Research And Analysis Of Image Quality Improvement For TFT-LCD

The Image quality improvement is generally the main mission of Quality Management of the manufacturers of TFT-LCD (Thin Film Transistor - Liquid Crystal Display) panel. However, besides Bright Pixel, Dim Pixel and Bright Line, all kinds of defects are the main factors to effect the image quality. So it is very important to improve the image quality by reducing these defects in fact.The paper mainly focuses on three factors that is Vertical Block Mura,Greenish Block Mura and Contrast Ratio to research, which depends image quality, to study and improve image quality throughout phenomenon inspection, performance analysis, process tendency, mechanism analysis and so on. Finally a solution would be suggested to increase yield and improve image quality.Applied researches and improving methods are as follows:1) Asymmetry of peripheral capacity of pixel causes Vertical Block Mura, which is the main reason of the defect. The defect could be avoided by improving capacity design of parasitic and coupling in array.2) Low thickness of Green sub-pixel in CF that makes CIE coordinate shift causes Greenish Block Mura. The analysis shows that the defect is caused by instability of process capacity in despite that data of CF pixel thickness all fall into spec. So it is necessary to renew the spec range to solve the problem.3) Contrast Ratio can be increased up 100:1 by advisable modification in TFT-LCD design,process parameter and raw materials under the base of analysis and comparable experiments.The analysis in experiments and problem-solving ideas above lay the foundations of improvement of TFT-LCD image quality in the future. The analysis and its reseach in this paper have a very important referenced value of improving image quality and increasing yield in the TFT-LCD productions.