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US 4,904,061 AGranted
Projection-type liquid crystal display device with even color
AssigneeSeiko Epson Corporation
InventorShuji Aruga
Life of this patent
Estimating the term…
Abstract
A projection-type display device for producing a faithful colored synthesized image based on equating the luminous intensity distributions and light patterns produced by three twisted nematic liquid crystal light valves for three primary color images. Each light valve includes a twisted nematic liquid crystal composition which is twisted to the right or left depending on the number of times that color light is reflected. Each light valve may include an active switching matrix arranged in mirror-like symmetry with light shield layers also arranged symmetrically.
Claims28
A projection-type display device comprising:
- a light source for generating light;
- color separating means for separating the light into at least its primary colors;
- liquid crystal light valve means for producing colored images based on the colored light;
- optical synthesizing means for combining the colored images to form a synthesized image;
- and
- projection lens means for projecting the synthesized image toward an object for viewing of the image;
- said optical synthesizing means including reflection means for reflecting at least one of the colored images and directing the synthesized image toward the projection lens means;
- wherein the liquid crystal light valve means includes three light valves filled with liquid crystal material, the liquid crystal material of one light valve being twisted in a direction opposite to the directions in which the liquid crystal materials of the other two light valves are twisted.
5 more elements
A projection-type display device comprising:
- a light source for generating light;
- color separating means for separating the light into at least its primary colors and including dichroic mirror means for reflecting a predetermined wavelength of light and transmitting all other wavelengths of light;
- liquid crystal light valve means associated with each colored light for producing colored images and including three light valves wherein each of the light valves has a pair of substrates, two of these pairs of substrates being rubbed in directions which are mirror-like symmetric to the rubbing directions of the third pair of substrates, each of the light valves also having a light shield layer for shielding portions of the light valve from light passing through the light valve in the form of a repeated pattern of openings which are symmetric about their respective center axes in a vertical direction;
- optical synthesizing means for combining the colored images to form a synthesized image;
- and
- projection lens means for projecting the synthesized image toward an object for viewing of the image;
- said optical synthesizing means including reflection means having at least one reflective dichroic mirror for reflecting at least one of the color images and directing the color images to the lens means;
- wherein the three light valves are filled with liquid crystal material, the liquid crystal material of one light valve being twisted in a direction opposite to the direction in which the liquid crystal materials of the other two light valves are twisted and wherein each liquid crystal light valve includes a plurality of switching elements disposed therein for controlling the photoelectric characteristics of that valve, the switching elements of said one light valve having a mirror-like symmetrical arrangement relative to the arrangement of the switching elements disposed within said other two light valves.
5 more elements
A method of producing substantially the same luminous intensity distribution for each of three different liquid crystal light valves within a projection-type display device comprising:
- segregating light into its primary colors;
- directing the colored light towards the three liquid crystal light valves for producing corresponding color images;
- reflecting at least one of the primary color images towards an optical synthesizer;
- reflecting said at least one of the primary color images again;
- and
- symmetrizing the primary color images based on which of the primary color images is to be reflected an odd number of times and which of the primary color images is to be reflected an even number of times to make the luminous intensity distributions of the color images substantially equal.
3 more elements
A method of producing substantially the same luminous intensity distribution for each of three different liquid crystal light valves within a projection-type display device, comprising:
- segregating light into its primary colors;
- directing the colored light towards the three liquid crystal light valves for producing corresponding color images;
- reflecting at least one of the primary color images towards an optical synthesizer;
- reflecting said at least one of the primary color images again;
- and
- symmetrizing the primary color images based on which of the primary color images is to be reflected an odd number of times and which of the primary color images is to be reflected an even number of times to make the luminous intensity distributions of the color images substantially equal, the primary color images being symmetrized by providing a light shield layer for each light valve in which one of the light shield layers has a mirror-like symmetric pattern of openings relative to the pattern of openings of the other two light shield layers by providing two light valves with a liquid crystal material having a twist in a first direction and the remaining light valve with a liquid crystal material having a twist in the opposite direction, the color images produced by said two light valves reflected an even or odd number of times and the color image produced by said remaining light valve being reflected an odd or even number of times, respectively, and by providing that each liquid crystal light valve includes an active switching matrix array with the active switching matrix of said remaining light valve in mirror-like arrangement relative to the arrangements of the active switching matrixes in said two light valves.
3 more elements
A method of producing substantially the same luminous intensity distribution for each of three different liquid crystal light valves within a projection-type display device comprising:
- segregating light into its primary colors;
- directing the colored light towards the three liquid crystal light valves for producing corresponding colored images;
- reflecting at least one of the primary colored images an odd number of times;
- and
- symmetrizing the primary colored images based on which of the primary colored images is to be reflected an odd number of times and which of the primary colored images is to be transmitted through said optical synthesizer to make to luminous intensity distributions of the colored images substantially equal.
2 more elements
A projection-type display device comprising:
- means for producing colored lights;
- liquid crystal light valve means associated with each colored light for producing colored images;
- optical synthesizing means for combining the colored images to form a synthesized image;
- and
- projection lens means for projecting the synthesized image toward an object for viewing of the image;
- said optical synthesizing means including reflection means for reflecting at least one of the colored images and directing the synthesized image toward the projection lens means;
- wherein the liquid crystal light valve means includes more than one light valve each of which has a light shield layer for shielding portions of the light valve from light passing through the light valve and includes a repeated pattern of openings, the repeated pattern of openings of one of said light shield layers being mirror-like symmetric to the pattern of openings of each of the other light shield layers.
4 more elements
A projection-type display device comprising:
- means for producing colored lights;
- liquid crystal light valve means associated with each colored light for producing colored images;
- optical synthesizing means for combining the colored images to form a synthesized image;
- and
- projection lens means for projecting the synthesized image toward an object for viewing of the image;
- said optical synthesizing means including reflection means for reflecting at least one of the colored images and directing the synthesized image toward the projection lens means;
- wherein the liquid crystal light valve means includes more than one light valve each of which has a plurality of switching elements for controlling the photoelectric characteristics of the light valve, the switching elements of one light valve having a mirror-like symmetrical arrangement relative to the arrangement of switching elements of each of the other light valves.
4 more elements
Dependencies are inferred from the claim text.