| 摘要 |
PURPOSE:To detect a correct resonance frequency by disposing a vibration detecting electrode by avoiding a center of a part where the rigidity of an elastic unit is varied or the part where the rigidity is varied. CONSTITUTION:First grooves 3 each having a width (t) and a depth h1 are formed on an elastic unit 1, and deep grooves 4 each having a depth h2 are formed partly of the grooves 3. In this case, the rigidity of the unit 1 is varied near the grooves 4 but since an electrode S for a sensor is disposed by avoiding the grooves 4, the rigidity of the unit 1 becomes uniform. On the other hand, a phase difference thetaA-S of a normal resonance frequency fr is -225 deg. in the case of a CW rotation and -135 deg. in the case of a CCW rotation with a difference of 90 deg., but curves of frequency (f) vs. phase difference thetaA-S coincide in all the frequencies. Thus, the position of the electrode S for the sensor is located by avoiding the part where the rigidity of the unit 1 is varied. |
