| 摘要 |
PROBLEM TO BE SOLVED: To provide a cellulose ester film excellent in optical isotropy, particularly in optical isotropy in a direction of film thickness, and to provide a method for producing the cellulose ester film, a polarizing plate for a display device, and the display device.SOLUTION: A cellulose ester film has planar orientation degree S represented by a following formula (I) of 0.0004 or less, and has retardation Rt in a direction of film thickness of less than 10 nm. The formula (I) is S=(Nx+Ny)/2-Nz, Rt=((Nx+Ny)/2-Nz)*d. In this formula, Nx represents a refractive index in a slow axis direction in a cellulose ester film plane, Ny represents a refractive index in a film plane in a direction perpendicular to the slow axis direction, Nz represents a refractive index in a thickness direction of the film, and d represents film thickness (nm) of the cellulose ester film. |
