Patent ID: 9563321
Date: 2017-02-07
CPC Classifications: G06F

Claim:
1. A method for detecting background signals of a capacitive sensing device, comprising: detecting a reference point selected from a plurality of sensing points according to a charge-float-discharge cycle and a first number of no operation performed commands to derive a first capacitance value, wherein the sensing points are configured to form an array in a manner of having a plurality of electrodes be intersected with one another; detecting the reference point according to the charge-float-discharge cycle and a second number of no operation performed commands to derive a second capacitance value, wherein the second number is greater than the first number; detecting the reference point according to the charge-float-discharge cycle and a third number of no operation performed commands to derive a third capacitance value, wherein the third number is greater than the second number; calculating a present difference value according to the first capacitance value, the second capacitance value, and the third capacitance value; and selectively executing a procedure for refreshing the background signals according to the present difference value and a predetermined threshold.