ACOUSTIC TOUCHSCREEN CONSTRUCTED DIRECTLY ON A CATHODE RAY TUBE

摘要

A touchscreen is constructed directly on the glass surface of a cathode ray tube (CRT) (15). To solve the problem of insufficient space between the CRT' s bezel and frontal region (16) to accomodate the transducers (20) for the touchscreen, the transducers (20) are moved away from the frontal region (16 ), to the highly curved shoulder region (17) of the CRT (15). To preserve acoustic signal strength, the positioning of the transducers (20) is chosen to take advantage of the fact that an acoustic wave on a non-Euclidian surface travels along a geodesic path (31). Allowance is also made for the acoustic lens and prism effect of the corner regions (26) of the CRT (15), where the transducer (20) may be located.