Touch screen using echo-location

摘要

A plurality of acoustic wave transducers are coupled to a substrate at predetermined spaced apart locations. At least one of the transducers is operative to emit an acoustic wave that propagates along the substrate, with the other transducers operating as receivers of acoustic waves. The receivers are coupled to a control system that is operative to determine a location at which the substrate is perturbed based on time associated with travel of an acoustic wave from a transmitter, to the location of the perturbation, and from the perturbation to each of the respective receivers.