OPTICAL RETARDATION FILM, METHOD FOR MANUFACTURING THE SAME, AND ELLIPTICALLY POLARIZING PLATE

摘要

PROBLEM TO BE SOLVED: To provide a method for manufacturing an optical retardation film having a lag axis which is parallel to a lateral direction perpendicular to a lengthwise direction of the film and extends almost over a full film width, having positive chromatic dispersion characteristics and having respectively uniform retardation in an in-plane direction and in a thickness direction and a direction of the lag axis and to provide an elliptically polarizing plate having a dark field without any unevenness and being excellent in productivity. SOLUTION: The method for manufacturing the optical retardation film is characterized by stretching a web removed from a metal supporting body in the lateral direction (a width direction) keeping temperature of edge parts of the web higher than that of a central part by 1-30 deg.C in film forming the cellulose ester film with a solution casting film forming method.