| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical film which, when used with a circularly polarizing plate, generates retardation of substantially λ/4 on light in a wide band of visible light wavelengths, suppresses variation in optical performance due to variation in degree of substitution of a phenyl carbamoyl group or benzoyl group, and functions also as a polarizing plate protection film, and to provide a circularly polarizing plate and an organic EL display device.SOLUTION: An optical film of the present invention is made of a cellulose ester (C) prepared by mixing a cellulose ester (A) and a cellulose ester (B) having a phenyl carbamoyl group or benzoyl group introduced as some of substitution groups belonging to a glucose skeleton of the cellulose ester (A), where a substitution degree of the phenyl carbamoyl group or benzoyl group is within a range of 0.05-0.6 per glucose skeleton unit of the cellulose ester (C). The optical film satisfies conditions listed as (a) through (e).SELECTED DRAWING: Figure 5 |
