| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical film manufacturing method which allows for efficiently manufacturing an optically isotropic optical film while preventing meandering of the optical film and winding shifts of a film roll. ! SOLUTION: An optical film manufacturing method includes a relaxation step for obtaining an optically isotropic optical film by heat-treating an elongate resin film while conveying the same, in which two ends of the resin film in a width direction are supported by support fixtures that move in a conveying direction keeping contact with the two ends of the resin film and a central portion of the resin film in the width direction is lifted by a gas jet. The support fixtures follow dimensional change of the resin film due to heat by changing at least one of moving speed in the conveying direction and a pitch of the support fixtures in the width direction. Tension applied to the resin film in the conveying direction and heating temperature of the resin film are kept in predetermine |
