Patent attributes
A driving velocity of a motor is detected by processing a position information signal output from a sensor in accordance with a driving position of a motor. The signal processing device includes a position information signal processor (410) that processes the position information signal and calculates driving velocity information of the motor, and an internal position information generator (460) that reflects a latest driving velocity information (ωn) calculated by the position information signal processor (410) and generates a latest presumed position of the motor as internal position information. An amplitude correcting unit (465) detects the amplitude of the position information signal from the sensor and corrects the amplitude of the internal position information signal based on the detected amplitude.
