| 摘要 |
PURPOSE:To prevent thermal deterioration of polarization and make polarization characteristic of regions of different polarities approximately equal by carrying out a polarization treatment for providing polarity of one direction and a polarization treatment for providing polarity of a reverse direction and by carrying out a polarization treatment by making a split electrode on a surface wherein the polarization treatments are not carried out and an electrode approximately all over the rear at the same electric potential. CONSTITUTION:In a piezoelectric element 1, split electrodes 2-a, 2-b and an entire surface electrode 3 are formed. A voltage is applied between the split electrode 2-a and the entire surface electrode 3 opposite thereto. A voltage is also applied between the split electrode 2-b and the entire surface electrode 3 opposit thereto changing polarity and a polarization treatment is carried out. Since the spilt electrodes 2-a, 2-b wherein polarization is not carried out are shortcircuiting with the entire surface electrode 3 opposite thereto, a polarization treatment is carried out by making them the same electric potential. Thereby, it is possible to prevent thermal deterioration, etc., of polarization and to make polarization characteristic of regions of different polarities approximately equal. |
