Patent ID: 7696986

Claim:
A touch sensing apparatus comprising: a flip-flop having a first input, a second input, and an output; an alternating current (AC) signal source for supplying AC signals to the first input and the second input of the flip-flop; a sensor connected to the first inputs of the flip-flop and configured for receiving electricity signals from an object that touches the sensor; a first integration circuit interposed between the second input of the flip-flop and the AC signal source and for delaying the AC signal inputted to the second input of the flip-flop; a second integration circuit connecting the first input of the flip-flop to the AC signal source and for delaying the AC signal inputted to the first input of the flip-flop; and a detector electrically connected to the output of the flip-flop and for detecting a change at the output of the flip-flop; wherein the flip-flop outputs a first output signal at the output thereof when the sensor is not touched; the sensor receives electricity signals from the object, and causes a delay of the AC signal inputted to the first input of the flip-flop, the delay of the AC signal inputted to the first input of the flip-flop further causing the flip-flop to output a second output signal at the output thereof; and the detector detects a change from the first output signal to the second output signal at the output of the flip-flop and accordingly identifies a touch on the sensor.