| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical film having excellent phase difference compensation performance and visual field angle expansion function, and its production method by precisely controlling the orientation angle of the optical film having a substantially perpendicular or substantially parallel orientation axis in the longitudinal direction to not larger than a predetermined value to be required about the optical film equipped with a phase difference function and the visual field angle expansion function used for a liquid crystal display device (LCD) or the like. SOLUTION: In the method for producing the optical film using a stretching apparatus which carries out the resin film and performs the stretching while applying tension in a transverse direction by holding both the right and left sides of a continuous resinous film, the stretching is performed so that an optical delay phase axis is substantially perpendicular (the average value is within 90°±1.5°) or substantially parallel (the average value is within 0°±1.5°) to the film conveying direction by independently controlling right and left edge holding length of the film (distance between an initiation position and a cessation position) by the right and left holding means of the stretching device. COPYRIGHT: (C)2006,JPO&NCIPI |
