| 摘要 |
PROBLEM TO BE SOLVED: To obtain a piezoelectric element with frequency stability excellent against aging, vibration, impact, etc., by arranging a pair of electrodes on a piezoelectric substrate, keeping a prescribed space between a resonance part and nearly equalizing the resonance frequency of the pair of electrodes and the resonance frequency of the resonance part to acoustically combine. SOLUTION: A two-terminal pair crystal vibrator of structure obtained by adding a pair of electrodes 5a, 5b at positions symmetrical with the electrodes 3a and 3b with the resonance part 2 as a center excites and picks up a signal by the electrodes 5a and 5b of a receiving part 5 through the part 2. Concerning the transmission-type two-terminal pair crystal vibrator, the resonance frequencies of three vibration parts of the part 2, an exciting part 3 and the part 5 are set to be nearly coincident with each other and the vibration parts are acoustically combined while respectively making thickness-torsional vibration in this structure. Then, the acoustic combination rate of an adjacent vibration part is properly set to acoustically combine the electrode pairs 3a, 3b, 5a and 5b and the part 2, thereby frequency stability excellent against vibration, impact, etc., can be obtained.
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