反射式液晶顯示器之白色色彩分析

Abstract

隨著多媒體資訊（Multimedia）與網路（Internet）時代的來臨，影像與資訊的交流益形迅速，各種新型顯示影像文字的顯示技術應運而生。而伴隨著這些顯示技術的發展，各種各樣顯示器技術也不斷被提出，來解決與因應各種顯示應用所面臨不同的問題。其中平面顯示器（Flat-Panel）在輕量化、薄型化、與高影像品質等各項要求下，發展十分迅速，亦逐漸被應用在新型的資訊顯示系統上，而成為顯示器的主流。 其中彩色反射式液晶顯示器(Color Reflective Liquid Crystal Display)由於具有低消耗功率(Low power consumption)、體積小(Thin format, light weight)、日光下可視(Sunlight readability)的優點，已成為戶外個人顯示攜帶裝置的重要應用。但是相較傳統的穿透式液晶顯示器(Transmissive Liquid Crystal Display)，反射式液晶顯示器仍有飽和度不足、亮度不足、白色色彩不足的問題。由於反射式液晶顯示器擁有戶外強光下可視的特性，因此具有電子紙張(Electric-Paper)的發展潛力。本論文致力於研究及分析反射式液晶顯示器白色色彩不足之原因以使其能達成如白紙之外觀以增加其電子紙張之達成性。其中我們提出可能造成其白色色彩不足的原因有:反射板的反射頻譜、彩色濾光片之頻譜、液晶層的色散、斜向觀測、斜向入射、以及面板的亮度分佈與均勻度，都將在此篇論文中被討論。此外，我們利用了模擬或量測個別對兩片不同的反射式液晶顯示器研究以上所提出原因模擬或量測，並且個別針對其面板特性提出其主要影響白色色彩之原因。最後，亦對其分別提出改善的方法以達到白色紙張般的影像品質。

As the trend of multimedia, Internet and communication applications, various display technologies to present mass information in image, text, and video, are rapidly developed to fulfill the demands of vast amount of information exchange. To facilitate the development of display technologies, various new information display technologies are proposed to resolve the issues in various display applications. Among the display technologies, flat panel technologies, due to the advantages of light weight, thin format, and planar structure, are being rapidly developed and well applied for novel applications. Reflective LCDs have become the important applications of portable, hand-held information devices due to the advantages of light weight, thin format, low power consumption, and sunlight readability. However, compared with transmissive ones, reflective LCDs have some issues such as inadequate color saturation, inadequate brightness, and inadequate whiteness appearance. As reflective LCDs possess the potential of ‘Electicel-Paper’ resulted from the sunlight readability. In this thesis, inadequate whiteness of reflective LCDs has been analyzed in order to achieve the paper-white image to accomplish the ‘Electical-Paper’ performance. Among the factors caused inadeqaute whiteness, such as reflective spectrum of an Al reflector, dispersion of LC layer, spectrum of color filter, oblique viewing, oblique incidence, brightness, and uniformity of reflective LCDs caused inadequate whiteness will be examined and illustrated. Moreover, two panels were utilized to analyze the factors above individually by some simulation and measurements to find out the major factors affecting the whiteness appearance. Furthermore, the improving methods will be proposed for the two panels, respectively, to achieve the paper-white image.