LG Display Develops UV Aligned-N LCD For Smartphones
UV alignment is a technology to create a path for liquid placement using photo-induced polymerization monomer. Until now, IPS liquid crystal has been applied using a method to rub petroleum on the surface of a polymer film to cut a groove in a consistent direction, and thus to have liquid crystal aligned along the groove. The rubbing method is associated with such problems as static electricity or scratches formed on the film surface. Therefore, UV alignment that does not involve any physical friction drew attention. UV alignment minimizes light leakage, and thus produces high contrast ratio. In addition, the pre-tilt angle of liquid crystal is close to 0. Therefore, consistent display quality is achieved regardless of the viewing directions.
N type liquid crystal produces higher transmittance than the existing P-type (positive) liquid crystal, and thus can improve display brightness. N-type liquid crystal refers to a liquid crystal of which the difference in permittivity between major and minor axes is negative (-). When applied with voltage, N-type crystal display moves centering on the minor axis. Therefore, the area of light transmission becomes wider. It has been difficult to use N-type liquid crystal in IPS mode where liquid crystal moves horizontally when applied with voltage.