Flexible display apparatus and hardness-enhancing layer for enhancing surface hardness and mechanical strength of flexible display panel

1. A flexible display apparatus, comprising:

a flexible display panel; and

a hardness-enhancing layer on the flexible display panel, the hardness-enhancing layer for enhancing surface hardness and mechanical strength of the flexible display panel;

wherein the hardness-enhancing layer comprises an inorganic material sublayer and a composite material sublayer, the composite material sublayer comprising a polymer matrix and an inorganic material dispersed in the polymer matrix;

wherein the flexible display apparatus further comprises one or more openings extending through at least the inorganic material sublayer of the hardness-enhancing layer for reducing mechanical stress in the hardness-enhancing layer when the flexible display apparatus is bent;

the flexible display panel is a foldable display panel configured to be folded along a folding axis;

the one or more openings are configured to reduce mechanical stress in the hardness-enhancing layer induced by folding the flexible display apparatus along the folding axis;

the folding axis extends through a region having multiple ones of the one or more openings or a region having multiple ones of the one or more openings on both sides thereof;

the one or more openings are arranged in a plurality of columns of openings;

openings in each column of the plurality of columns of openings are consecutively arranged along an overall direction substantially parallel to the folding axis; and

the openings in each column of the plurality of columns of openings have a misaligned arrangement so that not all of the openings in a respective one of the plurality of columns of openings are collinear along the overall direction.

2. The flexible display apparatus of claim 1 , wherein the flexible display panel comprises:

a flexible base substrate;

a plurality of light emitting elements on the flexible base substrate; and

an encapsulating layer on a side of the plurality of light emitting elements distal to the flexible base substrate, and encapsulating each of the plurality of light emitting elements;

wherein the hardness-enhancing layer is on a side of the encapsulating layer distal to the plurality of light emitting elements.

3. The flexible display apparatus of claim 1 , wherein each of the inorganic material sublayer and the inorganic material dispersed in the polymer matrix comprises silicon element.

4. The flexible display apparatus of claim 3 , wherein the inorganic material sublayer and the inorganic material dispersed in the polymer matrix comprise one or a combination of SiO x , SiO x C y , SiN x , and SiO x N y .

5. The flexible display apparatus of claim 2 , further comprising one or a combination of:

a touch electrode layer on a side of the encapsulating layer distal to the plurality of light emitting elements;

a black matrix on a side of the touch electrode layer distal to the encapsulating layer; and

a color filter on a side of the touch electrode layer distal to the encapsulating layer;

wherein the hardness-enhancing layer is on a side of one or a combination of the touch electrode layer, the black matrix, and the color filter distal to the encapsulating layer.

6. The flexible display apparatus of claim 1 , wherein the inorganic material sublayer and the composite material sublayer are laminated together.

7. The flexible display apparatus of claim 1 , wherein the hardness-enhancing layer has a pencil hardness greater than 7H.

8. The flexible display apparatus of claim 1 , further comprising a flexible cover glass on a side of the hardness-enhancing layer distal to the flexible display panel.

9. The flexible display apparatus of claim 8 , further comprising an optical clear resin layer between the flexible cover glass and the hardness-enhancing layer, the optical clear resin layer adhering the flexible cover glass onto a surface of the hardness-enhancing layer.

10. A hardness-enhancing layer for enhancing surface hardness and mechanical strength of a flexible display panel, comprising an inorganic material sublayer and a composite material sublayer, the composite material sublayer comprising a polymer matrix and an inorganic material dispersed in the polymer matrix;

wherein the hardness-enhancing layer has a pencil hardness of greater than 7H;

wherein the hardness-enhancing layer further comprises one or more openings extending through at least the inorganic material sublayer of the hardness-enhancing layer for reducing mechanical stress in the hardness-enhancing layer when the hardness-enhancing layer is bent;

the one or more openings are configured to reduce mechanical stress in the hardness-enhancing layer induced by folding the hardness-enhancing layer along a folding axis;

the folding axis extends through a region having multiple ones of the one or more openings or a region having multiple ones of the one or more openings on both sides thereof

the one or more openings are arranged in a plurality of columns of openings;

openings in each column of the plurality of columns of openings are consecutively arranged along an overall direction substantially parallel to the folding axis; and

the openings in each column of the plurality of columns of openings have a misaligned arrangement so that not all of the openings in a respective one of the plurality of columns of openings are collinear along the overall direction.