06313454 is referenced by 466 patents and cites 34 patents.

A vehicular rain sensor system for detecting precipitation on an exterior surface of a window including a illumination sensor that is decoupled from the window. The illumination sensor is preferably an imaging array sensor which communicates a signal to a control which further determines whether rain is present on the window. The control preferably includes an edge detection function for detecting edges of precipitation droplets on the window and activating the windshield wipers of the vehicle when the number of edges detected exceeds a predetermined threshold value. A smoothing algorithm or filter is provided to account for surface irregularities on the window, thereby substantially precluding such irregularities from being erroneously detected as rain droplets by the edge detection function. The rain sensor system may further include a polarizing filter and an illumination source, such that the rain sensor system may not only prevent false signals of rain when only fog is present on an interior surface of the window, but also allows the rain sensor system to actually detect fog particles on an interior surface of the window, thereby allowing the control to further be connected to a ventilation blower within the vehicle for the purpose of activating the blower to eliminate the fog.

Title
Rain sensor
Application Number
9/346352
Publication Number
6313454 (B1)
Application Date
July 2, 1999
Publication Date
November 6, 2001
Inventor
Niall R Lynam
Holland
MI, US
Mark L Larson
Grand Haven
MI, US
Kenneth Schofield
Holland
MI, US
Brent J Bos
Tucson
AZ, US
Agent
VanDyke Gardner Linn & Burkhart
US
Assignee
Donnelly Corporation
MI, US
IPC
B60S 1/08
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