Display apparatus
First Claim
1. An apparatus for displaying an image on a screen by projecting an unpolarized reading light from a light source onto a spatial light modulator of reflective type in which said image is written, and projecting a reflected light from said modulator corresponding to said image onto said screen through a projection lens, said modulator, lens and screen being provided so that their optical axes are substantially in agreement on one optical path, comprising:
- converging means for converging said unpolarized reading light from said light source on said optical axis of said projection lens and located between said projection lens and said screen;
a polarization beam splitter, provided between said projection lens and said screen, for reflecting S-polarized light in said unpolarized reading light thus converged to said modulator via said projection lens; and
said spatial light modulator having a photomodulation member of birefringence type, responsive to said S-polarized light, for generating P-polarized light corresponding to said image written in said modulator by birefringence, said P-polarized light being projected onto said screen by said projection lens via said polarization beam splitter.
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Accused Products
Abstract
There is provided an apparatus for displaying an image on a screen by projecting a reading light from a light source onto a spatial light modulator of reflective type in which the image is written, and projecting a reflected light from the modulator corresponding to the image onto the screen through a projection lens, the modulator, lens and screen being provided so that their optical axes are in agreement on one optical path. The apparatus comprises an optical device provided between the lens and screen for the reading light toward the modulator and passing the reflected light to the screen and a converging element for converging the reading light on the position which is on the optical axis of the lens and located between the lens and screen so that the reading light thus turned becomes a parallel pencil beam which is projected onto the modulator in parallel with the optical axis.
89 Citations
10 Claims
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1. An apparatus for displaying an image on a screen by projecting an unpolarized reading light from a light source onto a spatial light modulator of reflective type in which said image is written, and projecting a reflected light from said modulator corresponding to said image onto said screen through a projection lens, said modulator, lens and screen being provided so that their optical axes are substantially in agreement on one optical path, comprising:
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converging means for converging said unpolarized reading light from said light source on said optical axis of said projection lens and located between said projection lens and said screen; a polarization beam splitter, provided between said projection lens and said screen, for reflecting S-polarized light in said unpolarized reading light thus converged to said modulator via said projection lens; and said spatial light modulator having a photomodulation member of birefringence type, responsive to said S-polarized light, for generating P-polarized light corresponding to said image written in said modulator by birefringence, said P-polarized light being projected onto said screen by said projection lens via said polarization beam splitter.
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2. An apparatus for displaying a color image on a screen by splitting an unpolarized reading light from a light source into three reading lights, corresponding to three primary colors respectively, projecting said reading lights onto three spatial light modulators of reflective type in which images of said colors are written respectively, combining reflected lights from said modulators, each reflected light corresponding to one of said images, to form a combined reflected light and projecting said combined reflected light onto said screen by a projection lens, said lens and screen being provided so that their optical axes are substantially in agreement on one optical path, comprising:
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converging means for converging said unpolarized reading light from said light source on said optical axis of said projection lens and located between said projection lens and said screen; a polarization beam splitter, provided between said projection lens and said screen, for reflecting S-polarized light in said unpolarized light thus converged to said projection lens; three-color splitting means, provided between said projection lens and said modulators so that said three-color splitting means is irradiated with said S-polarized light via said projection lens, for splitting said S-polarized light into three beams of S-polarized light corresponding to said three primary colors respectively, and for guiding said three beams of S-polarized light onto said three modulators respectively; and said three-color splitting means having three-color synthesis means for combining said reflected lights from said modulators to form said combined reflected light which is projected onto said screen by said projection lens via said polarization beam splitter. - View Dependent Claims (3, 4, 5, 6, 7)
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8. An apparatus for displaying an image on a screen by projecting a unpolarized reading light from a light source onto a spatial light modulator of reflective type in which said image is written, and projecting a reflected light from said modulator corresponding to said image onto said screen through a projection lens, said modulator, lens and screen being provided so that their optical axes are substantially in agreement on one optical path, comprising:
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converging means for converging said unpolarized reading light from said light source on a position which is in the vicinity of a focal point of said projection lens and is located between said projection lens and said screen; polarization beam splitter, provided between said projection lens and said screen, for reflecting S-polarized light in said unpolarized reading light thus converged on said position to said projection lens, wherein said S-polarized light is converted into a parallel pencil beam by said projection lens; polarization plane rotation means, provided between said modulator and projection lens, for rotating said polarization plane of said parallel pencil beam of said S-polarized light, so that said parallel pencil beam of S-polarized light is converted into a parallel pencil beam of circularly polarized light; said spatial light modulator having photomodulation member for scattering said parallel pencil beam of circularly polarized light according to said image written in said modulator to generate a first linearly polarized reflected light parallel to said optical axis of said modulator and a second linearly polarized reflected light not parallel to said optical axis of said modulator, said first and second linearly polarized reflected lights being projected onto said screen via said polarization plane rotation means and said polarization beam splitter; and light splitting means provided between said polarization beam splitter and said screen on said optical path for passing said first linearly polarized reflected light to said screen and reflecting said second linearly polarized reflected light. - View Dependent Claims (9)
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10. An apparatus for displaying an image on a screen by projecting a unpolarized reading light from a light source onto a spatial light modulator of reflective type in which said image is written, and projecting a reflected light from said modulator corresponding to said image onto said screen through a projection lens, said modulator, lens and screen being provided so that their optical axes are substantially in agreement on one optical path, comprising:
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converging means for converging said unpolarized reading light from said light source on a position which is in the vicinity of a focal point of said projection lens and is located between said projection lens and said screen; a polarization splitter, having an aperture and a reflection member, provided between said projection lens and said screen, for reflecting S-polarized light in said unpolarized reading light thus converged on said position to said modulator via said projection lens, wherein said S-polarized light is converted into a parallel pencil beam by said projection lens; and said spatial light modulator having photomodulation means for scattering said parallel pencil beam according to said image to generate a first linearly polarized reflected light parallel to said optical axis of said modulator and a second linearly polarized reflected light not parallel to said optical axis of said modulator, wherein said first linearly polarized reflected light is projected onto said screen through said aperture of said polarization beam splitter and said second linearly polarized reflected light is reflected by said reflection member of said polarization beam splitter.
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Specification