초박형 LED BLU용 색 혼합 렌즈 개발

Abstract

This thesis proposes new types of package level color mixing lens (CMLs) for ultra-slim light emitting diode (LED) backlight unit (BLU). The novel color mixing structures are thinner than the conventional color mixing structure, and achieve high efficiency and uniformity. Additionally, we can control the radiation patterns by introducing appropriate output couplers. In this study, we have designed two types of CML. One is an edge emitting CML, and the other is a surface emitting CML. The CMLs consist of input coupler, mixing zone, and output coupler, made of polymethyl methacrylate (PMMA) which is transparent and transmits up to 98% of visible light. The input coupler is formed at the bottom of the CML, and collects light from four LEDs - one red, one blue and two green LEDs. In the mixing zone, RGB rays are mixed up as light travels in the PMMA body, satisfying total internal reflection condition. The output coupler can be designed to achieve desired radiation patterns. Finally, to improve output efficiency, we use metal coating or jacket on each CML. We have designed and demonstrated new CMLs with high performances and various radiation patterns. We expect that these CMLs can be used for ultra-slim LED BLUs and various illumination systems as well.