The Use of Aspheric Surfaces in Waveguide Illumination Systems for Automotive Displays

Thick optical waveguides (or “light pipes”) which utilize aspheric surfaces are shown to greatly improve illumination system efficiency over those that use linear or spherical surfaces only. An aspheric collection optic that is tailored to the filament of a particular bulb is demonstrated. Bending light around a ninety degree turn is also investigated, and the use of aspheric surfaces is once again shown to be more effective than linear or spherical mirrors. Optical design software is used to provide illustrative examples of general problems and solutions that are often encountered in waveguide illumination system design.