| 摘要 |
PROBLEM TO BE SOLVED: To provide a retardation film with excellent axis accuracy, with smaller phase difference change and dimensional change at heating, and having a slow axis in an oblique direction.SOLUTION: A retardation film is long-sized and has a slow axis in a direction at a certain angle to a longer direction. An absolute value of a change rate of an in-plane phase difference is 4.1% or lower. In one embodiment, the in-plane phase difference satisfies a relation of Re(450)<Re(550)<Re(650). Here, Re(λ) denotes an in-plane phase difference of the film measured with light of a wavelength λnm at 23°C. |
