Patent ID: 6954063

Claim:
A motion detecting device for a movable body comprising: a biasing magnet for generating magnetic flux which passes to the movable body; and a magnetoresistive unit disposed between the movable body and the biasing magnet for generating an electric output varying with a motion of the movable body, wherein the magnetoresistive unit is placed at a position away from a line of magnetic center of the biasing magnet, the magnetoresistive unit is inclined from the line of magnetic center of the biasing magnet in a direction of the magnetic flux, the magnetoresistive unit has a pair of magnetoresistive sensing elements arranged in line symmetry, a line of symmetry of the sensing elements is inclined from the line of magnetic center of the biasing magnet, the magnetoresistive sensing elements are formed on a sensor chip having a side surface that is parallel with a side plane surface of the movable body, and the magnetoresistive sensing elements are placed at a different elevation than the movable body, and the movable body is a magnetized rotor that faces the side surface of the sensor chip that is opposite a surface for the magnetoresistive sensing elements.