Patent ID: 7683637
Filing Date: 2010-03-23
Classification: H03K

Abstract:
1. A touch sensor, comprising: a first sensing electrode; a first discharge element, wherein a first terminal of the first discharge element is coupled to the first sensing electrode; a first sensing-control terminal, coupled to the first sensing electrode and the first terminal of the first discharge element; and an input-output control terminal, coupled to a second terminal of the first discharge element; wherein, when the first sensing-control terminal charges the first sensing electrode to a first voltage, a voltage of the input-output control terminal is set to the first common voltage and then the first sensing-control terminal is set to high-impedance, when a voltage of the first sensing-control terminal is discharged from the first voltage to a second voltage, the voltage of the first sensing-control terminal is set to the first common voltage for a preset period, and then the first sensing-control terminal is set to high-impedance, and then the voltage of the input-output control terminal is set to a second common voltage, when the voltage of the first sensing-control terminal is charged from the first common voltage to a third voltage, determining whether a conductor contacts the first sensing electrode according to a period when the voltage of the first sensing electrode is discharged from the first voltage to the second voltage plus a period when the voltage of the first sensing electrode is charged from the first common voltage to the third voltage.