Touch screen input system

摘要

A touch screen input system for use with a display screen having a photo-active display surface including a controllable sweeping beam. The system includes at least one photo-detector in combination with detection circuitry for continuously registering the position of the beam in the display surface. A pointer is adapted to reflect light from the beam to the photo-detector to provide a latch signal which is used to hold a signal identifying display screen location corresponding to pointer means location.