Abstract: The liquid crystal display includes a patterned mirror disposed between the backlight assembly and the black matrix to reflect light back into the backlight assembly that otherwise would impinge on the black matrix. Apertures through the patterned mirror are so shaped that parallax effects with respect to the black matrix provides desirable luminance versus viewing angle profiles.

Abstract: A multigap liquid crystal color display having RED, GREEN and BLUE pixels with TFT activating transistors and with the pixels being constructed and arranged so that the offset voltages at the RED, GREEN and BLUE pixels induced by the gate pulses applied to the TFTs are equalized. In one embodiment, the pixel storage capacitors are customized to equalize the offset voltages. In a second embodiment, the pixel areas are adjusted so as to provide the offset voltage equalization.

Abstract: A memory unit, made up of a plurality of BY-4 memory devices, has a plurality of computer words, each computer word including a predetermined number of data bits and a predetermined number of check bits. An error detection and correction (EDAC) apparatus interfaces with the memory unit for detecting and correcting a single bit error of the computer word, detecting a two bit error of the computer word, and detecting all two, three, and four bit errors of a single memory device. Matrix logic generates the check bits from preselected participating data bits of the data bits of the computer word being fetched. Compare gate logic compares check bits from the memory unit to corresponding check bits generated by the matrix logic to generate syndrome bits.

Abstract: A modulator for providing modulating voltages across the anode and cathode of a negatively pulsed magnetron includes a switch which, when activated, couples the modulating voltage source to the cathode terminal, a current regulator which maintains a constant current flow through the anode and cathode when the modulating voltage is applied, and a voltage control circuit that reduces an excessive time rate of voltage change across the switch caused by arcing across the anode-cathode gap. A filament power supply is provided which supplies filament current while isolating the modulating voltage at the cathode from high voltage sensitive components in the filament power supply.

Abstract: A fault detection apparatus and method combines each of a plurality of redundant digital data signals with a unique key signal for transmission over one of a plurality of signal lines and recombines each with its unique key signal at a receiving end. The recombined signals are then compared at the receiving end to detect certain faults between or among the plurality of what should be identical received signals.

Abstract: An improved asymmetrical data tracking digital phase locked loop including separate baud rate counters for both the positive data pulse edge and the negative data pulse edge. The outputs of the two independent baud rate counters are added together and divided by two in a virtual counter for each local oscillator clock cycle. This provides a data clock pulse located at the midpoint between the corresponding data pulse edges as defined by the two baud rate counters. A digital filter is utilized to dampen the tracking loop correction to reduce maximum phase errors by not allowing continuous phase corrections.

Abstract: An active hand controller system is provided wherein a feedback loop detects the position of a control stick to control a motor driving the control stick to thereby provide certain force feel characteristics to the control stick. The feedback loop includes a detector for detecting force exerted for the control stick to generate a signal indicative of the force or torque being applied to the control stick. In a more specific aspect, the invention includes the use of variable reluctance transformers, preferably in a push/pull configuration to detect the forces being exerted on the control stick.

Abstract: A solder spacer device and method for use in positioning a grid pin array having a plurality of pins over a circuit board having a plurality of pin holes respectively receiving the pins. The spacer is pulled through a central opening in the circuit board after the pins are soldered in the holes to the circuit board. The spacer has a cylindrical body which is positioned in the central opening and has a plurality of radial legs having respective flexure portions for separating the pin grid array from the circuit board during soldering and for folding into the central opening during extraction through the central opening after the soldering is finished.

Abstract: A moving altitude tape for a flight instrument display adapted to provide intuitive visual cues for determining deviation from a desired altitude. A window incorporates a digital altitude readout and a pointer index which is aligned with calibration marks on the altitude tape. In use the tape exhibits a motion in accordance with deviations in altitude of the aircraft and displays a vernier indication of such deviations with respect to the reference index. The tape further includes indicia associated with the reference index for defining predetermined increments of altitude deviation in accordance with commonly commanded altitudes, and a further pointer indicative of actual altitude deviation from a preset altitude.

Abstract: A pulse Doppler radar altimeter designed to resolve the ambiguous range problem associated with the use of a pulse repetition interval, which is less than the aircraft altitude, includes a radar transmitter configured to transmit first and second series of pulses where the first series has a pulse repetition interval slightly different from the pulse repetition interval of the second series. At a time when the first series is being transmitted, the receiver electronics including a range gate and a tracker searches for ground returns and positions the range gate in time coincidence with the detected ground return. Control then shifts so that the second series of pulses is transmitted and a determination is made whether overlap of the range gate with the ground return from the second series corresponds to the same altitude as when the first series was involved.

Abstract: A path capture forcing function generator utilizes integrations from an initial altitude rate error signal and an initial altitude error signal to provide an altitude rate signal and an altitude signal which are compared to the altitude rate error and altitude error signals to provide path rate error and path error signals to the autopilot. In the process of providing the altitude rate and altitude error signals an altitude acceleration signal is established which is used as a feed forward predictor for expected normal acceleration of the aircraft.

Abstract: An MOS FET pass element for a switching voltage regulator is driven by a dual voltage booster configuration. The pulse width modulator of the regulator provides a two-phase logic signal for alternately energizing and charging each booster. Each booster is comprised of a capacitor charged from a charging voltage source and coupled to the gate of the FET for providing a turn-on voltage thereto. A switching transistor associated with each booster alternately couples the associated booster capacitor to a predetermined voltage and to ground. The capacitors alternately provide the turn-on voltage to the FET when the predetermined voltage is applied thereto. On alternate half cycles, each capacitor is charged from the charging voltage source. The two-phase logic signal alternately renders the switching transistors conductive. A NAND gate responsive to the two-phase logic signal, permits the FET to be turned on by the voltage boosters only during the presence of each of the logic signals.

Abstract: A system wherein TCAS transmissions have two jitter components added to the jitter component utilized in the interscan interval to minimize TCAS interference with ground station operation. The jitter components minimize the establishment of false intruder tracks caused by responses to ground station interrogations or interrogations by other TCAS interrogators which are received in synchronism with the TCAS interrogation signals.

Abstract: The vector generator employs a digital accumulator for each vector component. The accuracy of generated vectors is optimized by presetting the fractional portions of the accumulators to a value of either 1/2 or to 1/2 less 1 LSB. Accumulation of errors over concatenated vectors is eliminated by employing high enough fractional resolution relative to the maximum vector length so that error accumulation on any single vector is limited to the fractional portions of the accumulators, and by setting the fractional portions of the accumulators, on the last clock cycle of each vector, to a value of 1/2 to 1/2 less 1 LSB. Also, by setting/presetting the fractions to only 1/2 less 1 LSB, and by enabling the carry input to a given accumulator on only the first clock cycle of vectors that have certain orientations, then symmetry is forced or favored in complex symbology that is generated by concatenated vectors.

Abstract: The horizontal stabilizer position is provided to the automatic flight control system software where it is passed through a second order Chebychev motion filter to provide horizontal stabilizer rate. A threshold and hysteresis function detects when the motion exceeds 0.08.degree. per second. While the stabilizer motion exceeds the threshold, a displacement detector determines when the stabilizer position has exceeded 1.degree. since the motion was first detected. When the 1.degree. change in position has occurred while the rate was exceeded, a motion flag is transmitted to the warning system. A sign change detector determines when the output of the motion filter changes sign. A holding latch responsive to the stabilizer position and to the threshold and hysteresis function latches the stabilizer position when the 0.08.degree. per second rate is exceeded. The difference between the latched position and the current position is applied to a threshold detector to determine when the difference exceeds the 1.

Abstract: A cladded optical fiber is secured in a slot in a substrate which is ground and polished to access the evanescent field. A thin electro-optically active layer of PLZT is deposited on the top of the fiber substrate. A pair of parallel electrodes is then deposited on top of the crystal PLZT film. An electric field distribution parallel to the electro-optical film is generated at the center of the electrode gap by applying a voltage to the electrode pair so as to effect a phase shift of the light wave propagating in the fiber.

Abstract: A capacitor is charged and discharged through switch selectable resistors from regulated DC voltage supplies and clamping diodes to provide the bias signal to control the rise and fall times of the RF output pulse of a PIN diode attenuator. An isolation buffer isolates charging and discharging transients from the bias signal. An adjustable AC gain and adjustable DC offset inverting amplifier provides the isolation buffered signal to a high impedance, very low output AC impedance source for driving the bias input of the PIN diode attenuator. The DC offset is provided by an adjustable regulated voltage source coupled to the inverting amplifier.

Abstract: An apparatus for electronically narrowing the beam width of interrogation transmissions of an interrogator utilizes three beams of the four beam system not used as the main beam for the transmission of suppression pulses. One side of the main beam is suppressed by the first sidelobe suppression pulse of the interrogation pulse sequence and then the other side of the main beam is suppressed by the second sidelobe suppression pulse within the interrogation pulse sequence. In another mode of operation, the interrogation beam width is controlled by transmitting a suppression pulse on a beam positioned 180.degree. from the main beam. This electronic narrowing of the interrogation beam width reduces the number of overlapping replies received by the interrogator and enables the interrogator to properly sort out and not lose or misinterpret replies received by proximity transponder equipped aircraft.