It has been widely accepted that solid state lighting, in terms of white light emitting diodes (LEDs), will be the fourth illumination sources due to their superior performance. In this study, an effective compact freeform lens design method for LED packaging was introduced. A compact silicone LED packaging lens with the refract index of 1.54 was designed for street lighting based on this method. Integrated with this small lens, a novel application-specific LED package, whose manufacturing process can be easily integrated into current LED packaging processes, was suggested. Two application-specific LED array modules, with the type of chip on board (CoB) package, were also designed by integrating 3×3 freeform silicone and polycarbonate (PC) lens arrays. Numerical simulation results demonstrated that the optical performances of these application-specific LED modules could directly meet the requirements of street lighting. By comparing with the traditional LED illumination module consisting of an LED and secondary optics, the novel application-specific LED packages have the advantages of low profile, small volume, high light output efficiency (LOE), low cost and convenience for customers to use, and they will probably become the trend of LED packages, providing more cost-effective solution to general lighting.
Development of the Design Method of Refractive-type Asymmetric Beam Shaping Optical Elements