Molding and Optical Performance Simulations of a New Plastic Grating Lens for an Asymmetric LED Fog Lamp

Abstract

This research focuses on the effect manufacture factors about the brightness and uniformity of multi-stage reflector. Trace-pro and 3D CAD model were used for optical simulations. The optical simulation results of grating lens and reflector were done as well as successfully developed the LED fog lamp. The results meet the regulations, R19 CLASS F3, of Economic Commission for Europe (ECE) at the test distance of 25 meters, and central zone under line6 achieves average over 3200cd. The optimal design of reflector is of third-order paraboloidal one to improve the brightness and uniformity. The acuter the microstructure’s tip is(R below 0.1mm), the better the apparent improving of eliminating stray light. In accordance with microstructure of grating lens, Moldex-3D is used to help the mold flow filling simulation and mold design. The mold cavity with microstructure was manufactured by the wire cutting and polishing processing. And the molding plastic was optics level PC (Polycarbonate). Both Taguchi’s method applied in Moldex-3D and real injection molding experiments showed that high melt temperature, low injection speed and suitable holding time can reduce warpage; in addition, using higher melt temperature, mold temperature and injection pressure can achieve higher degree of replication of micro features.