Polarizing plate and optical display apparatus comprising the same
A polarizing plate and an optical display apparatus including the same are provided. A polarizing plate includes: a polarizer; a protective layer stacked on a surface of the polarizer; and a retardation layer stacked on another surface of the polarizer, and the protective layer has an in-plane retardation of 3,000 nm or more at a wavelength of 550 nm, an optical axis of the protective layer is tilted at an angle of −2° to +2° with respect to a light absorption axis of the polarizer, and the polarizer has a single transmittance of 44.0% or more and a minimum crossed transmittance of 0.005% or more at a wavelength of 400 nm to 700 nm.
1 . A polarizing plate comprising: a polarizer; a protective layer stacked on a surface of the polarizer; and a retardation layer stacked on another surface of the polarizer, wherein:
the polarizer comprises a polyvinyl alcohol based film dyed in a dyeing solution containing 1 wt % to 5 wt % of at least one of iodine or a dichroic dye;
the protective layer comprises at least one selected from among a polyester based resin, a cyclic olefin polymer based resin, and a (meth)acrylic based resin;
the protective layer has an in-plane retardation of 3,000 nm or more at a wavelength of 550 nm;
an optical axis of the protective layer is tilted at an angle of −2° to +2° with respect to a light absorption axis of the polarizer;
the polarizer has a single transmittance of 44.0% or more; and
the polarizer has a minimum crossed transmittance of 0.005% to 5% at a wavelength of 400 nm to 700 nm.
2 . The polarizing plate according to claim 1 , wherein the protective layer has a water vapor transmission rate of 30 g/m 2 ·day or less.
3 . The polarizing plate according to claim 1 , wherein the optical axis is a slow axis or a fast axis of the protective layer.
4 . The polarizing plate according to claim 1 , wherein the protective layer further comprises an antireflection layer, a low reflectivity layer, an antiglare layer, a hard coating layer, a fingerprint resistant layer, or a primer layer on a surface thereof or on another surface thereof.
5 . The polarizing plate according to claim 1 , wherein the protective layer has a reflectivity of 1% or less.
6 . The polarizing plate according to claim 1 , wherein the polarizer has a maximum crossed transmittance at a wavelength of 480 nm to 550 nm in a wavelength range of 450 nm to 580 nm.
7 . The polarizing plate according to claim 1 , wherein the retardation layer comprises a first retardation layer and a second retardation layer.
8 . The polarizing plate according to claim 7 , wherein an absolute value of a tilted angle of a slow axis of the first retardation layer with reference to the light absorption axis of the polarizer is in a range of 10° to 30°.
9 . The polarizing plate according to claim 7 , wherein an absolute value of a tilted angle of a slow axis of the second retardation layer with reference to the light absorption axis of the polarizer is in a range of 79° to 89°.
10 . The polarizing plate according to claim 7 , wherein an angle defined between a slow axis of the first retardation layer and a slow axis of the second retardation layer is in a range of 49° to 79°.
11 . The polarizing plate according to claim 7 , wherein the first retardation layer has an in-plane retardation of 210 nm to 270 nm at a wavelength of 550 nm, and the second retardation layer has an in-plane retardation of 60 nm to 150 nm at a wavelength of 550 nm.
12 . The polarizing plate according to claim 1 , wherein the polarizing plate has a deviation of crossed optical characteristics of 10% or less, as calculated by the following Equation 3:
Deviation of crossed optical characteristics=|( A−B )/ B|× 100,
where A is a value of the crossed optical characteristics, as measured on the polarizing plate including the protective layer stacked on an upper surface of the polarizer and having the optical axis, and B is a value of the crossed optical characteristics, as measured on a reference polarizing plate including a protective layer stacked on the upper surface of the polarizer and having no optical axis.
13 . An optical display apparatus comprising the polarizing plate according to claim 1 .