Patent ID: 7738064

Claim:
A method of manufacturing a retardation plate comprising the steps of: transporting and stretching in an identical direction to the transport direction a Material A to form a machine direction-stretched film, transporting and stretching in a perpendicular direction to the transport direction a Material B to form a transverse direction-stretched film, wherein the stretching in the identical direction to the transport direction of the Material A is simultaneous to the stretching in the perpendicular direction to the transport direction of the Material B, and laminating the machine direction-stretched film and the transverse direction-stretched film, wherein the Material A and B have different positive intrinsic double refraction values, and the retardation plate comprises: a laminate of at least the machine direction-stretched film and the transverse direction-stretched film having different intrinsic double refraction values, wherein the retardation plate satisfies the relation: Re (450)< Re (550)< Re (650), where Re(450), Re(550) and Re(650) are retardation values in wavelengths 450 nm, 550 nm and 650 nm, respectively.