Patent ID: 8512825

Claim:
An optical film comprising: a copolymer of a (meth)acrylate derivative and maleimide; and an aromatic based resin including 5 to 5,000 phenoxy based units that are represented by the following Formula 6: wherein: (A) the in-plane retardation R in according to the following Equation is in the range of 30 to 80 nm and the thickness retardation R th according to the following Equation is in the range of 100 to 250 nm: R in =( n x −n y )× d, R th =[( n x +n y )/2 −n z ]×d wherein: (1) n x is the largest refractive index among in-plane refractive indexes of the optical film; (2) n y is the refractive index in a direction that is vertical to n x of the in-plane refractive index of the optical film; and (3) n z is the thickness refractive index of the optical film; and (B) the aromatic based resin includes a phenoxy based resin including the phenoxy based units that are represented by the Formula 6; (C) the content of maleimide in the copolymer of (meth)acrylate derivative and maleimide is in the range of about 1% by weight to about 50% by weight; and (D) the content of the copolymer of the (meth)acrylate derivative and maleimide is in the range of about 40% by weight to about 99% by weight, and the content of the aromatic based resin is in the range of about 1% by weight to about 60% by weight.