Freeform road lighting lens design

摘要

Road lighting can benefit strongly from LEDs and freeform lenses. However, freeform lenses design for road lighting applications is complicated and difficult when balancing energy efficiency and lighting quality. In addition, the asymmetric properties of the required light distributions and non-neglectable sizes of LEDs make the design more challenging. Currently, we prefer an efficient design strategy with two steps: light distribution optimization and freeform lens construction. In the first step, we employ a modified polynomial representation of the illuminance distribution and perform constrained optimization. In the second step, we construct the freeform lens with double freeform surfaces to realize the optimized light distribution using the ray mapping method associated with over compensation.