| 摘要 |
PURPOSE:To reduce the displacement of vibration at the base part and to ensure the firm holding of lengthwise oscillator having three vibrating branches, by having a larger width of the center vibrating branch than the sum of widths of branches at both sides. CONSTITUTION:The metallic thin film electrodes 54 and 55 having different electric polarities to each other are adhered to side surfaces of vibrating branches 51, 52 and 53. An additional mass 58 for control of frequency is provided at the tip of each vibrating branch. Then the AC voltage which is equal to the resonance frequency of an oscillator 50 is applied to electrode terminals 56 and 57. As a result, parallel electric fields are generated as shown by arrows 59a and 59b at the inside of branches 51, 52 and 53 respectively. Then the oscillator 50 vibrates in a primary vertical oscillation mode due to an adverse voltage effect of a crystal. In this case, the width of the center branch 53 is set larger than the sum of widths of side branches 51 and 52. |
