Abstract: A silicon accelerometer includes a plurality of silicon layers. The silicon layers form first and second silicon beams supported by flexure members. An acceleration responsive silicon mass is arranged to bend the flexure members in response to accelerations. The silicon beams are vibrated in vacuum chambers and gas damping is provided for the acceleration responsive mass and the flexure members. A sensor is provided for sensing vibration of the first and second silicon beams.

Abstract: A backscatter or secondary wave error reducer for an interferometric fiber optic gyroscope having at least one phase modulator for receiving a square wave bias phase modulation signal and a sine wave carrier suppression modulation signal. The amplitude of the carrier suppression modulation signal is sufficient to greatly reduce the interference between two sets of backscattered or secondary waves of light originating in the Sagnac loop of the gyroscope. Reduction or elimination of the interference of the two sets of secondary waves reduces or eliminates the secondary wave induced rotation rate sensing error. The frequency of the carrier suppression signal is near or equal to an even harmonic of the proper frequency of the Sagnac loop to reduce the sinusoidal or periodic rotation rate sensing error caused by the carrier suppression modulation signal.

Abstract: A device for eliminating coherent pickup error in a fiber optic gyroscope. The polarity of the drive signal to the phase modulator of the gyroscope is switched periodically. The scale factor consequently changes. The phase and amplitude of coherent pickup error generated in the gyroscope circuits do not change during the switching. Therefore, nearly all of the coherent pickup error is subtracted out of the gyroscope signal during the digital signal processing of the signal.

Abstract: A vertical cavity surface emitting laser having a planar structure, having an implantation or diffusion at the top of the mirror closest to the substrate or at the bottom of the mirror farthest from the substrate, to provide current confinement with the gain region, and having an active region and another mirror formed subsequent to the implantation or diffusion. This structure has an implantation or diffusion that does not damage or detrimentally affect the gain region, and does provide dimensions of current confinement that are accurately ascertained. Alternatively, the implantation or diffusion for current confinement may be placed within the top mirror, and several layers above the active region, still with minimal damage to the gain region and having a well-ascertained current confinement dimension.

Abstract: A micromechnical sensor having a polysilicon beam that is an integral part of the diaphragm resulting in a frequency of the beam that is a direct result of the pressure applied to the external surface of the diaphragm. Fabrication of this resonant microbeam sensor has no backside wafer processing, and involves a process and layout independent of wafer thickness for high yield and robustness. Both the diaphragm and resonant beam are formed from polysilicon. The sensor may have more than one resonant beam. The sensor beam or beams may be driven and sensed by electrical or optical mechanisms. For stress isolation, the sensor may be situated on a cantilevered single crystal silicon paddle. The sensor may be recessed on the isolating die for non-interfering interfacing with optical or electrical devices.

Abstract: A switch actuator is provided in which any one of a plurality of rotatable cams is capable of actuating a single switch simultaneously with controlling another mechanism, such as a gas valve that is associated with that particular rotatable cam. When used in conjunction with a kitchen range, each of the rotatable cams controls an associated gas valve which, in turn, controls the flow of natural gas to an associated burner. Each of the rotatable cams is disposed within an associated one of a plurality of openings formed through the thickness of a movable member. The movable member is attached in sliding relation with a stationary member which, in turn, can be attached to a stationary device such as a kitchen range. Each of the openings formed through the thickness of the movable member is provided with an edge that is shaped to perform the function of a cam follower. This cam following edge is disposed in contact with a cam surface attached to the rotatable cam.

Abstract: A device for providing a bias modulation at a proper frequency to the counterpropagating light waves in the sensing coil of an interferometric fiber optic gyroscope. The photodetector detects the light which has exited the sensing loop, and converts it to an electrical signal that is demodulated by two phase sensitive detector. One phase sensitive detector demodulates the signal that is in phase with the bias modulation signal and the other phase sensitive detector demodulates the quadrature signal with respect to the modulation signal, and controls the frequency of the bias phase modulator driver so as to reduce the quadrature to a minimum and to keep the modulator frequency at the proper frequency of the sensing coil. Increased intensity modulation can be attained with a DC voltage applied to an electrode of the modulator to produce the quadrature signal.

Abstract: An occupancy sensor having a primary infrared radiation sensor and a secondary infrared radiation sensor in an integrated vacuum package having a window that provides separate fields of view to the sensors, respectively. The primary sensor is for monitoring occupancy of a selected space. The secondary sensor is for monitoring the background radiation of the space. Signals from the primary and secondary sensors are electronically processed and compared, and the occupancy level of the selected space is determined. Temperature and visible light sensors may also be incorporated. Sensor information is used to control temperature, ventilation, lighting and other parameters of the selected space.

Abstract: A temperature sensor is made with a rigid substrate disposed within a metallic tube for the purpose of supporting a resistive temperature detector and conductive strips disposed on the substrate. The conductive strips of palladium silver are deposited on the substrate and in electrical communication with gold pads that are used to permit the RTD to be connected to the gold pads by wire bonding techniques. A sleeve is provided at an opposite end of the sensor to support a first end region of the rigid substrate at a preselected position within the tube. The second end region of the substrate extends away from the sleeve and toward an opposite end of the tube, which is crimped to seal it. Conductive wires are avoided within the main portion of the outer metallic tube, thus eliminating the need for fiber glass sleeved wires extending through the tube.

Abstract: A sensor bridge circuit (20) sensitive to a proximate target (12). The bridge circuit (20) has two inductor (24, 28) and two resistors (32, 34). One inductor (24) has a reactance that varies with respect to the distance (26) of the target (12) from the inductor (24), which affects a balance of the bridge parameters of which is an indication of the distance (26). Another resistor (86) is connected in parallel to one bridge resistor (34) via an input (82) in the event where the target (12) is removed so that the displacement (26) of the sensor transfer characteristic is affected by an amount which results in a change of a diagnostic status indication (62). When the input (82) is not present, the status indication (62) should not appear in the event where the target (12) is far removed. Other resistors (42, 44) connected in parallel to bridge resistors (32, 34), via several inputs (46, 48), respectively, debalance or detune the bridge (20) so as to provide certain diagnostic information.

Abstract: A multi-domain halftone gray scale active matrix liquid crystal display utilizing a mono-gap configuration for achieving a very wide viewing angle at a low-cost. The substrate of the display has areas having a rub or an alignment of different directions from the direction of the rub or alignment in other adjacent areas. Each pixel of the gray scale matrix has a plurality of subpixels such that each subpixel turns on at a different voltage than that of the other subpixels. The areas involving different rubs or alignments on the substrates may be areas of pixels or subpixels. At least one compensating retardation layer is formed on the display. The technique of enabling the combining of multiple domains and compensation with halftone grayscale pixels results in a display having significantly wider viewing angles than either a multi-domain display or a halftone grayscale display, whether compensated for or not.

Abstract: The pH of a material containing lignin is determined by directing an ultraviolet light at the material. One of the characteristics of lignin is giving off a fluorescence in response to an ultraviolet light. A monochrometer is used to observe the fluorescence and produces a signal of the intensity of the fluorescent light at varying wavelengths. This signal is displayed on a display means such as a computer screen. Calibration occurs before the pH measurement of the material occurs. The calibration data along with information from the signal is used to calculate the pH of the material. No contact with the material is required in determining the pH of the material.

Abstract: An electrostatically controlled, micromachined micromechanical capacitor having an adjustable, extensive tuning range. A configuration consists of a set of various sized beams or plates adjacent to a common plate or plates. The pairs of plates are linearly moved relative to each other to provide an adjustable capacitance. The movement of the plates is caused electrostatically by an application of a DC or low frequency voltage to the respective plates. The signals that are processed by these micromechanical capacitors are typically in the megahertz range and higher. The process for micromachining the micromechanical capacitor is similar to the process utilized in integrated circuit fabrication.

Abstract: A magnetic sensor circuit provides current sources that create a feedback loop for an amplifier of one magnetically sensitive component in order to maintain the sensor output and the corresponding amplifier input at a first preselected magnitude which can be generally equal to zero. The other current source maintains a generally identical current as a reference against which the output of another magnetically sensitive component is compared. The magnetically sensitive components can be Hall effect elements, indium antimonide sensors or magnetoresistive elements. The output of the circuit is representative of the difference between the magnetic field intensities imposed on the first and second magnetically sensitive components.

Abstract: A rotational position sensor, or angular position sensor, that having two pole pieces. Each of the pole pieces has a first end portion and a second end portion. The two second end portions are arranged in overlapping parallel association to provide a gap between them. Two magnetically sensitive components are disposed in the gap between the second end portions of the two pole pieces. The two magnetically sensitive components are used to provide redundancy in the event that one of the magnetically sensitive components experiences a failure.

Abstract: A proximity sensing circuit is provided with various attributes, including the connection of a proximity sensor coil in a feedback loop of an amplifier, the frequency hopping technique that periodically changes the two frequencies used by its proximity sensor circuit to avoid deleterious interference by constant frequency EMI sources and the provision of a self diagnosis technique. The connection of the proximity sensor coil in the feedback loop of an amplifier results in several advantages including the connection of the coil to a virtually infinite impedance, the reduction of the number of components needed in the proximity sensing circuit and decreased temperature sensitivity of the overall circuit. The frequency hopping technique that periodically changes the two frequencies used by the proximity sensor significantly decreases the likelihood that a constant frequency EMI source in the vicinity of the circuit will have a continually adverse affect on its accuracy and reliability.

Abstract: A bit serial decoder is disclosed decoding an encoded non-return to zero (NRZ) signal without the use of external clock. Transitions within the encoded NRZ signal cause a differential voltage signal to be output. This differential voltage increases at a constant rate between two transitions. At the second transition the magnitude of the differential voltage is compared to a preset value to determine a number of consecutive like bits. These consecutive bits can then be transmitted in one step to a storage means.

Abstract: The present invention relates generally to a pressure sensor and, more specifically, to a pressure equalization structure that balances the forces on the pressure sensitive component in order to reduce the stress that could otherwise be imposed on its piezoresistors. The pressure sensor provides a housing in which a cavity is formed. Within the cavity, a pressure sensitive component is disposed between a first seal and a second seal in order to expose a first surface of the pressure sensitive component to a first conduit and a second surface of the pressure sensitive component to a second conduit. The pressure surrounding the pressure sensitive structure is generally equalized to one of the first and second conduits by providing a bypass conduit connected therebetween.

Abstract: A pumped rare-earth fiber source wavelength control device, having source wavelength control effected by pump source wavelength and power control. The maintaining of pump wavelength and power control can be attained several ways such as by use of a wavelength sensitive coupler, a short length of fiber having an embedded grating, and a modulated grating embedded fiber.

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.