摘要 |
A touch sensor, having an acoustic wave transmissive medium having a surface and a touch sensitive portion of the surface, a transducer system for emitting acoustic energy into the medium, and a receiver system for receiving the acoustic energy from the substrate as at least two distinct sets of waves, a portion of each of which overlap temporally at the receiver system or overlap physically by propagating in the touch sensitive portion along axes which are substantially non-orthogonal, the receiver system determining a position or a waveform perturbing characteristic of a touch on the touch sensitive portion. The receiver may be an amplitude detector or be sensitive to a phase-amplitude characteristic of the received acoustic waves.
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