TWI599601B

The invention relates to an optical film manufacturing method and a manufacturing device. The manufacturing method for an optical film (F) includes a cutting step. In the cutting step, a first cutting part (8a) and a second cutting part (8b) respectively cut two end parts (Ta`Tb) of a long-sized tilting orientation film in the width direction. The part left from the cutting serves as the optical film (F). In the cutting step, in the first cutting part (8a) and the second cutting part (8b), relative to one side and the other side in the width direction of a lower blade (10b), an upper blade (10a) is tilted with respect to the direction in which the toe-in angle of the lower blade (10b) increases, and the upper blade (10a) is configured on the side whereby the angle [theta] between the surface (S) where the toe-in angle is formed and the orientation direction of the long-sized tilted orientation film (F) decreases. Cutting is conducted by clamping the long-sized tilted orientation film (F) with the lower blade