ADAPTIVE THRESHOLD CONVERSION SYSTEM FOR OPTICAL BASE TOUCH SCREEN

摘要

The sensitivity of an optically-based touch screen is substantially improved by adaptively establishing the detection threshold based on the peak trapped light measured over a number of frames on the screen being painted. In accordance with one feature of the invention, the peak trapped light from a target area painted on the screen is compared with a priorly established threshold as a way of determining that a target area is being touched by the user. In accordance with another feature of the invention, the threshold is modified in a way that compensates for possible erroneous touch indications due, for example, to bright spots on the screen.