Polarization film and display apparatus including the same

Patent metadata

Field	Value
Publication number	US-12468080-B2
Application number	US-202318134427-A
Country	US
Kind code	B2
Filing date	Apr 13, 2023
Priority date	Jul 20, 2022
Publication date	Nov 11, 2025
Grant date	Nov 11, 2025

Abstract

A polarization film includes: a polarization layer; a first light compensation film arranged on one side of the polarization layer and including a positive A plate; and a second light compensation film arranged on one side of the first light compensation film and including a positive C plate. A value of ne(+C)−ne(+A) is positive at a wavelength of 450 nm and negative at a wavelength of 650 nm. Here, ne(+A) denotes an extraordinary refractive index of the first light compensation film and ne(+C) denotes an extraordinary refractive index of the second light compensation film.

First claim

What is claimed is:

1 . A polarization film comprising:
a polarization layer; a first light compensation film arranged on one side of the polarization layer and comprising a positive A plate; and a second light compensation film arranged on one side of the first light compensation film and comprising a positive C plate, wherein a value of n e (+C)−n e (+A) is positive at a wavelength of 450 nanometers (nm) and negative at a wavelength of 650 nm, where n e (+A) denotes an extraordinary refractive index of the first light compensation film and n e (+C) denotes an extraordinary refractive index of the second light compensation film.

2 . The polarization film of claim 1 , wherein the value of n e (+C)−n e (+A) is about 0.02 to about 0.08 at a wavelength of 450 nm and about −0.08 to about −0.02 at a wavelength of 650 nm.

3 . The polarization film of claim 1 , wherein an azimuthal angle color distribution (AACD) value at a polar angle of 60° of the polarization film is 10 or less,
wherein AACD={Max(e)−Min(a*)}x{Max(b*)−M(b*)},
where a* and b* are coordinate values in a CIE L*a*b* coordinate system, Max(a*) and Min(a*) are a maximum value and a minimum value among a* coordinate values measured for an azimuth angle φ=0° to 360°, respectively, and
Max(b*) and Min(b*) are a maximum value and a minimum value of b* coordinate values measured for an azimuth angle φ=0° to 360°, respectively.

4 . The polarization film of claim 1 , wherein the second light compensation film comprises liquid crystal molecules.

5 . The polarization film of claim 4 , wherein the liquid crystal molecules are rod-shaped.

6 . The polarization film of claim 1 , wherein the first light compensation film comprises a quarter-wave plate (QWP).

7 . The polarization film of claim 6 , wherein the first light compensation film has reverse wavelength dispersion.

8 . The polarization film of claim 7 , wherein the wavelength dispersion (DSP) of the first light compensation film satisfies the following conditions:
DSP(450 nm)=R(450 nm)/R(550 nm)<1, DSP(650 nm)=R(650 nm)/R(550 nm)>1, where R(λ) denotes a phase difference value at a wavelength λ.

9 . The polarization film of claim 1 , further comprising a third light compensation film arranged on one side of the second light compensation film and comprising a negative C plate.

10 . The polarization film of claim 9 , further comprising a fourth light compensation film arranged on one side of the third light compensation film and comprising a positive C plate.

11 . A display apparatus comprising:
a substrate; a plurality of display elements disposed over the substrate; an encapsulation member encapsulating the plurality of display elements; and a polarization film disposed over the encapsulation member, wherein the polarization film comprises:
a polarization layer;
a first light compensation film arranged on one side of the polarization layer and comprising a positive A plate; and
a second light compensation film arranged on one side of the first light compensation film and comprising a positive C plate,
wherein a value of n e (+C)−n e (+A) is positive at a wavelength of 450 nm and negative at a wavelength of 650 nm, where n e (+A) denotes an extraordinary refractive index of the first light compensation film and n e (+C) denotes an extraordinary refractive index of the second light compensation film.

12 . The display apparatus of claim 11 , wherein the value of n e (+C)−n e (+A) is about 0.02 to about 0.08 at a wavelength of 450 nm and about −0.08 to about −0.02 at a wavelength of 650 nm.

13 . The display apparatus of claim 11 , wherein an azimuthal angle color distribution (AACD) value at a polar angle of 60° of the polarization film is 10 or less,
wherein AACD={Max(a*)−Min(a*)}x{Max(b*)−M(b*)},
where a* and b* are coordinate values in a CIE L*a*b* coordinate system, Max(a*) and Min(a*) are a maximum value and a minimum value among a* coordinate values measured for an azimuth angle φ=0° to 360°, respectively, and
Max(b*) and Min(b*) are a maximum value and a minimum value of b* coordinate values measured for an azimuth angle φ=0° to 360°, respectively.

14 . The display apparatus of claim 11 , wherein the encapsulation member comprises a thin film encapsulation layer, and the thin film encapsulation layer comprises a first inorganic encapsulation layer, an organic encapsulation layer, and a second inorganic encapsulation layer that are sequentially stacked.

15 . The display apparatus of claim 11 , wherein the second light compensation film is arranged closer to the encapsulation member than the polarization layer.

16 . The display apparatus of claim 11 , wherein the second light compensation film comprises rod-shaped liquid crystal molecules.

17 . The display apparatus of claim 11 , wherein the first light compensation film comprises a quarter-wave plate (QWP).

18 . The display apparatus of claim 17 , wherein wavelength dispersion (DSP) of the first light compensation film satisfies the following conditions:
DSP(450 nm)=R(450 nm)/R(550 nm)<1, DSP(650 nm)=R(650 nm)/R(550 nm)>1, where R(λ) denotes a phase difference value at a wavelength λ.

19 . The display apparatus of claim 11 , wherein the polarization film further comprises a third light compensation film arranged on one side of the second light compensation film and comprising a negative C plate.

20 . The display apparatus of claim 19 , wherein the polarization film further comprises a fourth light compensation film arranged on one side of the third light compensation film and comprising a positive C plate.

Assignees

• Samsung Display Co Ltd

Inventors

• Lee Dukjin
• Beon Beonghun

Classifications

• G02B5/3016 Primary

  involving passive liquid crystal elements (optical properties of liquid crystals G02F1/0063; polarising elements associated with active liquid crystal devices G02F1/133528) · CPC title

• H10K59/8793

  Arrangements for polarized light emission (H10K59/8791 takes precedence) · CPC title

• H10K59/873

  Encapsulations · CPC title

• H10K59/8791

  Arrangements for improving contrast, e.g. preventing reflection of ambient light · CPC title

• G02F1/133528

  Polarisers · CPC title