| 摘要 |
PURPOSE:To detect a mist like raindrop or the wiping-off state of a wiper with good accuracy, in a detection apparatus for detecting the raindrop adhered to the window glass of a car, by allowing infrared rays to be incident to the surface of glass so as to penetrate the same into said glass and receiving infrared rays reflected by the raindrop adhered to the glass. CONSTITUTION:A light emitting elements 2 is attached to the side end part of window glass 1 and infrared rays with specific frequency are oscillated from a light emitter 3 to be incident to the window glass 1. When a raindrop 6 is adhered to the window glass 1, infrared rays are reflected by the raindrop 6. In this case, the light blocking cylinder 8 of a light receiver 5 is provided at a predetermined angle so as to be coincided with the reflected direction 9 thereof and the reflected light is received by a light receiving element 7. Because the light receiving element 7 is provided in the light blocking cylinder 8, infrared rays with specific frequency are received without being affected by exterior light and a raindrop amount is detected from a light receiving amount. Therefore, by utilizing infrared rays with specific frequency, even a mist like raindrop can be detected with good accuracy. |
