JP2017161799A - Image projection device and image projection method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image projection device that can accurately detect the position of an image creation part to increase the resolution of an image.SOLUTION: There is provided an image projection device comprising: an image creation unit including an image creation part that is displaceably provided; a position detection part that detects the position of the image creation part; a temperature detection part that detects the temperature of the surroundings of the position detection part; a temperature adjustment part that adjusts the temperature of the surroundings of the position detection part; and a temperature control part that controls the temperature adjustment part on the basis of a result of detection performed by the temperature detection part.SELECTED DRAWING: Figure 12

Description

  The present invention relates to an image projection apparatus and an image projection method.

  For example, an image projection apparatus that projects an image generated based on image data input from a PC or the like onto a screen or the like has been put into practical use.

  In such an image projection apparatus, for example, an image with a higher resolution than the resolution of the display element is displayed by shifting the pixel by shifting the optical axis with respect to light rays emitted from a plurality of pixels of the display element. A method is known (see, for example, Patent Document 1).

  When the pixel shift is performed by displacing an optical member such as a parallel plate by an actuator or the like as disclosed in Patent Document 1, for example, the actuator is controlled based on the position detection result of the optical member. In this case, if the pixel shift position fluctuates, the image quality deteriorates. Therefore, it is necessary to accurately detect the position of the optical member and control the actuator.

  However, for example, when a magnetic sensor or the like is used for position detection, the position detection result varies depending on the environmental temperature, and it may be difficult to perform pixel shift control with high accuracy and image quality may deteriorate.

  The present invention has been made in view of the above, and an object of the present invention is to provide an image projection apparatus capable of detecting the position of an image generation unit with high accuracy and increasing the resolution of an image.

  According to an image generation device according to an aspect of the present invention, an image generation unit including an image generation unit provided in a displaceable manner, a position detection unit that detects the position of the image generation unit, and the position detection unit A temperature detection unit that detects an ambient temperature, a temperature adjustment unit that adjusts an ambient temperature of the position detection unit, and a temperature control unit that controls the temperature adjustment unit based on a detection result by the temperature detection unit, Have.

  According to the embodiment of the present invention, there is provided an image projection apparatus capable of detecting the position of the image generation unit with high accuracy and increasing the resolution of the image.

It is a figure which illustrates the image projector in an embodiment. It is a figure which illustrates a mode that the image projector in embodiment projects an image. It is a block diagram which illustrates the composition of the image projection device in an embodiment. It is a figure which illustrates the internal structure of the image projector in embodiment. It is a perspective view of the optical engine in an embodiment. It is a section schematic diagram which illustrates the composition of the optical engine in an embodiment. It is a perspective view of the image generation unit in an embodiment. It is a disassembled perspective view of the fixed unit in embodiment. It is a figure explaining the support structure of the 2nd movable plate by the fixed unit in embodiment. It is a disassembled perspective view of the movable unit in embodiment. It is a figure which illustrates the structure containing the position detection part in embodiment. It is a figure which illustrates the flowchart of the temperature control process in embodiment.

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

<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, and includes an operation unit 7, an external I / F 9, an intake port 21, and an exhaust port 23, and an optical engine that generates a projection image is covered with an exterior cover 2. 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. 2. An image is projected 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.

  FIG. 3 is a block diagram illustrating the configuration of the projector 1 in the embodiment.

  As shown in FIG. 3, the projector 1 includes a power source 4, a main switch SW 5, an operation unit 7, an external I / F 9, a system control unit 10, an optical engine 15, an intake fan 22, and an exhaust fan 24.

  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 optical engine 15, the intake fan 22, the exhaust fan 24, 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 source 4 is connected to a commercial power source via a power cord or the like, the power source 4 starts to supply power to each part of the projector 1. When the main switch SW5 is turned off, the power source 4 stops supplying power 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 drive control unit 12, and a temperature control unit 13. The system control unit 10 includes, for example, a CPU, a ROM, a RAM, and the like. Each function of the system control unit 10 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 DMD (hereinafter simply referred to as “DMD”) provided in the image generation 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 drive control unit 12 controls a drive unit that moves the movable unit 55 that is movably provided in the image generation unit 50, and controls the position of the DMD 551 provided in the movable unit 55.

  The temperature control unit 13 is provided in the image generation unit 50 to the intake fan 22, the exhaust fan 24, and the image generation unit 50 so that the temperature around the position detection unit 540 that detects the position of the DMD 551 is within a predetermined range. The heater 545 provided is controlled.

  The intake fan 22 sucks air from the intake port 21 of the projector 1 and blows it to the optical engine 15 or the like, thereby cooling, for example, the light source 30 or the image generation unit 50 of the optical engine 15. The exhaust fan 24 exhausts heat generated in the optical engine 15 and the like by exhausting from the exhaust port 23 of the projector 1. The intake fan 22 and the exhaust fan 24 rotate at the number of rotations set by the temperature control unit 13 of the system control unit 10.

  The optical engine 15 includes a light source 30, an illumination optical system unit 40, an image generation 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 is controlled by the system control unit 10 to irradiate the illumination optical system unit 40 with light.

  The illumination optical system unit 40 includes, for example, 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 generation unit 50.

  The image generation unit 50 is an example of an image generation apparatus, and includes a fixed unit 51 that is fixedly supported and a movable unit 55 that is movably supported by 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 drive control unit 12 of the system control unit 10. The DMD 551 is an example of an image generation unit, and is controlled by the image control unit 11 of the system control unit 10 and modulates the light guided by the illumination optical system unit 40 to generate a projection image.

  Further, the image generation unit 50 includes a position detection unit 540, a temperature sensor 544, and a heater 545.

  The position detection unit 540 detects the position of the DMD 551 provided in the movable unit 55. The temperature sensor 544 is, for example, a thermistor, and detects the temperature around the position detection unit 540 as a temperature detection unit. The heater 545 is provided in the vicinity of the position detection unit 540 and heats the periphery of the position detection unit 540. The heater 545 constitutes a temperature adjusting unit together with the intake fan 22 and the exhaust fan 24.

  The projection optical system unit 60 is an example of a projection unit, and includes, for example, a plurality of projection lenses, mirrors, and the like. The projection optical system unit 60 enlarges and projects an image generated by the DMD 551 of the image generation 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. 4 is a diagram illustrating a state where the exterior cover 2 of the projector 1 in the embodiment is removed. As shown in FIG. 4, an intake fan 22, an exhaust fan 24, an optical engine 15, and the like are provided inside the projector 1.

  FIG. 5 is a perspective view illustrating the optical engine 15 in the embodiment. As shown in FIG. 5, the optical engine 15 includes a light source 30, an illumination optical system unit 40, an image generation unit 50, and a projection optical system unit 60.

  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 generation unit 50. The image generation unit 50 generates a projection image using the light guided by the illumination optical system unit 40. The projection optical system unit 60 projects the projection image generated by the image generation unit 50 to the outside of the projector 1.

  The optical engine 15 according to the present embodiment is configured to project an image in the Y1 direction using light emitted from the light source 30, but is different from the present embodiment, for example, in the Z1 direction. It may be configured to project an image in the direction.

  FIG. 6 is a schematic view illustrating the internal configuration of the optical engine 15 in the embodiment.

  As shown in FIG. 6, the illumination optical system unit 40 includes a color wheel 401, a light tunnel 402, relay lenses 403 and 404, a plane 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 flat mirror 405 and the concave mirror 406 reflect the light time-divided into RGB colors by the color wheel 401 to the DMD 551 provided in the image generation unit 50.

  The DMD 551 of the image generation unit 50 modulates the reflected light from the concave mirror 406 to generate a projection image. The projection image generated by the DMD 551 is guided to the projection optical system unit 60 through the illumination optical system unit 40.

  The projection optical system unit 60 includes a projection lens 601 including a plurality of lenses, and enlarges the projection image generated by the DMD 551 and projects it on the screen S or the like outside the projector 1.

[Image generation unit]
FIG. 7 is a perspective view of the image generation unit 50 in the embodiment.

  As shown in FIG. 7, the image generation unit 50 includes a fixed unit 51 and a movable unit 55. The fixed unit 51 is fixedly supported by the illumination optical system unit 40. The movable unit 55 is movably supported by the fixed unit 51.

  The fixed unit 51 includes a first fixed plate 511, a second fixed plate 512, and a third fixed plate 513. The first fixing plate 511, the second fixing plate 512, and the third fixing plate 513 are stacked so as to be parallel to each other with a predetermined gap.

  The movable unit 55 includes a DMD 551, a first movable plate 552, a second movable plate 553, and a heat sink 554 as a heat radiating member, and is movably supported by the fixed unit 51.

  The DMD 551 is provided on the upper surface of the first movable plate 552. 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 inclination angle is controlled in a direction in which light from the light source 30 is reflected toward an OFF light plate (not shown).

  As described above, the DMD 551 controls the 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 guided to the illumination optical system unit 40, and is projected. Is generated.

  The first movable plate 552 is provided between the first fixed plate 511 and the second fixed plate 512 of the fixed unit 51. The second movable plate 553 is movably supported between the second fixed plate 512 and the third fixed plate 513. The heat sink 554 is connected to the second movable plate 553 and is displaced together with the second movable plate 553. The first movable plate 552 is supported by the heat sink 554 and is displaced together with the second movable plate 553 and the heat sink 554.

  The heat sink 554 contacts the DMD 551 and radiates heat generated in the DMD 551. Since the heat sink 554 suppresses the temperature rise of the DMD 551, occurrence of malfunctions such as malfunctions and failures due to the temperature rise of the DMD 551 is reduced. The heat sink 554 is provided so as to move together with the first movable plate 552 and the second movable plate 553, so that the heat generated in the DMD 551 can be radiated at all times.

  In the following description, in the Y1Y2 direction, the first fixed plate 511 side may be described as the upper side and the heat sink 554 side may be described as the lower side.

(Fixed unit)
FIG. 8 is an exploded perspective view of the fixed unit 51 in the embodiment.

  As shown in FIG. 8, the fixing unit 51 includes a first fixing plate 511, a second fixing plate 512, and a third fixing plate 513.

  The first fixing plate 511, the second fixing plate 512, and the third fixing plate 513 are flat members formed of a magnetic material such as iron or stainless steel, for example.

  The first fixed plate 511 is fixed to the upper ends of a plurality of support columns 525 provided on the second fixed plate 512, and is provided in parallel to the second fixed plate 512 with a predetermined gap therebetween. A central hole 514 is provided in the first fixed plate 511 at a position facing the DMD 551 of the movable unit 55. The DMD 551 of the movable unit 55 is exposed from the central hole 514 of the first fixed plate 511 to the illumination optical system unit 40 side.

  A plurality of position detection magnets 541 are provided on the lower surface of the first fixed plate 511. The position detecting magnet 541 is composed of two rectangular parallelepiped permanent magnets arranged so that their longitudinal directions are parallel to each other, and is a first movable plate provided between the first fixed plate 511 and the second fixed plate 512. A magnetic field spanning the plate 552 is formed. The position detection magnet 541 constitutes a position detection unit 540 that detects the position of the DMD 551 with the Hall element provided on the first movable plate 552.

  The second fixed plate 512 supports a plurality of support columns 525 that support the first fixed plate 511, a heat transfer hole 516 through which a heat transfer portion of the heat sink 554 is inserted, and a second movable plate 553 so as to be movable from above. A support hole 522 is formed to hold the support sphere 521 rotatably. In addition, driving magnets 531a, 531b, 531c, and 531d are provided on the lower surface of the second fixed plate 512. Hereinafter, the drive magnets 531a, 531b, 531c, and 531d may be simply referred to as “drive magnet 531”.

  The column 525 has a lower end fixed to the second fixing plate 512 and a first fixing plate 511 fixed to the upper end with a screw or the like. The support columns 525 form a predetermined interval between the first fixed plate 511 and the second fixed plate 512 and support the first fixed plate 511 in parallel with the second fixed plate 512.

  A cylindrical holding member 523 having an internal thread groove on the inner peripheral surface is inserted into the support hole 522. The holding member 523 is closed at the upper end side by the position adjusting screw 524 and holds the support sphere 521 rotatably.

  The drive magnet 531 is composed of two rectangular parallelepiped permanent magnets arranged so that the longitudinal directions thereof are parallel to each other, and is a second movable plate provided between the second fixed plate 512 and the third fixed plate 513. A magnetic field extending to 553 is formed. The drive magnet 531 constitutes a magnetic actuator that moves the movable unit 55 as a drive unit with a drive coil provided on the upper surface of the second movable plate 553.

  The third fixing plate 513 is provided in parallel to the second fixing plate 512 by a support column 515 with a predetermined gap. The third fixed plate 513 is inserted with a support hole 526 for rotatably supporting a support sphere 521 that supports the second movable plate 553 of the movable unit 55 so as to be movable from below, and a heat transfer portion of the heat sink 554. Heat transfer holes 517 are formed. The support hole 526 is closed at the lower end by the lid member 527 and holds the support sphere 521 rotatably.

  The plurality of support spheres 521 rotatably held by the second fixed plate 512 and the third fixed plate 513 are in contact with the second movable plate 553 of the movable unit 55, respectively, so that the second movable plate 553 can be moved from both sides. To support.

  FIG. 9 is a view for explaining a support structure of the second movable plate 553 by the fixed unit 51 in the embodiment.

  As shown in FIG. 9, in the second fixed plate 512, the support sphere 521 is rotatably held by the holding member 523 inserted into the support hole 522. Further, in the third fixing plate 513, the support sphere 521 is rotatably held in 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 abuts on a second movable plate 553 provided between the second fixed plate 512 and the third fixed plate 513. The second movable plate 553 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 surface.

  Further, the amount of protrusion of the support sphere 521 provided on the second fixing plate 512 side from the lower end of the holding member 523 changes according to the position of the position adjusting screw 524. For example, when the position adjusting screw 524 is displaced in the Y2 direction, the protruding amount of the support sphere 521 increases, and the distance between the second fixed plate 512 and the second movable plate 553 increases. For example, when the position adjusting screw 524 is displaced in the Y1 direction, the protruding amount of the support sphere 521 is reduced, and the interval between the second fixed plate 512 and the second movable plate 553 is reduced.

  Thus, by changing the protruding amount of the support sphere 521 using the position adjusting screw 524, the interval between the second fixed plate 512 and the second movable plate 553 can be adjusted as appropriate.

  Note that the numbers and positions of the support columns 515 and 525 and the support spheres 521 provided in the fixed unit 51 are not limited to the configuration exemplified in this embodiment.

(Movable unit)
FIG. 10 is an exploded perspective view of the movable unit 55 in the embodiment.

  As shown in FIG. 10, the movable unit 55 includes a DMD 551, a first movable plate 552, a second movable plate 553, and a heat sink 554.

  The first movable plate 552 is provided between the first fixed plate 511 and the second fixed plate 512 of the fixed unit 51. On the upper surface of the first movable plate 552, a DMD 551, a hall element 542 as a magnetic sensor, a temperature sensor 544, and a heater 545 are provided.

  The DMD 551 is exposed to the illumination optical system unit 40 side from the central hole 514 provided in the first fixed plate 511 of the fixed unit 51 and modulates the light from the light source 30 guided to the illumination optical system unit 40 to generate an image. Is generated.

  The hall element 542 is disposed at a position facing the position detection magnet 541 provided on the lower surface of the first fixed plate 511 of the fixed unit 51. The hall element 542 and the position detection magnet 541 provided on the first fixed plate 511 constitute a position detection unit 540 that detects the position of the DMD 551.

  The temperature sensor 544 is provided in the vicinity of the Hall element 542 and detects the ambient temperature. The heater 545 is provided in the vicinity of the hall element 542 and heats the surroundings.

  Here, the detection result of the Hall element 542 may vary depending on the environmental temperature. Therefore, for example, the temperature control unit 13 controls each unit so that the temperature around the Hall element 542 is within a predetermined range (for example, temperature T1 or more and temperature T2 or less).

  For example, when the temperature detected by the temperature sensor 544 is less than T1, the drive control unit 12 drives the heater 545 to increase the temperature around the Hall element 542. Further, when the temperature detected by the temperature sensor 544 is higher than T2, the drive control unit 12 increases the rotation speeds of the intake fan 22 and the exhaust fan 24 provided in the projector 1. When the rotational speeds of the intake fan 22 and the exhaust fan 24 are increased, the amount of air blown to the image generation unit 50 and the amount of heat exhausted from the apparatus are increased, whereby the image generation unit 50 is cooled and the temperature around the temperature sensor 544 is decreased. To do.

  As described above, by keeping the ambient environmental temperature within a predetermined range, the output of the Hall element 542 is suppressed from fluctuating depending on the temperature, and the position of the DMD 551 can be controlled with high accuracy.

  The second movable plate 553 is supported so as to be movable between the second fixed plate 512 and the third fixed plate 513 of the fixed unit 51. The second movable plate 553 is provided with a heat transfer hole 559 through which the heat transfer part 563 of the heat sink 554 is inserted, a movable range limiting hole 571, and drive coils 581a, 581b, 581c, 581d. Hereinafter, the drive coils 581a, 581b, 581c, and 581d may be simply referred to as “drive coil 581”.

  The movable range limiting hole 571 is inserted into the support column 515 of the fixed unit 51, and contacts the support column 515 when the second movable plate 553 is largely displaced due to vibration or some abnormality, for example, so that the movable range of the second movable plate 553 is reached. Limit. Note that the number, position, shape, and the like of the movable range restriction hole 571 are not limited to the configuration exemplified in this embodiment.

  The drive coil 581 and the drive magnet 531 provided on the lower surface of the second fixed plate 512 of the fixed unit 51 constitute a magnetic actuator that moves the movable unit 55 relative to the fixed unit 51 as a drive unit.

  The heat sink 554 includes a heat radiating unit 556, a column 561, a connecting column 562, and a heat transfer unit 563, and radiates heat generated in the DMD 551 provided on the first movable plate 552.

  A plurality of fins 557 are formed at a lower portion of the heat radiating portion 556 and radiates heat generated in the DMD 551. The support column 561 extends in the Y1 direction from the upper surface of the heat radiating unit 556, and the first movable plate 552 is fixed to the upper end. The second movable plate 553 is formed with a through hole 555 through which the support column 561 is inserted.

  The connecting column 562 extends in the Y1 direction from the upper surface of the heat radiating portion 556, and the second movable plate 553 is fixed to the upper end. The support columns 561 and the connecting columns 562 have different heights in the Y1Y2 direction, and form a predetermined interval between the first movable plate 552 and the second movable plate 553.

  The heat transfer unit 563 extends in the Y1 direction from the upper surface of the heat dissipation unit 556, is inserted into the heat transfer hole 559 of the second movable plate 553, and the upper end surface contacts the lower surface of the DMD 551. The heat transfer unit 563 transfers the heat generated in the DMD 551 to the heat dissipation unit 556.

  Here, the heat transfer portion 563 of the heat sink 554 is provided so as to press the lower surface of the DMD 551 in order to enhance the cooling effect in a state where the first movable plate 552 is fixedly supported by the support column 561. Thus, when the DMD 551 is pressed against the heat transfer part 563 of the heat sink 554, the first movable plate 552 may be warped. When the influence of the warp generated on the first movable plate 552 reaches the second movable plate 553, it becomes difficult to control the position of the movable unit 55 with high accuracy, and the shift operation of the DMD 551 becomes unstable, and the projection image Quality may be reduced.

  However, in the movable unit 55 according to this embodiment, as described above, the first movable plate 552 is supported by the support column 561 of the heat sink 554, and the second movable plate 553 is connected to the connection column 562 of the heat sink 554. As described above, the first movable plate 552 and the second movable plate 553 are connected to or supported by different portions of the heat sink 554, so that even if the first movable plate 552 is warped, for example, The influence of the warp of the first movable plate 552 on the second movable plate 553 is reduced.

  Therefore, the image generation unit 50 according to the present embodiment can improve the stability of the shift operation of the projection image, and can control the position of the DMD 551 with high accuracy to shift the projection image and increase the resolution. It has become.

(Drive part)
The drive unit in the present embodiment is a magnetic actuator including a drive magnet 531 provided on the second fixed plate 512 and a drive coil 581 provided on the second movable plate 553.

  As shown in FIG. 8, the driving magnet 531a and the driving magnet 531d are each composed of two permanent magnets whose longitudinal direction is parallel to the Z1Z2 direction. The driving magnet 531b and the driving magnet 531c are composed of two permanent magnets whose longitudinal direction is parallel to the X1X2 direction. Each of the driving magnets 531 forms a magnetic field that reaches the second movable plate 553.

  The drive coils 581 provided on the second movable plate 553 are each formed by winding an electric wire around an axis parallel to the Y1Y2 direction.

  The driving magnet 531 of the second fixed plate 512 and the drive coil 581 of the second movable plate 553 are provided at positions facing each other in a state where the movable unit 55 is supported by the fixed unit 51. When a current is passed through the drive coil 581, a Lorentz force that is a drive force for moving the movable unit 55 to the drive coil 581 is generated by the magnetic field formed by the drive magnet 531.

  The movable unit 55 receives a Lorentz force as a driving force generated between the driving magnet 531 and the driving coil 581 and is displaced linearly or rotated in the XZ plane with respect to the fixed unit 51.

  In the present embodiment, as the first drive unit, a drive coil 581b and a drive magnet 531b, and a drive coil 581c and a drive magnet 531c are provided so as to be aligned in the X1X2 direction. When a current is passed through the drive coil 581b and the drive coil 581c, a Lorentz force in the Z1 direction or the Z2 direction is generated.

  The movable unit 55 moves in the Z1 direction or the Z2 direction by Lorentz force generated in the drive coil 581b and the drive coil 581c. Further, the movable unit 55 is displaced so as to rotate in the XZ plane by a Lorentz force generated in opposite directions by the drive coil 581b and the drive coil 581c.

  For example, when a Lorentz force in the Z1 direction is generated in the drive coil 581b and a current is applied so that a Lorentz force in the Z2 direction is generated in the drive coil 581c, the movable unit 55 rotates in the clockwise direction when viewed from above. In addition, when a Lorentz force in the Z2 direction is generated in the drive coil 581b and a current is applied so that a Lorentz force in the Z1 direction is generated in the drive coil 581c, the movable unit 55 rotates counterclockwise in a top view. .

  In the present embodiment, a drive coil 581a and a drive magnet 531a, and a drive coil 581d and a drive magnet 531d are provided as the second drive unit. The drive magnet 531a and the drive magnet 531d are arranged so that the longitudinal directions thereof are orthogonal to the drive magnet 531b and the drive magnet 531c. In such a configuration, when a current flows through the drive coil 581a and the drive coil 581d, a Lorentz force in the X1 direction or the X2 direction is generated. The movable unit 55 moves in the X1 direction or the X2 direction by the Lorentz force generated in the drive coil 581b and the drive coil 581c.

  The magnitude and direction of the current flowing through each drive coil 581 is controlled by the drive control unit 12 of the system control unit 10. The drive control unit 12 controls the movement (rotation) direction, the movement amount, the rotation angle, and the like of the movable unit 55 according to the magnitude and direction of the current flowing through each drive coil 581.

(Position detector)
FIG. 11 is an exploded perspective view illustrating the configuration including the position detection unit 540 in the embodiment.

  The position detection unit 540 in the present embodiment includes a position detection magnet 541 provided on the first fixed plate 511 and a Hall element 542 provided on the first movable plate 552. The position detection magnet 541 and the hall element 542 are provided at three locations, respectively, and are arranged to face each other in the Y1Y2 direction.

  The Hall element 542 is an example of a magnetic sensor, and transmits a signal corresponding to a change in magnetic flux density from the position detection magnet 541 provided in an opposing manner to the drive control unit 12 of the system control unit 10. The drive control unit 12 detects the position of the DMD 551 provided on the first movable plate 552 based on the signal transmitted from the Hall element 542.

  Here, in the present embodiment, the first fixed plate 511 and the second fixed plate 512 formed of a magnetic material function as a yoke plate and constitute a magnetic circuit including the position detecting magnet 541. In addition to the second fixed plate 512, the third fixed plate 513 functions as a yoke plate and constitutes a magnetic circuit including the drive magnet 531 and the drive coil 581.

  In this way, a magnetic circuit including the position detection unit 540 and a magnetic circuit including the drive unit are formed, and the position detection unit 540 and the drive unit generate position detection and driving force without being affected by the magnetic field formed with each other. It is possible to make it.

  For example, the magnetic flux generated in the drive magnet 531 provided in the second fixed plate 512 and the drive coil 581 provided in the second movable plate 553 is converted into the second fixed plate 512 and the third fixed plate that function as yoke plates. Leakage to the position detection unit 540 is suppressed by concentrating on 513.

  Therefore, the Hall element 542 provided on the upper surface of the first movable plate 552 between the first fixed plate 511 and the second fixed plate 512 is formed in the drive unit including the drive magnet 531 and the drive coil 581. The influence of the magnetic field is reduced. Further, since the position detection magnet 541 forms a magnetic circuit between the first fixed plate 511 and the second fixed plate 512, the influence of magnetic flux from other than the position detection magnet 541 is reduced in the Hall element 542. Yes.

  With the above-described configuration, the Hall element 542 can output a signal corresponding to a change in magnetic flux density of the position detection magnet 541 without being affected by a magnetic field generated in the driving unit. Therefore, the drive control unit 12 can grasp the position of the DMD 551 with high accuracy.

  As described above, the drive control unit 12 can accurately detect the position of the DMD 551 based on the output of the Hall element 542 in which the influence from the drive unit or the like is reduced. Therefore, the drive control unit 12 can control the magnitude and direction of the current flowing through each drive coil 581 according to the detected position of the DMD 551, and can control the position of the DMD 551 with high accuracy.

  In the present embodiment, a temperature sensor 544 and a heater 545 are provided in the vicinity of each Hall element 542 of the first movable plate 552. The detection result of the Hall element 542 may vary depending on the environmental temperature. Therefore, in the present embodiment, the temperature control unit 13 controls the intake fan 22, the exhaust fan 24, and the heater 545 based on the temperature detection result by the temperature sensor 544 so that the temperature around the Hall element 542 is within a predetermined range. Control. By keeping the temperature around the Hall element 542 within a predetermined range, it is possible to suppress a decrease in position detection accuracy by the Hall element 542 and to control the position of the DMD 551 with high accuracy.

(Temperature control processing)
FIG. 12 is a diagram illustrating a flowchart of the temperature control process in the embodiment. In the temperature control process according to the present embodiment, the temperature control unit 13 performs the hole control so that the environmental temperature is within a temperature range in which the detection accuracy of the Hall element 542 can be maintained (from the first temperature T1 to the second temperature T2). The temperature around the element 542 is adjusted. The temperature range is appropriately set according to the Hall element 542 used.

  In the temperature control process in the present embodiment, first, in step S101, the temperature sensor 544 detects the temperature. Next, in step S102, the temperature control unit 13 compares the temperature detected by the temperature sensor 544 with the first temperature T1.

  When the detected temperature is lower than the first temperature T1 (step S102: YES), the process proceeds to step S103. In this case, the output of the Hall element 542 may fluctuate due to a decrease in the environmental temperature, and the position detection accuracy of the DMD 551 may decrease. Therefore, in step S <b> 103, the temperature control unit 13 drives the heater 545 to heat the periphery of the hall element 542. When the heater 545 is driven, the temperature around the Hall element 542 increases.

  When the detected temperature is equal to or higher than the first temperature T1 (step S102: NO), the process proceeds to step S104. In step S <b> 104, the temperature control unit 13 stops driving the heater 545. Next, in step S105, the temperature control unit 13 compares the detected temperature with the second temperature T2.

  When the detected temperature is higher than the second temperature T2 (step S105: YES), the process proceeds to step S106. In this case, the output of the Hall element 542 may fluctuate due to an increase in the environmental temperature, and the position detection accuracy of the DMD 551 may decrease. Therefore, in step S106, the temperature control unit 13 sets the rotation speeds of the intake fan 22 and the exhaust fan 24 to a rotation speed R1 that is larger than the rotation speed R2 at the normal time. As the rotation speed of the intake fan 22 and the exhaust fan 24 increases, the amount of air blown to the image generation unit 50 and the amount of heat exhausted from the inside of the apparatus increase, and the temperature around the Hall element 542 decreases.

  When the detected temperature is equal to or lower than the second temperature T2 (step S105: NO), the process proceeds to step S107. In this case, the environmental temperature is within a temperature range in which the detection accuracy of the Hall element 542 can be maintained. Therefore, in step S107, the temperature control unit 13 sets the rotation speeds of the intake fan 22 and the exhaust fan 24 to the normal rotation speed R2.

  In the projector 1 according to the present embodiment, the temperature control process described above is repeatedly executed at a predetermined cycle during image projection, and the ambient temperature around the Hall element 542 is within a temperature range in which the detection accuracy of the Hall element 542 can be maintained. Controlled. For this reason, the drive control unit 12 can accurately detect the position of the DMD 551 based on the detection result of the Hall element 542, and the position control of the DMD 551 can be performed with high accuracy.

  Note that the temperature adjustment unit that adjusts the temperature of the position detection unit 540 including the Hall element 542 is not limited to the intake fan 22, the exhaust fan 24, and the heater 545 exemplified in this embodiment. As long as it is possible to raise or lower the temperature of the position detection unit 540 and keep it within a predetermined temperature range, a configuration different from that of the present embodiment may be used as the temperature adjustment unit.

  Further, the configuration of the drive unit and the position detection unit 540 described above is not limited to the configuration illustrated in the present embodiment. The number, position, and the like of the drive magnet 531 and the drive coil 581 provided as the drive unit may be different from the present embodiment as long as the movable unit 55 can be moved to an arbitrary position. Good. Further, the number, position, and the like of the position detection magnets 541 and the Hall elements 542 provided as the position detection unit 540 may be different from those of the present embodiment as long as the position of the DMD 551 can be detected.

  For example, the position detecting magnet 541 may be provided on the second fixed plate 512, and the Hall element 542 may be provided on the lower surface of the first movable plate 552. Further, the driving magnet 531 may be provided on the third fixing plate 513. Furthermore, the drive unit may be provided between the first fixed plate 511 and the second fixed plate 512, and the position detection unit 540 may be provided between the second fixed plate 512 and the third fixed plate 513.

  Even in such a configuration, the first fixing plate 511, the second fixing plate 512, and the third fixing plate 513 are formed of a magnetic material to function as a yoke plate, and the magnetic circuit including the driving unit and the position detection unit 540 are provided. Preferably, each of the magnetic circuits is formed to reduce the influence of the magnetic field on each other.

  In addition, since the weight of the movable unit 55 may increase and position control may become difficult, the driving magnet 531 and the position detection magnet 541 are fixed units 51 (first fixed plate 511 and second fixed plate 512, respectively). Or the third fixing plate 513). However, it is preferable that the driving magnet 531 and the position detecting magnet 541 are provided on different fixing plates so that the position adjustment can be performed independently.

  Furthermore, the first fixing plate 511, the second fixing plate 512, or the third fixing plate 513 is partially formed of a magnetic material as long as leakage of magnetic flux to each other in the drive unit and the position detection unit can be reduced. May be. For example, the first fixed plate 511, the second fixed plate 512, or the third fixed plate 513 may be formed by laminating a plurality of members including a flat plate or sheet member formed of a magnetic material. Good.

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

  For example, the drive 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 drive 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. . 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.

  In this way, the drive control unit 12 shifts the DMD 551 together with the movable unit 55, and the image control unit 11 generates a projection image corresponding to the position of the DMD 551, thereby projecting an image with a resolution higher than the resolution of the DMD 551. It becomes possible to do.

  Further, in the projector 1 according to the present embodiment, the drive control unit 12 controls the DMD 551 to rotate with the movable unit 55, so that the projection image can be rotated without being reduced. For example, a projector in which image generation means 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, the image generation unit 50 in the present embodiment is provided with the DMD 551 so as to be movable, and can generate a high-resolution image by shifting the DMD 551.

  In the present embodiment, the ambient temperature around the Hall element 542 of the position detection unit 540 is controlled within a temperature range in which the detection accuracy of the Hall element 542 can be maintained. For this reason, the drive control unit 12 can accurately detect the position of the DMD 551 based on the detection result of the Hall element 542, and the position control of the DMD 551 can be performed with high accuracy.

  Further, in the present embodiment, the first fixed plate 511, the second fixed plate 512, and the third fixed plate 513 are each formed of a magnetic material and function as a yoke plate. With such a configuration, the position detection magnet 541 provided as the position detection unit 540 between the first fixed plate 511 and the second fixed plate 512 has a magnetic circuit between the first fixed plate 511 and the second fixed plate 512. Form. A driving magnet 531 provided as a driving unit between the second fixed plate 512 and the third fixed plate 513 forms a magnetic circuit with the second fixed plate 512 and the third fixed plate 513.

As described above, the magnetic circuit including the position detection unit 540 and the magnetic circuit including the driving unit are formed, so that the influence of the magnetic field between them is reduced. Therefore, the drive control unit 12 can detect the position of the DMD 551 that shifts at high speed based on the output of the Hall element 542 with high accuracy, and can control the position of the DMD 551 with high accuracy. Although the projection apparatus and the image projection method have been described, the present invention is not limited to the above-described embodiments, and various modifications and improvements can be made within the scope of the present invention.

1 Projector (image projection device)
DESCRIPTION OF SYMBOLS 10 System control part 11 Image control part 12 Drive control part 13 Temperature control part 22 Intake fan (temperature adjustment part)
24 Exhaust fan (temperature adjustment part)
30 Light Source 40 Illumination Optical System Unit 50 Image Generation Unit (Image Generation Device)
51 Fixed unit 55 Movable unit 60 Projection optical system unit (projection unit)
511 First fixed plate 512 Second fixed plate 513 Third fixed plate 531 Driving magnet 541 Position detecting magnet 581 Driving coil 542 Hall element (magnetic sensor)
544 Temperature sensor (temperature detector)
545 Heater (Temperature adjuster)
551 DMD (image generator)
552 First movable plate 553 Second movable plate 554 Heat sink (heat radiating member)
556 Heat Dissipation Part 563 Heat Transfer Part

JP 2004-180011 A

Claims (7)

An image generation unit including an image generation unit provided in a displaceable manner;
A position detector for detecting the position of the image generator;
A temperature detection unit for detecting a temperature around the position detection unit;
A temperature adjusting unit for adjusting the temperature around the position detecting unit;
An image projection apparatus comprising: a temperature control unit that controls the temperature adjustment unit based on a detection result by the temperature detection unit. The temperature adjustment unit has a fan for blowing air to the image generation unit,
The image projection apparatus according to claim 1, wherein the temperature control unit controls the number of rotations of the fan based on a detection result by the temperature detection unit. The temperature adjustment unit has a heater for heating the periphery of the position detection unit,
The image projection apparatus according to claim 1, wherein the temperature control unit controls the heater based on a detection result by the temperature detection unit. The image generation unit includes:
A movable unit including a first movable plate provided with the image generation unit;
A fixed unit that movably supports the movable unit,
The position detector is
A magnetic sensor provided on the first movable plate;
4. The image projection apparatus according to claim 1, further comprising a position detection magnet provided on the fixed unit so as to face the magnetic sensor. 5. The fixing unit is
A first fixed plate;
A second fixed plate supported by the first fixed plate with the first movable plate interposed therebetween, and provided with the position detecting magnet,
The image projection apparatus according to claim 4, wherein at least a part of each of the first fixing plate and the second fixing plate is formed of a magnetic material. A drive unit that includes a drive magnet and a drive coil that are disposed opposite to each other between the fixed unit and the movable unit, and moves the movable unit relative to the fixed unit;
A drive control unit for controlling the drive unit,
The image generation unit is a digital micromirror device in which a plurality of micromirrors that modulate light emitted from a light source based on an image signal are arranged,
6. The image according to claim 4, wherein the drive control unit controls the drive unit to move the movable unit by a predetermined cycle at a distance less than an arrangement interval of the plurality of micromirrors. Projection device. An image projecting method in an image projecting apparatus, comprising: an image generating unit provided so as to be displaceable; a position detecting unit that detects a position of the image generating unit; And
A position detecting step for detecting a position of the image generating unit;
A temperature detection step of detecting a temperature around the position detection unit;
And a temperature control step of controlling the temperature adjustment unit based on a detection result of the temperature detection step.

Images