Patent ID: 8368859

Claim:
An optical film having retardations satisfying relations (1) to (3): 0 ≦Re(550)≦5 nm; (1) −15 ≦Rth(550)≦15 nm; and (2) |I|+|II|+|III|+|IV|>0.5 (nm), (3) with definitions: I =Re(450)−Re(550); II =Re(650)−Re(550); III =Rth(450)−Rth(550); and IV =Rth(650)−Rth(550), wherein Re(450), Re(550) and Re(650) are in-plane retardations measured with lights of wavelength of 450, 550 and 650 nm, respectively; and Rth(450), Rth(550) and Rth(650) are retardations in a thickness direction of the optical film, which are measured with lights of wavelength of 450, 550 and 650 nm, respectively, wherein I, II, III and IV satisfy relations (4-D) to (7-D): 0<I≦50; (4-D) −50≦II<0; (5-D) −50≦III≦0; and (6-D) 0≦IV≦50, (7-D) wherein a material for forming the optical film comprises an acrylic polymer, a styrenic polymer, a polyolefinic polymer, a norbornene resin or cellulose acylate.