JP2016110018A - Image projection device and control method for image projection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To curb luminance unevenness or color unevenness occurring upon pixel shift.SOLUTION: An image projection device comprises: a light source 30 that emits light; an image display unit 50 that has a DMD 551 forming an image by use of the light from the light source 30; an illumination optical system unit 40 that guides the light form the light source 30 to the image display unit 50; a projection optical system unit 60 that performs an enlargement projection of the image formed by the image display unit 50; and a movement control unit 12 that causes the DMD 551 to be periodically displaced between a first state serving as a prescribed position and a second state displaced from the first state. The illumination optical system unit 40 has a color wheel performing a time-division of the light from the light source 30, and the color wheel has an even color segment every 1/2 circle.SELECTED DRAWING: Figure 2

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 a personal computer, digital camera, etc., the modulation element generates an image using light emitted from the light source, and the generated image is projected onto a screen or the like through an optical system including a plurality of lenses. An image projection apparatus is known. For example, a liquid crystal panel or a digital micromirror device (DMD) is used as the modulation element.

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

  On the other hand, an image projection apparatus that forms an image by decentering a lens provided in the projection optical system and shifts an image on the projection surface (hereinafter referred to as pixel shift), and increases the resolution of the projection image. Is disclosed (for example, see Patent Document 1).

  Patent Document 2 discloses an image display device that displays an easy-to-see color image by delaying the pixel displacement period with respect to the color switching period in order to suppress crosstalk that occurs when the pixels are shifted. Is disclosed.

  With the conventional pixel shifting technique, there is a risk that luminance unevenness or color unevenness may occur in an image generated by pixel shifting (hereinafter referred to as an intermediate image). On the other hand, Patent Document 2 attempts to reduce luminance unevenness and color unevenness by slowing the pixel displacement period. However, if the pixel displacement period is slowed, the projection image has jaggies and discontinuities. The quality, hardness, etc. occurred, and the image was not high quality. As described above, there is a problem in reducing luminance unevenness and color unevenness when shifting pixels.

  Therefore, an object of the present invention is to provide an image projection apparatus that can suppress luminance unevenness and color unevenness that occur during pixel shifting.

  In order to achieve the above object, an image projection apparatus according to the present invention includes a light source that emits light, an image display unit that includes a modulation element that forms an image using light from the light source, and light from the light source. An illumination optical unit that leads to the image display unit, a projection optical unit that magnifies and projects an image formed by the image display unit, a first state that is a predetermined position, and a first state that is displaced from the first state A movement control unit that periodically displaces between the two states, and the illumination optical unit includes a color wheel that time-divides the light from the light source, Each has a color segment in which the proportion of each color is equal.

  According to the present invention, it is possible to suppress luminance unevenness and color unevenness that occur when shifting pixels, and to improve the quality of an image.

It is a figure which illustrates an image projector. It is a block diagram which illustrates the functional composition of an image projection device. It is a perspective view which illustrates the optical engine of an image projector. It is a figure which illustrates an illumination optical system unit. It is a figure which illustrates the internal structure of a projection optical system unit. It is a perspective view which illustrates an image display unit. It is a side view which illustrates 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 which illustrates a top cover. 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 which showed the image of the display state of the pixel shifted by the half pixel by pixel shifting. It is explanatory drawing which showed the image of the display state of 1 pixel in FIG. It is explanatory drawing which shows the prior art example of the color wheel with which an illumination optical system unit is provided. It is explanatory drawing which shows an example of the color wheel with which an illumination optical system unit is provided. It is explanatory drawing which shows the color rank of the color wheel shown in FIG. 21, and the light intensity to output. It is explanatory drawing which shows the other example of the color wheel with which an illumination optical system unit is provided.

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

  An image projection apparatus (projector 1) according to the present embodiment includes an image display unit (image display) including a light source (light source 30) that emits light and a modulation element (DMD551) that forms an image using light from the light source. A unit 50), an illumination optical unit (illumination optical system unit 40) for guiding light from the light source to the image display unit, and a projection optical unit (projection optical system unit 60) for enlarging and projecting an image formed by the image display unit. A movement control unit (movement control unit 12) for periodically displacing the modulation element between a first state which is a predetermined position and a second state displaced from the first state, and an illumination optical unit Has a color wheel (color wheel 401) for time-sharing the light from the light source, and the color wheel has a color segment (color segment 41) in which the proportion of each color is equal every 1/2 turn. . In addition, the code | symbol in embodiment and the example of application are shown in a parenthesis.

<Configuration of image projector>
FIG. 1 is a diagram illustrating a projector 1 in the embodiment.

  The projector 1 is an example of an image projection apparatus, has an exit window 3 and an external I / F 9, and is provided with an optical engine that generates a projection image. For example, when image data is transmitted from a personal computer or digital camera connected to the external I / F 9, the projector 1 generates a projection image based on the transmitted image data, as shown in FIG. The image P is projected from the exit window 3 onto the screen S.

  In the drawings shown below, the X1X2 direction is the width direction of the projector 1, the Y1Y2 direction is the depth direction of the projector 1, and the Z1Z2 direction is the height direction of the projector 1. In the following description, the exit window 3 side of the projector 1 may be described as the upper side and the side opposite to the exit window 3 as the lower side.

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

  As shown in FIG. 2, the projector 1 includes a power supply 4, a main switch SW <b> 5, an operation unit 7, an external I / F 9, a system control unit 10, a fan 20, and an optical engine 15.

  The power source 4 is connected to a commercial power source, converts voltage and frequency for the 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 the 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 power supply to each part of the projector 1.

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

  The external I / F 9 has a connection terminal connected to, for example, a personal computer or a digital camera, and outputs image data transmitted from the connected device to the system control unit 10.

  The system control unit 10 includes an image control unit 11, a movement control unit 12, a synchronization control unit 13, and a light source control unit 14. The system control unit 10 includes, for example, a CPU, a ROM, a RAM, and the like, and the function of each unit is realized by the CPU executing a program stored in the ROM in cooperation with the RAM.

  The image control unit 11 is a digital micromirror device (hereinafter simply referred to as “DMD”) provided in the image display unit 50 of the optical engine 15 based on image data input from the external I / F 9. 551 is controlled to generate an image to be projected on the screen S.

  The movement control unit 12 moves the movable unit 55 provided in the image display unit 50 so as to be movable, and controls the position of the DMD 551 provided in the movable unit 55.

  The synchronization control unit 13 synchronously controls the cycle in which the movement control unit 12 displaces the DMD 551 and the cycle in which the color wheel of the illumination optical system unit 40 rotates once.

  The light source control unit 14 controls the output of the light source 30 by controlling the power supplied to the light source 30.

  The fan 20 is rotated by being controlled by the system control unit 10 to cool the light source 30 of the optical engine 15.

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

  The light source 30 is, for example, a mercury high pressure lamp, a xenon lamp, an LED, or the like, and irradiates the illumination optical system unit 40 with light.

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

  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 movable unit 55 has a DMD 551, and the position with respect to the fixed unit 51 is controlled by the movement control unit 12 of the system control unit 10. The DMD 551 is an example of a modulation element, and is controlled by the image control unit 11 of the system control unit 10 to modulate light guided by the illumination optical system unit 40 and generate a projection image.

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

<Configuration of optical engine>
Next, the configuration of each part of the optical engine 15 of the projector 1 will be described.

  FIG. 3 is a perspective view illustrating the optical engine 15 in the embodiment. As shown in FIG. 3, the optical engine 15 includes a light source 30, an illumination optical system unit 40, an image display unit 50, and a projection optical system unit 60, and is provided inside the projector 1.

  The light source 30 is provided on the side surface of the illumination optical system unit 40 and irradiates light in the X2 direction. The illumination optical system unit 40 guides the light emitted from the light source 30 to the image display unit 50 provided below. The image display unit 50 generates a projection image using the light guided by the illumination optical system unit 40. The projection optical system unit 60 is provided on the illumination optical system unit 40 and projects the projection image generated by the image display unit 50 to the outside of the projector 1.

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

[Illumination optical system unit]
FIG. 4 is a diagram illustrating the illumination optical system unit 40 in the embodiment.

  As shown in FIG. 4, the illumination optical system unit 40 includes a color wheel 401, a light tunnel 402, relay lenses 403 and 404, a cylinder mirror 405, and a concave mirror 406.

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

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

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

  The cylinder mirror 405 and the concave mirror 406 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.

[Projection optical system unit]
FIG. 5 is a diagram illustrating the internal configuration of the projection optical system unit 60 in the embodiment.

  As shown in FIG. 5, the projection optical system unit 60 includes a projection lens 601, a folding mirror 602, and a curved mirror 603 provided inside the case.

  The projection lens 601 includes a plurality of lenses, and forms a projection image generated by the DMD 551 of the image display unit 50 on the folding mirror 602. The folding mirror 602 and the curved mirror 603 reflect the projected image formed in an enlarged manner and project it onto the screen S or the like outside the projector 1.

[Image display unit]
FIG. 6 is a perspective view illustrating the image display unit 50 in the embodiment. FIG. 7 is a side view illustrating the image display unit 50 in the embodiment.

  As shown in FIGS. 6 and 7, 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, and are fixed to the lower part of the illumination optical system unit 40.

  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 its mirror surface can be tilted around the torsion axis, and is driven ON / OFF based on an image signal transmitted from the image control unit 11 of the system control unit 10.

  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 image control unit 11, 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 a heat radiating means, 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 projector 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 in the embodiment. FIG. 9 is an exploded perspective view illustrating the fixed unit 51 in the embodiment.

  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 abut on the movable plate 552 provided between the top plate 511 and the base plate 512, respectively, and 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 in the embodiment. 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 in the embodiment. 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 in the embodiment. FIG. 14 is an exploded perspective view illustrating the movable unit 55 in the embodiment.

  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 in the embodiment.

  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 and direction of the current flowing through each of the coils 581, 582, 583, 584 is controlled by the movement control unit 12 of the system control unit 10. The movement control unit 12 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 movement control unit 12 of the system control unit 10 controls the magnitude and direction of the current flowing through the coils 581, 582, 583, 584, thereby moving the movable plate within the movable range. 552 can be moved to any 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 illustrating the DMD holding structure of the movable unit 55 in the embodiment. 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 movement control unit 12 of the system control unit 10. 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.

<Image projection>
As described above, in the projector 1 according to this 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. .

  For example, the movement control unit 12 moves the movable unit 55 so as to move at 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. Control the position of the. 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 in a predetermined cycle between a position P1 and a position P2 that are 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 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 double the resolution of the DMD 551. Become. Further, by increasing the movement 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 in a predetermined cycle, and the image control unit 11 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.

  In the projector 1 according to the present embodiment, the movement control unit 12 controls the DMD 551 to rotate together with the movable unit 55, so that the projection image can be rotated without being reduced. For example, a projector in which a modulation element such as DMD551 is fixed cannot be rotated while maintaining the aspect ratio of the projected image unless the projected image is reduced. On the other hand, in the projector 1 according to the present embodiment, the DMD 551 can be rotated, so that the tilt or the like can be adjusted by rotating the projection image without reducing it.

  As described above, in the projector 1 according to this embodiment, the DMD 551 is configured to be movable, so that the resolution of the projected image can be increased. Further, since the heat sink 554 for cooling the DMD 551 is mounted on the movable unit 55 together with the DMD 551, it is possible to cool the DMD 551 in contact with the DMD 551, and the temperature rise of the DMD 551 is suppressed. Therefore, in the projector 1, problems such as malfunctions and failures that occur due to the temperature rise of the DMD 551 are reduced.

<Pixel shift and intermediate image>
In the projector 1 described so far, an image projected on the screen S is generated according to the angle of each micromirror of the DMD 551 that is a modulation element. For this reason, changing the DMD 551 such as translation and rotation while maintaining the angle of each micromirror means that the projection position is displaced while maintaining the image information projected on the screen S. become.

  For this reason, for example, when the DMD 551 is displaced by a predetermined period by a half pixel, the image itself projected on the screen S is shifted by a predetermined period by a half pixel, and as a result, an intermediate image is displayed on the screen S. An image is formed, and the apparent number of pixels and pixel density can be increased. That is, it becomes possible to form on the screen S a number of pixels that is larger than the number of pixels that the DMD 551 originally has, and it is possible to project a high-resolution image on the screen S that is more than the number of pixels of the DMD 551 in a pseudo manner. It becomes possible.

  FIG. 18 is an explanatory diagram showing an image of a display state of pixels shifted by half a pixel by pixel shift (pixel shift).

  A solid line portion in FIG. 18 indicates each pixel S1 in the first state in which the display position is not shifted (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).

  19A to 19C are explanatory diagrams showing images of the display state of one pixel in FIG. 19 indicates that the portion displayed in gray is in the projected state, FIG. 19A shows the state in which the pixel S1 in the first state is projected, and FIG. 19B shows the state in the second state. FIG. 19C shows a state in which the pixel S2 is projected, and a state in which the pixel S2 is being displaced from the first state to the second state and from the second state to the first state. 19B and 19C show a state in which an intermediate image is projected.

  That is, when the DMD 551 is moved by a predetermined period by half a pixel, the first state (FIG. 19A) → (during displacement, FIG. 19C) → second state (FIG. 19B) → (displacement) 19 (C)) → first state (FIG. 19 (A)). This one cycle is called a displacement cycle of DMD551.

<Color wheel>
As described above, the color wheel 401 is a color time-division element that time-divides light emitted from the light source 30 into each color such as RGB by rotating at high speed.

  In the projector 1, the color wheel 401 is rotating while the DMD 551 is displaced and the pixel moves. At this time, the synchronization control unit 13 performs synchronous control of the displacement cycle of the DMD 551 by the movement control unit 12 and the rotation cycle of the color wheel 401 in order to prevent image blurring and the like.

  That is, since the color wheel 401 makes one rotation in one cycle of the first state → the second state → the first state, the displacement period from the first state to the second state and the displacement period from the second state to the first state are , Each of which corresponds to a period during which the color wheel 401 rotates 1/2.

  Here, for example, a case where pixel shift control is performed using a color wheel 401A composed of general color segments of R (red), G (green), and B (blue) as shown in FIG.

  The color wheel 401A shown in FIG. 20 is configured to be rotatable about the rotation shaft 42 in the rotation direction shown in the drawing. The color wheel 401A includes a color segment 41. Here, an R segment 41R, a G segment 41G, and a B segment that are transmissive color filters are provided in three fan-shaped regions partitioned along the rotation direction of the color wheel 401A. Each segment 41B is formed.

  Here, as shown in FIG. 20, a case where the first state is a boundary portion between the B segment 41B and the R segment 41R in the rotation direction of the color wheel 401A is considered.

  Since the displacement period from the first state to the second state corresponds to ½ rotation of the color wheel 401A, the second state is the central portion of the G segment 41G. The displacement period from the second state to the first state also corresponds to ½ rotation of the color wheel 401A. At this time, the color balance of the color segment 41 of the color wheel 401A is different between the displacement period A from the first state to the second state and the displacement period B from the second state to the first period.

  The difference in the color balance of the half of the color wheel 401A means that the output of the light source 30 controlled by the light source control unit 14 is different between the displacement period A and the displacement period B along with each color segment of the color wheel 401A. It becomes. For this reason, there is a risk that uneven brightness occurs in the intermediate image. In addition, since the wavelength of light is different between the displacement period A and the displacement period B, there is a possibility that uneven color occurs in the intermediate image. As described above, there is a possibility that uneven luminance and uneven color may occur in the intermediate image generated by pixel shifting.

  Therefore, in the projector 1 according to the present embodiment, as shown in FIG. 21, pixel shift control is performed using a color wheel 401B provided with a color segment 41 in which the proportion of each color occupies every 1/2 turn. is there.

  FIG. 21 shows an example of a color wheel 401B provided with a color segment 41 in which the proportion of each color is equal every ½ round. FIG. 22 is an explanatory diagram showing the color order of the color wheel 401B and the output light intensity.

  Consider a case where pixel shift control is performed using the color wheel 401B shown in FIG. 21, and the first state is the boundary between the B segment 41B and the R segment 41R in the rotation direction of the color wheel 401B. As shown in FIG. 22, the color order at this time is in the order of R segment 41R → G segment 41G → B segment 41B along the rotation direction. Since the B segment 41B and the R segment 41R are halved, this position corresponds to the second state. Then, again, in the order of R segment 41R → G segment 41G → B segment 41B, one rotation is made and the original position is restored.

  Therefore, when the pixel shift control is performed using the color wheel 401B, the intensity of the output light is, as shown in FIG. 22, the displacement period A from the first state to the second state and the second state from the second state. It becomes equal in the displacement period B to 1 state. Therefore, color unevenness does not occur in the intermediate image generated by pixel shifting. In addition, since the output of the light source 30 is controlled by the light source control unit 14 together with the color segment 41 of the color wheel 401, luminance unevenness does not occur in the intermediate image. For this reason, it is possible to suppress the occurrence of uneven luminance and uneven color in the intermediate image, and it is possible to improve the quality of the projected image.

  FIG. 23 shows another example of the color wheel 401 provided with the color segments 41 in which the proportions of the respective colors are uniform every ½ round. Like the color wheel 401C shown in FIG. 23, the W (white) segment 41W is provided in addition to the R segment 41R, the G segment 41G, and the B segment 41B every ½ turn, thereby further improving the brightness. It becomes possible.

  In the color wheel 401 shown in FIGS. 21 and 23, an example is shown in which the order of colors is the same every ½ turn along the rotation direction. According to this configuration, the output control of the light source 30 by the light source control unit 14 can be made the same waveform every ½, but if the proportion of each color occupies every half lap, The order of the colors every 1/2 turn in the rotation direction may be different.

  Further, in the color wheel 401 shown in FIGS. 21 and 23, the proportion of each color is equal every 1/2 turn even when the boundary portion of any color segment 41 is in the first state in the rotation direction. However, the present invention is not limited to this configuration, and the color segments 41 in which the proportion of each color is uniform every ½ turn as viewed from the boundary portion of any color segment 41 are included. What is necessary is just to have it, and what is necessary is just to control it as a position corresponded to a 1st state.

  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. For example, the pixel shifting mechanism included in the image projection apparatus is not limited to the above-described example described with reference to FIGS. 6 to 17, and a modulation element is provided between the first state and the second state. What is necessary is just to be displaced periodically.

1 Projector (image projection device)
DESCRIPTION OF SYMBOLS 10 System control part 11 Image control part 12 Movement control part 13 Synchronization control part 14 Light source control part 30 Light source 40 Illumination optical system unit (illumination optical part)
41 color segment 42 rotating shaft 50 image display unit (image display unit)
60 Projection optical system unit (projection optical unit)
401, 401A to 401C Color wheel 551 DMD

JP-A-2005-84581 JP 2001-272630 A

Claims (8)

A light source that emits light;
An image display unit having a 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 for enlarging and projecting the image formed by the image display unit;
A movement control unit that periodically displaces the modulation element between a first state that is a predetermined position and a second state that is displaced from the first state;
The illumination optical unit includes a color wheel that time-divides light from the light source, and the color wheel includes color segments having an equal ratio of each color every ½ round. .   The image projection apparatus according to claim 1, further comprising a synchronization control unit configured to synchronize a cycle in which the movement control unit displaces the modulation element and a cycle in which the color wheel is rotated once.   The image projection apparatus according to claim 1, wherein the color wheel includes the color segments of R (red), G (green), and B (blue) every ½ turn.   3. The image according to claim 1, wherein the color wheel has the color segments of R (red), G (green), B (blue), and W (white) every ½ round. Projection device.   5. The image projection apparatus according to claim 3, wherein the color wheel has the same order of the color segments every ½ round along a rotation direction. 6.   6. The color wheel according to claim 1, wherein the color wheel has the color segment that is uniform every ½ turn in the rotation direction when viewed from the boundary of any of the color segments. The image projection apparatus described in 1.   The image projection apparatus according to claim 1, further comprising a light source control unit configured to control an output of the light source according to the color segment of the color wheel. A light source that emits light;
An image display unit having a 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 for enlarging and projecting an image formed by the image display unit,
The illumination optical unit has a color wheel that time-divides light from the light source, and the color wheel has a color segment in which the ratio of each color is uniform every ½ round,
The modulation element is periodically displaced between a first state that is a predetermined position and a second state that is displaced from the first state, and the displacement period of the modulation element and the color wheel are rotated once. A method for controlling an image projection apparatus, wherein a process for synchronizing a period is performed.