Patent ID: 7319320
Filing Date: 2008-01-15
Classification: G01D

Abstract:
1. A rotation angle detecting device for detecting a rotation angle of a first member relative to a second member, said rotation angle detecting device comprising a magnet unit fixed to the first member and a pair of magnetic sensors fixed to the second member to provide output signals whose phase is different from each other at 90 degrees in angle, wherein: said magnet unit comprises a pair of radially magnetized disk plates that have the same magnetic poles at the same peripheral positions of said disk plates and are disposed at a prescribed axial distance and a shaft that is made of magnetic material to support said disk plates at their centers, wherein said magnetic unit provides a space defined by said shaft and said pair of disk plates and lines of magnetic force in said space are oriented predominantly in parallel with said disk plates; and said pair of magnetic sensors is disposed in said space, between said disk plates.