Analysis of Drop Mura in Fringe Field Switching Liquid Crystal Display

As one of the most frequent Mura defect in Fringe-Field Switching Liquid Crystal Display (FFS LCD), the liquid crystal (LC) drop Mura was analyzed in this paper. Three aspects were investigated: rubbing process, polyimide layer, rubbing cloth. It's confirmed that Drop Mura is caused by the weaker anchoring of polyimide (PI) alignment to LC molecule. Provably, three approaches are feasible to improve Drop Mura: 1. increasing rubbing pressure, 2. densifying or reinforcing the fibres of rubbing cloth, 3. tuning the composition of PI to obtain largish pretilt angle.