An optical design and simulation of LED low-beam headlamps

The low-beam headlamp is an important component for the automobile safety. With the improvement of optical efficiency and heat dissipation' technology of white LEDs, it becomes feasible to design low-beam headlamps with LEDs. The principle of B-spline surfaces is used to construct the free-form surface reflector meeting the requirement. First, the initial B-spline surface reflector is established on the basis of the light source structure, emitting features and capability of light distribution. Optical simulation is carried out according to the principle of ray tracing. And then the simulation results will be compared with the standard of photometric characteristics. The segmented surfaces fine-tuning method and the method of trial and error are used to trim the part that failed to meet requirements gradually. The vector groups of surfaces are obtained. Finally, the desired free-form surface reflector meeting the ECE regulations is got. The experimental results can meet the standard of photometric characteristics. The impact of the technique showed in this paper in the field of LED illumination design seems to be a very promising topic.