Polarizing plate for minimizing reflecting properties in an organic light emitting device
Provided are a polarizing plate and a display. The illustrative polarizing plate may exhibit desired characteristics in a wide range of wavelengths, and have excellent reflection and visibility at an inclined angle. For example, the polarizing plate may be used in a reflective or transflective liquid crystal display or an organic light emitting device.
1. A polarizing plate for minimizing reflecting properties in an organic light emitting device, comprising:
a polarizer; and
a retardation layer that is laminated on one side of the polarizer, and that comprises an uniaxial retardation film or a biaxial retardation film,
wherein a reflectivity of the polarizing plate is 12% or less at an inclined angle of 50 degrees,
wherein the retardation layer comprises a positive uniaxial retardation film and a C plate, or comprises a monolayer structure of a positive biaxial retardation film, or comprises a positive biaxial retardation film and a negative biaxial retardation film, or comprises a negative biaxial retardation film and a C plate,
wherein a thickness direction retardation (Rth) of the retardation layer according to the equation Rth=d×(Nz−Ny) is from 5 nm to 270 nm,
wherein, d is a thickness of the retardation layer, and Ny and Nz are refractive indexes in y and z axes of the retardation layer, respectively, wherein the y axis is a direction parallel to a fast axis of the retardation layer and the z axis is a normal direction of a plane formed by the x and y axes, wherein the x axis is a direction parallel to a slow axis of the retardation layer.
2. The polarizing plate according to claim 1 , of which a reflectivity at all radial angles measured at the inclined angle of 50 degrees is 12% or less.
3. The polarizing plate according to claim 1 , wherein the retardation layer satisfies
R (450)/ R (550)< R (650)/ R (550),
where R(450) is in-plane retardation of the retardation layer with respect to light having a wavelength of 450 nm, R(550) is in-plane retardation of the retardation layer with respect to light having a wavelength of 550 nm, and R(650) is in-plane retardation of the retardation layer with respect to light having a wavelength of 650 nm.
4. The polarizing plate according to claim 1 , wherein the retardation layer comprises the positive uniaxial retardation film and the C plate, and the C plate is disposed closer to the polarizer than the positive uniaxial retardation film.
5. The polarizing plate according to claim 4 , wherein an angle between a slow axis of the positive uniaxial retardation film and a light absorption axis of the polarizer is from 40 degrees to 50 degrees.
6. The polarizing plate according to claim 4 , wherein a thickness-direction retardation of the C plate is from 0 nm to 200 nm.
7. The polarizing plate according to claim 1 , wherein the retardation layer comprises the positive uniaxial retardation film and the C plate, and the positive uniaxial retardation film is disposed closer to the polarizer than the C plate.
8. The polarizing plate according to claim 7 , wherein an angle between a slow axis of the positive uniaxial retardation film and a light absorption axis of the polarizer is from 40 degrees to 50 degrees.
9. The polarizing plate according to claim 7 , wherein a thickness-direction retardation of the C plate is from 0 nm 200 nm.
10. The polarizing plate according to claim 1 , wherein the retardation layer comprises the monolayer structure of the positive biaxial retardation film, and an angle between a slow axis of the positive biaxial retardation film and a light absorption axis of the polarizer is from 40 degrees to 50 degrees.
11. The polarizing plate according to claim 10 , wherein a thickness-direction retardation of the positive biaxial retardation film is 160 nm or less.
12. The polarizing plate according to claim 1 , wherein the retardation layer comprises the positive biaxial retardation film and the negative biaxial retardation film, and the positive biaxial retardation film is disposed closer to the polarizer than the negative biaxial retardation film.
13. The polarizing plate according to claim 12 , wherein the slow axis of the positive biaxial retardation film is parallel to the light absorption axis of the polarizer, and an angle between a slow axis of the negative biaxial retardation film and the light absorption axis of the polarizer is from 40 degrees to 50 degrees.
14. The polarizing plate according to claim 12 , wherein the sum of a thickness-direction retardation of the positive biaxial retardation film and a thickness-direction retardation of the negative biaxial retardation film is from 60 m to 270 nm.
15. The polarizing plate according to claim 1 , wherein the retardation layer includes the positive biaxial retardation film and the negative biaxial retardation film, and the negative biaxial retardation film is disposed closer to the polarizer than the positive biaxial retardation film.
16. The polarizing plate according to claim 15 , wherein an angle between the slow axis of the positive biaxial retardation film and the light absorption axis of the polarizer is from 40 degrees to 50 degrees, and a slow axis of the negative biaxial retardation film is parallel to the light absorption axis of the polarizer.
17. The polarizing plate according to claim 15 , wherein the sum of a thickness-direction retardation of the positive biaxial retardation film and a thickness-direction retardation of the negative biaxial retardation film is from 60 nm to 200 nm.
18. The polarizing plate according to claim 1 , wherein the retardation layer comprises the negative biaxial retardation film and the C plate, and the C plate is disposed closer to the polarizer than the negative biaxial retardation film.
19. The polarizing plate according to claim 18 , wherein an angle between a slow axis of the negative biaxial retardation film and a light absorption axis of the polarizer is from 40 degrees to 50 degrees.
20. The polarizing plate according to claim 18 , wherein the sum of a thickness-direction retardation of the C plate and a thickness-direction retardation of the negative biaxial retardation film is from 70 nm to 250 nm.
21. The polarizing plate according to claim 1 , wherein the retardation layer comprises the negative biaxial retardation film and the C plate, and the negative biaxial retardation film is disposed closer to the polarizer than the C plate.
22. The polarizing plate according to claim 21 , wherein an angle between a slow axis of the negative biaxial retardation film and the light absorption axis of the polarizer is from 40 degrees to 50 degrees.
23. The polarizing plate according to claim 21 , wherein the sum of a thickness-direction retardation of the C plate and a thickness-direction retardation of the negative biaxial retardation film is from 50 nm to 250 nm.
24. An organic light emitting device comprising the polarizing plate of claim 1 .