Optical control system

Abstract

An optical control system (10) comprises an optical reflector element (100) and a control device (20). The optical reflector element (100) comprises a reflective body (110), and a first swinging part (210) and second swinging part (220) disposed at positions sandwiching the reflective body. When the first swinging part (210) and second swinging part (220) are swung so as to rotate in the same direction around a first axis, the control device (20) causes each of a first actuator (214) and a second actuator (215) of the first swinging part to vibrate so as to respectively generate, in the first actuator (214) and the second actuator (215), a first location and a second location having opposite directions of vibration in the through-thickness direction, and causes a first actuator (224) and a second actuator (225) of the second swinging part (220) to vibrate so as to respectively generate, in the first actuator (224) and the second actuator (225), a third location and a fourth location having opposite directions of vibration in the through-thickness direction.

Description

Technical Field

[0001] The present invention relates to an optical control system that reciprocates the irradiation position of laser light or the like.

Background Art

[0002] Conventional optical reflection elements that reciprocate the irradiation position of laser light, for example, as shown in Patent Document 1, include a reflector that reflects laser light or the like, a connector connected to the reflector that twists itself to rotate and swing the reflector, two arm-shaped vibrators extending in a direction intersecting the rotation axis of the reflector to generate reciprocating twists in the connector, and a driver including piezoelectric elements or the like that vibrate these vibrators respectively. Such an optical reflection element is configured such that the reflector rotates only in the twisting direction of the connector.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] An object of the present invention is to improve the performance of an optical reflection element.

Means for Solving the Problems

[0005] An optical control system according to an aspect of the present disclosure is an optical control system including an optical reflection element that reflects and reciprocates light and a control device that controls the optical reflection element. The optical reflection element includes a reflector that reflects light, and a first swing portion and a second swing portion that are respectively disposed at positions sandwiching the reflector along a first axis and swing the reflector. Each of the first swing portion and the second swing portion includes a first connector disposed along the first axis and having a tip end connected to the reflector, a first vibrator extending in a direction intersecting the first axis and connected to a base end portion of the first connector, a second vibrator extending in a direction intersecting the first axis on the opposite side of the first vibrator with respect to the first axis and connected to the base end portion of the first connector, a first driver extending along the first axis and having a base end connected to the tip end of the first vibrator and operating the first connector via the first vibrator, a second driver extending along the first axis and having a base end connected to the tip end of the second vibrator and operating the first connector via the second vibrator, and a second connector that connects the first vibrator and the second vibrator to the base body so as to be swingable. The control device vibrates the first driver and the second driver of the first swing portion so as to generate a first portion and a second portion in which the directions of vibration in the thickness direction of the optical reflection element are opposite to each other in each of the first driver and the second driver of the first swing portion when swinging the first swing portion and the second swing portion so as to rotate in the same direction around the first axis, and vibrates the first driver and the second driver of the second swing portion so as to generate a third portion and a fourth portion in which the directions of vibration in the thickness direction are opposite to each other in each of the first driver and the second driver of the second swing portion.

[0006] In an optical control system including an optical reflection element that reflects and reciprocates light and a control device that controls the optical reflection element, the optical reflection element includes a reflector that reflects light and a swing unit for swinging the reflector. The swing unit includes a first connector having a distal end connected to the reflector, a first oscillator connected to a proximal end of the first connector, a second oscillator connected to the proximal end of the first connector on the opposite side of the first oscillator, a first driver having a proximal end connected to the distal end of the first oscillator and operating the first connector via the first oscillator, a second driver having a proximal end connected to the distal end of the second oscillator and operating the first connector via the second oscillator, and a second connector that connects the first oscillator and the second oscillator to the base body so as to be swingable. When swinging the swing unit, the control device vibrates the first driver and the second driver of the swing unit so as to generate a first portion and a second portion in which the directions of vibration in the thickness direction of the optical reflection element are opposite to each other in each of the first driver and the second driver of the swing unit.

Advantages of the Invention

[0007] According to the present invention, the performance of the optical reflection element can be enhanced.

Brief Description of the Drawings

[0008]

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[0009] Next, embodiments of the optical control system according to the present invention will be described with reference to the drawings. Note that the embodiments described below are all illustrative or specific examples. The numerical values, shapes, materials, components, arrangement positions and connection forms of the components, steps, order of steps, etc. shown in the following embodiments are merely examples and are not intended to limit the present invention. In addition, among the components in the following embodiments, components not described in the independent claims indicating the most general concept are described as optional components.

[0010] The drawings are schematic diagrams that are appropriately emphasized, omitted, or adjusted in ratio to show the present invention, and may differ from the actual shapes, positional relationships, and ratios.

[0011] In the following description and drawings, the thickness direction of the optical reflection element is defined as the Z-axis direction. The direction parallel to the first axis of the optical reflection element is defined as the Y-axis direction, and the direction intersecting the first axis is defined as the X-axis direction. These X-axis direction, Y-axis direction, and Z-axis direction are directions that intersect (hereinafter, orthogonal in the embodiments) with each other. Furthermore, expressions indicating relative directions or postures such as parallel and orthogonal also include cases where they are not strictly in that direction or posture. For example, two directions being orthogonal means not only that the two directions are completely orthogonal, but also that they are substantially orthogonal, that is, including a difference of, for example, about several percent.

[0012] [Embodiment 1] (Optical reflection element) First, the optical reflection element 100 according to the present invention will be described. FIG. 1 is a plan view showing the optical reflection element 100 according to Embodiment 1.

[0013] The optical reflection element 100 is a device that periodically changes the reflection angle of light such as laser light and periodically sweeps the irradiation position of the light. As shown in FIG. 1, the optical reflection element 100 includes a rectangular frame-shaped base 105, a reflector 110, a first swinging portion 210 and a second swinging portion 220 for swinging the reflector 110. In the present embodiment, a part of the reflector 110, a part of the first swinging portion 210, a part of the second swinging portion 220, and the base 105 are integrally formed by removing unnecessary portions from a single substrate. Specifically, for example, by using an etching technique used in the semiconductor manufacturing process to remove unnecessary portions of a silicon substrate, a part of the reflector 110, a part of the first swinging portion 210, a part of the second swinging portion 220, and the base 105 are integrally formed. The optical reflection element 100 is a so-called MEMS (Micro Electro Mechanical Systems).

[0014] Here, the material constituting the substrate is not particularly limited, but materials having mechanical strength and a high Young's modulus such as metals, crystals, glass, and resins are preferable. Specifically, examples include metals and alloys such as silicon, titanium, stainless steel, Invar, and brass alloy. By using these metals, alloys, etc., an optical reflection element 100 excellent in vibration characteristics and workability can be realized.

[0015] The reflector 110 is a part that reflects light by swinging. The shape of the reflector 110 is not particularly limited. In the case of this embodiment, the reflector 110 is in the shape of a circular plate and has a reflecting portion 111 on its surface that can reflect the light to be reflected with a high reflectivity. The material of the reflecting portion 111 can be arbitrarily selected, and examples include metals such as gold, silver, copper, and aluminum, and metal compounds. Further, the reflecting portion 111 may be composed of a plurality of layers. Furthermore, the reflecting portion 111 may be formed by smoothly polishing the surface of the reflector 110. The reflecting portion 111 may be not only a flat surface but also a curved surface. The first axis 11 is a central axis passing through the center of the reflector 110.

[0016] The first swinging portion 210 and the second swinging portion 220 are respectively arranged at positions sandwiching the reflector 110 along the first axis. Specifically, the first swinging portion 210 is arranged in the minus Y-axis direction with respect to the reflector 110, and the second swinging portion 220 is arranged in the plus Y-axis direction with respect to the reflector 110.

[0017] The first swinging portion 210 and the second swinging portion 220 have the same basic configuration and are arranged to be point-symmetrical with respect to the center point of the optical reflection element 100. Therefore, the specific configuration of the first swinging portion 210 will be described in detail, and the specific structure of the second swinging portion 220 will be briefly described.

[0018] The first swinging portion 210 includes a first connector 211, a first oscillator 212, a second oscillator 213, a first driver 214, a second driver 215, and a second connector 216.

[0019] The first connecting body 211 is a long rod-shaped part extending along the first axis 11. A reflector 110 is connected to the tip of the first connecting body 211, and the base ends of the first vibrating body 212 and the second vibrating body 213 are respectively connected to the base end of the first connecting body 211. The first connecting body 211 is a part for transmitting power to the reflector 110 held at the tip. Specifically, when the first connecting body 211 is twisted about the first axis 11, it transmits a rotational rocking about the first axis 11 to the reflector 110.

[0020] The shape of the first connecting body 211 is not particularly limited, but since it is a member that rotates and rocks the reflector 110 by twisting itself, it has a thin rod shape narrower in width (length in the X-axis direction in the figure) than the reflector 110.

[0021] "Along the first axis 11" means that, as in this embodiment, not only when the first connecting body 211 extends straight, but also when the first connecting body 211 is curved in a meandering shape or bent in a zigzag shape, it is included as long as it generally follows the virtual straight first axis 11.

[0022] Also, in this specification and the claims, "intersect" is used to include not only the intersection where two lines touch but also the three-dimensional intersection where two lines do not touch.

[0023] The vibrating bodies including the first vibrating body 212 and the second vibrating body 213 are parts extending in the X-axis direction and are arm-shaped parts for operating the reflector 110 by vibrating. Specifically, the first vibrating body 212 and the second vibrating body 213 generate a torque for rotating and rocking the reflector 110 about the first axis 11 by vibrating in the circumferential direction about the first axis 11.

[0024] The first vibrating body 212 is arranged in a direction intersecting the first axis 11 and is connected to the base end of the first connecting body 211. The second vibrating body 213 is arranged in a direction intersecting the first axis 11 on the opposite side of the first vibrating body 212 with respect to the first axis 11 and is connected to the base end of the first connecting body 211.

[0025] In the case of this embodiment, the first vibrating body 212 is a rectangular bar-shaped member extending in the X-axis direction, and the second vibrating body 213 is a rectangular bar-shaped member extending in the opposite direction of the first vibrating body 212 in the X-axis direction.

[0026] Also, the base end portion of the first vibrating body 212 and the base end portion of the second vibrating body 213 are integrally connected by a connecting body 217. As a result, the first vibrating body 212 and the second vibrating body 213 are straight bar-shaped members extending in the orthogonal direction about the first axis 11.

[0027] The driving body including the first driving body 214 and the second driving body 215 is a member that generates a driving force for vibrating the vibrating body. The first driving body 214 is a member that is connected to the tip end portion of the first vibrating body 212 and vibrates the first vibrating body 212. The second driving body 215 is a member that is connected to the tip end portion of the second vibrating body 213 and vibrates the second vibrating body 213.

[0028] The first driving body 214 includes a first driving main body portion 2141 and a first piezoelectric element 2142. The base end portion of the first driving main body portion 2141 is integrally connected to the tip end portion of the first vibrating body 212, and it is a rod-shaped body extending along the first axis 11 toward the reflector 110. The overall length (the length in the Y-axis direction) of the first driving main body portion 2141 is longer than the overall length (the length in the X-axis direction) of the first vibrating body 212. The first piezoelectric element 2142 is provided on the surface of the first driving main body portion 2141.

[0029] The first piezoelectric element 2142 is an elongated plate-shaped piezoelectric element arranged along the first axis 11 on the surface of the first driving main body portion 2141. The first piezoelectric element 2142 is arranged at a position including the central portion of the first driving body 214. Specifically, the first piezoelectric element 2142 is arranged over the entire length of the first driving main body portion 2141.

[0030] By applying a periodically varying voltage to the first piezoelectric element 2142, the first piezoelectric element 2142 repeats expansion and contraction. Corresponding to the movement of the first piezoelectric element 2142, the first drive main body 2141 repeats bending and returning. The tip of the first drive main body 2141 that protrudes more than the base end portion connected to the first vibrating body 212 vibrates greatly, and the vibration energy of the entire first drive body 214 is transmitted to the tip of the first vibrating body 212.

[0031] Similar to the first drive body 214, the second drive body 215 includes a second drive main body 2151 and a second piezoelectric element 2152, and is arranged at a position symmetric to the first drive body 214 with respect to a virtual plane that includes the first axis 11 and is orthogonal to the surface of the reflector 110. The base end portion of the second drive body 215 is connected to the tip of the second vibrating body 213. Also, the operation of the second drive body 215 is the same as the operation of the first drive body 214.

[0032] In the case of this embodiment, the piezoelectric element is, for example, a thin film laminated type piezoelectric actuator. The thin film laminated type piezoelectric actuator has a laminated body structure in which an electrode and a piezoelectric body are laminated in the thickness direction on the surface of the drive main body. As a result, the drive body can be made thinner.

[0033] Note that the drive body does not have to be only one that vibrates due to the strain of the piezoelectric element. As other drive bodies, for example, members and devices in which a force is generated by the interaction with a magnetic field or an electric field are provided, and at least one of the magnetic field and the electric field generated by an external device is changed, and at least one of the magnetic field and the electric field generated by itself is changed to vibrate. Also, examples of the material constituting the piezoelectric body can include piezoelectric body materials having a high piezoelectric constant such as lead zirconate titanate (PZT).

[0034] The base body 105 is a member for attaching the optical reflection element 100 to an external structural member or the like, and has a rectangular frame shape that is long in the Y-axis direction. Specifically, the base body 105 has a first side portion 51 and a second side portion 52 that each extend in the X-axis direction and face each other in the Y-axis direction. Further, the base body 105 has a third side portion 53 and a fourth side portion 54 that each extend in the Y-axis direction and face each other in the X-axis direction.

[0035] At the inner central portion of the first side portion 51, a second connector 216 that connects the first vibrating body 212 and the second vibrating body 213 in a vibration-free manner is connected. The second connector 216 is arranged along the first axis 11, the base end portion is connected to the first side portion 51, and the tip end portion is connected to the base end portions of the first vibrating body 212 and the second vibrating body 213 via a connecting body 217.

[0036] The shape of the second connector 216 is not particularly limited, but since it is a member that allows the torsional deformation of the first connector 211 with respect to the first side portion 51 due to its own torsional deformation caused by the vibrations of the first vibrating body 212 and the second vibrating body 213, it has a rod shape with higher torsional rigidity than the first connector 211.

[0037] Note that, similar to the first connector 211, the second connector 216 may not only extend straight along the first axis 11, but may also be curved in a meandering shape or bent in a zigzag shape. Even in such a case, when comparing the torsional rigidity around the first axis 11 between the first connector 211 and the second connector 216, the torsional rigidity of the first connector 211 is weaker.

[0038] Next, the specific structure of the second swinging portion 220 will be described. As described above, the second swinging portion 220 has the same basic configuration as the first swinging portion 210. The second swinging portion 220 is arranged so as to be point-symmetric with respect to the first swinging portion 210 with reference to the center point of the optical reflection element 100. Therefore, the description will be centered on the correspondence relationship between the respective portions of the second swinging portion 220 and the respective portions of the first swinging portion 210.

[0039] The second swinging part 220 includes a first connecting body 221, a first vibrating body 222, a second vibrating body 223, a first driving body 224, a second driving body 225, and a second connecting body 226.

[0040] The first connecting body 221 is a part corresponding to the first connecting body 211 of the first swinging part 210. The first vibrating body 222 is a part corresponding to the first vibrating body 212 of the first swinging part 210, and the second vibrating body 223 is a part corresponding to the second vibrating body 213 of the first swinging part 210. The first vibrating body 222 and the second vibrating body 223 have an inverse positional relationship in the X-axis direction with respect to the first vibrating body 212 and the second vibrating body 213 of the first swinging part 210. The base end of the first vibrating body 222 and the base end of the second vibrating body 223 are integrally connected by a connecting body 227.

[0041] The first driving body 224 is a part corresponding to the first driving body 214 of the first swinging part 210, and the second driving body 225 is a part corresponding to the second driving body 215 of the first swinging part 210. The first driving body 224 and the second driving body 225 have an inverse positional relationship in the X-axis direction with respect to the first driving body 214 and the second driving body 225 of the first swinging part 210. The first driving body 224 has a first driving main body part 2241 and a first piezoelectric element 2242, and these correspond to the first driving main body part 2141 and the first piezoelectric element 2142 of the first driving body 214. The second driving body 225 has a second driving main body part 2251 and a second piezoelectric element 2252, and these correspond to the second driving main body part 2151 and the second piezoelectric element 2152 of the second driving body 215.

[0042] The second connecting body 226 is a part corresponding to the second connecting body 216 of the first swinging part 210. The second connecting body 226 is arranged along the first axis 11, the base end is connected to the second side part 52, and the tip end is connected to the base ends of the first vibrating body 222 and the second vibrating body 223 via the connecting body 227.

[0043] (Optical control system) Next, the optical control system 10 including the above-described optical reflection element 100 will be described. FIG. 2 is a block diagram showing the control configuration of the optical control system 10 according to Embodiment 1.

[0044] As shown in FIG. 2, the optical control system 10 includes an optical reflection element 100 and a control device 20 that controls the optical reflection element 100. A plurality of monitor elements are attached to the optical reflection element 100 at appropriate positions. The monitor element is an element that detects the curved state of each vibrating body as strain. By measuring the output from the monitor element, the rocking state of the reflector 110 can be accurately monitored. Specifically, the first rocking portion 210 is provided with a first monitor element 218 that detects the strain of the first vibrating body 212 and a second monitor element 219 that detects the strain of the second vibrating body 213. The second rocking portion 220 is provided with a first monitor element 228 that detects the strain of the first vibrating body 222 and a second monitor element 229 that detects the strain of the second vibrating body 223.

[0045] The control device 20 includes an angle detection circuit 21, a drive circuit 22, and a control circuit 23. The angle detection circuit 21 receives detection signals from each monitor element (the first monitor elements 218 and 228, and the second monitor elements 219 and 229), detects the angle information of the reflector 110 based on the detection signals, and outputs the angle information to the control circuit 23.

[0046] The drive circuit 22 is a circuit that outputs a periodic voltage to each piezoelectric element (the first piezoelectric elements 2142 and 2242, and the second piezoelectric elements 2152 and 2252) based on a drive signal from the control circuit 23.

[0047] The control circuit 23 is a circuit that adjusts the drive signal output to the drive circuit 22 so that the reflector 110 assumes an arbitrary angle based on the angle information of the reflector 110 input from the angle detection circuit 21.

[0048] Here, the case where the angle detection circuit 21, the drive circuit 22, and the control circuit 23 are dedicated circuits has been exemplified. However, the control device 20 may be executed by one or more electronic circuits including a semiconductor device, a semiconductor integrated circuit (IC), or an LSI (large scale integration). The LSI or IC may be integrated on one chip or may be configured by combining a plurality of chips.

[0049] Also, the monitor element may be provided on the reflector 110 or may not be provided on the optical reflector element 100.

[0050] (Operation) Next, the operation of the optical reflector element 100 will be described. The optical reflector element 100 operates based on the control of the control device 20. The control device 20 rotates and swings the reflector 110 around the first axis 11. That is, the control device 20 rotates and swings the first swing part 210 and the second swing part 220 in the same direction around the first axis 11. At this time, the control device 20 causes the first driving body 214 and the second driving body 215 of the first swing part 210 to generate a first part and a second part in which the vibration directions in the thickness direction (Z-axis direction) of the optical reflector element 100 are opposite to each other. Similarly, the control device 20 causes the first driving body 224 and the second driving body 225 of the second swing part 220 to generate a third part and a fourth part in which the vibration directions in the thickness direction are opposite to each other.

[0051] Hereinafter, the control method by the control device 20 will be described.

[0052] FIG. 3 is an explanatory diagram showing an example of a drive signal for operating the optical reflection element 100 according to Embodiment 1. The drive signal is a signal for applying an AC voltage that periodically varies each piezoelectric element, and has a resonance frequency at which each driving body can vibrate. In FIG. 3, as an example of the drive signal, the waveforms of the first drive signal W1 and the second drive signal W2 are illustrated for one period. The second drive signal W2 has a waveform that is out of phase with the first drive signal W1. The control device 20 applies the first drive signal W1 to the first piezoelectric element 2142 of the first swinging portion 210 and the second piezoelectric element 2252 of the second swinging portion 220, and applies the second drive signal W2 to the second piezoelectric element 2152 of the first swinging portion 210 and the first piezoelectric element 2242 of the second swinging portion 220. Thereby, the first swinging portion 210 and the second swinging portion 220 rotate and swing in the same direction around the first axis 11.

[0053] Here, taking the first swinging portion 210 as an example, specific examples of the first drive signal W1 and the second drive signal W2 will be described. The first drive signal W1 is set to a resonance frequency that resonates in a mode that generates first portions 214a, 215a and second portions 214b, 215b in which the directions of vibration in the thickness direction are opposite in each of the first driving body 214 and the second driving body 215 of the first swinging portion 210. That is, it can be said that the first drive signal W1 is determined based on the natural vibration frequency of the first swinging portion 210.

[0054] Although the second drive signal W2 is out of phase with the first drive signal W1, it is set to substantially the same frequency. In the present embodiment, the first drive signal W1 and the second drive signal W2 are set to frequencies that resonate in a natural mode having one inflection point between the first portions 214a, 215a and the second portions 214b, 215b in each of the first driving body 214 and the second driving body 215 of the first swinging portion 210. Note that the first drive signal W1 and the second drive signal W2 may be frequencies that resonate in a natural mode having two or more inflection points between the first portions 214a, 215a and the second portions 214b, 215b.

[0055] In the second swing part 220, the first drive signal W1 corresponds to the second drive body 225, and the second drive signal W2 corresponds to the first drive body 224.

[0056] FIG. 4 is a perspective view showing the states of respective parts when the optical reflection element 100 according to Embodiment 1 is operating. As shown in FIG. 4, in the first swing part 210, when the first drive signal W1 is applied to the first piezoelectric element 2142 and the second drive signal W2 is applied to the second piezoelectric element 2152 by the control device 20, first parts 214a, 215a and second parts 214b, 215b in which the vibration directions in the thickness direction are opposite to each other are generated in the first drive body 214 and the second drive body 215, respectively. Specifically, in the first drive body 214, the first part 214a is the base end part of the first drive body 214, and the second part 214b is the tip end part of the first drive body 214. When the first part 214a of the first drive body 214 moves in the +Z axis direction (arrow Z11 in FIG. 4), the second part 214b moves in the -Z axis direction (arrow Z12 in FIG. 4). Conversely, when the first part 214a of the first drive body 214 moves in the -Z axis direction, the second part 214b moves in the +Z axis direction.

[0057] In the second drive body 215, the first part 215a is the tip end part of the second drive body 215, and the second part 215b is the base end part of the second drive body 215. When the first part 215a of the second drive body 215 moves in the +Z axis direction (arrow Z21 in FIG. 4), the second part 215b moves in the -Z axis direction (arrow Z22 in FIG. 4). Conversely, when the first part 215a of the second drive body 215 moves in the -Z axis direction, the second part 215b moves in the +Z axis direction.

[0058] As a result, in the first swing part 210, the first drive body 214 and the first vibrating body 212, and the second drive body 215 and the second vibrating body 213 rotate and swing in the same direction in the circumferential direction about the first axis 11.

[0059] On the other hand, in the second swing part 220, when a first drive signal W1 is applied to the second piezoelectric element 2252 and a second drive signal W2 is applied to the first piezoelectric element 2242 by the control device 20, third parts 224c, 225c and fourth parts 224d, 225d where the vibration directions in the thickness direction are opposite are generated in the first drive body 224 and the second drive body 225, respectively. Specifically, in the first drive body 224, the third part 224c is the tip of the first drive body 224, and the fourth part 224d is the base end of the first drive body 224. When the third part 224c of the first drive body 224 moves in the +Z axis direction (arrow Z31 in FIG. 4), the fourth part 224d moves in the -Z axis direction (see arrow Z32 in FIG. 4). Conversely, when the third part 224c of the first drive body 224 moves in the -Z axis direction, the fourth part 224d moves in the +Z axis direction.

[0060] In the second drive body 225, the third part 225c is the base end of the second drive body 225, and the fourth part 225d is the tip of the second drive body 225. When the third part 225c of the second drive body 225 moves in the +Z axis direction (arrow Z41 in FIG. 4), the fourth part 225d moves in the -Z axis direction (arrow Z42 in FIG. 4). Conversely, when the third part 225c of the second drive body 225 moves in the -Z axis direction, the fourth part 225d moves in the +Z axis direction. That is, also in the second swing part 220, similar to the first swing part 210, the first drive body 224 and the first vibrating body 222, and the second drive body 225 and the second vibrating body 223 rotate and swing in the same direction in the circumferential direction around the first axis 11.

[0061] In this way, when the first swing part 210 and the second swing part 220 rotate and swing in the same direction around the first axis 11, torsions centered on the first axis 11 occur in the first connectors 211, 221, so that the reflector 110 also rotates and swings around the first axis 11 (see arrow Y1 in FIG. 1). In the present embodiment, when the first swing part 210 and the second swing part 220 rotate and swing in the same direction around the first axis 11, the reflector 110 also rotates and swings around the first axis 11 in the same direction as these.

[0062] FIG. 5 is a graph schematically showing vibrations in the case where a resonance frequency that does not generate an inflection point is imparted to the driving bodies (the first driving bodies 214 and 224 and the second driving bodies 215 and 225) according to the first embodiment (first mode), and in the case where a resonance frequency that generates an inflection point is imparted (second mode). It can be seen that the displacement of the base end portion of the driving body is larger in the second mode than in the first mode. As a result, the first vibrating bodies 212 and 222 and the second vibrating bodies 213 and 223 also rotate and swing greatly, so the first connecting bodies 211 and 221 are also greatly twisted. Therefore, the contact angle of the reflector 110 also becomes larger.

[0063] (Effects, etc.) As described above, according to the optical control system 10 according to the present embodiment, an optical reflection element 100 that reflects light and reciprocates it, and a control device 20 that controls the optical reflection element 100 are provided. The optical reflection element 100 includes a reflector 110 that reflects light, and a first swing portion 210 and a second swing portion 220 that are respectively disposed at positions sandwiching the reflector 110 along the first axis 11 and swing the reflector 110. Each of the first swing portion 210 and the second swing portion 220 is disposed along the first axis 11, and first connectors 211 and 221 whose tip ends are connected to the reflector 110, extend in a direction intersecting the first axis 11, and are connected to the base ends of the first connectors 211 and 221. First vibrating bodies 212 and 222, extend in a direction intersecting the first axis 11 on the opposite side of the first vibrating bodies 212 and 222 with respect to the first axis 11, and are connected to the base ends of the first connectors 211 and 221. Second vibrating bodies 213 and 223, extend along the first axis 11, the base ends are connected to the tip ends of the first vibrating bodies 212 and 222, and first driving bodies 214 and 224 that operate the first connectors 211 and 221 via the first vibrating bodies 212 and 222, extend along the first axis 11, the base ends are connected to the tip ends of the second vibrating bodies 213 and 223, and second driving bodies 215 and 225 that operate the first connectors 211 and 221 via the second vibrating bodies 213 and 223, and second connectors 216 and 226 that connect the first vibrating bodies 212 and 222 and the second vibrating bodies 213 and 223 to the base body 105 so as to be swingable. When swinging the first swing portion 210 and the second swing portion 220 so as to rotate in the same direction around the first axis 11, the control device 20 causes the first driving bodies 214 and 215 of the first swing portion 210 to generate first portions 214a and 215a and second portions 214b and 215b in which the vibration directions in the thickness direction of the optical reflection element 100 are opposite directions, and vibrates the first driving bodies 214 and 215 of the first swing portion 210. At the same time, in each of the first driving bodies 224 and 225 of the second swing portion 220, third portions 224c and 225c and fourth portions 224d and 225d in which the vibration directions in the thickness direction are opposite directions are generated, and the first driving bodies 224 and 225 of the second swing portion 220 are vibrated.

[0064] According to this, in each of the first driving bodies 214 and 215 of the first swinging part 210, first parts 214a, 215a and second parts 214b, 215b are generated in which the directions of vibration in the thickness direction are opposite to each other. Thereby, the displacement at the base end of each of the first driving body 214 and the second driving body 215 can be increased.

[0065] On the other hand, in each of the first driving bodies 224 and 225 of the second swinging part 220, third parts 224c, 225c and fourth parts 224d, 225d are generated in which the directions of vibration in the thickness direction are opposite to each other. Thereby, the displacement at the base end of each of the first driving body 224 and the second driving body 225 can be increased.

[0066] Due to these, the first vibrating bodies 212, 222 and the second vibrating bodies 213, 223 also rotate and swing greatly, so the first connecting bodies 211, 221 are also greatly twisted, and the contact angle of the reflector 110 can also be increased. Therefore, the swinging range of the reflector 110 can be widened, and the performance of the optical reflection element 100 can be improved.

[0067] In addition, the total length of each of the first driving bodies 214, 224 and the second driving bodies 215, 225 is longer than the total length of each of the first vibrating bodies 212, 222 and the second vibrating bodies 213, 223.

[0068] According to this, for example, since the total length of the first driving body 214 is longer than the total length of the first vibrating body 212, the rotational torque with respect to the base end of the first driving body 214 can be increased. This is the same for the other driving bodies (the first driving body 224, the second driving body 215, 225). In this way, since the rotational torque with respect to the base end of each first driving body is increased, the driving efficiency can be improved.

[0069] Note that the ratio of the total length of the driving bodies (the first driving bodies 214 and 224, the second driving bodies 215 and 225) to the total length of the vibrating bodies (the first vibrating bodies 212 and 222, the second vibrating bodies 213 and 223) is preferably 0.15 or more and 0.5 or less. With this relationship, it is possible to suitably increase the rotational torque with respect to the base end portion of the driving body.

[0070] Also, in each driving body having a longer total length than each vibrating body, piezoelectric elements (the first piezoelectric elements 2142 and 2242, the second piezoelectric elements 2152 and 2252) are provided over the entire length thereof. For this reason, the volume of the piezoelectric element can be made relatively large. If the volume of the piezoelectric element is large, a larger vibration can be generated in each driving body, so that the driving efficiency can also be improved.

[0071] [Embodiment 2] Next, Embodiment 2 will be described. In the following description, the same parts as those in the above Embodiment 1 may be denoted by the same reference numerals and the description thereof may be omitted.

[0072] In Embodiment 2, an optical reflection element 100A in which piezoelectric elements are provided on the first vibrating body and the second vibrating body is exemplified. FIG. 6 is a plan view showing the optical reflection element 100A according to Embodiment 2. Specifically, FIG. 6 corresponds to FIG. 1.

[0073] As shown in FIG. 6, in the first swinging portion 210a of the optical reflection element 100A, the first vibrating body 212a includes the third piezoelectric element 2122, and the second vibrating body 213a includes the fourth piezoelectric element 2132. Specifically, the third piezoelectric element 2122 is disposed on the surface of the first vibrating body 212a. The third piezoelectric element 2122 is disposed at a position including the central portion of the first vibrating body 212a. In the present embodiment, the third piezoelectric element 2122 is disposed over the entire length of the first vibrating body 212a. As described above, the first piezoelectric element 2142 is disposed over the entire length of the first driving body 214. Therefore, the inflection point in the entirety of the first driving body 214 and the first vibrating body 212a that occurs when the first driving body 214 and the first vibrating body 212a vibrate is included within the first piezoelectric element 2142. That is, between the base point of the first vibrating body 212a and the inflection point, the entire third piezoelectric element 2122 and at least a part of the first piezoelectric element 2142 are included.

[0074] On the other hand, the fourth piezoelectric element 2132 is disposed on the surface of the second vibrating body 213a. The fourth piezoelectric element 2132 is disposed at a position including the central portion of the second vibrating body 213a. In the present embodiment, the fourth piezoelectric element 2132 is disposed over the entire length of the second vibrating body 213a. As described above, the second piezoelectric element 2152 is disposed over the entire length of the second driving body 215. Therefore, the inflection point in the entirety of the second driving body 215 and the second vibrating body 213a that occurs when the second driving body 215 and the second vibrating body 213a vibrate is included within the second piezoelectric element 2152. That is, between the base point of the second vibrating body 213a and the inflection point, the entire fourth piezoelectric element 2132 and at least a part of the second piezoelectric element 2152 are included.

[0075] Note that also in the second swinging portion 220a, the first vibrating body 222a includes the third piezoelectric element 2222, and the second vibrating body 223a includes the fourth piezoelectric element 2232. However, basically, it is the same as the first swinging portion 210a, and thus the description thereof is omitted.

[0076] These third piezoelectric elements 2122 and 2222 and fourth piezoelectric elements 2132 and 2232 are electrically connected to the control device 20 respectively. When the control device 20 rotationally oscillates the first swing part 210a and the second swing part 220a so as to rotate in the same direction around the first axis 11, the control device 20 vibrates the third piezoelectric elements 2122 and 2222 and the fourth piezoelectric elements 2132 and 2232.

[0077] Specifically, the control device 20 applies a first drive signal W1 to the first piezoelectric element 2142 and the fourth piezoelectric element 2132 of the first swing part 210a, and to the second piezoelectric element 2252 and the third piezoelectric element 2222 of the second swing part 220a, and applies a second drive signal W2 to the second piezoelectric element 2152 and the third piezoelectric element 2122 of the first swing part 210a, and to the first piezoelectric element 2242 and the fourth piezoelectric element 2232 of the second swing part 220a. FIG. 7 is a schematic diagram showing signals applied to respective parts in the optical reflection element 100A according to Embodiment 2.

[0078] Thereby, in the first swing part 210a, the first vibrating body 212a vibrates in a direction opposite to the thickness direction with respect to the first driving body 214, and the second vibrating body 213a vibrates in a direction opposite to the thickness direction with respect to the second driving body 215. On the other hand, in the second swing part 220a, while the first vibrating body 222a vibrates in a direction opposite to the thickness direction with respect to the first driving body 224, the second vibrating body 223a vibrates in a direction opposite to the thickness direction with respect to the second driving body 225. Thereby, for example, in the first driving body 214, since it is excited by the vibration stimulus of the first vibrating body 212a, it vibrates more greatly. Since this is the same for each driving body, each of the first swing part 210a and the second swing part 220a rotates and oscillates greatly.

[0079] (Effects, etc.) As described above, according to the present embodiment, the control device 20 vibrates the first vibrating body 212a of the first swinging part 210a in the direction opposite to the first driving body 214 in the thickness direction, and vibrates the second vibrating body 213a of the first swinging part 210a in the direction opposite to the second driving body 215 in the thickness direction. At the same time, while vibrating the first vibrating body 222a of the second swinging part 220a in the direction opposite to the first driving body 224 in the thickness direction, the second vibrating body 223a of the second swinging part 220a is vibrated in the direction opposite to the second driving body 225 in the thickness direction.

[0080] According to this, since the vibration of each vibrating body excites each driving body, the vibration of each driving body can be amplified. Therefore, each of the first swinging part 210a and the second swinging part 220a will rotate and swing greatly, and the driving efficiency can be improved.

[0081] Further, the first driving bodies 214, 224 include first piezoelectric elements 2142, 2242 controlled by the control device 20. The second driving bodies 215, 225 include second piezoelectric elements 2152, 2252 controlled by the control device 20. The first vibrating bodies 212a, 222a include third piezoelectric elements 2122, 2222 controlled by the control device 20. The second vibrating bodies 213a, 223a include fourth piezoelectric elements 2132, 2232 controlled by the control device 20. The first piezoelectric elements 2142, 2242 are arranged at positions including the inflection points during vibration in the entirety of the first driving bodies 214, 224 and the first vibrating bodies 212a, 222a. The second piezoelectric elements 2152, 2252 are arranged at positions including the inflection points during vibration in the entirety of the second driving bodies 215, 225 and the second vibrating bodies 213a, 223a.

[0082] According to this, in the entirety of the first driving bodies 214 and 224 and the first vibrating bodies 212a and 222a, between the base points and the inflection points of the first vibrating bodies 212a and 222a, the entirety of the third piezoelectric elements 2122 and 2222 and at least a part of the first piezoelectric elements 2142 and 2242 are included. That is, since a plurality of piezoelectric elements are included between the base points and the inflection points of the first vibrating bodies 212a and 222a, it is possible to easily excite the first driving bodies 214 and 224 and the first vibrating bodies 212a and 222a.

[0083] Similarly, in the entirety of the second driving bodies 215 and 225 and the second vibrating bodies 213a and 223a, between the base points and the inflection points of the second vibrating bodies 213a and 223a, the entirety of the fourth piezoelectric elements 2132 and 2232 and at least a part of the second piezoelectric elements 2152 and 2252 are included. That is, since a plurality of piezoelectric elements are included between the base points and the inflection points of the second vibrating bodies 213a and 223a, it is possible to easily excite the second driving bodies 215 and 225 and the second vibrating bodies 213a and 223a.

[0084] [Embodiment 3] Next, Embodiment 3 will be described. In Embodiment 1, when the first swinging portion 210 and the second swinging portion 220 rotate and swing in the same direction around the first axis 11, the case where the reflector 110 also rotates and swings around the first axis 11 in the same direction as these was exemplified. In Embodiment 3, the case where when the first swinging portion 210 and the second swinging portion 220 rotate and swing in the same direction around the first axis 11, the reflector 110 rotates and swings in the opposite direction to these will be described. Also, in Embodiment 3, the optical reflection element 100 of Embodiment 1 will be exemplified and its control method will be described.

[0085] Specifically, each of the first connectors 211 and 221 has, for example, a shape in which odd nodes are generated when the first driving signal W1 and the second driving signal W2 are applied to the first driving bodies 214 and 224 and the second driving bodies 215 and 225. For example, by adjusting the overall length, cross-sectional shape, outer shape, etc. of each of the first connectors 211 and 221, a shape in which odd nodes are generated is set.

[0086] FIG. 8 is a schematic diagram showing nodes generated in the optical reflection element 100 according to Embodiment 3. As shown in FIG. 8, one node 211s, 221s is generated at an intermediate position of each of the first connectors 211, 221. Here, the "node" refers to a portion where the torsional direction of the first connectors 211, 221 is reversed at its peripheral position.

[0087] When, under the control of the control device 20, a counterclockwise rotation (arrow Y11 in FIG. 8) occurs around the first axis 11 at the base ends of the first connectors 211, 221, a clockwise rotation (arrow Y12 in FIG. 8) occurs around the first axis 11 at the tip ends rather than at the nodes 211s, 221s. As a result, the reflector 110 also rotates clockwise. Conversely, when a clockwise rotation occurs around the first axis 11 at the base ends of the first connectors 211, 221, a counterclockwise rotation occurs around the first axis 11 at the tip ends rather than at the nodes 211s, 221s. As a result, the reflector 110 also rotates counterclockwise.

[0088] That is, when these operations are repeated, when the first swinging portion 210 and the second swinging portion 220 rotate and swing in the same direction around the first axis 11, the reflector 110 rotates and swings in the opposite direction to the first swinging portion 210 and the second swinging portion 220.

[0089] (Effects, etc.) As described above, according to the present embodiment, each of the first connectors 211, 221 of the first swinging portion 210 and the second swinging portion 220 has a shape in which an odd number of nodes 211s, 221s are generated when the first swinging portion 210 and the second swinging portion 220 are rotated and swung in the same direction.

[0090] According to this, when the first swinging part 210 and the second swinging part 220 rotate and swing in the same direction around the first axis 11, the reflector 110 rotates and swings in the opposite direction to these. At this time, within the first connectors 211 and 221, since the torsional direction is reversed with respect to the nodes 211s and 221s, a vibration confinement effect occurs. As a result, the resonance mode for rotating the reflector 110, that is, the resonance sharpness (Q value) of the resonance mode (driving mode) that the optical reflection element 100 has, becomes higher. If the resonance sharpness (Q value) becomes higher, the swing angle characteristic of the reflector 110 can be increased. That is, in the third embodiment, it is possible to rotate and swing the reflector 110 within a larger range than the reflector 110 of the first embodiment.

[0091] In addition, in the present embodiment, the case where one node 211s and 221s is generated in each of the first connectors 211 and 221 is illustrated, but the number of nodes generated for one connector may be an odd number of 3 or more. If the number of generated nodes is odd, when the first swinging part 210 and the second swinging part 220 rotate and swing in the same direction around the first axis 11, the reflector 110 rotates and swings in the opposite direction to these.

[0092] [Embodiment 4] Next, Embodiment 4 will be described. In the following description, parts that are the same as those in the above-described Embodiment 1 may be denoted by the same reference numerals and their description may be omitted.

[0093] In the above-described Embodiment 1, a disc-shaped reflector 110 was illustrated, but in this Embodiment 4, a reflector 110b with a higher stress relaxation effect than the disc-shaped reflector 110 will be described.

[0094] FIG. 9 is a plan view showing the reflector 110b according to Embodiment 4. As shown in FIG. 9, the reflector 110b includes a reflector main body 114, a plurality of pillar parts 115, and a frame body 116.

[0095] The reflector body 114 is disc-shaped, and a reflecting portion 111 is provided on its surface. A plurality of pillar portions 115 are arranged at a predetermined interval in the circumferential direction from the periphery of the reflector body 114. Each pillar portion 115 protrudes outward from the outer peripheral surface of the reflector body 114. The frame body 116 is annular and is arranged concentrically with the reflector body 114. The frame body 116 is connected to the tip ends of the plurality of pillar portions 115. The tip end of the first connector 211 of the first swing portion 210 and the tip end of the first connector 221 of the second swing portion 220 are connected to the outer peripheral surface of the frame body 116. Therefore, the torsions and vibrations from the first connectors 211 and 221 are transmitted to the reflector body 114 via the frame body 116 and the plurality of pillar portions 115. That is, since the torsions and vibrations from the first connectors 211 and 221 are not directly transmitted to the reflector body 114, the stress applied to the reflector body 114 is relaxed.

[0096] Note that as long as a stress relaxation effect can be obtained, the shape of the reflector may be any shape. FIG. 10 is a plan view showing a modification of the reflector according to the fourth embodiment. As shown in FIG. 10, the reflector 110c does not have pillar portions, and the frame body 116c is substantially hexagonal annular. The tip end of the first connector 211 of the first swing portion 210 and the tip end of the first connector 221 of the second swing portion 220 are joined to a pair of corner portions facing each other in the Y-axis direction of the frame body 116c. Further, inside the frame body 116c, the reflector body 114c is joined to a pair of sides facing each other in the X-axis direction. Even in the reflector 110c having a gap between a part of the frame body 116c and the reflector body 114c in this way, a stress relaxation effect can be obtained.

[0097] [Others] Note that the present invention is not limited to the above-described embodiments. For example, another embodiment realized by arbitrarily combining the components described in this specification and excluding some of the components may be an embodiment of the present invention. Further, modification examples obtained by applying various modifications conceived by those skilled in the art without departing from the gist of the present invention, that is, the meaning indicated by the language described in the claims, with respect to the above-described embodiments are also included in the present invention.

[0098] For example, in the above-described Embodiment 1, in each of the first driving body 214 and the second driving body 215 of the first swinging part 210, first parts 214a, 215a and second parts 214b, 215b that vibrate in opposite directions in the thickness direction were generated. That is, for example, in the first driving body 214, two locations (first part 214a, second part 214b) that vibrate in opposite directions are generated, and in the second driving body 215, two locations (first part 215a, second part 215b) that vibrate in opposite directions are generated. However, in one driving body, three or more locations that vibrate in opposite directions may be provided. This is the same for each of the first driving body 224 and the second driving body 225 of the second swinging part 220.

[0099] Further, in the above-described Embodiment 1, the optical control system 10 including the two swinging parts of the first swinging part 210 and the second swinging part 220 was exemplified. However, the optical control system may be provided with only one swinging part.

Industrial Applicability

[0100] The present invention can be used in optical devices such as, for example, a small display device, a small projector, an in-vehicle head-up display device, an electrophotographic copying machine, a laser printer, an optical scanner, and an optical radar.

Explanation of Signs

[0101] 10 Optical control system 11 First axis 20 Control device 21 Angle detection circuit 22 Driving circuit 23 Control circuit 51 First side part 52 Second side part 53 Third side part 54 Fourth side part 100, 100A Optical reflection element 105 Substrate 110, 110b, 110c Reflector 111 Reflection part 114, 114c Reflector body 115 Column part 116, 116c Frame 210, 210a First swinging part 211, 221 First connector 211s, 221s Node 212, 212a, 222, 222a First vibrator 213, 213a, 223, 223a Second vibrator 214, 224 First driver 214a, 215a First part 214b, 215b Second part 215, 225 Second driver 216, 226 Second connector 217, 227 Link 218, 228 First monitor element 219, 229 Second monitor element 220, 220a Second swinging part 224c, 225c Third part 224d, 225d Fourth part 2122, 2222 Third piezoelectric element 2132, 2232 Fourth piezoelectric element 2141, 2241 First driver body part 2142, 2242 First piezoelectric element 2151, 2251 Second driver body part 2152, 2252 Second piezoelectric element W1 First drive signal W2 Second drive signal

Claims

1. In an optical control system including an optical reflection element that reflects light and reciprocates it, and a control device that controls the optical reflection element, the optical reflection element includes a reflector that reflects the light, a first swing part and a second swing part that are respectively arranged at positions sandwiching the reflector along a first axis and swing the reflector, each of the first swing part and the second swing part includes a first connector that is arranged along the first axis and has a tip connected to the reflector, a first oscillator that extends in a direction intersecting the first axis and is connected to a base end of the first connector, a second oscillator that extends in a direction intersecting the first axis on the opposite side of the first oscillator with respect to the first axis and is connected to the base end of the first connector, a first driver that extends along the first axis and has a base end connected to the tip of the first oscillator and operates the first connector via the first oscillator, a second driver that extends along the first axis and has a base end connected to the tip of the second oscillator and operates the first connector via the second oscillator, and a second connector that connects the first oscillator and the second oscillator to the base body so as to be swingable, when the control device swings the first swing part and the second swing part so as to rotate in the same direction around the first axis, in each of the first driver and the second driver of the first swing part, the first driver and the second driver of the first swing part are vibrated so as to generate a first part and a second part in which the vibration directions in the thickness direction of the optical reflection element are opposite, in each of the first driver and the second driver of the second swing part, the first driver and the second driver of the second swing part are vibrated so as to generate a third part and a fourth part in which the vibration directions in the thickness direction are opposite, and while vibrating the first oscillator of the first swing part in a direction opposite to that of the first driver of the first swing part in the thickness direction, the second oscillator of the first swing part is vibrated in a direction opposite to that of the second driver of the first swing part in the thickness direction, and while vibrating the first oscillator of the second swing part in a direction opposite to that of the first driver of the second swing part in the thickness direction, the second oscillator of the second swing part is vibrated in a direction opposite to that of the second driver of the second swing part in the thickness direction an optical control system.

2. The first driving body includes a first piezoelectric element controlled by the control device. The second driving body includes a second piezoelectric element controlled by the control device. The first vibrating body includes a third piezoelectric element controlled by the control device. The second vibrating body includes a fourth piezoelectric element controlled by the control device. The first piezoelectric element is disposed at a position including an inflection point during vibration in the entirety of the first driving body and the first vibrating body. The second piezoelectric element is disposed at a position including an inflection point during vibration in the entirety of the second driving body and the second vibrating body. The optical control system according to claim 1.

3. Each of the first connecting bodies of the first swinging portion and the second swinging portion has a shape in which an odd number of nodes are generated when the first swinging portion and the second swinging portion are rotated and swung in the same direction. The optical control system according to claim 1 or 2.

4. The overall length of each of the first driving body and the second driving body is longer than the overall length of each of the first vibrating body and the second vibrating body. The optical control system according to any one of claims 1 to 3.

5. In an optical control system including an optical reflection element that reflects light and reciprocates it, and a control device that controls the optical reflection element, The optical reflection element includes a reflector that reflects the light, and a swinging portion for swinging the reflector. The swinging portion includes a first connecting body whose tip is connected to the reflector, a first vibrating body connected to the base end portion of the first connecting body, a second vibrating body connected to the base end portion of the first connecting body on the opposite side of the first vibrating body, a first driving body whose base end is connected to the tip of the first vibrating body and operates the first connecting body via the first vibrating body, a second driving body whose base end is connected to the tip of the second vibrating body and operates the first connecting body via the second vibrating body, and a second connecting body that connects the first vibrating body and the second vibrating body to the base body so as to be vibrationally free. When the control device swings the swinging portion, in each of the first driving body and the second driving body of the swinging portion, the first driving body and the second driving body of the swinging portion are vibrated so as to generate a first portion and a second portion in which the vibration directions in the thickness direction of the optical reflection element are opposite, and While vibrating the first vibrating body of the swinging part in a direction opposite to that of the first driving body of the swinging part in the thickness direction, the second vibrating body of the swinging part is vibrated in a direction opposite to that of the second driving body of the swinging part in the thickness direction. Optical control system. Claim 6 The first driving body includes a first piezoelectric element controlled by the control device. The second driving body includes a second piezoelectric element controlled by the control device. The first vibrating body includes a third piezoelectric element controlled by the control device. The second vibrating body includes a fourth piezoelectric element controlled by the control device. The first piezoelectric element is disposed at a position including an inflection point during vibration over the entire first driving body and the first vibrating body. The second piezoelectric element is disposed at a position including an inflection point during vibration over the entire second driving body and the second vibrating body. The optical control system according to claim 5. Claim 7 The total length of each of the first driving body and the second driving body is longer than the total length of each of the first vibrating body and the second vibrating body. The optical control system according to claim 5 or 6.

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