Apparatus for detecting approach distance of a living body

摘要

An apparatus for detecting a proximity distance of a living body is provided. The device detects hover-touch. The surfaces of a first electrode and a second electrode are covered by an insulator to form an electrode portion. A high frequency power source is connected to the first electrode by means of an inductive element for forming a resonant circuit. An ammeter is connected to the second electrode. A correlation between a resonance frequency and a resonance resistance is obtained. It is determined that the living body is in hover-touch with the electrode portion when the resonance resistance is higher than an initial resistance corresponding to a leakage resistance between the first and second electrodes, and based on the correlation that the resonance resistance increases - or decreases, whereas the resonance frequency decreases or increases.