Simple dynamic energy core equivalent rays method to design freeform surface for extended source

Abstract

A simple method is proposed to design freeform surface for Lambertian extended source. In this method, it can take advantage of the designing method for point source via substituting each incident ray with a dynamically calculated equivalent ray. For each facet on the freeform surface, the equivalent ray emits from the energy weighted average-emitting-position for the corresponding incident beam, and redirects into the direction which is determined by a source-to-target mapping. The results of the designing examples show that the light distributions’ uniformities can be improved by this method, e.g., even the improvement of 59% can be achieved.

Keywords

nonimaging optics / illumination design / light emitting diodes (LEDs)

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Acknowledgements

This work was supported by the National Key Basic Research Program of China (Nos. 2015CB351900, 2011CB301902 and 2011CB301903), the National Key Technology Research and Development Program of the Ministry of Science and Technology of China (No. 2012BAE01B03), the Science and Technology Planning Project of Guangdong Province (No. 2011A081301003), the Opened Fund of the State Key Laboratory on Integrated Optoelectronics (No. IOSKL2012KF09), the High Technology Research and Development Program of China (Nos. 2011AA03A112, 2011AA03A106 and 2011AA03A105), the National Natural Science Foundation of China (Grant Nos. 61307024, 61176015 and 61176059).

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2014 Higher Education Press and Springer-Verlag Berlin Heidelberg