Hughes Aircraft Company

Xonics, Inc.

Other

Murray S Welkowsky

Jan Grinberg

Eric Phillip Muntz

Uzi Efron

Paul O Braatz

Arno G Ledebuhr

William P Bleha

Philip G Reif

John B Fenn, Jr

Norman W Goodwin

Yuri Owechko

Thomas R O'Meara

Michael J Little

John H Lewis

Chiung-Sheng Wu

Alan S Hersh

Nobuo J Koda

Frank V Allan

Stephen D Blake

Phillip G Reif

Robert N Schwartz

Emil M Kaegi

Fremont Reizman

Kathrine J Lewis

Nubuo J Koda

P K Vasudev

A method for producing optically flat thin semiconductor wafers (12) bonded to a substrate (16). The wafer (12) is bonded without touching the top surface of the wafer (12). Also, the bond is created without the use of pressure. Electrostatic bonding, or contact bonding or both may be employed. After the wafer (12) is bonded, it is then polished to a desired thickness and flatness. After contact bonding and polishing the wafer (12) may then be removed for further processing. The wafer may then be contact bonded to a final substrate (b 34) or electrostatically bonded to a final substrate (42). The contact bonding technique may also be employed as a means for holding the wafer (12) during precise photolithography. The optical flatness achieved permits improved yields over conventional means for securing wafers during photolithography. The electrostatic bonding technique permits extremely thin optically flat silicon wafers to be produced.

Method of producing optically flat surfaces on processed silicon wafers

An infrared (IR) simulator is disclosed in which an array of pixels is defined on an insulative substrate by resistor bridges which contact the substrate at spaced locations and are separated from the substrate, and thereby thermally insulated therefrom, between the contact locations. Semiconductor drive circuits on the substrate enable desired current flows through the resistor bridges in response to input control signals, thereby establishing the appropriate IR radiation from each of the pixels. The drive circuits and also at least some of the electrical lead lines are preferably located under the resistor bridges. A thermal reflector below each bridge shields the drive circuit and reflects radiation to enhance the IR output. The drive circuits employ sample and hold circuits which produce a substantially flicker-free operation, with the resistor bridges being impedance matched with their respective drive circuits. The resistor bridges may be formed by coating insulative base bridges with a resistive layer having the desired properties, and overcoating the resistive layers with a thermally emissive material. The array is preferably formed on a silicon-on-sapphire (SOS) wafer. Arrays of electromagnetic radiation bridge detectors may also be formed, with the bridges having either resistor, thermocouple or Schottky junction constructions.

Radiation detector array using radiation sensitive bridges

An adaptive optics system is disclosed which has a phase detector to detect phase distortions acquired by an input beam, and a separate phase adjustor which predistorts a transmission beam so that it is restored to its proper phase during transmission back through the same medium travelled by the input beam. The phase adjustor consists of a liquid crystal mechanism with an area substantially greater than that of the phase detector, thereby permitting high power operation. Liquid crystal pixels in the phase adjustor have dual transistor signal storage circuits which apply operating signals to the pixels without significant decay or flicker. The phase adjustor can be constructed in either a reflective or transmissive mode. Two phase adjustors may be placed in series to enhance response time and/or process an unpolarized beam. A data processor interfaces between the phase detector and phase adjustor. The data processor may include a capability for providing phase adjustment information for a plurality of transmission wavelengths based upon the detected distortion of an input beam at only one of the wavelengths.

Liquid crystal adaptive optics system

Flicker free infrared simulator with resistor bridges

A liquid crystal light valve is provided with a microgrid of grooves in the photoconductor surface to divide the photoconductor into high resolution pixels. The liquid crystals fill the grooves to seal them and contribute to a potential barrier at the grooves that prevents lateral charge migration between pixels. In a metal oxide semiconductor (MOS) embodiment an oxide layer extends over the pixels and partially overhangs the grooves. A metal matrix mirror is formed over the insulative layer, and extends into a portion of the grooves to shield the underlying silicon from photoactivation while maintaining an electrical isolation between pixels.

Liquid crystal light valve with grooved microgrid and method of forming

A video projector system is used to produce a substantially flicker-free optical video image, which is then applied to a liquid crystal light valve (LCLV) to modulate and impose the video image upon a readout infrared (IR) or ultra-violet (UV) beam. The optical projector preferably employs a high impedance electro-optical crystal which receives a video pattern of electric charges from an electron beam operating in conjunction with a conductive grid adjacent the crystal, the grid receiving a video signal in synchronism with the scanning electron beam. The LCLV is preferably of the type which includes a liquid crystal layer integrated within a metal-oxide-semiconductor structure. The undesirable effects of any asymmetry between the WRITE and ERASE response times of the video projector are reduced by making the WRITE response faster than the ERASE response, and having the LCLV operational voltage threshold above the voltage level attained at the end of an ERASE period. An incomplete video projector ERASE thus results in a complete LCLV ERASE.

System and method for producing a flicker-free video image

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

A pulsed readout technique is described for liquid crystal light valves which eliminates the problem of readout beam leakage through the light valve mirror. The readout beam is pulsed on only when the light valve's semiconductor layer is out of a depletion state. This can occur during an accumulation state or, in certain applications, during a specially inserted quiescent period in the light valve voltage cycle. The invention is applicable to light valves with various types of modulating inputs, and can be used with either dielectric or metal matrix mirrors.

Light valve system and method with pulsed readout

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 hand-held hair dryer with a high level of sound and vibration suppression. The hair dryer includes sound absorbing material attached to the inner surface of the hair dryer housing and having a selected density to provide maximum sound absorption in a relatively thin layer of material. A motor with integral fan is mounted on the hair dryer handle by an elastomeric vibration isolator so as to be isolated from the dryer housing. The fan blade noise, in part absorbed by the sound absorbing material on the inner surface of the hair dryer housing, is further grossly suppressed by special sound absorbing structures located at the extreme inlet and outlet of the housing, such as a structure functioning as a Helmholtz resonator, with that structure itself being vibration isolated from the hair dryer housing. Preferably an aerodynamically designed heater is used downstream of the fan to minimize the vortex noise. Also, vibration isolation between the handle and the main housing assembly provides good low frequency vibration absorption, particularly with the motor being supported through the handle rather than through the main housing itself. Various embodiments and other features of the invention are also disclosed.

Low noise hand-held hairdryer

An electrostatic imaging chamber providing a real time visual image. An imaging chamber with electrophoretic particles in the electrode gap, with the particles being selectively moved to a transparent electrode as a result of the electrostatic charge image formed by incoming radiation. An imaging chamber which can be cyclicly operated at a relatively high repetition rate, typically 10 to 20 images per second, thereby providing real time viewing of the object. A conductivity control layer at the gap for discharging the electrostatic charge image each cycle after viewing.

Image charge relaxation in electrophoretic displays

A receptor sheet for use with an electronradiography system and having a relatively thick core layer bonded between a relatively thin image carrier layer and a relatively thin antistatic conducting layer.

Electron radiograph receptor

A fountain for moving liquid toner into engagement with a receptor for developing an electrostatic image into a visible image. A fountain for providing improved edge enhancement in an image, and incorporating an electrode positioned at the bottom of a liquid toner pool formed by electrical insulating end, side and bottom members.

Electrostatic fountain developer

A photo-optical imaging system suitable for use in an electronradiography system which produces an electrostatic charge image at an electrode. An electrode having a photoconductor layer and a transparent electrical conducting layer, with the charge image at the photoconductor layer. A light beam and various arrangements for scanning the beam over the photoconductor layer through the transparent layer for selectively transferring charge to the electrically conducting layer through the photoconductor layer as portions of the photoconductor layer are illuminated by the beam, and a data storage unit for receiving and storing data corresponding to the magnitude of charge at the photoconductor layer.

Direct charge readout electron-radiography chamber

An electrostatic image developer of the powder cloud type incorporating an image field screen or plate adjacent the receptor sheet carrying the electrostatic image, and including means for varying the image field plate potential and spacing during the developing cycle for improved contrast in the resultant visual picture. A method of developing including varying the image field screen potential and spacing during the developing cycle.

Growing community of inventors

Chatsworth, CA, United States of America

Murray S Welkowsky