科技的蓬勃發展為人類帶來許多便利，但隨之而來的問題是能源消耗量也與日俱增，根據台灣電力公司所提供105年發購電量，再生能源僅佔5.1 %，發展再生能源成為刻不容緩目標。其中太陽能為最被廣泛使用，除可用以節能以外，對於工作效率提升、加速手術後病人傷口恢復等皆有益處。為有效應用室內高品質日照光源，台科大PSSDL團隊提出自然光照明系統概念，將系統分為集光、傳光、放光系統，整體系統效率為三個子系統相互疊加。然而，光線在介質傳遞過程中易造成能量損耗，且角度偏折的光線在傳光系統發散，而無法達成長距離傳輸。
針對傳光問題本論文提出一雙面式準直器，以自由曲面及微稜鏡結構組成。透過分析面設置得到集光元件出口光線入射角、位置等資訊，並且利用網格切割法分割準直器為稜鏡單元，針對大角度光線及最強出射光進行篩選，以控制準直器曲率方式收斂發散光源，使光線出光方向一致。透過裝設準直器，成功收斂光線至"±" 2.91°，且根據不同網格精度、擺放距離，距離50 mm處準直效率達72.36 %，平均角度差控制於0.3度以內。

The flourishing of the technology makes human beings’ life more convenient; however, the outcome of consuming energy increases day by day. Based on the resource from Taiwan Power Company (TPC) in 2016, the renewable energy is only 5.1 percent, which makes developing the renewable energy an immediate task. Among the renewable energy, the solar power is the most extensively used. Except for saving energy, it is also benefit for elevating working efficiency and recovering wounds. In order to use the interior solar power effectively, the Team PSSDL from National Taiwan University of Science and Technology (NTUST) has brought up the idea of a natural light illumination system(NLIS), which is divided into light collection, light transmission, and light emission. The effect is overlay by three systems. However, the rays are easily consumed while passing through a medium, and the deflection rays would diverge in light transmission system, so that it couldn’t transport in a long distant.
To solve the problem, we have designed a double-sided collimator consist of freeform lens and micro prism arrays and have collected the information such as the incident angle of output light and position through the light collection element set on the analysis. Then, we cut the collimator into prism unit by the Tessellation method to sieve out the large-angled rays and the strongest ray. Therefore, the divergence light would be converged by controlling the slope of the collimator and toward the same direction. By setting the collimator, we converge the rays till ± 2.91°. By different mesh accuracy and distance would cause different results. The collimated efficiency is up to 72.36 percentage when the distance is 50 mm and the average angle is less than 0.3 degrees.

[1] L. M. Fraas, W. R. Pyle, and P. R. Ryason, "Concentrated and piped sunlight for indoor illumination," Applied Optics, vol. 22, no. 4, pp. 578-582, 1983.
[2] C. Benton, "Daylighting can improve the quality of light and save energy," Architectural Lighting, vol. 1, pp. 46-48 1986.
[3] A. J.-W. Whang et al., "Natural light illumination system," Applied Optics, vol. 49, no. 35, pp. 6789-6801, 2010.
[4] M. Kischkoweit-Lopin, "An overview of daylighting systems," Solar Energy, vol. 73, no. 2, pp. 77-82, 2002.
[5] Photopic and scotopic vision. Retrieved from
http://www.prismalenceuk.com/light_vision
[6] K. Wang, F. Chen, Z. Liu, X. Luo, and S. Liu, "Design of compact freeform lens for application specific light-emitting diode packaging," Optics Express, vol. 18, no. 2, pp. 413-425, 2010.
[7] 大田登 （2008）。 色彩工程學：理論與應用 （第 17-24頁）： 全華圖書。
[8] R. W. Boyd, Radiometry and the detection of optical radiation. New York: Wiley & Sons, 1983.
[9] S.-H. Yang, Y.-Y. Chen, and A. J.-W. Whang, "Using prismatic structure and brightness enhancement film to design cascadable unit of static solar concentrator in natural light guiding system," Proceedings of SPIE, vol. 7423, pp. 74230J1-74230J9, 2009.
[10] 林育正 （2016）。 以嵌入式系統設計與分析用於自然光照明的自動對準定鏡，電子工程所。 臺北市： 國立臺灣科技大學。
[11] A. J. W. Whang, P. C. Li, Y. Y. Chen, and S. L. Hsieh, "Guiding Light From LED Array Via Tapered Light Pipe for Illumination Systems Design," Journal of Display Technology, vol. 5, no. 3, pp. 104-108, 2009.
[12] A. J. W. Whang, Y. Y. Chen, and Y. T. Teng, "Designing Uniform Illumination Systems by Surface-Tailored Lens and Configurations of LED Arrays," Journal of Display Technology, vol. 5, no. 3, pp. 94-103, 2009.
[13] GLASS TIR LENS FOR LED.(2016). Retrieved from
https://www.auer-lighting.com/en/shop/range/_shop/p/showP/lenses/glass-tir-lens-for-led-bern-cavity-7-mm-spot-12/
[14] K.-H. Chou, Y.-Y. Chen, and A. J.-W. Whang, "An optical switch of natural light guiding system based on cubic structure with fresnel surface," Proceedings of SPIE, vol. 7428, pp. 74280O-74280O-9, 2009
[15] Z. Zhenrong, H. Xiang, and L. Xu, "Freeform surface lens for LED uniform illumination," Applied Optics, vol. 48, no. 35, pp. 6627-6634, 2009.
[16] M. A. Moiseev, L. L. Doskolovich, and N. L. Kazanskiy, "Design of high-efficient freeform LED lens for illumination of elongated rectangular regions," Optics Express, vol. 19, no. S3, pp. A225-A233, 2011.
[17] S. Wang, L. Zhang, Z. He, and M. Li, "The Secondary Optical Design of LED," Optoelectronics, vol. 3, no. 4, pp. 39-44, 2013.
[18] B. Parkyn and D. Pelka, "Free-form illumination lenses designed by a pseudo-rectangular lawnmower algorithm," Proceedings of SPIE, vol. 6338, pp. 633808-633808-7, 2006
[19] L. Wang, K. Qian, and Y. Luo, "Discontinuous free-form lens design for prescribed irradiance," Applied Optics, vol. 46, no. 18, pp. 3716-3723, 2007.
[20] 郝翔（2008）。 基于自由曲面的LED照明系統研究，信息科學與工程學院。 浙江省： 浙江大學。
[21] H. Ries and J. A. Muschaweck, "Tailoring freeform lenses for illumination," Proceedings of SPIE, vol. 4442, pp. 43-50.
[22] 呂明君 （2011）。 以LED矮路燈設計為例之非軸對稱式自由曲面設計，光 電工程研究所。 臺北市： 國立臺灣科技大學。
[23] W. Kai, L. Sheng, C. Fei, Q. Zong, L. Zongyuan, and L. Xiaobing, "Freeform LED lens for rectangularly prescribed illumination," Journal of Optics A: Pure and Applied Optics, vol. 11, no. 10, p. 105501, 2009.
[24] 顏佐融 （2015）。 自然光照明系統之稜鏡陣列結構光準直器設計， 電子工程所。 臺北市： 國立臺灣科技大學。
[25] 陳妍郿 （2015）。 應用於自然光照明系統之自由曲面微透鏡準直器， 光電工程研究所。 臺北市： 國立台灣科技大學。
[26] Cree XLamp CXA1310 Data. Retrieved from
http://www.cree.com/led-components/products/xlamp-leds-integrated-arrays/xlamp-cxa1310

[27] 李維 （2016）。 應用於自然光照明系統之低損耗微稜鏡陣列準直器設計方法，電子工程所。 臺北市： 國立臺灣科技大學。
[28] 黃兆鵬 （2016）。 應用於自然光照明系統光傳輸之自由曲面準直器設計方法，電子工程所。 臺北市： 國立臺灣科技大學。