| 摘要 |
PROBLEM TO BE SOLVED: To provide a touch sensor that is not susceptible to variance in an object capacitance and a change in environment, hardly receives the effect of induction noise, withstands radiation of an illegal radio wave and of which the sensing stability and the stability against external disturbance are enhanced. SOLUTION: The touch sensor has a contact electrode exposed externally and an oscillation circuit connected directly or via a protective element such as a resistor and a capacitor to the contact electrode. In the oscillation circuit, an oscillating stop point is set to output a usual oscillation when no sensing object is in contact with the contact electrode and to stop the usual oscillation when the sensing object is in contact with the contact electrode and an equivalent impedance of the sensing object exceeds a reference value specific to the circuit. Or when no sensing object is in contact with the contact electrode, the oscillation is stopped and an oscillation start point is set to start the oscillation when the sensing object is in contact with the sensing object and the equivalent impedance of the sensing object exceeds the reference value specific to the circuit. The oscillating operation of contact and disconnection of a human body is outputted in terms of presence of steady-state oscillation.
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