Light Distribution Lens Design Of LED Based On Free-form Surface

With the rapid development of LED lighting,light distribution is one of the key technologies,which has been able to achieve a variety of needs of light distribution through the free surface.However,the free surface design method has a large amount of iterative computation.In this paper,based on the energy grid method and SMS method,illumination angle method and illumination coordinates method are proposed.Then,two cases of free-form surface design are presented and simulated.Through the investigation of the development of LED lighting industry,free surface design and LED lighting technology.The problems in free-form surface design are presented.Based on the theory of imaging optics,the flux conservation law,refraction law and edge light law as the theoretical basis,free surface iterative optimization,the final design to meet the actual needs of the free-form lens using a variety of software.The design results are applied to the LED street lamp glare suppression and simplify the coupling structure of the optical fiber,specific research contents include:1: The principle of energy grid method and SMS design method are introduced and analyzed in detail.According to the design defects of the two methods,illumination angle method and illumination coordinates method are proposed.The illumination angle method is used to describe the light field distribution on the inner and outer surfaces of the free surface on the premise that the illumination surface is infinite,so as to establish the mapping relationship between the two sides of the curved surface;The whole process is completely coordinate by the method of lighting coordinate,coordinate equation is used to replace the light and optical devices to complete the construction of the optical path and the design of the free surface.These two methods can be used to design the ideal free-form surface lens under the actual demand of the extended light source and two kinds of illumination surfaces.2: Describing the detailed design method of the free-form surface in two practical cases.Based on the illumination angle method and illumination coordinates method,according to the different light distribution requirements of LED lights glare suppression and simplified coupling system of the optical fiber,the detailed design procedure of two different design schemes for free-form surfaces is presented.Write the calculation program of corresponding surface busbar in Matlab software,using the Matlab toolkit to complete the fitting of the free-form surface bus.Finally,the 3D modeling of the free surface lens is realized in Solid Works software.3: Simulation of free surface lens operation in two simulation software.Results show that in a one-way lighting environment,new LED street lamp can maintain uniformity better than 0.65 meanwhile eliminating glare;new coupling system has a good processing ability for circular LED light source and can maintain 89% coupling efficiency on the simplified structure.To sum up,the free surface lens obtained by this design conforms to the national standard and has good application prospect.