TFT-LCD螢幕在電源驅動，點亮背光模組燈管，當持續一段時間後，因燈管釋放熱量，造成液晶面板翹曲變形，在螢幕上方角落產生色彩白化現象，影響影像品質。為探討此問題機制，本研究分三部份實驗來探討其發生原因，進而找出較佳解決方案，改善畫質不良現象。實驗使用熱電偶量測 TFT-LCD TV模組溫度，量測部份包含燈管電極端及背光模組空氣層溫度及液晶面板溫度等，藉以獲得各部位之溫度分佈。另使用XY直線運動平台，搭配電容式位移感測器，量測液晶面板熱變形位移，藉以量測面板變形趨勢及變形量。此外，運用應變規量測液晶面板表面應變量，以瞭解縱向及橫向應變之關係。 經由實驗瞭解色彩白化現象發生機制，並由實驗獲得數據，進一步探討設計改善方式。由溫度量測，瞭解面板上方為溫度較高，因此增加開孔散熱之設計；由位移計獲得之面板熱變形，得知面板上方角落之變形量最大，因此微增面板與前框之間隙量，以減少因變形而與前框壓迫干涉，兩種設計改善方式，均再以實驗驗證其效果。 TFT-LCD deforms due to the heat released by lamp when powering on and lighting up the backlight of TFT-LCD monitor several minutes. Deformation results in the white phenomenon of color on the corners of screen, up-left and up-right, and worsens the image quality. In order to analysis the problem, this study provides three different experiments and tries to find the best solution for improving the defect. The first measure uses thermocouples to measure temperature at different parts, including lamps, air-gap in backlight module and surface on TFT-LCD. Then the temperature distribution in different areas could be shown. In order to know the general situation about TFT-LCD’s deformation, the second one uses X-Y stage with displacement sensor to get the displacement of heat deformation. The last one we apply strain gage to measure surface of TFT-LCD and understand the relationship between lateral strain and longitudinal strain. Thought experiment of the first one, we knew the reason why white phenomenon happens. Then we present another mechanical design to avoid it. We added holes on shell to cool down faster because in the second experiment we know the TFT-LCD’s upper side have the higher temperature. From the displacement sensor measurement, the deformation of panel is obtained, we knew the biggest displacement which happens at the corners of upper side. So it would be better to add some distances between TFT-LCD and frame to reduce interferences. Two modifications would be experimented to show the effect.
