JP2020101590A - Optical deflector, image projection device, and movable body - Google Patents

Abstract

To easily remove or reduce a fluctuation in the deflection angle of a reflection unit.SOLUTION: An optical deflector according to an aspect of the disclosed technology comprises a reflection unit that has a reflection surface and a movable unit that supports the reflection unit, and the movable unit has two means to be driven and deflects light incident on the reflection surface. The optical deflector includes: driving means that drives the two means to be driven; driving signal generation means that generates two driving signals for driving the two means to be driven; high frequency component extraction means that extracts two high frequency components of detection signals for the deflection angle of the movable unit corresponding to the respective two driving signals; and phase adjustment means that adjusts at least one phase of the two driving signals so that the phases of the two high frequency components become opposite phases to each other.SELECTED DRAWING: Figure 28

Description

The present invention relates to a light deflection device, an image projection device, and a moving body.

2. Description of the Related Art There is known an optical deflecting device that drives a movable portion including a reflecting portion such as a MEMS (Micro Electro Mechanical Systems) mirror in horizontal and vertical directions to deflect (scan) light incident on the reflecting portion. There is also known an image projection device that projects an image on a projection surface by using scanning light from such a light deflection device.

In the conventional optical deflecting device, fluctuations may occur in the deflection angle of the reflecting portion during rotation due to elastic vibration or the like of the supporting portion that drivably supports the movable portion.

On the other hand, a device for removing or reducing the fluctuation of the deflection angle of the reflecting section by adjusting the amplitude and phase of the drive signal for driving the movable section according to the detected value of the deflection angle of the moving section during driving. Is disclosed (for example, see Patent Document 1).

However, in the technique of Patent Document 1, since both the amplitude and the phase of the drive signal of the movable portion are adjusted so that the fluctuation is reduced, the adjustment process may be complicated.

The present invention has been made in view of the above points, and it is an object of the present invention to easily reduce fluctuations in the deflection angle of a reflecting portion.

An optical deflecting device according to an aspect of the disclosed technique includes a reflecting portion having a reflecting surface and a movable portion supporting the reflecting portion, and the movable portion has two driven means, and the reflecting surface. An optical deflecting device for deflecting the light incident on the light source, the drive means driving the two driven means, and the drive signal generating means generating two drive signals for driving the two driven means. A high-frequency component extracting unit that extracts two high-frequency components of the deflection angle detection signal of the movable portion corresponding to each of the two drive signals, and the two high-frequency components have opposite phases to each other. Phase adjusting means for adjusting the phase of at least one of the two drive signals.

According to the disclosed technology, it is possible to easily remove or reduce the fluctuation of the deflection angle of the reflecting portion.

1 is a schematic diagram of an example of an optical scanning system. It is a hardware block diagram of an example of an optical scanning system. It is a functional block diagram of an example of a control device. It is a flow chart of an example of processing concerning an optical scanning system. It is a schematic diagram of an example of a car carrying a head-up display device. It is a schematic diagram of an example of a head-up display device. FIG. 3 is a schematic view of an example of an image forming apparatus equipped with an optical writing device. It is a schematic diagram of an example of an optical writer. It is a schematic diagram of an example of a car carrying a lidar device. It is a schematic diagram of an example of a lidar device. It is a schematic diagram explaining an example of composition of a laser headlamp. It is a schematic perspective view which shows an example of a structure of a head mounted display. It is a figure which shows an example of a part of structure of a head mounted display. It is the schematic which shows an example of the packaged movable device. It is a top view when an example of a movable device is seen from the +Z direction. FIG. 16 is a sectional view of the movable device shown in FIG. 15 taken along the line P-P′. FIG. 16 is a QQ′ cross-sectional view of the movable device illustrated in FIG. 15. It is a schematic diagram which represented typically the deformation|transformation of the drive beam of a movable device. (A) is an example of the waveform of the drive voltage A applied to the piezoelectric drive part group A of a movable device. (B) is an example of a waveform of the drive voltage B applied to the piezoelectric drive unit group B of the movable device. (C) is a diagram in which the waveform of the drive voltage in (a) and the waveform of the drive voltage in (b) are superimposed. It is a figure explaining the relationship between the time change of a shake angle and a projection image in case the time change of a shake angle is linear, (a) is a figure explaining the time change of a shake angle, and (b) is a figure. It is a figure explaining the projection image by the scanning light of a). It is a figure explaining the time change of a shake angle when there is fluctuation in the change of a shake angle with time, and a figure explaining a time change of a shake angle, and (b) is a figure explaining (b). It is a figure explaining the projection image by the scanning light of a). It is a top view when an example of the movable device concerning a 1st embodiment is seen from the +Z direction. FIG. 23 is a cross-sectional view taken along the line RR′ of the movable device illustrated in FIG. 22. It is a hardware block diagram of an example of the optical deflection apparatus which concerns on 1st Embodiment. FIG. 6 is a diagram illustrating an example of changes over time of the drive voltages A and B and the deflection angle, (a) is a diagram illustrating the drive voltages A and B, and (b) is a diagram of the deflection angle time due to the drive voltages A and B. It is a figure explaining a change. It is a figure explaining the time change of the deflection angle when drive voltage A and B are applied independently respectively, (a) is a figure explaining drive voltage A, (b) is a deflection angle by drive voltage A. It is a figure explaining a time change, and (c) is a figure explaining a high frequency ingredient extracted from a time change of a shake angle of (b). (D) is a diagram for explaining the drive voltage B, (e) is a diagram for explaining the change over time of the deflection angle due to the drive voltage B, and (f) is extracted from the change over time of the deflection angle in (e). It is a figure explaining the high frequency component. 6A and 6B are diagrams illustrating an example of a method of adjusting the slope of the drive voltage B according to the first embodiment, FIG. 7A is a diagram illustrating the slope of the drive voltage B, and FIG. It is a figure explaining the high frequency component of the time change of. It is a figure explaining an example of the adjustment method of the phase of drive voltage A and B concerning a 1st embodiment, (a) is a figure explaining the phase of drive voltage A and B, (b) is a drive voltage. FIG. 6 is a diagram illustrating a high frequency component of a change in shake angle with time due to A, (c) is a diagram illustrating a high frequency component of a change with time of shake angle due to a drive voltage B, and (d) is a diagram illustrating an adjusted drive voltage A. FIG. 6 is a diagram for explaining a change over time of the deflection angle due to B and B. It is a functional block diagram of an example of a control device according to the first embodiment. 6 is a flowchart showing an example of an operation of tilt and phase adjustment by the optical deflecting device according to the first embodiment. 6 is a flowchart showing an example of an optical scanning operation by the optical deflecting device according to the first embodiment. It is a functional block diagram of an example of a control device concerning a 2nd embodiment. It is a figure explaining an example of the extraction method of the period corresponding to 1 cycle of the high frequency component concerning a 2nd embodiment.

Hereinafter, embodiments of the present invention will be described in detail.

[Optical scanning system]
First, an optical scanning system to which the movable device according to the embodiment is applied will be described in detail with reference to FIGS.

FIG. 1 shows a schematic diagram of an example of the optical scanning system. As shown in FIG. 1, the optical scanning system 10 is a system that optically scans a surface 15 to be scanned by deflecting the light emitted from the light source device 12 under the control of the control device 11 by the reflecting surface 14 of the movable device 13. is there.

The optical scanning system 10 includes a control device 11, a light source device 12, and a movable device 13 having a reflecting 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 having a reflective surface 14 and capable of moving the reflective surface 14. The light source device 12 is, for example, a laser device that emits a laser. The scanned surface 15 is, for example, a screen.

The control device 11 generates a control command for the light source device 12 and the movable device 13 based on the acquired optical scanning information, and outputs a drive signal to the light source device 12 and the movable device 13 based on the control command.

The light source device 12 irradiates the light source based on the input drive signal. The movable device 13 moves the reflecting surface 14 in at least one of the uniaxial direction and the biaxial direction based on the input drive signal.

As a result, for example, by the control of the control device 11 based on the image information which is an example of the optical scanning information, the reflecting surface 14 of the movable device 13 is reciprocally moved in the biaxial direction within a predetermined range and is incident on the reflecting surface 14. By deflecting the irradiation light from the light source device 12 around a certain axis and scanning the light, an arbitrary image can be projected on the surface 15 to be scanned. The details of the movable device of the embodiment and the control by the control device will be described later.

Next, a hardware configuration of an example of the optical scanning system 10 will be described with reference to FIG. FIG. 2 is a hardware configuration diagram of an example of the optical scanning system 10. As shown in FIG. 2, the optical scanning system 10 includes a control device 11, a light source device 12, and a movable device 13, which are electrically connected to each other. Of these, 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 programs and data from a storage device such as the ROM 22 onto the RAM 21 and executes processing to realize the overall control and functions of the control device 11.

The RAM 21 is a volatile storage device that temporarily holds programs and data.

The ROM 22 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 that the CPU 20 executes to control each function of the optical scanning system 10. There is.

The FPGA 23 is a circuit that outputs a control signal 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. The external device includes, for example, a host 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 a car, a LAN (Local Area Network), the Internet, or the like. The external I/F 24 may have a configuration that enables connection or communication with an external device, and the external I/F 24 may be prepared for each external device.

The light source device triber is an electric circuit that outputs a drive signal such as a drive voltage to the light source device 12 according to the input control signal.

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

In the control device 11, the CPU 20 acquires optical scanning information from an external device or a network via the external I/F 24. It should be noted that the CPU 20 may be configured to acquire the optical scanning information, and the optical scanning information may be stored in the ROM 22 or the FPGA 23 in the control device 11, or the control device 11 may be newly provided with an SSD or the like. A storage device may be provided and the optical scanning information may be stored in the storage device.

Here, the optical scanning information is information indicating how the surface to be scanned 15 is optically scanned. For example, when an image is displayed 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 the writing location. In addition, for example, when the distance measurement is performed by optical scanning, the optical scanning information is irradiation data indicating the timing and the irradiation range of the distance measuring light.

The control device 11 can realize the functional configuration described below by the instruction of the CPU 20 and the hardware configuration shown in FIG.

Next, the functional configuration of the control device 11 of the optical scanning system 10 will be described with reference to FIG. FIG. 3 is a functional block diagram of an example of a control device of the optical scanning system.

As shown in FIG. 3, the control device 11 has a control unit 30 and a drive signal output unit 31 as functions.

The control unit 30 is realized by, for example, the CPU 20, the FPGA 23, and the like, 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. For example, the control unit 30 acquires image data as optical scanning information from an external device or the like, generates a control signal from the image data by a predetermined process, 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, and the like, 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. Further, for example, in the movable device 13, it is a drive voltage for controlling the timing and the movable range in which the reflecting surface 14 of the movable device 13 is moved.

Next, a process in which the optical scanning system 10 optically scans the surface 15 to be scanned will be described with reference to FIG. FIG. 4 is a flowchart of an example of processing related to the optical scanning system.

In step S11, the control unit 30 acquires optical scanning information from an external device or the like.

In step S12, the control unit 30 generates a control signal from the acquired optical scanning information and outputs the control signal to the drive signal output unit 31.

In step S13, the drive signal output unit 31 outputs a drive signal to the light source device 12 and the movable device 13 based on the input control signal.

In step 14, the light source device 12 irradiates light based on the input drive signal. The movable device 13 also moves the reflecting 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.

In the optical scanning system 10, one control device 11 has a device and a function for controlling the light source device 12 and the movable device 13. However, a control device for the light source device and a control device for the movable device, It may be provided separately.

Further, in the above optical scanning system 10, one control device 11 is provided with the functions of the control unit 30 of the light source device 12 and the movable device 13 and the function of the drive signal output unit 31, but these functions exist separately. Alternatively, the drive signal output device having the drive signal output unit 31 may be provided separately from the control device 11 having the control unit 30, for example. In the above optical scanning system 10, the movable device 13 having the reflecting surface 14 and the control device 11 may constitute an optical deflection system for performing optical deflection.

[Image projection device]
Next, an image projection device to which the movable device according to the embodiment is applied will be described in detail with reference to FIGS. 5 and 6.

FIG. 5 is a schematic diagram according to an embodiment of an automobile 400 equipped with a head-up display device 500, which is an example of an image projection device. Further, FIG. 6 is a schematic view of an example of the head-up display device 500.

The image projection device is a device that projects an image by optical scanning, and is, for example, a head-up display device.

As shown in FIG. 5, the head-up display device 500 is installed, for example, near the windshield (the windshield 401 or the like) of the automobile 400. The projection light L emitted from the head-up display device 500 is reflected by the windshield 401 and travels to the observer (driver 402) who is the user. Accordingly, the driver 402 can visually recognize the image projected by the head-up display device 500 as a virtual image. A combiner may be installed on the inner wall surface of the windshield to allow the user to visually recognize the virtual image by the projection light reflected by the combiner.

As shown in FIG. 6, the head-up display device 500 emits laser light from red, green, and blue laser light sources 501R, 501G, and 501B. The emitted laser light passes through an incident optical system including collimator lenses 502, 503, 504 provided for each laser light source, two dichroic mirrors 505, 506, and a light amount adjusting unit 507, and It is deflected by the movable device 13 having the reflecting surface 14. Then, the deflected laser light is projected on the screen through a projection optical system including a free-form surface mirror 509, an intermediate screen 510, and a projection mirror 511. In the head-up display device 500, the laser light sources 501R, 501G, 501B, the collimator lenses 502, 503, 504, and the dichroic mirrors 505, 506 are unitized by the optical housing as the 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 to cause the driver 402 to visually recognize the intermediate image as a virtual image. Here, the windshield 401 is an example of a “light transmitting member”.

The laser lights of the respective colors emitted from the laser light sources 501R, 501G, and 501B are made into substantially parallel lights by the collimator lenses 502, 503, and 504, respectively, and are combined by the two dichroic mirrors 505 and 506. The combined laser light is two-dimensionally scanned by the movable device 13 having the reflecting surface 14, after the light amount is adjusted by the light amount adjusting unit 507. The projection light L two-dimensionally scanned by the movable device 13 is reflected by the free-form surface mirror 509 to correct the distortion, and then is condensed 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 projection light L incident on the intermediate screen 510 in units of microlenses.

The movable device 13 reciprocally moves the reflecting surface 14 in two axial directions, and two-dimensionally scans the projection light L incident on the reflecting surface 14. 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.

The head-up display device 500 as an example of the image projection device has been described above, but the image projection device may be any device that projects an image by performing optical scanning with the movable device 13 having the reflecting surface 14. .. For example, a projector placed on a desk or the like, which projects an image on a display screen, or a mounting member mounted on an observer's head or the like, is projected on a reflection/transmission screen of the mounting member, or an eyeball is used as a screen. The present invention can be similarly applied to a head mounted display device that projects an image.

Further, the image projection device is not limited to the vehicle and the mounting member, and is, for example, a moving body such as an aircraft, a ship, or a mobile robot, or a work robot that operates a driving target such as a manipulator without moving from the place. It may be mounted on a non-moving body.

[Optical writing device]
Next, an optical writing device to which the movable device 13 of the embodiment is applied will be described in detail with reference to FIGS. 7 and 8.

FIG. 7 is an example of an image forming apparatus incorporating the optical writing device 600. FIG. 8 is a schematic diagram of an example of the optical writing device.

As shown in FIG. 7, the optical writing device 600 is used as a constituent member of an image forming apparatus represented by a laser printer 650 or the like having a printer function using laser light. In the image forming apparatus, the optical writing device 600 performs optical writing on the photosensitive drum by optically scanning the photosensitive drum, which is the surface to be scanned 15, with one or a plurality of laser beams.

As shown in FIG. 8, in the optical writing device 600, the laser light from the light source device 12 such as a laser element passes through an image forming optical system 601 such as a collimator lens, and then is moved by a movable device 13 having a reflecting surface 14 to one. It is deflected axially or biaxially. Then, the laser light deflected by the movable device 13 then passes through a scanning optical system 602 including a first lens 602a, a second lens 602b, and a reflection mirror section 602c, and then a surface to be scanned 15 (for example, a photosensitive drum or a photosensitive paper). ) To perform optical writing. The scanning optical system 602 forms a light beam in a spot shape on the surface 15 to be scanned. The movable device 13 having the light source device 12 and the reflecting surface 14 is driven under the control of the control device 11.

As described above, the optical writing device 600 can be used as a constituent member of an image forming apparatus having a printer function using laser light. Further, by making the scanning optical system different so that the optical scanning can be performed not only in the one-axis direction but also in the two-axis direction, the laser beam is deflected to the thermal medium, optically scanned, and heated to print a laser label device. Can be used as a constituent member of the image forming apparatus.

The movable device 13 having the reflecting surface 14 applied to the above-mentioned optical writing device consumes less power for driving than a rotary polygon mirror using a polygon mirror or the like. It is advantageous. Further, since the wind noise when the movable device 13 vibrates is smaller than that of the rotary polygon mirror, it is advantageous for improving the quietness of the optical writing device. The optical writing device requires a much smaller installation space than the rotary polygon mirror, and the amount of heat generated by the movable device 13 is small, so that the optical writing device can be easily downsized, which is advantageous for downsizing the image forming apparatus. is there.

[Distance measuring device]
Next, a distance measuring device to which the movable device of the above embodiment is applied will be described in detail with reference to FIGS. 9 and 10.

FIG. 9 is a schematic diagram of an automobile equipped with a LiDAR (Laser Imaging Detection and Ranging) device which is an example of a distance measuring device. Further, FIG. 10 is a schematic diagram of an example of a lidar device.

The distance measuring device is a device that measures the distance in the target direction, and is, for example, a lidar device.

As shown in FIG. 9, the lidar device 700 is mounted on, for example, an automobile 701, optically scans in a target direction, and receives reflected light from a target object 702 existing in the target direction, whereby the target object 702 is detected. To measure the distance.

As shown in FIG. 10, the laser light emitted from the light source device 12 is reflected by an incident optical system including a collimator lens 703, which is an optical system that makes divergent light into substantially parallel light, and a plane mirror 704. The movable device 13 having the surface 14 scans in a uniaxial or biaxial direction. Then, the object 702 in front of the apparatus is irradiated with light through a light projecting lens 705 which is a light projecting optical system. The drive of the light source device 12 and the movable device 13 is controlled by the control device 11. The reflected light reflected by the object 702 is detected by the photodetector 709. That is, the reflected light is received by the image sensor 707 through the condenser lens 706, which is an incident light detection and light receiving optical system, and the image sensor 707 outputs a detection signal to the signal processing circuit 708. The signal processing circuit 708 performs predetermined processing such as binarization and noise processing on the input detection signal, and outputs the result to the distance measuring circuit 710.

The distance measuring circuit 710 uses the time difference between the timing at which the light source device 12 emits the laser light and the timing at which the photodetector 709 receives the laser light, or the phase difference for each pixel of the image pickup element 707 that receives the object. The presence or absence of 702 is recognized, and the distance information to the object 702 is calculated.

Since the movable device 13 having the reflecting surface 14 is less likely to be damaged than the polygon mirror and is small in size, it is possible to provide a small radar device having high durability. Such a lidar device is attached to, for example, a vehicle, an aircraft, a ship, a robot, or the like, and can optically scan a predetermined range to measure the presence or absence of an obstacle and the distance to the obstacle. The mounting position of the rider device 700 is not limited to the front of the upper part of the automobile 701 and may be mounted on the side or the rear.

In the above distance measuring device, the lidar device 700 as an example has been described. However, the distance measuring device performs optical scanning by controlling the movable device 13 having the reflecting surface 14 by the control device 11, and uses the photodetector. The device is not limited to the above-described embodiment as long as it is a device that measures the distance of the object 702 by receiving the reflected light.

For example, the object information such as the shape is calculated from the distance information obtained by optically scanning the hand or face, and the object is recognized by referring to the record, and the invading object is recognized by the optical scanning to the object range. Similarly, it can be applied to a security sensor, a constituent member of a three-dimensional scanner that calculates and recognizes object information such as a shape from distance information obtained by optical scanning, and outputs it as three-dimensional data.

[Laser headlamp]
Next, a laser headlamp 50 in which the movable device of the above embodiment is applied to a headlight of an automobile will be described with reference to FIG. FIG. 11 is a schematic diagram illustrating an example of the configuration of the laser headlamp 50.

The laser headlamp 50 includes a control device 11, a light source device 12b, a movable device 13 having a reflecting surface 14, 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 reflecting surface 14. The movable device 13 moves the reflection surface in the XY directions based on the signal from the control device 11, and two-dimensionally scans the blue laser light from the light source device 12b in the XY directions.

The scanning light from the movable device 13 is reflected by the mirror 51 and enters the transparent plate 52. The transparent plate 52 has a front surface or a back surface covered with a yellow phosphor. When the blue laser light from the mirror 51 passes through the coating of the yellow phosphor on the transparent plate 52, it changes to white within the range legally stipulated as the color of the headlight. 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 a predetermined amount when passing through the phosphor of the transparent plate 52. As a result, glare on the illumination target in front of the vehicle is reduced.

When the movable device 13 is applied to an automobile headlight, the colors of the light source device 12b and the phosphor are not limited to blue and yellow, respectively. For example, the light source device 12b may be near-ultraviolet light, and the transparent plate 52 may be covered with a mixture of the phosphors of the three primary colors of light, that is, blue, green, and red. Even in this case, the light passing through the transparent plate 52 can be converted to white, and the front of the vehicle can be illuminated with white light.

[Head mounted display]
Next, a head mounted display 60 to which the movable device according to the above embodiment is applied will be described with reference to FIGS. Here, the head-mounted display 60 is a head-mounted display that can be mounted on a human head, and may have a shape similar to glasses, for example. The head mounted display is abbreviated as HMD hereinafter.

FIG. 12 is a perspective view illustrating the appearance of the HMD 60. In FIG. 12, the HMD 60 is composed of a front 60a and a temple 60b which are provided substantially symmetrically one by one on the left and right. The front 60a can be configured by, for example, the light guide plate 61, and the optical system, the control device, and the like can be built in the temple 60b.

FIG. 13 is a diagram partially illustrating the configuration of the HMD 60. Note that FIG. 13 illustrates the configuration for the left eye, but the HMD 60 has the same configuration for the right eye.

The HMD 60 includes a control device 11, a light source unit 530, a light amount adjustment unit 507, a movable device 13 having a reflection surface 14, a light guide plate 61, and a half mirror 62.

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

The light from the light source unit 530 is incident on the movable device 13 after the light amount is adjusted by the light amount adjusting unit 507. The movable device 13 moves the reflecting surface 14 in the XY directions based on the signal from the control device 11, and two-dimensionally scans 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 the scanning light.

The scanning light from the movable device 13 enters the light guide plate 61. The light guide plate 61 guides the scanning light to the half mirror 62 while reflecting the scanning light on the inner wall surface. The light guide plate 61 is formed of a 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 to the back side of the HMD 60 and emits the light toward the eye of the wearer 63 of the HMD 60. The half mirror 62 has, for example, a free-form surface shape. An image formed by the scanning light is focused on the retina of the wearer 63 by being reflected by the half mirror 62. Alternatively, an image is formed on the retina of the wearer 63 due to the reflection at the half mirror 62 and the lens effect of the crystalline lens in the eyeball. In addition, the spatial distortion of the image is corrected by the reflection on the half mirror 62. The wearer 63 can observe the image formed by the light scanned in the XY directions.

Since 62 is a half mirror, the wearer 63 observes the image formed by the light from the outside and the image formed by the scanning light in a superimposed manner. By providing a mirror instead of the half mirror 62, it is possible to eliminate the light from the outside and to observe only the image by the scanning light.

[Packaging]
Next, packaging of the movable device according to the embodiment will be described with reference to FIG.

FIG. 14 is a schematic diagram of an example of a packaged movable device.

As shown in FIG. 14, the movable device 13 is mounted on a mounting member 802 arranged inside the package member 801, and a part of the package member 801 is covered with a transparent member 803 to be hermetically sealed. To be done. Further, the package is sealed with an inert gas such as nitrogen. As a result, deterioration of the movable device 13 due to oxidation is suppressed, and the durability against changes in the environment such as temperature is further improved.

15 to 19 for details of the movable device used for the optical deflection system, the optical scanning system, the image projection device, the optical writing device, and the distance measuring device described above and the control by the control device of the present embodiment. Will be explained.

[Details of mobile device]
First, the movable device will be described in detail with reference to FIGS.

FIG. 15 is a plan view of a movable device of a cantilever support type capable of deflecting light in two axial directions. 16 is a cross-sectional view taken along the line P-P' of FIG. FIG. 17 is a sectional view taken along line QQ' of FIG. However, although a cantilever support type will be described here, a double-end support type may be used.

As shown in FIG. 15, the movable device 13 includes a reflector 101 that reflects incident light, and a first driver 110a that is connected to the reflector and drives the reflector around a first axis parallel to the Y axis. 110b, a first support 120 for supporting the reflector and the first driver, and a second support connected to the first support for driving the reflector and the first support around a second axis parallel to the X axis. The driving units 130a and 130b, the second supporting unit 140 that supports the second driving unit, and the electrode connecting unit 150 that is electrically connected to the first driving unit, the second driving unit, and the control device are included.

The movable device 13 is, for example, one SOI (Silicon On Insulator) substrate formed by etching or the like, and the reflecting surface 14, the first piezoelectric drive units 112a and 112b, and the second piezoelectric drive units 131a to 131a to the formed substrate. By forming 131f, 132a to 132f, the electrode connecting portion 150, and the like, each component is integrally formed. Note that the above-described components may be formed after the SOI substrate is molded or may be formed during the molding of the SOI substrate.

In the SOI substrate, a silicon oxide layer 162 is provided on a first silicon layer made of single crystal silicon (Si), and a second silicon layer made of single crystal silicon is further provided on the silicon oxide layer. It is a substrate. Hereinafter, the first silicon layer will be referred to as a silicon support layer 161, and the second silicon layer will be referred to as a silicon active layer 163.

Since the silicon active layer 163 has a small thickness in the Z-axis direction with respect to the X-axis direction or the Y-axis direction, the member formed of only the silicon active layer 163 has a function as an elastic portion having elasticity.

Note that the SOI substrate does not necessarily have to be planar and may have a curvature or the like. The member used for forming the movable device 13 is not limited to the SOI substrate as long as it is a substrate that can be integrally formed by etching or the like and can have elasticity partially.

The reflecting portion 101 includes, for example, a circular reflecting portion base 102 and a reflecting surface 14 formed on the +Z side surface of the reflecting base. The reflector base 102 is composed of, for example, a silicon active layer 163. The reflecting surface 14 is made of, for example, a metal thin film containing aluminum, gold, silver, or the like. Further, in the reflecting portion 101, a rib for reinforcing the reflecting portion may be formed on the −Z side surface of the reflecting portion base 102. The rib is composed of, for example, a silicon support layer 161 and a silicon oxide layer 162, and can suppress the distortion of the reflecting surface 14 caused by the movement.

The first driving units 110a and 110b have two ends connected to the reflection unit base 102 and two torsion bars 111a and 111b that extend in the first axis direction and movably support the reflection unit 101, and one ends serve as torsion bars. The first piezoelectric drive units 112a and 112b are connected to each other and the other end is connected to the inner peripheral portion of the first support unit.

As shown in FIG. 16, the torsion bars 111 a and 111 b are composed of a silicon active layer 163. The first piezoelectric driving units 112a and 112b are formed by sequentially forming the lower electrode 201, the piezoelectric unit 202, and the upper electrode 203 on the +Z side surface of the silicon active layer 163 that is the elastic unit. 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.

Returning to FIG. 15, the first support part 120 is a rectangular support formed of, for example, a silicon support layer 161, a silicon oxide layer 162, and a silicon active layer 163 and formed so as to surround the reflection part 101.

The second driving units 130a and 130b are composed of, for example, a plurality of second piezoelectric driving units 131a to 131f and 132a to 132f connected so as to be folded back, and one end of the second driving units 130a and 130b is the first support. It is connected to the outer peripheral portion of the portion 120, and the other end is connected to the inner peripheral portion of the second support portion 140. At this time, the connection part between the second drive part 130a and the first support part 120, the connection part between the second drive part 130b and the first support part 120, the connection part between the second drive part 130a and the second support part 140, and the first connection part The connection portion between the second driving unit 130b and the second supporting unit 140 is point-symmetric with respect to the center of the reflecting surface 14.

As shown in FIG. 17, the second driving units 130a and 130b are formed by sequentially forming the lower electrode 201, the piezoelectric unit 202, and the upper electrode 203 on the +Z side surface of the silicon active layer 163 that is the elastic unit. It 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.

Returning to FIG. 15, the second support part 140 is composed of, for example, a silicon support layer 161, a silicon oxide layer 162, and a silicon active layer 163, and the reflection part 101, the first driving parts 110 a and 110 b, the first support part 120, and It is a rectangular support body formed so as to surround the second drive units 130a and 130b.

The electrode connecting portion 150 is formed, for example, on the +Z side surface of the second supporting portion 140, and each upper electrode 203 and each lower electrode 201 of the first piezoelectric driving portions 112a and 112b and the second piezoelectric driving portions 131a to 131f. , And the control device 11 are electrically connected via electrode wiring such as aluminum (Al). The upper electrode 203 or the lower electrode 201 may be directly connected to the electrode connecting portion, or may be indirectly connected by connecting the electrodes to each other.

Note that, in the present embodiment, the case where the piezoelectric portion 202 is formed only on one surface (the surface on the +Z side) of the silicon active layer 163 that is the elastic portion has been described as an example, but the other surface of the elastic portion (for example, -Z). It may be provided on one surface and the other surface of the elastic portion.

Further, the shape of each component is not limited to the shape of the embodiment as long as the reflecting section can be driven around the first axis or the second axis. For example, the torsion bars 111a and 111b and the first piezoelectric drive units 112a and 112b may have a shape having a curvature.

Further, on the +Z side surface of the upper electrode 203 of the first driving units 110a and 110b, on the +Z side surface of the first supporting unit, on the +Z side surface of the upper electrode 203 of the second driving units 130a and 130b, 2 An insulating layer made of a silicon oxide film may be formed on at least one of the +Z side surfaces of the support portions. At this time, the electrode wiring is provided on the insulating layer, and only the connection spot where the upper electrode 203 or the lower electrode 201 and the electrode wiring are connected is partially removed as the opening or the insulating layer is not formed. As a result, the degree of freedom in designing the first drive units 110a and 110b, the second drive units 130a and 130b, and the electrode wiring can be increased, and a short circuit due to contact between electrodes can be suppressed. The silicon oxide film also has a function as an antireflection material.

[Details of control of control device]
Next, details of the control of the control device that drives the first drive unit and the second drive unit of the movable device will be described.

When a positive or negative voltage is applied in the polarization direction, the piezoelectric unit 202 included in the first driving units 110a and 110b and the second driving units 130a and 130b is deformed (for example, expands and contracts) in proportion to the potential of the applied voltage. The so-called reverse piezoelectric effect is exhibited. The first driving units 110a and 110b and the second driving units 130a and 130b move the reflecting unit 101 by using the above-described inverse piezoelectric effect.

At this time, an angle formed by the reflecting surface 14 and the XY plane when the reflecting surface 14 of the reflecting portion 101 is tilted in the +Z direction or the −Z direction with respect to the XY plane is called a deflection angle. At this time, the +Z direction is a positive deflection angle and the −Z direction is a negative deflection angle.

First, the control of the control device that drives the first drive unit will be described.

In the first driving units 110a and 110b, when a driving voltage is applied in parallel to the piezoelectric units 202 included in the first piezoelectric driving units 112a and 112b via the upper electrode 203 and the lower electrode 201, the respective piezoelectric units 202 are changed. Deform. Due to the action of the deformation of the piezoelectric portion 202, the first piezoelectric drive portions 112a and 112b are bent and deformed. As a result, the driving force around the first axis acts on the reflecting portion 101 via the twist of the two torsion bars 111a and 111b, and the reflecting portion 101 moves around the first axis. The drive voltage applied to the first drive units 110a and 110b is controlled by the control device 11.

Therefore, by applying a drive voltage having a predetermined sine waveform in parallel to the first piezoelectric drive units 112a and 112b included in the first drive units 110a and 110b by the control device 11, the reflection unit 101 is moved around the first axis. In addition, it can be moved in a cycle of a drive voltage having a predetermined sine waveform.

In particular, for example, when the frequency of the sine waveform voltage is set to about 20 kHz which is about the same as the resonance frequency of the torsion bars 111a and 111b, the mechanical resonance due to the torsion of the torsion bars 111a and 111b occurs, The reflector 101 can be resonantly oscillated at about 20 kHz.

Next, control of the control device that drives the second drive unit will be described with reference to FIGS. 18 to 19.

FIG. 18 is a schematic diagram schematically showing driving of the second driving unit 130b of the movable device. What is indicated by a dotted line is the reflecting portion 101 and the like. The right direction toward the paper surface is the +X direction, the upward direction toward the paper surface is the +Y direction, and the front side is the +Z direction.

As shown in FIG. 18A, when the drive voltage is not applied to the second drive unit 130b, the deflection angle of the second drive unit is zero.

Of the plurality of second piezoelectric drive units 131a to 131f included in the second drive unit 130a, an even-numbered second piezoelectric drive unit (131a) counted from the second piezoelectric drive unit (131a) closest to the reflection unit, that is, the second piezoelectric drive unit 131a to 131f. The piezoelectric drive units 131b, 131d, 131f are referred to as a piezoelectric drive unit group A. Further, among the plurality of second piezoelectric drive units 132a to 132f included in the second drive unit 130b, an odd-numbered second piezoelectric drive unit counting from the second piezoelectric drive unit (132a) closest to the reflection unit, That is, the second piezoelectric drive units 132a, 132c, 132e are similarly set as the piezoelectric drive unit group A. When the drive voltage is applied in parallel to the piezoelectric drive unit group A, the piezoelectric drive unit group A is bent and deformed in the same direction and the reflection unit 101 is moved in the −Z direction to the second direction as shown in FIG. 18B. Move around the axis.

In addition, of the plurality of second piezoelectric drive units 131a to 131f included in the second drive unit 130a, the second piezoelectric drive unit that is an odd number counted from the second piezoelectric drive unit (131a) closest to the reflection unit, that is, The second piezoelectric drive units 131a, 131c, 131e are referred to as a piezoelectric drive unit group B. Further, among the plurality of second piezoelectric driving units 132a to 132f included in the second driving unit 130b, an even-numbered second piezoelectric driving unit counting from the second piezoelectric driving unit (132a) closest to the reflecting unit, That is, 132b, 132d, and 132f are similarly set as the piezoelectric drive unit group B. When the driving voltage is applied in parallel, the piezoelectric driving unit group B is bent and deformed in the same direction as shown in FIG. 18D, and the reflecting unit 101 is moved in the +Z direction by the second axis. Move around.

As shown in FIGS. 18B and 18D, in the second drive unit 130a or 130b, the plurality of piezoelectric units 202 included in the piezoelectric drive unit group A or the plurality of piezoelectric units 202 included in the piezoelectric drive unit group B are simultaneously formed. By bending and deforming, the movable amount due to bending and deformation can be accumulated, and the deflection angle of the reflecting portion 101 around the second axis can be increased. For example, as shown in FIG. 15, the second driving units 130a and 130b are connected to the first supporting unit in point symmetry with respect to the center point of the first supporting unit. Therefore, when a drive voltage is applied to the piezoelectric drive unit group A, a drive force for moving in the +Z direction is generated in the connection portion between the first support unit and the second drive unit 130a in the second drive unit 130a, and in the second drive unit 130b, the drive force is generated. A driving force for moving in the −Z direction is generated at the connecting portion between the first supporting portion and the second driving portion 130b, the movable amount is accumulated, and the deflection angle of the reflecting portion 101 around the second axis can be increased.

Further, as shown in FIG. 18C, when the moving amount of the reflecting portion 101 by the piezoelectric driving unit group A by voltage application and the moving amount of the reflecting unit 101 by the piezoelectric driving unit group B by voltage application are balanced, The deflection angle becomes zero.

By applying a drive voltage to the second piezoelectric drive unit so as to continuously repeat FIGS. 18B to 18D, the reflection unit can be driven around the second axis.

The drive voltage applied to the second drive unit is controlled by the control device.

The drive voltage applied to the piezoelectric drive unit group A (hereinafter, drive voltage A) and the drive voltage applied to the piezoelectric drive unit group B (hereinafter, drive voltage B) will be described with reference to FIG.

FIG. 19A is an example of a waveform of the drive voltage A applied to the piezoelectric drive unit group A of the movable device. FIG. 19B is an example of a waveform of the drive voltage B applied to the piezoelectric drive unit group B of the movable device. FIG. 19C is a diagram in which the waveform of the drive voltage A and the waveform of the drive voltage B are superimposed.

As shown in FIG. 19A, the drive voltage A applied to the piezoelectric drive unit group A is, for example, a drive voltage having a sawtooth waveform, and the frequency is, for example, 60 HZ. Further, the waveform of the drive voltage A is TrA, which is the time width of the rising period in which the voltage value increases from the minimum value to the next maximum value, and the falling period in which the voltage value decreases from the maximum value to the next minimum value. When the time width of TfA is TfA, for example, a ratio of TrA:TfA=9:1 is set in advance. At this time, the ratio of TrA to one cycle is called symmetry of the drive voltage A.

As shown in FIG. 19B, the drive voltage B applied to the piezoelectric drive unit group B is, for example, a drive voltage having a sawtooth waveform, and the frequency is, for example, 60 HZ. The waveform of the drive voltage B is TrB, which is the time width of the rising period in which the voltage value increases from the minimum value to the next maximum value, and the falling period in which the voltage value decreases from the maximum value to the next minimum value. When the time width of TfB is TfB, for example, a ratio of TfB:TrB=9:1 is set in advance. At this time, the ratio of TfB to one cycle is called the symmetry of the drive voltage B. Further, as shown in FIG. 19C, for example, the cycle TA of the waveform of the drive voltage A and the cycle TB of the waveform of the drive voltage B are set to be the same.

The sawtooth waveforms of the drive voltage A and the drive voltage B are generated by superposition of sine waves. Further, in the present embodiment, the drive voltage having a sawtooth waveform is used as the drive voltages A and B, but the drive voltage is not limited to this, and the drive voltage having a waveform with the apex of the sawtooth waveform rounded or the sawtooth waveform. It is also possible to change the waveform according to the device characteristics of the movable device, such as a drive voltage having a waveform in which the linear region is curved.

[Relationship between deflection angle of reflecting portion, driving speed, and projected image]
Here, when the above-described optical scanning system 10 is applied to a head-up display device (see FIGS. 5 to 6), a change over time (driving speed) of the deflection angle of the reflecting portion 101 due to driving around the second axis and the reflecting portion The relationship with the projection image projected by the scanning light 101 will be described with reference to FIGS. By driving the reflecting portion 101 around the second axis, light is scanned in the sub-scanning direction (Y direction) of the projected image.

FIG. 20 is a diagram illustrating the relationship between the time change of the shake angle and the projected image when the time change of the shake angle around the second axis of the reflecting section is linear. (A) is a figure explaining the time change of the deflection angle around the 2nd axis of a reflective part, (b) is a figure explaining the projection image by the scanning light of (a).

In FIG. 20A, the horizontal axis represents time and the vertical axis represents the deflection angle of the reflection section 101. Further, the time change 301 of the shake angle shows the time change of the shake angle around the second axis of the reflecting section 101, and the period 302 shows the scanning period of the light in the Y direction.

In FIG. 20B, the horizontal axis represents the X direction and the vertical axis represents the Y direction. The X and Y directions correspond to the X and Y directions shown in FIGS. A rectangular frame 20 indicated by a chain line indicates a scanning range of the scanning light in the X direction and the Y direction, and a rectangular frame 21 indicated by a solid line indicates an effective image area used as a projection image in the scanning range. There is. Further, the scanning line 22 indicates the locus of the scanning light by the reflection unit 101.

As shown in FIG. 20A, since the change 301 of the deflection angle with time is linear in the period 302, the reflecting section 101 is driven around the second axis at a constant driving speed, and the scanning light by the reflecting section 101 is Scanning is performed at a constant speed in the Y direction. As a result, as shown in FIG. 20B, the scanning line spacing of the scanning lines 22 in the Y direction becomes constant.

On the other hand, FIG. 21 is a diagram illustrating the relationship between the time change of the shake angle and the projected image when there is fluctuation in the time change of the shake angle around the second axis of the reflecting section. (A) is a figure explaining the time change of the deflection angle around the 2nd axis of a reflective part, (b) is a figure explaining the projection image by the scanning light of (a). The way of viewing FIG. 21 is the same as that of FIG.

In FIG. 21A, a time change 303 of the shake angle shows a time change of the shake angle of the reflecting section 101 around the second axis, and a period 304 shows a scanning period of light in the Y direction. In the period 304, the time variation 303 of the shake angle is not linear, and the shake angle changes in a wavy manner. In other words, fluctuations are included in the temporal change 303 of the deflection angle in the period 304.

As a result, the driving speed of the reflecting portion 101 around the second axis is not constant, and the driving speed includes fluctuations corresponding to fluctuations of the deflection angle. It is considered that such a fluctuation is caused by elastic vibration or the like in the second support portion 140 that supports the second drive portions 130a and 130b.

Fluctuations in the driving speed of the reflecting portion 101 around the second axis cause the scanning line intervals in the Y direction to be uneven. That is, as shown in FIG. 21B, the scanning line interval becomes narrow (dense) in the portion where the driving speed is slow, and the scanning line interval becomes wide (rough) in the portion where the driving speed is fast. The portion 24a shown by hatching in FIG. 21B is a portion having a close scanning line interval, and the portion 24b shown by a satin hatching is a portion having a rough scanning line interval. In a dense portion, the image may shrink in the Y direction or become bright, and in a rough portion, the image may expand in the Y direction or become dark, so that the projected image may be defective.

Therefore, in the optical scanning system (optical deflecting device) according to the first embodiment, the driving speed around the second axis of the reflecting section 101 is made constant by adjusting the inclination and phase of the driving voltage A and the driving voltage B. , Prevents image defects in the projected image.

The optical deflector according to the first embodiment will be described below.

[First Embodiment]
First, the configuration of the optical deflecting device according to the first embodiment will be described with reference to FIGS. In the following description, description of the same components as those already described may be omitted.

<Structure of the movable device according to the first embodiment>
22 is a plan view of an example of the movable device according to the present embodiment as viewed from the +Z direction, and FIG. 23 is a sectional view of the movable device shown in FIG.

As shown in FIG. 22, the movable device 13a has detectors 140a and 140b. The detector 140a is composed of piezoelectric sensors 141a to 141f, and the detector 140b is composed of piezoelectric sensors 142a to 142f.

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

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

As shown in FIG. 23, similarly to the second driving unit 130a, the detecting unit 140a has a lower electrode 201, a piezoelectric unit 202, and an upper electrode 203 formed in this order on the +Z side surface of the silicon active layer 163 that is an elastic unit. Is configured. 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 unit 140a is formed to have substantially the same length in the Y direction and a narrow width in the X direction as compared with the second piezoelectric drive units 131a to 131f. Further, the piezoelectric sensors 141a to 141f of the detection unit 140a are included in the respective second piezoelectric drive units 131a to 131f at intervals so as not to contact the second piezoelectric drive units 131a to 131f of the second drive unit 130a. Is provided on the +Z side surface of the silicon active layer. The detection unit 140b has the same configuration as the detection unit 140a.

The second drive units 130a and 130b are driven (moved) by bending and deforming the piezoelectric drive unit groups A and B by applying a drive voltage. On the contrary, the detection units 140a and 140b can detect the voltage generated in the piezoelectric unit 202 according to the deformation of the silicon active layer 163 by the second driving units 130a and 130b and output it to the control device 11a. .. Here, since the detection signals of the deflection angles of the second drive units 130a and 130b (movable portions) by the detection units 140a and 140b represent the deflection angles of the reflection unit 101, they are hereinafter referred to as the deflection angles of the reflection unit 101.

The second driving units 130a and 130b indirectly support the reflecting unit 101 via the first driving units 110a and 110b and the first supporting unit 120, and are examples of “movable units”. The piezoelectric drive unit groups A and B are examples of “two driven units”. The drive voltages A and B are examples of “two drive signals”, and the “slope” of the drive voltages A and B means the slope of the voltage change with time in the waveforms of the drive voltages A and B.

<Hardware Configuration of Optical Deflection Device According to First Embodiment>
FIG. 24 is a hardware configuration diagram of an example of the optical deflecting device according to the present embodiment.

The light deflection device 10a includes a control device 11a, a light source device 12, and a movable device 13a. The control device 11a includes a sensor voltage input circuit 27 and an SSD (Solid State Drive) 28. The sensor voltage input circuit 27 is an electric circuit that functions as an interface for inputting the voltage generated in the piezoelectric unit 202 of the detection units 140a and 140b to the control device 11a. The sensor voltage input circuit 27 includes an amplifier circuit that amplifies the voltage generated in the piezoelectric portion 202 and an A/D (Analog/Digital) converter circuit that converts an analog voltage signal into a digital voltage signal. It can be output to a CPU or the like.

The SSD 28 is a non-volatile storage device that stores programs and data. An HDD (Hard Disk Drive) or the like may be provided instead of the SSD 28.

<Adjustment Method of Inclinations and Phases of Drive Voltages A and B according to First Embodiment>
Next, a method of adjusting the inclinations and phases of the drive voltages A and B by the optical deflecting device 10a will be described with reference to FIGS.

FIG. 25 is a diagram for explaining an example of changes over time of the drive voltages A and B and the deflection angle of the reflecting portion around the second axis. (A) is a figure explaining drive voltage A and B, (b) is a figure explaining the time change of the deflection angle by drive voltage A and B. FIG.

In FIG. 25A, the waveform 310a shown by the solid line is the waveform of the drive voltage A, and the waveform 310b shown by the broken line is the waveform of the drive voltage B. Note that the drive voltages A and B for two cycles are shown in FIG. By applying the driving voltages A and B to the second driving units 130a and 130b of the movable device 13a, the reflecting unit 101 can be driven around the second axis.

In FIG. 25B, a time change 301 indicates a time change of the deflection angle of the reflecting section 101 around the second axis. In FIG. 25B, the change over time of the deflection angle for two cycles is shown corresponding to the drive voltages A and B for two cycles.

As described above, the deflection angle of the reflection unit 101 may fluctuate due to elastic vibration or the like in the second support unit 140, and the period 302 of the time change 301 corresponds to such fluctuation. It contains high frequency components.

Next, FIG. 26 is a diagram for explaining a change over time in the deflection angle around the second axis of the reflecting section 101 when the drive voltages A and B are applied individually. (A) is a figure explaining drive voltage A, (b) is a figure explaining the time change of the deflection angle by drive voltage A, (c) is extracted from the time change of the deflection angle of (b). It is a figure explaining the high frequency component. Further, (d) is a diagram for explaining the drive voltage B, (e) is a diagram for explaining the change over time of the deflection angle due to the drive voltage B, and (f) is a diagram for explaining the change over time of the deflection angle in (e). It is a figure explaining the extracted high frequency component.

It should be noted that the change over time of the deflection angle when both the drive voltages A and B are applied is calculated from the change over time of the deflection angle when the drive voltage A is applied alone and the deflection when the drive voltage B is applied alone. It is almost the same as the one obtained by subtracting the change in angle over time.

When the drive voltage A having the waveform 310a is applied alone to the movable device 13a, the deflection angle of the reflecting section 101 becomes like a time change 303a. In FIG. 26B, a regression line 370a indicated by a dashed-dotted line is a regression line obtained by linearly approximating the deflection angle data of the time change 303a detected by the detection unit 140a in the period 305 from the time t1 to the time t2. Is. The period 305 is a period in which the drive voltage A is applied in order to scan the light in the Y direction by the reflective portion 101. Further, the period 305 is an example of “a period from the beginning of the slope to the end”, the time t1 is an example of the “start”, and the time t2 is an example of the “end”.

When the deflection angle data based on the regression line 370a is subtracted from the deflection angle data of the time change 303a at each time, the linear inclination component is removed from the time variation 303a, which corresponds to the fluctuation as shown in FIG. The high frequency component 380a can be extracted. The amplitude Aa0 indicates the amplitude of the high frequency component 380a.

On the other hand, when the drive voltage B having the waveform 310b is applied alone to the movable device 13a, the deflection angle of the reflecting portion 101 changes like a time change 303b. In FIG. 26(e), a regression line 370b indicated by a one-dot chain line is a regression line obtained by linearly approximating the deflection angle data of the time change 303b detected by the detection unit 140b in the period 306 from the time t3 to the time t4. Is. Here, the period 306 is an example of “the period from the tilt start time to the tilt end time”, the time t3 is an example of the “tilt start time”, and the time t4 is an example of the “tilt end time”.

When the shake angle data based on the regression line 370b is subtracted from the shake angle data of the time change 303b at each time, the linear inclination component is removed from the time change 303b, which corresponds to the fluctuation as shown in FIG. The high frequency component 380b can be extracted. The amplitude Ab0 indicates the amplitude of the high frequency component 380b.

Here, the high frequency components 380a and 380b are examples of "two high frequency components". Further, the frequencies (cycles) of the high frequency components 380a and 380b are generated due to a common characteristic such as elastic vibration, and thus are substantially equal.

In the present embodiment, the inclinations and phases of the drive voltages A and B are adjusted to cancel the high frequency component 380a and the high frequency component 380b, thereby removing or reducing the high frequency component corresponding to the fluctuation.

Next, FIG. 27 is a diagram illustrating an example of a method of adjusting the slope of the drive voltage B according to the present embodiment. (A) is a figure explaining the inclination of drive voltage B, (b) is a figure explaining the high frequency component of the time change of the deflection angle by drive voltage B. Since the adjustment of the inclination is the adjustment of the relative inclination of the drive voltages A and B, it can be performed by adjusting at least one of the drive voltages A and B. Therefore, the adjustment of the slope of the drive voltage B will be described here.

In FIG. 27A, the waveform 310b indicated by the broken line is the waveform before adjustment, and the waveform 311b indicated by the alternate long and short dash line is obtained by shifting the apex position of the sawtooth wave by the shift amount S in the direction of the white arrow. , Is a waveform after symmetry adjustment. Due to the symmetry adjustment, the negative slope portion included in the waveform 311b is changed so that the slope becomes smaller (gradient) with respect to the waveform 310b. This symmetry adjustment can be performed only by shifting the apex position of the sawtooth wave, and it is not necessary to change the amplitude (maximum voltage value) of the drive voltage B.

When the inclination of the waveform of the drive voltage is reduced, the drive speed is reduced, and elastic vibration or the like on the second support 140 is reduced. Therefore, by applying the drive voltage B of the waveform 311b, the amplitude Ab1 of the high frequency component 381b can be made smaller than the amplitude Ab0 (see FIG. 26(f)). However, it is also possible to increase the amplitude Ab0 by increasing the inclination of the waveform of the drive voltage and increasing the drive speed.

In this way, by adjusting the symmetry, the inclination of the waveform of the drive voltage B can be changed and the amplitude Ab1 of the high frequency component 381b can be changed without changing the amplitude of the drive voltage B. In the present embodiment, the symmetry of the drive voltage B is adjusted so that the amplitude Aa1 of the high frequency component 381a and the amplitude Ab1 of the high frequency component 381b substantially match. However, the symmetry adjustment is an example, and another adjustment method may be used as long as the slope of the waveform can be adjusted.

Next, FIG. 28 is a diagram illustrating an example of a method of adjusting the phases of the drive voltages A and B according to the present embodiment. (A) is a figure explaining the phase of drive voltage A and B, (b) is a figure explaining the high frequency component of the time change of the deflection angle by drive voltage A. Further, (c) is a diagram for explaining a high-frequency component of a change in shake angle with time due to the drive voltage B, and (d) is a diagram for explaining a change with time in shake angle due to the adjusted drive voltages A and B.

In FIG. 28A, the waveform 311a is the waveform of the drive voltage A, and the waveform 311b is the waveform of the drive voltage B after the above-described symmetry adjustment. The phase difference H indicates the phase difference between the drive voltage A and the drive voltage B. By adjusting at least one phase of the drive voltages A and B, the phase difference H can be adjusted, and the phase difference J between the high frequency component 380a (see FIG. 28B) and the high frequency component 380b can be changed. The adjustment of the phases of the drive voltages A and B can be performed by adjusting the start of at least one of the waveforms 311a and 311b.

In the present embodiment, the phase of the drive voltage A is adjusted so that the phase of the high frequency component 380a and the phase of the high frequency component 380b are opposite phases (reverse phases). That is, the phase of the drive voltage A is adjusted so that the phase difference H becomes 180 degrees. Further, as described above, the amplitudes of the high frequency components 380a and 380b are made substantially equal by adjusting the inclination by symmetry. By superposing the high frequency component 380a and the high frequency component 380b whose inclination and phase are adjusted in this manner, the high frequency component is canceled.

When the drive voltages A and B after adjusting the inclination and the phase difference are applied to the movable device 13a, the high frequency components 380a and 380b are superposed, and the high frequency components are removed or reduced as shown in FIG. 28(d). Further, it is possible to obtain the time variation 312 of the deflection angle of the reflecting portion 101 around the second axis.

<Functional Configuration of Optical Deflection Device According to First Embodiment>
Next, a functional configuration of the optical deflector for realizing the method of adjusting the inclinations and phases of the drive voltages A and B will be described.

FIG. 29 is a functional block diagram of an example of the control device according to the present embodiment.

The control device 11a includes a light source drive unit 31a, a piezoelectric drive unit 31b, a waveform storage unit 32, a drive voltage generation unit 33, a drive voltage output unit 34, a swing angle detection unit 35, and a high frequency component extraction unit 36. , And a waveform adjusting section 37.

Here, the piezoelectric drive unit 31b is an example of a “drive unit”, and the drive voltage generation unit 33 is an example of a “drive signal generation unit”. The high frequency component extraction unit 36 is an example of “high frequency component extraction means”, and the symmetry adjustment unit 41 is an example of “tilt adjustment means”. The phase adjusting unit 43 is an example of “phase adjusting means”.

The light source drive unit 31a is realized by the light source device driver 25 and the like, and outputs a drive signal such as a drive voltage for controlling the irradiation timing and irradiation intensity of the light source to the light source device 12 based on the control signal input from the control unit 30. To do.

The piezoelectric drive unit 31b is realized by the movable device driver 26 and the like, and sets the timing and the rotation range for rotating the reflecting unit 101 to the movable device 13a according to the waveform of the drive voltage input from the drive voltage output unit 34. The drive signal to control is output.

The waveform storage unit 32 is realized by the SSD 28 or the like and stores data indicating the waveforms of the drive voltages A and B.

The drive voltage generation unit 33 refers to the waveform storage unit 32 to generate data indicating a waveform (hereinafter, simply referred to as “waveform”) to generate a waveform, and generates the waveform according to a control signal input from the control unit 30. The drive voltage having the above waveform is output to the drive voltage output unit 34.

The drive voltage output unit 34 can output the input drive voltage to the piezoelectric drive unit 31b. The drive voltage output section 34 can individually output the drive voltage A and the drive voltage B to the piezoelectric drive section 31b, or can output both of them simultaneously.

The deflection angle detection unit 35 is realized by the sensor voltage input circuit 27 and the like, converts the voltage generated in the piezoelectric unit 202 of the detection units 140a and 140b into a digital voltage signal, and detects the deflection angle detection signal of the reflection unit 101 (deflection angle). (Data) is output to the high frequency component extraction unit 36.

The high frequency component extraction unit 36 includes a scanning period identification unit 38 and a regression line calculation unit 39, and has a function of extracting a high frequency component from the deflection angle data of the reflection unit 101 and outputting it to the waveform adjustment unit 37. The scanning period specifying unit 38 specifies the period from the time when the deflection angle data is minimum (the beginning of the inclination) to the time when the deflection angle data is the maximum (the ending of the inclination) as the scanning period, and the regression line calculation unit determines the data indicating the scanning period. It has a function of outputting to 39.

The regression line calculation unit 39 can calculate a regression line that is a linear approximation of the deflection angle data during the scanning period. The high frequency component extraction unit 36 calculates the difference between the detected shake angle data and the shake angle data based on the regression line, and extracts the high frequency component from which the linear tilt component is removed from the detected shake angle data. be able to. The high frequency component extraction unit 36 outputs the extracted high frequency component data to the waveform adjustment unit 37.

The high frequency component extraction unit 36 extracts the high frequency component 380a from the deflection angle data based on the drive voltage A, extracts the high frequency component 380b from the deflection angle data based on the drive voltage B, and converts the two high frequency component data into the waveform adjustment unit 37. Output to.

The waveform adjustment unit 37 includes an amplitude comparison unit 40, a symmetry adjustment unit 41, a phase comparison unit 42, and a phase adjustment unit 43, and has a function of adjusting the slopes (symmetry) and phases of the drive voltages A and B. Have. The waveform adjustment unit 37 inputs the data of two high frequency components from the high frequency component extraction unit 36, and inputs the waveform before adjustment from the waveform storage unit 32.

The amplitude comparison unit 40 compares the amplitudes of the two high frequency components and outputs data indicating the amplitude difference, which is the difference between the two, to the symmetry adjustment unit 41. The symmetry adjustment unit 41 adjusts the symmetry of the drive voltage B based on the data indicating the amplitude difference so that the amplitudes of the two high frequency components substantially match. However, the symmetry adjustment unit 41 may adjust at least one symmetry of the waveforms of the drive voltages A and B.

For this symmetry adjustment, a theoretical formula of the symmetry of the drive voltage and the amplitude of the high frequency component is obtained in advance, and based on the input amplitude difference, the symmetry is calculated so that the amplitude difference becomes zero by referring to the theoretical formula. Can be done by In addition, the relationship between the symmetry of the drive voltage and the amplitude of the high frequency component is obtained in advance by experiments or simulations, and a table is created, and based on the input amplitude difference, the table is referenced to obtain the symmetry where the amplitude difference becomes zero. You may.

The phase comparison unit 42 compares the phases of the two high frequency components and outputs data indicating the phase difference, which is the difference between the two, to the phase adjustment unit 43. The phase adjuster 43 adjusts the phase difference between the drive voltages A and B so that the phases of the two high frequency components are opposite to each other based on the data indicating the phase difference. However, the phase adjustment unit 43 may adjust at least one phase of the drive voltages A and B.

The waveform adjustment unit 37 outputs the waveforms of the drive voltages A and B whose slopes and phases have been adjusted to the waveform storage unit 32. As a result, the waveforms of the drive voltages A and B stored in the waveform storage unit 32 are updated.

<Operation of Optical Deflection Device According to First Embodiment>
The adjustment of the inclinations and phases of the drive voltages A and B described above can be performed separately from the optical scanning by the optical deflecting device 10a. The timing of adjusting the inclinations and the phases of the drive voltages A and B is, for example, the factory shipment of the optical deflecting device 10a or an image projection device including the optical deflecting device 10a, or the inspection. The inspection may be a regular inspection performed every predetermined period, or may be an irregular inspection performed each time the light deflecting device 10a is used.

The optical deflecting device 10a adjusts the slopes and phases of the drive voltages A and B, and stores the adjusted waveforms of the drive voltages A and B in the waveform storage unit 32. Then, during the optical scanning, the optical deflecting device 10a can refer to the waveform storage unit 32 to acquire the waveform, and apply the drive voltages A and B having the acquired waveform to the movable device 13a.

FIG. 30 is a flowchart showing an example of the tilt and phase adjustment operation by the optical deflector according to the present embodiment.

First, in step S301, the drive voltage generation unit 33 refers to the waveform storage unit 32, acquires the waveform before adjustment, and outputs the drive voltage A of the acquired waveform to the drive voltage output unit 34.

Subsequently, in step S302, the drive voltage output unit 34 outputs the drive voltage A to the piezoelectric drive unit 31b, and the piezoelectric drive unit 31b applies the drive voltage A to the movable device 13a.

Subsequently, in step S303, the deflection angle detection unit 35 converts the voltage generated in the piezoelectric unit 202 of the detection unit 140a of the movable device 13a into a digital voltage signal, and changes the deflection angle of the reflection unit 101 over time 303a to a high frequency component. Output to the extraction unit 36. The high frequency component extraction unit 36 temporarily stores the data of the time change 303a in the RAM 21 or the like.

Subsequently, in step S304, the drive voltage generation unit 33 refers to the waveform storage unit 32, acquires the waveform before adjustment, and outputs the drive voltage B of the acquired waveform to the drive voltage output unit 34.

Subsequently, in step S305, the drive voltage output unit 34 outputs the drive voltage B to the piezoelectric drive unit 31b, and the piezoelectric drive unit 31b applies the drive voltage B to the movable device 13a.

Then, in step S306, the deflection angle detection unit 35 converts the voltage generated in the piezoelectric unit 202 of the detection unit 140b of the movable device 13a into a digital voltage signal, and changes the deflection angle 101 of the reflection unit 101 with time to a high frequency component 303b. Output to the extraction unit 36. The high frequency component extraction unit 36 temporarily stores the data of the time change 303b in the RAM 21 or the like.

The order of the processes of steps S301 to S303 and the processes of steps S304 to 306 can be changed appropriately.

Subsequently, in step S307, the scanning period specifying unit 38 reads the data of the time changes 303a and 303b from the RAM 21 and the like, specifies the scanning periods of the time changes 303a and 303b, and calculates the regression line of the data indicating the respective scanning periods. It is output to the unit 39.

Subsequently, in step S308, the regression line calculation unit 39 calculates a regression line that is a linear approximation of the temporal change 303a in the input scanning period, and also calculates a regression line that is a linear approximation of the temporal change 303b.

Subsequently, in step S309, the high frequency component extraction unit 36 calculates the difference between the detected shake angle data and the shake angle data based on the regression line at each time of the time change 303a, and linearly calculates from the detected shake angle data. The high frequency component 380a from which the inclination component of is removed is extracted. Further, the high frequency component extraction unit 36 calculates the difference between the detected shake angle data and the shake angle data based on the regression line at each time of the time change 303b, and removes the linear tilt component from the detected shake angle data. The extracted high frequency component 380b is extracted. The high frequency component extraction unit 36 outputs the data of the two extracted high frequency components 380a and 380b to the waveform adjustment unit 37.

Subsequently, in step S310, the amplitude comparison unit 40 compares the amplitudes of the two high frequency components 380a and 380b, and outputs data indicating the amplitude difference, which is the difference between the two, to the symmetry adjustment unit 41.

Subsequently, in step S311, the symmetry adjustment unit 41 adjusts the symmetry of the drive voltage B based on the data indicating the amplitude difference so that the amplitudes of the two high frequency components substantially match.

Subsequently, in step S312, the phase comparison unit 42 compares the phases of the two high frequency components 380a and 380b, and outputs data indicating the phase difference, which is the difference between the two, to the phase adjustment unit 43.

Subsequently, in step S313, the phase adjustment unit 43 adjusts the phase of the drive voltage A based on the data indicating the phase difference so that the phases of the two high frequency components 380a and 380b are opposite to each other.

Subsequently, in step S314, the waveform adjustment unit 37 outputs the waveforms 311a and 311b of the drive voltages A and B after adjusting the symmetry and the phase to the waveform storage unit 32, and the waveform storage unit 32 inputs the input waveforms 311a and 311b. Memorize the data of.

In this way, the optical deflecting device 10a can store the waveforms 311a and 311b of the drive voltages A and B whose inclination and phase are adjusted in the waveform storage unit 32.

Next, FIG. 31 is a flowchart showing an example of an optical scanning operation by the optical deflecting device according to the present embodiment.

First, in step S311, the drive voltage generation unit 33 refers to the waveform storage unit 32 and acquires the waveforms 311a and 311b.

Subsequently, in step S312, the control unit 30 acquires optical scanning information from an external device or the like.

Subsequently, in step S313, the control unit 30 generates a control signal from the acquired optical scanning information, and outputs the control signal to the light source drive unit 31a and the drive voltage generation unit 33.

Subsequently, in step S314, the light source drive unit 31a outputs a drive signal to the light source device 12 based on the input control signal, and the light source device 12 performs light irradiation based on the input drive signal.

Subsequently, in step S315, the drive voltage output unit 34 outputs the drive voltages A and B input from the drive voltage generation unit 33 to the piezoelectric drive unit 31b.

Subsequently, in step S316, the piezoelectric drive unit 31b outputs the drive voltages A and B to the movable device 13a.

Subsequently, in step S317, the movable device 13a drives the reflection unit 101 based on the input drive voltages A and B. By rotating the light source device 12 and the reflecting portion 101 of the movable device 13a, the light incident on the reflecting surface 14 of the reflecting portion 101 is deflected in an arbitrary direction, and optical scanning (optical deflection) is performed.

Subsequently, in step S318, the control unit 30 determines whether to end the optical scanning based on the optical scanning information or the like. When it is determined in step S318 to end (Yes in step S318), the optical deflecting device 10a ends the optical scanning. On the other hand, if it is determined in step S318 that the processing is not completed (No in step S318), the process returns to step S311 and the processing in step S311 and subsequent steps is continued.

In this way, the optical deflecting device 10a can be driven around the second axis of the reflecting section 101 by the drive voltages A and B whose inclination and phase are adjusted.

<Effect>
As described above, in the present embodiment, the piezoelectric drive unit 31b that drives the piezoelectric drive unit groups A and B and the drive voltage generation unit that generates the drive voltages A and B that drive the piezoelectric drive unit groups A and B. 33, the high-frequency component extraction unit 36 that extracts the two high-frequency components 380a and 380b of the deflection angle detection signals of the second drive units 130a and 130b, and the two high-frequency components 380a and 380b so that their phases are opposite to each other. And a phase adjuster 43 for adjusting the phases of the drive voltages A and B.

Then, the inclinations and phases of the drive voltages A and B are adjusted according to the detected deflection angle data of the second driving units 130a and 130b to cancel the high frequency component 380a and the high frequency component 380b. Remove or reduce components.

As a result, the driving speed of the reflecting section 101 around the second axis can be made constant, and image defects in the projected image can be prevented.

Further, in the present embodiment, since the slopes and phases of the drive voltages A and B are adjusted, it is not necessary to adjust both the amplitude and phase of the drive voltages A and B. Further, since the high frequency component 380a and the high frequency component 380b are not reduced but are canceled out to remove or reduce the high frequency component, the amplitudes and phases of the drive voltages A and B for reducing the high frequency component are complicated. No need to make adjustments. This makes it possible to easily remove or reduce the fluctuation of the deflection angle of the reflecting section 101.

[Second Embodiment]
Next, the optical deflector according to the second embodiment will be described. Note that the description of the same components as those of the above-described embodiment will be omitted.

FIG. 32 is a functional block diagram of an example of the control device 11b included in the optical deflecting device 10b according to the present embodiment. The control device 11b has a high frequency component extraction unit 36b.

The high frequency component extraction unit 36b includes a cycle period identification unit 44 and a regression line calculation unit 39b, and has a function of extracting a high frequency component from the deflection angle data of the reflection unit 101 and outputting it to the waveform adjustment unit 37.

The cycle period specifying unit 44 may specify a period corresponding to one cycle of the high frequency component in the middle of the period from the start to the end of the inclination of the deflection angle data, and output the specified period to the regression line calculation unit 39b. it can.

The regression line calculation unit 39b can calculate a regression line by linearly approximating the shake angle data in the period corresponding to one cycle of the high frequency component. The high-frequency component extraction unit 36b calculates the difference between the detected shake angle data and the shake angle data based on the regression line, and extracts the high-frequency component from which the linear inclination component has been removed, from the detected shake angle data. be able to. Further, the high frequency component extraction unit 36 can output the extracted high frequency component data to the waveform adjustment unit 37.

Here, FIG. 33 is a diagram illustrating an example of a method of extracting a period corresponding to one cycle of the high frequency component according to the present embodiment. In FIG. 33, the timing t3 indicates the beginning of the inclination, the timing t4 indicates the ending of the inclination, and the timing t5 indicates an intermediate timing between the beginning and the ending.

The cycle period specifying unit 44 specifies, for example, a time t5 that is in the middle of the time period from the time t3 when the deflection angle data becomes the minimum to the time t4 when the deflection angle data becomes the maximum. Then, in the vicinity of the time t5, the period from the time of the inflection point where the deflection angle data has the minimum value to the time of the inflection point where the deflection angle data has the maximum value is obtained, and twice the period is specified as the period for one cycle. The inflection point can be specified from the time when the differential value of the deflection angle data becomes zero. In FIG. 33, the time t5 is the time of the inflection point where the minimum value is reached, and the time t6 is the time of the inflection point where the time t6 reaches the maximum value. The cycle period specifying unit 44 can output data indicating the specified period 307 to the regression line calculation unit 39.

As described above, in the present embodiment, the high frequency component extraction unit 36b determines the deflection angle data in the period corresponding to one cycle of the high frequency component, which is specified in the middle of the period from the beginning to the end of the inclination of the deflection angle data. The high frequency component is extracted from the difference between the regression line and the deflection angle data. Since the period corresponding to one cycle of the high-frequency component is shorter than the scanning period described in the first embodiment, the regression line calculation process and the high-frequency component extraction process are executed on a small amount of deflection angle data. be able to. As a result, the processing load can be reduced and the processing speed can be improved as compared with the case where the regression line calculation processing and the high frequency component extraction processing are executed in the scanning period described in the first embodiment.

The effects other than the above are the same as those described in the above-described embodiment.

Although the example of the embodiment of the present invention has been described above, the present invention is not limited to such a specific embodiment, and various modifications are possible within the scope of the gist of the present invention described in the claims. It can be modified and changed.

The optical deflection devices 10a and 10b described in the embodiments are similar to the optical scanning system 10 in that the head-up display, the optical writing device, the lidar device, the laser headlamp, and the head mount described in FIGS. It can be applied to displays and the like.

10 Optical Scanning System 10a, 10b Optical Deflection Device 11, 11a, 11b Control Device 12 Light Source Device 13, 13a Movable Device 14 Reflective Surface 15 Scanned Surface 27 Sensor Voltage Input Circuit 28 SSD
30 control section 31 drive signal output section 31a light source drive section 31b piezoelectric drive section (an example of drive means)
32 waveform storage unit 33 drive voltage generation unit (an example of drive signal generation means)
34 Drive Voltage Output Section 35 Swing Angle Detection Sections 36, 36b High Frequency Component Extraction Section (Example of High Frequency Component Extraction Means)
37 Waveform Adjusting Section 38 Scanning Period Identifying Sections 39 and 39b Regression Straight Line Calculating Section 40 Amplitude Comparison Section 41 Symmetry Adjusting Section (an example of inclination adjusting means)
42 Phase Comparing Section 43 Phase Adjusting Section (Example of Phase Adjusting Means)
44 Cycle Period Identifying Part 101 Reflecting Part 102 Reflecting Part Bases 110a, 110b First Driving Part a, b
111a, 111b Torsion bar a, b
112a, 112b 1st piezoelectric drive part 120 1st support part 130a, 130b 2nd drive part (an example of a movable part)
131a-131f 2nd piezoelectric drive part a
132a-132f 2nd piezoelectric drive part b
140 2nd support part 140a, 140b Detection part 141a-141f Piezoelectric sensor 142a-142f Piezoelectric sensor 150 Electrode connection part 161 Silicon support layer 162 Silicon oxide layer 163 Silicon active layer 201 Lower electrode 202 Piezoelectric part 203 Upper electrode 301, 301a, 301b , 303a, 303b, 312 Time change 302, 304, 305, 306, 307 Periods 310a, 310b, 311a, 311b Waveforms 370a, 370b Regression lines 380a, 380b High-frequency components 381a, 381b Before inclination and phase adjustment After inclination and phase adjustment High frequency component 400 Automobile 500 Head-up display device (an example of image projection device)
600 Optical Writing Device 650 Laser Printer 700 Lidar Device A, B Piezoelectric Drive Unit Group (Example of Two Driven Means)
Aa0, Ab0, Ab1 Amplitude H of high frequency component Phase difference J between drive voltages A and B Phase difference t1, t2, t3, t4, t5, t6 High frequency component Timing

Japanese Patent No. 6332736

Claims (10)

An optical deflecting device comprising: a reflecting portion having a reflecting surface; and a movable portion supporting the reflecting portion, the movable portion having two driven means and deflecting the light incident on the reflecting surface. hand,
Drive means for driving the two driven means,
Drive signal generating means for generating two drive signals for driving the two driven means,
High-frequency component extraction means for extracting two high-frequency components of the deflection angle detection signal of the movable part corresponding to each of the two drive signals,
An optical deflecting device comprising: a phase adjusting unit that adjusts at least one phase of the two drive signals so that the phases of the two high-frequency components are opposite to each other. The optical deflection device according to claim 1, further comprising a phase comparison unit that compares the phases of the two high-frequency components. The optical deflecting device according to claim 1, further comprising a tilt adjusting unit that adjusts the tilt of at least one of the two drive signals. The optical deflector according to claim 3, wherein the tilt adjusting unit adjusts at least one symmetry of the two drive signals. The optical deflection device according to claim 3, further comprising an amplitude comparison unit that compares the amplitudes of the high frequency components. 6. The high frequency component extracting means extracts the high frequency component from a difference between a regression line of the detection signal and the detection signal in a period from the beginning to the end of the slope of the detection signal. The optical deflector according to item 1. The high-frequency component extraction means is a regression line of the detection signal in a period corresponding to one cycle of the high-frequency component, which is specified in the middle of the period from the beginning to the end of the slope of the detection signal, and the detection signal, The optical deflector according to claim 1, wherein the high-frequency component is extracted from the difference between the two. An image projection device comprising the light deflection device according to claim 1. The image projection device according to claim 8, wherein the light deflection device scans the reflected light of the light from the light source on the surface of the light transmission member. A moving body comprising the light deflecting device according to any one of claims 1 to 7 or the image projecting device according to claim 8 or 9.

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