JP2020013024A - Image display unit, image projection device, and method for controlling image display unit - Google Patents

Abstract

To improve vibration resistance or quietness of an image display unit according to the usage state.SOLUTION: An image display unit comprises: an image creation element that creates an image by using light from a light source; a movable part that is provided with the image creation element; an electromagnetic actuator that moves the movable part; a driving unit that applies a periodic driving voltage to the electromagnetic actuator; and a movement control unit that controls the driving unit to change the frequency of the driving voltage according to a predetermined condition.SELECTED DRAWING: Figure 11

Description

  The present invention relates to an image display device, an image projection device, and a method for controlling an image display device.

  Based on image data transmitted from a personal computer, a digital camera, or the like, an image generating element generates an image using light emitted from a light source, and the generated image is output to a screen or the like through an optical system including a plurality of lenses. 2. Related Art An image projection apparatus such as a projector that projects an image is known. As the image generation element, for example, a liquid crystal panel, a digital micro mirror device (DMD), or the like is used.

  In order to increase the resolution of a projected image in such an image projection device, it is conceivable to increase the pixel density of the image generating element, but the manufacturing cost of the image generating element increases.

  Therefore, it has been proposed that the image generation element is movable, and a plurality of projection images generated by moving the image generation element to shift the pixels are superimposed to achieve a pseudo high resolution (for example, And Patent Document 1).

  In the high resolution processing, the image generating element reciprocates within a range shorter than the pixel pitch. As a moving unit for moving the image generation element, for example, an electromagnetic actuator including a magnet and a coil is used. The electromagnetic actuator is driven by, for example, a pulse drive (for example, PWM (Pulse Width Modulation) drive) method that applies a periodic pulse-like drive voltage.

  However, since the image projection device described in Patent Document 1 has a vibration source such as a cooling fan, when performing the above-described high resolution processing, the movement of the image generating element may not be affected by the vibration from the vibration source. The received image may deteriorate the projected image.

  The higher the frequency of the drive voltage applied to the electromagnetic actuator, the more times the drive force (Lorentz force) is generated within a unit time, so that the movement accuracy of the image generating element is improved and the vibration resistance is improved. Therefore, it is conceivable to increase the frequency of the drive voltage in order to suppress the deterioration of the projected image due to the above-described vibration.

  However, when the frequency of the driving voltage is increased, a driving force is applied until immediately before the moving direction of the image generating element is reversed, so that a noise sound is generated, and depending on circumstances, the user may be uncomfortable.

  The disclosed technology has been made in view of the above circumstances and has been made to solve the problem, and has as its object to improve the vibration resistance or the silence of the image display device according to the use situation.

  The disclosed technology includes an image generation element that generates an image using light from a light source, a movable section provided with the image generation element, an electromagnetic actuator that moves the movable section, An image display device comprising: a driving unit that applies a driving voltage; and a movement control unit that controls the driving unit and changes a frequency of the driving voltage according to a predetermined condition.

  Vibration resistance or quietness of the image display device can be improved according to the use situation.

FIG. 2 is a perspective view illustrating the image projection device according to the first embodiment. FIG. 2 is a block diagram illustrating a functional configuration of the image projection device according to the first embodiment. It is a perspective view which illustrates an illumination optical system unit. It is a perspective view which illustrates an image display unit. FIG. 5 is a side view of the image display unit shown in FIG. 4. It is a bottom view which illustrates a top plate. It is a perspective view which illustrates a movable unit. FIG. 8 is an exploded perspective view of the movable unit shown in FIG. 7. It is a perspective view which illustrates a movable plate. FIG. 9 is an explanatory diagram illustrating a display state of a pixel shifted by a half pixel by the DMD shift. 5 is a flowchart illustrating a control for changing a driving frequency. It is a flowchart explaining change control of the drive frequency in 2nd Embodiment. It is a flow chart explaining change control of a drive frequency in a 3rd embodiment. It is a flowchart explaining change control of the drive frequency in 4th Embodiment.

  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.

<First embodiment>
Hereinafter, an image projection device according to the first embodiment of the present invention will be described.

[Configuration of Image Projection Apparatus]
FIG. 1 is a perspective view illustrating a projector 1 according to the first embodiment. The projector 1 is an example of an image projection device, has an emission window 3, an external I / F 9, and is provided with an optical engine for generating a projection image. When image data is transmitted from, for example, a personal computer or a digital camera connected to the external I / F 9, the projector 1 generates a projection image based on the transmitted image data by the optical engine, and as shown in FIG. An image is projected from the exit window 3 onto the screen S.

  In the drawings described 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. Further, in the following description, the exit window 3 side of the projector 1 may be described as up, and the opposite side to the exit window 3 may be described as lower.

  FIG. 2 is a block diagram illustrating a functional configuration of the projector 1 according to the embodiment.

  As shown in FIG. 2, the projector 1 has a power supply 4, a main switch SW5, an operation unit 7, an external I / F 9, a system control unit 10, a fan 20, and an optical engine 15.

  The power supply 4 is connected to a commercial power supply, converts a voltage and a frequency for an internal circuit of the projector 1, and supplies power to the system control unit 10, the fan 20, the optical engine 15, and the like.

  The main switch SW5 is used for ON / OFF operation of the projector 1 by a user. When the main switch SW5 is turned on while the power supply 4 is connected to a commercial power supply via a power cord or the like, the power supply 4 starts supplying power to each part of the projector 1 and the main switch SW5 is turned off. Then, the power supply 4 stops supplying power to each part of the projector 1.

  The operation unit 7 is a button or the like that receives various operations by the user, and is provided on, for example, the upper surface of the projector 1. The operation unit 7 receives 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 control unit 10.

  The external I / F 9 is an interface for inputting a video signal, and includes a VGA (Video Graphics Array) input terminal such as a D-Sub connector, an HDMI (High-Definition Multimedia Interface) (registered trademark) terminal, an S-VIDEO terminal, A video input terminal such as an RCA terminal; The external I / F 9 receives a video signal from a video supply device such as a connected computer or AV device.

  The system control unit 10 includes an image control unit 11, a movement control unit 12, and an image processing unit 13. The system control unit 10 includes, for example, a CPU, a ROM, and a RAM, and the functions of each unit are realized by the CPU executing a program stored in the ROM in cooperation with the RAM.

  The image control unit 11 controls a digital micromirror device (DMD) 551 provided in the image display unit 50 of the optical engine 15 based on a video signal input from the external I / F 9. Further, the image control unit 11 controls the output of the light source 30 according to the video mode.

  The movement control unit 12 controls a movable unit 55 as a movable unit via a drive unit 57 included in the image display unit 50, and controls the position of the DMD 551 provided in the movable unit 55. Specifically, the movement control unit 12 reciprocates the DMD 551 between the first position and the second position which are shifted by half a pixel when the resolution is increased. Further, the movement control unit 12 controls a frequency of a driving voltage described later.

  The image processing unit 13 performs image processing for increasing the resolution of one frame of the video signal (image data) input from the external I / F 9 by shifting the pixels (also referred to as DMD shift).

  Specifically, the image processing unit 13 operates at the time of increasing the resolution, generates first image data and second image data in which an image is shifted by half a pixel from a video signal for one frame, and generates the image control unit 11. To supply. Note that the image processing unit 13 may be configured by a programmable logic device such as an FPGA (Field-Programmable Gate Array).

  When increasing the resolution, the image controller 11 controls the DMD 551 based on the first image data when the DMD 551 is at the first position, and controls the DMD 551 based on the second image data when the DMD 551 is at the second position. Control.

  The fan 20 rotates under the control of the system control unit 10 to cool the light source 30 of the optical engine 15.

  The optical engine 15 has a light source 30, an illumination optical system unit 40, an image display unit 50, and a projection optical system unit 60, and projects an image on a screen S under the control of the system control unit 10.

  The light source 30 is, for example, a mercury high-pressure lamp, a xenon lamp, an LED, or the like, and is controlled by the system control unit 10 to irradiate the illumination optical system unit 40 with light.

  The illumination optical system unit 40 has, for example, a color wheel, a light tunnel, a relay lens, and the like, and guides light emitted from the light source 30 to the DMD 551 provided in the image display unit 50.

  The image display unit 50 includes a fixed unit 51 fixedly supported, a movable unit 55 movably provided with respect to the fixed unit 51, and a driving unit 57.

  The movable unit 55 has a DMD 551 and is driven by the driving unit 57.

  The drive unit 57 generates a periodic pulse-like drive voltage based on a control signal from the movement control unit 12 of the system control unit 10, and applies the drive voltage to an electromagnetic actuator for moving the movable unit 55 described later. . That is, the electromagnetic actuator is driven by pulse driving (for example, PWM driving). As described above, the position of the movable unit 55 with respect to the fixed unit 51 is controlled by the movement control unit 12.

  The frequency (drive frequency) of the drive voltage output from the drive unit 57 is changed by the movement control unit 12 according to a predetermined condition. For example, the drive frequency is a value within the range of 400 Hz to 2500 Hz. Note that the lower the driving frequency is, the higher the driving voltage is set.

  The DMD 551 is controlled by the image control unit 11 of the system control unit 10 and modulates the light guided by the illumination optical system unit 40 to generate a projection image. That is, the DMD 551 is an image generation element that generates an image using light from the light source 30.

  The projection optical system unit 60 is, for example, a projection unit that includes a plurality of projection lenses, mirrors, and the like, and enlarges a projection image generated by the DMD 551 of the image display unit 50 and projects the image on the screen S.

[Illumination optical system unit]
FIG. 3 is a perspective view illustrating the illumination optical system unit 40. 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 provided with filters of R (red), G (green), and B (blue) at different portions in the circumferential direction. The color wheel 401 rotates at high speed to time-division the light emitted from the light source 30 into each of RGB colors.

  The light tunnel 402 is formed in a square tubular shape by, for example, laminating plate glass or the like. The light tunnel 402 guides the light of each color of RGB transmitted 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 condense the light emitted from the light tunnel 402 while correcting the axial chromatic aberration.

  The cylinder mirror 405 and the concave mirror 406 reflect the light emitted from the relay lenses 403 and 404 to the DMD 551 provided in the image display unit 50. The DMD 551 modulates the reflected light from the concave mirror 406 to generate a projection image.

[Image display unit]
FIG. 4 is a perspective view illustrating the image display unit 50. FIG. 5 is a side view of the image display unit 50 shown in FIG.

  As shown in FIGS. 4 and 5, the image display unit 50 has a fixed unit 51 fixedly supported and a movable unit 55 provided movably with respect to the fixed unit 51.

  The fixing unit 51 has a top plate 511 as a first fixing plate and a base plate 512 as a second fixing plate. In the fixing unit 51, a top plate 511 and a base plate 512 are provided in parallel with a predetermined gap.

  The movable unit 55 has a DMD 551, a movable plate 552 as a first movable plate, a coupling plate 553 as a second movable plate, and a heat sink 554, and 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. In the coupling plate 553, the DMD 551 is fixedly provided on the upper surface side, and the heat sink 554 is fixed on the lower surface side. The coupling plate 553 is fixed to the movable plate 552, and is movably supported by the fixed unit 51 together with the movable plate 552, the DMD 551, and the heat sink 554.

  The DMD 551 is provided on a 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 551 has an image generating surface on which a plurality of movable micromirrors are arranged in a lattice. Each micro mirror of the DMD 551 is provided so that its mirror surface can be tilted around a torsion axis, and is driven ON / OFF based on an image signal transmitted from the image control unit 11.

  When the micro mirror is, for example, “ON”, the tilt angle is controlled so that the light from the light source 30 is reflected to the projection optical system unit 60. 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).

  As described above, the DMD 551 controls the inclination angle of each micromirror by the image signal transmitted from the image control unit 11, modulates the light emitted from the light source 30 and passed through the illumination optical system unit 40, and modulates the projected image. Generate.

  FIG. 6 is a bottom view illustrating the top plate 511 in the embodiment. As shown in FIG. 6, magnets 531, 532, 533, and 534 are provided on the 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 each composed of two rectangular parallelepiped magnets arranged so that their longitudinal directions are parallel to each other, and each form a magnetic field that reaches the movable plate 552.

  The magnets 531, 532, 533, and 534 face coils 581, 582, 583, and 584 (see FIG. 9) provided on the upper surface of the movable plate 552, respectively.

[Movable unit]
FIG. 7 is a perspective view illustrating the movable unit 55. FIG. 8 is an exploded perspective view of the movable unit 55 shown in FIG.

  As shown in FIGS. 7 and 8, the movable unit 55 has a DMD 551, a movable plate 552, a coupling plate 553, a heat sink 554, a holding member 555, and a DMD substrate 557, and is movably supported by the fixed unit 51. Have been.

  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 the plurality of support spheres 521 so as to be movable in a direction parallel to the surface.

  FIG. 9 is a perspective view illustrating the movable plate 552 in the embodiment. As shown in FIG. 9, the movable plate 552 is formed of a plate-shaped member, has a center hole 570 at a position corresponding to the DMD 551 provided on the DMD substrate 557, and has coils 581 and 582 around the center hole 570. , 583 and 584 are provided.

  Each of the coils 581, 582, 583, and 584 is formed by winding an electric wire around an axis parallel to the Z1Z2 direction, and is provided in a concave portion formed on a surface of the movable plate 552 on the top plate 511 side. Covered with a cover.

  The magnets 531, 532, 533, and 534 and the coils 581, 582, 583, and 584 are provided at positions facing each other in a state where the movable unit 55 is supported by the fixed unit 51.

  An electromagnetic actuator is constituted by the coils 581, 582, 583, 584 and the magnets 531, 532, 533, 534 fixedly arranged on the coils. The electromagnetic actuator is an example of a moving unit that moves the movable plate 552.

  When a driving voltage is applied to the coils 581, 582, 583, and 584 and a current flows, a Lorentz force as 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 the Lorentz force and is displaced in the XY plane with respect to the fixed unit 51.

  The magnitude and direction of the current flowing through each of the coils 581, 582, 583, and 584 are controlled by the movement control unit 12 of the system control unit 10. The movement control unit 12 controls the direction and amount of movement of the movable plate 552 based on the magnitude and polarity of the drive voltage applied to each of the coils 581, 582, 583, and 584 via the drive unit 57.

  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 the X2 direction is generated. In this case, the movable plate 552 moves in the X1 direction or the X2 direction due to the Lorentz force.

  The coil 582 and the magnet 532 and the coil 583 and the magnet 533 are provided side by side in the X1X2 direction, and the magnet 532 and the magnet 533 are arranged so that the longitudinal direction is orthogonal to the magnet 531 and the magnet 534. . In such a configuration, when a current flows through the coil 582 and the coil 583, a Lorentz force in the Y1 direction or the Y2 direction is generated. In this case, the movable plate 552 moves in the Y1 direction or the Y2 direction due to the Lorentz force.

  Note that the movement control unit 12 can also control the movable plate 552 to rotate in the XY plane.

[Image projection]
As described above, in the projector 1 according to the present embodiment, the DMD 551 that generates a projection image is provided in the movable unit 55, and the position is controlled together with the movable unit 55 by the movement control unit 12 of the system control unit 10. .

  The movement control unit 12 moves the movable unit 55 at high speed between a plurality of positions separated by a distance smaller than the arrangement interval of the plurality of micromirrors of the DMD 551 at a predetermined cycle corresponding to the frame rate during image projection. Control the position of. At this time, the image control unit 11 transmits an image signal to the DMD 551 so as to generate a projection image shifted according to each position.

  For example, the movement control unit 12 reciprocates the DMD 551 at a predetermined cycle between a position P1 and a position P2 separated by a distance smaller than the arrangement interval of the micro mirrors of the DMD 551 in the X1X2 direction and the Y1Y2 direction. At this time, the image control unit 11 controls the DMD 551 so as to generate a projection image shifted according to each position, so that the resolution of the projection image can be approximately twice the resolution of the DMD 551. Become. Further, by increasing the moving position of the DMD 551, the resolution of the projected image can be made twice or more that of the DMD 551.

  As described above, the movement control unit 12 moves the DMD 551 together with the movable unit 55 at a predetermined cycle (for example, 30 to 50 Hz), and the image control unit 11 causes the DMD 551 to generate a projection image corresponding to the position, thereby enabling the DMD 551 to operate. It becomes possible to project an image of a resolution or higher.

  FIG. 10 is an explanatory diagram illustrating a display state of a pixel shifted by a half pixel by the DMD shift. FIG. 10A shows each pixel S1 at the position P1. Note that the size of each pixel is XL × YL. FIG. 10B shows each pixel S2 at the position P2 shifted by half a pixel (XL / 2, YL / 2). Then, by alternately projecting the two images shifted by half a pixel, pseudo high resolution is performed as shown in FIG.

[Drive frequency change control]
Next, the control for changing the driving frequency performed by the movement control unit 12 will be described.

  FIG. 11 is a flowchart illustrating the control for changing the driving frequency. As shown in FIG. 11, first, the movement control unit 12 determines whether or not the projector 1 is projecting an image (step S100). When the projector 1 is projecting an image (Step S100: Yes), the movement control unit 12 determines whether or not the high-resolution processing is effective (Step S101). If the resolution increasing process is invalid (Step S101: No), the movement control unit 12 returns the process to Step S100.

  If the resolution increasing process is valid (step S101: Yes), the movement control unit 12 checks the current operation mode set for the projector 1 (step S100).

  The operation mode of the projector 1 is set by the operation unit 7, for example. As the setting of this operation mode, it is possible to switch between a silent priority mode in which noise is prioritized and a vibration tolerance priority mode in which vibration tolerance is prioritized. The switching of the operation mode can be performed by a menu display on the projection image and a selection operation by the remote controller or the operation unit 7 in addition to the switching by the operation unit 7.

  When the operation mode being set is the silent priority mode (Step S102: Yes), the movement control unit 12 sets the first drive frequency as the drive frequency (Step S103). On the other hand, when the operation mode being set is not the silent priority mode but the vibration tolerance priority mode (Step S102: No), the movement control unit 12 sets the second drive frequency as the drive frequency (Step S104). . Here, the second drive frequency is a value larger than the first drive frequency. For example, the first driving frequency is a value equal to or lower than a predetermined value (for example, 500 Hz), and the second driving frequency is a value higher than the predetermined value. The second drive frequency is, for example, 1500 Hz.

  After setting the first drive frequency or the second drive frequency as the drive frequency, the movement control unit 12 performs a high-resolution process (step S105). Thereafter, the process returns to step S100.

  In the high resolution processing, the drive unit 57 generates a drive voltage having the drive frequency (first drive frequency or second drive frequency) set by the movement control unit 12 and applies the drive voltage to the coil of the electromagnetic actuator.

[effect]
The higher the driving frequency, the more times the electromagnetic actuator generates a driving force (Lorentz force) within a unit time. Therefore, the accuracy of the movement of the DMD 551 is high, and the electromagnetic actuator is resistant to vibration generated by a vibration source such as the fan 20. Becomes stronger. However, when the driving frequency is high, the driving force is applied until just before the moving direction of the movable unit 55 is reversed, so that the sudden braking is applied to the movable unit 55, and the generated noise noise increases. On the other hand, when the drive frequency is reduced, the accuracy of the movement of the DMD 551 is reduced and the vibration resistance is reduced, but noise noise can be suppressed. Note that the lower the driving frequency is, the higher the driving voltage is set.

  Therefore, when the user selects the silent priority mode, the noise sound generated in the movable unit 55 is reduced and becomes silent, and the vibration resistance is improved by selecting the vibration resistance priority mode. As described above, in the projector 1 of the present embodiment, since it is possible to select between silence and vibration resistance according to the situation, the comfort of the user when appreciating the high-resolution projected image is improved. be able to.

<Second embodiment>
Hereinafter, an image projection device according to a second embodiment of the present invention will be described. The image projection device according to the second embodiment has the same configuration as that of the image projection device according to the first embodiment except that the drive frequency change control is different.

  FIG. 12 is a flowchart illustrating the control for changing the drive frequency in the second embodiment. As shown in FIG. 12, only the steps S202 and S203 are different from the change control of the first embodiment. Hereinafter, only different points from the first embodiment will be described.

  In the present embodiment, when the resolution increasing process is valid (Step S201: Yes), the movement control unit 12 acquires the current rotation speed of the fan 20 driven by the system control unit 10 (Step S201). S202). The movement control unit 12 determines whether or not the acquired rotation speed is equal to or less than a threshold (Step S203). When the rotation speed is equal to or less than the threshold (Step S203: Yes), the movement control unit 12 sets the first drive frequency as the drive frequency (Step S204). On the other hand, when the rotation speed is larger than the threshold (Step S203: No), the movement control unit 12 sets the second drive frequency as the drive frequency (Step S205).

  The values of the first drive frequency and the second drive frequency are the same as in the first embodiment.

  In the second embodiment, when the rotation speed of the fan 20 is low and the vibration is small, the first drive frequency suitable for the quietness is applied, so that the user can achieve high resolution in a quiet environment with little noise. The projected image can be appreciated. On the other hand, when the rotation speed of the fan 20 is high and the vibration is large, the second drive frequency suitable for vibration resistance is applied, so that a high-resolution projected image can be viewed with little image blurring. .

<Third embodiment>
Hereinafter, an image projection device according to a third embodiment of the present invention will be described. The image projection device according to the third embodiment has the same configuration as that of the image projection device according to the first embodiment except that the control for changing the driving frequency is different.

  FIG. 13 is a flowchart illustrating the control for changing the driving frequency in the second embodiment. As shown in FIG. 13, only steps S302 and S303 are different from the change control of the first embodiment. Hereinafter, only different points from the first embodiment will be described.

  In the present embodiment, when the resolution increasing process is valid (step S301: Yes), the movement control unit 12 acquires the current video mode set in the system control unit 10 (step S302). The movement control unit 12 determines whether or not the obtained video mode is the moving image mode (Step S303). When the video mode is the moving image mode (Step S303: Yes), the movement control unit 12 sets the first drive frequency as the drive frequency (Step S304). On the other hand, when the video mode is not the moving image mode (Step S303: No), the movement control unit 12 sets the second drive frequency as the drive frequency (Step S305).

  The values of the first drive frequency and the second drive frequency are the same as in the first embodiment. The video mode is set by the operation unit 7, for example.

  For example, when the video mode is set to the moving image mode, the image control unit 11 determines that the luminance of the light source 30 during the period when the G (green) filter of the color wheel 401 traverses the optical path of the light emitted by the light source 30 is higher than the luminance of the light source 30. , B (blue) are increased during the period in which the filters cross. On the other hand, when the video mode is set to a mode other than the moving image mode, the image control unit 11 determines the luminance of the light source 30 during the period when the G (green) filter of the color wheel 401 crosses the optical path of the light emitted by the light source 30. Also, the brightness of the light source 30 during the period when the B (blue) filter is traversed is reduced.

  The movement control unit 12 controls a movable unit 55 as a movable unit via a drive unit 57 included in the image display unit 50, and controls the position of the DMD 551 provided in the movable unit 55.

  In the third embodiment, one of silentness and vibration resistance is selected according to the video mode, and in the case of the moving image mode, silentness is selected. Therefore, the user can watch a moving image (for example, a movie) in a quiet environment with little noise sound. On the other hand, when the video is other than a moving image (for example, a still image), the user can view a high-resolution projected image with little image blurring.

<Fourth embodiment>
Hereinafter, an image projection device according to a fourth embodiment of the present invention will be described. The image projection device according to the fourth embodiment has the same configuration as that of the image projection device according to the first embodiment except that the control for changing the driving frequency is different.

  FIG. 14 is a flowchart illustrating the control for changing the drive frequency in the second embodiment. As shown in FIG. 14, only the steps S402 and S403 are different from the change control of the first embodiment. Hereinafter, only different points from the first embodiment will be described.

  In the present embodiment, when the resolution increasing process is valid (step S401: Yes), the movement control unit 12 acquires the current installation state of the projector set in the system control unit 10 (step S402). ). The movement control unit 12 determines whether the acquired installation state is the suspended state (Step S403). When the installation state is the ceiling suspension state (Step S403: Yes), the movement control unit 12 sets the second drive frequency as the drive frequency (Step S405). On the other hand, when the installation state is other than the ceiling suspension state (for example, the floor installation state) (Step S403: No), the movement control unit 12 sets the first drive frequency as the drive frequency (Step S404). For example, the first drive frequency is a value smaller than a predetermined value (for example, 1500 Hz), and the second drive frequency is a value equal to or more than the predetermined value.

  The installation state of the projector is set by, for example, the operation unit 7. Note that an angle sensor or the like may be provided in the projector, and the installation state may be acquired based on a value detected by the angle sensor.

  In the fourth embodiment, either the quietness or the vibration resistance is selected according to the installation state of the projector. When the installation state is the ceiling suspension state, the vibration resistance is selected. . When the projector is suspended from the ceiling, the user is at a position distant from the projector, so that even if a noise sound is generated, the user is hard to hear it and does not give any discomfort. On the other hand, when the projector is in a state other than the ceiling-hanging state (for example, on the floor), the user often comes close to the projector, and thus, by selecting the quietness, a quiet environment with little noise noise is selected. To view the projected image.

  In each of the above embodiments, the magnet provided in the fixed unit 51 and the coil provided in the movable unit 55 constitute an electromagnetic actuator. On the contrary, the fixed unit 51 is provided with a coil. Alternatively, an electromagnetic actuator may be configured by providing the movable unit 55 with a magnet.

  Further, in each of the above embodiments, the DMD is used as the image generating element, but a liquid crystal panel or the like can be used instead of the DMD. The present invention is not limited to an image projection device, but is also applicable to an image display device.

  As described above, the present invention has been described based on the embodiments. However, the present invention is not limited to the requirements described in the above embodiments. Regarding these points, the gist of the present invention can be changed within a range that does not impair the gist, and can be appropriately determined according to the application form.

Reference Signs List 1 projector 3 emission window 4 power supply 7 operation unit 10 system control unit 11 image control unit 12 movement control unit 13 image processing unit 15 optical engine 20 fan 30 light source 40 illumination optical system unit 50 image display unit 51 fixed unit 55 movable unit (movable) Part)
57 drive unit 60 projection optical system unit (projection unit)
511 Top plate 512 Base plate 513 Central hole 521 Supporting sphere 531, 532, 533, 534 Magnet 551 Digital micromirror device (image generation element)
552 Movable plate 553 Coupling plate 554 Heat sink 555 Holding member 557 Substrate 570 Central hole 581, 582, 583, 584 Coil

JP 2004-102079 A

Claims (9)

An image generating element that generates an image using light from a light source,
A movable section provided with the image generating element,
An electromagnetic actuator for moving the movable part,
A drive unit for applying a periodic drive voltage to the electromagnetic actuator,
A movement control unit that controls the driving unit and changes the frequency of the driving voltage according to a predetermined condition;
An image display device comprising:   2. The image display device according to claim 1, wherein the electromagnetic actuator includes a coil provided on the movable unit, and a magnet fixedly arranged to face the coil. 3. Have more fans,
The predetermined condition is that the rotation speed of the fan is equal to or less than a threshold value,
The image display device according to claim 1, wherein the movement control unit sets the frequency to a value equal to or less than a first predetermined value when the predetermined condition is satisfied. The predetermined condition is that the video mode is a moving image mode,
The image display device according to claim 1, wherein the movement control unit acquires a video mode being set, and sets the frequency to a value equal to or less than a first predetermined value when the predetermined condition is satisfied. . The predetermined condition is that the installation state is a suspended state,
The image display device according to claim 1, wherein the movement control unit acquires an installation state, and sets the frequency to a value equal to or greater than a second predetermined value when the predetermined condition is satisfied.   The image display device according to claim 3, wherein the first predetermined value is 500 Hz.   The image display device according to claim 5, wherein the second predetermined value is 1500 Hz. An image generating element that generates an image using light from a light source,
A projection unit that projects an image generated by the image generation element,
A movable section provided with the image generating element,
An electromagnetic actuator for moving the movable part,
A drive unit for applying a periodic drive voltage to the electromagnetic actuator,
A movement control unit that controls the driving unit and changes the frequency of the driving voltage according to a predetermined condition;
An image projection device having: An image generating element that generates an image using light from a light source,
A movable section provided with the image generating element,
An electromagnetic actuator for moving the movable part,
A drive unit for applying a periodic drive voltage to the electromagnetic actuator,
A method for controlling an image display device having:
A control method for an image display device, wherein the driving unit is controlled to change a frequency of the driving voltage according to a predetermined condition.

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