ROTATION ANGLE DETECTING DEVICE

摘要

Provided is a rotation angle detecting device including first rotation detecting means (50) and second rotation detecting means (72) for detecting the rotation angle of an object rotor (S) continuously for periods different from each other. In these individual rotating detecting means, the individual output signals obtained to correspond to the rotations of the object rotor are increased or decreased in the same direction in accordance with the rotational direction of the object rotor. The difference of the individual output signals corresponding to the rotations of the object rotor and obtained by the first rotation detecting means and the second rotation detecting means is taken, and this output difference is used to detect the absolute rotation angle, which is defined by the least common multiple between the period of the first output signal obtained by the first rotation detecting means and the period of the second output signal obtained by the second rotation detecting means, within the detectable rotation angle. As a result, the rotation angle detecting device can reduce the number of parts to constitute itself, thereby to achieve its size reduction and to detect the rotation angle highly precisely.