| 摘要 |
<p>PROBLEM TO BE SOLVED: To avoid mis-detection or missing of sensing an obstruction due to a temperature change around a sensor electrode that forms a static capacitance with respect to the object. SOLUTION: In this sensor, a resonance circuit 2 to which a sensor electrode 10a and a 1st varactor diode VD1 are connected is coupled with an oscillation circuit 3 to correct an oscillating level of the oscillation circuit 3 by controlling a static capacitance control voltage V2 applied to the diode VD1 thereby sensing a change in an oscillation level due to access of an object to the sensor electrode 10a. A temperature compensation circuit 5 is provided with a temperature sensor 51n and a 2nd varactor diode VD2, the diode VD2 connects to the resonance circuit 2 and the static capacitance of the diode VD2 is adjusted corresponding to the sensing temperature to compensate a change in the static capacitance of the sensor electrode 10a due to a temperature change.</p> |
