Touch input devices for display/sensor screen

摘要

A method and apparatus used in conjunction with a combined display/sensing screen (DSS) includes a transparent outer layer overtop of the sensing screen. A plurality of IR emitters inject IR light edgewise into the outer layer, where it undergoes total internal reflection. Touch input devices have reflective pads on them with a high index of refraction which alters the critical angle in the contact area so that some of the IR is refracted out of the surface and then reflected back through the outer layer to the DSS, where the IR sensor array will detect the position of the reflected light and register a signal. The sensor array signals may be combined into a sensor image to detect touch input devices and movement thereof.