Patent ID: 7573576
Filing Date: 2009-08-11
Classification: B60S,G01N

Abstract:
1. A sensor for use in sensing the presence of moisture on an outer side surface of a windshield of a vehicle, said sensor comprising: an optical transmitter having a source of light rays which is energizable to provide an array of light rays, an optical receiver which receives an array of light rays reflected from the outer side surface of the windshield, and a photoconductor structure which receives the array of light rays from said optical transmitter, directs light rays from said optical transmitter toward an inner side surface of the windshield, receives light rays reflected from the outer side surface of the windshield, and directs light rays reflected from the outer side surface of the windshield to said optical receiver, said photoconductor having a first aspherical lens disposed adjacent to said optical transmitter with a central axis of an curving surface of said first aspeherical lens coincident with a central axis of said source of light rays of said optical transmitter, said first aspherical lens being effective to receive peripheral rays of light exiting from said source of light rays along paths which diverge in opposite directions from the central axis of said source of light rays and to receive a ray of light exiting from said source of light rays along a path which is coincident with the central axis of said source of light rays, said curving surface of said first aspherical lens being convex in a direction toward said optical transmitter, said photoconductor having a second aspherical lens disposed adjacent to said optical receiver with a central axis of an curving surface of said second aspherical lens coincident with a central axis of said optical receiver, said second aspherical lens being effective to direct peripheral rays of light exiting from said second aspherical lens along paths which converge in opposite directions toward the central axis of said optical receiver and to direct a ray of light exiting from said second asymmetrical lens along a path which is coincident with the central axis of said optical receiver, said arcuately curving surface of said second aspherical lens being convex in a direction toward said optical receiver.