JP2008129148A - Screen, rear projector, projection system - Google Patents

Abstract

A screen, a rear projector, and a projection system capable of improving image quality by reliably preventing scintillation due to projection light and avoiding occurrence of display unevenness and glare.
A screen of the present invention is a screen for displaying a projection image generated by a light modulation element, and includes a plurality of optical element elements (lens elements 32) capable of reflecting or transmitting light. The number of optical element elements is equal to or greater than the number of pixels of the projected image, the number of optical element elements in the horizontal direction is greater than or equal to the number of pixels in the horizontal direction of the projected image, and the number of optical element elements in the vertical direction is the projected image. And a plurality of light beams emitted from the plurality of optical element elements are converged at predetermined positions.
[Selection] Figure 7

Description

  The present invention relates to a screen, a rear projector, and a projection system.

  In recent years, projectors are rapidly spreading. In addition to front-type projectors used mainly for presentation purposes, rear-type projectors have recently been gaining recognition as a form of large-screen display. The greatest advantage of the projection-type image display device is that it can provide a product with the same screen size at a lower price than a direct-view display such as a liquid crystal television and a plasma display. However, recently, the cost of direct view type has also been reduced, and higher image quality performance is required for the projection type image display apparatus. The projector displays an image by irradiating light emitted from a light source to a light modulation element such as a liquid crystal light valve and enlarging and projecting the projection light modulated by the light modulation element on a screen. At this time, not only the image is displayed on the screen but also the viewer sees glare on the entire screen. This is due to luminance unevenness caused by light interference, and is called speckle noise or scintillation.

Here, the principle of scintillation generation will be briefly described.
As shown in FIGS. 28A and 28B, the light emitted from the light source 70 passes through a liquid crystal light valve (not shown) and is projected onto the screen 74. The projection light projected on the screen 74 is diffracted by a large number of scattering materials 72 included in the screen 74, and diffused by the scattering materials 72 acting like a secondary wave source. As shown in FIG. 28 (b), two spherical waves from the secondary wave source cause light intensification and weakening in accordance with the phase relationship between each other, thereby causing bright and dark stripes between the screen 74 and the viewer. A pattern (interference fringe) appears. When the viewer's eyes are focused on the image plane S where the interference fringes are generated, the viewer recognizes the interference fringes as scintillation that makes the screen glaring. Scintillation gives an uncomfortable feeling to a viewer who wants to see an image formed on the screen surface as if a veil, a lace cloth, a spider web, etc. are stretched between the screen surface and the viewer. In addition, the viewer sees a double image of the image on the screen and the scintillation and tries to match the viewpoint with each image, which causes great fatigue. Therefore, this scintillation gives a great stress to the viewer.

  By the way, in recent projectors, the development of a new light source that replaces the conventional high-pressure mercury lamp has been developed. In particular, the laser light source is a light source for next-generation projectors in terms of energy efficiency, color reproducibility, long life, and instantaneous lighting. Expectations are rising. However, the projection light on the screen by the laser light source has very high coherence because the phases of the light beams in the adjacent regions are aligned. Since the coherent length of the laser light may be several tens of meters, when the same light source is divided and recombined, the light synthesized through an optical path difference shorter than the coherent length causes strong interference. Therefore, scintillation (interference fringes) clearer than that of the high-pressure mercury lamp appears. Therefore, reduction of scintillation is an indispensable technique especially in the commercialization of projectors using laser light sources.

The following techniques have been proposed as measures for reducing such scintillation.
The technique described in Patent Document 1 optimizes the diffusibility of the screen, and describes a screen having a three-layer structure of a diffusion layer, a transparent layer (lenticular lens), and a diffusion layer. Thus, the randomness of the interference spots increases as the structure of the scattering layer becomes complicated. Therefore, if there are many fine components in interference spots (interference fringes with low spatial frequency), the interference fringes will be integrated and averaged by the afterimage characteristics of the human eye when any eye movement occurs, and the interference fringes will disappear. Arise. In particular, when moving images are viewed, the line of sight is frequently moved, so that an effect of reducing scintillation can be expected.

In Patent Document 2, light, an electric field, a magnetic field, heat, stress, and the like are applied to the light scattering layer, and the shape, relative positional relationship, and refractive index of the light scattering body contained in the light diffusion layer are temporally changed. A screen is disclosed. In this way, it is expected that scintillation is prevented from occurring by temporally changing the scattering distribution and phase of the scattered wave by the light diffusion layer.
Japanese Patent Laid-Open No. 11-038512 JP 2001-100316 A

  However, in Patent Document 1, since the scattering state of the final scattering surface is fixed, the phase distribution of the light beam in the space between the screen and the viewer, where interference between the light beams emitted from each point on the scattering surface is fixed. Has been. Therefore, the interference spot is visually recognized as a fixed image. Therefore, unless frequent line-of-sight movement occurs, the interference spots do not completely disappear, and in particular, a projector having a highly coherent laser light source can hardly obtain the effect. That is, no matter how high the scattering degree of the screen is, interference fringes will be visually recognized if the viewpoint is fixed. In addition, such countermeasures against high scattering cannot cause the original purpose of achieving high image quality because there is a risk of image blurring.

  In Patent Document 2, a great amount of driving energy is required to change the shape, relative positional relationship, refractive index, and the like of the light scatterer. In addition, when the above driving means is used, the energy transmission efficiency to the scattering layer is low, and vibration, sound, unnecessary electromagnetic waves, exhaust heat, and the like are generated, and there is a possibility that comfortable viewing is hindered. Furthermore, the size of the image changes in a configuration in which the scattering layer moves in the focus direction. As a result, the position of the contour line of the image in the horizontal direction also changes, causing image blurring.

  The present invention has been made in view of the above-described problems, and is capable of reliably preventing scintillation due to projection light and avoiding display unevenness and glare, thereby improving the screen quality and the rear. It is an object to provide a projector and a projection system.

  In order to achieve the above object, a screen of the present invention is a screen for displaying a projection image generated by a light modulation element, and includes a plurality of optical element elements capable of reflecting or transmitting light. And the number of the optical element elements equal to or greater than the number of pixels of the projection image, the number of the optical element elements in the horizontal direction being equal to or greater than the number of pixels in the horizontal direction of the projection image, and the vertical direction of the optical element elements Is greater than or equal to the number of pixels in the vertical direction of the projected image, and the plurality of light beams emitted from the plurality of optical element elements are focused at predetermined positions.

  The “number of pixels in the projection image (the number of pixels in the horizontal direction, the number of pixels in the vertical direction)” referred to here is not the number of pixels of the light modulation element, but the pixels of the actually displayed projection image It is a number. For example, the light modulation element has m pixels, but in actuality, m1 of the m pixels is black and does not contribute to the display, and m2 (= m−m1) is projected. A case where a screen on which an image is displayed is configured may be considered. In this case, the number of pixels of the projected image is m2. At this time, m2 or more optical element elements are sufficient, and display is possible thereby. The black display position may be, for example, the entire outer periphery of the frame portion or a part of the outer periphery. Further, when the number of pixels of the light modulation element is n and the number of pixels of the optical element element is p, if there is a relationship of n ≦ p, naturally, the number of pixels of the projected image and the number of pixels of the optical element element Since the magnitude relationship is the same, display is possible. Which part of the plurality of optical element elements is used for display when n <p is arbitrary.

  In conventional general screens, a large number of randomly arranged scattering materials serve as secondary wave sources, and overlapping spherical waves cause interference. On the other hand, the present inventor has realized that an image without scintillation can be realized by transmitting the image of the light modulation element to the viewer's retina without scattering. That is, the configuration of the screen of the present invention includes a plurality of optical element elements that can reflect or transmit light instead of the randomly arranged scattering materials. In addition, since the total number of optical element elements and the number in the horizontal and vertical directions are equal to or greater than the total number of pixels in the projection image and the number of horizontal and vertical pixels, all the optical element elements are included in the projection image. All the pixels correspond one-on-one. Since a plurality of light beams emitted from the plurality of optical element elements are focused on a predetermined position, as long as the viewer looks at the screen at this position, the light beams emitted from the optical element elements are viewed by the viewer. There is no overlap on the path to reach the retina. Thus, according to the screen of the present invention, scintillation can be reliably prevented.

  Further, according to the present invention, since it is not necessary to move the scattering layer as in the prior art, generation of unpleasant noise and vibration can be suppressed, and a quiet projector (projection system) can be constructed. Furthermore, since the image projection onto the screen is not accompanied by a light scattering phenomenon, the viewer can see a clear image without blur that cannot be obtained with a general screen.

As the optical element element, a mirror or a lens can be used.
By using a mirror for the optical element element, a reflective screen can be realized, and a front type projector (projection system) can be configured. Alternatively, a transmissive screen can be realized by using a lens for the optical element element, and a rear projector (projection system) can be configured. At this time, if the mirror and the lens are movable or the shape is optimized as will be described later, it is possible to give a slight diffusibility to the light toward the viewer.

  In the screen of the present invention, since light beams from a plurality of optical element elements are focused at a predetermined position, scintillation is not visually recognized if the viewer looks at the screen at this position, but this alone limits the viewing position of the viewer. Will be. Therefore, the following two configurations can be broadly classified as configurations for expanding the viewing angle so as not to limit the viewing position of the viewer.

As a first configuration for widening the viewing angle, each of the plurality of optical element elements is supported so as to be swingable with respect to a frame, and when the light is incident on the optical element element, the optical element element is swung. By moving, it is possible to adopt a configuration in which a light beam emitted from the optical element element is emitted with a predetermined diffusion angle in terms of time.
According to this configuration, since the optical element element is oscillating when light is incident, the direction of the optical element element changes every moment, and the emission direction of the light beam from the optical element element changes every minute time. Thereby, the light beam emitted from the optical element element has a predetermined diffusion angle in terms of time, and the viewing angle can be expanded.

However, in this case, it is desirable to provide a swing range regulating means for regulating the swing range of the optical element element.
Although it is good that the viewing angle is widened, when the optical element element is swung unnecessarily, a plurality of light beams from the plurality of optical element elements are overlapped with each other, which may cause scintillation. Therefore, by providing the swing range regulating means for regulating the swing range of the optical element element, it is possible to reliably prevent scintillation while widening the viewing angle.

As one of the means for swinging the optical element element (passive means), it is possible to configure the optical element element so that it can swing by receiving an external force from the external environment. Examples of the external force from the external environment include vibrations caused by sound and a force from a fluid flowing around the screen (wind (airflow), water when the screen is used in a water tank, etc.).
According to this configuration, little energy is consumed for swinging the optical element element, and since the movement is relatively slow, a quiet system can be realized without increasing power consumption.

As another means (active means) for swinging the optical element element, there is a configuration including swing means for swinging the optical element element. As a driving force of the swinging means, an electrostatic force, an electromagnetic force, a mechanical bending force by a piezoelectric element, or the like can be used.
In this configuration, a little energy is required to oscillate the optical element element, but less energy is required and less noise and vibration are required compared to the conventional configuration that drives the entire scattering layer. In this configuration, the swing range of the optical element element can be controlled, and the diffusion angle can be adjusted as appropriate.

Further, in the configuration provided with the swinging means, the viewer position detecting means for detecting the position of the viewer is provided, and the plurality of optical elements are based on the viewer position information obtained from the viewer position detecting means. A configuration in which the swing range of the optical element element by the swing means is controlled so that a plurality of light beams from the element are focused on the viewer's position can be adopted.
According to this configuration, the viewing angle can be controlled according to the number of viewers and the viewing position at that time.

As a second configuration for widening the viewing angle, each of the plurality of optical element elements is fixed to a frame, and emitted from each of the plurality of optical element elements, instead of the configuration in which the optical element element is swung. It is possible to adopt a configuration in which the emitted light beam is emitted spatially with a predetermined diffusion angle. In this case, it is desirable to use a convex mirror or a concave lens as the optical element element.
According to this configuration, the viewing angle can be expanded without using the energy for swinging the optical element element, and the durability is improved because there is no movable part.

The rear projector of the present invention includes a light source that emits light, a light modulation element that modulates the light emitted from the light source, the screen of the present invention on which the light modulated by the light modulation element is projected, And projection means for projecting the light modulated by the light modulation element onto the screen.
According to the rear projector of the present invention, since the screen of the present invention is provided, scintillation is surely removed without causing image blur, and the viewer can view the image comfortably.

The projection system of the present invention includes the screen of the present invention, and a projection engine that projects image light onto the screen.
According to the projection system of the present invention, since the screen of the present invention is provided, scintillation is surely removed without image blurring, and the viewer can view the image comfortably.

[First Embodiment]
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.
FIG. 1 is a perspective view showing a schematic configuration of a rear projector according to the present embodiment. FIG. 2 is a side sectional view of the rear projector. FIG. 3 is a schematic diagram showing the configuration of the projection optical system of the rear projector. FIG. 4 is a sectional view of the entire screen of the rear projector. FIG. 5 is a front view of the screen. FIG. 6 is a front view of a lens element (optical element element) constituting the screen, and FIG. 7 is a sectional view thereof.
In the following drawings, in order to make the drawings easy to see, the film thicknesses and dimensional ratios of the respective components are appropriately changed. In the following description, an xyz rectangular coordinate system is set, and the positional relationship of each member will be described with reference to the xyz rectangular coordinate system. The horizontal direction on the screen (left and right direction viewed by the viewer) is the x direction, the vertical direction on the screen (up and down direction viewed by the viewer) is the y direction, and the depth direction of the screen is the z direction.

  The rear projector according to the present embodiment is a rear projection type projector that modulates light emitted from a light source by a light modulation element and enlarges and projects the modulated light onto a screen. Therefore, a transmissive screen is used as the screen. As shown in FIG. 1, the rear projector 1 includes a housing 2 and a screen 3. The screen 3 is attached to the front surface side of the housing 2, and image light is projected from the rear surface side of the screen 3, and a viewer positioned on the front surface side of the screen 3 views the image. A front panel 4 is provided below the screen 3 on the front surface of the housing 2, and openings 5 for outputting sound from speakers (not shown) are provided on the left and right sides of the front panel 4.

Next, the structure inside the housing 2 will be described.
As shown in FIG. 2, a projection engine 7 is disposed below the inside of the housing 2. On the optical path between the projection engine 7 and the screen 3, a reflection mirror 8 and a reflection mirror 9 are installed. With this configuration, the light emitted from the projection engine 7 is reflected by the two reflection mirrors 8 and 9 and is enlarged and projected onto the projection area T on the screen 3.

Next, a schematic configuration of the projection engine 7 will be described with reference to FIG.
However, in FIG. 3, for the sake of simplification of the drawing, the illustration of the housing 2 constituting the appearance of the rear projector 1 is omitted.
The projection engine 7 includes a light source 11, a light modulation element 12 that modulates light emitted from the light source 11, and a projection lens 13 that projects light modulated by the light modulation element 12. In the present embodiment, liquid crystal light valves 12R, 12G, and 12B are used as the light modulation element 12. That is, the rear projector 1 of the present embodiment is a so-called liquid crystal projector.

  As shown in FIG. 3, the projection engine 7 includes a light source 11, dichroic mirrors 14, 15, reflection mirrors 16, 17, 18, an incident lens 19, a relay lens 20, an exit lens 21, liquid crystal light valves 12R, 12G, 12B, It comprises a cross dichroic prism 22, a projection lens 13, and the like. In addition, an integrator optical system for uniformizing the illuminance distribution of the light emitted from the light source 11, and a polarization conversion optical system for aligning the polarization state of the light emitted from the light source 11 with the polarization used in the liquid crystal light valves 12R, 12G, and 12B. May be provided.

  The light source 11 includes a lamp 24 such as a high-pressure mercury lamp or a metal halide lamp, and a reflector 25 that reflects light from the lamp 24. The dichroic mirror 14 has a function of transmitting red light contained in white light from the light source 11 and reflecting blue light and green light. The dichroic mirror 15 has a function of transmitting blue light and reflecting green light. Therefore, the red light transmitted through the dichroic mirror 15 is reflected by the reflection mirror 16 and enters the red light liquid crystal light valve 12R. The green light reflected by the dichroic mirror 14 is reflected by the dichroic mirror 15 and enters the green light liquid crystal light valve 12G.

  Further, the blue light reflected by the dichroic mirror 14 passes through the dichroic mirror 15. For blue light, in order to prevent light loss due to a long optical path, a light guide optical system 26 including a relay lens system including an incident lens 19, a relay lens 20, and an output lens 21 is provided. Blue light is incident on the blue light liquid crystal light valve 12B through the light guide optical system 26.

  The three color lights modulated by the liquid crystal light valves 12R, 12G, and 12B are incident on the cross dichroic prism 22. The cross dichroic prism 22 is formed by bonding four right-angle prisms. A dielectric multilayer film that reflects red light and a dielectric multilayer film that reflects blue light are formed in an X shape at the interface. Yes. These dielectric multilayer films combine the three color lights to form light representing a color image. The synthesized light is projected onto the screen 3 by the projection lens 13 which is a projection optical system, and the image is enlarged and displayed.

Next, the configuration of the screen 3 will be described. In the present embodiment, a configuration in which a lens element described later passively swings is illustrated.
As shown in FIG. 4, the screen 3 of the present embodiment is configured by stacking a Fresnel lens plate 29, a lens array plate 30, and a movable lens array plate 31 in this order. These members are on the optical path of the projection light L such that the Fresnel lens plate 29 side is located on the inner side of the housing 2 and the movable lens array plate 31 side is located on the outer side (viewer side) of the housing 2. Are stacked. As the Fresnel lens plate 29, a conventional one can be used. As shown in FIG. 7, the lens array plate 30 has a plurality of microlenses 30a arranged in a matrix to collect incident light on each lens element 32 of a movable lens array plate 31 to be described later.

  As shown in FIG. 5, the movable lens array plate 31 includes a plurality of lens elements 32 (optical element elements) and a frame 33 (base material) that supports the lens elements 32. A plurality of lens elements 32 are arranged in a matrix in the horizontal direction and the vertical direction and supported by the frame 33. The total number of lens elements 32 in the movable lens array plate 31, the number in the horizontal direction, and the number in the vertical direction are the total number of pixels, the number of pixels in the horizontal direction, and the number of pixels in the vertical direction. It matches the number. That is, each lens element 32 of the movable lens array plate 31 corresponds to each pixel of each liquid crystal light valve 12R, 12G, 12B 1: 1. In other words, the total number of lens elements 32 in the movable lens array plate 31, the number in the horizontal direction, and the number in the vertical direction coincide with the total number of pixels in the projection image, the number of pixels in the horizontal direction, and the number of pixels in the vertical direction. ing. That is, each lens element 32 of the movable lens array plate 31 corresponds to each pixel of the projected image in a 1: 1 ratio. Therefore, as shown in FIG. 7, when the light emitted from the lens array plate 30 reaches the movable lens array plate 31, a light beam L <b> 1 corresponding to each pixel is incident on each lens element 32. Yes.

  As shown in FIG. 5, the frame 33 has an outer frame portion 33a and a lattice portion 33b, and is formed of a material such as resin or metal. The frame 33 may be made of a light-shielding material and function as a black mask for the screen 3. As shown in FIGS. 6 and 7, one lens element 32 is attached to each opening of each lattice of the frame 33. The upper end of the lens element 32 is supported by the frame 33 via a connecting member 34 made of a flexible elastic material such as rubber. With this configuration, each lens element 32 can be easily swung on the lower end side around the upper end of the lens element 32 by receiving an external force from the external environment. The external force from the external environment may be, for example, vibration by a speaker such as a subwoofer attached to the screen 3 or wind (airflow) flowing around the screen 3. Alternatively, if the screen 3 is installed separately from the projection engine in an application to a front projector rather than a rear projector, the flow of water when the screen 3 is installed in water may be used. Therefore, in the case of this embodiment, all the lens elements 32 are directed in substantially the same direction.

  In the screen 3 of the present embodiment, as shown in FIG. 4, a plurality of light beams L emitted from a movable lens array plate 31 including a plurality of lens elements 32 are focused at a predetermined position. However, as long as the screen 3 is viewed at this position, the light beams emitted from the lens elements 32 do not overlap on the route until they reach the viewer's retina. In this way, according to the screen 3 of the present embodiment, scintillation can be reliably prevented. Further, since it is not necessary to move the scattering layer as in the prior art, generation of unpleasant noise and vibration can be suppressed, and a quiet rear projector can be constructed. Further, since the image projection onto the screen 3 is not accompanied by a light scattering phenomenon, the viewer can see a clear image without blur.

  In this type of screen 3, since the light beams from the plurality of lens elements 32 are focused at a predetermined position, scintillation is not visually recognized if the viewer looks at the screen 3 at this position, but this is the position the viewer sees. Will be limited. However, in this embodiment, since the lens element 32 is configured to be swingable by an external force, the direction of the lens element 32 changes every moment, and the emission direction of the light beam from the lens element 32 changes every minute time. To change. As a result, the luminous flux emitted from each lens element 32 has a predetermined diffusion angle in time and the viewing angle is widened, so that the scintillation is not visually recognized even if the viewing position is shifted. Furthermore, since the lens element 32 is easily swung by an external force such as vibration or air current, almost no energy is consumed for rocking the lens element 32. Further, since the movement of the lens element 32 is relatively slow, a quiet system can be realized without increasing power consumption.

  In addition to the above configuration, a swing range restricting means for restricting the swing range of the lens element 32 may be provided. For example, a lattice-like swing range regulating member 36 as shown in FIG. 8 may be disposed on the viewing side of the movable lens array plate 31. In this case, as shown in FIG. 9, when the lens element 32 swings, when the lens element 32 rotates to a predetermined angle, the lower end of the lens element 32 comes into contact with the swing range regulating member 36, and the lens element 32 is prevented from swinging further.

  When the lens element 32 is swung, it is preferable that the viewing angle is widened. However, when the lens element 32 is swung unnecessarily, the light beams from the lens element 32 are overlapped, and scintillation may occur. Therefore, as described above, the configuration including the swing range regulating member 36 that regulates the swing range of the lens element 32 can reliably prevent scintillation while widening the viewing angle.

[Second Embodiment]
Hereinafter, a second embodiment of the present invention will be described with reference to FIGS.
In the first embodiment, the transmissive screen used for the rear projector is exemplified. However, in the present embodiment, an example of the reflective screen used for the front projector will be described.
FIG. 10 is a front view of the screen of this embodiment. FIG. 11 is a sectional view of the screen. 12A and 12B are a front view and a sectional view of a mirror element (optical element element) constituting the screen. FIG. 13 is a view showing a modification of the mirror element.
Since the entire configuration of the screen is the same as that of FIG. 4 of the first embodiment, the illustration is omitted.

  The screen of this embodiment has a movable mirror array plate 38. As shown in FIGS. 10 and 11, the movable mirror array plate 38 includes a plurality of mirror elements 39 (optical element elements) and a frame body 40 (base material) that supports the mirror elements 39. A plurality of mirror elements 39 are arranged in a matrix in the horizontal direction and the vertical direction and supported by the frame body 40. The total number of mirror elements 39 in the movable mirror array plate 38, the number in the horizontal direction, and the number in the vertical direction are the total number of pixels of each liquid crystal light valve 12R, 12G, 12B, the number of pixels in the horizontal direction, and the number of pixels in the vertical direction. It matches the number. That is, each mirror element 39 of the movable mirror array plate 38 corresponds to each pixel of each liquid crystal light valve 12R, 12G, 12B 1: 1.

  As shown in FIG. 10, the frame 40 has an outer frame portion 40a and a lattice portion 40b, and is formed of a material such as resin or metal. One mirror element 39 is attached to each opening of each lattice of the frame body 40. As shown in FIGS. 12A and 12B, the upper side of the mirror element 39 is supported by the frame body 40 via the hinge portion 39a, so that the mirror element 39 can be rotated. With this configuration, each mirror element 39 can be easily swung on the lower end side around the upper end of the mirror element 39 by receiving external force from an external environment such as vibration, airflow, water flow or the like from the speaker 41. . Therefore, in the case of the present embodiment, all the mirror elements 39 are directed in substantially the same direction.

  In the screen of the present embodiment, the plurality of light beams emitted from the movable mirror array plate 38 including the plurality of mirror elements 39 do not overlap on the path until they reach the viewer's retina. Therefore, even in the screen of the present embodiment, it is possible to realize a quiet rear projector that can reliably prevent scintillation while ensuring a predetermined viewing angle without causing image blurring, and that does not generate unpleasant noise or vibration. The same effect as in the first embodiment can be obtained.

  Further, instead of the configuration in which the upper end of the mirror element 39 is supported via the hinge 39a, the mirror element 42 is made of a flexible material such as a thick metal foil as shown in FIG. Only the upper end of the element 42 may be fixed to the frame body 43. In this case, the frame body 43 does not need to be formed in a lattice shape, and may be a flat plate shape.

  In addition to the above-described configuration, a swing range restricting means for restricting the swing range of the mirror element 39 may be provided. For example, as shown in FIG. 14, claw portions 44 (oscillation range regulating members) are formed on the frame body 40 of the movable mirror array plate 38 so as to correspond to the respective mirror elements 39. On the other hand, a hook-shaped portion 39b is formed by bending the lower end of each mirror element 39 into a hook shape. Then, when the mirror element 39 swings and rotates to a predetermined angle, the hook-shaped portion 39b at the lower end of the mirror element 39 engages with the claw portion 44 so that the mirror element 39 does not swing further. Become. Thereby, scintillation can be reliably prevented while widening the viewing angle.

  Alternatively, as shown in FIG. 15, a transparent protective plate 45 (swing range regulating member) is arranged at a predetermined interval on the viewing side of the movable mirror array plate 38. Then, when the mirror element 39 swings and rotates to a predetermined angle, the lower end of the mirror element 39 comes into contact with the transparent protective plate 45, and the mirror element 39 does not swing further. Thereby, scintillation can be reliably prevented while widening the viewing angle.

[Third Embodiment]
Hereinafter, a third embodiment of the present invention will be described with reference to FIGS.
In the first and second embodiments, a configuration in which optical element elements such as a lens element and a mirror element constituting a screen are passively oscillated by receiving a force from the external environment is exemplified. On the other hand, in the following third and fourth embodiments, the optical element element is actively oscillated, that is, the optical element element is oscillated by the driving force from the oscillating means for oscillating the optical element element. The configuration is illustrated. Since the overall configuration of the screen is substantially the same as that of the above embodiment, the description is omitted, and only the portion of each optical element element is extracted and described.
In addition, as an optical element element in the following third and fourth embodiments, either a lens element or a mirror element can be used. In the present embodiment, an example using a mirror element will be described.
FIGS. 16A to 16C are cross-sectional views of the optical element elements constituting the screen of this embodiment. 17 and 18 are cross-sectional views showing other modifications of the optical element element.

  In the screen of this embodiment, as shown in FIGS. 16A to 16C, the center of each mirror element 50 is connected to the tip of a support member 52 via a hinge 51, and each mirror element 50 is shaken. It is supported movably. The mirror element 50 is made of conductive metal or the like. In addition, electrodes 53a and 53b are respectively provided below both ends of each mirror element 50 (on the base material side). Here, as shown in FIG. 16A, when a reverse polarity voltage is applied between the mirror element 50 and the left electrode 53a in the figure, an electrostatic force is generated between the mirror element 50 and the electrode 53a, The mirror element 50 pivots about the hinge 51 and swings so as to tilt to the left. Then, as shown in FIG. 16B, when no voltage is applied between the mirror element 50 and the left electrode 53a and the right electrode 53b in the figure, the mirror element 50 is not inclined in either direction. Return to neutral position. Also, as shown in FIG. 16C, when a reverse polarity voltage is applied between the mirror element 50 and the right electrode 53b in the figure, an electrostatic force is generated between the mirror element 50 and the electrode 53b, and the mirror The element 50 swings so as to tilt to the right. Further, as in the above embodiment, all the mirror elements 50 in the screen are controlled so as to face substantially the same direction.

  In the screen of the present embodiment, the plurality of light beams emitted from the plurality of mirror elements 50 do not overlap on the route until they reach the viewer's retina. Therefore, even in the screen of the present embodiment, it is possible to realize a quiet rear projector that can reliably prevent scintillation while ensuring a predetermined viewing angle without causing image blurring, and that does not generate unpleasant noise or vibration. The same effects as those of the first and second embodiments can be obtained. In this embodiment, a little energy is required for swinging the mirror element 50, but less energy is required and noise and vibration are less than in the conventional configuration for driving the entire scattering layer. Further, in this configuration, the swing range of the mirror element 53 can be controlled by changing the magnitude of the electrostatic force according to the applied voltage, and the diffusion angle can be adjusted as appropriate.

  Instead of the configuration in which the center of the mirror element 50 shown in FIG. 16 is supported by the hinge 51, a configuration may be adopted in which a flexible support member 54 is connected to the center of the mirror element 50 as shown in FIG. In this case, when a reverse polarity voltage is applied between the mirror element 50 and one of the electrodes 53a and 53b, and an electrostatic force is generated between the mirror element 50 and the electrodes 53a and 53b, the support member 54 is The mirror element 50 swings due to elastic deformation. Alternatively, as shown in FIG. 18, one end of the mirror element 50 may be supported by a support member 55.

[Fourth Embodiment]
The fourth embodiment of the present invention will be described below with reference to FIG.
In the third embodiment, an example in which an electrostatic force is used as a driving force for swinging the optical element element is shown. However, in this embodiment, an example in which an electromagnetic force is used as the driving force is shown.
19A to 19C are plan views showing a schematic configuration of the screen of the present embodiment.

  As shown in FIGS. 19A to 19C, the screen according to the present embodiment includes a frame body 57 and a lens element 58. As shown in FIG. 19A, the frame body 57 is a lattice-shaped frame in which a coil 59 is built. The coil 59 is wound around each opening 57a of the frame 57, and all the coils 59 provided for each opening 57a are connected in series. The coil 59 is supplied with an alternating current. On the other hand, as shown in FIG. 19B, the lens element 58 is magnetized by bonding or applying a magnetic material 59 to the periphery of the lens body. Alternatively, in the case of a mirror element, a configuration having the above-described magnetic body may be used, or the mirror itself may be a magnetic body (for example, an aluminum or silver plating is applied to an iron foil to form a reflecting surface). Then, as shown in FIG. 19C, when the lens element 58 is supported on each opening 57a of the frame 57 by an arbitrary method and an alternating current is supplied to the coil 59, the lens element 58 receives electromagnetic force. Rocks. As in the above embodiment, all the lens elements 58 in the screen are controlled so as to face substantially the same direction.

  In the screen of the present embodiment, the plurality of light beams emitted from the plurality of lens elements 58 do not overlap on the route until they reach the viewer's retina. Therefore, even in the screen of the present embodiment, it is possible to realize a quiet rear projector that can reliably prevent scintillation while ensuring a predetermined viewing angle without causing image blurring, and that does not generate unpleasant noise or vibration. The same effects as those of the first and second embodiments can be obtained. In this embodiment, a little energy is required for swinging the lens element 58, but less energy is required compared to the conventional configuration, and noise and vibration are also reduced. Further, the swing range of the lens element 58 can be controlled by changing the electromagnetic force by changing the magnitude of the alternating current, and the diffusion angle can be adjusted as appropriate.

[Fifth Embodiment]
The fifth embodiment of the present invention will be described below with reference to FIG.
The third embodiment shows an example in which an electrostatic force is used for the driving force of the optical element element, and the bending force of the piezoelectric element is used in the fourth embodiment.
20A and 20B are cross-sectional views showing the configuration of each optical element element of the screen of this embodiment.

  As shown in FIGS. 20A and 20B, the screen according to the present embodiment includes a frame 61, a mirror element 62 (or a lens element), and a piezoelectric element 63. As shown in FIG. 20A, the mirror element 62 is connected to the frame body 61 via the piezoelectric element 63. As shown in FIG. 20B, the piezoelectric element 63 is an electrostrictive element (piezoactuator) of a type that is curved by voltage application or extends flatly. Therefore, when an AC voltage is applied to the piezoelectric element 63, the mirror element 62 swings at the lower end side that is not supported by the frame body 61. As in the above embodiment, all the mirror elements 62 in the screen are controlled so as to face substantially the same direction.

  In the screen of the present embodiment, a plurality of light beams emitted from the plurality of mirror elements 62 do not overlap on a route until they reach the viewer's retina. Therefore, even in the screen of the present embodiment, it is possible to realize a quiet rear projector that can reliably prevent scintillation while ensuring a predetermined viewing angle without causing image blurring, and that does not generate unpleasant noise or vibration. The same effect as the above embodiment can be obtained. In this embodiment, a little energy is required for swinging the mirror element 62, but less energy is required compared to the conventional configuration, and noise and vibration are also reduced. Further, the swing range of the mirror element 62 can be controlled by changing the degree of warping of the piezoelectric element 63 by changing the magnitude of the AC voltage, and the diffusion angle can be adjusted as appropriate.

  In the case of having the oscillating means described in the third to fifth embodiments, the oscillating range of the optical element element is provided by providing a driving circuit 65 as shown in FIG. Can be regulated. That is, a voltage (current) limiting means 67 such as a limiter may be provided between the signal source 66 and the driver 68 and actuator 69.

[Sixth Embodiment]
Hereinafter, a sixth embodiment of the present invention will be described with reference to FIGS.
In the first to fifth embodiments, the optical element element is oscillated to increase the light diffusion angle. However, in the following sixth and seventh embodiments, the optical element element does not move constantly. An example of a configuration that can widen the diffusion angle of light will be described.
FIG. 22 is a cross-sectional view of the screen of this embodiment. FIG. 23 is a sectional view of each mirror element constituting the screen. FIG. 24 is a cross-sectional view showing a modification of the mirror element.

  The screen of the present embodiment has a fixed mirror array plate 70. As shown in FIG. 22, the fixed mirror array plate 70 includes a plurality of mirror elements 71 (optical element elements) and a frame body 72 (base material) that supports these mirror elements 71. Each mirror element 71 is tilted upward and fixed so as to form a predetermined angle with respect to the surface of the frame body 72. In the case of this embodiment, all the mirror elements 71 face substantially the same direction. As a result, the image light projected from above the screen is reflected toward substantially the front of the screen. The total number of mirror elements 71 in the fixed mirror array plate 70, the number in the horizontal direction, and the number in the vertical direction are the total number of pixels of each liquid crystal light valve 12R, 12G, 12B, the number of pixels in the horizontal direction, and the number of pixels in the vertical direction. It matches the number. That is, each mirror element 71 of the fixed mirror array plate 70 corresponds to each pixel of each liquid crystal light valve 12R, 12G, 12B 1: 1.

  As shown in FIG. 23, one mirror element 71 is attached at a position corresponding to each pixel on the frame 72. In FIG. 22, the mirror element 71 is shown in a flat plate shape, but the actual mirror element 71 is a reflective mirror on the upper surface side and a convex mirror convex on the upper side. Alternatively, as shown in FIG. 24, the mirror element 71 may be a concave mirror having a reflecting surface on the lower surface side and a convex surface on the lower side. Thereby, the diffusion angle of the reflected light L can be expanded.

  In the screen of the present embodiment, the plurality of light beams emitted from the fixed mirror array plate 70 including the plurality of mirror elements 71 do not overlap on the route until they reach the viewer's retina. Therefore, even in the screen of the present embodiment, it is possible to realize a quiet rear projector that can reliably prevent scintillation while ensuring a predetermined viewing angle without causing image blurring, and that does not generate unpleasant noise or vibration. The same effect as the above embodiment can be obtained.

[Seventh Embodiment]
Hereinafter, a seventh embodiment of the present invention will be described with reference to FIGS.
In the sixth embodiment, an example of a reflective screen with a mirror element fixed is given. In the present embodiment, an example of a transmissive screen with a lens element fixed will be described.
FIG. 25 is a sectional view of a lens element constituting the screen of this embodiment. FIG. 26 is a cross-sectional view showing a modification of the lens element.

  As shown in FIG. 25, the screen of the present embodiment has one lens element 75 attached to a position corresponding to each pixel on the frame 74. Each lens element 75 is a concave lens. All the lens elements 75 are fixed so as to be inclined upward so as to form a predetermined angle with respect to the surface of the frame 74. In the case of this embodiment, all the lens elements 75 face substantially the same direction. Alternatively, as shown in FIG. 26, each lens element 76 may be a convex lens. A hinge 77 is provided at the upper end of each lens element 75, 76 so that the inclination angle of each lens element 75, 76 can be adjusted. However, the hinge 77 does not steadily swing the lens elements 75 and 76 during use.

  In the screen of the present embodiment, the plurality of light beams emitted from the plurality of lens elements 75 and 76 do not overlap on the route until they reach the viewer's retina. Therefore, even in the screen of the present embodiment, it is possible to realize a quiet rear projector that can reliably prevent scintillation while ensuring a predetermined viewing angle without causing image blurring, and that does not generate unpleasant noise or vibration. The same effect as the above embodiment can be obtained.

[Eighth Embodiment]
The eighth embodiment of the present invention will be described below with reference to FIG.
In the first to fifth embodiments, examples of screens provided with swinging means for swinging the optical element element are given. The present embodiment further includes viewer position detecting means for detecting the position of the viewer on this type of screen, and a plurality of light beams from a plurality of optical element elements are placed at the viewer's position based on the viewer's position information. An example of controlling the swing range of the optical element element so as to be focused will be described.
FIG. 27 is a perspective view of a schematic configuration of the projector according to the present embodiment.

  As viewer position detection means of this embodiment, as shown in FIG. 27, an infrared light source 80 is installed above the center of the screen 3, and cameras 81 are installed on both sides of the infrared light source 80. The viewer wears a marker 82 on the head. In this configuration, the reflected light when the infrared ray R emitted from the infrared light source 80 hits the marker 82 is observed by the two cameras 81 to detect where the viewer is with respect to the screen 3. be able to. Note that the viewer may wear an acceleration sensor or a gyro sensor on the head and integrate the acceleration to obtain viewer position information. In addition, a known method such as a method using image processing (optical method) or a method of capturing a change in magnetic field (magnetic method) may be used as appropriate.

  Then, based on the viewer position information obtained by the viewer position detection means, the controller 83 controls the optical element so that a plurality of light beams from the plurality of optical element elements are focused on a position where the viewer is present. Controls the swing range of the element. Therefore, when the position of the viewer changes, the optical element swings so as to follow the changed position. According to this configuration, the viewing angle can be controlled in accordance with the number of viewers and the viewing position from time to time, and images can be viewed in an optimum environment.

  The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention. For example, the specific configuration of the optical element element support structure, the swinging unit, and the like exemplified in the above embodiment is not limited to the above embodiment, and can be changed as appropriate. The present invention can also be applied to a rear projector as a whole that uses a liquid crystal light valve as a light modulation element, or a reflection type light modulation element such as a DMD (Digital Micromirror Device) element. .

1 is a perspective view showing a configuration of a rear projector according to a first embodiment of the present invention. It is a sectional side view of the rear projector. It is a schematic block diagram of the optical system of the projection engine of the rear projector. It is sectional drawing of the whole screen of the rear projector. It is a front view of the screen. It is a front view of the lens element which comprises the screen. FIG. It is a front view of the rocking | fluctuation range control member used for the screen. It is sectional drawing of the state which incorporated the rocking | fluctuation range control member in the screen. It is a front view of the screen of 2nd Embodiment of this invention. It is sectional drawing of the screen. It is the front view and sectional drawing of the mirror element of the screen. It is a figure which shows the modification of the mirror element. It is sectional drawing of the rocking | fluctuation range control member used for the screen. It is sectional drawing of the other rocking | fluctuation range control member used for the screen. It is sectional drawing of the optical element element of 3rd Embodiment of this invention. It is sectional drawing which shows the modification of the same optical element element. It is sectional drawing which shows the other modification of the same optical element element. It is a top view which shows schematic structure of the screen of 4th Embodiment of this invention. It is a top view which shows schematic structure of the screen of 5th Embodiment of this invention. It is a circuit diagram of the rocking | fluctuation range control means used for the screen. It is sectional drawing of the screen of 6th Embodiment of this invention. It is sectional drawing of each mirror element which comprises the screen. It is sectional drawing which shows the modification of the mirror element. It is sectional drawing of the lens element of the screen of 7th Embodiment of this invention. It is sectional drawing which shows the modification of the lens element. It is a perspective view of schematic structure of the projector of 8th Embodiment of this invention. It is a figure for demonstrating the generation | occurrence | production principle of scintillation.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Rear projector (image display apparatus), 3 ... Screen, 7 ... Projection engine, 12, 12R, 12G, 12B ... Liquid crystal light valve (light modulation element), 13 ... Projection lens, 31, 38 ... Movable lens array board, 32, 58, 75, 76 ... lens element (optical element element), 33, 40, 43, 57, 61, 72, 74 ... frame (base material), 36 ... swing range regulating member (swing range regulating means) ), 39, 42, 62, 71 ... mirror element (optical element element), 44 ... claw portion (swing range regulating means), 45 ... transparent protective plate (swing range regulating means), 53a, 53b ... electrode (swing) Moving means), 59 ... coil (oscillating means), 63 ... piezoelectric element (oscillating means), 70 ... fixed mirror array plate, 80 ... infrared light source (observer position detecting means), 81 ... camera (observer position detecting) hand ), 82 ... marker (the viewer position detection means).

Claims (11)

A screen for displaying a projection image generated by a light modulation element,
A plurality of optical element elements capable of reflecting or transmitting light, and having the number of the optical element elements equal to or greater than the number of pixels of the projection image, wherein the number of the optical element elements in the horizontal direction of the projection image The number of pixels in the direction is equal to or greater than the number of pixels in the vertical direction of the projection image, and a plurality of light beams emitted from the plurality of optical element elements are placed at predetermined positions. A screen characterized by being focused.   The screen according to claim 1, wherein the optical element element includes a mirror or a lens.   Each of the plurality of optical element elements is supported so as to be swingable with respect to a substrate, and the optical element element swings when light is incident on the optical element element, thereby exiting the optical element element. The screen according to claim 1, wherein the emitted light beam is emitted with a predetermined diffusion angle in terms of time.   The screen according to claim 3, further comprising a swing range regulating unit that regulates a swing range of the optical element element.   5. The screen according to claim 3, wherein the optical element element is configured to be able to swing by receiving an external force from an external environment.   The screen according to claim 3, further comprising a swinging unit that swings the optical element element.   Viewer position detecting means for detecting the position of the viewer, and based on the position information of the viewer obtained from the viewer position detecting means, a plurality of light beams from the plurality of optical element elements are The screen according to claim 6, wherein a swing range of the optical element element by the swing means is controlled so as to be focused at a position.   3. Each of the plurality of optical element elements is fixed to a base material, and a light beam emitted from each of the plurality of optical element elements is emitted with a predetermined spatial diffusion angle. As described in the screen.   The screen according to claim 8, wherein the optical element element is constituted by a convex mirror or a concave lens. A light source that emits light;
A light modulation element that modulates light emitted from the light source;
The screen according to any one of claims 1 to 9, wherein light modulated by the light modulation element is projected;
A rear projector comprising: projection means for projecting light modulated by the light modulation element onto the screen.   A projection system comprising: the screen according to any one of claims 1 to 9; and a projection engine that projects image light onto the screen.

Images