TOUCH POSITION SENSITIVE DEVICE

摘要

TOUCH POSITION SENSITIVE DEVICE A touch sensitive screen is arranged with substantially parallel surfaces which are at least partially transparent to light. A flexible membrane is supported above the top surface of the screen and when the overlay is flexed into contact with the screen, light which had passed through the screen, is trapped between the screen surfaces by total internal reflection. The edges of the screen are fitted with light detectors for gathering the trapped light. Using this arrangement positional determination of one or more screen touches is possible.