公开(公告)号：US09740356B1

公开(公告)日：2017-08-22

申请号：US15016484

申请日：2016-02-05

Applicant: PIXART IMAGING INC.

Inventor： Hsin-Chia Chen ,  Kenneth Crandall ,  Thomas Patrick Murphy

IPC: G06F3/044 ,  G06F3/041

CPC classification number: G06F3/044 ,  G06F3/0416 ,  G06F3/0418

Abstract: A capacitive touch system including a drive end, a capacitive sensing matrix and a detection end is provided. The drive end concurrently inputs encoded and modulated drive signals into a plurality of channels of the capacitive sensing matrix within each drive time slot of a frame. The detection end detects a detection matrix of the channels in the frame and decodes the detection matrix to respectively generate a two-dimensional detection vector corresponding to each of the channels. The detection end further calculates a subtraction between components of the two-dimensional detection vectors associated with two receiving electrodes of the capacitive sensing matrix to eliminate interference from noises.

公开(公告)号：US09606671B2

公开(公告)日：2017-03-28

申请号：US14697923

申请日：2015-04-28

Applicant: PIXART IMAGING INC.

Inventor： Kenneth Crandall ,  Thomas Patrick Murphy ,  Hsin-Chia Chen

IPC: G06F3/045 ,  G06F3/041 ,  G06F3/044

CPC classification number: G06F3/0418 ,  G06F3/044

Abstract: A capacitive sensing device including a touch panel and a controller chip is provided. The touch panel includes a plurality of first electrodes and a plurality of second electrodes. The controller chip includes a plurality of input capacitors and a plurality of output resistors. The input capacitors are selectively coupled to signal inputs of the first electrodes and the second electrodes, respectively. The output resistors are respectively coupled to signal outputs of the first electrodes and the second electrodes. The input capacitors and the output resistors are configured to form bridge circuits to suppress the influence of mutual capacitance between the first electrodes and the second electrodes.