本文旨在採用動態掃描之LED背光驅動電路來降低背光源之功率損耗。將LCD面板分成6區控制，每一區以8顆RGB LED作為背光源。
為了降低功率損耗以及穩定性的考慮，文中使用返馳式轉換器做為電源供應器，搭配控制器IC(UC3843)，以電流迴授模式的脈波寬度調變方式得到穩定輸出電壓。控制部分使用數位邏輯電路和延遲電路結合電腦影像端子D-SUB的水平、垂直同步訊號，應用數位邏輯之觀念，設計出計數器電路，具有將LED分區點亮、畫面輪流顯示的功能。
實驗結果顯示，倘若LED全亮的耗電量為100%時，分區點亮的耗電量為16.52%。

The purpose of thesis is to design a dynamic scanning LED backlight driving circuit to achieve the reduction of power consumption. An LCD panel was divided into six regions and each region had eight RGB LEDs as the backlight was used as an object for the experiments.
Regarding the power supply, a flyback converter, which can provide a constant output voltage by using the fixed frequency current mode pulse width modulation (PWM), is used to achieve the purpose of circuit stability and power saving.The controlling part, which is the brain of lighting the regional LED in turn, is basically a counter circuit that consists of digital logic circuit, mono-stable circuit and the synchronous horizontal and vertical signal of D-sub.
The experimental results show that power consumption could be reduced drastically from 100% of the full lighting to 16.52% of the regional lighting.

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