Flexible display device
A flexible display device is disclosed. The disclosed flexible display device includes a display panel configured to display an image; and a back film under the display panel. The back film includes a plurality of depressed patterns at a surface adjacent to the display panel. The plurality of depressed patterns are spaced apart from each other and extend in a direction away from a center of the back film.
1. A flexible display device, comprising:
a flexible display panel configured to display an image; and
a back film under the display panel,
wherein the back film includes a plurality of depressed patterns at a surface adjacent to the display panel,
wherein the plurality of depressed patterns are spaced apart from each other and extend in a direction away from a center of the back film,
wherein the back film has an elongation of 6% to 15% and a modulus of 3.5 GPa to 3.9 GPa, and
wherein each of the plurality of depressed patterns has a rectangular or square cross section, and widths of the plurality of depressed patterns gradually decrease as a distance from the center of the back film increases in a plan view; and
a total area of portions of the back film contacting the display panel is 50% to 70% of a total overlapping area between the back film and the display panel in the plan view.
2. The flexible display device of claim 1 , wherein each of the plurality of depressed patterns has a straight line shape.
3. The flexible display device of claim 2 , wherein the plurality of depressed patterns are positioned at a distance from the center of the back film such that the plurality of depressed patterns form a rectangle.
4. The flexible display device of claim 2 , wherein spaces between the plurality of depressed patterns increase as a distance from the center of the back film increases.
5. The flexible display device of claim 1 , wherein each of the plurality of depressed patterns has a curved line shape.
6. The flexible display device of claim 5 , wherein the plurality of depressed patterns are positioned at a distance from the center of the back film such that the plurality of depressed patterns form a circle.
7. The flexible display device of claim 5 , wherein spaces between the plurality of depressed patterns increase with a distance from the center of the back film.
8. The flexible display device of claim 1 , wherein a depth of each of the plurality of depressed patterns is 0.4 to 0.6 times a thickness of the back film.
9. The flexible display device of claim 1 , wherein the back film is formed of polyethylene terephthalate (PET), polyethylene naphthalate (PEN), cyclic olefin copolymer (COC), or polyamide-imide (PAI).