Polarizing plates and optical display apparatuses including the polarizing plates

A polarizing plate comprising:

• a polarizer;
• at least one optical film on at least one side of the polarizer;
• and
• wherein the optical film comprises a polyester film stretched in a transverse direction (TD) and not stretched in the mechanical direction (MD),
• the polyester film having an in-plane phase difference (Ro) of about 5,000 nm to about 15,000 nm at a wavelength of 550 nm,
• the polyester film has a shrinkage difference between length shrinkage in a first diagonal direction and length shrinkage in a second diagonal direction of about −0.1% to about +0.1% with respect to a reference direction, the reference direction being either the mechanical direction (MD) or the transverse direction (TD) of the polyester film,
• the length shrinkage in the first diagonal direction being represented by Equation 1:
• Length shrinkage in the first diagonal direction (%)=(A−B)/A×100 Equation 1
• wherein, in Equation 1, A is an initial length of a specimen of the polyester film corresponding to the first diagonal direction with respect to the reference direction, and B is a length of the specimen of the polyester film corresponding to the first diagonal direction after allowing the specimen to stand at 85±5° C. for 30 minutes,
• the length shrinkage in the second diagonal direction being represented by Equation 2:
• Length shrinkage in the second diagonal direction (%)=(C−D)/C×100 Equation 2
• wherein in Equation 2, C is an initial length of a specimen of the polyester film corresponding to the second diagonal direction with respect to the reference direction, and D is a length of the specimen of the polyester film corresponding to the second diagonal direction after allowing the specimen to stand at 85±5° C. for 30 minutes,
• an angle between the first diagonal direction and the second diagonal direction is about 60° to about 120°,
• the polyester film is a polyethylene terephthalate film,
• the polyester film consists of a single layer film and has a thickness of about 25 μm to about 500 μm, and
• the polyester film has a refractive index, nx, in an x-axis direction of the polyester film, and a refractive index, ny, in a y-axis direction of the polyester film, one of nx and ny being 1.65 or greater, and the other of nx and ny being less than 1.65,
• the polyester film having an out-of-plane retardation (Rth) of about 12,000 nm or less at a wavelength of 550 nm, as represented by Equation 4:
• Rth=((nx+ny)/2−nz)×d, Equation 4
• wherein, nx and ny are the refractive indexes in the x-axis and y-axis directions, respectively, of the polyester film, nz is a refractive index in a z-axis direction of the polyester film at a wavelength of 550 nm, and d is a thickness of the polyester film in nm,
• wherein the polarizing plate having the at least one optical film on the at least one side of the polarizer has R axis scattering as a measure of optical axis distortion of about 0.1° to about 0.5°.