Patent ID: 6118383
Filing Date: 2000-09-12
Classification: B60S,Y10S

Abstract:
An arrangement for detecting the presence of water droplets on a windshield of a vehicle, the windshield having interior and exterior surfaces so as to have interior and exterior sides, the arrangement comprising:an energy source disposed on the interior side of the windshield, for producing a radiant energy, a first portion of the radiant energy being directed toward the interior surface of the windshield and a second portion, corresponding to a portion of the first portion, being reflected in a direction away from the windshield, said energy source having a time varying characteristic whereby a predetermined characteristic of the radiant energy varies over time;a first sensor disposed on the interior side of the windshield and having a first sensor input for receiving the second portion of the radiant energy; said first sensor further having a sensor output for producing a first sensor output electrical signal responsive to the radiant energy received at the first sensor input;a second sensor disposed on the interior side of the windshield and having a second sensor input for receiving a third portion of the radiant energy produced by said energy source, said second sensor having a sensor output for producing a second sensor output electrical signal responsive to the third portion of the radiant energy received at the second sensor input; anda processor for receiving information responsive to the first and second sensor output electrical signals, and an output for producing a control signal, the control signal being responsive to a first information component in said first sensor output electrical signal responsive to the presence of water droplets on the exterior surface of the windshield, a second information component in said first sensor output electrical signal responsive to the time-varying characteristic of said energy source, and a third information component derived from said second sensor output electrical signal.