JP2018004955A - Image projection device and image projection method of image projection device - Google Patents

Abstract

An image projection apparatus capable of projecting an image that gives a strong impression to a viewer without wearing dedicated glasses. A light source; an image display unit for displaying an image using light of the light source; an illumination optical unit for guiding light from the light source to the image display unit; and the image display unit. A projection optical unit 60 for enlarging and projecting a displayed image composed of a plurality of pixels, wherein the image display unit 50 uses light from the light source 30; A display element 551 that updates and displays the image at a predetermined vertical synchronization frequency, and actuators 581 to 584 that move the display element 551 relative to the projection optical unit 60 are provided, and the display element 551 is moved. Two or more moving frequencies of the actuators 581 to 584 are provided, and the moving frequency depends on the display mode of the image to be displayed. It is constant, the image projection apparatus 1. [Selection] Figure 8

Description

  The present invention relates to an image projecting apparatus and an image projecting method of the image projecting apparatus.

  In an image projection apparatus such as a projector, a 3D projection technique, a 3D hologram, or the like is already known as a realistic image in order to give a strong impression to the viewer.

  Here, with 3D projection technology, you can switch between different images for left and right when watching movies, movie theaters, theme parks, museums, home TV, etc., and wear special glasses to view the images in three dimensions. Was the premise. On the other hand, in the 3D hologram technology, it is necessary to project an image simultaneously from a plurality of directions onto a projection target composed of a special three-dimensional film standing in space.

  Patent Document 1 discloses using a pixel shifting technique that moves an optical lens by half a pixel for the purpose of displaying a high-definition image with a smaller number of pixels than an input image.

  However, although the technique of Patent Document 1 can display a high-definition image, the only method for giving a strong impression is a method for displaying a 3D image that requires special glasses.

  In addition, when using an image projection apparatus for digital signage applications, the projection target cannot be made stereoscopic unless the unspecified number of viewers wear dedicated glasses. It was difficult to make a strong impression with a simple projection.

  SUMMARY OF THE INVENTION In view of the above circumstances, an object of the present invention is to provide an image projection apparatus that can project an image that gives a strong impression to a viewer without wearing dedicated glasses.

In order to solve the above problems, in one embodiment of the present invention,
A light source;
An image display unit for displaying an image using light of the light source;
An illumination optical unit for guiding light from the light source to the image display unit;
A projection optical unit that magnifies and projects an image composed of a plurality of pixels displayed on the image display unit, and an image projection apparatus comprising:
The image display unit includes:
A display element that updates and displays the image at a predetermined vertical synchronization frequency using light of the light source, and an actuator that moves the display element relative to the projection optical unit;
Two or more moving frequencies of the actuator for moving the display element are provided, and the moving frequency is set according to a display mode of the displayed image.

  According to one aspect, the image projection apparatus can project an image that gives a strong impression to the viewer without wearing dedicated glasses.

The figure which illustrates the projector which is an example of the image projector in one Embodiment of this invention. The perspective view which illustrates the image engine in one embodiment of the present invention. The figure which illustrates the illumination optical system contained in the image engine shown in FIG. FIG. 3 is a perspective view illustrating an image display unit included in the image engine shown in FIG. 2. FIG. 5 is an exploded perspective view illustrating a fixed unit and a movable unit included in the image display unit shown in FIG. 4. The figure explaining the movement of the DMD element with respect to the fixed unit in one Embodiment of this invention. The control block diagram regarding the image shift control of the image projector in one Embodiment of this invention. 6 is a flowchart illustrating a setting process of image shift control according to the present invention. Explanatory drawing which shows the image which moved the position of the DMD element, and the pixel by the image shift control of this invention. The timing chart which shows the correlation with the vertical frequency of an image at the time of performing the high-resolution mode of this invention, the image-processed signal, and the movement frequency of a DMD element. FIG. 6 shows an example of the position of a pixel created by moving a DMD element and a projected image of a character formed by these pixels when executing the high resolution mode of the present invention. Explanatory drawing of the projected landscape image made high resolution by moving a DMD element. The timing chart which shows the correlation with the vertical synchronizing frequency of an image at the time of performing the fluctuation mode of this invention, and the movement frequency of a DMD element. FIG. 6 is a diagram illustrating an example of a position of a pixel created by moving a DMD element and a projected image of a character formed by these pixels when executing the fluctuation mode of the present invention. Explanatory drawing of the projected landscape image which will be in fluctuation mode by moving a DMD element. Explanatory drawing of the other structural example which can implement | achieve the image shift control of this invention.

  Hereinafter, embodiments for carrying out the invention will be described with reference to the drawings. In the drawings, the same components are denoted by the same reference numerals, and redundant description may be omitted.

<Configuration of image projector>
FIG. 1 is a diagram illustrating a projector 1 according to an embodiment of the invention. The projector 1 is an example of an image projection device (image projection device), and an exit window 13, an operation unit 7, a wireless processing unit 8, an external I / F 9, and the like are provided outside the housing. In addition, an image engine or the like that generates a projection image is provided inside the projector 1.

  For example, when image data is transmitted from a personal computer or digital camera connected to the external I / F 9, the projector 1 generates a projection image based on the transmitted image data, as shown in FIG. An image is projected onto the screen (projection plane) S from the exit window 13.

  In the drawings shown below, the X1X2 direction is the width direction of the projector 1, the Y1Y2 direction is the depth direction of the projector 1, and the Z1Z2 direction is the height direction of the projector 1. In the following description, there is a case where the exit window 13 side of the projector 1 is on the upper side and the opposite side to the exit window 13 is on the lower side.

  A main switch 7P provided in the operation unit 7 is used for ON / OFF operation of the projector 1 by the user. When the main switch 7P is turned on while the projector 1 is connected to a commercial power supply via a power cord or the like, power supply to each part of the projector 1 is started, and when the main switch 7P is turned off. Then, power supply to each part of the projector 1 is stopped.

  The operation unit 7 is a button or the like for receiving various operations by the user, and is provided on the upper surface of the projector 1, for example. The operation unit 7 accepts user operations such as the size, color tone, and focus adjustment of the projected image. The user operation received by the operation unit 7 is sent to the system controller 10 (see FIG. 7).

  The external I / F 9 has a connection terminal (video input terminal) connected to, for example, a personal computer or a digital camera, and outputs image data transmitted from the connected device to the system controller 10 (see FIG. 7).

  The wireless processing unit 8 is connected to wireless communication devices such as a personal computer, a smartphone, and a tablet via wireless (for example, Wi-Fi (registered trademark) or Bluetooth (registered trademark)).

<Configuration of optical engine>
Next, the configuration of each part of the optical engine 15 of the projector 1 will be described. FIG. 2 is a perspective view illustrating the optical engine 15 according to an embodiment of the invention.

  As shown in FIG. 2, the optical engine 15 includes a light source 30, an illumination optical system unit 40, an image display unit 50, and a projection optical system unit 60, and is provided inside the projector 1.

  The light source 30 is, for example, a mercury high-pressure lamp, a xenon lamp, an LED, or the like, and is provided on the side surface of the illumination optical system unit 40 and irradiates light in the X2 direction.

  The illumination optical system unit (illumination optical unit) 40 guides the light emitted from the light source 30 to the DMD element 551 (see FIG. 3) of the image display unit 50 provided below. The image display unit 50 generates a projection image using the light guided by the illumination optical system unit 40.

  The projection optical system unit (projection optical unit) 60 is provided above the illumination optical system unit 40 and projects the projection image generated by the image display unit 50 onto the screen S (see FIG. 1) outside the projector 1.

  Note that the optical engine 15 according to the present embodiment is configured to project an image upward using light emitted from the light source 30, but may be configured to project an image in the horizontal direction. Good.

  Although illustration is omitted, the projector 1 may be provided with a cooling mechanism (for example, a cooling fan) inside. The cooling fan is provided in the vicinity of the light source 30 and is controlled and rotated by the main microcomputer 3 (see FIG. 7) to cool the light source 30 of the optical engine 15.

[Illumination optical system unit]
FIG. 3 is a diagram illustrating the illumination optical system unit 40 in the embodiment.
As shown in FIG. 3, the illumination optical system unit 40 includes a color wheel 401, a light tunnel 402, relay lenses 403 and 404, a cylinder mirror 405, and a concave mirror 406.

  The color wheel 401 is, for example, a disk in which filters for each color of R (red), G (green), and B (blue) are provided at different portions in the circumferential direction. The color wheel 401 rotates at high speed, and time-divides light emitted from the light source 30 into RGB colors.

  The light tunnel 402 is formed in a square cylinder shape by bonding, for example, plate glass or the like. The light tunnel 402 guides the light of each color of RGB that has passed through the color wheel 401 to the relay lenses 403 and 404 by making multiple reflections on the inner surface to make the luminance distribution uniform.

  The relay lenses 403 and 404 collect light while correcting the axial chromatic aberration of the light emitted from the light tunnel 402.

  The cylinder mirror 405 and the concave mirror 406 convert the light emitted from the relay lenses 403 and 404 into a DMD element 551 (Digital Micromirror Device, hereinafter simply referred to as DMD) provided in the image display unit 50. Reflect on.

  The DMD element 551 is an example of an image generation unit, a modulation unit, and a display element. The DMD element 551 is controlled by a control device (see FIG. 7) and modulates reflected light from the concave mirror 406 of the illumination optical system unit 40 to generate a projection image. Generate.

[Image display unit]
FIG. 4 is a perspective view illustrating the image display unit 50 in the embodiment of the invention.

  As shown in FIG. 4, the image display unit 50 includes a fixed unit 51 that is fixedly supported, and a movable unit 55 that is movable with respect to the fixed unit 51.

  The fixed unit 51 includes a top plate 511 and a base plate 512. In the fixing unit 51, a top plate 511 and a base plate 512 are provided in parallel via a predetermined gap, and are fixed to the lower part of the illumination optical system unit 40 shown in FIG.

  The movable unit 55 includes a DMD element 551, a movable plate 552, a coupling plate 553, and a heat sink 554. The movable unit 55 is movably supported by the fixed unit 51.

  The movable plate 552 is provided between the top plate 511 and the base plate 512 of the fixed unit 51, and is supported by the fixed unit 51 so as to be movable in a direction parallel to the top plate 511 and the base plate 512 and parallel to the surface.

  The coupling plate 553 is fixed to the movable plate 552 with the base plate 512 of the fixed unit 51 interposed therebetween. The coupling plate 553 is provided with the DMD element 551 fixed on the upper surface side and the heat sink 554 fixed on the lower surface side.

  The coupling plate 553 is formed of a flat plate member, has a central hole at a position corresponding to the DMD element 551, and a bent portion provided around is fixed to the lower surface of the movable plate 552 by three screws 591. Yes.

  The coupling plate 553 is fixed to the movable plate 552 so that it can be moved to the fixed unit 51 together with the movable plate 552, the DMD element 551, and the heat sink 554.

  The DMD element 551 is provided on the surface of the coupling plate 553 on the movable plate 552 side, and is provided so as to be movable together with the movable plate 552 and the coupling plate 553.

  The DMD element 551 modulates and projects the light irradiated from the light source 30 and passing through the illumination optical system unit 40 by controlling the tilt angle of each micromirror by the image signal transmitted from the main microcomputer 3 (see FIG. 7). Generate an image.

  The heat sink 554 is an example of a heat radiating unit, and is provided so that at least a part thereof is in contact with the DMD element 551. The heat sink 554 is provided together with the DMD element 551 on the coupling plate 553 that is supported so as to be movable, so that the heat sink 554 can abut against the DMD element 551 and efficiently cool (dissipate heat). With such a configuration, in the projector 1 according to the present embodiment, the heat sink 554 suppresses the temperature rise of the DMD element 551, and the occurrence of malfunctions such as malfunction and failure due to the temperature rise of the DMD element 551 is reduced.

(Fixed unit)
FIG. 5A is an exploded perspective view illustrating the fixed unit 51 included in the image display unit 50 shown in FIG.

  As shown in FIGS. 4 and 5A, the fixing unit 51 includes a top plate 511 and a base plate 512.

  The top plate 511 and the base plate 512 are formed of flat members, and central holes (openings) 513 and 514 are provided at positions corresponding to the DMD elements 551 of the movable unit 55, respectively. The top plate 511 and the base plate 512 are provided in parallel by a plurality of support columns 515 with a predetermined gap therebetween.

  As shown in FIG. 5A, the support column 515 is press-fitted into a support hole 516 formed in the top plate 511 at the upper end portion, and the lower end portion formed in the male screw groove is formed in the base plate 512. It is inserted into the support hole 517. The support columns 515 form a fixed interval between the top plate 511 and the base plate 512, and support the top plate 511 and the base plate 512 in parallel.

  The top plate 511 and the base plate 512 are formed with a plurality of support holes 522 and 526 for holding the support sphere 521 rotatably.

  A cylindrical holding member 523 having an internal thread groove on the inner peripheral surface is inserted into the support hole 522 of the top plate 511. The holding member 523 rotatably holds the support sphere 521, and the position adjusting screw 524 is inserted from above. The lower end side of the support hole 526 of the base plate 512 is closed by the lid member 527, and the support sphere 521 is rotatably held.

  The support spheres 521 that are rotatably supported by the support holes 522 of the top plate 511 and the support holes 526 of the base plate 512 respectively contact the movable plate 552 (see FIG. 4) provided between the top plate 511 and the base plate 512. The movable plate 552 is supported so as to be movable.

  Further, as shown in FIG. 5A, magnets 531, 532, 533, and 534 are provided on the surface (lower surface) of the top plate 511 on the base plate 512 side.

  The magnets 531, 532, 533, and 534 are provided at four locations so as to surround the central hole 513 of the top plate 511. The magnets 531, 532, 533, and 534 are composed of two rectangular parallelepiped magnets that are arranged so that their longitudinal directions are parallel to each other, and each form a magnetic field that reaches the movable plate 552.

  Note that the number, position, and the like of the support columns 515 and the support spheres 521 provided in the fixed unit 51 are not limited to the configuration exemplified in the present embodiment as long as the movable plate 552 can be movably supported.

(Movable unit)
FIG. 5B is an exploded perspective view illustrating the movable unit 55 included in the image display unit 50 shown in FIG.

  4 and 5B, the movable unit 55 includes a DMD element 551, a movable plate 552, a coupling plate 553, a heat sink 554, a holding member 555, and a DMD substrate 557. It is supported so that it can move.

  The coupling plate 553 is formed from a flat plate-like member, has a central hole at a position corresponding to the DMD element 551, and has a bent portion provided around the three plates 591 (see FIG. 4) of the movable plate 552. It is fixed to the lower surface.

  As described above, the movable plate 552 is provided between the top plate 511 and the base plate 512 of the fixed unit 51 and is supported by a plurality of support spheres 521 so as to be movable in a direction parallel to the surface.

  As shown in FIG. 5B, the movable plate 552 is formed from a flat plate-like member, has a central hole 570 at a position corresponding to the DMD element 551 provided on the DMD substrate 557, and surrounds the central hole 570. Are provided with coils (voice coils) 581, 582, 583, 584.

  Coils 581, 582, 583, 584 are formed by winding an electric wire around an axis parallel to the Z 1 Z 2 direction, and are provided in a recess formed on the surface of the movable plate 552 on the top plate 511 side. Covered with a cover.

  The magnet 531, 532, 533, 534 provided on the lower surface of the top plate 511 and the coils 581, 582, 583, 584 provided on the upper surface of the movable plate 552 are supported by the fixed unit 51. In the state, they are provided at positions facing each other. Coils (actuators) 581, 582, 583, 584 and corresponding magnets 531, 532, 533, and 534 constitute moving means for moving the movable plate 552.

  When a current is passed through the coils 581, 582, 583, 584, a Lorentz force that is a driving force for moving the movable plate 552 is generated by a magnetic field formed by the magnets 531, 532, 533, and 534.

  The movable plate 552 receives a Lorentz force as a driving force generated between the magnets 531, 532, 533 and 534 and the coils 581, 582, 583 and 584, and is linear with respect to the fixed unit 51 in the XY plane. Or it is displaced to rotate.

  The movable plate 552 is provided with a movable range limiting hole 571 at a position corresponding to the column 515 of the fixed unit 51. The movable range limiting hole 571 limits the movable range of the movable plate 552 by contacting the column 515 when the column 515 of the fixed unit 51 is inserted and the movable plate 552 moves greatly due to vibration or some abnormality, for example.

  Note that the number, position, and the like of the magnets 531, 532, 533, 534 and the coils 581, 582, 583, 584 are different from the present embodiment as long as the movable plate 552 can be moved to an arbitrary position. It may be.

  For example, a magnet that forms a magnetic field together with an actuator (coil) may be provided on the top surface of the top plate 511 or may be provided on any surface of the base plate 512. Further, for example, a magnet may be provided on the movable plate 552 and a coil may be provided on the top plate 511 or the base plate 512.

  Further, the number, position, shape, and the like of the movable range restriction hole 571 are not limited to the configuration exemplified in this embodiment. For example, the movable range restriction hole 571 may be one or plural. Further, the shape of the movable range limiting hole 571 may be different from the present embodiment, such as a rectangle or a circle.

  In addition, since the heat sink 554 for cooling the DMD element 551 is mounted on the movable unit 55 together with the DMD element 551, it becomes possible to cool the DMD element 551 by contacting the DMD element 551, and the DMD element 551. Temperature rise is suppressed. Therefore, in the projector 1, problems such as malfunctions and failures that occur due to the temperature rise of the DMD element 551 are reduced.

<Movement of DMD element>
FIG. 6 is a diagram for explaining the movement of the DMD element with respect to the fixed unit in the embodiment of the present invention. (A) is a translational movement operation in the horizontal direction in the drawing, (b) is a translational movement operation in the vertical direction in the drawing, and (c) is a translational movement operation in an oblique direction in the drawing.

  As shown in FIGS. 4, 5, and 6, when the actuators 581 to 584 apply Lorentz force, the DMD element 551 provided in the movable unit 55 including the movable plate 552 includes the fixed unit 51 and the projection optical system unit. Move relative to 60.

  As shown in FIG. 6A, in order to move the created image in the horizontal direction, the Lorentz force acting on the coils (voice coils) 581 and 584 arranged in the left and right (X2 direction and / or X1 direction). Thus, the translational motion in the left-right direction in FIG. 6 of the DMD element 551 is executed.

  Specifically, the coil 581 and the magnet 531, and the coil 584 and the magnet 534 are provided to face each other in the X1X2 direction. When a current flows through the coil 581 and the coil 584, a Lorentz force in the X1 direction or X2 is generated as shown in FIG. The movable plate 552 that moves together with the DMD element 551 moves in the X1 direction or the X2 direction by the Lorentz force generated in the coil 581 and the magnet 531, and the coil 584 and the magnet 534.

  Further, as shown in FIG. 6B, in order to move the created image in the vertical direction, the DMD element 551 is moved by the Lorentz force acting on the coils 582 and 583 arranged in the lower part (Y1 direction) in the figure. Realizes vertical translation.

  Specifically, the coil 582 and the magnet 532, and the coil 583 and the magnet 533 are provided side by side in the X1X2 direction. That is, the magnet 532 and the magnet 533 are arranged so that the longitudinal directions thereof are orthogonal to the magnet 531 and the magnet 534. In such a configuration, when a current is passed through the coil 582 and the coil 583, a Lorentz force in the Y1 direction or the Y2 direction is generated as shown in FIG. 6B.

  Also, as shown in FIG. 6C, moving the displayed image in an oblique direction can be realized by combining the horizontal and vertical translational motions of FIGS. 6A and 6B. .

  A rotational movement is also possible by a plurality of combinations. For example, the movable plate 552 moves in the Y1 direction or the Y2 direction by the Lorentz force generated in the same direction in the coil 582 and the magnet 532 and in the coil 583 and the magnet 533. Further, the movable plate 552 is displaced so as to rotate in the XY plane by the Lorentz force generated in the opposite direction by the coil 582 and the magnet 532 and the coil 583 and the magnet 533.

  For example, when a Lorentz force in the Y1 direction is generated in the coil 582 and the magnet 532 and a current is applied so that a Lorentz force in the Y2 direction is generated in the coil 583 and the magnet 533, the movable plate 552 is rotated in the clockwise direction when viewed from above. Displace to rotate. Further, when a Lorentz force in the Y2 direction is generated in the coil 582 and the magnet 532 and a current is applied so that a Lorentz force in the Y1 direction is generated in the coil 583 and the magnet 533, the movable plate 552 rotates counterclockwise in a top view. Displace to rotate in the direction.

  The magnitude and direction of the current flowing through each of the coils 581, 582, 583, 584 is controlled by the movement control unit 6 (see FIG. 7) of the system controller 10. The movement control unit 6 moves (rotates) the movable plate 552, that is, the movement direction and movement of the relative movement of the DMD element 551 with respect to the fixed unit 51, depending on the magnitude and direction of the current flowing through the coils 581, 582, 583, 584. Control the amount and rotation angle.

  As an example, the pseudo-high resolution technology can be achieved by combining the movement of the DMD element 551 in the oblique 45 ° direction and image processing.

<Control block>
FIG. 7 is a control block diagram regarding image shift control of the image projection apparatus according to the embodiment of the present invention.

  The image projection apparatus (projector 1) includes a fixed unit 11 and a movable unit 55 that can be moved by actuators 581 to 584.

  A system controller 10 including a video signal processing unit 2, an image processing unit 4, a main microcomputer 3, a memory 5, and a movement control unit (actuator control unit) 6 is provided inside the fixed unit 11. .

  The fixed unit 11 is further provided with a video input terminal 9, a wireless processing unit 8, an operation unit 7, and the like.

  The video input terminal 9 receives a PC image or a DVD video signal output from an external device such as a PC connected by wire. The video signal input to the video input terminal 9 is sent to the video signal processing unit 2.

  The wireless processing unit 8 is provided to wirelessly connect to wireless communication devices such as a PC, a smartphone, and a tablet via wireless. The wireless processing unit 8 receives a video signal output from the wireless communication device. The wireless processing unit 8 sends a digital signal generated by decoding the input video signal to the main microcomputer 3.

  As shown in FIG. 1, the operation unit 7 includes a key input unit on the operation panel of the projector main body, a key input unit of a remote control transmitter, or the like. For example, a menu screen for performing various settings and selections of the projector Menu key to display. The operation unit 7 receives adjustment information such as the tilt and size of the projected image.

  The video signal processing unit 2 of the system controller 10 receives the video signal from the video input terminal 9 and converts it into a video digital signal that can be received by the main microcomputer 3.

  The main microcomputer 3 has a scaling function (image size adjustment) and a driver function for controlling the display element (DMD or the like) 55. The main microcomputer 3 receives the video digital signal output from the video signal processing unit 2 or the digital signal decoded by the wireless processing unit 8 and determines the number of vertical and horizontal pixels from the timing of the video signal. Then, scaling is automatically performed so that the displayed image is optimally displayed with respect to the aspect ratio of the number of output pixels of the projector 1.

  The main microcomputer 3 includes a microcontroller (microcomputer), and includes arithmetic circuits and storage circuits such as a CPU (Central Processing Unit), ROM (Read Only Memory), and RAM (Random Access Memory). The function of each unit is realized by the CPU executing a program stored in the ROM in cooperation with the RAM.

  The main microcomputer 3 performs general control of the projector 1 and also performs control for performing various settings and comparisons.

  Furthermore, when the HDMI (High-Definition Multimedia Interface) connector or the DisplayPort connector is connected to the video input terminal 9, the main microcomputer 3 passes information on the projector 1 side (in this case, the DMD can be rotated). CEC (Consumer Electronics Control) control is also performed.

  The memory 5 is configured by a non-volatile memory or the like that stores the content set by the main microcomputer 3, and the projector 1 stores the previous setting content (such as language setting) even after the power is turned off.

  The main microcomputer 3 has a built-in drive circuit for driving the display element 551, and drives the display element (DMD element) 551 by using the video signal scaled inside the main microcomputer 3 and its synchronization signal.

  The image processing unit (image processing dedicated chip) 4 executes image generation processing for creating an image shifted by half a pixel or less from the original image in order to achieve high resolution. Note that image processing relating to shifting is not performed in the image processing unit 4 when image shifting is not performed or in a fluctuation mode described later.

  The display element 551 includes a display panel such as a DLP (Digital Light Processing (registered trademark)) DMD, displays a scaled image, and is enlarged and projected by projection optical system components such as a light source and a projection lens.

  The display element 551 is provided in the movable unit 55 to which coils 581 582 583 584 which are actuators for shifting or rotating vertically and horizontally are attached. There is a movement control unit 6 for controlling the coils 581, 582, 583, 584. The actuators are coils 581, 582, 583, 584 provided on the movable unit 51 side, currents flowing through the coils 581, 582, 583, 584, and magnets 531, 532, 533, 534 provided on the fixed unit 51 side. The fixed unit 51 is moved by the Lorentz force generated by the magnetic field.

  The movement control unit 6 also performs current control for flowing through the coils 581 to 584 that are actuators of the movable unit 55 and detection of whether or not the shift amount in the vertical and horizontal directions is maximized. The movement control unit 6 can move the movable plate 552 to an arbitrary position within the movable range by controlling the magnitude and direction of the current flowing through the coils 581 to 584.

  In addition, the movement frequency, movement distance, etc. of the actuators 581 to 584 for moving the movable unit 55 may be stored in the memory 5 in advance, and the movement control unit 6 may be selected and set as appropriate.

  Further, the movement control unit 6 communicates with the main microcomputer 3, and the main microcomputer 3 performs time measurement and keystone correction parameter calculation based on information from the movement control unit 6.

  By driving the coils 581 to 584 which are actuators that move the movable unit 55, image shift control such as pseudo high resolution and fluctuation effect is performed.

<Setting flow>
FIG. 8 is a flowchart for explaining the image shift control setting process of the present invention.

  This flow is started when an image is projected and the image shift control is ON (START).

  In S <b> 1, whether the image shift control is the high-resolution mode or the fluctuation mode is set by the user by inputting to the operation unit 7. At this time, if the image shift is ON and the movie is a moving image, the process automatically proceeds to the high resolution mode.

  When the image shift control is in the high resolution mode, the process proceeds to step S5, and predetermined frequencies and movement distances for driving the actuators 581 to 584 determined in advance are set. The high resolution mode is a mode for controlling the projected image so as to show a high definition. Here, it is assumed that the predetermined frequency for high resolution is a multiple of the image frequency.

  When the image shift control is the fluctuation mode, the previous display mode or the default display mode is temporarily displayed as the test mode for the fluctuation mode in step S2. The step S2 is optional and can be omitted. The fluctuation mode is a mode for controlling at least a part of the still image to move.

  In step S <b> 3, the user adjusts the moving frequency of the actuators 581 to 584 that move the movable unit 55. Note that the movement frequency of the actuators 581 to 584 of the movable unit 55 for the fluctuation mode is different from a multiple of the vertical synchronization frequency (refresh rate) of the image signal. The drive frequency may be selected from a plurality of values stored in the memory 5 (see FIG. 7) or may be arbitrarily adjusted by the user. For example, as the moving frequency is set to a frequency far from a multiple of the vertical synchronization frequency, the random fluctuation is generated.

  Next, in step S4, the user adjusts the moving distance of the movable unit 55 in the fluctuation mode. The moving distance of the movable unit 55 is, for example, 0.5 pixels (half pixel), and the moving distance of 45 ° obliquely has a maximum fluctuation width in consideration of overlapping images. Therefore, the movement distance can be adjusted in the range of 0 pixel to 0.5 pixel according to the projection image.

  Further, in the setting of the movement distance, the movement direction may be set. For example, the DMD movement example of FIG. 6 shows an example of movement in the vertical direction, the horizontal direction, and the 45 ° direction, but adjustment in any direction is possible by a combination of directions.

  In step S2, since the fluctuation mode is executed in the previous mode or the default mode, the user can adjust the driving frequency and the moving distance for movement while viewing the projected image. is there.

  Thus, the movement frequency and movement distance of the actuators 581 to 584 of the movable unit 55 adjusted in steps S3 and S4 or set for high resolution in step S5 are stored in the execution memory ( Step S6).

  This completes the image shift control setting (END).

  Next, a pseudo high resolution technique will be described.

<Image shift control>
FIG. 9 is an explanatory diagram showing the position of the DMD element and the pixel movement in the pixel shift control of the present invention. FIG. 9 shows an example in which the element operation of the DMD element is operated at an angle of 45 ° at twice the refresh rate (double speed) of the input signal. In this case, since the frequency of the element operation (the movement operation of the display element) is an integral multiple of the refresh rate, the high resolution mode is assumed.

  9A is an explanatory diagram for alternately displaying an original image and an image shifted by half a pixel, FIG. 9B is a diagram for explaining the movement of one DMD element, and FIG. 9C is a pixel shift by 5 × 5 pixels. It is a figure explaining.

  Here, since the projector 1 displays an image by a DLP (Digital Light Processing) method, the display element 551 has 480,000 to 2,000,000 square micromirrors (micromirrors) that are spread over the semiconductor substrate without gaps. The image is produced by controlling the light at high speed and reflecting the light. The number of pixel-sized micromirrors in the DMD corresponds to the resolution of the projected video image.

  The display element 551 has an image generation surface (see FIG. 9A) in which a plurality of movable micromirrors are arranged in a lattice pattern. Each micromirror of the DMD element 551 is provided so that the mirror surface can be tilted around the torsion axis, and is driven ON / OFF so as to blink on the basis of an image signal transmitted from the main microcomputer 3 of the system controller 10. Is done.

  For example, when the micromirror is “ON”, the tilt angle is controlled so that the light from the light source 30 is reflected to the projection optical system unit 60, and an image is displayed during this period. In addition, when the micromirror is “OFF”, for example, the tilt angle is controlled in a direction in which light from the light source 30 is reflected toward an OFF light plate (not shown), and in this state, the projection image is in a completely black state. Become.

  Here, the refresh rate (vertical synchronization frequency) for switching ON / OFF of the micromirror (DMD) is a driving speed and is “number of times that the screen can be updated in one second”. In the following control example of the present invention, for example, an example of 60 Hz will be described, but this frequency is an example and may be another frequency.

  As shown in FIG. 9A, the image processing unit 4 shown in FIG. 7 generates an image in which the pixels of the input signal are shifted by half a pixel in the oblique 45 ° direction as shown in FIG. Two images are switched and displayed for each refresh rate. That is, (1) the original image and (2) the image shifted by half a pixel are alternately displayed.

  Thus, in order to alternately display (1) the original image and (2) the image shifted by half a pixel, the movable unit 55 is moved by the actuators 581 to 584 as shown in FIG. 9B. Thus, the DMD element can be moved. FIG. 9C is a diagram illustrating pixel shifting by 5 × 5 pixels as a specific example.

  Note that the image processing for realizing high resolution and the movement of the DMD element by the actuator are independent of each other, and the two image generation processing is image processing implemented in the main microcomputer 3 or the previous stage of the microcomputer 3. Part 4 is implemented.

  As described above, the DMD element 551 that generates the projection image is provided in the movable unit 55, and its position is controlled together with the movable unit 55 by the movement control unit 6 of the system controller 10.

  For example, the movement control unit 6 performs high-speed operation between a plurality of positions separated by a distance less than the arrangement interval of the plurality of micromirrors of the DMD element 551 (less than one pixel) at a predetermined period corresponding to the frame rate at the time of image projection. The position of the movable unit 55 is controlled so as to move. At this time, the main microcomputer 3 transmits an image signal to the DMD element 551 so as to generate a projection image shifted according to each position.

  For example, the movement control unit 6 reciprocates the DMD element 551 shown in FIG. 9B with a predetermined cycle between positions separated by a distance less than the arrangement interval of the micromirrors of the DMD element 551 (less than one pixel). . At this time, the main microcomputer 3 controls the DMD element 551 so as to generate a projection image shifted according to each position, so that the resolution of the projection image is about twice the resolution of the DMD element 551. Is possible.

  As described above, the movement control unit 6 moves the DMD element 551 together with the movable unit 55 at a predetermined period, and the main microcomputer 3 causes the DMD element 551 to generate a projection image corresponding to the position, thereby allowing the resolution of the DMD element 551 to be determined. The above image can be projected.

  Alternatively, as a further increase in resolution, the resolution of the projection image can be made twice or more that of the DMD element 551 by increasing the movement end position that is the tip position of the movement of the DMD element 551.

  Here, in the control example described in the present specification, an example is described in which a half pixel (0.5 pixel) is shifted in one direction and the wavelength is doubled with respect to a wavelength twice the vertical synchronization frequency of the input image signal. However, the moving direction is not limited to one direction.

  As another example, when the actuators 581 to 584 that move the movable unit 55 to which the DMD element 551 is attached draw a circle, for example, in the upper right, lower right, lower left, upper left, and one frame, It is preferable to shift the moving frequency with respect to a frequency four times the vertical synchronizing frequency of the image signal. Note that the circumferential motion is an example, and it may be reversed or other regular movements may be performed.

  Although the high resolution can be realized by synchronizing the movement of the DMD element due to the movement of the movable unit 55 as described above with the image processing, the present invention further does not synchronize with the image processing and the movable unit for each frame. By shifting the position 55, it is possible to give a fluctuation effect that looks moving even in a still image. These two different image shift controls will be described below.

<High resolution>
FIG. 10 is a diagram illustrating timing when the high resolution mode is executed. The upper part shows the vertical synchronization frequency of the input image, the middle part shows the image processing signal by image processing, and the lower part shows the timing chart of the DMD element operation (movement operation).

  In FIG. 10, the vertical synchronization frequency (refresh rate) of the input image is 60 Hz.

  In the high resolution mode, the image processing shown in the middle part of FIG. 10 generates a video signal as one image that is alternately output as two images (an image shifted from the original image by 45 °, half pixel), When the two images are projected at a refresh rate of 60 Hz, the vertical synchronization frequency is 120 Hz. Therefore, each image is switched every 120 Hz.

  In addition, as shown in the lower part of FIG. 10, the movement frequency of the DMD element is 120 Hz (first frequency) that is twice the vertical synchronization frequency, and moves in a half cycle (oblique 45 °, 0.5 pixel movement). At 60 Hz, it becomes one cycle and returns to the original position.

  As described above, by image processing, the original image and the half-pixel shifted image are alternately displayed, and the image switching cycle (middle in FIG. 10) and the movement cycle (lower in FIG. 10) are synchronized. As a result, the total number of pixels is increased, and the resolution is increased in a pseudo manner. That is, the image quality can be improved.

  Thus, since a high-definition image can be displayed with fewer pixels than the input image, the manufacturing cost of the DMD element can be reduced.

  Here, if an attempt is made to increase the resolution in a case other than a multiple of the vertical synchronization frequency (refresh rate), it becomes difficult to create an image shifted from the multiple of the vertical synchronization frequency by image processing. Therefore, even if an image is created and switched by image processing at the timing when the movable unit 55 is moved, the switching timing of the image and the update timing of the image are not synchronized, and the calculation processing becomes complicated. The projected image becomes irregular.

  Therefore, in the control of the present invention, a pixel shift image by image processing is created at the time of high resolution, and the refresh rate is updated without creating an image shift image by image processing in the fluctuation mode. Create an original image every time.

  Since the movement operation of the DMD element is independent of the vertical synchronization frequency of the image signal, it is possible to easily cope with both image shift of a multiple of the vertical synchronization frequency and pixel shift other than the multiple.

  FIG. 11 shows a specific example of the position of the pixel created by moving the DMD element and the projected image of the character formed by these pixels when executing the high resolution mode.

  In FIG. 11, the character “mountain” is an example of 5 × 5 pixels. As shown in the middle part of FIG. 10, the image processing unit 4 does not create an image in which pixels are shifted by image processing, and the image processing unit 4 displays the original image at the same position for each update so as to display the original image every 60 Hz. Thus, the same one frame is projected. Since one frame is the reciprocal of the vertical synchronization frequency, it is set to 16.6 ms (60 [Hz] / 1 [s]).

  Next, when the DMD element 551 is driven to move half a pixel diagonally to the right at 45 ° at 120 Hz, an image moved in the direction of the oblique 45 ° in a half cycle is projected, and an image that has returned to the default position in an integer cycle is returned. Projected. This one round-trip operation matches one frame of the input image.

  Specifically, the DMD element 551 has a moving frequency of 120 Hz and a period of 4.15 ms which is a quarter period of a vertical synchronizing frequency of 60 Hz, and a moving frequency of 3/2 periods and a vertical synchronizing frequency of 3 times. After 12.45 ms which is a / 4 period, the DMD element 551 is moved so that the pixel comes to a position (moving end position) where the pixel is moved by 45 ° diagonally to the right.

  In addition, after 8.3 ms, which is an integer cycle of the moving frequency, which is ½ cycle of the vertical synchronization frequency, and after 16.6 ms, which is one cycle of the vertical synchronization frequency, the pixel comes to the original position. The DMD element 551 is moved.

  The same processing is performed for the second and subsequent frames, and an image obtained by superimposing the two images becomes an actually projected image, and the original image is projected with a thick line as shown on the right in FIG. 11B.

  FIG. 12 is an explanatory diagram of a projected landscape image that is improved in resolution by moving the DMD element 55.

  A case where the same operation is performed on a natural image will be described. (A) is an image obtained by projecting the original image. (B) is a projected image when the DMD element is moved to the right diagonal 45 ° by half a pixel in a cycle of 120 Hz. That is, the composite image becomes equal every frame.

  Therefore, if the DMD element 55 is moved by a multiple of the vertical synchronization frequency of the input signal (projection signal) by the actuators 581 to 584 without performing image switching by image processing, the movement included in the composite image is performed in the projection image. The images at the edges overlap, resulting in a totally blurred image.

<Fluctuation mode>
FIG. 13 is a timing chart showing the correlation between the vertical synchronization frequency of the image signal and the movement frequency of the DMD element when the fluctuation mode of the present invention is executed.

  In the control example of the fluctuation mode of the present invention shown in FIG. 13, the moving frequency of the actuators 581 to 584 for moving the DMD element 551 is 121 Hz slightly shifted from twice the vertical synchronization frequency of the image signal, and is a half cycle. The movement is slightly faster than the movement (slanting 45 °, 0.5 pixel movement), and it becomes one cycle at 60.5 Hz and returns to the original position.

  As described above, when the operation of the DMD element and the image switching of the image processing are slightly shifted without being synchronized, images having different half pixels and positions are shifted for each frame.

  FIG. 14 shows an example of the position of the pixel created by moving the DMD element 551 and the projected image of the character formed by these pixels when executing the fluctuation mode.

  Similar to FIG. 11, description will be made by taking the character “mountain” as an example with 5 × 5 pixels as described above.

  The refresh rate (vertical synchronization frequency) of the input image is set to 60 Hz, the operating frequency of the DMD element is set to 121 Hz (second frequency), slightly shifted from an integral multiple of the vertical synchronization frequency, and the movement is 45 ° diagonally, moving half a pixel. The flow when this is done will be described.

  For the image “mountain”, the DMD element 55 starts to move from the default position in FIGS. 11 and 14. In the high imaging mode, since the DMD element 55 moves at 120 Hz, the movement end position is just reached in a half cycle as shown in FIG. 11, but in the fluctuation mode, the DMD element 55 As shown in FIG. 14, 55 has already reached a position where it has slightly returned to the original position from the moving end position.

  Therefore, in the fluctuation mode, in one frame period of the vertical synchronization frequency of 60 Hz of the input image, the reciprocation of one DMD element is finished, the next drive is started, and the position is slightly moved.

  For example, in the first frame shown in FIG. 14, the first position starts from the default position, and in the half cycle of the vertical synchronization frequency (after 8.3 ms), the first position that is close to a half-pixel shift at 45 ° to the right Has moved to. At the end of one cycle of the vertical synchronization frequency of the first frame (after 16.6 ms), the first frame has moved to the second position that is close to the default position.

  Further, in the second frame of FIG. 14, the second position at the end of the first frame described above is started, and in the half cycle (after 8.3 ms) of the vertical synchronization frequency, the angle is halfway to 45 ° diagonally to the right. Although it is a position close to pixel movement, it has moved to a third position that is closer to the default position than the first position. At the end of one cycle of the vertical synchronization frequency of the second frame (after 16.6 ms), the second frame moves to a fourth position that is close to the default position and closer to the half-pixel moving end than the second position. ing.

  The same processing is performed for the third and subsequent frames, and the start of the third frame starts from the fourth position, and an image different from both the first and second frames is created.

  Therefore, unlike the case of operating at a double speed of the vertical synchronization frequency of the input image as shown in FIG. 11, the composite image is different for each frame as shown in FIG.

  In other words, since the image is moved slightly every frame, it appears to move as a projected image due to an afterimage despite a still image like a flip book. Each update of the frame, that is, an update for each cycle of the vertical synchronization frequency of the input signal corresponds to a page turning in the flip book.

  FIG. 15 is an explanatory diagram of a projected landscape image that is in the fluctuation mode by moving the DMD element.

  As described with reference to FIGS. 13 and 14, when the moving frequency of the actuators 581 to 584 of the DMD element 551 is driven with a period slightly shifted from the double speed driving of the refresh rate of the input image, the projection image for each frame is Thus, the image is slightly moved as in the case of four images other than the central portion of FIG. An image obtained by synthesizing these images becomes a final projection image (the central portion in FIG. 15).

In the case of a still image, the same image is displayed for each frame. In this case, the movable unit 55 is moved by driving the actuators 581 to 584 without performing image processing. Since the image is moving slightly, it appears to move like a flip book.
As shown in FIG. 15, if four images are generated as projection images, these images are switched during four frames, and switching back to the original image is repeated. Then the leaves appear to be swaying in the wind.

  In the example of FIG. 15, how the DMD element 551 is viewed by the viewer, such as the user, varies depending on the driving frequency, moving distance, and the like. Therefore, the user and the setter can adjust the driving frequency and moving distance of the actuator as appropriate.

  Furthermore, as shown in FIG. 15, the images are slightly overlapped each time a plurality of frames are updated, so that the viewer feels as if they are moving in a three-dimensional manner with a depth. it can.

  As described above, in the image shift control, in the high resolution mode, the moving frequency of the actuator is set in accordance with the periodic vertical synchronization frequency for displaying an image. In the fluctuation mode, the vertical synchronization of the image signal is set. The moving frequency is set so as to slightly deviate from the periodic motion cycle of the actuator so as to slightly deviate from the frequency. Thereby, a special effect can be given even with a still image.

  In addition, it is considered that the driving state of the DMD element 551 can be changed to a stationary state or a moving image by changing the driving condition depending on the type of image (still image or copper) and can be used for signage or the like. .

  As described above, in the fluctuation mode, the projected image is gradually moved frame by frame by shifting the DMD element 551 as a display element in the horizontal and vertical directions or in an oblique direction with a slightly different period from the refresh rate of the input image. It appears to move in the human eye as a composite image. That is, the viewer of the projected image can feel as if a part is moving like a moving image although it is a still image. At that time, it is not necessary to wear special glasses as when viewing normal 3D images, and many people can feel the same with the naked eye.

  Therefore, according to the present invention, a viewer can feel as if a viewer is moving without wearing dedicated glasses, and a strong impression can be given.

  Moreover, although it is a still image, by making it appear as if a part is moving, it is possible to leave a strong impression on an unspecified number of viewers without using stereoscopic projection when using digital signage.

  Note that such fluctuation mode control is effective only when the input image is a still image in which the original image does not change for a predetermined frame period. When the input image is a moving image, the original image itself changes for each frame. Therefore, when combined with the current control, the image quality deteriorates and cannot be used for a moving image.

  Therefore, it is preferable to provide a determination unit that determines whether the input image is a still image or a moving image. When the input image is a moving image, it is preferable to stop the movement of the actuator. For example, the determination unit may be realized by the main microcomputer 3 illustrated in FIG.

  In the above-described control, both the high-resolution mode and the fluctuation mode are realized by moving the DMD element 551 relative to the projection optical system unit 60 by the movable unit 55. Image projection that executes both modes is performed. The configuration for realizing the method is not limited to the above configuration. For example, the image projection method described above may be realized by providing a separate image shifting element after the DMD element and before the projection optical unit. Note that the position of the image shifting element can be arranged in the rear stage of the projection optical unit because the optical path to the screen (projection plane, see FIG. 1) can be deflected as long as it is inside the projector 1.

  FIG. 16 shows another configuration example that can realize the above-described image projection method. In the example of FIG. 16A, the image shifting element is a deflection member 70 whose angle can be adjusted. In the image display unit 50A, the deflecting member 70 transmits or reflects the projection light from the DMD element 551A toward the projection optical system unit 60A.

  By moving (adjusting the angle) by the actuators 71 and 72 so that the transmission surface or the reflection surface of the deflecting member 70 is covered, the optical path is deflected, and the state is shifted by 45 ° diagonally and half pixel as in the above control. be able to. Specifically, in order to implement both the high resolution mode and the fluctuation mode with this configuration, two or more moving frequencies of the actuators 71 and 72 are provided, and the moving frequencies are set according to the display mode of the displayed image. The

  Alternatively, in the example of FIG. 16B, in the image display unit 50B, the image shifting element is a variable deflection member 75 whose refractive index can be adjusted. Similarly to FIG. 16A, the variable deflection member 75 transmits or reflects the projection light from the DMD element 551B toward the projection optical system unit 60B.

  In this configuration, the optical path is deflected by changing the refractive index of the variable deflection member 75 based on the refractive index adjustment signal, which is an electrical signal output from the refractive index adjustment unit 76, and obliquely 45 °, A half-pixel shifted state can be obtained. Specifically, in order to implement both the high resolution mode and the fluctuation mode with this configuration, two or more frequencies (refractive index modulation frequencies) of the refractive index adjustment signal instructing the change (switching) of the refractive index are provided. The rate modulation frequency is set according to the display mode of the image to be displayed.

  The image projection apparatus according to the embodiment has been described above, but the present invention is not limited to the above embodiment, and various modifications and improvements can be made within the scope of the present invention.

1 Projector (image projection device)
3 Main microcomputer (determination unit)
40 Illumination optical system unit (illumination optical unit)
50, 50A, 50B Image display unit 60, 60A, 60B Projection optical system unit (projection optical unit)
51 Fixed unit 531, 532, 533, 534 Magnet (actuator)
55 Movable units 551, 551A, 551B DMD elements (display elements)
554 heat sink (heat dissipation means)
581,582,583,584 Coil (actuator)
70 Deflection member 71, 72 Actuator 75 Variable deflection member 76 Refractive index adjustment unit

JP 2008-286908 A

Claims (14)

A light source;
An image display unit for displaying an image using light of the light source;
An illumination optical unit for guiding light from the light source to the image display unit;
A projection optical unit that magnifies and projects an image composed of a plurality of pixels displayed on the image display unit, and an image projection apparatus comprising:
The image display unit includes:
A display element that updates and displays the image at a predetermined vertical synchronization frequency using light of the light source, and an actuator that moves the display element relative to the projection optical unit;
Two or more moving frequencies of the actuator for moving the display element are provided, and the moving frequency is set according to a display mode of the displayed image. The two or more moving frequencies of the actuator are:
The vertical synchronization corresponding to a first frequency that is a multiple of the vertical synchronization frequency, corresponding to a high-resolution mode in which the image is displayed in high definition, and a fluctuation mode in which at least a part of a still image is viewed as moving. The image projection apparatus according to claim 1, comprising a second frequency that is not a multiple of the frequency. The image projection device according to claim 2, wherein the second frequency can set two or more values. The image projection device according to any one of claims 1 to 3, wherein the movement distance by which the actuator moves the display element can be set to two or more, with a distance shifted by half a pixel from the original image as a maximum. An image processing unit that forms an image shifted by half a pixel or less from an original image corresponding to a moving distance by which the actuator moves the display element in the high resolution mode;
The image projection apparatus according to claim 2, wherein in the high-resolution mode, the original image and an image shifted by one pixel or less are alternately displayed in a cycle in which the actuator moves at the first frequency. A determination unit that determines whether an input image is a still image or a moving image,
The image projection device according to any one of claims 1 to 5, wherein when the input image is a moving image, the movement of the actuator is stopped or set to a multiple of the vertical synchronization frequency. The image display unit is in contact with at least a part of the display element, and heat radiating means for radiating heat generated by the light of the light source;
A movable unit that holds the display element and the heat dissipating means, and
The image projection device according to any one of claims 1 to 5, wherein the actuator moves the display unit relative to the projection optical unit by moving the movable unit. A light source, an image display unit for displaying an image using light from the light source, an illumination optical unit for guiding light from the light source to the image display unit, and a projection for enlarging and projecting an image displayed by the image display unit An image projecting method of an image projecting device comprising an optical unit,
A display element provided in the image display unit, using the light of the light source, updating an image at a predetermined vertical synchronization frequency to display an image;
An image projecting method comprising: setting a moving frequency of an actuator for moving the display element relative to the projection optical unit according to a display mode of an image to be displayed. In the step of setting the moving frequency of the actuator,
The vertical synchronization corresponding to a first frequency that is a multiple of the vertical synchronization frequency corresponding to a high-resolution mode in which the image is displayed in high definition, or a fluctuation mode in which at least a part of a still image is viewed as moving. The image projection method according to claim 8, wherein one of the second frequencies that is not a multiple of the frequency is set. The image projection method according to claim 9, wherein when setting the second frequency in the step of setting the moving frequency of the actuator, two or more values can be selected and set. Further comprising setting a moving distance by which the actuator moves the display element;
The image projecting method according to any one of claims 8 to 10, wherein the moving distance can be adjusted by two or more values, with a distance shifted by half a pixel from the original image as a maximum. The step of determining whether an input image is a still image or a moving image is included, and when the input image is a moving image, the movement of the actuator is stopped or set to a multiple of the vertical synchronization frequency. The image projection method according to any one of claims 11 to 11. A light source;
An image display unit for displaying an image using light of the light source;
An illumination optical unit for guiding light from the light source to the image display unit;
A projection optical unit that magnifies and projects an image composed of a plurality of pixels displayed on the image display unit, and an image projection apparatus comprising:
The image display unit includes:
A display element that updates and displays the image at a predetermined vertical synchronization frequency using light of the light source;
A deflection member that deflects an optical path from the display element to the projection surface, and an actuator that moves the deflection member;
Two or more moving frequencies of the actuator are provided, and the moving frequency is set according to a display mode of the displayed image. A light source;
An image display unit for displaying an image using light of the light source;
An illumination optical unit for guiding light from the light source to the image display unit;
A projection optical unit that magnifies and projects an image composed of a plurality of pixels displayed on the image display unit, and an image projection apparatus comprising:
The image display unit includes:
Using the light from the light source, the display element that updates and displays the image at a predetermined vertical synchronization frequency, the variable deflection member that can switch the refractive index by deflecting the optical path from the display element to the projection surface, and the variable A refractive index adjustment unit for changing the refractive index of the deflecting member;
Two or more refractive index modulation frequencies of the refractive index adjustment signal for instructing a change in the refractive index output from the refractive index adjustment unit are provided, and the refractive index modulation frequency depends on the display mode of the image to be displayed. The image projection device to be set.