Abstract: An activating treatment method for an optical film includes feeding the optical film along a roll, and subjecting the optical film to the activating treatment from a side of the optical film that is opposite to a side of the optical film at which the roll is located. The activating treatment is conducted while the roll is cooled.

Abstract: The method of cleaning a coated sheet according to the present invention is characterized in that dry wind is brown along the traveling direction of a film onto the surface of a coating layer wherein the solid content and the viscosity of the coating solution are within specified ranges. By this method, the thickness precision of the coating film can be improved in its large area, and the evenness of its in-plane optically functional property can be made even therein. The speed of the dry wind, the temperature of the wind, and the thickness of the dried coating film are preferably within specified ranges. In particular, the coated sheet is very useful as an optical material having good properties in an optically functional layer which is frequently used as a large-area coated sheet, an optical device having such an optically functional layer, an optically compensating layer, or an optically compensating plate. The coated sheet is particularly effective for an image display on which they are mounted.

Abstract: The present invention relates to a method of drying a coating film, and its object is to produce a coating film with small variations in thickness with stability. Thus, in the method of drying a coating film 11 formed by application of a coating solution to a long-length substrate 10 which is traveling, the coating film 11 is dried immediately after the application of a coating solution to the long-length substrate 10, with an evaporation rate of a solvent kept at 0.1 g/m2 s or less. Preferably, on a travel path of the coating film 11 immediately after coating, a plate 20 should be provided with a predetermined air gap between itself and the coating film 11 thereby to control the evaporation rate of the coating solution.

Abstract: The method of cleaning a coated sheet according to the present invention is characterized in that dry wind is brown along the traveling direction of a film onto the surface of a coating layer wherein the solid content and the viscosity of the coating solution are within specified ranges. By this method, the thickness precision of the coating film can be improved in its large area, and the evenness of its in-plane optically functional property can be made even therein. The speed of the dry wind, the temperature of the wind, and the thickness of the dried coating film are preferably within specified ranges. In particular, the coated sheet is very useful as an optical material having good properties in an optically functional layer which is frequently used as a large-area coated sheet, an optical device having such an optically functional layer, an optically compensating layer, or an optically compensating plate. The coated sheet is particularly effective for an image display on which they are mounted.