Patent ID: 8174648

Claim:
A cellulose acylate film comprising a cellulose acylate satisfying relations (I)-(III): 2.0≦ A+B≦ 2.45, (I) 0.8 ≦A≦ 1.4, and (II) 0.6 ≦B≦ 1.65 (III) where “A” represents a degree of acetyl substitution of hydroxy in a glucose unit of cellulose acylate; and “B” represents a degree of with C 3 or longer acyl substitution of hydroxy in a glucose unit of cellulose acylate; and satisfying relations (IV)-(VI) 50 nm≦ Re (590)≦70 nm, (IV) 100 nm≦ Rth (590)≦120 nm, and (V) 1.4≦ Rth (590)/ Re (590)≦2.6 (VI) where, in relations (IV) and (VI), Re(λ) indicates retardation (unit: nm) in-plane for an incident light having a wavelength of λnm at 25 degrees Celsius and 60% RH; and in relations (V) and (VI), Rth(λ) indicates retardation (unit: nm) along the thickness direction for an incident light having a wavelength of λnm at 25 degrees Celsius and at 60% RH.