Theoretical Research On Uniformity Illumination Design For High Power LED

Abstract:As a new generation of light source with a rapidly improved on its performances, LED is ready to replace the traditional light source soon after. How to design the optical system for LED to guarantee uniform illumination on the target plan, and ensure the system compact with high energy utilization, is the urgent problem of LED lighting system, which is also the key issues of replacing the traditional light sources. Based on non-imaging optic theory, theory of freeform surface and differential geometry, researching the general design theory of LED’s uniform illuminate, establish common models for optic system in this paper. Research on the method of two-demensional and three-dimensional uniformity system, and apply to indoor and outdoor illumination. Here are the main contents:1. Work out three kinds of uniform illumination design methods, Grid parathion method and differential equation method which regard LED as a point in the systems, simultaneous multiple surface methods that regard LED as a extended light source.2. Design secondary optical lens by Grid parathion method. Regard LED as a point in the optical systems, establish the math models of the rotational symmetry optical systems by Grid parathion method, which is based on non-imaging optic. And derive formulas for the freeform surfaces of the lenses, solve them by Matlab, work out the lens models by Rhino, and ray tracing the optical systems in Trace-pro, analyze their properties and effects. Design three rotational symmetry lens solutions with different freeform surfaces for different applications.3. Design secondary optical lens by differential equation method. Research the theory of differential equation method, design a lens for un-rotational symmetry optical systems which can illuminate uniformity on a rectangle target surface. Besides, LED is regarded as a point in the system too, and this method also based on non-imaging optic. 4. To correspond with the development trend of LED, research the method of Simultaneous Multiple Surface (SMS) to solve the problem that LED’s size cannot be seen as a point source. Set up its math models for extended light source, built the equations for two freeform surfaces, and solve the equations to get the points of the curves in Matlab, fit theses points to be a curve by NURBs, then set up the lens model. Emulate and ray tracing the system in Trace-pro and analyze the properties of the lens.5. Use the lenses designed in this paper, offer the proposals of indoor illumination and street illumination and emulate them in optic software DIAlux.