Patent ID: 7154210
Filing Date: 2006-12-26
Classification: H02N

Abstract:
1. A driving device comprising: an electromechanical transducer element; a driving member fixed to an end of the electromechanical transducer element; a movable member that is movably held on the driving member; and a driving circuit for applying drive voltage to the electromechanical transducer element; the driving circuit including a self-oscillating circuit that oscillates at a series resonance frequency of the electromechanical transducer element and a non-linear circuit for adding distortion to the drive voltage so as to make the drive voltage have a generally sawtooth-shaped waveform, wherein a frequency of the drive voltage is equal to a primary resonance frequency and a frequency two times the frequency of the drive voltage is near to a secondary resonance frequency in a frequency transfer characteristic of velocity of the driving member with respect to voltage inputted into the electromechanical transducer element, and the non-linear circuit is composed of a current-limiting resistor, a first diode and a first switch connected to a cathode terminal thereof, and a second diode and a second switch connected to an anode terminal thereof, which are connected in parallel with each other.