運用光學檢測系統於PLED瑕疵檢測之設計

Abstract

高分子有機發光二極體（Polymer Light Emitting Display，PLED）其具製程簡單、自發性不需背光光源、高對比、高亮度、高發光效率、低視角限制、高反應速度以及可全彩化等優點。然而，在實際量產方面，由於製程技術面臨瓶頸，加上發展時間尚短造成PLED成品上有許多瑕疵，例如：暗點、亮度不均勻、色度不均勻、封膠寬度不足等缺陷。目前製造商以人工目視檢測成品上的瑕疵，但是人工目視有許多缺點，例如：人眼容易產生疲勞、檢測容易產生誤判導致正確率偏低，如此在產品的品管控制上較不穩定。 本研究首先使用色彩分析儀實際量測PLED面板的亮度與色度，來驗證光電耦合元件（CCD）除了在價格、速度上具有優勢外，拍攝後進行影像處理分析結果與色彩分析儀在色彩與亮度上具有相似的分佈趨勢，為可靠的檢測取像工具。其次，開發光學檢測演算法，進行成品PLED瑕疵檢驗，特別針對在過去相關的成品PLED檢測研究[15，16]中，改良亮度不均勻與封膠寬度瑕疵項目的檢測演算法，並且加入PLED色度不均勻瑕疵檢測項目，期望能提供製造商一套快速、穩定、準確的檢測系統。

Polymer light emitting diode (PLED) is generally stacked up by different kinds of materials of layers including PF layer, metal layer, and Indium Tin Oxide (ITO) layer. PLED panels can electrify themselves without any backlight system or lighting source. One advantage of using PLED panels is that people can see the text on panels from almost any angle of view. However, because of chemical reactions and materials, there are some kinds of defects occurred on panels such as non-uniformity of luminance, lack of chromaticity, and irregular rubber width. One efficient way to detect the defects of PLED panels is the AOI system, which is used to inspect the image of defects on the panels. Our research can be described in two parts. First, in order to compare the efficiency of colorimeter and CCD, we analyzed the results of measurement by using both of them. Second, we designed a set of hardware structure and algorithms for detecting the defect of non-uniformity luminance, lack of chromaticity, and irregular rubber width. We also verified the effectiveness of the proposed methods with several samples and experiments. Experimentation results showed that proposed AOI system has a good performance in PLED panel.