摘要 |
An optical film is provided and has retardations satisfying relations (1) to (3): <?in-line-formulae description="In-line Formulae" end="lead"?>0<=Re(550)<=10; (1) <?in-line-formulae description="In-line Formulae" end="tail"?> <?in-line-formulae description="In-line Formulae" end="lead"?>-25<=Rth(550)<=25; and (2) <?in-line-formulae description="In-line Formulae" end="tail"?> <?in-line-formulae description="In-line Formulae" end="lead"?>|I|+|II|+|III|+|IV|>0.5 (nm), (3) <?in-line-formulae description="In-line Formulae" end="tail"?> with definitions: <?in-line-formulae description="In-line Formulae" end="lead"?>I=Re(450)-Re(550); <?in-line-formulae description="In-line Formulae" end="tail"?> <?in-line-formulae description="In-line Formulae" end="lead"?>II=Re(650)-Re(550); <?in-line-formulae description="In-line Formulae" end="tail"?> <?in-line-formulae description="In-line Formulae" end="lead"?>III=Rth(450)-Rth(550); and <?in-line-formulae description="In-line Formulae" end="tail"?> <?in-line-formulae description="In-line Formulae" end="lead"?>IV=Rth(650)-Rth(550), <?in-line-formulae description="In-line Formulae" end="tail"?> 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. |