Abstract: An automatic trigger circuit for an oscilloscope includes a clock driven up-down counter and a digital-to-analog converter to automatically seek a suitable triggering level in the absence of an input triggering signal. When such level is established, the associated sweep generator is triggered, producing a display trace. Thereafter,the sweep generator is cyclically retriggered as the sweep "free runs.

Abstract: A Constant Velocity Vector Generator is disclosed for connecting X, Y coordinate points of a rectangular coordinate display system. A pair of absolute value amplifier circuits, a square-root-of-the-sum-of-the-squares circuit, a pair of dividers, and a pair of integrators are employed to convert simultaneous .DELTA.X and .DELTA.Y step voltages to ramp voltage pairs which are applied to appropriate X and Y deflection circuits of a graphic display device to produce straight-line traces whose velocities are constant for all vectors regardless of magnitude (line length) or direction (angle). Each vector may be drawn to any length or direction, immediately after which new data may be applied to the vector generator to initiate a new vector whose origin is the end point of the preceding vector. Such a system is particularly applicable to computer-drawn displays. The vector generating circuits are suitable for realization in a monolithic integrated circuit.

Abstract: A pair of clock driven voltage comparators are arranged in a master-slave configuration so that voltage comparisons are made only on a clock edge and the output is held valid over the entire clock period. Each comparator stage includes a latch to lock the comparator output in the logical state it was in when the latch was enabled.

Abstract: A high-impedance programmable attenuator utilizing field-effect transistor (FET) switching in both the high-impedance and low-impedance sections. In the high-impedance section, hybrid passive attenuator elements are employed to provide attenuation of electrical signals, and both series and shunt forms of active switching are employed to align the appropriate signal paths. The low-impedance amplifier section includes a FET-switched resistive network.

Abstract: A pulse peak detector for producing a D.C. voltage level corresponding to the peak amplitude of an input signal. A differential comparator is utilized to compare the input signal to the output level, and to activate a control circuit when the peak amplitude of such input signal exceeds the output voltage. The control circuit includes a current source which operates for a predetermined resettable time interval to provide a charging current path for a storage capacitor. An emitter follower is disposed between the storage capacitor and the system output to isolate the capacitor from any output loading. For short-duration repetitive input pulses, for example, 10 nanoseconds or less, a latch circuit insures activation of the timing circuit.

Abstract: An electromagnetic interference (EMI) shielding device for use in supporting members that receive enclosure covers of electrical or electronic instruments. The EMI device comprises a strip of metal having first spring means including first contact means which contain the device in position in a groove in the supporting member and provide electrical contact therewith and second spring means against which an edge of an enclosure member disposed in the groove engages thereby providing electrical contact therewith and securely maintaining the enclosure member in position.

Abstract: A system for inputting data into a display device by touch-sensitive contact areas disposed adjacent the display device and including state of the art electronic recognition circuitry associated with the contact areas for synchronously converting the data to discrete elements of information. Specifically, the transparent contact pads are overlayed over a display with each pad coupled with a multiplexer followed by a synchronous quadrature filter function performed by yet another multiplexer in such a manner that data displayed may be altered.

Abstract: An admixture of Yttrium oxide, or yttrium oxysulfide, or yttrium oxide or yttrium oxysulfide activated by a rare earth element and P1 phosphor, manganese-activated zinc orthosilicate provides a viewable bistable storage target for cathode ray tubes having increased operating life.

Abstract: An improved delayed sweep system is disclosed for an oscilloscope having main and delayed sweeps. A trigger pickoff circuit has means for providing a pair of pre-selected trigger pickoff points on the delaying sweep so that delayed sweeps may be generated in accordance with the two points selected. An alternating display mode facilitates presentation of the delaying sweep and both delayed sweeps in a single display, with the relative time positions of both delayed sweeps appearing on the delaying sweep as a pair of intensified zones. Either delay time measurement between the sweep start and a point of interest on the display, or differential time measurement between two points of interest on the display may be made. Voltages proportional to the selected time measurement may be applied to a properly scaled digital voltmeter to provide a direct readout in units of time.

Abstract: A cathode ray storage tube provided with a storage target having a multiplicity of segments of the collector electrode extending through the dielectric layer of the storage target. These segments comprise dots or continuous or broken protrusions of conductive particles that have been photo-deposited into position onto the collector electrode and then the storage dielectric layer is applied thereover which has proper thickness so that the segments extend above the dielectric thereby providing collector areas for collecting secondary emitted electrons from the dielectric.

Abstract: A simplified keyboard for a terminal device, calculator, or the like, in which each key is sequentially scanned and parallel key code data is sent to an entry register. A pair of flip-flops in combination with firmware ascertain that only valid key code data is sent to the entry register for utilization by the system, providing double entry and key bounce protection. The firmware further provides N-key rollover and auto repeat with a variable repeat rate, and expands the keyboard from a single-mode to an eight-mode capability.

Abstract: A slewed-pulse display is provided for calibrating the time-base axis of an oscilloscope. In a repetitive-sweep display, the leading edges of incrementally delayed successive pulses are slewed across the display screen. Timing and linearity adjustments may be made in the time-base generator circuits so that a leading edge of a pulse is aligned with each vertically scribed graticule line overlaying the display area.

Abstract: A lightweight stand that attaches to the bottom of a portable electronic instrument, such as an oscilloscope. Used in one assembled form to support the instrument at a convenient, working height and attitude, the stand can be dismantled easily and reassembled in compact, self-contained form for transit or storage.

Abstract: A system for indicating the sweep rate of an oscilloscope time base. A counter is enabled by a sweep gate signal to permit clock pulses having a predetermined repetition rate to be counted during the time a sweep-driving ramp waveform is generated. The count output, which is proportional to the length of a time-base sweep, is decoded to generate specific control signals indicative of the sweep rate thereof. The control signals may then be used by a utilization means to provide a visual readout of the time-base sweep rate or to provide auto ranging for a digital voltmeter scaled in time units for time interval measurements.

Abstract: A two stage surface wave termination for a surface acoustic wave device, such as a filter or delay line. The termination includes a wafer of an acoustically lossy, relatively hard polymeric material that is bonded to the surface of the SAW device's piezoelectric substrate between an end of the substrate and an interdigitated transducer provided thereon. A band of an elastomeric material is bonded to the substrate along the edge of the wafer nearest the transducer.

Abstract: A broadband electron beam deflection apparatus particularly for a tube in which its electron beam can be focused, varied in position and varied in intensity, consisting in the form of a pair of helices each having a flat surface adjacent to the optical axis of the electron beam and also being precisely maintained in a diverging direction to such axis over the length thereof is provided. The apparatus consists of two individual helix assemblies each composed of separate components combined into a single unit in a manner whereby symmetry and desired characteristic impedance is controlled by the dimensions of the helix and having an end-to-end propagation time equal to the electron beam velocity due to the pitch and circumference of the helix.

Abstract: A television transmitter video stabilization system having zero carrier reference drive pulse synchronized and referenced to demodulated video having zero carrier reference pulse and vertical interval reference signal for automatically maintaining uniform transmitted signal by maintaining a percentage ratio between the zero carrier reference pulse and the vertical interval reference signal.

Abstract: This invention relates to the display, in monochrome, of color television component decoded signals red, green and especially blue, and particularly to a method of displaying transmission and recording system produced defects of color television signals which gives improved visual perception of the defects in the chrominance signal thereof in National Television System Committee and Phase Alternation Line color television systems.

Abstract: A circuit for accurately extracting the synchronization information contained within a composite video waveform includes a means for establishing the back porch level of the waveform to a first voltage through a first feedback loop, a means for establishing the sync tip level of the waveform to a second voltage through a second feedback loop, a means for providing the extracted synchronization information at a time determined midway between the first and second voltages, and a system which achieves these ends. An automatic gain control amplifier is included as a portion of the circuit within the system and whose gain is linearly proportional to the logarithm of the AGC voltage and wherein changes in AGC voltage do not interrupt the DC potentials within the amplifier nor do DC changes change the gain of the amplifier.