| 摘要 |
PURPOSE:To eliminate a waterdrop clinging to a window surface, by detecting the poor visibility of a window with the strength of attenuation of light transmitting a rear window and on the basis of this finding, energizing the hot wire embedded in the window with a continuous rating current. CONSTITUTION:Light out of a light generator 3 outside a window 2 transmits the window 2 and is received by a light receiver 5. The light receiver 5 converts the strength of light into an electrical signal which is transmitted to a detector 8. A detection circuit 12 inside the detector 8 discriminates the strength of the signal and then detects whether or not the field of vision in the window 2 is good. And, when poor visibility is detected, the detector 8 operates a power control unit 9 so as to cause power to be fed to a hot wire 10 being embedded in the rear window 2, thus a waterdrop clinging to the window is eliminated. |
