초록 ▼

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

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.

대표청구항 ▼

An adaptive thresholding circuit for use with an optically-based touch screen of the type which is overlaid on the face of a display, said display being used to display a plurality of touch targets, said targets being respective sources of signals, said circuit comprising: means for receiving signal

An adaptive thresholding circuit for use with an optically-based touch screen of the type which is overlaid on the face of a display, said display being used to display a plurality of touch targets, said targets being respective sources of signals, said circuit comprising: means for receiving signals from said plurality of targets, means for establishing a single threshold for said targets based on the levels of said signals as they are received from said plurality of targets over a predetermined period of time, and means for comparing said threshold with the level of ones of said signal received from said plurality of targets over a subsequent period of time, and for generating a predetermined signals for each of said ones of said subsequently received signals that exceeds said threshold.