Movable device, distance measuring device, display device and wavelength tunable laser

Abstract

To provide a movable device with which it is possible to cause a movable unit to stop moving without applying voltage or current.SOLUTION: A movable device pertaining to one aspect of the present invention comprises a mechanism unit for driving a movable unit, and a drive unit for driving the mechanism unit. The mechanism unit has a gear that includes a first projection and a cam that is capable of rotating in accordance with the rotation of the gear, and the cam rotates to drive the movable unit in contact with the cam. The drive unit has a second projection that engages with the first projection and an actuator for reciprocating the second projection in accordance with an applied voltage or current, and the second projection reciprocates to rotate the gear in a prescribed direction. The first projection has a shape in which a downstream side is lower than an upstream side in the prescribed direction. The second projection has a shape in which a downstream side is higher than an upstream wide in the prescribed direction.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a movable device, a distance measuring device, a display device, and a tunable laser. [Background technology]

[0002] 2. Description of the Related Art In recent years, with the advancement of micromachining technology that utilizes semiconductor manufacturing technology, the development of movable devices such as MEMS (Micro Electro Mechanical Systems) devices manufactured by microfabricating silicon or glass has progressed.

[0003] As such a movable device, a configuration has been disclosed in which a mirror part is connected to a pair of torsion bars that serve as the rotation axis, and the bending motion of an actuator connected to a torsion bar support part that supports the other end of the torsion bar is converted into rotational motion of the mirror part (see, for example, Patent Document 1). Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the configuration of Patent Document 1, when a movable part such as a mirror part is stopped at a desired angle, it is necessary to continuously apply a voltage to the actuator, which increases power consumption and raises concerns that the movable part may not be stopped at the desired angle due to a change over time in the movable part angle characteristic with respect to the applied voltage. Therefore, there is a demand for a movable device that can stop a movable part without applying a voltage or current.

[0005] An object of the present invention is to provide a movable device capable of bringing a movable part to a standstill without applying a voltage or current. [Means for solving the problem]

[0006] A movable device according to one embodiment of the present invention comprises a mechanism for driving a movable part, and a drive unit for driving the mechanism, wherein the mechanism has a gear including a first convex portion and a cam that can rotate in response to rotation of the gear, and the cam rotates to drive the movable part in contact with the cam, and the drive unit has a second convex portion that meshes with the first convex portion, and an actuator that moves the second convex portion back and forth in response to an applied voltage or current, and the gear rotates in a predetermined direction by the second convex portion moving back and forth, and the first convex portion has a shape that is lower on the downstream side than on the upstream side in the predetermined direction, and the second convex portion has a shape that is higher on the downstream side than on the upstream side in the predetermined direction. Effect of the Invention

[0007] According to the present invention, it is possible to provide a movable device in which a movable part can be made stationary without applying a voltage or current. [Brief description of the drawings]

[0008] [Figure 1] FIG. 2 is a plan view illustrating the overall configuration of the movable device according to the first embodiment. [Diagram 2] FIG. 2 is a cross-sectional view taken along the line AA in FIG. [Diagram 3] FIG. 2 is a plan view illustrating the configuration of a first layer in a movable device. [Figure 4] FIG. 4 is a cross-sectional view taken along line BB in FIG. [Diagram 5] FIG. 11 is a plan view illustrating the configuration of a second layer in the movable device. [Figure 6] 6 is a cross-sectional view taken along line CC in FIG. 5. [Figure 7] FIG. 13 is a plan view illustrating the configuration of a third layer in the movable device. [Figure 8] FIG. 8 is a cross-sectional view taken along line DD in FIG. [Figure 9] FIG. 11 is a plan view showing an example of meshing between gear teeth and claw portions. [Figure 10] FIG. 2 is a plan view showing a first example of driving a movable part. [Figure 11]FIG. 11 is a plan view showing a second example of driving the movable part. [Figure 12] 11 is a plan view showing an example of the swing of a movable part. FIG. [Figure 13] 13 is a cross-sectional view taken along line EE in FIG. 12. [Figure 14] FIG. 4 is a diagram showing an example of a driving voltage of a piezoelectric actuator. [Figure 15] 15 is a diagram showing an example of change in the inclination angle of the reflecting surface according to the driving voltage in FIG. 14. [Figure 16] FIG. 11 is a plan view showing a second example of the cam. [Figure 17] FIG. 11 is a plan view showing a third example of the cam. [Figure 18] FIG. 13 is a plan view showing a fourth example of the cam. [Figure 19] 13 is a plan view showing a first example of driving a movable part according to the second embodiment. FIG. [Figure 20] 13 is a plan view showing a second example of driving the movable portion according to the second embodiment. FIG. [Figure 21] 13A and 13B are cross-sectional views showing a third example of driving the movable part according to the second embodiment. [Figure 22] 13A and 13B are cross-sectional views showing a fourth example of driving the movable part according to the second embodiment. [Figure 23] FIG. 1 is a schematic diagram of an example of an automobile equipped with a lidar device. [Figure 24] FIG. 1 is a schematic diagram of an example of a lidar device. [Diagram 25] FIG. 1 is a schematic diagram of an example of a retinal projection display device. [Figure 26] FIG. 2 is a diagram showing a first example of the stationary state of a movable device in a retinal projection display device. [Figure 27] FIG. 13 is a diagram showing a second example of the stationary state of a movable device in a retinal projection display device. [Figure 28] FIG. 13 is a diagram showing a third example of the stationary state of a movable device in a retinal projection display device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same components are designated by the same reference numerals, and duplicated descriptions will be omitted where appropriate.

[0010] In the directions indicated by the arrows in the figures below, the stacking direction of each layer in the actuator, etc. is the Z direction, and the directions perpendicular to each other in a plane perpendicular to the Z direction are the X direction and the Y direction. Also, a planar view means that the object is viewed from the Z direction. However, these do not limit the orientation of the movable device when in use, and the orientation of the movable device is arbitrary.

[0011] [First embodiment] (Configuration example of movable device 100) The configuration of a movable device 100 according to a first embodiment will be described with reference to Fig. 1 to Fig. 8. Fig. 1 is a plan view illustrating the overall configuration of the movable device 100. Fig. 2 is a cross-sectional view taken along the line AA in Fig. 1. The movable device 100 is, for example, a MEMS device manufactured by a semiconductor process.

[0012] 1 and 2, the movable device 100 includes a first layer 10 including a movable section 3, a second layer 20 including a mechanism section 1 and a driving section 2, and a third layer 30. For example, the first layer 10 is formed by etching a single SOI (Silicon On Insulator) substrate, and the second layer 20 and the third layer 30 are formed by etching a single SOI substrate. The movable device 100 is manufactured by bonding the two formed substrates together via a bonding member 40 such as an adhesive.

[0013] FIG. 3 is a plan view illustrating the configuration of the first layer 10. FIG. 4 is a cross-sectional view taken along the line BB in FIG. 3. FIG. 5 is a plan view illustrating the configuration of the second layer 20. FIG. 6 is a cross-sectional view taken along the line CC in FIG. 5. FIG. 7 is a plan view illustrating the configuration of the third layer 30. FIG. 8 is a cross-sectional view taken along the line DD in FIG. 7.

[0014] 1 to 8, a movable device 100 includes a mechanism unit 1 and a drive unit 2. The mechanism unit 1 and the drive unit 2 are arranged side by side in the Y direction.

[0015] The mechanical unit 1 includes a gear 11 including teeth (first convex portion), and a cam 12 that is rotatable in response to the rotation of the gear 11. The gear 11 and the cam 12 are connected using a shaft member 13, and are rotatable around a rotation axis L that passes through the center of the shaft member 13 and is parallel to the Z axis. The driving unit 2 includes a claw portion 21 (second convex portion) that meshes with the teeth of the gear 11, a piezoelectric actuator 22, and a connection portion 23 that connects the claw portion 21 and the piezoelectric actuator 22.

[0016] The piezoelectric actuator 22 is an example of an actuator that reciprocates the claw portion 21 in response to an applied voltage or current. The piezoelectric actuator 22 includes an elastic portion 221 and a piezoelectric portion 222.

[0017] 5 and 6, the elastic portion 221 includes a frame portion 221a surrounding the piezoelectric portion 222 and a beam portion 221b spanning the frame portion 221a. The elastic portion 221 is made of, for example, a silicon active layer and has elasticity. An end portion 221c on the +X direction side of the frame portion 221a is connected to the fixed portion 24, and an end portion 221d on the -X direction side is connected to the connection portion 23. The connection portion 23 is made of a silicon active layer and has elasticity.

[0018] The piezoelectric portion 222 is configured by laminating a lower electrode, a piezoelectric element, and an upper electrode in this order on the surface of the beam portion 221b in the +Z direction. The upper electrode and the lower electrode include, for example, gold (Au) or platinum (Pt), etc. The piezoelectric element includes, for example, PZT (lead zirconate titanate), which is a piezoelectric material.

[0019] The driving unit 2 expands and contracts the piezoelectric portion 222 in the Y direction in response to an applied voltage, thereby causing the end portion 221d on the -X direction side of the elastic portion 221 to move back and forth in the X direction, and also causes the claw portion 21 connected to the end portion 221d via the connection portion 23 to move back and forth in the X direction.

[0020] The teeth of the claw portion 21 and the gear 11 mesh with each other, and the driving force of the reciprocating movement of the claw portion 21 is transmitted to the gear 11, causing the gear 11 to rotate in a rotation direction 21a around a rotation axis L parallel to the Z direction. In other words, the driving unit 2 can rotate the gear 11 in the rotation direction 21a (predetermined direction) by causing the claw portion 21 to reciprocate in the X direction.

[0021] In the mechanical unit 1, the cam 12 rotates in response to the rotation of the gear 11, thereby reciprocating the support post 31, which is integrally formed with the movable part 3 and contacts the outer circumferential surface 121 of the cam 12, in the Y direction. The press plates 14a to 14c are members that suppress the displacement of the gear 11 in the Z direction due to the rotation.

[0022] The movable part 3 is disposed on the +Z direction side of the mechanism part 1, and is a plate-like member having a reflecting surface 34 on the surface on the +Z direction side. The movable part 3 is connected to one end of each of torsion bars 32a and 32b, which are torsion beams arranged to sandwich the movable part 3 along the X direction. The torsion bars 32a and 32b are made of silicon active layers and have elasticity.

[0023] The other end of each of the torsion bars 32a and 32b is connected to the support frame 33. The torsion bars 32a and 32b are an example of a support part that supports the movable part 3 to be swingable around an oscillation axis M that passes through the central axis of each of the torsion bars 32a and 32b and is parallel to the X direction.

[0024] The movable part 3 changes its inclination continuously around the oscillation axis M as the support 31 reciprocates in the Y direction.

[0025] As shown in FIG. 7, the third layer 30 includes a mechanism section support section 41 that supports the mechanism section 1 and a drive section support section 42 that supports the drive section 2. As shown in FIG.

[0026] (Example of driving the movable part 3) 9 to 13, the manner in which the movable part 3 is driven will be described.

[0027] Fig. 9 is a plan view showing an example of meshing between gear 11 and claw portion 21. As shown in Fig. 9, teeth 111 are formed on the outer circumferential surface of gear 11. Teeth 111 have a shape in which the downstream side is lower than the upstream side in rotation direction 21a.

[0028] The shape of the tooth 111 in which the downstream side is lower than the upstream side in the rotation direction 21a means a shape of the tooth 111 in which, in the direction in which the tooth 111 and the claw portion 21 face each other (for example, the Y direction), the downstream portion of the tooth 111 in the rotation direction 21a is located farther from the drive unit 2 than the upstream portion of the tooth 111. The shape of such a tooth 111 is, for example, an inclined surface in which the downstream side is lower than the upstream side in the rotation direction 21a.

[0029] The claw portion 21 of the drive portion 2 is provided so as to be able to engage (mesh) with the teeth 111. The claw portion 21 has a shape in which the downstream side is higher than the upstream side in the rotation direction 21a.

[0030] The shape of the claw portion 21 in which the downstream side is higher than the upstream side in the rotation direction 21a means a shape of the claw portion 21 in which the downstream part of the claw portion 21 in the rotation direction 21a is located closer to the mechanical unit 1 than the upstream part of the claw portion 21 in the direction in which the claw portion 21 and the teeth 111 face each other (for example, the Y direction). The shape of such a claw portion 21 is, for example, an inclined surface in which the downstream side is higher than the upstream side in the rotation direction 21a.

[0031] When the piezoelectric portion 222 of the piezoelectric actuator 22 contracts in the -Y direction in response to the applied voltage, the frame portion 221a contracts in the -Y direction and the claw portion 21 is displaced in the -X direction. As a result, the claw portion 21 moves in the -X direction while pressing the connection portion 23 in the +Y direction in accordance with the inclination of the claw portion 21. When the claw portion 21 passes the highest part of the tooth 111 due to this movement, the claw portion 21 is urged in the -Y direction by the connection portion 23 and is pushed back to the lowest part of the tooth 111.

[0032] When the voltage applied to the piezoelectric portion 222 becomes 0 [V] while the claw portion 21 is pushed back to the lowest part of the tooth 111, the piezoelectric portion 222 expands from the contracted state to return to its original state, and the frame portion 221a expands to return to its original state by elastic restoring force. When the claw portion 21 is displaced in the +X direction in response to the expansion of the frame portion 221a, the claw side vertical surface 211 pushes the tooth side vertical surface 112 in the +X direction. This causes the gear 11 to rotate in the rotation direction 21a. Here, the claw side vertical surface 211 means the surface of the claw portion 21 that is approximately perpendicular to the X direction, and the tooth side vertical surface 112 means the surface of the tooth 111 that is approximately perpendicular to the X direction.

[0033] The gear 11 rotates by an angle corresponding to the interval (pitch) of the teeth 111 as the piezoelectric portion 222 expands and contracts once in the Y direction. The driving unit 2 can rotate the gear 11 by repeating the expansion and contraction actions of the piezoelectric portion 222 in the Y direction.

[0034] Fig. 10 is a plan view showing a first example of driving the movable part 3. Fig. 11 is a plan view showing a second example of driving the movable part 3.

[0035] 10 and 11, cam 12 is a plate-like member that includes a linear portion extending in the radial direction in a plan view and has a shape that is asymmetrical with respect to rotation axis L. Due to this shape in a plan view, cam 12 is configured such that the distance between rotation axis L and contact portion 311 changes in response to rotation of cam 12. Contact portion 311 refers to the portion where cam 12 comes into contact with support post 31.

[0036] In the state shown in Fig. 10, the distance between the rotation axis L and the contact portion 311 is d1. On the other hand, in the state shown in Fig. 11, which is rotated approximately 270 degrees in the rotation direction 21a from the state shown in Fig. 10, the distance between the rotation axis L and the contact portion 311 is d2, which corresponds to the longest distance.

[0037] 11 due to the rotation of cam 12, the support pillar 31 is pushed by outer peripheral surface 121 of cam 12 and moves a distance of "d2-d1" in the -Y direction. As cam 12 rotates further after that, the distance between rotation axis L and contact portion 311 becomes shorter, and support pillar 31 moves in the +Y direction according to this distance. As cam 12 rotates further after that, the distance between rotation axis L and contact portion 311 gradually becomes longer, and support pillar 31 gradually moves in the -Y direction according to this distance.

[0038] In this way, when the driving unit 2 rotates the gear 11, the cam 12 rotates in response to the rotation of the gear 11, and the mechanism unit 1 can move the support 31 of the movable unit 3, which contacts the outer circumferential surface 121 of the cam 12, in the Y direction. The support 31 of the movable unit 3 moves back and forth in the Y direction as the cam 12 repeatedly rotates.

[0039] Fig. 12 is a plan view showing an example of how the movable part 3 swings as a result of the support 31 of the movable part 3 reciprocating in the Y direction. Fig. 13 is a cross-sectional view taken along the line EE in Fig. 12.

[0040] Since the movable part 3 is supported by the torsion bars 32a and 32b, its position does not change even if the support pillar 31 moves in the Y direction, and the torsion bars 32a and 32b twist to tilt the movable part 3 around the oscillation axis M. As the support pillar 31 of the movable part 3 moves back and forth in the Y direction, the movable part 3 continuously changes its inclination and swings around the oscillation axis M.

[0041] By swinging, the movable portion 3 can change, for example, the reflection direction of the laser light incident on the reflection surface 34, and change the irradiation position of the reflected laser light.

[0042] (An example of the driving voltage of the piezoelectric actuator 22) Fig. 14 is a diagram showing an example of the drive voltage of the piezoelectric actuator 22. Fig. 15 is a diagram showing an example of the change in the tilt angle of the reflecting surface 34 according to the drive voltage of Fig. 14.

[0043] 14, a pulsed voltage of voltage value V is applied to piezoelectric actuator 22 with period T. Piezoelectric portion 222 contracts in the -Y direction in response to application of a voltage of voltage value V, and frame portion 221a also contracts in the -Y direction together with piezoelectric portion 222 (see FIG. 9). When the applied voltage value becomes 0 [V], piezoelectric portion 222 expands to return to its original state, and frame portion 221a contracts from the contracted state to its original state due to an elastic restoring force.

[0044] When the frame portion 221a extends, the claw side vertical surface 211 presses the tooth side vertical surface 112 in the +X direction, causing the gear 11 to rotate in the rotation direction 21a. In response to the rotation of the gear 11, the outer circumferential surface 121 of the cam 12 presses the support post 31, causing the inclination angle of the reflecting surface 34 of the movable part 3 to change.

[0045] The inclination angle of the reflecting surface 34 changes immediately when the frame portion 221a expands, and stops changing the inclination angle when the frame portion 221a returns to its original state. Therefore, as shown in FIG. 15, the inclination angle of the reflecting surface 34 changes to increase stepwise in response to the repeated application of a pulse-like voltage with a period T to the piezoelectric actuator 22. Then, when the distance between the rotation axis L and the contact portion 311 becomes the longest, d2, the inclination angle of the reflecting surface 34 becomes maximum. Thereafter, as the distance between the rotation axis L and the contact portion 311 becomes shorter, the inclination angle of the reflecting surface 34 becomes minimum once, and then changes to gradually increase in response to the rotation of the cam 12.

[0046] The piezoelectric actuator 22 is driven by application of a voltage of a voltage value V, and stops driving when the applied voltage is 0 [V], i.e., when no voltage is applied. Even when the piezoelectric actuator 22 stops driving, the teeth 111 of the gear 11 and the claw portion 21 mesh, so that the mechanical part 1 does not move. Depending on the state of this mechanical part 1, the movable part 3 maintains a stationary state even when no voltage is applied. In other words, the movable device 100 can drive the movable part 3 by applying a voltage, and can keep the movable part 3 stationary by not applying a voltage.

[0047] (Function and effect of the movable device 100) Next, the effects of the movable device 100 will be described.

[0048] Technological development is gaining momentum to realize the optical scanning units mounted on display devices such as projectors and sensing devices such as LiDAR (Light Detection And Ranging) using MEMS devices, and some applications have already been put to practical use.

[0049] On the other hand, in recent years, there has been an increasing demand for MEMS devices to have functions other than the function of scanning laser light using the resonance of the moving part. For example, in display device applications, there is a demand for functions such as changing the drawing position according to the user's line of sight. In sensing device applications, there is a demand for functions such as changing the sensing position according to the area to be sensed in more detail.

[0050] In order to meet such demands, there is a need for a MEMS device that can remain stationary at a desired angle. For example, a MEMS device used as an optical switch in communication applications has been disclosed that switches an optical signal input between on and off depending on the angle of the MEMS device, and maintains the on or off state of the optical signal input by keeping the MEMS device stationary.

[0051] However, in the conventional configuration, when a movable part such as a mirror part is to be stopped at a desired angle, it is necessary to continuously apply a voltage to the actuator. This increases power consumption, and there is a concern that the movable part cannot be stopped at a desired angle due to a change over time in the movable part angle characteristic with respect to the applied voltage. For this reason, there is a demand for a movable device that can stop a movable part without applying a voltage or current.

[0052] The movable device 100 according to this embodiment includes a mechanism 1 that drives a movable part 3, and a drive unit 2 that drives the mechanism 1. The mechanism 1 has a gear 11 that includes teeth 111 (first convex portion), and a cam 12 that is rotatable in response to the rotation of the gear 11. The movable device 100 drives the movable part 3 that is in contact with the cam 12 as the cam 12 rotates.

[0053] The drive unit 2 has a claw portion 21 (second convex portion) that meshes with the teeth 111, and a piezoelectric actuator 22 (actuator) that moves the claw portion 21 back and forth in response to an applied voltage, and the reciprocating movement of the claw portion 21 rotates the gear 11 in a rotational direction 21a (predetermined direction).

[0054] The teeth 111 have a shape in which the downstream side is lower than the upstream side in the rotation direction 21a, and the claw portions 21 have a shape in which the downstream side is higher than the upstream side in the rotation direction 21a.

[0055] When no voltage is applied, the driving unit 2 stops driving the piezoelectric actuator 22. Even in this case, the teeth 111, which have a shape in which the downstream side is lower than the upstream side in the rotation direction 21a, mesh with the claws 21, which have a shape in which the downstream side is higher than the upstream side in the rotation direction 21a, so that the mechanism unit 1 does not move. Therefore, the movable unit 3 can be maintained in a stationary state, and the movable device 100 can keep the movable unit 3 stationary without applying a voltage.

[0056] In this manner, in this embodiment, it is possible to provide the movable device 100 capable of stopping the movable part 3 without applying a voltage or current. The power consumption of the movable device 100 is suppressed, and the change over time in the angular characteristics of the movable part 3 with respect to the applied voltage is suppressed, so that the movable part 3 can be stopped at a desired angle.

[0057] In this embodiment, the distance between the rotation axis L of the cam 12 and the contact portion 311 changes in response to the rotation of the cam 12. With this configuration, it is possible to move the support 31 of the movable portion 3 in response to the rotation of the gear 11 based on the reciprocating movement of the piezoelectric actuator 22.

[0058] In this embodiment, the cam 12 has a shape that is asymmetrical with respect to the rotation axis L, but is not limited to this. As long as the distance between the rotation axis L of the cam 12 and the contact portion 311 changes in response to the rotation of the cam 12, a cam of any shape can be used.

[0059] 16 to 18 are diagrams showing the configurations of cams 12a to 12c according to the modified examples. As shown in FIG. 16, cam 12a is a disk-shaped member that is eccentric with respect to the rotation axis L. As shown in FIG. 17, cam 12b is a plate-shaped member with an elliptical outer shape. As shown in FIG. 18, cam 12c is a plate-shaped member with a sector-shaped outer shape. Each of cams 12a to 12c rotates around the rotation axis L, and the distance between the rotation axis L and contact portion 311 changes in response to the rotation. Therefore, even when cams 12a to 12c are used, the same effect as in the above-mentioned embodiment can be obtained.

[0060] Since the amount of movement of the movable part 3 can be changed depending on the distance between the rotation axis L and the contact portion 311 of the cam 12, it is preferable to determine the distance between the rotation axis L and the contact portion 311 according to the required amount of movement of the movable part 3.

[0061] Since the larger the diameter of the gear 11 is, the smaller the force required to move the movable part 3 is, it is preferable to determine the diameter of the gear 11 according to the required amount of movement of the movable part 3.

[0062] Moreover, the movable device 100 includes a movable part 3 integrally formed with a support 31, and torsion bars 32a and 32b (supports) that swingably support the movable part 3. The movable part 3 swings when a part of the support 31 is moved by the mechanism part 1. With this configuration, the movable part 3 can be used as a swinging mirror, and it becomes possible to reflect light incident on a reflective surface 34 provided on the movable part 3 in a desired direction, and to scan the light reflected by the reflective surface 34 on a surface to be scanned.

[0063] Moreover, in this embodiment, the movable device 100 includes a piezoelectric actuator 22 as an actuator. The piezoelectric actuator 22 can generate a strong force, and therefore can move the claw portion 21 with a force larger than the elastic restoring force of the frame portion 221a. However, the actuator is not limited to the piezoelectric actuator 22, and an electrostatic actuator, an electromagnetic actuator, or the like can also be used.

[0064] In this embodiment, a configuration in which the movable device 100 has a movable part 3 is exemplified, but the movable device 100 does not necessarily have to have a movable part 3, and may be configured so that the movable device 100 drives a movable part provided in an external device.

[0065] In this embodiment, the movable device 100 is a MEMS device that can be manufactured by a semiconductor process, but is not limited to this. The movable device may be a device other than a MEMS device, and may be manufactured by a manufacturing method other than a semiconductor process. However, from the viewpoint of miniaturizing the movable device, it is more preferable to configure the movable device as a MEMS device.

[0066] [Second embodiment] Next, a movable device 100a according to a second embodiment will be described. Note that the same components as those in the first embodiment are given the same reference numerals, and duplicated descriptions will be omitted as appropriate.

[0067] 19 to 22 are diagrams for explaining an example of the configuration of the movable device 100a. FIG. 19 is a plan view showing a first example of driving the movable part 3a provided in the movable device 100a. FIG. 20 is a plan view showing a second example of driving the movable part 3a. FIG. 21 is a cross-sectional view showing a third example of driving the movable part 3a. FIG. 20 is a cross-sectional view showing a fourth example of driving the movable part 3a.

[0068] 19 to 22, the movable device 100a includes a movable part 3a and a periodic structure 6. The movable part 3a is connected to a support 5 via a support beam 35. The periodic structure 6 is provided on the inner periphery side of the support 5.

[0069] The movable part 3a is a rectangular parallelepiped member provided so as to contact the cam 12 included in the mechanism part 1. As shown in Fig. 21 and Fig. 22, the movable part 3a reciprocates along the Y direction in response to the rotation of the cam 12 within a range in which the distance between the rotation axis L and the contact part 311a changes from d3 to d4.

[0070] The rotational drive of gear 11 by drive unit 2, the rotation of cam 12 in response to the rotation of gear 11, and the reciprocating movement of movable unit 3a in response to the rotation of cam 12 are similar to those in the first embodiment. However, movable unit 3a differs from movable unit 3 in the first embodiment in that it moves translationally along the Y direction.

[0071] The support beam 35 is an elastic member that supports the movable part 3a from both sides in the X direction, and is made of, for example, a silicon active layer. The support beam 35 is deformable in response to the movement of the movable part 3a.

[0072] The periodic structure 6 includes a periodic structure formed at a predetermined period, one end of which is fixedly supported by the support 5, and the other end of which is provided so as to be pressable by a movable part. The periodic structure included in the periodic structure 6 is pressed by the movable part 3a driven by the mechanism part 1, whereby the periodic structure 6 is deformed, and the period of the periodic structure changes.

[0073] The periodic structure 6 has a configuration in which movable grating structures and fixed grating structures are arranged alternately. As disclosed in Japanese Patent No. 6598184, for example, when the periodic structure 6 is deformed in a direction in which the period of the periodic structure increases, the wavelength of the light transmitted through the periodic structure 6 or the light reflected by the periodic structure 6 can be shifted to the longer wavelength side. When the periodic structure 6 is deformed in a direction in which the period of the periodic structure decreases, the wavelength of the light transmitted through the periodic structure 6 or the light reflected by the periodic structure 6 can be shifted to the shorter wavelength side.

[0074] However, the configuration of the periodic structure 6 is not limited to one in which movable grating structures and fixed grating structures are arranged alternately. As long as it is possible to change the wavelength of light incident on the periodic structure 6, the periodic structure 6 may have a configuration in which movable periodic structures and fixed structures are arranged alternately, or a configuration in which the distance between the grating structures or periodic structures is expandable.

[0075] As one application of the movable device 100a, a tunable laser can be configured by including a laser light source that emits a laser light of a predetermined wavelength and the movable device 100a. The tunable laser can shift the wavelength of the transmitted or reflected light to a desired wavelength by making the laser light emitted by the laser light source incident on the periodic structure 6 of the movable device 100a.

[0076] As described above, in this embodiment, even when the applied voltage is 0 [V] and the driving of the piezoelectric actuator 22 in the driving unit 2 is stopped, the mechanism unit 1 does not move, the movable unit 3a maintains a stationary state, and the periodic structure 6 maintains a deformed state. As a result, the movable device 100a can suppress and stabilize the change in wavelength of the light transmitted through the periodic structure 6 or the light reflected by the periodic structure 6 without applying a voltage or current. Other effects are similar to those shown in the first embodiment.

[0077] [Other Preferred Embodiments] Application examples of the above-described movable device 100 or 100a will be described with reference to FIGS.

[0078] (distance measuring device) Fig. 23 is a schematic diagram of an example of an automobile 701 equipped with a lidar device 700. Fig. 24 is a schematic diagram of an example of the lidar device 700. The lidar device 700 is an example of a distance measuring device including a movable device 100.

[0079] As shown in FIG. 23, a lidar device 700 is mounted on, for example, an automobile 701, and recognizes an object 702 by optically scanning the object in the target direction and receiving reflected light from the object 702 present in the target direction.

[0080] 24, the laser light emitted from the light source device 712 passes through an incident optical system composed of a collimator lens 703, which is an optical system that converts divergent light into approximately parallel light, and a plane mirror 704, and is scanned in one or two axial directions by the movable device 100 having a reflecting surface 34. Then, the light passes through a projection lens 705, which is a projection optical system, and is irradiated onto an object 702 in front of the device. The light source device 712 and the movable device 100 are controlled by a control device that controls the movable device 100.

[0081] The light reflected by the object 702 is detected by a photodetector 709. That is, the reflected light passes through a condenser lens 706 and the like, which is an incident light detection and light receiving optical system, and is received by an image sensor 707, which outputs a detection signal to a signal processing circuit 708. The signal processing circuit 708 performs predetermined processing, such as binarization and noise processing, on the input detection signal, and outputs the result to a distance measurement circuit 710.

[0082] The distance measurement circuit 710 recognizes the presence or absence of the object 702 based on the time difference between when the light source device 712 emits laser light and when the laser light is received by the photodetector 709, or the phase difference between each pixel of the image sensor 707 that receives the light, and further calculates distance information from the object 702.

[0083] The movable device 100 having the reflective surface 34 is less likely to break than a polygonal mirror and is small, making it possible to provide a small, highly durable radar device. Such a lidar device can be attached to, for example, a vehicle, an aircraft, a ship, a robot, etc., and can optically scan a predetermined range to determine the presence or absence of an obstacle and the distance to the obstacle.

[0084] In this manner, by using the movable device 100 of the embodiment in a distance measuring device, it is possible to reduce the power consumption of the movable device 100 and to suppress the change over time in the angular characteristics of the movable part 3 in response to the applied voltage, thereby providing a distance measuring device that can stop the movable part 3 at the desired angle.

[0085] (Retinal projection display device 800) 25 is a schematic diagram of an example of a retinal projection display device 800. The retinal projection display device 800 is a wearable terminal, and is a retinal drawing type head mounted display (HMD) that forms (draws) an image directly on the user's retina by laser scanning using Maxwellian vision. This retinal projection display device 800 is an example of a display device.

[0086] 25, the retinal projection display device 800 includes an image laser light source unit 801, a lens 802, a lens 803, a scanning mirror 804, a movable device 100, a projection optical element 806, a detection laser light source 807, a photodetection element 808, and a reflection element 809. The retinal projection display device 800 also includes a glasses frame 810 and a control unit 811.

[0087] The eyeglass frame 810 includes temples 101 and rims 102, and the eyeglass lenses 103 are held by the rims 102. The image laser light source unit 801, the lens 802, the lens 803, the scanning mirror 804, the movable device 100, and the control unit 811 are provided inside the temple 101. The projection optical element 806 is provided on the surface of the eyeglass lenses 103 held by the rims 102. A user can wear the retinal projection display device 800 on his / her head by putting the eyeglass frame 810 on his / her ears.

[0088] The image laser light source unit 801 is a semiconductor laser that emits an image laser beam Li of a single or multiple wavelengths. When a monochrome image is displayed, a laser light source that emits an image laser beam Li of a single wavelength is used as the image laser light source unit 801. When a color image is displayed, a laser light source that emits laser beams of multiple wavelengths, such as a red semiconductor laser, a green semiconductor laser, and a blue semiconductor laser, is used as the image laser light source unit 801. The image laser light source unit 801 emits the image laser beam Li in response to a formation drive signal SL1 from the control unit 811.

[0089] The scanning mirror 804 is a mirror that swings around two axes that are substantially perpendicular to each other, and scans the imaging laser beam Li irradiated from the imaging laser light source unit 801. The scanning mirror 804 swings to change the angle, thereby scanning the imaging laser beam Li that is incident thereon, and forms an image displayed in one field of view on the retina 832 of the eyeball 830.

[0090] The scanning mirror 804 scans the incident imaging laser beam Li in the X and Y directions. The X direction in FIG. 25 corresponds to the main scanning direction in which pixels are drawn successively in time to form a series of pixel groups. The Y direction is perpendicular to the main scanning direction and corresponds to the sub-scanning direction in which a series of pixel groups are arranged. The scanning speed in the main scanning direction is set to be faster than the scanning speed in the sub-scanning direction. An image is formed by the scanned imaging laser beam Li.

[0091] Moreover, the scanning mirror 804 can discretely switch the deflection direction of the image light in n steps along the Y direction under the control of the scanning drive signal SS, and switch the position on the retina 832 of the image formed on the retina 832. n is an integer of 1 or more. In this embodiment, an example is shown in which the deflection direction of the image light is switched in n=3 steps, but this is not limited to this, and the value of n can be selected appropriately. Note that the image light means light for forming an image. A two-axis MEMS mirror or the like can be used for the scanning mirror 804.

[0092] The movable device 100 is provided between the scanning mirror 804 and the projection optical element 806. The movable device 100 deflects the image light generated by the image laser beam Li by changing the inclination. The movable device 100 deflects the scanned image laser beam Li so as to irradiate the retina 832. The deflection direction of the movable device 100 can be switched discretely and selectively. The movable device 100 swings around an axis along the Y direction, and is fixed stationary at any one of m stages of inclination by a deflection drive signal ST.

[0093] The deflected image light is irradiated towards the projection optical element 806. The movable device 100 can switch the deflection direction of the image light by the scanning mirror 804 in m steps along the X direction, where m is an integer equal to or greater than 1. In this embodiment, an example is shown in which the deflection direction of the image light is switched in m=3 steps, but the present invention is not limited to this, and the value of m can be selected appropriately.

[0094] The projection optical element 806 is disposed between the scanning mirror 804 and the retina 832. The projection optical element 806 includes a holographic optical element that reflects and focuses the image laser beam Li emitted from the movable device 100 toward the user's eyeball 830.

[0095] The projection optical element 806 is an element in which n×m=x [number] of hologram regions having different light-collecting characteristics are optically recorded. Note that x is an integer equal to or greater than 2. For example, when n=1, m=2 can be set, and when m=1, n=2 can be set.

[0096] Each hologram region focuses the image laser beam Li in a different x=9 [number] viewing zone near the pupil 831 of the eyeball 830. The x=9 [number] viewing zones are positioned so that the image laser beam Li is included in the pupil 831 of the user's eye when the user looks in the x=9 [number] line of sight direction.

[0097] The configuration including the detection laser light source 807 and the photodetector 808 detects the line of sight of a user wearing the retinal projection display device 800. The detection laser light source 807 irradiates the eyeball 830 with a detection laser beam Ls, and the photodetector 808 receives the reflected light of the irradiated detection laser beam Ls by the eyeball 830 and outputs a detection signal SD according to the intensity of the received light to the control unit 811.

[0098] The control unit 811 estimates the user's line of sight direction based on the detection signal SD, and acquires information indicating the line of sight direction. The control unit 811 also controls the position at which the image is projected onto the retina 832 according to the acquired line of sight information.

[0099] The detection signal SD is projection position information or image formation target position information for providing the projection position to the control unit 811. The light detection element 808 outputs the projection position information or image formation target position information to the control unit 811. However, the configuration of the gaze direction detection unit is not limited to a configuration including the detection laser light source 807 and the light detection element 808, and any eye tracking technology may be applied.

[0100] The detection laser light source 807 is an array light source such as a VCSEL (Vertical Cavity Surface Emitting Laser) or an LDA (Laser Diode Array) that irradiates a detection laser beam Ls toward the cornea of ​​the eyeball 830. The detection laser light source 807 has 9 light emitting units corresponding to the number of visual fields provided by the x=9 visual zones. The wavelength of the detection laser beam Ls emitted from the detection laser light source 807 is preferably a wavelength of near-infrared light, which is invisible light, so as not to impede the visibility of the user whose line of sight is to be detected. However, the wavelength is not limited to this and may be visible light.

[0101] The light detection element 808 is at least one photodiode that receives the detection laser beam Ls emitted from x [number] light-emitting elements of the detection laser light source 807, incident on the eyeball 830 via the reflection element 809, and reflected by the eyeball 830.

[0102] The control unit 811 inputs image data Dat that is the basis of the image to be formed, and controls the emission of the image laser beam Li by the image laser light source unit 801 based on the image data Dat. The detection laser light source 807 sequentially lights up x=9 [light-emitting units] by a detection drive signal SL2, and controls the emission of the detection laser beam Ls. Based on the emission timing of each light-emitting unit of the detection laser light source 807 and the detection signal SD by the photodetector 808, the line of sight direction corresponding to which of the x=9 [predetermined] fields of view the line of sight is directed to is estimated. The scanning mirror 804 controls the scanning of the image laser beam Li by the scanning mirror 804 based on the scanning drive signal SS of the scanning mirror 804. The movable device 100 controls the inclination of the movable device 100 based on the deflection drive signal ST of the movable device 100.

[0103] 26 to 28 are diagrams showing the stationary state of the movable device 100 in the retinal projection display device 800. FIG.

[0104] FIG. 26 is a diagram showing a first example, in which the movable part 3 of the movable device 100 is stopped at an angle θ so that an image is projected onto a projection area 84 located at the center of the scanned surface 83 in the X direction.

[0105] FIG. 27 is a diagram showing a second example, in which the movable part 3 of the movable device 100 is stopped at an angle θL so that an image is projected onto a projection area 84′ located on the −X-direction side of the scanned surface 83 in the X-direction.

[0106] FIG. 28 is a diagram showing a third example, in which the movable part 3 of the movable device 100 is stopped at an angle θR so that an image is projected onto a projection area 84″ located on the +X-direction side of the scanned surface 83 in the X direction.

[0107] In this way, the movable device 100 can change the position of the image projection area in three stages along the X direction by deflecting the scanned image laser beam Li. By applying the movable device 100, it is possible to reduce the power consumption of the retinal projection display device 800, suppress the change over time in the angular characteristics of the movable part 3 with respect to the applied voltage, stop the movable part 3 at a desired angle, and suppress the change in the position of the image projection area.

[0108] Although preferred embodiments have been described above in detail, the present invention is not limited to the above-described embodiments, and various modifications and substitutions can be made to the above-described embodiments without departing from the scope of the claims.

[0109] For example, in each of the above embodiments, the movable part has a mirror part, but the movable part may have a diffraction grating, a photodiode, a heater (e.g., a heater using SiN), a light source (e.g., a surface-emitting laser), etc. instead of the mirror part. [Explanation of symbols]

[0110] 1 Mechanism 10 First Layer 11 Gears 111 Tooth (an example of the first convex portion) 112 Tooth side vertical plane 12. Cam 121 Outer surface 13 Shaft core member 2 Drive unit 20 Second Layer 21 Claw portion (an example of a second convex portion) 211 Claw side vertical surface 21a Rotation direction (an example of a specified direction) 22 Piezoelectric actuator (an example of an actuator) 221 Elastic part 221a Frame 221b Beam section 221c End of the elastic part on the +X direction side 221d -X direction end of elastic part 222 Piezoelectric section 23 Connection 3 Moving parts 30 The Third Layer 31 Post 311 Contact part 32a, 32b Torsion bar (an example of a support part) 33 Support Frame 34 Reflective surface 35 Support beam 41 Mechanism support part 42 Drive unit support 5 Support 6 Periodic structure 100 Mobile 700 LIDAR device (an example of a distance measuring device) 800 Retinal projection display device (an example of a display device) L Rotation Axis M Swing Axis d1, d2, d3, d4 Distance T period V Voltage value [Prior art documents] [Patent documents]

[0111] [Patent Document 1] Patent No. 5323155

Claims

1. A mechanism for driving the movable part; A drive unit that drives the mechanism unit, the mechanism portion has a gear including a first protrusion and a cam rotatable in response to rotation of the gear, and the rotation of the cam drives the movable portion in contact with the cam; the drive unit has a second convex portion that meshes with the first convex portion, and an actuator that reciprocates the second convex portion in response to an applied voltage or current, and the second convex portion reciprocates to rotate the gear in a predetermined direction; the first convex portion has a shape in which a downstream side is lower than an upstream side in the predetermined direction, The second protrusion has a shape in which the downstream side is higher than the upstream side in the predetermined direction.

2. The movable device according to claim 1 , wherein the cam has a distance between a rotation axis of the cam and a contact portion where the cam comes into contact with the movable portion that changes in accordance with the rotation of the cam.

3. The movable device according to claim 1 or 2, wherein the actuator comprises a piezoelectric element.

4. A movable device according to claim 1 , comprising the movable part.

5. A movable device according to any one of claims 1 to 4, which is a MEMS device.

6. The movable portion having a support pillar integrally formed therewith; A support portion that supports the movable portion so that the movable portion can swing, The movable device according to claim 1 , wherein the movable portion swings when a part of the support column is moved by the mechanical portion.

7. The movable portion, a periodic structure including a periodic structure formed at a predetermined period, one end of which is fixedly supported and the other end of which is provided so as to be pressable by the movable portion; The movable device according to claim 1 , wherein the period of the periodic structure is changed by being pressed against the movable portion driven by the mechanical portion to deform the periodic structure.

8. A distance measuring device comprising the movable device according to claim 6.

9. A display device comprising the movable device according to claim 6.

10. A tunable laser comprising the movable device according to claim 7.

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