Polarizer having adhesive-covered polarizing layer, display device having the polarizer, and method of fabricating the polarizer

Patent metadata

Field	Value
Publication number	US-10429550-B2
Application number	US-201615394685-A
Country	US
Kind code	B2
Filing date	Dec 29, 2016
Priority date	Jun 30, 2016
Publication date	Oct 1, 2019
Grant date	Oct 1, 2019

Abstract

Penetration of moisture and propagation of cracks is prevented in a polarizer. An adhesive is provided to cover one or more edges of the polarizer to seal the side section of the polarizer. The adhesive fills initial cracks to prevent the initial crack from being propagated to the inside of the polarizer. A protective film and the adhesive include a material having a hydrophobic characteristic. In a method of fabricating a polarizer, a polarizing film is shaped to form a polarizing layer, and a protective film is then attached by applying an adhesive onto the edges of the polarizing layer. Then, the adhesive is cured, and the protective film having the polarizing layer attached is processed, thereby dividing the protective film into a plurality of polarizers. The adhesive can firmly fix the crack since the adhesive is fills in cracks in the polarizing layer.

First claim

What is claimed is:

1. A polarizer, comprising:
a polarizing layer;
a first protective film on a first surface of the polarizing layer, an area of a surface of the first protective film parallel to the first surface larger than an area of the first surface of the polarizing layer;
a second protective film on a second surface of the polarizing layer, an area of a surface of the second protective film parallel to the second surface larger than the area of the second surface of the polarizing layer; and
an adhesive between the first protective film and the second protective film, wherein the adhesive covers one or more edges of the polarizing layer,
wherein a lateral surface of the adhesive is in contact with and disposed on a same plane as both a corresponding lateral surface of the first protective film and a corresponding lateral surface of the second protective film, and extends continuously between the lateral surface of the first protective film and the lateral surface of the second protective film.

2. The polarizer of claim 1 , wherein the adhesive is a hydrophobic material that includes one or more kinds of acrylic monomers having a hydrophilic functional group.

3. The polarizer of claim 1 , wherein the adhesive covers entire edges of the polarizing layer.

4. The polarizer of claim 1 , wherein a thickness of the adhesive at the one or more edges of the polarizing layer is 1 μm to 10 μm, and a width of the adhesive that covers the one or more edges of the polarizing layer is 1 μm to 1.5 mm.

5. The polarizer of claim 1 , wherein the one or more edges of the polarizing layer covered by the adhesive have one or more cracks.

6. The polarizer of claim 5 , wherein the one or more cracks contain a crack having a size of 40 μm or more.

7. The polarizer of claim 5 , wherein the polarizing layer has a stretching axis, and wherein the adhesive covers edges of the polarizing layer from which cracks in the edges propagate in a direction parallel to the stretching axis.

8. The polarizer of claim 5 , wherein the polarizing layer has a stretching axis, and wherein the one or more edges of the polarizing layer having the one or more cracks includes edges along a first direction parallel to the stretching axis and edges extending in a second direction perpendicular to the first direction.

9. The polarizer of claim 1 , further comprising a compensating layer that receives incident light and outputs light having a polarization state different from a polarization state of the incident light.

10. The polarizer of claim 9 , wherein the compensating layer includes one or both of a quarter-wave retardation plate (QWP) or a half-wave retardation plate (HWP).

11. The polarizer of claim 9 , wherein the adhesive is curable by a ultraviolet light of a first wavelength range and the compensating layer is curable by ultraviolet light curable by a second wavelength range different from the first wavelength range.

12. The polarizer of claim 9 , wherein the compensating layer includes an alignment layer and a liquid crystal layer on the alignment layer, and wherein a bottom surface of the alignment layer contacts the adhesive.

13. The polarizer of claim 9 , wherein the area of the surface of the first protective film and the area of the surface of the second protective film is greater than an area of a surface of the compensating layer parallel to the first surface, and wherein the adhesive covers one or more edges of the compensating layer.

14. The polarizer of claim 1 , wherein the polarizing layer has a concave shape, is curved, is polygonal, or has a hole.

15. A display device including a polarizer, the polarizer comprising:
a polarizing layer;
a first protective film on a first surface of the polarizing layer, an area of a surface of the first protective film parallel to the first surface larger than an area of the first surface of the polarizing layer;
a second protective film on a second surface of the polarizing layer, an area of a surface of the second protective film parallel to the second surface larger than the area of the second surface of the polarizing layer; and
an adhesive between the first protective film and the second protective film, wherein the adhesive covers one or more edges of the polarizing layer,
wherein a lateral surface of the adhesive is in contact with and disposed on a same plane as both a corresponding lateral surface of the first protective film and a corresponding lateral surface of the second protective film, and extends continuously between the lateral surface of the first protective film and the lateral surface of the second protective film.

16. A method of fabricating a polarizer, comprising:
shaping a polarizing film to form a polarizing layer;
attaching a first protective film on a first surface of the polarizing layer, an area of a surface of the first protective film parallel to the first surface larger than an area of the first surface of the polarizing layer;
applying an adhesive on the polarizing layer to cover one or more edges of the polarizing layer;
attaching a second protective film on a second surface of the polarizing layer, an area of a surface of the second protective film parallel to the second surface larger than the area of the second surface of the polarizing layer;
curing the adhesive to secure the first protective film and the second protective film to the polarizing layer; and
cutting the first protective film, the second protective film, and the adhesive along a shape of the polarizing layer such that a lateral surface of the adhesive is in contact with and disposed on a same plane as both a corresponding lateral surface of the first protective film and a corresponding lateral surface of the second protective film, and extends continuously between the lateral surface of the first protective film and the lateral surface of the second protective film.

17. The method of claim 16 , wherein the polarizing film is shaped with the polarizing film adhered to a guide film.

18. The method of claim 17 , further comprising removing the guide film after attaching the first protective film on the first surface of the polarizing layer.

19. The method of claim 16 , wherein the one or more edges of the polarizing layer have one or more cracks, and the adhesive fills in the one or more cracks in the polarizing layer.

20. The method of claim 16 , wherein curing the adhesive comprises irradiating ultraviolet light of a first wavelength range onto the adhesive.

21. The method of claim 16 , further comprising shaping the first protective film and the second protective film such that boundaries of the first protective film and the second protective film extend further from a boundary of the polarizing layer.

22. The method of claim 16 , further comprising:
forming a compensating film of at least one layer on the polarizing film; and
shaping the compensating film to form a compensating layer.

23. The method of claim 22 , wherein the shaping of the compensating film is simultaneously performed with the shaping of the polarizing film.

24. The method of claim 22 , wherein curing the adhesive comprises irradiating ultraviolet light of a first wavelength range onto the adhesive, and wherein the compensating film of the at least one layer comprises a layer of ultraviolet curable liquid crystal, and wherein the forming of the compensating film comprises:
applying the ultraviolet curable liquid crystal onto the polarizing

Assignees

• Lg Display Co Ltd

Inventors

• Cho Wonjong
• Park Wonki

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

• G02B5/3016

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

• G02B5/3041

  comprising multiple thin layers, e.g. multilayer stacks · CPC title

• G02B5/3033

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

• B29D11/00644

  polarizing · CPC title