Movable device, projection device, mobile body, head-mounted display, head-up display, laser headlamp, object recognition device, position detection device, and method of movement

Abstract

By reducing the number of drive signals applied to the drive unit, we can suppress the increase in the size of the circuit that generates the drive signals and the complexity of the circuit configuration. [Solution] A movable device 13 comprising a movable part 101, drive units 110a and 110b for driving the movable part 101, and a control unit for applying a drive signal to the drive units, wherein the drive units 110a and 110b have at least one of the following configurations: one in which a pair of drive members 112a and 112b are arranged at asymmetrical positions on either side of the movable part 101, and the other in which a pair of drive members with different shapes are arranged at each position on either side of the movable part 101.

Description

Technical Field

[0001] The present invention relates to a movable device, a projection device, a moving body, a head-mounted display, a head-up display, a laser headlamp, an object recognition device, a position detection device, and a moving method.

Background Art

[0002] Conventionally, a movable device including a movable part, a driving part for driving the movable part, and a control part for applying a driving signal to the driving part is known.

[0003] For example, Patent Document 1 discloses a micromirror device (movable device) connected by two opposing first connection parts to an annular actuator (driving part) in which a mirror part (movable part) is arranged so as to surround it. The annular actuator is connected by two opposing second connection parts to a fixed part arranged so as to surround it. Eight piezoelectric parts (driving members) arranged so as to surround the mirror part (movable part) are arranged in the actuator. In this device, by applying mutually different individual driving signals to the eight piezoelectric parts to bend and displace the actuator, a rotational torque around the axis passing through the first connection part and a rotational torque around the axis passing through the second connection part are generated with respect to the mirror part. Thereby, two-dimensional driving using one annular actuator is realized.

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, since the number of driving signals applied to the driving part of the conventional movable device is large, there is a problem in that it causes an increase in the circuit scale for generating the driving signals and a complication of the circuit configuration.

Means for Solving the Problems

[0005] To solve the above-mentioned problems, the present invention provides a movable device comprising a movable part, a drive unit for driving the movable part, and a control unit for applying a drive signal to the drive unit, wherein the drive unit has at least one of the following configurations: a configuration in which each of a pair of drive members is arranged at asymmetrical positions on either side of the movable part, and a configuration in which each of a pair of drive members having different shapes is arranged at each position on either side of the movable part. [Effects of the Invention]

[0006] According to the present invention, the number of drive signals applied to the drive unit can be reduced, thereby suppressing an increase in the circuit size and complexity of the circuit configuration that generates the drive signals. [Brief explanation of the drawing]

[0007] [Figure 1] This is a plan view illustrating a movable device according to Embodiment 1. [Figure 2] This is an end view of the movable device along the second axis in Figure 1. [Figure 3] This is a cross-sectional view showing the cross-section along the line III-III in Figure 1. [Figure 4] This is a plan view illustrating a movable device according to Embodiment 2. [Figure 5] This is a plan view illustrating a movable device according to Embodiment 3. [Figure 6] This is a plan view illustrating a movable device according to Embodiment 4. [Figure 7] This is a plan view illustrating a movable device according to Embodiment 5. [Figure 8] This is a plan view illustrating a movable device according to Embodiment 6. [Figure 9] This is an explanatory diagram showing the phase of the drive cycle of the mirror section when the same drive signal is applied to all four piezoelectric drive sections of the movable device of Embodiment 6. [Figure 10] This is a plan view illustrating a movable device according to Embodiment 7. [Figure 11] This is a plan view illustrating another configuration of the movable device according to Embodiment 7. [Figure 12] It is a plan view which illustrates the movable device which concerns on Embodiment 8. [Figure 13] It is a plan view which illustrates the movable device which concerns on Embodiment 9. [Figure 14] It is a plan view which illustrates the movable device which concerns on Embodiment 10. [Figure 15] It is a plan view which illustrates the movable device which concerns on Embodiment 11. [Figure 16] It is a schematic diagram of an example of an optical scanning system. [Figure 17] It is a hardware configuration diagram of an example of an optical scanning system. [Figure 18] It is a functional block diagram of an example of a control device. [Figure 19] It is a flowchart of an example of the process which concerns on an optical scanning system. [Figure 20] It is a schematic diagram of an example of an automobile equipped with a head-up display device. [Figure 21] It is a schematic diagram of an example of a head-up display device. [Figure 22] It is a schematic diagram of an example of an image forming apparatus equipped with an optical writing device. [Figure 23] It is a schematic diagram of an example of an optical writing device. [Figure 24] It is a schematic diagram of an example of an automobile equipped with a lidar device. [Figure 25] It is a schematic diagram of an example of an automobile equipped with a lidar device. [Figure 26] It is a schematic diagram of an example of a lidar device. [Figure 27] It is a schematic diagram of an example of a laser headlamp. [Figure 28] It is a perspective view of the appearance of an example of a head-mounted display. [Figure 29] It is a figure which illustrates partly the structure of a head-mounted display. [Figure 30] It is a schematic block diagram which shows an example of a position detection device of a pupil or a cornea. [Figure 31]It is a schematic configuration diagram showing an example of a pupil or corneal position detection device.

Embodiments for Carrying out the Invention

[0008] Hereinafter, embodiments for carrying out the invention will be described with reference to the drawings. In each drawing, the same reference numerals are given to the same constituent parts, and redundant explanations may be omitted.

[0009] In the following description of the embodiments, rotation, oscillation, and movement are assumed to be synonymous. In each figure, the X-axis direction, Y-axis direction, and Z-axis direction orthogonal to each other may be shown. The Z-axis direction is along the stacking direction of each layer in the piezoelectric drive unit or the like. The case of viewing from the Z-axis direction may be described as "plan view". Also, in each figure, parallel oblique lines may be attached to parts that are not cross-sections.

[0010] The X-axis direction includes the direction indicated by the arrow and the opposite direction. Among the X-axis directions, the direction in which the arrow points may be denoted as the +X direction, and the opposite direction of the +X direction may be denoted as the -X direction. The Y-axis direction includes the direction indicated by the arrow and the opposite direction. Among the Y-axis directions, the direction in which the arrow points may be denoted as the +Y direction, and the opposite direction of the +Y direction may be denoted as the -Y direction. The Z-axis direction includes the direction indicated by the arrow and the opposite direction. Among the Z-axis directions, the direction in which the arrow points may be denoted as the +Z direction, and the opposite direction of the +Z direction may be denoted as the -Z direction. These directions do not limit the orientation of the movable device 13, and the orientation of the movable device 13 is arbitrary. The movable device may be called an "optical deflector".

[0011] 〔Embodiment 1〕 Referring to FIGS. 1 to 3, an embodiment of the movable device 13 (hereinafter, this embodiment is referred to as "Embodiment 1") will be described. FIG. 1 is a plan view illustrating the movable device 13 according to the first embodiment. FIG. 2 is an end view of the movable device 13 along the second axis in FIG. 1. FIG. 3 is a cross-sectional view showing a cross-section along line III-III in FIG. 1.

[0012] As shown in Figure 1, the movable device 13 includes a mirror section 101 as a movable part, first drive sections 110a and 110b, a first support frame 120, second drive sections 130a and 130b, a second support frame 140, an electrode connection section 150, and a control device 11.

[0013] The mirror section 101 has a reflective surface 14 that reflects incident light. The mirror section 101 is an example of a movable part. The first drive units 110a and 110b are each connected to the mirror section 101 and cause the mirror section 101 to swing around a first axis parallel to the Y-axis. The support frame 120 supports the mirror section 101 and the first drive units 110a and 110b.

[0014] The second drive units 130a and 130b are connected to the first support frame 120 and cause the mirror unit 101 and the first support frame 120 to swing around a second axis parallel to the X-axis. The second support frame 140 supports the second drive units 130a and 130b. The electrode connection unit 150 is electrically connected to the first drive units 110a and 110b, the second drive units 130a and 130b, and the control device 11.

[0015] The movable device 13 is formed by, for example, shaping a single SOI (Silicon On Insulator) substrate by etching or the like, and then forming a reflective surface 14, first piezoelectric drive units 112a, 112b, second piezoelectric drive units 131a-131f and 132a-132f, electrode connection units 150, etc., on the formed substrate, thereby integrally forming each component. The formation of each component may be performed after the SOI substrate is formed, or during the SOI substrate is formed.

[0016] The SOI substrate on which the movable device 13 is formed includes, as shown in Figures 2 and 3, a silicon support layer 161 made of single-crystal silicon (Si), a silicon oxide layer 162 formed on the silicon support layer 161 (on the +Z side), and a silicon active layer 163 made of single-crystal silicon formed on the silicon oxide layer 162. The silicon oxide layer 162 can also be called a BOX (Buried Oxide) layer.

[0017] A component composed solely of the silicon active layer 163 functions as an elastic part with elastic properties.

[0018] The SOI substrate does not necessarily have to be planar; it may have curvature or other properties. The components used to form the movable device 13 can be integrally molded by etching or the like, and may be partially elastic substrates; they are not limited to SOI substrates.

[0019] The mirror portion 101 includes, for example, a circular mirror portion base 102 and a reflective surface 14 formed on the +Z side surface of the mirror portion base. The mirror portion base 102 includes, for example, a silicon active layer 163. The reflective surface 14 includes, for example, a thin metal film containing aluminum, gold, silver, etc.

[0020] A movable thickened portion 103 for reinforcing the mirror portion is formed on the -Z side surface of the mirror base 102. The movable thickened portion 103 includes, for example, a silicon support layer 161 and a silicon oxide layer 162, and can suppress distortion of the reflective surface 14 caused by movement.

[0021] As shown in Figure 1, the first drive units 110a and 110b include torsion bars 111a and 111b and first piezoelectric drive units 112a and 112b as drive members.

[0022] Each of the torsion bars 111a and 111b has one end connected to the mirror portion 101 and is an example of a support portion that extends in the first axial direction and elastically supports the mirror portion 101.

[0023] Each of the first piezoelectric drive units 112a and 112b has one end connected to the torsion bar 111a and 111b, and is an example of a drive beam that swings the mirror unit 101 around the first axis by deforming the torsion bar 111a and 111b. The first axis is an example of a predetermined swing axis. The other ends of each of the first piezoelectric drive units 112a and 112b are connected to the inner circumference of the first support frame 120, respectively. The first drive units 110a and 110b also include detection piezoelectric elements 160a and 160b.

[0024] As shown in Figure 3, the torsion bars 111a and 111b include a silicon active layer 163. The first piezoelectric drive units 112a and 112b have a lower electrode 301, a piezoelectric part 302, and an upper electrode 303 stacked in this order on the +Z side surface of the silicon active layer 163, which is the elastic part. The upper electrode 303 and the lower electrode 301 include, for example, gold (Au) or platinum (Pt). The piezoelectric part 302 includes, for example, PZT (lead zirconate titanate), which is a piezoelectric material.

[0025] As shown in Figures 1 and 3, the first support frame 120 is a rectangular support composed of a silicon support layer 161, a silicon oxide layer 162, and a silicon active layer 163, and is formed to surround the mirror portion 101.

[0026] The second drive units 130a and 130b include a plurality of second piezoelectric drive units 131a to 131f and 132a to 132f, which are connected in a folded manner as drive members. One end of the second drive units 130a and 130b is connected to the outer circumference of the first support frame 120, and the other end is connected to the inner circumference of the second support frame 140.

[0027] The connection points between the second drive unit 130a and the first support frame 120, and between the second drive unit 130b and the first support frame 120, are point-symmetric with respect to the center of the reflective surface 14. Furthermore, the connection points between the second drive unit 130a and the second support frame 140, and between the second drive unit 130b and the second support frame 140, are point-symmetric with respect to the center of the reflective surface 14.

[0028] As shown in Figure 2, the second piezoelectric drive units 131a-131f and 132a-132f are arranged on the +Z side surface of the silicon active layer 163, which is an elastic part, with the lower electrode 201, piezoelectric part 202, and upper electrode 203 stacked in this order. The upper electrode 203 and lower electrode 201 include, for example, gold (Au) or platinum (Pt). The piezoelectric part 202 includes, for example, PZT (lead zirconate titanate), which is a piezoelectric material.

[0029] As shown in Figures 1 and 2, the second support frame 140 includes a silicon support layer 161, a silicon oxide layer 162, and a silicon active layer 163. The second support frame 140 is a rectangular support formed to surround the mirror portion 101, the first drive units 110a and 110b, the first support frame 120, and the second drive units 130a and 130b.

[0030] The electrode connection section 150 is formed on the +Z side surface of the second support frame 140 and is electrically connected to the upper electrodes 303 and lower electrodes 301 of the first piezoelectric drive units 112a and 112b, the upper electrodes 203 and lower electrodes 201 of the second piezoelectric drive units 131a to 131f and 132a to 132f, and the control device 11 via electrode wiring made of aluminum (Al). A signal voltage is applied to the lower electrode 201, and the upper electrode 203 is connected to ground (GND).

[0031] The upper electrode 203 or the lower electrode 201 may be directly connected to the electrode connection part 150, or they may be indirectly connected by connecting the electrodes to each other.

[0032] In this embodiment 1, the piezoelectric element 202 was described as being formed only on one surface (the +Z side) of the elastic silicon active layer 163, but it may also be provided on other surfaces of the elastic part (for example, the -Z side), or on both one and the other surface of the elastic part.

[0033] Furthermore, the shape of each component is not limited to that of this embodiment 1, as long as the mirror portion 101 can be driven around the first axis or the second axis. For example, the torsion bars 111a, 111b and the first piezoelectric drive units 112a, 112b may have a curved shape.

[0034] Furthermore, an insulating layer made of a silicon oxide film may be formed on at least one of the following surfaces: the +Z side surface of the upper electrode 303 of the first drive unit 110a, 110b; the +Z side surface of the first support frame; the +Z side surface of the upper electrode 203 of the second drive unit 130a, 130b; or the +Z side surface of the second support frame.

[0035] In this case, electrode wiring is provided on the insulating layer, and the insulating layer is partially removed or left blank only at the connection spots where the upper electrode 203, upper electrode 303, lower electrode 201 or lower electrode 301 are connected to the electrode wiring, creating openings. This increases the design flexibility of the first drive units 110a, 110b, second drive units 130a, 130b, and electrode wiring, and suppresses short circuits caused by contact between electrodes. Furthermore, the silicon oxide film also functions as an anti-reflective material.

[0036] Furthermore, a piezoelectric detection element 160a for detecting the elastic deformation of the first drive unit 110a is provided in close proximity to the first piezoelectric drive unit 112a. Also, a piezoelectric detection element 160b for detecting the elastic deformation of the first drive unit 110b is provided in close proximity to the first piezoelectric drive unit 112b.

[0037] The first piezoelectric drive unit 112a is provided on the first drive unit 110a and deforms the first drive unit 110a in accordance with the applied drive voltage. The first piezoelectric drive unit 112b is provided on the first drive unit 110b and deforms the first drive unit 110b in accordance with the applied drive voltage.

[0038] The detection piezoelectric element 160a generates a detection signal by piezoelectric effect in response to the deformation of the first drive unit 110a and outputs it to the control device 11 via the electrode connection unit 150. The detection piezoelectric element 160b generates a detection signal by piezoelectric effect in response to the deformation of the first drive unit 110b and outputs it to the control device 11 via the electrode connection unit 150.

[0039] Next, we will explain the control provided by the control device 11. The control device 11 has the function of a control unit 30 that applies drive voltage to the first drive units 110a, 110b and the second drive units 130a, 130b of the movable device 13.

[0040] The piezoelectric elements 302 of the first drive units 110a and 110b, and the piezoelectric elements 202 of the second drive units 130a and 130b, undergo deformation (e.g., expansion and contraction) proportional to the potential of the applied voltage when a positive or negative voltage is applied in the polarization direction, exhibiting a so-called inverse piezoelectric effect. The first drive units 110a and 110b, and the second drive units 130a and 130b, utilize the inverse piezoelectric effect to move the mirror unit 101.

[0041] In this case, the angle formed between the XY plane and the reflective surface 14 of the mirror portion 101 when the reflective surface 14 is tilted in the +Z or -Z direction with respect to the XY plane is called the deflection angle. The +Z direction is defined as the positive deflection angle, and the -Z direction as the negative deflection angle.

[0042] In the first drive units 110a and 110b, when a drive voltage, which is a drive signal, is applied to the piezoelectric parts 302 of the first piezoelectric drive units 112a and 112b via the upper electrode 303 and the lower electrode 301, each piezoelectric part 302 deforms. Due to the action of this deformation of the piezoelectric parts 302, the first piezoelectric drive units 112a and 112b undergo bending deformation. As a result, a driving force around the first axis acts on the mirror part 101 via the twisting of the two torsion bars 111a and 111b, causing the mirror part 101 to swing around the first axis. The drive voltage applied to the first drive units 110a and 110b is controlled by the control device 11.

[0043] The control device 11 applies a predetermined sinusoidal waveform drive voltage in parallel to the first piezoelectric drive units 112a and 112b of the first drive units 110a and 110b, thereby allowing the mirror unit 101 to move around the first axis at a period equal to the predetermined sinusoidal waveform drive voltage.

[0044] The control device 11 can also control the oscillation of the first drive units 110a and 110b based on information regarding the oscillation of the first drive units 110a and 110b, which is acquired based on the detection signals output by the detection piezoelectric elements 160a and 160b, respectively.

[0045] For example, if the frequency of the drive voltage is set to approximately 20 kHz, which is about the same as the resonant frequency of the torsion bars 111a and 111b, the mirror section 101 can be made to resonate and vibrate at approximately 20 kHz by utilizing the mechanical resonance caused by the twisting of the torsion bars 111a and 111b.

[0046] The movable device 13 according to this embodiment 1 may be a cantilever type in which the first piezoelectric drive units 112a and 112b extend from the torsion bars 111a and 111b toward the +X direction. The movable device 13 is not limited to this. The movable device 13 only needs to be able to swing the mirror unit 101 by the piezoelectric unit 202 to which a drive voltage is applied. The movable device 13 may be, for example, a double-supported type.

[0047] In this embodiment 1, the first drive units 110a and 110b are arranged such that the first piezoelectric drive units 112a and 112b are positioned asymmetrically across the mirror unit 101. This asymmetrical arrangement allows for different amplitudes, phases, or both between the displacement period when one of the pair of first piezoelectric drive units 112a and 112b deforms the torsion bar 111a and displaces one part of the mirror unit 101 (for example, the connection between the mirror unit 101 and the torsion bar 111a) and the displacement period when the other first piezoelectric drive unit 112b deforms the torsion bar 111b and displaces the other part of the mirror unit 101 (for example, the connection between the mirror unit 101 and the torsion bar 111b). In this way, by intentionally creating a difference in the movement of two different points on the mirror section 101 (amplitude or phase of the displacement period, or both), it is possible to induce the oscillation of the mirror section 101 around the first axis, thereby causing the mirror section 101 to oscillate (resonant drive) around the first axis.

[0048] There are no particular restrictions on the drive signals applied to each of the paired first piezoelectric drive units 112a and 112b. Therefore, the drive signal may be a waveform signal with a constant amplitude, or a periodic waveform in which the amplitude and DC component are modulated in intensity over time.

[0049] In this embodiment 1, the physical asymmetrical configuration between the pair of first piezoelectric drive units 112a and 112b, which are arranged on either side of the mirror unit 101, is achieved by making the positions in which each of the first piezoelectric drive units 112a and 112b is arranged asymmetrically, but is not limited to this. For example, the physical asymmetrical configuration can be achieved by making the pair of first piezoelectric drive units 112a and 112b, which are arranged at each position on either side of the mirror unit 101, have different shapes from each other. In this case, even if the pair of first piezoelectric drive units 112a and 112b are arranged symmetrically with respect to the mirror unit 101, as described above, even if the same drive signal is applied to each of the pair of first piezoelectric drive units 112a and 112b, the amplitude, phase, or both of the displacement period in which one first piezoelectric drive unit 112a displaces one part of the mirror unit 101 and the displacement period in which the other first piezoelectric drive unit 112b displaces the other part of the mirror unit 101 can be made to differ from each other.

[0050] The same can be achieved even if the first piezoelectric drive units 112a and 112b, which are a pair with different shapes, are arranged in asymmetrical positions with the mirror unit 101 in between.

[0051] Methods for differentiating the shapes of the first piezoelectric drive units 112a and 112b include differentiating the in-plane shape (planar shape, planar size) or thickness of the piezoelectric drive units. However, if the thickness of the piezoelectric drive units is different, the symmetry of the resonance modes of the entire structure may be greatly disrupted, so it is preferable to differ the in-plane shape of the piezoelectric drive units.

[0052] Furthermore, in this embodiment 1, the second drive units 130a and 130b are also configured with a physically asymmetrical structure between the pair of second piezoelectric drive units 131a-131f and 132a-132f, which are positioned on either side of the mirror unit 101. This allows the amplitude, phase, or both of the displacement period between the displacement period caused by one of the second piezoelectric drive units 131a-131f to displace one part of the mirror unit 101 and the displacement period caused by the other second piezoelectric drive unit 132a-132f to displace the other part of the mirror unit 101 to be different from each other, even when the same drive signal is applied to each of the pair of second piezoelectric drive units, similar to the first drive units 110a and 110b. By intentionally creating a discrepancy in the movement of two different parts of the mirror unit 101 in this way, the mirror unit 101 can be made to oscillate around the second axis.

[0053] Therefore, according to this embodiment 1, it is no longer necessary to apply individual drive signals to each of the pair of piezoelectric drive units arranged on either side of the mirror unit 101, and the number of drive signals applied to the piezoelectric drive units can be reduced. As a result, it is possible to suppress the increase in system size and cost due to the increase in the scale of the circuit that generates the drive signals, or the increase in system complexity due to complex signal control.

[0054] [Embodiment 2] Next, another embodiment of the movable device 13 (hereinafter referred to as "Embodiment 2") will be described. Figure 4 is a plan view illustrating the movable device 13 according to this second embodiment. The difference between the movable device 13 of this second embodiment and the movable device 13 of the first embodiment is that it is equipped with first drive units 210a and 210b instead of first drive units 110a and 110b. Note that the same explanations as those for the first embodiment will be omitted in the description of this second embodiment.

[0055] The first drive unit 210a includes a torsion bar 211a and first piezoelectric drive units 212a and 212c. The first piezoelectric drive unit 212a extends from the torsion bar 211a in the +X direction. The first piezoelectric drive unit 212c extends from the torsion bar 211a in the -X direction.

[0056] The first drive unit 210b includes a torsion bar 211b and first piezoelectric drive units 212b and 212d. The first piezoelectric drive unit 212b extends from the torsion bar 211b in the +X direction. The first piezoelectric drive unit 212d extends from the torsion bar 211b in the -X direction. Thus, the movable device 13 may be of a double-supported type. The movable device 13 may also be designed to move the reflective surface 14 in only one axial direction.

[0057] In this second embodiment, as in the first embodiment, the first drive units 210a and 210b are arranged with their respective first piezoelectric drive units 212a, 212c and 212b, 212d positioned asymmetrically across the mirror unit 101. This asymmetrical arrangement allows for different amplitudes, phases, or both between the displacement period in which one of the pair of first piezoelectric drive units 212a, 212c deforms the torsion bar 211a and displaces one part of the mirror unit 101, and the displacement period in which the other first piezoelectric drive unit 212b, 212d deforms the torsion bar 211b and displaces the other part of the mirror unit 101. By intentionally creating a discrepancy in the movement of two different points on the mirror section 101 in this way, it becomes possible to induce the oscillation of the mirror section 101 around the first axis, thereby causing the mirror section 101 to oscillate (resonant drive) around the first axis.

[0058] In this second embodiment as well, the physically asymmetrical configuration between the pair of first piezoelectric drive units arranged on either side of the mirror unit 101 can be achieved, as in the first embodiment, by, for example, making the pairs of piezoelectric drive units arranged at each position on either side of the mirror unit 101 different in shape from each other.

[0059] Furthermore, as with Embodiment 1, the second drive units 130a and 130b in this Embodiment 2 may also be physically asymmetrical, with a pair of second piezoelectric drive units 131a-131f and 132a-132f arranged on either side of the mirror unit 101.

[0060] [Embodiment 3] Next, another embodiment of the movable device 13 (hereinafter referred to as "Embodiment 3") will be described. Figure 5 is a plan view illustrating the movable device 13 according to this third embodiment. The movable device 13 according to this third embodiment is equipped with four drive units 110a to 110d and is capable of two-dimensional optical deflection. This movable device 13 is suitable for vector scanning, Lissajous scanning, and spiral scanning. The drive units 110a to 110d are examples of the first and second drive units.

[0061] In describing this third embodiment, descriptions similar to those for the movable device 13 in embodiments 1 and 2 described above may be omitted. The driving method of the drive unit is not limited to piezoelectric driving. The driving method of the drive unit may be electrostatic driving, electromagnetic driving, or thermoelectric driving. In the movable device 13, the movable part and the drive units 110a to 110d are formed from the same substrate. The movable part and the drive unit can be made from, for example, the silicon active layer of an SOI substrate, but the in-plane and thickness-direction configurations are not limited to those described in this embodiment.

[0062] The movable device 13 shown in Figure 5 comprises a mirror section (movable section) 101, a support frame 140, and drive sections 110a to 110d. The support frame 140 may be a rectangular frame in plan view. A rectangular frame has sides that align with the X-axis and Y-axis directions in plan view.

[0063] The drive units 110a to 110d are each positioned corresponding to the corners of the support frame 140. Drive unit 110a has a torsion bar 111a and a piezoelectric drive unit 112a. The piezoelectric drive unit 112a is formed to have a rectangular shape in plan view. The torsion bar 111a protrudes from the piezoelectric drive unit 112a toward the mirror unit 101. Similarly, drive unit 110b has a torsion bar 111b and a piezoelectric drive unit 112b. Drive unit 110c has a torsion bar 111c and a piezoelectric drive unit 112c. Drive unit 110d has a torsion bar 111d and a piezoelectric drive unit 112d.

[0064] In this third embodiment, the piezoelectric drive units 112a to 112d are arranged at asymmetrical positions on either side of the mirror unit 101 for the drive units 110a to 110d. Specifically, for the pair of drive units 110a and 110c arranged on either side of the mirror unit 101, the piezoelectric drive units 112a and 112c are arranged at asymmetrical positions on either side of the mirror unit 101. Furthermore, for the other pair of drive units 110b and 110d arranged on either side of the mirror unit 101, the piezoelectric drive units 112b and 112d are arranged at asymmetrical positions on either side of the mirror unit 101.

[0065] This asymmetrical arrangement allows the pair of piezoelectric drive units 112a and 112c to have different amplitudes, phases, or both of the displacement period when one piezoelectric drive unit 112a deforms the torsion bar 111a and displaces one part of the mirror unit 101, and when the other piezoelectric drive unit 112c deforms the torsion bar 111c and displaces the other part of the mirror unit 101. By intentionally creating a discrepancy in the movement of two different parts of the mirror unit 101 in this way, the mirror unit 101 can be oscillated (resonantly driven) around the rotation axis (first axis) of the resonant mode that is easily driven by the pair of piezoelectric drive units 112a and 112c.

[0066] Similarly, in the other pair of drive units 110b, 110d, even if the same drive signal is applied to the pair of piezoelectric drive units 112b, 112d, the amplitude, phase, or both of the displacement period in which one of the pair of piezoelectric drive units 112b deforms the torsion bar 111b and displaces one part of the mirror unit 101, and the displacement period in which the other piezoelectric drive unit 112d deforms the torsion bar 111d and displaces the other part of the mirror unit 101 can be made to differ from each other. By intentionally creating a discrepancy in the movement of two different parts of the mirror unit 101 in this way, the mirror unit 101 can be oscillated (resonantly driven) around the rotation axis (second axis) of the resonant mode that is easily driven by the drive of the pair of piezoelectric drive units 112b, 112d.

[0067] In this third embodiment, the axis of rotation from which the mirror section 101 swings due to a pair of drive units 110a and 110c and the axis of rotation from which the mirror section 101 swings due to another pair of drive units 110b and 110d are orthogonal to each other. Therefore, two-dimensional drive of the mirror section 101 is possible by driving the four drive units 110a to 110d.

[0068] In this third embodiment, as in the first embodiment, the physically asymmetrical configuration between the pair of piezoelectric drive units arranged on either side of the mirror unit 101 can be achieved, for example, by making the pairs of piezoelectric drive units arranged at each position on either side of the mirror unit 101 have different shapes, or by making their positions and shapes different from each other.

[0069] Furthermore, as in this third embodiment, by providing separate drive units 110 and 130 for driving around the mutually orthogonal first and second axes, it becomes possible to provide different speeds and different drive characteristics between these two axes. In particular, if resonant driving is used for driving around the first axis and non-resonant driving is used for driving around the second axis, raster scanning can be suitably performed.

[0070] Furthermore, when non-resonant drive is used for both the drive around the first axis and the drive around the second axis, the movement of the mirror section 101 itself scans the light emitted from the optical output section in a desired direction, making it possible to suitably perform vector scanning to draw shapes, characters, or pictures.

[0071] Furthermore, when resonant drive is used for both the drive around the first axis and the drive around the second axis, the amplitude of the mirror section 101 can be increased for both axes, making it possible to suitably perform Lissajous scanning that draws over a wide field of view.

[0072] Furthermore, by operating the oscillation amplitude around the first axis and the oscillation amplitude around the second axis at the same or a specific ratio, the scanning position of the light reflected by the mirror section 101 can trace a circular or elliptical scanning trajectory, that is, circular scanning can be suitably performed.

[0073] Furthermore, it is already known that by increasing or decreasing the oscillation amplitude around the first axis and the oscillation amplitude around the second axis over time, the scanning position of the light reflected by the mirror section 101 moves in a swirling motion, that is, a spiral scan operation can be suitably performed, and it is also possible to draw figures, characters, pictures, etc., within the field of view.

[0074] [Embodiment 4] Next, another embodiment of the movable device 13 (hereinafter referred to as "Embodiment 4") will be described. Figure 6 is a plan view illustrating the movable device 13 according to this embodiment 4. The movable device 13 according to this fourth embodiment is a simple movable device that drives the mirror portion 101 in one dimension.

[0075] As shown in Figure 6, the drive units 110a and 110b have the same configuration as the drive units described in the above-described embodiment, and include torsion bars 111a and 111b and piezoelectric drive units 112a and 112b as drive members. Each of the torsion bars 111a and 111b has one end connected to the mirror unit 101 and is an example of a support unit that extends in an axial direction parallel to the Y-axis and elastically supports the mirror unit 101.

[0076] Each support section, equipped with piezoelectric drive units 112a and 112b, has one end connected to torsion bars 111a and 111b, respectively. This is an example of a drive beam that oscillates the mirror section 101 around a pivot axis parallel to the Y-axis by deforming the torsion bars 111a and 111b. The other ends of the piezoelectric drive units 112a and 112b are connected to the inner circumference of the support frame 140, which serves as a fixed part.

[0077] In this fourth embodiment, the piezoelectric drive units 112a and 112b are positioned asymmetrically on either side of the mirror unit 101. This asymmetrical arrangement allows for a difference in amplitude, phase, or both between the displacement period when one of the pair of piezoelectric drive units 112a deforms the torsion bar 111a and displaces one part of the mirror unit 101, and the displacement period when the other piezoelectric drive unit 112b deforms the torsion bar 111b and displaces the other part of the mirror unit 101. By intentionally creating a discrepancy in the movement of two different parts of the mirror unit 101 in this way, it is possible to induce oscillation of the mirror unit 101 around its pivot axis, causing the mirror unit 101 to oscillate around its pivot axis (resonant drive).

[0078] In this embodiment 4 as well, the physically asymmetrical configuration between the pair of piezoelectric drive units arranged on either side of the mirror unit 101 can be achieved, for example, by making the pairs of piezoelectric drive units arranged at each position on either side of the mirror unit 101 have different shapes, or by making their positions and shapes different from each other.

[0079] [Embodiment 5] Next, another embodiment of the movable device 13 (hereinafter referred to as "Embodiment 5") will be described. Figure 7 is a plan view illustrating the movable device 13 according to this embodiment 5. The movable device 13 according to this embodiment 5 is equipped with four drive units 110a to 110d and is capable of two-dimensional light deflection. The basic configuration of the movable device 13 according to this embodiment 5 is the same as the basic configuration of the movable device of embodiment 3 described above, and the common explanatory parts will be omitted as appropriate.

[0080] The movable device 13 shown in Figure 7 comprises a mirror section 101, a support frame 140, and drive sections 110a to 110d. The drive section 110a has a torsion bar 111a and two piezoelectric drive sections 112a1 and 112a2. The two piezoelectric drive sections 112a1 and 112a2 are formed to form a rectangular shape in plan view, but their shapes (sizes) are different from each other. Of the two piezoelectric drive sections 112a1 and 112a2, one piezoelectric drive section 112a1 is positioned far from the mirror section 101, and the other piezoelectric drive section 112a2 is positioned close to the mirror section 101.

[0081] Similarly, the drive unit 110b has a torsion bar 111b and two piezoelectric drive units 112b1 and 112b2. Similarly, the drive unit 110c has a torsion bar 111c and two piezoelectric drive units 112c1 and 112c2. Similarly, the drive unit 110d has a torsion bar 111d and two piezoelectric drive units 112d1 and 112d2.

[0082] In this embodiment 5, the piezoelectric drive units 112a1 to 112d2 of the drive units 110a to 110d are arranged at asymmetrical positions with respect to the mirror unit 101. Specifically, for the pair of drive units 110a and 110c arranged on either side of the mirror unit 101, the corresponding piezoelectric drive units 112a1 and 112c1 are arranged at asymmetrical positions with respect to the mirror unit 101. Furthermore, for the pair of drive units 110a and 110c, the corresponding piezoelectric drive units 112a2 and 112c2 are also arranged at asymmetrical positions with respect to the mirror unit 101.

[0083] This asymmetrical arrangement allows the pair of drive units 110a and 110c to apply the same drive signal to the pair of piezoelectric drive units 112a1 and 112c1, and also to the other pair of piezoelectric drive units 112a2 and 112c2. However, the drive signals applied to the pair of piezoelectric drive units 112a1 and 112c1 and the drive signals applied to the other pair of piezoelectric drive units 112a2 and 112c2 may have different voltages or phases. By driving these pair of drive units 110a and 110c, the mirror unit 101 can be oscillated (resonantly driven) around a rotation axis (first axis) in a resonant mode that is easily moved by the driving of the pair of piezoelectric drive units 112a1 and 112c1 and the piezoelectric drive units 112a2 and 112c2.

[0084] Similarly, in the other pair of drive units 110b, 110d, the same drive signal is applied to each pair of piezoelectric drive units 112b1, 112d1, and the same drive signal is also applied to each other to the other pair of piezoelectric drive units 112b2, 112d2. However, the drive signals applied to the pair of piezoelectric drive units 112b1, 112d1 and the drive signals applied to the other pair of piezoelectric drive units 112b2, 112d2 may have different voltages or phases. By driving such a pair of drive units 110b, 110d, the mirror unit 101 can be oscillated (resonant drive) around the rotation axis (second axis) of the resonant mode that is easily moved by the driving of the pair of piezoelectric drive units 112b1, 112d1 and the piezoelectric drive units 112b2, 112d2.

[0085] In this embodiment 5, as in embodiment 3, the axis of rotation from which the mirror section 101 swings due to a pair of drive units 110a and 110c and the axis of rotation from which the mirror section 101 swings due to another pair of drive units 110b and 110d are orthogonal to each other. Therefore, two-dimensional drive of the mirror section 101 is possible by driving the four drive units 110a to 110d.

[0086] In particular, in this embodiment 5, the pair of piezoelectric drive units in the pair of drive units 110a and 110c consist of multiple pairs (two pairs in this embodiment), namely the pair of piezoelectric drive units 112a1 and 112c1 and the pair of piezoelectric drive units 112a2 and 112c2. Although the mirror unit 101 can be oscillated around the first axis with just one pair, having multiple pairs allows for more precise control of the oscillation of the mirror unit 101.

[0087] Similarly, in the other pair of drive units 110b and 110d, there are multiple pairs of piezoelectric drive units, namely the pair of piezoelectric drive units 112b1 and 112d1 and the pair of piezoelectric drive units 112b2 and 112d2 (two pairs in this embodiment). Therefore, more precise oscillation control of the mirror unit 101 around the second axis becomes possible.

[0088] In this embodiment 5 as well, the physically asymmetrical configuration between the pair of piezoelectric drive units arranged on either side of the mirror unit 101 can be achieved, for example, by making the pairs of piezoelectric drive units arranged at each position on either side of the mirror unit 101 have different shapes, or by making their positions and shapes different from each other.

[0089] [Embodiment 6] Next, another embodiment of the movable device 13 (hereinafter referred to as "Embodiment 6") will be described. Figure 8 is a plan view illustrating the movable device 13 according to this embodiment 6. Note that the support frame 140 is not shown in Figure 8. The movable device 13 according to this embodiment 6 also has four drive units 110a to 110d and is capable of two-dimensional light deflection. The basic configuration of the movable device 13 according to this embodiment 6 is the same as the basic configuration of the movable device of embodiment 3 described above, and the common explanatory parts will be omitted as appropriate.

[0090] In the movable device 13 shown in Figure 8, the drive unit 110a has a torsion bar 111a and one piezoelectric drive unit 112a. Similarly, the drive unit 110b has a torsion bar 111b and one piezoelectric drive unit 112b, and similarly the drive unit 110d has a torsion bar 111d and one piezoelectric drive unit 112d.

[0091] On the other hand, in this embodiment 6, the drive unit 110c paired with the drive unit 110a has a torsion bar 111c and two piezoelectric drive units 112c1 and 112c2. Of the two piezoelectric drive units 112c1 and 112c2, one piezoelectric drive unit 112c1 is positioned close to the mirror unit 101, and the other piezoelectric drive unit 112c2 is positioned farther from the mirror unit 101.

[0092] In this embodiment 6 as well, the piezoelectric drive units 112a to 112d are arranged at asymmetrical positions on either side of the mirror unit 101 for the drive units 110a to 110d. Specifically, for the pair of drive units 110a and 110c arranged on either side of the mirror unit 101, the corresponding piezoelectric drive units 112a and 112c1 and 112c2 are arranged at asymmetrical positions on either side of the mirror unit 101. Moreover, one pair of piezoelectric drive units 112a and 112c1 and 112c2 consists of one piezoelectric drive unit 112a, while the other consists of two piezoelectric drive units 112c1 and 112c2, so the number of piezoelectric drive units differs between them.

[0093] This asymmetrical arrangement allows the mirror section 101 to oscillate (resonant drive) around a rotation axis (first axis) of a resonant mode that is easily driven by the driving of the pair of piezoelectric drive sections 112a and 112c1 and 112c2, even when the same drive signal is applied to the pair of piezoelectric drive sections 112a and 112c1 and 112c2.

[0094] Furthermore, in the other pair of drive units 110b and 110d, even if the same drive signal is applied to the pair of piezoelectric drive units 112b and 112d, the mirror unit 101 can be oscillated (resonant drive) around the rotation axis (second axis) of the resonant mode that is easily driven by the drive of the pair of piezoelectric drive units 112b and 112d.

[0095] In this embodiment 6, as in embodiment 3, the axis of rotation from which the mirror portion 101 swings due to a pair of drive units 110a and 110c and the axis of rotation from which the mirror portion 101 swings due to another pair of drive units 110b and 110d are orthogonal to each other. Therefore, two-dimensional drive of the mirror portion 101 is possible by driving the four drive units 110a to 110d.

[0096] In particular, in this embodiment 6, the position and shape of each piezoelectric drive unit 112a, 112c1, 112c2 in the pair of drive units 110a, 110c and the position and shape of each piezoelectric drive unit 112b, 112d in the other pair of drive units 110b, 110d are also asymmetrically configured. This makes it easier to control two-dimensional scanning using the resonance of the structure of the movable device 13, especially circular scanning, spiral scanning, and Lissajous scanning.

[0097] Figure 9 is an explanatory diagram showing the phase of the drive cycle of the mirror section 101 when the same drive signal is applied to all four piezoelectric drive units 110a to 110d in the movable device 13 of this embodiment 6. In Figure 9, the solid line represents the drive signal, the dashed line represents the oscillation period of the mirror section 101 around the first axis by the pair of drive units 110a and 110c, and the dashed line represents the oscillation period of the mirror section 101 around the second axis by the other pair of drive units 110b and 110d. As shown in Figure 9, the mirror section 101 can be oscillated individually around each axis.

[0098] In this embodiment 6 as well, the physically asymmetrical configuration between the pair of piezoelectric drive units arranged on either side of the mirror unit 101 can be achieved, for example, by making the pairs of piezoelectric drive units arranged at each position on either side of the mirror unit 101 have different shapes, or by making their positions and shapes different from each other.

[0099] [Embodiment 7] Next, another embodiment of the movable device 13 (hereinafter referred to as "Embodiment 7") will be described. Figure 10 is a plan view illustrating the movable device 13 according to this embodiment 7. The movable device 13 according to this embodiment 7 is a simple movable device that includes two drive units 110a and 110b and drives the mirror unit 101 in one dimension. The basic configuration of the movable device 13 according to this embodiment 7 is the same as the basic configuration of the movable device of embodiment 4 described above, and the common explanatory parts will be omitted as appropriate.

[0100] As shown in Figure 10, the drive unit 110a has a torsion bar 111a and two piezoelectric drive units 112a1 and 112a2. Of the two piezoelectric drive units 112a1 and 112a2, one piezoelectric drive unit 112a1 is positioned far from the mirror unit 101, and the other piezoelectric drive unit 112a2 is positioned close to the mirror unit 101.

[0101] Similarly, the drive unit 110b also has a torsion bar 111b and two piezoelectric drive units 112b1 and 112b2. Of the two piezoelectric drive units 112b1 and 112b2, one piezoelectric drive unit 112b1 is positioned close to the mirror unit 101, and the other piezoelectric drive unit 112b2 is positioned farther from the mirror unit 101.

[0102] In this embodiment 7, the piezoelectric drive units 112a1 to 112b2 are arranged at asymmetrical positions on either side of the mirror unit 101. Specifically, a pair of piezoelectric drive units 112a1 and 112b1 are arranged at asymmetrical positions on either side of the mirror unit 101, and furthermore, another pair of piezoelectric drive units 112a2 and 112b2 are also arranged at asymmetrical positions on either side of the mirror unit 101.

[0103] This asymmetrical arrangement applies the same drive signal to each pair of piezoelectric drive units 112a1 and 112b1, and also to each other pair of piezoelectric drive units 112a2 and 112b2. However, the drive signals applied to each pair of piezoelectric drive units 112a1 and 112c1 and the drive signals applied to each other pair of piezoelectric drive units 112a2 and 112c2 may have different voltages or phases. By driving these pairs of drive units 110a and 110b, the mirror unit 101 can be oscillated (resonantly driven) around a rotation axis in a resonant mode that is easily moved by the driving of the pairs of piezoelectric drive units 112a1 and 112b1 and the piezoelectric drive units 112a2 and 112b2.

[0104] In this embodiment 7, there are multiple pairs of piezoelectric drive units, namely the pair of piezoelectric drive units 112a1 and 112b1, and the pair of piezoelectric drive units 112a2 and 112b2 (two pairs in this embodiment). Although the mirror unit 101 can be oscillated around the rotation axis with just one pair, having multiple pairs allows for more precise control of the oscillation of the mirror unit 101.

[0105] In this embodiment 7 as well, the physically asymmetrical configuration between the pair of piezoelectric drive units arranged on either side of the mirror unit 101 can be achieved, for example, by making the pairs of piezoelectric drive units arranged at each position on either side of the mirror unit 101 have different shapes, or by making their positions and shapes different from each other.

[0106] For example, the example shown in Figure 11 is a physically asymmetrical configuration between a pair of piezoelectric drive units arranged on either side of the mirror unit 101, in which the positions and shapes of the pairs of piezoelectric drive units arranged on either side of the mirror unit 101 are different from each other. Specifically, the pair of piezoelectric drive units 112a1 and 112b1 have different shapes (sizes) and are arranged at asymmetrical positions on either side of the mirror unit 101. Similarly, the other pair of piezoelectric drive units 112a2 and 112b2 also have different shapes (sizes) and are arranged at asymmetrical positions on either side of the mirror unit 101.

[0107] [Embodiment 8] Next, another embodiment of the movable device 13 (hereinafter referred to as "Embodiment 8") will be described. Figure 12 is a plan view illustrating the movable device 13 according to this embodiment 8. The movable device 13 according to this embodiment 8 also has four drive units 110a to 110d and is capable of two-dimensional light deflection. The basic configuration of the movable device 13 according to this embodiment 8 is the same as the basic configuration of the movable device of embodiment 6 described above, and the common explanatory parts will be omitted as appropriate.

[0108] In the movable device 13 shown in Figure 12, the drive unit 110a has a torsion bar 111a and three piezoelectric drive units 112a1 to 112a3. The three piezoelectric drive units 112a1 to 112a3 are each positioned at different distances from the mirror unit 101. Similarly, the drive unit 110c which is paired with the drive unit 110a has a torsion bar 111c and three piezoelectric drive units 112c1 to 112c3.

[0109] Furthermore, the drive unit 110b has a torsion bar 111b and two piezoelectric drive units 112b1 and 112b2. The two piezoelectric drive units 112b1 and 112b2 are positioned at different distances from the mirror unit 101. Similarly, the drive unit 110d, which is paired with the drive unit 110b, also has a torsion bar 111d and two piezoelectric drive units 112d1 and 112d2.

[0110] In this embodiment 8 as well, the piezoelectric drive units 112a1 to 112d2 of the drive units 110a to 110d are arranged at asymmetrical positions with respect to the mirror unit 101. Specifically, for the pair of drive units 110a and 110c arranged at positions with respect to the mirror unit 101, the corresponding piezoelectric drive units 112a1 to 112a3 and piezoelectric drive units 112c1 to 112c3 are arranged at asymmetrical positions with respect to the mirror unit 101.

[0111] With this asymmetrical arrangement, even if the same drive signal is applied to the pair of piezoelectric drive units 112a1 and 112c1, the same drive signal is applied to the pair of piezoelectric drive units 112a2 and 112c2, and the same drive signal is applied to the pair of piezoelectric drive units 112a3 and 112c3, the mirror unit 101 can still be oscillated (resonant drive) around the rotation axis (first axis) of the resonant mode.

[0112] In particular, in this embodiment 8, the pair of piezoelectric drive units in the pair of drive units 110a and 110c consist of multiple pairs (three pairs in this embodiment), such as the pair of piezoelectric drive unit 112a1 and piezoelectric drive unit 112c1, the pair of piezoelectric drive unit 112a2 and piezoelectric drive unit 112c2, and the pair of piezoelectric drive unit 112a3 and piezoelectric drive unit 112c3. Therefore, more precise oscillation control of the mirror unit 101 around the first axis is possible.

[0113] Furthermore, in the other pair of drive units 110b and 110d, the mirror unit 101 can be oscillated (resonant drive) around the rotation axis (second axis) of the resonant mode whether the same drive signal is applied to the pair of piezoelectric drive units 112b and 112d, whether the same drive signal is applied to the pair of piezoelectric drive units 112b1 and 112d1, or whether the same drive signal is applied to the pair of piezoelectric drive units 112b2 and 112d2.

[0114] In the other pair of drive units 110b and 110d, there are multiple pairs (two pairs in this embodiment) of paired piezoelectric drive units, which enables more precise control of the oscillation of the mirror unit 101 around the second axis.

[0115] In this embodiment 8, as in embodiment 6, the axis of rotation from which the mirror section 101 swings due to a pair of drive units 110a and 110c and the axis of rotation from which the mirror section 101 swings due to another pair of drive units 110b and 110d are orthogonal to each other. Therefore, two-dimensional drive of the mirror section 101 is possible by driving the four drive units 110a to 110d.

[0116] In particular, in this embodiment 8, the position (number) and shape of each piezoelectric drive unit in the pair of drive units 110a and 110c are asymmetrical with respect to the position (number) and shape of each piezoelectric drive unit in the other pair of drive units 110b and 110d. This makes it easier to control two-dimensional scanning using the resonance of the structure of the movable device 13, especially circular scanning, spiral scanning, and Lissajous scanning.

[0117] As is also the case with the embodiments described above, it is not necessarily required to apply the same drive signal to the pair of piezoelectric drive units.

[0118] For example, in this embodiment 8, in the pair of drive units 110a and 110c, the same first drive signal S1 is applied to the piezoelectric drive units 112a1 and 112a3 of drive unit 110a and the piezoelectric drive unit 112c1 of drive unit 110c, and the same second drive signal S2 is applied to the piezoelectric drive units 112a1 and 112a3 of drive unit 110b and the piezoelectric drive unit 112c1 of drive unit 110c. In this case, the same first drive signal S1 is applied to the pair of piezoelectric drive unit 112a1 and piezoelectric drive unit 112c1, and the same second drive signal S2 is applied to the pair of piezoelectric drive unit 112a2 and piezoelectric drive unit 112c2. However, different drive signals S1 and S2 are applied to the pair of piezoelectric drive unit 112a3 and piezoelectric drive unit 112c3, respectively.

[0119] Even in this case, only two drive signals are required for the pair of drive units 110a and 110c. Furthermore, in this embodiment 8, the drive signals used by the other pair of drive units 110b and 110d are the same as the two drive signals S1 and S2 used by the pair of drive units 110a and 110c. That is, the same first drive signal S1 is applied to the piezoelectric drive units 112b1 and 112d3, and the same second drive signal S2 is applied to the piezoelectric drive units 112b2 and 112d2. Therefore, only two drive signals are used in the movable device 13 of this embodiment 8. Thus, by reducing the number (types) of drive signals to be applied, it is possible to suppress the increase in system size and cost due to the increase in the scale of the circuit that generates the drive signals, or the increase in system complexity due to complex signal control.

[0120] However, if the drive signals applied between the pair of drive units 110a, 110c and the other pair of drive units 110b, 110d are different from each other, the drive sensitivity will be further increased. Even in this case, in this embodiment 8, only a total of four drive signals are needed: two for the pair of drive units 110a, 110c and two for the other pair of drive units 110b, 110d.

[0121] [Embodiment 9] Next, another embodiment of the movable device 13 (hereinafter referred to as "Embodiment 9") will be described. Figure 13 is a plan view illustrating the movable device 13 according to this embodiment 9. In the movable device 13 according to this embodiment 9, the basic configuration is the same as that of the above-described embodiment 8, except that the drive unit 110, which has a pair of piezoelectric drive units, is an integrated structure. That is, the drive unit 110 is equipped with a part having a torsion bar 111a and three piezoelectric drive units 112a1 to 112a3, a part having a torsion bar 111c and three piezoelectric drive units 112c1 to 112c3, a part having a torsion bar 111b and two piezoelectric drive units 112b1 and 112b2, and a part having a torsion bar 111d and two piezoelectric drive units 112d1 and 112d2.

[0122] In this embodiment 9, the four parts of the drive unit 110 have piezoelectric drive units 112a1 to 112d2 positioned asymmetrically with respect to the mirror unit 101. Specifically, in the pair of parts positioned on either side of the mirror unit 101, the corresponding pairs of piezoelectric drive units 112a1 to 112a3 and piezoelectric drive units 112c1 to 112c3 are positioned asymmetrically with respect to the mirror unit 101. Similarly, in the other pair of parts positioned on either side of the mirror unit 101, the corresponding pairs of piezoelectric drive units 112b1, 112b2 and piezoelectric drive units 112d1, 112d2 are positioned asymmetrically with respect to the mirror unit 101.

[0123] In this embodiment 9 as well, even if the same drive signal is applied to the paired piezoelectric drive units for each pair of parts, it is possible to intentionally create a discrepancy in the movement of two different locations on the mirror unit 101, causing the mirror unit 101 to oscillate (resonant drive) around the rotation axis (first axis) of the resonant mode. Similarly, for the other pair of parts, even if the same drive signal is applied to the paired piezoelectric drive units, it is possible to intentionally create a discrepancy in the movement of two different locations on the mirror unit 101, causing the mirror unit 101 to oscillate (resonant drive) around the rotation axis (second axis) of the resonant mode. Therefore, as in embodiment 8, two-dimensional driving of the mirror unit 101 becomes possible.

[0124] [Embodiment 10] Next, another embodiment of the movable device 13 (hereinafter referred to as "Embodiment 10") will be described. Figure 14 is a plan view illustrating a movable device 13 according to this embodiment 10. In the movable device 13 according to this embodiment 10, similar to embodiments 1 and 2 described above, it is configured to include a first drive unit 110 that swings the mirror unit 101 around a first axis and a second drive unit 130 that swings the mirror unit 101 around a second axis.

[0125] The first drive unit 110 is connected to the mirror unit 101 via torsion bars 111a and 111b, which are connected to both ends of the mirror unit 101, respectively. The first drive unit 110 is an integrated structure arranged to surround the mirror unit 101, and similar to the drive unit of Embodiment 9 described above, the piezoelectric drive units 112a1 to 112b2 are arranged at asymmetrical positions on either side of the mirror unit 101. Specifically, a pair of piezoelectric drive units 112a1 and 112b1 are arranged at asymmetrical positions on either side of the mirror unit 101, and a pair of piezoelectric drive units 112a2 and 112b2 are arranged at asymmetrical positions on either side of the mirror unit 101.

[0126] As a result, even when the same drive signal is applied to the pair of piezoelectric drive units in the first drive unit 110, an intentional discrepancy is created in the movement of two different points on the mirror unit 101, causing the mirror unit 101 to oscillate around the first axis.

[0127] Furthermore, the first drive unit 110 is connected to the second drive unit 130 via torsion bars 133a and 133b that extend in a direction perpendicular to the axial direction of the torsion bars 111a and 111b of the first drive unit 110. The second drive unit 130 is connected to the support frame 140 via torsion bars 133a and 133b.

[0128] The second drive unit 130 is an integrated structure arranged to surround the first drive unit 110, and, similar to the drive unit of Embodiment 9 described above, the piezoelectric drive units 134a1 to 134b2 are arranged at asymmetrical positions on either side of the mirror unit 101. Specifically, a pair of piezoelectric drive units 134a1 and 134b1 are arranged at asymmetrical positions on either side of the mirror unit 101, and a pair of piezoelectric drive units 134a2 and 134b2 are arranged at asymmetrical positions on either side of the mirror unit 101.

[0129] As a result, even when the same drive signal is applied to the paired piezoelectric drive units in the second drive unit 130, an intentional discrepancy is created in the movement of two different points on the mirror unit 101, allowing the mirror unit 101 to oscillate around the second axis.

[0130] As in this embodiment 10, even if the drive unit around the first axis connected to the mirror unit 101 is supported by the drive unit around the second axis, similar to embodiments 1 and 2, two-dimensional driving of the mirror unit 101 becomes possible.

[0131] Furthermore, when employing a meander structure, it is possible to reduce the size compared to a movable device with four or three drive units by including two meanders connected at approximately 45° angles to the X and Y directions. In addition, in the meander structure, the A channel and B channel of the meander drive unit have a phase difference of approximately 180°, so unintended vibration components can cancel each other out. This increases the options for phase control of the drive beam, resulting in complex resolution control, but it also increases the number of signals. Therefore, a cantilever (beam structure) like that of this embodiment 10 has the fewest number of signals and makes it easy to obtain high drive sensitivity for the mirror unit 101.

[0132] [Embodiment 11] Next, another embodiment of the movable device 13 (hereinafter referred to as "Embodiment 11") will be described. Figure 15 is a plan view illustrating the movable device 13 according to this embodiment 11. The movable device 13 according to this embodiment 11 is also an example that enables two-dimensional optical deflection by three drive units 110a to 110c. The movable device 13 of this embodiment 11 can be used particularly suitably for spiral scanning.

[0133] In the movable device 13 according to this embodiment 11, the drive unit 110a has a torsion bar 111a and three piezoelectric drive units 112a1 to 112a3. The three piezoelectric drive units 112a1 to 112a3 are each positioned at different distances from the mirror unit 101. Similarly, the drive unit 110b has a torsion bar 111b and three piezoelectric drive units 112b1 to 112b3. Similarly, the drive unit 110c has a torsion bar 111c and three piezoelectric drive units 112c1 to 112c3.

[0134] In this embodiment 11, the three drive units 110a to 110c are positioned at 120° intervals with respect to the mirror unit 101. In this configuration as well, the piezoelectric drive units 112a1 to 112c3 are positioned at asymmetrical locations with respect to the mirror unit 101. Specifically, looking between drive unit 110a and drive units 110b and 110c, the pair of piezoelectric drive units 112a1 and 112b1 and 112c1 are positioned at asymmetrical locations with respect to the mirror unit 101. Also, looking between drive unit 110b and drive units 110a and 110c, the pair of piezoelectric drive units 112b1 and 112a1 and 112c1 are positioned at asymmetrical locations with respect to the mirror unit 101. Furthermore, when viewed between the drive unit 110c and the drive units 110a and 110b, the paired piezoelectric drive units 112c1 and 112a1 and 112b1 are positioned asymmetrically across the mirror unit 101.

[0135] The same applies to the paired piezoelectric drive units 112a2, 112b2, 112c2, and also to the paired piezoelectric drive units 112a3, 112b3, 112c3. Even in a configuration like that of this embodiment 11, two-dimensional driving of the mirror unit 101 is possible even when the same drive signal is applied to a pair of piezoelectric drive units.

[0136] In the embodiments described above, the detailed shape of each component is not limited to the shape of the embodiment. Furthermore, the materials, manufacturing processes, electrical connections, and control methods are not limited to the examples of the embodiments. For example, in the embodiments described above, the movable part is an example of an optical deflector in which the mirror part 101 is used, but the movable part may have a diffraction grating, a photodiode, a light-receiving element, a heater (e.g., a heater using SiN), a light source (e.g., a surface-emitting laser), etc. instead of the mirror part.

[0137] [Optical scanning system] Next, we will describe the optical scanning system 10 to which the movable device 13 is applied. Figure 16 is a schematic diagram of an example of an optical scanning system. The optical scanning system 10 is a system that optically scans the surface to be scanned 15 by deflecting light emitted from the light source device 12 using the reflective surface 14 of the movable device 13, in accordance with the control of the control device 11.

[0138] The optical scanning system 10 includes a movable device 13. The movable device 13 has a control device 11, a light source device 12, and a reflective surface 14.

[0139] The control device 11 is an electronic circuit unit equipped with, for example, a CPU (Central Processing Unit) and an FPGA (Field-Programmable Gate Array). The movable device 13 is a MEMS device having, for example, a reflective surface 14, the reflective surface 14 of which is movable.

[0140] The light source device 12 is, for example, a laser device that emits a laser. The scanning surface 15 is, for example, a screen.

[0141] The control device 11 generates control commands for the light source device 12 and the movable device 13 based on the acquired optical scanning information. Based on the control commands, the control device 11 outputs drive signals to the light source device 12 and the movable device 13. The light source device 12 emits light from the light source based on the input drive signals. The movable device 13 can swing the reflective surface 14 around the X axis based on the input drive signals. The movable device 13 can swing the reflective surface 14 around the Y axis based on the input drive signals. The movable device 13 may also swing the reflective surface 14 around axes extending in other directions.

[0142] The optical scanning system 10 can perform optical scanning by oscillating the reflective surface 14, thereby projecting the light reflected by the reflective surface 14 onto the surface to be scanned 15. The optical scanning system 10 can project any image onto the surface to be scanned 15.

[0143] [Hardware configuration of optical scanning system 10] Next, we will describe the hardware configuration of an example of the optical scanning system 10. Figure 17 is a hardware configuration diagram of an example of an optical scanning system 10. The control device 11, the light source device 12, and the movable device 13 are electrically connected to each other. The control device 11 includes a CPU 20, RAM 21 (Random Access Memory), ROM 22 (Read Only Memory), FPGA 23, external I / F 24, light source device driver 25, and movable device driver 26.

[0144] The CPU 20 is an arithmetic unit that reads programs and data from storage devices such as ROM 22 onto RAM 21, executes processing, and realizes the overall control and functions of the control device 11. RAM 21 is a volatile storage device that temporarily holds programs and data. ROM 22 is a non-volatile storage device that can retain programs and data even when the power is turned off. ROM 22 stores processing programs and data that the CPU 20 executes to control each function of the optical scanning system 10.

[0145] FPGA23 is a circuit that outputs control signals suitable for the light source driver 25 and the movable device driver 26 according to the processing of the CPU 20. External I / F24 is an interface to external devices or networks, for example. External devices include, for example, higher-level devices such as PCs (Personal Computers), and storage devices such as USB memory, SD cards, CDs, DVDs, HDDs, and SSDs. Networks include, for example, automotive CAN (Controller Area Network), LAN (Local Area Network), and the internet. External I / F24 only needs to be configured to enable connection or communication with external devices, and an external I / F24 may be provided for each external device.

[0146] The light source driver 25 is an electrical circuit that outputs a drive signal, such as a drive voltage, to the light source device 12 according to the input control signal. The movable device driver 26 is an electrical circuit that outputs a drive signal, such as a drive voltage, to the movable device 13 according to the input control signal.

[0147] In the control device 11, the CPU 20 acquires optical scanning information from external devices or networks via the external I / F 24. The CPU 20 can acquire optical scanning information as long as it is configured to do so. This could involve storing the optical scanning information in the ROM 22 or FPGA 23 within the control device 11, or by adding a new storage device such as an SSD within the control device 11 and storing the optical scanning information in that device.

[0148] Optical scanning information refers to information indicating how to perform optical scanning on the surface to be scanned 15. For example, when displaying an image by optical scanning, the optical scanning information may be image data. Also, for example, when performing optical writing by optical scanning, the optical scanning information is writing data indicating the writing order and writing locations. For example, when performing object recognition by optical scanning, the optical scanning information is irradiation data indicating the timing and irradiation range of the light used for object recognition.

[0149] The control device 11 can realize the functional configuration described later through the instructions of the CPU 20 and the hardware configuration.

[0150] [Functional configuration of the control device 11] Next, the functional configuration of the control device 11 of the optical scanning system 10 will be described. Figure 18 is a functional block diagram of an example of the control device 11. The control device 11 includes a control unit 30 and a drive signal output unit 31. The control unit 30 is implemented by, for example, a CPU 20, an FPGA 23, etc. The control unit 30 acquires optical scanning information from an external device, converts the optical scanning information into a control signal, and outputs it to the drive signal output unit 31. For example, the control unit 30 acquires image data as optical scanning information from an external device, generates a control signal from the image data through predetermined processing, and outputs it to the drive signal output unit 31. The drive signal output unit 31 is implemented by, for example, a light source device driver 25, a movable device driver 26, etc. The drive signal output unit 31 outputs a drive signal to the light source device 12 or the movable device 13 based on the input control signal.

[0151] The drive signal is a signal for controlling the drive of the light source device 12 or the movable device 13. For example, the drive signal output to the light source device 12 is a drive voltage that controls the irradiation timing and irradiation intensity of the light source. The drive signal output to the movable device 13 is a drive voltage that controls the timing and range of movement of the reflective surface 14. The drive signal output to the movable device 13 may be the drive signal according to the first embodiment described above, or the drive signal according to the second embodiment.

[0152] [Light scanning process] Next, we will describe the process by which the optical scanning system 10 optically scans the surface to be scanned 15. Figure 19 is a flowchart showing an example of processing related to an optical scanning system.

[0153] In step S11, the control unit 30 acquires optical scanning information from an external device or the like. In step S12, the control unit 30 generates a control signal from the acquired optical scanning information and outputs the control signal to the drive signal output unit 31. In step S13, the drive signal output unit 31 outputs a drive signal to the drive units 110a to 1110d of the light source device 12 and the movable device 13 based on the input control signal. In step S14, the light source device 12 irradiates light based on the input drive signal. The drive units 110a to 110d of the movable device 13 also oscillate the reflective surface 14 based on the input drive signal. According to the optical scanning system 10, the light is deflected in any direction and optical scanning is performed by driving the light source device 12 and the movable device 13.

[0154] The optical scanning system 10 may also include a control device 11 that controls the drive units 110a to 110d of the movable device 13 and a control device that controls the light source device 12 separately.

[0155] The optical scanning system 10 can suppress the decrease in the resonant frequency that occurs when the size of the movable mirror portion 101 is increased. The optical scanning system 10 can perform optical scanning with high precision.

[0156] [Head-Up Display Device] Next, we will describe the head-up display device 500. Figure 20 is a schematic diagram of an example of an automobile 400 equipped with a head-up display device 500. The automobile 400 is equipped with a head-up display device 500. The head-up display device 500 is an image projection device that projects images by optical scanning. The automobile 400 is an example of a mobile device.

[0157] As shown in Figure 20, the head-up display device 500 is installed, for example, near the windshield (windshield 401, etc.) of a car 400. Projected light L emitted from the head-up display device 500 is reflected by the windshield 401 and directed towards the user, the observer (driver 402). As a result, the driver 402 can see the image projected by the head-up display device 500 as a virtual image. Alternatively, a combiner may be installed on the inner wall surface of the windshield, and the virtual image may be seen by the user by the projected light reflected by the combiner.

[0158] Figure 21 is a schematic diagram of an example of a head-up display device 500. The head-up display device 500 is equipped with laser light sources 501R, 501G, and 501B. Laser light source 501R emits red laser light. Laser light source 501G emits green laser light. Laser light source 501B emits blue laser light.

[0159] The head-up display device 500 includes an incident optical system. The incident optical system includes collimator lenses 502, 503, and 504, two dichroic mirrors 505 and 506, and a light intensity adjustment unit 507. The collimator lenses 502 to 504 are provided for laser light sources 501R, 501G, and 501B. Laser light emitted from the laser light sources 501R, 501G, and 501B passes through the incident optical system and enters the movable device 13. The laser light that enters the movable device 13 is reflected by the reflective surface 14. The laser light is deflected by the movable device 13.

[0160] The head-up display device 500 includes a projection optical system. The projection optical system includes a free-form surface mirror 509, an intermediate screen 510, and a projection mirror 511. The laser light deflected by the movable device 13 is projected onto the windshield 401 via the projection optical system. The head-up display device 500 may also project the laser light onto a screen. The head-up display device 500 may also include a unitized light source unit 530 having an optical housing. The optical housing may house, for example, laser light sources 501R, 501G, 501B, collimator lenses 502, 503, 504, and dichroic mirrors 505, 506.

[0161] The head-up display device 500 can project the intermediate image displayed on the intermediate screen 510 onto the windshield 401. According to the head-up display device 500, the intermediate image projected onto the windshield 401 can be viewed by the driver 402 as a virtual image.

[0162] The laser light of each color emitted from the laser light sources 501R, 501G, and 501B is made into approximately parallel light by collimator lenses 502, 503, and 504, respectively, and then combined by two dichroic mirrors 505 and 506. The dichroic mirrors 505 and 506 may each be examples of the combining section. After the combined laser light is adjusted in intensity by the light intensity adjustment section 507, it is scanned in two dimensions by the movable device 13. The projected light L scanned in two dimensions by the movable device 13 is reflected by the free-form mirror 509 to correct distortion, and then focused onto the intermediate screen 510. The intermediate screen 510 displays an intermediate image. The intermediate screen 510 is composed of a microlens array in which microlenses are arranged in two dimensions. The intermediate screen 510 magnifies the incident projected light L in units of microlenses.

[0163] The movable device 13 oscillates (reciprocates) the reflective surface 14 in two axial directions. The movable device 13 scans the projected light L incident on the reflective surface 14 in two dimensions. The drive control of the movable device 13 is synchronized with the light emission timing of the laser light sources 501R, 501G, and 501B.

[0164] The image projection device can project an image by performing a light scan using a movable device 13 having a reflective surface 14. The image projection device may be, for example, a projector placed on a desk or the like that projects an image onto a display screen. The image projection device may also be a head-mounted display device that is mounted on a wearable member attached to the observer's head or the like, and projects an image onto a reflective-transmitting screen on the wearable member, or projects an image onto the eyeballs as a screen.

[0165] The image projection device is not limited to those mounted on a vehicle or mounting member. For example, the image projection device may be mounted on a moving object such as an aircraft, ship, or mobile robot. Alternatively, the image projection device may be mounted on a non-moving object such as a work robot that operates a drive target such as a manipulator without moving from its location.

[0166] An image projection device equipped with a movable device 13 can suppress the decrease in resonant frequency that occurs when the movable part is enlarged, and can perform optical scanning with high precision. According to the image projection device equipped with a movable device 13, the resolution of the light trajectory near the center O of the field of view can be improved.

[0167] [Optical writing device 600] Next, we will describe the optical writing device 600 equipped with the movable device 13. Figure 22 is a schematic diagram of an example of an image forming apparatus equipped with an optical writing device 600. The image forming apparatus may be a laser printer 650. The laser printer 650 has a printer function using laser light. The laser printer 650 includes an optical writing device 600. The optical writing device 600 optically scans the photoreceptor drum, which is the scanning surface 15, with one or more laser beams. The optical writing device 600 performs optical writing on the photoreceptor drum by optical scanning. The optical writing device 600 includes a movable device 13.

[0168] Figure 23 is a schematic diagram of an example of an optical writing device. In the optical writing device 600, the laser light emitted from the light source device 12, such as a laser element, passes through the imaging optical system 601, such as a collimator lens, and is then deflected in one axis direction or two axis directions by the movable device 13.

[0169] The optical writing device 600 includes a scanning optical system 602. The scanning optical system has a first lens 602a, a second lens 602b, and a reflective mirror section 602c. The laser light deflected by the movable device 13 passes through the scanning optical system 602 and is irradiated onto the surface to be scanned 15 (for example, a photosensitive drum or photosensitive paper). As a result, the optical writing device 600 performs optical writing on the surface to be scanned 15. The scanning optical system 602 forms a spot-shaped image of the light beam on the surface to be scanned 15. As described above, the control device 11 applies drive signals to the drive units 110a to 110d of the movable device 13 to oscillate the reflective surface 14.

[0170] Thus, the optical writing device 600 can be applied to an image forming apparatus that has a printer function using laser light. The image forming apparatus equipped with the optical writing device 600 may also be a laser labeling apparatus. The optical writing device 600 may be mounted on an image forming apparatus such as a laser labeling apparatus that has a scanning optical system capable of optical scanning in two axes, and prints by deflecting laser light onto a thermal media, optical scanning, and heating.

[0171] The movable device 13 having a reflective surface 14 consumes less power to drive compared to a rotating polyhedron mirror using a polygon mirror or the like. The optical writing device 600 equipped with the movable device 13 allows for power saving. The wind noise generated by the movable device 13 during vibration is less than that of a rotating polyhedron mirror. Therefore, the optical writing device 600 equipped with the movable device 13 allows for improved quietness. The installation space required for the movable device 13 is significantly less than that required for a rotating polyhedron mirror. The heat generated by the movable device 13 is significantly less than that generated by a rotating polyhedron mirror. The image forming apparatus equipped with the optical writing device 600 allows for easy miniaturization of the entire apparatus.

[0172] Thus, by applying the movable device 13 of the embodiment to the optical writing device 600, the decrease in resonant frequency that occurs when increasing the size of the movable part can be suppressed, and an optical writing device capable of high-precision optical scanning can be provided. With the optical writing device 600 equipped with the movable device 13, the resolution of the light trajectory near the center O of the field of view can be improved.

[0173] [Laser radar equipment] Next, we will explain the laser radar system 700. Figures 24 and 25 are schematic diagrams of an example of a vehicle equipped with a 700 laser radar system. Figure 26 is a schematic diagram of an example of a laser radar system 700. The laser radar device 700 is a distance measuring device that measures the distance to an object in the target direction. A distance measuring device is an example of an object recognition device. The laser radar device 700 has a movable device 13. The laser radar device 700 is mounted on, for example, an automobile 701, and measures the distance to an object 702 by optically scanning the target direction and receiving reflected light from the object 702 present in the target direction. The automobile 701 is an example of a mobile device.

[0174] As shown in Figure 26, the laser radar device 700 includes an incident optical system. The incident optical system has a collimator lens 703 and a plane mirror 704. The collimator lens 703 is an optical system that converts divergent light into approximately parallel light. The laser light emitted from the light source device 12 passes through the incident optical system and is scanned in one or two axes by the movable device 13.

[0175] The laser radar device 700 includes a light projection optical system having a light projection lens 705. Light reflected from the reflective surface 14 of the movable device 13 passes through the light projection lens 705 and is projected onto the target object 702 in front. The control device 11 drives and controls the light source device 12 and the movable device 13. The reflected light reflected from the target object 702 is detected by the photodetector 709. The reflected light is received by the image sensor 707 via the incident light detection and reception optical system, such as the condensing lens 706. The image sensor 707 outputs the detection signal to the signal processing device 708. The signal processing device 708 performs predetermined processing on the input detection signal, such as binarization and noise processing, and outputs the result to the distance measuring circuit 710.

[0176] The distance measuring circuit 710 recognizes the presence or absence of the object 702 based on the time difference between the timing when the light source device 12 emits laser light and the timing when the photodetector 709 receives the laser light, or the phase difference of each pixel of the image sensor 707 that receives the light, and calculates distance information to the object 702.

[0177] The movable device 13 having a reflective surface 14 is less prone to damage and smaller than a polyhedron, thus enabling the provision of a highly durable, compact radar device. Such a laser radar device can be mounted on vehicles, aircraft, ships, robots, etc., and can optically scan a predetermined range to measure the presence or absence of obstacles and the distance to those obstacles.

[0178] The distance measuring device measures the distance to the object 702 by performing an optical scan by controlling a movable device 13 having a reflective surface 14 with a control device 11, and receiving the reflected light with a photodetector. The object recognition device is not limited to the distance measuring device. The object recognition device only needs to be able to detect the object 702 by having a movable device 13, performing an optical scan, and receiving the reflected light with a photodetector.

[0179] The object recognition device may be, for example, a biometric authentication device that recognizes an object by calculating object information such as shape from distance information obtained by optical scanning of a hand or face, and then recording and referencing this information. The object recognition device may also be a security sensor that recognizes intruders by optical scanning within a target area. The object recognition device may also be a 3D scanner that calculates and recognizes object information such as shape from distance information obtained by optical scanning and outputs it as 3D data.

[0180] By incorporating the movable device 13, such a distance measuring device can suppress the decrease in resonant frequency that occurs when increasing the size of the movable part, and can perform optical scanning with high precision. With a distance measuring device equipped with the movable device 13, the resolution of the light trajectory near the center O of the field of view can be improved.

[0181] [Laser headlamp] Next, a laser headlamp 50 equipped with a movable device 13 will be described. Figure 27 is a schematic diagram of an example of a laser headlamp 50. The laser headlamp 50 may also be an automobile headlight. The laser headlamp 50 includes a light source device 12b, a movable device 13, a mirror 51, and a transparent plate 52. The movable device 13 may include a control device 11, which is a control unit.

[0182] The light source device 12b is a light source that emits blue laser light. The light emitted from the light source device 12b enters the movable device 13 and is reflected by the reflective surface 14. The drive units 110a to 110d of the movable device 13 oscillate the reflective surface 14 based on signals from the control device 11. The movable device 13 oscillates the reflective surface 14 to scan the laser light in two dimensions in the X and Y directions.

[0183] The scanning light from the movable device 13 is reflected by the mirror 51 and incident on the transparent plate 52. The transparent plate 52 is coated on either its front or back surface with a yellow phosphor. The blue laser light reflected by the mirror 51 changes to white light within the range legally defined for headlights as it passes through the yellow phosphor coating on the transparent plate 52. As a result, the area in front of the vehicle equipped with the laser headlamp 50 is illuminated with white light.

[0184] The scanning light from the movable device 13 undergoes a predetermined scattering as it passes through the phosphor in the transparent plate 52. This reduces glare on the illuminated object in front of the vehicle.

[0185] In the laser headlamp 50, the colors of the light source device 12b and the phosphor are not limited to blue and yellow, respectively. The laser headlamp 50 may also include a light source device 12b that emits near-ultraviolet light. In the laser headlamp 50, the transparent plate 52 may be covered with a uniform mixture of blue, green, and red phosphors, which are the three primary colors of light. With this configuration, the light passing through the transparent plate 52 can be converted to white light, and the area in front of the vehicle can be illuminated with white light.

[0186] By incorporating a movable device 13, such a laser headlamp 50 can suppress the decrease in resonant frequency that occurs when increasing the size of the movable part, and can perform optical scanning with high precision. With a laser headlamp 50 equipped with a movable device 13, the resolution of the light trajectory near the center O of the field of view can be improved.

[0187] [Head-mounted display] Next, we will describe the head-mounted display 60. Figure 28 is a perspective view of an example of a head-mounted display. Figure 29 is a diagram illustrating a partial configuration of a head-mounted display. The head-mounted display 60 is a head-mounted display that can be worn on a human head. The head-mounted display 60 can be shaped like, for example, eyeglasses. Hereinafter, the head-mounted display may be abbreviated as HMD. The HMD 60 is equipped with a movable device 13.

[0188] The HMD60 comprises a front 60a and temples 60b, each provided in a roughly symmetrical arrangement on the left and right sides. The front 60a has, for example, a light guide plate 61. The temples 60b can house optical systems, control devices 11, etc.

[0189] Figure 29 shows the left eye portion of the HMD60. The right eye portion of the HMD60 has the same configuration as the left eye portion. The HMD60 includes a light source unit 530, a light intensity adjustment unit 507, a movable device 13, a light guide plate 61, and a half mirror 62. The movable device 13 may include a control device 11 as a control unit.

[0190] As described above, the light source unit 530 is unitized by an optical housing. The optical housing houses the laser light sources 501R, 501G, and 501B, the collimator lenses 502, 503, and 504, and the dichroic mirrors 505 and 506. In the light source unit 530, the three colors of laser light emitted from the laser light sources 501R, 501G, and 501B are combined by the dichroic mirrors 505 and 506. The light source unit 530 emits the combined parallel light.

[0191] Light emitted from the light source unit 530 is adjusted in intensity by the light intensity adjustment unit 507 before being incident on the movable device 13. The movable device 13 oscillates the reflective surface 14 based on the drive signal input from the control device 11. The movable device 13 performs a two-dimensional scan of the light incident from the light source unit 530. The control device 11 drives and controls the drive units 110a to 110d of the movable device 13 in synchronization with the light emission timing of the laser light sources 501R, 501G, and 501B. The HMD 60 forms a color image using the scanning light.

[0192] The scanning light from the movable device 13 is incident on the light guide plate 61. The light guide plate 61 guides the scanning light to the half mirror 62 while reflecting it off its inner wall surface. The light guide plate 61 is made of a resin or the like that is transparent to the wavelength of the scanning light.

[0193] The half-mirror 62 reflects light from the light guide plate 61 to the back side of the HMD 60 and emits it towards the eyes of the wearer 63. The half-mirror 62 has, for example, a free-form surface shape. The image formed by the scanning light is projected onto the wearer's retina by reflection from the half-mirror 62. Alternatively, the HMD 60 projects onto the wearer's retina by reflection from the half-mirror 62 and the lens effect of the crystalline lens in the eyeball. In the HMD 60, spatial distortion in the image is corrected by reflection from the half-mirror 62. The wearer 63 can observe the image formed by light scanned in the XY direction.

[0194] By equipping the HMD60 with a half-mirror 62, the wearer 63 can observe an image in which the image from light from the outside and the image from scanning light are superimposed. The HMD60 may also be equipped with a mirror instead of the half-mirror 62. With this configuration of the HMD60, by eliminating light from the outside, the wearer 63 can observe only the image from scanning light.

[0195] In this way, by applying the movable device 13 of the embodiment to a head-mounted display, the decrease in resonant frequency that occurs when increasing the size of the movable part can be suppressed, and a head-mounted display capable of high-precision optical scanning can be provided.

[0196] By incorporating the movable device 13, such an HMD60 can suppress the decrease in resonant frequency that occurs when increasing the size of the movable part, and can perform optical scanning with high precision. With the HMD60 equipped with the movable device 13, the resolution of the light trajectory near the center O of the field of view can be improved.

[0197] [Eyeball tilt position detection device (pupil or corneal position detection device 80)] Next, we will describe an eyeball tilt position detection device equipped with a movable device 13. The eyeball tilt position detection device is a pupil or corneal position detection device 80 that detects the position of the pupil or cornea. Figure 30 is a schematic diagram showing an example of the pupil or corneal position detection device 80.

[0198] In this embodiment, the "tilt position of the eyeball" refers to the position of the pupil or cornea of ​​the eyeball, or the direction of the user's gaze. Hereafter, the "tilt position of the eyeball" will be described as the position of the pupil or cornea, and the "eyeball tilt position detection device" will be described as the "pupil or cornea position detection device." Furthermore, the pupil or cornea position detection device described below is synonymous with a gaze direction tracking device (eye tracking device) that detects or tracks the user's gaze direction continuously or at time intervals.

[0199] The pupil or corneal position detection device 80 shown in Figure 30 comprises a light source 82, a first light deflection unit 83, a movable device 13, a second light deflection unit 85, and a light receiving unit 86.

[0200] The light source 82 includes, for example, laser light sources 82r, 82g, and 82b that emit red, green, and blue laser light, and an infrared laser light source 82ir that emits infrared laser light. The laser light sources 82r, 82g, and 82b may be any one or any combination of two. The laser light sources 82r, 82g, and 82b emit light for drawing an image using the movable device 13.

[0201] The infrared laser light source 82ir emits light for detecting the position of the pupil or cornea. The light used to detect the position of the pupil or cornea is not limited to infrared light; visible light may also be used. From the viewpoint of improving the visibility of the drawn image, invisible light is preferred for detecting the position of the pupil or cornea.

[0202] The first light deflection unit 83 is, for example, a dichroic mirror, and deflects the light emitted from the light source 82 toward the reflective surface 14 of the movable device 13 while combining the light. The pupil or corneal position detection device 80 may include a plurality of first light deflection units 83-1, 83-2, 83-3, 83-4, 83-5 depending on the number of laser light sources 82r, 82g, 82b and infrared laser light sources 82ir. The first light deflection unit 83 includes a plurality of first light deflection units 83-1, 83-2, 83-3, 83-4, 83-5. The plurality of first light deflection units 83-1, 83-2, 83-3, 83-4, 83-5 deflect the light while combining the light from each unit.

[0203] The movable device 13 is equipped with a reflective surface 14 and scans the light deflected by the first light deflection unit 83 toward the second light deflection unit 85 in a two-dimensional direction. At this time, the movable device 13 scans the light deflected by the first light deflection unit 83 by, for example, raster scanning and forms an image. The movable device 13 can scan the light deflected by the first light deflection unit 83 by spiral scanning.

[0204] The second light deflection unit 85 is, for example, a holographic optical element, which deflects the light L1 scanned by the movable device 13 toward the user's eyeball 87. At least a portion of the light L2 deflected by the second light deflection unit 85 is incident on the user's eyeball 87 as the displayed image light. The second light deflection unit 85 may also be equipped with multiple light deflection members. For example, multiple types of light deflection members that reflect specific light from the light emitted from the light source 82 may be used, so that the reflective surface differs for each type of light emitted from the light source 82. A specific example is a configuration in which light deflection members that reflect light emitted from laser light sources 82r, 82g, and 82b are stacked in order from closest to the eyeball 87, and a light deflection member that reflects light emitted from an infrared laser light source 82ir is stacked.

[0205] The light-receiving unit 86 receives light L3 reflected by the user's eyeball 87 from the light L2 deflected by the second light deflection unit 85, and outputs a detection signal SD corresponding to the received light. The light-receiving unit 86 is, for example, an image sensor capable of detecting infrared light. Multiple light-receiving units 86 may be provided at positions capable of receiving light L3 reflected by the user's eyeball 87. The light intensity of the light received by the light-receiving unit 86 changes depending on the position of the eyeball (pupil, cornea, etc.), i.e., the direction of line of sight. Therefore, the pupil or corneal position detection device 80 in this embodiment detects or estimates the pupil or corneal position based on the intensity of the light received by the light-receiving unit 86. The light-receiving unit 86 may also be configured to image the eyeball 87 illuminated by the light L2 deflected by the second light deflection unit 85. In this case, the pupil or corneal position detection device 80 detects or estimates the tilt position of the eyeball based on the position of the pupil or cornea included in the captured image (detection signal SD) and the position where the light L2 deflected by the second light deflection unit 85 is reflected in the eyeball 87.

[0206] As described above, the pupil or corneal position detection device 80 according to this embodiment can detect the position of the pupil or cornea while forming an image with the movable device 13. Furthermore, since the movable device 13 is configured to scan light more efficiently, it is possible to achieve image formation and detection of the pupil or corneal position with lower power consumption. Moreover, the movable device 13 can achieve the above effects without changing the area required for mounting on the pupil or corneal position detection device 80 compared to the configuration of the conventional technology. As a result, the pupil or corneal position detection device 80 can be configured without becoming larger.

[0207] Furthermore, the pupil or corneal position detection device 80 can also be mounted on a head-mounted display as, for example, an eye-tracking device to detect or track the user's gaze direction. In this case, for example, by reducing the resolution of the image displayed in other areas compared to the image displayed in the area near the user's gaze direction (foveal rendering), image processing can be sped up compared to displaying a high-resolution image across the entire area.

[0208] Figure 31 is a schematic diagram showing an example of a pupil or corneal position detection device 80. As shown in Figure 31, the pupil or corneal position detection device 80 comprises a light source 82, first light deflection units 83-1 to 83-4, lens 92, lens 93, scanning mirror 94, deflection mirror 95, second light deflection unit 85, light receiving unit 86, and control unit 96.

[0209] Lens 92 is an optical system that converts light emitted from the light source 82 into substantially parallel light. Lens 93 is an optical system that shapes the light converted into substantially parallel light by lens 92 into a desired laser beam state. In this embodiment, a configuration having lens 92 and lens 93 is shown, but lenses 92 and 93 are not necessarily required.

[0210] Light formed by lenses 92 and 93 is incident on the scanning mirror 94 (movable device 13). The scanning mirror 94 scans the incident light and forms image light. The formed image light is incident on the deflection mirror 95 and reflected in the direction toward the second light deflection unit 85. The deflection mirror 95 corresponds to the first light deflection unit 83-5 described in Figure 30, but it is preferable that it has a configuration that allows it to scan light and is equipped with the movable device 13. By making the deflection mirror 95 capable of light scanning, an image can be projected over a wider area.

[0211] In the above description, a configuration in which the deflection mirror 95 is positioned between the scanning mirror 94 and the second light deflection unit 85 is given as an example, but the pupil or corneal position detection device 80 is not limited to this. In the pupil or corneal position detection device 80, the scanning mirror 94 may be positioned between the deflection mirror 95 and the second light deflection unit 85, and the light reflected by the deflection mirror 95 may be scanned in two axial directions by the scanning mirror 94 and incident on the second light deflection unit 85.

[0212] The control unit 96 detects the position of the user's pupil or cornea based on the detection signal SD output by the light receiving unit 86 and acquires information indicating the direction of gaze. The control unit 96 also controls the emission and light intensity of the light source 82 by providing a formation drive signal SL1 to the light source 82 to form an image to be projected onto the retina 32, and drives the scanning mirror 94 by providing a scanning drive signal SS to the scanning mirror 94. Furthermore, if the deflection mirror 95 is configured to be optically scannable, the control unit 96 drives the deflection mirror 95 by providing a deflection drive signal ST to control the projection position of the image according to the acquired gaze information.

[0213] Although examples of embodiments of the present invention have been described above, the present invention is not limited to these specific embodiments, and various modifications and changes are possible within the scope of the gist of the present invention as described in the claims.

[0214] In the embodiments described above, a configuration in which a reflective surface is provided on the movable part is illustrated, but the invention is not limited to this. The movable part may also be equipped with other optical elements such as a diffraction grating, a photodiode, a heater (for example, a heater using SiN), or a light source (for example, a surface-emitting laser), or it may be equipped with both a reflective surface and other optical elements.

[0215] [Processing circuit] Each of the functions of the embodiments described above can be realized by one or more processing circuits. Hereinafter, "processing circuit" as used herein includes processors programmed to execute each function by software, such as processors implemented by electronic circuits, as well as devices such as ASICs (Application Specific Integrated Circuits), DSPs (digital signal processors), FPGAs (field programmable gate arrays), and conventional circuit modules designed to execute each of the functions described above.

[0216] The above is just one example; each of the following embodiments produces its own unique effects. [First aspect] The first embodiment is a movable device 13 comprising a movable part (e.g., a mirror part 101), a drive unit 110 for driving the movable part, and a control unit (e.g., a control device 11) for applying a drive signal to the drive unit, wherein the drive unit has at least one of the following configurations: a configuration in which each of a pair of drive members (e.g., a piezoelectric drive unit 112) is arranged at asymmetrical positions on either side of the movable part, and a configuration in which each of a pair of drive members with different shapes is arranged at each position on either side of the movable part. In this embodiment, the drive unit to which a drive signal is applied by the control unit has an asymmetrical configuration in terms of position and shape between a pair of drive members arranged on either side of the movable part. As a result, even if the same drive signal is applied to each of the pair of drive members, the movement of one drive member displacing one part of the movable part and the movement of the other drive member displacing the other part of the movable part can be made to be different from each other. Therefore, it is not necessary to apply individual drive signals to each of the pair of drive members arranged on either side of the movable part, and the number of drive signals applied to the drive unit can be reduced.

[0217] [Second aspect] The second embodiment is characterized in that, in the first embodiment, the phase of the displacement period in which one of the pair of drive members displaces one location in the movable part and the phase of the displacement period in which the other drive member displaces the other location in the movable part are different from each other. According to this, the movable part can be driven by intentionally introducing a phase difference in the displacement period at multiple different points on the movable part.

[0218] [Third aspect] The third embodiment is characterized in that, in the first or second embodiment, the control unit applies the same drive signal to each of the pair of drive members. This allows for a reduction in the number of drive signals applied to the drive unit.

[0219] [Fourth aspect] The fourth aspect is characterized in that, in any of the first to third aspects, the drive unit drives the movable part in a substantially resonant manner. According to this, it becomes possible to move the movable parts by resonant drive.

[0220] [Fifth aspect] The fifth embodiment is characterized in that, in any of the first to fourth embodiments, there are a plurality of drive units that drive the movable part in mutually different drive directions (for example, around the first axis and around the second axis). According to this, the movable parts can be driven in two dimensions.

[0221] [Sixth aspect] The sixth aspect is characterized in that, in any of the first to fifth aspects, the movable part is driven to perform a substantially circular scan, a spiral scan, or a Lissajous scan. According to this, the number of drive signals applied to the drive unit can be reduced, and a roughly circular scan, spiral scan, or Lissajous scan can be performed.

[0222] [Seventh aspect] The seventh aspect is characterized in that, in any of the first to sixth aspects, the drive unit has a plurality of pairs of the paired drive members, and the control unit applies drive signals with different phases between the plurality of pairs. This makes it possible to achieve two-dimensional driving with higher drive sensitivity.

[0223] [8th aspect] The eighth aspect is a projection device characterized by having an optical scanning system equipped with a movable device according to any of the first to seventh aspects. This makes it possible to provide a projection device that reduces the number of drive signals applied to the drive unit.

[0224] [Ninth aspect] The ninth embodiment is a mobile body, characterized by comprising the projection device of the eighth embodiment. This makes it possible to provide a mobile body with a reduced number of drive signals applied to the drive unit.

[0225] [Tenth aspect] The tenth embodiment is a head-mounted display characterized by comprising a movable device according to any of the first to seventh embodiments. This makes it possible to provide a head-mounted display that reduces the number of drive signals applied to the drive unit.

[0226] [Phase 11] The eleventh embodiment is a head-up display characterized by comprising a movable device according to any of the first to seventh embodiments. This makes it possible to provide a head-up display that reduces the number of drive signals applied to the drive unit.

[0227] [Twelfth aspect] The twelfth embodiment is a laser headlamp characterized by comprising a movable device according to any of the first to seventh embodiments. This makes it possible to provide a laser headlamp that reduces the number of drive signals applied to the drive unit.

[0228] [The 13th aspect] The 13th embodiment is an object recognition device characterized by comprising a movable device according to any of the first to seventh embodiments. This makes it possible to provide an object recognition device that reduces the number of drive signals applied to the drive unit.

[0229] [Aspect 14] The fourteenth aspect is a pupil or corneal position detection device, characterized by comprising a movable device according to any of the first to seventh aspects. This makes it possible to provide a pupil or corneal position detection device that reduces the number of drive signals applied to the drive unit.

[0230] [Aspect 15] The 15th embodiment is a method of moving a movable part by applying a drive signal to a drive unit that drives the movable part, wherein the drive unit has at least one of the following configurations: a configuration in which each of a pair of drive members is arranged at asymmetrical positions on either side of the movable part, and a configuration in which each of a pair of drive members having different shapes is arranged at each position on either side of the movable part, and the same drive signal is applied to each of the pair of drive members, and the movable part is moved such that the phase of the displacement period in which one of the pair of drive members displaces one part of the movable part and the phase of the displacement period in which the other drive member displaces the other part of the movable part are different from each other. According to this embodiment, it is no longer necessary to apply individual drive signals to each of the pair of drive members arranged on either side of the movable part, thereby reducing the number of drive signals applied to the drive unit. [Explanation of Symbols]

[0231] 10: Optical scanning system 11: Control device 13: Movable device 50: Laser headlamp 60: Head-mounted display 80: Position detection device 101: Mirror section 110, 110a~110d, 210a, 210b: Drive unit 112a~112d, 112a1~112d3, 212a~212d: Piezoelectric drive unit 130, 130a, 130b: Drive unit 131a~131f: Piezoelectric drive unit 132a~132f: Piezoelectric drive unit 134a1~134b2: Piezoelectric drive unit 140: Support frame 400: Automobile 500: Head-up display device 600: Optical writing device 650: Laser printer 700: Laser radar equipment [Prior art documents] [Patent Documents]

[0232] [Patent Document 1] Japanese Patent Publication No. 2023-162175

Claims

1. A movable device comprising a movable part, a drive unit for driving the movable part, and a control unit for applying a drive signal to the drive unit, The movable device is characterized in that the drive unit has at least one of the following configurations: a configuration in which each of a pair of drive members is arranged at asymmetrical positions on either side of the movable unit, and a configuration in which each of a pair of drive members having different shapes is arranged at each position on either side of the movable unit.

2. In the movable device according to claim 1, A movable device characterized in that the phase of the displacement period in which one of the pair of drive members displaces one part of the movable part and the phase of the displacement period in which the other drive member displaces the other part of the movable part are different from each other.

3. In the movable device according to claim 1 or 2, The control unit is characterized by applying the same drive signal to each of the pair of drive members.

4. In the movable device according to claim 1 or 2, The drive unit is characterized by driving the movable part in a substantially resonant manner.

5. In the movable device according to claim 1 or 2, A movable device characterized by having a plurality of drive units that drive the movable part in mutually different drive directions.

6. In the movable device according to claim 1 or 2, The movable part is characterized by being driven to perform a substantially circular scan, spiral scan, or Lissajous scan.

7. In the movable device according to claim 1 or 2, The drive unit has a plurality of pairs of the paired drive members, The control unit is characterized by applying drive signals with different phases between the plurality of pairs.

8. A projection apparatus characterized by having an optical scanning system equipped with a movable device as described in claim 1 or 2.

9. A mobile body characterized by comprising the projection device described in claim 8.

10. A head-mounted display characterized by comprising the movable device described in claim 1 or 2.

11. A head-up display characterized by comprising the movable device described in claim 1 or 2.

12. A laser headlamp characterized by comprising the movable device described in claim 1 or 2.

13. An object recognition device characterized by comprising the movable device described in claim 1 or 2.

14. A pupil or corneal position detection device characterized by comprising the movable device described in claim 1 or 2.

15. A method for moving a movable part by applying a drive signal to a drive unit that drives the movable part, The drive unit has at least one of the following configurations: one in which a pair of drive members are arranged at asymmetrical positions on either side of the movable part, and another in which a pair of drive members with different shapes are arranged at each position on either side of the movable part. The same drive signal is applied to each of the pair of drive members, A method for moving a movable part, characterized in that the phase of the displacement period in which one of the pair of drive members displaces one part of the movable part and the phase of the displacement period in which the other drive member displaces the other part of the movable part are different from each other.

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