The present invention relates to a projection display apparatus having a projection optical unit for projecting image light on a projection plane.
Conventionally, there has been known a projection display apparatus having: a light valve for modulating light emitted from a light source; and a projection lens for projecting the light emitted from the light valve on a projection plane (screen).
Hence, a long distance between the projection lens and the screen needs to be assured for displaying a large-size image on the screen. In contrast to this, a projection display system has been proposed which aims to shorten a distance between the projection display apparatus and the screen by using a reflection mirror for reflecting the light emitted from the projection lens, toward the screen side (for example, Japanese Patent Application Publication No. 2006-235516).
With the aim of shortening a distance between the projection display apparatus and the screen, the projection display apparatus becomes in proximity to the screen, and the projection display apparatus becomes within a user's field of view. Thus, there is a need to perform vertically or laterally oblique projection of the screen. For example, in the above-described projection display system, a projection distance is shortened and oblique projection is performed by shifting a positional relationship between a light valve and a projection optical unit in a vertical direction and employing a concave mirror as a reflection mirror.
Incidentally, as a method of setting up a projection display apparatus which aims to shorten a projection distance, there is considered a new setup method, such as a method of setting up a projection display apparatus on a wall surface or the like, since the device is capable of projecting an image even in a small space, or alternatively, a method of setting up a projection display apparatus on a ceiling or a floor surface. On the other hand, a screen provided on a projection plane is not considered so much.
A first aspect of a projection display apparatus, includes: an image light generating unit (image light generating unit 200) configured to generate image light; and a projection optical unit (projection optical unit 300) configured to project the image light on a projection plane (projection plane 210). The projection optical unit has a reflection mirror (reflection mirror 320) configured to reflect the image light emitted from the image light generating unit. The projection display apparatus further includes a screen (screen 220) provided on the projection plane. The screen is switchably configured as to whether to diffuse the image light reflected by the reflection mirror or to transmit the image light reflected by the reflection mirror.
According to the above aspect, the screen is switchably configured as to whether or not the image light reflected by the reflection mirror forms an image. Therefore, the display/non-display of an image can be readily switched.
In the first aspect, the screen comprised of a dispersive liquid crystal. The dispersive liquid crystal adjusts a diffusion ratio of the image light reflected by the reflection mirror, in accordance with a voltage applied to the dispersive liquid crystal.
In the first aspect, the screen has an image forming region (image forming region 220a) in which an image is comprised of the image light, and a non-image forming region (non-image forming region 220b) in which an image is not comprised of the image light. The screen is configured to be slidable on the projection plane. The non-image forming region is comprised of a light-transmissive member and is adjacent to the image forming region in a sliding direction of the screen.
In the first aspect, the projection display apparatus further includes a protection cover (protection cover 400 provided on an optical path of the image light reflected by the reflection mirror. The protection cover has a transmissive region (transmissive region 410) for transmitting the image light. The reflection mirror focuses the image light emitted from the image light generating unit, between the reflection mirror and the projection plane. The transmissive region is disposed in proximity to a position at which the image light is focused by the reflection mirror.
In the first aspect, the protection cover has an opening communicating from a side of the reflection mirror to a side of the projection plane. The transmissive region is the opening.
In the first aspect, at least part of the protection cover is comprised of a light-transmissive member. The transmissive region is comprised of the light-transmissive member.
In the first aspect, the screen includes a first screen and a second screen. A respective one of the first screen and the second screen is switchably configured as to whether to diffuse the image light reflected by the reflection mirror or to transmit the image light reflected by the reflection mirror.
In the first aspect, the screen is comprised of a plurality of regions. The screen is switchably configured, in a respective one of the plurality of regions as to whether to diffuse the image light reflected by the reflection mirror or to transmit the image light reflected by the reflection mirror.
Hereinafter, a projection display apparatus according to embodiments of the present invention will be described with reference to the drawings. In the following description of the drawings, the same or similar reference signs are attached to the same or similar units and portions.
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. Moreover, as a matter of course, the drawings also include portions having different dimensional relationships and ratios from each other.
Hereinafter, a configuration of a projection display apparatus according to a first embodiment will be described with reference to the drawings.
As shown in
The image light generating unit 200 generates image light. Specifically, the image light generating unit 200 has at least a display element 40 for emitting image light. The display element 40 is provided at a position which is shifted relative to an optical axis L of the projection optical unit 300. The display element 40 is a reflective liquid crystal panel, a transmissive liquid crystal panel, a DMD (Digital Micromirror Device) or the like, for example. A detailed description of the image light generating unit 200 will be given later (see
The projection optical unit 300 projects the image light emitted from the image light generating unit 200. Here, the projection optical unit 300 projects the image light on a projection plane 210 (screen 220). Specifically, the projection optical unit 300 has a projection lens 310 and a reflection mirror 320.
The projection lens 310 emits the image light emitted from the image light generating unit 200, to the side of the reflection mirror 320.
The reflection mirror 320 reflects the image light emitted from the projection lens 310. The reflection mirror 320 widely angles the image light after focusing the image light. The reflection mirror 320 is a non-spherical mirror having a concave face on the side of the image light generating unit 200, for example.
The protection cover 400 is a cover for protecting the reflection mirror 320. The protection cover 400 is provided on an optical path of the image light reflected by the reflection mirror 320. The protection cover 400 has a transmissive region 410 for transmitting image light. That is, the transmissive region 410 transmits the image light reflected by the reflection mirror 320 to the side of the screen 220.
In this manner, the projection optical unit 200 projects the image light transmitting the transmissive region 410 on the screen 220 provided on the projection plane 210.
The screen 220 is provided on the projection plane 210 on which image light is to be projected. The screen 220 is switchably configured as to whether to diffuse the image light reflected by the reflection mirror 320 or transmit the image light reflected by the reflection mirror 320. In other words, the screen 220 is switchably configured as to whether or not an image is formed by the image light reflected by the reflection mirror 320. The screen 220 is a screen comprised of a dispersive liquid crystal, for example. The dispersive liquid crystal, as described later, adjusts a diffusion ratio of the image light reflected by the reflection mirror 320, in accordance with a voltage to be applied to the dispersive liquid crystal (see
It is preferable that the screen 220 is transparent. In addition, the screen 220 may be a reflective screen or may be a transmissive screen.
(Configuration of Image Light Generating Unit)
Hereinafter, a configuration of an image light generating unit according to the first embodiment will be described with reference to the drawings.
The image light generating unit 200 has a light source 10, a fly-eye lens unit 20, a Polarizing Beam Splitter (PBS) array 30, a plurality of liquid crystal panels 40 (liquid crystal panel 40R, liquid crystal panel 40G, liquid crystal panel 40B), and a crass-dichroic prism 50.
The light source 10 is a UHP lamp or the like comprised of a burner and a reflector. The light emitted from the light source 10 includes red component light, green component light, and blue component light.
The fly-eye lens unit 20 uniformizes the light emitted from the light source 10. Specifically, the fly-eye lens unit 20 is comprised of a fly-eye lens 20a and a fly-eye lens 20b.
The fly-eye lens 20a and the fly-eye lens 20b are comprised of a plurality of micro-lenses, respectively. Each micro-lens focuses the light emitted from the light source 10 so that the light emitted from the light source is irradiated to all over the liquid crystal panel 40.
The PBS array 30 coordinates a polarization state of the light emitted from the fly-eye lens unit 20. In the first embodiment, the PBS array 30 coordinates the light emitted from the fly-eye lens 20 with P-polarization.
The liquid crystal panel 40R modulates red component light by rotating the polarization direction of the red component light. An incidence-side polarization plate 41R, for transmitting the light having one polarization direction (for example, P-polarization) and interrupting the light having the other polarization direction (for example, S-polarization), is provided on the light-incidence plane side of the liquid crystal panel 40R. An emission-side polarization plate 42R, for interrupting the light having one polarization direction (for example, P-polarization) and transmitting the light having the other polarization direction (for example, S-polarization), is provided on the light-emission plane side of the liquid crystal panel 40R.
Similarly, the liquid crystal panel 40G and the liquid crystal panel 40B modulate green component light and blue component light by rotating the polarization direction of the green component light and the blue component light, respectively. The incidence-side polarization plate 41G is provided on the light-incidence plate side of the liquid crystal panel 400 and an emission-side polarization plate 42G is provided on the light-emission plane side of the liquid crystal panel 40G. An incidence-side polarization plate 41B is provided on the light-incidence plane side of the liquid crystal panel 40B and an emission-side polarization plate 42B is provided on the light-emission plane side of the liquid crystal panel 40B.
The cross-dichroic prism 50 combines the light emitted from the liquid crystal panel 40R, the liquid crystal panel 40G, and the liquid crystal panel 40B with each other. The cross-dichroic prism 50 emits the combined light to the side of the projection lens 310.
In addition, the image light generating unit 200 has: a mirror group (dichroic mirror 111, dichroic mirror 112, reflection mirror 121 to reflection mirror 123); and a lens group (condenser lens 131, condenser lens 140R, condenser lens 1400, condenser lens 140B, relay lens 151 and relay lens 152).
The dichroic mirror 111 transmits red component light and green component light of the light emitted from the PBS array 30. The dichroic mirror 111 reflects blue component light of the light emitted from the PBS array 30.
The dichroic mirror 112 transmits red component light of the light transmitting the dichroic mirror 111. The dichroic mirror 112 reflects green component light of the light transmitting the dichroic mirror 111.
The reflection mirror 112 reflects blue component light and guides the reflected light to the side of the liquid crystal panel 4013. The reflection mirror 122 and the reflection mirror 123 reflect red component light and guide the reflected light to the side of the liquid crystal panel 40R.
The condenser lens 131 is a lens for focusing incandescent light emitted from the light source 10.
The condenser lens 140R substantially collimates red component light so that the liquid crystal panel 40R is irradiated with the red component light. The condenser lens 140G substantially collimates green component light so that the liquid crystal panel 40G is irradiated with the green component light. The condenser lens 140B substantially collimates blue component light so that the liquid crystal panel 40B is irradiated with the blue component light.
The relay lens 151 and the relay lens 152 substantially form an image with the red component light on the liquid crystal panel 40R while restraining expansion of the red component light.
(Configuration of Dispersive Liquid Crystal)
Hereinafter, a dispersive liquid crystal configuring the screen 220, according to the first embodiment, will be described with reference to the drawings.
As shown in
The transparent conductive film 221 is a transparent film having conductivity. Indium Tin Oxide (ITO) can be employed as the transparent conductive film 221, for example.
The liquid crystal capsule 222 is comprised of the plurality of liquid crystal elements 222a. As the liquid crystal element 222a, for example, a nematic liquid crystal or a cholesteric liquid crystal can be employed. The liquid crystal capsule 222 disperses in the polymer 223.
The polymer 223 is comprised of a high polymer. As the high polymer, polymethyl methacrylate (PMMA) can be employed, for example. The polymer 223 is filled between the transparent conductive film 221a and the transparent conductive film 221b.
Here, as shown in
On the other hand, as shown in
It is preferable that a ratio (transmission/diffusion ratio) of a dispersive liquid crystal diffusing image light is adjustable in accordance with a voltage applied to the transparent conductive film 221. In addition, in a case in which the screen 220 is a reflective screen as well, it is also preferable that a ratio (reflection/diffusion ratio) of the dispersive liquid crystal diffusing image light is adjustable in accordance with the voltage applied to the transparent conductive film 221.
Here, from the viewpoint of energy saving or the like, it is preferable that the screen 220 is configured in a state in which image light is diffused in a case where no voltage is applied. In this manner, in a case where the projection display apparatus 100 is not powered on, a voltage does not need to be applied to the screen 220, disabling an object or the like provided on the rear side of the screen 220 to be seen by default.
In addition, from the viewpoint of energy saving or the like, in a case where the screen 220 is controlled in a state in which image light is transmitted, it is preferable that the projection display apparatus 100 is powered off. In a case where the screen 220 is controlled in a state in which image light is transmitted, there is no need for the image light from the projection display apparatus 100, thus enabling energy saving to be achieved by turning off the power of the projection display apparatus 100.
(Image Display Example(s))
Hereinafter, image display examples according to the first embodiment will be described with reference to the drawings.
First, a case in which the screen 220 is provided on a wall surface will be described with reference to
As shown in
As described above, in a case where no voltage is applied to the screen 220, the image light emitted from the projection display apparatus 100 forms an image on the screen 220. Therefore, a user can see the image formed on the screen 220.
On the other hand, in a case where a voltage is applied to the screen 220, the image light emitted from the projection display apparatus 100 does not form an image on the screen 220. Here, in a case where the voltage is applied to the screen 220, it is preferable that the projection display apparatus 100 provides black display. That is, no image light is emitted from the projection display apparatus 100. As described above, since the screen 220 is transparent, a user can see an opposite scene of the screen 220 from the user's field of view.
In “black display”, for example, a polarization plate provided at the light incidence-side or light emission-side of the display element 40 interrupts the light emitted from a light source 10. That is, it should be kept in mind that the light source 10 does not need to migrate to a non-illuminative state. In the “black display”, the light source 10 may migrate to the non-illuminative state”.
As the cases shown in
Next, a case in which the screen 220 is provided on a floor surface will be described with reference to
As shown in
As described above, in a case where no voltage is applied to the screen 220, the image light emitted from the projection display apparatus 100 forms an image on the screen 220. Therefore, a user can see the image formed on the screen 220.
On the other hand, in a case where a voltage is applied to the screen 220, the image light emitted from the projection display apparatus 100 does not form an image on the screen 220. Here, in a case where a voltage is applied to the screen 220, it is preferable that the projection display apparatus 100 provides black display. That is, no image light is emitted from the projection display apparatus 100. As described above, since the screen 220 is transparent, a user can see an opposite scene of the screen 220 from the user's field of view.
As the cases shown in
In the case shown in
(Function(s) and Advantageous Effect(s))
In the first embodiment, the protection cover 400 is provided on an optical path of the image light that is reflected by the reflection mirror 320. Therefore, an angle or the like of the reflection mirror 320 can be restrained from being varied by a user touching the reflection mirror 320. In addition, the protection cover 400 has a transmissive region 410 for transmitting the image light reflected by the reflection mirror 320. Therefore, the image light emitted on the screen 220 provided on the projection plane 210 is never interrupted by the protection cover 400. In this manner, the disposition precision of the reflection mirror 320 provided to shorten a distance between the projection display apparatus 100 and the screen 220 can be appropriately maintained.
In the first embodiment, the screen 220 is switchably configured as to whether or not the image light reflected by the reflection mirror 320 forms an image. Therefore, the display/non-display of an image can be readily switched.
In addition, in a case where the screen 220 is not illuminated with the image light reflected by the reflection mirror 320, where the screen 220 is transparent, the opposite scene of the screen 220 from the user's field of view and an image can be switched as an object to be shown to a user.
Hereinafter, a second embodiment will be described with reference to the drawings. Hereinafter, differences between the first embodiment and the second embodiment will be mainly described.
In the first embodiment, the screen 220 is comprised of a dispersive liquid crystal. On the other hand, in the second embodiment, the screen 220 has an image forming region and a non-image forming region, and is configured to be slidable on the projection plane 210.
(Screen Configuration)
Hereinafter, a configuration of a screen according to the second embodiment will be described with reference to the drawings.
The image forming region 220a is a region in which the image light reflected by the reflection mirror 320 forms an image. The image forming region 220a has a configuration which is similar to that of a reflective screen or a transmissive screen.
The non-image forming region 220b is a region in which the image light reflected by the reflection mirror 320 does not form an image. The non-image forming region 220b is adjacent to the image forming region 220a in a sliding direction of the screen 220. The non-image forming region 220b is comprised of a light-transmissive member.
It is preferable that the non-image forming region 220b has its shape and size which are substantially similar to those of the image forming region 220a.
(Screen Sliding)
Hereinafter, sliding of the screen according to the second embodiment will be described with reference to the drawings.
As shown in
The winding mechanism 230a and the winding mechanism 230b have a mechanism of winding the screen 220. Similarly, the winding mechanism 230a and the winding mechanism 230b have a mechanism of feeding out the screen 220. For example, the winding mechanism 230a and the winding mechanism 230b are turnably configured around a rotary shaft 231a and a rotary shaft 231b, respectively.
As shown in
In this manner, the screen 220 is configured to be slidable on the projection plane 210 by means of the winding mechanism 230.
As a matter of course, a method of sliding the screen 220 is not limitative to winding of the screen 220.
(Function(s) and Advantageous Effect(s))
In the second embodiment, the screen 220 is configured to be slidable on the projection plane 210. Therefore, a configuration, which is capable of switching whether or not the image light emitted from the projection display apparatus 100 forms an image even without a need to employ a screen comprised of a dispersive liquid crystal, can be achieved with ease and at a low cost.
Hereinafter, a third embodiment will be described with reference to the drawings. The third embodiment describes examples of application of the above-described projection display apparatus 100.
First, a case in which the screen 220 is provided at a display window's glass at a shop will be described with reference to
As shown in
On the other hand, as shown in
Subsequently, a case in which the screen 220 is provided at a shop's display window will be described with reference to
As shown in
On the other hand, as shown in
Hereinafter, a fourth embodiment will be described with reference to the drawings. Hereinafter, differences from the first embodiment will be mainly described.
Specifically, in the fourth embodiment, a screen includes a first screen and a second screen, and a respective one of the first and second screens is switchably configured as to whether to diffuse image light or transmit image light.
(Screen Configuration)
Hereinafter, a configuration of a screen according to the fourth embodiment will be described with reference to the drawings.
As shown in
A respective one of the first screen 510 and the second screen 520 has a configuration which is similar to that of the screen 220. For example, the respective one of the first screen 510 and the second screen 520 is comprised of a dispersive liquid crystal or the like.
Specifically, the respective one of the first screen 510 and the second screen 520 is switchably configured as to whether to diffuse the image light reflected by the reflection mirror 320 or transmit the image light reflected by the reflection mirror 320.
As shown in
As shown in
As shown in
Here, as shown in
On the other hand, as shown in
In this manner, a viewing angle priority (see
(Image Display Example(s))
Hereinafter, image display examples according to the fourth embodiment will be described with reference to the drawings.
First, a case in which the projection display apparatus 100 is embedded beneath a floor and the screen 500 is provided on a floor surface will be described with reference to
As shown in
As shown in
As shown in
Second, a case in which the projection display apparatus 100 is embedded in a wall and the screen 500 is provided on a wall surface will be described with reference to
As shown in
As shown in
As shown in
Although not set forth in the fourth embodiment, the user's position may be detected by means of a sensor or a camera provided on a wall surface or a floor surface.
(Function(s) and Advantageous Effect(s))
In the fourth embodiment, the screen 500 includes the first screen 510 and the second screen 520. The respective one of the first screen 510 and the second screen 520 transmits the image light reflected by the reflection mirror 320 or diffuses the image light reflected by the reflection mirror 320.
Therefore, the directivity of the image light emitted from the projection display apparatus 100 can be controlled. In addition, an image displayed on the screen 500 can be appropriately shown to a user in accordance with the user's position.
Hereinafter, a fifth embodiment will be described with reference to the drawings. Hereinafter, differences from the fourth embodiment will be mainly described.
Specifically, in the fifth embodiment, a screen has a plurality of dispersive liquid crystal films sandwiched between glass plates. The glass plates and the dispersive liquid crystal films are bonded with each other by means of adhesive.
(Screen Configuration)
Hereinafter, a configuration of a screen according to the fifth embodiment will be described with reference to the drawings.
As shown in
The respective one of the dispersive liquid crystal Mm 610 and the dispersive liquid crystal film 620 transmits the image light reflected by the reflection mirror 320 or diffuses the image light reflected by the reflection mirror 320. It is preferable that an interval between the dispersive liquid crystal Mm 610 and the dispersive liquid crystal Mm 620, namely, the thickness of the adhesive 652 is smaller than a pixel interval on the screen 600. For example, in a case where the size of the screen 600 is 100 inches and the pixel interval on the screen 600 is on the order of 500 microns, the interval between the dispersive liquid crystal film 610 and the dispersive liquid crystal film 620 is 20 microns.
Since the dispersive liquid crystal film 610 and the dispersive liquid crystal film 620 have a configuration which is similar to those of the first screen 510 and the second screen 520, a detailed description of the dispersive liquid crystal film 610 and the dispersive liquid crystal film 620 is omitted.
Hereinafter, a sixth embodiment will be described with reference to the drawings. Hereinafter, differences from the first embodiment will be mainly described.
Specifically, in the sixth embodiment, a screen is comprised of a plurality of regions. In addition, the screen is switchably configured as to whether or not to diffuse image light or transmit image light in a respective one of a plurality of regions.
(Screen Configuration)
Hereinafter, a configuration of a screen according to the sixth embodiment will be described with reference to the drawings.
As shown in
(Image Display Example(s))
Hereinafter, image display examples according to the sixth embodiment will be described with reference to the drawings.
First, utilization of the screen 700 will be described with reference to
As shown in
Second, a case in which the projection display apparatus 100 is provided on a ceiling and the screen 700 is disposed in substantially parallel to a wall surface 810 will be described with reference to
As shown in
As shown in
Therefore, as shown in
Third, a case in which the projection display apparatus 100 is embedded beneath a floor and the screen 700 is provided on a floor surface will be described with reference to
As shown in
(Alignment Processing)
Hereinafter, alignment processing according to the sixth embodiment will be described. Specifically, alignment between an image, which is displayed by the projection display apparatus 100, and the region 710, which is provided on the screen 700, will be described.
(1) The projection display apparatus 100 displays a white image, for example.
(2) An edge of the white image displayed by the projection display apparatus 100 is manually aligned with an edge of the screen 700.
(3) Among a plurality of regions 710 provided on the screen 700, any one region 710 is controlled in a dispersive state, and the remaining regions 710 are controlled in a transparent state.
(4) The region 710 in the dispersive state is picked up by means of an image pickup device provided in the projection display apparatus 100.
(5) The position (coordinate) of the region 710 in the diffusive state is specified by way of image picked up by means of the image pickup device.
(6) The positions (coordinates) of all, of the regions 710 are specified by performing the processes (3) to (5) as to all of the regions 710 provided on the screen 700.
In this manner, the positions (coordinates) of all of the regions 710 are specified by means of the projection display apparatus 100, so that the projection display apparatus 100 can project the image light to be projected on the region 710 (region 710B), on the region 710 (region 710B) on which an image is to be displayed. That is, the projection display apparatus 100 can display an appropriate image on the region 710 (region 710B).
(Function(s) and Advantageous Effect(s))
In the sixth embodiment, the screen 700 is comprised of the plurality of regions 710. The screen 700 is configured to switch whether to diffuse image light or transmit image light in a respective one of the regions 710. Therefore, it is possible to selectively use the region 710A (transparent state) for showing an object provided on the rear-plane side of the region 710 and the region 7108 (diffusive state) for showing an image displayed on the region 710. In this manner, application and usage of the projection display apparatus 100 expand.
As described above, the details of the present invention have been described by using the embodiments of the present invention. However, it should not be understood that the description and drawings which constitute part of this disclosure limit the present invention. From this disclosure, various alternative embodiments, examples, and operation techniques will be easily found by those skilled in the art.
Although not set forth in the foregoing embodiments in particular, the protection cover 400 may have an opening communicating from the reflection mirror 320 to the side of the projection plane 210. The transmissive region 410 may be such an opening.
Although not set forth in the foregoing embodiments in particular, at least part of the protection cover 400 may be comprised of a light-transmissive member such as a transparent resin or a glass. The transmissive region 410 may be comprised of such a light-transmissive member.
Although not set forth in the foregoing embodiments in particular, the reflection mirror 320 focuses the image light emitted from the image light generating unit 200, between the reflection mirror 320 and the projection plane 210. It is preferable that the transmissive region 410 is provided in proximity to a position at which image light is focused by means of the reflection mirror 320.
Although the foregoing embodiments illustrated a case in which a non-spherical mirror is employed as the reflection mirror 320, the reflection mirror 320 is not limitative thereto. For example, a free curved-face mirror may be employed as the reflection mirror 320. A spherical mirror may be employed as the reflection mirror 320 as long as contrivance is made as to aberration or resolution.
While the foregoing embodiments illustrated a case (triple-plate system) in which a plurality of display elements 40 are employed as constituent elements of the image light generating unit 200, the constituent elements of the image light generating unit 200 are not limitative thereto. A single display element 40 may be employed as a constituent element of the image light generating unit 200 (single-plate system).
According to each of the embodiments, as described above, a distance between a projection display apparatus and a projection plane is shortened by providing the reflection mirror 320. Therefore, image light can be restrained from being interrupted by a foreign object such as a person standing between the projection display apparatus and the projection plane. In addition, in a case where a laser diode (LD) is employed as a light source 10, a possibility that a person is irradiated with laser beams can be reduced.
In the fifth embodiment, a respective one of the first screen 510 and the second screen 520 is configured to transmit image light or diffuse image light in accordance with a voltage to be applied. However, the embodiment is not limitative thereto. For example, the following cases are considered.
(1) In a case in which a transparent state is not required, either one of the first screen 510 and the second screen 520 may be a diffusion film configured to diffuse image light irrespective of a voltage to be applied. In such a case, a state of the screen 500 can be switched between a highly directive state and a lowly directly state.
(2) In a case in which a highly directive state is not required, where a desired degree of diffusion is not obtained, two screens (first screen 510 and second screen 20) may be employed. In such a case, a state of the screen 500 can be switched between a highly directive state and a lowly directly state.
According to the present invention, there can be provided a projection display apparatus which is capable of readily switching display/non-display of an image, with the aim of shortening a distance between the projection display apparatus and a projection plane. The projection display apparatus can be employed in signage, amusement, catering establishment, multistory building or the like. A menu can be displayed on a screen by disposing the screen on a desk of catering establishment, for example. A screen is disposed on a floor surface of a higher floor of multistory building, whereby image display (diffusive state) and image non-display (transparent state) are switched from each other, enabling provision of a user-startling effect.
Number | Date | Country | Kind |
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2008-088347 | Mar 2008 | JP | national |
2009-068944 | Mar 2009 | JP | national |
This application is a continuing application according to 37 C.F.R. 1.53(b) and (j) of the international application number PCT/JP2009/056077 filed on Mar. 26, 2009, which in turn claims the benefit of Japanese patent application number 2008-088347, filed on Mar. 28, 2008 and Japanese application number 2009-068944, filed on Mar. 19, 2009, the disclosures of which applications are incorporated by reference herein.
Number | Date | Country | |
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Parent | PCT/JP2009/056077 | Mar 2009 | US |
Child | 12892140 | US |