Projector utilizing liquid crystal light-valve and color selection by diffraction
First Claim
1. A projector system including a projection lens for projecting on a screen a color image corresponding to electronic video information comprising:
- a first light modulating liquid crystal panel containing a first diffraction grating having parameters corresponding to a first primary color;
a second light modulating liquid crystal panel containing second and third diffraction gratings having parameters corresponding to second and third primary colors, respectively;
a schlieren optical system having input and output light masks each comprising an array of bars and slits;
a first dichroic mirror for separating a beam of polychrome light into two beams, a first beam containing said first primary color and a second beam containing said second and third primary colors;
a light source for projecting substantially parallel beams of polychrome light through said input light mask onto said first dichroic mirror;
means including first and second mirrors for directing said first and second beams onto said first and second liquid crystal panels, respectively; and
a second dichroic mirror for combining the light passed by said first and second liquid crystal panels and directing the combined beam through said output light mask to said projection lens.
1 Assignment
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Accused Products
Abstract
A projection system which produces a color image on a screen corresponding to an applied color signal. In a preferred embodiment, light beams from a source of white light are separated by a dichroic mirror into two beams, one containing green and the other containing blue and red. The beam containing green illuminates a first active matrix liquid crystal panel which contains electrodes which define a diffraction grating having parameters corresponding to green, and the beam containing blue and red illuminates a second active matrix liquid crystal panel which contains electrodes which form two separate diffraction gratings, one having parameters corresponding to red and the other having parameters corresponding to blue. As each beam passes through its respective LC panel its transmittance is modulated in accordance with video information signals applied to the panels, and the red and blue colors are selected by diffraction. The LC panels are embodied in a schlieren optical system for converting modulations of the LC panels and the colors selected by diffraction into an image.
105 Citations
18 Claims
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1. A projector system including a projection lens for projecting on a screen a color image corresponding to electronic video information comprising:
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a first light modulating liquid crystal panel containing a first diffraction grating having parameters corresponding to a first primary color; a second light modulating liquid crystal panel containing second and third diffraction gratings having parameters corresponding to second and third primary colors, respectively; a schlieren optical system having input and output light masks each comprising an array of bars and slits; a first dichroic mirror for separating a beam of polychrome light into two beams, a first beam containing said first primary color and a second beam containing said second and third primary colors; a light source for projecting substantially parallel beams of polychrome light through said input light mask onto said first dichroic mirror; means including first and second mirrors for directing said first and second beams onto said first and second liquid crystal panels, respectively; and a second dichroic mirror for combining the light passed by said first and second liquid crystal panels and directing the combined beam through said output light mask to said projection lens. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A projection color system for producing a color image on a screen corresponding to an applied color signal, said system comprising:
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a light source for producing a beam of primary red, blue and green colors, first dichroic mirror means for separating said beam into a first beam containing green and a second beam containing red and blue, first and second panels positioned generally perpendicular to said first and second beams, respectively, and each containing a liquid crystal medium, said first panel containing a diffraction grating having parameters corresponding to green and said second panel containing two superimposed diffraction gratings respectively having parameters corresponding to red and blue, which by diffraction separates red from blue, second dichroic mirror means for combining light passed by said first and second liquid crystal panels; and a first light mask provided with slits for transmitting to a projection lens first order diffracted light diffracted by said gratings. - View Dependent Claims (11, 12, 13, 14)
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15. A projector system for producing a color image on a screen corresponding to an applied color signal, said system comprising:
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a schlieren optical system having input and output light masks each comprising an array of bars and slits; a light source for producing and directing onto said input light mask a beam of primary red, blue and green colors; means including a first light modulating liquid crystal panel containing a first diffraction grating having parameters corresponding to green; means including a second light modulating liquid crystal panel containing superimposed second and third diffraction gratings having parameters corresponding to red and blue, respectively; first mirror means including a first dichroic mirror for separating the light beams passed by said input light mask into a first beam containing green and a second beam containing red and blue and directing said first and second beams onto said first and second liquid crystal panels, respectively; and means including mirror means for combining and directing onto said output light mask the light passed by said first and second liquid crystal panels and transmitting to a projection lens first order diffracted light diffracted by said gratings. - View Dependent Claims (16, 17, 18)
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Specification