JP2013122490A - Projection type video display system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide projection type video display technique excellent in user's convenience.SOLUTION: A projection type video display system 400 includes a projection type image display device 100 that emits video light, and a screen 300 on which the video light from the projection type image display device 100 is projected. The screen 300 is composed of a member whose light transmittance reversibly varies in accordance with a temperature of the screen 300, the light transmittance at a high temperature being lower than that at a low temperature. The projection type image display device 100 includes an exhaust heat unit that conducts heat generated in the projection type image display device 100 to the screen.

Description

  The present invention relates to a projection-type image display system, and more particularly to a system including a projection-type image display apparatus that has a super short focus projection system and enables desktop projection with a short projection distance.

  Projectors are often used for various meetings, presentations, advertisements, and the like. In general, projection images of these projectors project image light onto a wall surface that is far from the projector. Since the distance between the projector and the member for projecting the image light is large, it cannot be said that the convenience for the user is necessarily excellent in view of the adjustment of the image. Further, when there is no wall surface at a suitable distance for projecting an image, or when the projector is used in a place where there is no wall surface, it is necessary to prepare the projector and the screen separately.

  Normally, the angle of view and focus of an image projected from a projector onto a screen can be changed by operating an optical system attached to the projector. A projector having a tilt mechanism has also been proposed (see Patent Document 1).

JP-A-2-195386

  The inventor of the present application integrates a projector that enables projection on a desk with a short projection distance by having an ultra short focus projection system including an aspherical mirror with a desk that is a projection surface, thereby combining the projector and the screen. By constructing a projection-type video display system that includes the above, the present inventors have come to recognize that a projection-type video display technology with excellent user convenience is realized.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a projection-type image display technology excellent in user convenience.

  In order to achieve the above object, an aspect of the present invention is a projection display system. This system includes a projection display apparatus that emits image light, and a screen on which the image light from the projection display apparatus is projected. Here, the screen is a member whose light transmittance is reversibly changed according to the temperature of the screen, and the light transmittance is smaller when the temperature of the member is higher than when the temperature is low. The projection display apparatus includes a heat exhaust unit that conducts heat in the projection display apparatus to the screen.

  Another aspect of the present invention is also a projection image display system. This system includes a projection display device that emits image light, a plate member including a screen on which image light from the projection display device is projected, and a first surface side pivotally attached to the plate member. And a support member for connecting the bottom surface of the projection display apparatus to a second surface orthogonal to the first surface. Here, the support member has a first position where the projection display apparatus is disposed on the screen side of the plate-shaped member, and a first position where the projection display apparatus is disposed on the opposite side of the screen of the plate-shaped member. It can be rotated between two positions.

  ADVANTAGE OF THE INVENTION According to this invention, the projection type video display technique excellent in the convenience of the user can be provided.

It is a figure which shows the projection type video display apparatus (floor surface projection) which concerns on embodiment of this invention. It is a figure which shows the projection type video display apparatus (wall surface projection) which concerns on embodiment of this invention. It is a figure which shows the optical structure of the projection type video display apparatus concerning embodiment of this invention. 1 is a perspective view showing a projection display system according to Embodiment 1 of the present invention. FIGS. 5A and 5B are schematic views showing an example of the arrangement of the internal configuration of the projection display apparatus according to Embodiment 1 of the present invention. It is a perspective view which shows the projection type video display system which concerns on Embodiment 2 of this invention. FIGS. 7A and 7B are perspective views showing an example of the rotation direction of the support member in the projection display system according to Embodiment 2 of the present invention. It is a perspective view which shows another example of a supporting member in the projection type video display system concerning Embodiment 2 of this invention. It is a perspective view which shows a mode that a support member is located in the middle of a 1st position and a 2nd position by rotation centering on a rotating shaft. It is a perspective view which shows the rotation direction of the projection type video display apparatus concerning Embodiment 2 of this invention.

  Hereinafter, a projection display apparatus according to an embodiment of the present invention will be described with reference to the drawings. In the description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic and ratios of dimensions and the like are different from actual ones. Therefore, specific dimensions and the like should be determined in consideration of the following description. It should also be noted that the drawings include parts having different dimensional relationships and ratios.

(Schematic configuration of the projection display device)
A projection display apparatus according to an embodiment of the present invention is a projector that enables desktop projection with a short projection distance by having an ultra-short focus projection system including an aspherical mirror, and the projection image is a main body installation bottom surface. Projected on the same plane.

  Hereinafter, the schematic configuration of the projection display apparatus will be described with reference to the drawings. This schematic configuration is substantially common to some embodiments described below, but some configurations may be different depending on the embodiments. FIG. 1 is a diagram showing a projection display apparatus 100 (floor surface projection). FIG. 2 is a diagram showing the projection display apparatus 100 (wall surface projection).

  As shown in FIGS. 1 and 2, the projection display apparatus 100 has a housing 200 and projects an image on a projection surface. The housing 200 is provided with a projection port 210 through which light emitted from a projection optical system 110 described later passes. The projection port 210 may be a window using a member that transmits light, such as glass.

  The projection plane may be formed on a horizontal plane as shown in FIG. 1, or may be formed on a vertical plane as shown in FIG. When formed on a horizontal plane, it is formed on a floor, a desk, a screen, a white board, and the like. When formed on a vertical surface, it is formed on a wall surface, a screen, a whiteboard or the like. The projection display apparatus 100 may be disposed so as to project image light onto a horizontal plane, or may be disposed so as to project onto a vertical plane.

  Of the surfaces of the substantially rectangular parallelepiped housing 200, the first surface 220 is the installation surface (that is, the bottom surface 220) in the case shown in FIG. 1, and the second surface 230 is the installation surface in the case shown in FIG.

  The projection display apparatus 100 is configured in a small size, and the projection display apparatus 100 displays an image of about 20 to 40 inches on the projection surface. For example, an A3 size video is displayed. The projection display apparatus 100 is a so-called ultra-short focus type that is very close to the projection surface.

(Optical configuration of the projection display)
Hereinafter, the optical configuration of the projection display apparatus 100 will be described with reference to the drawings. FIG. 3 is a diagram illustrating an optical configuration of the projection display apparatus 100.

  As shown in FIG. 3, the projection display apparatus 100 includes a projection optical system 110, an illumination optical system 120, a DMD (Digital Micromirror Device) 70, a reflecting prism 80, a cooling fan 130, a battery 140, a power supply board 150, a main control board. 160 and an operation board 170.

  The projection optical system 110 projects image light emitted from the DMD 70 that is a light modulation element onto a projection surface. In this embodiment, since a color image is projected, the image light has a color component. The projection optical system 110 includes a projection lens group 111 and a reflection mirror 112. The projection lens group 111 emits the color component light emitted from the DMD 70 to the reflection mirror 112 side. The projection optical system 110 functions as an emission unit that emits image light.

  The projection lens group 111 includes substantially circular and substantially semicircular lenses centered on the optical axis L of the projection optical system 110. It should be noted that the diameter of the lens included in the projection lens group 111 is larger as it is closer to the reflection mirror 112.

  The reflection mirror 112 reflects the image light emitted from the projection lens group 111. The reflection mirror 112 condenses the image light and widens the image light. For example, the reflection mirror 112 is an aspherical mirror having a concave surface on the projection lens group 111 side, and has a substantially semicircular shape centered on the optical axis L of the projection optical system 110. The reflection mirror 112 functions as a reflection unit that reflects the image light emitted from the projection optical system 110.

  The image light collected by the reflection mirror 112 is guided to the outside from a projection port 210 provided in the housing 200. The projection port 210 provided in the housing 200 is preferably provided in the vicinity of the position where the image light is collected by the reflection mirror 112.

  The illumination optical system 120 includes a light source 10, a dichroic prism 30, a rod integrator 40, a first mirror 51, a second mirror 52, a first lens 61, a second lens 62, and a third lens 63.

  The light source 10 is configured to individually emit a plurality of color component lights. The light source 10 may be provided with a heat sink that dissipates heat generated by the light source 10. In FIG. 3, the light source 10 includes a red light source 10R, a green light source 10G, and a blue light source 10B.

  The red light source 10R is a light source that emits red component light R. For example, a red LED (Light Emitting Diode) or a red LD (Laser Diode) can be used as the red light source 10R. The green light source 10G is a light source that emits green component light G. For example, a green LED or a green LD can be used as the green light source 10G. The blue light source 10B is a light source that emits blue component light B. For the blue light source 10B, for example, a blue LED or a blue LD can be used. Each of the red light source 10 </ b> R, the green light source 10 </ b> G, and the blue light source 10 </ b> B may be provided with a heat sink made of a member having good heat dissipation such as metal.

  The dichroic prism 30 combines the red component light R emitted from the red light source 10R, the green component light G emitted from the green light source 10G, and the blue component light B emitted from the blue light source 10B.

  The rod integrator 40 has a light incident surface, a light emitting surface, and a light reflecting side surface provided from the outer periphery of the light incident surface to the outer periphery of the light emitting surface. The rod integrator 40 makes the color component light emitted from the dichroic prism 30 uniform. More specifically, the rod integrator 40 makes the color component light uniform by reflecting the color component light on the light reflection side surface. The rod integrator 40 may be a solid rod made of glass or the like, or a hollow rod whose inner surface is constituted by a mirror surface.

  In the example illustrated in FIG. 3, the rod integrator 40 has a tapered shape in which a cross section perpendicular to the light traveling direction increases toward the traveling direction of the light emitted from the light source 10. The rod integrator 40 may have an inversely tapered shape in which the cross section perpendicular to the light traveling direction becomes smaller toward the traveling direction of the light emitted from the light source 10.

  The first mirror 51 and the second mirror 52 are reflection mirrors that bend the optical path in order to guide the light emitted from the rod integrator 40 to the DMD 70. The first lens 61, the second lens 62, and the third lens 63 are relay lenses that form an image of the color component light on the DMD 70 while suppressing the expansion of the color component light emitted from the light source 10.

  The cooling fan 130 communicates with the outside of the housing 200 and releases heat in the housing 200. Alternatively, air outside the housing 200 is sent into the housing 200. Or do both. The cooling fan 130 is provided in the vicinity of the light source 10 and cools the light source 10.

  The battery 140 stores electric power used in the projection display apparatus 100. The power supply board 150 includes an AC-DC converter, and the AC-DC converter converts AC power supplied from a commercial power source into DC power. The AC-DC converter stores the converted DC power in the battery 140 or supplies it to various circuits in the projection display apparatus 100. When the power supply board 150 and the commercial power supply are not connected, the power stored in the battery 140 is supplied to various circuits. In addition, it is good also as a structure which does not mount the battery 140 from a viewpoint of size reduction and weight reduction.

  The main control board 160 is equipped with a control circuit that controls the operation of the projection display apparatus 100. The operation board 170 is connected to an operation unit installed in the projection display apparatus 100. The control circuit mounted on the operation board 170 transmits an operation signal input from the operation unit to the control circuit mounted on the main control board 160.

  DMD 70 is composed of a plurality of micromirrors. The plurality of micromirrors are independently movable. In principle, one micromirror corresponds to one pixel. The DMD 70 changes the angle of each micromirror according to the set video signal. Thereby, it is possible to switch whether or not the color component light is reflected to the projection optical system 110 side for each display pixel. Note that gradation control is possible by controlling the time of reflection to the projection optical system 110 side.

  Although FIG. 3 shows an example in which a DMD is used as the light modulation element, a reflective or transmissive liquid crystal panel may be used instead of the DMD.

  The reflecting prism 80 transmits the light emitted from the illumination optical system 120 to the DMD 70 side, and reflects the light emitted from the DMD 70 to the projection optical system 110 side.

(Embodiment 1)
Hereinafter, the projection display system according to the first embodiment will be described.

  FIG. 4 is a perspective view showing a projection display system 400 according to the first embodiment. A projection display apparatus 400 according to Embodiment 1 includes a projection display apparatus 100 that emits image light, and a screen 300 on which the image light from the projection display apparatus 100 is projected.

  The screen 300 according to Embodiment 1 has a property that can be reversibly changed between a transparent state and a clouded state or a colored state in accordance with a temperature change of the screen 300. The screen 300 can be realized by including, for example, a known thermochromic material. In this case, the screen 300 is a transparent glass or film at room temperature, but becomes cloudy and becomes a white screen when it exceeds 35 degrees, for example. In the projection display system 400 according to the first embodiment, the projection display apparatus 100 is installed on a desk using this glass material as a top plate, and the top plate is used when it is necessary to project image light. When the screen 300 is heated and no image light is projected, it is configured as a normal glass table.

  Although not shown in FIG. 4, inside the housing 200 of the projection display apparatus 100, the projection optical system 110 that functions as an emitting unit that emits image light, and the image light emitted from the projection optical system 110 are received. A reflecting mirror 112 that functions as a reflecting part for reflecting is housed.

  The projection port 210 is an opening provided on one surface of the housing 200 in order to pass the image light reflected from the reflection mirror 112. In the projection display apparatus 100 according to the first embodiment, unlike the example shown in FIG. 3, the projection image display apparatus 100 is provided on the surface of the housing 200 on the surface where the projection port 210 is provided. An exhaust heat unit that conducts heat to the screen 300 is provided.

  Specifically, the exhaust heat unit includes an exhaust port 240 for exhausting the gas inside the projection display apparatus 100, and the exhaust port 240 is connected to the screen 300 and the housing so that the exhausted gas is directed to the screen 300. It is formed in the vicinity of the bottom surface 220 of the housing that is in contact with the body 200. A cooling fan 130 is provided inside the housing 200 at a position in contact with the exhaust port 240. The cooling fan 130 blows heat generated when the projection display apparatus 100 is driven onto the screen 300 through the exhaust port 240. . The air discharged from the exhaust port 240 flows in the direction away from the exhaust port 240, that is, in the height direction of the image projected on the screen 300 by the projection display apparatus 100, and warms the screen 300. The other heat that warms the screen 300 spreads in the width direction of the image projected on the screen 300 by diffusion.

  As described above, the screen 300 includes a member whose light transmittance reversibly changes depending on the temperature, and includes a thermochromic material in which the light transmittance is lower when the temperature of the member is higher than when the temperature is low. It is out. For this reason, when the heated air in the projection display apparatus 100 is blown through the exhaust port 240, the screen 300 becomes cloudy and the light transmittance decreases, and the projection of the image light is possible. In FIG. 4, the closed region indicated by the reference numeral 322 is the projectable region 322, and the display unit 320 fits inside the projectable region 322.

  FIG. 5 is a schematic diagram illustrating an example of the arrangement of the internal configuration of the projection display apparatus 100 according to the first embodiment. FIG. 5A is a diagram illustrating an arrangement example of the internal configuration when the projection display 100 is viewed from the front, and FIG. 5B is a view when the projection display 100 is viewed from the side. It is a figure which shows the example of arrangement | positioning of an internal structure.

  As described above, the projection display apparatus 100 includes the substantially rectangular parallelepiped casing 200 and the projection optical system 110 at the center thereof. The image light emitted from the projection optical system 110 is reflected by the reflection mirror 112, which is an aspherical mirror on the top surface side of the housing 200, and then projected onto the screen 300 through the projection port 210. The projection display apparatus 100 includes an illumination optical system 120 on the bottom side of the projection optical system 110. Although not shown in FIGS. 5 (a) and 5 (b), the illumination optical system 120 includes each color LED light source that emits red (R) light, green (G) light, and blue (B) light, and a light source. It has an integrator optical system and a relay optical system for uniformly illuminating the emitted light on the DMD panel that is the modulation element.

  Of the constituent members of the projection display apparatus 100, members serving as heat sources are mainly LED light sources, DMDs, and LED drivers. These are each cooled by air cooling. The R light source, the B light source, the DMD, and the LED driver include a heat sink (HS), and release heat generated in each device into the air in the housing. The G light source moves heat with a heat pipe (HP) and then releases heat into the air with a heat sink. The cooling system 190 of the projection display apparatus 100 is configured by the heat sink, the heat pipe, the cooling fan 130, the exhaust port 240, and the like. The heat source and the cooling system 190 are arranged around the illumination optical system 120 and in the vicinity of the bottom surface of the housing 200, and heat-containing gas is discharged to the outside of the housing 200 from the exhaust port 240 near the bottom surface of the housing 200. Is done. In the example shown in FIG. 5, the circuit system 180 that drives the projection display apparatus 100 is disposed on the back and side surfaces of the projection lens.

  FIG. 5 is a diagram illustrating an example of the case where the heat source and the cooling system 190 are arranged near the bottom surface of the housing 200. However, it is essential to arrange the heat source and the cooling system 190 near the bottom surface of the housing 200. is not. Regardless of the position of the heat source in the housing 200, heat can be radiated from the exhaust port 240 by moving heat to the bottom surface of the housing 200 using a heat pipe.

  As described above, according to projection-type image display system 400 according to Embodiment 1 of the present invention, a desk on which a projector that projects an image and a desk that includes a screen on which the image is projected as a top plate are integrated. Type image projection system can be provided. The top plate of the desk constituting the projection display system 400 is transparent when no image is projected, and becomes a screen for capturing image light when the projector is in use. Thereby, although it is a glass table normally, it can be made cloudy when projecting image light, and the area | region required for projection can be made into the screen 300. FIG. Compared to the case where a normal screen and a projector are integrated, it is possible to provide an environmentally harmonious screen that is superior in design and harmonizes with the environment. Technology can be provided.

(Embodiment 2)
Hereinafter, a projection display system according to Embodiment 2 will be described.

  FIG. 6 is a perspective view showing a projection display system 400 according to the second embodiment. A projection display apparatus 400 according to Embodiment 2 includes a projection display apparatus 100 that emits image light, and a plate-like member 302 that includes a screen 300 on which the image light from the projection display apparatus 100 is projected. And a support member 330 that is pivotally attached to the plate-like member 302. Here, the support member 330 is pivotally attached to the plate-like member 302 on the first surface 332 side, and is a surface different from the first surface 332, and is projected on the second surface 334 orthogonal to the first surface 332. The bottom surface 220 of the device 100 is connected. In the example of the projection display system 400 shown in FIG. 6, a foot 340 that supports the plate member 302 is connected to the plate member 302, and the plate member 302 and the foot 340 constitute a desk.

  It should be noted that “the support member 330 and the projection display apparatus 100 are connected” is sufficient if the support member 330 and the projection display apparatus 100 can move together. It does not mean that the projection display 100 is fixed in an inseparable manner. The support member 330, the projection display apparatus 100, and a known lock mechanism may be used, and both may be detachable. This is because the projection display apparatus 100 can be used alone.

  FIG. 7 is a perspective view showing an example of the rotation direction of the support member 330 in the projection display system 400 according to Embodiment 2. FIG. In the projection display system 400 according to Embodiment 2, the support member 330 connected to the bottom surface 220 of the projection display apparatus 100 arranges the projection display apparatus 100 on the screen 300 side of the plate-like member 302. It can be rotated between a first position and a second position where the projection display apparatus 100 is disposed on the opposite side of the plate-like member 302 from the screen 300.

  FIG. 7A is a perspective view illustrating a state in which the support member 330 is positioned between the first position and the second position by rotation. In the example shown in FIG. 7A, the support member 330 is centered on a rotation axis 500 parallel to the height direction of the image formed on the screen 300 by the image light projected on the screen 300 by the projection display apparatus 100. To turn. In FIG. 7A, “the height direction of the image formed on the screen by the image light projected on the screen by the projection display apparatus 100” is an orthogonal coordinate system stretched on the plate-like member 302. The direction is parallel to the “y-axis”. In the example illustrated in FIG. 7A, the rotation shaft 500 is orthogonal to the first surface 332 of the support member 330.

  FIG. 7B is a perspective view illustrating a state in which the support member 330 is positioned at the second position by the rotation about the rotation shaft 500. As illustrated in FIG. 7B, when the support member 330 is located at the second position, the projection port 210 of the projection display apparatus 100 is compared with the case where the support member 330 is located at the first position. , Located on the opposite side of the plate-like member 302.

  In this way, a rear projection (desk rear projection) type system in which the projection display apparatus 100 is projected from the back side of the screen 300 by configuring the support member 330 to be rotatable about the rotation axis 500 is provided. It is also possible. In this case, the screen 300 is configured using a translucent member (rear screen) capable of rear projection. When the support member 330 is disposed at the first position and the projection display apparatus 100 performs front projection, visibility is ensured by covering the screen 300 with, for example, paper.

  Accordingly, it is possible to achieve both front projection and rear projection with one desk included in the projection display system 400. Depending on the application, for example, front projection is used for writing in projected images, and rear projection is used for sharing information displayed by multiple people using a desk widely. Thus, it is possible to select a projection method, and it is possible to provide a projection display system 400 that is convenient for the user.

  FIG. 8 is a perspective view showing another example of the support member 330 in the projection display system 400 according to Embodiment 2. In FIG. In FIG. 8, only a part of the plate-like member 302 is shown to avoid complication. Further, only the bottom surface 220 of the projection display apparatus 100 connected to the support member 330 is shown, and the main body of the projection display apparatus 100 is not shown.

  In the example shown in FIG. 8, the support member 330 rotates around a rotation axis 502 parallel to the width direction of the image formed on the screen 300 by the image light projected on the screen 300 by the projection display apparatus 100. . In FIG. 8, “the width direction of the image formed on the screen by the image light projected on the screen by the projection display apparatus 100” is the “x axis” of the orthogonal coordinate system stretched on the plate-like member 302. Parallel to the direction. In the example illustrated in FIG. 7A, the rotation shaft 502 is parallel to the first surface 332 and the second surface 334 of the support member 330.

  When the support member 330 moves from the first position to the second position about the rotation shaft 502, a plate-like member is included in the space scanned by the projection display apparatus 100 connected to the support member 330. A part of 302 exists. Therefore, the partial member 350 that is a part of the plate-like member 302 and includes a space that the projection display apparatus 100 scans as the support member 330 rotates is provided in the projection display apparatus 100. Is configured to be evacuated from the scanning space. Specifically, as shown in FIG. 8, the partial member 350 is configured to be slidable in a direction parallel to the y-axis, and the projection display apparatus 100 scans as the support member 330 rotates. Can be evacuated from space.

  FIG. 9 is a perspective view showing a state in which the support member 330 is positioned between the first position and the second position by the rotation about the rotation shaft 502. As shown in FIG. 9, the partial member 350 is retracted from the space scanned by the projection display apparatus 100, and the projection display apparatus 100 can rotate without being blocked by the plate-like member 302.

  FIG. 10 is a perspective view showing the rotation direction of the projection display apparatus 100 according to the second embodiment. A support member 330 (not shown in FIG. 10) for connecting the projection display apparatus 100 has a rotation axis 504 perpendicular to the surface in contact with the bottom surface 220 of the projection display apparatus 100, that is, the second surface of the support member 330. It has more. The projection display apparatus 100 is pivotally attached to the support member 330 by a rotation shaft 504, and the projection display apparatus 100 is configured to be rotatable about the rotation shaft 504.

  With this configuration, according to the projection display system 400 according to the second embodiment, even when the direction of the user and the projection screen changes, for example, when the user surrounds the projection display apparatus 100, By rotating the projection display apparatus 100 around the rotation shaft 504, the optimum state can be easily achieved.

  Further, as shown in FIGS. 8 and 9, it is assumed that the support member 330 is disposed at the second position when the support member 330 rotates about the rotation shaft 502. At this time, it is necessary to further rotate the projection display apparatus 100 on the back surface of the plate-shaped member 302 in order to cause the projection display apparatus 100 to project the image light rearward in the same direction as when projecting the image light to the front. This can be realized by rotating the projection display apparatus 100 about the rotation shaft 504.

  As described above, according to the projection display system 400 according to the second embodiment, a single desk included in the projection display system 400 can be configured to achieve both front projection and rear projection. it can. It is possible to select a projection method according to the user's application, and it is possible to provide the projection display system 400 that is highly convenient for the user.

  The first and second embodiments have been described above. Combinations of these embodiments are also useful as embodiments of the present invention. A new embodiment resulting from the combination has the effect of each of the combined embodiments.

  The present invention has been described based on some embodiments. Those skilled in the art will understand that these embodiments are exemplifications, and that various modifications can be made to combinations of the respective constituent elements and processing processes, and such modifications are also within the scope of the present invention. By the way.

  In the first embodiment, the case where the temperature of the screen 300 is changed by blowing hot air from the exhaust port 240 onto the screen 300 has been described. However, the mechanism for changing the temperature of the screen 300 is not limited to this. I can't. For example, a heat sink or a heat spreader may be disposed on the bottom surface 220 of the projection display apparatus 100, and a part thereof may protrude from the housing 200 of the projection display apparatus 100 toward the screen 300. .

  As a result, heat generated by driving the projection display apparatus 100 is conducted to the screen 300 through a part of the heat sink or heat spreader protruding toward the screen 300, and the screen 300 is heated. Since the projection display system 400 according to Embodiment 1 is a desktop projection display system with a short projection distance, it is considered that the projection display apparatus 100 and the user are often close to each other. In the case of a configuration in which hot air is blown from the exhaust port 240 to the screen 300, it is assumed that the hot air hits the user, and it cannot be said that the user is bothered. If it is set as said structure, the discharge | emission of the gas heated from the projection type video display apparatus 100 can be reduced.

  In Embodiment 1 described above, the screen 300 has been described for the case where the light transmittance changes reversibly according to the temperature. However, the physical quantity for changing the light transmittance of the screen 300 is not limited to the temperature, For example, a current may be used. That is, the screen 300 may be configured using a known electrochromic material whose light transmittance reversibly changes depending on the magnitude of the current flowing through the screen 300. In this case, it can be realized by applying a conductive material around the display unit 320 of the screen 300 and supplying power from the power source of the projection display apparatus 100. Since the current speed is generally faster than the heat diffusion speed, it is advantageous in that the response time until the light transmittance is changed can be shortened as compared with the case where the temperature of the screen 300 is controlled.

  DESCRIPTION OF SYMBOLS 10 Light source, 30 Dichroic prism, 40 Rod integrator, 51 1st mirror, 52 2nd mirror, 61 1st lens, 62 2nd lens, 63 3rd lens, 70 DMD, 80 reflective prism, 100 Projection type image display apparatus, DESCRIPTION OF SYMBOLS 110 Projection optical system, 111 Projection lens group, 112 Reflection mirror, 120 Illumination optical system, 130 Cooling fan, 140 Battery, 150 Power supply board, 160 Main control board, 170 Operation board, 180 Circuit system, 190 Cooling system, 200 Case , 210 projection port, 220 bottom surface, 230 second surface, 240 exhaust port, 300 screen, 302 plate member, 320 display unit, 322 projectable area, 330 support member, 332 first surface, 334 second surface, 350 part Wood, 400 projection display system, 500, 502, 504 rotation axis.

Claims (6)

A projection display device that emits image light; and
A screen on which image light from the projection display apparatus is projected,
The screen is a member whose light transmittance is reversibly changed according to the temperature of the screen, and the light transmittance is lower when the temperature of the member is higher than when the temperature is low. Has been
The projection display apparatus includes a heat exhaust unit that conducts heat in the projection display to the screen. The exhaust heat unit includes an exhaust port for exhausting the gas inside the projection display apparatus,
The projection image display system according to claim 1, wherein the exhaust port is formed so that a gas to be exhausted is directed to the screen. A projection display device that emits image light; and
A plate-like member including a screen on which image light from the projection display apparatus is projected;
The first surface side is pivotally attached to the plate-like member, and a support member that connects a bottom surface of the projection display apparatus to a second surface orthogonal to the first surface,
The support member has a first position where the projection display apparatus is disposed on the screen side of the plate-shaped member, and a second position where the projection display apparatus is disposed on the opposite side of the screen of the plate-shaped member. A projection-type image display system that is rotatable between positions. The support member includes a shaft for rotating the projection display apparatus between a first position and a second position;
The projection image display system according to claim 3, wherein the axis is parallel to a height direction of an image formed on the screen by the image light projected on the screen by the projection image display device. The support member includes a shaft for rotating the projection display apparatus between a first position and a second position;
4. The projection display system according to claim 3, wherein the axis is parallel to a width direction of an image formed on the screen by the image light projected on the screen by the projection display apparatus.   The said support member is further provided with the axis | shaft for rotating the said projection type video display apparatus centering on the axis | shaft perpendicular | vertical to the 2nd surface of the said support member. Projection image display system.

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