| 摘要 |
PURPOSE:To enhance an SN ratio by taking out the change portion in charge induced in a detection electrode, by mechanicaly vibrating the detection electrode in parallel to electric line of force incident to the detection electrode to make the capacity between a surface to be detected and the detection electrode variable. CONSTITUTION:When high voltage is applied to a surface 1 to be detected, charge corresponding to the capacity of a capacitor formed by the surface 1 to be detected and a detection electrode 2 is induced in the detection electrode 2 opposed to the surface 1 to be detected. Herein, because mechanical vibration is imparted to a piezoelectric tuning fork main body 4 to the detection electrode 2, the distance between the surface 7 to be detected and the detection electrode changes and the capacity of the air capacitor constituted between the surface 1 to be detected and the detection electrode 2 is changed with the change in said capacity. Therefore, the charge induced in the detection electrode 2 is also changed. This change portion in the charge flows to a resistor 8 and voltage corresponding to the resistance value of the resistor 8, high voltage applied to the surface 1 to be detected and mechanical vibration added to the detection electrode 2 is generated. Detected voltage receives impedance conversion due to FET9. |
