Optical film, manufacturing method thereof, and display device

1. An optical film comprising:

a polarization film comprising a polymer resin and a dichroic dye; and

a phase delay layer disposed on the polarization film,

wherein the phase delay layer comprises a first phase delay layer and a second phase delay layer,

the first and second phase delay layers have different retardation from each other,

each of the first and second phase delay layers comprises liquid crystal,

an angle between a slow axis of the first phase delay layer and a slow axis of the second phase delay layer is in a range from about 50 degrees to about 70 degrees,

in-plane phase retardation (R e1 ) of the first phase delay layer for 550 nm wavelength is in a range from about 230 nm to about 270 nm,

in-plane phase retardation (R e2 ) of the second phase delay layer for 550 nm wavelength is in a range from about 100 nm to about 140 nm,

entire in-plane phase retardation (R e0 ) of the first phase delay layer and the second phase delay layer for 550 nm wavelength is in a range from about 120 nm to about 160 nm,

each of the first phase delay layer and the second phase delay layer has a refractive index satisfying the following relationship: nx>ny=nz or nx<ny=nz,

wherein

each of the first phase delay layer and the second phase delay layer has a refractive index satisfying the following relationship: nx<ny=nz, or

one of the first phase delay layer and the second phase delay layer has refractive index satisfying the following relationship: nx>ny=nz, and the other of the first phase delay layer and the second phase delay layer has refractive index satisfying the following relationship: nx<ny=nz,

wherein nx denotes a refractive index of the first or second phase delay layer at a slow axis thereof, ny denotes a refractive index of the first or second phase delay layer at a fast axis thereof, and nz denotes a refractive index of the first or second phase delay layer in a direction perpendicular to the fast and slow axes thereof.

2. The optical film of claim 1 , wherein entire in-plane phase retardation (R e0 ) of the first phase delay layer and the second phase delay layer for 450 nm, 550 nm, and 650 nm wavelengths satisfies the following inequality:

R e0 (450 nm)≦R e0 (550 nm)<R e0 (650 nm) or R e0 (450 nm)<R e0 (550 nm)≦R e0 (650nm).

3. The optical film of claim 2 , wherein

the first phase delay layer and the second phase delay layer have entire short wavelength dispersion in a range from about 0.70 to about 0.99, and

the first phase delay layer and the second phase delay layer have entire long wavelength dispersion in a range from about 1.01 to about 1.20.

4. The optical film of claim 1 , wherein

the first phase delay layer is a λ/2 phase delay layer, and

the second phase delay layer is a λ/4 phase delay layer.

5. The optical film of claim 4 , wherein in-plane phase retardation (R e1 ) of the first phase delay layer for 450 nm, 550 nm and 650 nm wavelengths satisfies the following inequality: R e1 (450 nm)>R e1 (550 nm)>R e1 (650 nm),

in-plane phase retardation (R e2 ) of the second phase delay layer for 450 nm, 550 nm and 650 nm wavelengths satisfies the following inequality: R e2 (450 nm)>R e2 (550 nm)>R e2 (650 nm), and

entire in-plane phase retardation (R e0 ) of the first phase delay layer and the second phase delay layer for 450 nm, 550 nm and 650 nm wavelengths satisfies the following inequality: R e0 (450 nm)≦R e0 (550 nm)<R e0 (650 nm) or R e0 (450 nm)<R e0 (550 nm)≦R e0 (650 nm).

6. The optical film of claim 5 , wherein

the first phase delay layer and the second phase delay layer each has short wavelength dispersion in a range from about 1.1 to about 1.2, and

the first phase delay layer and the second phase delay layer have entire short wavelength dispersion in a range from about 0.70 to about 0.99.

7. The optical film of claim 5 , wherein

the first phase delay layer and the second phase delay layer each has long wavelength dispersion in a range from about 0.9 to about 1.0, and

the first phase delay layer and the second phase delay layer have entire long wavelength dispersion in a range from about 1.01 to about 1.20.

8. The optical film of claim 4 , further comprising:

an adhesion layer disposed between the first phase delay layer and the second phase delay layer.

9. The optical film of claim 1 , wherein the entire thickness of the first phase delay layer and the second phase delay layer is less than or equal to about 10 μm.

10. The optical film of claim 1 , further comprising:

an adhesion layer disposed between the polarization film and the phase delay layer, the phase delay layer comprising the first phase delay layer and the second phase delay layer.

11. The optical film of claim 1 , wherein the polymer resin comprises a polyolefin, a polyamide, a polyester, a polyacryl, polystyrene, a copolymer thereof, or a combination thereof.

12. The optical film of claim 11 , wherein the polymer resin comprises polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), polyethylene terephthalate glycol (PETG), polyethylene naphthalate (PEN), nylon, a copolymer thereof, or a combination thereof.

13. The optical film of claim 1 , wherein the polarization film has a thickness less than or equal to about 100 μm.

14. The optical film of claim 1 , wherein the polarization film comprises a melt blend of the polymer resin and the dichroic dye.

15. The optical film of claim 1 , wherein a transparent substrate is not present between the polarization film and the phase delay layer, the phase delay layer comprising the first phase delay layer and the second phase delay layer.

16. A display device including the optical film of claim 1 .

17. A method of manufacturing an optical film, the method comprising:

melt-blending a polymer resin and a dichroic dye to prepare a polarization film;

preparing a phase delay layer comprising a liquid crystal on a substrate; and

providing the phase delay layer on the polarization film,

wherein the phase delay layer comprises a first phase delay layer and a second phase delay layer,

the first and second phase delay layers have different retardation from each other,

each of the first and second phase delay layers comprises liquid crystal,

an angle between a slow axis of the first phase delay layer and a slow axis of the second phase delay layer is in a range from about 50 degrees to about 70 degrees,

in-plane phase retardation (R e1 ) of the first phase delay layer for 550 nm wavelength is in a range from about 230 nm to about 270 nm,

in-plane phase retardation (R e2 ) of the second phase delay layer for 550 nm wavelength is in a range from about 100 nm to about 140 nm,

entire in-plane phase retardation (R e0 ) of the first phase delay layer and the second phase delay layer for 550 nm wavelength is in a range from about 120 nm to about 160 nm,

each of the first phase delay layer and the second phase delay layer has a refractive index satisfying the following relationship: n x >n y =n z or n x <n y =n z ,

wherein

each of the first phase delay layer and the second phase delay layer has a refractive index satisfying the following relationship: n x <n y =n z , or

one of the first phase delay layer and the second phase delay layer has refractive index satisfying the following relationship: n x >n y =n z , and the other of the first phase delay layer and the second phase delay layer has refractive index satisfying the following relationship: n x <n y =n z ,

wherein n x denotes a refractive index of the first or second phase delay layer at a slow axis thereof, n y denotes a refractive index of the first or second phase delay layer at a fast axis thereof, and n z denotes a refractive index of the first or second phase delay layer in a direction perpendicular to the fast and slow axes thereof.

18. The method of claim 17 , wherein the providing the phase delay layer on the polarization film comprises:

removing the phase delay layer from the substrate; and

transferring the phase delay layer to a surface of the polarization film.

19. The method of claim 17 , further comprising:

providing an adhesion layer on a surface of the polarization film.

20. The method of claim 17 , wherein the preparing the phase delay layer comprises stacking a λ/2 phase delay layer and a λ/4 phase delay layer on the substrate.