摘要 |
A dew condensation detecting apparatus is independent of a wavelength of a detected light beam, and has a heat capacity of the detecting apparatus body so as to miniaturize the apparatus. A light beam is introduced from a light emitting element into the transparent plate and travels through the transparent plate with repetitions of total reflection. It is then detected by a light receiving element to detect a degree of dew condensation on a surface of the transparent plate in accordance with a variation in detected light quantity. The transparent plate is formed of two sheet glasses bonded to each other by an intermediate film, a part of which is a reflection film. A micro-mirror array for turn-back reflection, composed of oblique reflection surfaces inclined to the surfaces of the spaced sheet glasses, is provided near one end of the reflection film.
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