Design Of The LED Optical Freeform Lens

With the advancement of Science and Technology,LED(Light Emitting Diode)light source is gradually replacing most of the illumination light source in daily life because of its unique merits.But compared with the traditional lighting,LED light beam divergence angle is larger,for some specific lighting requirements,In the direction of the LED light source,need to add some refraction or reflective structure,so that the light emitted by the LED can achieve the specific lighting requirements,such an optical structure,is the freeform secondary optical lens in this paper that need to study.In the field of life illumination and imaging illumination,the introduction of LED light source makes the miniaturization of optical elements remarkable.Based on the non-imaging optics and photometry theory,this paper researches the uniform light system in the simple projection system,the square rod illumination system and the compound eye array illumination system,and analyzes the limitations of these two systems in the projection illumination system which tends to be miniaturized.These two kinds of lighting systems are longer in length,more optical components,for now the application of a wide range of micro-projection lamp system,such a lighting system will not only increase the length of the projector lamp products,and the multi-component lighting system,making the assembly error greatly increased,the production cost of the product can't be effectively reduced.Aiming at these problems,two different projection lamp structures are presented,a kind of freeform TIR lens as a uniform light system,a double convex lens with freeform as a uniform light illumination system.The first structure of the projection lamp,the illumination part is the vector method programmed to obtain the TIR lens,its diameter is 25 mm,the height of 13.5 mm,lens material for PC(Polycarbonate),single-chip projection lens diameter of 15 mm,thickness of 5.5 mm,projection lens material is PMMA(polymethacrylate),the overall system structure length is 81 mm,projection pattern uniformity can reach 80%.The second kind of structure projection lamp,it's illumination part is based on the ODE method,the convex lens obtains the programming,it's diameter is 24 mm,thickness is 5.9 mm,lens material is PMMA,in the distance lens 2 mm on the Philippine Forest slice pattern Area illumination uniformity can reach 85%,the lens of the film to the position of the film as the symmetrical surface,symmetrical placement in the projection lens system,and to optimize the projection objective.The final projection lens has a full range of 40 degrees,F number is 5.6,at the distance of 1000 mm can form a diameter of 600 mm pattern.According to the results of the design,to borrow high-tech enterprise production platform,the optical components were produced and tested,after one to two optimization,finally got a projection lamp matching the target design.