High luminance polarizing plate, and liquid crystal panel and image display using same

A high-brightness polarizing plate, comprising:

• a polarizing plate;
• wherein the polarizing plate comprises a polarizer and a protective film prepared on one or both sides of the polarizer, and the polarizer and the protective film are adhered with an adhesive;
• a brightness enhancement film;
• and an adhesive layer through which the polarizing plate and the brightness enhancement film are laminated with the protective film interposed between them, wherein
• the protective film has an in-plane retardation Re of 0 to 10 nm and a thickness-direction retardation Rth of −30 to 10 nm, wherein
• Re=(nx−ny)d and Rth={(nx+ny)/(2−nz)} d, wherein
• nx is a refractive index in an X-axis direction in which a maximum in-plane refractive index is obtained, ny is a refractive index in a Y-axis direction perpendicular to the X-axis, nz is a refractive index in a Z-axis direction which is the film thickness direction, and d is a thickness (nm) of the protective film.