直下式LED背光模組之二次光學透鏡設計

環保及綠能意識抬頭的今日，LED一直為世界照明未來趨勢，尤其是應用於一般照明及顯示器背光源為最主要方向，其可取代傳統照明及應用於顯示器之冷陰極燈管(CCFL)，是目前最為熱門的題材，但LED一直存在光源指向性問題，常對於使用者造成困擾，而無法大量運用於市場。本論文主要是探討LED二次光學透鏡元件，使用於顯示器背光模組產品，比較於一般傳統直下式LED背光皆只有一次光學設計，LED光源指向性問題沒有辦法解決，無法將光源均勻化，造成LED使用顆數無法減少，導致製作及材料成本增加，以及驅動功率過高無法達到環保的要求，但使用二次光學透鏡將可使指向性問題解決，讓光源均勻化，更能讓光源發散角增大，進而減少LED使用顆數，將利用模擬的方式，設計出最佳化光源透鏡，使直下式LED背光模組也能夠做到節能環保效果。

關鍵字

直下式背光模組；二次光學透鏡； LED發光源

並列摘要

At present, the awareness of environmental protection and green energy is rising. The LED has been the coming lighting trends in whole-world, especially for general lighting and backlighting module (BLM) of display because LED can be used to replace the cold cathode fluorescent lamp (CCFL) used in traditional lighting and display. The LED application is the most popular discipline in saving-energy filed. Even LED is an excellent light source, the directivity characteristic of ray emitted from LED is always an existed problem that often causes problems for users. This is the main reason why LED can not be largely applied in the lighting market. This essay focus on the secondary optic lens for LED BLM of display. At past, there was only the primary optical design used in the traditional direct-type LED BLM. The light uniformity can not be very well by primary optics method. That means the directivity characteristic can not be solved. The used quantity of LED in BLM can not be reduced. Too many LEDs lead the cost and power of driver too high. However, the light source can be uniformed and the angle of intensity distribution of light can be increased through the secondary optic lens. The quantity of LED can be naturally reduced. We can use simulation methods to design a matrix form that can be modularized. The secondary optic lens module method presented by this essay can reduce the cost and working hour of BLM assembly. The efficiency of saving-energy and environment protection will be higher.