Patent ID: 7205777

Claim:
Capacitive proximity switch for detecting a change in a capacitance ΔC relative to a setpoint capacitance C set by the approach or retreat of an object in a sensitive area of the proximity switch having an electrode system with at least, one response electrode, an evaluation unit and a switching output, a measured value which corresponds to the change in capacitance being compared to a operating threshold and a switching signal being produced at the switching output depending on the measured value, wherein: the evaluation unit is adapted to produce an evaluation of the measured value which corresponds to the change in capacitance ΔC over time, and based on the time behavior of the measured value, the evaluation unit is adapted to deactivate a first operating threshold S 1 and to activate a second operating threshold S 2 , the second operating threshold S 2 which is reached only at a change in capacitance ΔC 2 which is caused by a target object coming into or out of the sensitive area of the proximity switch with is greater than the first operating threshold S 1 , which is reached at a smaller change in the capacitance ΔC 1 which can be caused by a false object coming into or out of the sensitive area of the proximity switch, and wherein the operating threshold S 1 is a default operating threshold for producing the switching signal when the measured value has been reached, while the second operating threshold S 2 is activated for producing the switching signal only when the measured value has reached the second operating threshold S 2 .