The Optimization Design Of Freeform Surface Lens Of LED

With the many advantages of the long life, sturdy and durable， andenvironmental protection, LED, the one of the hottest topics in the21st century, asthe new energy of fourth generation has been widely used in many illuminationfields. Because ofthe angle of its emitted light is relatively large, and the intensitydistribution is also approximate Lambert distribution, so it cannot be directly usedfor lighting. To satisfy the requirement of different applications and different opticalsystem, reasonable reallocation of the energy of LED chip is particularly important.Compared to those methods of redistribution the light energy, which is thepermutations and combinations of multi-chip or multi-device, and the use of thetraditional parabolic reflector or the spherical lens, the optical device of the freeformsurface, to its name, can freely allocation energy and thus achieving a betterillumination effect. However, the traditional design can no longer meet therequirement for small size lens viewing the extended light source as a point source[1,2]. To solve this problem, the optimization methods of freeform surface lens aredeveloped.On the basis of the above and the use of TracePro software, quadratic B-splinetheory, Scheme language, and optimization engine are used in combination, finally,an optimization design method of freeform surface lens is proposed. First of all,through the forward optimization method which is optimizing the quadratic curve-changing model-achieving the redistribution of the light energy, it can avoidthe establishment of the feedback function; secondly, adopting the regular quadraticcurve to replace the freeform curve for initial model can avoid the calculation offreeform surface; what’s more, the method can achieve local control andoptimization of freeform surface, that is to focus on optimizing the bad parts andretain the good parts, which can avoid the bad affect for the results and theoptimization time.In this thesis, different types of uniform lenses and collimator lenses aredesigned. And through the optimization design of single-lens, their array structuresare also designed. Ultimately, the results all meet the lighting requirements.