Design method of a light emitting diode front fog lamp based on a freeform reflector

We propose a novel method for the design of a light emitting diode front fog lamp based on a freeform reflector.A method is presented to figure out an integrable mapping.A new and effectively feedback method is introduced to optimize the freeform reflector.The reflector designed by our method has a high light control efficiency.The front fog reflector has a small and compact size, and it is eligible for injection molding and production.

We propose a method for the design of a light emitting diode front fog lamp based on a freeform reflector. The source–target mapping is used to establish the relationship between the solid angle of the source and the target plane. The reflector is then constructed based on the non-imaging optics theory and Snell's law. A feedback function is deduced from the deviation in the simulated light pattern based on the sampling method. The reflector is then regenerated with feedback modifications and the variance is minimized after several feedbacks. A reflector for the automobile front fog lamp is designed for the OSTAR Headlamp LED source whose emitting surface is 2.8 mm×2.5 mm. Simulation results indicate that the light performance can well meet the standard of the front fog lamps in ECE R19 Revision 7.