An optimization method is proposed for designing an LED freeform lens which produces a uniform circular pattern with high energy efficiency.This method is composed of three main aspects:design of the initial guess,par...An optimization method is proposed for designing an LED freeform lens which produces a uniform circular pattern with high energy efficiency.This method is composed of three main aspects:design of the initial guess,parameterization of the freeform surface,and construction of the merit function.The initial guess is created by solving an ordinary differential equation numerically.An approach of selecting optimization points is introduced for parameterization of the freeform surface.The merit function is constructed by use of the irradiance uniformity and the efficiency of the lens.Design examples are given,and the results show that the irradiance distribution is well controlled with a maximum uniformity(the relative standard deviation of irradiance,RSD) of 0.0122 and a maximum efficiency of 93.88%.This optimization method can be generalized to design freeform lenses with different lighting patterns or without rotational symmetry.展开更多
A simple method is proposed to design free- form 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 dynamic...A simple method is proposed to design free- form 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 corre- sponding 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.展开更多
基金Project supported by the National Natural Science Foundation of China (No. 61177015)the National High-Tech R & D Program (863)of China (No. 2012AA10A503-2)the Fundamental Research Funds for Central Universities,China
文摘An optimization method is proposed for designing an LED freeform lens which produces a uniform circular pattern with high energy efficiency.This method is composed of three main aspects:design of the initial guess,parameterization of the freeform surface,and construction of the merit function.The initial guess is created by solving an ordinary differential equation numerically.An approach of selecting optimization points is introduced for parameterization of the freeform surface.The merit function is constructed by use of the irradiance uniformity and the efficiency of the lens.Design examples are given,and the results show that the irradiance distribution is well controlled with a maximum uniformity(the relative standard deviation of irradiance,RSD) of 0.0122 and a maximum efficiency of 93.88%.This optimization method can be generalized to design freeform lenses with different lighting patterns or without rotational symmetry.
基金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）.
文摘A simple method is proposed to design free- form 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 corre- sponding 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.
