JP2018120086A - Image projection device and method for controlling image projection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a load on driving means of an image display element in pixel shift control to reduce power consumption.SOLUTION: An image projection device comprises: an image display element (DMD) that forms an image by using light from a light source; driving means that displaces the image display element; and a drive control part that controls the driving means during image projection to cause the image display element to reciprocate between two points. When the image projection device is in an energy-saving mode (S102: Yes), the drive control part causes the image display element to reciprocate on a non-linear movement locus passing through the two points (S103).SELECTED DRAWING: Figure 20

Description

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

  Based on image data (video data) transmitted from an information processing device such as a personal computer, a video playback device such as a DVD player, an image pickup device such as a digital camera, an image display element (using a light emitted from a light source) 2. Description of the Related Art An image projection apparatus (projector) is known in which an optical modulation element) generates an image and projects the generated image onto a projection surface such as a screen through an optical system including a plurality of lenses.

  Image projection devices are widely used for presentations, conferences, lectures, educational sites, movie appreciation, signage, etc. for a large number of people, and image quality is being improved. When the resolution of a projection image is increased in the image projection apparatus, it is conceivable to increase the pixel density of the image display element, but the manufacturing cost of the image display element increases.

  On the other hand, in the image projection apparatus, in order to shift the pixels, the pixel density of the image display element is controlled by performing a control for shifting a part of the pixels (referred to as pixel shift control) and performing image processing for pixel shift control. It is known that a higher-definition image can be displayed without increasing the image quality.

  In pixel shift control, a method of moving an optical element such as a part of a projection lens and a method of moving an image display element that forms an image are known. As a method for moving an image display element, for example, in Patent Document 1, a movable unit including a digital micromirror device (DMD) as an image display element is movable with respect to a fixed unit, thereby increasing a projected image. An image projecting device for resolution is disclosed.

  In the conventional pixel shift control for shifting the image display element, the resolution of the projected image is increased by causing the image display element to vibrate between two points. When the image display element is simply vibrated between two points, the moving distance of the image display element can be shortened because it passes through the shortest distance between the two points, while the traveling direction and the inertial force are 180 degrees at the top of the movement locus. Since the rotation is reversed, the load on the driving means for driving the image display element is increased.

  In particular, when the heat sink is integrated as in the movable unit of Patent Document 2, since the heat sink is heavy, the influence of the inertial force on the load of the driving means increases, leading to an increase in power consumption.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an image projection apparatus capable of suppressing power consumption by suppressing a load on a driving unit of an image display element in pixel shift control.

  In order to achieve such an object, an image projection apparatus according to the present invention includes an image display element that forms an image using light from a light source, a drive unit that displaces the image display element, and the drive unit during image projection. A drive control unit configured to control and reciprocate the image display element between two points. When the image projection apparatus is in a predetermined mode, the drive control unit controls the image display element. It moves reciprocally along a non-linear movement trajectory passing through the two points.

  According to the present invention, it is possible to suppress power consumption by suppressing a load on a driving unit of an image display element in pixel shift control.

It is an external appearance perspective view which shows one Embodiment of an image projector. It is a side view of an image projection device, and is a diagram showing a projection state on a projection surface. 2A is a perspective view showing a state in which an exterior cover of the image projection apparatus is removed, and FIG. 3B is an enlarged configuration diagram of a circled portion of FIG. It is sectional drawing of an illumination optical system unit, a projection optical system unit, an image display unit, and a light source unit. It is a block diagram which illustrates the functional composition of an image projection device. 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 a figure explaining the movement locus | trajectory of 1 pixel of DMD which reciprocated between 2 points | pieces. It is a figure explaining the advancing direction and inertial force of a pixel. It is a flowchart which shows the selection process of pixel shift control according to the drive mode of an image projector.

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

(Image projection device)
The image projection apparatus (image projection apparatus 1) according to the present embodiment includes an image display element (DMD551) that forms an image using light from a light source, and a drive unit (movable unit 55) that displaces the image display element. A drive control unit (movable unit control unit) that reciprocates the image display element between two points by controlling the drive means during image projection, and the drive control unit includes: In the case of the predetermined mode, the image display element is reciprocated along a non-linear movement trajectory passing through two points. In addition, the code | symbol in embodiment and the example of application are shown in a parenthesis.

  FIG. 1 is an external perspective view showing an embodiment of an image projector 1. FIG. 2 is a side view of the image projecting apparatus 1 and shows a state of projection onto the screen S that is the projection surface.

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

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

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

  As shown in FIG. 3, an intake fan 18 and an exhaust fan 19 are provided inside the intake port 16 and the exhaust port 17, respectively. By discharging the outside air drawn from the intake fan 18 from the exhaust fan 19, Air cooling by forced air flow in the apparatus is performed.

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

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

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

  The illumination optical system unit 40 of the optical engine 3 includes a color wheel 5 (rotating color filter) that separates light emitted from the light source, a light tunnel 6 that guides light emitted from the color wheel 5, a relay lens 7, A plane mirror 8 and a concave mirror 9 are provided. An image display unit 50 is provided in the illumination optical system unit 40.

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

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

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

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

  In the present embodiment, the horizontal projector has been described as an example. However, it is needless to say that the projector may have other configurations such as a vertical ultrashort focus projector using optical reflection.

  FIG. 5 is a functional block diagram illustrating an example of the image projection apparatus 1 according to the present embodiment. The image projection apparatus 1 includes a system control unit 10, a pixel shift image processing unit 11, a color wheel control unit 12, a DMD control unit 13, a movable unit control unit 14, a fan control unit 15, a remote control reception unit 22, and a main body operation unit 23. , Input terminal 24, video signal control unit 25, nonvolatile memory 26, power supply unit 27, temperature sensor 28, fan 29, light source 30, lamp control unit 31, illumination optical system unit 40, image display unit 50, projection optical system unit 60 is an image projection apparatus 1 that projects an image onto a screen S. Moreover, the remote control 21 as a remote control means is provided.

  The system control unit 10 is a main control unit that performs overall control of the image projection apparatus 1. In addition, contrast control, brightness adjustment, sharpness adjustment, scaling processing, display control of superimposed screen (OSD: On Screen Display) such as menu information, and other various controls are performed on the input video signal (input image). .

  In addition, the pixel shift image processing unit 11, the color wheel control unit 12, the DMD control unit 13, the movable unit control unit 14, the fan control unit 15, the remote control receiving unit 22, the main body operation unit 23, the video signal control unit 25, and the non-volatile It is connected to the memory 26, the temperature sensor 28, and the lamp control unit 31, and controls these functional units.

  Each control unit such as the system control unit 10 includes, for example, a microcontroller (microcomputer), and includes a calculation unit and a storage unit such as a CPU (Central Processing Unit) and a RAM (Random Access Memory). The function of each unit is realized by executing a program (control program) stored in a storage unit (nonvolatile memory 26 or the like) in cooperation with.

  The pixel shift image processing unit 11 is a block that performs image processing such as frame generation for generating two images (two frames) with respect to an input video signal (one frame) during pixel shift control. Thus, the control means is independent of at least the system control unit 10. The pixel shifting image processing unit 11 is configured by, for example, a programmable logic device (PLD) such as an FPGA (Field-Programmable Gate Array), and a bit stream is provided integrally with the image display unit 50.

  In addition, when generating two images from one image, the pixel shift image processing unit 11 performs correction processing as necessary, for example, processing for dividing and analyzing the image and performing correction based on the characteristics. Run.

  The input terminal 24 is an interface for inputting a video signal, and is a VGA (Video Graphics Array) input terminal such as a D-Sub connector, an HDMI (High-Definition Multimedia Interface) (registered trademark) terminal, an S-VIDEO terminal, an RCA. Video input terminals such as terminals. A video signal is received from a video supply device such as a computer or AV device via a cable connected to the input terminal 24. Further, a plurality of input terminals 24 may be provided.

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

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

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

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

  The user can perform various settings by operating the main body operation unit 23 or the remote controller 21. For example, on / off setting of pixel shift control, display instruction for a menu screen, selection of the installation state of the image projection apparatus 1, a request to change the aspect ratio of the projection image, a request to turn off the power of the image projection apparatus 1, and a change in the light amount of the light source 30 Execute a lamp power change request, video mode change request to change the image quality (high brightness, standard, natural, etc.) of the projected image, drive mode setting (energy saving mode on / off), freeze request to stop the projected image, etc. be able to.

  The fan control unit 15 acquires the internal temperature of the image projection apparatus 1 detected by the temperature sensor 28, and controls the fan 29 so that the internal temperature of the image projection apparatus 1 and the temperature of the light source 30 become a predetermined temperature.

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

  The temperature sensor 28 is a temperature detection unit that is provided at a predetermined position in the image projection apparatus 1 and detects the internal temperature of the apparatus. The detection result (that is, the internal temperature) of the temperature sensor 28 is based on the system control unit 10. Is input.

  The fan 29 includes an intake fan 18, an exhaust fan 19, a light source fan 20, and the like. By discharging the outside air sucked from the intake fan 18 from the exhaust fan 19, an air flow is generated in the image projection apparatus 1 and air cooling is performed. Further, a light source fan 20 as a light source cooling means is provided in the vicinity of the light source 30, and the amount of rotation of the light source fan 20 is controlled based on the internal temperature.

  The light source 30 is, for example, a high-pressure mercury lamp in which a luminescent material emits light by a discharge between a pair of electrodes, and irradiates the illumination optical system unit 40 with light. In addition, a xenon lamp, an LED, or the like can be used as the light source 30. The lamp control unit 31 also controls on / off of the light source 30 and lighting power.

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

  The color wheel control unit 12 controls the rotational drive of the color wheel 5.

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

  The image display unit 50 includes a fixed unit 51 (FIG. 6) 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 of the movable unit 55 relative to the fixed unit 51 is controlled by the movable unit control unit 14.

  The movable unit 55 is provided with an electromagnetic actuator (motor) as drive means, and the movable unit controller 14 controls the amount of movement of the DMD 551 by controlling the amount of current that flows to the drive means of the movable unit 55. To do. The control (pixel shift control) for reciprocating the DMD 551 by the movable unit control unit 14 can be turned on / off by operating the main body operation unit 23 or the remote controller 21. When the control for reciprocating the DMD 551 is set to OFF, a normal projection screen display in which the control for reciprocating the DMD 551 is not performed is performed.

  Further, the position of the movable unit 55 (that is, the DMD 551) can be detected by position detection means 52 (position sensor) such as an optical sensor or a magnetic sensor provided in the image display unit 50. The movable unit control unit 14 determines whether or not the movable unit 55 is at the target position based on the amount of current (control content) supplied to the drive unit and the detection result (control result) of the position detection unit 52, that is, the movable unit. It is detected whether 55 is operating normally, and the detection result is input to the system control unit 10. As a result, the system control unit 10 can detect whether the pixel shift control is operating normally.

  The DMD 551 has a substantially rectangular mirror surface composed of a plurality of micromirrors, and each micromirror is driven in a time-sharing manner based on video data, thereby processing and reflecting the projection light so as to form a predetermined video. This is an image display element. Further, the DMD control unit 13 controls on / off of the micromirror of the DMD 551.

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

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

(Image display unit)
FIG. 6 is a perspective view illustrating the image display unit 50. FIG. 7 is a side view illustrating the image display unit 50.

  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.

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

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

  The coupling plate 553 is fixed to the movable plate 552 with the base plate 512 of the fixed unit 51 interposed therebetween. The coupling plate 553 is provided with the DMD 551 fixed on the upper surface side and the heat sink 554 fixed on the lower surface side. The coupling plate 553 is fixed to the movable plate 552 so that it can be moved to the fixed unit 51 together with the movable plate 552, the DMD 551, and the heat sink 554.

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

  For example, when the micromirror is “ON”, the tilt angle is controlled so that the light from the light source 30 is reflected to the projection optical system unit 60. When the micromirror is “OFF”, for example, the tilt angle is controlled in a direction in which the light from the light source 30 is reflected toward the OFF light plate.

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

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

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

  As shown in FIGS. 8 and 9, the fixing unit 51 includes a top plate 511 and a base plate 512.

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

  As shown in FIG. 9, the support column 515 is press-fitted into a support column hole 516 formed in the top plate 511 at the upper end, and a support column hole 517 formed in the base plate 512 at the lower end portion where the male screw groove is formed. Inserted into. The support columns 515 form a fixed interval between the top plate 511 and the base plate 512, and support the top plate 511 and the base plate 512 in parallel.

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

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

  The support spheres 521 rotatably held in the support holes 522 and 526 of the top plate 511 and the base plate 512 are in contact with the movable plate 552 provided between the top plate 511 and the base plate 512, respectively, so that the movable plate 552 can move. To support.

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

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

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

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

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

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

  FIG. 12 is a bottom view illustrating the top plate 511. As shown in FIG. 12, magnets 531, 532, 533, and 534 are provided on the surface of the top plate 511 on the base plate 512 side.

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

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

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

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

  As shown in FIGS. 13 and 14, the movable unit 55 includes a DMD 551, a movable plate 552, a coupling plate 553, a heat sink 554, a holding member 555, and a DMD substrate 557, and is movably supported with respect to the fixed unit 51. Has been.

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

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

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

  Coils 581, 582, 583, 584 are formed by winding an electric wire around an axis parallel to the Z 1 Z 2 direction, and are provided in a recess formed on the surface of the movable plate 552 on the top plate 511 side. Covered with a cover. Coils 581, 582, 583, and 584 constitute moving means for moving the movable plate 552 with the magnets 531, 532, 533, and 534 of the top plate 511, respectively.

  The magnets 531, 532, 533 and 534 of the top plate 511 and the coils 581, 582, 583 and 584 of the movable plate 552 are provided at positions facing each other in a state where the movable unit 55 is supported by the fixed unit 51. ing. When a current is passed through the coils 581, 582, 583, 584, a Lorentz force that is a driving force for moving the movable plate 552 is generated by a magnetic field formed by the magnets 531, 532, 533, and 534.

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

  The magnitude | size and direction of the electric current sent through each coil 581,582,583,584 are controlled by the movable unit control part 14. FIG. The movable unit controller 14 controls the movement direction, movement amount, movement speed, rotation direction, rotation angle, and the like of the movable plate 552 according to the magnitude and direction of the current flowing through the coils 581, 582, 583, 584.

  In the present embodiment, as the first driving means, a coil 581 and a magnet 531, and a coil 584 and a magnet 534 are provided facing each other in the X1X2 direction. When a current is passed through the coil 581 and the coil 584, a Lorentz force in the X1 direction or X2 is generated as shown in FIG. The movable plate 552 moves in the X1 direction or the X2 direction by the Lorentz force generated in the coil 581 and the magnet 531 and the coil 584 and the magnet 534.

  In the present embodiment, as the second driving means, a coil 582 and a magnet 532, and a coil 583 and a magnet 533 are provided side by side in the X1X2 direction, and the magnet 532 and the magnet 533 are the same as the magnet 531 and the magnet 534. It arrange | positions so that a longitudinal direction may orthogonally cross. In such a configuration, when a current is passed through the coil 582 and the coil 583, a Lorentz force in the Y1 direction or the Y2 direction is generated as shown in FIG.

  The movable plate 552 moves in the Y1 direction or the Y2 direction by the Lorentz force generated in the coil 582 and the magnet 532, and the coil 583 and the magnet 533. Further, the movable plate 552 is displaced so as to rotate in the XY plane by the Lorentz force generated in the opposite direction by the coil 582 and the magnet 532 and the coil 583 and the magnet 533.

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

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

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

  It should be noted that the number, position, etc. of the magnets 531, 532, 533, 534 as the moving means and the coils 581, 582, 583, 584 can be adjusted as long as the movable plate 552 can be moved to an arbitrary position. Different configurations may be used. For example, the magnet as the moving unit may be provided on the upper surface of the top plate 511 or may be provided on any surface of the base plate 512. Further, for example, a magnet may be provided on the movable plate 552 and a coil may be provided on the top plate 511 or the base plate 512.

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

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

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

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

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

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

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

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

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

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

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

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

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

  The configuration of the image display unit 50 described so far is merely an example, and a drive unit that displaces the DMD 551, a drive control unit that controls the drive unit during image projection and moves the DMD 551 back and forth between two points, What is necessary is just to have.

(Pixel shift control)
As described above, the DMD 551 that generates a projection image in the image projection apparatus 1 receives the reaction force when a force is applied to the fixed unit 51 and moves relative to the fixed unit 51. The position is controlled together with the movable unit 55 by the movable unit controller 14.

  For example, the movable unit controller 14 moves the movable unit at a high speed between a plurality of positions separated by a distance less than the arrangement interval of the plurality of micromirrors of the DMD 551 at a predetermined period corresponding to the frame rate at the time of image projection. The position of 55 is controlled. At this time, the pixel shift image processing unit 11 generates a projection image shifted according to each position, and transmits an image signal to the DMD 551 via the DMD control unit 13.

  The movable unit controller 14 reciprocates the DMD 551 in a predetermined cycle between a first position and a second position separated by a distance less than the arrangement interval of the micromirrors of the DMD 551 in the X1X2 direction and the Y1Y2 direction. At this time, the DMD control unit 13 controls the DMD 551 so as to generate a projection image shifted according to each position, so that the resolution of the projection image can be approximately double the resolution of the DMD 551. Become.

  As described above, the movable unit control unit 14 moves the DMD 551 together with the movable unit 55 in a predetermined cycle, and the pixel shift image processing unit 11 and the DMD control unit 13 cause the DMD 551 to generate a projection image corresponding to the position. An image having a resolution higher than that of the DMD 551 can be projected.

  With reference to FIG. 18, the movement trajectory (driving trajectory) of one pixel of the DMD 551 that is reciprocated between two points by pixel shift control will be described.

  In the pixel shift control, as shown in FIG. 18 (a), one pixel is reciprocated between two positions (pixel A and pixel B) shifted by half a pixel in the direction of 45 degrees diagonally, and alternately at each pixel. By projecting an image, it is possible to achieve a high resolution in a pseudo manner. Here, assuming that the center of the pixel A is A ′ and the center of the pixel B is B ′, the movement trajectory that differs depending on the drive mode will be described below. Note that the amount of movement is normally half a pixel, but is not limited to half a pixel.

As shown in FIG. 18B, when the pixel is reciprocated so as to form a linear movement locus between two points, that is, when a single vibration is made between A ′ and B ′, the drive parameter of the pixel is as follows. It can be represented by Formula (1).
X = α cos θ
Y = β cos θ (1)
Here, α is the driving amount in the X direction, and β is the driving amount in the Y direction.

  θ is a value linked to the video synchronization signal. For example, in the case of a video signal with a frame rate of 60 Hz, θ changes from 0 to 2π at a frequency of 60 Hz, and the pixel moves for one cycle at 60 Hz.

  FIG. 19 is a schematic diagram for explaining the traveling direction and inertial force of a pixel. Here, FIG. 19A shows the traveling direction and the inertial force at the apex (A ′ position) of the movement locus in the case of the simple vibration shown in FIG. In the case of simple vibration, the traveling direction at the apex (A ′ position) of the movement trajectory and the direction of the inertial force are opposite to each other and hinder the movement, so that the load on the driving means increases. The same applies to the B ′ position. As described above, in the case of simple vibration, the traveling direction and the inertial force are reversed for each vertex of the reciprocating movement, and the load on the driving unit increases. And power consumption becomes large by the load increase of a drive means.

  Therefore, in the pixel shift control, the image projection apparatus according to the present embodiment has two positions (pixel A and pixel A) that are shifted by half a pixel in a 45-degree oblique direction in order to reduce the load on the driving unit of the image display element. When reciprocating between the pixels B), the reciprocating movement is performed so that the movement locus becomes a non-linear movement locus between two points. The movable unit controller 14 moves the movable plate 552 in a non-linear manner between two points by adjusting the magnitude and direction of the current flowing through each coil 581, 582, 583, 584 (control of drive parameters). It can be reciprocated so that it becomes a locus.

For example, as shown in FIG. 18C, the pixels are moved so as to form a circular orbit passing through two points A′-B ′. In this case, the pixel drive parameter can be expressed by the following equation (2). FIG. 18C shows an example in which the pixel is moved so as to have a circular orbit (circular motion) passing through two points A′-B ′. However, two points A′-B ′ are shown. The pixel may be moved so as to have an elliptical trajectory (elliptical motion).
X = α cos θ
Y = βsinθ (2)

  FIG. 19B shows the traveling direction and inertial force at the apex (A ′ position) of the movement locus in the case of the circular orbit shown in FIG. In the case of a circular orbit, the direction of travel and the direction of inertial force at the apex (A ′ position) of the movement locus are shifted by 90 °, so that the movement is not hindered compared to the case of simple vibration, and the drive means The load can be suppressed. The same applies to the B ′ position. As described above, in the case of a circular (elliptical) orbit, by suppressing the load of the driving unit in the pixel shift control, an increase in power consumption can be prevented and energy saving can be realized.

  FIG. 20 is a flowchart illustrating an example of processing for selectively controlling the movement locus in the pixel shift control in accordance with the drive mode of the image projection apparatus.

  In this process, first, the drive mode set from the main body operation unit 23 or the remote controller 21 is read (S101), and it is determined whether or not the set drive mode is the energy saving mode (S102). When the drive mode is the energy saving mode (S102: Yes), the drive parameter is set to the parameter represented by the above equation (2) in order to change the movement locus of the image display element to a circular orbit (or elliptical orbit). (S103).

  On the other hand, when the drive mode is the normal mode that is not the energy saving mode (S102: No), the drive parameter is set to the parameter represented by the above equation (1) in order to change the movement trajectory of the image display element to simple vibration ( S104). In either step of S103 or S104, after the drive parameter setting is completed, pixel shift control is started (S105).

  According to the image projection apparatus according to the present embodiment described above, when the energy saving mode is set, the movement locus of the movable unit at the time of pixel shift control is nonlinearly like a circular or elliptical orbit. By changing so as to move between the two points, it is possible to suppress the load on the driving means of the image display element and suppress the power consumption.

  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.

DESCRIPTION OF SYMBOLS 1 Image projector 2 Exterior cover 3 Optical engine 4 Light source unit 5 Color wheel 6 Light tunnel 7 Relay lens 8 Plane mirror 9 Concave mirror 10 System control part 11 Pixel shift image processing part 12 Color wheel control part 13 DMD control part 14 Movable Unit control unit 15 Fan control unit 16 Intake port 17 Exhaust port 18 Intake fan 19 Exhaust fan 20 Light source fan 21 Remote control 22 Remote control reception unit 23 Main unit operation unit 24 Input terminal 25 Video signal control unit 26 Non-volatile memory 27 Power supply unit 28 Temperature Sensor 29 Fan 30 Light source 31 Lamp control unit 40 Illumination optical system unit 50 Image display unit 51 Fixed unit 52 Position detection means 55 Movable unit 551 DMD
60 Projection optical system unit S Screen

JP, 2006-85363, A

Claims (7)

An image display element that forms an image using light from a light source;
Driving means for displacing the image display element;
In an image projection apparatus comprising: a drive control unit that controls the drive means during image projection to reciprocate the image display element between two points;
The drive control unit
When the image projection apparatus is in a predetermined mode, the image display apparatus is configured to reciprocate the image display element along a non-linear movement locus passing through the two points. The predetermined mode is an energy saving mode,
2. The image projection apparatus according to claim 1, wherein when the image projection apparatus is not in an energy saving mode, the image display element is reciprocated between the two points along a linear movement locus.   The image projection apparatus according to claim 1, wherein the non-linear movement trajectory is a circular trajectory passing through the two points.   The image projection apparatus according to claim 1, wherein the non-linear movement trajectory is an elliptical trajectory passing through the two points. The image display element is fixed to a movable unit movable in a direction parallel to the image display surface of the image display element,
The image projection apparatus according to claim 1, wherein the drive control unit controls a movement direction, a movement amount, and a movement speed of the movable unit.   The image projecting apparatus according to claim 5, wherein the movable unit includes a cooling unit that cools the image display element. An image display element that forms an image using light from a light source;
Driving means for displacing the image display element,
In a control method of an image projection apparatus for controlling the driving means during image projection to reciprocate the image display element between two points,
When the image projection apparatus is in a predetermined mode, the image projection apparatus is controlled to reciprocate along a non-linear movement locus passing through the two points.