| 摘要 |
PURPOSE:To reduce the thickness of a piezoelectric oscillator unit and to increase the accuracy of frequency adjustment, by containing a plurality of piezoelectric oscillators in a flat type case and performing frequency adjustment after vacuum sealing. CONSTITUTION:In a flat type case consisting of a recessed base 21 and a cover 22, piezoelectric oscillators 10a and 10b almost the same shape and size are mounted closely but not overlappingly. The base 21 and the cover 22 are sealed in vacuum. Further, the oscillators 10a and 10b are provided with weights 25a and 25b for frequency coarse adjustment and weights 26a and 26b for frequency fine adjustment, and the position is shifted to the lengthwise direction of the oscillators. Thus, in frequency adjustment with a laser beam, no effect is given on the adjusting weights of other oscillators. Thus, the thickness of the piezoelectric oscillator unit can be made thin and the accuracy of the frequency adjustment can be increased. |
