Optical film, manufacturing method thereof, and display device

1. An optical film comprising:

a polarization film; 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, each of the first and second phase delay layers including liquid crystal,

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 ,

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.

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 (650 nm).

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 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.

5. 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.

6. The optical film of claim 1 , 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).

7. The optical film of claim 6 , wherein

the first phase delay layer and the second phase delay layer each have 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.

8. The optical film of claim 6 , wherein

the first phase delay layer and the second phase delay layer each have 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.

9. The optical film of claim 1 , wherein 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.

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

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

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

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

13. The optical film of claim 11 , wherein the polarization film comprises a melt blend of the polymer resin and the dichroic dye.

14. The optical film of claim 1 , wherein the polarization film has a thickness less than or equal to about 100 μm and the phase delay layer has a thickness less than or equal to about 10 μm.

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

an adhesion layer disposed between the polarization film and the 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 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, each of the first and second phase delay layers including liquid crystal,

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 ,

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 , wherein the preparing the phase delay layer comprises stacking the first phase delay layer and the second phase delay layer on the substrate, the first phase delay layer being a λ/2 phase delay layer and the second phase delay layer being a λ/4 phase delay layer.