ULTRASONIC WAVE RADIATION PATTERN DISPLAY SYSTEM INCORPORATING PHASE CONTRAST MEANS

摘要

ULTRASONIC WAVE RADIATION PATTERN DISPLAY SYSTEM INCORPORATING PHASE CONTRAST MEANS The present system permits image of internal structure of ultrasonic wave scattering object to be visually revealed on a cathode ray tube display with good contrast and good resolution, even when acoustic attenuation characteristics of object are relatively uniform and scattering points in object are due substantially to differences in acoustic index of refraction. This is accomplished by employing an acoustic quarter-wave plate to relatively phase shift unscattered wave energy passed through object with respect to scattered wave energy passed through object, thereby transforming a phase pattern manifesting the object's internal structure into an intensity image pattern thereof which insonifies a flexible pellicle mirror. The remainder of the system converts this pattern into a visual display on the cathode ray tube.