Vibration type motor device

摘要

A vibration type motor device excites a vibration member by applying frequency signals to piezoelectric elements so as to obtain a driving force. A vibration state detection piezoelectric element is arranged on the vibration member, and when a vibration state is determined by detecting the phase difference between the output from the detection piezoelectric element and a driving frequency signal, a predetermined signal is superposed on the output from the detection piezoelectric element, thus allowing accurate detection of the vibration state even when the output from the piezoelectric element includes noise.