| 摘要 |
A real-time display device or fast imager for ultrasonic echography comprises a first electroacoustic transducer array 2 for periodically and simultaneously emitting a multiplicity of parallel ultrasonic wave trains toward a body O to be examined and receives from it reflected ultrasonic wave trains which it converts into electrical echo signals. These signals are transmitted through respective amplifiers 4 to a second electroacoustic transducer array 3 or 30 which retransmits them in the form of regenerated ultrasonic waves to an acousto-optical converter including a transparent tank 5 which contains a piezo-optical liquid 6, serving as an acousto-optical interaction medium, wherein the regenerated waves are focused by one or two focalizing elements, i.e. acoustic lenses and/or mirrors or simply by an arcuate shape of the second transducer array 30. The ultrasonic wavefronts form streaks or schlieren at image points spatially correlated with reflection-generating points of the test object O, these schlieren coming into existence in an image space of the tank at different instants depending upon the spacing of the respective object points from the first transducer array 2. The image space is transluminated by an oscillating light beam of narrow elongate cross-section whose velocity matches the apparent schlieren speed in the direction of wave propagation; the diffracted part of the beam, clearing a spatial filter or mask, is intercepted by a visualizer such as a vidicon tube.
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