Abstract: The present invention provides a method of displaying characteristics of a signal, where minimum amplitude of the signal during an interval is graphed versus time, maximum amplitude of the signal during the interval is graphed versus time, and the color or greyness of the area between the minimum amplitude graph and the maximum amplitude graph represents the average frequency during the interval of the amplitude measurements.

Abstract: A mechanical holder for receiving an integrated circuit chip and an etched circuit board probe and holding them in predetermined relative positions includes an alignment block including alignment elements and having a main surface against which the probe is positioned, and a chip receiver having a main surface and including alignment elements that are complementary to the alignment elements of the alignment member. The chip receiver is attached to the alignment member with the main surface of the chip receiver in confronting relationship with the main surface of the alignment member and with the alignment elements of the chip receiver in registration with the alignment elements of the alignment member. The chip receiver defines a cavity that opens at its main surface.

Abstract: A video signal in component form is processed by generating high frequency linear color component signals from wideband linear color component input signals. The high frequency linear color component signals are combined to produce a high frequency linear luminance component signal, which is combined with color component signals that contain low frequency components present in the wideband linear color component input signals to produce high-frequency-corrected linear color component signals.

Abstract: A timer circuit provides a wide range of precise and substantially accurate time intervals. The timer circuit includes a ramp generator circuit having a first input for receiving an input signal to start a ramp signal, a second input for receiving a ramp timing control signal, and an output for providing a ramp signal. A comparator has a first input coupled to the output of the ramp generator, a second input coupled to a reference voltage source, and an output for providing an end ramp signal. A counter circuit has a first input for receiving the end ramp signal to begin counting, a second input for receiving a counter timing control signal, and an output for providing a terminal count signal. The end ramp signal and the terminal count signal are combined in an AND gate to provide a signal that is delayed by a predetermined amount from the input signal.

Abstract: A non-interference method of determining the frequency characteristics of a cable television (CATV) system adds an RF test pulse to an RF video signal in the vertical interval between equalizer pulses. A gated receiver coupled to the distribution system receives the RF video signal only during the vertical interval and extracts the envelope of the RF test pulse, with the sync pulses being attenuated. RF pulses of different frequencies within each channel of the CATV system are used to determine the frequency characteristics of each channel.

Abstract: A Moire measurement system uses spectral analysis to characterize the moire effect on a television signal introduced by a particular device. A known television signal is processed by the particular device, such as a video tape recorder, and the output is input to a spectral analyzer, such a windowed fast Fourier transform. The spectral analyzer includes input gating to select a portion of the known television signal from the particular device. The frequency of the desired component of the known television signal, together with the rms values of all the other components introduced by the Moire effect, give the X- and Y-coordinates of a point on an output display. The window is moved across the test signal, giving a family of X- and Y-coordinates that characterize the Moire effect as a function of amplitude, frequency or video pedestal. The Moire characteristics of the particular device then may be used to correct the output of the particular device.

Abstract: An adaptive spatio-temporal compression/decompression algorithm for a video image uses a quadtree hierarchy to represent each frame of the image, the quadtree hierarchy including intermediary nodes and leaves. For each leaf a temporal bit is added indicative of whether a significant intensity change occurred between two frames of the video image. If the temporal bit indicates the significant intensity change occurred between frames, then a new intensity value also is added to that leaf. A decoder using a state machine extracts from the resulting compressed data stream a start address, a block size and the new intensity value for each leaf having the significant intensity change between frames to update a display memory with the new intensity value at each pixel within the area defined by the start address and block size.

Abstract: An ink jet printer (10) having a print head (14) for directing an ink jet toward a sheet of paper (16) includes automatic print head spacing apparatus (80) that holds the print head apart from the sheet of paper by a preselected distance. In a preferred embodiment, the printer includes a rotatable drum (20) for supporting the sheet of paper and media securing system (24) of a first predetermined thickness for securing the paper to the drum. The print head is positioned at the preselected distance after a major surface (130) of the print head engages and is pushed back by the media securing system.

Abstract: The present invention provides a stable, high performance system for driving one or more masses in precise incremental movements. More particularly, the present invention provides a method and system for deriving and implementing motion profiles that govern the movement of one or more masses, such as a printer drum as it is indexed along a rotational path by a stepper motor.

Abstract: A signal acquisition and sampling system mounted in an oscilloscope probe includes an input buffer amplifier (30) featuring shunt feedback, offset capability, input bias current compensation, and very low input capacitance. Signal sampling is accomplished by a cascaded pair of differential sampling bridges including a fast track-and-hold stage (40) followed by a slow track-and-hold stage (50). The differential configuration of the bridges features common mode rejection of strobe signal coupling into the signal path and reduces aberrations and voltage droop. The fast track-and-hold stage features Schottky diode switching bridges (42A) and (42B), low value storage capacitors (44A) and (44B), thereby resulting in a fast tracking time. The slow track-and-hold stage features low-leakage diode-connected transistor switching bridges (52A) and (52B) and a FET buffer stage, thereby resulting in fast acquisition of the fast stage output and long hold time for quantization of the sample.

Abstract: An improved coplanar transmission structure has a coplanar transmission line formed on one surface of a substrate and a lossy resistive material formed on the opposite surface of the substrate for suppressing spurious electromagnetic modes propagating through the substrate. The lossy resistive material may be nichrome or the like and is patterned on the substrate using thin or thick film processing.

Abstract: A triggerable ink transfer system that simultaneously transfers ink from a plurality of ink preload chambers to corresponding load chambers and ink reservoirs is disclosed. The delivery system permits an untrained operator to safely load ink without inadvertently interchanging different types (e.g. colors) of ink, and without inadvertently overfilling any of the ink reservoirs. A processing unit that coordinates ink delivery system monitoring and control features is in communication with an operator interface unit that provides ink loading instructions to the operator.

Abstract: A high-speed, low-profile logic analyzer test probe has a body of insulating material molded directly onto a narrow elongate substrate having electrical circuitry disposed thereon. The molded insulating material has a notch formed therein for exposing a conductive surface formed on the substrate. The exposed conductive surface is used for making a ground connection between the substrate and the ground of a device under test. The probe may be adapted for use in probe holder for multichannel probing wherein the probe holder has an electrically conductive chip disposed within the probe holder housing for providing the shortest possible ground connections between the ground pins on the device under test and the ground connections on the probes.

Abstract: A method and circuit for triggering an electronic instrument only once during a period of an input signal having multiple triggering events during that period. A signal applied to an electronic instrument, such as an oscilloscope, is acquired. Qualified triggering events occurring on the acquired signal are identified. A selected one of the qualified triggering events during the period of the applied signal causes a trigger signal output to occur, while other qualified triggering events are ignored. In the preferred embodiment a triggering event is qualified by a first comparator that compares the input signal to a first reference level and produces a predetermined logic level output if the input signal bears a predetermined relationship to the reference level. When a qualified triggering event occurs, a buffer amplifier applies the predetermined logic level to charge a capacitor, which thereafter stores some energy from the input signal and applies it to a comparator for a predetermined period of time.

Abstract: A digital architecture for a pulse generator provides a method of synchronizing signals of the pulse generator. The pulse generator has a timebase card, a microprocessor and a plurality of pulse cards. The microprocessor controls the parameters of the timebase card and pulse cards, and the timebase card provides a common master clock signal to all of the pulse cards determined by a triggerable voltage controlled oscillator that has two sources of frequency control voltage, an internal DAC for absolute frequency and a frequency comparison circuit for synchronization with an external timebase. The pulse cards produce pulses, either singly or in bursts, with the leading and trailing edges being separately positionable using quantum, sliver and vernier controls. A pattern RAM on each pulse card provides a pulse pattern that provides an approximation of the desired pulses to one quantum, and repeated iterations through the pattern RAM provide bursts of pulses.

Abstract: The present invention includes a cathode-ray tube (10) capable of providing a high-brightness, high-resolution large screen display that is compatible with, for example, field sequential liquid crystal color display systems and monochrome imaging systems. Preferably, the tube includes a small-diameter cathode assembly (14 of 110) with an adjacent small-diameter control grid electrode (38 or 114). The small diameters of the cathode assembly and the control grid electrode result in relatively little capacitance and are, therefore, compatible with relatively high video signal bandwidths. A thick accelerating electrode (66 or 150) is positioned adjacent the control grid electrode to prefocus the electron beam and, thereby, form it with relatively low spherical aberration. In a preferred embodiment, the electron beam is modulated in a push-pull manner by applying a video modulation signal and its inverse to the cathode and the control grid electrode.

Abstract: A probe for testing integrated circuits includes a stiff elastic substrate including a conductive plane, the substrate having a major portion with fingers projecting therefrom in cantilever fashion. A layer of dielectric material is adhered to the substrate and has a main surface remote from the substrate. A plurality of conductor runs are adhered to the layer of dielectric material at the main surface thereof. The conductor runs extend over at least some of the fingers and are configured to form transmission lines when the conductive plane is connected to a reference potential level.

Abstract: An electrical switch usable in an electrical test probe has electrical contact pads formed on a substrate acting as fixed electrical switch contacts. A frame member is laterally disposed from the fixed electrical switch contacts. An actuator is disposed within the frame member having a movable switch pole contact extending from the actuator past the frame member for wipingly engaging the fixed electrical contacts on the substrate as the actuator is moved between first and second switch positions. For use in a switchable passive voltage probe, the electrical switch is formed on a circuit board that is disposed in an electrically conductive tubular body. Insulating material surrounds the fixed switch contacts on the circuit board to electrically isolate the contacts from the tubular body. The switch pole contact reaches into the electrically isolated region to perform the switching function.

Abstract: A sequence of events detector provides a way to continuously monitor serial digital data and precisely define the behavior that it must exhibit in order to qualify as the sequence of events that the user wishes to detect. A plurality of evaluation windows each sequentially examine the behavior of one or more signals, comparing this behavior with predefined criteria. Each evaluation window is activated to begin its portion of the overall evaluation process by a match signal from the preceding window, indicating that its predefined criteria were met. In one version, a sequence starting circuit activates the first evaluation window in response to an external signal or the occurrence of a predefined condition, and a multiplexer trigger source circuit selects as the overall detector output the match signal output of the last evaluation window used to define the overall sequence of events. In another version, each evaluation window explicitly reports a failure if its predefined criteria are not met.

Abstract: Spatial bandwidth testing for digital data-compressed video systems is performed using a complex, or high entropy, test signal. A portion of the test signal is acquired as a control frame. This control frame is divided into a plurality of blocks. Each block is processed by a two-dimensional Discrete Fourier Transform (DFT). The test signal is input to a digital data-compressed video system and a corresponding portion of the output of the video system, a test frame, is acquired and processed in the same manner as the control frame. The resulting coefficient arrays from the control and test frames are compared to each other to obtain an output array of ratios for each block. The ratio of those coefficients corresponding to the predominant frequency of each block of the control frame are displayed as a three-dimensional gain plot. The ratio of those coefficients corresponding to low frequencies of each block of the control frame are displayed as a three-dimensional noise plot.