應用於DLP投影系統之高對比稜鏡設計

Abstract

在這篇論文中，我們提出一個可用於DLP投影系統的高對比且可同時保持光學效率的新型稜鏡。這個新型的稜鏡主要功能在雜散光進入鏡頭前將其轉向移除。此新型稜鏡的工作原理在這篇論文中將被推導。因為雜散光可以在進入鏡頭前藉由全反射面轉向，因此可以有效的改善影像品質。跟傳統的提升對比方法比較，FO:FO對比度將從839:1提升到48250:1，ANSI對比度從174:1提升到306:1。在提升對比度的同時，投影系統的光學效率可以維持在76.2%。

In this thesis, a novel prism with contrast ratio enhancement but maintaining the optical efficiency of the DLP projection system is proposed. The main capability of the novel prism is to direct the uncontrolled light away from the image system. The working theorem for the novel prism is derived as well. Uncontrolled light is kept away from the image system by a total internal reflection surface, thereby effectively improving the image quality. Compared with the conventional contrast ratio enhancement method, the FO:FO contrast ratio can be improved from 839:1 to 48250:1, the ANSI contrast ratio can be improved from 174:1 to 306:1, while the image system efficiency remains at 76.2%.