Measurement of multiple JNDs for developing Mura ranking standard in LCD

量測多倍視覺差異對比閾值建立液晶顯示器不均勻現象之分級標準

蘇琬婷(HASH(0x1ad24ce0))

指導教授 ： 黃雪玲

國立清華大學/工學院/工業工程與工程管理學系/碩士(2008年)

摘要

At present, the domestic industries of flat panel liquid crystal display have grown up rapidly, and the quality of LCDs becomes more and more important when there are a lot of LCDs around our lives. A critical factor of LCD panel quality is“Mura”. It is the un-uniform phenomenon in LCD panels. Traditionally, the quality of LCD panels is detected by human eyes, but it is subjective without any common criterion. In the recent years, an automation Mura inspection system has been developed by TTLA (Taiwan TFT LCD Association), which can calculate the attributes of Mura defects quickly to make the inspection process efficient and to make the judgment consistently.

In addition, evaluating the ranks of Mura is always subjective, and serious disagreements and controversy may arise between LCD manufacturers and customers. There is lacking of Mura classification system in the present automation Mura inspection system. Although the serious degree of Mura defects was presented by JND values (Mura quality criterion), multiple JNDs in this vision model were defined as the comparison ratio of the Mura contrast (C) to the “one contrast threshold” according to SEMI (2002). However, some literatures reporting a non-linear relationship between contrast and multiple JNDs in human visual performance, so it is not uniformly to apply JND values in this vision model to establish the Mura rank standards from 1 to 3, 3 to 5……etc. Therefore, the experiment was designed in this research to obtain fitting functions of multiple JNDs for six typical Mura types.

From the experimental result, non-linear functions were obtained, and then, the transformed function was found to modify original vision model. Finally, Mura ranking standard and Mura classification system were developed to be a standard communication platform for customers and suppliers.

關鍵字

平面液晶顯示器 ； Mura ； 自動檢測系統 ； JND ； 多倍視覺差異對比閾値 ； 分級

並列摘要

無資料

並列關鍵字

LCD ； Mura ； automation Mura inspection system ； multiple JNDs ； Mura classification system ； HASH(0x1ad25ab0)

參考文獻

Aldridge, R., Davidoff, J., Ghanbari, M., Hands, D., & Pearsone, D. (1995). Measurement of scene-dependent quality variations in digitally coded television pictures. IEE Proc.-Vis. Image Signal Process, 142(3), 149-154.

Barten, P. G. J. (2003). Formula for the contrast sensitivity of the human eye. Paper presented at the Proceedings of the SPIE, 5294, 231-238.

Chirimuuta, M., & Tolhurst, D. J. (2005). Does a Bayesian model of V1 contrast coding offer a neurophysiological account of human contrast discrimination? Vision Research, 45, 2943–2959.

Dillon, A. (1992). Reading from paper versus screens: a critical review of the empirical literature. Ergonomics, 35 (10), 1297-1326.

Farell, B., & Pelli, D. G. (1999). Psychophysical methods, or how to measure a threshold and why. In Vision Research: A Practical Guide to Laboratory Methods. New York: Oxford University Press.