| 摘要 |
PURPOSE:To detect a raindrop, etc., and to control automatically a wiper, by providing a light emitting element and a photodetector at an angle for executing a total reflection when a raindrop, etc. are not adhering onto the outside face of a wind shield, and supporting them as one body to the inside face by a light transmitting material. CONSTITUTION:A liquid detector 20 is provided with a supporting body 21 consisting of a material having the same refractive index as that of a wind shield 10, a light emitting element 22, a photodetector 23 and a cover 24. The detector 20 is made to adhere to a part of an inside face 10b corresponding to a sliding area on an outside face 10a of the wind shield 10, and a light emitting shaft of the light emitting element 22 is placed in a direction for executing a total reflection when a raindrop, etc. are not adhering. A thin plate 25 is made of aluminum and light is subjected to a total reflection. Whether a raindrop, etc. are adhering to the outside face of the wind shield 10 or not can be detected by the quantity of light which is made incident to the photodetector 23, and the wiper is controlled automatically. |
