| 摘要 |
PURPOSE:To facilitate the lead-out of a lead electrode, by setting the driving electrode to both faces of the center polarized region of a piezoelectric porcelain plate having nonpolarized both ends in the length direction of the porcelain. CONSTITUTION:A strip type driving electrode 2 is set to both faces of the central polarized part of a piezoelectric porcelain plate 1 having nonpolarized both ends in the length direction of the plate 1. Thus the width 2H1 of the electrode 2 is reduced. The width/length vibration propagating a thin piezoelectric porcelain plate having a finite width shows the high range cutoff type decentralizing properties, and the energy can be enclosed by setting a higher curoff frequency at a region where a frequency rising type electrode, i.e., a driving electrode than its peripheral area. Furthermore the cutoff frequency of the width/length vibration increases by decreasing the ratio between the width of the electrode 2 and the width of the plate 1. And this cutoff frequency can be increased more than that of the nonpolarized mode. |
