Color Space Based Uniformity Analysis for Flexible Displays-A Case Study on Cholesteric Liquid Crystal Displays

• Main Authors: Cing-Jhong Siao, 蕭清中
• Other Authors: Yi-Hung Liu
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/72104173015701110898

碩士 === 中原大學 === 機械工程研究所 === 97 === The Bistable Cholesteric liquid crystal display (BS-ChLCD) is the innovative technology of display of flexible panel, having the advantages of high-brightness, of high-contrast, of energy-efficiency, of memory ability, of broad visual angle, of non-glittery functions, and in the future it can be exercised widely on out-door huge advertisement signboards as well as portable products. During the manufacturing process of the panel and commercialization, quantitative production, it will be inevitable that the BS-ChLCD have defects generated from human or machines, and which will certainly damage the performance of the panel. Nowadays it is not extremely definite to explain the relationships between malfunction modes of varied panels and manufacturing process designs, so this thesis aims at the BS-ChLCD to develop a set of image- analyzing and inspection system of color uniformity, which will have a significant contribution. The effective analysis will assist factory owners to accelerate research and development during the manufacturing process and lower the cost of research and development. In addition, the image of the panel is obtained from a high resolution scanner. The analysis system consists of three parts: at the first stage, firstly, the image of the panel was divided into several small portions; next, at the second stage, several small portions of the image are combined with color space provided by Commission internationale de l'éclairage (CIE). The image of the panel, RGB color information, was transferred into CIE 1976 UCS chromaticity chart and into CIE 1976 color space, which creates the value of color quantity to chromaticity, to brightness and to color difference. Finally, according to the principle of statistics, this thesis calculated the standard deviation of chromaticity and brightness, and the standard deviation is viewed as the index to judge color uniformity. The result of the experiment demonstrates that quantitative index above can effectively reflect the presence of the defect of the image on the panel and its damage degree. Moreover, the value of the chromaticity from inspection system can be used to speculate the cause of the defect.