Abstract: Systems and related methods providing for touch sensors using high sensitivity Lamb waves are disclosed herein. A touch apparatus may include a substrate having a front surface and a back surface, where the touch region is on the front surface. The touch apparatus may be configured to propagate surface acoustic waves on at least a portion of the back surface and high sensitivity lamb waves, such as near-longitudinal-resonance Lamb waves, in at least a portion of the touch region of the substrate. The touch system may further include circuitry configured to determine a location of a touch on the front surface based on received attenuations in the high sensitivity Lamb waves. Some embodiments may provide for bezel-less touch sensor designs and anti-dispersion techniques that enhance touch sensor reliability.

Abstract: A touch pad includes transducers for receiving acoustic signals resulting from touch events, such as the continuous movement of a fingertip across the surface of the touch pad. The acoustic signals are acquired at different transducer locations in the surface. Signals from different transducers are combined, preferably in antiphase, to improve signal characteristics. The transducer signals are supplied to a stereo analogue to digital converter. Phase differences are obtained and compared with phase difference profiles of known location, in order to identify the location of the touch event. An index is used to identify candidate locations to reduce the amount of processing. Interpolation is used to locate the touch event between profile locations.

Abstract: Methods for determining a touch-and-hold touch event on a touch sensitive interaction surface of a touch sensing device are provided and comprise the steps of: a) determining a touch location of the touch event based on vibrations, such as bending waves, propagating through the interaction surface and b) determining whether the touch event comprises a hold touch event based on a sensed airborne signal. A device configured to carry out such methods is also provided.