Abstract: A system for detecting and measuring fast scan jitter having first and second photosensors combined in a unitary detector positionable in the path of a scanning beam; means for generating a packet of test pixels for modulating the scanning beam for jitter through a succession of scan lines; said first and second photosensors outputting signal pulses representing the intensity of said scanning beam following modulation by said test pixels; a differential integrator for integrating the signal pulse outputs of said first and second photosensors with one another to provide a test signal for each line scanned; a filter for smoothing said test signal, an amplifier for amplifying said test signal, a peak to peak detector for comparing the test signal of one scan line with the test signal from the succeeding scan lines to provide a jitter signal where said test signals are different; and a meter for converting said jitter signal to a visual readout.

Abstract: A transducer assembly is provided which performs simultaneous imaging and flow measurement. Separate imaging and Doppler transducers are mounted on one face of the assembly. Each transducer type is backed by backing material which provides damping in accordance with the performance criteria of the different transducer types. The transducer types may be mechanically focused in the same direction so that flow measurements are made in the center of the area being imaged.

Abstract: A control for modulating the scanning beam of a raster output scanner in response to both video image signal levels and beam intensity signal levels through a single port modulator driver with linear balanced amplifier. A control circuit combines the video image signals with an analog beam intensity signal to provide a composite image/intensity control signal which is input to the modulator port to regulate scanning beam intensity. The image intensity signals are derived from a memory previously loaded with data reflecting image beam intensity variations across the scan line, the memory output being updated by a signal representing current beam intensity prior to use by the control circuit.