An automatic device for actuation of components for cleaning motor vehicle glass which includes a system for detection of the dirtiness of the glass, made up of a measuring photosensitive element receiving light directly through the glass and a reference photosensitive element isolated from any direct...http://www.google.com.au/patents/US4636698?utm_source=gb-gplus-sharePatent US4636698 - Automatic device for actuation of components to clean a motor vehicle window
