Flexible display apparatus

Patent metadata

Field	Value
Publication number	US-11693272-B2
Application number	US-202217682636-A
Country	US
Kind code	B2
Filing date	Feb 28, 2022
Priority date	Nov 28, 2016
Publication date	Jul 4, 2023
Grant date	Jul 4, 2023

Abstract

A flexible display apparatus includes a bending area and a non-bending area. The flexible display apparatus further includes a display panel and a polarizing structure disposed on the display panel. The polarizing structure includes a λ/4 phase retardation layer, a linear polarizer disposed on the λ/4 phase retardation layer, and a first adhesive structure disposed between the λ/4 phase retardation layer and the linear polarizer. The linear polarizer includes a stretched polymer film. The first adhesive structure is an adhesive layer with a glass transition temperature that is greater than or equal to 40° C. and less than or equal to 150° C. Accordingly, deformation of the λ/4 phase retardation layer may be prevented or reduced when the flexible display apparatus is folded or bent, thereby improving display quality.

First claim

What is claimed is:

1. A flexible display apparatus comprising:
a display panel; and
a polarizing structure disposed on the display panel,
wherein the polarizing structure comprises:
a λ/4 phase retardation layer;
a linear polarizer disposed on the λ/4 phase retardation layer;
a λ/2 phase retardation layer disposed between the λ/4 phase retardation layer and the linear polarizer;
a first adhesive structure disposed between the λ/4 phase retardation layer and the λ/2 phase retardation layer; and
a second adhesive structure disposed between the λ/2 phase retardation layer and the linear polarizer in direct contact with the linear polarizer, and
wherein:
a thickness of the second adhesive structure is greater than a thickness of the first adhesive structure; and
in a plan view, an angle between an absorption axis or a transmission axis of the linear polarizer and a bending axis of the flexible display apparatus is 45 degrees ±30 degrees.

2. The flexible display apparatus of claim 1 , wherein the thickness of the first adhesive structure and the thickness of the second adhesive structure is less than or equal to 5 μm, respectively.

3. The flexible display apparatus of claim 2 , a thickness of the λ/4 phase retardation layer and a thickness of the λ/2 phase retardation layer is greater than or equal to 0.5 μm and less than or equal to 2 μm, respectively, and
wherein the total thickness including the λ/4 phase retardation layer, the first adhesive structure, the λ/2 phase retardation layer, and the second adhesive structure is greater than or equal to 1.2 μm and less than or equal to 14 μm.

4. The flexible display apparatus of claim 1 , wherein a thickness of the λ/4 phase retardation layer and a thickness of the λ/2 phase retardation layer is greater than or equal to 0.5 μm and less than or equal to 5 μm, respectively.

5. The flexible display apparatus of claim 1 , wherein a glass transition temperature of the first adhesive structure is greater than a glass transition temperature of the second adhesive structure.

6. The flexible display apparatus of claim 5 , wherein the first adhesive structure being an adhesive layer with the glass transition temperature that is greater than or equal to 40° C. and less than or equal to 150° C.; and
the second adhesive structure being an adhesive layer with the glass transition temperature that is greater than or equal to −35° C. and less than or equal to 0° C.

7. The flexible display apparatus of claim 1 , wherein:
the first adhesive structure comprises an ultraviolet curable adhesive; and
the second adhesive structure comprises a pressure sensitive adhesive.

8. The flexible display apparatus of claim 1 , wherein the λ/4 phase retardation layer is a liquid crystal coating layer.

9. The flexible display apparatus of claim 1 , wherein, in a plan view:
an angle between an absorption axis or a transmission axis of the linear polarizer and a first optical axis of λ/4 phase retardation layer is 75 degrees ±30 degrees; and
an angle between the absorption axis or the transmission axis and a second optical axis of the λ/2 phase retardation layer is 15 degrees ±13 degrees.

10. The flexible display apparatus of claim 1 , wherein, in a plan view, an angle between a first optical axis of the λ/4 phase retardation layer and a second optical axis of the λ/2 phase retardation layer is 60 degrees ±30 degrees.

11. The flexible display apparatus of claim 1 , wherein:
the λ/4 phase retardation layer is a nematic liquid crystal coating layer; and
the λ/2 phase retardation layer is a discotic liquid crystal coating layer.

12. The flexible display apparatus of claim 1 , wherein:
the flexible display apparatus comprises a bending area and a non-bending area; and
the bending area is bent from one side of the non-bending area and,
wherein a radius of curvature of the bending area is greater than 0 mm and less than or equal to 5 mm.

13. A flexible display apparatus comprising:
a display panel; and
a polarizing structure disposed on the display panel,
wherein the polarizing structure comprises:
a λ/4 phase retardation layer;
a linear polarizer disposed on the λ/4 phase retardation layer;
a λ/2 phase retardation layer disposed between the λ/4 phase retardation layer and the linear polarizer;
a first adhesive structure disposed between the λ/4 phase retardation layer and the λ/2 phase retardation layer; and
a second adhesive structure disposed between the λ/2 phase retardation layer and the linear polarizer in direct contact with the linear polarizer, and
wherein:
a thickness of the first adhesive structure and a thickness of the second adhesive structure is less than or equal to 5 μm, respectively; and
in a plan view, an angle between an absorption axis or a transmission axis of the linear polarizer and a bending axis of the flexible display apparatus is 45 degrees ±30 degrees.

14. The flexible display apparatus of claim 13 , wherein a thickness of the λ/4 phase retardation layer and a thickness of the λ/2 phase retardation layer is greater than or equal to 0.5 μm and less than or equal to 5 μm, respectively.

15. The flexible display apparatus of claim 13 , a thickness of the λ/4 phase retardation layer and a thickness of the λ/2 phase retardation layer is greater than or equal to 0.5 μm and less than or equal to 2 μm, respectively,
wherein the thickness of the first adhesive structure and the thickness of the second adhesive structure is greater than or equal to 0.1 μm and less than or equal to 3 μm, respectively, and
wherein the total thickness including the λ/4 phase retardation layer, the first adhesive structure, the λ/2 phase retardation layer, and the second adhesive structure is greater than or equal to 1.2 μm and less than or equal to 10 μm.

16. The flexible display apparatus of claim 13 , wherein the first adhesive structure being an adhesive layer with a glass transition temperature that is greater than or equal to 40° C. and less than or equal to 150° C.; and
the second adhesive structure being an adhesive layer with a glass transition temperature that is greater than or equal to 40° C. and less than or equal to 150° C.

17. The flexible display apparatus of claim 13 , wherein each of the first adhesive structure and the second adhesive structure comprises an ultraviolet curable adhesive.

18. The flexible display apparatus of claim 13 , wherein the λ/4 phase retardation layer is a liquid crystal coating layer.

19. The flexible display apparatus of claim 13 , wherein, in a plan view:
an angle between an absorption axis or a transmission axis of the linear polarizer and a first optical axis of λ/4 phase retardation layer is 75 degrees ±30 degrees; and
an angle between the absorption axis or the transmission axis and a second optical axis of the λ/2 phase retardation layer is 15 degrees ±13 degrees.

20. The flexible display apparatus of claim 13 , wherein, in a plan view, an angle between a first optical axis of the λ/4 phase retardation layer and a second optical axis of the λ/2 phase retardation layer is 60 degrees ±30 degrees.

21. The flexible display apparatus of claim 13 , wherein:
the λ/4 phase retardation layer is a nematic liquid crystal coating layer; and
the λ/2 phase retardation layer is a discotic liquid crystal coating layer.

22. The flexible display apparatus of claim 13 , wherein:
the flexible display apparatus comprises a bending area and a non-bending area; and
the bending area is b

Assignees

• Samsung Display Co Ltd

Inventors

• Lee Heeyoung
• Seo Eunmi

Classifications

• H10K59/8791

  Arrangements for improving contrast, e.g. preventing reflection of ambient light · CPC title

• G02F1/133528 Primary

  Polarisers · CPC title

• G02B5/3016 Primary

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

• G02B5/3083

  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

• H01L27/323

  Electricity · mapped topic