Optical Design of the Polyellipsoid Reflectors for Automotive Headlamps Using LED Sources

[[abstract]]本文主要是為了研究車燈的反射鏡，主要的研究目的有二個：第一，我們要讓位於橢圓第一焦點上的光源經由橢圓反射鏡反射後可以有效的聚焦在橢圓的第二焦點上，以致於投射在屏幕上的明暗截止線比傳統反射鏡更加清楚。然而，關於球面像差的詳盡研究並非本論文的必要目的；首先，本文針對多橢圓反射鏡的數學模型進行推導並確定其設計參數,接著確定遮片的幾何形狀與位置，並整理反射鏡的公式與透鏡的相關公式作配合，進而對車燈進行光學模擬；我們先將光源置於多橢圓反射鏡的第一焦點處並從第一焦點到第二焦點進行光線追跡，接著，被追跡的光線會繼續前進並通過遮片和透鏡然後投射到屏幕上，本文再針對模擬結果與ECE R112做一個對照，觀察其結果是否有符合ECE R112之明暗截止線的光型，最後再經由觀察屏幕上的結果依照不同情況做不同的比較；主要包括：1.將使用LED光源的單元車燈與左右兩車燈做比較；2.針對兩車燈，將LED光源與點光源和H7光源做比較；3.將多橢圓反射鏡與傳統反射鏡做比較。[[abstract]]This paper is intended as an investigation of the reflectors of headlamp. There are two questions to make by ourselves as follows: First, we deduce the mathematical formulations and confirm the parameters for multi-ellipse reflector in this paper, then, we decide the geometrical model of aperture plate, and then we integrate the mathematical formulations of reflector with the mathematical formulations of lens. The next step is to simulate the entire headlamp; we put the light source on the first focus of multi-ellipse reflector and trace rays from the first focus to the second focus, next the rays pass an aperture plate and a projection lens, furthermore project it on a screen, and then we take the effect of the simulation to contrast the cut-off line of ECE regulations, we can observe the effect whether it conform the cut-off line of ECE regulations R112; finally, we make different comparisons for different cases by observing the effect through the screen, including: 1. compare the one headlamp with the two headlamps for LED source; 2. compare the LED source with the point source and H7 source for headlamps; 3. compare the multi-ellipse reflector with the traditional reflector for two headlamps