| 摘要 |
PURPOSE:To deteriorate the Q value of the n-th higher harmonic vibration without deteriorating the vibration sharpness Q of the basic wave vibration, by forming an electrode thin film part at the center of an exciting electrode film formed on a piezoelectric element plate. CONSTITUTION:The electrode films 12 and 13 for excitation of piezoelectric element plate are formed in desired forms on both sides of a thickness-shear piezoelectric element plate 11. Then an electrode thin film part 14 is formed at the center of the film 12 within an area of <=1/2 the film 12. The energy enclosing distribution of a thickness-shear piezoelectric vibrator is concentrated at the center of the electrode film as the degree of higher harmonic vibrations is increased. Thus it is possible to change the balance of the frequency reduction value caused by the mass addition effect. Then the frequency difference can be increased between the basic wave vibration and the n-th higher harmonic vibration.
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