Abstract: In a optical fiber coil arrangement for use in rotation sensors, for example, errors resulting from axial and/or radial time varying temperature gradients can be minimized or substantially eliminated by employing reverse quadrupoles for the sensor coil. One of the quadrupoles is wound in a + - - + winding configuration. However, the next adjacent quadrupole is wound in a - + + - winding configuration. This reverse quadrupole arrangement substantially eliminates radial time varying temperature gradient dependent errors and reduces axial time varying temperature gradient dependent errors. The axial time varying temperature gradient dependent errors can be substantially eliminated by winding a reverse octupole arrangement. Accordingly, a reverse octupole arrangement is wound with a + - - + - + + - - + + - + - - + winding configuration.

Abstract: A liquid crystal display wherein each pixel has a thin film transistor with a silicon pixel electrode. A doping and recrystallization of the silicon is effected to increase the electrical conductivity and light transmittance of the silicon adequately for the pixel electrode.

Abstract: A noise reducer for reducing the results in the system output signal of optical noise introduced into an optical subsystem therein, having a phase modulator, by a source through obtaining a noise representation signal used to offset the noise components in the signal obtained from the output of the optical subsystem. This noise representation signal is not delayed in the obtaining thereof by any more than half the delays of the waves emitted from the source in reaching the optical subsystem output. The noise reducer may incorporate a device for adjusting the amplitude of the noise representation signal. It may also include another device for adjusting the phase of the noise representation signal, which may be used to affect the amplitude of the noise representation signal. These adjustments can result in an optimization of the noise representation signal so as to better effectively cancel the optical noise signal at the output of the fiber optic gyro having the noise reducer.

Abstract: A field emitter structure with emitter edge comprising of individual comb elements. A resistive film is inserted between the lead-in conductor and the emitter edge and a conductive film is electrically attached to the conductor and capacitively coupled to the emitter.

Abstract: An error reducer for reducing rotation rate errors arising because of an optical Kerr effect occurring in a coiled optical fiber in a rotation sensor. Through amplitude modulating electromagnetic waves propagating in that coil. A signal obtained from the coil based on the amplitude modulation component therein is used in a feedback loop to reduce or eliminate such errors.

Abstract: A thermostat capable of accommodating primary and secondary loads is taught. Preferably a hydronic valve actuator is the primary load and a fan coil of variable speed is the secondary load. Temperature sensing is electronic and both heating and cooling as well as multiple fan modes are accommodated.

Abstract: A HIGFET having a gate pad situated over a non conducting portion of the channel layer of the heterostructure wafer. The method of producing this device involves application of a very thin layer of gate metal on the wafer to protect the wafer surface during further processing. A photoresist coating is formed over the active area of the channel layer of the FET. An ion isolation implantation is applied to the wafer resulting in a non conducting portion of the channel layer that is not covered by the photoresist layer. The photoresist layer is removed and a thick layer of gate metal is applied on the thin layer of gate metal. The gate layers are fashioned into a pad over the non conducting portion of the channel layer and at least one finger over the conducting portion of the channel layer, resulting in the gate having minimized parasitic gate capacitance.

Abstract: A temperature and static pressure compensated differential pressure sensor includes a semiconductor substrate in which a flexible, pressure responsive diaphragm is formed. A pressure responsive resonant microbeam is fabricated at the diaphragm periphery. For temperature compensation, a secondary resonant microbeam sensor is fabricated on the substrate at a peripheral location beyond the point of substrate attachment to a pressure tube or other support. For static pressure compensation, another secondary resonant microbeam can be positioned remote from the diaphragm and at a location of maximum substrate response to static pressure. A further resonant microbeam can be mounted at the diaphragm center to augment the signal due to diaphragm deflections. Also disclosed is an accelerometer including a proof mass, a rigid rim surrounding the proof mass, and a series of narrow, flexible bridges supporting the proof mass relative to the rim.

Abstract: A rotation sensor for sensing rotation, particularly about an axis of a coiled optical fiber, wherein the coiled optical fiber has with light waves propagating in opposite directions in the coiled optical fiber, the phase relationship of the counter-propagating light waves providing a basis for indicating rotation of the sensor. A portion of the coiled optical fiber is a part of and affected by a bias optical phase modulator which causes a varying phase relationship between the light waves at a fundamental frequency. However, the varying phase relation ship has at least one harmonic which is due to mechanical vibration of the optical fiber that is a part of the modulator. This harmonic contributes to an erroneous indication of rotation. The amplitude of such harmonic is reduced by lowering the Q of the resonating fiber. This is effected by applying a damping material to the optical fiber and a portion of the modulator.

Abstract: A HIGFET having a gate with a pad which is isolated from the FET heterostructure wafer by a dielectric layer to minimize leakage current between the gate and the wafer. The method of production of this device involves application of the gate metal only over the active area of the FET and a photo resist covering on the gate metal. The wafer, including the area covered by the photo resist, is covered with the dielectric layer. The photo resist layer is removed along with the dielectric layer from over the gate metal. Another layer of gate metal is formed on the preexisting gate metal including a gate pad on part of the remaining dielectric layer.

Abstract: In a microbolometer infrared radiation sensor, a detector material (VO.sub.2) having a high thermal coefficient of resistance to increase the sensitivity of the apparatus.

Abstract: A process for fabricating a flow control device which includes a housing with separate main flow and flow control (servo) passages between an inlet port and an exit port. A control chamber in the housing is in fluid communication with the servo passage. A flexible membrane forms a partition between the main flow passage and the control chamber. The servo passage includes a variable servo orifice upstream of the control chamber and a fixed orifice downstream of the chamber. When the servo valve is open to permit passage of fluid into the control chamber, the resultant pressure on the membrane maintains the main valve closed. The main valve opens in response to closing the servo valve. The fixed orifice has a profile sufficiently small to provide for an acceptable leak or continuous fluid flow through the device when the servo valve is open, and further provides for a soft start when the servo valve is closed to open the main valve.

Abstract: A multi-band high-speed videometric head tracking system having a gradient reflector array attached to a helmet on a person's head, ultraviolet light source emitting light which is reflected by the reflector array to a video camera which provides an image to a spot location estimator providing accurate locations of spots in the image representing the reflectors' reflecting light to image location accuracies within a pixel of the image. The location information from the spot location estimator goes to a track point 3-D location and helmet LOS estimator that provides location and orientation information to a Kalman Filter that accurately estimates and predicts the helmet position at faster rates than would be possible for a process that uses just the image-based measurements of the helmet.

Abstract: A retroreflective array projection screen for displaying virtual images wherein the apparent distances from the observer to the viewed subject is greater than the distance from the observer to the retroreflective screen. Real images from a source are collimated and then partially reflected onto the retroreflective array. Virtual images are reflected from the array through the beamsplitter onto an observer at an exit pupil.

Abstract: A light source with wavelength compensation for a fiber optic rotation sensor includes a light source to provide light for input to the fiber optic rotation sensor. A source control circuit generates a source control signal representative of the temperature of the light source. A driver generates a drive signal as a function of the source control signal to drive the light source. One of a plurality of scale factors for the fiber optic rotation sensor is generated also as a function of the source control signal over a predetermined temperature range. The source control circuit includes a temperature sensor which provides a current signal representative of the temperature of the light source and a buffer network for sinking the current signal and for generating a source control voltage as the source control signal.

Abstract: A control loop for controlling a process or plant which controls the process or plant via an actuator. The control loop receives from the process or plant a signal representative of the process or plant output. The loop includes a nominal controller that generates a control signal for the actuator which is used only in the absence of a predicted disturbance to the process or plant signal from a disturbance mode controller unit having a neural network conditioned for predicting and indicating a disturbance.

Abstract: A light source device having a controlled current source that maintains a constant intensity of light from the source during changes in light source temperature, particularly at warm-up. The light source is heated to speed up warm-up and to maintain constant temperature of the source during operation under varying ambient temperatures. Control of the current to the light source is determined by the temperature profile circuit with signals via a temperature signal conditioner from a temperature sensor proximate to the light source. Control of the heater is ultimately dictated by temperature sensor signals.

Abstract: A multiple-fail-operational fault-tolerant clock having a plurality of interconnected and identical clock modules, that provides a fault tolerant clock signal despite some clock module failures. The clock incorporates fault-tolerant operational diagnostics so that a working clock module may be voted for supplying the output clock signal.

Abstract: An uncooled IR array, in conjunction with an array of binary optical microlenses, having a large effective fill factor.

Abstract: A low cost fiber optic gyro includes a Sagnac interferometer configured in a minimum reciprocal configuration and modified to use a 0.8 micron wavelength laser diode as the interferometer light source and 1.3 micron, single-mode fiber for the sensing coil.