有機發光二極體面板電壓降之數學模型建立與補償

Abstract

近年來有機發光二極體(Organic light emitting diode；OLED)已成為國內外非常熱門之新興平面顯示器產業，其受到青睞的原因為具有主動發光、高應答速度特性、省電、輕薄、廣視角、低操作電壓、面板輕薄等優點外，另有製程簡單低成本、可應用於可繞式面板等特色，號稱為最理想的顯示器。然而，元件壽命不足以及面板之電壓降效應導致目前此新興顯示器至今仍然無法投入大量生產。隨著時代的進步，大尺寸、高解析度的顯示器逐漸成為現今主流，相對地，如此裝置也需較大的面板及較多的像素，面板導線長度將越來越長，導線寄生電阻也越大，使得每一個畫素所獲得之電源供給分布不均，進而造成面板各像素的亮度失真。不同導線的材質、網目結構亦使電源供給在導線上有著不同的電壓降。導線的電阻值使得每一個Pixel 電路獲得的電源不同，而使得每一個不同的Pixel在相同的Vdata輸入下，有不同的電流、亮度輸出，而導致亮度不均勻。本論文將提出一個非線性數學模型來模擬有機發光二極體面板之電壓降，利用迭代解析來求解此非線性方程，以達到估測面板電壓降的目標，並利用此模型發展出一個亮度補償演算法來補償面板之不均勻度現象，最後透過LTPS-ELA TFT backplane之full- HD AMOLED面板進行模擬結果之驗證，其中面板電壓降的估測精確度平均值高達99%以上，補償後面板均勻度平均提升約26.7%。

An active matrix organic light-emitting diode (AMOLED) display is expected to be a leading display due to its high brightness, high efficiency, wide viewing angle, simple structure and low cost. However, emission non-uniformity over the display is a problem that has to be solved before commercialization. For a large-sized and high-resolution display, an AMOLED display has to be formed by a number of pixels in a larger-size panel. The IR-drop on the large-size and high-resolution display panel becomes a very serious problem, which now hinder the commercialization of the large-sized AMOLED displays, like TVs. The thesis work presents a study to establish a mathematical model for simulating IR-drop of an AMOLED display. By using the iteration analysis, the non-linear system of IR-drop on the panel can be solved. Furthermore, a luminance compensation algorithm which applies the model is presented, which is used to compensation the non-uniformity of the AMOLED. Finally, to verify the model by an AMOLED panel with LTPS ELA process TFT backplane, the average error of IR-drop estimation is less than 1% and the uniformity with compensation is raised about 26.3% in average.