Patent ID: 7521924

Claim:
A member position detecting apparatus for detecting that a metallic moving member guided by a metallic stationary rail has reached a predetermined position of the stationary rail, wherein one of a magnet and a magnetic sensor is disposed at a position corresponding to the predetermined position of the stationary rail, wherein the other of the magnet and the magnetic sensor is disposed at a position of the moving member facing the stationary rail, wherein the magnet is disposed on an inner side of the stationary rail, and the magnetic sensor is disposed on an inner side of the moving member, wherein a central region of a facing plane of the magnet faces the magnetic sensor, and a magnetic polarity is different at both sides of the central region, and the magnetic polarity of a rear surface of the magnet is different from the magnetic polarity of the facing plane facing the magnetic sensor, wherein the magnet and the magnetic sensor are surrounded by the metallic stationary rail and the metallic moving member, wherein the magnet is provided on one end portion of the stationary rail, and another end portion of the stationary rail does not have the magnet, and wherein a border of the different magnetic polarities of the facing plane of the magnet is parallel to the movement of the magnetic sensor disposed on the metallic moving member.