Abstract: A display memory and controller for displaying waveforms and vectors on raster-scanned conventional video monitors so that the display appears the same as oscilloscope or monitor displays. The brightness of any spot is set by the number of times that an input signal is at the same position on repetitive equivalent sweeps. As the signal passes a time and voltage point, the memory is read to determine the brightness level from before, and a new level is written in to approximate the intensity function of CRT phosphor. As the memory is displayed, the values are decreased to approximate the decay of a CRT phosphor. A memory controller allows the signal to be directly input to memory for later processing for fault determination.

Abstract: A graticule display processor that can produce an adaptive graticule for a raster-scan output waveform monitor. The graticule may be displayed in front of the waveform, behind the waveform or mixed with the waveform. The graticule can change the waveform's color or intensity in specific regions, thereby enhancing the appearance of over range conditions. A specific use is to allow the vector functions of phase and gain to be monitored in the waveform mode.

Abstract: A digital processing system that generates signals for multiple digital video systems and formats including the specific case of PAL D2. The output is either from direct memory or component memory; encoded to composite at line rate, then and scan rate converted to subcarrier rates. The scan rate conversion process includes multiplication process of the signal by coefficients that are changeable with the signal so that conversion error is minimized. A single line of direct memory can be switched in for direct comparison of the outputs to allow detection of scan and encoding errors.

Abstract: A method of displaying phase characteristics of a video signal is employed in a system that determines the phase angle between the color synchronization burst signal and horizontal synchronization pulses of a color video signal. The method includes selecting an image location on a display screen of video monitor and forming at the image location an image representing the value of the phase angle. The image is formed with a length along one axis passing through the image location and with a light intensity. One of the length or the light intensity is proportional to the value of the phase angle to provide an indication of the value.

Abstract: A color enhancement circuit according to the present invention extracts "sine-squared" (haversine) pulses representing absolute values for the derivatives of R-Y and B-Y color difference "sine-squared" transitions; multiples by offset, sign-inverted luminance, and adds the luminance-weighted "singe-squared" pulses to the composite video as color enhancement signals which exceed the NTSC-legal chroma bandwidth but are within the NTSC-legal luminance bandwidth. The pulses augment luminance during chroma transitions, restoring luminance contributions from chrominance which are lost when chroma subcarrier packet risetimes and bandwidth are limited by NTSC broadcast requirements.

Abstract: A linear switch with high off-state isolation in provided for use in video waveform monitors and/or graphic encoders and mixers. The linear switch provides a proportional mix of two signal sources in response to a control voltage for fading and keying from one source to another in order to allow complete elimination of either source from the output (high isolation when a source is fully off) which can be achieved with minimal circuitry.

Abstract: A NTSC/PAL subcarrier based H-lock with color framing method is disclosed which makes possible color frame detection and a digital lock to horizontal sync on a NTSC or PAL video signal, using timing from a sync separator and an oscillator which is phase locked to the color burst of the input.

Abstract: A video test signal generator system with removable memory card and display provides a combination of a front panel display and a removable memory card in a video test signal generator. The memory card allows a user to program the generator in a number of configurations never before possible. The removable memory card can be used to store signal data which is used by the generator in producing test signals, signal selectio protocol and status information which is printed on the front panel display to indicate the generator settings.

Abstract: A method of sampling a color video signal arranged as a sequence of color frames provides identification of a selected one of the color frames. In a preferred embodiment, the method is directed to sampling a PAL-type color video signal in which each color frame includes multiple video image scan lines that have phase characteristics in one of two polarities. Samples of the color video signal are acquired during preselected first and second successive video image scan lines within one of the color frames in the sequence. The polarities of the samples are then identified to determine whether they correspond to the polarities of analogous video image scan lines during the selected color frame. The selected color frame is identified whenever the polarities of the sampled and the analogous video image scan lines are the same.

Abstract: A method and an electrical circuit determines the phase relationship between the color synchronization burst signal and horizontal synchronization pulses of a single color video signal and the color frame relationship between two color video signals. This is accomplished by regenerating on a line-by-line basis a color subcarrier signal which has a fixed phase relative to the leading edge of a horizontal synchronization pulse. A phase comparison is then made between regenerated color subcarrier signal and the color synchronization burst signal to develop a signal that represents the amount of phase error. The phase error signal is sampled to determine an average phase error for successive lines of the color video signal. Simultaneously, a phase comparison is also made between a 90.degree. phase-displaced version of the color synchronization burst signal and the regenerated color subcarrier signal to provide a quadrature phase error signal.

Abstract: A multistandard vectorscope providing vector displays of two or more composite video standards in a single vectorscope. The present invention utilizes a DC controlled phase shifter and a demodulator that are not frequency sensitive along with a switchable oscillator for switching between multiple video standards.

Abstract: A method and an electrical circuit determines the phase relationship between the color synchronization burst signal and horizontal synchronization pulses of a single color video signal and the color frame relationship between two color video signals. This is accomplished by regenerating on a line-by-line basis a color subcarrier signal which has a fixed phase relative to the leading edge of a horizontal synchronization pulse. A phase comparison is then made between regenerated color subcarrier signal and the color synchronization burst signal to develop a signal that represents the amount of phase error. The phase error signal is sampled to determined an average phase error for successive lines of the color video signal. Simultaneously, a phase comparison is also made between a 90.degree. phase-displaced version of the color synchronization burst signal and the regenerated color subcarrier signal to provide a quadrature phase error signal.