Patent ID: 6848187
Filing Date: 2005-02-01
Classification: G01D

Abstract:
1. An apparatus for detecting an absolute rotation angle of a detection body, the apparatus comprising: a first rotation angle detector connected to said detection body for generating a first detection signal having a cycle corresponding to the rotation of said detection body, wherein said first rotation angle detector includes a first rotating body that is connected to said detection body and rotates together with said detection body; a second rotation angle detector connected to said first rotation angle detector; said second rotation angle detector including a second rotating body that rotates together with said first rotating body and generating a second detection signal having a cycle corresponding to the rotation of said second rotating body in accordance with the rotation of said second rotating body, wherein the rotation rate of said second rotating body is greater than that of said first rotating body; a control device connected to said first rotation angle detector and said second rotation angle detector for detecting an absolute rotation angle of said detection body in accordance with said first detection signal and said second detection signal, wherein: said absolute rotation angle is determined based on the combination of a value of said first detection signal and a value of said second detection signal; and when there is an absolute rotation angle having the same combination of the value of said first detection signal and the value of said second detection signal, said control device specifies an absolute rotation angle based on the relationship between the change of the value of said first detection signal and the change of the value of said second detection signal.