Flexible display apparatus

Patent metadata

Field	Value
Publication number	US-11262613-B2
Application number	US-201916552725-A
Country	US
Kind code	B2
Filing date	Aug 27, 2019
Priority date	Nov 28, 2016
Publication date	Mar 1, 2022
Grant date	Mar 1, 2022

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, 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
a second adhesive structure disposed between the λ/2 phase retardation layer and the linear polarizer in direct contact with the linear polarizer, the second adhesive structure being an adhesive layer with a glass transition temperature that is greater than or equal to −35° C. and less than or equal to 0° C.

2. The flexible display apparatus of claim 1 , wherein a thickness of the first adhesive structure is greater than or equal to 0.1 μm and less than or equal to 5 μm.

3. 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.

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

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

6. The flexible display apparatus of claim 1 , further comprising:
a first optical compensation layer disposed between the display panel and the λ/4 phase retardation layer; and
a third adhesive structure disposed between the first optical compensation layer and the λ/4 phase retardation layer,
wherein the third adhesive structure is:
a pressure sensitive adhesive layer with a glass transition temperature that is greater than or equal to −35° C. and less than or equal to 0° C.; or
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.

7. The flexible display apparatus of claim 6 , further comprising:
a second optical compensation layer disposed between the λ/4 phase retardation layer and the λ/2 phase retardation layer; and
a fourth adhesive structure disposed between the second optical compensation layer and the λ/2 phase retardation layer,
wherein the fourth 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.

8. The flexible display apparatus of claim 7 , wherein each of the first optical compensation layer and the second optical compensation layer is a positive C-plate or a negative C-plate.

9. The flexible display apparatus of claim 7 , 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.

10. 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 the λ/4 phase retardation layer is 45 degrees±30 degrees.

11. 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.

12. 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.

13. The flexible display apparatus of claim 1 , wherein:
in a first mode, the display panel and the polarizing structure are bent with respect to a bending axis such that the polarizing structure is disposed closer to the bending axis than the display panel; and
in a second mode, the display panel and the polarizing structure are unfolded.

14. The flexible display apparatus of claim 1 , wherein:
in a third mode, the display panel and the polarizing structure are bent with respect to a bending axis such that the display panel is disposed closer to the bending axis than the polarizing structure; and
in a fourth mode, the display panel and the polarizing structure are unfolded.

15. 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.

16. The flexible display apparatus of claim 15 , wherein a radius of curvature of the bending area is greater than 0 mm and less than or equal to 5 mm.

17. The flexible display apparatus of claim 1 , further comprising:
a touch sensing structure disposed on the display panel,
wherein the touch sensing structure is disposed on an upper surface or a lower surface of the polarizing structure.

18. A flexible display apparatus comprising:
a display panel comprising a bending area that is transformable into a bent shape or has a bent shape with respect to a bending axis extending in one direction; and
a polarizing structure disposed on the display panel,
wherein the polarizing structure comprises:
a first phase retardation layer including a liquid crystal coating layer;
a linear polarizer disposed on the first phase retardation layer;
a second phase retardation layer including a liquid crystal coating layer disposed between the first phase retardation layer and the linear polarizer;
a first adhesive structure with a glass transition temperature that is greater than or equal to 40° C. and less than or equal to 150° C., and disposed between the first phase retardation layer and the second phase retardation layer; and
a second adhesive structure with a glass transition temperature that is greater than or equal to −35° C. and less than or equal to 0° C., and disposed directly between the second phase retardation layer and the linear polarizer,
wherein the first and second phase retardation layers are a λ/4 phase retardation layer and λ/2 phase retardation layer.

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

• G02F1/133305

  Flexible substrates, e.g. plastics, organic film · CPC title

• G09F9/301 Primary

  flexible foldable or roll-able electronic displays, e.g. thin LCD, OLED · CPC title