| 摘要 |
PURPOSE:To attain high stability of frequency, miniaturization, low power consumption and low cost by using a crystal oscillator comprising crystal chips having three oscillating branches as the crystal oscillator of a parallel oscillator. CONSTITUTION:The crystal chip 10 has the three oscillating branches 11a, 11b and 12, the length of each oscillating branch is nearly equal and the width of the oscillating branches 11a and 11b is identical. Since thin metallic film electrodes 13a, 13b for excitation are fixed to the side face of the oscillating branches 11a, 11b of both sides and the oscillating branch 12 at the middle, the oscillating mode of the E type oscillator is the lengthwise longitudinal oscillation. When a voltage to generate a frequency equal to the resonance frequency of the lengthwise longitudinal oscillating mode of the E type oscillator is impressed to stems 15a, 15b, the two oscillating branches 11a, 11b with in-phase and the oscillating branch 12 with opposite phase are vibrated to be contracted and expanded in the lengthwise direction of the oscillating branches by the piezoelectric effect of the crystal. Since the top temperature of the oscillator at the high temperature side is attained to a temperature as high as 70 deg.C, the frequency versus temperature characteristic of the parallel oscillator is kept in an excellent value over a wide range from the low to the high temperature side. |
