| 摘要 |
PURPOSE:To attain thinning, and to improve the detection accuracy of rotational angle frequency by providing a tabular piezoelectric element excited in the thickness direction and a tabular vibrator fixed onto the plate surface of the tabular piezoelectric element. CONSTITUTION:The electric signal of natural resonance frequency as the in- plane vibration mode of a tabular vibrator 6 is applied to a tabular piezoelectric element 5 from a signal generator 7. When a rotary motion is applied around an axis 8 vertical to the surface of the piezoelectric element 5 under the state, Coriolis force is generated, and the natural resonance frequency of the vibrator 6 is changed. When rotational speed is applied around the axis 8 under the state, in which the piezoelectric element 5 and the vibrator 6 are excited by natural resonance frequency in rotational frequency OHz, resonance frequency is altered, thus varying the impedance of the piezoelectric element 5 and the vibrator 6 in response to rotational frequency. Accordingly, an input voltage value and an input current value or the phase difference of input voltage and input currents at that time are measured, thus detecting rotational frequency (rotational angular velocity). |
