Omni-directional rain sensor utilizing scattered light reflection by water particle on automotive windshield glass

Omni-directional rain sensor utilizing scattered light detection reflected by rain or moisture on windshield glass is realized, while conventional rain sensor senses disturbances at point or line on windshield glass along light path. Modulated light from light source is emitted without directional pattern, and light block fixture is placed between light source and photodiode to prevent direct propagation to photodiode. Water particle on windshield glass behaved as scattering medium, and it relayed light signal from light source to photodiode over light block fixture. This sensing mechanism eliminated any optical elements such as lens, while this expanded sensing area in 2 dimensions in contrast to conventional narrow sensing spot or line pattern. Time division sensing algorithm was used to discriminate raining intensity in 7 steps to apply as rain sensor in automobile. Experiments using simulated rain facility showed possibility as rain sensor for automotive application.