| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical film having high retardation expressibility, superior inverse wavelength dispersibility, and low haze, and to provide a circularly polarizing plate having the same, and an image display device with little contrast irregularity.SOLUTION: An optical film contains a cellulose-ester having an average total acyl substitution degree of 2.00-2.60 and a wavelength dispersion modifier. The wavelength dispersion modifier is a compound having a melting point, as measured with a differential scanning calorimeter, in a range of 50 to 180°C and having either a cooling crystallization temperature of no more than 130°C or no observable crystallization exothermic peak. An angle between an in-plane slow axis of the optical film and a conveying direction of the optical film is in a range of 40 to 50°. An in-plane retardation value at a specific wavelength and wavelength dependency thereof satisfy predefined conditions. |
