| 摘要 |
PURPOSE:To obtain a tuning fork vibrator possible for low voltage drive and very small capacitance ratio by designing the vibrator so that adjacent piezoelectric material layers clipped by an internal electrode are polarized oppositely and each internal electrode is connected to an outer electrode at a different face of an arm at each other layer. CONSTITUTION:The piezoelectric material layers clipped by the internal electrodes 1 are connected in parallel so that the direction of polarization is opposed at each layer, that is, the internal electrode is positive and a negative electrode at each other layer. In applying a DC electric field to the tuning fork in parallel with the direction of polarization, displacement (elongation) is caused to the piezoelectric ceramic layer clipped between the inner electrodes 1 because of the piezoelectric longitudinal effect. On the other hand, since the length of a part not applied with adjacent electric field in the same arm remains the same, a bending displacement is generated vertically to the tuning fork face. The electric field applied thereto is selected as an AC electric field and the frequency is selected properly, then the tuning fork arm is vibrated perpendicularly to the face.
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