Free-form lens design of LED extended light source based on improved weighted superposition optimization

Abstract

Free-form surface has a wide range of applications in imaging and non-imaging optics, which can simplify the optical components, support structures required by the system and make the overall optical space more compact, but because of the large freedom of design, the design difficulty is greatly increased, how to meet the design requirements while improving efficiency, is the focus and difficulty of current research. Therefore, this paper proposed an improved optimization method for designing of free-form lens for light-emitting diode (LED) light distribution. Based on the lens matching curve obtained by weighted superposition, feedback optimization method was used to further improve the optimization possibility of lens. The weight factors of each surface are optimized by particle swarm optimization algorithm to minimize the evaluation function based on illuminance uniformity of the target surface. The illuminance uniformity on the target plane is optimized from 72.8% to 93.2% start form initial structure. The results show that the proposed algorithm has the advantages of high optimization efficiency and good optimization effect.