微型投影機中可作為RGB白平衡調校與LED功率消耗控制之控制器設計

A Controller Design for RGB White Balance and LED Power Consumption in Pico Projector

謝志福(Chih-Fuh Shieh)

指導教授 ： 彭先覺

國立虎尾科技大學/電機資訊學院/電機工程研究所/碩士(2010年)

摘要

進入21世紀後，無線通訊基礎設施的日漸完備及隨著無線通訊科技的快速進步，各種電子產品開始著重「移動、攜帶」功能，但是目前熱門產品中的行動電話、可攜式媒體播放機、數位相機等這類輕薄短小的可攜式設備，其螢幕的尺寸過小因而限制多媒體的互動性，故使得微型投影機應運而起。發光二極體是投影機的光源，由於目前發光二極體製程的品質不一導致存在亮度不均與溫度變異的問題，若採用單一功率消耗控制與篩選發光二極體等方法來解決上述問題，將花費更長的時間才能精確達到白平衡目標。本研究旨在探討發光二極體配合比例-積分-微分控制器為基礎之色座標控制器與功率消耗控制器，以求同時達到白平衡的目標與功率消耗調校的要求。本研究以Simulink模擬比例-積分-微分控制器分別控制紅、綠和藍色發光二極體，其中控制器配合脈波寬度調變法調節回饋訊號使得發光二極體可以達到白平衡的目標與功率消耗調校的要求。進而應用微控制器建構硬體電路原型以驗證本研究所提方法的可行性，系統模擬與實驗結果均顯示本研究可以快速達成白平衡的目標與功耗消耗調校的要求。

關鍵字

紅藍綠發光二極體 ； 微型投影機 ； 白平衡 ； 比例-積分-微分控制器

並列摘要

Since 21st century, due to the rapid progress of wireless communication, many electronic products are considered to be portable. However, the main concern for all those kinds of electronic products is their screen. Because the LCD screen size is too small for limiting the interaction with multimedia. Thus, the application of pico projector is rapidly grossing to solve the this problem. As there is a difference in luminous efficiency within red, green and blue light-emitting diodes (LEDs), the main object of this research is to pay more attention on power consumption and duty cycle in order to maintain white balance and luminous efficiency because red, blue and green light emitting diodes and power consumption affect the characteristic of the chrominance coordinate. The controller based on Proportional-Integral-Derivative (PID) configuration is proposed for power consumption and white balance of red, green and blue light-emitting diodes (LEDs). In this study, pulse width modulation (PWM) and feedback signals are respectively obtained by Simulink. The controller is implemented on the freescale microcontroller to verify the effectiveness of the proposed method. The microcontroller also generates the necessary pulse width modulation (PWM) control signals to achieve the regulation of the white balance of three light emitting diodes (LEDs) and to adjust power consumption of target. Besides, the hardware circuits built with presented in the proposed method are constructed so that users can quickly and easily achieve the goal of white balance adjustment with prespecified power consumption.

並列關鍵字

RGB LED ； Pico projector ； White balance ； PID controller

參考文獻

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