Abstract: A circuit for producing a video signal representing a measuring signal is already known, said circuit comprising a video storage circuit, a horizontal address control circuit for controlling said video storage circuit, a circuit for producing a vertical signal and a comparator circuit which, when the vertical signal essentially corresponds to a signal derived from the video storage circuit, produces a comparison signal representative of a point of the measuring signal in the instantaneously produced line of the video signal. For the purpose of improving the measuring signal representation quality, the invention provides the feature that a video D/A converter and a low-pass filter circuit are inserted between the video storage circuit and the comparator circuit.

Abstract: A logic analyzer includes a plurality of data sampling channels which are operative in response to respective different clock signals independent of one another. Information of the sequence in time in which the sampled data are produced in the plurality of the sampling channels is stored in a memory for the purpose of display. To this end, each of the sampling channels is provided with a clock discriminating circuit having two inputs supplied with a common clock signal generated internally and a clock signal specific to the associated sampling channel. The outputs of all the clock discriminating circuits are stored in a memory whose contents thus indicate the sequence in time in which the data are sampled in the plurality of the sampling channels.

Abstract: A man-machine interface type portable ultrasonic composite measuring apparatus includes an oscilloscope, a position-detecting panel mounted on the display surface of the oscilloscope, a keyboard for effecting a man-machine interface, and a computer which introduces position signals detected from the panel and contents designated by the keyboard. The waveforms to be observed include all objects to be measured, that can be observed in the form of electric signals and that form optimum ultrasonic echos. A position-detecting panel is constructed in the form of a touch panel.

Abstract: Methods and apparatus for random repetitive sampling in digital oscilloscopes is disclosed using a psuedo-random noise generator to vary randomly the beginning of a search for a trigger event to enable the acquiring of data which has no gaps.

Abstract: An apparatus is disclosed which provides a display of the stereo image and aural perspective of stereophonic sounds. Left and right signal are processed to form rectified sum and difference signals which are applied to the signals which are applied to the vertical and horizontal deflection electrodes of an oscilloscope.

Abstract: A horizontal position control for a television waveform monitor includes a potentiometer that has a substantially linear input position/output voltage transfer function, and a circuit for reducing the sensitivity of the horizontal position control over a predetermined range of input positions of the potentiometer. The reduced sensitivity is preferably provided over a band approximately at the center of the range of horizontal positions covered by the horizontal position control.

Abstract: Acquired sampled waveform data is displayed on a screen as a busform, wherein a change of state in the waveform during a sampling interval is represented by a solid block character on the screen, and wherein the lack of a change of state in any of the channels during a sampling interval is represented by a space character of the same width as the block character. The blocks and spaces representing contiguous sampling intervals are of the same width and are displayed in horizontal sequence across the screen such that the time between state changes is graphically represented by the horizontal distance between the blocks. Numbers indicating the associated waveform state are displayed when possible in the space or spaces following each block character.

Abstract: A sequence of digital data values is processed by deriving the average W.sub.n of two of the data values X.sub.n-1 and X.sub.n+1. If W.sub.n lies within the quantization step q centered on the data value X.sub.n, W.sub.n is adopted as a modified value of X.sub.n, but if W.sub.n lies outside the quantization step the modified value of X.sub.n is taken to be X.sub.n +q/2 or X.sub.n -q/2, depending on whether W.sub.n is greater or less than X.sub.n.

Abstract: A digital oscilloscope provides sine interpolation between sampled data points and includes means for intensifying the cathode-ray-tube display to emphasize portions of the cathode-ray-tube trace corresponding to original samples while deemphasizing portions of the trace representing interpolated information.

Abstract: A delayed sweep oscilloscope having a word recognizer displays multi-digit parameters representing an event count necessary to initiate a delayed sweep, and a word to be recognized on oscilloscope data input lines. The numbers are modified digit-by-digit by rotating a first control knob to move a cursor on the screen to select a digit to be altered and then by rotating a second control knob to alter the selected digit. The control knobs are mounted on the oscilloscope front panel and when not used to modify these parameters, the control knobs may be used to control other oscilloscope functions.

Abstract: Apparatus and method for extracting the fundamental component of a complex waveshape (E.sub.T) and for determining the magnitude (V) and phase .theta. of the fundamental component are disclosed. The complex waveshape is converted into digital data relative to a reference signal (E.sub.R) and the in-phase (x.sub.1) and quadrature (y.sub.1) components of the fundamental component are determined by a graphical Fourier analysis of the digital data so that the magnitude and phase of the fundmental component relative to the reference signal (E.sub.R) can be determined.

Abstract: An oscilloscope displays a menu consisting of set of field codes and one configuration code set grouped with each field code. Each field code represents an oscilloscope operating parameter while each configuration code represents an alternative oscilloscope operating mode associated with the operating parameter. A configuration cursor is displayed underlining one configuration code in each field thereby indicating the current operating configuration of the oscilloscope. The configuration of the oscilloscope may be changed by first rotating a first control knob, mounted on the oscilloscope front panel, to locate a field selection cursor under a selected field code and then by rotating a second control knob to move the associated configuration cursor under the desired configuration code. The configuration of each field may be altered by selective operation of the two control knobs in this manner.

Abstract: In a digital wave observation apparatus having an A/D converter for A/D converting an input signal, a trigger level setting device for setting a trigger level, a trigger signal generator for comparing the input signal with a set trigger level and generating a trigger signal, a wave memory for storing an A/D converted input signal in response to the trigger signal, and a display for displaying the input signal stored in the wave memory, the apparatus has a trigger level display device for displaying a horizontal line corresponding to a trigger level on the display irrespective of generation of the trigger signal.

Abstract: A sampling digitizer system which may be expanded for the dynamic testing of high speed data conversion components is provided. The system includes latching comparators which are supplied with the waveform under test and the comparator digital output is integrated by an operational amplifier integrator and fed back to the reference input of the latching comparator to form a comparator-integrator loop. A circuit provides strobe pulses which repeatedly sample the latch enable input of the comparators at a selected time/point until the integrator feedback forces the comparator reference input to be equal to the sample value of the input signal. At this point, an equilibrium state is reached where the integrator output oscillates about the sampled value, and when the loop settles, an analog-to-digital converter reads the final value under computer command. The sample point is computer controlled through a programmable delay line.

Abstract: A raster display digital oscilloscope includes an analog to digital converter and a memory array for developing and storing a digital measurement signal amplitude-dependent on an acquired input signal. After processing stored digital signals are conveyed to an output circuit which includes a raster-scanned CRT and three display memory planes independently addressable by the CPU for receiving in discrete address locations the digital data. Corresponding address locations in the three planes are read in synchronism with the CRT scan to develop a display signal for application to the CRT to produce a display corresponding to the sum of the data stored in the three planes. The digital signals are automatically spread out or bunched up within the display planes to compensate for differences between the data acquisition rate and the scan rate.

Abstract: A method for digitally measuring waveforms is provided in which absolute and relative amplitudes and time information of electrical signals is electronically determined. A pair of cursors, which are operable in both independent and tracking modes, are used to provide alignment with reference points and selected measurement points so that the voltage difference between the cursors may be utilized by a digital voltmeter to provide the measurement data.

Abstract: A digital storage oscilloscope is provided with an anti-aliasing filter circuit utilizing a first plurality of switchable analog filters that bandwidth limit frequencies greater than half the oscilloscope's sampling frequency, and a digital transversal filter effective at lower sweep rates and sampling rates for also bandwidth limiting frequencies greater than half the sampling frequency. The digital transversal filter is controllable to provide a different band pass characteristic for different sweep and sample rates. Both the selection of filters and the control of the digital filter are responsive to the oscilloscope's selection of sweep rate.

Abstract: This invention relates to a waveform observation apparatus such as an oscilloscope, and more particularly to a waveform observation apparatus suitable for a liquid crystal oscilloscope having a liquid crystal display of low power consumption.The waveform observation apparatus comprises at least a waveform memory in which a waveform data is to be written, an input circuit to control the waveform memory to write the waveform data therein and a power supply circuit to drive the waveform memory and the input circuit. The power supply circuit includes means to only intermittently apply the power supply voltage for at least part of the input circuit for a time necessary for writing a waveform. This causes the power consumption to be lowered.

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.

Abstract: An oscilloscope vertical amplifier with Boolean combinatorial trigger generator capability is disclosed. While the display output is fully analog, the trigger output to the time base is digital with a user selectable Boolean function of the analog input signals. Also included is nested triggering, edge as well as level sensitivity, and a trigger filter to selectively inhibit high frequency events. The delay times of the analog and digital signal paths are matched by means of analog delay lines before presentation by a visual display to present the analog and digital signals in time coincidence to the oscilloscope main frame.

Abstract: An oscilloscope having multiple controls, wherein control functions are selected from a plurality of functions. Controls are located adjacent to the oscilloscope display which indicate the control parameter label and control parameter values. The control parameter selection is implemented by software program control.

Abstract: A video synthesizer is adapted for connection to the input circuitry of an oscilloscope, and includes sampling and multiplexing circuitry for presentation of a multiplicity of input signals to a single channel of the oscilloscope. The signals are sampled sequentially, and the samples of respective ones of the signals are multiplexed with corresponding reference voltage levels of a voltage divider so as to vertically displace the signals on the face of the oscilloscope. For periodic input signals, the sequential sampling is repeated at a rate which is not harmonically related to the periodicity of the input signals to fully regenerate the signal waveforms on the oscilloscope. A memory is provided for storing intervals of the input signals in the case of nonperiodic signals, the stored signals then being outputted to the sampling and multiplexing circuitry.

Abstract: An oscillographic device receives plural vertical inputs which are multiplexed to provide plural traces by means of the same electron beam. Switching times of the multiplexer are varied during the display to avoid gaps in waveform presentation when the period of the device's horizontal sweep is a near multiple of the switching period of the multiplexer.

Abstract: The sweep trigger pulses generated internally in an oscilloscope are coupled to a pulse counter, which counter is reset periodically and a number proportional to the count accumulated during each period is displayed.

Abstract: In a sampling digital oscilloscope means operable to measure the time period from the occurrence of a trigger signal to the onset of signal sampling period so that commulatively stored samples of a repetitively sampled signal visually coincide, producing a clear, jitter-free signal image. Moreover, the trigger signal is also produced according to a hold-off mode to allow the user to evaluate the results of processing the sampled signals by the digital oscilloscope before adding new data samples. In addition, a triggered update of stored data by new signals is provided, which is further controllable via an arm/disarm control to interrupt realtime updating of signals, allowing the user to observe signal changes as they occur.

Abstract: An oscilloscope vertical calibration system is provided in which gain control elements in one or more vertical input channels are automatically controlled with respect to cursor voltages applied to the vertical output amplifier. Such calibration process is performed for each deflection factor setting either manually or automatically and the correct gain control signals are stored in memory.

Abstract: A cathode ray oscilloscope having a vertical or signal amplifier connected between a signal input terminal and a cathode ray tube for amplifying an input signal to be observed or measured. Upon disconnection of the vertical amplifier from the input terminal the cathode ray tube exhibits on its screen a bright horizontal line representative of a zero signal level. For the easy adjustment or setting of this zero signal level there is provided a one-hand-operable dual control knob assembly typically in the form of a concentric arrangement of first and second knobs. The first knob is to be pushed for activating a zero level switch, thereby to disconnect the vertical amplifier from the signal input. Sleeved upon the first knob, the second knob is to be turned for operating a potentiometric vertical position adjuster thereby to cause the bright line to move up and down on the cathode ray tube screen.

Abstract: A CRO comprising a scan converter storage tube for storing the input waveform, and a CRT for displaying the input waveform received either directly from the signal input of the instrument or via the storage tube. As the center-to-center distance between the vertical and horizontal deflection plates of the storage tube unavoidably differs from the center-to-center distance between the vertical and horizontal deflection plates of the CRT, the input waveform is displayed in horizontally different positions on the CRT screen depending upon whether it is fed directly from the signal input or has been stored in the storage tube. In order to minimize this horizontal positional difference a position corrector circuit is provided which puts out a correction signal in proportion with a horizontal sweep speed determined by a sweep speed selector switch built into a sweep generator in a horizontal deflection circuit.

Abstract: A delay compensation method and apparatus for digital display systems includes a differential clock generator which controls the timing of progenitor digital signals in separate signal-processing channels so that reconstructed horizontal and vertical analog signals arrive at a display device in a precise time match. Thus, timing errors may be adjusted out while the signals are still in digital form to provide an undistorted display.

Abstract: An apparatus for generating a video signal suitable to cause a representation of repetitive waveform to be displayed on a raster scan display device comprises a differential amplifier which forms an output signal representing a clipped version of the instantaneous difference between the voltage of the waveform and a voltage representing the position of the raster scan line then being executed. An absolute value circuit receives the output signal of the differential amplifier and generates an output signal representing the absolute value of the output signal of the differential amplifier with respect to a reference level. The absolute value signal is inverted and level shifted, and is amplified so that its excursions are of predetermined magnitude.

Abstract: A signal-envelope display system for a digital oscilloscope includes a memory for storing minimum and maximum signal values in adjacent storage locations, an address counter for sequentially addressing the memory, and a control circuit for selectively inverting the least significant bit of the address count signal. The values retrieved from the memory are converted to analog values and a low-pass filter connects the analog values to provide a signal envelope display.

Abstract: The invention offers the opportunity of reproducing measurement values of arbitrary measurement variables, in color as well, on a screen and of storing them as needed. According to the invention, a measurement voltage (Ux) corresponding to a measurement variable is supplied to an adding amplifier (12), which is simultaneously supplied with a voltage (Us) of sawtooth-like course, which is synchronized by the frame-frequency pulses or line-frequency pulses (fsynV or fsynH), as a result of which if a threshold value is exceeded, a signal (tx) which is time-proportional to the measurement voltage (Ux) is emitted for further processing to a video signal. The reproduction of the measurement value (or values) on the video display terminal can take place in the form of a horizontal or vertical bar, and threshold value markers, scaling lines, character symbols and so forth can be reproduced as well.

Abstract: A signal processing system employing charge transfer devices for fast-in slow-out operation is disclosed. A push-pull input analog signal is applied to two charge transfer devices, and the clock pulses applied thereto are shifted one-half clock cycle with respect to one another. The output signals from the two charge transfer devices are differentially summed, and thereby providing cancellation of dark current and clock related noise in the charge transfer device, and doubled sample rate.

Abstract: Digital measuring device, including a trigger generator having an input for receiving an analog measuring input signal, a variable delay line being connected to the trigger generator and having an output, an analog/digital converter receiving the analog measuring input signal, a transient memory connected to the analog/digital converter, a picture refresh memory connected to the transient memory for storing the measuring input signal, a Walsh function generator connected to the picture refresh memory, a liquid-crystal picture screen being connected to and addressed by the Walsh function generator, the output of the variable delay line being connected to the analog/digital converter, the transient memory and the picture refresh memory, and a selectable time base being connected to the variable delay line, the analog/digital converter and the transient memory.

Abstract: A timing analyzer incorporates pattern transition and pattern duration triggering. A transition detector detects transitions into or out of selected patterns occurring among the inputs of the analyzer. A time duration comparator compares a selected logical sense of the pattern against a variable duration reference. The outputs of the transition detector and of the time duration comparator are combined with logic circuits to produce a qualified trigger signal indicative of a simple transition into or out of a selected pattern, duration of the pattern longer than some reference, or shorter than that reference.

Abstract: A waveform measurement and display apparatus comprises a pair of signal-processing channels in addition to a sweep generator arranged so as to provide both Y-T and X-Y display modes. A time marker generator system is provided to insert time markers into the same relative time positions of the respective Y-T and X-Y displays so as to precisely ascertain the time relationship between the two displays. Additionally, such time markers may be inserted into corresponding time positions for expanded and unexpanded waveforms in the Y-T display mode so as to precisely ascertain the relative time position therebetween.

Abstract: A waveform measurement system includes a feature in which a readout of an absolute ground-reference voltage at a particular selectable time point along a waveform is provided. A ground reference potential is sampled and stored, and the instantaneous voltage value of the waveform at the time point is arithmetically combined with the reference potential to provide the measurement. Intensified dots, as well as horizontal volts cursors, are generated and displayed on the waveform at the ground reference and selected instantaneous voltage value positions.

Abstract: A digital test point monitoring system for continuously monitoring n digital test points (where "n" is any desired whole integer)--test points which may, for example, be associated with m data processors, computer processing units (CPU's), machine tool controls, or any similar control system (where "m" is any desired whole integer)--and dynamically acquiring n signal values which may, for example, be indicative of performance, utilization (activity) levels, or similar data point parameters; processing such n signal values; and, simultaneously displaying y of such processed n signal values (where "y" is any whole integer from "1" to on the order of "8") on a living display containing y discrete independent channels of digital information each portraying a pseudo real time digital representation of the monitored signal values and a digitally pictorial historic representation of previously monitored signal values over a preselected period of time ranging up to on the order of 90 minutes, or more; and the digital

Abstract: A waveform searching system for a sampling oscilloscope, in which the instantaneous level of a high-speed sawtooth signal generated by a trigger signal synchronized with an input analog signal and the instantaneous level of a properly attenuated or amplified X-axis sweep wave are compared with each other to generate a pulse in a case of coincidence therebetween, thereby to generate sampling pulses sequentially delayed after the trigger signal by a constant time; the input analog signal is sampled by the sampling pulses to produce sampled pulses; and the sampled pulses are displayed by the X-axis sweep signal on a CRT.

Abstract: A calibration apparatus for analog-to-digital converter or transient recorder including both analog and digital sections is disclosed. A built-in calibrator automatically calibrates the gain and DC level of the entire system to substantially the same accuracy as that of the digital section, thereby avoiding relatively large errors of the analog section. The amplitude or gain calibration is always performed over the full range of the digitizer used in the digital section.

Abstract: A combined logic timing and state analyzer comprises an internally clocked, timing analyzer section receiving a first set of logic signals, and an externally clocked, state analyzer section receiving a second set of logic signals. The timing analyzer section samples the first set of logic signals, as well as the external clock signal associated with the second set of logic signals, at a rate determined by the internal clock pulses and stores the samples in a first set of memories. The state analyzer section samples the second set of logic signals at a rate determined by the external clock pulses and stores the samples in a second set of memories. Data introduction into the memories terminates when they are triggered, as in the event of a malfunction of the system being investigated.

Abstract: A triggerable oscilloscope having a digital clock selectably connected to two digital counters accurately measures a time interval between two recurring events. The first digital counter is connected to the digital clock to count clock pulses during a timer interval between the initiation of a horizontal sweep signal and the occurrence of the first recurring event. A second digital counter is connected to the digital clock to count clock pulses during a time interval between the initiation of a sequent horizontal sweep signal and the occurrence of the second recurring event. A subtractor circuit coupled to the first and second digital counters subtracts the count of the first digital counter from the count of the second digital counter and determines the time interval between the first and second recurring events.Time averaging techniques increase the accuracy of the time interval measurements for high speed recurring events by accumulating counts during a plurality of horizontal sweep signals.

Abstract: A digital oscilloscope is provided with a position control circuit which permits positioning of a signal both before and after digitizing. A track and hold circuit is coupled to the position control potentiometer to generate a reference voltage which tracks the position voltage in a waveform acquisition mode, and which is held at a fixed level in a display mode while the position voltage, which is applied to the acquisition preamp, is variable adjustable. A summation circuit subtracts the reference voltage from the position voltage to provide an altered positioning voltage for the display amplifier which is zero in the acquisition mode and variable in the display mode.

Abstract: Inrush current measuring apparatus with an instantaneous power interruption device is provided an external power input terminal connected to a commercial power supply and an external power output terminal connected to a power unit under test, which terminals are connected together via a switching circuit section; and is equipped with a power interruption device in which the power supply from the external power input terminal to the external power output terminal is cut off or conducted by opening or closing the switching circuit section.

Abstract: An apparatus for measuring phase and amplitude jitter and simultaneously and audibly counting and monitoring transient excursions of two linear bar-chart type readouts calibrated in degrees and modulation percents and which are capable of displaying jitter measurements. The transient excursions in the form of phase hits, gain hits, drop outs and impulse noise are simultaneously counted in parallel registers and means are provided for visually indicating the cumulative real time count total of each register in numerical display. The method of evaluating parameters affecting voiceband data transmission includes simultaneously displaying phase and amplitude jitter components onto linear bar-chart displays and separately deriving the information for each of said displays and providing continuous and sequential illumination on each display encompassing the range of fluctuations from the jitter detectors.

Abstract: A spectrum display apparatus comprises a plurality of band-pass filters respectively having filtering bands of different center frequencies and operating to filter an input signal thereby to band-divide the input signal, a holding circuit normally passing the output signals of the band-pass filters and, upon the application thereto of a control signal, operating in response to the control signal to hold output signal voltages of the band-pass filters at the time of the control signal application, a display section having displaying elements of systems of the same number as the band-pass filters respectively corresponding to the band-pass filters, a circuit for supplying output signals of the holding circuit to the displaying elements and causing level displaying by the displaying elements of those systems corresponding respectively to the output signal levels of the band-pass filters, a control manipulation switch, and a circuit for producing the control signal and applying the same to the holding circuit dur

Abstract: A cathode-ray tube for a multipurpose test and measurement or information display instrument is provided with multiple internal graticules. One of the graticules is permanently visible and functional at all times the instrument is in operation. Another of the graticules is formed in a manner such that it is not easily visible in normal ambient lighting conditions alone, but becomes plainly visible when edge lighted by suitable means.

Abstract: A waveform acquisition circuit for both real-time and equivalent-time acquisition modes with a smooth transition between modes. The circuit includes a control circuit which causes an analog-to-digital converter to take samples of an analog waveform in precise time relationship with preselected data points along the time axis of the waveform. The data points may be preselected in accordance with a variable increment.

Abstract: A digital voltmeter device is disclosed which displays both the numerical value of a measured voltage and a visual representation of an input waveform. The device includes an electro-optical display matrix utilizing display elements arranged in lines and columns. In order to make maximum use of the display matrix for representing input waveforms, the peak-to-peak voltage of the input waveform is measured and utilized as a reference for an analog to digital converter having output signals which form the address signals for the display matrix. The peak values of the input waveform thus appear at the top and bottom of the display matrix respectively.

Abstract: A time variant measured variable is graphically displayed in moving strip chart format on a cathode ray tube. During a scan line the electron beam is intensity modulated at a position on the scan line whith represents the magnitude of the measured variable at a given time. The intensity of the electron beam at positions in successive scan lines is similarly intensitymodulated to produce a trend line representing the magnitude of the variable along the strip chart format. During the scanning of a subsequent raster frame, a new data value of the measured variable is displayed at a selected position at an edge of the viewing area of the strip chart format in thwe location previously occupied by the next sequential value and the older data values are simultaneously displaced. The oldest data value is deleted from the format. During a raster scan the electron beam is modulated at different intensity levels to produce chart lines and time lines on the strip chart format.