Patent ID: 8227053

Claim:
An optically-compensatory film comprising: a cyclic polyolefin film satisfying expression (I); and a cellulose acylate film satisfying expressions (II) and (III): 35 ≦Re (630) ≦350 and 70 ≦Rth (630) ≦400, (I) 0 ≦Re (630) ≦10 and | Rth (630) |≦25, and (II) | Re (400) −Re (700) |≦10 and | Rth (400) −Rth (700) |≦35, (III) wherein Re(λ) represents an in-plane retardation value (unit: nm) at a wavelength of λ nm; and Rth(λ) represents a thickness-direction retardation value (unit: nm) at a wavelength of λ nm; wherein the cellulose acylate film contains at least one compound for lowering the thickness-direction retardation Rth in a range satisfying expressions (IV) and (V), ( Rth ( A )− Rth (0))/ A≦− 1.0, and (IV) 0.01 ≦A≦ 30, (V) wherein Rth(A) represents Rth (nm) of a film containing a compound for lowering Rth at A%; Rth(0) represents Rth (nm) of a film which does not contain any compound for lowering Rth (nm); and A represents a mass (%) of a compound for lowering Rth when a mass of the polymer as a material for the film is 100; wherein the at least one compound for lowering Rth is represented by formula (1) or formula (2): wherein in formula (1), R 1 represents an alkyl group or an aryl group, and R 2 and R 3 each independently represents a hydrogen atom, an alkyl group or an aryl group; wherein in formula (2), R 31 represents an alkyl group or an aryl group, and R 32 and R 33 each independently represents a hydrogen atom, an alkyl group or an aryl group.