本文目的是非對稱 Fresnel 透鏡搭配 LED 應用於歐規新修訂之 ECE R6 汽車方向燈的光學設計，並藉由ASAP 光學設計分析軟體來模擬配光。結果顯示非對稱 Fresnel 透鏡搭配Lambertian LED 可產生左右約 20度、上下約 10 度的非對稱配光，LED 最低流明數需求僅 38－55 lm，可比「薄」平凸透鏡的設計方式來得低一些，也比一般汽車常用方向燈傳統光源白熾燈泡低很多。

The paper presents the LED direction indicators design with asymmetric Fresnel lens, which meets the ECE R6 criterion. The opto-mechanical design software, ASAP, is adopted for the analysis of light flux. The results show that Lambertian LED and the asymmetric Fresnel lens can produce an asymmetric lightspot which is about 20 degree in horizontal and 10 degree in vertical. Therefore, the minimum requirement of LED light flux is 38－55 lm lower in the design; it is lower than that for thin flat-convex lens, and much lower than the traditional bulb P21W.