Research And Design Of Uniform Light Source Based On High Power LED

With the widespread use of high-power white LEDs,the use of large lumens and higher luminous efficiency make them more widely used,indicating the development of solid state lighting.LED market continues to expand demand,applications also will be expanded,high-power LED lighting system is more promising than traditional light sources.However,high-power LEDs still have unimaginable shortcomings.For example,the Lambertian characteristics of LED light sources and high-power LEDs are difficult to obtain high brightness on the screen,so further secondary optical design is needed.Secondary optical design is present in the LED package,it can gather LED light source,and has the advantages of high efficiency,high accuracy.In this paper,the secondary optical design method is used to model and simulate the uniformity of high power LEDs and to measure and study the data of the solid uniform light source.In the secondary optical design,software simulation is an essential part.With the improvement of computer processing speed,computer software simulation becomes an effective method to design and optimize high-power light sources.The design of the physical properties of LEDs and optical components is described by mathematical exact mathematical modeling of the relationships between the various components.The most important part is the reflector and lens,which are two integral parts of the secondary optical design.This article focuses on the uniformity design of high-power LED did the following four aspects of research:(1)The development status and trends of LED at home and abroad are expounded in detail.The basic concepts and methods of secondary optical design are systematically summarized.At the same time,the necessity of design of uniformity of LED light source is fully illustrated with practical cases.(2)The photoluminescence is explained in detail.The parameters commonly used in photometry and the relationship between them are introduced.The theoretical basis of the secondary optical design is deeply described,that is,the non-imaging optical design theory,Luminous mechanism and optoelectronic specific made a clear statement.(3)Based on the concept of conservation of optical extension,a high power LED uniform light source based on Fresnel lens and compound paraboloid reflector was designed.Simulated by the TracePro software light reflection / refraction simulation of a uniform light source,the design of the compound parabolic mirror parameters and the Fresnel parameters are mainly carried out.Get the optimal simulation parameters and processing,developed a high-power LED uniform light source experimental device.At a distance of 2.5 m from the light source,a circular surface with a diameter of 38 cm and a divergence angle of about 2.63 ° is obtained.The uniformity of light in the effective area of the light spot is better than 94.40% and the overall light output efficiency is over 80%.(4)In order to further analyze the LED's light-emitting characteristics and secondary optical design can achieve the excellent characteristics of the following research.According to the principle of light output of aspheric lens,three types of low power LED radiation simulator with 30 W power were designed and compared.According to the results of three types of optimization simulation experiments,the design parameters with the best effect were selected and processed in-kind.After the physical inspection,the effective spot diameter of 45 cm and the divergence angle of ± 10.81 ° were obtained on the screen 1m away from the exit surface.The uniformity of the light spot measured was better than 98.5%,and the overall optimal uniformity was better than that of the third Chapter uniform power produced by high-power LED,but the divergence angle is too large.Combined with the results of two design analysis can be obtained: high-power LED easier to obtain a smaller beam divergence angle,low-power LED easier to achieve better uniformity.