Flexible display panel and flexible display device

• US 10,644,074 B2
• Filed: 09/07/2017
• Issued: 05/05/2020
• Est. Priority Date: 04/05/2017
• Status: Active Grant

• Current Assignee: Shanghai Tianma Micro-Electronics Company Limited (Tianma Microelectronics Company Limited)
• Original Assignee: Shanghai Tianma Micro-Electronics Company Limited (Tianma Microelectronics Company Limited)
• Inventors: Leng, Chuanli, Cai, Yu
• Primary Examiner(s): Payne, Sharon E
• Application Number:
  US15/698,024
• Publication Number:
  US 20170373121A1
• Time in Patent Office: 971 Days
• CPC Class Codes: G09G 2380/02 Flexible displays
• CPC Class Codes: G09G 3/20 for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
• CPC Class Codes: H10K 2102/311 Flexible OLED
• CPC Class Codes: H10K 50/844 Encapsulations
• CPC Class Codes: H10K 59/00 Integrated devices, or assemblies of multiple devices, comprising at least one organic light-emitting element covered by group H10K50/00
• CPC Class Codes: H10K 59/12 Active-matrix OLED [AMOLED] displays
• CPC Class Codes: H10K 77/111 Flexible substrates
• CPC Class Codes: Y02E 10/549 Organic PV cells

Abstract

A flexible display panel and a flexible display device are provided. The flexible display panel comprises a display region and a non-display region surrounding the display region, wherein the non-display region includes a bonding area; a flexible substrate having a first surface and an opposite second surface; a light-emitting unit formed on the first surface of the flexible substrate; a first protective film formed on the second surface of the flexible substrate and covering the entire second surface of the flexible substrate, wherein the first protective film has a first side facing the flexible substrate and an opposite second side far away from the flexible substrate; and a second protective film formed on the second side of the first protective film. The flexible display panel includes at least one folding area and at least one non-folding area, and the second protective film only covers the at least one non-folding area.

Claims

1. A flexible display panel, comprising:

a display region and a non-display region surrounding the display region, wherein the non-display region includes a bonding area;

a flexible substrate having a first surface and an opposite second surface;

an array substrate comprising a thin-film-transistor (TFT) array on the first surface of the flexible substrate;

a light-emitting unit formed on a surface of the thin-film transistor array away from the flexible substrate;

a first protective film formed on the second surface of the flexible substrate and covering the entire second surface of the flexible substrate, wherein the first protective film has a first side facing the flexible substrate and an opposite second side away from the flexible substrate;

a second protective film formed on the second side of the first protective film;

a first adhesive layer on one side of the first protective film adjacent to the flexible substrate for bonding the first protective film with the flexible substrate; and

a second adhesive layer on the other side of the first protective film away from the first adhesive layer for bonding the first protective film with the second protective film, and in direct contact with the first and the second protective films,

wherein the flexible display panel includes at least one folding area and at least one non- folding area,

the second protective film only covers the at least one non-folding area,

the second adhesive layer covers the at least one folding area and the at least one non-folding area of the first protective film and includes a portion, in the at least one folding area, that is uncovered by the second protective film,

the first adhesive layer has a larger adhesive force than the second adhesive layer, and

the first adhesive layer has a larger thickness than the second adhesive layer.

2. The flexible display panel according to claim 1, wherein:

a thickness of the second protective film is larger than a thickness of the first protective film.

3. The flexible display panel according to claim 2, wherein:

the thickness of the first protective film is approximately 10 μ

m to 30 μ

m; and

the thickness of the second protective film is approximately 50 μ

m to 100 μ

m.

4. The flexible display panel according to claim 1, wherein:

an elastic modulus of the second protective film is larger than an elastic modulus of the first protective film.

5. The flexible display panel according to claim 4, wherein:

the elastic modulus of the first protective film is approximately 100 Mpa to 10 Gpa; and

the elastic modulus of the second protective film is approximately 1 Gpa-20 Gpa.

6. The flexible display panel according to claim 1, wherein:

the at least one folding area is arranged across the flexible display panel in a first direction,

wherein the first direction is located in a same plane as the flexible display panel.

7. The flexible display panel according to claim 6, wherein:

the at least one folding area has a rectangular shape.

8. The flexible display panel according to claim 7, wherein:

the first direction is same as an extending direction of a gate line of the flexible display panel, and

one side of the rectangular shape extends in the first direction.

9. The flexible display panel according to claim 7, wherein:

the flexible display panel includes at least two folding areas; and

the at least two folding areas and the at least one non-folding area are alternately arranged in a direction perpendicular to the first direction.

10. The flexible display panel according to claim 9, wherein:

the flexible display panel includes two folding areas having different widths in the direction perpendicular to the first direction.

11. The flexible display panel according to claim 10, wherein:

in the direction perpendicular to the first direction, the two folding areas have a width of π

r and π

R, respectively,

where r and R are bending radii of curvature of the flexible display panel at the two folding areas, respectively.

12. The flexible display panel according to claim 1, wherein:

the at least one folding area is the bonding area.

13. The flexible display panel according to claim 1, wherein:

the at least one folding area is a region between the bonding area and the display region.

14. The flexible display panel according to claim 1, wherein:

the non-display region further includes frame areas located on both sides of the bonding area, respectively; and

the frame area is a folding area.

15. The flexible display panel according to claim 1, wherein:

a thickness of the first protective film and a thickness of the second protective film are adjusted to change flexibility of the at least one non-folding area and the at least one folding area.

16. The flexible display panel according to claim 1, wherein:

the first protective film and the second protective film each includes an organic material, wherein the organic material includes at least one of polyethylene terephthalate, polyethylene naphthalate and polyethylene.

17. A flexible display device, comprising:

a flexible display panel, comprising;

a display region and a non-display region surrounding the display region, wherein the non-display region includes a bonding area;

a flexible substrate having a first surface and an opposite second surface;

an array substrate comprising a thin-film-transistor (TFT) array on the first surface of the flexible substrate;

a light-emitting unit formed on a surface of the thin-film transistor array away from the flexible substrate;

a first protective film formed on the second surface of the flexible substrate and covering the entire second surface of the flexible substrate, wherein the first protective film has a first side facing the flexible substrate and an opposite second side away from the flexible substrate;

a second protective film formed on the second side of the first protective film;

a first adhesive layer on one side of the first protective film adjacent to the flexible substrate for bonding the first protective film with the flexible substrate; and

a second adhesive layer on the other side of the first protective film away from the first adhesive layer for bonding the first protective film with the second protective film, and in direct contact with the first and the second protective films,

wherein the flexible display panel includes at least one folding area and at least one non-folding area,

the second protective film only covers the at least one non-folding area,

the second adhesive layer covers the at least one folding area and the at least one non-folding area of the first protective film and includes a portion, in the at least one folding area, that is uncovered by the second protective film,

the first adhesive layer has a larger adhesive force than the second adhesive layer, and

the first adhesive layer has a larger thickness than the second adhesive layer.

18. A flexible display panel, comprising:

a display region and a non-display region surrounding the display region, wherein the non-display region includes a bonding area;

a flexible substrate having a first surface and an opposite second surface;

an array substrate comprising a thin-film-transistor (TFT) array on the first surface of the flexible substrate;

a light-emitting unit formed on a surface of the thin-film transistor array away from the flexible substrate;

a first protective film formed on the second surface of the flexible substrate and covering the entire second surface of the flexible substrate, wherein the first protective film has a first side facing the flexible substrate and an opposite second side away from the flexible substrate;

a second protective film formed on the second side of the first protective film;

a first adhesive layer on one side of the first protective film adjacent to the flexible substrate for bonding the first protective film with the flexible substrate; and

a second adhesive layer on the other side of the first protective film away from the first adhesive layer for bonding the first protective film with the second protective film, and in direct contact with the first and the second protective films,

wherein the flexible display panel includes at least one folding area and at least one non-folding area,

the second protective film only covers the at least one non-folding area, and

an elastic material is disposed on a portion of a surface of the first protective film, on the other side of the first protective film away from the first adhesive layer, not covered by the second protective film in the at least one folding area, the elastic material having a smaller elastic modulus than the first protective film and the second protective film to increase elasticity of the at least one folding area, and a surface of the elastic material away from the first protective film being configured to be at a same level as a surface of the second protective film away from the first protective film to increase a flatness of the flexible display panel.