Patent ID: 7958672

Claim:
An opening and closing apparatus comprising: a conductive movable body which is movable in a closing direction and an opening direction opposite the closing direction so as to open and close an opening portion formed in a conductive opening forming body, the movable body having a front edge portion positioned in a front side in the closing direction of the movable body, and the opening portion having an opposing edge portion opposing to the front edge portion; a sensor arranged in a layout body, which is one of the opening forming body and the movable body, the sensor being arranged in one of the front edge portion and the opposing edge portion, the sensor having a sensor electrode, and the sensor being capable of detecting a conductive object-to-be-detected on the basis of a change of a capacitance between the sensor electrode and the object-to-be-detected coming close to the sensor electrode; a support member made of insulative resin material for fixing the sensor to the layout body, the support member having a frame member made of a conductive material; a guard electrode supported by the frame member to be provided between the layout body and the sensor electrode, the guard electrode made of a conductive resin material being electrically connected to the sensor electrode and the frame member; and a circuit device electrically connected to the gaurd electrode, wherein the circuit device controls a voltage of the guard electrode to keep an electric potential of the guard electrode equal to an electric potential of the sensor electrode or at a fixed rate with respect to the electric potential of the sensor electrode.