Multi-domain vertical alignment liquid crystal displays with ink-jet printed protrusions

For the fabrication of protrusions in multi-domain vertical alignment liquid crystal displays (MVA-LCDs), a series of complicated and expensive photolithographic processes has to be gone through for the wide viewing angles. In this research, we proposed and demonstrated a new manufacturing approach of the protrusion utilising ink-jet printing technology. Parallel lines were ink-jet printed on the substrates and solidified by a subsequent baking process, and then used as the protrusions of MVA-LCDs. The geometric dimensions of the protrusion patterns were optimised by the comparison of experimental observations and computer simulation results. The MVA-LCD cell was fabricated by arranging the protrusion lines forming right angles between the top and the bottom lines, which resulted in cross-line protrusions. Due to the square-shaped geometric arrangement of the protrusions, the vertically aligned LCs formed the symmetric four-domains in the MVA-LCD cell. With the help of a surface polymer-stabilisation technique, the response time of the LC molecules under the electric field was significantly improved. Therefore, we can conclude that, without sacrificing the viewing angle and response time of MVA-LCD, the printing technique for the formation of the protrusions can give us a new fabrication opportunity with low cost in contrast to the conventional photolithography process.