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, the polyester film has a shrinkage difference between a length shrinkage in a first diagonal direction and a length shrinkage in a second diagonal direction of about −0.1% to about +0.1% with respect to either the mechanical direction (MD) or the transverse direction (TD) of the polyester film (as a reference direction),
• 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
• 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 be represented by Equation 2:
• Length shrinkage in the second diagonal direction(%)=(C−D)/C×100 Equation 2
• 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, and
• an angle between the first diagonal direction and the second diagonal direction is not 0°.