Flexible cover panels, flexible display panels, and foldable display devices.

Abstract

The invention relates to a flexible cover (10), a flexible display panel, and a foldable display device. The flexible cover (10) has a bending zone (ZW) and a non-bending zone (FZW) arranged in the first direction (X). The flexible cover (10) consists of an unequal thickness ultra-thin glass layer (1), a flexible layer (2), and a reinforcing layer (3). The concave structure (11) is made on the unequal thickness ultra-thin glass layer (1), and at least part of the concave structure (11) is in the bending zone (ZW). The flexible layer (2) is at least arranged in the concave structure (11). The reinforcing layer (3) is at least arranged in the concave structure (11), the stiffness of the reinforcing layer (3) is greater than the stiffness of the flexible layer (2), and the stiffness of the reinforcing layer (3) is less than the stiffness of the unequal thickness ultra-thin glass layer (1). The flexible cover (10) can be easily bent in the bending zone (ZW), and has strong impact resistance and superior performance in drop tests of spherical objects.

Description

Flexible cover, flexible display panel and foldable display device

[0001] Cross-references

[0002] This disclosure claims priority to Chinese patent application number 202311434398.5 filed on October 31, 2023, entitled “Flexible cover, flexible display panel and foldable display device”, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present disclosure relates to the field of display technology, and in particular, to a flexible cover plate, a flexible display panel including the flexible cover plate, and a foldable display device including the flexible display panel. Background Art

[0004] To ensure the bending performance of foldable display devices, the cover plates of foldable display devices are made of materials with low modulus, which reduces the cover plate's protective effect on the display substrate. However, the cover plates of foldable display devices made of materials with high modulus result in high stress after bending, which affects the display quality and service life of the display substrate and is prone to creases. Therefore, the flexibility and hardness of the cover plates of current foldable display devices are not compatible.

[0005] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present disclosure, and therefore may include information that does not constitute prior art known to ordinary technicians in the field.

[0006] Summary of the Invention

[0007] The purpose of the present disclosure is to overcome the deficiencies of the above-mentioned prior art and to provide a flexible cover, a flexible display panel including the flexible cover, and a foldable display device including the flexible display panel.

[0008] According to one aspect of the present disclosure, a flexible cover is provided, having a bending area and a non-bending area arranged along a first direction, the flexible cover comprising:

[0009] Ultra-thin glass layers of unequal thickness, wherein a recessed structure is provided on the ultra-thin glass layers of unequal thickness, and at least a portion of the recessed structure is located in the bending region;

[0010] a flexible layer, at least disposed within the recessed structure;

[0011] The reinforcing layer is at least arranged in the recessed structure, the modulus of the reinforcing layer is greater than the modulus of the flexible layer, and the modulus of the reinforcing layer is less than the modulus of the ultra-thin glass layers of unequal thickness.

[0012] In an exemplary embodiment of the present disclosure, a groove is provided on the reinforcement layer, and the groove extends along a second direction, and the second direction is perpendicular to the first direction.

[0013] In an exemplary embodiment of the present disclosure, the groove is provided on a side of the reinforcement layer close to the bottom wall of the recessed structure, or the groove is provided on a side of the reinforcement layer away from the bottom wall of the recessed structure.

[0014] In an exemplary embodiment of the present disclosure, the depth of the groove is less than or equal to 50% of the thickness of the reinforcement layer.

[0015] In an exemplary embodiment of the present disclosure, the groove arranged on the side of the reinforcing layer close to the bottom wall of the recessed structure is a first groove, and the groove arranged on the side of the reinforcing layer away from the bottom wall of the recessed structure is a second groove. The first groove and the second groove are staggered, or the first groove and the second groove are opposite to each other.

[0016] In an exemplary embodiment of the present disclosure, the sum of the depth of the first groove and the depth of the second groove is less than or equal to 50% of the thickness of the reinforcement layer.

[0017] In an exemplary embodiment of the present disclosure, the ratio of the absolute value of the difference between the refractive index of the flexible layer and the refractive index of the ultra-thin glass layer of unequal thickness to the refractive index of the ultra-thin glass layer of unequal thickness is less than or equal to 0.5%, and the ratio of the absolute value of the difference between the refractive index of the strengthening layer and the refractive index of the ultra-thin glass layer of unequal thickness to the refractive index of the ultra-thin glass layer of unequal thickness is less than or equal to 0.5%.

[0018] In an exemplary embodiment of the present disclosure, the ratio of the absolute value of the difference between the refractive index of the flexible layer and the refractive index of the ultra-thin glass layer of unequal thickness to the refractive index of the ultra-thin glass layer of unequal thickness is less than or equal to 0.3%, and the ratio of the absolute value of the difference between the refractive index of the strengthening layer and the refractive index of the ultra-thin glass layer of unequal thickness to the refractive index of the ultra-thin glass layer of unequal thickness is less than or equal to 0.3%.

[0019] In an exemplary embodiment of the present disclosure, the modulus of the reinforcement layer is greater than or equal to 0.1 GPa and less than or equal to 6 GPa, and the modulus of the flexible layer is greater than or equal to 0.01 GPa and less than or equal to 1 GPa.

[0020] In an exemplary embodiment of the present disclosure, a ratio of a total thickness of the reinforcement layer to a depth of the recessed structure is greater than or equal to 0.2 and less than or equal to 0.7.

[0021] In an exemplary embodiment of the present disclosure, a ratio of the total thickness of the reinforcement layer to the depth of the recessed structure is greater than or equal to 0.3 and less than or equal to 0.5.

[0022] In an exemplary embodiment of the present disclosure, in the second direction, the ratio of the length of the reinforcing layer to the length of the recessed structure is greater than or equal to 0.75 and less than or equal to 1; in the first direction, the ratio of the width of the reinforcing layer to the width of the recessed structure is greater than or equal to 0.75 and less than or equal to 1, and the first direction intersects with the second direction.

[0023] In an exemplary embodiment of the present disclosure, the reinforcement layer includes a first part, a second part and a third part connected in sequence along the first direction, the thickness of the first part is greater than the thickness of the second part, and the thickness of the third part is greater than the thickness of the second part.

[0024] In an exemplary embodiment of the present disclosure, in the first direction, the width of the first portion is less than or equal to 50% of the width of the second portion, and the width of the third portion is less than or equal to 50% of the width of the second portion.

[0025] In an exemplary embodiment of the present disclosure, the recessed structure includes a first side wall, a first transition surface, a bottom wall, a second transition surface and a second side wall connected in sequence; the bottom wall is connected to the first transition surface to form a first connecting portion, and the first connecting portion is arranged opposite to the first portion; the bottom wall is connected to the second transition surface to form a second connecting portion, and the second connecting portion is arranged opposite to the third portion.

[0026] In an exemplary embodiment of the present disclosure, the ultra-thin glass layer of unequal thickness has two surfaces arranged opposite to each other; both surfaces are provided with the recessed structure, and the recessed structures on the two surfaces are arranged opposite to each other, or the recessed structure is provided on only one of the surfaces.

[0027] In an exemplary embodiment of the present disclosure, the flexible layer and the reinforcing layer are provided in the recessed structures on the two surfaces; or,

[0028] The two oppositely arranged surfaces of the ultra-thin glass layer of unequal thickness are a first surface and a second surface, the concave structure arranged on the first surface is a first concave structure, and the concave structure arranged on the second surface is a second concave structure, only the flexible layer is arranged in the first concave structure, and the flexible layer and the reinforcing layer are arranged in the second concave structure.

[0029] In an exemplary embodiment of the present disclosure, within one of the recessed structures, the flexible layer is provided as at least two layers, the reinforcing layer is provided as at least one layer, and the reinforcing layers and the flexible layers are alternately provided.

[0030] In an exemplary embodiment of the present disclosure, the outermost flexible layer extends outside the recessed structure.

[0031] In an exemplary embodiment of the present disclosure, within one of the recessed structures, the reinforcement layer is provided as two layers, the flexible layer is provided as one layer, and at least one reinforcement layer is located on a side of the flexible layer away from the ultra-thin glass layers of unequal thickness.

[0032] In an exemplary embodiment of the present disclosure, within one of the recessed structures, the flexible layer is provided as one layer, the reinforcing layer is provided as one layer, and the reinforcing layer is located on a side of the flexible layer away from the ultra-thin glass layers of unequal thickness.

[0033] According to another aspect of the present disclosure, there is provided a flexible display panel, comprising:

[0034] display substrate;

[0035] The flexible cover plate is any one of the flexible cover plates described above, and the flexible cover plate is arranged on the light-emitting side of the display substrate.

[0036] According to another aspect of the present disclosure, a foldable display device is provided, comprising the flexible display panel described above.

[0037] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The accompanying drawings are incorporated into and constitute a part of the specification, illustrate embodiments consistent with the present disclosure, and together with the specification, are used to explain the principles of the present disclosure. Obviously, the drawings described below are only some embodiments of the present disclosure, and those skilled in the art can derive other drawings based on these drawings without inventive effort.

[0039] FIG1 is a schematic structural diagram of an exemplary embodiment of a flexible cover disclosed herein.

[0040] FIG2 is a schematic cross-sectional view of a first exemplary embodiment of ultra-thin glass layers of unequal thickness in the flexible cover plate in FIG1 .

[0041] FIG3 is a schematic cross-sectional view of a second exemplary embodiment of ultra-thin glass layers of unequal thickness in the flexible cover plate in FIG1 .

[0042] FIG4 is a partial enlarged schematic diagram of the portion indicated by I in FIG3 .

[0043] FIG5 is a schematic structural diagram of the reinforcement layer in FIG3 .

[0044] FIG6 is a schematic structural diagram of a second exemplary embodiment of a reinforcement layer.

[0045] FIG. 7 is a schematic structural diagram of a third exemplary embodiment of a reinforcement layer.

[0046] FIG8 is a schematic structural diagram of a third exemplary embodiment of ultra-thin glass layers of unequal thickness in the flexible cover plate in FIG1 .

[0047] FIG9 is a schematic structural diagram of the reinforcement layer in FIG8 .

[0048] FIG. 10 is a schematic structural diagram of a fifth exemplary embodiment of a reinforcement layer.

[0049] FIG. 11 is a schematic structural diagram of a sixth exemplary embodiment of a reinforcement layer.

[0050] FIG. 12 is a schematic structural diagram of a seventh exemplary embodiment of a reinforcement layer.

[0051] FIG13 is a schematic diagram of the top structure of the reinforcement layer in FIG9-FIG12.

[0052] FIG14 is a schematic structural diagram of a fourth exemplary embodiment of ultra-thin glass layers of unequal thickness in the flexible cover plate in FIG1 .

[0053] FIG15 is a schematic structural diagram of a fifth exemplary embodiment of ultra-thin glass layers of unequal thickness in the flexible cover plate in FIG1 .

[0054] FIG16 is a structural diagram of a sixth exemplary embodiment of ultra-thin glass layers of unequal thickness in the flexible cover plate in FIG1 .

[0055] FIG17 is a structural diagram of a seventh exemplary embodiment of ultra-thin glass layers of unequal thickness in the flexible cover in FIG1 .

[0056] FIG18 is a schematic structural diagram of an eighth exemplary embodiment of ultra-thin glass layers of unequal thickness in the flexible cover plate in FIG1 .

[0057] FIG19 is a schematic structural diagram of a ninth exemplary embodiment of ultra-thin glass layers of unequal thickness in the flexible cover plate in FIG1 .

[0058] FIG20 is a schematic structural diagram of an exemplary embodiment of a flexible display panel disclosed herein.

[0059] Description of reference numerals:

[0060] 1. Ultra-thin glass layer of unequal thickness; 1a. First surface; 1b. Second surface; 11. Recessed structure; 11a. First recessed structure; 11b. Second recessed structure; 111. First sidewall; 112. First transition surface; 112-3. First connecting portion; 113. Bottom wall; 113-4. Second connecting portion; 114. Second transition surface; 115. Second sidewall;

[0061] 2. Flexible layer;

[0062] 3. Reinforcement layer; 31. First portion; 32. Second portion; 33. Third portion; 34. Groove; 34a. First groove; 34a1. First groove sidewall; 34b. Second groove; 34b1. Second groove sidewall;

[0063] 10. Flexible cover;

[0064] 20. Display substrate; 201. Base substrate; 202. Driving backplane; 203. Light-emitting device;

[0065] 30. Touch substrate;

[0066] X, first direction; Y, second direction; Z, thickness direction; ZW, bending area; FZW, non-bending area. DETAILED DESCRIPTION

[0067] Example embodiments will now be described more fully with reference to the accompanying drawings. However, the example embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete and will fully convey the concepts of the example embodiments to those skilled in the art. Like reference numerals in the figures represent identical or similar structures, and thus their detailed descriptions will be omitted. Furthermore, the figures are merely schematic illustrations of the present disclosure and are not necessarily drawn to scale.

[0068] Although relative terms such as "upper" and "lower" are used in this specification to describe the relationship of one illustrated component to another, these terms are used herein for convenience only, such as in accordance with the orientation of the illustrations in the accompanying drawings. It will be understood that if the illustrated device were flipped upside down, the component described as "upper" would become the component "lower." When a structure is referred to as "on" another structure, this may mean that the structure is integrally formed with the other structure, that the structure is "directly" disposed on the other structure, or that the structure is "indirectly" disposed on the other structure via the other structure.

[0069] The terms "a", "an", "the", "said" and "at least one" are used to indicate the presence of one or more elements / components / etc.; the terms "including" and "having" are used to express open-ended inclusion and mean that additional elements / components / etc. may be present in addition to the listed elements / components / etc.; the terms "first", "second" and "third" etc. are used only as labels and are not intended to limit the quantity of their objects.

[0070] In this application, unless otherwise specified or limited, the term "connected" should be understood broadly. For example, "connected" can mean fixed, removable, or integrated; it can be directly connected or indirectly connected through an intermediary. "And / or" simply describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can mean: A exists alone, A and B exist simultaneously, or B exists alone. Additionally, the character " / " in this document generally indicates that the related objects are in an "or" relationship.

[0071] An example embodiment of the present disclosure provides a flexible cover 10, as shown in Figures 1 to 19, the flexible cover 10 has a bending area ZW and a non-bending area FZW arranged along a first direction X, and the flexible cover 10 may include an ultra-thin glass layer 1 of unequal thickness, a flexible layer 2 and a reinforcing layer 3; a recessed structure 11 is provided on the ultra-thin glass layer 1 of unequal thickness, and at least a portion of the recessed structure 11 is located in the bending area ZW; the flexible layer 2 is at least provided in the recessed structure 11; the reinforcing layer 3 is at least provided in the recessed structure 11, and the modulus of the reinforcing layer 3 is greater than the modulus of the flexible layer 2, and the modulus of the reinforcing layer 3 is less than the modulus of the ultra-thin glass layer 1 of unequal thickness.

[0072] The flexible cover plate 10 disclosed herein, on the one hand, reduces the hardness of the ultra-thin glass layer 1 of unequal thickness in the bending area ZW by providing a recessed structure 11 on the ultra-thin glass layer 1 of unequal thickness in the bending area ZW, so that the ultra-thin glass layer 1 of unequal thickness can be easily bent in the bending area ZW; on the other hand, the modulus of the reinforcing layer 3 is greater than the modulus of the flexible layer 2, so that the reinforcing layer 3 can improve the impact resistance of the ultra-thin glass layer 1 of unequal thickness in the bending area ZW (for example, pen and ball drops), and the flexibility of the reinforcing layer 3 is better than that of the ultra-thin glass layer 1 of unequal thickness, which is beneficial to the bending of the flexible cover plate 10; and the flexible layer 2 can ensure the bending performance of the ultra-thin glass layer 1 of unequal thickness in the bending area ZW.

[0073] The flexible cover 10 is bendable, and therefore, the flexible cover 10 has a bending region ZW, and the flexible cover 10 is bent in the bending region ZW. Specifically, as shown in FIG1 , the flexible cover 10 may include two non-bending regions FZW and one bending region ZW, the two non-bending regions FZW and one bending region ZW being arranged along a first direction X, and the bending region ZW being connected between the two non-bending regions FZW. Of course, in some other example embodiments of the present disclosure, the number of non-bending regions FZW and bending regions ZW may be more as needed, which will not be described here one by one.

[0074] The flexible cover 10 can be set to a single-layer structure, in which case the flexible cover 10 can include a layer of inorganic material; the flexible cover 10 can also be set to a multi-layer structure, in which case the flexible cover 10 can include at least one layer of inorganic material and at least one layer of organic material, or at least two layers of inorganic material; the inorganic material layer can be ultra-thin glass (Ultra Thin Glass, UTG), ultra-thin glass of unequal thickness (Ultra Flexible Glass, UFG), etc.; the organic material can be one or more of polyimide (PI), polyethylene terephthalate, polyethylene naphthalate (PEN), polycarbonate (PC), polymethyl methacrylate (PMMA), etc.

[0075] In this example embodiment, the flexible cover plate 10 may include an ultra-thin glass layer 1 of unequal thickness. The thickness of the ultra-thin glass layer 1 of unequal thickness is greater than 30 μm and less than or equal to 500 μm. For example, the thickness of the ultra-thin glass layer 1 of unequal thickness can be 50 μm, 80 μm, 100 μm, 120 μm, 150 μm, 170 μm, 200 μm, 230 μm, 250 μm, 280 μm, 300 μm, 320 μm, 350 μm, 370 μm, 400 μm, 430 μm, 450 μm, 480 μm, etc. The ultra-thin glass layer 1 of unequal thickness can be produced by conventional processes such as overflow method, down-draw method, and casting method.

[0076] 2 , a recessed structure 11 is provided on the ultra-thin glass layer 1 of unequal thickness. For example, the recessed structure 11 can be formed by etching a portion of the ultra-thin glass layer 1 of unequal thickness through a thinning process such as photolithography. The thickness of the ultra-thin glass layer 1 of unequal thickness remaining at the recessed structure 11 is greater than or equal to 30 μm and less than or equal to 470 μm. For example, the thickness of the ultra-thin glass layer 1 of unequal thickness remaining at the recessed structure 11 can be 50 μm, 80 μm, 100 μm, 120 μm, 150 μm, 170 μm, 200 μm, 230 μm, 250 μm, 280 μm, 300 μm, 320 μm, 350 μm, 370 μm, 400 μm, 430 μm, 450 μm, and the like.

[0077] At least part of the recessed structure 11 is located in the bending area ZW. For example, the entire recessed structure 11 may be located in the bending area ZW, and the recessed structure 11 may be slightly smaller than the bending area ZW; the entire recessed structure 11 may be located in the bending area ZW, and the recessed structure 11 basically occupies the bending area ZW; or a part of the recessed structure 11 may be located in the bending area ZW, and the other part of the recessed structure 11 may be located in the non-bending area FZW.

[0078] As shown in Figure 1, the recessed structure 11 extends along the second direction Y, and the second direction Y is perpendicular to the first direction X, or it can be said that the second direction Y is perpendicular to the bending direction of the flexible cover 10; the recessed structure 11 can be a through groove that penetrates the ultra-thin glass layers 1 of unequal thickness in the second direction Y, and the recessed structure 11 can also be a blind groove that does not penetrate the ultra-thin glass layers 1 of unequal thickness at one end or both ends.

[0079] 2 , the recessed structure 11 may be configured as a rectangular groove, that is, the cross-sectional shape of the recessed structure 11 perpendicular to the second direction Y may be a rectangle.

[0080] As shown in FIG3 , the recessed structure 11 can be configured as a U-shaped groove, that is, the cross-sectional shape of the recessed structure 11 perpendicular to the second direction Y can be U-shaped. Specifically, the recessed structure 11 can include a first side wall 111, a first transition surface 112, a bottom wall 113, a second transition surface 114, and a second side wall 115 connected in sequence. The first transition surface 112 and the second transition surface 114 can be configured as arcuate surfaces, so that there is a smooth transition between the first side wall 111 and the bottom wall 113, and a smooth transition between the bottom wall 113 and the second side wall 115. In addition, stress concentration at the corners caused by forming right-angled, acute-angled, or obtuse-angled structures is avoided, so that the corners of the recessed structure 11 are not easily cracked, thereby ensuring the strength of the ultra-thin glass layers 1 of unequal thickness. In addition, the first transition surface 112 and the second transition surface 114 may include a plane and curved surfaces connected to both sides of the plane, which can also make the first side wall 111 and the bottom wall 113 transition smoothly, and the bottom wall 113 and the second side wall 115 transition smoothly, so as to ensure the strength of the ultra-thin glass layer 1 of unequal thickness.

[0081] In some other exemplary embodiments of the present disclosure, the sidewalls of the recessed structure 11 can be configured as stepped, i.e., the first sidewall 111 and the second sidewall 115 can be configured as stepped surfaces, so that the recessed structure 11 forms a structure with a gradually expanding opening. The stepped recessed structure 11 can be formed through multiple thinning processes. The recessed structure 11 can also be provided in a plurality of intervals, with the plurality of recessed structures 11 arranged in the bending region ZW along the second direction Y.

[0082] Of course, in some other example embodiments of the present disclosure, the flexible cover 10 may include two or more layers of ultra-thin glass layers 1 of unequal thickness. In this case, a recessed structure 11 is provided on at least one layer of ultra-thin glass layers 1 of unequal thickness. That is, the recessed structure 11 may be provided on one layer of ultra-thin glass layers 1 of unequal thickness, or the recessed structure 11 may be provided on two or more layers of ultra-thin glass layers 1 of unequal thickness. The specific structure of the recessed structure 11 has been described in detail above, so it will not be repeated here. By providing the recessed structure 11 on the ultra-thin glass layers 1 of unequal thickness in the bending area ZW, the hardness of the ultra-thin glass layers 1 of unequal thickness in the bending area ZW is reduced, so that the ultra-thin glass layers 1 of unequal thickness can be easily bent in the bending area ZW.

[0083] In this example embodiment, a flexible layer 2 is provided at least in the recessed structure 11, and a reinforcing layer 3 is provided at least in the recessed structure 11, and the modulus of the reinforcing layer 3 is greater than the modulus of the flexible layer 2, and the modulus of the reinforcing layer 3 is less than the modulus of the ultra-thin glass layer 1 of unequal thickness, so that the reinforcing layer 3 can improve the impact resistance of the ultra-thin glass layer 1 of unequal thickness in the bending area ZW (for example, pen dropping and ball dropping), and the flexibility of the reinforcing layer 3 is better than the flexibility of the ultra-thin glass layer 1 of unequal thickness, which is conducive to the bending of the flexible cover 10; and the flexible layer 2 can ensure the bending performance of the ultra-thin glass layer 1 of unequal thickness in the bending area ZW.

[0084] Specifically, the modulus of the reinforcement layer 3 is greater than or equal to 0.1 Gpa and less than or equal to 6 Gpa. For example, the modulus of the reinforcement layer 3 can be 0.3 Gpa, 0.5 Gpa, 0.8 Gpa, 1 Gpa, 1.2 Gpa, 1.5 Gpa, 1.7 Gpa, 2 Gpa, 2.3 Gpa, 2.5 Gpa, 2.8 Gpa, 3 Gpa, 3.2 Gpa, 3.5 Gpa, 3.7 Gpa, 4 Gpa, 4.3 Gpa, 4.5 Gpa, 4.8 Gpa, 5 Gpa, 5.2 Gpa, 5.5 Gpa, 5.7 Gpa, and the like.

[0085] The modulus of the flexible layer 2 is greater than or equal to 0.01 GPa and less than or equal to 1 GPa. For example, the modulus of the flexible layer 2 can be 0.03 GPa, 0.05 GPa, 0.08 GPa, 0.1 GPa, 0.12 GPa, 0.15 GPa, 0.17 GPa, 0.2 GPa, 0.23 GPa, 0.25 GPa, 0.28 GPa, 0.3 GPa, 0.32 GPa, 0.35 GPa, 0.37 GPa, 0.4 GPa, 0.43 GPa, 0.45Gpa, 0.48Gpa, 0.5Gpa, 0.52Gpa, 0.55Gpa, 0.57Gpa, 0.6Gpa, 0.63Gpa, 0.65Gpa, 0.68Gpa, 0.7Gpa, 0 .72Gpa, 0.75Gpa, 0.77Gpa, 0.8Gpa, 0.83Gpa, 0.85Gpa, 0.88Gpa, 0.9Gpa, 0.92Gpa, 0.95Gpa, 0.97Gpa, etc.

[0086] In this exemplary embodiment, the ratio of the absolute value of the difference between the refractive index λ2 of the flexible layer 2 and the refractive index λ1 of the ultra-thin glass layer 1 of unequal thickness to the refractive index λ1 of the ultra-thin glass layer 1 of unequal thickness is less than or equal to 0.5%. The specific formula is |λ2-λ1| / λ1≤0.5%. That is, the refractive index of the flexible layer 2 can be larger or smaller than the refractive index of the ultra-thin glass layer 1 of unequal thickness. For example, the ratio of the absolute value of the difference between the refractive index λ2 of the flexible layer 2 and the refractive index λ1 of the ultra-thin glass layer 1 of unequal thickness to the refractive index λ1 of the ultra-thin glass layer 1 of unequal thickness can be 0.05%, 0.1%, 0.15%, 0.2%, 0.25%, 0.3%, 0.35%, 0.4%, 0.45%, etc.

[0087] The ratio of the absolute value of the difference between the refractive index λ3 of the strengthening layer 3 and the refractive index λ1 of the ultra-thin glass layer 1 of unequal thickness to the refractive index λ1 of the ultra-thin glass layer 1 of unequal thickness is less than or equal to 0.5%. The specific formula is |λ3-λ1| / λ1≤0.5%. That is, the refractive index of the strengthening layer 3 can be larger than the refractive index of the ultra-thin glass layer 1 of unequal thickness, or smaller than the refractive index of the ultra-thin glass layer 1 of unequal thickness. For example, the ratio of the absolute value of the difference between the refractive index λ3 of the strengthening layer 3 and the refractive index λ1 of the ultra-thin glass layer 1 of unequal thickness to the refractive index λ1 of the ultra-thin glass layer 1 of unequal thickness can be 0.05%, 0.1%, 0.15%, 0.2%, 0.25%, 0.3%, 0.35%, 0.4%, 0.45%, etc.

[0088] Such an arrangement ensures that the refractive index of the flexible layer 2 is slightly different from that of the ultra-thin glass layer 1 of unequal thickness, thereby preventing the outline of the flexible layer 2 from being generated due to the difference in refractive index between the edge of the flexible layer 2 and the ultra-thin glass layer 1 of unequal thickness, thereby ensuring the display effect; the refractive index of the strengthening layer 3 is also slightly different from that of the ultra-thin glass layer 1 of unequal thickness, and similarly, preventing the outline of the strengthening layer 3 from being generated due to the difference in refractive index between the edge of the strengthening layer 3 and the ultra-thin glass layer 1 of unequal thickness, thereby ensuring the display effect.

[0089] Optionally, the ratio of the absolute value of the difference between the refractive index λ2 of the flexible layer 2 and the refractive index λ1 of the ultra-thin glass layer 1 of unequal thickness to the refractive index λ1 of the ultra-thin glass layer 1 of unequal thickness is less than or equal to 0.3%, and the specific formula is |λ2-λ1| / λ1≤0.3%; the ratio of the absolute value of the difference between the refractive index λ3 of the strengthening layer 3 and the refractive index λ1 of the ultra-thin glass layer 1 of unequal thickness to the refractive index λ1 of the ultra-thin glass layer 1 of unequal thickness is less than or equal to 0.3%, and the specific formula is |λ3-λ1| / λ1≤0.3%.

[0090] Such an arrangement makes the difference between the refractive index of the flexible layer 2 and the refractive index of the unequal thickness ultra-thin glass layer 1 smaller, thereby avoiding the outline of the flexible layer 2 due to the difference in refractive index between the edge of the flexible layer 2 and the unequal thickness ultra-thin glass layer 1, thereby ensuring the display effect; the difference between the refractive index of the strengthening layer 3 and the refractive index of the unequal thickness ultra-thin glass layer 1 is also smaller. Similarly, the outline of the strengthening layer 3 due to the difference in refractive index between the edge of the strengthening layer 3 and the unequal thickness ultra-thin glass layer 1 is avoided, thereby ensuring the display effect.

[0091] The flexible layer 2 may be made of an organic material or an inorganic material. Organic materials may include polyimide (PI), polyethylene terephthalate, polyethylene naphthalate (PEN), polycarbonate (PC), polymethyl methacrylate (PMMA), polyurethane, polyaramid, acrylic, polyacrylate, polyvinylidene chloride, polyvinylidene fluoride (PVDF), polystyrene, ethylene vinyl alcohol copolymer, polyethersulfone (PES), polyetherimide (PEI), polyphenylene sulfide (PPS), polyallyl ester, triacetate film (TAC), cellulose acetate propionate (CAP), and the like. Inorganic materials may include flexible glass.

[0092] The reinforcing layer 3 may be made of an organic material or an inorganic material. Organic materials may include polyimide (PI), polyethylene terephthalate, polyethylene naphthalate (PEN), polycarbonate (PC), polymethyl methacrylate (PMMA), polyurethane, polyaramid, acrylic, polyacrylate, polyvinylidene chloride, polyvinylidene fluoride (PVDF), polystyrene, ethylene vinyl alcohol copolymer, polyethersulfone (PES), polyetherimide (PEI), polyphenylene sulfide (PPS), polyallyl ester, triacetate film (TAC), cellulose acetate propionate (CAP), and the like. Inorganic materials may include flexible glass.

[0093] The flexible layer 2 and the reinforcing layer 3 can be formed by coating and dispensing processes. The reinforcing layer 3 can be a finished film and fixed on the ultra-thin glass layer 1 of unequal thickness by laminating. The above process methods can be used on a flexible cover plate 10.

[0094] In this exemplary embodiment, the ratio of the total thickness of the reinforcement layer 3 to the depth of the recessed structure 11 is greater than or equal to 0.2 and less than or equal to 0.7. For example, the ratio of the total thickness of the reinforcement layer 3 to the depth of the recessed structure 11 can be 0.23, 0.25, 0.28, 0.3, 0.32, 0.35, 0.37, 0.4, 0.43, 0.45, 0.48, 0.5, 0.52, 0.55, 0.57, 0.6, 0.63, 0.65, 0.68, etc.

[0095] If the ratio of the total thickness of the reinforcing layer 3 to the depth of the recessed structure 11 is too small, the total thickness of the reinforcing layer 3 is too small, and the reinforcing effect of the reinforcing layer 3 is not obvious. If the ratio of the total thickness of the reinforcing layer 3 to the depth of the recessed structure 11 is too large, the total thickness of the reinforcing layer 3 is too large, resulting in excessive strength and poor bending performance.

[0096] The above numerical range not only ensures the strengthening effect of the reinforcing layer 3 , but also ensures the bending effect of the flexible cover plate 10 in the bending area ZW.

[0097] Optionally, the ratio of the total thickness of the reinforcing layer 3 to the depth of the recessed structure 11 is greater than or equal to 0.3 and less than or equal to 0.5, to further ensure the reinforcing effect of the reinforcing layer 3 and the bending effect of the flexible cover plate 10 in the bending area ZW.

[0098] It should be noted that, when the reinforcing layer 3 is provided as a single layer in the thickness direction Z of the ultra-thin glass layer 1 of unequal thickness, the total thickness of the reinforcing layer 3 naturally refers to the thickness of one reinforcing layer 3; when the reinforcing layer 3 is provided as two or more layers in the thickness direction Z of the ultra-thin glass layer 1 of unequal thickness, the total thickness of the reinforcing layer 3 naturally refers to the thickness of two or more reinforcing layers 3. Moreover, when the thickness of the reinforcing layer 3 varies at different locations, the ratio of the total thickness of the reinforcing layer 3 at each location to the depth of the recessed structure 11 may vary, as long as it is within the above range.

[0099] 2 , the reinforcement layer 3 may be configured as a flat plate structure, that is, the thickness of the reinforcement layer 3 is substantially the same at all locations.

[0100] 8 to 13 , a groove 34 is provided on the reinforcing layer 3. The groove 34 extends along the second direction Y, and the second direction Y is perpendicular to the first direction X, that is, the extension direction of the groove 34 is perpendicular to the bending direction of the flexible cover plate 10. The groove 34 can increase the flexibility of the reinforcing layer 3, making the reinforcing layer 3 more conducive to bending, and the stress after bending is smaller; the side wall of the groove 34 can ensure the strength of the reinforcing layer 3, so that the reinforcing layer 3 has a better reinforcement effect.

[0101] The groove 34 can be provided on one side of the reinforcing layer 3. Referring to FIG8 , the groove 34 can be provided on the side of the reinforcing layer 3 away from the bottom wall 113 of the recessed structure 11. Of course, in some other exemplary embodiments of the present disclosure, the groove 34 can also be provided on the side of the reinforcing layer 3 close to the bottom wall 113 of the recessed structure 11;

[0102] The depth of the groove 34 is less than or equal to 50% of the thickness of the reinforcement layer 3 . For example, the depth of the groove 34 may be 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45% or the like of the thickness of the reinforcement layer 3 .

[0103] If the depth of the groove 34 is too large, the impact resistance of the reinforcing layer 3 is lost; therefore, the above numerical range allows the reinforcing layer 3 to have both flexibility and impact resistance.

[0104] At least two grooves 34 may be provided. In the first direction X, the ratio of the total width of the grooves 34 to the width of the reinforcement layer 3 is greater than or equal to 0.2 and less than or equal to 0.7. For example, the ratio of the total width of the grooves 34 to the width of the reinforcement layer 3 may be 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, etc.

[0105] If the ratio of the total width of the groove 34 to the width of the reinforcing layer 3 is too small, the groove 34 has little effect on increasing the flexibility of the reinforcing layer 3; if the ratio of the total width of the groove 34 to the width of the reinforcing layer 3 is too large, the strength of the reinforcing layer 3 cannot be guaranteed.

[0106] The above numerical range not only ensures that the flexibility of the reinforcing layer 3 can be increased by the groove 34, making the reinforcing layer 3 more conducive to bending and having less stress after bending; but also ensures the strength of the reinforcing layer 3, so that the reinforcing layer 3 has a better strengthening effect.

[0107] 9, 11, and 12, the groove 34 may be a rectangular groove, that is, the shape of the cross section of the groove 34 perpendicular to the second direction Y may be a rectangle. As shown in FIG10, the groove 34 may be an arcuate groove, that is, the shape of the cross section of the groove 34 perpendicular to the second direction Y may be semicircular, less semicircular, semi-elliptical, less semi-elliptical, etc. Of course, the groove 34 may also have other shapes, which are not described here one by one.

[0108] In addition, in some other exemplary embodiments of the present disclosure, as shown in Figures 11 and 12, the grooves 34 can be provided on both sides of the reinforcement layer 3. Specifically, the groove 34 provided on the side of the reinforcement layer 3 close to the bottom wall 113 of the recessed structure 11 is a first groove 34a, and the groove 34 provided on the side of the reinforcement layer 3 away from the bottom wall 113 of the recessed structure 11 is a second groove 34b. As shown in Figure 12, the first groove 34a and the second groove 34b can be staggered, that is, the first groove 34a is directly opposite the second groove sidewall 34b1 between two adjacent second grooves 34b, and the second groove 34b is directly opposite the first groove sidewall 34a1 between two adjacent first grooves 34a. In addition, depending on the difference in the width of the first groove 34a and the width of the second groove 34b, as well as the difference in the width of the first groove sidewall 34a1 and the width of the second groove sidewall 34b1, the first groove 34a can be provided opposite a portion of the second groove 34b.

[0109] As shown in Figure 11, the first groove 34a and the second groove 34b can be arranged relative to each other. For example, the first groove 34a and the second groove 34b can be arranged directly opposite to each other. Of course, directly opposite does not only mean completely directly opposite, but there can also be a certain error. Depending on the process and equipment, the error range is also different. As long as it is within the error range, it is considered to be relatively set.

[0110] In this case, the sum of the depth of the first groove 34a and the depth of the second groove 34b is less than or equal to 50% of the thickness of the reinforcement layer 3. For example, the sum of the depth of the first groove 34a and the depth of the second groove 34b can be 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45% and so on of the thickness of the reinforcement layer 3.

[0111] If the sum of the depths of the first groove 34 a and the second groove 34 b is too large, the impact resistance of the reinforcing layer 3 is lost; therefore, the above numerical range allows the reinforcing layer 3 to have both flexibility and impact resistance.

[0112] In this example embodiment, in the second direction Y, the ratio of the length of the reinforcement layer 3 to the length of the recessed structure 11 is greater than or equal to 0.75 and less than or equal to 1. For example, the ratio of the length of the reinforcement layer 3 to the length of the recessed structure 11 can be 0.78, 0.8, 0.82, 0.85, 0.87, 0.9, 0.93, 0.95, 0.98, etc.

[0113] Furthermore, in the first direction X, the ratio of the width of the reinforcing layer 3 to the width of the recessed structure 11 is greater than or equal to 0.75 and less than or equal to 1. For example, the ratio of the width of the reinforcing layer 3 to the width of the recessed structure 11 can be 0.78, 0.8, 0.82, 0.85, 0.87, 0.9, 0.93, 0.95, 0.98, etc. The first direction X intersects the second direction Y. For example, the first direction X can be perpendicular to the second direction Y.

[0114] The length and width of the reinforcement layer 3 may be the same as those of the recessed structure 11 , or slightly smaller than those of the recessed structure 11 .

[0115] If the ratio of the length of the reinforcement layer 3 to the length of the recessed structure 11 and the ratio of the width of the reinforcement layer 3 to the width of the recessed structure 11 are too small, it is not conducive to the full area protection function of the reinforcement layer 3. The above numerical range enables the reinforcement layer 3 to achieve full protection.

[0116] In addition, according to the actual processing accuracy, the dimensions of the reinforcement layer 3 and the recessed structure 11 are allowed to have a tolerance of ±500 μm.

[0117] 3 , when the length and width of the reinforcing layer 3 are slightly smaller than those of the recessed structure 11 , the flexible layer 2 fills the gap between the reinforcing layer 3 and the sidewalls of the recessed structure 11 , that is, the flexible layer 2 wraps the reinforcing layer 3 .

[0118] In some exemplary embodiments of the present disclosure, as shown in FIG3 and FIG5 to FIG7 , the reinforcement layer 3 may include a first portion 31, a second portion 32, and a third portion 33 sequentially connected along a first direction X. In the thickness direction Z, the thickness of the first portion 31 is greater than the thickness of the second portion 32, and the thickness of the third portion 33 is greater than the thickness of the second portion 32. That is, in the first direction X, the thickness of the middle portion of the reinforcement layer 3 is less than the thickness of the end portions. The thickness of the first portion 31 and the thickness of the third portion 33 may be the same or different.

[0119] Since the curvature radius of the second part 32 of the reinforcing layer 3 after bending is small and the stress is large, setting the thickness of the second part 32 of the reinforcing layer 3 to be thinner can reduce the stress after bending; and setting the thickness of the first part 31 and the third part 33 of the reinforcing layer 3 to be thicker can ensure the strength and impact resistance of the reinforcing layer 3.

[0120] In the first direction X, the width of the first portion 31 is less than or equal to 50% of the width of the second portion 32. For example, the width of the first portion 31 may be 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, etc. of the width of the second portion 32. The width of the third portion 33 is less than or equal to 50% of the width of the second portion 32. For example, the width of the third portion 33 may be 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, etc. of the width of the second portion 32.

[0121] If the width of the first part 31 and the width of the third part 33 are set too wide, making the width of the second part 32 too narrow, the stress of the second part 32 will be too concentrated after the reinforcing layer 3 is bent, resulting in the loss of the bending performance of the reinforcing layer 3, and easily causing cracks or breakage in the second part 32.

[0122] 3 and 4 , the approximate positions of the first connection portion 112-3 and the second connection portion 113-4 are indicated by circular dashed lines, and the relative relationship between the first connection portion 112-3 and the first portion 31, as well as the relative relationship between the second connection portion 113-4 and the third portion 33, are indicated by straight dashed lines. The bottom wall 113 is connected to the first transition surface 112 to form the first connection portion 112-3. The first connection portion 112-3 may include a portion of the bottom wall 113 close to the first transition surface 112 and a portion of the first transition surface 112 close to the bottom wall 113. After the flexible cover 10 is bent, stress is concentrated at the first connection portion 112-3, and the thickness of the first connection portion 112-3 is relatively thin, making it easy for cracks or even breakage to occur at the first connection portion 112-3.

[0123] The first connection part 112-3 is arranged opposite to the first part 31; since the first part 31 is thicker and stronger, a part of the bending stress can be borne by the first part 31, so that the stress at the first connection part 112-3 is smaller, and it is not easy to generate cracks or breakage at the first connection part 112-3.

[0124] The bottom wall 113 and the second transition surface 114 are connected to form a second connection portion 113-4. The second connection portion 113-4 may include a portion of the bottom wall 113 near the second transition surface 114 and a portion of the second transition surface 114 near the bottom wall 113. After the flexible cover 10 is bent, stress is concentrated at the second connection portion 113-4, and the thickness of the second connection portion 113-4 is relatively thin, making it prone to cracks or even breakage.

[0125] The second connection part 113-4 is arranged opposite to the third part 33; since the third part 33 is thicker and stronger, it can bear part of the bending stress through the third part 33, so that the stress at the second connection part 113-4 is smaller, and it is not easy to produce cracks or breakage at the second connection part 113-4.

[0126] 5-7 , the first portion 31 and the third portion 33 can be configured as a cylinder, a cuboid, a rounded cuboid, etc., so that the cross-section of the first portion 31 and the third portion 33 perpendicular to the second direction Y can be circular, rectangular, or rectangular with rounded corners, etc. The second portion 32 is configured as a cuboid film layer, so that the cross-section of the second portion 32 perpendicular to the second direction Y can be rectangular. Of course, the first portion 31 and the third portion 33 can also have other shapes, which are not described here.

[0127] In addition, in this case, a groove 34 can also be set on the reinforcing layer 3, and the ratio of the depth of the groove 34 to the thickness of the reinforcing layer 3 can be within the range described above, wherein the thickness of the reinforcing layer 3 refers to the thickness of the reinforcing layer 3 at the position where the groove 34 is set.

[0128] As shown in Figures 2, 3, 8, 14, and 15, in some exemplary embodiments of the present disclosure, an ultra-thin glass layer 1 of unequal thickness has two opposing surfaces. A recessed structure 11 may be provided on only one of the surfaces. The flexible layer 2 and the reinforcing layer 3 are disposed within the recessed structure 11.

[0129] 16 to 19 , in some other example embodiments of the present disclosure, recessed structures 11 may be provided on both surfaces, and the recessed structures 11 on the two surfaces may be arranged relative to each other. For example, the recessed structures 11 on the two surfaces may be arranged directly opposite each other. Of course, directly opposite does not only mean completely directly opposite, but may also have a certain error. The error range may vary depending on the process and equipment. As long as it is within the error range, it is considered to be relatively arranged.

[0130] 16 , the recessed structures 11 on both surfaces are provided with flexible layers 2 and reinforcing layers 3. The flexible layers 2 and reinforcing layers 3 in the recessed structures 11 on both surfaces can be provided symmetrically or asymmetrically.

[0131] 17 to 19 , the two oppositely disposed surfaces of the ultra-thin glass layer 1 of unequal thickness are the first surface 1a and the second surface 1b, the recessed structure 11 disposed on the first surface 1a is the first recessed structure 11a, and the recessed structure 11 disposed on the second surface 1b is the second recessed structure 11b. Only the flexible layer 2 is disposed in the first recessed structure 11a, and the flexible layer 2 and the reinforcing layer 3 are disposed in the second recessed structure 11b.

[0132] The specific structures of the flexible layer 2 and the reinforcement layer 3 have been described in detail above, and therefore will not be repeated here.

[0133] The number of layers and positional relationship of the flexible layer 2 and the reinforcing layer 3 in a recessed structure are described below. It should be noted that when the flexible layer 2 and the reinforcing layer 3 are provided in the recessed structures 11 on both surfaces, the following exemplary embodiments can be arbitrarily combined.

[0134] As shown in Figure 19, in a recessed structure 11, the flexible layer 2 is set as a layer, and the reinforcing layer 3 is set as a layer. The reinforcing layer 3 is located on the side of the flexible layer 2 away from the ultra-thin glass layer 1 of unequal thickness, that is, the flexible layer 2 is located on the inner side and the reinforcing layer 3 is located on the outer side. The reinforcing layer 3 can protect the flexible layer 2.

[0135] As shown in Figures 14 and 15 , within a recessed structure 11, two reinforcing layers 3 are provided, and one flexible layer 2 is provided. At least one reinforcing layer 3 is located on the side of the flexible layer 2 facing away from the ultra-thin glass layer 1 of unequal thickness. For example, as shown in Figure 15 , the flexible layer 2 may be located between two reinforcing layers 3, such that one reinforcing layer 3 is located on the side of the flexible layer 2 facing away from the ultra-thin glass layer 1 of unequal thickness, and one reinforcing layer 3 is located on the side of the flexible layer 2 closer to the ultra-thin glass layer 1 of unequal thickness. As shown in Figure 14 , both reinforcing layers 3 may be located on the side of the flexible layer 2 facing away from the ultra-thin glass layer 1 of unequal thickness. The moduli of the two reinforcing layers 3 may be the same or different.

[0136] As shown in Figures 16-18, within a recessed structure 11, the flexible layer 2 is provided as at least two layers, and the reinforcement layer 3 is provided as at least one layer, with the reinforcement layers 3 and the flexible layer 2 being arranged alternately. For example, as shown in Figures 16 and 17, within a recessed structure 11, the flexible layer 2 is provided as two layers, and the reinforcement layer 3 is provided as one layer, with the reinforcement layer 3 being arranged between the two flexible layers 2, such that the reinforcement layers 3 and the flexible layers 2 are arranged alternately, and the moduli of the two flexible layers 2 can be the same or different. As shown in Figure 18, within a recessed structure 11, the flexible layer 2 is provided as three layers, and the reinforcement layer 3 is provided as two layers, with each reinforcement layer 3 being arranged between two flexible layers 2, such that the reinforcement layers 3 and the flexible layers 2 are also arranged alternately.

[0137] In a recessed structure 11 , the sum of the thicknesses of all the flexible layers 2 and all the reinforcement layers 3 may be less than or equal to the depth of the recessed structure 11 .

[0138] In other exemplary embodiments, the outermost flexible layer 2 extends outside the recessed structure 11. For example, the outermost flexible layer 2 may protrude from the ultra-thin glass layer 1 of varying thickness. That is, within a recessed structure 11, the sum of the thicknesses of all the flexible layers 2 and all the reinforcing layers 3 may be greater than the depth of the recessed structure 11. Referring to FIG. 18 , the outermost flexible layer 2 may cover the surface of the ultra-thin glass layer 1 of varying thickness in the non-bending region FZW. This can improve the connection strength between the flexible layer 2 and the reinforcing layer 3 filled in the recessed structure 11 and the recessed structure 11, thereby preventing the flexible layer 2 and the reinforcing layer 3 from falling out of the recessed structure 11.

[0139] Of course, in some other exemplary embodiments of the present disclosure, the outermost reinforcement layer 3 may extend outside the recessed structure 11. For example, the outermost reinforcement layer 3 may protrude from the ultra-thin glass layer 1 of varying thickness. That is, within a recessed structure 11, the sum of the thicknesses of all the flexible layers 2 and all the reinforcement layers 3 may be greater than the depth of the recessed structure 11. Alternatively, the outermost reinforcement layer 3 may cover the surface of the ultra-thin glass layer 1 of varying thickness in the non-bending region FZW. This can also improve the connection strength between the flexible layer 2 and the reinforcement layer 3 filled in the recessed structure 11 and the recessed structure 11, preventing the flexible layer 2 and the reinforcement layer 3 from falling out of the recessed structure 11. Furthermore, the impact resistance of the ultra-thin glass layer 1 of varying thickness in the non-bending region FZW can be improved.

[0140] Based on the same inventive concept, an example embodiment of the present disclosure provides a flexible display panel. As shown in FIG20 , the flexible display panel may include a display substrate 20 and a flexible cover plate 10. The flexible cover plate 10 is any one of the flexible cover plates 10 described above. The flexible cover plate 10 is arranged on the light-emitting side of the display substrate 20. The specific structure of the flexible cover plate 10 has been described in detail above, so it will not be repeated here.

[0141] The display substrate 20 can be an OLED (Organic Electroluminescence Display) display substrate, a QLED (Quantum Dot Light Emitting Diodes) display substrate, a Micro-LED (Micro-light emitting diode) display substrate, etc.; the display substrate 20 has a light-emitting side and a non-light-emitting side, the light-emitting side and the non-light-emitting side are arranged opposite to each other, and a picture can be displayed on the light-emitting side, and the side that displays the picture is the display surface.

[0142] The display substrate 20 may include a base substrate 201, a driving backplane 202, and a light-emitting device 203. The driving backplane 202 can drive the light-emitting device 203 to emit light. The driving backplane 202 is disposed on one side of the base substrate 201, and the light-emitting device 203 is disposed on the side of the driving backplane 202 facing away from the base substrate 201. A touch substrate 30 may be disposed on the light-emitting side of the display substrate 20, that is, on the side of the light-emitting device 203 facing away from the base substrate 201. A flexible cover 10 may be disposed on the side of the touch substrate 30 facing away from the display substrate 20, such that the flexible cover 10 is disposed on the light-emitting side of the display substrate 20.

[0143] Based on the same inventive concept, an exemplary embodiment of the present disclosure provides a foldable display device, which may include the flexible display panel described above.

[0144] The specific type of the foldable display device is not particularly limited. Any type of foldable display device commonly used in the field can be used, such as mobile devices such as mobile phones, wearable devices such as watches, VR devices, etc. Those skilled in the art can make corresponding choices based on the specific purpose of the foldable display device, which will not be repeated here.

[0145] It should be noted that, in addition to the flexible display panel, the foldable display device also includes other necessary components and components. Taking the display as an example, these include a housing, a circuit board, a power cord, etc. Those skilled in the art can make corresponding supplements based on the specific usage requirements of the display device, which will not be elaborated here.

[0146] Those skilled in the art will readily appreciate other embodiments of the present disclosure after considering the specification and practicing the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the present disclosure that follow the general principles of the present disclosure and include common knowledge or customary techniques in the art not disclosed herein. The description and examples are to be considered as exemplary only, with the true scope and spirit of the present disclosure being indicated by the appended claims.

Claims

1. A flexible cover having a bending area and a non-bending area arranged along a first direction, wherein: The flexible cover plate comprises: Ultra-thin glass layers of unequal thickness, wherein a concave structure is provided on the ultra-thin glass layers of unequal thickness, and at least a portion of the concave structure is located in the bending area; A flexible layer, at least disposed in the recessed structure; The reinforcing layer is at least arranged in the recessed structure, the modulus of the reinforcing layer is greater than the modulus of the flexible layer, and the modulus of the reinforcing layer is less than the modulus of the ultra-thin glass layers of unequal thickness.

2. The flexible cover according to claim 1, wherein: The reinforcement layer is provided with a groove, and the groove extends along a second direction, and the second direction is perpendicular to the first direction.

3. The flexible cover according to claim 2, wherein: The groove is arranged on a side of the reinforcing layer close to the bottom wall of the recessed structure, or the groove is arranged on a side of the reinforcing layer away from the bottom wall of the recessed structure.

4. The flexible cover according to claim 3, wherein: The depth of the groove is less than or equal to 50% of the thickness of the reinforcement layer.

5. The flexible cover according to claim 2, wherein: The groove arranged on the side of the reinforcing layer close to the bottom wall of the recessed structure is a first groove, and the groove arranged on the side of the reinforcing layer away from the bottom wall of the recessed structure is a second groove. The first groove and the second groove are staggered, or the first groove and the second groove are opposite to each other.

6. The flexible cover according to claim 5, wherein: The sum of the depth of the first groove and the depth of the second groove is less than or equal to 50% of the thickness of the reinforcement layer.

7. The flexible cover according to any one of claims 1 to 6, wherein: The ratio of the absolute value of the difference between the refractive index of the flexible layer and the refractive index of the ultra-thin glass layer of unequal thickness to the refractive index of the ultra-thin glass layer of unequal thickness is less than or equal to 0.5%, and the ratio of the absolute value of the difference between the refractive index of the strengthening layer and the refractive index of the ultra-thin glass layer of unequal thickness to the refractive index of the ultra-thin glass layer of unequal thickness is less than or equal to 0.5%.

8. The flexible cover according to any one of claims 1 to 6, wherein: The ratio of the absolute value of the difference between the refractive index of the flexible layer and the refractive index of the ultra-thin glass layer of unequal thickness to the refractive index of the ultra-thin glass layer of unequal thickness is less than or equal to 0.3%, and the ratio of the absolute value of the difference between the refractive index of the strengthening layer and the refractive index of the ultra-thin glass layer of unequal thickness to the refractive index of the ultra-thin glass layer of unequal thickness is less than or equal to 0.3%.

9. The flexible cover according to any one of claims 1 to 6, wherein: The modulus of the reinforcement layer is greater than or equal to 0.1 GPa and less than or equal to 6 GPa, and the modulus of the flexible layer is greater than or equal to 0.01 GPa and less than or equal to 1 GPa.

10. The flexible cover according to any one of claims 1 to 6, wherein: The ratio of the total thickness of the reinforcement layer to the depth of the recessed structure is greater than or equal to 0.2 and less than or equal to 0.

7.

11. The flexible cover according to any one of claims 1 to 6, wherein: The ratio of the total thickness of the reinforcement layer to the depth of the recessed structure is greater than or equal to 0.3 and less than or equal to 0.

5.

12. The flexible cover according to any one of claims 1 to 6, wherein: In the second direction, the ratio of the length of the reinforcing layer to the length of the recessed structure is greater than or equal to 0.75 and less than or equal to 1; in the first direction, the ratio of the width of the reinforcing layer to the width of the recessed structure is greater than or equal to 0.75 and less than or equal to 1, and the first direction intersects with the second direction.

13. The flexible cover according to any one of claims 1 to 6, wherein: The reinforcement layer includes a first portion, a second portion, and a third portion sequentially connected along the first direction, the thickness of the first portion is greater than the thickness of the second portion, and the thickness of the third portion is greater than the thickness of the second portion.

14. The flexible cover according to claim 13, wherein: In the first direction, a width of the first portion is less than or equal to 50% of a width of the second portion, and a width of the third portion is less than or equal to 50% of a width of the second portion.

15. The flexible cover according to claim 13, wherein: The recessed structure includes a first side wall, a first transition surface, a bottom wall, a second transition surface and a second side wall connected in sequence; the bottom wall is connected to the first transition surface to form a first connecting portion, and the first connecting portion is arranged opposite to the first portion; the bottom wall is connected to the second transition surface to form a second connecting portion, and the second connecting portion is arranged opposite to the third portion.

16. The flexible cover according to any one of claims 1, wherein: The ultra-thin glass layer of unequal thickness has two surfaces arranged opposite to each other; the two surfaces are both provided with the recessed structure, and the recessed structures of the two surfaces are arranged opposite to each other, or the recessed structure is only provided on one of the surfaces.

17. The flexible cover according to claim 16, wherein: The flexible layer and the reinforcing layer are disposed in the recessed structures on the two surfaces; or, The two oppositely arranged surfaces of the ultra-thin glass layers of unequal thickness are a first surface and a second surface, the recessed structure arranged on the first surface is a first recessed structure, and the recessed structure arranged on the second surface is a second recessed structure, only the flexible layer is arranged in the first recessed structure, and the flexible layer and the reinforcement layer are arranged in the second recessed structure.

18. The flexible cover according to claim 16 or 17, wherein: In one of the recessed structures, the flexible layer is provided as at least two layers, the reinforcing layer is provided as at least one layer, and the reinforcing layer and the flexible layer are alternately provided.

19. The flexible cover according to claim 18, wherein: The outermost flexible layer extends outside the concave structure.

20. The flexible cover according to claim 16 or 17, wherein: In one of the recessed structures, the reinforcement layer is provided as two layers, the flexible layer is provided as one layer, and at least one reinforcement layer is located on a side of the flexible layer away from the ultra-thin glass layers of unequal thickness.

21. The flexible cover according to claim 16 or 17, wherein: In one of the recessed structures, the flexible layer is provided as one layer, the reinforcing layer is provided as one layer, and the reinforcing layer is located on a side of the flexible layer away from the ultra-thin glass layers of unequal thickness.

22. A flexible display panel, wherein: include: Display substrate; The flexible cover plate is the flexible cover plate according to any one of claims 1 to 21, and the flexible cover plate is arranged on the light output side of the display substrate.

23. A foldable display device, wherein: Includes the flexible display panel as described in claim 22.

Images