TRANSPARENT FILM AND OPTICAL COMPENSATORY FILM, POLARIZING PLATE AND LIQUID-CRYSTAL DISPLAY DEVICE EMPLOYING IT

摘要

A novel transparent film is disclosed. Re (lambda) and Rth (lambda) of the film defined by the following formulae (I) and (II) satisfy the following formulae (III) and (IV):(I) Re (lambda) = (nx - ny) x d,(II) Rth (lambda) = {(nx + ny)/2 - nz} x d, (III) <= 0 <= || Re (630) || <= 50, (IV) Rth (400) x Rth (700) <= 0, and <= 0 || Rth (700) - Rth (400) || <= 150,wherein Re (lambda) means an in-plane retardation value at a wavelength lambda nm (unit: nm); Rth (lambda) means a thickness-direction retardation value at a wavelength lambda nm (unit: nm); nx means a refractive index in the in-plane slow-axis direction; ny means a refractive index in the in-plane fast-axis direction; nz means a refractive index in the film thickness direction; and d means a thickness of the film.