Polarizer and display device comprising the same

Patent metadata

Field	Value
Publication number	US-10330842-B2
Application number	US-201815935842-A
Country	US
Kind code	B2
Filing date	Mar 26, 2018
Priority date	Mar 10, 2015
Publication date	Jun 25, 2019
Grant date	Jun 25, 2019

Abstract

A polarizer for a display device is disclosed. In one aspect, the polarizer includes a linear polarizer and a phase retardation layer on the linear polarizer and comprising a quarter-wave plate and a half-wave plate. The half-wave plate includes a refractive index anisotropic layer. The refractive index anisotropic layer has a refractive index Nx defined in a direction of an x axis, a refractive index Ny defined in a direction of a y axis, and a refractive index Nz defined in a direction of a z axis, wherein Nx=Nz>Ny.

First claim

What is claimed is:

1. A polarizer comprising:
a linear polarizer; and
a phase retardation layer on the linear polarizer and comprising a quarter-wave plate and a half-wave plate,
wherein the half-wave plate comprises a refractive index anisotropic layer,
wherein the refractive index anisotropic layer has a refractive index Nx defined in a direction of an x axis, a refractive index Ny defined in a direction of a y axis, and a refractive index Nz defined in a direction of a z axis,
wherein the linear polarizer, the quarter-wave plate and the half-wave plate are arranged along the z axis, and
wherein Nx=Nz>Ny.

2. The polarizer of claim 1 , wherein the refractive index anisotropic layer comprises a liquid crystal layer.

3. The polarizer of claim 2 , wherein the liquid crystal layer comprises a discotic compound.

4. The polarizer of claim 3 , wherein the discotic compound has a disc surface, and wherein the disc surface has an inclination angle in the range of about 60 degrees to about 90 degrees with respect to a surface of the half-wave plate.

5. The polarizer of claim 1 , wherein each of Nx and Nz is in the range of about 1.6 to about 1.8.

6. The polarizer of claim 1 , wherein Ny is in the range of about 1.5 to about 1.7.

7. The polarizer of claim 1 , wherein the difference between Nx and Ny is in the range of about 0.05 to about 0.2.

8. The polarizer of claim 1 , wherein the refractive index anisotropic layer has a thickness in the range of about 1 micrometer (μm) to about 5 μm.

9. The polarizer of claim 1 , wherein the refractive index anisotropic layer has a thickness of “a” μm, and wherein “b”=Nx−Ny, where 0.1<a×b<0.5.

10. The polarizer of claim 1 , wherein the half-wave plate comprises an alignment layer, and wherein the refractive index anisotropic layer is on the alignment layer.

11. The polarizer of claim 1 , wherein the quarter-wave plate comprises a cyclic olefin polymer (COP).

12. The polarizer of claim 1 , wherein the quarter-wave plate is on the linear polarizer, and wherein the half-wave plate is on the quarter-wave plate.

13. The polarizer of claim 1 , wherein the half-wave plate is on the linear polarizer, and the quarter-wave plate is on the half-wave plate.

14. A polarizer comprising:
a linear polarizer; and
a quarter-wave plate on the linear polarizer; and
a half-wave plate on the quarter-wave plate and comprising a refractive index anisotropic layer,
wherein the refractive index anisotropic layer has a refractive index Nx defined in a direction of an x axis, a refractive index Ny defined in a direction of a y axis, and a refractive index Nz defined in a direction of a z axis,
wherein the linear polarizer, the quarter-wave plate and the half-wave plate are arranged along the z axis, and
wherein Nx=Nz>Ny.

15. The polarizer of claim 14 , wherein each of the half-wave and quarter-wave plates is thinner than the linear polarizer.

Assignees

• Samsung Display Co Ltd

Inventors

• Son Junghee
• Jung Woosuk
• Park Hyejung
• Lee Dukjin

Classifications

• H01L51/0076

  Electricity · mapped topic

• G02B27/286

  for controlling or changing the state of polarisation, e.g. transforming one polarisation state into another (G02B5/3083 takes precedence; light guide coupling means utilising polarising elements G02B6/34) · CPC title

• H01L2251/5315

  Electricity · mapped topic

• H01L51/5256

  Electricity · mapped topic

• H01L51/004

  Electricity · mapped topic