Fraunhofer Institute for Industrial Mathematics ITWM
Freeform lenses are used for the specific illumination of surfaces (screens) with respect to a required light distribution. They can be used for optical and lighting technologies, in automotive industry, for advertisement, text design and graphic arts. Because of the fact that freeform lenses make no use of additional dim or projection elements they ensure an optimal light effect with minimal optics.
Subject of geometrical optics is the calculation of the light distribution on the screen for a given light source and given lens. The inverse problem - the design of the lens which realizes a required light distribution on the screen for a given light source - is much more complex and difficult to solve.
We have created an algorithm solving this problem and developed an appropriate software tool. Based on a given light source and a required light distribution on the screen the tool calculates the freeform of the surface in few seconds. Using a forward ray tracing one can simulate the light distribution on the screen resulting from the designed freeform lens.
