Foldable display panel

1. A foldable display panel, comprising a first display area, a second display area, a third display area, an inwardly folding area defined between the first display area and the second display area, and an outwardly folding area defined between the second display area and the third display area, wherein the foldable display panel further comprises a metal supporting layer, a display module disposed on a surface of the metal supporting layer, a touch layer disposed on a surface of the display module, and a polarizing cover layer disposed on a surface of the touch layer, wherein the metal supporting layer is provided with a complete SUS stainless steel layer in the first display area, the second display area, the third display area, and the outwardly folding area, and the metal supporting layer is provided with an SUS stainless steel layer with a hollow pattern in the inwardly folding area; and

wherein the polarizing cover layer comprises a polarizing layer and a cover layer attached to each other, the polarizing layer is a liquid crystal layer and/or a polyvinyl alcohol film, and the cover layer is an organic and inorganic laminated layer, wherein a fan-out area is disposed on an edge of the display area, a driving circuit is disposed in the fan-out area, a protection layer is disposed on a surface of the driving circuit, and the protection layer and the metal supporting layer are made of a same material and provided in a same layer.

2. The foldable display panel as claimed in claim 1 , wherein the inwardly folding area is defined on a bending axis of the first display area and the second display area, and connects the first display area to the second display area.

3. The foldable, display panel as claimed in claim 2 , wherein the hollow pattern is a complete cut-out, and the cut-out is same in shape and size as the inwardly folding area, and the metal supporting layer has a segmented structure.

4. The foldable display panel as claimed in claim 2 , wherein the hollow pattern is separately arranged in parallel with or perpendicular to the bending axis, and the metal supporting layer is an integrated grid structure.

5. The foldable display panel as claimed in claim 4 , wherein the hollow pattern comprises one or more of a rectangle, a parallelogram, or a trapezoid, and a long side of the hollow pattern is parallel to the bending axis.

6. The foldable display panel as claimed in claim 1 , wherein angles between the outwardly folding area and the inwardly folding area are greater than 0 degrees, and less than or equal to 90 degrees.

7. The foldable display panel as claimed in claim 1 , wherein a thickness of the metal supporting layer is in the range of 10 um to 30 um.

8. The foldable display panel as claimed in claim 1 , wherein the display module is an OLED display module or a mini-LED display module, a stress buffer layer is disposed between the display module and the metal supporting layer, and the stress buffer layer is made of foam or rubber.

9. The foldable display panel as claimed in claim 8 , wherein the display module is the OLED display module, the OLED display module comprises a flexible substrate, a driving circuit layer disposed on a surface of the flexible substrate, a functional layer disposed on a surface of the driving circuit layer, and a packaging layer disposed on a surface of a light emitting layer, and a rigidity of the metal supporting layer is greater than a rigidity of the flexible substrate.

10. A foldable display panel, comprising a first display area, a second display area, a third display area, an inwardly folding area defined between the first display area and the second display area, and an outwardly folding area defined between the second display area and the third display area, wherein the foldable display panel further comprises a metal supporting layer, a display module disposed on a surface of the metal supporting layer, a touch layer disposed on a surface of the display module, and a polarizing cover layer disposed on a surface of the touch layer, wherein the metal supporting layer is provided with a complete SUS stainless steel layer in the first display area, the second display area, the third display area, and the outwardly folding area, and the metal supporting layer is provided with an SUS stainless steel layer with a hollow pattern in the inwardly folding area, wherein a fan-out area is disposed on an edge of the display area, a driving circuit is disposed in the fan-out area, a protection layer is disposed on a surface of the driving circuit, and the protective layer and the metal supporting layer are made of a same material and provided in a same layer.

11. The foldable display panel as claimed in claim 10 , wherein the inwardly folding area is defined on a bending axis of the first display area and the second display area, and connects the first display area to the second display area.

12. The foldable display panel as claimed in claim 11 , wherein the hollow pattern is a complete cut-out, and the cut-out is same in shape and size as the inwardly folding area, and the metal supporting layer has a segmented structure.

13. The foldable display panel as claimed in claim 11 , wherein the hollow pattern is separately arranged in parallel with or perpendicular to the bending axis, and the metal supporting layer is an integrated grid structure.

14. The foldable display panel as claimed in claim 13 , wherein the hollow pattern comprises one or more of a rectangle, a parallelogram, or a trapezoid, and a long side of the hollow pattern is parallel to the bending axis.

15. The foldable display panel as claimed in claim 10 , wherein angles between the outwardly folding area and the inwardly folding area are greater than 0 degrees, and less than or equal to 90 degrees.

16. The foldable display panel as claimed in claim 10 , wherein a thickness of the metal supporting layer is in the range of 10 um to 30 um.

17. The foldable display panel as claimed in claim 11 , wherein the display module is an OLEO display module or a mini-LED display module, a stress buffer layer is disposed between the display module and the metal supporting layer, and the stress buffer layer is made of foam or rubber.

18. The foldable display panel as claimed in claim 17 , wherein the display module is the OLED display module, the OLED display module comprises a flexible substrate, a driving circuit layer disposed on a surface of the flexible substrate, a functional layer disposed on a surface of the driving circuit layer, and a packaging layer disposed on a surface of a light emitting layer, and a rigidity of the metal supporting layer is greater than a rigidity of the flexible substrate.