LED TV背光模組熱流狀態解析及最佳化設計

Abstract

LED為液晶顯示器產業近年來積極發展之替代性光源，除了具有體積小、重量輕等優點之外，更符合無汞的環保訴求。但由於LED之發光效率仍未臻理想，僅有不到30％之輸入能量轉換成光，其餘仍以熱的形式傳出，此結果會直接影響LED亮度及波長等光學特性，而造成顯示結果偏差的影響，因此LED背光模組散熱不良是截至目前LED仍無法廣泛應用於液晶顯示器產業的主要原因之一。 本論文主要探討LED應用於大尺寸液晶顯示背光模組時之熱流狀態，並提出一套TEC熱電致冷器散熱系統，即時監控背光模組溫度，藉由回饋系統於適當時機啟動散熱機制作為動態調整，使模組溫度可維持於一穩定狀態，亦使LED在穩定狀態下操作可得到更長時間的壽命保證。

LED is the alternative light source developed in recent years of TFT-LCD industry, it has the advantages of small size, light weight, etc. And more in line with the environmental demand of mercury-free. However, due to the efficiency of LED has not yet attained the ideal, more than 70% of input energy are converted into heat. It will directly affect the LED optical properties of brightness and wavelength, and cause the deviation in display. Therefore thermal issue of backlight modules is one of the main reasons that LED still unable to widely application in TFT-LCD industry.

This article focused on the thermal state of large-size TFT-LCD backlight module used LEDs and proposed a set of TEC cooling system. Real-time monitoring the backlight module temperature and the feedback system can dynamically adjusted the module temperature and maintain at a steady state.