JP2017167287A - Image projection device and image projection device control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress reduction in sense of resolution in pixel shift control.SOLUTION: An image projection device having a light source, an image display unit that has an optical modulation element forming an image using light from the light source, an illumination optical unit that guides the light from the light source to the image display optical unit, and a projection optical unit that projects the image formed by the image display unit to a projected surface comprises: a projection control unit that controls the light source, the image display unit and the illumination optical unit; and a movement control unit that causes the optical modulation element to periodically move between a first position (an original pixel position) and a second position (a pixel position after the pixel is shifted). The movement control unit is configured to, when causing the optical modulation element to move from the first position to the second position and from the second position to the first position, cause the optical modulation element so as to be caused to stop at a target position after caused to overshoot once in a movement direction, respectively, and the projection control unit is configured to control so that the image is not projected to the projected surface during a period when the optical modulation element overshoots.SELECTED DRAWING: Figure 21

Description

  The present invention relates to an image projection apparatus and a control method for the image projection apparatus.

  Based on image data transmitted from an information processing apparatus such as a personal computer or a video reproduction device such as a DVD player, an optical modulation element (image display element or light modulation element) is imaged using light emitted from a light source. And an image projection apparatus (projector, image projection apparatus) that projects the generated image onto a projection surface such as a screen through an optical system including a plurality of lenses or the like is known.

  Image projectors are widely used for presentations, conferences, lectures, educational sites, signage, etc. for large numbers of people, as well as improved resolution and low brightness due to higher resolution of LCD panels and higher lamp efficiency. Pricing is progressing.

  In addition, DLP (Digital Light Processing) type image projection apparatuses using DMD (Digital Micro-mirror Device) are widely used, and these image projection apparatuses are widely used not only in offices and schools but also at home. ing. In addition, development of a short focus type image projection apparatus in which a projection distance to a projection surface such as a screen is shortened is also active.

  In such an image projection apparatus, when the resolution of a projected image is increased, it is conceivable to increase the pixel density of the optical modulation element, but the manufacturing cost of the optical modulation element increases.

  In contrast, Patent Document 1 discloses an image projection apparatus that forms an image by decentering a lens provided in a projection optical system and shifts an image on a projection surface to increase the resolution of the projection image. It is disclosed.

  Further, Patent Document 2 discloses light valve, time-division illumination means for sequentially illuminating monochromatic light in a time-division manner, and image display information of the light valve so as to form a color image for each color illumination time. Color sequential image projection with control means for controlling and pixel shifting means for shifting the projection pixel of the light valve so as not to overlap another pixel, and shifting the light modulation element to make it a pseudo high resolution An apparatus is disclosed.

  However, in the prior art, in the pixel shift control, there is a problem that during the period of movement from pixel to pixel, the pixel becomes larger and the resolution is lowered.

  SUMMARY An advantage of some aspects of the invention is that it provides an image projection apparatus that can suppress a decrease in resolution in pixel shift control.

  In order to achieve such an object, an image projection device according to the present invention includes a light source that emits light, an image display unit that includes an optical modulation element that forms an image using light from the light source, and light from the light source. In an image projection apparatus comprising: an illumination optical unit that guides the image to the image display unit; and a projection optical unit that projects an image formed by the image display unit onto a projection surface. The light source, the image display unit, and the illumination A projection control unit that controls the optical unit; and a movement control unit that periodically moves the optical modulation element between a first position and a second position, and the movement control unit includes the optical modulation element. When moving from the first position to the second position and from the second position to the first position, each is moved to the target position after once overshooting in the moving direction, and the projection control is performed. Parts for a period of time in the optical modulation element from overshooting is to control so that the image is not projected on the projection surface.

  According to the present invention, it is possible to suppress a decrease in resolution in pixel shift control.

1A is an external perspective view showing an embodiment of an image projection apparatus, and FIG. 1B is a side view of the image projection apparatus, showing a projection state on a projection surface. 2A is a perspective view showing a state in which an exterior cover of the image projection apparatus is removed, and FIG. 3B is an enlarged configuration diagram of a circled portion of FIG. It is sectional drawing of an illumination optical system unit, a projection optical system unit, an image display unit, and a light source unit. It is a block diagram (1) which illustrates the functional composition of an image projection device. It is explanatory drawing of the light source unit using LED. It is a block diagram (2) which illustrates the functional composition of an image projection device. FIG. 2A is a perspective view illustrating an image display unit, and FIG. 3B is a side view illustrating an image display unit. It is a perspective view which illustrates a fixed unit. It is a disassembled perspective view which illustrates a fixed unit. It is a figure explaining the support structure of the movable plate by a fixed unit. It is the elements on larger scale explaining the support structure of the movable plate by a fixed unit. It is a bottom view illustrating a top plate. It is a perspective view which illustrates a movable unit. It is a disassembled perspective view which illustrates a movable unit. It is a perspective view which illustrates a movable plate. It is a perspective view which illustrates the movable unit from which the movable plate was removed. It is a figure explaining the DMD holding structure of a movable unit. It is explanatory drawing of the translational motion of DMD of the left-right direction, the translational motion of an up-down direction, and rotational motion. It is explanatory drawing which showed the image of the display state of the pixel shifted by the half pixel by pixel shift. It is explanatory drawing which showed the image of the display state of 1 pixel in FIG. It is a graph which shows the behavior of the pixel by pixel shift, Comprising: (A) When moving a pixel so that a square wave-like behavior may be shown, (B) When moving a pixel so that a sine wave-like behavior may be shown (C) It is an example of the behavior control of the pixel by the image projector which concerns on this embodiment. It is explanatory drawing about the pixel shift and the lighting timing of a light source. It is explanatory drawing about pixel shift and rotation position control of a color wheel. It is a plane schematic diagram of a color wheel.

  Hereinafter, the configuration according to the present invention will be described in detail based on the embodiment shown in FIGS.

(Image Projector (1))
FIG. 1A is an external perspective view showing an embodiment of the image projector 1. FIG. 1B is a side view of the image projection apparatus 1 and shows a projection state on the screen S that is a projection surface.

  FIG. 2A is a perspective view showing a state in which the exterior cover 2 of the image projector 1 is removed. FIG. 2B is an enlarged configuration diagram of the optical engine 3 and the light source unit 4 indicated by a circled portion in FIG.

  The image projection apparatus 1 is required to be able to make the projection space required outside the image projection apparatus as small as possible along with the enlargement of the projection screen. In recent years, the performance of the optical engine 3 has improved, and the image projector 1 that can achieve a projection image size of 60 inches to 80 inches with a projection distance of 1 to 2 m has become mainstream.

  In the case of the conventional image projection apparatus 1 with a long projection distance, there is a conference desk or the like between the image projection apparatus 1 and the screen S, and the image projection apparatus 1 is arranged behind the conference desk. In recent years, as the projection distance has been shortened, it can be arranged on the front side of the conference desk, and the space behind the image projection apparatus 1 can be freely utilized.

  The image projection apparatus 1 includes a lamp as a light source and a large number of electronic boards inside the apparatus, and the internal temperature of the apparatus rises as time passes after startup. This is remarkable in recent years when the housing size of the image projecting apparatus 1 has been reduced, and therefore, the image projecting apparatus 1 includes an intake port 16 and an exhaust port so that the internal components do not exceed the heat-resistant temperature. 17 is provided.

  As shown in FIG. 2, the image projection apparatus 1 includes an optical engine 3 and a light source unit 4. FIG. 3 is a cross-sectional view of the illumination optical system unit 40, the projection optical system unit 60, the image display unit 50, and the light source unit 4, which are illumination devices, as viewed from above. The optical engine 3 includes an illumination optical system unit 40, an image display unit 50, and a projection optical system unit 60.

  As shown in FIG. 2, an intake fan 18 and an exhaust fan 19 are respectively provided inside the intake port 16 and the exhaust port 17, and the outside air sucked from the intake fan 18 is discharged from the exhaust fan 19. Air cooling by forced air flow in the apparatus is performed.

  In the image projection apparatus 1, light (white light) from the light source of the light source unit 4 is applied to the illumination optical system unit 40 of the optical engine 3. In the illumination optical system unit 40, the emitted white light is separated into RGB, and then guided to the image display unit 50 by a lens, a mirror, and the like, and the image display unit 50 that forms an image according to the modulation signal and the image are projected optically. The system unit 60 enlarges and projects the image onto the screen S.

  Various lamps can be used as the lamp of the light source unit 4 (light source 30). For example, an arc lamp such as a high-pressure mercury lamp or a xenon lamp can be used. For example, it is preferable to use a high-pressure mercury lamp.

  A fan 20 for cooling the light source is provided on one side of the side surface of the light source unit 4. The rotation speed of the fan 20 is controlled so that each part of the light source unit 4 has a temperature within a set rated temperature range. Further, the emission direction of light from the light source unit 4 and the emission direction of image light from the projection optical system unit 60 are approximately 90 ° as shown in FIG.

  The illumination optical system unit 40 of the optical engine 3 includes a color wheel 5 (rotating color filter) that separates light emitted from the light source, a light tunnel 6 that guides light emitted from the color wheel 5, a relay lens 7, A plane mirror 8 and a concave mirror 9 are provided.

  In the illumination optical system unit 40, first, white light, which is emitted light from the light source, is converted into light that repeats each color of RGB every unit time by the disk-shaped color wheel 5 and emitted. The color-separated light emitted from the color wheel 5 is guided to the light tunnel 6. The light tunnel 6 is an illumination uniform conversion optical member that makes incident light uniform by being reflected and combined multiple times inside (inner wall).

  Next, the light emitted from the light tunnel 6 is condensed by correcting a longitudinal chromatic aberration of the light by a relay lens 7 formed by combining two lenses. Further, the light emitted from the relay lens 7 is reflected by the plane mirror 8 and the concave mirror 9 and is condensed on the image display unit 50. The image display unit 50 has a substantially rectangular mirror surface made up of a plurality of micromirrors, and each micromirror is driven in a time-sharing manner based on image data, thereby processing the projection light so as to form a predetermined image. The DMD 551 is provided as an optical modulation element that reflects the light.

  The image display unit 50 selects the light that is output to the projection unit by switching the micromirror on and off according to the input signal, and expresses the gradation. That is, the DMD 551 reflects the light used by the plurality of micromirrors to the projection lens and reflects the discarded light to the OFF light plate based on the image data in a time division manner. The light used in the image display unit 50 is reflected to the projection optical system unit 60, and the image light magnified through the plurality of projection lenses in the projection optical system unit 60 is magnified and projected onto the screen S.

  The incident side of the relay lens 7, the plane mirror 8, the concave mirror 9, the image display unit 50, and the projection optical system unit 60 inside the illumination optical system unit 40 is held by a housing (not shown) so as to cover each component. In addition, the mating surface of the housing has a dustproof structure sealed with a sealing material.

  FIG. 4 is a functional block diagram illustrating an example of the image projection apparatus 1 according to the present embodiment.

  The image projection apparatus 1 includes a system control unit 10, a light source control unit 11, a color wheel control unit 12, a DMD control unit 13, a movable unit control unit 14, a fan control unit 15, a fan 20, a remote control receiving unit 22, and a main body operation unit 23. , Input terminal 24, video signal control unit 25, setting information storage unit 26, power supply unit 27, light source 30, illumination optical system unit 40, image display unit 50, projection optical system unit 60, and the like. An image projection apparatus for projecting. Moreover, the remote control 21 as a remote control means is provided.

  The system control unit 10 performs overall control of the image projection apparatus 1. In addition, image processing such as contrast adjustment, brightness adjustment, sharpness adjustment, scaling processing, display control of a superimposed screen (OSD: On Screen Display) such as menu information, and the image projection apparatus 1 are applied to the input video signal. Start control and other various controls. In addition, the image data input from the video signal control unit 25 is subjected to predetermined image processing for increasing the resolution by pixel shift.

  The system control unit 10 includes a light source control unit 11, a color wheel control unit 12, a DMD control unit 13, a movable unit control unit 14, a fan control unit 15, a remote control receiving unit 22, a main body operation unit 23, and a video signal control unit 25. Are connected to the setting information storage unit 26 and control each of these functional units.

  Each control unit such as the system control unit 10 is configured by a microcontroller (microcomputer), and a calculation unit and a storage unit such as a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory). The function of each unit is realized by the CPU executing the program stored in the ROM in cooperation with the RAM.

  The input terminal 24 is an interface for inputting a video signal, and is 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, an RCA. Video input terminals such as terminals. A video signal is received from a video supply device such as a computer or AV device via a cable connected to the input terminal 24. Further, a plurality of input terminals 24 may be provided.

  The video signal control unit 25 processes the video signal input to the input terminal 24. For example, the video signal control unit 25 performs various processes such as serial-parallel conversion and voltage level conversion on the video signal. It also has a signal determination function that analyzes the resolution and frequency of the video signal.

  The setting information storage unit 26 stores data in image processing and other various processing on the video signal. As the setting information storage unit 26, for example, a nonvolatile semiconductor memory such as an EPROM, an EEPROM, or a flash memory can be employed. The image projecting apparatus 1 can store the previous setting contents (such as language settings) even after the power is turned off.

  The main body operation unit 23 is an interface for operating the image projection apparatus 1 and accepts various operation requests from the user. When accepting an operation request, the main body operation unit 23 notifies the system control unit 10 of the operation request. The main body operation unit 23 includes operation keys (operation buttons) provided on the outer surface of the image projection apparatus 1.

  The remote control receiving unit 22 receives an operation signal from the remote control 21. When receiving the operation signal, the remote control receiving unit 22 notifies the system control unit 10 of the operation signal.

  The user can perform various settings by operating the main body operation unit 23 or the remote controller 21. For example, a display instruction for a menu screen, selection of the installation state of the image projection apparatus 1, a request to change the aspect ratio of the projection image, a request to turn off the image projection apparatus 1, a lamp power change request to change the light amount of the light source 30, and projection A video mode change request for changing the image quality (high brightness, standard, natural, etc.), a freeze request for stopping the projected image, and the like can be executed.

  The fan control unit 15 controls the fan 20 so that the temperature in the image projection apparatus 1 and the temperature of the light source 30 become predetermined temperatures.

  The power supply unit 27 is connected to each device in the image projection apparatus 1, converts AC (alternating current) power input from an outlet or the like into DC (direct current), and supplies power to each device in the image projection apparatus 1. Supply.

  The fan 20 includes an intake fan, an exhaust fan, a cooling fan, and the like. By discharging the outside air sucked from the intake fan from the exhaust fan, an air flow is generated in the image projection apparatus 1 and air cooling is performed. A cooling fan as a light source cooling unit is provided in the vicinity of the light source 30, and the amount of rotation of the cooling fan is controlled based on the temperature of the light source 30.

  The light source 30 is, for example, a high-pressure mercury lamp in which a luminescent material emits light by a discharge between a pair of electrodes, and irradiates the illumination optical system unit 40 with light. Also, a xenon lamp or the like can be used as the light source 30. Further, the system control unit 10 instructs the light source control unit 11 to turn on the light source 30 according to the setting value of the setting information storage unit 26. The light source controller 11 controls on / off of the light source 30 and lighting power.

  The light emitted from the light source 30 is split into light that repeats each color per unit time by the disk-shaped color wheel 5 in the illumination optical system unit 40.

  The color wheel control unit 12 controls the rotational drive of the color wheel 5. The light emitted from the color wheel 5 is condensed on the DMD 551 as an optical modulation element in the image display unit 50 through the light tunnel 6, the relay lens 7, the plane mirror 8 and the concave mirror 9.

  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 (details will be described later). The movable unit 55 has a DMD 551, and the position of the movable unit 55 relative to the fixed unit 51 is controlled by the movable unit control unit 14.

  The movable unit 55 is provided with an electromagnetic actuator (voice coil, magnet) as drive means. The movable unit control unit 14 controls the amount of current to flow to the driving unit of the movable unit 55, and controls pixel shift for high resolution at a predetermined displacement amount and cycle.

  The shift control of the DMD 551 by the movable unit control unit 14 can be turned on / off by operating the main body operation unit 23 or the remote controller 21. When the shift control of the DMD 551 is set to OFF, a normal projection screen display in which the DMD 551 is not shifted is displayed.

  The DMD 551 has a substantially rectangular mirror surface composed of a plurality of micromirrors, and each micromirror is driven in a time-sharing manner based on video data, thereby processing and reflecting the projection light so as to form a predetermined video. This is an optical modulation element.

  The DMD control unit 13 controls on / off of the micromirror of the DMD 551.

  The DMD 551 reflects the light used by the plurality of micromirrors to the projection optical system unit 60 based on the video data in a time division manner, and reflects the discarded light to the OFF light plate. The light to be used is reflected to the projection optical system unit 60, and the image light enlarged through the projection optical system unit 60 is enlarged and projected onto the screen S.

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

(Image Projector (2))
In the example of FIGS. 2 to 4, an example in which a high pressure mercury lamp is used as the light source 30 of the light source unit 4 has been described. However, a solid light source such as a light emitting diode (LED) may be used as the light source 30. FIG. 5 is a diagram illustrating an example of the light source unit 4 that collects each monochromatic light from each solid light source of the three primary colors.

  In FIG. 5, R_LED 31, G_LED 32, and B_LED 33 that are light emitting diodes of three primary colors (R, G, and B) are used as the light source 30. Moreover, the light of the three primary colors from each LED 31-33 is synthesize | combined by the dichroic filter 37 as a synthetic | combination means via the condensing elements 34-36 suitable for each. The light synthesized by the dichroic filter 37 is guided to the light tunnel 6 through a plurality of lenses. Thereafter, similarly to FIG. 3, the light collected by the relay lens 7 and emitted from the relay lens 7 is reflected by the plane mirror 8 and the concave mirror 9 and collected on the image display unit 50.

  FIG. 6 is a functional block diagram showing another example of the image projection apparatus 1 according to this embodiment. The light source control unit 11 controls on / off and lighting power of the LEDs 31 to 33.

(Image display unit)
FIG. 7A is a perspective view illustrating the image display unit 50. FIG. 7B is a side view illustrating the image display unit 50.

  As shown in FIGS. 7A and 7B, the image display unit 50 includes a fixed unit 51 that is fixedly supported and a movable unit 55 that is provided so as to be movable with respect to the fixed unit 51.

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

  The movable unit 55 includes 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. The coupling plate 553 is provided with the DMD 551 fixed on the upper surface side and the heat sink 554 fixed on the lower surface side. 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 551, and the heat sink 554.

  The DMD 551 is provided on the surface of the coupling plate 553 on the movable plate 552 side, and is movably provided together with the movable plate 552 and the coupling plate 553. The DMD 551 has an image generation surface on which a plurality of movable micromirrors are arranged in a grid pattern. Each micromirror of the DMD 551 is provided so that the mirror surface can tilt around the torsion axis, and is driven ON / OFF based on an image signal transmitted from the DMD control unit 13.

  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. When the micromirror is “OFF”, for example, the tilt angle is controlled in a direction in which the light from the light source 30 is reflected toward the OFF light plate.

  As described above, the DMD 551 controls the tilt angle of each micromirror by the image signal transmitted from the DMD control unit 13, modulates the light emitted from the light source 30 and passes through the illumination optical system unit 40, and generates a projection image. Generate.

  The heat sink 554 is an example of an enlarged heat radiating portion, and is provided so that at least a part thereof is in contact with the DMD 551. The heat sink 554 is provided together with the DMD 551 on the coupling plate 553 that is movably supported, so that the heat sink 554 can be efficiently abutted against the DMD 551 and cooled. With such a configuration, in the image projection apparatus 1 according to the present embodiment, the heat sink 554 suppresses the temperature rise of the DMD 551, and the occurrence of malfunctions such as malfunction and failure due to the temperature rise of the DMD 551 is reduced.

[Fixed unit]
FIG. 8 is a perspective view illustrating the fixed unit 51. FIG. 9 is an exploded perspective view illustrating the fixed unit 51.

  As shown in FIGS. 8 and 9, 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 plate-like members, and central holes 513 and 514 are provided at positions corresponding to the DMD 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. 9, the support column 515 is press-fitted into a support column hole 516 formed in the top plate 511 at the upper end portion, and a support column hole 517 formed in the base plate 512 at the lower end portion where the male screw groove is formed. Inserted into. 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 rotatably held in the support holes 522 and 526 of the top plate 511 and the base plate 512 are in contact with the movable plate 552 provided between the top plate 511 and the base plate 512, respectively, so that the movable plate 552 can move. To support.

  FIG. 10 is a view for explaining a support structure of the movable plate 552 by the fixed unit 51. FIG. 11 is a partial enlarged view illustrating a schematic configuration of a portion A shown in FIG.

  As shown in FIGS. 10 and 11, in the top plate 511, the support sphere 521 is rotatably held by the holding member 523 inserted into the support hole 522. Further, in the base plate 512, the support sphere 521 is rotatably held by the support hole 526 whose lower end side is closed by the lid member 527.

  Each support sphere 521 is held so that at least a part thereof protrudes from the support holes 522 and 526, and supports and supports a movable plate 552 provided between the top plate 511 and the base plate 512. The movable plate 552 is supported from both sides by a plurality of support spheres 521 that are rotatably provided so as to be movable in a direction parallel to the top plate 511 and the base plate 512 and parallel to the surface.

  Further, the amount of protrusion of the support sphere 521 provided on the top plate 511 side from the lower end of the holding member 523 varies depending on the position of the position adjusting screw 524 that contacts the opposite side of the movable plate 552. For example, when the position adjusting screw 524 is displaced in the Z1 direction, the protrusion amount of the support sphere 521 is reduced, and the interval between the top plate 511 and the movable plate 552 is reduced. For example, when the position adjusting screw 524 is displaced in the Z2 direction, the protruding amount of the support sphere 521 increases, and the interval between the top plate 511 and the movable plate 552 increases.

  As described above, the distance between the top plate 511 and the movable plate 552 can be appropriately adjusted by changing the protruding amount of the support sphere 521 using the position adjusting screw 524.

  8 and 9, magnets 531, 532, 533, and 534 are provided on the surface of the top plate 511 on the base plate 512 side.

  FIG. 12 is a bottom view illustrating the top plate 511. As shown in FIG. 12, 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 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.

  The magnets 531, 532, 533, and 534 constitute moving means for moving the movable plate 552 with coils provided on the upper surface of the movable plate 552 so as to face the magnets 531, 532, 533, and 534, respectively.

  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. 13 is a perspective view illustrating the movable unit 55. FIG. 14 is an exploded perspective view illustrating the movable unit 55.

  As shown in FIGS. 13 and 14, the movable unit 55 includes 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 with respect to the fixed unit 51. Has 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 a plurality of support spheres 521 so as to be movable in a direction parallel to the surface.

  FIG. 15 is a perspective view illustrating the movable plate 552.

  As shown in FIG. 15, the movable plate 552 is formed of a flat plate-like member, has a central hole 570 at a position corresponding to the DMD 551 provided on the DMD substrate 557, and coils 581, 582 around the central hole 570. , 583, 584 are provided.

  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. Coils 581, 582, 583, and 584 constitute moving means for moving the movable plate 552 with the magnets 531, 532, 533, and 534 of the top plate 511, respectively.

  The magnets 531, 532, 533 and 534 of the top plate 511 and the coils 581, 582, 583 and 584 of the movable plate 552 are provided at positions facing each other in a state where the movable unit 55 is supported by the fixed unit 51. ing. 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 magnitude | size and direction of the electric current sent through each coil 581,582,583,584 are controlled by the movable unit control part 14. FIG. The movable unit control unit 14 controls the movement (rotation) direction, the movement amount, the rotation angle, and the like of the movable plate 552 according to the magnitude and direction of the current flowing through the coils 581, 582, 583, 584.

  In the present embodiment, as the first driving means, a coil 581 and a magnet 531, and a coil 584 and a magnet 534 are provided facing each other in the X1X2 direction. When a current is passed 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 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.

  In the present embodiment, as the second driving means, a coil 582 and a magnet 532, and a coil 583 and a magnet 533 are provided side by side in the X1X2 direction, and the magnet 532 and the magnet 533 are the same as the magnet 531 and the magnet 534. It arrange | positions so that a longitudinal direction may orthogonally cross. 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.

  The movable plate 552 moves in the Y1 direction or the Y2 direction by the Lorentz force generated in the coil 582 and the magnet 532, and 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 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.

  As described above, in the present embodiment, the movable unit control unit 14 controls the magnitude and direction of the current flowing through the coils 581, 582, 583, 584, so that the movable plate 552 can be arbitrarily moved within the movable range. Can be moved to a position.

  It should be noted that the number, position, etc. of the magnets 531, 532, 533, 534 as the moving means and the coils 581, 582, 583, 584 can be adjusted as long as the movable plate 552 can be moved to an arbitrary position. Different configurations may be used. For example, the magnet as the moving unit may be provided on the upper 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.

  As shown in FIG. 13, a coupling plate 553 is fixed to the lower surface side (base plate 512 side) of the movable plate 552 that is movably supported by the fixed unit 51. The coupling plate 553 is formed of a flat plate member, has a central hole at a position corresponding to the DMD 551, and a bent portion provided around is fixed to the lower surface of the movable plate 552 with three screws 591.

  FIG. 16 is a perspective view illustrating the movable unit 55 with the movable plate 552 removed.

  As shown in FIG. 16, the coupling plate 553 is provided with a DMD 551 on the upper surface side and a heat sink 554 on the lower surface side. The coupling plate 553 is fixed to the movable plate 552, so that it can move with respect to the fixed unit 51 along with the movable plate 552 together with the DMD 551 and the heat sink 554.

  The DMD 551 is provided on the DMD substrate 557, and is fixed to the coupling plate 553 by sandwiching the DMD substrate 557 between the holding member 555 and the coupling plate 553. As shown in FIGS. 14 and 16, the holding member 555, the DMD substrate 557, the coupling plate 553, and the heat sink 554 are overlapped and fixed by a stepped screw 560 as a fixing member and a spring 561 as a pressing means.

  FIG. 17 is a diagram for explaining the DMD holding structure of the movable unit 55. FIG. 17 is a side view of the movable unit 55, and the movable plate 552 and the coupling plate 553 are not shown.

  As shown in FIG. 17, the heat sink 554 has a protruding portion 554 a that contacts the lower surface of the DMD 551 through a through hole provided in the DMD substrate 557 while being fixed to the coupling plate 553. Note that the protrusion 554 a of the heat sink 554 may be provided on the lower surface of the DMD substrate 557 and in contact with a position corresponding to the DMD 551.

  In order to enhance the cooling effect of the DMD 551, a heat transfer sheet that can be elastically deformed may be provided between the protrusion 554a of the heat sink 554 and the DMD 551. The heat transfer sheet improves the thermal conductivity between the protrusion 554a of the heat sink 554 and the DMD 551, and the cooling effect of the DMD 551 by the heat sink 554 is improved.

  As described above, the holding member 555, the DMD substrate 557, and the heat sink 554 are overlapped and fixed by the stepped screw 560 and the spring 561. When the stepped screw 560 is tightened, the spring 561 is compressed in the Z1Z2 direction, and a force F1 in the Z1 direction shown in FIG. Due to the force F1 generated from the spring 561, the heat sink 554 is pressed against the DMD 551 by the force F2 in the Z1 direction.

  In the present embodiment, the stepped screw 560 and the spring 561 are provided at four locations, and the force F2 applied to the heat sink 554 is equal to the combined force F1 generated on the four springs 561. The force F2 from the heat sink 554 acts on the holding member 555 that holds the DMD substrate 557 on which the DMD 551 is provided. As a result, a reaction force F3 in the Z2 direction corresponding to the force F2 from the heat sink 554 is generated in the holding member 555, and the DMD substrate 557 can be held between the holding member 555 and the coupling plate 553.

  A force F4 in the Z2 direction acts on the stepped screw 560 and the spring 561 from a force F3 generated on the holding member 555. Since the springs 561 are provided at four locations, the force F4 acting on each of them corresponds to a quarter of the force F3 generated on the holding member 555, and balances with the force F1.

  The holding member 555 is a member that can be bent as shown by an arrow B in FIG. The holding member 555 is pressed and bent by the protruding portion 554a of the heat sink 554, and a force that pushes the heat sink 554 back in the Z2 direction is generated, so that the contact between the DMD 551 and the heat sink 554 can be kept stronger.

  As described above, the movable unit 55 is supported by the fixed unit 51 so that the movable plate 552 and the coupling plate 553 having the DMD 551 and the heat sink 554 are movable. The position of the movable unit 55 is controlled by the movable unit controller 14. Further, the movable unit 55 is provided with a heat sink 554 that abuts on the DMD 551, thereby preventing malfunctions such as malfunction and failure due to the temperature rise of the DMD 551.

(Pixel shift control)
As described above, the DMD 551 that generates a projection image in the image projector 1 is provided in the movable unit 55, and the position of the DMD 551 is controlled together with the movable unit 55 by the movable unit controller 14.

  For example, the movable unit controller 14 moves the movable unit at a high speed between a plurality of positions separated by a distance less than the arrangement interval of the plurality of micromirrors of the DMD 551 at a predetermined period corresponding to the frame rate at the time of image projection. The position of 55 is controlled. At this time, the DMD control unit 13 transmits an image signal to the DMD 551 so as to generate a projection image shifted according to each position.

  In addition, the movable unit controller 14 reciprocates the DMD 551 in a predetermined cycle between a first position and a second position separated by a distance less than the arrangement interval of the micromirrors of the DMD 551 in the X1X2 direction and the Y1Y2 direction. At this time, the DMD control unit 13 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 double the resolution of the DMD 551. Become.

  FIG. 18 is an explanatory diagram of translational motion in the left-right direction (X1X2 direction), translational motion in the vertical direction (Y1Y2 direction), and rotational motion of the DMD 551. FIG. 18A shows a state in which the movable plate 552 is moved by the first driving means to translate the DMD 551 in the left-right direction (also referred to as a shift). FIG. 18B shows a state in which the movable plate 552 is moved by the second driving unit to cause the DMD 551 to translate in the vertical direction. FIG. 18C shows a state where the DMD 551 is rotated by rotating the movable plate 552 by the second driving means.

  As described above, the movable unit control unit 14 moves the DMD 551 together with the movable unit 55 in a predetermined cycle, and the DMD control unit 13 causes the DMD 551 to generate a projection image corresponding to the position, thereby projecting an image having a resolution higher than that of the DMD 551. It becomes possible to do.

  In addition, the mechanism for pixel shift control with which the image projector 1 demonstrated so far is not restricted to the above-mentioned example demonstrated with reference to FIGS. 7-18, By displacing an optical modulation element, it is. What is necessary is just to displace a projection position in the state which maintained the image information currently projected. In this embodiment, an example of shifting by half a pixel is described, but the shift amount is not limited to this.

  FIG. 19 is an explanatory diagram showing an image of a display state of pixels shifted by half a pixel by pixel shift.

  A solid line portion in FIG. 19 indicates each pixel S1 in the first state in which the display position is not shifted (the state before the shift), and the size of each pixel is XL × YL. The dotted line portion indicates each pixel S2 in the second state, which is shifted by half a pixel (XL / 2, YL / 2). Since each pixel S1 in the first state and each pixel S2 in the second state do not fluctuate instantaneously between the two values, a moving period exists.

  20A to 20C are explanatory views showing images of the display state of one pixel in FIG. 20 indicates that the portion displayed in gray is in the projected state, and FIG. 20A shows a state in which the pixel S1 in the first state is projected (non-moving period), and FIG. FIG. 20C shows a state in which the second state pixel S2 is projected (non-moving period), and FIG. 20C shows a state in which the first state is displaced from the second state and from the second state to the first state. (Travel period).

  That is, when the DMD 551 is moved by a predetermined period by half a pixel, the first state (FIG. 20A) → the movement period (FIG. 20C) → the second state (FIG. 20B) → the movement period ( 20C) → first state (FIG. 20A)...

  In the pixel shift, as shown in FIG. 20, the pixel is moved to a position shifted by half a pixel, and an image at each pixel is alternately projected to achieve a high resolution in a pseudo manner. Here, in the pixel shift non-moving period shown in FIGS. 20A and 20B, pixels can be provided at desired positions. In the moving period shown in FIG. Therefore, the pixel becomes larger and the resolution becomes lower, resulting in lower resolution.

  Therefore, the image projection apparatus (image projection apparatus 1) according to the present embodiment includes an image including a light source (light source 30) that emits light and an optical modulation element (DMD551) that forms an image using light from the light source. A display unit (image display unit 50), an illumination optical unit (illumination optical system unit 40) that guides light from the light source to the image display unit, and a projection optical unit that projects an image formed by the image display unit onto a projection surface (Projection optical system unit 60), a projection control unit (system control unit 10, light source control unit 11, color wheel control unit 12, DMD control) that controls a light source, an image display unit, and an illumination optical unit. Unit 13) and a movement control unit (system control unit 10, movable unit control unit 14) that periodically moves the optical modulation element between the first position and the second position, the movement control unit When the optical modulation element is moved from the first position to the second position and from the second position to the first position, the optical modulation element is moved to the target position after being overshot once in the moving direction, and projection control is performed. The unit controls so that the image is not projected onto the projection surface during the period in which the optical modulation element overshoots. In addition, the code | symbol in embodiment and the example of application are shown in a parenthesis.

  FIG. 21 is a graph showing the behavior of a pixel in pixel shift. In the graph of FIG. 21, the horizontal axis indicates the elapsed time (t), and the vertical axis indicates the movement amount (position) of the pixel, indicating that the pixel is moving with the passage of time.

  As described above, the image projection apparatus 1 causes the image display unit 50 to function as an electromagnetic actuator and displaces the DMD 551. Here, as shown in FIG. 21A, when considering moving a pixel so as to exhibit a rectangular wave-like behavior, the original pixel position (the pixel position (first position) in the first state) and the pixel The non-movement period at the pixel position after the shift (the pixel position (second position) in the second state) is long, and the movement period is short. As described above, when the pixel moving period is short, the resolution is hardly lowered and a desired resolution can be obtained.

  On the other hand, as shown in FIG. 21B, when the pixel is moved so as to exhibit a sinusoidal behavior, the original pixel position and the pixel position after the pixel shift are compared with the case where the pixel is moved in a rectangular wave shape. A certain non-movement period is short and the movement time is long. As described above, when the pixel moving period is long, the resolution is lowered as compared with the case where the pixel is moved in a rectangular wave shape.

  For this reason, it is ideal to move in a rectangular wave shape. However, in practice, it is difficult to control the movable plate 552 and the DMD 551 to be displaced in a rectangular wave shape as shown in FIG. In many cases, it is displaced in a sine wave shape as shown in FIG. In this case, the pixel moving period becomes long, and a desired resolution cannot be obtained.

  FIG. 21C is an example of pixel behavior control by the movable unit controller 14 of the image projector 1 according to the present embodiment. In the present embodiment, the pixel is displaced in a rectangular wave shape, but is not stopped at the position where the pixel is stopped (first position and second position), but is temporarily overshot in the moving direction and then stopped at the target position. It is a thing.

  As shown in FIG. 21A, rectangular wave-shaped shift control without overshoot is difficult, and if displacement control is performed so that overshoot does not occur, it takes time for pixel shift, and as a result, FIG. It approaches the sinusoidal behavior shown. On the other hand, as shown in FIG. 21C, the control for once overshooting in the moving direction is relatively easy compared to the behavior shown in FIG. In addition, in the case of overshooting, the movement period becomes longer compared to the behavior shown in FIG. 21A, but compared to the sinusoidal behavior as shown in FIG. It is long and the moving period can be shortened, and a reduction in resolution can be suppressed.

  FIG. 22 is an explanatory diagram regarding the pixel shift by the movable unit controller 14 and the lighting timing of the light source by the light source controller 11 of the image projector 1 according to the present embodiment. In the graph of FIG. 22, the horizontal axis indicates the elapsed time (t), and the vertical axis indicates the movement amount (position) of the pixel, indicating that the pixel is moving with the passage of time. Here, control of the image projection apparatus 1 (FIGS. 5 and 6) using an LED as a light source will be described.

  As shown in FIG. 21C, in the control for overshooting in the pixel moving direction, if an image is projected even during the overshoot period, the pixel position during overshoot is separated from the specified position. Therefore, the image quality is deteriorated.

  For this reason, in the image projection apparatus 1, when control is performed to overshoot the pixel position, during the overshoot period, as shown in FIG. 22, the light source is off during which no image is projected, and the image is projected during other periods. A projection image is formed as the light source on period. As a result, it is possible to prevent a reduction in resolution and to prevent a reduction in image quality due to overshooting.

  Further, instead of turning on and off the light source itself, a shutter mechanism that blocks or transmits light from the light source may be provided, and the on / off of the light may be controlled by the shutter mechanism.

  When the light source is a lamp, the light source cannot be turned on / off at high speed. Therefore, when on / off control of the light source is performed, the light source is a solid light source such as an LED.

  Next, control of the image projection apparatus 1 (FIGS. 2 to 4) having the color wheel 5 in the illumination optical system unit 40 will be described. FIG. 23 is an explanatory diagram regarding pixel shift by the movable unit control unit 14 and rotation position control of the color wheel 5 by the color wheel control unit 12 of the image projection apparatus 1 according to the present embodiment.

  FIG. 24 is a schematic plan view of the color wheel 5. The color wheel 5 is a member in which a plurality of color filters 52 are fixed on the rotation circumference of the rotary motor 53. The color filter 52 has a shape arranged at a position shifted from the rotation center of the color wheel 5. The color filter 52 rotates at a high speed by driving the rotation motor 53, and the light emitted from the light source is rotated. Transparent in order. The light transmitted through the color wheel 5 is switched in order for each color segment, so that the naked eye can visually recognize it as an image in which the colors of all the segments are integrated.

  For example, as shown in FIG. 24, the color wheel 5 includes white (W), red (R), green (G), blue (B), yellow (Y), and cyan (C) corresponding to the three primary colors and complementary colors. Color filters (segments 52W, 52R, 52G, 52B, 52Y, and 52C) having the above transmission characteristics.

  FIG. 23 shows the relationship between the pixel position at the time of pixel shift by the movable unit controller 14 and the transmission position of the color wheel 5. In the graph of FIG. 23, the horizontal axis indicates the elapsed time (t), and the vertical axis indicates the movement amount (position) of the pixel, indicating that the pixel is moving with the passage of time.

  As shown in FIG. 21C, in the control for overshooting in the pixel moving direction, if an image is projected even during the overshoot period, the pixel position during overshoot is separated from the specified position. Therefore, the image quality is deteriorated.

  For this reason, when the image projector 1 performs control to overshoot the pixel position, for example, as shown in FIG. 24, the pixel position is assigned to the white segment 52W of the color wheel 5 during the overshoot period. is there.

  The portion of the white segment 52W that has little influence on the image quality of the projected image is assigned to the overshoot period, and during that time, light is prevented from going to the screen by controlling the DMD 551 (the optical modulation element is controlled to be turned off). Therefore, high image quality can be achieved. This is suitable for a projection mode (image quality emphasis mode) in which the brightness of the projected image is not emphasized and the image quality is emphasized.

  On the other hand, not using the portion of the white segment 52 for the projection image suppresses the brightness of the projection image. For this reason, in the projection mode (high luminance mode) in which the brightness of the projected image is emphasized, for example, the blue segment 52B and the red segment 52R that have little influence on the brightness, or the portion of the segment that is most unnecessary depending on the projected image Is assigned to the overshoot period, and during that time, by controlling the DMD 551, it is possible to obtain a high-luminance projection image by preventing light from going to the screen.

  In this way, by controlling which segment of the color wheel 5 is assigned the overshoot period according to the projection mode of the image projection apparatus 1, it is possible to suppress a decrease in resolution and to obtain a desired projection image. Can be obtained.

  The pixel shift control itself may be turned on / off according to the projection mode of the image projection apparatus 1. For example, in the image quality emphasis mode, as described above, the pixel shift is executed so that the white segment 52W portion is assigned to the overshoot period, and in the high luminance mode, the pixel shift control is turned off. You may make it do.

  The segment of the color wheel 5 shown in FIG. 24 is an example, and the present invention is not limited to this. For example, you may use the color wheel 5 which does not have the white segment 52W.

  Further, regarding the control of the overshoot period of the pixel shift, the overshoot period is controlled by the on / off control of the light source in the image projection apparatus 1 having the solid light source and the control of the rotation position of the color wheel 5 in the image projection apparatus having the color wheel 5 so far. In the image projection apparatus 1 having any configuration, the overshoot period is set so that the optical modulation element (DMD551) is turned off and the overshoot period is set to be off. Control that does not affect the projected image may be performed. In this case as well, as in the case described above, it is possible to suppress a decrease in resolution and to prevent a decrease in image quality due to overshooting.

  In the image projector 1 having a solid light source, it is also preferable to control the brightness of the projection light to be substantially uniform when the pixel shift is executed and when it is not executed. For example, when performing pixel shift, it may be possible to cause the light source to emit more than a specified value when turned on by partially turning off the light source. By using this, it is possible to prevent the user from feeling uncomfortable without changing the brightness depending on whether or not the pixel shift is used.

  According to the image projection apparatus according to the present embodiment described above, it is possible to suppress a decrease in resolution in pixel shift control. In other words, when executing pixel shift, the pixel is moved so as to be as close to a rectangular wave behavior as possible, but it is difficult to achieve a complete rectangular wave shape, and the pixel position overshoots at a position exceeding the specified position in the moving direction. . At this time, a projection image is not generated during the overshoot period by controlling the light source, the optical modulation element, and the color wheel so that the light does not go to the screen during the pixel overshoot period. Therefore, by making the movement of the pixel close to a rectangular wave-like behavior, it is possible to suppress a decrease in resolution, and it is possible to prevent a decrease in image quality due to overshooting.

  The above-described embodiment is a preferred embodiment of the present invention, but is not limited thereto, and various modifications can be made without departing from the gist of the present invention.

  In the above-described embodiment, the image projection apparatus is described by taking a DLP (Digital Light Processing) type projector as an example. However, the image projection apparatus is not limited to this, and is not limited to this. The present invention can be applied to other systems such as the above) as long as the optical modulation element is shifted.

DESCRIPTION OF SYMBOLS 1 Image projector 2 Exterior cover 3 Optical engine 4 Light source unit 5 Color wheel 6 Light tunnel 7 Relay lens 8 Plane mirror 9 Concave mirror 10 System control part 11 Light source control part 12 Color wheel control part 13 DMD control part 14 Movable unit control part DESCRIPTION OF SYMBOLS 15 Fan control part 16 Intake port 17 Exhaust port 18 Intake fan 19 Exhaust fan 20 Fan 21 Remote control 22 Remote control receiving part 23 Main body operation part 24 Input terminal 25 Video signal control part 26 Setting information storage part 27 Power supply unit 30 Light source 31-33 LED
34 to 36 Light collecting element 37 Dichroic filter 40 Illumination optical system unit 50 Image display unit 51 Fixed unit 52 Color filter (segment)
53 Rotating Motor 55 Movable Unit 551 DMD
60 Projection optical system unit S Screen

JP-A-2005-84581 Japanese Patent No. 5073195

Claims (8)

A light source that emits light;
An image display unit having an optical modulation element that forms an image using light from the light source;
An illumination optical unit that guides light from the light source to the image display unit;
A projection optical unit that projects an image formed by the image display unit onto a projection surface;
A projection control unit that controls the light source, the image display unit, and the illumination optical unit;
A movement control unit that periodically moves the optical modulation element between a first position and a second position;
The movement control unit, when moving the optical modulation element from the first position to the second position and from the second position to the first position, once overshoots in the movement direction, respectively, And move it to become
The image projection apparatus, wherein the projection control unit performs control so that an image is not projected onto a projection surface during a period in which the optical modulation element overshoots. The light source is a solid light source,
The image projection apparatus according to claim 1, wherein the projection control unit controls the light source to be off during a period in which the optical modulation element overshoots.   The projection control unit controls the optical modulation element so that light is not guided from the image display unit to the projection optical unit during a period in which the optical modulation element overshoots. The image projection apparatus described. The illumination optical unit has a color wheel that time-divides light from the light source,
The said projection control part controls so that light may permeate | transmit in the white segment of the said color wheel during the period when the said optical modulation element overshoots, The Claim 1 characterized by the above-mentioned. Image projection device. The illumination optical unit has a color wheel that time-divides light from the light source,
The projection control unit performs control so that light is transmitted through a segment of a predetermined color of the color wheel according to a projection mode of the image projection apparatus during a period in which the optical modulation element overshoots. The image projection apparatus according to any one of claims 1 to 3.   The said projection control part controls on-off of the movement control of the said optical modulation element by the said movement control part according to the projection mode of the said image projector, The any one of Claim 1 to 4 characterized by the above-mentioned. Image projector. The light source is a solid light source,
The projection control unit controls the brightness of the projection light to be substantially uniform when the movement control of the optical modulation element by the movement control unit is turned on and when it is turned off. The image projection apparatus according to claim 1. A light source that emits light;
An image display unit having an optical modulation element that forms an image using light from the light source;
An illumination optical unit that guides light from the light source to the image display unit;
In a control method of an image projection apparatus comprising: a projection optical unit that projects an image formed by the image display unit onto a projection surface;
In the process of periodically moving the optical modulation element between the first position and the second position, when the optical modulation element is moved from the first position to the second position and from the second position to the first position. , A movement control process for moving the target position after overshooting in the moving direction,
A control method for an image projection apparatus, comprising: performing a projection control process for controlling an image not to be projected onto a projection surface during a period in which the optical modulation element overshoots.