Polarizing plate and display device

Patent metadata

Field	Value
Publication number	US-11415836-B2
Application number	US-201916962191-A
Country	US
Kind code	B2
Filing date	Mar 27, 2019
Priority date	Mar 28, 2018
Publication date	Aug 16, 2022
Grant date	Aug 16, 2022

Abstract

Provided is a polarizing plate and a display device. The polarizing plate has excellent durability against an external environment, for example, moisture, due to a protective film of a polarizer, and can prevent color distortion upon observation with polarized sunglasses, and a display device comprising the polarizing plate.

First claim

The invention claimed is:

1. A display device comprising:
a display panel;
a first polarizing plate which is disposed on a viewing side of the display panel and comprises a first protective film, a first polarizer, and a second protective film sequentially; and
a second polarizing plate which is disposed on an opposite side of the viewing side of the display panel and comprises a third protective film, a second polarizer, and a fourth protective film sequentially,
wherein the second and third protective films are disposed close to the display panel side, and the first and fourth protective films are disposed outside the display device,
wherein the first protective film and the fourth protective film are each a protective film for preventing color distortion and each is a polyethylene terephthalate film, and each has an angle formed by a slow axis of the protective film with respect to a TD (transverse direction) axis of the protective film in a range of 0 to 4.5 degrees, wherein the slow axis means an axis with the highest refractive index on a surface of the protective film, and
wherein the protective film for preventing color distortion has an in-plane retardation value (Rin) of 300 nm to 400 nm for light having a wavelength of 550 nm, and
wherein the second protective film and the third protective film are each a TAC (triacetyl cellulose) film.

2. The display device according to claim 1 , wherein the protective film for preventing color distortion has an angle formed by the slow axis with respect to the TD axis in a range of 0 to 3 degrees.

3. The display device according to claim 1 , wherein the protective film for preventing color distortion has an in-plane retardation value (Rin) for light having a wavelength of 550 nm of 10 nm to 1000 nm.

4. The display device according to claim 1 , wherein in the protective films for color-distortion prevention, the difference in absolute values of the angles formed by the slow axes of the respective protective films with respect to the TD axes is 3.5 degrees or less.

5. The display device according to claim 1 , wherein in the at least two protective films for preventing color distortion, the TD axes of the respective protective films are orthogonal to each other.

6. The display device according to claim 1 , wherein the display panel comprises a liquid crystal panel.

7. The display device according to claim 1 , wherein a magnitude of the angle formed by a slow axis of the protective film with respect to a TD axis of the protective film in the first protective film and the fourth protective film are equal to each other.

Assignees

• Lg Chemical Ltd
• Shanjin Optoelectronics Suzhou Co Ltd

Inventors

• Kim Tae Woo
• Park Jin Yong
• Lee Won Chul
• Shin Jun Cheol
• Jung ki jun
• Choi Jae Min

Classifications

• G02F1/13363 Primary

  Birefringent elements, e.g. for optical compensation · CPC title

• C08J5/18

  Manufacture of films or sheets · CPC title

• G02B5/3033 Primary

  in the form of a thin sheet or foil, e.g. Polaroid · CPC title

• G02F1/133528

  Polarisers · CPC title

• C08L67/02

  Polyesters derived from dicarboxylic acids and dihydroxy compounds (C08L67/06 takes precedence) · CPC title