JP2020086316A - Movable device, image projection device, head-up display, laser head lamp, head-mount display, object recognition device and vehicle - Google Patents

Abstract

To provide a movable device at a low cost.SOLUTION: A movable device according to an aspect of a disclosed technique comprises a movable part having a reflective surface, a pair of drive beams having one ends connected to the movable part and supporting the movable part rotatably while sandwiching the movable part therebetween, and a fixing part connected to the other ends of the pair of drive beams and fixing the pair of drive beams. The movable part includes a support layer and a movable layer provided in a lamination direction of the support layer. The fixing part includes a fixing support layer composed of the same material as that of the support layer. When thickness of the support layer is t, thickness of the movable layer is tand thickness of the fixing support layer is t, t≥tand t<tare satisfied.SELECTED DRAWING: Figure 16

Description

The present invention relates to a movable device, an image projection device, a head-up display, a laser headlamp, a head mounted display, an object recognition device, and a vehicle.

2. Description of the Related Art In recent years, with the development of micromachining technology to which semiconductor manufacturing technology is applied, development of MEMS (Micro Electro Mechanical Systems) devices manufactured by microfabrication of silicon or glass has been advanced.

As a MEMS device, a movable part having a reflecting surface and an elastic beam are integrally formed on a wafer, and the movable beam is driven (rotated) by a drive beam configured by stacking a thinned piezoelectric material on the elastic beam. Movable devices are known.

In such a movable device, it is necessary to secure a space for driving the movable unit under the movable unit, which may complicate the structure of the package that houses the movable device. On the other hand, a movable device has been disclosed in which the fixed support layer forms an internal space that allows the movable part to be driven while accommodating the movable part (see, for example, Patent Document 1).

However, in the device of Patent Document 1, it is necessary to form the fixed support layer by a glass wafer bonded in a wafer state, and since a plurality of wafers of different materials are used, the manufacturing process becomes complicated and the cost of the movable device increases. There was a case to do.

The present invention has been made in view of the above points, and an object thereof is to reduce the cost of a movable device.

A movable device according to an aspect of the disclosed technique includes a movable part having a reflecting surface, and a pair of movable ends that are connected to each other and rotatably support the movable part with the movable part interposed therebetween. Drive beams and fixed portions that are connected to the other ends of the pair of drive beams and fix the pair of drive beams, and the movable portion includes a support layer and a support layer. And a movable layer provided in the stacking direction, wherein the fixed portion includes a fixed support layer made of the same material as the support layer, and the thickness of the support layer is t ₁ and the thickness of the movable layer is When t ₂ and the thickness of the fixed support layer are t ₃ , t ₁ ≧t ₂ and t ₁ <t ₃ .

According to the disclosed technology, the cost of the movable device can be reduced.

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 diagram of an example of an image forming apparatus including 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 which shows an example of a structure of the movable device of 1st Embodiment. It is sectional drawing which shows an example of a structure of the movable device of 1st Embodiment. It is sectional drawing which shows the structure of the movable device of a comparative example. It is a figure which shows an example of the relationship of the thickness ratio of a movable layer and a support layer, and the gravity center position of a movable part. It is the schematic which shows the packaged movable device of 1st Embodiment. It is sectional drawing which shows an example of the movable device of 2nd Embodiment. It is the schematic which shows the packaged movable device of a comparative example. It is a schematic diagram showing a packaged movable device of a 2nd embodiment. It is sectional drawing which shows an example of a structure of the modification of the movable device of 2nd Embodiment. It is a perspective view which shows an example of a structure of the movable device of 3rd Embodiment. It is sectional drawing which shows an example of a structure of the movable device of 4th Embodiment. It is a top view which shows an example of a structure of the movable device of 5th Embodiment. It is a top view which shows an example of a structure of the modification of the movable device of 5th 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 present embodiment is applied will be described in detail with reference to FIGS.

FIG. 1 shows a schematic diagram of an example of an optical scanning system. As shown in FIG. 1, the optical scanning system 10 is a system that optically scans a surface to be scanned 15 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 reflecting surface 14 and capable of moving the reflecting 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, under the control of the control device 11 based on image information, which is an example of 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 performing optical scanning, it is possible to project an arbitrary image on the scanned surface 15. The details of the movable device and the control by the control device of this embodiment will be described later.

Next, a hardware configuration 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, a 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 be any 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 according to the input control signal.

In the control device 11, the CPU 20 acquires optical scanning information from an external device or network via the external I/F 24. It should be noted that the CPU 20 only needs to have a configuration capable of obtaining 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 a writing order and a writing location. In addition, for example, when the object recognition is performed by optical scanning, the optical scanning information is irradiation data indicating the timing and the irradiation range of the light for object recognition.

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 performs light irradiation based on the input drive signal. Further, the movable device 13 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-described 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. 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 present 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. FIG. 6 is a schematic diagram 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. As a result, 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 so that the user can visually recognize the virtual image by the projection light reflected by the combiner.

As shown in FIG. 6, in the head-up display device 500, laser light is emitted 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 a movable device 13 having a 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 and 501B, the collimator lenses 502, 503 and 504, and the dichroic mirrors 505 and 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 make the driver 402 visually recognize the intermediate image as a virtual image.

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 light 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 or the mounting member, but is, for example, an aircraft, a ship, a moving body such as 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.

The head-up display device 500 is an example of the "head-up display" described in the claims. The automobile 400 is an example of the “vehicle” described in the claims.

[Optical writing device]
Next, an optical writing device to which the movable device 13 of this 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 typified by a laser printer 650 having a printer function using laser light. In the image forming apparatus, the optical writing device 600 performs optical writing on the 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 It is deflected axially or biaxially. Then, the laser light deflected by the movable device 13 then passes through the scanning optical system 602 including the first lens 602a, the second lens 602b, and the reflection mirror section 602c, and the 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. Also, 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 light 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 as compared with the rotary polygon mirror using a polygon mirror or the like, and therefore saves power in the optical writing device. 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 in 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.

[Object recognition device]
Next, an object recognition device to which the movable device according to the present embodiment is applied will be described in detail with reference to FIGS. 9 and 10.

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

The object recognition device is a device that recognizes an object 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. Recognize.

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. A movable device 13 having a surface 14 scans in a uniaxial or biaxial direction. Then, the object 702 in front of the apparatus is irradiated with the 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/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 rider 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 recognize the presence or absence of an obstacle and the distance to the obstacle.

In the above object recognition device, the lidar device 700 as an example has been described. However, the object recognition 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 recognizes the target 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, or the intruder is recognized by the optical scanning to the object range. The present invention can be similarly applied to a security sensor, a component of a three-dimensional scanner that calculates and recognizes object information such as a shape from distance information obtained by optical scanning, and outputs the three-dimensional data as three-dimensional data.

[Laser headlamp]
Next, a laser headlamp 50 in which the movable device of the present 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 reflecting 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, the 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 three primary light colors of blue, green, and red phosphors. 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 present 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. Although FIG. 13 illustrates the configuration for the left eye, the HMD 60 has the same configuration for the right eye.

The HMD 60 includes the control device 11, a light source unit 530, a light amount adjustment unit 507, the movable device 13 having the 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 three color laser lights 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 made 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. The 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. Further, due to the reflection on the half mirror 62, the spatial distortion of the image is corrected. 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 of this embodiment will be described with reference to FIG.

FIG. 14 is a schematic view 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.

The details of the movable device of the present embodiment used for the optical deflection system, the optical scanning system, the image projection device, the optical writing device, the object recognition device, the laser headlamp, and the head mounted display described above are described below. Will be described with reference to. In addition, in each drawing, the same components may be denoted by the same reference numerals, and redundant description may be omitted.

In the description of the embodiment, the optical scanning with the first axis as the center of rotation is the sub-scan, and the optical scanning with the second axis as the center of the rotation is the main scan. Further, in the terms of the embodiments, turning, swinging, and moving are synonymous. Further, among the directions indicated by the arrows, the X direction is parallel to the first axis, the Y direction is parallel to the second axis, and the Z direction is orthogonal to the XY plane. The Z direction is an example of the “stacking direction”.

[First Embodiment]
<Movable device configuration>
FIG. 15 is a plan view showing an example of the configuration of the movable device according to the first embodiment. The movable device 13 is a both-sided type (both ends supporting beam) movable device that is rotatable around the first axis and the second axis.

As shown in FIG. 15, the movable device 13 includes a movable portion 110, first drive beams 120a and 120b, a fixed portion 130, and an electrode terminal 140. Further, the movable part 110 has a reflection part 112 including the reflection surface 14, a support part 113, connection parts 114a and 114b, torsion bars 115a and 115b, and second drive beams 116a and 116b.

The reflection part 112 is formed of a silicon active layer or the like. However, the material is not limited to this, and may be made of an oxide material, an inorganic material, an organic material, or the like. The reflecting surface 14 is formed on the surface of the reflecting portion 112 in the positive Z direction. The reflecting surface 14 is formed in a circular shape using a metal thin film containing aluminum, gold, silver or the like or a multilayer film thereof as shown in the drawing.

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

The torsion bars 115a and 115b extend in the Y direction and are formed so as to sandwich the reflecting section 112 in the Y direction. One end of the torsion bar 115a is connected to the reflection part 112, and one end of the torsion bar 115b is connected to the reflection part 112. The reflector 112 is supported by the torsion bars 115a and 115b.

The other end of the torsion bar 115a is connected to the second drive beam 116a, and the other end of the torsion bar 115b is connected to the second drive beam 116b. The second drive beams 116a and 116b are provided with piezoelectric portions on the surfaces of the elastic beams in the positive Z direction. When a drive voltage is applied to the second drive beam 116a through the electrical wiring laid out from the electrode terminal 140, the second drive beam 116a bends and deforms, causing the torsion bar 115a to twist.

Similarly, the second drive beam 116b bends and deforms when the drive voltage is applied through the electrical wiring laid out from the electrode terminal 140, causing the torsion bar 115b to be twisted.

Such torsion of the torsion bars 115a and 115b serves as a turning force, and the reflecting portion 112 rotates about the second axis.

On the other hand, the support portion 113 is formed so as to surround the reflection portion 112, the torsion bars 115a and 115b, and the second drive beams 116a and 116b from all sides. The support portion 113 is connected to the second drive beams 116a and 116b and supports and restrains the second drive beams 116a and 116b. Further, the support portion 113 indirectly supports the reflection portion 112 and the torsion bars 115a and 115b via the second drive beams 116a and 116b.

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

A connecting portion 114b is formed at the lower left corner of the supporting portion 113 in the figure, and the supporting portion 113 is connected to the first drive beam 120b via the connecting portion 114b. The connection portion 114b extends in the positive X direction from the connection portion with the first drive beam 120b and connects the first drive beam 120b and the support portion 113.

The first drive beam 120a and the first drive beam 120b support the support portion 113 so as to sandwich the support portion 113 from both sides in the X direction.

The first drive beam 120a has three folded portions and three connecting portions, and includes a meander structure in which a plurality of elastic beams are connected. Piezoelectric portions are provided on the surfaces of the plurality of elastic beams in the positive Z direction. The end portion of the first drive beam 120a on the side not connected to the connection portion 114a is connected to the fixed portion 130, and the fixed portion 130 fixes (supports and restrains) the first drive beam 120a.

Similarly, the first drive beam 120b includes three meandering structures in which a plurality of elastic beams are connected to each other, which has three folded portions and three connecting portions. A piezoelectric portion is provided on each of the positive Z-side surfaces of the plurality of elastic beams. The end portion of the first drive beam 120b on the side not connected to the connection portion 114b is connected to the fixed portion 130, and the fixed portion 130 fixes (supports and restrains) the first drive beam 120b. The first drive beams 120a and 120b are examples of “a pair of drive beams”.

As shown in FIG. 15, the fixed part 130 has a rectangular frame structure having four frame sides, and the four frame sides surround the movable part 110 and the first drive beams 120a and 120b from four sides. I'm out.

On the other hand, a drive voltage is applied to the piezoelectric portions provided on the first drive beams 120a and 120b through electrical wiring laid out from the electrode terminals 140.

Here, among the plurality of elastic beams included in the first drive beam 120a, the piezoelectric units provided on the odd-numbered elastic beams counted from the one having the closest distance to the reflection unit 112 are referred to as a piezoelectric drive unit group 150A. Further, among the plurality of elastic beams included in the first drive beam 120b, the piezoelectric units provided on the even-numbered elastic beams counting from the one having the closest distance to the reflecting unit 112 are similarly defined as the piezoelectric drive unit group 150A. The piezoelectric drive unit group 150A bends and deforms in the same direction when a drive voltage is simultaneously applied to each piezoelectric unit. The movable portion 110 rotates about the first axis by using this deformation as a turning force.

Further, among the elastic beams included in the first drive beam 120a, the piezoelectric units provided in the even-numbered elastic beams counted from the closest one to the reflection unit 112 are referred to as a piezoelectric drive unit group 150B. Further, among the elastic beams included in the first drive beam 120b, an odd-numbered elastic beam counted from the one having the closest distance to the reflection section 112 is similarly defined as the piezoelectric drive section group 150B. The piezoelectric drive unit group 150B bends and deforms in the same direction when a drive voltage is simultaneously applied to each piezoelectric unit. The movable portion 110 rotates about the first axis in the opposite direction to the rotation by the piezoelectric drive unit group 150A by using this deformation as a turning force.

In the first drive beams 120a and 120b, the plurality of piezoelectric units included in the piezoelectric drive unit groups 150A and 150B are simultaneously bent and deformed to accumulate the amount of rotation due to the bending deformation, and the swing angle of the movable unit 110 around the first axis. Can be increased. When the amount of rotation of the movable unit 110 by the piezoelectric drive unit group 150A when a voltage is applied and the amount of rotation of the movable unit 110 by the piezoelectric drive unit group 150B when a voltage is applied are balanced, the deflection angle is It becomes zero.

Here, a semiconductor such as an SOI (Silicon On Insulator) substrate can be used for the substrate (wafer) forming the movable device 13. By processing with the semiconductor manufacturing technology, each component of the movable device 13 can be integrally formed. The first drive beams 120a and 120b and the second drive beams 116a and 116b may be formed after the SOI substrate is molded or may be formed during the molding of the SOI substrate.

<Driving method of movable device>
Next, an example of a method of driving the movable device 13 will be described with reference to FIG. Due to the rotation about the second axis, the drive voltage is applied to the second drive beams 116a and 116b at the resonance frequency of the integral structure including the reflection portion 112, the torsion bars 115a and 115b, and the second drive beams 116a and 116b. Is applied. The resonance frequency is 20 kHz or the like.

The piezoelectric portion of the second drive beam 116a, to which one end of the torsion bar 115a is connected, deforms when a drive voltage is applied through the upper electrode and the lower electrode. Due to the deformation of the piezoelectric portion, the second drive beam 116a is bent and deformed, and the torsion bar 115a is twisted.

Similarly, the piezoelectric portion of the second drive beam 116b to which one end of the torsion bar 115b is connected is deformed when a drive voltage is applied through the upper electrode and the lower electrode. Due to the deformation of the piezoelectric portion, the second drive beam 116b is bent and deformed, and the torsion bar 115b is twisted.

The torsion of the torsion bars 115a and 115b serves as a turning force, and the reflecting portion 112 reciprocally rotates about the second axis. The waveform of the drive voltage applied to the second drive beams 116a and 116b is a sine wave or the like. The reflector 112 is resonantly driven and reciprocally rotates in a cycle of a sinusoidal drive voltage waveform.

In the rotation around the first axis, the waveform of the drive voltage applied to the piezoelectric drive unit group 150A includes, for example, a sawtooth waveform. The frequency of the drive voltage is 60 HZ or the like. In the waveform of the driving voltage, the time width of the rising period in which the voltage value increases from the minimum value to the next maximum value is Tr, and the time width of the falling period in which the voltage value decreases from the maximum value to the next minimum value is Tf. For example, the ratio of Tr:Tf=9:1 is preset. At this time, the ratio of Tr to one cycle is called the symmetry of the drive voltage.

Similarly, the waveform of the drive voltage applied to the piezoelectric drive unit group 150B includes a sawtooth waveform. The frequency of the drive voltage is 60 HZ or the like. The waveform of the drive voltage is preset with a ratio of Tf:Tr=9:1, for example.

Further, the cycle of the waveform of the drive voltage applied to the piezoelectric drive unit group 150A and the cycle of the waveform of the drive voltage applied to the piezoelectric drive unit group 150B are set to be the same.

The sawtooth waveform of the drive voltage is generated by superposition of sine waves. Here, in the present embodiment, an example in which a sawtooth waveform is used as the drive voltage waveform is shown, but the present invention is not limited to this. The waveform may be changed according to the device characteristics of the movable device, such as a drive voltage having a waveform with the apex of the sawtooth waveform rounded or a drive voltage having a curved linear region of the sawtooth waveform.

The operation of the first drive beams 120a and 120b when the drive voltage is applied is as described above, and the movable portion 110 reciprocally rotates about the first axis due to the bending deformation of the piezoelectric drive portion groups 150A and 150B.

<Cross-sectional shape of movable device>
Next, the cross-sectional shape of the movable device 13 will be described with reference to FIG. 16 is a cross-sectional view of the AA cross section indicated by the broken line in FIG.

FIG. 16 shows a cross-sectional structure of the first drive beams 120a and 120b, the movable part 110, and the fixed part 130.

The first drive beams 120a and 120b have an active layer 303 and piezoelectric drive unit groups 150A and 150B formed on the surface of the active layer 303 on the positive Z direction side.

The active layer 303 is an elastic body that deforms according to the deformation of the piezoelectric drive unit groups 150A and 150B, and is composed of a silicon active layer of the SOI substrate.

The piezoelectric drive unit groups 150A and 150B include a lower electrode 201, a piezoelectric material 202, and an upper electrode 203 which are sequentially formed on the surface of the active layer 303 in the positive Z direction. The lower electrode 201 and the upper electrode 203 are made of a metal thin film such as gold (Au) or platinum (Pt), and the piezoelectric material 202 is made of a piezoelectric material such as PZT (lead zirconate titanate).

Each of the piezoelectric drive units included in the piezoelectric drive unit groups 150A and 150B includes the same layer structure as described above. The piezoelectric drive unit groups 150A and 150B may be covered with an insulating layer such as SiO2 (silicon oxide), and electrical wiring may be provided in the positive Z direction.

Next, the movable portion 110 includes a support layer 351, an interlayer film 352 stacked on the surface of the support layer 351 in the positive Z direction, and a movable layer 353 stacked on the surface of the interlayer film 352 in the positive Z direction. have.

The support layer 351 is made of single crystal silicon of an SOI substrate, or an inorganic material, an organic material, or the like, and the interlayer film 352 is made of silicon oxide or the like. The movable layer 353 is an elastic body that deforms according to the deformation of the second drive beams 116a and 116b, and is composed of a silicon active layer or the like of the SOI substrate. Here, in the support layer 351, as shown in FIG. 16, the reflection surface support layer 351a on the negative Z direction side of the reflection surface 14 and the support portion support layer 351b on the negative Z direction side of the support portion 113. And are included.

Next, the fixed part 130 includes a fixed support layer 361, an interlayer film 362 stacked on the surface of the fixed support layer 361 in the positive Z direction, and an active layer stacked on the surface of the interlayer film 362 in the positive Z direction. 363 and.

The fixed support layer 361 is made of single crystal silicon of an SOI substrate, or an inorganic material, an organic material, or the like, and the interlayer film 362 is made of silicon oxide or the like. The active layer 363 is composed of a silicon active layer of the SOI substrate.

The active layers 303 and 363 and the movable layer 353 are not limited to the silicon active layer of the SOI substrate, and may be made of an oxidizer, an inorganic material, an organic material, or the like. The support layer 351 and the fixed support layer 361 may be made of an inorganic material, an organic material, or the like.

By the way, the second drive beams 116a and 116b (see FIG. 15) in the movable portion 110 have a beam-shaped member and an upper electrode, a piezoelectric member, and a lower electrode on the beam-shaped member, and at least the upper electrode, the piezoelectric member, and the lower portion. The electrodes are covered with an insulating layer. Further, the insulating layer expands and contracts together with the piezoelectric member when the drive beam is driven.

Further, one end of the second drive beam 116a is connected to the torsion bar 115a, and the other end of the second drive beam 116a is connected to the movable frame (support portion 113), and at least one of the upper electrode and the lower electrode is connected. The corner of the tip of the electrode on the one end side of the second drive beam 116a has a chamfered shape (for example, an arc shape or a tapered shape).

Similarly, one end of the second drive beam 116b is connected to the torsion bar 115b, the other end of the second drive beam 116b is connected to the movable frame (support portion 113), and at least the upper electrode and the lower electrode are connected. The corner of the tip of one electrode on the one end side of the second drive beam 116b has a chamfered shape (for example, an arc shape or a tapered shape).

In addition, in the present embodiment, the example in which the second drive beams 116a and 116b have the both-end supported beam structure in which both ends thereof are connected to the support portion 113 is shown, but the second drive beams 116a and 116b are the cantilever structure. May be In the cantilever structure, one end of the second drive beam 116a is connected to the support 113 and the other end is connected to the torsion bar 115a. Further, one end of the second drive beam 116b is connected to the support portion 113, and the other end is connected to the torsion bar 115b.

In the case of the cantilever structure, at least one of the upper electrode and the lower electrode provided on the second drive beams 116a and 116b has an arc-shaped or taper-shaped corner at the tip on the side connected to the torsion bar. Formed in. More preferably, both the upper electrode and the lower electrode are similarly formed in an arc shape or a taper shape.

With the above configuration, even if the dielectric strength is reduced due to the driving of the second drive beams 116a and 116b, the creeping discharge can be suppressed, and the durability of the movable device 13 can be improved.

Returning to FIG. 16, in the movable device 13 in the present embodiment, the thickness of the support layer 351 of the movable portion 110 is t ₁ , the thickness of the movable layer 353 of the movable portion 110 is t _2, and the fixed support layer 361 of the fixed portion 130. The respective portions are formed so as to satisfy the relationship of the following mathematical formula (1) and mathematical formula (2) when the thickness of is defined as t ₃ .

t ₁ ≧t ₂ (1)
t ₁ <t ₃ (2)
Further, in this embodiment, the movable device 13 is formed by a semiconductor manufacturing technique from an SOI substrate (wafer) having a multi-layered structure including a silicon active layer, an interlayer film, and a silicon supporting layer. Since the support layer 351 and the fixed support layer 361 are formed from the same silicon support layer, the support layer 351 and the fixed support layer 361 are made of the same material. The interlayer films 352 and 362 are also made of the same layer and therefore made of the same material, and the movable layer 353 and the active layers 303 and 363 are also made of the same silicon support layer, and thus made of the same material.

FIG. 17 shows a cross-sectional view of the movable device 13G of the comparative example. In the movable device 13G, the thickness t ₁ and the thickness t ₃ are equal. On the other hand, in the movable device 13 of the present embodiment shown in FIG. 16, the thickness t ₃ is larger (thicker) than the thickness t ₁ , and as a result, a void portion is formed on the negative Z direction side of the movable portion 110. Has been done.

By the way, when the thickness t ₂ of the movable layer 353 of the movable portion 110 is larger than the thickness t ₁ of the support layer 351, the weight of the movable portion 110 is increased, so that the resonance frequency of the movable portion 110 is lowered or the first driving is performed. The beams 120a and 120b and the second drive beams 116a and 116b may be more likely to be damaged.

When the position of the center of gravity of the movable section 110 is lower than the surface of the movable layer 353 on the negative Z direction side, the movable section 110 and the like are easily translated in the Z direction, and resistance to disturbance and uniformity of scanning are improved. It may decrease.

According to the present embodiment, by satisfying the relationship of the mathematical expression (1), it is possible to maintain the position of the center of gravity of the movable portion 110 high relative to the surface of the movable layer 353 on the negative Z direction side. As a result, it is possible to avoid the above-mentioned decrease in the resonance frequency, the risk of beam damage, the decrease in resistance to disturbance, the decrease in scanning uniformity, and the like.

Here, FIG. 18 is a diagram showing an example of the relationship between the ratio of the thickness t ₁ of the support layer 351 and the thickness t ₂ of the movable layer 353 in the movable portion 110 and the position of the center of gravity of the movable portion 110. The horizontal axis of FIG. 18 represents the ratio t ₁ /t ₂ of the thickness t ₁ and the thickness t ₂ , and the vertical axis represents the position of the center of gravity of the movable portion. The state where the center of gravity is on the negative Z-direction side surface of the movable layer 353 is the state where the center of gravity is zero.

As shown in FIG. 18, when the ratio t ₁ /t ₂ is larger than 5, the position of the center of gravity of the movable portion 110 becomes lower than the surface of the movable layer 353 on the negative Z direction side. Therefore, by setting the thickness t ₁ to 5 times or less than the thickness t ₂ , it is possible to maintain the center of gravity of the movable portion 110 in a high state with respect to the surface of the movable layer 353 on the negative Z direction side, which is preferable. .. That is, it is preferable to form the movable portion 110 so that t ₁ ≧t ₂ and t ₁ ≦5×t ₂ .

Returning to FIG. 16, by satisfying the relationship of Expression (2), the fixed support layer 361 of the fixed portion 130 becomes thicker, so that the rigidity of the fixed portion 130 increases. Accordingly, the fixing portion 130 can stably fix the first drive beams 120a and 120b. Further, since the rigidity of the fixed portion 130 is increased, it is possible to suppress damage to the movable device 13 during handling, and it is possible to ensure stability during die bonding.

When packaging the movable device 13 in a packaging member, if the movable unit 110 collides with the bottom of the packaging member during rotation unless a space is secured on the negative Z direction side of the movable unit 110. There is. Therefore, in order to secure a space on the negative Z direction side of the movable portion 110, it may be necessary to provide a counterbore hole or a spacer member at the bottom of the packaging member.

In the present embodiment, by satisfying the relationship of the mathematical expression (2), the void portion can be formed on the negative Z direction side of the movable portion 110, so that the space for rotating the movable portion 110 can be secured. Since it is not necessary to provide a counterbore hole or a spacer member, the cost of the packaged movable device 13 can be reduced.

FIG. 19 is a diagram showing an example of a configuration in which the movable device 13 is packaged in a housing. Compared with FIG. 13, the movable member 110 has a negative member without the mounting member 802 functioning as a spacer member. A space for rotating the movable portion 110 is secured on the Z direction side.

The packaging member 801 is an example of a “housing”, and the packaging is an example of “housing”.

On the other hand, it is possible to form a movable device by combining different substrates such as a semiconductor substrate and a glass substrate to form a void portion on the negative Z direction side of the movable portion 110. However, in this case, a plurality of different materials are used. Since a wafer is used, the manufacturing process may be complicated and the cost of the movable device may increase.

In this embodiment, the movable device 13 is formed by a semiconductor manufacturing technique from an SOI substrate (wafer) having a multi-layered structure including a silicon active layer, an interlayer film, and a silicon supporting layer, and the supporting layer 351 and the fixed supporting layer 361 are made of the same material. Constitute. Therefore, the movable device 13 can be manufactured without complicating the manufacturing process, and the cost of the movable device 13 can be reduced.

In the above description, an example in which the piezoelectric material is formed on the surface of the active layer 303 in the positive Z direction has been described, but it may be provided on the surface of the active layer 303 in the negative Z direction, or on both surfaces of the active layer 303. It may be provided.

Further, the shape of each component is not limited to the shape described in the present embodiment as long as the reflecting section 112 can be rotated around the first axis or the second axis. For example, the torsion bars 115a and 115b, the first drive beams 120a and 120b, the second drive beams 116a and 116b, etc. may have a shape having a curvature instead of a plane shape.

[Second Embodiment]
Next, the movable device of the second embodiment will be described with reference to FIG. In addition, in the second embodiment, description of the same components as those of the above-described embodiment may be omitted.

As described above with reference to FIG. 14, the movable device 13 may be packaged inside the package member 801 including the transparent member 803, and the movable device 13 may scan the light via the transparent member 803. In this case, the movable member 13 is arranged on the package member 801 by inclining the transparent member 803 and the movable device 13 relative to each other so that light that is multiply reflected by the transparent member 803 does not go out of the package member 801. There are cases.

As a comparative example, FIG. 21 shows a case where the transmissive member 803 and the movable device 13 are relatively inclined. In this example, the transmissive member 803 is inclinedly attached to the package member 801, so that the transmissive member 803 is inclined with respect to the movable device 13 arranged in the package member 801. The inclination angle is set to an angle such that the light multiply reflected between the reflecting surface 14 included in the movable device 13 and the transmitting member 803 does not go out of the package member 801.

With such a configuration, image noise or the like due to multiple reflected light is prevented. However, since a member for inclining the transparent member 803 and the movable device 13 relative to each other is necessary, the cost of the packaged movable device 13 may increase.

Therefore, in the movable device 13A of the present embodiment, the fixed portion 130A surrounds the movable portion 110 and the first drive beams 120a and 120b, is provided with four frame sides each including a fixed support layer, and fixedly supports each frame side. The layers have different thicknesses.

FIG. 20 is a cross-sectional view showing an example of the configuration of the movable device 13A of this embodiment. The plan view of the movable device 13A is similar to that shown in FIG. 15, and FIG. 20 is a cross-sectional view showing the AA cross section in FIG.

The movable device 13A includes a fixed portion 130A. The fixed part 130A has a rectangular frame structure having four frame sides like the fixed part 130, and the four frame sides surround the movable part 110 and the first drive beams 120a and 120b ( (See FIG. 15).

Of the four frame sides, the fixed support layer 361a on one of the two frame sides facing each other in the X direction and the fixed support layer 361b on the other frame side have different thicknesses as shown in FIG. ..

On the other hand, FIG. 22 is a diagram showing an example of a configuration when the movable device 13A is packaged inside a package member 801 including a transparent member 803.

Since the fixed support layer 361a and the fixed support layer 361b of the fixed portion 130A have different thicknesses, when the movable device 13A is arranged at the bottom of the package member 801, as shown in FIG. The movable device 13A tilts.

Thereby, the transmissive member 803 and the movable device 13 can be relatively inclined, and the multiple reflected light can be suppressed. Since the member for relatively inclining the transparent member 803 and the movable device 13 is not provided, the cost of the packaged movable device 13A can be reduced.

Further, FIG. 23 is a cross-sectional view showing an example of the configuration of a movable device 13B which is a modification of the movable device of the second embodiment. In the fixed portion 130B of the movable device 13B, the surfaces of the fixed support layers 361c and 361d on the negative Z direction side are inclined with respect to the stacking direction (thickness direction) of the active layer 363 and the like.

Accordingly, when the movable device 13B is arranged inside the package member 801 including the transparent member 803 and the movable device 13B is packaged, the movable device 13B can be tilted with respect to the transparent member 803, and the same as above. The effect of can be obtained.

The surfaces of the fixed support layers 361c and 361d on the negative Z direction side are examples of “a surface inclined with respect to the stacking direction”.

[Third Embodiment]
Next, the movable device according to the third embodiment will be described with reference to FIG.

When light is scanned in the Y direction (see FIG. 15) by the movable device 13C, the distance between the reflecting surface 14 and the frame side is short in the Y direction, so when the scanning angle becomes large, the light is blocked by the frame side of the fixed portion 130C. May be done.

Therefore, in the present embodiment, of the four frame sides of the fixing portion 130C, the thickness of the fixed support layer on the longer frame side is smaller than the thickness of the fixed support layer on the shorter frame side. ..

FIG. 24 is a perspective view showing an example of the configuration of the movable device 13C of the third embodiment.

As shown in FIG. 24, the thickness of the fixed support layer on the longer frame side is smaller than the thickness of the fixed support layer on the shorter frame side. The longer frame side is closer to the reflecting surface 14 than the shorter frame side. Further, by reducing the thickness of the frame side, the height of the light shielding part of the frame side can be made closer to the height of the reflecting surface.

Thus, by making the thickness of the fixed support layer on the longer frame side thinner than the thickness of the fixed support layer on the shorter frame side, blocking of the scanning light by the frame side is suppressed, and the light amount of the scanning light is reduced. Can be suppressed.

Note that the thickness of the fixed support layer on the longer frame side may be partially reduced.

[Fourth Embodiment]
Next, the movable device according to the fourth embodiment will be described with reference to FIG.

In the packaged movable device 13, the fixed part 130 is bonded to the bottom of the package member 801. In this case, when the entire bottom surface of the fixed portion 130 (the surface of the fixed support layer 361 on the negative Z direction side) contacts the package member 801, the connection portions 109a and 109b (the connecting portions 109a and 109b of the fixed portion 130 and the first drive beams 120a and 120b ( (See FIG. 15) may be directly affected by vibration applied to the package member 801 or electrical disturbance noise. As a result, the movable part 110 may not rotate properly.

Therefore, in the movable device 13D according to the present embodiment, the thickness of the fixed portion 130D is partially changed so that the noise transmission path from the bottom of the package member 801 to the connection portions 109a and 109b (see FIG. 15) is long (in a detour). is doing.

FIG. 25 is a cross-sectional view showing an example of the BB cross section in FIG.

As shown in FIG. 25, the fixed support layer 361D of the fixed portion 130D is provided with a recess 361Da, and the thickness t ₃ of the fixed support layer 361D is partially the thickness t _3D . The recess 361Da is a groove that penetrates the fixed support layer 501D in the Y direction. However, it is not limited to this, and may be a depression.

With such a configuration, the noise transmission path from the bottom of the package member 801 to the connecting portions 109a and 109b (see FIG. 15) is lengthened (circumnavigated), and vibration or electrical disturbance noise applied to the package member 801 is increased. The influence of can be suppressed.

The location where the recess 361Da for partially changing the thickness is provided is not limited to one location, and a plurality of locations may be provided. Further, the recess 361Da may be provided by a post process after the movable device 13D is manufactured.

[Fifth Embodiment]
FIG. 26 is a plan view showing an example of the configuration of the movable device 13E of the fifth embodiment.

The movable device 13E is a uniaxial movable device that includes the first drive beams 120a and 120b and the movable portion 110E including the reflecting surface 14, and is rotatable only around the X axis.

27 is a plan view showing an example of the configuration of a movable device 13F that is a modification of the movable device 13E of the fifth embodiment.

The movable device 13F includes the torsion bars 115a and 115b, the second drive beams 116a and 116b, and the movable portion 110F including the reflecting surface 14, and is a uniaxial movable device that can rotate only around the Y axis. is there.

The above-described embodiment can be applied to the uniaxial movable devices 13E and 13F to obtain the above-described effects.

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.

10 Optical Scanning System 11 Control Device 12, 12b Light Source Device 13, 13A, 13B, 13C, 13D, 13E, 13F Movable Device 14 Reflective Surface 15 Scanned Surface 25 Light Source Device Driver 26 Movable Device Driver 30 Control Unit 31 Drive Signal Output Unit 50 Laser headlamp 51 Mirror 52 Transparent plate 60 Head mount display 60a Front 60b Temple 61 Light guide plate 62 Half mirror 63 Wearer 110 Movable part 112 Reflecting part 113 Support part 114a, 114b Connecting part 115a, 115b Torsion bar 116a, 116b Second Driving beam 120a, 120b First driving beam 130 Fixed part 140 Electrode terminal 150A, 150B Piezoelectric drive part group 201 Lower electrode 202 Piezoelectric material 203 Upper electrode 303 Active layer 351 Support layer 351a Reflective surface support layer 351b Support part support layer 352 Interlayer film 353 movable layer 361, 361a, 361b, 361c, 361d fixed support layer 362 interlayer film 363 active layer 400 automobile (an example of vehicle)
500 Head-up display device (one example of image projection device, one example of head-up display)
650 laser printer 700 lidar device (an example of an object recognition device)
702 Object 801 Package member 802 Mounting member 803 Transparent member

Japanese Patent No. 6092590

Claims (13)

A movable part having a reflecting surface,
A pair of drive beams, each of which has one end connected to the movable portion and rotatably supports the movable portion with the movable portion interposed therebetween.
A fixing portion that is connected to the other end of each of the pair of drive beams and that fixes the pair of drive beams,
The movable part includes a support layer and a movable layer provided in the stacking direction of the support layers,
The fixed portion includes a fixed support layer made of the same material as the support layer,
When the thickness of the support layer is t ₁ , the thickness of the movable layer is t _2, and the thickness of the fixed support layer is t ₃ , then t ₁ ≧t ₂ and t ₁ <t ₃ . Mobile device. The movable device according to claim ₁ , wherein t ₁ ≧t ₂ and t ₁ ≦5×t ₂ . The fixed portion includes four frame sides that surround the movable portion and the pair of drive beams, each of which includes the fixed support layer, and the fixed support layer has a different thickness for each frame side. Or the movable device according to item 2. The movable device according to claim 1, wherein the fixed portion includes a surface inclined with respect to the stacking direction. The fixed part surrounds the movable part and the pair of drive beams, and includes four rectangular frame sides each including the fixed support layer, and the longer frame side of the four frame sides. The movable device according to any one of claims 1 to 4, wherein the fixed support layer has a smaller thickness with respect to the shorter frame side. The movable device according to any one of claims 1 to 5, wherein the fixed support layer has a recess having a partially different thickness. 7. The movable device according to claim 1, further comprising a transparent member and a housing that houses the movable device. An image projection apparatus comprising the movable device according to claim 1. A head-up display comprising the movable device according to claim 1. A laser headlamp comprising the movable device according to claim 1. A head mount display comprising the movable device according to claim 1. An object recognition device comprising the movable device according to claim 1. A vehicle comprising at least one of the head-up display according to claim 9, the laser headlamp according to claim 10, and the object recognition device according to claim 12.

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