Study On LED Automobile Headlamps Optical System Based On Micro-lens Array

With the fast development of LED technology, LED source is becoming more and morepopular in the automobile’s lighting. Due to some characters of LED sources are differentfrom that of traditional lamps, we need redesign the secondary optical system in order tosatisfy the requirement of the national regulation. Headlamp system design based on LEDsources has a very important practical research value.Freeform surface design based on micro-lenses possesses flexible spatial arrangementand design degrees. It can simplify the optical structure and improve the light efficiency.Especially in the automobiles’ headlamp it can well control the light intensity and the beamangle. It is very suitable for the LED headlamp design. This paper takes an exploratoryresearch on the LED automobile’s headlamp based on micro-lenses.LED’s application on the present automobile headlamp is presented and rosy vista isanalyzed. We summarize the national regulation GB25991-2010, propose the LED automobileheadlamp design method based on micro-lenses. The light emitting from the LED source iscollimated by the collimated optics, refracted and redistributed by the micro-lenses out to themeasuring plane. According to the spatial intensity distribution of the LED source and thelight pattern requirement of the national regulation, we use non-imaging optics theory andconservation of energy to calculate the data of the micro-lenses freeform surfaces. Then weuse3D software to fit the data into freeform surfaces, and introduce the surface model intothe optical software for simulation by using Monte Carlo method. Simulation results verifyour proposal.On the basis of our proposed optical system we make the model into physical object andapply the micro-lenses optics into the LED high-beam headlamp. The experimental resultsshow that our design method is absolutely feasible. It can be widely used in the LEDautomobile’s headlamp system.