An ultrasonic to electronic image converter tube for operation at 1.20 Mc/s

From 1949 to 1954 a programme of work was undertaken into the design of a cathode-ray image converter tube for transforming a plane section through a continuous-wave ultrasonic field to a television picture. Eleven different types of high-vacuum sealed-off experimental tubes were investigated. The final tube had a resonant quartz front-plate 5.7 cm diameter and operated at 1.20 Mc/s with a threshold acoustic sensitivity of 7 × l0¿7 watts/cm2. The overall acuity was 1 mm on the front-plate and the resulting picture appeared on a monitor cathode-ray tube at 16¿ frames per second with 110 lines per frame. This tube is compared with those reported by other workers since 1954.