Abstract: An optical film having a desired wavelength dispersion characteristic, a low photoelastic coefficient and a desired Nz coefficient. The optical film is formed from a copolymer and meets the following conditions (i) to (v): (i) the thickness (d) is 20 to 80 ?m; (ii) the following formulas (1) and (2) are satisfied: 0.6<R(450)/R(550)<1??(1) 1.01<R(650)/R(550)<1.40??(2) (R(450), R(550) and R(650) are retardations within the plane of the film at respective wavelengths); (iii) R(550) is 120 to 160 nm; (iv) the birefringence (?n) is not less than 1.5×10?3; and (v) the Nz coefficient represented by the following formula (4) is 1.18 to 2.40: Nz=(nx?nz)/(nx?ny)??(4) (nx, ny and nz are 3-dimensional birefringences of the film).

Abstract: An optical film having a desired wavelength dispersion characteristic, a low photoelastic coefficient and a desired Nz coefficient. The optical film is formed from a copolymer and meets the following conditions (i) to (v): (i) the thickness (d) is 20 to 80 ?m; (ii) the following formulas (1) and (2) are satisfied: 0.6<R(450)/R(550)<1??(1) 1.01<R(650)/R(550)<1.40??(2) (R(450), R(550) and R(650) are retardations within the plane of the film at respective wavelengths); (iii) R(550) is 120 to 160 nm; (iv) the birefringence (?n) is not less than 1.5×10?3; and (v) the Nz coefficient represented by the following formula (4) is 1.18 to 2.40: Nz=(nx?nz)/(nx?ny)??(4) (nx, ny and nz are 3-dimensional birefringences of the film).

Abstract: An optical film comprising a copolycarbonate composed of 25 to 90 mol % of unit (A) of the following formula, and 10 to 75 mol % of unit (B) of the following formula, wherein the substituents are defined herein, and the optical film satisfies the following expression (1), R(450)<R(550)<R(650) (1), wherein R(450), R(550) and R(650) are in-plane retardation values of the film at wavelengths of 450 nm, 550 nm and 650 nm. The optical film exhibits a desired chromatic dispersion, low photoelasticity and excellent melt processability.

Abstract: An optical film comprising a copolycarbonate composed of 25 to 90 mol % of unit (A) of the following formula, and 10 to 75 mol % of unit (B) of the following formula, wherein the substituents are defined herein, and the optical film satisfies the following expression (1), R(450)<R(550)<R(650) (1), wherein R(450), R(550) and R(650) are in-plane retardation values of the film at wavelengths of 450 nm, 550 nm and 650 nm. The optical film exhibits a desired chromatic dispersion, low photoelasticity and excellent melt processability.

Abstract: An optical film comprising a copolycarbonate composed of 25 to 90 mol % of unit (A) of the following formula, and 10 to 75 mol % of unit (B) of the following formula, wherein the substituents are defined herein, and the optical film satisfies the following expression (1), R(450)<R(550)<R(650) (1), wherein R(450), R(550) and R(650) are in-plane retardation values of the film at wavelengths of 450 nm, 550 nm and 650 nm. The optical film exhibits a desired chromatic dispersion, low photoelasticity and excellent melt processability.

Abstract: An optical film having a desired wavelength dispersion characteristic, a low photoelastic coefficient and a desired Nz coefficient. The optical film is formed from a copolymer and meets the following conditions (i) to (v): (i) the thickness (d) is 20 to 80 ?m; (ii) the following formulas (1) and (2) are satisfied: 0.6<R(450)/R(550)<1??(1) 1.01<R(650)/R(550)<1.40??(2) (R(450), R(550) and R(650) are retardations within the plane of the film at respective wavelengths); (iii) R(550) is 120 to 160 nm; (iv) the birefringence (?n) is not less than 1.5×10?3; and (v) the Nz coefficient represented by the following formula (4) is 1.18 to 2.40: Nz=(nx?nz)/(nx?ny)??(4) (nx, ny and nz are 3-dimensional birefringences of the film).

Abstract: The object of this invention is to provide an optical film formed of a copolycarbonate having a desired chromatic dispersion and low photoelasticity and having excellent melt processability.