OPTICAL FILM PRODUCTION METHOD, OPTICAL FILM, POLARIZING PLATE, AND LIQUID CRYSTAL DISPLAY DEVICE

摘要

Provided are an optical film and production method thereof that are capable of sufficiently suppressing occurrences of image unevenness even when a high-definition liquid crystal display device is used. Specifically, provided is a production method of forming a thin optical film using a melt flow casting film forming method. Also provided are a polarizing plate and a liquid crystal display device equipped with the optical film. The method of producing the optical film comprises a flow step of extruding a melt including a thermoplastic resin from a flow die in a film shape onto the surface of a rotating support, and a compression step of compressing the film-shaped melt extruded in the flow step by introducing it into a compressing portion formed in a gap between the rotating support and a compression rotator, and the method producing the optical film is characterized in that deposits adhering to the compression rotator surface are removed by performing high energy irradiation during film formation in a melt non-contacting interval from immediately after compression by the compression rotator surface until when the compression rotator surface is once again contacted with the melt.