| 摘要 |
PURPOSE:To enable the improvement in linearity of I/O characteristics by a method wherein the mechanical strength is much more increased than in the case of a flat plate, and at the same time longitudinal resonance is effectively led out by enhancing the anisotropic effect, by using a piezoelectric ceramic provided with a cylinder having an inner diameter aperture at the part where the drive is arranged. CONSTITUTION:The piezoelectric ceramic 6 has a structure of providing a cylinder 8 having an inner diameter aperture 7 to at least on end in the axial direction. The cylinder 8 has an L-length about half of the full length 2L of the piezoelectric ceramic 6 and is polarized P1 between the inner and outer peripheries in the thickness direction at the thick part, then constituting the drive by forming electrodes 9 and 10 on the outer peripheral and inner peripheral surfaces which agree with the direction of polarization P1. Further, the remaining half of the ceramic 6 is polarized P2 in the axial direction and constitutes the power generator by forming an electrode 11 at the axial- directional end surface on the opposite side of the drive. |
