Abstract: Improper operation of a digital data processing apparatus is detected by applying a predetermined pattern of test digits to a data input of the apparatus and determining whether the pattern of digits provided at the data output of the apparatus in response to the application of the predetermined pattern of test digits to the data input is the same as the pattern that would be provided at the data output if the apparatus were operating properly.

Abstract: A frequency domain characteristic of a system under test (SUT) is measured by using a digital signal corresponding to a swept frequency analog signal. In the case of a digital SUT, the digital signal is applied to the SUT, the output signal from the SUT is converted to analog form, and a measure of the peak-to-peak amplitude of the analog signal is derived. In the case of an analog SUT, the digital signal is converted to digital form, the analog signal is applied to the SUT, and a measure of the peak-to-peak amplitude of the output signal from the SUT is derived.

Abstract: A cathode-ray tube shadow mask mounting system that allows the mask to be removed from the faceplate and replaced in exactly the same position as it occupied before removal includes screw-receiving inserts permanently embedded in the inner surface of the faceplate outside the viewing area of the display screen. Tubular screw guides are secured to the shadow mask frame in corresponding positions, the guides and the inserts having complementary beveled surfaces for drawing them into alignment when a screw is inserted through the guide and threaded into the insert.

Abstract: A calibration strip (80) is described for use in calibrating an optical document digitizer. The strip (80) includes an optically detectible pattern including plural discrete blocks (82) with orthogonal first and second edges (84, 86). Edges (84) are parallel to the drum axis when strip (80) is mounted to the drum (10). As the drum (10) rotates, these first edges (84) are detected and provide a reference for a Y-coordinate axis. With the drum (10) stopped, the second edges (86) are detected by a scanning array (53), as it is stepped by a motor (60) along an X-coordinate axis. The microstep location of each of the detected edges (86) is stored. During document scanning, the array (53) moves along the X-axis to the known microstep locations. The strip (80) has shaft indexing and optics magnification patterns (210, 212).

Abstract: A dual regulated DC power supply produces an output voltage which is the sum of a variable DC control voltage and a floating DC voltage. The control voltage, generated by a first differential amplifier having an inverted input coupled to the power supply output through a feedback scaling circuit, varies in inverse relation to the change in power supply output voltage. The floating DC voltage is produced by isolating, rectifying and filtering the output of an oscillator having a peak voltage controlled by an applied bias voltage. The applied bias voltage is generated by a second differential amplifier coupled to compare the control voltage with a selected reference voltage so that a change in control voltage causes a change in the floating voltage. The control voltage changes rapidly in compensating response to transient changes in power supply voltage while the floating voltage changes more slowly in compensating response to output voltage changes due to sustained load swings.

Abstract: Signals suitable for displaying the phase relationship between the subcarrier wave and the horizontal sync pulse of a composite video signal are provided by establishing coincidence between the d.c. level of the 50 percent point of the sync pulse and the zero crossing point of the subcarrier wave, and generating a reference voltage level at the d.c. level of the 50 percent point of the sync pulse.

Abstract: A latch and detent mechanism for use with a sliding tray 12 mounted in a cabinet 10 is disclosed. The mechanism includes a stationary detent bar 18 having one or more detent slots 22, a latch bar 20 that is pivotably coupled to the sliding tray with a finger 46 at one end for engaging a detent slot to lock the tray in position and a handle 14 at the other end for disengaging the finger to unlock the tray, and biasing means 54 for urging the finger toward the detent slot.

Abstract: A graphics display terminal is disclosed having a capability of responding to at least two unique input commands. A first assigns a segment to a group of classes and also removes the segment from membership in another group of classes. A second is a matching condition which requests that all the segments lying within a certain group of classes and/or not lying within another group of classes be identified, the CRT terminal highlighting these identified segments in response to a command from the operator. The second command is called a matching condition. Once all of the segments in a memory are located, which satisfy the matching condition, the operator can direct the terminal to blink or otherwise highlight the identified segments retrieved from memory.

Abstract: An electrical connection between two semiconductor devices employs a coplanar microstrap waveguide comprising a plurality of thin straps of conductive metal embedded in a polyimide substrate and dimensioned to exhibit the properties of a coplanar waveguide. The waveguide structure provides the proper impedance matching between the two devices and enables them to handle signals having frequencies in the gigahertz range.

Abstract: An apparatus for calibrating a timer of the type having a first and a second input channel in which an initial signal arriving over one input channel initiates a timing cycle, while a subsequent signal arriving over the other input channel terminates the timing cycle, the initial and subsequent signals being transported to remote ends of the first and second input channels from remote sources by means of first and second signal conductors. The apparatus comprises a commoning conductor, a test signal source, and first and second signal routing networks, the first signal routing network being capable of selectively coupling the first signal cable, the test signal source, one end of the commoning cable, and the first timer input channel, while the second signal routing network is capable of selectively coupling the second signal cable, the test signal source, or another end of the commoning cable and the second timer input channel.

Abstract: A cross bar multiplexer includes a plurality of small memory units addressable to indicate combinations of output conductors. The outputs of a plurality of memory units are ORed to provide the outputs for a full array.

Abstract: A pressure interconnect package for connecting an integrated circuit chip to an etched circuit board comprising a pressurized stack of circuit elements in which a flexible interconnecting circuit is disposed between the IC chip and the etched circuit board to cause them to make electrical contact upon the application of pressure to the stack.

Abstract: A digital electron optics correction circuit for correcting the focus and astigmatism in a displayed image on a CRT is disclosed. The circuit includes a clock generator for generating a selected number of pulses between each horizontal blanking synchronization pulse. These clock pulses are then counted by an X-address counter and a first address signal is generated corresponding to a particular horizontal position on the CRT screen for each count of the X-address counter. A pulse generator circuit is also provided which is coupled to receive the vertical blanking synchronization pulses and which provides a selected number of output pulses for each vertical blanking synchronization pulse. A Y-address counter counts the output pulses from the pulse generator circuit and provides a second address signal corresponding to a particular vertical position on the CRT screen for each count.

Abstract: In an apparatus for processing an analog signal, a successive approximation ADC comprises a successive approximation register and a DAC. The final digital signal generated by the ADC is applied to digital processing equipment, such as a digital delay, and the output signal from the processing equipment is converted to analog form using the DAC of the ADC.

Abstract: A method and apparatus is disclosed for operating an ink jet print head 14 of the type having an air chamber 64 to which a stream of air is delivered and an ink chamber 32. A valve 48 interrupts the flow of air to the air chamber 64 from time to time, such as after each copy of a print is printed by the print head. This reduces the air pressure within the air chamber 64 and permits ink from ink chamber 32 to enter the air chamber 64 and replenish ink within the air chamber. The ink pressure is increased while the air pressure is reduced. This reduces the time required to replenish the ink. With the ink in the air chamber maintained at a consistent quantity and shape, the convergence of ink drops on printing medium is enhanced.

Abstract: A capacitive tuning screw comprises a threaded portion with a longitudinal cavity for slidably receiving a plunger shaft. If the capacitive element on the tip of the plunger shaft contacts the corresponding capacitive element on the surface of an electrical circuit board or substrate, further turning of the screw will cause the shaft to slide into the cavity and prevent crushing the circuit board or substrate. A shoulder on the screw stops rotation and longitudinal movement of the screw before the entire length of the plunger shaft slides into the cavity.

Abstract: A signal processing apparatus comprises first and second switches connected respectively to an input terminal and an output terminal of the apparatus and defines first and second signal channels extending in parallel from the first switch to the second switch. The first and second switches are operable to connect a selected one of the signal channels between the input terminal and the output terminal. The first signal channel includes a signal processor, such as a frame synchronizer. The input terminal is connected to the signal processor even when the second channel is selected for connecting the input terminal to the output terminal so that a signal applied to the input terminal is applied to the signal processor as well as to the output terminal when the second channel is selected. Thus, the signal processor can be exercised and the output of the signal processor can be monitored while the second channel is utilized for transmitting a signal from the input terminal to the output terminal.

Abstract: A tooling plate for a circuit board drill wherein the locating apertures for the circuit board is located in the plate by the drill. A bushing cavity is provided in the tooling plate at the approximate desired position. An inner bushing having the locating aperture is laterally moveable in the cavity and an alignment pin in the drill chuck is positioned over the inner bushing at the desired location. The inner bushing is laterally adjusted to enable insertion of the alignment pin in the aperture. While being held in the desired position, a lock ring forces a clamping washer against the inner bushing to lock that position of the inner bushing member within the cavity.

Abstract: An end portion of an elongate member of generally cylindrical form, such as an optical fiber, is placed in a predetermined position utilizing a substrate having a surface that is defined by a generatrix that is a straight line, e.g. a flat surface. A foil of flexible material is secured to the surface of the substrate and defines with the substrate a generally straight, elongate passageway that is parallel to the generatrix of the surface and has a first portion of substantially uniform cross-section adapted to receive an end of the elongate member in closely fitting relationship and also has a second portion that tapers towards the first portion. The end portion of the elongate member is inserted into the first portion of the passageway by way of the second portion thereof.

Abstract: In accordance with the present invention, a control circuit for operating a delayed sweep oscilloscope includes a reversible counter which may be selectively incremented or decremented to establish a number of trigger-circuit operating functions and modes, such as trigger source selection, coupling, level, and sweep mode. A plurality of light sources behind a plastic overlay laminated to the front panel indicate the various functions and modes.