Patent ID: 7884600
Filing Date: 2011-02-08
Classification: F16C,G01D

Abstract:
1. A rotation angle detecting device which comprises: a magnetic generating element arranged on a rotatable member and having a magnetic anisotropy in a circumferential direction about the axis of rotation; four linear magnetic sensor arrays arranged on a non-rotatable member confronting the magnetic generating element in a direction along the axis of rotation and arranged in a plane perpendicular to the axis of rotation, each of the sensor arrays being arranged along one of four sides of an imaginary rectangular shape; a signal read-out circuit for reading respective outputs of the four magnetic sensor arrays; an AD converting circuit for converting each of the signals so read out into a respective digital signal; and an angle calculating circuit for calculating the angle of rotation of the magnetic generating element from an output of the AD converting circuit, wherein the magnetic sensor arrays, the signal read-out circuit, the AD converting circuit and the angle calculating circuit are all mounted on one semiconductor chip, the signal read-out circuit and the AD converting circuit are arranged outside the magnetic sensor arrays arranged in a generally rectangular pattern, and the angle calculating circuit is arranged inside the magnetic sensor arrays arranged in a generally rectangular pattern.