利用滾筒微壓印技術製作次波長結構之導光棒

The Sub-wavelength Gratings Applied for Light Bar by the Roll-to-Roll Imprinting Process

劉俊葳(Chun-Wei Liu)

指導教授 ： 林士傑

國立清華大學/工學院/動力機械工程學系/碩士(2010年)

摘要

近年由於液晶顯示器的輕薄短小，故廣為應用於電腦、通訊和消
費性產品等。然而LCD 背光模組所面臨到的問題是光使用率很低，
所以為了改進光輝度值和均勻性，很多研究在探討藉由幾何光學和物
理光學的方法，從導光棒上之優化結構控制出光角度以消除暗帶和熱
點現象。
本研究使用UV滾壓製程製作次波長結構以應用於液晶顯示器。
基於嚴格耦合波理論(RCWA)，我們探討光由從光密介質經次波長光
柵到光疏介質的一級穿透與反射效率及光柵週期和結構幾何形狀之
間的關係。其目的為使入射R、G、B 三原色光(625 nm、525nm、465nm)經次波長光柵後可在出光面產生均勻且垂直出射的高輝度的白光。

關鍵字

液晶顯示器 ； 背光模組 ； 導光棒 ； 滾壓製程 ； 次波長光柵

並列摘要

In recent years, liquid crystal displays (LCDs) have been the most widely used apparatus in various applications as information display devices, such as computer, communication, and consumer electronics due to the thinner size and lighter weight. One problem facing current LCD backlight unit is its low efficiency in the viewing direction. Several geometrical optics or physical optics methods have been proposed to improve the light illuminance and uniformity by optimizing the structures on the light bar to control the scattering directions and eliminate the dark region or hot spots in this viewing direction.
This research uses a roll-to-roll imprinting process based UV resin process to make sub-wavelength gratings for display applications. Based on the rigorous coupling wave analysis (RCWA), we analyze the relationship between the 1st order transmission/reflection efficiency and grating’s pitch under various shapes while rays passes through sub-wavelength gratings, which are patterned on a backlight. The target is to turn the R/G/B (625 nm、525nm、465nm) incident rays into a uniformly and normally output white light with high illuminance from the surface of a light bar.

並列關鍵字

LCDs ； Backlight unit ； Light bar ； Roll-to-roll imprinting process ； sub-wavelength grating

參考文獻

[1] S.Y. Lee, “Technical trends and requirements/Specifications for LCD

TV backlights,” John Wiley & Sons, Ltd, 2009.

[2] Y. Kondo, “Technological trends of LED backlight units,” John

Wiley & Sons, Ltd, 2009.

H. J. Cornelissen, “Short period holographic structures for backlight