Hughes Aircraft Company

Hughes Electronics Corporation

Hrl Laboratories, LLC

Raytheon Company

California Institute of Technology

University of Southern California

Wintek Corporation

Shin-Tson Wu

Tsung-Yuan Hsu

David M Pepper

Chiung-Sheng Wu

Qing Feng Zhang

Daniel Frederic Sievenpiper

Seth R Marder

Robert Y Loo

Uzi Efron

J David Margerum

Yi-Chun Wu

Anson Y Au

Khoon-Cheng Lim

Larry Raymond Dalton

Wayne P Schoenmakers

Mary E Neubert

Hsiang-Hui B Meng

Zheng Chai

High-dielectric colorless or virtually colorless dopants for low-voltage and tunable clearing temperature liquid-crystal devices. These dopant compounds help reduce the operation voltage for both polar and non-polar liquid-crystal (LC) mixtures. Methods for making and using these dopant compounds are also disclosed.

Dopants for liquid-crystal devices

New tolane and bis-tolane compounds:in which X is F (fluoro), CN (cyano), OCF(trifluoromethoxy), or NCS (isothiocyanate) at least one of the pairs Yand Y, Zand Z, and Aand Aare fluoro groups.

Polar tolane liquid crystals

A high contrast ratio reflective STN LCD structure including an glass substrate panel, a liquid crystal layer and a lower glass substrate panel. The upper glass substrate panel includes only one optical deflector. The phase compensating film disposed under the optical deflector has a quarter of wavelength. The liquid crystal molecules of the liquid crystal layer have torsion angle within 180&deg; to 210&deg;. The retardation value of the liquid crystal molecules is within 580 nm to 650 nm.

High contrast ratio reflective STN LCD structure

A tuneable impedance surface for steering and/or focusing a radio frequency beam. The tunable surface comprises a ground plane; a plurality of elements disposed a distance from the ground plane, the distance being less than a wavelength of the radio frequency beam; and a capacitor arrangement for controllably varying the capacitance of adjacent top plates, the capacitor arrangement including a dielectric material which locally changes its dielectric constant in response to an external stimulus.

Electronically tunable reflector

Dopants for improving the thermal and UV stability of high birefringence liquid crystals

Colorless and low viscosity compounds for low voltage liquid crystal operation

A new class of asymmetric polar diphenyldiacetylene liquid crystal compounds and method for preparation are disclosed. The new class of liquid crystal compounds comprises the basic structure:

Polar diphenyldiacetylene liquid crystals

An optical display employs a liquid crystal cell with a d.DELTA.n/.lambda. of approximately 0.2-0.8, allowing the cell's optical transmissivity to be modulated by an applied electric field through a dominant non-polarization rotation effect. For visible wavelengths, d.DELTA.n is approximately 0.1-0.4 microns, with a preferred value of about 0.25 microns. Applications include a reflective projection display in which input light is polarized at a greater than 0.degree. and less than 90.degree. angle, preferably about 20.degree., to the input LC directors of a twisted nematic cell; a reflective direct view system in which a quarter-wave plate is substituted for a polarization analyzer; and both a reflective and a transmissive guest-host system in which optical absorption by dye molecules is the dominant modulation mechanism.

Reflective liquid crystal display and transmissive dye-doped liquid

Reflective-type liquid crystal display using polarizer free mixed-mode

Reflective-type liquid crystal displays using mixed-mode twist nematic

An imaging system that can tolerate high intensity optical beams without a reduction in the system's field-of-view, comprises an imager, a fiber array positioned at the image plane of the imager, a sensor array positioned at the output end of the fiber array, a panel display positioned in proximity of the fiber array and an image processor for electronically processing the information from the sensor array.

Laser-hardened eye protection goggles

A focal-plane detector imaging system that can tolerate higher intensity optical beams than prior systems, without a reduction in the system's field-of-view, comprises an imaging lens, a fiber optic array positioned at the image plane of the imaging lens and an image detector positioned at the output end of the fiber optic array. The optical fibers that make up the fiber array have core diameters that are larger than the focal spot of an incoming optical beam. In operation, the fiber array transfers the imaged scene to the image detector at its output end. The focused optical beam is also transferred to the image detector at the array's output end, but its diameter is enlarged due to its angular divergence. In a preferred embodiment, the f-number of the imaging lens, diameter of the fiber cores, and the lengths of the fibers in the array are designed so that, as the power of an incoming optical beam increases, the optical damage threshold of the fiber array is reached before that of the image detector. An LCLV imaging system that incorporates the present invention is also provided.

Focal-plane detector imaging system with improved optical damage

A new class of asymmetrical diphenyl-diacetylene liquid crystal compounds exhibit ideal properties for formulating eutectic mixtures suitable for infrared and microwave applications. The new class of liquid crystal compounds comprise asymmetrical nonpolar end groups. These compounds exhibit low melting points, wide nematic temperature range and low heat fusion enthalpy. Eutectic mixtures containing entirely diphenyl-diacetylene homologs using the new compounds have high birefringence, low viscosity and wide nematic range. These unique properties are especially advantageous when these mixtures are used in infrared spatial light modulators, high speed liquid crystal modulators and polymer dispersed liquid crystals shutters. The new asymmetrical diphenyl-diacetylene liquid crystal compounds comprise the following basic structure:

Asymmetrical nonpolar diphenyl-diacetylene liquid crystals eutectic

A liquid crystal (LC) display method and apparatus applies respective active LC bias voltages to both a master LC cell, and a phase compensation LC cell for the master cell. The bias voltages are selected to reduce the response time of the master cell, and to establish a common multicolor dark state for that cell. With a proper selection of the bias voltages, the products of the liquid crystal thickness and birefringence for each cell are substantially equal and mutually cancel. A bias voltage is first established for one cell, and the bias voltage for the other cell is then scanned to locate the point of mutual cancellation. A range of different bias voltages are possible, and a suitable bias is selected to balance response time against the required operating voltage range. A multicolor display system using only a single light valve can be realized.

Liquid crystal display method and apparatus with tuneable phase

An eye protection device 10 comprising a liquid crystal light valve 20 for providing an image of a scene. The light valve images the field of view under observation in a spectral range which matches the human eye. It will automatically reject a laser threat by simply absorbing the energy therefrom in the photoconductive layer thereof. Thus, the invention 10 provides a broad spectrum, zero response time, angle and polarization independent, sensitive eye protection device having a fast recovery time, high extinction coefficient and a high damage threshold. Hence, the invention is expected to be of significant utility to personnel operating in hostile environments.

Growing community of inventors

Northridge, CA, United States of America

Shin-Tson Wu