Patent ID: 8810237
Filing Date: 2014-08-19
Classification: G01D

Abstract:
1. A relative angle detection device that detects a relative angle between a first rotary shaft and a second rotary shaft, the relative angle detection device comprising: a magnet that is provided to any one rotary shaft out of the first rotary shaft and the second rotary shaft; a first magnetic field sensing unit that is provided to the other rotary shaft different from the one rotary shaft, and outputs a value according to a magnetic field of the magnet; a second magnetic field sensing unit that is provided to the other rotary shaft, outputs a value according to a magnetic field of the magnet, and outputs a value different from an output value of the first magnetic field sensing unit even if being placed in a magnetic field equal to a magnetic field of the first magnetic field sensing unit; a correction unit that corrects any one output value out of the output value of the first magnetic field sensing unit and an output value of the second magnetic field sensing unit in accordance with an amplitude ratio between magnetic field components orthogonal to each other in the magnetic field of the magnet; and a computing unit that computes a relative angle between the first rotary shaft and the second rotary shaft on the basis of the one output value having been corrected by the correction unit and the other output value different from the one output value.