METHOD FOR PRODUCING PHASE-DIFFERENCE FILM AND METHOD FOR PRODUCING CIRCULARLY POLARIZING PLATE

摘要

Provided is a method by which a retardation film suppressed in biaxiality, having a small Nz coefficient, and having a slow axis in an oblique direction can be produced with high production efficiency. The production method for a retardation film of the present invention includes: holding left and right end portions of a film with left and right variable pitch-type clips configured to have clip pitches changing in a longitudinal direction, respectively; preheating the film; reducing, under a state in which the clip pitch of the clips on one side out of the left and right clips is kept constant, the clip pitch of the clips on another side to obliquely stretch the film; and releasing the film from being held with the clips.