Capacitive proximity sensor and human body detection method using capacitive proximity sensor

摘要

A capacitive proximity sensor 1 comprises an oscillation means 33; a sensor circuit 10, which includes a sensor electrode 11; a detection circuit 20, which outputs a determination voltage signal corresponding to the capacitance of the sensor electrode 11, based on the electrical signal output from the sensor circuit 10; and a control unit 32. The sensor electrode 11 is connected in parallel to a connection point P1 between a coil L and a capacitor C in an LCR series resonance circuit. The detection circuit 20 outputs a determination voltage signal S₁ based on the electrical signal at the detection point P3 between the capacitor C and the resistor R. The control unit 32 detects the proximity of a human body to the sensor electrode 11, based on the determination voltage signal S₁.