Hughes Aircraft Company

Hughes-jvc Technology Corporation

William P Bleha

Jan Grinberg

Paul O Braatz

Murray S Welkowsky

Arno G Ledebuhr

Stephen J Reinsch

Alexander D Jacobson

Paul F Robusto

Nobuo J Koda

Eliezer Wiener-Avnear

Philip G Reif

Phillip G Reif

Harry W Giehll

Nubuo J Koda

A projection system includes first and second light valve projectors which project a composite image onto a screen by overlapping the first and second images in an overlap region. Each projector includes a light source, a light valve for reflecting or transmitting image light, a condensing lens for directing light from the light source to the light valve, and a projection lens. An improved light valve projector includes a blending device, associated with the first and second light valve projectors and being located in the path of the light between the light valve and the projection lens, the light source and the condensing lens, or the projection lens and the screen. The blending device smoothes off-state and on-state illumination levels in the overlap region without reducing the contrast ratio of said light valve projector. The blending device includes physical devices such as filters, solid masks, and/or a combination thereof as a substitute for electronic blending. By physically blending off-state illumination levels, the present invention avoids loss of contrast ratio associated with electronic blending.

Projected image blending for multiple images

An electron beam addressed liquid crystal light valve (LCLV) produces an AC voltage across a liquid crystal layer from a single polarity electron beam, and exhibits very high resolution. A thin layer of partially conductive material is deposited on a support membrane on the electron beam side of the liquid crystal. A conductive, electron beam permeable sheet is formed on the back of the partially conductive layer. Electrons from the beam are absorbed by the partially conductive layer, and then flow back out to the conductive sheet to produce an AC voltage prior to the next electron beam scan. The conductive sheet is connected in circuit with a transparent electrode which provides a voltage reference on the readout side of the liquid crystal. The device is designed with electrical parameters that produce a discharge rate from the partially conductive layer fast enough to complete an AC cycle between successive electron beam scans, but slow enough for the liquid crystal to respond and produce an image. A separate mirror can be provided to reflect the readout beam back through the liquid crystal, or the conductive sheet can itself serve as a mirror.

Electron beam addressed liquid crystal light valve with input sheet

An electron beam addressed crystal light valve (LCLV) produces an AC voltage across a liquid crystal layer from a single polarity electron beam, and exhibits very high resolution. A mirror and a thin layer of partially conductive material are deposited on a support membrane on the electron beam side of the liquid crystal. The partially conductive layer is divided into a series of pixel elements by a conductive matrix which faces the electron beam. Electrons from the beam are absorbed by the partially conductive layer to establish a negative voltage across the liquid crystal, and then flow out to the conductive matrix to produce an AC voltage prior to the next electron beam scan. The conductive matrix is connected in circuit with a transparent electrode which provides a voltage reference on the readout side of the liquid crystal. The elements of the device are designed with electrical parameters that produce a discharge rate from the partially conductive layer fast enough to complete an AC cycle between successive electron beam scans, but slow enough for the liquid crystal to respond and produce an image.

Electron beam addressed liquid crystal light valve

A compact, full color, light projection system using a liquid crystal light valve (LCLV) and a unique combination of optical devices. The LCLV operates to modulate a light beam which has been polarized by one of the optical devices. The modulated light beam is converged and registered by other optical devices to form the output image.

Liquid crystal light value color projector

Method of and apparatus for operating an image display system using a hybrid field effect liquid crystal light valve of the type wherein the molecules of the nematic liquid crystal layer are helically twisted through an acute angle. A polarized projection beam is oriented with its polarization direction within the acute twist angle and applied to a reflective face of the light valve. A writing light input image is applied to a photoresponsive opposite face in order to modulate the reflected projection beam. An electric field applied across the light valve is adjusted between two levels to produce either a simultaneous display of multicolor symbology and achromatic (black-white) gray scale images or a separate display of either one of them.

Method of and apparatus for a multimode image display with a liquid

Method of and apparatus for operating an electro-optical system for producing high quality images from a liquid crystal light valve. A polarized projection beam is directed to the reflective surface of a liquid crystal light valve for polarization modulation by means of an input image. The beam is polarization analyzed to thereby generate an output image which typically suffers from color and brightness defects caused by economically unavoidable tolerance variations in the electro-optical system. A second beam of light is generated having a light of a selected color different from the projection beam, is spatially varied in intensity by a spatially graded filter, and super-imposed on the output image so as to eliminate the color and brightness defects as well as enhance color contrast and brightness of the image. The color of the second beam is selected so as to mask background color variations and improve color contrast on the output image while the graded intensity filter is selected to additively compensate for background brightness variation of the output image.

Liquid crystal light valve

This invention is directed to a semiconductor structure that includes at least one wafer that is fully depleted of all mobile carriers and is used as a medium for the movement of spatially modulated signal represented by charge carriers through the wafer with a spatial resolution that is smaller than the thickness of the wafer. This may be used in the form of a continuous high resolution silicon photodiode substrate to serve as an image input means for an electro-optical display medium, such as a liquid crystal. Next to the photoactivated substrate is a liquid crystal and next to the crystal is a transparent electrode. The photodiode is reverse biased and both of its sides are depleted of all mobile charges throughout its entire thickness. Thus, charges generated in the substrate move to the display not by diffusion as in prior art devices (e.g. the solid state silicon vidicon) but by the influence of the electric field which tends to minimize their lateral spread and thereby achieves a high spatial resolution in spite of the continuous character of this silicon diode device.

High resolution continuously distributed silicon photodiode substrate

There is disclosed a reflective type liquid crystal light valve means for converting a visible wavelength dynamic image to an infrared wavelength dynamic image. The device employs an infrared reflecting and visible transmitting indium-tin-oxide film which is external to the liquid crystal layer and active films and which also serves as a conductive electrode for the device. In operation, a visible image is transmitted through a visible transmitting faceplate and through this ITO film to a photosensor to modify its impedance. An infrared projection beam is transmitted through a second infrared transmissive faceplate, through the liquid crystal means and the photosensor to the IR reflective dichroic film and thence back through the rest of the liquid crystal cell for projection.

Visible-to-infrared converter light valve

There is disclosed an anisotropically conductive interface comprising a plurality of cermet and dielectric layers for use in electro-optical devices to separate a substrate driver from an electro-optical display medium to prevent display light from affecting the driver. The substrate may be a photosensor, a charge coupled device or other matrix addressing circuitry arrangement. In general the substrate is one which can provide spatially modulated voltage and/or current patterns. The display medium may be a liquid crystal, an electro-chromic, an electro-luminescent material or the like. The interface provides direct current conductivity through the interface, insulative maintenance of the spatial modulation of the signal across the interface, light reflectivity, and high attenuation of transmitted light.

Growing community of inventors

Carlsbad, CA, United States of America

William P Bleha