Greyhawk Systems, Inc.

Hewlett-packard Company

Bell Telephone Laboratories

Sharp Corporation

Frederic J Kahn

Jerry Leff

David E Stepner

Bryan E Loucks

Kenneth G Witte

Linden J Livoni

Paul N Kendrick

Henryk Birecki

Robert A Burmeister

Duane A Haven

Gary N Taylor

Evan D Laganis

David E Slobodin

Richard Albert

Michael Stefanov

Matthew Bone

Neil G Bergstrom

Howard Simmons, Iii

A liquid crystal light valve, comprising a layer of liquid crystal for storing image information and a photoconductor aligned with the liquid crystal and positioned in closed proximity thereto for effecting an electric field applied across the liquid crystal. Apparatus is provided for simultaneously applying an electric field across the liquid crystal and photoconductor while impinging optical image information on the photoconductor, the photoconductor and applied field combining to produce a modified electric field across the liquid crystal which impresses the image information on the photoconductor into the liquid crystal.

Apparatus for and method of operation of smectic liquid crystal light

A hard copy such as a printed wiring board is fabricated by exposing to radiation a liquid crystal cell in which a desired pattern is written and directing the pattern-carrying radiation projected from the cell by transmission or reflection to a substrate which is coated with a material sensitive to the radiation and disposed alignedly at an exposure position by optical registration. The duration of the exposure is controlled for a given light intensity and for the type of the coating material. A pattern may be written in one cell substantially simultaneously as another cell is used for the projection imaging. After a produced pattern is compared with a reference pattern, corrections may be effected through a processor which controls the writing of a pattern in a cell.

Fabrication of printed wiring boards by projection imaging

An optical system having a projection lens for imaging a scattering type thermo optic cell on an image receiving surface, comprising optical source apparatus for generating an optical beam and an image created on the scattering type thermo optic cell having a minimum feature size, the optical beam propagating through the object on the scattering type thermo optic cell. Also provided is a condenser system which illuminates the scattering cell and underfills the aperture of the projection lens, thereby creating a partially coherent imaging system. As a result, a relatively higher contrast ratio for the minimum features of the image is obtained at the image receiving surface.

Partially coherent optical system with scattering type object

An image projection apparatus in which an image object plane contains a plurality of reflecting images and a light source and optical system projects a beam on each of said plurality of images. Spaced projection lenses are positioned to receive the light reflected from the images and direct the light on a projection surface with the plurality of reflected images in coregistration.

Apparatus and method of forming and projecting high precision optical

An apparatus for a liquid crystal image projection system having a liquid crystal cell, including optical apparatus for inducing a uniform texture of scattering centers in a liquid crystal cell by impinging a pulse of optical energy on the liquid crystal cell, thereby the optical energy is absorbed and converted to thermal energy heating the liquid cyrstal to a second temperture, the end of the pulse bringing about a cooling which causes the liquid crystal centers within the liquid crystal cells to scatter in a uniform texture.

Biphenyl derivatives for photostabilization in pulsed optical darkening

An active matrix liquid crystal light valve is disclosed. The addressing matrix has an array of electrodes to create electric fields across the liquid crystal layer. The light valve has a continuous nonconductive reflector layer, separate and distinct from the electrode array of the active matrix. This light valve has a leveling layer disposed on the active matrix to form a planar surface. The reflector layer is formed as a continuous sheet on the planar surface of the leveling layer. An additional invention is the use of fringing fields to switch substantially all of the liquid crystal, including areas not directly over the electrodes.

Active matrix liquid crystal liquid crystal light valve including a

An image projection apparatus in which an image object plane contains a plurality of reflecting images and a light source and optical system projects a beam on each of said plurality of images. Spaced projection lenses are positioned to receive the light reflected from the image and direct the light on a projection surface with the plurality of reflected images in coregistration.

An apparatus for projecting high precision optical images with a selective heating source, advantageously a laser, on a writable, erasable, editable electronic slide and simultaneously or sequentially projecting the images in registration, onto a receiving surface such as a projection screen or photosensitive material, in the former case for the purpose of displaying the projected image and in the latter case for the purpose of creating a hard copy of the projected image.

An optical erasable liquid crystal disc memory system is provided which includes a rotating liquid crystal information storage medium confined by two surfaces. Various thin films on the surfaces are used to establish the proper conditions within the liquid crystal medium which, in combination with incident radition and applied voltages, accomplish the read, write, and erase functions. The resulting system provides a locally erasable optical disc memory with high density storage, long-term information stability under a wide range of temperature, and read, write, and erase times compatible with modern high speed computers.

Liquid crystal disc memory system

An optical erasable thermally addressed, liquid crystal information storage and retrieval system is disclosed having an information density and the order of 10.sup.7 bits/cm.sup.2 while using liquid crystal cell thickness of relatively standard dimensions (.about.10 .mu.m). The system includes two substrates containing a smectic-A phase liquid crystal medium, and several thin filing attached to the substrates for establishing the proper conditions within the liquid crystal medium for creating a radiation scattering defect which is small in size (&lt;1.0 .mu.m), and for performing erase functions in conjunction with an optical beam. A device according to the invention has an array of such defects in the liquid crystal medium representing information bits, with the array having a ratio of the shortest distance between individual defects to the thickness of the liquid crystal medium of less than 0.4, for a liquid crystal medium having thickness larger than 5 microns.

Liquid crystal information storage and retrieval system

The use of dopants enhances optical contrast and range of writing speeds in liquid crystal display devices. Such dopants are characterized by greater solubility in the isotropic phase than in the liquid-crystalline phase of a liquid crystal material.

Growing community of inventors

Palo Alto, CA, United States of America

Frederic J Kahn