Flexible substrate and flexible display device having the same

1. A flexible substrate comprising:

a flexible base substrate;

a common electrode on a first surface of the flexible base substrate;

a plurality of display structures on the common electrode;

a single-layer barrier coating of an oxide-based metal layer on a second surface of the flexible base substrate to prevent contaminants from penetrating into the display structures; and

a ground physically connected to the barrier coating,

wherein the plurality of display structures is not between the common electrode and the barrier coating.

2. The flexible substrate according to claim 1 , wherein the display structures include an ink layer having fine particles.

3. The flexible substrate according to claim 1 , wherein the barrier coating and the common electrode include one of an indium-tin-oxide layer and an indium-zinc-oxide layer.

4. A flexible substrate comprising:

a flexible base substrate;

a common electrode on a first surface of the flexible base surface;

an ink layer on the common electrode, the ink layer including fine particles reacting to an electric field to display an image;

a single-layer barrier coating of an oxide-based metal layer on a second surface of the flexible base substrate; and

a ground physically connected to the barrier coating,

wherein the ink layer is not between the common electrode and the barrier coating.

5. The flexible substrate according to claim 4 , wherein the barrier coating and the common electrode include one of indium-tin-oxide and indium-zinc-oxide.

6. A flexible display device comprising:

an ink substrate having a common electrode and an ink layer;

a driving substrate having a plurality of pixel driving devices, wherein the driving substrate is on the ink substrate such that the ink layer contacts the plurality of pixel driving devices;

a first and a second single-layer barrier coating of an oxide-based metal layer on an outer surface of the ink substrate and the driving substrate; and

a ground directly contacted to the barrier coating,

wherein the ink layer is not between the common electrode and a first single-layer barrier coating.

7. The flexible substrate according to claim 1 , wherein the thickness of the barrier coating is such that the flexibility of the base substrate is substantially maintained.

8. The flexible substrate according to claim 1 , after deposition process equipment has formed the common electrode on the first surface of the base substrate, the base substrate is put upside down, and the barrier layer is formed on the second surface of the base substrate.