Ultrasonically clearing precipitation

摘要

A system for clearing precipitation from a window comprises one or more transducers (1-8) fixed to the window. The transducers are driven by a generator (13) to produce surface acoustic waves that propagate through the window. The window may be a laminated window such as a windscreen (10) for a vehicle. A sensing system (122) may be used for detecting the presence of precipitation to actuate the clearing system.