[1] Chen J J, Lin C T. Freeform surface design for a light-emitting diode-based collimating lens[J]. Optics Express, 2010, 49 (9): 093001-1.

[2] Yan X T, Yang J F, Xue B. Design of a novel LED collimating element based on freeform surface[J].Optoelectronics Letters, 2013, 9(1): 1-2.

[3] Murat H Y, Cuypers D, Smet H D, et al. Two liquid crystal on silicon panel projector with efficient light-emitting diode illumination engine[J]. Optical Engineering, 2007, 46(12): 124002.

[4] Pan J W, Lin S H. Achromatic design in the illumination system for a mini projector with LED light source[J]. Optics Express, 2011, 19(17): 15750-15759.

[5] 丁纾姝, 余桂英, 郝雯雯.用于室内照明的自由曲面均匀配光透镜设计[J]. 激光与光电子进展, 2012, 49(04): 042201-1-6.

    Ding Shushu, Yu Guiying, Hao Wenwen. A freeform surface lens for indoor uniform illumination[J]. Laser & Optoelectronics Progress, 2012, 49(04): 042201-1-6.

[6] Ries H R, Winston R. Tailored edge-ray reflectors for illumination[J]. The Journal of the Optical Society of America A, 1990,11(4): 1260-1-4.

[7] Ong P T, Gordon J M, Rabl A. Tailoring lighting reflectors to prescribed illumination distributions: compact partial-involute designs[J]. Applied Optics, 1995, 34: 7877-7887.

[8] Bortz J C, Shatz N E, Pitou D. Optimal design of a nonimaging projection lens for use with an LED source and a rectangular target[J]. SPIE, 2000, 4092: 130-138.

[9] Wu R M, Zheng Z R, Li H F. Optimization design of irradiance array for LED uniform rectangular illumination[J]. Applied Optics, 2012, 51(13): 2257-2263.

[10] Luo Y, Feng Z X, Han Y J. Design of compact and smooth free-form optical system with uniform illuminance for LED source[J]. Optics Express, 2010, 18(9): 9055-9063.