Protective cover plate, flexible display assembly, and foldable electronic device

Abstract

The application provides a protective cover plate, a flexible display screen assembly and a foldable electronic device. The protective cover plate comprises a protective layer, the protective layer comprises a first planar part, a bendable part and a second planar part connected in sequence, the thickness of the bendable part is less than the thickness of the first planar part, and the thickness of the bendable part is less than the thickness of the second planar part, the first planar part, the bendable part and the second planar part enclose a groove; and a buffer layer, the buffer layer comprises a body part and a protruding part connected, the protruding part is arranged in the groove, the body part is arranged on the side of the protruding part away from the protective layer, and the body part is stacked with the first planar part and the second planar part respectively; wherein the ratio of the elastic modulus E1 of the protective layer to the elastic modulus E2 of the buffer layer ranges from 10 to 30. The first planar part and the second planar 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 electronic field, in particular to a protective cover plate, a flexible display screen assembly and a foldable electronic device. BACKGROUND

[0002] With the development of technology and the improvement of living standards, people have higher requirements for portable electronic devices, therefore, foldable electronic devices such as foldable mobile phones appear, and the existing cover plates applied to the screens of foldable mobile phones are difficult to balance mechanical strength and bending performance. SUMMARY

[0003] Embodiments of the present application provide a protective cover plate, which has good impact resistance and good bending performance.

[0004] The first aspect of the present application provides a protective cover plate, which comprises:

[0005] a protective layer, the protective layer comprises a first planar part, a bendable part and a second planar part connected in sequence, the thickness of the bendable part is less than the thickness of the first planar part, and the thickness of the bendable part is less than the thickness of the second planar part, the first planar part, the bendable part and the second planar part enclose a groove; and

[0006] a buffer layer, the buffer layer comprises a body part and a protruding part connected, the protruding part is arranged in the groove, the body part is arranged on the side of the protruding part away from the protective layer, and the body part is laminated with the first planar part and the second planar part respectively;

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

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

[0009] a flexible display screen, the flexible display screen has a display surface; and

[0010] the protective cover plate of the first aspect of the present application is laminated and arranged on the display surface of the flexible display screen, and is used for protecting the flexible display screen.

[0011] The third aspect of the present application provides a foldable electronic device, which comprises:

[0012] the flexible display screen assembly of the second aspect of the present application;

[0013] A foldable mechanism for carrying the flexible display assembly and for driving the flexible display assembly to fold or flatten, wherein the protective cover plate of the flexible display assembly is farther away from the foldable mechanism than the flexible display of the flexible display assembly; and

[0014] A processor electrically connected with the flexible display assembly for controlling the flexible display assembly to display.

[0015] The protective cover plate of the embodiment of the present application comprises a protective layer and a buffer layer, the protective layer comprises a first planar part, a bendable part and a second planar part connected in sequence, the thickness of the bendable part is less than the thickness of the first planar part, and the thickness of the bendable part is less than the thickness of the second planar part, the ratio of the elastic modulus E1 of the protective layer to the elastic modulus E2 of the buffer layer ranges from 10 to 30; in the present application, the protective layer with higher modulus and the buffer layer with lower modulus are used in cooperation, the protective layer can provide the protective cover plate with higher mechanical strength and impact resistance, the buffer layer can improve the buffering performance of the protective cover plate and further improve the impact resistance of the protective cover plate; at the same time, the protective layer with higher modulus is designed to be of unequal thickness, the thinner bendable part can make the protective cover plate have better bending performance and lower bending stress of the bendable part, preventing the bendable part from cracking when the protective cover plate is bent; the thicker first planar part and second planar part make the protective layer not easy to deform and have better impact resistance; so that the protective cover plate has better bending performance and higher mechanical strength at the same time, and can better protect the flexible display of the flexible display assembly when applied to the flexible display assembly. BRIEF DESCRIPTION OF DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed in the embodiments will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

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

[0018] Figure 2 is a schematic diagram of the cross-sectional structure of the protective cover plate of an embodiment of the present application along the direction of A-A in the figure. Figure 1

[0019] Figure 3 is an enlarged view of the dashed box I in the figure. Figure 2

[0020] ​​Figure 4 is a schematic diagram of a cross section of the buffer layer along the A-A direction of the embodiment of the present application. Figure 1

[0021] Figure 5 is a schematic diagram of a cross section of the protective cover plate along the A-A direction of the embodiment of the present application. Figure 1

[0022] Figure 6 is a schematic diagram of a cross section of the protective cover plate along the A-A direction of the embodiment of the present application. Figure 1

[0023] Figure 7 is a schematic diagram of a cross section of the protective cover plate along the A-A direction of the embodiment of the present application. Figure 1

[0024] Figure 8 is a schematic diagram of a cross section of the protective cover plate along the A-A direction of the embodiment of the present application. Figure 1

[0025] Figure 9 is a schematic diagram of a cross section of the protective cover plate along the A-A direction of the embodiment of the present application. Figure 1

[0026] Figure 10 is a schematic diagram of a cross section of the protective cover plate along the A-A direction of the embodiment of the present application. Figure 1

[0027] Figure 11 is a schematic diagram of a cross section of the protective cover plate along the A-A direction of the embodiment of the present application. Figure 1

[0028] Figure 12 is a schematic diagram of a flow of the method for manufacturing the protective cover plate of the embodiment of the present application.

[0029] Figure 13 is a schematic diagram of a flow of the method for manufacturing the protective layer of the embodiment of the present application.

[0030] Figure 14 is a schematic diagram of a flow of the method for manufacturing the protective cover plate of the embodiment of the present application.

[0031] Figure 15 is a schematic diagram of a structure of the flexible display screen assembly of the embodiment of the present application.

[0032] Figure 16 is a schematic diagram of a cross section of the flexible display screen assembly along the B-B direction of the embodiment of the present application. Figure 15

[0033] Figure 17 ​​​​​​​​​is a structural schematic diagram of a foldable electronic device in a flat state according to an embodiment of the present application.

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

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

[0036] Legend of reference signs:

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

[0038] In order to enable persons skilled in the art to better understand the schemes of the present application, the technical schemes in the embodiments of the present application will be described clearly and completely below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by persons skilled in the art without creative labor fall within the scope of protection of the present application.

[0039] The terms "first", "second", etc. in the specification and claims of the present application and the above-described drawings are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device including a series of steps or units is not limited to the listed steps or units, but can optionally further include steps or units not listed, or can optionally further include other steps or units inherent to the process, method, product or device.

[0040] The technical schemes in the embodiments of the present application will be described below in combination with the drawings.

[0041] It should be noted that, for the convenience of description, the same reference signs represent the same components in the embodiments of the present application, and for the sake of brevity, the detailed description of the same components is omitted in different embodiments.

[0042] The protective cover plate of the flexible display screen assembly requires that it has good bending performance in the bending area and good impact resistance in the planar area. However, the related protective cover plate is difficult to have both. Unequal-thickness ultra-thin glass can be used as the protective cover plate, but the cost of processing the glass into unequal thickness is high, and it is difficult to popularize on a large scale. In addition, the glass is fragile, and a layer of organic protective film needs to be covered on the surface of the glass. The glass is cut when it breaks.

[0043] Please refer to Figure 1 and Figure 2 The protective cover plate 100 provided in the embodiments of the present application includes a protective layer 10 and a buffer layer 20. The protective layer 10 includes a first planar part 11, a bendable part 12 and a second planar part 13 connected in sequence. The thickness of the bendable part 12 is less than the thickness of the first planar part 11, and the thickness of the bendable part 12 is less than the thickness of the second planar part 13. The first planar part 11, the bendable part 12 and the second planar part 13 enclose a groove 14. The buffer layer 20 is arranged on one side of the protective layer 10 having the groove 14, and part of the buffer layer 20 is arranged in the groove 14. 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 provided in the embodiments 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 bends around the bendable part 12 to make the first planar part 11 and the second planar part 13 superimposed. When the flexible display screen assembly is unfolded, the first planar part 11, the bendable part 12 and the second planar part 13 are coplanar. When the protective cover plate 100 provided in the present application is applied to the flexible display screen assembly, the protective layer 10 is farther 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 part 12, and the thickness of the bendable part 12 is less than the thickness of the first planar part 11 and the second planar part 13, so that one side surface of the bendable part 12 is recessed in the first planar part 11 and the second planar part 13, thereby forming the groove 14.

[0046] It can be understood that the surface of the bendable part 12 facing the buffer layer 20 is recessed in the surface of the first planar part 11 facing the buffer layer 20 and the surface of the second planar part 13 facing the buffer layer 20. The surface of the bendable part 12 away from the buffer layer 20, the surface of the first planar part 11 away from the buffer layer 20, and the surface of the second planar part 13 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 abutment with the buffer layer 20, the buffer layer 20 is arranged in abutment with the first planar portion 11, the bendable portion 12 and the second planar portion 13 in part, and the portion of the buffer layer 20 in abutment with the bendable portion 12 is in abutment with the side wall and the bottom wall 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 can 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, which greatly reduces the bending performance of the protective layer 10, especially in a low-temperature environment, the risk of cracking of the protective layer 10 is greatly increased when bending.

[0049] The protective cover plate 100 of the embodiment of the present application comprises a protective layer 10 and a buffer layer 20, the protective layer 10 comprises 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 smaller than the thickness of the first planar portion 11, and the thickness of the bendable portion 12 is smaller than the thickness of the second planar portion 13, 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; in the present application, by using the protective layer 10 with a higher modulus and the buffer layer 20 with a lower modulus, the protective layer 10 can provide a higher mechanical strength and impact resistance for the protective cover plate 100, the buffer layer 20 can improve the buffering performance of the protective cover plate 100 and 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, the thinner bendable portion 12 can make the protective cover plate 100 have better bending performance, and the bendable portion 12 has lower bending stress, preventing the bendable portion 12 from cracking when the protective cover plate 100 is bent; the thicker first planar portion 11 and second planar portion 13 make the protective layer 10 not easy to deform and have better impact resistance; so that the protective cover plate 100 has better bending performance while having higher mechanical strength, and when applied to a flexible display screen assembly, the flexible display screen of the flexible display screen assembly can be better protected.

[0050] Optionally, the elastic modulus E1 of the protective layer 10 ranges from 50Mpa to 2000Mpa. Specifically, the elastic modulus E1 of the protective layer 10 can be, but is not limited to, 50Mpa, 80Mpa, 100Mpa, 150Mpa, 200Mpa, 250Mpa, 300Mpa, 350Mpa, 400Mpa, 450Mpa, 500Mpa, 600Mpa, 700Mpa, 800Mpa, 900Mpa, 1000Mpa, 1200Mpa, 1400Mpa, 1600Mpa, 1800Mpa, 2000Mpa, etc. If the elastic modulus of the protective layer 10 is too low, the mechanical strength, such as the impact resistance, of the protective layer 10 is reduced, and when the protective cover plate 100 is applied to a flexible display screen assembly, the protection of the flexible display screen of the flexible display screen assembly by the protective cover plate 100 is reduced. If the elastic modulus of the protective layer 10 is too high, the bending performance of the bendable portion 12 is reduced, and in particular when the protective cover plate 100 is bent along the bendable portion 12 in a low-temperature environment, the bendable portion 12 is prone to cracking, and the service life of the protective cover plate 100 is reduced.

[0051] Further, the elastic modulus E1 of the protective layer 10 ranges from 100Mpa to 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 have good mechanical strength, and the bendable portion 12 can have good bending performance, so that the protective cover plate 100 has a small bending radius.

[0052] Further, the elastic modulus E1 of the protective layer 10 ranges from 100Mpa to 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 have good mechanical strength, and the bendable portion 12 can have good bending performance, so that the protective cover plate 100 has a small bending radius.

[0053] Please refer to Figure 3In some embodiments, the bendable part 12 comprises a first transition sub-part 121, an equal-thickness sub-part 122 and a second transition sub-part 123 connected in sequence, the first transition sub-part 121 is connected to the first planar part 11 at one end away from the equal-thickness sub-part 122, the second transition sub-part 123 is connected to the second planar part 13 at one end away from the equal-thickness sub-part 122, the thickness of the equal-thickness sub-part 122 is less than the thickness of the first planar part 11 and the thickness of the second planar part 13, the thickness of the first transition sub-part 121 gradually decreases from the end connected to the first planar part 11 to the end connected to the equal-thickness sub-part 122, and the thickness of the second transition sub-part 123 gradually decreases from the end connected to the second planar part 13 to the end connected to the equal-thickness sub-part 122. By designing the first transition sub-part 121 and the second transition sub-part 123, the thickness of the first planar part 11, the equal-thickness sub-part 122 and the second planar part 13 can be smoothly transitioned, the mechanical strength of the entire protective layer 10 can be improved, and stress weak points at the connection between the first planar part 11 and the bendable part 12 and the connection between the second planar part 13 and the bendable part 12 can be avoided, so as to avoid stress concentration and reduce the mechanical strength of the protective layer 10.

[0054] Understandably, the thickness of the first transition sub-part 121 gradually and smoothly transitions from the thickness of the first planar part 11 to the thickness of the equal-thickness sub-part 122, and the thickness of the second transition sub-part 123 gradually and smoothly transitions from the thickness of the second planar part 13 to the thickness of the equal-thickness sub-part 122.

[0055] Optionally, the ratio of the thickness d1 of the first planar part 11 to the thickness d2 of the equal-thickness sub-part 122 is in the range of 1.5≤d1 / d2≤4. Specifically, the ratio of the thickness d1 of the first planar part 11 to the thickness d2 of the equal-thickness sub-part 122 can 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 part 11 to the thickness d2 of the equal-thickness sub-part 122 is too small, the difference between the thick area and the thin area of the protective layer 10 is too small, and in order to ensure that the bendable part 12 has good bending performance, the thickness of the first planar part 11 is too small, which reduces the impact resistance of the first planar part 11 and cannot well protect the flexible display screen of the flexible display screen assembly when applied to the flexible display screen assembly. If the ratio of the thickness d1 of the first planar part 11 to the thickness d2 of the equal-thickness sub-part 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 part 11 has good impact resistance, but 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 part 11) and the thin area (i.e. the bendable part 12) in the preparation process is easy to cause appearance defects such as bubbles, wrinkles, concave-convex, etc., in addition, the thickness of the bendable part 12 is too small, which reduces the protection effect of the bendable part 12.

[0056] Optionally, the ratio of the thickness d3 of the second planar portion 13 to the thickness d2 of the uniform 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 uniform thickness sub-portion 122 can 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 uniform 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, and 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, and when applied to a flexible display assembly, the flexible display assembly cannot be well protected. If the ratio of the thickness d2 of the second planar portion 13 to the thickness d2 of the uniform 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, but it will increase the process difficulty of preparing the protective layer 10, in addition, the shrinkage difference between the thick area (i.e. the second planar portion 13) and the thin area (i.e. the bendable portion 12) in the preparation process is easy to cause appearance defects such as bubbles, wrinkles, concave-convex, etc. In addition, the thickness of the bendable portion 12 is too small, which reduces the protection of the bendable portion 12.

[0057] Optionally, the thickness of the first planar portion 11 is uniform, and the thickness d1 of the first planar portion 11 is in the range of 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 are reduced, and when applied to a flexible display assembly, the support and protection of the first planar portion 11 to the flexible display of the flexible display assembly are 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 assembly is too thick, which is not conducive to the ultra-thin of the flexible display assembly.

[0058] Optionally, the thickness of the equal-thickness sub-section 122 is equal, and the thickness d2 of the equal-thickness sub-section 122 ranges from 10 μm to 50 μm. Specifically, the thickness d2 of the equal-thickness sub-section 122 can be, but is not limited to, 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, 50 μm, etc. The thinner the thickness of the equal-thickness sub-section 122, the better the bending resistance of the equal-thickness sub-section 122, but when the thickness of the equal-thickness sub-section 122 is too thin, the mechanical strength of the equal-thickness sub-section 122 is reduced, and when applied to the flexible display screen assembly, the protection and support of the equal-thickness sub-section 122 on the flexible display screen assembly are reduced; and the thicker the thickness of the equal-thickness sub-section 122, the lower the bending performance of the equal-thickness sub-section 122.

[0059] Optionally, the thickness of the second planar section 13 is equal, and the thickness d3 of the second planar section 13 ranges from 30 μm to 200 μm. Specifically, the thickness d3 of the second planar section 13 can be, but is not limited to, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, 110 μm, 120 μm, 130 μm, 140 μm, 150 μm, 170 μm, 180 μm, 190 μm, 200 μm, etc. The thinner the thickness of the second planar section 13, the lower the mechanical strength and impact resistance of the second planar section 13, and when applied to the flexible display screen assembly, the support and protection of the second planar section 13 on the flexible display screen of the flexible display screen assembly are affected; the thicker the thickness of the second planar section 13, the better the support and flatness of the second planar section 13, but the thickness of the second planar section 13 is too thick, which makes the flexible display screen assembly too thick, which is not conducive to the ultra-thinning of the flexible display screen assembly.

[0060] Optionally, along the arrangement direction of the first planar section 11, the bendable section 12, and the second planar section 13, the width w1 of the first transition sub-section 121 ranges from 10 mm to 50 mm. Specifically, the width of the first transition sub-section 121 can 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 section 11, the bendable section 12, and the second planar section 13, the width w2 of the equal-thickness sub-section 122 ranges from 10 mm to 30 mm. Specifically, the width of the equal-thickness sub-section 122 can 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, the width w3 of the second transition sub-portion 123 ranges from 10mm to 50mm along the arrangement direction of the first planar portion 11, the bendable portion 12 and the second planar portion 13. Specifically, the thickness of the second transition sub-portion 123 can be, but is not limited to, 10mm, 11mm, 12mm, 13mm, 14mm, 15mm, 20mm, 25mm, 30mm, 35mm, 40mm, 45mm, 50mm, etc.

[0063] Optionally, the material of the protective layer 10 is resin. Compared with the glass, the resin can better avoid scratching the hand after the protective layer 10 is broken. In addition, compared with the glass with different thicknesses, the resin 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 comprises at least one of thermoplastic polyurethane, polyurethane acrylate, polydimethylsiloxane and saturated polyester. When the protective layer 10 adopts these materials, the first planar portion 11 and the second planar portion 13 of the protective layer 10 can have better impact resistance, and the bendable portion 12 can have better bending performance.

[0065] Optionally, the elastic modulus E2 of the buffer layer 20 ranges from 0.2Mpa to 80Mpa. Specifically, the elastic modulus E2 of the buffer layer 20 can 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, the buffer layer 20 cannot 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, the impact resistance of the protective cover plate 100 can be improved, but the bending performance of the bendable portion 12 of the protective cover plate 100 is reduced, thereby reducing the bending performance of the protective cover plate 100.

[0066] Further, the elastic modulus E2 of the buffer layer 20 ranges from 5Mpa to 50Mpa. When the elastic modulus of the buffer layer 20 ranges from 5Mpa to 50Mpa, the buffer layer 20 can have better buffering performance, the impact resistance of the protective cover plate 100 can be further improved, and the position corresponding to the bendable portion 12 of the protective cover plate 100 can have better bending performance.

[0067] Please refer to Figure 4Optionally, the buffer layer 20 comprises a body portion 21 and a protruding portion 22, the protruding portion 22 protruding from a surface of the body portion 21 facing the protective layer 10, the protruding portion 22 being arranged in the groove 14, and the body portion 21 being laminated with the first planar portion 11 and the second planar portion 13 respectively. It can be understood that the protruding portion 22 and the groove 14 are complementary in structure, 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 planar portion 11, a part is connected with the protruding portion 22, and a part is arranged to fit the second planar 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 can 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 planar portion 11 to the thickness d4 of the body portion 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 laminated part of the buffer layer 20 with the first planar portion 11 is prone to surface unevenness, surface defects increase, affecting the appearance effect of the protective cover plate 100, or the thickness of the first planar portion 11 is too large, making the flexible display screen assembly too thick, which is not conducive to the ultra-thin of the flexible display screen assembly; if the ratio of the thickness d1 of the first planar portion 11 to the thickness d4 of the body portion 21 is too small, the mechanical strength and impact resistance of the first planar portion 11 are reduced, thereby reducing the support and flatness of the first planar portion 11, which affects the support and protection of the first planar portion 11 on the flexible display screen assembly when applied to the flexible display screen assembly. When the ratio of the thickness d1 of the first planar portion 11 to the thickness d4 of the body portion 21 is between 1 and 2.5, the impact resistance, flatness, buffering performance, etc. of the protective cover plate 100 can be better balanced, and the thickness is relatively thin.

[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 can 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 planar 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 surface of the portion where the buffer layer 20 is laminated with the second planar portion 13 is prone to unevenness, the surface defects increase, affecting the appearance effect of the protective cover plate 100, or the thickness of the second planar portion 13 is too large, making the flexible display screen assembly too thick, which is not conducive to the ultra-thin of the flexible display screen assembly; if the ratio of the thickness d3 of the second planar portion 13 to the thickness d4 of the body portion 21 is too small, the mechanical strength and impact resistance of the second planar portion 13 are reduced, thereby reducing the support and flatness of the second planar portion 13, and when applied to the flexible display screen assembly, the support and protection of the second planar portion 13 on the flexible display screen assembly are affected. When the ratio of the thickness d3 of the second planar portion 13 to the thickness d4 of the body portion 21 is between 1 and 2.5, the impact resistance, flatness, and buffering performance of the protective cover plate 100 can be better balanced, and the thickness is relatively thin.

[0070] Optionally, the thickness d4 of the body portion 21 is in the range of 20μm≤d4≤150μm. Specifically, the thickness of the body portion 21 can 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 body portion 21 is too thin, the buffering performance of the buffer layer 20 as a whole is reduced, and when the protective cover plate 100 is subjected to external force, it is difficult to provide sufficient buffering effect; if the thickness of the body portion 21 is too thick, the mechanical strength of the protective cover plate 100 is too high, and the bending performance of the protective cover plate 100 corresponding to the bendable portion 12 is reduced.

[0071] Optionally, the buffer layer 20 comprises 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 plate 100.

[0072] Please refer to Figure 5 In some embodiments, the protective cover plate 100 further comprises a first adhesive layer 30, which is laminated on the side of the buffer layer 20 away from the protective layer 10, and is used to adhere 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 the "set on one side of an element" in the present application can be set on the surface of the element; it can also be set away from the element and spaced apart, and other elements are further arranged between the element. For example, in the present embodiment, the first adhesive layer 30 is set on one side of the buffer layer 20, which can be set on the surface of the buffer layer 20; it can also be set away from the buffer layer 20 and spaced apart, and other film layers are further arranged between the first adhesive layer 30 and the buffer layer 20.

[0074] Optionally, the first adhesive layer 30 can be, but is not limited to, an 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 can 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 adhesive role; if the thickness of the first adhesive layer 30 is too thick, the thickness of the protective cover plate 100 is increased, which is not conducive to the ultra-thinning of the protective cover plate 100.

[0076] In the embodiments of the present application, when a numerical range a to b is involved, if not specifically indicated, it means that the numerical value can be any numerical value between a and b, including the end point value a and the end point value b.

[0077] Please refer to Figure 6 In some embodiments, the protective cover plate 100 further comprises a first substrate layer 40, the first substrate layer 40 is arranged 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 arranging 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 gradually decreasing the elastic modulus of the first substrate layer 40, the protective layer 10 and the buffer layer 20, when the protective cover plate 100 is impacted by external force, the first substrate layer 40 and the protective layer 10 can provide higher rigidity to prevent the protective cover plate 100 from deforming or breaking, and the buffer layer 20 can more effectively absorb and buffer 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 higher elastic modulus and better bending performance at the same time, thereby the protective cover plate 100 has better flatness and support at the positions corresponding to the first and second flat parts 11 and 13, has better impact resistance, and has better bending performance at the position corresponding to the bendable part 12.

[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 can 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 is limited to be improved. 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 effect of the protective cover plate 100. If the thickness of the first substrate layer 40 is too thick, although the impact resistance of the protective cover plate 100 can be improved, the folding deformation of the protective cover plate 100 is reduced, but the bending performance of the protective cover plate 100 at the position corresponding to the bendable part 12 is also reduced.

[0080] Optionally, the first substrate layer 40 comprises 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 3 GPA≤E3≤6 GPA. Specifically, it can be, but is not limited to, 3 GPA, 3.5 GPA, 4 GPA, 4.5 GPA, 5 GPA, 5.5 GPA, 6 GPA, etc. If the elastic modulus of the first substrate layer 40 is too low, the impact resistance of the protective cover plate 100 is limited to be improved. If the elastic modulus of the first substrate layer 40 is too high, the bending performance of the protective cover plate 100 at the position corresponding to the bendable part 12 is reduced.

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

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

[0084] Please refer to Figure 7 In some embodiments, the protective cover plate 100 further comprises a second adhesive layer 50, which is arranged between the first substrate layer 40 and the protective layer 10, and is used to bond the first substrate layer 40 to the protective layer 10.

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

[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 can 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 adhesive role; if the thickness of the second adhesive layer 50 is too thick, the thickness of the protective cover plate 100 is increased, which is not conducive to the ultra-thinning of the protective cover plate 100.

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

[0088] Please refer to Figure 8 In some embodiments, the protective cover plate 100 further comprises a second substrate layer 60, which is arranged 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 that of the protective layer 10. It can be understood that in this embodiment, the protective cover plate 100 at least comprises a second substrate layer 60, a buffer layer 20, a protective layer 10 and a first substrate layer 40 arranged in sequence. By designing the elastic modulus of the first substrate layer 40 and the second substrate layer 60 to be greater than that of the protective layer 10, the first substrate layer 40 and the second substrate layer 60 with higher elastic modulus are arranged on both sides of the protective layer 10 or the buffer layer 20 with lower elastic modulus, thereby forming a configuration with high-low-high elastic modulus, so that the first substrate layer 40 and the second substrate layer 60 with higher elastic modulus can be made thinner, so that the protective cover plate 100 has higher impact resistance while having better bending performance at the position corresponding to the bendable part 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 higher elastic modulus and better bending performance at the same time, so that the protective cover plate 100 has better flatness and support at the positions corresponding to the first flat portion 11 and the second flat portion 13, has better impact resistance, and has better bending performance at the position corresponding to the bendable portion 12.

[0090] It can be understood that when the protective cover plate 100 includes 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 away from the buffer layer 20, and is used to bond the protective cover plate 100 to the flexible display screen assembly when the protective cover plate 100 is applied to the flexible display screen assembly.

[0091] Optionally, the thickness d7 of the second substrate layer 60 ranges from 10 μm to 25 μm. Specifically, the thickness of the second substrate layer 60 can be, but is not limited to, 10 μm, 12 μm, 14 μm, 16 μm, 18 μm, 20 μm, 22 μm, 24 μm, 25 μm, etc. If the thickness of the second substrate layer 60 is too small, the impact resistance of the protective cover plate 100 is 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, the surface of the first substrate layer 40 is difficult to achieve a mirror effect, and the appearance of the protective cover plate 100 is affected. If the thickness of the second substrate layer 60 is too thick, the impact resistance of the protective cover plate 100 can be improved, and the folding deformation of the protective cover plate 100 is reduced, but the bending performance of the part of the protective cover plate 100 corresponding to the bendable portion 12 is reduced.

[0092] Although the first substrate layer 40 and the second substrate layer 60 both require high light transmittance, the second substrate layer 60 is closer to the inner layer and is relatively thin, so the haze will increase and wrinkles or orange peel will inevitably occur. However, the two layers of the second substrate layer 60 have film layers with little difference in refractive index, which can cover the defects on the surface of the second substrate layer 60 and do not affect the visual effect of the second substrate layer 60.

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

[0094] Optionally, the elastic modulus of the second substrate layer 60 ranges from 2GPA to 4GPA. Specifically, it can 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 improvement of the impact resistance of the protective cover plate 100 is limited, and if the elastic modulus of the second substrate layer 60 is too high, the bending performance of the part of the protective cover plate 100 corresponding to the bendable part 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, and 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 plate 100 is applied to the flexible display screen assembly, the first substrate layer 40 is farther away from the flexible display screen 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 screen assembly is impacted, the energy is first transmitted 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, and 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 plate 100 can be better improved, and the protective cover plate 100 can better protect the flexible display screen of the flexible display screen assembly. In addition, the protective cover plate 100 is less likely to produce 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 ranges from 1 to 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 can 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 both the first substrate layer 40 and the second substrate layer 60 is small, the rigidity of the first substrate layer 40 is poor and scratches are easily produced, and the impact resistance of the protective cover plate 100 is reduced, or the elastic modulus of both the first substrate layer 40 and the second substrate layer 60 is large, and the bending performance of the part of the protective cover plate 100 corresponding to the bendable part 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 part of the protective cover plate 100 corresponding to the bendable part 12 has better bending performance. 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 the bending performance of the protective cover plate 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 can 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, the impact resistance is reduced, and scratches are prone to occur, or 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 at the position 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 increases, the second substrate layer 60 is prone to wrinkles or orange peel, the surface of the second substrate layer 60 is difficult to achieve a mirror effect, affecting the appearance effect of the protective cover plate 100, or the first substrate layer 40 is too thick, affecting the bendability of the first substrate layer 40.

[0098] In some embodiments, the protective cover plate 100 further comprises a third adhesive layer 70, which is arranged 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 can be, but is not limited to, optical glue.

[0100] Optionally, the thickness of the third adhesive layer 70 is in the range of 20μm to 50μm. Specifically, the thickness of the third adhesive layer 70 can be, but is not limited to, 20μm, 25μm, 30μm, 35μm, 40μm, 45μm, 50μm, etc. If the thickness of the third adhesive layer 70 is too small, the third adhesive layer 70 cannot play a good bonding role; if the thickness of the third adhesive layer 70 is too large, the thickness of the protective cover plate 100 is increased, which is not conducive to the ultra-thinning of the protective cover plate 100.

[0101] Please refer to Figure 9 In some embodiments, the protective cover plate 100 further comprises a hardening layer 80, which is arranged 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 arranging the hardening layer 80 on the side of the protective layer 10 away from the buffer layer 20, the hardening layer 80 serves as the outer surface of the protective cover plate 100 during use, so that the protective cover plate 100 has better hardness and wear resistance, and can better avoid scratches during use when the protective cover plate 100 is applied to a flexible display screen assembly, 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 plate 100 simultaneously includes the first substrate layer 40 and the hardening layer 80, the first substrate layer 40 is arranged on the surface of the protective layer 10 away from the buffer layer 20, and the hardening layer 80 is arranged on the surface of the first substrate layer 40 away from the protective layer 10.

[0103] Optionally, the thickness d5 of the hardening layer 80 ranges from 2 μm to 5 μm. Specifically, the thickness d5 of the hardening layer 80 can be, but is not limited to, 2 μm, 2.5 μm, 3 μm, 3.5 μm, 4 μm, 4.5 μm, 5 μm, etc. If the thickness of the hardening layer 80 is too low, the wear resistance of the hardening layer 80 is not enough, and scratches are likely to occur after a period of use. If the thickness of the hardening layer 80 is too thick, the bending performance of the hardening layer 80 is low, which affects the bending performance of the protective cover plate 100, and the hardening layer 80 is likely to crack when the protective cover plate 100 is bent.

[0104] Optionally, the pencil hardness of the hardening layer 80 ranges from 1H to 3H. Specifically, the pencil hardness of the hardening layer 80 can be, but is not limited to, 1H, 2H, 3H, etc. If the hardness of the hardening layer 80 is too low, the wear resistance of the hardening layer 80 is not enough, and scratches are likely to occur after a period of use. If the hardness of the hardening layer 80 is too high, the bending performance of the hardening layer 80 is reduced, which affects the bending performance of the protective cover plate 100, and the hardening layer 80 is likely to crack when the protective cover plate 100 is bent. The pencil hardness test of the embodiments of the present application adopts GB / T 6739-2006 to measure 1 kg pencil hardness.

[0105] Optionally, the hardening layer 80 uses 0000# steel wool, 1Kg weight, and is rubbed back and forth for more than 2500 times, and no scratches are observed.

[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 can be, but is not limited to, at least one of Diphenyl(2,4,6-Trimethylbenzoyl)Phosphine Oxide (TPO), propyl thioxanthone (ITX), benzophenone (BP), etc. Optionally, the solvent can 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, methyl butanone.

[0107] Please refer to Figure 10 and Figure 11In some embodiments, the protective cover plate 100 further comprises an anti-reflective film 90 (AR for short), which is arranged on the surface of the first base material layer 40 away from the protective layer 10, so as to reduce the reflection of light by the protective cover plate 100, and when applied to a flexible display screen assembly, the display effect of the flexible display screen assembly can be improved.

[0108] Optionally, the anti-reflective film 90 can be, but is not limited to, silicon oxide, silicon nitride, etc.

[0109] Optionally, when the protective cover plate 100 comprises both the anti-reflective film 90 and the hardening layer 80, the hardening layer 80 and the anti-reflective film 90 are sequentially arranged on the surface of the first base material layer 40 away from the protective layer 10. In other words, the hardening layer 80 is arranged on the surface of the first base material layer 40 away from the protective layer 10, and the anti-reflective 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 embodiments of the present application can be prepared by the methods of the following embodiments of the present application, and in addition, can be prepared by other methods. The preparation method of the embodiments 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 embodiments of the present application.

[0111] Please refer to Figure 12 The embodiments of the present application also provide a preparation method of a protective cover plate 100, which comprises:

[0112] S201, preparing a protective layer 10;

[0113] Please refer to Figure 13 and Figure 14 Optionally, the preparation of the protective layer 10 comprises:

[0114] S2011, providing a texture mold 100a, which comprises a mold body 10a and a protruding structure 30a, the protruding structure 30a being protruded on the surface of the mold body 10a;

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

[0116] Optionally, the slurry composed of raw material components of the protective layer 10 is coated on the surface of the texture mold 100a with 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, a monomer solution composed of isocyanate, polyol, etc. can be used for coating.

[0118] S2013, curing to obtain the protective layer 10.

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

[0120] Optionally, the method of preparing the protective layer 10 further comprises removing the texturing mold 100a.

[0121] Optionally, before the protective layer 10 is formed and the texturing mold 100a is removed, the method further comprises S202', using a second adhesive layer 50 to adhere the first substrate layer 40 to the surface of the protective layer 10 away from the recess 14.

[0122] For other aspects of the protective layer 10, please refer to the corresponding descriptions in 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 recess 14, and making the buffer layer 20 fill the recess 14, the buffer layer 20 comprising a body portion 21 and a protruding portion 22 connected to each other, the protruding portion 22 being disposed in the recess 14, the body portion 21 being disposed on the side of the protruding portion 22 away from the protective layer 10, and the body portion 21 being laminated with the first planar portion 11 and the second planar portion 13, respectively; 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 by the raw material components of the buffer layer 20 is coated on the surface of the protective layer 10 having the recess 14, and is cured to form the buffer layer 20.

[0125] For other aspects of the buffer layer 20, please refer to the corresponding descriptions in 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 comprises a protective layer 10 and a buffer layer 20, the protective layer 10 comprises a first planar part 11, a bendable part 12 and a second planar part 13 connected in sequence, the thickness of the bendable part 12 is less than the thickness of the first planar part 11, and the thickness of the bendable part 12 is less than the thickness of the second planar part 13, 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; in the embodiment, by using the protective layer 10 with a higher modulus and the 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, the buffer layer 20 can improve the buffering performance of the protective cover plate 100 and 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, the thinner bendable part 12 can make the protective cover plate 100 have better bending performance, the bending stress of the lower bendable part 12, prevent the bendable part 12 from cracking when the protective cover plate 100 is bent; the thicker first planar part 11 and second planar part 13 make the protective layer 10 not easy to deform and have better impact resistance; so that the protective cover plate 100 has better bending performance while having higher mechanical strength, and when applied to a flexible display screen assembly, the flexible display screen of the flexible display screen assembly can be better protected. In addition, the preparation method of the protective cover plate 100 of the present application has simple preparation process, is easy to mass produce and has low production cost.

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

[0128] Embodiments 1 to 5, Comparative Example 1 and Comparative Example 2

[0129] The protective cover plate 100 of each embodiment and comparative example comprises a protective layer 10 and a buffer layer 20 arranged in layers, the thickness of the first planar part 11 of the protective layer 10 is equal to the thickness of the second planar part 13, and the performance parameters of the protective layer 10 and the buffer layer 20 are shown in Table 1.

[0130] Embodiments 6 to 8, Comparative Example 3 and Comparative Example 4

[0131] The protective cover plate 100 of each embodiment comprises a 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) arranged in layers, and the performance parameters of the protective cover plate 100 are shown in Table 1.

[0132] Performance test of each embodiment and comparative example

[0133] Impact resistance test: refer to GB / T 39814-2021 Ultra-thin glass impact resistance test method - drop ball impact method, using 32g drop ball, impact height 100mm, the platform surface has real-time stress sensor of drop ball impact. Record the direct impact force of drop ball on the sensor when there is no protective cover 100, which is N0, and the impact force of drop ball when the protective cover 100 is placed, which is N1, then the impact resistance performance 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: using a mobile phone automatic bending test machine to test, the protective cover 100 is bent 25W times and 5W times under normal temperature (i.e. room temperature) and low temperature-15° conditions respectively, to test the minimum bending radius R of the protective cover 100 without cracks and delamination abnormalities on the surface and inner side.

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

[0136]

[0137]

[0138] From the test results of example 1 to example 3, comparative example 1 and comparative example 2, 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 resistance of the protective cover 100 is low, and the rigidity of the protective layer 10 and the buffer layer 20 is 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 resistance and bending performance of the protective cover 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 resistance of the protective cover 100 will also decrease, and the bending performance will be poor.

[0139] From the test results of example 2, example 3 and example 5, the smaller the ratio d1 / d2 of the thickness d1 of the first flat part 11 to the thickness d2 of the equal-thickness sub-part 122, the greater the thickness of the equal-thickness sub-part 122, the worse the bending performance of the protective cover 100.

[0140] As can be seen from Examples 6 to 8, Comparative Example 3 and Comparative Example 4, 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 resistance of the protective cover plate 100 is low, at this time, the elastic modulus of the first substrate layer 40 and the elastic modulus of the second substrate layer 60 are small, and the rigidity is 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 resistance of the protective cover plate 100 increases, and the bending performance is better; but 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 resistance of the protective cover plate 100 decreases, and the bending performance also decreases.

[0141] Please refer to Figure 15 and Figure 16 , the embodiment of the present application further provides a flexible display screen assembly 200, which comprises: a flexible display screen 210 and the protective cover plate 100 of the embodiment of the present application, the flexible display screen 210 has a display surface 211, and the protective cover plate 100 is stacked on the display surface 211 of the flexible display screen 210 and used for protecting the flexible display screen 210.

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

[0143] Optionally, the flexible display screen 210 can be adhered to the protective cover plate 100 by optical glue or other adhesives with high light transmittance.

[0144] For detailed description of the protective cover plate 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 screen assembly 200 in the embodiment is only one form of the flexible display screen assembly 200 to which the protective cover plate 100 is applied, and should not be understood as a limitation of the flexible display screen assembly 200 provided by the present application, nor should it be understood as a limitation of the protective cover plate 100 provided by each embodiment of the present application. For detailed description of the protective cover plate 100, please refer to the description of the corresponding part of the above embodiment, which will not be repeated here.

[0146] Please refer to Figure 17 to Figure 19 , the embodiment of the present application further provides a foldable electronic device 300, which comprises: the flexible display screen assembly 200 of the embodiment of the present application, a foldable mechanism 310 and a processor 330, the foldable mechanism 310 is used for carrying the flexible display screen assembly 200 and driving the flexible display screen assembly 200 to fold (as shown in Figure 18 ) or flatten (as shown in Figure 17As shown in FIG. 1, the flexible display assembly 200 is connected to the foldable mechanism 310, and the processor 330 is electrically connected to the flexible display assembly 200, and is configured to control the flexible display assembly 200 to display.

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

[0148] For detailed description of the flexible display assembly 200, the protective cover plate 100, etc., please refer to the description of the corresponding part of the above embodiment, 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 connected in sequence; the first carrier 311, the connecting shaft 313, and the second carrier 315 cooperate to carry the flexible display assembly 200 and drive the flexible display assembly 200 to fold or flatten; 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 shaft 313, and the second carrier 315 form a planar structure; when the foldable mechanism 310 is in the folded state, the first carrier 311 and the second carrier 315 overlap and drive the flexible display assembly 200 to fold.

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

[0151] Optionally, the processor 330 includes one or more general processors, wherein the general 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 configured to execute various types of digital storage instructions, such as software or firmware programs stored in the memory, which can enable the computing device to provide a wide variety of services.

[0152] Optionally, the foldable electronic device 300 of the present application further comprises a memory 350. The memory 350 is electrically connected with the processor 330 for storing program codes required by the processor 330, program codes required for controlling the flexible display assembly 200, display content of the flexible display assembly 200, etc.

[0153] Optionally, the memory 350 can comprise a volatile memory (Volatile Memory), such as a random access memory (Random Access Memory, RAM); the memory 350 can also comprise a non-volatile memory (Non-Volatile Memory, NVM), such as a read-only memory (Read-Only Memory, ROM), a flash memory (Flash Memory, FM), a hard disk (Hard Disk Drive, HDD) or a solid-state disk (Solid-State Drive, SSD). The memory 350 can further comprise a combination of the above-mentioned kinds of memories.

[0154] In some embodiments, the foldable electronic device 300 of the present application further comprises a camera module 370, which is carried on the foldable mechanism 310. The camera module 370 is electrically connected with the processor 330 for photographing under the control of the processor 330.

[0155] Optionally, the camera module 370 can be a rear camera module 370, or a front camera module 370. The present application does not make specific limitations.

[0156] In the present application, the phrase "embodiment" or "implementation" means that the specific features, structures or characteristics described in connection with the embodiment can be included in at least one embodiment of the present application. The appearance of the phrase in various places in the specification does not necessarily mean the same embodiment, nor is it an independent or alternative embodiment that is not mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described in the present application can be combined with other embodiments. In addition, it should be understood that the features, structures or characteristics described in the embodiments of the present application can be combined with each other without contradiction, to form another embodiment that does not depart from the spirit and scope of the technical solution of the present application.

[0157] Finally, it should be noted that the above implementations are only used to illustrate the technical solutions of the present application and not to limit it. Although the present application has been described in detail with reference to the above preferred embodiments, it should be understood by those skilled in the art that the technical solutions of the present application can be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present application.

Claims

1. A protective cover, characterized in that The protective layer comprises a first planar portion, a bendable portion and a second planar portion connected in sequence, the thickness of the bendable portion is less than the thickness of the first planar portion and the thickness of the bendable portion is less than the thickness of the second planar portion, the first planar portion, the bendable portion and the second planar portion enclose a groove; and The buffer layer comprises a body portion and a protruding portion connected in sequence, the protruding portion is arranged in the groove, the body portion is arranged on the side of the protruding portion away from the protective layer, and the body portion is stacked with the first planar portion and the second planar portion respectively; The ratio of the elastic modulus E1 of the protective layer to the elastic modulus E2 of the buffer layer is in the range of 10≤E1 / E2≤30; The protective cover plate further comprises a first substrate layer arranged on the 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; The protective cover plate further comprises a second substrate layer arranged on the surface of the buffer layer away from the protective layer, the elastic modulus of the second substrate layer is greater than the elastic modulus of the protective layer, and the elastic modulus of the first substrate layer is greater than the elastic modulus of the second substrate layer. The elastic modulus E1 of the protective layer is in the range of 50Mpa≤E1≤2000Mpa.

2. The protective cover sheet of claim 1, wherein, The elastic modulus E1 of the protective layer is in the range of 100Mpa≤E1≤800Mpa.

3. The protective cover sheet of claim 2, wherein, The elastic modulus E2 of the buffer layer is in the range of 0.2Mpa≤E2≤80Mpa.

4. The protective cover sheet of claim 1, wherein, The bendable portion comprises 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 planar portion at one end away from the equal-thickness sub-portion, the second transition sub-portion is connected to the second planar portion at one end away from the equal-thickness sub-portion, the thickness of the equal-thickness sub-portion is less than the thickness of the first planar portion and the thickness of the equal-thickness sub-portion is less than the thickness of the second planar portion, the thickness of the first transition sub-portion gradually decreases from one end connected to the first planar portion to 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 planar portion to one end connected to the equal-thickness sub-portion.

5. The protective cover sheet of claim 1, wherein, 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, and 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.

6. The protective cover sheet of claim 5, wherein, The thickness d1 of the first planar portion is in the range of 30μm≤d1≤200μm, the thickness d2 of the equal-thickness sub-portion is in the range of 10μm≤d2≤50μm, and the thickness d3 of the second planar portion is in the range of 30μm≤d3≤200μm.

7. The protective cover sheet of claim 5, wherein, The thickness d4 of the body portion is in the range of 20μm≤d4≤150μm.

8. The protective cover sheet of claim 1, wherein, ​ 9. The protective cover sheet of claim 1, wherein, The ratio of the thickness d1 of the first planar portion to the thickness d4 of the body portion is in the range of 1≤d1 / d4≤2.5; and the ratio of the thickness d3 of the second planar portion to the thickness d4 of the body portion is in the range of 1≤d3 / d4≤2.

5.

10. The protective cover sheet according to any one of claims 1 to 9, characterized in that The thickness of the first substrate layer is greater than or equal to the thickness of the second substrate layer.

11. The protective cover sheet of claim 1, wherein, The ratio of the elastic modulus E3 of the first substrate layer to the elastic modulus E4 of the second substrate layer is in the range of 1≤E3 / E4≤2.

5.

12. The protective cover sheet of claim 1, wherein, 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.

13. The protective cover sheet according to any of claims 1-9, 11-12, characterized in that, The protective cover plate further comprises: a hardening layer disposed on the side of the protective layer away from the buffer layer, the hardness of the hardening layer being in the range of 1H to 3H.

14. A flexible display screen assembly, characterized by comprising: a flexible display screen having a display surface; and the protective cover plate of any one of claims 1-13, the protective cover plate being disposed on the display surface of the flexible display screen assembly for protecting the flexible display screen assembly.

15. A foldable electronic device, characterized by comprising: the flexible display screen assembly of claim 14; a foldable mechanism for carrying the flexible display screen assembly and for driving the flexible display screen assembly to fold or flatten, wherein the protective cover plate of the flexible display screen assembly is further away from the foldable mechanism than the flexible display screen of the flexible display screen assembly; and a processor electrically connected with the flexible display screen assembly for controlling the flexible display screen assembly to display. ​

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