Patent ID: 7141911
Filing Date: 2006-11-28
Classification: G11B,H01L

Abstract:
1. A method of driving a piezoelectric actuator, wherein a piezoelectric element has an asymmetrical hysteresis characteristic of polarization-electric field different in each of absolute values of a coercive field of positive electric field and a coercive field of negative electric field, the method comprising the steps of: polarizing the piezoelectric element in a film thickness direction thereof and in a direction of electric field of smaller absolute value in comparison with the coercive field of the positive electric field and the coercive field of the negative electric field; and applying, as a position control voltage for position control by distorting said piezoelectric element in a direction orthogonal to the film thickness direction of said piezoelectric element, a voltage equivalent to an electric field of 0.4 or less of said large absolute value in the film thickness direction of said piezoelectric element in a direction of electric field of larger absolute value between the absolute value of the coercive field of the positive electric field and the coercive field of the negative electric field.