Patent ID: 7550182

Claim:
A polarizing plate comprising a polarizer and polarizing plate protective films A and B, each comprising a cellulose ester, provided on both surfaces of the polarizer, wherein: (i) a thickness of each of the polarizing plate protective films A and B is 30 to 60 μm; (ii) retardation value Ro of the polarizing plate protective film B is 20 to 100 nm; (iii) retardation value Rt of the polarizing plate protective film B is 10 to 300 nm; (iv) a thickness of the polarizing plate is 80 to 160 μm; (v) a stiffness of the polarizing plate under a condition of 23° C. and 55% RH is 20 to 80 g; (vi) the polarizing plate protective film A or B further comprising a polyester plasticizer containing an aromatic group represented by Formula (I): B-(G-A)n-G-B Formula (1) wherein B represents a benzene monocarboxylic acid residue; G represents an alkylene glycol residue having 2-12 carbon atoms, an aryl glycol residue having 6-12 carbon atoms, or an oxyalkylene glycol residue having 4-12 carbon atoms; A represents an alkylene dicarboxylic acid residue having 4-12 carbon atoms or an aryldicarboxylic acid residue having 6-12 carbon atoms; and n represents an integer of 1 or more; (vii) the polarizing plate protective film A has a hard coating layer having a thickness of 0.1-20 μm; and further (viii) the polarizing plate protective films A and B each has a stretching ratio from 1.05 to 1.5 in the lateral direction and from 0.8 to 1.3 in the longitudinal direction, wherein Ro and Rt are defined by the following equations: Ro =( nx−ny )× d Rt =(( nx+ny )/2− nz )× d wherein nx, ny, and nz represent refractive indexes in x, y, and z directions, respectively, x, y, and z representing three principal axes of a refractive index ellipsoid; nx and ny each represent an in-plane refractive index, while nx>ny; nz represents a refractive index in a thickness direction; and d represents a thickness (in nm) of polarizing plate protective film B.