Patent ID: 9417739
Filing Date: 2016-08-16
CPC Classification: G06F

Claim Text:
1. A touch-sensitive apparatus, comprising: a panel comprising a touch surface and a plurality of electrodes defining an electrode matrix, the plurality of electrodes comprising a plurality of drive electrodes and a plurality of receive electrodes, each drive electrode being capacitively coupled to each receive electrode at a respective node of the matrix, the panel being configured such that a touch on the touch surface proximate a given one of the nodes changes a coupling capacitance between the drive electrode and the receive electrode associated with the given node; a drive unit configured to generate a drive signal and to deliver the drive signal to the drive electrodes one at a time; a sense unit configured to generate, for each drive signal delivered to each drive electrode, response signals for the plurality of receive electrodes, each of the response signals comprising a differentiated representation of the drive signal, an amplitude of each of the response signals being responsive to the coupling capacitance at the associated node; and a measurement unit configured to measure the amplitude of each of the response signals for each of the nodes, and to determine therefrom the positions of multiple temporally overlapping touches, if present, on the touch surface, wherein the sense unit includes, for each of the receive electrodes, a peak detector configured to provide a peak detector output representative of a maximum amplitude of the respective response signal.