JP6790523B2 - Actuator control devices, drive systems, video equipment, image projection devices, actuator control methods, and moving objects - Google Patents

Description

The present invention relates to an actuator control device, a drive system, a video device, an image projection device, an actuator control method , and a moving body .

It is known that when a voltage is applied in the polarization direction, the piezoelectric element exhibits a so-called inverse piezoelectric effect, which causes distortion, that is, expansion and contraction, which is proportional to the potential of the applied voltage. Therefore, conventionally, a piezoelectric actuator that transmits a driving force to a driven body by using such a piezoelectric element has been realized.

A piezoelectric element used in a piezoelectric actuator, for example, exerts a driving force in a state of being polarized in one direction like a permanent magnet, and is a drive circuit between electrodes provided on both end faces in the polarization direction. Driving force can be obtained by connecting the outputs. The above-mentioned polarization can be obtained by continuously applying a certain voltage for a certain period of time in consideration of the composition of the device. Once polarized, the device is generally driven by applying a voltage between the polarized voltage direction and zero.

In general, the drive sensitivity of the piezoelectric element of the actuator with respect to the voltage (hereinafter referred to as the drive sensitivity of the actuator including this) varies depending on the ambient environment such as manufacturing error, deterioration over time, and temperature, and therefore varies from device to device. There is a problem of being there. If the drive sensitivity varies from device to device, the drive sensitivity to the applied voltage may deviate from the normal range, which causes problems such as the image display position shifting from device to device and the aspect ratio of the image becoming abnormal. May cause.

Therefore, the present invention has been made in view of the above problems, and provides an actuator control device, a drive system, a video device, an image projection device , an actuator control method , and a moving body capable of suppressing variations in the drive sensitivity of the actuator. The purpose is to provide.

In order to achieve the above object, the actuator control device according to the present invention is an actuator control device that controls an actuator having a drive unit for moving a reflection unit based on a signal acquired from a light detection unit, and is the drive unit. From a waveform generation unit that generates a voltage waveform for driving, a drive amplifier that amplifies the voltage waveform generated by the waveform generation unit, a power supply unit that supplies power to the drive amplifier, and an optical detection unit. It is characterized by including a control unit that acquires a detection signal and controls a voltage supplied by the power supply unit to the drive amplifier based on the acquired detection signal.

Further, the drive system according to the present invention is characterized by including the above-mentioned actuator control device, the actuator, and the photodetector.

Further, the video device according to the present invention is characterized by including the drive system described above.

Furthermore, the image projection device according to the present invention comprises the above-mentioned drive system, a mirror attached to the drive unit of the actuator and rotatable in two axial directions, a light source for outputting laser light, and the laser light. It is characterized by including an optical system incident on the mirror and a control unit that controls the drive system to drive the mirror.

Furthermore, the actuator control method according to the present invention is an actuator control method in which an actuator having a drive unit for moving a reflection unit is controlled based on a signal acquired from a light detection unit, and the waveform generation unit is the drive unit. The drive amplifier generates a voltage waveform for driving, the drive amplifier amplifies the voltage waveform generated by the waveform generator, the power supply unit supplies power to the drive amplifier, and the control unit detects the light. It is characterized in that a detection signal is acquired from the unit and the voltage supplied by the power supply unit to the drive amplifier is controlled based on the acquired detection signal. Furthermore, the moving body according to the present invention is characterized by having the image projection device according to the above-mentioned invention.

According to the present invention, it is possible to realize an actuator control device, a drive system, a video device, an image projection device , an actuator control method , and a moving body capable of suppressing variations in the drive sensitivity of the actuator.

FIG. 1 is a diagram showing a configuration example of a frame of a piezoelectric actuator. FIG. 2 is a diagram showing an arrangement example of the piezoelectric elements of the piezoelectric actuator. FIG. 3 is a diagram showing an example of connection to the piezoelectric actuator. FIG. 4 is a diagram showing an example of the arrangement of the piezoelectric actuator and the electrodes. FIG. 5 is a diagram showing a drive voltage on the X-axis side of the piezoelectric actuator. FIG. 6 is a schematic view showing the operation of the piezoelectric actuator with respect to the drive voltage shown in FIG. FIG. 7 is a diagram showing a drive voltage on the Y-axis side of the piezoelectric actuator. FIG. 8 is a schematic view showing the operation of the piezoelectric actuator with respect to the drive voltage shown in FIG. FIG. 9 is a diagram for explaining the shape of the piezoelectric actuator during operation on the Y-axis side (No. 1). FIG. 10 is a diagram showing the relationship between the scanning direction, the scanning area, and the drawing area and the emission line of light in the shape shown in FIG. FIG. 11 is a diagram for explaining the shape of the piezoelectric actuator during operation on the Y-axis side (No. 2). FIG. 12 is a diagram showing the relationship between the scanning direction, the scanning area, and the drawing area and the emission line of light in the shape shown in FIG. FIG. 13 is a schematic view showing a schematic configuration example of an actuator drive device as a comparative example. FIG. 14 is a diagram showing an operation of drawing a two-dimensional image using a piezoelectric actuator. FIG. 15 is a flowchart showing an operation example of the control unit according to the comparative example. FIG. 16 is a diagram showing an example of an amplitude change of the main scan until it settles in a steady state in the operation shown in FIG. FIG. 17 is a diagram showing an example of an amplitude change of the sub-scan until it settles in a steady state in the operation shown in FIG. FIG. 18 is a diagram showing an example of variation in drive sensitivity of the piezoelectric actuator. FIG. 19 is a schematic view showing a schematic configuration example of the drive system according to the first embodiment of the present invention. FIG. 20 is a flowchart showing an operation example of the control unit according to the first embodiment of the present invention. FIG. 21 is a schematic diagram showing a schematic configuration example of the drive system according to the second embodiment of the present invention. FIG. 22 is a flowchart showing an operation example of the control unit according to the second embodiment of the present invention. FIG. 23 is a schematic diagram showing a schematic configuration example of the image projection device according to the fourth embodiment of the present invention. FIG. 24 is a schematic diagram showing a schematic configuration example of the two-dimensional optical deflector according to the fourth embodiment of the present invention. FIG. 25 is a waveform diagram showing an example of the voltage application pattern according to the fourth embodiment of the present invention. FIG. 26 is a schematic view showing a schematic configuration example of a head-up display according to a modified example of the fourth embodiment of the present invention. FIG. 27 is a diagram for explaining a case where a laser enters a photodiode in a short cycle outside the drawing region in an operation of drawing a two-dimensional image using the piezoelectric actuators according to the first to fourth embodiments of the present invention. is there. FIG. 28 is a waveform diagram showing a waveform example of a detection signal detected by the photodiode in the operation shown in FIG. 27. FIG. 29 is a flowchart showing another example of each operation of the control unit according to the first to fourth embodiments of the present invention. FIG. 30 is for explaining a case where a laser enters two photodiodes arranged close to each other outside the drawing area in an operation of drawing a two-dimensional image using the piezoelectric actuators according to the first to fourth embodiments of the present invention. It is a figure of. FIG. 31 is a flowchart showing still another example of each operation of the control unit according to the first to fourth embodiments of the present invention. FIG. 32 is a block diagram showing a schematic configuration example of the actuator control device according to the first to fourth embodiments of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Since the embodiments described below are preferred embodiments of the present invention, various technically preferable limitations are attached, but the scope of the present invention is unreasonably limited by the following description. Not all of the configurations described in this embodiment are essential constituents of the present invention.

Here, a structural example of the piezoelectric actuator and its operation will be described below with an example. FIG. 1 is a diagram showing an example of a frame configuration of a piezoelectric actuator. FIG. 2 is a diagram showing an example of arrangement of the piezoelectric element with respect to the frame illustrated in FIG. FIG. 3 is a diagram showing a wiring example for the piezoelectric actuator illustrated in FIG. The piezoelectric actuator illustrated here is an actuator for scanning light in two axial directions, the X-axis and the Y-axis.

As shown in FIG. 1, the frame configuration of the piezoelectric actuator has a structure in which the mirror 1 is attached to the frame 11 of the piezoelectric actuator formed on the silicon substrate. The frame 11 includes a folded structure portion 12 to 15 and X-axis frames 16 and 17. The left side of the folded structure portion 12 is the connection portion with the frame 11, the left side of the folded structure portion 13 is the connection portion with the X-axis frames 16 and 17, and the right side of the folded structure portion 14 is the X-axis frames 16 and 17. The right side of the folded structure portion 15 is the connecting portion with the frame 11. In addition, although FIG. 1 shows an example in which the folded structure portions 12 to 15 are folded once, the folded structure may be formed twice or more. The folded structure portions 12 to 15 rotate the entire X-axis frames 16 and 17 in a twisting direction. The mirror 1 is attached to the rotation center of the X-axis frames 16 and 17, and irradiates light such as a laser beam to scan the light. In FIG. 1, the Y-axis direction of the scan is perpendicular to the vertical center line passing through the mirror 1, that is, the left-right direction. The X-axis frames 16 and 17 are also connected to the mirror 1. In FIG. 1, the X-axis direction of the scan is perpendicular to the center line in the left-right direction passing through the mirror 1, that is, the up-down direction. Therefore, in the case of FIG. 1, the vertical direction in the paper surface is the X axis, and the horizontal direction is the Y axis.

As shown in FIG. 2, the piezoelectric actuator 10 is provided with a drive piezoelectric element 22 to 25 and a detection piezoelectric element 32 to 35 in each of the folded structure portions 12 to 15 with respect to the frame 11 shown in FIG. Has a structure Further, each of the X-axis frames 16 and 17 is also provided with the piezoelectric elements 26 and 27 for driving and the piezoelectric elements 36 and 37 for detection.

As shown in FIG. 2, for the piezoelectric actuator 10 shown in FIG. 2, the wiring SDA (Sub Drive Ach) for driving the piezoelectric elements 22 and 24 in common and the piezoelectric elements 23 and 25 are commonly driven. SDB (Sub Drive Bch) for driving, MD (Main Drive) for driving piezoelectric elements 26 and 27 in common, and detection terminal SSA1 (Sub Sense Ach-1) connected to the folded structure portion 12. , The detection terminal SSB1 (Sub Sense Bch-1) connected to the folded structure unit 13, the detection terminal SSA2 (Sub Sense Ach-2) connected to the folded structure unit 14, and the detection connected to the folded structure unit 15. A terminal SSB2 (Sub Sense Bch-2) is provided.

Further, FIG. 4 shows an example of a combination of each piezoelectric element illustrated in FIG. 2 and an electrode provided on the back surface thereof and a wiring connected to each electrode. As shown in FIG. 4, electrodes 42 and 44 to which the common wiring SDAG is connected are arranged on the back surfaces of the driving piezoelectric elements 22 and 24, and the common wiring SDBG is connected to the back surfaces of the piezoelectric elements 23 and 25. The electrodes 43 and 45 are arranged, and the electrodes 46 and 47 to which the common wiring MDG is connected are arranged on the back surfaces of the piezoelectric elements 26 and 27. Further, an electrode 52 to which the wiring SSA1G is connected is arranged on the back surface of the piezoelectric element 32 for detection, an electrode 53 to which the wiring SSB1G is connected is arranged on the back surface of the piezoelectric element 33, and an electrode 53 to which the wiring SSB1G is connected is arranged on the back surface of the piezoelectric element 34. The electrode 54 to which the wiring SSA2G is connected is arranged, the electrode 55 to which the wiring SSB2G is connected is arranged on the back surface of the piezoelectric element 35, and the electrode 56 to which the common wiring MSG is connected is arranged on the back surface of the piezoelectric elements 36 and 37. And 57 are placed.

Generally, when a voltage having the same polarity as the voltage applied during polarization is applied to the piezoelectric element, a pulling force is generated on the piezoelectric element. For example, if + 30V is applied based on the GND standard at the time of polarization, the entire piezoelectric element is deformed in the direction of contraction by applying a positive voltage based on the GND reference. As a result, a pulling force is generated on the piezoelectric element. Further, when a force is applied to the piezoelectric element, a weak voltage is generated. An electric charge is charged by this voltage, and a current flows between the piezoelectric element and the electrode. The piezoelectric elements 22 to 27 and the piezoelectric elements 32 to 37 are driven and detected by utilizing these characteristics.

Although the cases in which the piezoelectric elements are arranged on only one surface are illustrated in FIGS. 1 to 4, they may be arranged on both sides in order to improve the degree of freedom in the arrangement and wiring and the production of the piezoelectric elements. Further, since the formation of these piezoelectric elements and electrodes is almost the same as that of the semiconductor process, it is possible to reduce the cost by mass production.

FIG. 5 is a diagram illustrating the operation of the piezoelectric actuator 10 in the X-axis direction, and FIG. 6 is a view of the piezoelectric actuator 10 viewed from the lateral direction. Since it is common to operate the piezoelectric actuator 10 by resonance in the X-axis direction in order to obtain as large an amplitude as possible with a small input energy, the piezoelectric actuator 10 is operated at a resonance frequency in FIGS. 5 and 6. As shown in FIG. 5, the voltage between the electrodes MD and MDG is zero at time t1. As shown in FIG. 6, in the piezoelectric actuator 10 at this time t1, the displacement of the piezoelectric element is zero on the left side of the center of the mirror 1. At time t2, the piezoelectric element is deformed in the direction of contracting to the center, whereby the center of the mirror 1 is slightly tilted to the left. At time t3, the shrinkage of the piezoelectric element becomes maximum, and as a result, the center of the mirror 1 is tilted to the maximum to the left. In this way, the piezoelectric actuator 10 operates in the X-axis direction.

FIG. 7 is a diagram illustrating the operation of the piezoelectric actuator 10 in the Y-axis direction, and FIG. 8 is a view of the piezoelectric actuator 10 viewed from below. In FIG. 7, the solid line shows the voltage waveform between the electrodes SDA and SDAG, and the broken line shows the voltage waveform between the electrodes SDB and SDBG. These waveforms are sawtooth waves whose phase is inverted by 180 degrees. At time t0, the voltage between the electrodes SDA and SDAG becomes maximum, and the voltage between the electrodes SDB and SDBG becomes zero. At that time (time t0), as shown in FIG. 8, the mirror 1 is tilted to the maximum to the right with respect to the mirror 1. At time t1, the voltage between the electrodes SDA and SDAG is about one-fourth of the maximum voltage, the voltage between the electrodes SDB and SDBG is about three-quarters of the maximum voltage, and the inclination of the mirror 1 is about the maximum inclination and the horizontal. It will be roughly in the middle. At time t2, the voltage between the electrodes SDA and SDAG and between the electrodes SDB and SDBG is approximately intermediate to the maximum voltage, and the inclination of the mirror 1 is approximately horizontal. At time t3, the voltage between the electrodes SDA and SDAG is about three-quarters of the maximum voltage, the voltage between the electrodes SDB and SDBG is about one-fourth of the maximum voltage, and the inclination of the mirror 1 is the maximum inclination at time t0. The maximum inclination in the opposite direction is approximately halfway between the horizontal and horizontal. At time t4, the voltage between the electrodes SDA and SDAG is zero, the voltage between the electrodes SDB and SDBG is the maximum voltage, and the inclination of the mirror 1 is the maximum inclination opposite to the maximum inclination at time t0. At time t5, the voltage between the electrodes SDA and SDAG becomes maximum, the voltage between electrodes SDB and SDBG becomes zero, and the mirror 1 tilts to the maximum to the right as at time t0.

9 to 12 are also views for explaining the operation of the piezoelectric actuator 10 in the Y-axis direction, and are views when the operation of FIG. 8 is viewed three-dimensionally. FIG. 9 is a diagram showing the states at times t0 and t5 in FIG. 8, and shows a case where the electrodes SDA, that is, the piezoelectric elements 22 and 24 belonging to Ach are maximally contracted. FIG. 11 is a diagram showing a state at time t4 in FIG. 8, and shows a case where the electrodes SDB, that is, the piezoelectric elements 23 and 25 belonging to Bch are maximally contracted. 10 and 12 are views in which detailed description is added to FIGS. 9 and 11, respectively. As shown in FIGS. 9 to 12, when light is incident on the mirror 1, it can be seen that the reflected light is scanned in the Y-axis direction (horizontal direction). When such a piezoelectric actuator is applied to a system such as an optical scanner, it is generally scanned linearly in the Y-axis direction, that is, a raster scan operation is performed. FIGS. 9 to 12 describe a situation in which a raster scan is operated. The frequency of the voltage applied in this operation is about several tens of Hz. When handling a general image or video, it is often operated at 60 to 70 Hz.

In the above-mentioned operation, the X-axis operates with as little energy as possible by utilizing the resonance phenomenon, while the Y-axis operates in a non-resonant manner. Therefore, the amount of displacement of the piezoelectric element in the Y-axis direction is small. Therefore, the piezoelectric actuator 10 is provided with the folded structure portions 12 to 15 and the X-axis frames 16 and 17, and a plurality of piezoelectric elements 22 to 27 are operated in parallel to obtain a displacement amount in the Y-axis direction.

In the above description, the piezoelectric actuator 10 having a structure called a so-called cantilever beam has been illustrated, but the structure is not limited to this. That is, it is possible to apply piezoelectric actuators having various structures to the following embodiments.

FIG. 13 shows a schematic configuration example of an actuator drive device as a comparative example. As shown in FIG. 13, the actuator drive device 900 includes a waveform generation unit 910, amplifiers 921 and 923, an actuator 930, a control unit 950, a photodiode (PD) 951 and a photodiode (PD-X) 952. To be equipped. From the waveform generation unit 910, the main scanning drive voltage M is output to the amplifier 921, and the sub-scanning drive voltage S is output to the amplifier 923. For the power supplies of the respective amplifiers 921 and 923, a negative power supply Vee and a positive power supply Vh, which is a voltage higher than the required maximum output voltage, are used so that 0 V to the required maximum output voltage can be obtained. Further, the output M-AMP (main scan) of the amplifier 921 and the output S-AMP (secondary scan) of the amplifier 923 are connected to the drive unit of the actuator 930.

Here, as shown in FIG. 14, when the main scan and the sub scan are driven in a steady state to draw a two-dimensional image, the scan area starts from the upper left corner at time t0, and the scan area of one screen is in the lower right corner. finish. Photodiodes 951 and 952 for detecting laser light are arranged outside the drawing area. A photodiode 952 provided at a position where the scanned laser enters when only the main scan is driven without driving the sub scan, and scanning when both the main scan and the sub scan are driven. The amplitudes of the main scan and the sub scan are controlled by the photodiode 951 provided at the position where the emitted laser enters the light. When the amplitude of the main scan is controlled by the photodiode 952, both the time when the light enters outside the drawing area in a short cycle and the time when the light enters the drawing area and returns can be used. .. For example, in the case of a short cycle, drawing outside the drawing area can be made small by making this cycle as small as possible, so that drawing can be performed efficiently, but there is a drawback that the margin is small and it is vulnerable to disturbance. On the contrary, in the case of a long cycle, there is an advantage that the efficiency is lowered but it becomes strong against disturbance. The sub-scan can be controlled in the same manner as the main scan by using the photodiode 951.

Here, the flow until the main scan and the sub scan settle in a steady state in the drawing operation of the two-dimensional image will be described with reference to the drawings. FIG. 15 is a flowchart showing an operation example of the control unit until the main scan and the sub scan settle in a steady state. FIG. 16 is a diagram showing an example of an amplitude change of the main scan until the steady state is settled. FIG. 17 is a diagram showing an example of an amplitude change of the sub-scan until the steady state is settled.

As shown in FIGS. 15 to 17, when the drawing of the two-dimensional image is started, first, while gradually increasing the gain of the main scan and gradually increasing the gain of the sub scan (steps S901 and S902), the photodiode. Detecting the incoming light to 952 (step S903). At that time, the amplitude of the sub-scan gradually increases, but the control unit 950 controls the main scan so that the limit is reached earlier. After that, when the position is larger than the position of the photodiode 952 (hereinafter referred to as PD-X position) and the limit X is reached, the gain of the main scan is maintained and the amplitude is temporarily fixed (step S904), but the gain of the sub scan is obtained. The increase continues until the number of incoming light detections in the Y-axis direction by the photodiode 951 exceeds a predetermined number of predetermined values, that is, until the sub-scan reaches the amplitude including the margin Y (step). S905; NO). After that, when the sub-scan reaches the amplitude including the margin Y (step S905; YES), the gain of the sub-scan is determined and the amplitude is fixed (step S906).

Regarding the amplitude of the main scan, if the number of incoming light detections in the X-axis direction by the photodiode 951 is not equal to or greater than the predetermined number of times (step S907; NO), the gain is determined as it is and the amplitude is fixed. (Step S909), this operation is terminated. On the other hand, when the number of incoming light detections in the X-axis direction is equal to or greater than the specified number (step S907; YES), the amplitude is reduced from the limit to the amplitude including the margin X at the time when the amplitude of the sub-scan is determined (step). S908), return to step S907. By the above operation, as shown in FIGS. 16 and 17, the main scan and the sub scan settle in a steady state.

FIG. 18 shows an example of variation in drive sensitivity of the piezoelectric actuator. In FIG. 18, the vertical axis represents the voltage required for driving, and the horizontal axis represents the amplitude sensitivity of the piezoelectric actuator. As shown in FIG. 18, when the voltage required for driving is the highest, the power supply voltage Vh is obtained by adding the power supply voltage variation to the headroom (voltage region where output is not possible) of the circuit. The voltage required for driving is the highest when driving the actuator with the lowest driving sensitivity of the sub-scan. In the case of sub-scan, a high voltage is inevitably required because raster scan is performed. On the other hand, since the main scan is driven by resonance as described above, a drive voltage lower than that of the sub scan is generally required.

Subsequently, the drive system and the drive control method according to the first embodiment will be described in detail with reference to the drawings. FIG. 19 is a schematic diagram showing a schematic configuration example of the drive system according to the first embodiment. As shown in FIG. 19, the drive system 100 includes an actuator 130, a main scan drive amplifier 121, a sub scan drive amplifier 123, a waveform generation unit 110, a control unit 150, a photodiode (PD) 151, and a photodiode (PD-). X) 152 and a power supply unit 160 are provided. The actuator 130, the main scanning drive amplifier 121, the sub-scanning drive amplifier 123, the waveform generator 110, the photodiode (PD) 151 and the photodiode (PD-X) 152 are the same as the drive system 900 illustrated in FIG. It may be there. However, the drive system 100 according to the first embodiment is configured so that the main scan drive amplifier 121 and the sub scan drive amplifier 123 are driven by the voltage Vhs supplied from the power supply unit 160.

FIG. 20 is a flowchart showing the operation of the control unit until the main scan and the sub scan settle in a steady state in the drawing operation of the two-dimensional image using the drive system shown in FIG. As shown in FIG. 20, in the first embodiment, the control unit 150 executes the same operation (steps S101 to S109) as the operations (steps S901 to S909) described with reference to FIGS. 15 to 17. The gain of the main scan is determined to fix the amplitude. Next, the control unit 150 obtains the voltage Vhs by dividing the sub-scanning gain by the parameter A (step S110), and subsequently sets the voltage of the power supply unit 160 to the voltage Vhs (step S111).

Here, in order to make it easier to understand the flowchart shown in FIG. 20, a specific numerical example will be described. It is assumed that the power supply voltage Vh is fixed. Further, the required runout angle of the sub-scan is set to 10 degrees, the standard value (TYP) of the drive sensitivity of the sub-scan is set to 0.375 degrees / V, the minimum value (MIN) is set to 0.25 degrees / V, and the maximum thereof is set. The value (MAX) is 0.5 degree / V. In that case, the voltage is 40 V (= 10 degrees / (0.25 degrees / V)), so if the margin and headroom are expected to be 20%, the power supply voltage Vh will be 48 V.

Next, assuming that the limit (maximum set value) of the runout angle of the drive circuit is 1000 and the margin is 100, the set value is adjusted at the time of the drive sensitivity (MIN), so that the limit of the runout angle is 900. Next, in the case of the drive sensitivity of the standard value (TYP), when the deflection angle of the main scan is gradually increased, the data when the light enters the photodiode 952 becomes approximately 675. That is, a desired swing angle can be obtained with a power supply voltage of 675/900 with respect to the drive sensitivity (MIN). Therefore, in this case, 900 is substituted for the parameter A in step S110 of FIG. 20, and 675 is substituted for the sub-scanning gain. As a result, the voltage Vhs is calculated to be 36V. This voltage Vhs is a value in consideration of the margin and the headroom, and is reduced by 12V as compared with the power supply voltage (48V). Finally, in the case of drive sensitivity (MAX), since the data is about 450, the voltage Vhs can be obtained as 24V, which is half the value of the power supply voltage Vh, by performing the same calculation.

As described above, in the first embodiment, since the actuator 130 is actually driven to set the voltage Vhs, an unnecessarily large power supply voltage Vh is not required. As a result, power consumption can be suppressed. Further, even when the drive sensitivity variation of the actuator 130 is large, the voltage Vhs can be optimally set for each, so that the allowable range of the sensitivity variation of the actuator 130 can be widened, thereby improving the yield of the actuator 130. Is possible. Since other configurations and operations may be the same as those of the above-described comparative example, detailed description thereof will be omitted here.

Next, the drive system and the drive control method according to the second embodiment will be described in detail with reference to the drawings. FIG. 21 is a schematic diagram showing a schematic configuration example of the drive system according to the second embodiment. As shown in FIG. 21, the drive system 200 includes a configuration in which the power supply unit 160 is replaced with two power supply units 261 and 262 in the same configuration as the drive system 100 according to the first embodiment. The power supply unit 261 is a power supply for the main scanning drive, and supplies a voltage Vhm to the main scanning drive amplifier 121 according to the control from the control unit 150. The power supply unit 262 is a power supply for sub-scanning drive, and supplies voltage Vhs to the sub-scanning drive amplifier 123 according to control from the control unit 150.

FIG. 22 is a flowchart showing the operation of the control unit until the main scan and the sub scan settle in a steady state in the drawing operation of the two-dimensional image using the drive system shown in FIG. As shown in FIG. 22, in the second embodiment, the control unit 150 determines the gain of the main scan and fixes the amplitude by executing the same operation as in steps S101 to S109 in FIG. Next, the control unit 150 divides the main scanning gain by the parameter B to obtain the voltage Vhm, and divides the sub scanning gain by the parameter A to obtain the voltage Vhs (step S210). The calculation method of the voltages Vhm and Vhs may be the same as the calculation method described in step S110 in the first embodiment. Next, the control unit 150 sets the voltage of the power supply unit 261 for the main scanning drive to the voltage Vhm, and sets the voltage of the power supply unit 262 for the sub-scanning drive to Vhs (step S211).

As described above, in the second embodiment, since the voltages Vhm and Vhs for driving the main scan and the sub scan can be set separately, the voltage Vhm for driving the main scan can be independently reduced. It can be done, which makes it possible to further reduce power consumption. In addition, unlike the circuit components for the sub-scan drive, which require a relatively high withstand voltage, the circuit components for the main scan drive can use general components, so that the cost of the circuit components can be reduced. It becomes. Since other configurations, operations, and effects are the same as those in the above-described embodiment, detailed description thereof will be omitted here.

Next, the third embodiment will be described. The drive system and drive control method exemplified in the above-described embodiment can also be adopted for video equipment. As a result, it is possible to obtain a video device equipped with a high-performance optical scanner with low power consumption.

Next, the fourth embodiment will be described. The drive system exemplified in the above-described first and second embodiments can act as a light deflector. Therefore, these drive systems can be mounted on an image projection device such as a projector, a head-mounted display, or a head-up display, or a mobile device equipped with the image projection device. Hereinafter, the image projection device equipped with the drive system illustrated in the above-described first and second embodiments will be described in detail as the fourth embodiment with reference to the drawings.

FIG. 23 is a schematic diagram showing a schematic configuration example of the image projection device according to the fourth embodiment. As shown in FIG. 23, the image projection device 1000 includes a red laser light source 1001, a green laser light source 1002, a blue laser light source 1003, a collimating lens 1004, an optical path synthesis means 1005, a two-dimensional light deflector 1009, and the like. It includes an LD drive unit 1011, an optical deflector drive unit 1012, a control unit 1013, and a storage unit 1014. The drive system according to the first or second embodiment described above is incorporated in the optical deflector drive unit 1012. However, the photodiodes 151 and 152 in the drive system can be appropriately changed as long as they are at positions where the scanned laser light enters, such as the two-dimensional optical deflector 1009.

The collimating lens 1004 and the optical path synthesizing means 1005 constitute an optical system in which the laser light output from the laser light sources 1001 to 1003 is incident on the reflection mirror 1100 (see FIG. 24) of the two-dimensional light deflector 1009. The light emitted from each of the red laser light source 1001, the green laser light source 1002, and the blue laser light source 1003 is emitted as parallel light by the collimating lens 1004. In the example shown in FIG. 23, a light source having a wavelength of 642 nm was used as the red laser light source 1001, a light source having a wavelength of 520 nm was used as the green laser light source 1002, and a light source having a wavelength of 450 nm was used as the blue laser light source 1003.

The laser beam collimated by the collimating lens 1004 is incident on the optical path synthesizing means 1005. The optical path synthesizing means 1005 synthesizes three optical paths into one optical path, and is composed of an optical path synthesizing prism such as a dichroic mirror. The optical path synthesizing means 1005 may have a number of reflecting surfaces corresponding to the number of light sources. Therefore, in the example shown in FIG. 23, the optical path synthesizing means 1005 has three reflecting surfaces 1006, 1007 and 1008.

A dichroic film that reflects a laser beam having a red wavelength and transmits a laser beam having a green or blue wavelength is formed on the reflecting surface 1006. A dichroic film that reflects a laser beam having a green wavelength and transmits a laser beam having a blue wavelength is formed on the reflecting surface 1007. The reflecting surface 1008 reflects a laser beam having a blue wavelength. By providing such reflecting surfaces 1006 to 1008, the optical path synthesizing means 1005 synthesizes three optical paths into one optical path.

The combined laser light is deflected by the two-dimensional light deflector 1009 so as to scan the screen 1010 in two dimensions. The formation of an image on the screen 1010 is performed by two-dimensional optical scanning of laser light by a two-dimensional optical deflector 1009 and intensity modulation of each laser light source 1001 to 1003. At this time, the intensity modulation signals of the laser light sources 1001 to 1003 are sent from the LD drive unit 1011. The operation signal to the two-dimensional optical deflector 1009 is sent from the optical deflector drive unit 1012. The control unit 1013 controls the LD drive unit 1011 and the two-dimensional optical deflector 1009 for forming an image. Initial data for driving the two-dimensional optical deflector 1009 is stored in the storage unit 1014.

Subsequently, a more specific configuration example of the two-dimensional optical deflector 1009 according to the fourth embodiment will be described in detail below with reference to the drawings. FIG. 24 is a schematic diagram showing a schematic configuration example of the two-dimensional optical deflector according to the fourth embodiment.

As shown in FIG. 24, the two-dimensional light deflector 1009 includes a reflection mirror 1100 that reflects laser light at a central portion. The reflection mirror 1100 is supported by a pair of torsion bars 1101. Each end of the torsion bar 1101 is supported by one end of the piezoelectric cantilever 1102. The other ends of the piezoelectric cantilever 1102 are supported by the movable frame 1103, respectively. The movable frame 1103 is supported by a pair of beam portions (meandering beam portions) 1104 formed by meandering with a plurality of folded portions. The meandering beam portion 1104 is supported by the element frame member 1105. Independent piezoelectric members 1106a and 1106b are provided on each meandering beam portion.

In the configuration shown in FIG. 24, by driving the piezoelectric cantilever 1102, the torsion bar 1101 supporting the reflection mirror 1100 is twisted, so that the reflection mirror 1100 rotates and vibrates around the Y axis. Here, the piezoelectric cantilever 1102 is driven by a sine wave, and mechanical resonance is used for the rotation of the reflection mirror 1100.

On the other hand, by driving the meandering beam portion 1104, the movable frame 1103 rotates about the X-axis, and the reflection mirror 1100 also rotates about the X-axis accordingly. Specifically, a voltage is applied by a sawtooth wave to every other piezoelectric member 1106a and 1106b independently provided on each meandering beam portion of the meandering beam portion 1104. Here, the piezoelectric members 1106a have the same waveform voltage application pattern, and the piezoelectric members 1106b have the same waveform voltage application pattern. An example of the voltage application pattern is shown in FIG. In FIG. 25, the vertical axis represents the voltage value and the horizontal axis represents the time. According to the voltage application pattern as illustrated in FIG. 25, the phase of the sawtooth wave is adjusted every other meandering beam portion 1104, whereby the meandering beam portion 1104 is rotationally driven. Such driving enables highly uniform optical scanning.

Note that FIG. 23 shows a projector device as an example of the image projection device 1000, but the present invention is not limited to this, and a head-mounted display worn on the head, a diffuser plate or a microlens array as a screen, a windshield, etc. It can be applied to a head-up display or the like that forms a virtual image using a semi-transparent plate or the like. FIG. 26 shows a schematic configuration example of the head-up display. As shown in FIG. 26, the head-up display 1200 has a configuration similar to that of the image projection device 1000 shown in FIG. 23, and is a microlens array 1115 including a plurality of microlenses on the optical path ahead of the two-dimensional light deflector 1009. And a semi-transparent plate 1116 (for example, a combiner or a windshield) are arranged. In the configuration shown in FIG. 26, an image is formed on the microlens array 1115 as the laser light is deflected around the first axis and the second axis by the two-dimensional light deflector 1009. Then, the virtual image 1117 whose image is enlarged via the translucent plate 1116 can be visually recognized from the viewpoint 1118. In this case, since the laser beam is diffused by the microlens array 1115, the virtual image 1117 with reduced speckle noise is obtained. A vehicle window glass or the like can also be used for the semitransparent plate 1116.

The head-up display 1200 having such a configuration can be mounted on a moving body such as a vehicle, an aircraft, a ship, or a robot. Therefore, it is possible to provide a mobile device including a head-up display 1200 and a mobile body on which the head-up display 1200 is mounted.

Although the invention made by the present inventor has been specifically described above based on the preferred embodiment, the present invention is not limited to the one described in the above embodiment, and various modifications are made without departing from the gist thereof. It goes without saying that it is possible.

The drive system of the above embodiment is applicable as long as it is a device that operates by driving an actuator. For example, by driving an actuator having a reflecting surface, a laser beam emitted from a laser light source is directed in a target direction. It can be applied to an object recognition device that scans light and recognizes an object existing in the target direction by reflected light from the target direction. The object recognition device is, for example, a laser radar, a laser three-dimensional measurement device, a biometric authentication device, or the like.

Further, in the drive systems 100 and 200 of the above-described embodiment, the number of times of light incoming detection by the photodiode 151 (corresponding to PD951 in FIG. 14) / 152 (corresponding to PD-X952 in FIG. However, as shown in FIGS. 27 and 28, the scanning of the laser such that the light enters the photodiode 151/152 in a short period outside the drawing area (see FIG. 14) is also increased. In the case of a locus, the light that enters the photodiode 151/152 first (outward route) passes through the photodiode 151/152 at T1, and then returns to the photodiode 151/952 (return route) and enters the photodiode 951/952. The gain may be increased until the time difference T3 (see FIG. 28) from the time T2 is larger than a predetermined value. As a result, the energy saving effect is further improved by setting the margin to a certain value or more at the time of setting and reducing the voltage value when the margin becomes too large with the passage of time. Further, if the margin cannot be made equal to or higher than a certain value even if the gain is maximized, the control device may be configured to output failure information as if it has failed.

Further, the control unit 150 of the above-described embodiment performs the amplitude adjustment described in the above-described embodiment again as a check mode when the information that the environmental temperature has changed is acquired or when a predetermined time has elapsed since the start-up. May be good. As a result, a stable amplitude can be maintained even when the amplitude changes due to changes in the environment or time.

Here, as shown in FIGS. 27 and 28, the gain is increased until the time (time difference T3) until the light passing through the photodiode 151/152 re-enters the light becomes larger than a predetermined value. The flow until the main scan and the sub scan settle in a steady state will be described with reference to FIG. 29. FIG. 29 is a flowchart showing an operation example of the control unit until the main scan and the sub scan settle in a steady state. In the operation shown in FIG. 29, in the same operation as the operation described with reference to FIG. 15 above, step S905 in FIG. 15 is replaced with step S301, and step S907 is replaced with step S302.

In step S301 of FIG. 29, the control unit 150 uses the detection signal acquired from the photodiode 152 to set the time T1 in which the light entering the photodiode 152 earlier (outward path) passes through the photodiode 152 and later ( These time differences (time difference in the Y-axis direction) T3 are obtained from the time T2 when the light enters the photodiode 152 after returning to the return path), and the obtained Y-axis direction time difference T3 is equal to or greater than a predetermined value defined in advance. This is continued until the subscan reaches the amplitude including the margin Y (step S301; NO). After that, when the sub-scan reaches the amplitude including the margin Y (step S301; YES), the process proceeds to step S906, the gain of the sub-scan is determined, and the amplitude is fixed. Since the detection signal acquired from the photodiode 152 contains noise, the control unit 150 extracts a signal having a value larger than a predetermined value from the acquired signals as a detection signal, and the above-mentioned Y-axis direction. The time difference T3 may be obtained.

In step S302 of FIG. 29, by using the detection signal acquired from the photodiode 151, the light enters the main scan amplitude after the time T1 at which the light that first entered the photodiode 151 was emitted and later. These time differences (time difference in the X-axis direction) T3 are obtained from the time T2, and if the obtained time difference T3 in the X-axis direction is not equal to or more than a predetermined value specified in advance (step S302; NO), the gain is obtained as it is. Is determined to fix the amplitude (step S909), and this operation is terminated. On the other hand, when the time difference T3 in the X-axis direction is equal to or greater than a predetermined value specified in advance (step S302; YES), the time from the limit to the amplitude including the margin X at the time when the amplitude of the sub-scan is determined It is reduced (step S908) and returns to step S302. By the above operation, the main scan and the sub scan settle in the steady state in the same manner as the operations described with reference to FIGS. 16 and 17. Since the detection signal acquired from the photodiode 151 contains noise as in the signal acquired from the photodiode 152, the control unit 150 transmits a signal having a value larger than a predetermined value among the acquired signals. It may be taken out as a detection signal to obtain the above-mentioned time difference T3 in the X-axis direction. Further, since the operations other than steps S301 and S302 may be the same as the operations described with reference to FIG. 15, duplicate description will be omitted here.

Further, in the configuration described above with reference to FIG. 27, a case where the scanning path of light reciprocates outside the drawing area (see FIG. 14) and enters the same photodiode 151/152 is illustrated. It is not limited to. For example, in the above embodiment, it is also possible to provide two photodiodes, which are photodetectors, in close proximity to each other so that light is continuously incident on these two photodiodes in one outward path or path. .. In the case of such a configuration, the time difference between the time T3 received by one photodiode (for example, the PD on the upstream side in the scanning path) and the time T4 received by the other photodiode (for example, the PD on the downstream side in the scanning path). The gain can be increased until T6 becomes smaller than a predetermined value.

As a result, the energy saving effect is further improved by setting the margin of the time difference T6 to a certain value or more at the time of setting and reducing the voltage value when the margin becomes too large due to the passage of time. Further, if the margin cannot be made equal to or higher than a certain value even if the gain is maximized, the control device may be configured to output failure information as if it has failed.

Here, when FIG. 30 and FIG. 31 are used, the gain is increased until the time difference (time difference T6) of the incident time of the light incident on the two adjacent photodiodes becomes larger than a predetermined value. The flow until the main scan and the sub scan settle in the steady state will be described. FIG. 30 is a diagram for explaining an example in which two photodiodes, which are photodetectors in the above embodiment, are provided in close proximity to each other. The time difference T6 is the time difference between the time T3 received by one photodiode (for example, PD151a on the upstream side in the scanning path) and the time T4 received by the other photodiode (for example, PD151b on the upstream side in the scanning path). In FIG. 30, the photodiodes 151a and 151b correspond to the photodiodes 151 or 152 in FIG. 19 or 21, for example. That is, in this description, the photodiodes 151 and 152 in the above-described embodiment are composed of two photodiodes 151a and 151b, respectively.

FIG. 31 is a flowchart showing an operation example of the control unit until the main scan and the sub scan settle in a steady state. In the operation shown in FIG. 31, in the same operation as the operation described with reference to FIG. 15 above, step S905 in FIG. 15 is replaced with step S401, and step S907 is replaced with step S402.

In step S401 of FIG. 31, the control unit 150 uses the detection signal acquired from the photodiode 151a and the detection signal acquired from the photodiode 151b to light the time T4 at which light is incident on the photodiode 151a and the light on the photodiode 151b. The time T5 in which the light is incident is obtained, and the time difference (time difference in the Y-axis direction) T6 between T4 and T5 is calculated. It continues until the calculated time difference T6 becomes equal to or less than a predetermined value defined in advance, that is, until the sub-scan reaches the amplitude including the margin Y (step S401; NO). After that, when the sub-scan reaches the amplitude including the margin Y (step S401; YES), the process proceeds to step S906, the gain of the sub-scan is determined, and the amplitude is fixed. Since the detection signals acquired from the photodiodes 151a and 151b contain noise, the control unit 150 extracts a signal having a value larger than a predetermined value from the acquired signals as a detection signal, and the above-mentioned Y The axial time difference T6 may be obtained.

In step S402 of FIG. 31, by using the detection signals acquired from the photodiodes 151a and 151b, the time T4 at which light is incident on the photodiode 151a and the time T5 at which light is incident on the photodiode 151b are used for the amplitude of the main scan. Is calculated, and the time difference T6 (time difference in the X-axis direction) between T4 and T5 is calculated. If the calculated X-axis direction time difference T6 is not equal to or less than a predetermined value specified in advance (step S402; NO), the gain is determined as it is to fix the amplitude (step S909), and this operation is terminated. To do. On the other hand, when the time difference T6 in the X-axis direction is equal to or less than a predetermined value defined in advance (step S402; YES), the time from the limit to the amplitude including the margin X at the time when the amplitude of the sub-scan is determined It is reduced (step S908) and returns to step S302. By the above operation, the main scan and the sub scan settle in the steady state in the same manner as the operations described with reference to FIGS. 16 and 17. Since the detection signal acquired from the photodiode 151 contains noise as in the signal acquired from the photodiode 152, the control unit 150 transmits a signal having a value larger than a predetermined value among the acquired signals. It may be taken out as a detection signal to obtain the above-mentioned time difference T6 in the X-axis direction. Further, since the operations other than steps S401 and S402 may be the same as the operations described with reference to FIG. 15, duplicate description will be omitted here.

Further, the configuration excluding the actuator 130 in the drive systems 100 and 200 of the above embodiment is also referred to as an actuator control device. FIG. 32 shows a schematic configuration example of the actuator control device. As shown in FIG. 32, the actuator control device 1500 includes a CPU (Central Processing Unit) 1501, a RAM (Random Access Memory) 1502, a ROM (Read Only Memory) 1503, an FPGA (Field-Programmable Gate Array) 1504, and an external interface ( It includes an I / F) 1505 and an actuator driver 1506. Of these configurations, the CPU 1501, the RAM 1502, the ROM 1503, and the external I / F 1505 constitute, for example, the control unit 150 (see FIGS. 19, 21, etc.) described above. Further, the FPGA 1504 corresponds to the waveform generation unit 110 described above, and the actuator driver 1506 is, for example, the main scan drive amplifier 121 in FIG. 19, the sub scan drive amplifier 123 and the power supply unit 160, or the main scan drive in FIG. It corresponds to the amplifier 121, the sub-scanning drive amplifier 123, and the two power supply units 261 and 262.

The CPU 1501 is an arithmetic unit that reads programs and data from a storage device such as the ROM 1503 onto the RAM 1502, executes processing, and realizes overall control and functions of the control unit 150. The RAM 1502 is a volatile storage device that temporarily holds programs and data. The ROM 1503 is a non-volatile storage device that can retain programs and data even when the power is turned off, and stores processing programs and data executed by the CPU 1501 to control each function of the drive system 100/200. ing. The RAM 1502 and / or ROM 1503 has a function of a storage unit for storing control-related parameters and signals acquired from an optical detection unit (PD151, PD-X152, etc.).

The FPGA 1504 is a circuit that outputs a control signal suitable for the actuator driver 1506 according to the processing of the CPU 1501, and has the function of the waveform generation unit 110 described above. The external I / F 1505 is, for example, an interface with an external device, a network, or the like. The external device includes, for example, an optical detection unit (PD151, PD-X152, etc.), a higher-level device such as a PC (Personal Computer), and a storage device such as a USB memory, an SD card, a CD, a DVD, an HDD, and an SSD. The network is, for example, a CAN (Controller Area Network) of an automobile, a LAN (Local Area Network), the Internet, or the like. The external I / F1505 may be configured to enable connection or communication with an external device, and an external I / F1505 may be prepared for each external device.

As described above, the actuator driver 1506 includes, for example, the main scanning drive amplifier 121 and the sub-scanning drive amplifier 123 and the power supply unit 160 in FIG. 19, or the main scanning drive amplifier 121 and the sub-scanning drive amplifier 123 in FIG. It is an electric circuit corresponding to two power supply units 261 and 262, which amplifies a signal input from FPGA 1504 by an amplifier (AMP121, 123, etc.) and outputs it to an actuator 130. The actuator driver 1506 may be incorporated in the FPGA 1504.

In the actuator control device 1500, the CPU 1501 acquires the signals of the photodiodes 151 and 152 via the external I / F 1505. The actuator control device 1500 according to the above-described embodiment can realize the functional configuration described above by the instruction of the CPU 1501 and the hardware configuration shown in FIG. 32.

100,200 Drive system 110 Waveform generator 121 Main scan drive amplifier 123 Sub-scan drive amplifier 130 Actuator 150 Control unit 151, 151a, 151b, 152 Photo diode 160, 261,262 Power supply unit 1000 Image projection device 1001 to 1003 Laser Light source 1004 Collimating lens 1005 Optical path synthesis means 1009 Two-dimensional optical deflector 1115 Microlens array 1116 Semi-transparent plate 1500 Actuator control device 1501 CPU
1502 RAM
1503 ROM
1504 FPGA
1505 External I / F
1506 actuator driver

Japanese Patent No. 292218 Japanese Patent No. 2570237 Japanese Unexamined Patent Publication No. 2008-116668 JP-A-2007-155984 JP-A-2007-226108 JP-A-2007-240626 JP-A-2007-241169 Japanese Patent No. 3804312 Japanese Unexamined Patent Publication No. 2011-004339 JP-A-2010-026443 Japanese Unexamined Patent Publication No. 2014-132996

Claims (13)

An actuator control device that controls an actuator having a drive unit that moves a reflection unit based on a signal acquired from a light detection unit.
A waveform generator that generates a voltage waveform for driving the drive unit,
A drive amplifier that amplifies the voltage waveform generated by the waveform generator, and
A power supply unit that supplies power to the drive amplifier and
A control unit that acquires a detection signal from the light detection unit and controls the voltage supplied by the power supply unit to the drive amplifier based on the acquired detection signal.
An actuator control device characterized by being equipped with. The waveform generation unit generates the voltage waveform on the basis of the control of the control unit,
The actuator control device according to claim 1, wherein the control unit controls the power supply unit based on a control value for the waveform generation unit. The drive unit includes a first drive unit that moves the reflection unit around a first axis, and a second drive unit that moves the reflection unit around a second axis.
The drive amplifier includes a first drive amplifier that applies a voltage to the first drive unit and a second drive amplifier that applies a voltage to the second drive unit.
The power supply unit includes a first power supply unit that supplies the first power to the first drive amplifier, and a second power supply unit that supplies the second power to the second drive amplifier.
The actuator control device according to claim 1 or 2, wherein the control unit separately controls the first power supply unit and the second power supply unit. The control unit acquires a signal whose signal strength is greater than a predetermined value among the signals acquired from the optical detection unit as the detection signal, and the power supply unit supplies the drive amplifier based on the acquired detection signal. The actuator control device according to any one of claims 1 to 3, wherein the voltage is controlled. Claims 1 to 1, wherein the control unit fixes the voltage supplied by the power supply unit to the drive amplifier when the number of times the detection signal of the light detection unit is acquired exceeds a predetermined value. 4. The actuator control device according to any one of 4. Wherein the control unit, the time for acquiring the detection signal from the light detection unit measures, when acquiring at least two detection signals from the light detecting section, the time difference between the time obtained the two detection signals The actuator control device according to any one of claims 1 to 5, wherein the voltage supplied by the power supply unit to the drive amplifier is fixed when the value is equal to or higher than a predetermined value. Wherein, when said driving amplifier and the power supply unit applying a maximum voltage that can be applied to the drive unit, when the time difference does not exceed a predetermined value, the fault as the actuator is faulty The actuator control device according to claim 6, wherein a signal is output. The actuator control device according to any one of claims 1 to 7.
With the actuator
And the light-detecting section,
A drive system characterized by being equipped with. A video device including the drive system according to claim 8. The drive system according to claim 8 and
A mirror attached to the drive unit of the actuator and rotatable in two axial directions,
A light source that outputs laser light and
An optical system that causes the laser beam to enter the mirror,
A control unit that controls the drive system to drive the mirror,
An image projection device comprising. The actuator includes a support portion that supports the mirror.
The support portion includes a plurality of beams that are continuous in a meandering manner and a plurality of piezoelectric members that are individually provided on the plurality of beams.
10. The drive system according to claim 10, wherein two voltages having dissimilar waveforms are individually applied in parallel to two piezoelectric members individually provided on two adjacent beams. Image projection device. It is an actuator control method that controls an actuator having a drive unit that moves a reflection unit based on a signal acquired from a light detection unit.
The waveform generator generates a voltage waveform for driving the drive unit,
The drive amplifier amplifies the voltage waveform generated by the waveform generator,
The power supply unit supplies power to the drive amplifier,
An actuator control method characterized in that a control unit acquires a detection signal from the light detection unit and controls a voltage supplied by the power supply unit to the drive amplifier based on the acquired detection signal. A mobile body comprising the image projection device according to claim 10 or 11.

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