ROTATION-ANGLE DETECTION DEVICE AND METHOD, AND IMAGE PROCESSING APPARATUS

According to an embodiment of the present invention, a rotation-angle detection device for detecting a rotation angle of a rotor includes: plural rotation detectors that output detection signals which vary with the rotation angle of the rotor; a rotation calculator that outputs a rotated vector by rotating a vector expressed by the detection signals; an amplitude detector that outputs an amplitude signal indicating amplitude of the detection signals by performing computation on at least one of signals expressing the rotated vector using a predetermined target amplitude; a drive-power adjuster that adjusts the amplitude of the detection signals by changing drive power applied to the rotation detectors according to the amplitude signal; a corrector that corrects the amplitude based on the amplitude signal and outputs a corrected detection signal; and a rotation angle detector that detects a rotation angle of the rotor based on the corrected detection signal.