Abstract: A normally white twisted nematic liquid crystal display which uses multigap liquid crystal cells where the gaps are selected to have a cell gap which is less than that which would produce a maximum transmittance during an on-state and thereby provides for reduced hue variation over viewing angle.

Abstract: A system and apparatus for enhancing the satellite based navigation systems which includes providing an aircraft with an interrogating radar for interrogating beacons disposed at a predetermined location in front of a runway wherein the beacons are radar-activated passively powered runway beacons.

Abstract: An optical device for transforming light and an associated liquid crystal display is disclosed. The device includes a layer of cholesteric material of the type which transmits light having a first circular helicity and reflects light having a second circular helicity. A quarter-wave plate positioned on a first side of the layer of cholesteric material converts the transmitted light having the first circular helicity into linearly polarized light. A compensator including a positively birefringent C-plate layer is disposed between the layer of cholesteric material and the quarter-wave plate. The compensator reduces undesirable phase effects in the transmitted light introduced by the layer of cholesteric material. The disclosed LCD employs the optical device to increase backlighting efficiency while improving field of view and chromaticity of the display.

Abstract: A system for receiving, correlating and interpreting secured wireless transmissions, periodic or otherwise, including multiplexed receivers, robust correlator design, a state machine device for controlling the receivers and correlation function, and the ability to determine signal spatial diversity via switched antenna signal processing. The correlator is constructed to include a synchronization scheme adaptive to any variety of input signals from the coupled receiver tuned frequencies.

Abstract: A system for self-calibrating a clock of a communication terminal for use with communication systems in which a central communication node generates time base correction signals for the terminal clock includes a terminal oscillator which generates an oscillator frequency that includes an error amount. An oscillator calibration filter generates a frequency error estimate amount. Circuitry is provided for subtracting the frequency error estimate amount generated by the calibration filter from the oscillator frequency error amount. Circuitry is provided for applying the time base correction signals to the calibration filter to thereby modify the frequency error estimate amount generated by the calibration filter based upon the time base correction signals generated by the communication central node.

Abstract: A liquid crystal display having an non-uniform heat producing element disposed therein which produces more heat around the periphery of the display by providing a transparent heating element on the display surface and a plurality of shorting bars which provide for a lower impedance path around the display periphery, and therefore a higher current and higher heat generation in the resistive film disposed immediately about the shorting bars.

Abstract: The power factor/harmonic correction circuitry accomplishes this by using a non-linear ramp signal and/or by using a negative feedforward technique. The power factor/harmonic correction circuitry accomplishes the feedforward technique by using a modulated ramp circuit which adds to the ramp signal a constant value that is proportional to the input voltage. Furthermore, the power factor/harmonics correction circuitry can provide improved performance and stability by using a non-linear ramp circuit which produces the non-linear ramp signal which has an increasing slope over the switching cycle.

Abstract: A transmission medium consists of a dielectric waveguide shielded by a metal guide. The guide is particularly suitable for providing low insertion loss, convenient transfer of power from one such transmission line to another and for the trouble free handling of high power levels at many hundreds of watts. This type of transmission medium may be used to provide low loss combination of power signals that is low loss, compact while containing the solid state power amplifying elements (MMICs) and capable of high power.

Abstract: A liquid crystal display is provided which has improved wide angle viewing characteristics. The liquid crystal display includes a liquid crystal matrix. A non-planar fluorescent lamp positioned on a first side of the liquid crystal matrix has a center which traverses the fluorescent lamp in at least one longitudinal direction. A distance between the first side of the liquid crystal matrix and the fluorescent lamp center in a first portion of the fluorescent lamp is less than a distance between the first side of the liquid crystal matrix and the fluorescent lamp center in a second portion of the fluorescent lamp.

Abstract: An enhanced modular avionics system for communication and processing in an air transport aircraft including a modular avionic cabinet having a first scsi bus for a first processor and associate memory wherein the first scsi bus extends across a first portion of the cabinet and a second scsi bus for connection to a second processor and associate memory which extends across a second portion of the cabinet where the first portion of the cabinet and the second portion of the cabinet together equal the entire cabinet and there is no overlapping between the first portion and the second portion. Also shown is an extended bus which extends the entire length of the cabinet. The extended bus is located a predetermined distance from the top edge of the cabinet, while the first and second buses are located in a parallel line with each other and with the extended bus, the same predetermined distance from the bottom edge of the cabinet.

Abstract: A system for preventing theft of cargo from a cargo area of a truck is disclosed. The system includes a lock for locking shut a door to the cargo area of the truck when the lock is engaged. The lock allows the door to the cargo area to be opened when the lock is disengaged. A receiver receives a signal from a remote location. The lock is controlled in response to the signal received from the remote location such that the lock is disengaged when the signal received from the remote location is indicative of predetermined information.

Abstract: An optical O-plate compensation device, in accordance with the invention, uses an inorganic thin film which is grown by physical vapor deposition at oblique incidence. The resulting thin film exhibits a biaxial form birefringence and performs, in a liquid crystal display (LCD), in a similar manner to uniaxial films with its extraordinary axis oriented obliquely at about 45.degree. with respect to the surface of the film. The invention makes possible a significant improvement in the gray scale properties and contrast ratios of liquid crystal displays (LCDs) over a wide range of viewing angles.

Abstract: A data distribution device transfers digitized audio and digital data between memories of processors in a multi-processor communications system on a sample bus without protocols or handshaking between the source and destination processors. The device is capable of dynamic reconfiguration of its distribution pattern when peripherally commanded and has individual control over all memory read, chip select and write lines. Through an indirect register addressing scheme the present system has the ability to read from an address within any single memory and then write to an address within any or all other memories of the processors within the communications system.

Abstract: A twisted/splayed O-plate compensation device, in accordance with the invention, is comprised of an organic liquid crystal polymer thin film and possibly one or more other birefringent layers. The O-plate thin film is a birefringent medium with its optical symmetry axis, on average, oriented obliquely with the surface of the film. Within this constraint, the direction of the material's optical symmetry axis is allowed to vary continuously along the axis normal to the film surface. Such films may be fabricated by applying thin layers of chiral doped nematic or semectic liquid crystal monomer solutions in inert solvents to transparent substrates. The carrier solvents are then evaporated and the monomers polymerized by UV irradiation. Compensation devices may also be comprised of multiple layers of twisted/splayed O-plate material in conjunction with A-plates, C-plates, and simple O-plates. Fabrication techniques for twisted/splayed O-plates are described.

Abstract: A composite signal recognizer, separator, and FM demodulator apparatus for processing received radio signals. The receiver utilizes N demodulators to process a received signal, where N is equal to or greater than the number of co-channel signals or perceived interference. Detailed in both cross-coupled and cascaded fashion, the receiver first tracks to a predominant (stronger) signal, and regeneratively improves track on other (weaker) signals by subtracting the predominant signal or the predominant noise portion from the input of further demodulation stages.

Abstract: An apparatus having a distortion cancelling feedback signal that suppresses undesired signal components. One embodiment of the present invention is comprised of a balanced mixer coupled to a common-mode detector, a filter and having a resulting feedback signal that suppresses the common-mode component of the mixer output signal while allowing the differential component of the mixer output signal to pass on to additional processing.

Abstract: A monolithic O-plate optical compensator device, in accordance with the invention, comprises a plurality of thin-film compensation layers which are deposited on a single substrate. As used herein, the term "monolithic" is meant to imply that the O-plate and other thin-film compensator layers are formed by depositing (e.g., via solvent casting or vacuum deposition) one layer on top of another layer; with or without the use of surface modification treatments such as adhesion layers, alignment layers, and the like.

Abstract: A system for actively monitoring and controlling the effective ambient temperature in an application utilizing a fluorescent tube as the source of illumination. The system is the combination of a fluorescent tube, which may be thermally bonded to a reflector plate that is in physical contact with thermal electric cooler units and a heat sink. A temperature sensor in conjunction with drive circuitry and a power source, directs a magnitude and direction of current flow through the thermal electric cooler units thereby controlling the ambient operating temperature of the fluorescent tube.

Abstract: A system and method for monitoring and recording the mileage a truck travels within a particular state including a GPS receiver, an odometer, and a memory device which contains state boundary information and a processor for determining on a continual basis whether the positioned information received from the GPS receiver is in a particular state boundary and for recording mileage of the truck when the position and state boundary comparison determines that a change in state boundaries has occurred. Additionally, a storage device for storing the data output by the processor which includes the desired mileage within a particular state information is included.

Abstract: A wide viewing angle liquid crystal display and method of operating the same are disclosed. Each of a plurality of pixel elements of the display have individually driveable first and second pixel sub-elements. A desired average gray scale intensity for a first pixel element is determined. First and second drive voltages are determined as a function of the desired average gray scale intensity for the first pixel element. The first drive voltage is provided to the first pixel sub-element to drive it to a first gray scale intensity. The second drive voltage is provided to the second pixel sub-element to drive it to a second gray scale intensity. The average gray scale intensity for the first pixel element, which is a function of the first and second gray scale intensities, has reduced viewing angle dependence.