US Patent 7969145 Position detecting device with a magnetoresistive element

Disclosed is a position detecting device provided with a magnetoresistive element that can accurately detect a position using a magnet and a detector that moves opposite to the magnet. A front surface of a magnet having a circular shape is magnetized to the N-pole, and a rear surface thereof is magnetized to the S-pole. A detector moves in the X-Y plane at a position that is spaced from the front surface of the magnet. The detector is provided with an X direction detecting element and a Y direction detecting element. The X direction detecting element and the Y direction detecting element are magnetoresistive elements. The front surface of the magnet is tapered such that the center thereof protrudes.