本論文主要在設計一種應用於大發光面積LED光源的複合型準直透鏡。本研究提出一種準直照明的自由曲面透鏡設計演算法，並使用此演算法配合全反射的光路設計，設計出一種高準直的複合型透鏡。本研究透過設計光線路徑的方式建立數學方程式，去建立透鏡表面輪廓曲線上的點，並利用迭代的方式結合商用數學軟體Matlab計算，撰寫並求解出自由曲面輪廓曲線的數據分散點，並將各數據點的結果經過篩選比較後，最後將數據點代入光學軟體LightTools中，選用大面積LED光源對該透鏡進行光線追跡，模擬結果表明該光學系統能夠實現準直出射。 本研究以出光角度切割區分光線區域，優勢為可以針對各區域出光角度作光路的配光設計。將光線區分為三種出光角度，並利用全反射的方式使三種出光角度分散路徑，以利於後續光線經過透鏡曲面之設計，最後設計出配合的自由曲面二次光學透鏡以完成最後目標出光結果。研究利用自由曲面有較大的設計自由度，及相對較大的活用空間特性優勢，簡化了設計光學系統的結構，目標為利用設計自由曲面使燈具能達到更有效率的去分配光強度，並使出射光線的結果控制在接近準直出射。對於光學設計方法，本研究使用方程式進行初始求解，而後配合經驗法進行逐步修改出光學透鏡之元件輪廓，通過多次模擬結果嘗試進而求出較佳之結果。 本研究提出了一種自由曲面設計演算法，並通過一個實例設計了一種應用於大發光面積 LED的複合型準直透鏡。經光學模擬結果表示，此透鏡達到了設計之要求，實現了目標的準直效果。 ;This thesis aims for designing a collimating lens with large-area light-emitting diode (LED) as the light source. This research provides an algorithm which is designed with freeform surface lens of collimated illumination and designs a collimating lens by using that algorithm. Through setting an equation which is satisfied with the data points of the silhouette curve on the lens surface and using iteration method with the commercial mathematics software—MATLAB, to compute the data points of the silhouette curve. By putting data points in the illumination design software—LightTools, and using large-area LED as the light source to conduct ray tracing on the lens, it would make the simulation result show this optical system can achieve collimated and even emerging rays. This research views the partition of the divergence angle as the main part, making it more easily to design a freeform surface lens. It designs rays for every partition of the divergence angle to make the emerging rays more even. By using the flexibility of the freeform surface of the secondary optical lens, it can improve the result of the emerging rays and simplify the structure of the optical system. It also can control the view angle to approach collimation by using the freeform surface which is more effectively to distribute the light intensity. About the method of optical design, this research applies the equation solving method to conduct the initial solution, and cooperates with the empirical method to modify the silhouette curve of the optical lens step by step to achieve the best result through simulated testing. This thesis provides an algorithm which is designed with freeform surface lens and designs a composite collimating lens with round large-area LED as the light resource. The optical simulation research demonstrates that lens meets the requirements of the design and achieves ideal collimated result.
