Polarizing plate suitable for liquid crystal display device capable of displaying three-dimensional images, and liquid crystal display device

Patent metadata

Field	Value
Publication number	US-10175494-B2
Application number	US-201214118115-A
Country	US
Kind code	B2
Filing date	May 16, 2012
Priority date	May 18, 2011
Publication date	Jan 8, 2019
Grant date	Jan 8, 2019

Abstract

Provided is a polarizer whereby screen brightness does not become zero regardless of the direction in which a viewer faces when the polarizer is used in a liquid crystal display device capable of displaying three-dimensional images, in which three-dimensional images are visible through a polarizing filter. The polarizer comprises a polarizing film and protective films disposed on both sides of the polarizing film; at least one of the protective films being an oriented film; and the tilt of the orientation axis or an axis orthogonal to the orientation axis of the oriented film relative to the polarization axis of the polarizing film being 1° or more and less than 45°.

First claim

The invention claimed is:

1. A liquid crystal display device comprising a backlight light source, two polarizers, and a liquid crystal cell disposed between the two polarizers,
wherein
the polarizer on the viewing side of the liquid crystal cell comprises a polarizing film and an oriented film laminated on the viewing side of the polarizing film,
the tilt of the orientation axis or an axis orthogonal to the orientation axis of the oriented film relative to the polarization axis of the polarizing film is 1° or more and 10° or less,
the oriented film has an in-plane retardation of more than 7,200 nm and 30,000 nm or less, and
the oriented film has a ratio of in-plane retardation to thickness-direction retardation (Re/Rth) of 0.2 to 2.0.

2. The liquid crystal display device according to claim 1 , wherein the oriented film comprises at least three layers, contains an ultraviolet absorber in the layer other than the outermost layers, and has a light transmittance at 380 nm of 20% or less.

3. The liquid crystal display device according to claim 1 , wherein the oriented film has a ratio of in-plane retardation to thickness-direction retardation (Re/Rth) of 0.2 to 1.2.

4. The liquid crystal display device according to claim 1 , wherein the oriented film is made of a polyester resin or a polycarbonate resin.

5. The liquid crystal display device according to claim 1 , wherein the polarizer on the viewing side of the liquid crystal cell comprises a protective film disposed on the light-incoming side of the polarizing film.

6. The liquid crystal display device according to claim 1 , wherein the backlight light source is a white light source having a continuous emission spectrum.

7. The liquid crystal display device according to claim 1 for making a three-dimensional image visible through a polarizing filter.

8. The liquid crystal display device according to claim 1 , wherein the tilt of the orientation axis or an axis orthogonal to the orientation axis of the oriented film relative to the polarization axis of the polarizing film is 7° or more and 10° or less.

9. The liquid crystal display device according to claim 1 , wherein the oriented film has an in-plane retardation of 7,350 nm or more and 30,000 nm or less.

10. The liquid crystal display device according to claim 5 , wherein the protective film is selected from the group consisting of a triacetyl cellulose film, an acrylic film, and a norbornene film.

11. The liquid crystal display device according to claim 6 , wherein the white light source having a continuous emission spectrum is a white light-emitting diode.

12. The liquid crystal display device according to claim 1 , wherein the oriented film has a ratio of in-plane retardation to thickness-direction retardation (Re/Rth) of 0.5 to 1.2.

13. The liquid crystal display device according to claim 1 , wherein the oriented film has a thickness of 25 μm or more and 100 μm or less.

14. The liquid crystal display device according to claim 1 , wherein the oriented film has a thickness variation of 3.0% or less.

15. The liquid crystal display device according to claim 8 , wherein the polarizer on the viewing side of the liquid crystal cell comprises a protective film disposed on the light-incoming side of the polarizing film, and
wherein the protective film is selected from the group consisting of a triacetyl cellulose film, an acrylic film, and a norbornene film.

16. The liquid crystal display device according to claim 15 , wherein the backlight light source is a white light source having a continuous emission spectrum.

17. The liquid crystal display device according to claim 15 , wherein the oriented film has a thickness variation of 3.0% or less.

18. The liquid crystal display device according to claim 17 , wherein the oriented film has a ratio of in-plane retardation to thickness-direction retardation (Re/Rth) of 0.2 to 1.2.

19. The liquid crystal display device according to claim 11 , wherein the white light-emitting diode comprises a blue LED element and a yellow phosphor.

Assignees

• Murata Kouichi
• Ikehata Yoshitomo
• Toyo Boseki

Inventors

• Murata Kouichi
• Ikehata Yoshitomo

Classifications

• G02B5/3083

  Birefringent or phase retarding elements (G02B5/3008, G02B5/3016 take precedence; systems for polarisation control G02B27/286; manufacturing phase modulating patterns by lithographic processes G03F7/001) · CPC title

• G02B30/25 Primary

  using polarisation techniques · CPC title

• G02B5/3025 Primary

  Polarisers, i.e. arrangements capable of producing a definite output polarisation state from an unpolarised input state (G02B5/3008, G02B5/3016 take precedence) · CPC title

• G02F1/13362

  providing polarized light, e.g. by converting a polarisation component into another one · CPC title

• G02B5/3033 Primary

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