标题: 应用于红,蓝,绿发光二极体色彩稳定之控制回馈系统设计
Light Output Feedback Control System Design for RGB LED Color Stabilization
作者: 李仕龙
Shih Lung Lee
郭浩中
李柏璁
Hao-chung Kuo
Po-Tsung Lee
显示科技研究所
关键字: 发光二极体;回馈系统;色彩稳定;Color Stabilization;light emitting diode;Feedback control;LED
公开日期: 2007
摘要: 显示科技蓬勃发展,液晶显示器(Liquid Crystal Display)已成为取代阴极射线管显示器(Cathode Ray Tube Monitor)最强大的主流产品,由于液晶显示器并非主动发光元件,必须仰赖一个外加的光源系统,此即所谓的背光模组,而背光模组使用冷阴极射线管(Cold Cathode Fluorescent Lamp)充当光源已行之有年;发光二极体(Light Emitting Diode)因较冷阴极射线管具有寿命长,广色域、省电、环保、反应快速等多项优点,已成为液晶显示器背光源的新选择。然而,长时间使用下而产生的热,往往造成发光二极体的发光颜色偏移,此在显示器要求高色彩品质的标准下,是最不乐见的。
  本论文提出了使用光二极体感测发光二极体的光输出讯号,经类比数位转换的装置,套用反覆逼近的程式,设计建立一组μA等级的电流逼近的发光二极体色彩稳定回馈系统。回馈系统在 13 位元解析下,可将对应于使用 3250, 3969, 及4462小时的红色,蓝色及绿色发光二极体的色偏值(Δu’v’)维持在内 0.005 (人眼恰可接受的范围) 内。使用 14 位元解析下,可将红,蓝及绿色发光二极体的色偏值维持在内 0.004 之内。
LCD (Liquid Crystal Display) is the mainstream product to replace CRT (Cathode Ray Tube). Conventionally, CCFL (Cold Cathode Fluorescent Lamp) is used as a light source of LCD backlight. However, LED (Light Emitting Diode) is regarded as the candidate to replace CCFL (Cold Cathode Fluorescent Lamp) as light source of LCD backlight due to its wide color gamut, low operation voltage, mercuryfree characteristic, and fast switch response. The color shift due to heat effect after long time usage is an issue needed to resolve. In this thesis, a 14 bits recursive feedback control system is proposed and realized to stabilize the light output of RGB (red, green, and blue) LEDs by generating tiny recursive current in μA order. Whereas the just noticeable color difference (Δu’v’) of human is 0.005, feedback control system is proved that color difference (Δu’v’) of Red, Green, and Blue LEDs are kept within 0.005 under 13 bits resolution, and within 0.004 under 14 bits under aging simulation of 3250, 3969, and 4462 hours usage, respectively.
URI: http://140.113.39.130/cdrfb3/record/nctu/#GT009415522
http://hdl.handle.net/11536/81048
显示于类别:Thesis


文件中的档案:

  1. 552201.pdf

If it is a zip file, please download the file and unzip it, then open index.html in a browser to view the full text content.