JP2005128147A - Optical deflector and optical device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To integrally form a mirror substrate and a piezoelectric element, suppress axial deviation, prevent translational movement of a mirror due to the influence of piezoelectric vibration, enable high-speed operation, large deflection angle and large amplitude operation. An optical deflector that can be obtained and can be reduced in size, thickness, and weight is provided.
SOLUTION: Piezoelectric unimorph diaphragms 3a to 3d, a support body 9 having a gap 9 'for fixing and supporting one end of the piezoelectric unimorph diaphragms 3a to 3d, and piezoelectric unimorph diaphragms 3a to 3d are connected. Elastic support portions 2a and 2b, and a mirror portion 1 that is connected to the elastic support portions 2a and 2b and rotates and vibrates in the gap 9 'by driving the piezoelectric unimorph diaphragms 3a to 3d through the elastic support portions 2a and 2b. These are integrally formed.
[Selection] Figure 1

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 small movable mirror capable of high-speed and large-amplitude operation and an optical device using the same.

  An apparatus (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 for optically deflecting light, there are generally a rotary polygon mirror (polygon mirror) and a vibrating reflector (galvano mirror), but the galvano mirror type is superior in size reduction. Yes. In particular, as a small-sized optical deflector, a trial production of a micromirror using a silicon substrate manufactured by using a micromachine technique has been reported (for example, see Patent Documents 1 and 2).

  The optical deflector disclosed in Patent Document 1 (Japanese Patent Laid-Open No. 7-175005) is characterized in that it is driven using electromagnetic force, and a pair of left and right permanent magnets and a reflecting mirror disposed on the base. And a drive coil disposed on the outer periphery of the drive coil. 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. Further, since it is necessary to bond a permanent magnet, there is a problem that the element size cannot be reduced too much.

  The optical deflector described in Patent Document 2 (Japanese Patent Laid-open No. Hei 6-180428) is driven using electrostatic force, and a drive gap is formed with a slight gap immediately below the reflecting mirror. A capacitor is composed of a mirror made of a conductor arranged oppositely. 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.

  The optical deflector using the electrostatic force can be manufactured only by a semiconductor process and has an advantage that the size can be reduced. However, since the electrostatic force is inversely proportional to the square of the distance between the mirror and the driving electrode, the mirror is driven. 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.

  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. As a method for solving this problem, an optical deflector using the vibration of a piezoelectric element as shown in FIGS. 7, 8, and 9, for example, has been proposed (see, for example, Patent Documents 3, 4, and 5).

  The optical deflector shown in FIG. 7 includes a plate-like micromirror 101, a pair of rotating supports 102 that support both sides of the micromirror 101, a frame portion 103 that surrounds them, and a frame portion 103. And a piezoelectric element 104 that applies translational motion.

  The optical deflector shown in FIG. 8 includes a support 201, piezoelectric vibrators 202a and 202b fixed to the support 201 and reciprocating, and elastic bodies 203a and 203b connected to the piezoelectric vibrators 202a and 202b. And a reflector 204 that is driven and vibrated by the piezoelectric vibrators 202a and 202b via the elastic bodies 203a and 203b.

  The optical deflector shown in FIG. 9 is placed on the conversion mechanism 301, one end side of a pair of columnar parts is connected by a hinge part 302, and an actuator 303 is interposed on the other end side. A mirror 304, an elastic support portion 305, and a support substrate 306 are arranged as movable mirror portions at an upper position.

What is common to the above proposal is that the piezoelectric element is bonded to the mirror element substrate via an elastic body, and the vibration of the piezoelectric element is converted into the rotational movement of the mirror. In the optical deflector using these piezoelectric elements, there is no limitation on the rotation of the mirror, so that a large deflection angle is obtained.
JP-A-7-175005 JP-A-6-180428 JP-A-10-197819 JP 2001-272626 A JP 2003-29191 A

  However, in the optical deflector configured to convert the translational motion of the piezoelectric element into the rotational motion of the mirror via the elastic body, a plurality of components such as a base substrate, a piezoelectric element, an elastic body, and a mirror substrate are included. If the bonding and bonding are not performed accurately, the vibration from the piezoelectric element does not propagate well to the mirror, or even if there is no problem with the bonding, not all the translational movement of the piezoelectric element is converted into a rotational movement. There was also a problem that the light beam tends to shift due to translational movement. In addition, it is difficult to reduce the size because it uses bulk ceramics, such as piezoelectric elements, metal plates, or rods, as 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.

  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 and a piezoelectric element, to suppress axial misalignment, and to prevent the mirror from being affected by piezoelectric vibration. An object of the present invention is to provide an optical deflector that can prevent translational motion, that can operate at high speed, that can provide a large deflection angle and large amplitude operation, and that can be reduced in size, thickness, and weight.

  In order to achieve the above object, an optical deflector according to the present invention includes a piezoelectric unimorph diaphragm, a support having a hollow portion that fixes and supports one end of the piezoelectric unimorph diaphragm, and the piezoelectric unimorph vibration. An elastic body connected to a plate, and a reflection plate connected to the elastic body and rotating and oscillating in the cavity by driving the piezoelectric unimorph vibration plate through the elastic body, the piezoelectric unimorph vibration plate, A support, an elastic body and a reflector are integrally formed.

  Specifically, the piezoelectric unimorph diaphragm has a pair of or two pairs of diaphragms arranged symmetrically with respect to the rotation axis of the reflector, and the phase is not uniform for each diaphragm. By applying and driving two alternating voltages having different voltages, rotational torque is applied to the reflecting plate, and the reflecting plate is converted into rotational motion having a predetermined displacement angle with the elastic support portion as a rotation axis. The incident light incident on is deflected.

  An optical device according to the present invention includes the optical deflector having the above-described configuration.

  According to the present invention, the mirror substrate and the piezoelectric element can be integrally formed, the axial deviation can be suppressed, the translational movement of the mirror due to the influence of the piezoelectric vibration can be prevented, and the high-speed operation can be performed. An amplitude operation can be obtained, and the size, thickness, and weight can be reduced.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a perspective view showing a configuration of an optical deflector according to the present invention. This optical deflector includes a piezoelectric unimorph diaphragm (diaphragms 3a to 3d) and a support (support 9) having a cavity (gap 9 ') for fixing and supporting one end of the piezoelectric unimorph diaphragm. An elastic body (elastic support portions 2a to 2d) connected to the piezoelectric unimorph diaphragm, and connected to the elastic body, and rotationally vibrates in the cavity by driving the piezoelectric unimorph diaphragm through the elastic body. The piezoelectric unimorph diaphragm, the support, the elastic body, and the reflector are integrally formed.

  The piezoelectric unimorph diaphragm has a pair of or two pairs of diaphragms arranged symmetrically with respect to the rotation axis of the reflector, and an AC voltage applied to drive the piezoelectric element in each diaphragm. The phase is not unified. Specifically, two AC voltages that are 180 ° out of phase with each other are applied.

  In the configuration shown in the figure, the mirror portion 1 that reflects incident light is held by a pair of elastic support portions 2a and 2b, and can be tilted to a predetermined displacement angle using the support portions 2a and 2b as rotation axes. It is like that. The support portions 2a and 2b are both disposed at the center of gravity of the mirror portion 1 and have the same rotating rod. The width W of the support portions 2a and 2b is set to be sufficiently twisted so that the mirror portion 1 can be rotated to a predetermined displacement angle.

  The other ends of the support portions 2a and 2b are held by the support body 9, respectively. A gap 9 is provided in the central portion of the support 9, and the mirror portion 1 has a structure that does not hinder the rotation of the mirror portion 1 with a predetermined displacement angle about the support portions 2a and 2b. Further, two pairs of diaphragms 3a, 3b, 3c, and 3d are held at one end by the support 9, and the tip driving portions 4a, 4b, 4c, and 4d formed at the other end respectively. Each is connected to the mirror unit 1. The connection positions of the tip drive units 4a, 4b, 4c, and 4d are arranged symmetrically with respect to the support units 2a and 2b. In addition, the width W ′ of each of the tip driving portions 4a, 4b, 4c, and 4d is set to be larger than the width W of the support portions 2a and 2b and difficult to twist.

  On the diaphragms 3a, 3b, 3c, and 3d, lower electrodes 5a, 5b, 5c, and 5d, piezoelectric films 6a, 6b, 6c, and 6d, and upper electrodes 7a, 7b, 7c, and d are stacked. Thus, piezoelectric actuators 8a, 8b, 8c and 8d are configured. Then, by applying predetermined voltages between the lower electrodes 5a, 5b, 5c, and 5d and the upper electrodes 7a, 7b, 7c, and 7d, the piezoelectric actuator 8a is configured with the end connected to the support 9 as a fulcrum. , 8b, 8c, 8d, the diaphragms 3a, 3b, 3c, 3d vibrate in a unimorph manner. That is, the tip driving units 4a, 4b, 4c, and 4d vibrate in the direction of the arrow R in FIG.

  Here, as the configuration of the optical deflector, the mirror unit 1, the elastic support units 2a and 2b, the diaphragms 3a, 3b, 3c and 3d, and the tip driving units 4a, 4b, 4c and 4d are processed by removing the support body 9. It is preferable to integrally form them. For example, when a single crystal silicon substrate is used as the support, it can be integrally formed by removing a part of the silicon substrate using a semiconductor process. In this case, the alignment accuracy of each component can be improved as compared with processing methods such as bonding and adhesion.

  The piezoelectric elements constituting the piezoelectric actuators 8a, 8b, 8b, 8c, and 8d are directly formed on the support 9 by a technique such as CSD, MOCVD, sputtering, or reactive ion plating before the silicon substrate is removed. A film is formed and patterned by wet or dry etching. Specifically, a piezoelectric film is formed by an ion plating method using arc discharge plasma (see Japanese Patent Application Laid-Open Nos. 2001-234331, 2002-177765, and 2003-81694).

  Next, the operation of the optical deflector will be described with reference to FIG. 2 is a cross-sectional view taken along line AA ′ in FIG.

  An alternating voltage (for example, a sine wave) having the same phase and the opposite phase or phase shift is applied to the piezoelectric actuators 8a and 8b, and the diaphragms 3a and 3b and 3b and 3d are vibrated. Since one end of each of the diaphragms 3a, 3b and 3b, 3d is fixed and held on the support 9, the tip drive units 4a, 4b and 4c, 4d vibrate in the vertical direction of the arrow R, but the tip drive unit 4a The vibrations of 4b, 4c, and 4d have a phase difference. In particular, when the phase of the applied voltage is opposite, the vibration directions of the tip drive units 4a, 4b and 4c, 4d are opposite.

  That is, when the tip drive units 4a and 4b move in the upward direction, the tip drive units 4c and 4d move in the downward direction. At this time, rotational torque about the elastic support portions 2a and 2b acts on the mirror portion 1, and the mirror portion 1 is inclined with the support portion as a central axis. When each of the tip driving units 4a, 4b and 4c, 4d follows the AC applied voltage and repeats vertical vibrations, the seesaw-like rotational torque acts on the mirror unit 1 according to the above-described principle, and the mirror unit 1 Repeats rotational vibration to a predetermined angle. Even in the case of vibrations having a phase difference instead of an antiphase, the mirror unit 1 rotates and vibrates in the same manner as described above.

  When the driving frequency of the piezoelectric actuators 8a, 8b, 8c, and 8d is equal to or close to the mechanical resonance frequency of the structure (movable mirror unit) in which the mirror unit 1 and the elastic support units 2a and 2b are combined, the mirror unit 1 The maximum vibration is obtained, and the maximum displacement angle is obtained. If the resonance frequency of the diaphragms 3a, 3b, 3c, and 3d is set to be close to or close to the resonance frequency of the movable mirror portion, the large movable mirror portion even if the driving force of the piezoelectric actuators 8a, 8b, 8c, and 8d is small. Can be obtained. Of course, although the rotation angle is small, the mirror unit 1 can be rotated and vibrated at the drive frequency of the piezoelectric actuators 8a, 8b, 8c, and 8d.

  Moreover, since the mirror part 1 is rotationally vibrated by using the elastic support parts 2a and 2b connected at the center of gravity as a rotation axis, translational movement can be suppressed.

  Next, the results of actually producing the optical deflector as described above and conducting an evaluation experiment will be described. Hereinafter, this will be described as Examples 1, 2, and 3.

(Example 1)
In Example 1, the optical deflector shown in FIG. 1 was produced. The manufacturing method is shown in FIG. As the support 9, a bonded substrate (SOI substrate) of single crystal silicon (top layer) / silicon oxide (intermediate oxide film layer) / single crystal silicon (base layer) having a thickness of 552 μm was used. 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.

  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 and pt are sequentially formed on the top layer side (substrate surface) by sputtering so that the respective thicknesses become 50 nm and 150 nm, thereby forming the lower electrode 5. did. Next, lead zirconate titanate (a piezoelectric material) is formed by a reactive arc discharge ion plating method (see Japanese Patent Laid-Open Nos. 2001-234331, 2002-177765, and 2003-81694). A PZT film having a thickness of 3 μm was formed on the Pt electrode to form a piezoelectric film 6. Thereafter, Pt was deposited on the piezoelectric film 6 with a thickness of 150 nm by sputtering to form the upper electrode 7.

  Next, as shown in FIG. 3C, the pt upper electrode 7 was patterned on the substrate surface by photolithography and dry etching techniques to form upper electrodes 7a, 7b, 7c, and 7d. Similarly, the PZT piezoelectric film 6 and the lower electrode 5 are also patterned to form the piezoelectric films 6a, 6b, 6c, and 6d and the lower electrodes 5a, 5b, 5c, and 5d, and the piezoelectric actuators 8a, 8b, 8c, and 8d are manufactured. did. At this time, the lower electrode pt / Ti layer on the mirror part 1 was protected with dry resist and left as a reflective film. When it is desired to increase the light reflection efficiency of the mirror unit 1, a reflective film is formed on Pt of the mirror unit 1 using a photolithographic technique and a dry etching technique after sputtering with Al or Au.

  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), A hard mask of ICP-RIE was formed by sputtering Al and patterning by photolithography and wet etching. 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 is performed by dry etching, leaving the mirror portion 1, elastic support portions 2a and 2b, diaphragms 3a, 3b, 3c, and 3d, and tip drive portions 4a, 4b, 4c, and 4d, and finally the support body 9 A groove to be a gap 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 9 ′ of the support 9. Finally, as shown in FIG. 3G, the intermediate oxide film layer was removed using BHF to form a gap 9 ′ of the support 9, thereby completing the optical deflector of FIG.

  Then, a sine wave bias having a voltage of 10 Vpp and 20 kHz having the same phase is applied to the piezoelectric actuators 8 a and 8 b, and a sine wave bias having a voltage of 10 Vpp and 20 kHz having the same phase opposite to the above phase is applied to the piezoelectric actuators 8 c and 8 d. The rotation vibration of part 1 was tried. He-Ne laser light is incident on the mirror unit 1 and the reflected light is observed on a screen arranged at a predetermined distance, and when the rotation angle of the mirror unit 1 is measured, a rotation angle of ± 10 ° is obtained. It was. At this time, when the optical scanning deflected by the mirror unit 1 was observed over time, stable optical scanning with good linearity could be confirmed.

  In the optical deflector of the present embodiment, the drive frequency of the piezoelectric actuators 8a, 8b, 8c, 8d is set to the mechanical resonance frequency of the mirror unit 1 including the elastic support portions 2a, 2b and the tip drive portions 4a, 4b, 4c, 4d. By combining, it was confirmed that a large rotation angle could be obtained even with low voltage driving. Since the rotational torque acting point from the piezoelectric unimorph diaphragm is separated from the rotational axis, only the rotational motion with the elastic support portions 2a and 2b as the central axis is excited, and stable optical scanning can be performed. Was confirmed.

(Example 2)
In Example 2, the optical deflector shown in FIG. 4 was produced. The manufacturing method is basically the same as that shown in Example 1, but the element structure is slightly different. In the first embodiment, the rotational torque generated by the piezoelectric unimorph diaphragm is transmitted to the mirror section 1 through the four tip drive sections 4a, 4b, 4c, and 4d. In the second embodiment, the elastic support section is used as shown in FIG. The ends of 2a and 2b that are not on the mirror part side are held by the power plates 10a and 10b to which the tip driving parts 4a, 4b, 4c, and 4d are connected, not the support 9.

  That is, the front end drive portions 4a and 4c in FIG. 4 are connected to the power plate 10a, and one end of the elastic support portion 2a is also held by the power plate 10a. Similarly, the front end drive portions 4b and 4d are connected to the power plate 10b, and one end of the elastic support portion 2b is also held by the power plate 10b. Other configurations are the same as those of the first embodiment.

  Next, the same phase voltage was applied to the piezoelectric actuators 8a and 8b as in Example 1, and a sinusoidal voltage having the opposite phase to the above-described phase was applied to the piezoelectric actuators 8c and 8d to attempt rotational vibration of the mirror unit 1. . However, the voltage was 10 Vpp and 15 kHz. When the rotation angle of the mirror unit 1 was measured in the same manner as in Example 1, a rotation angle greater than ± 15 ° and Example 1 was obtained. This is because the rotational torque acting on the power plates 10a and 10b is directly converted into the torsional deformation of the elastic support portions 2a and 2b and the energy efficiency is improved, and the tip driving portions 4a, 4b, 4c and 4d in the first embodiment are Although effective for applying a rotational torque, it acts as a resistance component that suppresses the displacement angle against the rotational vibration of the mirror part 1, whereas in the second embodiment, the elastic support part is a rotating shaft. This is probably because the resistance component is reduced because there is no portion connected to the mirror portion 1 other than 2a and 2b. However, the mechanical resonance frequency of the mirror unit 1 decreased from 20 kHz to 15 kHz because the structure was mechanically softer than the optical deflector of Example 1.

  In the optical deflector of the present embodiment, as in the first embodiment, the rotation frequency of the piezoelectric actuator is matched to the mechanical resonance frequency of the mirror section 1 including the elastic support portions 2a and 2b, thereby providing a large rotation angle even at low voltage drive. It was confirmed that it was obtained. It was also confirmed that stable optical scanning can be performed as in Example 1.

(Example 3)
In Example 3, an optical deflector composed of a pair of piezoelectric unimorph diaphragms was produced as shown in FIG. The manufacturing method is the same as that shown in Example 1. The structure is a combination of four piezoelectric unimorph diaphragms in the optical deflector of Embodiment 2 shown in FIG.

  That is, the piezoelectric unimorph diaphragms 3a and 3b in FIG. 4 are combined into 3a ′ in FIG. 5 and 3c and 3d are combined into 3b ′, and the tip driving units 4a and 4b are connected to the piezoelectric unimorph diaphragm 3a ′. The drive units 4c and 4d are connected to the piezoelectric unimorph diaphragm 3b '. Along with this, the piezoelectric actuators are also integrated into two, 8a 'and 8b'. Other configurations are the same as those of the second embodiment.

  Next, as in Example 2, a sine wave voltage of 10 Vpp and 15 kHz was applied to the piezoelectric actuator 8a ′, and a sine wave voltage of 10 Vpp and 15 kHz having the same phase opposite to that of the above voltage was applied to the piezoelectric actuator 8b ′. The rotational vibration of the mirror unit 1 was tried. When the rotation angle of the mirror unit 1 was measured in the same manner as in Example 1, a rotation angle of ± 15 ° was obtained. Also in the optical deflector of the present embodiment, the driving frequency of the piezoelectric actuator is matched to the mechanical resonance frequency of the mirror portion 1 including the elastic support portions 2a and 2b, similarly to the first and second embodiments, so that it is large even at low voltage driving. It was confirmed that the rotation angle could be obtained. Moreover, it was confirmed that stable optical scanning can be performed as in Examples 1 and 2.

  Next, an application to the optical device using the optical deflector described in FIGS. 1, 4 and 5 will be described. FIG. 6 is a diagram illustrating an example of an image display device as an optical device. In the figure, reference numeral 11 denotes an optical deflector unit in which two optical deflectors shown in FIG. 1 or FIG. 4 are arranged so that the deflection directions are orthogonal to each other, and the incident light can be raster scanned in the horizontal and vertical directions.

  The laser light incident from the laser light source 12 is subjected to predetermined intensity modulation related to the timing of optical scanning, and after passing through the condenser lens or the lens group 13, is scanned two-dimensionally by the optical deflector unit 11. The scanned laser light forms an image on the projection surface 15 through the projection lens or lens group 14.

  In addition, the optical apparatus provided with the optical deflector according to the present invention can be used in an optical scanning apparatus (optical scanner) for forming an image on a photosensitive member such as an electrophotographic copying machine or a laser printer. The present invention can also be applied to an optical scanning device.

  As described above, in the present invention, the mirror substrate and the piezoelectric element can be integrally formed, the axial deviation can be suppressed, the translational movement of the mirror due to the influence of the piezoelectric vibration can be prevented, the high-speed operation is possible, the large deflection angle and An optical deflector and an optical device that can obtain a large amplitude operation and can be reduced in size, thickness, and weight can be realized.

That is, the following effects can be obtained.
(1) The support substrate, the piezoelectric element, the elastic body, and the mirror substrate can be integrally formed (no need for bonding or bonding).
(2) The translational movement of the mirror due to the influence of piezoelectric vibration can be suppressed.
(3) Since a piezoelectric film directly formed on the support is used as the piezoelectric element, batch processing in units of Si wafers is possible.
(4) It can be made smaller, thinner and lighter than conventional elements.
(5) Due to the miniaturization of the element, it is possible to operate at a higher speed than before and to obtain a large deflection angle.
(6) Since it is directly driven by the piezoelectric film actuator, it can operate even in a non-resonant mode.

  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. The present invention can be widely applied to raster scan displays for mobile devices (for automobiles and consumer devices), ranging sensors, shape measuring sensors, optical space communication units, and the like.

The perspective view which shows the structure of the optical deflector which concerns on this invention. Sectional drawing which shows operation | movement of the optical deflector which concerns on this invention Sectional drawing which shows the manufacturing method of the optical deflector by Example 1 The perspective view which shows the structure of the optical deflector by Example 2. FIG. The perspective view which shows the structure of the optical deflector by Example 3. FIG. Explanatory drawing which shows the structure of the optical apparatus which concerns on this invention The perspective view which shows the structure of the prior art example 1. The perspective view which shows the structure of the prior art example 2. The perspective view which shows the structure of the prior art example 3.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Mirror part 2a Elastic support part 2b Elastic support part 3a Vibration plate 3b Vibration plate 3c Vibration plate 3d Vibration plate 4a Tip drive part 4b Tip drive part 4c Tip drive part 4d Tip drive part 6a Piezoelectric film 6b Piezoelectric film 6c Piezoelectric film 6d Piezoelectric Membrane 8a piezoelectric actuator 8b piezoelectric actuator 8c piezoelectric actuator 8d piezoelectric actuator 9 support 9 'gap

Claims (6)

  A piezoelectric unimorph diaphragm; a support having a cavity for fixing and supporting one end of the piezoelectric unimorph diaphragm; an elastic body connected to the piezoelectric unimorph diaphragm; and an elastic body connected to the elastic body. And a reflector that rotates and vibrates in the cavity by driving the piezoelectric unimorph diaphragm through a body, and the piezoelectric unimorph diaphragm, the support, the elastic body, and the reflector are integrally formed. Deflector.   The piezoelectric unimorph diaphragm has a pair or two pairs of diaphragms arranged symmetrically with respect to the rotation axis of the reflector, and the phase of the AC voltage applied to drive the piezoelectric element in each diaphragm. The optical deflector according to claim 1, wherein the two are not unified.   3. The optical deflector according to claim 2, wherein the AC voltage is two AC voltages whose phases are different from each other by 180 [deg.].   4. The optical deflector according to claim 1, wherein the piezoelectric element constituting the piezoelectric unimorph is a piezoelectric film directly formed on a support.   5. The optical deflector according to claim 4, wherein the piezoelectric film is a piezoelectric film formed by a reactive ion plating method using arc discharge plasma.   An optical device comprising the optical deflector according to claim 1.

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