由於3C產品的發展快速，設計者為了增加產品的實用性與美觀性，於是運用了圓形結構的照明裝置到產品中，而受限於產品的輕薄短小、低耗電和低成本等訴求，光源於是選擇發光二極體(LED)，圓形結構則是以塑膠射出的導光管來製作，本文中，我們將對此圓形結構的照明裝置進行設計，並稱之為LED圓形導光管(Circular Light Pipe, CLP)。
市面上最常見的LED圓形導光管是以至少兩顆以上的LED，對稱的放置在無需經過設計的導光裝置正下方來逹成均勻照明目的。本文中，主要目的則是以單一顆LED，並搭配利用全反射(TIR)原理設計的圓形導光管來達成。圓形導光管上的TIR分光結構和微稜鏡結構將藉由TIR理論推導得到初始角度，而微稜鏡結構的數目、長度和密度分佈則先給定一組初始參數，並藉由機構軟體Pro/ENGINEER®來快速建構所需的微稜鏡結構之CLP，並輔以非序列光線追跡軟體TracePro® 來分析光輸出結果。為了得到最佳的光輸出均勻度，並節省不必要的試誤(try and error)過程所浪費的時間，故優化設計的過程將使用田口方法(Taguchi method)。

Due to the quickly development of 3C products, designers would like to add practicability and pretty on products. Because the requirements of light weight, thin, short, small, saving power and low cost, the light source will select LED and the Circular Light Pipe will use plastic materials by injection molding. In this study, we will focus on designing the illumination device with circular structure and called as LED Circular Light Pipe (CLP).
On the market, the common LED CLPs always use more than 2pcs LED and locate symmetrically under the un-designed CLP for the purpose of uniform illumination. In this study, we will use 1pcs LED to design CLP based on TIR principle. The initial angles of TIR beam-splitting structure and micro prisms on CLP will be decided by TIR principle. The numbers, lengths and distribution of micro prisms will be given a set of initial parameters. Then, we will create the initial LED CLP with micro prisms by 3D CAD software Pro/ENGINEER® and analyze the light output results by non-sequential ray tracing software TracePro®. For the better uniformity and saving time to avoid the try and error, we do optimization by Taguchi method.

參考文獻
[1] Juan Manuel Teijido,“Conception and design of illumination light pipes,” Ph.D. Dissertation, Institute of Microtechnology, The University of Neuchâtel in Switzerland, http://doc.rero.ch/lm.php?url=1000,40,4,20050621171029-ED/2_the se_TeijidoJM.pdf/, 2000.
[2] Jean-Charles Poli, Joachim Grupp, Juan Manuel Teijido, Hans Peter Herzig, “Uniform illumination device for the dail of a display device,” US Patent US5984485A1, 1999.
[3] Jean-Charles Poli, Joachim Grupp, Juan Manuel Teijido, Hans Peter Herzig, “Dispositif d’illumination uniforme du cadran d’un appareil d’affichage,” Europe Patent EP0860755A1, 1998.
[4] Juan Manuel Teijido, Jean-Charles Poli, Joachim Grupp, Hans Peter Herzig, “Dispositif d’illumination orientée d’une surface par un guide à microprismes,” Europe Patent EP1050711A1, 2000.
[5] Junwon Lee and John E. Greivenkamp, “Modeling of automotive interior illumination systems”, Optical Engineering, Vol. 43 No. 7, July, 2004.
[6] Mark Kaminski, “Lightpipe and integrating box provide uniform irradiance”, Laser Focus World, May, 2004.
[7] John F. Van Derlofske, “Computer modeling of LED light pipe systems for uniform display illumination”, Proc. SPIE, 2001.
[8] Pro/ENGINEER is trademark of Parametric Technology Corporation, http://www. ptc.com/.
[9] TracePro is trademark of Lambda Research Corporation, http://www.lambdares. com/.
[10] 林奕村，利用田口方法進行背光模組之設計，國立臺灣科技大學，碩士論
文，2006。
[11] 李佩君，導光板微結構分佈最佳化及模仁薄板取代製程之研究，國立高雄　　　
第一科技大學，碩士論文，2007。
[12] 吳復強，產品穩健設計：田口方法之原理與應用，全威圖書，7月，2005。
[13] 田口玄一 原著，陳耀茂 譯，田口實驗計畫法 － Introduction to Design of
Experiment，滄海書局，1997。