Abstract
In recent years, the domestic industries of flat panel liquid crystal display have grown up rapidly, and were able to compete with other industries of the world. The defects of flat panel liquid crystal display were usually un-uniform, and the defects were called as “Mura”. There were many factors to cause Mura phenomenon. At present, the seriousness of Mura was defined by human eyes, and different operators defined the same Mura phenomenon with different meanings. For this reason, there have been many conflicts between the suppliers of flat panel liquid crystal display and customers. In order to solve conflicts between supplier and customers, some researchers proposed a regression equation of luminance contrast threshold and size of Mura. However, only discussing relationship between Mura size and luminance contrast threshold was not enough to define the seriousness of Mura. In addition to the effect of Mura size on luminance contrast threshold, this study investigated the relationship between other factors and luminance contrast threshold. These factors were detection gray backgrounds, lengths of weak line, Mura position, and full screen (Red, Green, Blue) respectively. Analysis of results showed that Mura size, Mura position, and different color backgrounds significantly affected visual contrast threshold. However, polarity did not significantly affect visual contrast threshold. In this study, it was found that Mura size was more important than other factors for visual contrast threshold. Therefore, this study applied the experimental data to develop regression equations of Mura size and visual contrast threshold under different Mura positions. The results of this study were expected to be references for inspection of LCD industries.