| 摘要 |
<p>In a disclosed method, a piezoelectric element 1 has an asymmetrical hysteresis characteristic of polarization-electric field different in absolute values between a coercive field of positive electric side and a coercive field of negative electric field side, and is polarized in the film thickness direction of the piezoelectric element 1 and in a direction of smaller absolute value of the coercive field, and as a position control voltage Q1 for position control by ditorting the piezoelectric element 1 in a direction orthogonal to the film thickness direction of the piezoelectric element 1, a voltage equivalent to an electric field of 0.4 or less of the coercive field value is applied in the film thickness direction of the piezoelectric element 1 in a direction of larger absolute value of the coercive field. Further, a position control voltage Q2 for recovering from deterioration of polarization of the piezoelectric element 1 is applied by superposing on the position control voltage Q1, or changing over with the position control voltage Q1, or while the position control voltage Q1 is not applied, and therefore recovering from deterioration of polarization characteristic, the displacement characteristic is stabilized for a long period of time.</p> |
