Touch position coordinate detecting system

摘要

A touch position coordinate detecting system is provided that is based on surface acoustic waves and includes arrays of reflective patterns between a touch region of a touch panel. An initial burst that includes two frequency components is sent on the panel. The reflective arrays include two sub-arrays centered respectively at the two frequencies. A touch on the panel involves an absorption of the acoustic waves traveling in the region of the panel, and provides a localized damping in a time output signal. A time localized damping is detected for each reflected frequency components, thereby enhancing the signal-to-noise ratio of the system.