Patent ID: 6855947
Filing Date: 2005-02-15
Classification: B60S,G01N

Abstract:
1. An improved precipitation sensor to sense the presence of water upon an automotive glass of the type having an optical emitter, an optical receiver, a first mirror surface for collimating light emitted from said optical emitter and having a first leading edge, a second mirror surface for focusing said emitted light upon said optical receiver and having a second leading edge, and an electronic circuit in electrical communication with said optical emitter and said optical receiver, the improvement comprising: said precipitation sensor including an intermediate reflector having a first reflective region proximate said emitter and a second reflective region proximate said receiver; said second mirror surface being aspheric and positioned to focus said emitted light upon said receiver; said second reflective region having a second mean reflective point being displaced from said automotive glass at a distance at least as great as a distance said second leading edge of said second mirror surface is displaced from said automotive glass; said second leading edge laterally disposed such that said second mirror surface is positioned between said receiver and substantially all ambient light exiting from said automotive glass toward said receiver.