JP2023047818A - Optical path-changing device and projection image display device - Google Patents

Abstract

To provide an optical path-changing device capable of driving with low noise, and a projection image display device using the same.SOLUTION: The optical path-changing device includes: a light transmission part that transmits light; at least two actuators each have a movable part whose movement is controlled in one axis direction; an arm having elasticity with one end connected with the moving part of the actuator and the other end connected with the light transmission part; and a control unit that controls the reciprocating drive of the actuator at a specific cycle. The control unit is configured to control the actuator so as to drive the light transmission part to stop when the actuator stops when controlling the drive of the actuator from a position of maximum displacement on one side to the position of maximum displacement on the other in the reciprocating drive.SELECTED DRAWING: Figure 5

Description

The present disclosure relates to an optical path changing device and a projection image display device having the same.

Patent Literature 1 discloses an optical member drive control device that changes the optical path of an incident light beam by tilting a parallel plate glass.

WO2015/098120

In recent years, there has been a demand for higher resolution of projected images, and an optical path changing device that drives at a higher speed is desired. However, the higher the driving speed, the greater the driving force required, and the greater the vibration that is transmitted to the housing that supports the optical path changing device, which may result in the generation of loud noise.

An object of the present disclosure is to provide an optical path changing device that can be driven with lower noise and a projection type image display device using the same.

The optical path changing device of the present disclosure includes at least two actuators each having a light transmitting portion that transmits light and a movable portion whose movement is controlled in a uniaxial direction, one end of which is connected to the movable portion of the actuator, and the other end of which is light transmitting. and an elastic arm connected to the unit, and a control unit that controls the reciprocating drive of the actuator in a specific cycle. The control unit drives and controls the actuator so that the light transmission unit stops at the timing when the actuator stops when driving and controlling the actuator from the position of the maximum displacement amount on one side to the position of the maximum displacement amount on the other side in the reciprocating drive. do.

A projection-type image display device of the present disclosure includes the optical path changing device described above.

According to the present disclosure, it is possible to provide an optical path changing device that can be driven with lower noise and a projection type image display device using the same.

1 is an overall diagram showing the configuration of a projection-type image display device according to an embodiment; Perspective view of a projection lens unit attached to a projection type image display device Perspective view of the projection lens unit removed from the projection type image display device Cross-sectional view of an optical path changing device, a projection lens unit, and an optical chassis according to an embodiment 1 is an external perspective view of an optical path changing device according to an embodiment; The side view of the light transmission part of embodiment, and an arm 1 is a block diagram showing the structure of an optical path changing device according to an embodiment; FIG. Explanatory drawing explaining the amount of movement of the light transmission part in embodiment. Explanatory drawing explaining the movement amount of the light transmission part in a comparative example Graph showing the displacement of the movable portion and the displacement of the end portion of the light transmitting member in the embodiment Graph showing displacement of the position of the movable part in the embodiment Graph showing the displacement of the position of the end of the light transmitting member in the embodiment Graph showing the displacement of the position of the movable part in the comparative example Graph showing the displacement of the position of the end of the light transmitting member in the comparative example Explanatory drawing explaining the initial position of the actuator Explanatory diagram for explaining the driving operation of the actuator 105 Explanatory diagram for explaining the driving operation of the actuator in the first position Explanatory diagram for explaining the drive operation of the actuator in the second position Explanatory diagram for explaining the drive operation of the actuator in the third position Explanatory diagram for explaining the drive operation of the actuator in the fourth position Explanatory drawing explaining the initial position of the actuator in a modification Explanatory drawing explaining the drive operation of the actuator in a modification. Graph showing actuator drive control waveforms Graph showing actuator drive control waveforms Explanatory diagram showing the simulation model Table showing odd multiples of the fundamental frequency Explanatory diagram in which odd-numbered multiples of the fundamental frequency are arranged

Hereinafter, embodiments will be described in detail with reference to the drawings as appropriate. However, more detailed description than necessary may be omitted. For example, detailed descriptions of well-known matters and redundant descriptions of substantially the same configurations may be omitted. This is to avoid unnecessary verbosity in the following description and to facilitate understanding by those skilled in the art.

It is noted that the inventor(s) provide the accompanying drawings and the following description in order for those skilled in the art to fully understand the present disclosure, which are intended to limit the claimed subject matter. not something to do.

(Embodiment)
An embodiment will be described below with reference to FIG. FIG. 1 is an overall view for explaining the configuration of the optical system of a projection image display device 200 including the optical path changing device 100 of the present disclosure. In the following description, an X1Y1Z1 orthogonal coordinate system is set as shown in FIG.

[1-1. overall structure]
A laser light source is composed of a plurality of blue semiconductor lasers 301 in order to realize a high-luminance illumination device. Laser light emitted from each blue semiconductor laser 301 is collimated by a corresponding collimator lens 302 . The light emitted from the collimator lens 302 becomes substantially parallel light, the entire light flux is collected by the condenser lens 303 , passes through the diffusion plate 304 , and is again substantially parallelized by the lens 305 . A laser beam substantially collimated by the lens 305 is incident on a dichroic mirror 306 arranged at approximately 45 degrees with respect to the optical axis.

The diffusion plate 304 is a glass flat plate, and one side thereof is formed with a diffusion surface having fine unevenness. Further, the dichroic mirror 306 has a characteristic of reflecting light in the wavelength range of the blue semiconductor laser 301 and transmitting light in other wavelength ranges.

The laser beam incident on the dichroic mirror 306 in the -X1 direction is reflected by the dichroic mirror 306 and emitted in the -Z1 direction. After that, the laser light is condensed by condensing lenses 307 and 308 to excite the phosphor formed on the phosphor wheel 320 .

The phosphor wheel 320 is provided with segments in which red phosphors and green phosphors are formed in the circumferential direction on a disk-shaped substrate, and further provided with openings as light transmission regions.

Red light and green light obtained from the red and green phosphors of phosphor wheel 320 are emitted from phosphor wheel 320 . These red light and green light are collimated by condensing lenses 308 and 307 , pass through dichroic mirror 306 , condensed by condensing lens 317 , and enter rod integrator 318 .

On the other hand, the blue light from the blue semiconductor laser 301 that has passed through the opening of the phosphor wheel 320 travels along the route of the lens 309, lens 310, mirror 311, lens 312, mirror 313, lens 314, mirror 315, and lens 316, and is dichroic. The light is reflected by the mirror 306 , condensed by the condensing lens 317 , and enters the rod integrator 318 . Lenses 312, 314 and 316 function as relay lenses.

The light emitted from the rod integrator 318 passes through lenses 330, 331, and 332 and enters a total reflection prism 335 consisting of a pair of prisms 333 and 334. The light is modulated by a video signal at a DMD (Digital Mirror Device) 336, which is an optical modulation element. Incident light is modulated and emitted as image light. Lenses 330 and 331 are relay lenses, and lens 332 has a function of forming an image of light from the exit surface of rod integrator 318 on DMD 336 .

The image light emitted from the DMD 336 enters the light transmission member 101a arranged inside the optical path changing device 100 . The light transmitted through the light transmission member 108 is incident on the projection lens unit 337, and the light emitted from the projection lens unit 337 is enlarged and projected onto the screen as image light.

The optical path changing device 100 can move the display position of the image light by inclining the light transmitting member 101a with respect to the optical axis AL. With this function, wobbling display can be performed on the projection type image display device 200 . Here, the wobbling display is a method of displaying different images while shifting the display position multiple times during one frame period of the input image to equivalently improve the resolution of the displayed image, and is also called pixel shift display. . Drive control device 110 (see FIG. 5) drives actuator 105 with a control signal synchronized with the driving of DMD 336 .

Next, attachment/detachment of the projection lens unit 337 to/from the projection type image display apparatus 200 will be described with reference to FIGS. 2A, 2B, and 2C. FIG. 2A is a perspective view of a projection lens unit attached to a projection type image display device. FIG. 2B is a perspective view of the projection lens unit removed from the projection type image display apparatus. 2C is a cross-sectional view of optical path changing device 100, projection lens unit 337, and optical chassis 338. FIG. In FIG. 2 and subsequent drawings, an XYZ orthogonal coordinate system is set such that the direction of the optical axis AL is the Z-axis direction, and the plane perpendicular to the Z-axis direction is the XY plane.

The projection lens unit 337 has a projection lens 337a for enlarging and projecting incident image light. The projection lens unit 337 is attachable to and detachable from an optical chassis 338 that is part of the case of the projection image display apparatus 200 . The projection lens 337a is attached to a projection lens mounter 337b, and the projection lens mounter 337b is attached to the optical chassis 338. FIG. The optical path changing device 100 is attached to the optical chassis 338 . As shown in FIG. 2C, the light transmitting portion 101 of the optical path changing device 100 and the projection lens 337a are arranged on the optical axis AL. The optical path changing device 100 is arranged in a narrow space between the projection lens 337a and other optical system components in the optical chassis 338. As shown in FIG.

[1-2. Optical path changing device]
Next, the main configuration of the optical path changing device 100 will be described in detail with reference to FIG. FIG. 3 is an external perspective view of the optical path changing device 100. FIG.

The optical path changing device 100 includes a light transmission section 101, an arm 103, a first actuator 105A, a second actuator 105B, a third actuator 105C, a fourth actuator 105D, and a position detection element 107. .

The light transmission part 101 shifts the light on the optical axis AL and in parallel with the optical axis AL and transmits the light. The light transmitting portion 101 has a light transmitting member 101a and a support frame 101b. The light transmission member 101a is a member through which image light is transmitted, and is, for example, parallel plate glass. The support frame 102 has rigidity and supports the outer periphery of the light transmitting member 101a. The support frame 101b has, for example, a substantially square outer peripheral shape, and the four arms 103 are connected to the portions where the four corners are cut to form an oblique side. The light transmitting portion 101 can be tilted in a direction intersecting the optical axis AL by driving the arm 103 in the optical axis AL direction by the actuator 105 .

The actuators 105A, 105B, 105C, and 105D each reciprocate the connected arm 103 in a uniaxial direction, for example, along the optical axis AL direction. In the following description, actuators 105A to 105D are simply referred to as actuator 105 when common description is given. Actuator 105 uses, for example, a voice call motor (VCM).

The arm 103 supports the light transmitting portion 101 and drives the connection point with the light transmitting portion 101 in the optical axis AL direction. The arm 103 is made of an elastic member. The material used for the arm 103 is elastic enough to be angularly displaced by an external factor at the bending portion and to return to the original angle when the movement of the actuator 105 is reversed. Therefore, the arm 103 has greater elasticity due to bending and warping than elasticity due to expansion and contraction. The arm 103 is, for example, a SUS304-based or SUS301-based member. SUS304 series or SUS301 series members are steel types classified as austenitic stainless steels. The thickness of the arm 103 is, for example, 0.1 mm or more and 0.5 mm or less.

The arm 103 has a first bent portion 103a, a second bent portion 103b, and a third bent portion 103c, which are formed by bending a plate-like member at three points. Further, the arm 103 has a first plate-like portion 103d, a second plate-like portion 103e, a third plate-like portion 103f, and a fourth plate-like portion 103g that extend linearly.

One end of the first bent portion 103a is connected to the light transmitting portion 101 via the second plate-like portion 103e, and the other end of the first bent portion 103a is connected to one end of the first plate-like portion 103d. ing. One end of the second bent portion 103b connects to the actuator 105 via the third plate-like portion 103f, and the other end of the second bent portion 103b connects to the third plate-like portion 103g via the fourth plate-like portion 103g. It connects with the bent portion 103c. The third plate-like portion 103f is fixed to the upper end of the actuator 105 with screws, for example. One end of the third bent portion 103c is connected to one end of the first plate-like portion 103d.

The first bent portion 103a, the second bent portion 103b, and the third bent portion 103c have elasticity due to changes in bending angle. Also, the first plate-like portion 103d, the second plate-like portion 103e, the third plate-like portion 103f, and the fourth plate-like portion 103g have elasticity due to warping and twisting. Therefore, the first bent portion 103a, which is the first elastic portion, and the first plate-like portion 103d, which is the second elastic portion, have different elastic moduli.

Among the four arms 103 , one set of arms 103 is arranged orthogonal to the other set of arms 103 . In the set of arms 103, two arms 103 are arranged to face each other.

The position detection element 107 is attached to the movable portion 106 and detects the position of the portion of the arm 103 to which the actuator 105 is attached from the amount of movement of the movable portion 106 . A position detection element 107 detects the position of the arm 103 from the amount of movement of the movable portion 106 that reciprocates inside the actuator 105 .

Next, the configuration of the control system of the optical path changing device 100 will be described with reference to FIG. The optical path changing device 100 further includes a drive control device 110 that drives and controls each actuator 105 , a drive waveform generation circuit 111 that generates a drive waveform for each actuator, and a drive timing generation circuit 113 .

A drive timing generation circuit 113 generates a timing signal for generating each drive waveform corresponding to each actuator 105 based on a synchronization signal input having a period of the input image signal in synchronization with the input image signal. Occur.

The drive waveform generation circuit 111 uses the timing signal for generating the drive waveform supplied from the drive timing generation circuit 113 to generate the drive waveform corresponding to each actuator 105 in synchronization with the image signal input from the outside. do. Therefore, the drive waveform indicates the ideal amount of displacement of the movable portion 106 . Each generated drive waveform is sent to the corresponding drive controller 110 .

The drive control device 110 feedback-controls the drive amount of each actuator 105 based on the position signal input from the position detection element 107 according to the received drive waveform. The control method uses, for example, PID control. As a result, each actuator 105 is driven, and the portion connected to the movable portion 106 that reciprocates inside the actuator 105 of each connecting arm 103 is displaced. is displaced. In this manner, the movement of the light transmitting portion 101 with respect to the optical axis is controlled. The drive control device 110 can be composed of, for example, a microcomputer, CPU, MPU, GPU, DSP, FPGA, and ASIC. The drive controllers 110 associated with each actuator 105 may be integrated into one controller.

Next, referring to FIGS. 6 and 7, the function of the first bent portion 103a of the arm 103 will be described. FIG. 6 is an explanatory diagram for explaining the amount of movement of the light transmitting portion in the embodiment. FIG. 7 is an explanatory diagram for explaining the movement amount of the light transmitting portion in the comparative example.

In the embodiment, the distance from the central axis of the light transmitting portion 101 to the end of the support frame 101b of the light transmitting portion 101 is La, and the distance from the central axis of the light transmitting portion 101 to the movable portion 106 of the actuator 105 is Lb. and As an example, a case of La:Lb=1:2 will be described. In the embodiment, the arm 103 connected to the light transmitting portion 101 has a first bent portion 103a near the connection point P1 connected to the light transmitting portion 101 . As a result, the relationship between the movement amount L1 of the connection point P1 between the arm 103 and the light transmitting portion 101 and the movement amount L2 of the movable portion 106 along the optical axis AL direction is L1:L2=1.4: 2. in short. Since L1/L2>La/Lb, the amount of movement of the connection point P1 can be increased.

On the other hand, in the case of the comparative example shown in FIG. In this configuration, the plate-like portion in the central portion of is extended as it is and connected to the light transmission portion 101 . In this configuration, the angles θ between the arms 103Z and the light transmitting portions 101 are the same. The relationship between the movement amount L3 of the connection point P1 between the arm 103Z and the light transmitting portion 101 and the movement amount L2 of the movable portion 106 along the optical axis AL direction is L3:L2=1:2. in short. Since L3/L2=La/Lb, the amount of movement of the connection point P1 is smaller than in the embodiment. Here, the fact that the first bent portion 103a is located near the connection point P1 means that the second plate-like portion 103e has a length of 1/10 or less of the total length of the arm 103, or has a length of 5 mm or less. The length is:

As described above, according to the embodiment, the arm 103 has the first bent portion 103a near the connection point P1 connected to the light transmitting portion 101, so that the light transmitting portion 101 is bent by the elasticity of the bent shape. can be moved further along the optical axis AL direction. This is because when the movable portion 106 moves, the arm 103 bends by bending the first bent portion 103a of the arm 103 that interlocks with the movable portion 106. Therefore, as shown in FIG. occurs at point P1. FIG. 8 is a graph showing the displacement PV1 of the movable portion 106 and the displacement PV2 of the end portion of the light transmitting member 101a in the embodiment.

When the amount of movement of the movable portion 106 is small, the arm 103 bends due to the inertial force of the mass of the light transmitting portion 101, and the connection point P1 does not move. is accelerated by the spring force due to the bending of the arm 103, and after starting to move, it moves at high speed, reaches a movement amount larger than the movement amount of the movable part 106, and then decelerates due to the spring force due to the bending of the arm 103 in the opposite direction. and stop moving. Such movement allows the light transmitting portion 101 of the embodiment to be displaced at a higher speed.

FIG. 9 is a graph showing the actual displacement of the movable portion 106 according to the embodiment, and FIG. 10 is a graph showing the actual displacement of the end portion of the light transmitting member 101a according to the embodiment. FIG. 11 is a graph showing the actual displacement of the movable portion 106 of the comparative example, and FIG. 12 is a graph showing the actual displacement of the end portion of the light transmitting member 101a of the comparative example.

As shown in FIGS. 9 and 10, in the embodiment, when the movable part 106 is displaced by about 0.1 mm in 1.7 msec, the end of the light transmitting member 101a is displaced in 0.8 msec. It is displaced by about 0.07 mm. On the other hand, in the case of the conventional example, as shown in FIG. 11, when the movable portion 106 is displaced by approximately 0.1 mm in 1.7 msec, the end of the light transmitting member 101a is approximately 0.8 mm. It is displaced by 0.05 mm in ~1.7 msec. As described above, even if the movable portion 106 is moved by the same displacement amount, the displacement amount of the end portion of the light transmitting member 101a is larger in the embodiment than in the comparative example, and the displacement can be performed in a short time. Further, as shown in FIG. 10, in the embodiment, since the first bent portion 103a is used as the first elastic portion, compared with the case of using a coil spring, for example, the end portion of the light transmitting member is Shaking can be converged early.

Next, an example of driving operation of the four actuators 105 will be described with reference to FIGS. 13A to 17. FIG. FIG. 13A is an explanatory diagram showing the initial position of the actuator 105. FIG. 13B is a table showing drive positions of the actuator 105. FIG. 14 to 17 are explanatory diagrams explaining the driving operation of the actuator 105, respectively.

As shown in FIG. 13A, the axes obtained by parallelly moving the line connecting the opposing actuators 105 to the position of the center of gravity of the light transmitting portion 101 are defined by the two sets of actuators 105 so as to be orthogonal to each other, and the position of the intersection of these lines is defined as I try to make movements that do not move up, down, left, or right. In order to realize this movement, the actuator 105 is driven and controlled so that the light transmitting portion 101 rotates around the two rotation axes Ra1 and Ra2.

The drive control device 110 cooperatively controls the four actuators 105 so that the movable parts 106 of two actuators 105 out of the four actuators 105 are sequentially operated in any adjacent direction. As shown in FIG. 13B, the four actuators 105A to 105D are cooperatively controlled to four states of positions 1 to 4 in addition to position 0 which is the initial position. In FIG. 13B, for the four actuators 105A-105D, "0" indicates a centered position, "+1" indicates a raised position in the Z-axis direction, and "-1" indicates a raised position in the Z-axis direction. Indicates the lowered position. FIG. 13A shows the four actuators 105 at position 0 in their initial positions. When light is not projected in the pixel shift mode, light is transmitted in the state of position 0 without driving the respective actuators 105 .

FIG. 14 shows the state of the four actuators 105 at position 1. FIG. The second actuator 105B accommodates the movable portion 106, and the fourth actuator 105D drives the movable portion 106 to protrude. Accordingly, the first actuator 105A and the second actuator 105B do not protrude from their respective movable portions 106, and the third actuator 105C and the fourth actuator 105D drive their respective movable portions 106 to protrude. , the corresponding arms 103 are pushed out in the direction of the optical axis AL.

Next, FIG. 15 shows the state of the four actuators 105 at position 2. As shown in FIG. The third actuator 105C accommodates the movable portion 106, and the first actuator 105A drives the movable portion 106 to protrude. Accordingly, the second actuator 105B and the third actuator 105C do not protrude from their respective movable portions 106, and the fourth actuator 105D and the first actuator 105A drive their respective movable portions 106 to protrude. , the corresponding arms 103 are pushed out in the direction of the optical axis AL.

Next, FIG. 16 shows the state of the four actuators 105 at position 3. As shown in FIG. The fourth actuator 105D accommodates the movable portion 106, and the second actuator 105B drives the movable portion 106 to protrude. Accordingly, the third actuator 105C and the fourth actuator 105D do not protrude from their respective movable portions 106, and the first actuator 105A and the second actuator 105B drive their respective movable portions 106 to protrude. , the corresponding arms 103 are pushed out in the direction of the optical axis AL.

Next, FIG. 17 shows the state of the four actuators 105 at position 4. As shown in FIG. The first actuator 105A accommodates the movable portion 106, and the third actuator 105C drives the movable portion 106 to protrude. Accordingly, the fourth actuator 105D and the first actuator 105A do not protrude from their respective movable portions 106, and the second actuator 105B and the third actuator 105C drive their respective movable portions 106 to protrude. , the corresponding arms 103 are pushed out in the direction of the optical axis AL.

Then again we return to the state of the four actuators 105 at position 1, as shown in FIG. The first actuator 105A accommodates the movable portion 106, and the third actuator 105C drives the movable portion 106 to protrude. In this manner, each drive control device 110 drives and controls the corresponding actuators 105 so that the adjacent actuators 105 are sequentially operated in one direction, thereby tilting the light transmitting member 101a with respect to the optical axis AL. In this state, the inclination state can be changed one after another, and the transmitted light can be shifted to four positions in order.

Further, as shown in FIG. 18A, the two rotation axes Ra1 and Ra2 may be rotated 45 degrees from the above example about the optical axis and set in the extending direction of the respective arms 103. FIG. In this case, as shown in FIG. 18B, the four actuators 105A to 105D may be cooperatively controlled to four states of positions 5 to 9 in addition to position 0 which is the initial position.

By controlling the four actuators 105 cooperatively in this way, it is possible to shift the traveling direction of light in two axial directions of the horizontal direction and the vertical direction, thereby realizing more precise and high-speed pixel shift control. can be done.

The cooperative drive control of the four actuators 105 has been described above. Next, drive control of each actuator 105 will be described with reference to FIGS. 5, 19A, 19B, and 20. FIG. First, the drive waveform for the actuator 105 generated by the drive waveform generation circuit 111 will be described. In addition, in FIGS. 19A and 19B, the time is shown as the time normalized by the period T. FIG.

The drive timing generation circuit 113 shown in FIG. 5 performs driving as shown in FIG. Generate timing signals. (a) of FIG. 19A shows a synchronization signal having a period T. FIG. A synchronization signal is a repetitive timing signal having a period T. (b) of FIG. 19A shows the drive timing signal generated by the drive timing generation circuit 113 . The drive timing generation circuit 113 generates a drive timing signal, which is a time-series timing signal, based on the synchronization signal of period T. FIG.

The drive waveform generation circuit 111 shown in FIG. 5 is as shown in (c) of FIG. 19A. A control target position signal for the actuator 105 is generated. (c) of FIG. 19A shows the target signal for the actuator position generated by the drive waveform generation circuit 111 .

The drive control device 110 of FIG. 5 compares the output of the position detection element 107 with the actuator position target signal shown in (c) of FIG. 19A, and generates the acceleration force of the actuator 105 as shown in (d) of FIG. 19A. . (d) of FIG. 19A shows the acceleration force of the actuator 105 .

By integrating the graph of the acceleration force of the actuator 105 in (d) of FIG. 19A, the graph of the velocity of the actuator 105 shown in (e) of FIG. 19A can be obtained. (e) of FIG. 19A shows the speed of the actuator 105 . By further integrating the graph of (e) of FIG. 19A, a graph of the position of the actuator 105 shown in (f) of FIG. 19A can be obtained. The control target position signal of the actuator 105 as shown in (c) of FIG. 19A and the position of the actuator 105 shown in (f) of FIG. The actuator position target signals shown in (c) are compared and controlled to be equal by the configuration for generating the acceleration force of the actuator 105 as shown in (d) of FIG. 19A. (f) of FIG. 19A shows the waveform of the position of the actuator 105 .

It can be considered that the light transmitting portion 101 has an inertial force M and is connected to an arm 103 having an elastic modulus D. FIG. (g) of FIG. 19B shows the waveform of the relationship between the amount of displacement of the light transmitting portion 101 and the amount of displacement of the actuator 105 .

FIG. 19B (h) shows a graph of the difference between the position of the actuator 105 shown in (f) of FIG. 19A and the position of the light transmitting portion 101 based on the simulation results shown in (g) of FIG. 19B. A difference between the position of the actuator 105 and the position of the light transmitting portion 101 corresponds to the strain of the actuator 105 . An acceleration force proportional to the difference between the position of the actuator 105 and the position of the light transmitting portion 101 is generated in the light transmitting portion 101 . The speed of the light transmitting portion 101 shown in (i) of FIG. 19B is determined by time integration of this acceleration force. Further, by integrating the graph of (i) in FIG. 19B, the graph of the position of the light transmitting portion 101 shown in (g) of FIG. 19B is obtained. Also, when creating the waveform of (c) in FIG. 19A, the waveform of (g) in FIG. 19B obtained by simulation is referred to, and the waveform of (c) in FIG. 19A is slightly modified to further improve accuracy. can be made

The target actuator position transition time Tt shown in (c) of FIG. This transition time Tt is controlled by a transition time adjustment value entered by the user. The transition time adjustment value is adjusted to a value that does not cause overshoot or undershoot in the waveform by observing the waveform at the position of the light transmission portion corresponding to (g) in FIG. 19A of the actual device. The repetition period T of the driving waveform is the repetition period of the input synchronization signal. The transition time Tt is constant regardless of the period of the input synchronization signal, and the time Ti during which the actuator 105 stops varies according to the period of the input synchronization signal.

The transition time adjustment values input to the drive waveform generation circuit 111 and the drive timing generation circuit 113 are values for correcting variations in elastic modulus of the arms 103 of the four actuators 105 . The transition time adjustment value is a value that sets the time Tt from when the actuator 105 starts moving until it stops.

Also, the fundamental frequency of the video signal is input to the drive timing generation circuit 113 . The fundamental frequencies are 48, 50 and 60 Hz. Based on the input fundamental frequency, the time Ti during which the actuator 105 stops is determined.

As shown in FIG. 19(f), the drive waveform generation circuit 111 and the drive timing generation circuit 113 are configured so that the velocity of the light transmitting portion 101 becomes zero at the time Ti at which the actuator 105 stops, as shown in FIG. 19(c). A position target waveform for the actuator 105 is generated. The drive control device 110 drives and controls the actuator 105 by PID control, for example, so that the actuator position target waveform and the detected value from the position detection element 107 become equal.

Next, the target resonance frequency will be described with reference to FIGS. 21 and 22. FIG. The resonance frequency of the optical path changing device 100 is determined by the time constant determined by the inertial force M determined by the shape and weight of the light transmitting portion 101 and the elastic modulus D determined by the material, width, thickness and shape of the arm 103 . The target resonance frequency is set so as to avoid being an odd multiple of the frequency of the input synchronization signal, and the light transmitting section 101 and the arm 103 are designed to achieve the set resonance frequency. The frequencies of the incoming synchronization signals may be, for example, 48, 50, and 60 Hz, and FIG. 21 shows odd multiples of these frequencies.

When these odd multiple frequencies are arranged as shown in FIG. 22, there is a portion where the difference between adjacent frequencies is large. For example, between 350-420 Hz, between 420-528 Hz, between 550-624 Hz, and so on. By setting 385 Hz, 474 Hz, and 587 Hz, which are intermediate frequencies between these adjacent frequencies, as target values for the resonance frequency, even if the resonance frequency varies due to variations in the inertial force M and the elastic modulus D, the input It is possible to avoid matching the resonance frequency to odd multiples of 48, 50 and 60 Hz, which are the frequencies of the synchronization signal. Thereby, it is possible to avoid the occurrence of unnecessary vibrations in the light transmitting portion 101 .

[1-3. effects, etc.]
As described above, the optical path changing device 100 according to the present embodiment includes at least two actuators 105 each having a light transmitting portion 101 that transmits light, and a movable portion 106 that is controlled to move along the optical axis AL. is connected to the movable portion 106 of the actuator 105 and the other end is connected to the light transmitting portion 101 . The optical path changing device 100 further includes a drive control device 110 that reciprocates and controls the actuator 105 at a specific cycle. When driving and controlling the actuator 105 from the position of the maximum displacement amount on one side to the position of the maximum displacement amount on the other side in the reciprocating drive, the drive control device 110 controls the light transmitting portion 101 to stop at the timing when the actuator 105 stops. , drive and control the actuator 105 .

In the optical path changing device 100 according to the present embodiment, the speed at which the end surface of the light transmitting portion 101 moves is higher than the moving speed of the movable portion 106 of the actuator 105. In this case, the moving speed of the movable portion 106 can be reduced. The operating sound generated when the optical path changing device 100 operates is generated by a force generated as a reaction to the force that drives the light transmitting portion 101 and the movable portion 106 of the actuator 105, and is proportional to the square of the moving speed of the object. grow larger. In the optical path changing device 100 of the present invention, only the light transmission part 101 is the part that operates at high speed, so that the operation noise can be reduced.

The optical path changing device 100 also includes a drive waveform generation circuit 111 that generates a drive waveform for each actuator 105 and a position detection element 107 that detects the position of the actuator 105 . The drive control device 110 compares the drive waveform generated by the drive waveform generation circuit 111 and the detection value of the position detection element 107, and drives and controls the actuator 105 so that the drive waveform and the detection value become equal. When driving and controlling the actuator 105 from the position of the maximum displacement amount on one side to the position of the maximum displacement amount on the other side in the reciprocating drive, the drive waveform generation circuit 111 controls the light transmitting portion 101 to stop at the timing when the actuator 105 stops. to generate a smooth drive waveform.

The arm 103 has a first bent portion 103a as a first elastic portion having different elastic moduli and a first plate-like portion 103d as a second elastic portion. and a first plate-like portion 103d as a second elastic portion in the central portion of the arm.

Since the arm 103 has the first bent portion 103a closer to the light transmitting portion 101 than the central first plate-like portion 103d, the light transmitting portion 101 is moved to a value close to the displacement amount of the movable portion 106 of the actuator 105. It is possible to reduce the amount of displacement of the movable portion 106 of the actuator 105, reduce the operating speed, and reduce the operating noise.

One end of the arm 103 is connected to the actuator 105 via the third plate-like portion 103f, and the other end is connected to the first plate-like portion 103d. and a third bent portion 103c connected to the other end of the second bent portion 103b via a fourth plate-like portion 103g.

Since arm 103 has a plurality of bent portions in this way, optical path changing device 100 can be arranged without interference even in a narrow space in projection lens unit 337 .

(Other embodiments)
As described above, the above embodiment has been described as an example of the technique of the present disclosure. However, the technology in the present disclosure is not limited to this, and can also be applied to embodiments with modifications, replacements, additions, omissions, and the like. Further, it is also possible to combine the constituent elements described in the above embodiments to form a new embodiment.

In the embodiment described above, the arm 103 has the first bent portion 103a as the first elastic portion, but the present invention is not limited to this. For example, the first elastic portion may be a plate-like portion having a width smaller than that of the first plate-like portion 103d. Even with this configuration, the first elastic portion has a higher elastic modulus than the first plate-like portion 103d as the second elastic portion, and the same effects as in the embodiment can be obtained.

In the embodiment described above, the optical path changing device 100 has four arms 103, but the number of arms 103 is not limited to this. The optical path changing device 100 may have two, three, five or more arms 103 . Also, the optical path changing device 100 is not limited to the four actuators 105 and may have the number of actuators 105 corresponding to the number of the arms 103 .

As described above, the embodiment has been described as an example of the technique of the present disclosure. To that end, the accompanying drawings and detailed description have been provided. Therefore, among the components described in the attached drawings and detailed description, there are not only components essential for solving the problem, but also components not essential for solving the problem in order to illustrate the above technology. can also be included. Therefore, it should not be immediately recognized that those non-essential components are essential just because they are described in the attached drawings and detailed description.

In addition, the above-described embodiments are intended to illustrate the technology of the present disclosure, and various modifications, replacements, additions, omissions, etc. can be made within the scope of the claims or equivalents thereof.

(Overview of Embodiment)
(1) The optical path changing device of the present disclosure includes at least two actuators having a light transmitting portion that transmits light and a movable portion whose movement is controlled in a uniaxial direction, one end of which is connected to the movable portion of the actuator, and the other end of which is connected to the movable portion of the actuator. is connected to the light-transmitting portion, and has an elastic arm and a control portion that controls the reciprocating drive of the actuator at a specific cycle. The control unit drives and controls the actuator so that the light transmission unit stops at the timing when the actuator stops when driving and controlling the actuator from the position of the maximum displacement amount on one side to the position of the maximum displacement amount on the other side in the reciprocating drive. do.

The control unit drives and controls the actuator so that the light transmission unit stops at the timing when the actuator stops. As a result, in the optical path changing device according to the present embodiment, the speed at which the end surface of the light transmitting portion moves is greater than the moving speed of the movable portion of the actuator. , it becomes possible to reduce the moving speed of the movable part. The operating sound generated during the operation of the optical path changing device is generated by a force generated as a reaction to the force that drives the light transmitting portion and the movable portion of the actuator, and increases in proportion to the square of the moving speed of the object. In the optical path changing device of the present invention, the portion that operates at high speed is only the light transmission portion, so it is possible to reduce this operating noise.

(2) The optical path changing device of (1) includes a drive waveform generation circuit that generates a drive waveform for each actuator, and a position detection element that detects the position of the actuator. The control unit compares the drive waveform generated by the waveform generation unit and the detection value of the position detection element, and drives and controls the actuator so that the drive waveform and the detection value become equal. The waveform generation unit generates a drive waveform such that the light transmission unit stops at the timing when the actuator stops when driving and controlling the actuator from the position of the maximum displacement amount on one side to the position of the maximum displacement amount on the other side in the reciprocating drive. do.

(3) In the optical path changing device of (2), the drive waveform generation circuit causes the actuator to move based on the transition time set according to the time constant determined by the inertial force of the light transmitting portion and the elastic modulus of the arm. Adjust the time of the drive waveform to start and stop.

(4) In the optical path changing device of (2) or (3), the resonance frequency determined by the time constant determined by the inertial force of the light transmitting portion and the elastic modulus of the arm is set so as not to be an odd multiple of the synchronizing signal. there is

(5) In the optical path changing device according to any one of (1) to (4), the arm has a first elastic portion and a second elastic portion having different elastic moduli, and a second elastic portion is provided on the light transmitting portion side of the arm. It has one elastic portion and a second elastic portion in the middle of the arm.

(6) In the optical path changing device of (5), the first elastic portion is the first bent portion where the arm is bent, and the second elastic portion is the first plate-like portion where the arm extends linearly. . One end of the first bent portion is connected to the light transmitting portion via the second plate-like portion, and the other end of the first bent portion is connected to one end of the first plate-like portion.

(7) In the optical path changing device of (5), the arm has one end connected to the actuator via the third plate-shaped portion, and one end connected to the other end of the first plate-shaped portion. and a third bent portion, the other end of which is connected to the other end of the second bent portion via the fourth plate-like portion.

(8) In the optical path changing device of (6), the arm is made of SUS304-based or SUS301-based material.

(9) A projection-type image display device of the present disclosure includes the optical path changing device according to any one of (1) to (8).

The present disclosure is applicable to projection display devices that display images while changing the display positions of pixels.

REFERENCE SIGNS LIST 100 optical path changing device 101 light transmitting portion 101a light transmitting member 101b support frame 103 arm 103a first bent portion 103b second bent portion 103c third bent portion 103d first plate-like portion 103e second plate-like portion 103f Third plate-like portion 103g Fourth plate-like portion 105 Actuator 105A First actuator 105B Second actuator 105C Third actuator 105D Fourth actuator 106 Movable portion 107 Position detection element 109 Position detection circuit 110 Drive control device 111 Drive waveform generation circuit 200 Projection type image display device 337 Projection lens unit 337a Projection lens 338 Optical chassis AL Optical axis L1, L2, L3 Movement amount P1 Connection point PV1, PV2 Displacement

Claims (9)

a light transmitting portion that transmits light;
at least two actuators having movable parts whose movement is controlled in a uniaxial direction;
an elastic arm having one end connected to the movable portion of the actuator and the other end connected to the light transmission portion;
a control unit that controls the reciprocating drive of the actuator in a specific cycle,
The control unit controls the actuator so that the light transmission unit stops at the timing when the actuator stops when driving and controlling the actuator from the position of the maximum displacement amount on one side to the position of the maximum displacement amount on the other side in the reciprocating drive. , driving and controlling the actuator;
Optical path changer. a drive waveform generation circuit for generating a drive waveform for each of the actuators;
a position detection element that detects the position of the actuator,
The control unit compares the drive waveform generated by the drive waveform generation circuit and the detection value of the position detection element, and drives and controls the actuator so that the drive waveform and the detection value are equal. ,
The drive waveform generation circuit causes the light transmitting portion to stop at the timing when the actuator stops when driving and controlling the actuator from a position of the maximum displacement amount on one side to a position of the maximum displacement amount on the other side in the reciprocating drive. to generate a drive waveform like,
The optical path changing device according to claim 1. The drive waveform generation circuit generates a drive waveform from the time when the actuator starts moving until it stops, based on a transition time set according to a time constant determined by the inertial force of the light transmitting portion and the elastic modulus of the arm. adjust the time of
The optical path changing device according to claim 2. The resonance frequency determined by the time constant determined by the inertial force of the light transmitting portion and the elastic modulus of the arm is set so as not to be an odd multiple of the synchronization signal.
The optical path changing device according to claim 2 or 3. The arm has a first elastic portion and a second elastic portion having different elastic moduli, the first elastic portion is provided on the side of the light transmitting portion of the arm, and the second elastic portion is provided at the center of the arm. having two elastic portions,
The optical path changing device according to any one of claims 1 to 4. the first elastic portion is a first bent portion where the arm is bent;
the second elastic portion is a first plate-like portion from which the arm extends linearly;
One end of the first bent portion is connected to the light transmitting portion via the second plate-like portion, and the other end of the first bent portion is connected to one end of the first plate-like portion. there is
The optical path changing device according to claim 5. the arm has a second bent portion, one end of which is connected to the actuator via a third plate-shaped portion;
a third bent portion having one end connected to the other end of the first plate-like portion and the other end connected to the other end of the second bent portion via a fourth plate-like portion;
The optical path changing device according to claim 6. The arm is made of SUS304 series or SUS301 series material,
The optical path changing device according to claim 6. An optical path changing device according to any one of claims 1 to 8,
Projection type image display device.

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