Study On Optical Design For High Power LED Illumination System

Light Emitting Diode(LED) electro-optical conversion efficiency, with the progress of materials science and technology,have continuously improved,from lack of 11m/W to 1001m/W above.and it also been greatly improved that all colors within the visible light could be achieved in the chroma.The breakthrough of these technologies to expand the applications of LED,so that it could be applied to not only the traditional illumination and display,but also the field of high-power illumination.Illuminating by LED could not only save energy and reduce pollution,but also reduce the system size and extend the system life.The existing illumination systems could not be directly applied to LED and make system miniature because that the shape and optical properties of LED different from conventional light sources.New optical system should be designed for LED to improve illumination uniformity and efficiency.In this paper,the design process of free-form optical components are put forward based on researching and summarizing the previous design methods.Free-form optical components for uniform circular radiation pattern and uniform rectangular radiation pattern, as well as collimated beam are designed by using mesh method and equation which not only differential equation solver method.After the incidence light on the free-form surface was reflected or refracted,the desired illumination could be realized on the target plane.The equation sets were solved by using powerful numerical calculation function of Matlab,then the traditional illumination system optical design method mainly based on experience would turn into solving specific equations.The whole design process need not to optimize,which improving the work efficiency and the illumination performance.In addition,the traditional LED optical design method that is commom for the point source approximation,though that method plays an important role in the LED second optical design,it is not good for LED extended sources.In this paper,a effective and practical optical design method was present for LED extended sources,and an kind of lens was designed by this method.The results show that it could realize the uniform circular radiation pattern on the target plane.