United States of America As Represented by the Secretary of the Air Force

The Mead Corporation

Biswa N Ganguly

Larry P Goss

Suresh C Paranjpe

John L Dressler

Bertram VanBreemen

William M Roquemore

Benjamin Sarka

Darryl D Trump

Brian A Hibbeln

Sigmund W Kizirnis

Dennis F Grosjean

A high voltage high current semiconductor switching device in which the tendency to incur premature electrical breakdown through carrier channels formed slightly below the surface of the semiconductor material is avoided. This avoidance occurs through use of a current dispersing electrically insulating element added at one extremity of the switching device structure. The added current dispersing element may be in the form of a thin oxide layer added at the anode end of the device in the case of a silicon embodiment of the invention. Tunneling conduction is believed to occur in this silicon dioxide layer and such conduction has the effect of dispersing the current through the silicon over a cross-sectional area sufficiently large to prevent the current filamentation, localized heating, thermal runaway and self destruction sequence often encountered in previous arrangements of higher energy semiconductor switches. Although several semiconductor materials are believed feasible for fabricating the device, a silicon material embodiment is primarily disclosed.

Photoconductive switching with thin layer enhanced breakdown

Fiber optic probe apparatus usable for measuring temperatures with increased dynamic range and frequency domain response and desirable measurement accuracy. A black body signal source, fiber optic signal coupling, and extension of the transducer dynamic range with optical multiplexing are employed; the instrument operates in the range of 1.6 micrometers of optical energy wavelength and preferably employs recently improved indium gallium arsenide photodiode transducer devices and transducer frequency domain compensation. Use of the instrument in measuring combustion flame transient temperatures is disclosed.

Fiber optic pyrometry with large dynamic range

A novel laser beam deflection system and method for temperature measurement of combustion flames of known composition is described which comprises a thin wire for placement at a predetermined location within the flame; a pulsed laser source for directing a pulsed beam onto the wire for heating the wire and immediately surrounding gases of the flame to produce an acoustic pulse in the flame; a pair of probe laser sources for directing parallel probe beams through the flame in predetermined spaced relationship to each other and to the wire, and a pair of detectors and associated electronics for detecting the respective deflections of the probe beams resulting from interactions with the pulse and measuring the time difference between respective deflections of the probe beams to determine the speed of the acoustic pulse through the flame and the temperature of the flame from the speed determination.

Non-perturbing beam deflection system and method for high repetition

Glass fibers having an etchable or leachable core are used to fabricate glass nozzle arrays. A plurality of fibers are aligned in spaced parallel relationship with one another, and their major longitudinal portions are encapsulated with either a resin material or solder glass to form a block of material. This block is sliced orthogonally to the longitudinal axes of the fibers to form thin sections of nozzle arrays. After lapping and polishing, the inner cores of the glass fibers are etched out to form orifices. The use of solid core glass fibers prevents the nozzles from filling or becoming clogged with debris and dust from preceding forming operations.

Method of fabricating a glass nozzle array for an ink jet printing

An image scanner for scanning a document along a plurality of scan lines and providing a plurality of print control signal pulses in response to the image density of the document along the scan lines includes a means for projecting a moving document image onto a focal plane and a sensor array positioned in the focal plane. The sensor array includes columns of sensors extending parallel to the direction of image movement and a shift register associated with each column for sensors for shifting electrical outputs from the sensors in the direction of image movement. In a line copy mode of operation, the electrical outputs are shifted at the same rate at the rate of movement of the image such that the given pixel on the image is scanned sequentially by each of the sensors in a column. The electrical outputs are compared with a predetermined reference label to produce a print control signal. In a gray scale mode of operation, the outputs from all of the sensors in a sensor column are accumulated to produce an output related to the average image density of the area scanned by the column of sensors. The electrical outputs resulting from successively scanning overlapping image areas are integrated until a predetermined reference level is reached to produce a print control signal.

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Beavercreek, OH, United States of America

Biswa N Ganguly