Foldable display

1. A foldable display device comprising:

a first supporting member;

a second supporting member coupled to the first supporting member and configured to be rotated with respect to the first supporting member;

an ultra-elastic sheet adhered to a coupling region which connects the first supporting member and the second supporting member;

a mechanical bracket adhered to a non-coupling region except for the coupling region; and

a display module adhered to the ultra-elastic sheet and the mechanical bracket,

wherein the foldable display device is configured to outwardly expose the display module in a folded configuration,

wherein the ultra-elastic sheet and the mechanical bracket are disposed at the same layer and are connected to each other, and

wherein a modulus of elasticity of the ultra-elastic sheet is greater than a modulus of elasticity of the mechanical bracket.

2. The foldable display device of claim 1 , wherein the ultra-elastic sheet comprises a metal sheet or INVAR®.

3. The foldable display device of claim 2 , wherein the ultra-elastic sheet has a modulus of elasticity of about 50 GPa to about 80 GPa.

4. The foldable display device of claim 1 , wherein an end of the second supporting member is coupled to an end of the first supporting member by a hinge axis.

5. The foldable display device of claim 1 , wherein the display module comprises:

a display panel;

a touch screen panel on the display panel; and

a window layer on the touch screen panel.

6. The foldable display device of claim 5 , wherein the display panel comprises:

a flexible display substrate;

a display element layer on the flexible display substrate and comprising a plurality of pixels; and

a thin film encapsulation layer covering the flexible display substrate and the display element layer.

7. The foldable display device of claim 6 , wherein the display element layer comprises an organic light emission display element.

8. The foldable display device of claim 5 , wherein the window layer comprises polyimide (PI) and/or polyethylene terephthalate (PET).

9. The foldable display device of claim 5 , wherein the display module further comprises a polarization film between the display panel and the touch screen panel.

10. The display module of claim 1 , wherein the first supporting member, the ultra-elastic sheet, and the display module are stacked along a stacking direction, and

wherein the foldable display device is configured to outwardly expose the display module along the stacking direction in the folded configuration.

11. A foldable display device comprising:

a display panel including a bending region and a rigid region;

an ultra-elastic sheet under the display panel and overlapping the bending region; and

a mechanical bracket under the display panel and overlapping the rigid region,

wherein the ultra-elastic sheet and the mechanical bracket are disposed at the same layer and are connected to each other, and

wherein the ultra-elastic sheet is made of a material that is different from a material of the mechanical bracket.

12. The foldable display device of claim 11 , wherein the ultra-elastic sheet has a modulus of elasticity of about 50 GPa to about 80 GPa.

13. The foldable display device of claim 12 , wherein the modulus of elasticity of the ultra-elastic sheet is greater than a modulus of elasticity of the mechanical bracket.

14. The foldable display device of claim 11 , further comprising a supporting member overlapping the rigid region of the display panel.

15. The foldable display device of claim 11 , wherein the ultra-elastic sheet is made of a metal sheet or INVAR®.

16. The foldable display device of claim 11 , wherein the bending region is disposed between two rigid regions.

17. A foldable display device comprising:

a first supporting member;

a second supporting member coupled to the first supporting member and configured to be rotated with respect to the first supporting member;

an ultra-elastic sheet adhered to the first supporting member and the second supporting member; and

a display module adhered to the ultra-elastic sheet,

wherein the ultra-elastic sheet has a modulus of elasticity of about 50 GPa to about 80 GPa.

18. The foldable display device of claim 17 , wherein the modulus of elasticity of the ultra-elastic sheet is greater than a modulus of elasticity of a mechanical bracket adhered to a non-coupling region of the foldable display device.

19. The foldable display device of claim 17 , wherein an end of the second supporting member is coupled to an end of the first supporting member by a hinge axis.