| 摘要 |
<p>The invention concerns a device (1) for detecting water on a windscreen (PB), comprising an equipment for generating a microwave electromagnetic radiation in the proximity of a delimited portion (PD) of said windscreen (PB), said equipment comprising a microwave oscillator (OS) and reflected power detector (Pr). The generating equipment comprises a resonant cavity (CR) with an aperture (OU) closed by the windscreen portion (PD), and an excitation sensor (AN) arranged inside said resonant cavity (CR) and connected to the microwave oscillator (OS) by a coupler (CP) whereto is connected the reflected power detector. The microwave cavity (CR) and the excitation sensor (AN) are arranged such that the detection signal (Vd) is substantially proportional to the average thickness of the water film present on the windscreen portion (PD). The invention is useful for the automatic wipers.</p> |
