A control portion always monitors a present-position signal from a position sensor and monitors whether the present position of a moving body is a desired position, or not (Step 101). In the case where the control portion detects that the present position of the moving body reaches the desired position,...http://www.google.com/patents/US6717330?utm_source=gb-gplus-sharePatent US6717330 - Ultrasonic motor and electronic device having the ultrasonic motor
