Patent ID: 6091065
Filing Date: 2000-07-18
Classification: B60S,G02B

Abstract:
A moisture sensor for detecting 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 a pulsatile emitter signal which is influenced by the presence of moisture on the surface of the transparent material;a detector for receiving said pulsatile emitter signal and contributing to the production of a pulsatile detector output signal;a pre-demodulation circuit operatively connected to said detector and including an input for receiving said pulsatile detector output signal and an output for providing a pulsatile pre-demodulation signal, said pre-demodulation circuit further including a filter and an amplifier;a demodulation circuit for converting said pulsatile pre-demodulation signal to a dc signal having fluctuating noise components;a digital signal processing filter stage for filtering said fluctuating noise components from said dc signal and producing a filtered dc output.