Design Of Optical System For High-power LED Lamps Based On Fresnel Lens

LED with green environmental protection,small size,fast response,high light efficiency and long life,and other advantages,is widely used in daily life.With the application of LED light source more and more widely,lighting places require the lighting quality to improve,among which the uniform light design of high-power LED lamps is more and more important.Because white LEDs have Lambertian space lightemitting characteristics,not through optical design of LED light intensity distribution curve generally to suborbicular,but the light distribution curve does not apply to all of the lighting environment,they cannot meet market demands,in order to effectively reassign LED light,non-imaging optics design for secondary optical design of the light source is very important.LED secondary optical design is more concerned with improving the design of lighting environment by improving photometric parameters,using the law of energy conservation and the principle of edge light to simplify the complexity of optical system design.Fresnel lens is widely used in concentrated optical design because of its significant advantages of high transmittance,small size,light weight,easy to process and low cost.However,the uniformity of spotlight distribution of traditional Fresnel lens is very poor,which limits the use place of spotlight lamps and their further development.Therefore,this paper will study the uniform light design scheme of high-power LED lamps based on Fresnel lens,and improve the uniformity of concentrated light distribution by designing the structure of the lens and lamp reflector.Based on the principle of geometric optics and the design method of traditional Fresnel lens,this paper proposes a high-power LED uniform light source optical system based on split ring Fresnel lens and compound parabolic reflector.Firstly,the Fresnel lens calculation formula is designed through theoretical analysis,and then the crosssectional curve of the mirror is derived.The model is established in the software through the theoretical design of the Fresnel lens and the mirror.The transmission law of Fresnel lens with different focal lengths is calculated theoretically,and the sub-ring Fresnel lens is designed.The data of each ring is calculated by software and the model is established.Analyze the influence factors of different lens aperture,ring distance and incident wavelength on the focusing efficiency of Fresnel lens,and finally optimize the focal length of each ring-band Fresnel lens to obtain the optimal plan of the ring-band Fresnel lens;from theory The design obtains the parametric design of the compound parabolic concentrator(CPC),and establishes a model to analyze the effect of different collection angles,CPC length,incident aperture,etc.on the performance of the mirror,analyze the relationship between the convergence ratio of the receiving surface and the uniformity,and finally choose The CPC’s best optimization plan.According to the calculated parameters of the split-ring Fresnel lens and the mirror,the split-ring Fresnel lens optical system is established,and the focal plane of the split-ring Fresnel lens optical system is determined using Solid Works 3D modeling software and Tracepro optical simulation software.The irradiance distribution of the system was simulated and studied.In view of its uneven light distribution,the performance of different light collection angles of the reflector was analyzed to analyze the uniformity of the light source of the system.This research has certain significance for the high-power LED uniform light optical system.