| 摘要 |
PURPOSE:To adjust the oscillation frequency of an oscillator by forming a conductor layer which has no electric connection on the outer circumferential surfaces of an insulating seal container for a crystal vibrator, etc., and removing the conductor layer by a sand-blast or laser-beam method, etc. CONSTITUTION:The crystal piece 2 of the crystal vibrator 1 as a piezoelectric vibrator is shut in the insulating seal container 3. The seal container 3 is formed by pasting glass-made cylinder parts 3a and glass-made bases 3c and 3c which have sealed holding pins 3b and 3b together with glass paste having a low fusion point and a conductor layer 4 is provided on an outer circumferential surface of this seal container 3. The crystal oscillator 1 is connected to an oscillating circuit. Although the conductor layer 4 of the crystal vibrator 1 is not connected, but it covers the outer circumference of the crystal vibrator 1, so shielding effect is obtained, making external influence hard to exert. The conductor layer 4 has stray capacity to driving electrodes 2a and 2b, and this stray capacity is stable because of said shielding effect. This invention utilizes this stray capacity positively for an adjustment of the oscillation frequency. Namely, the conductor layer 4 is removed partially in the sand blast or laser light means, etc., and the area of the removed part 4a is increased to decrease the stray capacity value, adjusting the oscillation frequency. |
