Patent ID: 8692565

Claim:
A capacitive proximity sensor, comprising: a sensor electrode; an auxiliary electrode disposed coplanar with the sensor electrode in the vicinity of the sensor electrode; a detection circuit connected at least to the sensor electrode and operative to detect a capacitance value based on a capacitance on the connected electrode; a change-over switch selectively switching between a first connection state of not connecting the auxiliary electrode to the detection circuit with the sensor electrode being connected to the detection circuit and a second connection state of connecting the auxiliary electrode to the detection circuit with the sensor electrode being connected to the detection circuit; and a comparison/decision means operative to compare a first capacitance value from the detection circuit in the first connection state with a second capacitance value from the detection circuit in the second connection state to yield a comparison result, and decide whether or not a sense target locates within a range of a sense region based on the comparison result and the first or second connection state.