Design and Development of a Dual Integrated Windshield Defogging and Rain Sensor 2006-01-1323

The design and application objectives for windshield defogging and rain-sensing are to integrate these functions, currently realized with separate sensors, into a single sensor mounted on the inside of the windshield. Current sensors use different technologies to prevent windshield fogging and to detect rain. Both these functions can be combined in a dual-sensor system of equal size or even smaller than present sensor packages. Defogging and rain-sensing can be achieved by measuring capacitance at the windshield, detecting not only relative windshield humidity, but also the presence of external rain. This combined technical solution not only allows the integration of two individual sensors, but using capacitance to measure rain is significantly more precise than present optical systems.