A fast feedback method to design easy-molding freeform optical system with uniform illuminance and high light control efficiency

作者：Li Hongtao^*; Chen Shichao; Han Yanjun; Luo Yi

来源：Optics Express, 2013, 21(1): 1258-1269.

A feedback method combined with fitting technique based on variable separation mapping is proposed to design freeform optical systems for an extended LED source with prescribed illumination patterns, especially with uniform illuminance distribution. Feedback process performs well with extended sources, while fitting technique contributes not only to the decrease of pieces of sub-surfaces in discontinuous freeform lenses which may cause loss in manufacture, but also the reduction in the number of feedback iterations. It is proved that light control efficiency can be improved by 5%, while keeping a high uniformity of 82%, with only two feedback iterations and one fitting operation can improve. Furthermore, the polar angle theta and azimuthal angle phi is used to specify the light direction from the light source, and the (theta,phi)-(x, y) based mapping and feedback strategy makes sure that even few discontinuous sections along the equi-phi plane exist in the system, they are perpendicular to the base plane, making it eligible for manufacturing the surfaces using injection molding.

• 出版日期2013-1-14
• 单位清华大学