| 摘要 |
PURPOSE:To obtain larger displacement and energy, by noticing the polarization state of a piezoelectric element. CONSTITUTION:A power source V1 is applied only to one side of a piezoelectric element to give an auxiliary displacement. This electric field can be applied up to Emax because of the forward direction. A displacement quantity Y1a at this time becomes 3/4h.d31 Emaxl<2>. At the time when an electrostrictive element 3 is operated, the part of the element 1 is short-circuited, and the power source V1 is applied to the part of a piezoelectric element 2, and the sag becomes Y1=Y1a+Y1b= 3/4h.d31 Emaxl<2> similarly. Consequently, displacement Y1=Y1a+Y1b=3/4h.d31 Emaxl<2> is obtained. Therefore, a displacement twice as large as the displacement due to the conventional driving method is obtained in respect to materials which satisfy Emax=4Ep. In said equations, (l) and (h) are the length an the thickness of the vibrator, and d31is a piezoelectric constant. |
