In this contribution we discuss a smart design of an extremely flat direct-lit luminaire for general lighting applications. The main advantage of this concept is the increased DHR ratio compared to diffuser sheet only-approaches and a smaller thickness of the whole set-up compared to common freeform approaches. For this demand we have designed very thin freeform optical elements with a maximal height of 75 μm that allow to maintain a uniform illumination in direct-lit applications using an LED-array with a comparably large distance between the individual LEDs. The presented design concept in addition emphasizes the use of cost-effective manufacturing methods like grey scale laser lithography for mastering and roll-to-roll processing for large area manufacturing of these optical elements.
ACCESS THE FULL ARTICLE
Claude Leiner, Wolfgang Nemitz, Susanne Schweitzer, Franz P. Wenzl, Christian Sommer, "Smart freeform optics solution for an extremely thin direct-lit application," Proc. SPIE 9889, Optical Modelling and Design IV, 988911 (27 April 2016);