Windshield wiper control device

摘要

A windshield wiper control device for use on a vehicle includes a light-emitting unit mounted on the vehicle outside of a compartment for emitting a ray of infrared radiation, a photodetector unit mounted on the vehicle within the compartment and having a slit plate for producing an image of a striped pattern with bright and dark areas in response to exposure to the ray of electromagnetic radiation through the windshield and an array of photodetectors for sensing the bright and dark areas of the striped image and generating signals indicative of the bright and dark areas, and an arithmetic circuit arrangement for computing a contrast of the bright and dark areas based on the signals from the photodetectors and controlling the speed and/or period of operation of the windshield wiper based on the computed contrast.