Method for producing a birefringent optical film, the film obtained by the manufacturing method, a liquid crystal display device using an elliptically polarizing plate and those using the same

摘要

PROBLEM TO BE SOLVED: To provide a method for manufacturing a birefringent optical film with the improvement of an in-plane phase difference value Δnd, a phase difference value Rth in the thickness direction and an optical axis precision.;SOLUTION: This method for manufacturing a birefrigent optical film is to impart an optical anisotropy to the film by stretching a filmy coating film 6 when the film is formed by applying a film forming material solution and forming the filmy coating film and removing a solvent contained in the coating film by evaporation. For example, the film forming material solution is applied from an application die 5 onto a polymer film base material 4, to which a minimum required tension for conveying it in the arrow direction, is applied between two nip rolls 2 and 3, and thus the filmy coating film 6 is formed. In an oven 7, the birefringent optical film 8 can be obtained by heating the filmy coating film 6 at a glass transition temperature or higher and the melting point or lower of the polymer film base material 4 and drying/stretching the coating film 6 in the longitudinal direction.;COPYRIGHT: (C)2004,JPO&NCIPI