Patent ID: 6078056
Filing Date: 2000-06-20
Classification: B60S,G01N,G02B

Abstract:
A moisture sensor for detecting the presence of moisture on the surface of a transparent material and controlling the actuation of a moisture removal system accordingly, said moisture sensor comprising:an emitter for generating an emitter signal which is influenced by the presence of moisture on the surface of a transparent material;a detector for receiving said emitter signal and contributing to the production of a detector output signal;a pre-demodulation circuit connected to said detector and including an input for receiving said detector output signal and an output for providing a pre-demodulation signal, said pre-demodulation circuit further including a filter connected to said input for filtering unwanted signal components from said detector output signal, and an amplifier connected to said filter for providing gain to said pre-demodulation signal; andan autobalance circuit connected to said pre-demodulation circuit output for receiving said pre-demodulation signal and providing an autobalance signal to said pre-demodulation circuit input for at least partially canceling said detector output signal.