Design of primary optics for LED chip array in road lighting application.

In this study, we proposed an effective optical design method to solve the problem of prescribed illuminance for LED chip array packaging (LCAP). With this method, light energy redistribution can be obtained by optimizing meshing parameters on the target. Not only can it deal with light controlling of extended source, but also improve the uniformity of both illuminance and luminance for road lighting as well. As an example, we designed a 16W LED packaging with a smooth primary freeform lens for general road lighting. The simulation results demonstrated that optical performance of this lens can meet the requirements of Commission Internationale del'Eclairage (CIE) quite well. Longitudinal and overall uniformities are 0.7 and 0.5 respectively, and relative optical efficiency of luminaire can be enhanced 19.6% in theory compared with traditional optics.