Liquid crystal display device

摘要

A liquid crystal display device containing a liquid crystal cell and at least one reflective polarizer or a polarizer combination having at least one reflective polarizer as a means to generate circular polarized light. The reflective polarizer includes an optically active layer of an anisotropic polymer material with a helically twisted planar molecular orientation. The material is oriented so that the axis of the molecular helix extends transversely to the layer, and the pitch of the molecular helix is varied in such a manner that the difference between the maximum pitch and the minimum pitch is at least 100 nm. The reflective polarizer is obtainable by copolymerization of a mixture of a chiral polymerizable mesogenic material including a) at least one achiral polymerizable mesogenic compound having at least one polymerizable functional group in the presence of b) at least one chiral polymerizable mesogenic compound having one polymerizable functional group and/or at least one non-polymerizable chiral mesogenic compound, c) an initiator, d) optionally a non-mesogenic compound having at least one polymerizable functional group, e) optionally a dye and, f) optionally a stabilizer. The invention also discloses methods of manufacturing such a reflective polarizer. The invention further discloses a mixture of a chiral polymerizable mesogenic material used for manufacturing such a reflective polarizer.