JP7396147B2 - Movable devices, optical deflection devices, image projection devices, optical writing devices, object recognition devices, moving objects, head-mounted displays - Google Patents

Description

The present invention relates to a movable device, a light deflection device, an image projection device, an optical writing device, an object recognition device, a moving body, and a head-mounted display.

BACKGROUND ART Today, there is known an optical deflection device that includes a movable part having a mirror and deflects light incident on the mirror by deforming a beam supporting the movable part using a beam-shaped piezoelectric member. This optical deflection device tilts the mirror by deforming the beam using the piezoelectric member and scans the light emitted from the light output section.

In conventional image display devices, an optical member for scanning light is provided on a movable part that is elastically supported by a fixed frame, and by repeatedly performing a tilting operation to change the tilt angle of this movable part with respect to the fixed frame, The image is scanned horizontally and vertically.

In addition, Patent Document 1 (Japanese Patent Application Laid-Open No. 2019-191227) discloses that in order to suppress ringing included in the rocking of the mirror, a correlation value between the detection signal and the ringing frequency is calculated to reduce the ringing. A technique is disclosed in which a superimposed signal whose amplitude is adjusted is superimposed on a drive signal.

Here, when a conventional optical deflection device tries to repeatedly perform a tilting operation of a movable part having a mirror, a single tilting operation is performed in which the movable part is tilted from a tilting operation start position to a tilting operation end position (light scanning section). In some cases, the tilt deflection angle of the movable part changes over time with respect to the ideal tilt deflection angle at each point in time (high frequencies are superimposed).

Such tilting motion is thought to be caused by elastic vibrations generated in the elastic portion that supports the support frame and the movable portion when the movable portion repeats the tilting motion.

Therefore, in drive control using two drive signals, in order to cancel out each high frequency that is superimposed on the tilting motion of the movable part, by changing the rise/fall ratio (symmetry ratio) of the two drive signals, 2 A method of adjusting the phase difference between two drive signals is known.

However, when adjusting the phase difference between two drive signals by changing the rise/fall ratio (symmetry ratio) of the two drive signals, the change in symmetry ratio and phase difference settings associated with the adjustment may cause the drive signal to change. Vibration may occur (high frequencies may be superimposed). For this reason, adjustment work cannot be performed until the vibrations subside, and it takes a long time to complete the adjustment work, which leaves room for improvement.

In the case of the technique disclosed in Patent Document 1, by repeating the tilting operation of the movable part having a mirror, it is possible to suppress ringing caused by elastic vibrations occurring in the elastic part that supports the support frame and the movable part.

However, in the case of the technique disclosed in Patent Document 1, it is difficult to suppress the ringing component of the mirror that is separately generated due to a setting change to the drive signal.

The present invention has been made in view of the above-mentioned problems, and enables adjustment work to be performed without waiting for the complete convergence of high frequencies superimposed upon a setting change, thereby shortening the adjustment processing time. The purpose is to provide movable devices, optical deflection devices, image projection devices, optical writing devices, object recognition devices, moving objects, and head-mounted displays.

In order to solve the above-mentioned problems and achieve the objects, the present invention includes a movable part, a drive beam part that rotates the movable part, a voltage input part that inputs a drive voltage to the drive beam part, and a voltage input part that inputs a drive voltage to the drive beam part. A changing unit that changes the driving voltage input from the changing unit to the driving beam unit, a phase of a high frequency signal caused by the degree of change in the driving voltage by the changing unit, and a phase of a frequency signal due to the change of the driving voltage by the changing unit. and a detection unit that detects a frequency signal based on the deflection angle of the movable part when they are in phase.

According to the present invention, it is possible to carry out adjustment work without waiting for the complete convergence of high frequencies superimposed upon a setting change, thereby shortening the adjustment processing time.

FIG. 1 is a block diagram of a light deflection device according to a first embodiment. FIG. 2 is a diagram showing the hardware configuration of the control device. FIG. 3 is a diagram showing the functional configuration of the control device. FIG. 4 is a flowchart showing the flow of optical scanning of the surface to be scanned in the optical deflection device of the first embodiment. FIG. 5 is a plan view of the movable device provided in the optical deflection device of the first embodiment. FIG. 6 is a sectional view taken along the line QQ' of the movable device. FIG. 7 is a cross-sectional view of the packaged mobile device. FIG. 8 is a cross-sectional view of another packaging mobile device. FIG. 9 is a block diagram showing the drive configuration of the movable device. FIG. 10 is a diagram showing changes over time in the deflection angle of the movable part around the second axis when the movable speed of the movable part around the second axis is constant (uniform). FIG. 11 is a diagram showing a projected image when the movable speed of the movable part around the second axis is constant (uniform). FIG. 12 is a diagram showing a temporal change in the deflection angle of the movable part 110 around the second axis when the movable speed of the movable part 110 around the second axis is not constant (uniform). FIG. 13 is a diagram showing a projected image in which a difference in brightness (uneven brightness) occurs. FIG. 14 is a diagram showing a drive waveform and a deflection angle of a reflecting surface that is optically scanned at a non-uniform movable speed. FIG. 15 is a diagram showing high frequency components with respect to the drive voltage A and the deflection angle of the movable part. FIG. 16 is a diagram showing high frequency components with respect to the drive voltage B and the deflection angle of the movable part. FIG. 17 is a diagram showing the deflection angle of the movable part and the high frequency component with respect to the deflection angle when the rise/fall (symmetry) ratio is changed with respect to the drive voltage. FIG. 18 is a diagram showing adjustment of the phase difference between each drive voltage so that the high frequencies generated by each drive voltage have opposite phases. FIG. 19 is a diagram showing the deflection angle of the movable part and the high frequency component with respect to the deflection angle when the rise/fall (symmetry) ratio is changed with respect to the drive voltage and the phase difference of each drive voltage is changed. FIG. 20 is a diagram illustrating the deflection angle, the high frequency that is superimposed on the deflection angle depending on the adjustment degree of the settings after the setting change, and the high frequency that is superimposed as the settings are adjusted. FIG. 21 is a diagram illustrating a case where there is an initial phase difference between the deflection angle, the high frequency that is superimposed on the deflection angle depending on the degree of adjustment of the settings after the setting change, and the high frequency that is superimposed due to the adjustment change of the settings. FIG. 22 is a front view of a double-sided movable device. FIG. 23 is a diagram for explaining an image projection device according to the second embodiment. FIG. 24 is a diagram showing a head-up display device that is an example of an image projection device according to the second embodiment. FIG. 25 is a perspective view of an optical writing device according to a third embodiment. FIG. 26 is a diagram showing main parts of an optical writing device according to a third embodiment. FIG. 27 is a diagram showing an object recognition device according to the fourth embodiment. FIG. 28 is a diagram showing a car equipped with a laser radar device, which is an example of the object recognition device according to the fourth embodiment. FIG. 29 is a diagram showing a laser headlamp of an automobile headlight according to a fifth embodiment. FIG. 30 is a perspective view of a head mounted display according to the sixth embodiment. FIG. 31 is a diagram showing a partial configuration of a head mounted display according to the sixth embodiment.

Hereinafter, an optical deflection device according to an embodiment will be described with reference to the accompanying drawings.

(overview)
The optical deflection device of the present embodiment is configured to operate at the timing of the tilting operation when the high frequency superimposed by the elastic vibration caused by repeating the tilting motion of the movable part including the mirror and the high frequency superimposed due to the setting change are in phase. Determine the signal. Thereby, it is possible to relatively determine the high frequency that is superimposed due to elastic vibration based on the amplitude of the high frequency without considering the phase difference between the two high frequencies. Therefore, adjustment work can be performed without waiting for complete convergence of high frequencies superimposed upon setting changes, and work time can be shortened.

(First embodiment)
(overall structure)
First, FIG. 1 is a block diagram of a light deflection device according to a first embodiment. As shown in FIG. 1, the optical deflection device 10 includes a control device 11, a light source device 12, and a movable device 13 that scans a scanned surface (screen) 15 and includes a reflective surface 14.

The control device 11 is an electronic circuit unit including, for example, a CPU (Central Processing Unit) and an FPGA (Field-Programmable Gate Array). The movable device 13 is, for example, a MEMS (Micro Electromechanical Systems) device that can move the reflective surface 14 . The light source device 12 is, for example, a laser device that emits laser light.

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, and outputs drive signals to the light source device 12 and the movable device 13 based on the control commands. The light source device 12 performs irradiation with a light source based on the input drive signal. The movable device 13 moves the reflective surface 14 in at least one of a uniaxial direction and a biaxial direction based on the input drive signal.

As a result, the reflective surface 14 of the movable device 13 is reciprocated in two axial directions within a predetermined range under the control of the control device 11 based on, for example, image information, and the irradiation light from the light source device 12 that is incident on the reflective surface 14 is An arbitrary image can be projected onto the scanned surface 15 by optical scanning. Note that details of the movable device 13 and details of control by the control device 11 will be described later.

(Hardware configuration of control device)
Next, FIG. 2 is a diagram showing the hardware configuration of the control device 11. As shown in FIG. As shown in FIG. 2, the control device 11 includes a CPU 20, a RAM 21 (Random Access Memory), a ROM 22 (Read Only Memory), an FPGA 23, an external I/F 24, a light source device driver 25, and a movable device driver 26.

The CPU 20 is an arithmetic device that reads a program or data from a storage device such as a ROM 22 onto the RAM 21, executes processing, and realizes overall control or functions of the control device 11. The RAM 21 is a volatile storage device that temporarily holds programs or data. The ROM 22 is a nonvolatile storage device that can retain programs or data even when the power is turned off, and stores processing programs or data that the CPU 20 executes to control each function of the optical deflection device 10.

The FPGA 23 is a circuit that outputs control signals suitable for the light source device driver 25 and the movable device driver 26 according to the processing of the CPU 20. The external I/F 24 is an interface with, for example, an external device or a network. External devices include, for example, host devices such as personal computer devices (PCs), storage devices such as USB memory, SD cards, CDs, DVDs, HDDs, and SSDs. Further, the network is, for example, a CAN (Controller Area Network) or a LAN (Local Area Network) of an automobile, the Internet, or the like. The external I/F 24 may have any configuration as long as it enables connection or communication with an external device, and an external I/F 24 may be provided for each external device.

The light source device driver 25 is an electric circuit that outputs a drive signal such as a drive voltage to the light source device 12 according to an input control signal. The movable device driver 26 is an electric circuit that outputs a drive signal such as a drive voltage to the movable device 13 in accordance with an input control signal.

In the control device 11, the CPU 20 acquires optical scanning information from an external device or network via the external I/F 24. Note that any configuration may be sufficient as long as the CPU 20 can acquire the optical scanning information, and the optical scanning information may be stored in the ROM 22 or FPGA 23 in the control device 11. A configuration may also be adopted in which a storage device is provided and the optical scanning information is stored in the storage device.

Here, the optical scanning information is information indicating how to optically scan the scanned surface 15. For example, when displaying an image by optical scanning, the optical scanning information is image data. Further, for example, when optical writing is performed by optical scanning, the optical scanning information is write data indicating the writing order and writing location. In addition, for example, when object recognition is performed by optical scanning, the optical scanning information is irradiation data that indicates the timing and irradiation range of irradiation with light for object recognition.

(Functional configuration of control device)
FIG. 3 is a diagram showing the functional configuration of the control device 11. As shown in FIG. As shown in FIG. 3, the control device 11 has the functions of a control section 30 and a drive signal output section 31. The control unit 30 is realized by, for example, the CPU 20, the FPGA 23, etc., and acquires optical scanning information from an external device, converts the optical scanning information into a control signal, and outputs the control signal to the drive signal output unit 31. The drive signal output unit 31 is realized by the light source device driver 25, the movable device driver 26, etc., and outputs a drive signal to the light source device 12 or the movable device 13 based on the input control signal.

The drive signal is a signal for controlling the drive of the light source device 12 or the movable device 13. For example, in the light source device 12, it is a drive voltage that controls the irradiation timing and irradiation intensity of the light source. For example, in the movable device 13, it is a drive voltage that controls the timing and movable range of the reflective surface 14 of the movable device 13.

(Optical scanning operation)
FIG. 4 is a flowchart showing the flow of optical scanning of the scanned surface 15 in the optical deflection device 10. In step S1 of the flowchart of FIG. 4, the control unit 30 acquires optical scanning information from an external device or the like. In step S2, the control section 30 generates a control signal from the acquired optical scanning information, and outputs the control signal to the drive signal output section 31. In step S3, the drive signal output section 31 outputs a drive signal to the light source device 12 and the movable device 13 based on the input control signal. In step 4, the light source device 12 performs light irradiation based on the input drive signal. Furthermore, the movable device 13 moves the reflective surface 14 based on the input drive signal. By driving the light source device 12 and the movable device 13, light is deflected in an arbitrary direction and optically scanned.

Note that in the light deflection device 10, one control device 11 has a device and function for controlling the light source device 12 and the movable device 13, but the control device for the light source device and the control device for the movable device are separate. It may also be placed on the body.

In addition, in the optical deflection device 10, one control device 11 has the functions of the control section 30 of the light source device 12 and the movable device 13, and the function of the drive signal output section 31, but these functions exist separately. You may do so. For example, a configuration may be adopted in which a drive signal output device having a drive signal output section 31 is provided separately from the control device 11 having the control section 30.

(Configuration of mobile device)
FIG. 5 is a plan view of the movable device 13 provided in the optical deflection device 10 of the first embodiment. As shown in FIG. 5, the movable device 13 is a movable device that can rotate the reflecting portion 112 around a first axis and a second axis that are two-dimensionally orthogonal through the center of the movable device. Note that, as an example, the movable device 13 has a two-axis rotating configuration, but may have a single-axis rotating configuration.

The movable device 13 includes a movable part 110, a first drive beam 120a and a first drive beam 120b, a fixed part 130, and an electrode terminal 150. The movable part 110 also includes a reflecting part 112 having a reflecting surface 14 on the reflecting part base 102, a supporting part 113, connecting parts 110a and 110b, torsion bars 111a and 111b, a second driving beam 116a, and a second driving beam 116b. .

The first drive beam 120a, the first drive beam 120b, the second drive beam 116a, and the second drive beam 116b are examples of drive beam sections.

The reflective portion 112 is formed from a silicon active layer or the like. However, the material is not limited to this, and may be made of an oxidized material, an inorganic material, an organic material, or the like. The reflective surface 14 is formed on the surface of the reflective section 112 in the positive Z direction. The reflective surface 14 is formed into a circular shape as shown in the figure using a metal thin film containing aluminum, gold, silver, etc. or a multilayer film thereof. The reflecting portion 112 does not need to be circular, and may be formed in an elliptical or polygonal shape.

A rib for reinforcing the reflecting section 112 is provided on the surface of the reflecting section 112 in the negative Z direction. The ribs are formed of a silicon support layer, a silicon oxide layer, and the like. By providing the ribs on the reflecting section 112, deformation distortion of the reflecting section 112 and the reflecting surface 14 that occurs during movement can be suppressed.

The torsion bar 111a and the torsion bar 111b are formed to extend in the Y direction and sandwich the reflective portion 112 in the Y direction. One end of the torsion bar 111a is connected to the reflection section 112. Further, one end of the torsion bar 111b is also connected to the reflecting section 112. That is, the reflecting section 112 is supported by torsion bars 111a and 111b.

The other end of the torsion bar 111a is connected to the second drive beam 116a, and the other end of the torsion bar 111b is connected to the second drive beam 116b. The second driving beams 116a and 116b are provided with piezoelectric portions on the positive Z-direction surfaces of the elastic beams. That is, the second drive beam has a so-called unimorph structure, but may have a bimorph structure in which piezoelectric parts are provided on both positive and negative Z-direction surfaces of the elastic beam. When a drive voltage is applied to the second drive beam 116a via the electrode terminal 150, the second drive beam 116a bends and deforms, causing the torsion bar 111a to twist. Similarly, when a drive voltage is applied to the second drive beam 116b via the electrode terminal 150, the second drive beam 116b bends and deforms, causing the torsion bar 111b to twist. Such twisting of the torsion bars 111a and 111b becomes a turning force, and the reflecting section 112 turns around the second axis.

On the other hand, the support section 113 is formed to surround the reflection section 112, the torsion bars 111a and 111b, and the second drive beam 116a and the second drive beam 116b from all sides. The support portion 113 is connected to the second drive beams 116a and 116b, and supports and restrains the second drive beams 116a and 116b. Further, the support section 113 indirectly supports the reflection section 112, the torsion bar 111a, and the torsion bar 111b via the second drive beams 116a and 116b.

A connection part 114a is provided at the upper right corner of the support part 113 in the figure, and the support part 113 is connected to the first drive beam 120a via the connection part 114a. The connecting portion 114a extends in the negative X direction from the connection point with the first driving beam 120a, and connects the first driving beam 120a and the support portion 113.

Further, a connection part 114b is provided at the lower left corner of the support part 113 in the figure, and the support part 113 is connected to the first drive beam 120b via the connection part 114b. The connecting portion 114b extends in the positive X direction from the connection point with the first driving beam 120b, and connects the first driving beam 120b and the support portion 113.

That is, the connecting portion 114a and the connecting portion 114b have a point-symmetrical positional relationship with respect to the center point of the supporting portion 113. With such a configuration, rotation of the support portion 113 by the first drive beam 120a and the second drive beam 120b can be stabilized.

The first drive beam 120a and the first drive beam 120b support the support section 113 from both sides in the X direction so as to sandwich the support section 113 therebetween. The first drive beam 120a has a second drive portion 130b which has a meander structure in which a plurality of elastic beams 132a to 132f are connected in a folded manner. A piezoelectric portion is provided on each of the positive Z-direction surfaces of the plurality of elastic beams 132a to 132f. That is, the elastic beams 132a to 132f have a so-called unimorph structure, but may have a bimorph structure in which piezoelectric parts are provided on both positive and negative Z-direction surfaces of the elastic beams. The end 114c of the first drive beam 120a that is not connected to the connection part 114a is connected to a fixing part 130 at the upper right corner in the figure, and the fixing part 130 fixes (supports and restrains) the first drive beam 120a. .

Similarly, the first drive beam 120b has a second drive section 130a having a meander structure in which a plurality of elastic beams 131a to 131f are connected. A piezoelectric portion is provided on each of the positive Z side surfaces of the plurality of elastic beams 131a to 131f. That is, the elastic beams 131a to 131f have a so-called unimorph structure, but may have a bimorph structure in which piezoelectric parts are provided on both positive and negative Z-direction surfaces of the elastic beams. The end 114d of the first drive beam 120b that is not connected to the connection part 114b is connected to a fixing part 130 at the lower left corner in the figure, and the fixing part 130 fixes (supports and restrains) the first drive beam 120b. .

That is, the connection point between the first drive beam 120a and the fixed part 130 and the connection point between the second drive beam 120b and the fixed part 130 are in a point-symmetrical positional relationship with respect to the center point of the support part 113. There is. With such a configuration, rotation of the support portion 113 by the first drive beam 120a and the second drive beam 120b can be stabilized.

The fixed part 130 has a rectangular frame structure having four frame sides, and the four frame sides surround the movable part 110 and the first drive beam 120a and the first drive beam 120b from all sides. A driving voltage is applied to the piezoelectric portions provided on the first driving beams 120a and 120b via the electrode terminals 150.

Here, among the plurality of elastic beams 132a to 132f included in the first drive beam 120a, the piezoelectric portions provided in the odd-numbered elastic beams 132a, 132c, and 132e counting from the one closest to the reflecting portion 112 are piezoelectrically driven. It is referred to as a subgroup 150A. Furthermore, among the plurality of elastic beams included in the first drive beam 120b, the piezoelectric sections provided in the even-numbered elastic beams 132b, 132d, and 132f counting from the one closest to the reflecting section 112 are similarly connected to the piezoelectric drive section group. It will be 150B.

The piezoelectric drive unit group 150A bends and deforms in the same direction when a predetermined drive voltage is simultaneously applied to each piezoelectric unit. The movable portion 110 rotates around the first axis using this deformation as a rotational force.

Furthermore, among the elastic beams 131a to 131f included in the first driving beam 120b, the piezoelectric portions provided in the even-numbered elastic beams 132b, 132d, and 132f counting from the one closest to the reflecting portion 112 are connected to the piezoelectric driving portion group. It will be 150B. Further, among the elastic beams 131a to 131f included in the first driving beam 120b, the odd-numbered elastic beams 131a, 131c, and 131e counting from the one closest to the reflecting section 112 are similarly set as the piezoelectric driving section group 150A.

The piezoelectric drive unit group 150B bends and deforms in the same direction when a predetermined drive voltage is simultaneously applied to each piezoelectric unit. Using this deformation as a rotational force, the movable part 110 rotates around the first axis in a direction opposite to the rotation by the piezoelectric drive unit group 150A.

The first drive beam 120a and the first drive beam 120b simultaneously bend and deform the plurality of piezoelectric parts included in the piezoelectric drive unit group 150A and the piezoelectric drive unit group 150B, thereby accumulating the amount of rotation due to the bending deformation, and moving the movable unit 110. The deflection angle (rotation angle) around the first axis can be increased. When the amount of rotation of the movable portion 110 by the piezoelectric drive unit group 150A when voltage is applied is balanced with the amount of rotation of the movable unit 110 by the piezoelectric drive unit group 150B when voltage is applied, the deflection angle is zero.

Furthermore, the movable device 13 includes detection units 140a and 140b. The detection section 140a has piezoelectric sensors 141a to 141f, and the detection section 140b has piezoelectric sensors 142a to 142f.

The piezoelectric sensor 141a is provided on the silicon active layer of the second piezoelectric drive section 131a, the piezoelectric sensor 141b is provided on the silicon active layer of the second piezoelectric drive section 131b, and the piezoelectric sensor 141c is provided on the silicon active layer of the second piezoelectric drive section 131c. is provided on the silicon active layer. Furthermore, the piezoelectric sensor 141d is provided on the silicon active layer of the second piezoelectric drive section 131d, the piezoelectric sensor 141e is provided on the silicon active layer of the second piezoelectric drive section 131e, and the piezoelectric sensor 141f is provided on the silicon active layer of the second piezoelectric drive section 131e. It is provided on the silicon active layer 131f.

Similarly, the piezoelectric sensor 142a is provided on the silicon active layer of the second piezoelectric drive section 132a, the piezoelectric sensor 142b is provided on the silicon active layer of the second piezoelectric drive section 132b, and the piezoelectric sensor 142c is provided on the silicon active layer of the second piezoelectric drive section 132b. It is provided on the silicon active layer 132c. Furthermore, the piezoelectric sensor 142d is provided on the silicon active layer of the second piezoelectric drive section 132d, the piezoelectric sensor 142e is provided on the silicon active layer of the second piezoelectric drive section 132e, and the piezoelectric sensor 142f is provided on the silicon active layer of the second piezoelectric drive section 132f. is provided on the silicon active layer.

FIG. 6 is a cross-sectional view of the movable device 13 taken along the line QQ' shown in FIG. As shown in FIG. 6, the detection section 140a, like the second drive section 130a, is located on the +Z side surface of the silicon active layer 163, which is an elastic section supported by the silicon support layer 161 via the silicon oxide layer 162. A lower electrode 201, a piezoelectric part 202, and an upper electrode 203 are laminated in this order on top. The upper electrode 203 and the lower electrode 201 are made of, for example, gold (Au) or platinum (Pt). The piezoelectric portion 202 is made of, for example, PZT (lead zirconate titanate), which is a piezoelectric material.

The detection section 140a has approximately the same length in the Y direction and a narrow width in the X direction compared to the second piezoelectric drive sections 131a to 131f. By configuring the detecting section 140a and the second piezoelectric drive sections 131a to 131f to have substantially equal lengths in the Y direction, it is possible to accurately detect an oscillation frequency signal, which will be described later. By configuring the detection section 140a to have a narrower width in the X direction than the detection section 131f, it is possible to obtain a large rotational force from the second piezoelectric drive sections 131a to 131f. Note that the lengths of the detection section 140a and the second piezoelectric drive sections 131a to 131f in the Y direction do not necessarily have to be approximately equal, and may be shorter than the lengths of the second piezoelectric drive sections 131a to 131f. In this case, since the detection section 140a is shortened, the second piezoelectric drive sections 131a to 131f can be provided on more elastic beams, and even more rotational force can be obtained by the second piezoelectric drive sections 131a to 131f.

Each of the piezoelectric sensors 141a to 141f of the detection unit 140a is spaced apart from each other so as not to contact each of the second piezoelectric drives 131a to 131f of the second drive unit 130a. It is provided on the +Z side surface of the active layer. The detection section 140b also has the same configuration as the detection section 140a.

The second drive units 130a and 130b are movable by bending and deforming the piezoelectric drive unit groups A and B by application of a drive voltage. On the contrary, the detection units 140a and 140b detect the voltage generated in the piezoelectric unit 202 in response to the deformation of the silicon active layer 163 by the second driving units 130a and 130b, or information based on the voltage, and information regarding the deflection angle of the reflection unit 101. It is detected as an oscillation frequency signal shown and supplied to the control device 11.

Note that a semiconductor such as an SOI (Silicon On Insulator) substrate can be used as a substrate (wafer) forming the movable device 13. By processing using semiconductor manufacturing technology, each component of the movable device 13 can be integrally formed. Note that the first drive beam 120a and the first drive beam 120b, and the second drive beam 116a and the second drive beam 116b may be formed after forming the SOI substrate, or may be formed during forming the SOI substrate. It's okay.

(Packaging of mobile equipment)
FIG. 7 is a cross-sectional view of the packaged mobile device 13. As shown in FIG. 7, the movable device 13 is attached to a mounting member 802 disposed inside a package member 801, and is packaged by covering a part of the package member 801 with a transparent member 803 to seal it. Ru. The inside of the package is sealed with an inert gas such as nitrogen. This suppresses deterioration of the movable device 13 due to oxidation, and further improves durability against changes in the environment such as temperature.

(Other packaging examples)
FIG. 8 is a sectional view showing another packaging example of the movable device 13. The example shown in FIG. 8 is an example in which the transparent member 803 and the movable device 13 are tilted relative to each other. In this example, by attaching the transparent member 803 at an angle with respect to the package member 801, the transparent member 803 is inclined with respect to the movable device 13 arranged on the package member 801. The inclination angle is set to such an angle that light that is multiple-reflected between the reflective surface 14 and the transmitting member 803 included in the movable device 13 does not exit the package member 801 . Such a configuration prevents image noise and the like due to multiple reflected light.

(Drive operation of movable device)
FIG. 9 is a block diagram showing the drive configuration of the movable device 13. The optical deflection device 10 of the first embodiment supplies drive information from the voltage input section 30c of the control section 30 to the drive signal output section 31. The drive signal output unit 31 supplies a drive signal to the movable device 13 based on the supplied drive information.

The movable device 13 is driven by the supplied drive signal, and at this time, the detection units 140a and 140b detect the piezoelectric unit 202 according to the deformation of the silicon active layer 163 by the second drive unit 130a and the second drive unit 130b. The voltage generated by the reflector 101 is detected as a deflection frequency signal indicating information regarding the deflection angle of the reflection section 101, and is supplied to the detection section 30a of the control section 30.

The detection unit 30a calculates the ratio between the drive frequency of the drive signal supplied from the voltage input unit 30c to the drive signal output unit 31 and the resonance frequency with respect to the movable direction of the movable unit 110.

The detection unit 30a also calculates the initial phase difference between the drive signal and the setting change timing based on the setting change signal input to the voltage input unit 30c via the setting change unit 29 (an example of a change unit). Thereby, it is possible to calculate the initial phase difference between the high frequency caused by the setting change and the high frequency caused by the degree of adjustment of the setting.

The detection unit 30a sends a detection signal to the correction unit 30b, which detects a drive period in which the high frequency caused by the setting change and the high frequency caused by the degree of adjustment of the settings are in phase, based on the initial phase difference, the ratio of the drive frequency, and the resonance frequency. supply

Note that it is difficult to independently detect the high frequency itself associated with a setting change. For this reason, the detection unit 30a detects high frequencies caused by the degree of setting adjustment as well as high frequencies associated with setting changes. In other words, by detecting the high frequency caused by the degree of setting adjustment, the detection unit 30a simultaneously detects the high frequency associated with the setting change, which is included in the high frequency caused by the degree of setting adjustment.

The drive cycle in which the high frequency caused by the setting change and the high frequency caused by the degree of setting adjustment are in phase is the drive cycle in which the amplitude of the high frequency is maximum. For this reason, the correction unit 30b extracts the drive cycle in which the amplitude of the high frequency is the maximum among the amplitudes of the high frequency in the drive cycle indicated by the detection signal, and based on the extracted amplitude of the high frequency, the voltage input unit 30c Correct the drive waveform of the output drive signal. Further, the correction unit 30b adjusts the frequency of the voltage input unit 30c at a period obtained by multiplying the least common multiple of the drive frequency of the voltage input unit 30c and the resonant frequency of the movable unit 110 by the resonant frequency of the movable unit 110. Performs frequency signal correction.

(Modified example)
In this example, the detection unit 30a detects a drive cycle in which the high frequency caused by the setting change and the high frequency caused by the degree of setting adjustment are in phase, and the drive cycle in which the amplitude of the high frequency is maximum. However, the detection unit 30a may select a drive cycle in which the amplitude of the high frequency wave is maximum from among the plurality of drive cycles, and notify the selected drive cycle to the correction unit 30b.

(Details of drive operation of movable device)
First, with reference to FIGS. 10 to 13, a time change in the moving speed of the movable portion 110 of the movable device 13 around the second axis, that is, the swing angle of the movable portion 110 around the second axis will be described. FIG. 10 is a diagram showing changes over time in the deflection angle of the movable part 110 around the second axis when the movable speed of the movable part 110 around the second axis is constant (uniform). FIG. 11 shows a projected image when the movable speed of the movable part 110 around the second axis is constant (uniform), and the movable speed of the movable part 110 is constant for both the first axis and the second axis, Indicates that the scanning operation is appropriate. Note that the movable device 13 used in the first embodiment uses the inner side of the movable operation range of the movable portion 110 as an effective image area.

FIG. 12 is a diagram showing a temporal change in the deflection angle of the movable part 110 around the second axis when the movable speed of the movable part 110 around the second axis is not constant (uniform). If the moving speed is not uniform in this way, a difference in brightness (unevenness in brightness) will occur in the projected image, as shown in FIG.

It is desirable that the moving speed of the movable part 110 around the second axis, which is the time change of the swing angle of the movable part 110 around the second axis, be linear as shown in FIG. 10 . In other words, it is desirable that the movable speed of the movable portion 110 around the second axis does not fluctuate. If the moving speed of the movable part 110 around the second axis fluctuates, linear light scanning is hindered, and, for example, brightness unevenness and distortion occur in the image formed on the scanned surface 15, resulting in deterioration of image quality. Because it invites you.

However, in reality, as shown in FIG. 12, in the movable operation of the movable part 110 around the second axis by the second drive parts 130a and 130b, fluctuations (high frequency components) occur in the movable speed of the deflection angle. . This is thought to be caused by a high frequency component being superimposed on the deflection angle due to elastic vibrations occurring in the elastic part (silicon active layer 163: see FIG. 6) that supports the fixed part 130 and the driving parts 130a, 130b.

(Adjustment to drive signal)
Next, a method of adjusting the drive signal for the movable device 13 will be explained using FIGS. 14 to 18. As shown in FIG. 14(a), when the movable device 13 is driven with drive voltages A and B, each of which is a simple sawtooth wave, the movable speed varies due to the influence of high frequency components, as shown in FIG. 14(b). However, the moving speed of the movable part 110 becomes uneven. The high frequency component superimposed on the deflection angle at this time behaves as shown in FIG. 14(c).

On the other hand, when the movable device 13 is driven with the drive voltage A or the starting voltage B as shown in FIG. 15(a) or FIG. 16(a), the deflection angle of the movable part 110 is As shown in FIG. 15(b), the high frequency component shown in FIG. 15(c) or FIG. 16(c) is superimposed on the deflection angle. In addition, in the case where the movable device 13 has the structure as shown in FIG. The behavior is approximately equal to (deflection angle A of movable part 110) - (deflection angle B of movable part 110).

Next, as shown in FIG. 17(a), the deflection angle of the movable part 110 when the movable device 13 is driven by the drive voltage B alone is plotted by changing the symmetry (rising/falling ratio) of the drive voltage B. 17(b), and FIG. 17(c) shows the high frequency component superimposed on the deflection angle. At this time, as the voltage slope of the falling section (scanning section) of the drive voltage B becomes gentler, the amplitude of the high frequency becomes smaller.

Therefore, the amplitude of the high frequency wave generated by the driving voltage A shown in FIG. 18(b) is matched with the amplitude of the high frequency wave generated by the driving voltage B shown in FIG. 18(c), as shown in FIG. 18(a). In this case, only the symmetry of drive voltage B is changed without changing drive voltage A.

In addition, the phase difference between drive voltage A and drive voltage B is adjusted so that the high frequencies generated by drive voltage A and drive voltage B are in opposite phases, as shown in FIGS. 18(b) and 18(c). do. Thereby, as shown in FIG. 18(d), the high frequency of the driving voltage B can be canceled out by the high frequency of the driving voltage A superimposed on the deflection angle.

Next, as shown in FIG. 19(a), FIG. ). At this time, depending on the degree of change in the settings (symmetry of drive voltage B, phase difference between drive voltage A and drive voltage B), in addition to the high frequency superimposed on the deflection angle, as shown in FIG. Along with this, superimposed high frequencies are generated. These two high frequencies further increase non-uniformity in the moving speed of the movable portion 110. Note that the frequency components that are superimposed due to adjustment changes in settings are mainly resonance frequency components in the scanning axis direction. Further, the high frequency that is superimposed upon changing this setting is generated temporarily, and converges after a certain period of time has elapsed.

(Drive signal correction operation)
FIG. 20 shows the deflection angle of the support part 113 or the movable part 110, the high frequency that is superimposed on the deflection angle depending on the degree of adjustment of the settings after the setting change, and the high frequency that is superimposed with the change of the settings. Here, as an example, it will be explained that the settings are changed between the 0th frame (period) and the 1st frame shown in FIG. 20(a). In this case, the behavior of the high frequency caused by the degree of adjustment of the settings differs between the 0th frame and the 1st frame, as shown in FIG. 20(b), and the same high frequency is superimposed from the 1st frame onward. Moreover, as shown in FIG. 20(c), the high frequency accompanying the setting change is superimposed from the first frame after the setting change, and gradually attenuates as the number of frames increases.

Note that the explanation will proceed assuming that the frame frequency at this time is a ratio of 1/6.25 to the resonance frequency in the scanning direction (6.25 harmonics per frame), but this ratio is, for example, It may be possible to arbitrarily change the ratio, such as setting the ratio to 1/7 (7.0 harmonics per frame).

In the case of the example in FIG. 20, the high frequency caused by the degree of setting adjustment shown in FIG. 20(b) and the high frequency caused by the setting change shown in FIG. 20(c) are in phase (the amplitude of the high frequency is maximum). will be the 1st frame, 5th frame, 9th frame, etc. after the setting change. This is related to the value below the decimal point of the ratio of the resonance frequency to the frame frequency.

That is, they are in phase in one frame, and in the second and subsequent frames, a phase difference occurs every frame by a decimal point of the ratio of the resonant frequency to the frame frequency (0.25 period), and in the fifth frame, they are in phase again. In this way, by determining the drive signal adjustment process in a frame in which the high frequency caused by the degree of setting adjustment and the high frequency associated with the setting change are in phase, the high frequency can be adjusted as shown in FIG. On the other hand, it becomes possible to make a determination based only on the amplitude without considering the phase difference. As a result, it is possible to relatively judge the degree of setting adjustment without waiting for the high frequency to converge due to the setting change, and it is possible to shorten the drive signal adjustment processing time.

Next, a case will be described in which the initial phase of the high frequency caused by the setting change is advanced by 90° (0.25 cycle) with respect to the high frequency caused by the degree of adjustment of the setting. In this case as well, the settings are changed between the 0th frame (period) and the 1st frame shown in FIG. 21(a). Further, the behavior of the high frequency caused by the degree of adjustment of the settings differs between the 0th frame and the 1st frame, and the same high frequency is superimposed from the 1st frame onwards. Further, as described above, the frame frequency will be explained as 1/6.25 of the resonance frequency in the scanning direction.

In this example, as shown in FIGS. 21(b) and 21(c), the high frequency caused by the setting change and the high frequency caused by the degree of setting adjustment become in phase at the fourth frame after the setting change. , the 8th frame, and so on. In the first frame, a phase difference of +0.25 cycles of the initial phase occurs, and in the second and subsequent frames, a phase difference occurs every frame by a fraction of the ratio of the resonant frequency to the frame frequency (0.25 cycles), and in the fourth frame, Becomes the same phase.

If the high frequency caused by the setting change and the high frequency caused by the degree of adjustment of the setting are not in phase with each other due to the initial phase, the correction unit 30b changes the frame frequency and changes the ratio with the resonance frequency to achieve the above-mentioned two conditions. Adjustment may be made so that the two high frequencies are in phase.

(Completion process of correction process)
The correction unit 30a ends such correction processing at a setting combination (for example, the symmetry of drive voltage B and the phase difference between drive voltage A and drive voltage B) that results in the smallest amplitude of the high frequency. Alternatively, the correction unit 30a may end the correction process with a setting combination in which the amplitude of the high frequency is equal to or less than a predetermined value.

Further, the correction unit 30a may always perform such correction processing. By constantly performing the correction process, it is possible to cope with changes in external factors due to aging or temperature fluctuations, and it is possible to control the movable speed of the movable part 110 to always be constant.

(Effects of the first embodiment)
As is clear from the above description, in the optical deflection device of the first embodiment, the movable part 110 supporting the movable part 110 of the movable device 13 receives high-frequency waves superimposed by elastic vibrations caused by repeated tilting operations. The signal is determined at the timing of the tilting operation when the signal and the high frequency superimposed due to the setting change are in phase. Thereby, the amplitude of the high frequency can be determined relatively without considering the phase difference, and there is no need to wait for the high frequency that is superimposed upon a setting change to converge, and the adjustment processing time can be shortened.

In addition, in the above-mentioned 1st Embodiment, as shown in FIG. It was decided that it would be a so-called cantilever type movable device with a However, as shown in FIG. 22, the second drive beams 212a and 212c are connected to both sides of the torsion bar 111a, and the second drive beams 212b and 212d are connected to both sides of the torsion bar 111b. It may be a device. In this case as well, effects similar to those described above can be obtained.

[Second embodiment]
Next, the second embodiment will be explained. This second embodiment is an example in which the above-described light deflection device 10 is applied to an image projection device. FIG. 23 is a schematic diagram of an automobile 400 equipped with a head-up display device 500, which is an example of an image projection device. Further, FIG. 24 is a diagram showing the configuration of the head-up display device 500.

As shown in FIG. 23, the head-up display device 500 is installed, for example, near a windshield (windshield 401, etc.) of an automobile 400. Projection light L emitted from the head-up display device 500 is reflected by the windshield 401 and directed toward the viewer (driver 402) who is the user. Thereby, the driver 402 can visually recognize the image projected by the head-up display device 500 as a virtual image. Note that a combiner may be installed on the inner wall surface of the windshield, and a configuration may be adopted in which the user can visually recognize the virtual image by the projection light reflected by the combiner.

As shown in FIG. 24, in the head-up display device 500, laser light is emitted from red, green, and blue laser light sources 501R, 501G, and 501B. After the emitted laser light passes through an input optical system consisting of collimator lenses 502, 503, 504 provided for each laser light source, two dichroic mirrors 505, 506, and a light amount adjustment section 507, It is deflected by a movable device 13 having a movable part 110. The deflected laser beam passes through a projection optical system including a free-form mirror 509, an intermediate screen 510, and a projection mirror 511, and is projected onto a screen.

In the head-up display device 500, the laser light sources 501R, 501G, 501B, collimator lenses 502, 503, 504, and dichroic mirrors 505, 506 are unitized by an optical housing as a light source unit 530.

The head-up display device 500 projects the intermediate image displayed on the intermediate screen 510 onto the windshield 401 of the automobile 400, thereby allowing the driver 402 to view the intermediate image as a virtual image.

Laser beams of each color emitted from laser light sources 501R, 501G, and 501B are made into substantially parallel beams by collimator lenses 502, 503, and 504, respectively, and combined by two dichroic mirrors 505 and 506. The light intensity of the combined laser beams is adjusted by a light intensity adjustment section 507, and then two-dimensional scanning is performed by a movable device 13 having a movable section 110. The projection light L that has been two-dimensionally scanned by the movable device 13 is reflected by the free-form mirror 509 to correct distortion, and then is focused on the intermediate screen 510 to display an intermediate image. The intermediate screen 510 is composed of a microlens array in which microlenses are two-dimensionally arranged, and magnifies the projected light L incident on the intermediate screen 510 in units of microlenses.

The movable device 13 reciprocates the movable part 110 in two axial directions, and scans the projection light L incident on the movable part 110 two-dimensionally. This driving control of the movable device 13 is performed in synchronization with the emission timing of the laser light sources 501R, 501G, and 501B.

The head-up display device 500 has been described above as an example of an image projection device, but the image projection device may be any device that projects an image by performing optical scanning with the movable device 13 having the movable portion 110. . For example, a projector is placed on a desk or the like and projects an image onto a display screen, a projector is installed on a mounting member attached to the observer's head, and the image is projected onto a reflective/transmissive screen of the mounting member, or the eyeball is used as a screen. The present invention can be similarly applied to a head-mounted display device or the like that projects an image.

In addition, image projection devices can be used not only for vehicles and mounted members, but also for mobile objects such as aircraft, ships, and mobile robots, and for non-mobile objects such as work robots that operate drive objects such as manipulators without moving from the location. It may also be provided on a moving body.

Since the image projection device of this embodiment includes the light deflection device of the first embodiment, it is possible to realize an image projection device that can adjust drive vibration in a short time.

[Third embodiment]
Next, a third embodiment will be explained. This third embodiment is an example in which the above-described optical deflection device 10 is provided in an optical writing device. FIG. 25 is an example of an image forming apparatus incorporating an optical writing device 600. Further, FIG. 26 is a diagram showing the main parts of the optical writing device.

As shown in FIG. 25, the optical writing device 600 is used as a component of an image forming apparatus, such as a laser printer 650 having a printer function using laser light. In the image forming apparatus, the optical writing device 600 performs optical writing on the photoreceptor drum by optically scanning the photoreceptor drum, which is the scanned surface 150, with one or more laser beams.

As shown in FIG. 26, in an optical writing device 600, a laser beam from a light source device 12 such as a laser element passes through an imaging optical system 601 such as a collimator lens, and then is transferred to a movable device 13 having a movable portion 110. Deflected axially or biaxially. The laser beam deflected by the movable device 13 then passes through a scanning optical system 602 consisting of a first lens 602a, a second lens 602b, and a reflective mirror section 602c, and then passes through the scanning surface 15 (for example, a photosensitive drum or photosensitive paper). ) to perform optical writing. The scanning optical system 602 forms a spot-shaped light beam on the surface to be scanned 15 . Further, the movable device 13 having the light source device 12 and the movable part 110 is driven under the control of the control device 11.

In this way, the optical writing device 600 can be used as a component of an image forming apparatus having a laser beam printer function. In addition, by changing the scanning optical system to enable light scanning not only in one axis but also in two directions, laser label devices that print by deflecting laser light onto thermal media, scanning it, and heating it, etc. It can be used as a component of an image forming apparatus.

The movable device 13 having the movable part 110 applied to the optical writing device consumes less power for driving than a rotating polygon mirror using a polygon mirror or the like, so it is advantageous for power saving of the optical writing device. It is. Further, since the wind noise generated when the movable device 13 vibrates is smaller than that of a rotating polygon mirror, it is advantageous for improving the quietness of the optical writing device. The optical writing device requires far less installation space than a rotating polygon mirror, and the amount of heat generated by the movable device 13 is small, so it is easy to downsize, and is therefore advantageous in downsizing the image forming device. be.

Since the image forming apparatus of this embodiment includes the light deflection device of the first embodiment, it is possible to realize an image forming apparatus that can adjust drive vibration in a short time.

[Fourth embodiment]
Next, the fourth embodiment will be explained. This fourth embodiment is an example in which the above-described optical deflection device 10 is applied to an object recognition device. FIG. 27 is a schematic diagram of an automobile equipped with a laser radar device, which is an example of an object recognition device. Moreover, FIG. 28 is a diagram showing the main parts of the laser radar device.

As shown in FIG. 27, a laser radar device 700 is installed, for example, in a car 701, and scans a target direction with light and receives reflected light from a target object 702 existing in the target direction. 702 is recognized.

As shown in FIG. 28, the laser light emitted from the light source device 12 passes through an input optical system consisting of a collimating lens 703, which is an optical system that converts diverging light into substantially parallel light, and a plane mirror 704, and then moves Scanning is performed by a movable device 13 having a section 110 in one or two axes directions. The light is then irradiated onto a target object 702 in front of the apparatus through a light projecting lens 705, which is a light projecting optical system.

The driving of the light source device 12 and the movable device 13 is controlled by the control device 11. The reflected light reflected by the target object 702 is detected by a photodetector 709. That is, the reflected light is received by the image sensor 707 through a condenser lens 706 and the like, which is an incident light detection and reception optical system, and the image sensor 707 outputs a detection signal to a signal processing device 708. The signal processing circuit 708 performs predetermined processing such as binarization and noise processing on the input detection signal, and outputs the result to the ranging circuit 710.

The distance measuring circuit 710 determines the target object based on the time difference between the timing when the light source device 12 emits the laser beam and the timing when the photodetector 709 receives the laser beam, or the phase difference between each pixel of the image sensor 707 that receives the laser beam. The presence or absence of the target object 702 is recognized, and further distance information to the target object 702 is calculated.

Since the movable device 13 having the reflective surface 14 is less likely to be damaged and is smaller than a polygon mirror, it is possible to provide a small and highly durable radar device. Such a radar radar device is attached to, for example, a vehicle, an aircraft, a ship, a robot, etc., and can scan a predetermined range with light to recognize the presence or absence of an obstacle and the distance to the obstacle.

In the object recognition device, the laser radar device 700 has been explained as an example, but the object recognition device performs optical scanning by controlling the movable device 13 having the movable part 110 with the control device 11, and performs optical scanning with a photodetector. Any device may be used as long as it recognizes the target object 702 by receiving reflected light.

For example, biometric authentication that recognizes objects by calculating object information such as shape from distance information obtained by optically scanning a hand or face and recording and referencing it, and recognizing intruders by optically scanning a target area. The present invention can also be similarly applied to security sensors that calculate and recognize object information such as shape from distance information obtained by optical scanning, and components of three-dimensional scanners that output as three-dimensional data.

Since the object recognition device of this embodiment includes the optical deflection device of the first embodiment, it is possible to realize an object recognition device that can adjust drive vibration in a short time.

[Fifth embodiment]
Next, the fifth embodiment will be explained. The fifth embodiment is an example in which the above-described optical deflection device 10 is applied to a laser headlamp 50 of a headlight of an automobile, which is an example of a moving object. FIG. 29 is a diagram showing the configuration of the laser headlamp 50. As shown in FIG. 29, the laser headlamp 50 includes a control device 11, a light source device 12b, a movable device 13 having a movable part 110, a mirror 51, and a transparent plate 52.

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 movable device 13 moves the movable part 110 in the XY directions based on a signal from the control device 11, and performs two-dimensional scanning in the XY directions with the blue laser light from the light source device 12b.

The scanning light from the movable device 13 is reflected by the mirror 51 and enters the transparent plate 52 . The front or back surface of the transparent plate 52 is coated with a yellow phosphor. When the blue laser light from the mirror 51 passes through the yellow phosphor coating on the transparent plate 52, it changes to white, which is within the legal range of headlight color. As a result, the front of the vehicle is illuminated with white light from the transparent plate 52.

The scanning light from the movable device 13 is scattered in a predetermined manner when passing through the fluorescent material of the transparent plate 52 . This reduces the glare on the illuminated object in front of the vehicle.

When the movable device 13 is applied to an automobile headlight, the colors of the light source device 12b and the fluorescent material are not limited to blue and yellow, respectively. For example, the light source device 12b may use near ultraviolet light, and the transparent plate 52 may be coated with a uniform mixture of phosphors of the three primary colors of light, blue, green, and red. Even in this case, the light passing through the transparent plate 52 can be converted to white light, and the front of the vehicle can be illuminated with white light.
Since the laser headlamp of this embodiment includes the optical deflection device of the first embodiment, it is possible to realize a laser headlamp that can adjust drive vibration in a short time.

[Sixth embodiment]
Next, the sixth embodiment will be explained. This sixth embodiment is an example in which the above-described optical deflection device 10 is applied to a head-mounted display. The head-mounted display 60 is a head-mounted display that can be mounted on a human head, and can have a shape similar to glasses, for example. Hereinafter, the head mounted display will be abbreviated as HMD.

FIG. 30 is a perspective view illustrating the appearance of the HMD 60. In FIG. 30, the HMD 60 includes a front 60a and a temple 60b, which are provided substantially symmetrically, one on each side. The front 60a can be configured by, for example, a light guide plate 61, and an optical system, a control device, etc. can be built into the temple 60b.

FIG. 31 is a diagram partially illustrating the configuration of the HMD 60. Although FIG. 31 illustrates a configuration for the left eye, the HMD 60 has a similar configuration for the right eye. The HMD 60 includes a control device 11 , a light source unit 530 , a light amount adjustment section 507 , a movable device 13 having a movable section 110 including a reflective surface 14 , a light guide plate 61 , and a half mirror 62 .

As described above, the light source unit 530 is a unit made up of the laser light sources 501R, 501G, and 501B, the collimator lenses 502, 503, and 504, and the dichroic mirrors 505 and 506 using an optical housing. In the light source unit 530, the three-color laser beams from the laser light sources 501R, 501G, and 501B are combined by dichroic mirrors 505 and 506. The light source unit 530 emits combined parallel light.

The light from the light source unit 530 enters the movable device 13 after the light amount is adjusted by the light amount adjustment section 507. The movable device 13 moves the movable part 110 in the X and Y directions based on a signal from the control device 11, and performs two-dimensional scanning with the light from the light source unit 530. The drive control of the movable device 13 is performed in synchronization with the emission timing of the laser light sources 501R, 501G, and 501B, and a color image is formed by scanning light.

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 on the inner wall surface. The light guide plate 61 is made of resin or the like that is transparent to the wavelength of the scanning light.

The half mirror 62 reflects the light from the light guide plate 61 toward the back side of the HMD 60 and emits it toward the eyes of the person 63 wearing the HMD 60 . The half mirror 62 has, for example, a free-form surface shape. The image formed by the scanning light is reflected by the half mirror 62 and forms an image on the retina of the wearer 63. Alternatively, an image is formed on the retina of the wearer 63 due to the reflection by the half mirror 62 and the lens effect of the crystalline lens in the eyeball. Further, due to the reflection by the half mirror 62, the spatial distortion of the image is corrected. The wearer 63 can observe an image formed by light scanned in the XY directions.

The half mirror 62 allows the wearer 63 to observe a superimposed image of an image of light from the outside world and an image of scanning light. By providing a mirror in place of the half mirror 62, a configuration may be adopted in which light from the outside world is eliminated and only images generated by scanning light can be observed.
Since the HMD of this embodiment includes the optical deflection device of the first embodiment, it is possible to realize an HMD that allows adjustment of drive vibration in a short time.

Finally, each of the embodiments described above is presented as an example, and is not intended to limit the scope of the present invention. Each of the novel embodiments can be implemented in various other forms, and various omissions, substitutions, and changes can be made without departing from the gist of the invention. Further, each embodiment and modifications of each embodiment are included within the scope and gist of the invention, and are included within the scope of the invention described in the claims and its equivalents.

10 Light deflection device 11 Control device 12 Light source device 13 Movable device 14 Reflection surface 15 Screen 29 Setting change section 30 Control section 30a Detection section 30b Correction section 30c Voltage input section 31 Drive signal output section 102 Reflection section base 110 Movable section 110a Connection section 110b Connection part 111a Torsion bar 111b Torsion bar 112 Reflection part 113 Support part 116a Second drive beam 116b Second drive beam 120a First drive beam 120b First drive beam 130 Fixed part 130a Second drive part 130b Second drive part 131a~ 131f Elastic beam 132a-132f Elastic beam 150 Electrode terminal 140a Detection section 140b Detection section 141a-141f Piezoelectric sensor 142a-142f Piezoelectric sensor

JP2019-191227A

Claims (13)

A moving part,
a driving beam portion that rotates the movable portion;
a voltage input section that inputs a drive voltage to the drive beam section;
a changing unit that changes the drive voltage input from the voltage input unit to the drive beam unit;
a deflection angle of the movable part when the phase of a high-frequency signal caused by the degree of change of the drive voltage by the change unit and the phase of the high-frequency signal caused by the change of the drive voltage by the change unit are in phase; a detection unit that detects a frequency signal based on the
A mobile device having: When the phase of the high-frequency signal caused by the degree of change of the drive voltage by the change unit and the phase of the high-frequency signal resulting from the change of the drive voltage by the change unit are in phase, the detection unit detects the signal. The movable device according to claim 1, further comprising a correction section that corrects the drive voltage based on the frequency signal. The movable device according to claim 2, wherein the correction section corrects a ratio of a rise time and a fall time of the drive voltage based on the frequency signal detected by the detection section. The voltage input section inputs two different drive voltages to the drive beam section,
The movable device according to claim 2 or 3, wherein the correction section changes a phase difference between the two drive voltages. The correction unit corrects the frequency signal at a period obtained by multiplying the drive period by the least common multiple of the frequency of the drive voltage and the resonance frequency of the movable part divided by the resonance frequency. The movable device according to any one of claims 2 to 4. The correction unit terminates the correction operation when the amplitude of the frequency signal based on the deflection angle of the movable part detected by the detection unit becomes equal to or less than a predetermined value. 5. The movable device according to any one of 5. A movable device according to any one of claims 1 to 6,
a light projection unit that irradiates the movable part with light scanned by the movable device;
An optical deflection device comprising: An image projection device comprising the light deflection device according to claim 7. The image projection device according to claim 8, wherein the light deflecting device scans the reflected light from the light projecting section on a surface of a light transmitting member. An optical writing device comprising the optical deflection device according to claim 7. An object recognition device comprising the light deflection device according to claim 7. A moving body comprising the optical deflection device according to claim 7. A head mounted display comprising the optical deflection device according to claim 7.

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