適用於大尺吋掃描式液晶顯示器之二維串接型背光模組設計

Abstract

本篇論文主要目的為利用串接式楔型導光板達到大尺寸分區掃描式色序法之液晶顯示器背光模組。傳統色序法背光系統提供一種不需使用彩色濾光片及達到高效能高色彩飽和的方法。但是由於現今液晶的反應速度仍舊不足，在大尺寸的液晶顯示器運用上，等待整塊面板的液晶反應時間會壓縮到背光源點亮的時間，導致整體面板的亮度不足。因此，為了解決此問題，運用掃描式色序法的背光驅動的方式來達到補償等待液晶反應速度上的不足。然而此種掃描式色序法的背光模組在運作時，若使用傳統無分區的導光板，不同顏色的光場分布會同時出現在導光板內而出現混光錯誤造成顏色失真的現象。因此，掃描式色序法之液晶顯示器背光模組需要有良好的分區效果以降低混光錯誤的機率。利用串接式楔型導光板的設計，組合達到大尺吋的面板需求。經由實驗結果，導光板的均勻性可達到84%，而在掃描方向的半高全寬可降低到±30度，而從點亮的區塊中漏光至鄰近區域的漏光量只有9.8%。

The aim of this thesis is to utilize tandem wedge shaped light guides to accomplish the large scale scanning field-sequential-color liquid crystal display. The field-sequential-color system has a lot of advantages such as high efficiency, high color gamut. However, due to the response time of the liquid crystal is insufficient fast, the duty cycle of the light source is restricted. This situation leads to luminance reduction especially in large size application. In order to overcome this issue, the scanning field-sequential-color backlight system is proposed. In this system, the color state is sequentially scanned from up to down during a whole frame. Nevertheless, if the conventional light guide is used to perform the scanning field-sequential-color backlight module, two different color states will appear on the screen simultaneously. The light penetration will occur inside the light guide, and that will lead the image color distortion. For this reason, each scanning partition of the field-sequential-color scanning backlight application should be an isolated segment to avoid the color mixing error. Based on this purpose, the tandem wedge shaped light guides are assembled to realize large scale application. Through the experiment, the uniformity by 9 points of LG was 84% associated with the brightness enhance film and diffuser. The FHWM (Full Width at Half Maximum) of the extraction light is □30 degree in scanning direction. The leakage from the illuminated block to the adjacent stripes is only 9.8%.