Patents

Daniel M. Makowiecki and Alan F. Jankowski
Magnetron Sputtered Boron Films
U.S. Patent 5,766,747
June 16, 1998
A method for the production of thin boron and titanium-boron films by magnetron sputter deposition. The magnetron sputter deposition method requires the use of a high-density crystalline boron sputter target prepared by hot isostatic pressing. Thin boron films prepared by this method are useful for producing hardened surfaces or for surfacing machine tools and for making ultrathinband pass filters as well as the low-radioactive element in low-radioactive/high-radioactive optical components. They contain no morphological growth features, which are found in thin films prepared by various physical vapor-deposition processes.

Thomas E. McEwan
Light Beam Range Finder
U.S. Patent 5,767,953
June 16, 1998
A laser "tape measure" capable of measuring the distance to a target with a resolution of less than 1 millimeter and a precision of better than 0.1 percent. A transmitter (including a laser diode) transmits a sequence of electromagnetic pulses in response to a transmit-timing signal. A receiver samples reflections from objects within the field of the sequence of visible electromagnetic pulses with controlled timing in response to a receive-timing signal. In response to the samples, the receiver generates a sample that indicates distance to the object causing the reflections.

Thomas E. McEwan
Short Range Micro-Power Impulse Radar with High Resolution Swept Range Gate with Damped Transmit and Receive Cavities
U.S. Patent 5,774,091
June 30, 1998
A radar range finder and hidden-object locator based on ultrawideband radar with a high-resolution swept-range gate. The device generates an equivalent time-amplitude scan with a typical range of 4 inches to 20 feet and an analog range resolution limited by a jitter of about 0.01 inch. A differential sampling receiver eliminates ringing and other aberrations induced by the near proximity of the transmit antenna, so a background subtraction is not needed, which simplifies the circuitry while improving performance. Clutter in the receive signal is reduced by decoupling the receiver and transmit cavities by placing a space between them, using conductive or radiative damping elements on the cavities, and placing terminating plates on the sides of the openings. Uses include fluid-level sensing, automotive radar, hidden-object location, and collection of vehicle count and speed data for traffic control.

Abraham P. Lee, Peter A. Krulevitch, M. Allen Northrup, and Jimmy C. Trevino
Micromachined Actuators/ Sensors for Intratubular Position/Steering
U.S. Patent 5,771,902
June 30, 1998
Micromachined thin-film cantilever actuators with the means for individually controlling the deflection of the cantilevers, valve members, and rudders for steering the actuators through blood vessels or positioning them within a blood vessel. The cantilever actuators include tactile sensor arrays mounted on a catheter or guide-wire tip for navigation. They also include tissue identification, shape-memory-alloy-film-based catheter/guide-wire steering mechanisms, and rudder-based steering devices that allow the selective actuation of rudders that use flowing blood to help direct the catheter through the blood vessel. While particularly adapted for medical applications, these cantilever actuators can be used for steering through piping and tubing systems.

Kurt H. Weiner
Method for Producing Silicon Thin-Film Transistors with Enhanced Forward Current Drive
U.S. Patent 5,773,309
June 20, 1998
A method for fabricating amorphous silicon thin-film transistors (TFTs) with a polycrystalline silicon surface channel for enhanced forward current drive. The method is particularly adapted for producing top-gate silicon TFTs, which have the advantages of both amorphous and polycrystalline silicon TFTs, but without the problem of leakage current of polycrystalline silicon TFTs. The method uses a pulsed excimer laser to create a thin polycrystalline silicon layer at the amorphous silicon/gate-insulator surface. This layer has an increased mobility compared with that of the amorphous silicon during forward device operation so that increased drive currents are achieved. In reverse operation, the polysilicon layer is relatively thin compared to the amorphous silicon, so that the transistor exhibits the low leakage currents inherent in amorphous silicon. Silicon TFTs can be used as pixel switches in an active-matrix liquid crystal display to improve display refresh rates.

Daniel M. Makowiecki and Robert S. Rosen
Limited-Life Cartridge Primers
U.S. Patent 5,773,748
June 30, 1998
A cartridge primer using an explosive that can become inactive in a predetermined period of time. The primer's explosive or combustible material is an inorganic reactive multilayer (RML). The reaction products of the RML are submicrometer grains of noncorrosive inorganic compounds that have no harmful effects on firearms or cartridge cases. Unlike primers containing lead, primers with RMLs do not present a hazard to the environment. Physical structure and stored interfacial energy determine the sensitivity of an RML. The sensitivity lowers with time because of a decrease in interfacial energy resulting from interdiffusion of the elemental layers. Time-dependent interdiffusion is predictable, thereby enabling the functional life time of an RML primer to be predetermined by the materials selected for the reacting layers and their thickness.

Robert L. Druce, Hugh C. Kirbie, and Mark A. Newton
Light-Weight DC to Very High Voltage DC Converter
U.S. Patent 5,774,348
June 30, 1998
A dc-dc converter capable of generating output of 100 kilovolts without a transformer composed of a silicon-opening-switch (SOS) diode connected to allow a charging current from a capacitor to flow into an inductor. When a specified amount of charge has flowed through the SOS diode, it opens up abruptly, and the consequential collapsing field of the inductor causes a voltage and current reversal that is steered into a load capacitor by an output diode. A switch across the series combination of the capacitor, inductor, and SOS diode closes to periodically reset the SOS diode by inducing a forward-biased current.

Awards