Patent ID: 7304473
Filing Date: 2007-12-04
Classification: G01D

Abstract:
1. A rotational angle detecting device comprising: a sensor portion having a Hall element for detecting the rotational angle of the rotating shaft based upon the value of a Hall voltage output from the Hall element in accordance with the intensity of a magnetic field emitted from a magnet rotated in connection with rotation of the rotating shaft, wherein the sensor portion comprises: longitudinal Hall elements disposed in 90-degree arrangement relationship to detect a magnetic field component horizontal to a substrate surface of a semiconductor substrate; and an engaging mechanism for making the center of the rotation of the magnet mechanically coincident with a center of the sensor portion at which lines passing through the center points of the longitudinal Hall elements and perpendicular to the arrangement directions of the longitudinal Hall elements intersect to each other while the magnetic field emitted from the magnet is applied to the substrate surface of the semiconductor substrate in parallel is provided between the sensor portion and the magnet.