Abstract: A trigger re-synchronization circuit providing reduced trigger gate jitter for use in a high speed display device such as an oscilloscope or digitizer. The trigger re-synchronization circuit is cascadable.

Abstract: A microprocessor system debug tool has a mainframe which interfaces with a user. A ROM emulator replaces a ROM unit of the microprocessor system to be tested and has a monitor portion which is used to perform debug functions specified by the user. A user defined control line is connected to the interrupt system of the microprocessor system to cause the target microprocessor to stop execution of the user's program and jump to the monitor portion upon the occurrence of a user defined event to execute microprocessor specific debug code generated by the mainframe in response to the user's input. At the conclusion of debug code execution the microprocessor resumes the user's program. A word recognizer is connected to the microprocessor bus to detect the results of the debug code execution, the results being forwarded to the mainframe for display to the user.

Abstract: A delay element for producing an output signal in response to a change in state of an input signal includes variable gain first and second amplifiers and a delay buffer having a fixed delay. The input signal is applied as input to the first amplifier and the delay buffer while the output of the delay buffer is applied as input to the second amplifier. The outputs of the first and second amplifiers are summed to provide the output signal. When the gain of the first amplifier is high and the gain of the second amplifier is low, the output signal will respond to the change in state of the input signal with minimum delay. When the gain of the first amplifier is low and the gain of the second amplifier is high, the output signal will respond to the change in state of the input signal with maximum delay.

Abstract: A heat sink for a magnetically tuned filter provides an insulative gap between the magnetic coils and the magnetic housing and pole pieces and has a thermally conductive plate in thermal contact with the magnetic coils with a flange portion extending exterior of the magnetic housing so that heat generated by the magnetic coils is conducted for dissipation external of the magnetic housing. The thermally conductive plate has a central opening in which a filter housing is situated, has a plurality of channels between the central opening and the outer edge to provide for electrical and mechanical access to the filter housing, and has a radial insulative gap from the central opening to the outer edge to prevent the formation of eddy currents in the thermally conductive plate.

Abstract: A multiple phase clock generator includes a ring of an even number of phase cells, each phase cell generating a separate phased clock signal. Each phase cell supplies its phased clock signal and a prebias output signal in response to concurrent assertion of an enable signal and a prebias output signal from a preceding phase cell on the ring. Enable signals supplied to each phase cell around the ring are asserted and deasserted in response to state changes in a master clock signal, enable signals supplied to non-adjacent phase cells being provided concurrently. When initialized with one phase cell asserting its phased clock signal and prebias output signal, each transition of the master clock signal causes a next phase cell on the ring to supply its phased clock output signal.

Abstract: A component television timing corrector uses edge transitions in the program material of a television signal to determine the time differences between color component signals of the television signal due to the processing of the color component signals along different paths. One of the color component signal channels is made a reference channel, and the time differences between the edge transitions in the reference channel and in the other color component signal channels is determined. The time differences are used to delay the other two color component signal channels with respect to the reference color component signal channel so that the resulting color component signals are in time coincidence.

Abstract: An electrical circuit compensates for spatial variations in the light transmittance of the target surface (45) of an electron beam-addressed liquid crystal light valve (10). Such variations in light transmittance, which stem in part from the position dependent angle of incidence of the writing beam electrons and position dependent alignment layer variations arising out of manufacturing process limitations, affect the ability to achieve a monotonic gray scale luminance over the display surface. The compensating circuit adjusts the amount of beam current of the writing electron beam by varying the gain and offset voltage of the video signal, which modulates the writing beam current. This is accomplished by applying the X and Y scan position signals to a correction signal generator (102), which produces gain correction and offset correction signals whose magnitudes vary in response to instantaneous scan position of the writing electron beam on the target surface of a particular light valve.

Abstract: In a line scan fiber optic cathode ray graphic recorder a continuous sheet of light sensitive paper is drawn perpendicularly before a regularly timed intensity modulated beam from the cathode ray tube. Due to gearing inaccuracies and anomalies, the velocity at which the paper is drawn past the beam varies cyclically resulting in a variation in the spacing between each recorded data line on the paper. For higher paper velocities, the recorded lines are closer together, and for lower paper velocities, the recorded lines are farther apart. The closer lines create a darker image band on the paper and the more distant lines create a lighter image band on the paper. The present invention includes paper velocity monitoring means which provides an input signal to a compensation circuit for inversely varying the intensity information of each pixel dot as a function of the paper velocity.

Abstract: Method and apparatus for drawing vectors on limited precision display devices in amounts of time approximately proportional to the vector's geometric length. Vectors are drawn by a series of strokes. Each stroke is a series of counter control signals, each signal representing a vertical, horizontal, or diagonal movement of the CRT electron beam between adjacent addressable screen points. The counter control signals making up the strokes are stored on a look-up table.

Abstract: A digital pipelined heterodyne circuit includes sine and cosine function generators for generating m-bit digital coefficients and an m-stage digital multiplier for multiplying the coefficients by a digitized data input signal. A triangular shift register array connects the digital sine and cosine function generators with the multiplier stages and provides for simultaneous processing of successive bytes of input data at each multiplier stage by delaying the arrival of coefficient bits at each multiplier stage to coincide with the arrival of a predetermined data byte. This takes place simultaneously in all stages thereby decreasing the processing time by a factor of m.

Abstract: A predictive time base control circuit for a waveform sampling system of the type which converts a sequence of analog waveform samples into a sequence of digital quantities for storage in an addressable acquisition memory. The time base circuit generates a sampling control signal which initiates sampling at the end of a time interval of programmable duration following detection of a triggering event in the waveform, and which maintains sampling thereafter at regular intervals. The time base circuit permits the sampling system to operate in an equivalent time mode in which repetitive waveform sections are sampled at progressively skewed sampling intervals with respect to a repetitive triggering event. The sampling control signal is also frequency divided, delayed, and then applied as a write control signal to the sampling system acquisition memory.

Abstract: A processing circuit for a digital camera system enables capture of a visual event which falls within some user-defined range. A digital camera converts a target image into a set of digital data signals, each signal representing the brightness level of a pixel in a matrix. A memory stores a mask also comprising a matrix of pixels. As the digital camera scans the target image, each data pixel from the camera is compared to a corresponding pixel in the mask and differences in brightness between the two are counted. When the count reaches some predetermined valve, the current frame of video data is saved for further analysis and/or display.

Abstract: A switch device comprises a resilient contact member and a support member carrying the contact member. The support member is movable between a first position in which the contact member is in electrically-conductive contact with two conductor elements that are stationary relative to each other and a second position in which the contact member is spaced from at least one of the conductor elements. A resilient member urges the support member in the direction from the second position towards the first position.

Abstract: An apparatus for generating trigger signals responsive to a selected pattern of event detection signals, the apparatus comprising an interim function bus, programmable means to selectively energize conductors of the interim function bus on detection of the selected event detection signal pattern, and programmable means to generate the trigger signal on detection of a selected pattern of interim function bus signals. The generating means are programmed for pattern recognition by binary data appearing on control lines from a shift register, the shift register being loaded by serial data from external control circuits. The apparatus also includes provisions for synchronizing the generation of signal patterns on the interim function bus to a system clock, and for synchronizing the generation of trigger signals to clocks associated with triggerable devices.

Abstract: A rotary drive mechanism has a yoke mounted on a motor shaft which engages a crank connected to a device to be rotated, such as the rotary portion of a microwave switch. When the gear motor is activated, the yoke causes the crank to move from a first position to a position past top dead center. A spring connected to the crank causes the crank to snap from the position past top dead center to a second position. A microswitch at the second position provides a signal to brake the motor when the crank reaches the second position. The yoke is configured like a V with the attachment point to the motor being the base of the V. A post from the crank is contained within the area defined by the legs of the V at a point where the shaft will not contact the opposite leg when the crank passes top dead center and is snapped to the second position.

Abstract: A method and apparatus are disclosed which provide for the removal of distortion present in a digital output signal from a linear analog signal processing system. Two applications are disclosed: digital compensation and digital equalization. Digital compensation provides for the removal of distortion from a single signal processing system. In particular, an adaptive digital filter operates to provide processing of an output signal from the signal processing system in accordance with correction criteria determined by a controller in response to a training signal. Digital equalization is employed with respect to a plurality of signal processing systems, and provides equalization of an output signal from one signal processing system in accordance with characteristics of a selected signal processing system.

Abstract: A limiter circuit comprises a first and second differential transistor amplifiers, with the collectors of the transistors of the second amplifier receiving the outputs of the first amplifier. A high gain amplifier has its inverting and non-inverting inputs connected to the output of the first differential amplifier, and has its output connected to the base of one of the transistors of the second amplifier through a feedback network. The differential amplifiers have respective current sources, the current sources of the second amplifier providing a larger current than that of the first amplifier.

Abstract: A method and apparatus for securing enlongatge members of generally cylindrical form in end-to-end relationship, particularly for forming an optic fiber splice. Optic fibers are spliced by pressing a form, preferably an optic fiber of the same diameter as those to be spliced, into a deformable body to create a groove for receiving the ends of the optic fibers in close alignment. To secure the optic fibers, an index matching adhesive is cured by UV irradiation through a glass cover plate bonded to the deformable body.

Abstract: An adaptive filtering procedure reduces overshoot which may be present on a waveform having infinite slopes displayed on a digital oscilloscope as a result of interpolation between samples at the location of the infinite slopes. An adaptive filtering procedure identifies sampled points adjacent the infinite slope and moves the points closer to each other to avoid ringing or overshoot on the display. Before modification, a straightness test relative to the waveform before and after a discontinuity and a test for sudden changes in the waveform before and after the discontinuity are performed.

Abstract: The present invention involves a metal alloy heat sink containing tungsten, copper, and nickel. The heat sink is affixed to a ceramic substrate which supports one or more heat-generating electrical components. By adjusting the ratio of tungsten, copper, and nickel, substantial matching of the heat sink CTE with the substrate CTE is possible. Because the CTE of the heat sink is matched with that of the substrate, problems associated with differential thermal expansion are minimized, including micro-cracking and delamination. In addition, the completed heat sink has a relatively high thermal conductivity, and is capable of dissipating substantial amounts of heat.