Acoustic-optical image converter - uses density modulation of acoustic-electrical multiple electrode converter tube for low frequencies

摘要

The method of acoustic-optical image conversion using density modulation enables operation in a lower frequency range than hitherto possible, namely in the range below a few hundred megaHertz. It is applicable in ultrasonic microscopy and for materail and medical investigations. The object is subjected to ultrasound and an image projected onto a piezoelectric transducer layer (5) which produces a scanning modulated electron beam using an emission spot (7'). The beam power drives a circuit contg. an amplifier (V), demodulator (D), and video display (10). The electron beam emitted by the emissionspot is controlled in its flux density via the positional intensity of the image using an acoustic-electrical multiple electrode converter tube. The emission spot is made from photoelectrons which are released by a scanning light spot.