Patent ID: 7749411
Filing Date: 2010-07-06
Classification: B29C,B29D,B29K,C09K

Abstract:
1. A method of producing an optical film comprising the step of: stretching a continuous resinous film by apply tension to a transverse direction of the resinous film while conveying the resinous film, wherein the stretching is carried out with a stretching apparatus comprising right and left edge holding devices which hold right and left edges of the resinous film and move on a track; and the right and left edge holding devices of the stretching apparatus each independently controls right and left edge holding distances of the resinous film so that a slow axis of the resinous film is substantially perpendicular or substantially parallel to a film conveying direction, provided that the edge holding distance is defined as a distance between an initiation position and a cessation position of holding of the edge of the resinous film and wherein the right and left edge holding devices of the stretching apparatus each independently controls the initiation position of the right and left edges of the resinous film without changing the track so as to control the right and left edge holding distances of the resinous film.