Polarizer
The present application relates to a polarizer, a polarizing plate and a display device. The present application can provide a polarizer or a polarizing plate that is applied to various types of display devices, particularly to a display device having a highly reflective liquid crystal panel and that shows excellent characteristics. In addition, the present application can provide a display device including the polarizer or the polarizing plate.
1. A polarizing plate comprising a polarizer which has a light absorption axis formed in one direction and satisfies the following conditions 1 to 4:
Condition 1: −a value is 0.7 or more and 1.6 or less in CIE Lab color space;
Condition 2: b value is 4 or less in CIE Lab color space;
Condition 3: a ratio (−b/a) of −a value and b value is 2.5 or less in CIE Lab color space;
Condition 4: −b c value is 4 to 40 in CIE Lab color space,
wherein −a value and b value are color space coordinate measured for a sheet of PVA polarizer at a wavelength of 550 nm, and −b c value is a value multiplying b c value by −1 in color space coordinate measured in state that mutual light absorption axes in two sheets of PVA polarizers are crossed by 90 degrees at a wavelength of 550 nm.
2. The polarizing plate according to claim 1 , being applied to a liquid crystal panel which has a reflectance of 12% or more for light having a wavelength of 550 nm.
3. The polarizing plate according to claim 2 , wherein the liquid crystal panel is a liquid crystal panel without black matrix or a liquid crystal panel that a color filter is not present on an upper substrate, but present on a lower substrate.
4. The polarizing plate according to claim 1 , comprising a polarizer which has a polarization degree of 99.9% or more.
5. The polarizing plate according to claim 1 , comprising a polarizer which has a light blocking rate in a range of 5.1 to 6.0 for light having any one wavelength in a range of 560 nm to about 750 nm.
6. The polarizing plate according to claim 1 , wherein the polarizer comprises a PVA-based film and an anisotropic absorbent material adsorptively oriented on the PVA-based film.
7. The polarizing plate according to claim 6 , wherein the anisotropic absorbent material is iodine.
8. The polarizing plate according to claim 1 , further comprising a polarizer protective film, a pressure-sensitive adhesive layer, an adhesive layer, a retardation film or a low reflection layer.
9. A display device comprising the polarizing plate of claim 1 .
10. The display device according to claim 9 , further comprising a liquid crystal panel having a reflectance of 12% or more for light having a wavelength of 550 nm, wherein the polarizing plate is disposed on the visible side of said liquid crystal panel.
11. The display device according to claim 10 , further comprising a second polarizer or a second polarizing plate disposed on the back side of the liquid crystal panel.
12. The display device according to claim 11 , wherein the second polarizer or the second polarizing plate has a light blocking rate in a range of 4 to 6 at any one wavelength in a range of 380 nm to 520 nm.
13. The display device according to claim 9 , further comprising a liquid crystal panel without black matrix or a liquid crystal panel that a color filter is not present on an upper substrate, but present on a lower substrate, wherein the polarizing plate is disposed on the visible side of said liquid crystal panel.