Patent ID: 6536293
Filing Date: 2003-03-25
Classification: B62D,G01D,G01L

Abstract:
A rotational angle detecting apparatus, comprising:a rotor; at least one target provided on the rotor for outputting a signal which repeats periodically in accordance with increases and decreases in rotation of the rotor; a first detector for detecting an adjacent part of the target; a second detector for detecting another part of the target which is a predetermined angle distant in a circumferential direction of the rotor from the part detected by the first detector; a memory for storing pairs of detected signal values which should be synchronously outputted from the first detector and the second detector; means for detecting a rotational angle of the rotor based on the detected signal outputted from one of the first detector and the second detector; judging means for determining whether a pair of detected signal values is within a predetermined range greater than or less than the pairs of detected signal values stored in the memory; and means for outputting a malfunction indicating signal when the judging means determines that the pair of detected signal values is not within the predetermined range.