (for example, Patent Document 1, Patent Document). 2, see Patent Document 3), and the galvanometer mirror type is superior in miniaturization. In particular, as a small-sized optical deflector, a trial production of a micromirror using a silicon substrate manufactured using micromachine technology has been reported.

  The optical deflector disclosed in Patent Document 1 is characterized in that it is driven by using electromagnetic force, and is used for driving disposed at the outer peripheral portion of a pair of left and right permanent magnets disposed on a base and a reflecting mirror. The drive coil is configured to pass forward and reverse alternating drive currents. When the forward and reverse alternating drive currents are energized, the reflection mirror section vibrates due to the Lorentz force generated by the external magnetic field of the pair of permanent magnets and the drive coil current.

  In the optical deflector using the above electromagnetic force, the Lorentz force decreases as the angle increases. Therefore, in order to set the mirror rotation angle large, it is necessary to increase the magnetic force of the permanent magnet or increase the coil current. There was a problem of increasing the size and increasing the power consumption. In addition, since it is necessary to bond a permanent magnet, there is a problem that the element size cannot be reduced too much.

  In addition, the optical deflector described in Patent Document 2 is driven using electrostatic force, and a drive electrode is disposed oppositely with a slight gap immediately below the reflection mirror, and a mirror made of a conductor. The capacitor is configured with. The drive electrode is divided into left and right with the rotation axis of the mirror as the axis of symmetry. When a voltage is applied between the mirror and the drive electrode, an electrostatic force is generated, so that the mirror is attracted to the drive electrode. By alternately applying a voltage to the left and right drive electrodes, the mirror vibrates around the rotation axis. That's it.

An optical deflector using this electrostatic force can be manufactured only by a semiconductor process and thus has an advantage that it can be miniaturized. However, since the electrostatic force is inversely proportional to the square of the distance between the mirror and the drive electrode, it is necessary to drive the mirror. In order to provide a sufficient electrostatic force, it is necessary to narrow the gap.
Therefore, the rotational motion of the mirror is limited by contact with the drive electrode, and there is a problem that the rotational angle of the mirror cannot be increased. In addition, the electrostatic driving method generally requires a high driving voltage of 50 V or more, and a dedicated driver IC is also required.

  In addition, the optical deflector described in Patent Document 3 is driven by using electrostatic force, and a drive electrode is arranged in a comb-like shape with a slight gap right next to the reflection mirror. A capacitor is formed between the comb electrodes. When a voltage is applied between the comb electrodes facing each other, an electrostatic force is generated, so the mirror is attracted to both sides, and the initial inclination of the mirror gives this mirror a force to rotate about the rotation axis. Then, the mirror is swung.

  The optical deflector using this electrostatic force can be manufactured only by a semiconductor process and has the advantage that it can be downsized. However, if the mirror swing angle increases and the meshing of the opposing comb teeth is disengaged, the electrostatic force does not work. There has been a problem that the rotation angle of cannot be increased.

  As described above, the conventional optical deflector using electromagnetic force and electrostatic force has a problem that the rotation angle of the mirror cannot be set large.

  Therefore, as a technique for solving such a problem, an optical deflector using vibration of a piezoelectric actuator has been proposed (see, for example, Patent Document 4, Patent Document 5, and Patent Document 6).

  The optical deflector described in Patent Document 4 includes a plate-like micromirror, a pair of rotating supports that support both sides of the micromirror, a frame portion that surrounds the periphery, and a piezoelectric that translates the frame portion. And an actuator.

  The optical deflector described in Patent Document 5 includes a support, a piezoelectric vibrator fixed to the support and reciprocating, an elastic body connected to the piezoelectric vibrator, and a piezoelectric vibrator via the elastic body. And a reflector that is driven to vibrate.

  In the optical deflector described in Patent Document 6, in the conversion mechanism, one end side of a pair of columnar parts is connected by a hinge part, an actuator is interposed on the other end side, and a movable mirror part is provided above the hinge part. , A mirror, an elastic support portion, and a support substrate are disposed.

  What is common to the above-described prior art is that the piezoelectric actuator is joined to the mirror element substrate via an elastic body, and the vibration of the piezoelectric actuator is converted into the rotational motion of the mirror. In the optical deflector using these piezoelectric actuators, since there is no limitation on the rotation of the mirror, a large deflection angle is obtained.

  However, in the above-described prior art, in the optical deflector configured to convert the translational motion of the piezoelectric actuator into the rotational motion of the mirror via the elastic body, the base substrate, the piezoelectric actuator, the elastic body, the mirror substrate, etc. If the components are not bonded and bonded accurately, the vibration from the piezoelectric actuator does not propagate well to the mirror, or even if there is no problem with the bonding, all the translational motion of the piezoelectric actuator is not converted into rotational motion. There was a problem that not only the rotation but also the translational movement was performed, and the beam light tends to be shifted.

  Also, it is difficult to reduce the size because it uses bulk ceramics piezoelectric actuators and metal plates or rods as elastic components, and each component is joined and assembled with adhesives, solder, etc. There was also a process problem that the device could not be assembled at the silicon wafer level like a device.

  As described above, the conventional technique is not sufficiently small as an optical deflector that realizes a high speed and a large displacement angle as compared with a polygon mirror or a galvanometer mirror. Therefore, there has been a demand for an optical deflector that is easy to operate and has a high displacement angle and a high speed.

  Thus, as a solution to these problems, a vibration mirror suitable for manufacturing by semiconductor process technology has been proposed (see, for example, Patent Document 7).

  In the technique described in Patent Document 7, the optical deflector is a support having a piezoelectric unimorph vibrating body and a hollow portion for fixing and supporting one end of a piezoelectric unimorph plate made of a piezoelectric film directly formed on the support. A body, an elastic body connected to the piezoelectric unimorph vibrator, and a reflector that is connected to the elastic body and rotationally vibrates in the cavity by driving the piezoelectric unimorph vibrator through the elastic body. A support, an elastic body, and a reflector are integrally formed.

  That is, the device described in Patent Document 7 includes a reflecting plate 01, a support body 09 that supports the reflecting plate 01, and a piezoelectric unimorph vibrating body 010 that rotates and vibrates the reflecting plate 01, as shown in FIG. . The piezoelectric unimorph vibrating body 010 includes vibration plates 03a to 03d and piezoelectric actuators 08a to 08d made of a piezoelectric film directly formed on the support body 09. The vibration plates 03a to 03d reflect the support body 09 and the reflection body, respectively. It is connected to the plate 01. Moreover, the reflecting plate 01 is supported by the support body 09 via the elastic support portions 02a and 02b.

  The diaphragms 03a to 03d, the support body 09, the elastic support portions 02a and 02b, and the reflection plate 01 are integrally formed.

  The operation of this conventional optical deflector will be described with reference to FIG. 8 is a cross-sectional view taken along line S10-S10 in FIG.

  An AC voltage (for example, a sine wave) having the same phase and an opposite phase or phase shift is applied to the piezoelectric actuators 08a and 08b, and the diaphragms 03a and 03b and 03c and 03d are vibrated. Since one end of each diaphragm 03a, 03b and 03c, 03d is fixed and held on the support body 09, the tip drive units 04a, 04b, 04c, 04d vibrate in the vertical direction of the arrow R, but the tip drive unit The vibrations of 04a, 04b and 04c, 04d have a phase difference. In particular, when the phase of the applied voltage is opposite, the vibration directions of the tip driving units 04a, 04b and 04c, 04d are opposite to each other.

  That is, when the tip driving units 04a and 04b move in the upward direction, the tip driving units 04c and 04d move in the downward direction. At this time, rotational torque about the elastic support portions 02a and 02b acts on the reflecting plate 01, and the reflection plate 01 is inclined with the elastic support portions 02a and 02b as the central axis. When each of the tip driving units 04a, 04b and 04c, 04d repeats the vertical vibration following the AC applied voltage, a seesaw-like rotational torque acts on the reflecting plate 01 according to the above-described principle, and the reflecting plate 01 Repeats rotational vibration to a predetermined angle. Even in the case of vibration with a phase difference instead of an antiphase, the reflector plate 01 vibrates in the same manner as described above.

  When the driving frequency of the piezoelectric actuators 08a, 08b, 08c, and 08d is equal to or close to the mechanical resonance frequency of the structure (movable mirror portion) that combines the reflecting plate 01 and the elastic support portions 02a and 02b, the reflecting plate The rotational vibration of 01 is maximized, and the maximum displacement angle is obtained. Further, if the resonance frequencies of the diaphragms 03a, 03b, 03c, and 03d are set to be close to or close to the resonance frequency of the movable mirror portion, even if the driving force of the piezoelectric actuators 08a, 08b, 08c, and 08d is small, the large movable mirror portion Can be obtained. Of course, although the rotation angle is small, it is possible to rotationally vibrate the reflecting plate 01 at the drive frequency of the piezoelectric actuators 08a, 08b, 08c, 08d.

FIG. 9 shows an enlarged view of a joint portion between the tip drive unit 04d and the reflection plate 01. As shown in FIG. 9, the vibration plate 03d is joined to the reflection plate 01 via the tip drive unit 04d.
JP-A-7-175005 JP-A-6-180428 JP 2003-121776 A JP-A-10-197819 JP 2001-272626 A JP 2003-29191 A JP 2005-128147 A

  However, the width W01 of each of the tip drive units 04a, 04b, 04c, and 04d is larger than the width W02 of the elastic support portions 02a and 02b and is difficult to twist, but each of the tip drive units 04a, 04b, 04c, and 04d. If too large, the weights of the tip drive units 04a, 04b, 04c, and 04d become excessive, and the amplitudes of the tip drive units 04a, 04b, 04c, and 04d become small. Therefore, the tip drive units 04a, 04b, and 04c are reduced. , 04d has a limit in increasing the rigidity.

  Therefore, when the tip driving units 04a, 04b, 04c, and 04d are actually oscillating, when the diaphragms 03a to 03d are oscillating, the force generated thereby is transmitted to the reflecting plate 01. As shown in FIG. 10, the tip drive units 04a to 04d are deformed, and there is a problem that the force cannot be sufficiently transmitted and the deflection angle cannot be increased.

  As described above, the conventional technique is not sufficiently small as an optical deflector that realizes a high speed and a large displacement angle as compared with a polygon mirror or a galvanometer mirror. Therefore, there has been a demand for an optical deflector that is easy to operate and has a high displacement angle and a high speed.

  Therefore, the present invention has been made in view of the above-described conventional problems, and an object of the present invention is to make it possible to integrally form a mirror substrate (support) and a piezoelectric actuator, thereby suppressing axial deviation and piezoelectricity. An optical deflector that can prevent translational movement of the mirror due to the influence of vibration, can operate at high speed, can obtain a large deflection angle and large amplitude operation, and can be reduced in size, thickness, and weight. It is to provide an optical device.

In order to achieve the above-described object, the present invention provides a movable plate capable of reflecting light, one end fixed to the movable plate, the other end fixed to a support, and pivotally supporting the movable plate in a rotatable manner. a pair of torsion bars, comprising a piezoelectric actuator for driving the diaphragm and the diaphragm, and a piezoelectric unimorph vibrator two pairs of rotating vibrate the movable plate, a pair of the piezoelectric unimorph vibrating member, the pair The other pair of piezoelectric unimorph vibrators are arranged symmetrically across the other of the pair of torsion bars, and the vibration plate has one end at both ends. is connected to, is connect the other ends to the support, the diaphragm, the movable plate, torsion bars, the support is integrally formed, each of the piezoelectric unimorph vibrating But each example Bei a plurality of said diaphragm and a piezoelectric actuator, when driving of the piezoelectric actuator, an AC voltage the is applied to the piezoelectric actuator at a position sandwiching the torsion bar, 180 ° different phases two The AC deflector has an amplitude in a positive or negative unipolar region by superimposing a DC offset voltage .

According to a second aspect of the present invention, in the optical deflector according to the first aspect, the diaphragm and the piezoelectric actuator have a rectangular shape having a side perpendicular to the torsion bar as a long side. An optical deflector was used.

According to a third aspect of the present invention, in the optical deflector according to the first aspect, the piezoelectric unimorph vibrator is provided in pairs on both sides of the movable plate. .

According to a fourth aspect of the present invention, there is provided the optical deflector according to the first aspect, wherein the unimorph vibrator is provided symmetrically with the movable plate in between.

According to a fifth aspect of the present invention, in the optical deflector according to the first aspect, the piezoelectric unimorph vibrating body includes the diaphragm and the piezoelectric actuator extending in a direction perpendicular to the torsion bar. The optical deflector is divided into a plurality of parts in the extending direction of the torsion bar.

According to a sixth aspect of the present invention, in the optical deflector according to the first aspect, the contact area between the diaphragm and the torsion bar protrudes outward from the torsion bar in the connecting portion between the diaphragm and the torsion bar. The optical deflector is characterized in that a projecting portion is provided which is enlarged.

A seventh aspect of the present invention is the optical deflector according to the sixth aspect of the present invention, wherein the projecting portion has two or more planes.

According to an eighth aspect of the present invention, in the optical deflector according to the sixth aspect , the protrusion has a curved surface.

According to a ninth aspect of the present invention, in the optical deflector according to the first aspect, the plurality of diaphragms are united at an end portion on the torsion bar side and connected to the torsion bar by a single coupling portion. In addition, an optical deflector is characterized in that a cross-sectional area of a connection portion of the coupling portion to the torsion bar is formed in an area smaller than a sum of cross-sectional areas of the diaphragm.

According to a tenth aspect of the present invention, in the optical deflector according to the first aspect, the rigidity of the diaphragm is set lower than the rigidity of the torsion bar and the movable plate. It was.

The invention according to claim 11 is the optical deflector according to claim 1, wherein the piezoelectric actuator constituting the piezoelectric unimorph vibrator is a piezoelectric film directly formed on the support. An optical deflector is used.

The invention according to claim 12 is the optical deflector according to claim 11 , wherein the piezoelectric film is a piezoelectric film formed by a reactive ion plating method using arc discharge plasma. An optical deflector is used.

According to a thirteenth aspect of the present invention, in the optical deflector according to the twelfth aspect , the material of the piezoelectric film is lead zirconate titanate, and the composition is 0.4 / 0 in terms of the ratio of titanium to zirconium. The optical deflector is characterized in that it is in the range of .6 to 0.48 / 0.52.

According to a fourteenth aspect of the present invention, in the optical deflector according to the eleventh aspect , a polarization process is performed by applying a direct current voltage twice or more a drive voltage to the piezoelectric film for several minutes to several tens of minutes, The optical deflector is characterized in that it is unipolarly driven with the same polarity as that of the polarization treatment.

According to a fifteenth aspect of the present invention, there is provided an optical device comprising the optical deflector according to any one of the first to fourteenth aspects.

  In the optical deflector of the present invention, when the force generated by the piezoelectric unimorph vibrating body is directly transmitted to the torsion bar and becomes a torque for rotating the torsion bar, the diaphragm and piezoelectric actuator per piezoelectric unimorph vibrating body It is possible to increase the driving force and increase the torque applied to the torsion bar by the piezoelectric unimorph vibrator, and increase the torque applied to the torsion bar to obtain a larger deflection angle.

Furthermore, in the present invention , torque is transmitted from the piezoelectric unimorph vibrating body located symmetrically with the torsion bar to the torsion bar without being canceled out, so that torque for effectively rotating the torsion bar is generated. And a larger deflection angle can be obtained.
Further, in the present invention, there is no component that is canceled out by the torque of the piezoelectric unimorph vibrating bodies on both sides transmitted to the torsion bar, and the torque can be effectively transmitted, so that the torque transmitted to the torsion bar can be easily increased and a large deflection angle can be obtained. Become.
In addition, in the present invention, a large displacement can be obtained as compared with the conventional voltage application in which the polarity is reversed, thereby obtaining a large deflection angle.

In the invention described in claim 2 , since the piezoelectric actuator can reduce the displacement of the piezoelectric actuator in the direction orthogonal to the direction of displacement of the actuator necessary for applying torque to the torsion bar, the torque can be effectively applied to the torsion bar. Will be able to.

In the third and fourth aspects of the present invention, torque is transmitted from the piezoelectric unimorph vibrating body located symmetrically with the torsion bar to the torsion bar without being canceled, so that the torsion bar is effectively rotated. Torque can be generated, and a larger deflection angle can be obtained.

According to the fifth aspect of the present invention, when a piezoelectric actuator is produced in a large area in order to generate a large force, the amount of displacement in a direction orthogonal to the direction in which the displacement necessary for generating torque of the piezoelectric actuator is obtained. Thus, torque can be effectively applied to the torsion bar.

In the inventions according to claims 6 to 8 , since the projecting portion is formed outward from the torsion bar at the connecting portion between the diaphragm and the torsion bar to increase the contact area with the diaphragm, the piezoelectric unimorph vibration Torque transmitted to the torsion bar because the force per unit area on the joint surface when transmitting torque from the body to the torsion bar is kept small and the stress generated on the joint surface is suppressed, so that the fracture of the joint surface can be suppressed. Can be increased, and a large deflection angle can be obtained.
Furthermore, in the invention described in claim 8, since there is no corner at which stress tends to concentrate on the protrusion, the fracture of the joint surface can be further suppressed, the torque transmitted to the torsion bar can be increased, and a large deflection angle can be obtained. become.

In the ninth aspect of the present invention, torque generated by a plurality of piezoelectric unimorph vibrators can be transmitted from one coupling portion to one location of the torsion bar. Therefore, a plurality of piezoelectric unimorph vibrators connected to the same coupling portion are provided. It is only necessary to drive with the same displacement and phase, and it is easy to increase the torque transmitted to the torsion bar by an easy driving method, and a large deflection angle can be obtained.

In the invention according to claim 10 , the diaphragm can be easily bent, and the torque transmitted to the torsion bar is increased, so that a large deflection angle can be obtained.

In the invention according to the eleventh aspect , all can be manufactured by a semiconductor process, and a large number of optical deflectors can be manufactured at low cost.

In the invention described in claim 12 , high-performance piezoelectric films can be manufactured in large quantities at low cost, and optical deflectors can be manufactured in large quantities at low cost.

In the invention described in claim 13 , since the composition of lead zirconate titanate is close to the morphotropic phase boundary (MPB) and the generated torque is increased, a large deflection angle can be obtained.

In the invention according to the fourteenth aspect , a large displacement can be obtained as compared with the conventional voltage application in which the polarity is reversed, thereby obtaining a large deflection angle.

In the invention according to the fifteenth aspect , a high-performance and inexpensive optical device can be provided.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
The optical deflector in this embodiment includes a movable plate (1) capable of reflecting light, one end fixed to the movable plate (1) and the other end fixed to a support (9). 1) A pair of torsion bars (2a, 2b) that pivotally support 1) so as to be capable of rotational vibration, a diaphragm (23a-23d) and a piezoelectric actuator (28a-28d) for driving the diaphragm, And a piezoelectric unimorph vibrating body (210a to 210d) that rotationally vibrates, and the diaphragms (23a to 23d) are connected at one end to the torsion bars (2a, 2b). The other end of each end is connected to the support (9), and the diaphragm (23a to 23d), the movable plate (1), the torsion bars (2a, 2b), and the support (9) are integrally formed. The piezoelectric unimorph vibration (210a to 210d) are respectively a plurality of diaphragms (23a-1 to 23, 23b-1 to 23, 23c-1 to 23, 23d-1 to 3) and piezoelectric actuators (28a-1 to 28b-1). -3, 28c-1 to 3 and 28d-1 to 3).

  The optical deflector A according to Example 1 of the best mode for carrying out the invention will be described below with reference to FIGS.

  The optical deflector A according to the first embodiment is an example to which the inventions of claims 1 to 7, 9, and 11 to 15 are applied. As shown in the perspective view of FIG. Plate) 1, elastic support portions (torsion bars) 2a, 2b, elastic support portions 2a. 2b, piezoelectric unimorph vibrators 210a, 210b, 210c, and 210d provided on both sides, and rotational torque generated by the piezoelectric unimorph vibrators 210a, 210b, 210c, and 210d via the elastic support portions 2a and 2b. The light is transmitted to the reflecting plate 1.

Hereafter, each structure is demonstrated in order.
The support 9 supports the reflector 1 so as to be able to rotate at a predetermined displacement angle. The support 9 has a substantially rectangular shape surrounding a substantially rectangular gap 9b by a pair of vertical frames 9c and 9c and a pair of horizontal frames 9d and 9d. It is formed in a frame shape.
The reflector 1 is elastically supported by a pair of elastic support portions 2a and 2b at the central portion of the gap 9b so as to be able to rotate at a predetermined displacement angle around the elastic support portions 2a and 2b.

That is, each elastic support part 2a, 2b is formed in the shape of a prism having a substantially rectangular cross section, and is arranged on the same axis, and one end is the longitudinal center of the vertical frames 9c, 9c of the support 9 The other end is formed integrally with the reflecting plate 1 at the position of the center of gravity of the reflecting plate 1. The width W of the elastic support portions 2a and 2b is set to be sufficiently twisted so that the reflection plate 1 can be rotated to a predetermined displacement angle.
Therefore, the reflecting plate 1 can be tilted to a predetermined displacement angle with these elastic support portions 2a and 2b as rotation axes.

  The elastic support portions 2a and 2b are connected to the horizontal frames 9d and 9d of the support body 9 through a pair of piezoelectric unimorph vibrating bodies 210a and 210c and 210b and 210d, respectively.

The pair of piezoelectric unimorph vibrators 210a and 210c are arranged symmetrically with the elastic support portion 2a interposed therebetween, and the other pair of piezoelectric unimorph vibrators 210b and 210d are arranged symmetrically with the elastic support portion 2b interposed therebetween.
Furthermore, the piezoelectric unimorph vibrator 210a and the piezoelectric unimorph vibrator 210b are arranged symmetrically in the direction along the elastic support portions 2a and 2b with the reflector 1 as the center, and the piezoelectric unimorph vibrator 210c and the piezoelectric unimorph vibrator 210b. 210d is arranged symmetrically in the direction along the elastic support portions 2a and 2b with the reflector 1 as the center.

  Each of the piezoelectric unimorph vibrators 210 a, 210 b, 210 c, and 210 d is a diaphragm in which one end is connected to the elastic support portions 2 a and 2 b and the other end is connected to the horizontal frame 9 d of the support 9. 23a, 23b, 23c, and 23d, and piezoelectric actuators 28a, 28b, 28c, and 28d that vibrate the diaphragms 23a to 23d.

  In the first embodiment, each of the diaphragms 23a to 23d has three parallel diaphragms 23a-1, 23a-2, 23a-3 separated in the extending direction of the elastic support portions 2a, 2b, respectively. 23b-1, 23b-2, 23b-3, 23c-1, 23c-2, 23c-3, 23d-1, 23d-2, and 23d-3. Further, each of the parallel diaphragms 23a-1 to 23a-1 to 23b-1 to 23c-1 to 23 and 23d-1 to 3 has long sides perpendicular to the elastic support portions 2a and 2b as shown in the figure. It is formed in a rectangular shape with sides.

  Similarly, each piezoelectric actuator 28a, 28b, 28c, 28d is also arranged in parallel so that each parallel diaphragm 23a-1 to 23, 23b-1 to 23, 23c-1 to 23, and 23d-1 to 3 can vibrate. Three pieces of diaphragms 23a-1 to 23, 23b-1 to 23, 23c-1 to 23, and 23d-1 to 3 are laid on the upper surfaces of the diaphragms 23 and separated in the extending direction of the elastic support portions 2a and 2b. In parallel actuators 28a-1, 28a-2, 28a-3, 28b-1, 28b-2, 28b-3, 28c-1, 28c-2, 28c-3, 28d-1, 28d-2, 28d-3 It is configured. The parallel actuators 28a-1 to 28a-1 to 28b-1 to 28c-1 to 28d-1 to 3d are also formed in a rectangular shape having a long side in the direction perpendicular to the elastic support portions 2a and 2b. ing.

  In addition, the plate | board thickness of each parallel diaphragm 23a-1-3 of each diaphragm 23a, 23b, 23c, 23d, 23b-1-3, 23c-1-3, 23d-1-3 is the reflecting plate 1 and elasticity. By forming the support portions 2a and 2b to be thinner than the plate thickness, the rigidity is lower than that of the reflector 1 and the elastic support portions 2a and 2b.

  Furthermore, as shown in FIG. 2, the elastic support portions 2a and 2b and a pair of parallel diaphragms 23a-1 to 23b-1 to 23b-1 to 23c- arranged with the elastic support portions 2a and 2b interposed therebetween. 1 to 3 and 23d-1 to 3d are swelled in a semi-elliptical shape from the side surfaces of the elastic support portions 2a and 2b to the parallel diaphragms 23a-1 to 23b-1 to 23b-1. The protrusion part 211b which has the elliptical side surface 211a which increases the coupling area with 23c-1 to 23c and 23d-1 to 3 is formed.

  The reflector 1, the elastic support portions 2a and 2b, the vibration plates 23a, 23b, 23c and 23d, and the protruding portion 211b are integrated by removing unnecessary portions of the support 9 using a rectangular parallelepiped single crystal silicon substrate. Compared with processing methods such as bonding and adhesion, the alignment accuracy of each component can be improved. Details of the manufacturing procedure will be described later.

  Each of the piezoelectric actuators 28a to 28d is configured by stacking upper electrodes 25a, 25b, 25c, and 25d, piezoelectric films 26a, 26b, 26c, and 26d, and lower electrodes 27a, 27b, 27c, and 27d. .

  In each of the piezoelectric actuators 28a to 28d, a predetermined voltage is applied to each of the upper electrodes 25a, 25b, 25c, and 25d and the lower electrodes 27a, 27b, 27c, and 27d, and each of the piezoelectric actuators 28a, 28b, 28c, and 28d. Are driven, and the parallel diaphragms 23a-1 to 23b of the diaphragms 23a, 23b, 23c, and 23d are supported at the end where the support 9 and the elastic support parts 2a and 2b are connected. -1 to 3, 23c-1 to 23, and 23d-1 to 3 vibrate unimorphically.

  It is to be noted that when the piezoelectric actuators 28a, 28b, 28c, and 28d are driven, AC voltages having different phases are applied, and specifically, two AC voltages having phases different from each other by 180 ° are applied. ing.

  The piezoelectric actuators 28a, 28b, 28c, and 28d are formed by CSD (Chemical Solution Deposition), MOCVD (Metal Organic Chemical Vapor Depositon), sputtering, before the silicon substrate is removed. The film is formed directly on the support 9 by a method such as reactive ion plating, and patterned by wet or dry etching, specifically by an ion plating method using arc discharge plasma. The formed piezoelectric film is used.

Next, a manufacturing procedure of the optical deflector A according to the first embodiment will be described with reference to FIG. FIG. 3 shows the piezoelectric unimorph vibrators 210a and 210b on one side of the elastic support portions 2a and 2b among the piezoelectric unimorph vibrators 210a to 210d, but the piezoelectric unimorph vibrators on the opposite side. The same applies to 210c and 210d.
In Example 1, a single crystal silicon (top layer) / silicon oxide (intermediate oxide film layer) / single crystal silicon (base layer) bonded substrate (SOI substrate) having a thickness of 552 μm was used as the support 9. The thickness of each layer is 25 μm / 2 μm / 525 μm, respectively, and the surface of the top layer is subjected to optical polishing treatment.

  Therefore, first, as shown in FIG. 3A, a thermal silicon oxide film having a thickness of 500 nm to 1000 nm was formed on the surface of the SOI substrate by a diffusion furnace.

Next, as shown in FIG. 3B, Ti (titanium) and Pt (platinum) are sequentially formed on the top layer side (substrate surface) by sputtering so that their thicknesses become 50 nm and 150 nm, respectively. The lower electrode 7 was formed.
Next, zirconate titanate, which is a piezoelectric material, is prepared by a reactive arc discharge ion plating method (for example, see JP-A Nos. 2001-234331, 2002-177765, and 2003-81694). A lead (PZT) film having a thickness of 3 μm was formed on the upper electrode 5 to form a piezoelectric film 6.
Thereafter, Pt was formed on the piezoelectric film 6 with a thickness of 150 nm by sputtering to form the upper electrode 5.

Next, as shown in FIG. 3C, patterning of the upper electrode 5, the piezoelectric film 6 and the lower electrode 7 is performed on the substrate surface by photolithography and dry etching techniques, and each of the piezoelectric actuators 28a and 28b is arranged in parallel. Actuators 28a-1 to 28b-1 to 28b-1 to 3 were prepared.
At this time, the Pt / Ti layer of the lower electrode 7 on the reflection plate 1 was protected with dry resist and left as a reflection film. When it is desired to increase the light reflection efficiency of the reflecting plate 1, aluminum (Al) or gold (Au) is then sputtered and then reflected on the Pt of the reflecting plate 1 using photolithography and dry etching techniques. A film is formed.

  Next, as shown in FIG. 3D, after protecting the entire substrate surface with a thick film resist, and removing the thermal oxide film on the surface of the base layer on the back side with buffered hydrofluoric acid (BHF), An aluminum layer was formed by sputtering and patterned by photolithography and wet etching techniques to form an ICP-RIE (Inductive Coupled Plasma-Reactive Ion Etching) hard mask. Thereafter, as shown in FIG. 3E, the protective resist on the surface of the substrate is peeled off, photolithography is performed again using the resist pattern as a mask, and the top layer thermal oxide film and single crystal silicon are removed with an ICP-RIE apparatus. Removal processing was performed by dry etching to leave the reflection plate 1, elastic support portions 2 a and 2 b, and vibration plates 23 a and 23 b (23 c and 23 d), and finally, a groove to be a gap 9 b of the support 9 was formed.

  Next, as shown in FIG. 3F, the base layer single crystal silicon was dry-etched from the back side by an ICP-RIE apparatus to form a deep groove to be a gap 9b of the support 9. Finally, as shown in FIG. 3G, the intermediate oxide film layer is removed using BHF (buffered hydrofluoric acid) to form a gap 9b of the support 9, and the optical deflector A shown in FIG. Was completed.

Next, the operation of the optical deflector A according to the first embodiment will be described.
An AC voltage (for example, a sine wave) having the same phase and an opposite phase or shifted phase is applied to one piezoelectric unimorph vibrator 210a, 210b and the other piezoelectric unimorph vibrator 210c, 210d across the elastic support portions 2a, 2b. The diaphragms 23a, 23b and 23c, 23d are vibrated.

Since the base ends of the diaphragms 23a, 23b, 23c, and 23d are fixed integrally with the support body 9, the distal end portions on the elastic support portions 2a and 2b, which are the other ends, are free ends. Vibrates vertically.
As described above, the piezoelectric unimorph vibrators 210a and 210b and the piezoelectric unimorph vibrators 210c and 210d have different phases, so that the vibration plates 23a and 23b connected to the elastic support portion 2a and the vibration connected to the elastic support portion 2b are used. There is a phase difference in the vibration of the tip of the plates 23c and 23d. In particular, when the phase of the applied voltage is opposite, the vibration directions of these tip portions are opposite. That is, when the elastic support portions 2a and 2b end portions of the diaphragms 23a and 23b move upward, the elastic support portions 2a and 2b end portions of the vibration plates 23c and 23d move downward.

  At this time, a rotational torque centering on the elastic support portions 2a and 2b acts on the reflecting plate 1 and tilts about the elastic support portions 2a and 2b. When the tip portions of the diaphragms 23a, 23b, 23c, and 23d follow the AC applied voltage and repeat vertical vibrations, the seesaw-like rotational torque acts on the reflector 1 according to the above-described principle, and the reflection The plate 1 repeats rotational vibration up to a predetermined angle. Even in the case where the applied voltage is not in the opposite phase but in a vibration having a phase difference, the reflection plate 1 vibrates in the same manner as described above.

As an example of this, a sine wave bias having a voltage of 20 Vpp and 3.2 kHz having the same phase is applied to the piezoelectric actuators 28a and 28b of the piezoelectric unimorph vibrators 210a and 210b, and the piezoelectric actuators 28c and 28d of the piezoelectric unimorph vibrators 210c and 210d are subjected to the above operation. The rotation vibration of the reflector 1 was tried by applying a sine wave bias having a voltage of 20 Vpp and a frequency of 3.2 kHz in the same phase and opposite phase. Then, He—Ne laser light is incident on the reflecting plate 1, the reflected light is observed on a screen arranged with a predetermined distance, and the rotation angle of the reflecting plate 1 is measured. The rotation angle is ± 23 °. was gotten. At this time, when the optical scanning deflected by the reflecting plate 1 was observed over time, stable optical scanning with good linearity could be confirmed. The rotation angle is, for example, about ± 10 ° when the piezoelectric unimorph vibrating bodies 210a, 210b, 210c, and 210d and the piezoelectric actuator are used alone.
This is because the diaphragms 23a, 23b, 23c, and 23d of one piezoelectric unimorph vibrating body 210a, 210b, 210c, and 210d are respectively three parallel diaphragms 23a-1 to 23a, 23b-1 to 23, and 23c-1. -3, 23d-1 to 3 and three pairs of parallel actuators 28a-1 to 28, 28b-1 to 28, 28c-1 to 23, 23d-1 to 3 and their piezoelectric unimorph vibrators 210a to 210d. Since the force generated by 210d can generate a force larger than that of a conventional piezoelectric unimorph vibrating element composed of one diaphragm and one piezoelectric actuator, the elastic support portions 2a and 2b This is because the operating rotational torque is improved.

Here, when the driving frequency of the piezoelectric unimorph vibrators 210a, 210b, 210c, and 210d is equal to or close to the mechanical resonance frequency of the structure (movable mirror portion) in which the reflector 1 and the elastic support portions 2a and 2b are combined. Moreover, the rotational vibration of the reflector 1 is maximized, and the maximum displacement angle is obtained.
Further, when the resonance frequency of each of the vibration plates 23a, 23b, 23c, and 23d is set to be close to or close to the resonance frequency of the reflection plate 1, a large reflection plate even if the driving force of the piezoelectric actuators 28a, 28b, 28c, and 28d is small. A rotation angle of 1 can be obtained. Of course, although the rotation angle is small, it is possible to rotationally vibrate the reflector 1 at the drive frequency of the piezoelectric actuators 28a, 28b, 28c, 28d.
Furthermore, since the reflector 1 rotates and vibrates around the elastic support portions 2a and 2b connected at the center of gravity, translational movement can be suppressed.

Further, when the tip portions of the diaphragms 23a, 23b, 23c, and 23d vibrate in the vertical direction and force is transmitted to the elastic support portions 2a and 2b to which the vibration plates 23a, 23b, 23c, and 23d are coupled, Directional shear force acts. Therefore, when the structural strength of the connecting portion 211 is insufficient, or when stress due to a shearing force is concentrated on a part of the connecting portion 211, a problem that this portion breaks occurs.
On the other hand, in Example 1, each parallel diaphragm 23a-1 to 23b-1 to 23c-1 to 23c-1 to 23d of each diaphragm 23a, 23b, 23c, and 23d in the elastic support portions 2a and 2b, Since the protruding portions 211b are formed in the connecting portions 211 to 23d-1 to 23d-3, respectively, the dispersion of the shearing force generated in the connecting portions 211 and the concentration on a part thereof are suppressed. In addition, the occurrence of breakage is suppressed.

In the optical deflector A of the first embodiment, the driving frequency of the piezoelectric unimorph vibrators 210a, 210b, 210c, and 210d is adjusted to the mechanical resonance frequency of the reflector 1 including the elastic support portions 2a and 2b, thereby reducing the low voltage. It was confirmed that a large rotation angle can be obtained even by driving.
In addition, since the optical deflector A according to the first embodiment has a structure in which the operating point of the rotational torque from the piezoelectric unimorph vibrators 210a, 210b, 210c, and 210d is separated from the reflecting plate 1, the reflecting plate 1 has an elastic support portion. It was confirmed that only the rotational motion about the central axes 2a and 2b was excited and stable optical scanning could be performed.

As described above, in the optical deflector A of the first embodiment, the effects listed below can be obtained.
(1) Since the support body 9, the vibration plates 23a, 23b, 23c, and 23d, the elastic support portions 2a and 2b, and the reflection plate 1 are integrally formed, joining and adhesion work are not required, and manufacture is easy.
(2) Since the piezoelectric films directly formed on the support 9 are used as the piezoelectric actuators 28a to 28d, batch processing in units of Si wafers is possible, and this is also easy to manufacture.
(3) By the above (1) and (2), it is possible to reduce the size, the thickness, and the weight.
(4) Due to the miniaturization of the piezoelectric actuators 28a to 28d, it is possible to operate at a higher speed than before and to obtain a large deflection angle.
Furthermore, the protrusion part 211b is formed in the connection part 211 with each parallel diaphragm 23a-1 to 23b-1 to 23c-1 to 23d-1 to 23d in the elastic support parts 2a and 2b. Therefore, the dispersion of the shearing force generated in the connecting portion 211 and the concentration on a part thereof are suppressed, and the occurrence of breakage in the connecting portion 211 is suppressed. For this reason, the rigidity of the connecting portion can be increased to increase the deflection angle, and this high speed operation and a large deflection angle can be further achieved.
(5) Since the diaphragms 23a, 23b, 23c, and 23d are directly driven by the piezoelectric actuators 28a to 28d, the operation is possible even in the non-resonant mode.
(6) Each piezoelectric unimorph vibrating body 210a, 210b, 210c, 210d includes three parallel diaphragms 23a-1 to 23, 23b-1 to 23, 23c-1 to 23, 23d-1 to 3 and three pairs. Since the parallel actuators 28a-1 to 28a-3, 28b-1 to 28, 28c-1 to 23, and 23d-1 to 23 are provided, the force generated by the piezoelectric unimorph vibrators 210a to 210d is less than that of the conventional actuators. As described above, a larger force than that in which one piezoelectric unimorph vibrating body is constituted by one diaphragm and one piezoelectric actuator can be generated, and the rotational torque acting on the elastic support portions 2a and 2b is improved. Therefore, the torque applied to the elastic support portions 2a and 2b is increased so that the reflector 1 can take a larger deflection angle.

  Next, an optical deflector B according to Example 2 of the embodiment of the present invention will be described with reference to FIG. In addition, since this Example 2 is a modification of Example 1, only the difference will be described, and the same or equivalent configuration as in Example 1 is denoted by the same reference numeral, and description thereof is omitted. Also, the description of the same effect as the first embodiment is omitted.

  The optical deflector B of the second embodiment applies the invention of claims 1 to 7, 9, 10 to 15, and as shown in FIG. 4, the structure of piezoelectric unimorph vibrators 310a, 310b, 310c, 310d. Is different from Example 1.

  These piezoelectric unimorph vibrators 310a, 310b, 310c, and 310d have three diaphragms 33a-1, 33a-2, and 33a, each having three diaphragms 33a, 33b, 33c, and 33d, as in the first embodiment. -3, 33b-1, 33b-2, 33b-3, 33c-1, 33c-2, 33c-3, 33d-1, 33d-2, 33d-3. Each of the diaphragms 33a, 33b, 33c, and 33d is composed of the parallel diaphragms 33a-1 to 33, 33b-1 to 33, 33c-1 to 33, and 33d-1 to 33a. 13b, 13c, and 13d are coupled to the elastic support portions 2a and 2b.

  Thereby, in each piezoelectric unimorph type diaphragm 33a, 33b, 33c, 33d connected to the elastic support parts 2a, 2b, the parallel diaphragms 33a-1 to 33, 33b-1 to 33, 33c-1 to 33, 33d. Even if the number of sheets is increased from -1 to 3, the position where the torque is transmitted from the diaphragms 33a, 33b, 33c, 33d to the elastic support portions 2a, 2b can be set to the optimum position in consideration of the resonance frequency. A plurality of diaphragms 33a-1, 33a-2, 33a-3, 33b-1, 33b-2, 33b-3, 33c-1, 33c-2, 33c- connected to the portions 13a, 13b, 13c, 13d 3, 33d-1, 33d-2, and 33d-3 are driven with the same displacement and phase, the torque transmitted to the elastic support portions 2a and 2b can be easily increased by a simple driving method, and a large deflection angle can be obtained. It made. Thus, in the third embodiment, the resonance frequencies of the diaphragms 33a, 33b, 33c, and 33d are set to be close to or close to the resonance frequency of the reflector 1.

  The piezoelectric actuators 28a, 28b, 28c and 28d are the same as those shown in the first embodiment.

  In the optical deflector B of the second embodiment described above, a voltage having the same phase is applied to the piezoelectric actuators 28a and 28b as in the first embodiment, and a sine wave voltage having a phase opposite to the above phase is applied to the piezoelectric actuators 28c and 28d. The rotational vibration of the reflector 1 was tried. However, the voltage was 20 Vpp and 3 kHz.

  At this time, when the rotation angle of the reflecting plate 1 was measured in the same manner as in Example 1, a rotation angle greater than ± 27 ° and Example 1 was obtained. As in the first embodiment, the diaphragms 33a, 33b, 33c, and 33d include three parallel diaphragms 33a-1 to 33, 33b-1 to 33, 33c-1 to 33, and 33d-1 to 33d. In addition to obtaining a high rotational torque, the torque generated by the plurality of piezoelectric actuators 28a-1 to 28b-1 to 28c-1 to 28d-1 to This is because transmission can be concentrated on each of the elastic support portions 2a and 2b from the coupling portions 13a to 13d.

  Further, since the piezoelectric actuators 28a to 28d and the elastic support portions 2a and 2b are connected by the coupling portions 13a to 13d, the effective spring constants of the elastic support portions 2a and 2b can be easily calculated. The design of the resonance frequency is easy.

  Therefore, in the optical deflector C according to the second embodiment, the driving frequency of the piezoelectric actuators 28a to 28d is adjusted to the mechanical resonance frequency of the reflector 1 including the elastic support portions 2a and 2b, so that a large rotation is achieved even at low voltage driving. It was confirmed that the corner could be obtained. It was also confirmed that stable optical scanning can be performed as in Example 1.

  The optical apparatus including the optical deflectors A and B according to the first and second embodiments described above is an optical scanning apparatus (optical scanner) for forming an image on a photosensitive member such as an electrophotographic copying machine or a laser printer. It can also be applied to a barcode reader optical scanning device.

  Therefore, an optical device provided with optical deflectors A and B that can operate at high speed, obtain a large deflection angle and large amplitude operation, and can be reduced in size, thickness, and weight. Is possible.

  Next, an optical deflector according to Example 3 of the embodiment of the present invention will be described with reference to FIG. In addition, since this Example 3 is a modification of Example 1, only the difference is demonstrated, about the same or equivalent structure as Example 1, the same code | symbol is attached | subjected and description is abbreviate | omitted, Also, the description of the same effect as the first embodiment is omitted.

  In the third embodiment shown in FIG. 5, the connecting portion 411 is different from the connecting portion 211 of the first embodiment. In addition, in this Example 3, only what connects the elastic support part 2a and the parallel diaphragms 23a-1 and 23c-1 among the several connection parts 411 is shown as a representative, and other connection parts 411 are shown. Illustration is omitted.

  As for this connection part 411, the protrusion part 411b is formed in the substantially triangular pyramid shape in the cross-sectional shape, and the side surface 411a is formed in three surfaces.

  Also in the case of the fourth embodiment, since the protruding portion 411b is formed in the connecting portion 411, the dispersion of the shearing force generated in the connecting portion 411 and the concentration on a part thereof are suppressed. The occurrence of breakage is suppressed.

  Next, an optical deflector according to Example 4 of the embodiment of the present invention will be described with reference to FIG. In addition, since this Example 4 is a modification of Example 1, only the difference is demonstrated, about the same or equivalent structure as Example 1, the same code | symbol is attached | subjected and description is abbreviate | omitted, Also, the description of the same effect as the first embodiment is omitted.

  In the fourth embodiment shown in FIG. 6, the connecting portion 511 is different from the connecting portion 211 of the first embodiment. In addition, in this Example 4, only the thing which connects the elastic support part 2a and the parallel diaphragms 23a-1 and 23c-1 among the several connection parts 511 is shown as a representative, and other connection parts 511 are shown. Illustration is omitted.

  The fifth embodiment is an example in which the protruding portion is eliminated in the connecting portion 511 and the elastic support portion 2a is formed in a constant cross-sectional shape.

  As mentioned above, although embodiment and Example 1-4 of this invention were explained in full detail with reference to drawings, specific structure is not restricted to these embodiment and Example 1-4, this invention. Design changes that do not depart from the gist of the present invention are included in the present invention.

  For example, in Embodiments 1 to 4, a rectangular thin plate is used as the diaphragm, but the shape is not limited to that shown in Embodiments 1 to 4, and may be formed in a shape other than a rectangle. .

It is a perspective view which shows the optical deflector A of Example 1 of embodiment of this invention. It is a perspective view which shows the state which looked at the optical deflector A of Example 1 from the downward direction of FIG. It is explanatory drawing of the preparation procedure of the optical deflector A of Example 1. FIG. It is a perspective view which shows the optical deflector B of Example 2 of embodiment of this invention. FIG. 6 is a perspective view illustrating a main part of an optical deflector according to a third embodiment. It is a perspective view which shows the principal part of the optical deflector of Example 4. FIG. It is a perspective view which shows the optical deflector of a prior art. It is operation | movement explanatory drawing of a prior art. It is an enlarged view of the principal part of a prior art. It is an enlarged view of the principal part of a prior art.

Explanation of symbols

1 Reflector (movable plate)
2a Elastic support (torsion bar)
2b Elastic support (torsion bar)
23a diaphragm 23b diaphragm 23c diaphragm 23d diaphragm 23a-1 parallel diaphragm 23a-2 parallel diaphragm 23a-3 parallel diaphragm 23b-1 parallel diaphragm 23b-2 parallel diaphragm 23b-3 parallel diaphragm 23c- 1 Parallel diaphragm 23c-2 Parallel diaphragm 23c-3 Parallel diaphragm 23d-1 Parallel diaphragm 23d-2 Parallel diaphragm 23d-3 Parallel diaphragm 28a Piezoelectric actuator 28b Piezoelectric actuator 28c Piezoelectric actuator 28d Piezoelectric actuator 28a-1 Parallel Actuator 28a-2 Parallel actuator 28a-3 Parallel actuator 28b-1 Parallel actuator 28b-2 Parallel actuator 28b-3 Parallel actuator 28c-1 Parallel actuator 28c-2 Parallel actuator 28c-3 Parallel actuator 28d-1 Column actuator 28d-2 Parallel actuator 28d-3 Parallel actuator 9 Support body 210a Piezoelectric unimorph vibrating body 210b Piezoelectric unimorph vibrating body 210c Piezoelectric unimorph vibrating body 210d Piezoelectric unimorph vibrating body 211 Connection portion 211b Projection portion 13a Connection portion 13b Connection portion 13c Connection portion 13d joint

Claims (15)

A movable plate capable of reflecting light;
One end is fixed to the movable plate, the other end is fixed to the support, and a pair of torsion bars that pivotally support the movable plate so as to be able to rotate and vibrate,
Comprising a diaphragm and a piezoelectric actuator for driving the diaphragm, and two pairs of piezoelectric unimorph vibrators for rotating and vibrating the movable plate;
With
The pair of piezoelectric unimorph vibrators are arranged symmetrically across one of the pair of torsion bars,
The other pair of piezoelectric unimorph vibrators are arranged symmetrically across the other of the pair of torsion bars,
The diaphragm is connected at one end to a torsion bar and connected at the other end to the support,
The diaphragm, movable plate, torsion bar, and support are integrally formed,
Each of the piezoelectric unimorph vibrators, respectively, e Bei a plurality of said diaphragm and a piezoelectric actuator,
When the piezoelectric actuator is driven, the AC voltage applied to the piezoelectric actuator at a position sandwiching the torsion bar is two AC voltages that are 180 ° out of phase with each other, and the AC voltage is a DC offset voltage. An optical deflector that is amplified in the positive or negative unipolar region by superimposing the two . 2. The optical deflector according to claim 1, wherein the diaphragm and the piezoelectric actuator have a rectangular shape having a side perpendicular to the torsion bar as a long side . The optical deflector according to claim 1 , wherein at least one pair of the piezoelectric unimorph vibrators are provided on both sides of the movable plate . The optical deflector according to claim 1, wherein the unimorph vibrating body is provided symmetrically with the movable plate interposed therebetween . The piezoelectric unimorph vibrator is characterized in that the diaphragm and the piezoelectric actuator extend in a direction perpendicular to the torsion bar and are separated into a plurality in the extending direction of the torsion bar. The optical deflector according to claim 1. The protrusion part which protruded outward from the said torsion bar and expanded the contact area with the said diaphragm is provided in the connection part of the said diaphragm and the said torsion bar. Light deflector. The optical deflector according to claim 6, wherein the protrusion has two or more planes . The optical deflector according to claim 6, wherein the protrusion has a curved surface . The plurality of diaphragms are united at an end portion on the torsion bar side, connected to the torsion bar by a single coupling portion, and a cross-sectional area of a coupling portion of the coupling portion to the torsion bar is The optical deflector according to claim 1, wherein the optical deflector is formed in an area smaller than a total of sectional areas of the diaphragm . The optical deflector according to claim 1 , wherein rigidity of the diaphragm is set lower than rigidity of the torsion bar and the movable plate . 2. The optical deflector according to claim 1 , wherein the piezoelectric actuator constituting the piezoelectric unimorph vibrator is a piezoelectric film directly formed on the support . The optical deflector according to claim 11, wherein the piezoelectric film is a piezoelectric film formed by a reactive ion plating method using arc discharge plasma . The material of the piezoelectric film is lead zirconate titanate, and the composition is in the range of 0.4 / 0.6 to 0.48 / 0.52 in terms of the ratio of titanium to zirconium. Item 13. The optical deflector according to Item 12 . 12. The method according to claim 11 , wherein the piezoelectric film is subjected to a polarization process by applying a DC voltage more than twice a drive voltage to the piezoelectric film for several minutes to several tens of minutes, and is unipolarly driven with the same polarity as the polarity of the polarization process. The optical deflector as described. An optical apparatus comprising the optical deflector according to claim 1.

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