針對影像內容動態調整液晶顯示器背光電源之節能架構設計

Abstract

隨著科技日益進步，任何電子產品的需求都是需要低成本及機構上輕、薄的設計條件，同時也需要一個很好的人機溝通介面，液晶顯示器擔任了一個在電子產品發展過程中很重要的角色；所以在最近幾年，隨著智能型手機普遍率快速成長，也帶動了中小型尺寸的液晶顯示器的成長，也隨著晶片的小型化，也發展了更多各式各樣的配有液晶顯示器的可攜式電池產品；人類對產品外觀的要求及使用機構的友善條件更加限制了產品尺寸，所以在產品尺寸固定及電池容量固定的條件下，對待機時間要求日益嚴苛的條件下，所以節能環保就是一個很重要的議題。 因為TFT液晶顯示器本身無法自行發光，需要靠背光模組光源經過液晶的折射並穿過彩色濾光片才能讓影像的色彩呈現出來，而整個液晶顯示器模組最耗電的就是背光模組，所以本文會先就液晶顯示器及背光模組架構介紹。 本論文研究方法是透過影像內容分析回饋調整成新影像及PWM背光電源調整，來減少背光模組的功耗，又該如何調整新影像且使其不失畫面顯示的品質。所以本文兩大研究重點是在整體顯示亮度不變下的狀況達到節能要求及盡量不影響因亮度改變後調整的新影像品質，兩者兼顧下的方式研究探討。因為受限於硬體驗證平台的效能，所以先以概念式方法透過電腦端軟體發展方式對影像像素灰階的分析及統計，求得畫面的灰階平均值，再進一步經過影像回饋實現方法求得影像調整依據的Compensation gain調整成新影像後，雖然經過調整後的影像灰階會偏高，不過再藉由PWM Duty方式調整背光模組亮度來達到整體顯示亮度不變及節能的最終要求，最後再使用C8051F130硬體驗證平台來實際驗證實現方法的效能表現。

Along with the technology advancement now-a-days, low-cost and handy design are the main criteria for an outstanding electronic product. To be more interactive – LCD display plays as an important role in the electronic product development process. In recent years, the rapid growth of smart phones leads to the growth of small and medium-sized liquid crystal display (LCD). At the meantime, the IC miniaturization also speeds up developments of various portable battery products with LCD displays. Customers more focus on appearance of the product and user-friendly interface software, and limited product size as well. Under the size limitation and the demanding in the battery capacity, the increasingly stringent requirements of stand-by time conditions and therefore energy-saving and environmental protection will be a critical topic in this area. TFT LCD does not emit light directly. It needs back light to produce a visible image. The back light module is the most power consumption part of the LCD. T his thesis composed of two parts. The LCD display will be addressed in the first part and second part focuses on the back light module structure and its work.ind principle. In this thesis, we will analyze the image first and the PWM backlight power will be adjusted accordingly to reduce the power consumption of the background light module. To this end, we will create a new image by adjusting its screen display without losing the image’s quality. In this thesis, we will achieve energy saving with the overall display brightness unchanged. First, Sine limitation of hardware verification platform, image pixel grayscales are analyzed through the PC client software to obtain the grayscale average for the screen. Through a visual feedback method, we can obtain the new image based on "Compensation Gain" adjustment by adjusting its PWM duty cycle. In order to achieve the overall brightness of the display unchanged and energy-saving, we have applied hardware verification platform“C8051F130"to verify the performance of our method.