Patent ID: 7714848

Claim:
A touch sensing apparatus comprising: a differential signal source configured for generating two alternating current signals with same frequency and reverse phase, wherein the differential signal source comprises a cathode output end and an anode output end; two conductors respectively connected to the cathode output end and the anode output end of the differential signal source; a sensor located between the two conductors for receiving a noise; wherein the sensor and the two conductors form two simulated capacitors that offset environmental noise; a detector having a first input end and a second input end, the detector upon receiving the noise transferred from the sensor resulting in voltage differences between the first and second input ends thereof, and outputting a signal; a rectifying circuit for rectifying the alternating current signals generated by the differential signal source, simultaneously generating a noise, wherein an end of the rectifier circuit is connected to the signal source and another end of the rectifier circuit is connected to the second input end of the detector; a direct current power source electrically connected to the second input end and a positive power input end of the detector, and configured for providing a bias voltage for the detector; and a first resistance and a second resistance, wherein one end of the first resistance connects to the direct current power source, the other end of the first resistance, as well as one end of the second resistance, is connected to the second input end of the detector, the other end of the second resistance is grounded.