Liquid crystal display for projection systems
First Claim
1. An apparatus for use in conjunction with a means for projecting a beam of light along an optical path onto a surface, said apparatus, responsive to a means for generating display images, for generating liquid crystal display images on a screen when inserted into said optical path, said means for projecting including a light source, said apparatus comprising:
- control means, responsive to said generating means, for generating crystal means energizing signals;
twisted nematic crystal means for controlling polarization of light passing therethrough in response to localized energization and de-energization of said crystal means;
means, responsive to said control means signals, for locally energizing said crystal means;
back polarizing means, disposed in said beam and located between said crystal means and said light source, for polarizing light passing therethrough;
front analyzing means, located between said crystal means and said surface, for allowing light of a selected polarizing to pass therethrough and for blocking light not having said selected polarization; and
visible light transparent insulation means disposed in said beam and located between said light source and said crystal means.
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Accused Products
Abstract
Disclosed is a liquid crystal display unit comprising liquid twisted nematic liquid crystal material sandwiched between two polarizers. Transparent electrodes are provided on each side of the layer of liquid crystal for locally energizing liquid crystal material in the vicinity of two energized transparent electrodes. Polarized light passing through one polarizer is twisted or not twisted depending upon the energization state of the liquid crystal material and depending upon the second polarizer orientation does or does not pass therethrough. Accordingly, depending upon energization locations, images are formed which can be projected upon a screen. In preferred embodiments the liquid crystal display unit is used in conjunction with a cabinet to provide a low stress work station. A further embodiment includes a folded optical path in combination with the liquid crystal display so as to provide a compact projector. When operating in conjunction with an overhead projector, a preferred embodiment of the present invention is powered by light energy from the overhead projector and in a further preferred embodiment is controlled through the use of infrared or other non-visible electromagnetic communication.
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Citations
18 Claims
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1. An apparatus for use in conjunction with a means for projecting a beam of light along an optical path onto a surface, said apparatus, responsive to a means for generating display images, for generating liquid crystal display images on a screen when inserted into said optical path, said means for projecting including a light source, said apparatus comprising:
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control means, responsive to said generating means, for generating crystal means energizing signals; twisted nematic crystal means for controlling polarization of light passing therethrough in response to localized energization and de-energization of said crystal means; means, responsive to said control means signals, for locally energizing said crystal means; back polarizing means, disposed in said beam and located between said crystal means and said light source, for polarizing light passing therethrough; front analyzing means, located between said crystal means and said surface, for allowing light of a selected polarizing to pass therethrough and for blocking light not having said selected polarization; and visible light transparent insulation means disposed in said beam and located between said light source and said crystal means. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18)
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Specification