FOLDABLE DISPLAY DEVICE

• US 20150049428A1
• Filed: 02/07/2014
• Published: 02/19/2015
• Est. Priority Date: 08/19/2013
• Status: Active Grant

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Inventors: Lee, Kyu-Taek, Kim, Kyu Young, Min, Gui-Nam, Lee, Jongin, Han, Kyung Woo, Han, Soyeon
• Granted Patent: US 9,189,027 B2
• Time in Patent Office: Days
• US Class Current: 361/679.27
• CPC Class Codes: G06F 1/1641 the display being formed by a plurality of foldable display components G06F1/1647 takes precedence
• CPC Class Codes: G06F 1/1652 the display being flexible, e.g. mimicking a sheet of paper, or rollable
• CPC Class Codes: H10K 2102/311 Flexible OLED

Abstract

A foldable display device is disclosed. In one aspect, the foldable display device includes a display panel and a window panel provided on a front surface of the display panel. The window panel includes a flexible area and a rigid area provided adjacent to at least one side of the flexible area. The elastic modulus of the flexible area of the window panel is lower than that that of the rigid area.

Claims

1. A foldable display device, comprising:

a display panel; and

a window panel placed over the display panel, wherein the window panel includes;

i) a flexible area and ii) a rigid area adjacent to at least one side of the flexible area, wherein the rigid are is less flexible than the flexible area,

wherein the elastic modulus of the flexible area is less than that of the rigid area.

2. The device of claim 1, wherein the window panel further includes a folding line along which the window panel is configured to be folded and wherein the flexible area extends along the folding line.

3. The device of claim 2, wherein the window panel comprises a plurality of layers including a first layer, wherein the first layer has an elastic modulus different from the other layers, and wherein the thicknesses of the first layer are different in the rigid area and in the flexible area.

4. The device of claim 3, wherein the window panel further comprises a second layer, wherein the thicknesses of the second layer are different in the rigid area and in the flexible area, wherein the elastic modulus of the first layer is less than that of the second layer, and wherein the thickness of the first layer in the flexible area is greater than that of the second layer.

5. The device of claim 4, wherein the total thickness of the window panel is substantially uniform.

6. The device of claim 4, wherein the window panel comprises a third layer, wherein the elastic modulus of the third layer is greater than that of the second layer, and wherein the thickness of the third layer in the flexible area is less than that of the second layer.

7. The device of claim 4, wherein the first layer comprises a convex portion in the flexible area protruding toward the second layer.

8. The device of claim 7, wherein the convex portion extends in a direction substantially parallel to the folding line.

9. The device of claim 8, wherein the convex portion has a shape of a polygon, a portion of a circle, or a portion of an ellipse on a sectional view.

10. The device of claim 7, wherein the first layer further comprises a plurality of convex portions.

11. The device of claim 10, wherein the density of the convex portions decreases as the distance from the folding line increases.

12. The device of claim 10, wherein the height of the convex portions decreases as the distance from the folding line increases.

13. The device of claim 4, wherein the first layer is formed of a polymer resin.

14. The device of claim 13, wherein the polymer resin comprises an acrylic or silicone resin.

15. The device of claim 4, wherein the second layer is formed of at least one of polyimide, polycarbonate, poly(methyl methacrylate), polyethersulfone, polyamide, polyamide imide, or polycarbonate-poly(methyl methacrylate).

16. The device of claim 1, wherein the display panel comprises a liquid crystal display panel, an organic electroluminescence display panel, an electrophoresis display panel, or an electrowetting display panel.

17. The device of claim 16, wherein the display panel further comprises a touch screen panel.

18. The device of claim 1, wherein the display panel comprises a display area and a non-display area adjacent to at least one side of the display area, wherein at least a portion of the flexible area substantially overlaps the display area.

19. The device of claim 1, wherein the display panel comprises a display area and a non-display area adjacent to at least one side of the display area, and wherein the flexible area substantially overlaps the non-display area.

20. A foldable display device, comprising:

a base substrate comprising a flexible area and a rigid area adjacent to at least one side of the flexible area, wherein the rigid area is less flexible than the flexible area; and

an image display layer formed over the base substrate,

wherein the elastic modulus of the flexible area is less than that of the rigid area.

21. The device of claim 20, wherein the base substrate further comprises a folding line along which the base substrate is configured to be folded and wherein the flexible area extends along the folding line.

22. The device of claim 21, wherein the base substrate comprises a plurality of layers including a first layer, wherein the first layer has an elastic modulus different from the other layers, and wherein the thicknesses of the first layer are different in the rigid area and in the flexible area.

23. The device of claim 22, wherein the base substrate further comprises a second layer, wherein the thicknesses of the second layer are different in the rigid area and in the flexible area, wherein the elastic modulus of the first layer is less than that of the second layer, and wherein the thickness of the first layer in the flexible area is greater than that of the second layer.

24. The device of claim 23, wherein the base substrate comprises a third layer, wherein the elastic modulus of the third layer is greater than that of the second layer, and wherein the thickness of the third layer in the flexible area is less than that of the second layer.

25. The device of claim 23, wherein the first layer comprises a convex portion in the flexible area protruding toward the second layer.

26. The device of claim 25, wherein the convex portion extends in a direction substantially parallel to the folding line.

27. The device of claim 26, wherein the convex portion has a shape of a polygon, a portion of a circle, or a portion of an ellipse on sectional view.

28. The device of claim 25, wherein the first layer further comprises a plurality convex portions.

29. The device of claim 28, wherein the density of the convex portions decreases as the distance from the folding line increases.

30. The device of claim 28, wherein the height of the convex portions decreases as the distance from the folding line increases.

31. The device of claim 20, further comprising an encapsulation member encapsulating the image display layer.

32. The device of claim 31, wherein the image display layer comprises a liquid crystal display layer, an organic electroluminescence layer, an electrophoresis layer, or an electrowetting layer.

33. The device of claim 31, wherein the encapsulation member comprises an opposite substrate facing the base substrate and wherein the encapsulation member is spaced apart from the base substrate with the the image display layer interposed therebetween.

34. The device of claim 33, wherein the opposite substrate comprises a flexible area and a rigid area adjacent to at least one side of the flexible area, wherein the flexible and rigid areas of the opposite substrate are formed substantially directly above those of the base substrate, and wherein the opposite substrate has a lower elastic modulus in the flexible area than that in the rigid area.

35. A foldable display device, comprising:

a display panel; and

a window panel comprising first and second layers formed over the display panel, wherein the window panel includes a flexible area and a rigid area adjacent to at least one side of the flexible area, wherein the rigid area is less flexible than the flexible area

wherein the elastic modulus of the first layer is less than that of the second layer, and

wherein the thickness of the first layer is greater in the flexible area than in the rigid area.

36. The foldable display device of claim 35, wherein the total thickness of the window panel is substantially uniform.