使用於DLP 投影系統中的新型全反射稜鏡設計

Abstract

在此論文中，我們提出一個可使用於DLP投影系統的新型稜鏡。這個新型稜鏡可以增加DLP投影系統的對比度並同時保持其光學效率。這個新型的稜鏡能在雜散光進入鏡頭前將其轉向。由於雜散光根本不會進入鏡頭，對比度可以被更有效率的提升。跟傳統的提升對比的方法比起來，這種使用新型稜鏡的新方法能將FO:FO對比度從921:1提升到46347:1，ANSI對比度從177:1提升到295:1。在提升對比度的同時，同時將投影系統的光學效率維持在79.8%。

In this thesis, we present a novel light separator with the ability to enhance contrast ratio and maintain the optical efficiency in the DLP projection system. The working theorem for the novel light separator is derived well. With this novel light separator, the ghost ray can be directed away the projection lens by a total internal reflection surface. Since the ghost ray doesn’t even enter projection lens, the performance of contrast ratio enhancement is more effective than that by asymmetrical stop. Comparing with the conventional method, the FO:FO contrast ratio is increased from 921:1 to 46347:1 and the ANSI contrast ratio is increased from 177:1 to 295:1.With the contrast ratio improved, the imaging system efficiency is kept at 79.8%.