Multi-structured film having improved interference fringe, and display device comprising same

Patent metadata

Field	Value
Publication number	US-2023305206-A1
Application number	US-202117996350-A
Country	US
Kind code	A1
Filing date	Jun 18, 2021
Priority date	Jun 23, 2020
Publication date	Sep 28, 2023
Grant date	—

Abstract

The present invention provides a film comprising: a substrate; and a first coating layer on the substrate, wherein the film has, from a reflectance graph obtained by measuring the reflectance in a 380 nm to 780 nm wavelength region, a reflectance oscillation ratio (O r ) of 1.0 or less and a reflectance graph slope (G r ) of 0.122 or less, and has improved interference fringes.

First claim

1 . A film used for a display device comprising:
a substrate; and a first coating layer disposed on the substrate, wherein the film has a reflectance oscillation ratio O r , calculated using the following Equation 1, of 1.0 or less, and a reflectance graph slope G r , calculated using the following Equation 2, of 0.122 or less, based on a reflectance graph obtained by measuring reflectance in a wavelength range of 380 nm to 780 nm:
O r =[( O m1 *O m2 )−( O m1 +O m2 )]/Min( O m1 ,O m2 )  <Equation 1>

G r =|( R m1 −R m2 )|/ R m2   <Equation 2>

wherein in Equation 1, O m1 is a mean O m of reflectance oscillation values in a wavelength range of 500 nm to 550 nm, and O m2 is a mean O m of reflectance oscillation values in a wavelength range of 650 nm to 780 nm, wherein the means O m1 and O m2 of reflectance oscillation values are calculated using the following Equation 3, and Min(O m1 , O m2 ) is a smaller mean O m of the means O m1 and O m2 of reflectance oscillation values, wherein in Equation 2, R m1 is an arithmetic mean of a reflectance corresponding to a first peak P 1 and a reflectance corresponding to a first valley V 1 in a wavelength range of 500 nm to 780 nm in the reflectance graph, and R m2 is an arithmetic mean of a reflectance value corresponding to a final peak P f and a reflectance value corresponding to a final valley V f in the wavelength range of 500 nm to 780 nm in the reflectance graph,
O m =(1/ n )*Σ( O k )  <Equation 3>

wherein in Equation 3, O k is an oscillation value in the corresponding wavelength range, and n is a number of oscillation values in the corresponding wavelength range, and wherein each of the oscillation values is a difference in reflectance values corresponding to a pair of a peak P k and a valley V k adjacent to each other (|a reflectance corresponding to P k −a reflectance corresponding to V k |).

2 . The film used for a display device according to claim 1 , wherein the substrate is birefringent.

3 . The film used for a display device according to claim 1 , wherein the substrate has an X-axis direction refractive index N x of 1.57 to 1.67, a Y-axis direction refractive index N y of 1.57 to 1.67, and a Z-axis direction refractive index N z of 1.53 to 1.57.

4 . The film used for a display device according to claim 3 , wherein the first coating layer has a refractive index N 1 satisfying the following Equation 4:
0.927* N x ≤N 1 ≤0.978* N y   <Equation 4>

5 . The film used for a display device according to claim 3 , further comprising a second coating layer disposed on the substrate.

6 . The film used for a display device according to claim 5 , wherein the second coating layer is disposed between the substrate and the first coating layer.

7 . The film used for a display device according to claim 5 , wherein the first coating layer is disposed between the substrate and the second coating layer.

8 . The film used for a display device according to claim 5 , wherein the second coating layer has a refractive index N 2 satisfying the following Equation 5:
0.793* N x ≤N 2 ≤0.975* N y   <Equation 5>

9 . The film used for a display device according to claim 3 , further comprising a third coating layer disposed on the substrate.

10 . The film used for a display device according to claim 9 , wherein the third coating layer has a refractive index N 3 satisfying the following Equation 6:
0.793* N x ≤N 3 ≤0.975* N y   <Equation 6>

11 . The film used for a display device according to claim 1 , wherein the first coating layer comprises a light-transmissive matrix and particles dispersed in the light-transmissive matrix.

12 . The film used for a display device according to claim 11 , wherein the light-transmissive matrix comprises at least one of a siloxane-based resin, an acrylic-based resin, a urethane-based resin, or an epoxy-based resin.

13 . The film used for a display device according to claim 11 , wherein the particles comprise at least one of zirconia (ZrO 2 ), silica (SiO 2 ), alumina (Al 2 O 3 ), titanium dioxide (TiO 2 ), styrene, or acryl.

14 . The film used for a display device according to claim 1 , wherein the first coating layer has a thickness of 0.01 to 3.4 μm.

15 . The film used for a display device according to claim 5 , wherein the second coating layer has a thickness of 1 to 14 μm.

16 . The film used for a display device according to claim 9 , wherein the third coating layer has a thickness of 1 μm or less.

17 . A polyimide-based film comprising:
a polyimide-based substrate; and a first coating layer disposed on the polyimide-based substrate, wherein the polyimide-based film has a reflectance oscillation ratio O r , calculated using the following Equation 1, of 1.0 or less, and a reflectance graph slope G r , calculated using the following Equation 2, of 0.122 or less, based on a reflectance graph obtained by measuring reflectance in a wavelength range of 380 nm to 780 nm:
O r =[( O m1 *O m2 )−( O m1 +O m2 )]/Min( O m1 ,O m2 )  <Equation 1>

G r =|( R m1 −R m2 )|/ R m2   <Equation 2>

wherein in Equation 1, O m1 is a mean O m of reflectance oscillation values in a wavelength range of 500 nm to 550 nm, and O m2 is a mean O m of reflectance oscillation values in a wavelength range of 650 nm to 780 nm, wherein the means O m1 and O m2 of reflectance oscillation values are calculated using the following Equation 3, and Min(O m1 , O m2 ) is a smaller mean O m of the means O m1 and O m2 of reflectance oscillation values, wherein in Equation 2, R m1 is an arithmetic mean of a reflectance corresponding to a first peak P 1 and a reflectance corresponding to a first valley V 1 in a wavelength range of 500 nm to 780 nm in the reflectance graph, and R m2 is an arithmetic mean of a reflectance value corresponding to a final peak P f and a reflectance value corresponding to a final valley V f in the wavelength range of 500 nm to 780 nm in the reflectance graph,
O m =(1/ n )*Σ( O k )  <Equation 3>

wherein in Equation 3, O k is an oscillation value in the corresponding wavelength range, and n is a number of oscillation values in the corresponding wavelength range, and wherein each of the oscillation values is a difference in reflectance values corresponding to a pair of a peak P k and a valley V k adjacent to each other (|a reflectance corresponding to P k −a reflectance corresponding to V k |).

18 . A display device comprising:
a display panel; and the film used for a display device according to claim 1 disposed on the display panel.

Assignees

• Kolon Inc

Inventors

• An Byung-Joon

Classifications

• C08G73/14

  Polyamide-imides · CPC title

• C08G73/1067

  Wholly aromatic polyimides, i.e. having both tetracarboxylic and diamino moieties aromatically bound · CPC title

• C08G73/1042

  Copolyimides derived from at least two different tetracarboxylic compounds or two different diamino compounds · CPC title

• C08G73/1039

  comprising halogen-containing substituents · CPC title

• G02F1/133502

  Antiglare, refractive index matching layers · CPC title