A straightforward method for the design of freeform lenses and reflectors by numerically solving a set of partial differential equations is described. All available light from a small light source - such as an LED or a Xenon lamp - is redirected to exactly cast the intended irradiance distribution on a target surface. The optical surface is smooth without kinks or steps. The rim of the lens or mirror can be restricted to a given trimming surface, for instance the housing of a luminaire. The method is applicable to reflectors as well as lenses for signal lighting, interior lighting and headlamps. The performance of the designed surface with a complex light source model and the non-optical part of the luminaire is evaluated with ray-tracing. Relevant optical effects such as Fresnel reflections, dispersion, surface roughness and surface waviness are taken into account. A sensitivity analysis assesses the tolerances for manufacturing and alignment of the optical system. For the covering abstract see ITRD E123380.
Samenvatting