Protective cover plate, flexible display screen assembly and foldable electronic equipment

Abstract

The invention provides a protective cover plate, a flexible display screen assembly and foldable electronic equipment. The protective cover plate comprises a protective layer, the protective layer comprises a first plane part, a bendable part and a second plane part which are connected in sequence, the thickness of the bendable part is smaller than that of the first plane part, the thickness of the bendable part is smaller than that of the second plane part, and a groove is defined by the first plane part, the bendable part and the second plane part; the buffer layer comprises a body part and a protruding part which are connected, the protruding part is arranged in the groove, the body part is arranged on the side, away from the protective layer, of the protruding part, and the body part is stacked with the first plane part and the second plane part; wherein the range of the ratio of the elastic modulus E1 of the protective layer to the elastic modulus E2 of the buffer layer is 10 < = E1 / E2 < = 30. The first plane part and the second plane part of the protective cover plate have good impact resistance, and the bendable part has good bending performance.

Description

Technical Field

[0001] The present application relates to the field of electronics, and in particular to a protective cover, a flexible display screen assembly and a foldable electronic device. Background Art

[0002] With the development of technology and the improvement of living standards, people have put forward higher requirements for portable electronic devices. Therefore, foldable electronic devices such as foldable mobile phones have emerged. The existing cover plates used for foldable mobile phone screens are difficult to take into account both mechanical strength and bending performance. Summary of the invention

[0003] The embodiment of the present application provides a protective cover plate, wherein the first plane portion and the second plane portion have good impact resistance and the bendable portion has good bending performance.

[0004] A first embodiment of the present application provides a protective cover, which includes:

[0005] a protective layer, the protective layer comprising a first planar portion, a bendable portion, and a second planar portion connected in sequence, the bendable portion having a thickness less than that of the first planar portion, and the bendable portion having a thickness less than that of the second planar portion, and the first planar portion, the bendable portion, and the second planar portion enclose a groove; and

[0006] A buffer layer, the buffer layer comprising a main body portion and a protruding portion connected to each other, the protruding portion being arranged in the groove, the main body portion being arranged on a side of the protruding portion away from the protective layer, and the main body portion being respectively stacked with the first plane portion and the second plane portion;

[0007] Wherein, the range of the ratio of the elastic modulus E1 of the protective layer to the elastic modulus E2 of the buffer layer is: 10≤E1 / E2≤30.

[0008] A second aspect of the present application provides a flexible display screen assembly, which includes:

[0009] A flexible display screen having a display surface; and

[0010] The protective cover plate described in the embodiment of the first aspect is stacked on the display surface of the flexible display screen to protect the flexible display screen.

[0011] A third aspect of the present application provides a foldable electronic device, characterized in that it includes:

[0012] The flexible display screen assembly described in the second embodiment;

[0013] a foldable mechanism, the foldable mechanism being used to carry the flexible display assembly and to drive the flexible display assembly to be folded or flattened, wherein the protective cover of the flexible display assembly is further away from the foldable mechanism than the flexible display of the flexible display assembly; and

[0014] A processor is electrically connected to the flexible display screen assembly and is used to control the flexible display screen assembly to display.

[0015] The protective cover plate of the embodiment of the present application includes a protective layer and a buffer layer, the protective layer includes a first plane portion, a bendable portion and a second plane portion connected in sequence, the thickness of the bendable portion is less than the thickness of the first plane portion, and the thickness of the bendable portion is less than the thickness of the second plane portion, and the range of the ratio of the elastic modulus E1 of the protective layer to the elastic modulus E2 of the buffer layer is: 10≤E1 / E2≤30; in the present application, by using a protective layer with a higher modulus and a buffer layer with a lower modulus, the protective layer can provide the protective cover plate with higher mechanical strength and impact resistance, and the buffer layer can provide The buffering performance of the high protection cover plate can be further improved and the impact resistance of the protection cover plate can be further improved; at the same time, the protective layer with a higher modulus is designed to be of unequal thickness, and the thinner bendable portion can make the protection cover plate have better bending performance and lower the bending stress of the bendable portion to prevent the bendable portion from cracking when the protection cover plate is bent; the thicker first plane portion and the second plane portion make it difficult for the protective layer to deform and have better impact resistance; thereby, the protection cover plate has better bending performance and higher mechanical strength at the same time, and when applied to a flexible display screen assembly, it can better protect the flexible display screen of the flexible display screen assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0017] Figure 1 It is a schematic diagram of the planar structure of a protective cover according to an embodiment of the present application.

[0018] Figure 2 The protective cover of one embodiment of the present application is Figure 1 Schematic diagram of the cross-sectional structure in the AA direction.

[0019] Figure 3 yes Figure 2 Enlarged view of the dashed box I in the middle.

[0020] Figure 4 The buffer layer of one embodiment of the present application is Figure 1 Schematic diagram of the cross-sectional structure in the AA direction.

[0021] Figure 5 The protective cover edge of another embodiment of the present application Figure 1 Schematic diagram of the cross-sectional structure in the AA direction.

[0022] Figure 6 The protective cover edge of another embodiment of the present application Figure 1 Schematic diagram of the cross-sectional structure in the AA direction.

[0023] Figure 7 The protective cover edge of another embodiment of the present application Figure 1 Schematic diagram of the cross-sectional structure in the AA direction.

[0024] Figure 8 The protective cover edge of another embodiment of the present application Figure 1 Schematic diagram of the cross-sectional structure in the AA direction.

[0025] Fig. 9 The protective cover edge of another embodiment of the present application Figure 1 Schematic diagram of the cross-sectional structure in the AA direction.

[0026] Fig.10 The protective cover edge of another embodiment of the present application Figure 1 Schematic diagram of the cross-sectional structure in the AA direction.

[0027] Fig.11 The protective cover edge of another embodiment of the present application Figure 1 Schematic diagram of the cross-sectional structure in the AA direction.

[0028] Fig.12 It is a schematic diagram of a process of preparing a protective cover plate according to an embodiment of the present application.

[0029] Fig.13 It is a schematic diagram of a process for preparing a protective layer according to an embodiment of the present application.

[0030] Fig.14 It is a structural schematic diagram of the preparation process of the protective cover plate of an embodiment of the present application.

[0031] Fig.15 It is a structural schematic diagram of a flexible display screen assembly according to an embodiment of the present application.

[0032] Fig.16 The flexible display screen component of one embodiment of the present application is Fig.15 Schematic diagram of the cross-sectional structure in the BB direction.

[0033] Fig.17It is a schematic structural diagram of a foldable electronic device in a flattened state according to an embodiment of the present application.

[0034] Fig.18 It is a schematic structural diagram of a foldable electronic device in a folded state according to an embodiment of the present application.

[0035] Fig.19 It is a circuit block diagram of an electronic device according to an embodiment of the present application.

[0036] Description of reference numerals:

[0037] 100-protective cover, 10-protective layer, 11-first plane portion, 12-bendable portion, 121-first transition sub-portion, 122-equal thickness sub-portion, 123-second transition sub-portion, 13-second plane portion, 14-groove, 20-buffer layer, 21-main body, 22-protruding portion, 30-first adhesive layer, 40-first substrate layer, 50-second adhesive layer, 60-second substrate layer, 70-third adhesive layer, 80-hardening layer, 90-anti-reflective film, 100a-textured mold, 10a-mold body, 30a-convex structure, 200-flexible display assembly, 210-flexible display, 211-display surface, 300-foldable electronic device, 310-foldable mechanism, 311-first carrier, 313-connecting axis, 315-second carrier, 330-processor, 350-memory, 370-camera module. DETAILED DESCRIPTION

[0038] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0039] The terms "first", "second", etc. in the specification and claims of this application and the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally includes steps or units that are not listed, or optionally includes other steps or units inherent to these processes, methods, products or devices.

[0040] The technical solutions in the embodiments of the present application will be described below in conjunction with the accompanying drawings.

[0041] It should be noted that, for the convenience of explanation, in the embodiments of the present application, the same figure marks represent the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments.

[0042] The protective cover of the flexible display assembly requires good bending performance in the bending area and good impact resistance in the flat area. However, it is difficult for the relevant protective cover to achieve both. Ultra-thin glass of different thicknesses can be used as a protective cover, but the cost of processing glass into different thicknesses is high and it is difficult to popularize on a large scale. In addition, glass is fragile and needs to be covered with an organic protective film on the surface of the glass, which will cut your hands if the glass breaks.

[0043] See also Figure 1 and Figure 2 , an embodiment of the present application provides a protective cover plate 100, which includes a protective layer 10 and a buffer layer 20. The protective layer 10 includes a first planar portion 11, a bendable portion 12 and a second planar portion 13 connected in sequence, the thickness of the bendable portion 12 is less than the thickness of the first planar portion 11, and the thickness of the bendable portion 12 is less than the thickness of the second planar portion 13, and the first planar portion 11, the bendable portion 12 and the second planar portion 13 enclose a groove 14; the buffer layer 20 is stacked on one side of the protective layer 10 having the groove 14 and the buffer layer 20 is partially disposed in the groove 14; wherein, the ratio of the elastic modulus E1 of the protective layer 10 to the elastic modulus E2 of the buffer layer 20 is in the range of: 10≤E1 / E2≤30.

[0044] The protective cover plate 100 of the embodiment of the present application can be applied to a flexible display screen assembly to protect the flexible display screen of the flexible display screen assembly. When the flexible display screen assembly is folded or bent, the protective cover plate 100 is bent with the bendable portion 12 as the central axis so that the first plane portion 11 and the second plane portion 13 overlap; when the flexible display screen assembly is flattened, the first plane portion 11, the bendable portion 12 and the second plane portion 13 are coplanar. When the protective cover plate 100 of the present application is applied to a flexible display screen assembly, the protective layer 10 is further away from the flexible display screen than the buffer layer 20.

[0045] It can be understood that the groove 14 is located in the bendable portion 12, and the thickness of the bendable portion 12 is smaller than the first planar portion 11 and the second planar portion 13, so that one side surface of the bendable portion 12 is recessed into the first planar portion 11 and the second planar portion 13, thereby forming the groove 14.

[0046] It can be understood that the surface of the bendable portion 12 facing the buffer layer 20 is recessed in the surface of the first planar portion 11 facing the buffer layer 20 and is recessed in the surface of the second planar portion 13 facing the buffer layer 20, and the surface of the bendable portion 12 facing away from the buffer layer 20, the surface of the first planar portion 11 facing away from the buffer layer 20, and the surface of the second planar portion 13 facing away from the buffer layer 20 are located in the same plane (i.e., coplanar).

[0047] It can be understood that the protective layer 10 is arranged in a bonded manner with the buffer layer 20, the buffer layer 20 is partially bonded to the first planar portion 11, partially bonded to the bendable portion 12 and partially bonded to the second planar portion 13, and the portion of the buffer layer 20 that is bonded to the bendable portion 12 is bonded to the side walls and bottom walls of the groove 14.

[0048] Specifically, the ratio of the elastic modulus E1 of the protective layer 10 to the elastic modulus E2 of the buffer layer 20 may be, but is not limited to, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, etc. If the ratio of the elastic modulus E1 of the protective layer 10 to the elastic modulus E2 of the buffer layer 20 is too small, the difference between the elastic modulus of the protective layer 10 and the elastic modulus of the buffer layer 20 is too small, and the improvement of the impact resistance of the protective cover plate 100 is limited; if the ratio of the elastic modulus E1 of the protective layer 10 to the elastic modulus E2 of the buffer layer 20 is too large, the difference between the elastic modulus of the protective layer 10 and the elastic modulus of the buffer layer 20 is too large, and the bending performance of the protective layer 10 is greatly reduced, especially in a low temperature environment, when bending, the risk of cracking of the protective layer 10 is greatly increased.

[0049] The protective cover plate 100 of the embodiment of the present application includes a protective layer 10 and a buffer layer 20, the protective layer 10 includes a first plane portion 11, a bendable portion 12 and a second plane portion 13 connected in sequence, the thickness of the bendable portion 12 is less than the thickness of the first plane portion 11, and the thickness of the bendable portion 12 is less than the thickness of the second plane portion 13, and the range of the ratio of the elastic modulus E1 of the protective layer 10 to the elastic modulus E2 of the buffer layer 20 is: 10≤E1 / E2≤30; in the present application, by using a protective layer 10 with a higher modulus and a buffer layer 20 with a lower modulus, the protective layer 10 can provide the protective cover plate 100 with higher mechanical strength and impact resistance, and the buffer layer 20 can improve the protective cover The cushioning performance of the plate 100 can be further improved and the impact resistance of the protective cover plate 100 can be further improved; at the same time, the protective layer 10 with a higher modulus is designed to be of unequal thickness, and the thinner bendable portion 12 can make the protective cover plate 100 have better bending performance, and the bendable portion 12 has a lower bending stress, which prevents the bendable portion 12 from cracking when the protective cover plate 100 is bent; the thicker first planar portion 11 and the second planar portion 13 make it difficult for the protective layer 10 to deform and have better impact resistance; thereby, the protective cover plate 100 has better bending performance and higher mechanical strength at the same time, and when applied to a flexible display screen assembly, it can better protect the flexible display screen of the flexible display screen assembly.

[0050] Optionally, the elastic modulus E1 of the protective layer 10 is in the range of 50 MPa≤E1≤2000 MPa. Specifically, the elastic modulus E1 of the protective layer 10 may be, but is not limited to, 50 MPa, 80 MPa, 100 MPa, 150 MPa, 200 MPa, 250 MPa, 300 MPa, 350 MPa, 400 MPa, 450 MPa, 500 MPa, 600 MPa, 700 MPa, 800 MPa, 900 MPa, 1000 MPa, 1200 MPa, 1400 MPa, 1600 MPa, 1800 MPa, 2000 MPa, etc. If the elastic modulus of the protective layer 10 is too low, the mechanical strength of the protective layer 10, such as impact strength, is reduced. When the protective cover plate 100 is applied to a flexible display screen assembly, the protective effect of the protective cover plate 100 on the flexible display screen of the flexible display screen assembly is reduced. If the elastic modulus of the protective layer 10 is too high, the bending performance of the bendable portion 12 is reduced. In particular, when the protective cover plate 100 is in a low temperature environment, the bendable portion 12 is prone to cracking along the bendable portion 12, thereby reducing the service life of the protective cover plate 100.

[0051] Furthermore, the range of the elastic modulus E1 of the protective layer 10 is: 100Mpa≤E1≤800Mpa. When the elastic modulus of the protective layer 10 is between 100Mpa and 800Mpa, the first planar portion 11 and the second planar portion 13 of the protective layer 10 can be ensured to have good mechanical strength while the bendable portion 12 can have good bending performance, so that the protective cover 100 has a smaller bending radius.

[0052] Furthermore, the elastic modulus E1 of the protective layer 10 is in the range of 100 MPa≤E1≤500 MPa.

[0053] See also Figure 3In some embodiments, the bendable portion 12 includes a first transition sub-portion 121, an equal-thickness sub-portion 122 and a second transition sub-portion 123 which are connected in sequence. The first transition sub-portion 121 is connected to the first plane portion 11 at one end away from the equal-thickness sub-portion 122, and the second transition sub-portion 123 is connected to the second plane portion 13 at one end away from the equal-thickness sub-portion 122. The thickness of the equal-thickness sub-portion 122 is less than the thickness of the first plane portion 11 and the equal-thickness sub-portion 122 is less than the thickness of the second plane portion 13. The thickness of the first transition sub-portion 121 gradually decreases from one end connected to the first plane portion 11 toward one end connected to the equal-thickness sub-portion 122, and the thickness of the second transition sub-portion 123 gradually decreases from one end connected to the second plane portion 13 toward one end connected to the equal-thickness sub-portion 122. By designing the first transition sub-section 121 and the second transition sub-section 123, the thicknesses between the first planar section 11, the equal-thickness sub-section 122 and the second planar section 13 can be smoothly transitioned, thereby improving the overall mechanical strength of the protective layer 10 and avoiding the presence of stress weak points at the connection between the first planar section 11 and the bendable section 12 and at the connection between the second planar section 13 and the bendable section 12, which would lead to stress concentration and reduce the mechanical strength of the protective layer 10.

[0054] It can be understood that the thickness of the first transition sub-portion 121 gradually and smoothly transitions from the thickness of the first planar portion 11 to the thickness of the equal-thickness sub-portion 122 , and the thickness of the second transition sub-portion 123 gradually and smoothly transitions from the thickness of the second planar portion 13 to the thickness of the equal-thickness sub-portion.

[0055] Optionally, the ratio of the thickness d1 of the first planar portion 11 to the thickness d2 of the equal-thickness sub-portion 122 is in the range of 1.5≤d1 / d2≤4. Specifically, the ratio of the thickness d1 of the first planar portion 11 to the thickness d2 of the equal-thickness sub-portion 122 may be, but is not limited to, 1.5, 1.8, 2.0, 2.3, 2.4, 2.6, 2.8, 3.0, 3.3, 3.4, 3.6, 3.8, 4.0, etc. If the ratio of the thickness d1 of the first planar portion 11 to the thickness d2 of the equal-thickness sub-portion 122 is too small, the difference between the thick area and the thin area of ​​the protective layer 10 is too small. In order to ensure that the bendable portion 12 has good bending performance, the thickness of the first planar portion 11 is too small, which reduces the impact resistance of the first planar portion 11. When applied to a flexible display screen assembly, it cannot well protect the flexible display screen of the flexible display screen assembly; if the ratio of the thickness d1 of the first planar portion 11 to the thickness d2 of the equal-thickness sub-portion 122 is too large, the difference between the thick area and the thin area of ​​the protective layer 10 is too large. Although the first planar portion 11 has good impact resistance, it will increase the process difficulty of preparing the protective layer 10. In addition, the difference in shrinkage between the thick area (i.e., the first planar portion 11) and the thin area (i.e., the bendable portion 12) during the preparation process is likely to cause bubbles, wrinkles, bumps and other poor appearance. In addition, the thickness of the bendable portion 12 is too small, which reduces the protective effect of the bendable portion 12.

[0056] Optionally, the ratio of the thickness d3 of the second planar portion 13 to the thickness d2 of the equal-thickness sub-portion 122 is in the range of 1.5≤d3 / d2≤4. Specifically, the ratio of the thickness d2 of the second planar portion 13 to the thickness d2 of the equal-thickness sub-portion 122 may be, but is not limited to, 1.5, 1.8, 2.0, 2.3, 2.4, 2.6, 2.8, 3.0, 3.3, 3.4, 3.6, 3.8, 4.0, etc. If the ratio of the thickness d2 of the second planar portion 13 to the thickness d2 of the equal-thickness sub-portion 122 is too small, the difference between the thick area and the thin area of ​​the protective layer 10 is too small. In order to ensure that the bendable portion 12 has good bending performance, the thickness of the second planar portion 13 is too small, which reduces the impact resistance of the second planar portion 13. When applied to a flexible display screen assembly, the flexible display screen assembly cannot be well protected; if the ratio of the thickness d2 of the second planar portion 13 to the thickness d2 of the equal-thickness sub-portion 122 is too large, the difference between the thick area and the thin area of ​​the protective layer 10 is too large. Although the second planar portion 13 has good impact resistance, it will increase the process difficulty of preparing the protective layer 10. In addition, the difference in shrinkage between the thick area (i.e., the second planar portion 13) and the thin area (i.e., the bendable portion 12) during the preparation process is likely to cause bubbles, wrinkles, bumps and other poor appearance. In addition, the thickness of the bendable portion 12 is too small, which reduces the protective effect of the bendable portion 12.

[0057] Optionally, the thickness of the first planar portion 11 is uniform, and the range of the thickness d1 of the first planar portion 11 is: 30μm≤d1≤200μm. Specifically, the thickness d1 of the first planar portion 11 can be, but is not limited to, 30μm, 40μm, 50μm, 60μm, 70μm, 80μm, 90μm, 100μm, 110μm, 120μm, 130μm, 140μm, 150μm, 170μm, 180μm, 190μm, 200μm, etc. If the thickness of the first planar portion 11 is too thin, the mechanical strength and impact resistance of the first planar portion 11 will be reduced. When applied to a flexible display screen assembly, the supporting and protective effect of the first planar portion 11 on the flexible display screen of the flexible display screen assembly will be affected; if the thickness of the first planar portion 11 is increased, the first planar portion 11 has better support and flatness, but if the thickness of the first planar portion 11 is too thick, the flexible display screen assembly will be too thick, which is not conducive to ultra-thinning of the flexible display screen assembly.

[0058] Optionally, the thickness of the equal thickness sub-section 122 is uniform, and the range of the thickness d2 of the equal thickness sub-section 122 is: 10μm≤d2≤50μm. Specifically, the thickness d2 of the equal thickness sub-section 122 can be, but not limited to, 10μm, 15μm, 20μm, 25μm, 30μm, 35μm, 40μm, 45μm, 50μm, etc. The thinner the thickness of the equal thickness sub-section 122, the better the bending resistance of the equal thickness sub-section 122. However, when the thickness of the equal thickness sub-section 122 is too thin, the mechanical strength of the equal thickness sub-section 122 will be reduced. When applied to a flexible display screen assembly, the protection and support function of the flexible display screen assembly at the position of the equal thickness sub-section 122 is reduced; if the thickness of the equal thickness sub-section 122 is too thick, the bending performance of the equal thickness sub-section 122 is reduced.

[0059] Optionally, the thickness of the second planar portion 13 is uniform, and the range of the thickness d3 of the second planar portion 13 is: 30μm≤d3≤200μm. Specifically, the thickness d3 of the second planar portion 13 can be, but is not limited to, 30μm, 40μm, 50μm, 60μm, 70μm, 80μm, 90μm, 100μm, 110μm, 120μm, 130μm, 140μm, 150μm, 170μm, 180μm, 190μm, 200μm, etc. If the thickness of the second planar portion 13 is too thin, the mechanical strength and impact resistance of the second planar portion 13 will be reduced. When applied to a flexible display screen assembly, the supporting and protective effect of the second planar portion 13 on the flexible display screen of the flexible display screen assembly will be affected; if the thickness of the second planar portion 13 is increased, the second planar portion 13 has better support and flatness, but if the thickness of the second planar portion 13 is too thick, the flexible display screen assembly will be too thick, which is not conducive to the ultra-thinness of the flexible display screen assembly.

[0060] Optionally, along the arrangement direction of the first planar portion 11, the bendable portion 12, and the second planar portion 13, the width w1 of the first transition sub-portion 121 is in the range of 10 mm ≤ w1 ≤ 50 mm. Specifically, the thickness of the first transition sub-portion 121 may be, but is not limited to, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, 15 mm, 20 mm, 25 mm, 30 mm, 35 mm, 40 mm, 45 mm, 50 mm, etc.

[0061] Optionally, along the arrangement direction of the first planar portion 11, the bendable portion 12, and the second planar portion 13, the width w2 of the uniform thickness sub-portion 122 is in the range of 10 mm ≤ w2 ≤ 30 mm. Specifically, the thickness of the uniform thickness sub-portion 122 may be, but is not limited to, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, 15 mm, 18 mm, 20 mm, 22 mm, 25 mm, 28 mm, 30 mm, etc.

[0062] Optionally, along the arrangement direction of the first planar portion 11, the bendable portion 12, and the second planar portion 13, the width w3 of the second transition sub-portion 123 is in the range of 10 mm ≤ w3 ≤ 50 mm. Specifically, the thickness of the second transition sub-portion 123 may be, but is not limited to, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, 15 mm, 20 mm, 25 mm, 30 mm, 35 mm, 40 mm, 45 mm, 50 mm, etc.

[0063] Optionally, the material of the protective layer 10 is resin. Compared with using glass as the protective layer 10, using resin as the protective layer 10 can better prevent the protective layer 10 from scratching hands after it is broken. In addition, compared with using glass of unequal thickness, using resin as the protective layer 10 can better simplify the preparation process of the protective layer 10 and reduce the preparation cost of the protective layer 10.

[0064] Optionally, the protective layer 10 includes at least one of thermoplastic polyurethane, polyurethane acrylate, polydimethylsiloxane and saturated polyester. When the protective layer 10 is made of these materials, the first planar portion 11 and the second planar portion 13 of the protective layer 10 can have good impact resistance while the bendable portion 12 has good bending performance.

[0065] Optionally, the elastic modulus E2 of the buffer layer 20 is in the range of 0.2Mpa≤E2≤80Mpa. Specifically, the elastic modulus E2 of the buffer layer 20 may be, but is not limited to, 0.2Mpa, 0.6Mpa, 1Mpa, 3Mpa, 5Mpa, 10Mpa, 20Mpa, 30Mpa, 40Mpa, 50Mpa, 60Mpa, 70Mpa, 80Mpa, etc. If the elastic modulus of the buffer layer 20 is too small, it is difficult to play a good buffering role when the protective cover plate 100 is subjected to external force; if the elastic modulus of the buffer layer 20 is too large, although the impact strength of the protective cover plate 100 can be improved, the bending performance of the corresponding bendable portion 12 of the protective cover plate 100 is reduced, thereby reducing the bending performance of the protective cover plate 100.

[0066] Furthermore, the elastic modulus E2 of the buffer layer 20 is in the range of 5Mpa≤E2≤50Mpa. When the elastic modulus of the buffer layer 20 is in the range of 5Mpa to 50Mpa, the buffer layer 20 can have better buffering performance, further improve the impact strength of the protective cover 100, and at the same time, the protective cover 100 can have better bending performance at the position corresponding to the bendable portion 12.

[0067] See also Figure 4Optionally, the buffer layer 20 includes a body portion 21 and a protruding portion 22, the protruding portion 22 is protruding from the surface of the body portion 21 facing the protective layer 10, the protruding portion 22 is arranged in the groove 14, and the body portion 21 is respectively stacked with the first plane portion 11 and the second plane portion 13. It can be understood that the structures of the protruding portion 22 and the groove 14 are complementary, the surface of the protruding portion 22 is arranged to fit the side wall and the bottom of the groove 14, so as to fill the entire groove 14, a part of the body portion 21 is arranged to fit the first plane portion 11, a part is connected to the protruding portion 22, and a part is arranged to fit the second plane portion 13.

[0068] Optionally, the ratio of the thickness d1 of the first planar portion 11 to the thickness d4 of the body portion 21 is in the range of 1≤d1 / d4≤2.5. Specifically, the ratio of the thickness d1 of the first planar portion 11 to the thickness d4 of the body portion 21 may be, but is not limited to, 1, 1.2, 1.4, 1.6, 1.8, 2.0, 2.2, 2.4, 2.5, etc. If the ratio of the thickness d1 of the first plane portion 11 to the thickness d4 of the main body 21 is too large, the thickness of the buffer layer 20 is too small, which reduces the buffering effect of the buffer layer 20, and the buffer layer 20 is prone to surface unevenness in the portion stacked with the first plane portion 11, and the surface defects increase, which affects the appearance of the protective cover 100, or the thickness of the first plane portion 11 is too large, which makes the flexible display assembly too thick, which is not conducive to the ultra-thinness of the flexible display assembly; if the ratio of the thickness d1 of the first plane portion 11 to the thickness d4 of the main body 21 is too small, the mechanical strength and impact resistance of the first plane portion 11 are reduced, thereby reducing the support and flatness of the first plane portion 11, and when applied to the flexible display assembly, the first plane portion 11 is affected. Support and protection of the flexible display assembly. When the ratio of the thickness d1 of the first plane portion 11 to the thickness d4 of the main body 21 is between 1 and 2.5, the impact resistance, flatness, buffering and other properties of the protective cover 100 can be better balanced, and the thickness is thinner.

[0069] Optionally, the ratio of the thickness d3 of the second planar portion 13 to the thickness d4 of the body portion 21 is in the range of 1≤d3 / d4≤2.5. Specifically, the ratio of the thickness d3 of the second planar portion 13 to the thickness d4 of the body portion 21 may be, but is not limited to, 1, 1.2, 1.4, 1.6, 1.8, 2.0, 2.2, 2.4, 2.5, etc. If the ratio of the thickness d3 of the second plane portion 13 to the thickness d4 of the body portion 21 is too large, the thickness of the buffer layer 20 is too small, and the portion of the buffer layer 20 stacked with the second plane portion 13 is prone to surface unevenness, and the surface defects increase, which affects the appearance of the protective cover 100, or the thickness of the second plane portion 13 is too large, which makes the flexible display assembly too thick, which is not conducive to the ultra-thinness of the flexible display assembly; if the ratio of the thickness d3 of the second plane portion 13 to the thickness d4 of the body portion 21 is too small, the mechanical strength and impact resistance of the second plane portion 13 are reduced, thereby reducing the support and flatness of the second plane portion 13, and when applied to the flexible display assembly, the second plane portion 13 is affected. Support and protection of the flexible display assembly. When the ratio of the thickness d3 of the second plane portion 13 to the thickness d4 of the body portion 21 is between 1 and 2.5, the impact resistance, flatness, buffering and other properties of the protective cover 100 can be better balanced, and the thickness is thinner.

[0070] Optionally, the thickness d4 of the main body 21 is in the range of 20μm≤d4≤150μm. Specifically, the thickness of the main body 21 may be, but is not limited to, 20μm, 30μm, 40μm, 50μm, 60μm, 70μm, 80μm, 90μm, 100μm, 110μm, 120μm, 130μm, 140μm, 150μm, etc. If the thickness of the main body 21 is too thin, the overall buffering performance of the buffer layer 20 is reduced, and when the protective cover 100 is subjected to external force, it is difficult to play a sufficient buffering role; when the thickness of the main body 21 is too thick, the mechanical strength of the protective cover 100 is too high, which reduces the bending performance of the protective cover 100 corresponding to the bendable portion 12.

[0071] Optionally, the buffer layer 20 includes at least one of polydimethylsiloxane, polyborosiloxane, polyurethane elastomer, and polyolefin elastomer. These materials can make the buffer layer 20 have better buffering performance and further improve the impact resistance of the protective cover 100.

[0072] See also Figure 5 In some embodiments, the protective cover plate 100 further includes a first adhesive layer 30, which is stacked on the side of the buffer layer 20 facing away from the protective layer 10, and is used to bond the protective cover plate 100 to the flexible display screen of the flexible display screen assembly when the protective cover plate 100 is applied to the flexible display screen assembly.

[0073] It should be noted that, in the present application, "arranged on one side of a certain element" can be arranged on the surface of the element; it can also be arranged opposite to the element and spaced apart, with other elements arranged between the element. For example, in the present embodiment, the first adhesive layer 30 is arranged on one side of the buffer layer 20, it can be arranged on the surface of the buffer layer 20; it can also be arranged opposite to the buffer layer 20 and spaced apart, with other film layers arranged between the first adhesive layer 30 and the buffer layer 20.

[0074] Optionally, the first adhesive layer 30 may be, but is not limited to, optical adhesive.

[0075] Optionally, the thickness of the first adhesive layer 30 ranges from 20 μm to 50 μm. Specifically, the thickness of the first adhesive layer 30 may be, but is not limited to, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, 50 μm, etc. If the thickness of the first adhesive layer 30 is too thin, the first adhesive layer 30 cannot play a good bonding role; if the thickness of the first adhesive layer 30 is too thick, the thickness of the protective cover 100 is increased, which is not conducive to the ultra-thinness of the protective cover 100.

[0076] In the embodiments of the present application, when a numerical value range from a to b is involved, unless otherwise specified, it means that the numerical value can be any numerical value between a and b, including the endpoint numerical value a and the endpoint numerical value b.

[0077] See also Figure 6 In some embodiments, the protective cover plate 100 further includes a first substrate layer 40, which is disposed on the side of the protective layer 10 away from the buffer layer 20, and the elastic modulus of the first substrate layer 40 is greater than the elastic modulus of the protective layer 10. By disposing the first substrate layer 40 on the side of the protective layer 10 away from the buffer layer 20, and making the elastic modulus of the first substrate layer 40 greater than the elastic modulus of the protective layer 10, the impact resistance of the protective cover plate 100 can be further improved. In addition, by decreasing the elastic modulus of the first substrate layer 40, the protective layer 10 and the buffer layer 20 in sequence, when the protective cover plate 100 is impacted by an external force, the first substrate layer 40 and the protective layer 10 can provide higher rigidity to prevent the protective cover plate 100 from deformation or fragmentation, and the buffer layer 20 can more effectively absorb and buffer the impact energy. By gradually decreasing the elastic modulus, the protective cover plate 100 has better impact resistance.

[0078] Optionally, the first substrate layer 40 is prepared by stretching. Compared with the film layer obtained by curing the coating, the molecular chain of the first substrate layer 40 prepared by stretching has better orientation, so that the first substrate layer 40 has a higher elastic modulus and better bending performance. Therefore, the protective cover plate 100 corresponding to the first planar portion 11 and the second planar portion 13 has better flatness and support, and has better impact resistance. The protective cover plate 100 corresponding to the bendable portion 12 has better bending performance.

[0079] Optionally, the thickness d6 of the first substrate layer 40 is in the range of 25 μm ≤ d6 ≤ 125 μm. Specifically, the thickness of the first substrate layer 40 may be, but is not limited to, 25 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 85 μm, 90 μm, 100 μm, 110 μm, 125 μm, etc. If the thickness of the first substrate layer 40 is too thin, the impact resistance of the protective cover plate 100 will be limited. In addition, if the thickness of the first substrate layer 40 is too small, the haze will increase, the first substrate layer 40 will easily produce wrinkles or orange peel, and it will be difficult to achieve a mirror effect on the surface of the first substrate layer 40, which will affect the appearance of the protective cover plate 100. If the thickness of the first substrate layer 40 is too thick, although it can better improve the impact resistance of the protective cover plate 100 and reduce the folding deformation of the protective cover plate 100, it also reduces the bending performance of the protective cover plate 100 corresponding to the bendable portion 12.

[0080] Optionally, the first substrate layer 40 includes at least one of polymethyl methacrylate (PMMA), polyethylene terephthalate (PET), polycarbonate (PC), polystyrene (PS), thermoplastic polyurethane (TPU), triacetate cellulose (TAC), and polyimide (PI).

[0081] Optionally, the elastic modulus E3 of the first substrate layer 40 is in the range of 3GPA≤E3≤6GPA. Specifically, it may be, but is not limited to, 3GPA, 3.5GPA, 4GPA, 4.5GPA, 5GPA, 5.5GPA, 6GPA, etc. If the elastic modulus of the first substrate layer 40 is too low, the impact resistance of the protective cover 100 is limited. If the elastic modulus of the first substrate layer 40 is too high, the bending performance of the protective cover 100 corresponding to the bendable portion 12 is reduced.

[0082] Optionally, the transmittance T of the first substrate layer 40 is ≥ 90%, specifically, it can be but not limited to 90%, 93%, 95%, 97%, 98%, 99%, etc. The higher the transmittance of the first substrate layer 40, the higher the transmittance of the protective cover plate 100 when applied to the flexible display screen assembly, and the less it will affect the display effect of the flexible display screen assembly.

[0083] Optionally, the haze of the first substrate layer 40 is less than 1%. The smaller the haze of the first substrate layer 40 is, the higher the light transmittance of the first substrate layer 40 is. When applied to a flexible display screen assembly, the flexible display screen assembly can have a better display effect.

[0084] See also Figure 7 In some embodiments, the protective cover 100 further includes a second adhesive layer 50 , which is disposed between the first substrate layer 40 and the protective layer 10 , and is used to adhere the first substrate layer 40 to the protective layer 10 .

[0085] Optionally, the second adhesive layer 50 may be, but is not limited to, optical adhesive.

[0086] Optionally, the thickness of the second adhesive layer 50 ranges from 20 μm to 50 μm. Specifically, the thickness of the second adhesive layer 50 may be, but is not limited to, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, 50 μm, etc. If the thickness of the second adhesive layer 50 is too thin, the second adhesive layer 50 cannot play a good bonding role; if the thickness of the second adhesive layer 50 is too thick, the thickness of the protective cover 100 is increased, which is not conducive to the ultra-thinness of the protective cover 100.

[0087] In other embodiments, the first substrate layer 40 may also be attached before the protective layer 10 is cured. After the protective layer 10 is cured, the first substrate layer 40 and the protective layer 10 are bonded together by the adhesive force of the protective layer 10 itself.

[0088] See also Figure 8 In some embodiments, the protective cover 100 further includes a second substrate layer 60, which is disposed on the surface of the buffer layer 20 away from the protective layer 10, and the elastic modulus of the second substrate layer 60 is greater than the elastic modulus of the protective layer 10. It can be understood that in this embodiment, the protective cover 100 at least includes the second substrate layer 60, the buffer layer 20, the protective layer 10 and the first substrate layer 40 which are stacked in sequence. By designing that the elastic modulus of the first substrate layer 40 and the second substrate layer 60 are both greater than the elastic modulus of the protective layer 10, the first substrate layer 40 and the second substrate layer 60 with a higher elastic modulus are respectively disposed on both sides of the protective layer 10 or the buffer layer 20 with a lower elastic modulus, thereby forming a configuration of high-low-high elastic modulus, so that the first substrate layer 40 and the second substrate layer 60 with a higher elastic modulus can be made thinner, so that the protective cover 100 has a higher impact resistance and a better bending performance at the position corresponding to the bendable portion 12.

[0089] Optionally, the second substrate layer 60 is prepared by stretching. Compared with the film layer obtained by curing the coating, the molecular chain of the second substrate layer 60 prepared by stretching has better orientation, so that the second substrate layer 60 has a higher elastic modulus and better bending performance. Therefore, the protective cover plate 100 corresponding to the first planar portion 11 and the second planar portion 13 has better flatness and support, and has better impact resistance. The protective cover plate 100 corresponding to the bendable portion 12 has better bending performance.

[0090] It can be understood that when the protective cover plate 100 includes both the second substrate layer 60 and the first adhesive layer 30, the first adhesive layer 30 is arranged on the surface of the second substrate layer 60 facing away from the buffer layer 20, and when the protective cover plate 100 is applied to a flexible display screen assembly, it is used to bond the protective cover plate 100 to the flexible display screen assembly.

[0091] Optionally, the range of the thickness d7 of the second substrate layer 60 is: 10μm≤d7≤25μm. Specifically, the thickness of the second substrate layer 60 can be, but is not limited to, 10μm, 12μm, 14μm, 16μm, 18μm, 20μm, 22μm, 24μm, 25μm, etc. If the thickness of the second substrate layer 60 is too thin, the impact resistance of the protective cover 100 will be limited. In addition, if the thickness of the first substrate layer 40 is too small, the haze will increase, the first substrate layer 40 is prone to wrinkles or orange peel, and the surface of the first substrate layer 40 is difficult to achieve a mirror effect, which affects the appearance of the protective cover 100; if the thickness of the second substrate layer 60 is too thick, although it can better improve the impact resistance of the protective cover 100 and reduce the folding deformation of the protective cover 100, it also reduces the bending performance of the protective cover 100 corresponding to the bendable portion 12.

[0092] Although both the first substrate layer 40 and the second substrate layer 60 are required to have a higher light transmittance, the second substrate layer 60 is closer to the inner layer. If it is made thinner, the haze will increase and it is inevitable that certain wrinkles or orange peel will appear. However, the two layers of the second substrate layer 60 have a film layer with a refractive index that is not much different from that of the second substrate layer 60 to fill its surface, thereby covering the defects on the surface of the second substrate layer 60 without affecting the visual effect of the second substrate layer 60.

[0093] Optionally, the material of the second substrate layer 60 may be, but is not limited to, polyethylene terephthalate.

[0094] Optionally, the elastic modulus of the second substrate layer 60 is in the range of 2GPA to 4GPA. Specifically, it may be, but is not limited to, 2GPA, 2.5GPA, 3GPA, 3.5GPA, 4GPA, etc. If the elastic modulus of the second substrate layer 60 is too low, the impact resistance of the protective cover 100 is limited. If the elastic modulus of the second substrate layer 60 is too high, the bending performance of the protective cover 100 corresponding to the bendable portion 12 is reduced.

[0095] Optionally, the elastic modulus of the first substrate layer 40 is greater than or equal to the elastic modulus of the second substrate layer 60; the thickness of the first substrate layer 40 is greater than or equal to the thickness of the second substrate layer 60. When the protective cover 100 is applied to the flexible display assembly, the first substrate layer 40 is farther away from the flexible display assembly than the second substrate layer 60; in other words, the first substrate layer 40 is closer to the outer surface than the second substrate layer 60. When the flexible display assembly is impacted, the energy is first transferred to the first substrate layer 40, so that the elastic modulus of the first substrate layer 40 is greater than or equal to the elastic modulus of the second substrate layer 60; the thickness of the first substrate layer 40 is greater than or equal to the thickness of the second substrate layer 60, so that the impact resistance of the protective cover 100 can be better improved, so that the protective cover 100 can better protect the flexible display of the flexible display assembly. In addition, the protective cover 100 can be made less prone to scratches.

[0096] Optionally, the ratio of the elastic modulus E3 of the first substrate layer 40 to the elastic modulus E4 of the second substrate layer 60 is in the range of 1≤E3 / E4≤2.5. Specifically, the ratio of the elastic modulus E3 of the first substrate layer 40 to the elastic modulus E4 of the second substrate layer 60 may be, but is not limited to, 1, 1.2, 1.4, 1.6, 1.8, 2.0, 2.2, 2.4, 2.5, etc. If the ratio of the elastic modulus E3 of the first substrate layer 40 to the elastic modulus E4 of the second substrate layer 60 is too small, the elastic modulus of the first substrate layer 40 and the second substrate layer 60 are both small, the rigidity of the first substrate layer 40 is poor and scratches are easily generated, and the impact resistance of the protective cover 100 is reduced. Alternatively, if the elastic modulus of the first substrate layer 40 and the second substrate layer 60 are both large, the bending performance of the protective cover 100 corresponding to the bendable portion 12 is reduced; if the ratio of the elastic modulus E3 of the first substrate layer 40 to the elastic modulus E4 of the second substrate layer 60 is too large, the elastic modulus of the first substrate layer 40 is too high, so that the protective cover 100 has better bending performance at the position corresponding to the bendable portion 12. In this embodiment, by adjusting the elastic modulus of the first substrate layer 40 and the elastic modulus of the second substrate layer 60, the impact resistance and bending performance of the protective cover 100 can be better balanced.

[0097] Optionally, the ratio of the thickness d6 of the first substrate layer 40 to the thickness d7 of the second substrate layer 60 is in the range of 2≤d6 / d7≤5. Specifically, the ratio of the thickness d6 of the first substrate layer 40 to the thickness d7 of the second substrate layer 60 may be, but is not limited to, 2, 2.5, 3, 3.5, 4, 4.5, 5, etc. If the ratio of the thickness d6 of the first substrate layer 40 to the thickness d7 of the second substrate layer 60 is too small, the thicknesses of the first substrate layer 40 and the second substrate layer 60 are both too small, their impact resistance is reduced, and scratches are easily generated; or, if the thicknesses of the first substrate layer 40 and the second substrate layer 60 are both too large, the bending performance of the protective cover plate 100 corresponding to the bendable portion 12 is reduced; if the ratio of the thickness d6 of the first substrate layer 40 to the thickness d7 of the second substrate layer 60 is too large, the thickness of the second substrate layer 60 is too small, the haze will increase, the second substrate layer 60 is prone to wrinkles or orange peel, and it is difficult to achieve a mirror effect on the surface of the second substrate layer 60, which affects the appearance of the protective cover plate 100; or the first substrate layer 40 is too thick, which affects the bendability of the first substrate layer 40.

[0098] In some embodiments, the protective cover plate 100 further includes a third adhesive layer 70 , which is disposed between the second substrate layer 60 and the buffer layer 20 and is used to bond the second substrate layer 60 to the buffer layer 20 .

[0099] Optionally, the third adhesive layer 70 may be, but is not limited to, optical adhesive.

[0100] Optionally, the thickness of the third adhesive layer 70 ranges from 20 μm to 50 μm. Specifically, the thickness of the third adhesive layer 70 may be, but is not limited to, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, 50 μm, etc. If the thickness of the third adhesive layer 70 is too thin, the third adhesive layer 70 cannot play a good bonding role; if the thickness of the third adhesive layer 70 is too thick, the thickness of the protective cover 100 is increased, which is not conducive to the ultra-thinness of the protective cover 100.

[0101] See also Fig. 9 In some embodiments, the protective cover plate 100 further includes a hardening layer 80, which is disposed on the side of the protective layer 10 away from the buffer layer 20, and is used to improve the hardness and wear resistance of the protective cover plate 100. By disposing the hardening layer 80 on the side of the protective layer 10 away from the buffer layer 20, when in use, the hardening layer 80 serves as the outer surface of the protective cover plate 100, so that the protective cover plate 100 has better hardness and wear resistance, and can better prevent the protective cover plate 100 from being scratched during use when applied to the flexible display screen assembly, thereby affecting the display effect of the flexible display screen assembly, and improving the service life of the protective cover plate 100.

[0102] It can be understood that when the protective cover 100 includes both the first substrate layer 40 and the hardening layer 80 , the first substrate layer 40 is disposed on the surface of the protective layer 10 away from the buffer layer 20 , and the hardening layer 80 is disposed on the surface of the first substrate layer 40 away from the protective layer 10 .

[0103] Optionally, the range of the thickness d5 of the hardened layer 80 is: 2μm≤d5≤5μm. Specifically, the thickness d5 of the hardened layer 80 can be, but is not limited to, 2μm, 2.5μm, 3μm, 3.5μm, 4μm, 4.5μm, 5μm, etc. If the thickness of the hardened layer 80 is too low, the wear resistance of the hardened layer 80 is insufficient, and scratches are easily generated after a period of use; if the thickness of the hardened layer 80 is too thick, the bending performance of the hardened layer 80 is low, which affects the bending performance of the protective cover 100, and the hardened layer 80 is easy to crack when the protective cover 100 is bent.

[0104] Optionally, the pencil hardness of the hardened layer 80 ranges from 1H to 3H. Specifically, the pencil hardness of the hardened layer 80 may be, but is not limited to, 1H, 2H, 3H, etc. If the hardness of the hardened layer 80 is too low, the wear resistance of the hardened layer 80 is insufficient, and scratches are easily generated after a period of use; if the hardness of the hardened layer 80 is too high, the bending performance of the hardened layer 80 is reduced, affecting the bending performance of the protective cover 100, and the hardened layer 80 is prone to cracking when the protective cover 100 is bent. The pencil hardness test of the embodiment of the present application adopts GB / T 6739-2006 to measure the 1kg pencil hardness.

[0105] Optionally, the hardened layer 80 is made of 0000# steel wool, with a load of 1 kg, and rubbed back and forth for more than 2500 times without any scratches.

[0106] Optionally, the hardening layer 80 is formed by light curing of a hardening liquid. The hardening liquid includes a polyurethane acrylate oligomer, a photoinitiator and a solvent. The photoinitiator may be, but is not limited to, at least one of diphenyl (2,4,6-trimethylbenzoyl) phosphine oxide (TPO), propyl thioxanthone (ITX), and benzophenone (BP). Optionally, the solvent may be, but is not limited to, one or more of ethyl acetate, propyl acetate, butyl acetate, cyclohexanone, propylene glycol methyl ether, propylene glycol methyl ether acetate, ethylene glycol monobutyl ether, ethylene glycol monomethyl ether, isopropyl alcohol, butanone, and methyl butanone.

[0107] See also Fig.10 and Fig.11In some embodiments, the protective cover plate 100 further includes an anti-reflection film 90 (AR for short), which is disposed on the surface of the first substrate layer 40 facing away from the protective layer 10 to reduce the reflection of light by the protective cover plate 100. When applied to a flexible display screen assembly, the display effect of the flexible display screen assembly can be improved.

[0108] Optionally, the anti-reflection film 90 may be, but is not limited to, silicon oxide, silicon nitride, or the like.

[0109] Optionally, when the protective cover plate 100 includes both the anti-reflection film 90 and the hardening layer 80, the hardening layer 80 and the anti-reflection film 90 are sequentially stacked and arranged on the surface of the first substrate layer 40 away from the protective layer 10. In other words, the hardening layer 80 is arranged on the surface of the first substrate layer 40 away from the protective layer 10, and the anti-reflection film 90 is arranged on the surface of the hardening layer 80 away from the protective layer 10.

[0110] The protective cover plate 100 of the embodiment of the present application can be prepared by the method of the following embodiment of the present application. In addition, it can also be prepared by other methods. The preparation method of the embodiment of the present application is only one or more preparation methods of the protective cover plate 100 of the present application, and should not be understood as a limitation on the protective cover plate 100 provided by the embodiment of the present application.

[0111] See also Fig.12 The embodiment of the present application also provides a method for preparing a protective cover plate 100, which includes:

[0112] S201, preparing a protective layer 10;

[0113] Please also see Fig.13 and Fig.14 Optionally, preparing the protective layer 10 includes:

[0114] S2011, providing a texture mold 100a, the texture mold 100a comprising a mold body 10a and a protruding structure 30a, the protruding structure 30a being protrudingly disposed on a surface of the mold body 10a;

[0115] S2012, applying a slurry composed of raw material components of the protective layer 10 to the surface of the texture mold 100a having the protruding structure 30a; and

[0116] Optionally, a slurry composed of raw material components of the protective layer 10 is applied to the surface of the texture mold 100a having the protruding structure 30a, and the height of the slurry is higher than the height of the protruding structure 30a.

[0117] For example, when the protective layer 10 is polyurethane, it can be coated with a monomer solution composed of components such as isocyanate and polyol.

[0118] S2013, curing is performed to obtain a protective layer 10.

[0119] Optionally, curing is performed at a curing temperature of 80° C. to 120° C. (eg, 80° C., 90° C., 100° C., 110° C., etc.) to obtain the protective layer 10 .

[0120] Optionally, preparing the protective layer 10 further includes: removing the texture mold 100a.

[0121] Optionally, before the protective layer 10 is formed and the texture mold 100 a is removed, the method further includes: S202 ′, bonding the first substrate layer 40 to the surface of the protective layer 10 facing away from the groove 14 using the second adhesive layer 50 .

[0122] For detailed description of other aspects of the protective layer 10 , please refer to the description of the corresponding parts of the above embodiments, which will not be repeated here.

[0123] S202, forming a buffer layer 20 on the surface of the protective layer 10 having the groove 14, and filling the groove 14 with the buffer layer 20, the buffer layer 20 includes a main body 21 and a protruding portion 22 connected to each other, the protruding portion 22 is arranged in the groove 14, the main body 21 is arranged on the side of the protruding portion 22 away from the protective layer 10, and the main body 21 is respectively stacked with the first planar portion 11 and the second planar portion 13; wherein the ratio of the elastic modulus E1 of the protective layer 10 to the elastic modulus E2 of the buffer layer 20 is in the range of: 10≤E1 / E2≤30.

[0124] Optionally, a slurry formed of raw material components of the buffer layer 20 is applied to the surface of the protective layer 10 having the groove 14 , and is cured to form the buffer layer 20 .

[0125] For detailed description of other aspects of the buffer layer 20 , please refer to the description of the corresponding parts of the above embodiments, which will not be repeated here.

[0126] The protective cover plate 100 prepared by the preparation method of the protective cover plate 100 of the embodiment of the present application includes a protective layer 10 and a buffer layer 20, the protective layer 10 includes a first plane portion 11, a bendable portion 12 and a second plane portion 13 connected in sequence, the thickness of the bendable portion 12 is less than the thickness of the first plane portion 11, and the thickness of the bendable portion 12 is less than the thickness of the second plane portion 13, and the range of the ratio of the elastic modulus E1 of the protective layer 10 to the elastic modulus E2 of the buffer layer 20 is: 10≤E1 / E2≤30; in this embodiment, by using a protective layer 10 with a higher modulus and a buffer layer 20 with a lower modulus, the protective layer 10 can provide the protective cover plate 100 with higher mechanical strength and impact resistance, and the buffer layer 20 has a relatively low modulus. Layer 20 can improve the buffering performance of the protective cover plate 100 and can further improve the impact resistance of the protective cover plate 100; at the same time, the protective layer 10 with a higher modulus is designed to be of unequal thickness, and the thinner bendable portion 12 can make the protective cover plate 100 have better bending performance, and the lower bending stress of the bendable portion 12 can prevent the bendable portion 12 from cracking when the protective cover plate 100 is bent; the thicker first plane portion 11 and the second plane portion 13 make the protective layer 10 less likely to deform and have better impact resistance; thus, the protective cover plate 100 has better bending performance and higher mechanical strength, and when applied to a flexible display assembly, it can better protect the flexible display of the flexible display assembly. In addition, the preparation method of the protective cover plate 100 of the present application is simple in preparation process, easy to mass produce, and low in production cost.

[0127] The protective cover plate 100 of the present application is further described below through specific embodiments.

[0128] Examples 1 to 5, Comparative Examples 1 and 2

[0129] The protective cover plate 100 of each embodiment and comparative example includes a stacked protective layer 10 and a buffer layer 20 , the thickness of the first plane portion 11 of the protective layer 10 is equal to the thickness of the second plane portion 13 , and the performance parameters of the protective layer 10 and the buffer layer 20 are shown in Table 1 below.

[0130] Examples 6 to 8, Comparative Examples 3 and 4

[0131] The protective cover plate 100 of each embodiment includes a stacked second substrate layer 60 (PET layer), a third adhesive layer 70 (optical glue, 30 μm), a buffer layer 20, a protective layer 10 and a first substrate layer 40 (PET layer). The performance parameters of the protective cover plate 100 are shown in Table 1 below.

[0132] Performance tests of various embodiments and comparative examples

[0133] Impact resistance test: refer to GB / T 39814-2021 Ultra-thin glass impact strength test method - drop ball impact method, use 32g drop ball, impact height 100mm, and there is a real-time stress sensor on the platform surface with drop ball impact. The direct impact force of the drop ball on the sensor when the protective cover 100 is not placed is recorded as N0, and the drop ball impact force when the protective cover 100 is placed is N1, then the impact resistance calculation result is X = (N0-N1) / N0*100%. Each data needs to be measured 3-5 times to take the average value.

[0134] Bending radius test: The test is conducted using an automatic bending tester for a mobile phone. The protective cover 100 is bent 25W times and 5W times at normal temperature (i.e. room temperature) and low temperature of -15°, respectively, to test the minimum bending radius R at which no cracks or delamination abnormalities occur on the surface and inside of the protective cover 100.

[0135] Table 1 Performance parameters of each embodiment and comparative example

[0136]

[0137]

[0138] From the test results of Examples 1 to 3, Comparative Examples 1 and 2, it can be seen that when the ratio of the elastic modulus E1 of the protective layer 10 to the elastic modulus E2 of the buffer layer 20 is small (for example, 2), the impact strength of the protective cover plate 100 is low, and the rigidity of the protective layer 10 and the buffer layer 20 are both large, and the bending performance is poor (the bending radius is large); as the ratio of the elastic modulus E1 of the protective layer 10 to the elastic modulus E2 of the buffer layer 20 increases, the impact strength and bending performance of the protective cover plate 100 are greatly improved; however, when the ratio of the elastic modulus E1 of the protective layer 10 to the elastic modulus E2 of the buffer layer 20 increases to a certain extent, the impact strength of the protective cover plate 100 will also decrease, and the bending performance will deteriorate.

[0139] From the test results of Examples 2, 3 and 5, it can be seen that the smaller the ratio d1 / d2 of the thickness d1 of the first planar portion 11 to the thickness d2 of the equal-thickness sub-portion 122 is and the thicker the equal-thickness sub-portion 122 is, the worse the bending performance of the protective cover 100 is.

[0140] It can be seen from Examples 6 to 8, Comparative Examples 3 and 4 that when the ratio E3 / E4 of the elastic modulus E3 of the first substrate layer 40 to the elastic modulus E4 of the second substrate layer 60 is small, the impact strength of the protective cover plate 100 is low. At this time, the elastic moduli of the first substrate layer 40 and the second substrate layer 60 are slightly different, and the rigidity is relatively large, so the bending performance is also poor; as the ratio E3 / E4 of the elastic modulus E3 of the first substrate layer 40 to the elastic modulus E4 of the second substrate layer 60 increases, the impact strength of the protective cover plate 100 increases, and the bending performance is better; however, when the ratio E3 / E4 of the elastic modulus E3 of the first substrate layer 40 to the elastic modulus E4 of the second substrate layer 60 increases to a certain extent, the impact strength of the protective cover plate 100 decreases again, and the bending performance also decreases.

[0141] See also Fig.15 and Fig.16 The embodiment of the present application also provides a flexible display assembly 200, which includes: a flexible display 210 and a protective cover plate 100 of the embodiment of the present application, the flexible display 210 has a display surface 211, and the protective cover plate 100 is stacked on the display surface 211 of the flexible display 210 for protecting the flexible display 210.

[0142] Optionally, the flexible display screen 210 may be, but is not limited to, an organic flexible display screen 210 , such as an active matrix organic light emitting diode (AMOLED).

[0143] Optionally, the flexible display screen 210 may be bonded to the protective cover plate 100 by using an adhesive having high light transmittance such as optical adhesive.

[0144] For a detailed description of the protective cover 100 , please refer to the description of the corresponding part of the above embodiment, which will not be repeated here.

[0145] It can be understood that the flexible display assembly 200 in this embodiment is only one form of the flexible display assembly 200 applied to the protective cover 100, and should not be understood as a limitation on the flexible display assembly 200 provided in this application, nor should it be understood as a limitation on the protective cover 100 provided in each embodiment of this application. For a detailed description of the protective cover 100, please refer to the description of the corresponding part of the above embodiment, which will not be repeated here.

[0146] See also Figures 17 to 19 The embodiment of the present application further provides a foldable electronic device 300, which includes: the flexible display assembly 200 of the embodiment of the present application, a foldable mechanism 310 and a processor 330, wherein the foldable mechanism 310 is used to carry the flexible display assembly 200 and to drive the flexible display assembly 200 to fold (such as Fig.18 as shown) or flattened (as Fig.17As shown), wherein the protective cover 100 of the flexible display assembly 200 is farther away from the foldable mechanism 310 than the flexible display 210 of the flexible display assembly 200; the processor 330 is electrically connected to the flexible display assembly 200 for controlling the flexible display assembly 200 for display.

[0147] The foldable electronic device 300 of the embodiment of the present application may be, but is not limited to, a portable foldable electronic device 300 with a variable display screen size such as a mobile phone, a tablet computer, an e-reader, and a laptop computer. It can be understood that the foldable electronic device 300 in this embodiment is only a form of the foldable electronic device 300 applied by the flexible display screen assembly 200, and should not be understood as a limitation on the foldable electronic device 300 provided in the present application, nor should it be understood as a limitation on the flexible display screen assembly 200 provided in each embodiment of the present application. For a detailed description of the flexible display screen assembly 200, please refer to the description of the corresponding part of the above embodiment, which will not be repeated here.

[0148] For a detailed description of the flexible display screen assembly 200 , the protective cover plate 100 , etc., please refer to the description of the corresponding parts of the above embodiments, which will not be repeated here.

[0149] In some embodiments, the foldable mechanism 310 includes a first carrier 311, a connecting shaft 313 and a second carrier 315 that are movably connected in sequence; the first carrier 311, the connecting shaft 313 and the second carrier 315 are used to support the flexible display assembly 200 and drive the flexible display assembly 200 to fold or unfold; the foldable mechanism 310 has a flattened state and a folded state. When the foldable mechanism 310 is in the flattened state, the first carrier 311, the connecting member and the second carrier 315 form a planar structure; when the foldable mechanism 310 is in the folded state, the first carrier 311 overlaps with the second carrier 315 and drives the flexible display assembly 200 to fold.

[0150] It can be understood that the orthographic projection of the surface of the foldable mechanism 310 of the flexible display assembly 200 facing the flexible display assembly 200 falls within the range of the surface of the foldable mechanism 310 facing the flexible display assembly 200 .

[0151] Optionally, the processor 330 includes one or more general-purpose processors, wherein the general-purpose processor can be any type of device capable of processing electronic instructions, including a central processing unit (CPU), a microprocessor, a microcontroller, a main processor, a controller, and an ASIC, etc. The processor 330 is used to execute various types of digital storage instructions, such as software or firmware programs stored in a memory, which enables the computing device to provide a wide variety of services.

[0152] Optionally, the foldable electronic device 300 of the present application further includes a memory 350. The memory 350 is electrically connected to the processor 330 and is used to store program codes required for the processor 330 to run, program codes required for controlling the flexible display assembly 200, display content of the flexible display assembly 200, and the like.

[0153] Optionally, the memory 350 may include a volatile memory, such as a random access memory (RAM); the memory 350 may also include a non-volatile memory (NVM), such as a read-only memory (ROM), a flash memory (FM), a hard disk (DOLDD) or a solid-state drive (SSD). The memory 350 may also include a combination of the above-mentioned types of memory.

[0154] In some embodiments, the foldable electronic device 300 of the embodiment of the present application further includes a camera module 370, which is carried by the foldable mechanism 310. The camera module 370 is electrically connected to the processor 330, and is used to take pictures under the control of the processor 330.

[0155] Optionally, the camera module 370 may be a rear camera module 370 or a front camera module 370. This application does not make any specific limitation.

[0156] Mentioning "embodiment" and "implementation method" in this application means that the specific features, structures or characteristics described in conjunction with the embodiment may be included in at least one embodiment of the present application. The appearance of the phrases in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described in this application can be combined with other embodiments. In addition, it should also be understood that the features, structures or characteristics described in the various embodiments of the present application can be arbitrarily combined to form another embodiment that does not deviate from the spirit and scope of the technical solution of the present application, provided that there is no contradiction between them.

[0157] Finally, it should be noted that the above implementation modes are only used to illustrate the technical solution of the present application and are not intended to limit it. Although the present application has been described in detail with reference to the above preferred implementation modes, a person of ordinary skill in the art should understand that the technical solution of the present application may be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the present application.

Claims

1. A protective cover, characterized in that: include: a protective layer, the protective layer comprising a first planar portion, a bendable portion, and a second planar portion connected in sequence, the bendable portion having a thickness less than that of the first planar portion, and the bendable portion having a thickness less than that of the second planar portion, and the first planar portion, the bendable portion, and the second planar portion enclose a groove; and A buffer layer, the buffer layer comprising a main body portion and a protruding portion connected to each other, the protruding portion being arranged in the groove, the main body portion being arranged on a side of the protruding portion away from the protective layer, and the main body portion being respectively stacked with the first plane portion and the second plane portion; Wherein, the range of the ratio of the elastic modulus E1 of the protective layer to the elastic modulus E2 of the buffer layer is: 10≤E1 / E2≤30.

2. The protective cover according to claim 1, characterized in that: The elastic modulus E1 of the protective layer is in the range of 50Mpa≤E1≤2000Mpa.

3. The protective cover according to claim 2, characterized in that: The elastic modulus E1 of the protective layer is in the range of 100Mpa≤E1≤800Mpa.

4. The protective cover according to claim 1, characterized in that: The elastic modulus E2 of the buffer layer is in the range of 0.2Mpa≤E2≤80Mpa.

5. The protective cover according to claim 1, characterized in that: The bendable portion includes a first transition sub-portion, an equal thickness sub-portion and a second transition sub-portion connected in sequence, the first transition sub-portion is connected to the first plane portion at one end away from the equal thickness sub-portion, the second transition sub-portion is connected to the second plane portion at one end away from the equal thickness sub-portion, the thickness of the equal thickness sub-portion is smaller than the thickness of the first plane portion and the equal thickness sub-portion is smaller than the thickness of the second plane portion, the thickness of the first transition sub-portion gradually decreases from one end connected to the first plane portion toward one end connected to the equal thickness sub-portion, and the thickness of the second transition sub-portion gradually decreases from one end connected to the second plane portion toward one end connected to the equal thickness sub-portion.

6. The protective cover according to claim 5, characterized in that: The ratio of the thickness d1 of the first planar portion to the thickness d2 of the equal-thickness sub-portion is in the range of 1.5≤d1 / d2≤4; the ratio of the thickness d3 of the second planar portion to the thickness d2 of the equal-thickness sub-portion is in the range of 1.5≤d3 / d2≤4.

7. The protective cover according to claim 5, characterized in that: The range of the thickness d1 of the first planar portion is: 30 μm≤d1≤200 μm; the range of the thickness d2 of the equal-thickness sub-portion is: 10 μm≤d2≤50 μm; the range of the thickness d3 of the second planar portion is: 30 μm≤d3≤200 μm.

8. The protective cover according to claim 1, characterized in that: The thickness d4 of the main body is in the range of 20 μm≤d4≤150 μm.

9. The protective cover according to claim 1, characterized in that: The range of the ratio of the thickness d1 of the first plane portion to the thickness d4 of the main body portion is: 1≤d1 / d4≤2.5; the range of the ratio of the thickness d3 of the second plane portion to the thickness d4 of the main body portion is: 1≤d3 / d4≤2.

5.

10. The protective cover according to any one of claims 1 to 9, characterized in that: The protective cover also includes: The first substrate layer is arranged on a side of the protective layer away from the buffer layer, and the elastic modulus of the first substrate layer is greater than the elastic modulus of the protective layer.

11. The protective cover according to claim 10, characterized in that: The protective cover also includes: The second substrate layer is disposed on a surface of the buffer layer away from the protective layer, and the elastic modulus of the second substrate layer is greater than the elastic modulus of the protective layer.

12. The protective cover according to claim 11, characterized in that: The elastic modulus of the first substrate layer is greater than or equal to the elastic modulus of the second substrate layer; and the thickness of the first substrate layer is greater than or equal to the thickness of the second substrate layer.

13. The protective cover according to claim 11, characterized in that: The range of the ratio of the elastic modulus E3 of the first substrate layer to the elastic modulus E4 of the second substrate layer is: 1≤E3 / E4≤2.

5.

14. The protective cover according to any one of claims 11 to 13, characterized in that: The ratio of the thickness d6 of the first substrate layer to the thickness d7 of the second substrate layer is in the range of 2≤d6 / d7≤5.

15. The protective cover according to any one of claims 1-9, 11-13, characterized in that: The protective cover also includes: A hardening layer is provided on a side of the protective layer away from the buffer layer, and a pencil hardness of the hardening layer ranges from 1H to 3H.

16. A flexible display screen assembly, characterized in that: include: A flexible display screen having a display surface; as well as The protective cover plate according to any one of claims 1 to 15 is stacked on the display surface of the flexible display assembly to protect the flexible display assembly.

17. A foldable electronic device, characterized in that: include: The flexible display screen assembly according to claim 16; A foldable mechanism, the foldable mechanism is used to carry the flexible display screen assembly and drive the flexible display screen assembly to be folded or flattened, wherein the protective cover of the flexible display screen assembly is farther away from the foldable mechanism than the flexible display screen of the flexible display screen assembly; as well as A processor is electrically connected to the flexible display screen assembly and is used to control the flexible display screen assembly to display.

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