OPTICAL FILM

摘要

An optical film having a transparent polymer film (b) and, laminated thereon, a birefringent layer (a) formed from a polymer, wherein the birefringent layer (a) and the transparent polymer film (b) satisfy the following formula (1): Deltan(a) > Deltan(b) x 10 , wherein the birefringent layer (a) satisfies the following formula (2) : 1 < (nx - nz)/ (nx - ny) and formula (3) : 0.0005 <= Deltan(a) <= 0.5, and wherein the polymer constituting the birefringent layer (a) has a weight average molecular weight in the range of 10,000 to 400,000. The optical film allows the suppression of the occurrence of rainbow unevenness, the occurrence of cracks and the occurrence of variations in phase difference.