| 摘要 |
Provided is an optical film that has a desired wavelength dispersion characteristic, a low photoelastic coefficient, and a desired Nz coefficient. This optical film is formed from a copolymer and meets conditions (i)-(v). (i) The thickness (d) is 20-80 µm. (ii) formulas (1) and (2) are fulfilled. (1) (2) (where R(450), R(550) and R(650) are the phase differences within the film surface for each wavelength.) (iii) R(550) is 120-160 nm. (iv) The birefringence (?n) is 1.5 × 10-3 or greater. (v) The Nz coefficient, expressed with formula (4), is 1.18-2.40. (4) (where nx, ny, and nz are respectively the three dimensional birefringences of the film.) |
