近年來隨著筆記型電腦與可攜式資訊產品不斷推陳出新，液晶顯示器具有高畫面顯示能力、高亮度、高效率及體積小等優點，使得液晶顯示器的需求量逐漸上升。由於液晶本身不具有發光特性，因此需由背光模組提供光源；在眾多背光技術中，RGB LED具有高發光效率、壽命長、廣色域與低環境污染之特點，使得RGB LED有機會取代CCFL成為新一代LCD背光源。本文提出場色序法之可調輸出電壓RGB LED背光模組驅動電源系統，並將背光源分成4個獨立區域進行區域調光控制。在驅動電路方面，本文以數位控制之四相交錯式降壓轉換器驅動RGB LED面板，並搭配均流電路與人機介面完成背光模組區域調光控制。由於RGB LED順向導通特性不同，本文提出之四相交錯式降壓轉換器以一個固定時序提供變動輸出電壓驅動RGB LED，減少線性穩流電路功率損耗，以提高系統效率。根據實驗結果，本文提出之系統架構成功驅動RGB LED背光模組，並透過人機介面成功完成混色與區域調光控制。

The proliferation of portable devices and notebook computers places an ever-increasing demand on display technology. Liquid crystal display (LCD) is one of the strongest candidates in picture quality, brightness, efficiency, and size. LCD requires backlight units because the liquid crystal devices themselves do not inherently emit light. Among the various backlight technologies, the RGB LED backlight has the advantages such as wider color gamut, higher luminance efficacy, faster response, lower power consumption, longer operation life and lower environmental issues; therefore, RGB LED backlight has been regarded as the best potential backlight source for next-generation displays.
In this thesis, a field sequential color (FSC) voltage-adaptable RGB LED backlight driving system with local dimming control for LCD panels is proposed. Using the topology proposed in this thesis, the backlight can be divided into 4 individual areas. A digitally-controlled four-phase interleaved driving system for RGB LED lamp, a current sharing method, and a human machine interface (HMI) for dimming the backlight module is presented. The output voltage is self-adjusted so that RGB LED maintains the desired string current. Because the voltage across the linear current regulators in the system is the minimum voltage, the driving system efficiency is maximized. Finally, experimental results are presented to validate the effectiveness and correctness of the proposed system. According to the experimental results, the presented system can successfully drive the RGB LED backlight module, and the dimming and color-mixing function can be achieved using the developed HMI and driving system.

[1] C. C. Chen, C. Y. Wu, P. C. Lu, Y. M. Chen and T. F. Wu, “Sequential Color LED Back-Light Driving System for LCD Panels,” Proc. of IEEE Power Electronics and Motion Control Conference, Vol. 1, 14-16 Aug. 2006, pp.1-5.
[2] T. F. Wu, C. C. Chen, C. Y. Wu, P. C. Lu and Y. R. Chen “Sequential Color LED Backlight Driving System for LCD Panels with Area Control,” Proc. of IEEE Power Electronics Specialists Conference, 17-21 June 2007, pp. 2947 - 2952.
[3] C. C. Chen, C. Y. Wu and T. F. Wu “Fast Transition Current-Type Burst-Mode Dimming Control for the LED Back-Light Driving System of LCD TV,” Proc. of IEEE Power Electronics Specialists Conference, 18-22 June 2006, pp. 1 - 7.
[4] 何紹詩，「液晶顯示面板LED背光電路設計與實現」，中原大學電機工程研究所，民國九十五年六月。
[5] 朱之正，「適用於LCD TV之LED背光電源電路研製」，台灣科技大學電子工程系，民國95年。
[6] 周禎弘，「三色發光二極體背光模組之驅動與調光系統研製」，台灣科技大學電機工程系，民國97年。
[7] S. Muthu, F. J. Schuurmans and M. D. Pashley, “Red, Green, and Blue LED Based White Light Generation - Issues and Control,” Proc. of IEEE Industry Applications Conference, Vol. 1, 13-18 Oct. 2002, pp. 327 - 333.
[8] S. Muthu and J. Gaines, “Red, Green and Blue LED-Based White Light Source: Implementation Challenges and Control Design,” Proc. of IEEE Industry Applications Conference, Vol.1, 12-16 Oct. 2003, pp. 515 - 522.
[9] X. Qu, S. C. Wong and C. K. Tse, “Color Control System for RGB LED Light Sources Using Junction Temperature Measurement,” Proc. of Industrial Electronics Conference, 5-8 Nov. 2007, pp. 1363 - 1368.
[10] S.Y. Tseng and S.C. Lin, “LED Backlight Power System with Auto-tuning Regulation Voltage for LCD Panels,” Proc. of IEEE Applied Power Electronics Conference, 24-28 Feb. 2008, pp. 551 - 557.
[11] M. Doshi and R. Zane, “Digital Architecture for Driving Large LED Arrays with Dynamic Bus Voltage Regulation and Phase Shifted PWM,” Proc. of IEEE Applied Power Electronics Conference, Feb. 25 - Mar. 1 2007, pp. 287 - 293.
[12] Y. Hu and M.M. Jovanovic, “LED Driver with Self-Adaptive Drive Voltage,” IEEE Transactions on Power Electronics, Issue 6, Vol. 23, Nov. 2008, pp. 3116 - 3125.
[13] 田民波，「TFT液晶顯示器原理與技術」，五南圖書出版公司，2008年。
[14] 呂柏璋，「LCD 面板之LED背光燈色序法與區域控制驅動系統」，國立中正大學電機工程系，民國九十六年七月
[15] D. Maksimovic and S. CUK, “A Unified Analysis of PWM Converters in Discontinuous Modes,” IEEE Transactions on Power Electronics, Vol.6, No. 3, July 1991, pp. 476-790.
[16] R. W. Erickson and D. Maksimovic, “Fundamentals of Power Electronics Second Edition,” SCI-TECH Publishing Co. Ltd
[17] B. Shaffer, “Interleaving Contributes Unique Benefits to Forward and Flyback Converters” Texas Instruments Power Supply Design Seminar, 2005, Topic 4, SEM 1600.
[18] P.L. Wong, “Performance Improvements of Multi-channel Inter- leaving Voltage Regulator Modules with Integrated Coupling Inductors,” Ph.D. Dissertation, Virginia Polytech. Insit. State Univ., Mar. 2001.
[19] L. H. Dixon, “Average Current Mode Control of Switching Power Supplies,” Unitrode Application Note, U-140, pp. 356-369.
[20] C. Adragna, “L6561, Enhanced Transition Mode Power Factor Corrector,” ST Application Note, AN966.
[21] Texas Instruments, “Two Phase Interleaved CCM (Average Current Mode) PFC Controller,” Data Sheet, Preliminary, Oct. 2007.
[22] M. ’Loughlin, “An Interleaved PFC Pre-regulator for High Power Converters,” Texas Instruments Application Note, Topic 5, pp. 1-14.
[23] A.I. Pressman, “Switching Power Supply Design,” Second Edition, McGraw-Hill Company, 1998.
[24] Microchip Tech, “dsPIC30F1010/202x,” Data Sheet, Preliminary, 2006.
[25] 賴文能、林國祥、高志暐，「數位信號處理」第三版，高立圖書有限公司，2007年。
[26] Momentum Data System, Inc.,” Digital Filter Design and Analysis System for use with Microchip Technology dsPIC Microcontrollers,” Application note, 2002.
[27] Microchip Tech, “dsPIC30F Family Reference Manual,” Data Sheet, Preliminary, 2006.
[28] 劉金琨，「先進PID控制MATLAB仿真」第二版，電子工業出版社，2007年。
[29] 鄭群星，「FPGA/CPLD數位晶片設計入門使用XILINX ISE發展系統」，全華圖書2007年。
[30] 陳慶逸、林柏辰，「VHDL 數位電路實習與專題設計」，文魁資訊股份有限公司，2003年。