Optical detector for windshield wiper control

Abstract

An optical device is provided for detecting the degree of obscuring moisture or precipitation on the windshield of an automotive vehicle. A source of light, such as a light emitting diode (LED) or a laser diode, is positioned to illuminate the windshield. An optical imager and detector array senses light emitted by the source, either transmitted or reflected by the windshield, and imaged on the array. The light source and detector may be positioned in convenient, out-of-the-way locations inside or outside the windshield. When the windshield is free of obscuring precipitation, light from the source is imaged on a sensor of the array aligned with the optical axis of the imager. When obscuring moisture or precipitation is present on the windshield, light is scattered such that significant portions are imaged on sensors off the optical axis of the imager. The amount and spatial distribution of light received off the optical axis provides an indication of the degree of obscuration caused by light scattering moisture or precipitation present on the windshield. The detector is connected to the windshield wiper system of the vehicle to control activation of the wiper based on the optical detection of obscuring moisture or precipitation on the windshield.

Dependencies are inferred from the claim text.