| 摘要 |
PURPOSE:To reduce the spurious to generate a simple waveform by providing many through holes in the thickness direction of a piezoelectric ceramic element body to reduce the diametric oscillation mode or the transverse oscillation mode and its harmonic oscillation mode. CONSTITUTION:Many through holes 4 are formed in the thickness direction of a disc-shaped piezoelectric ceramic element body 1 at a proper area rate. Since these through holes 4 are provided, a characteristic similar to anisotropy is given to the oscillator without reducing the dielectric constant, and the diametric oscillation mode or the transverse oscillation mode is reduced to reduce the spurious. That is, only the spurious due to the small transverse oscillation mode is seen near 40kHz in this oscillator, and a considerable spurious improving effect is attained. |
