區域調光控制之紅綠藍發光二極體背光驅動系統

RGB LED Backlight Module with Individual Area Control for LCD Panels

對大尺吋液晶電視而言，具高發光效率、顯示色域更廣、狀態快速切換、操作壽命更長、無汞以及能夠達到區域調光控制的紅綠藍發光二極體顯得更適合當做液晶電視之背光源。加入區域調光控制技術使得背光模組切割成很多區塊並加以控制其發光二極體亮滅，不但減少消耗功率亦增強影像對比度、減少動態影像模糊等。本文製作一液晶電視背光驅動模組，將其區分成96 塊色區，並根據各區輸入之調光命令進行區塊的混光控制。文末透過實驗波形結果來驗證本文之正確性，並由實驗結果得知轉換器功率轉換效率在全負載範圍均可高於90%，且96個區域亦可個別控制發光二極體混光結果。

Higher luminance efficacy, local dimming capability, wider color gamut,faster response, longer operation life and fewer environmental issues make RGB LED backlight driving systems suitable for large scale LCD TVs.For these applications, area dimming control is often adopted to reducepower consumption and enhance the image contrast ratio. In this paper,an RGB backlight driving system for LCD panels with individual area controlis proposed. Using the topology proposed in this paper, the backlightcan be divided into 96 areas and the brightness of each area can be individuallycontrolled according to its corresponding dimming command.This technique can also be expanded to a higher number of areas easily.In order to verify the correctness of the proposed system, a prototype ispresented and experiments are carried out. According to the experimentalresults, the measured power conversion efficiencies of the proposed backlightdriving system are all higher than 90% under all load conditions andindividual area control can be achieved.