本論文成功提出使用雙晶封裝之白光LED 光源用於直下式背光板之二次光學設計方法。在商業考量下,此二次光學設計透鏡具有降低直下式背光板之光源使用顆數,來達成稀疏排列之效果。此論文研究具有四大部分,分別為光源模型建立、直下式背光板之二次光學設計、透鏡模型製作與透鏡實驗驗證,光形黃暈分析與黃暈解決技術。在本研究中,我們將雙晶封裝之白光LED藉由權重因子來建立其光源模型。在透鏡模型製作與實驗驗證階段,我們根據二次光學設計結果製作了相應的透鏡模型,並進行了實驗驗證。接著由於打樣模型的實驗光形具有黃暈的現象,此現象在我們使用單色之光源模型無法表現出,因此我們藉由藍光與黃光強度分布之權重因子優化原始的白光LED光源模型,此藍光與黃光之光源模型可於解釋實際樣品具有黃暈的問題。 ;This paper successfully proposes a secondary optical design method using white light LED with dual crystal packaging for direct-type backlight modules. From a commercial perspective, this secondary optical design approach allows for a sparse arrangement of light sources, reducing the number of LEDs required in the direct-type backlight module. The research in this paper consists of four main parts: the establishment of a light source model, the secondary optical design for direct-type backlight modules, the fabrication and experimental verification of lens models, and the analysis and resolution of yellow halo effects. In this study, we establish the light source model of Phosphor-converted white LED (abbreviated as pcW-LED) with dual crystal packaging using weighting factors. In the stage of lens model fabrication and experimental verification, we create corresponding lens models based on the results of the secondary optical design and conduct experimental validation. However, due to the appearance of yellow halo effects in the experimental light distribution, which does not match the simulation results, we optimize the original white light LED light source model by adjusting the weighting factors for blue and yellow light intensity distributions. This blue and yellow light source model effectively explains the occurrence of yellow halo effects in the actual samples.