| 摘要 |
PURPOSE:To enhance the detection sensitivity of dew condensation without enlarging the size of a dew condensation sensor, by partially covering only the electrode part of a comb-tooth shaped transparent electrode formed on a transparent substrate with an insulating protective film so as to follow the shape of the electrode part. CONSTITUTION:An insulating protective film 5 covering only an electrode part so as to follow the shape thereof is formed on a comb-tooth shaped transparent electrode 2. As the material of the insulating protective film, Al2O3 or SiO2 can be used and the thickness of the insulating protective film is set to about 0.2-0.3mum. A sensor is one kind of a condenser. The electrostatic capacity C of a parallel flat plate condenser is shown by C=epsilon0.epsilon.S/d (wherein epsilon0 is dielectric constant in vacuum, epsilon is specific dielectric constant, S is the area of electrodes and d is the distance between electrodes). Therefore, the initial capacity of the sensor becomes large in its change ratio as the average dielectric constant of the substance surrounding the electrode becomes lower and the sensitivity of the sensor is enhanced. If only the surface of the electrode is partially covered, a state such that a part of a conventional insulating protective film is replaced with air is obtained. Because the dielectric constant of this air is about 1/10 that of the insulating protective film, epsilon becomes small and the sensitivity of the sensor is enhanced.
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