Construction and Application of Near Field (TIR Type) Lenses for Automotive Lighting Functions 2007-01-1040
Light Emitting Diodes (LEDs) are fast becoming the preferred light sources for automotive lighting applications. They emit light at cone angles equal (hemispherical) or less (conical) than 2Π radians. One way for efficiently collecting and collimating light from LED light sources is to use Near Field Lenses (NFLs). NFLs are collimators using refraction and total internal reflection (TIR) to efficiently collect and direct light. They tend to have thick sections and therefore require challenging molding techniques, and they may have the LED source optically coupled directly into them. Beside these functional aspects, NFLs offer unique styling for different lighting functions such as those in rear combination lamps (RCLs), front turn signal lamps, daytime running lamps (DRLs) and headlamps. Beam shaping optic elements can be integrated directly on the NFLs for creating specific light patterns, or the NFLs themselves can be integrated into other optic elements such as disc or bar light manifolds which distribute the light to meet a variety of user specifications.