Display module and display device

Abstract

The application relates to a display module and a display device. The display module comprises a display panel, a first laminated structure located at a first side of the display panel, and a second laminated structure located at a second side of the display panel. The display module is bent towards the first side. The Young's modulus of the material of at least two film layers in the first laminated structure is greater than or equal to 10 Gpa. The Young's modulus of the material of at least one film layer in the second laminated structure is greater than or equal to 10 Gpa. The application increases the proportion of the film layer of the high-rigidity material in the structure of the display module, so that the crease problem is significantly improved while the bending characteristics of the display module are ensured, and the reliability of the folding display product is improved.

Description

Technical Field

[0001] This application relates to the field of display technology, and in particular to a display module and display device. Background Technology

[0002] As mobile terminals evolve towards portability and larger screens, flexible display technology has become a core approach to achieving "small size, large screen" product forms. Foldable phones, foldable tablets, and other products achieve portability in the closed state and a large-screen experience in the unfolded state through the combination of flexible organic light-emitting diode (OLED) display panels and composite substrates. However, existing foldable products generally suffer from the technical challenge of screen creases in practical applications. Creases arise from stress concentration during repeated bending of the flexible display layers, specifically manifested as physical deformation and fatigue accumulation of the protective layer, support layer, and adhesive layer materials at the bending radius. This not only leads to visible visual indentations but may also cause problems such as decreased touch accuracy and uneven local brightness, seriously affecting the long-term user experience. Currently, industry optimizations for creases mainly focus on improving the hinge structure or selecting flexible materials, but these solutions often involve complex processes, high costs, or can only "weaken" the creases to a certain extent without fundamentally solving the physical causes of the creases. Therefore, there is an urgent need for a technical solution that can effectively eliminate or significantly reduce the visual abruptness of creases while taking into account the requirements of product thinness and durability. Summary of the Invention

[0003] This application provides a display module and a display device. The display module of this application can significantly improve the crease problem while ensuring bending characteristics, thereby improving the reliability of foldable display products.

[0004] This application provides a display module configured in a first state and a second state. In the first state, the display module is in a flattened state, and in the second state, the display module is in a bent state. The display module includes: The display panel includes a first side and a second side opposite to each other, and in the second state, the display module is bent toward the first side; A first stacked structure is disposed on the first side of the display panel, and the first stacked structure includes a plurality of film layers stacked together. A second stacked structure is disposed on the second side of the display panel, and the second stacked structure includes a plurality of film layers stacked together. Wherein, the Young's modulus of the material of at least two films in the first stacked structure is greater than or equal to 10 GPa, and the Young's modulus of the material of at least one film in the second stacked structure is greater than or equal to 10 GPa.

[0005] In some embodiments, the first stacked structure includes: The first film layer is disposed on the side of the display panel away from the second laminated structure; The second film layer is disposed on the side of the first film layer away from the display panel; Wherein, the Young's modulus of the material of the second film layer is greater than or equal to the Young's modulus of the material of the first film layer.

[0006] In some embodiments, in the thickness direction of the display module, the thickness of the second film layer is greater than the thickness of the first film layer.

[0007] In some embodiments, the Young's modulus of the material of the first film layer is greater than or equal to 10 GPa and less than or equal to 80 GPa; the Young's modulus of the material of the second film layer is greater than or equal to 10 GPa and less than or equal to 80 GPa.

[0008] In some embodiments, the first stacked structure further includes: A third film layer is disposed on the side of the second film layer away from the first film layer, wherein the Young's modulus of the material of the third film layer is greater than or equal to 1 GPa and less than or equal to 80 GPa.

[0009] In some embodiments, the materials of the first film layer and the second film layer are selected from at least one of polyimide and ultrathin flexible glass; The material of the third membrane layer is selected from at least one of aromatic polyamide, polyimide, ultrathin flexible glass, polyethylene terephthalate, polymethyl methacrylate, polycarbonate, and cellulose triacetate.

[0010] In some embodiments, the first laminated structure further includes a first adhesive layer, which is disposed between any two adjacent film layers among the display panel, the first film layer, the second film layer and the third film layer, wherein the creep recovery rate of the first adhesive layer is greater than or equal to 95%.

[0011] In some embodiments, the second laminated structure includes at least one of a fourth film layer and a fifth film layer; Wherein, when the second stacked structure includes both the fourth film layer and the fifth film layer, the fourth film layer is disposed on the side of the display panel away from the first stacked structure, the fifth film layer is disposed on the side of the fourth film layer away from the display panel, and the Young's modulus of the material of the fifth film layer is greater than or equal to the Young's modulus of the material of the fourth film layer.

[0012] In some embodiments, in the thickness direction of the display module, the thickness of the fifth film layer is greater than the thickness of the fourth film layer.

[0013] In some embodiments, the Young's modulus of the material of the fourth film layer is greater than or equal to 10 GPa and less than or equal to 80 GPa; the Young's modulus of the material of the fifth film layer is greater than or equal to 10 GPa and less than or equal to 400 GPa.

[0014] In some embodiments, the second stacked structure further includes: A sixth film layer is disposed between the fourth film layer and the fifth film layer, wherein the Young's modulus of the material of the sixth film layer is greater than or equal to 1 GPa and less than or equal to 80 GPa.

[0015] In some embodiments, the materials of the fourth film layer, the fifth film layer, and the sixth film layer are selected from at least one of aromatic polyamide, polyimide, ultrathin flexible glass, metal, and carbon fiber.

[0016] In some embodiments, the second laminated structure further includes a second adhesive layer, which is disposed between any two adjacent film layers among the display panel, the fourth film layer, the fifth film layer, and the sixth film layer, wherein the creep recovery rate of the second adhesive layer is greater than or equal to 95%.

[0017] In some embodiments, the display module includes a bent area and non-bent areas located on opposite sides of the bent area; The thickness of the first film layer in the bending region is less than or equal to the thickness of the non-bending region, and / or the thickness of the second film layer in the bending region is less than or equal to the thickness of the non-bending region.

[0018] In some embodiments, the display module includes a bent area and non-bent areas located on opposite sides of the bent area; In the first state, on the same side of the display module, the maximum distance h between the surface of the display module located in the bending area and the surface of the display module located in the non-bending area in the thickness direction of the display module is less than 100 μm.

[0019] This application also provides a display device, which includes the display module described above.

[0020] This application provides a display module and a display device. The display module includes a display panel and a first stacked structure and a second stacked structure located on opposite sides of the display panel. In the first stacked structure, at least two film layers have a Young's modulus greater than or equal to 10 GPa, and in the second stacked structure, at least one film layer has a Young's modulus greater than or equal to 10 GPa. This application improves the undulation defects caused by unevenness in the bending area by increasing the proportion of high stiffness material (Young's modulus greater than or equal to 10 GPa) film layers in the display module structure, while reducing permanent deformation caused by multiple bends. While ensuring the bending characteristics of the display module, it significantly improves the crease problem and enhances the reliability of the foldable display product. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] To gain a more complete understanding of this application and its beneficial effects, the following description will be provided in conjunction with the accompanying drawings, wherein the same reference numerals in the following description denote the same parts.

[0023] Figure 1 This is a schematic diagram of the structure of a display module provided in this application; Figure 2 This is a schematic diagram of the first state of a display module provided in this application; Figure 3 This is a schematic diagram of the structure of a display module provided in the comparative example of this application; Figure 4 These are schematic diagrams of the structure of a display module provided in Embodiments 1 and 2 of this application; Figure 5 These are schematic diagrams of the structure of a display module provided in Embodiments 3 and 4 of this application.

[0024] Explanation of reference numerals in the attached figures: 10. Display module; 101. First protective layer; 102. Second protective layer; 103. Third protective layer; 104. Fourth protective layer; 105. Fifth protective layer; 106. Sixth protective layer; 107 (107a, 107b, 107c), First adhesive layer; 108 (108a, 108b), Second adhesive layer; 110. Display panel; 111. First side; 112. Second side; 120. First laminated structure; 121. First film layer; 122. Second film layer; 123. Third film layer; 124 (124a, 124b, 124c), First adhesive layer; 130. Second laminated structure; 131. Fourth film layer; 132. Fifth film layer; 133. Sixth film layer; 134 (134a, 134b) Second adhesive layer; AA1 - Bending area; AA2 - Non-bending area. Detailed Implementation

[0025] The technical solutions in the embodiments of this application will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0026] This application provides a display module 10, please refer to... Figures 1-2 The display module 10 is configured in a first state and a second state. In the first state, the display module 10 is in a flattened state, and in the second state, the display module 10 is in a bent state. The display module 10 includes a display panel 110, a first stacked structure 120, and a second stacked structure 130. The display panel 110 includes a first side 111 and a second side 112 opposite to each other. In the second state, the display module 10 is bent toward the first side 111. The first stacked structure 120 is disposed on the first side 111 of the display panel 110 and includes a plurality of film layers stacked together. The second stacked structure 130 is disposed on the second side 112 of the display panel 110 and includes a plurality of film layers stacked together. The Young's modulus of the material of at least two film layers in the first stacked structure 120 is greater than or equal to 10 GPa, and the Young's modulus of the material of at least one film layer in the second stacked structure 130 is greater than or equal to 10 GPa.

[0027] It is understandable that if the Young's modulus of a material is greater than or equal to 10 GPa, then the material is a high stiffness material. High stiffness materials usually have the characteristics of bending resistance, creep resistance, small deformation, and excellent stiffness, which are beneficial to improving the rigidity of the film layer and reducing deformation.

[0028] To achieve repeated bending at small radii, existing foldable display module structures require materials and structures with good flexibility and bending reliability. These structures employ multiple layers of low-modulus organic thin films. These materials have low rigidity and yield points, and after bending stress, they yield and undergo permanent deformation, resulting in visible creases. The balance between rigidity and flexibility is difficult to achieve mechanically, forcing existing display module structures to compromise between these two aspects. This results in the bending area AA1 failing to maintain an ideal planar shape, leading to noticeable creases and affecting visual appeal and user experience. Based on this situation, the display module 10 of this application addresses the issue by reducing the use of materials with low rigidity and low yield points. By increasing the proportion of high-stiffness materials (Young's modulus greater than or equal to 10 GPa) in the module's film layers, it optimizes bending stress. While meeting the basic requirement of flexibility for creases, it maximizes the proportion of high-stiffness materials in the display module 10, highlighting its rigidity. This significantly improves the crease problem while maintaining the bending characteristics of the display module 10, thereby enhancing the reliability of the foldable display product.

[0029] In some embodiments, please refer to Figure 1 The display panel 110 has a first side 111 and a second side 112 facing each other. A first stacked structure 120 is disposed on the first side 111 of the display panel 110, and a second stacked structure 130 is disposed on the second side 112 of the display panel 110. The first side 111 of the display panel 110 can be a light-emitting side, and the second side 112 of the display panel 110 can be a back side. Correspondingly, the surface of the display panel 110 located on the first side 111 is the light-emitting surface, and the surface of the display panel 110 located on the second side 112 is the back side. The first stacked structure 120 is disposed on the light-emitting side of the display panel 110, and the second stacked structure 130 is disposed on the back side of the display panel 110, respectively, to protect the display panel 110 and improve the reliability of the display module 10.

[0030] The display panel 110 may be an organic light-emitting diode (OLED) display panel, but is not limited to this.

[0031] It is understood that in some other embodiments, the first side 111 of the display panel 110 may also be the back side, and the second side 112 of the display panel 110 may be the light-emitting side. This application does not impose any specific restrictions.

[0032] In some embodiments, please refer to Figure 1The number of film layers with a Young's modulus greater than or equal to 10 GPa in the first stacked structure 120 can be greater than the number of film layers with a Young's modulus greater than or equal to 10 GPa in the second stacked structure 130. That is, the number of high stiffness material film layers on the first side 111 is greater than the number of high stiffness material film layers on the second side 112. This can significantly improve the crease problem of the display module 10 while taking into account both thinness and bending performance, effectively improving the overall reliability of the display module 10.

[0033] In this application, the display module 10 is bent toward the first side 111. When the display module 10 is bent, the first side 111 of the display panel 110 is subjected to compressive stress, and the second side 112 of the display panel 110 is subjected to tensile stress. Therefore, the film layer on the first side 111 is prone to local instability, inward depression, and surface wrinkles, which is the main cause of creases. This application provides at least two layers of high-stiffness material film layers on the first side 111 of the display panel 110. Through the constraint and dispersion of stress by multiple layers of high-stiffness film layers, deformation instability is suppressed, while ensuring the optical flatness of the surface of the first side 111. On the second side 112 of the display panel 110, at least one layer of high-stiffness material film layer is provided, which effectively resists tensile deformation and provides structural support, while taking into account both thinness and bending performance.

[0034] In some embodiments, please refer to Figure 1 The first laminated structure 120 includes a first film layer 121 and a second film layer 122. The first film layer 121 is disposed on the side of the display panel 110 away from the second laminated structure 130; the second film layer 122 is disposed on the side of the first film layer 121 away from the display panel 110; wherein, the Young's modulus of the material of the first film layer 121 is greater than or equal to 10 GPa; the Young's modulus of the material of the second film layer 122 is greater than or equal to 10 GPa.

[0035] In some embodiments, the Young's modulus of the material of the second film layer 122 is greater than or equal to the Young's modulus of the material of the first film layer 121, to further ensure the bending reliability of the display module 10. The Young's modulus of the material of the second film layer 122 may be greater than or equal to the Young's modulus of the material of the first film layer 121; this application does not impose any limitation on this.

[0036] In some embodiments, the Young's modulus of the material of the first film layer 121 is greater than or equal to 10 GPa and less than or equal to 80 GPa. For example, the Young's modulus of the material of the first film layer 121 may be 10 GPa, 15 GPa, 20 GPa, 25 GPa, 30 GPa, 35 GPa, 40 GPa, 45 GPa, 50 GPa, 55 GPa, 60 GPa, 65 GPa, 70 GPa, 75 GPa, 80 GPa, etc., but is not limited thereto.

[0037] In some embodiments, the Young's modulus of the material of the second film layer 122 is greater than or equal to 10 GPa and less than or equal to 80 GPa. For example, the Young's modulus of the material of the second film layer 122 may be 10 GPa, 15 GPa, 20 GPa, 25 GPa, 30 GPa, 35 GPa, 40 GPa, 45 GPa, 50 GPa, 55 GPa, 60 GPa, 65 GPa, 70 GPa, 75 GPa, 80 GPa, etc., but is not limited thereto.

[0038] In some embodiments, the thickness of the second film layer 122 is greater than the thickness of the first film layer 121 in the thickness direction of the display module 10. Since the greater the thickness of the high stiffness film layer, the greater the bending stress of the film layer, in order to improve the bending stress of the module, this application sets the thicker high stiffness film layer away from the display panel 110 to ensure the bending reliability of the display module 10.

[0039] In some embodiments, the thickness of the first film layer 121 is greater than 0 μm and less than or equal to 100 μm; for example, the thickness of the first film layer 121 may be 10 μm, 30 μm, 50 μm, 70 μm, 100 μm, etc., but is not limited thereto.

[0040] In some embodiments, the thickness of the second film layer 122 is greater than or equal to 30 μm and less than or equal to 300 μm; for example, the thickness of the second film layer 122 may be 30 μm, 50 μm, 70 μm, 100 μm, 120 μm, 150 μm, 200 μm, 250 μm, 300 μm, etc., but is not limited thereto.

[0041] In some embodiments, please refer to Figure 1 The first stacked structure 120 also includes a third film layer 123, which is disposed on the side of the second film layer 122 away from the first film layer 121; wherein the Young's modulus of the material of the third film layer 123 is greater than or equal to 1 GPa and less than or equal to 80 GPa.

[0042] In some embodiments, the Young's modulus of the material of the third film layer 123 is greater than or equal to 1 GPa and less than or equal to 10 GPa, that is, the third film layer 123 can be a medium stiffness material film layer. For example, the Young's modulus of the material of the third film layer 123 can be 1 GPa, 3 GPa, 5 GPa, 7 GPa, 10 GPa, etc., but is not limited thereto.

[0043] In some embodiments, the Young's modulus of the material of the third film layer 123 is greater than or equal to 10 GPa and less than or equal to 80 GPa, that is, the third film layer 123 can be a high stiffness material film layer. For example, the Young's modulus of the material of the third film layer 123 can be 10 GPa, 15 GPa, 20 GPa, 25 GPa, 30 GPa, 35 GPa, 40 GPa, 45 GPa, 50 GPa, 55 GPa, 60 GPa, 65 GPa, 70 GPa, 75 GPa, 80 GPa, etc., but is not limited thereto.

[0044] In some embodiments, when the Young's modulus of the material of the third film layer 123 is greater than or equal to 10 GPa, the thickness of the third film layer 123 is greater than the thickness of the first film layer 121, and the thickness of the third film layer 123 is greater than the thickness of the second film layer 122, so as to ensure the bending reliability of the display module 10.

[0045] It is understood that the material of the third film layer 123 can be a medium stiffness material or a high stiffness material, and the specific design can be made according to the actual performance requirements of the display module 10. This application does not impose any restrictions.

[0046] In some embodiments, the thickness of the third film layer 123 is greater than or equal to 30 μm and less than or equal to 300 μm; for example, the thickness of the third film layer 123 may be 30 μm, 50 μm, 70 μm, 100 μm, 120 μm, 150 μm, 200 μm, 250 μm, 300 μm, etc., but is not limited thereto.

[0047] In some other embodiments, the third film layer 123 may also be located between the first film layer 121 and the second film layer 122, or between the first film layer 121 and the display panel 110. The thickness of the third film layer 123 may be equal to or unequal to the thickness of the first film layer 121 or the second film layer 122, and this application does not impose any restrictions.

[0048] It is understood that the first stacked structure 120 may include three or more high stiffness film layers with a Young's modulus greater than or equal to 10 GPa, and may also include one or more film layers with a Young's modulus less than 10 GPa. This application does not impose any restrictions.

[0049] In some embodiments, please refer to Figure 1 The second laminated structure 130 includes a fourth film layer 131, which is disposed on the side of the display panel 110 away from the first laminated structure 120. The Young's modulus of the material of the fourth film layer 131 is greater than or equal to 10 GPa, that is, the material of the fourth film layer 131 is a high-stiffness material. The fourth film layer 131 is located on the second side 112 of the display panel 110. The fourth film layer 131 is made of a high-stiffness material, which can resist tensile deformation and at the same time provide structural support for the display panel 110.

[0050] In some embodiments, the Young's modulus of the material of the fourth film layer 131 is greater than or equal to 10 GPa and less than or equal to 80 GPa. For example, the Young's modulus of the material of the fourth film layer 131 may be 10 GPa, 15 GPa, 20 GPa, 25 GPa, 30 GPa, 35 GPa, 40 GPa, 45 GPa, 50 GPa, 55 GPa, 60 GPa, 65 GPa, 70 GPa, 75 GPa, 80 GPa, etc., but is not limited thereto.

[0051] In some embodiments, please refer to Figure 1 The second laminated structure 130 also includes a fifth film layer 132, which is disposed on the side of the fourth film layer 131 away from the display panel 110. The Young's modulus of the material of the fifth film layer 132 is greater than or equal to 10 GPa. The fifth film layer 132 is made of a high stiffness material and is laminated with the fourth film layer 131. This application provides multiple high stiffness film layers on the second side 112 of the display panel 110, which can further resist tensile deformation, suppress elongation and springback deviation, reduce warping and misalignment, disperse tensile stress, improve fatigue resistance and bending life, and further strengthen the overall structural strength, suppress creases, reduce deformation, and improve the overall reliability of the display module 10.

[0052] In some embodiments, the Young's modulus of the material of the fifth film layer 132 is greater than or equal to the Young's modulus of the material of the fourth film layer 131, to further ensure the bending reliability of the display module 10. The Young's modulus of the material of the fifth film layer 132 may be greater than or equal to the Young's modulus of the material of the fourth film layer 131; this application does not impose any limitation on this.

[0053] In some embodiments, the Young's modulus of the material of the fifth film layer 132 is greater than or equal to 10 GPa and less than or equal to 400 GPa. For example, the Young's modulus of the material of the fifth film layer 132 may be 10 GPa, 70 GPa, 110 GPa, 150 GPa, 200 GPa, 250 GPa, 290 GPa, 350 GPa, 400 GPa, etc., but is not limited thereto.

[0054] In some embodiments, the thickness of the fifth film layer 132 is greater than the thickness of the fourth film layer 131 in the thickness direction of the display module 10. Since the greater the thickness of the high stiffness film layer, the greater the bending stress of the film layer, in order to improve the bending stress of the display module 10, this application sets the thicker high stiffness film layer away from the display panel 110 to ensure the bending reliability of the display module 10.

[0055] In some embodiments, the thickness of the fourth film layer 131 is greater than or equal to 20 μm and less than or equal to 100 μm; for example, the thickness of the fourth film layer 131 may be 20 μm, 50 μm, 70 μm, 100 μm, etc., but is not limited thereto.

[0056] In some embodiments, the thickness of the fifth film layer 132 is greater than or equal to 50 μm and less than or equal to 200 μm; for example, the thickness of the fifth film layer 132 may be 50 μm, 70 μm, 100 μm, 120 μm, 150 μm, 200 μm, etc., but is not limited thereto.

[0057] In some embodiments, the second stacked structure 130 may include a fifth film layer 132 but not a fourth film layer 131 to reduce the overall thickness of the display module 10.

[0058] In some embodiments, please refer to Figure 1 The second stacked structure 130 also includes a sixth film layer 133, which is disposed between the fourth film layer 131 and the fifth film layer 132. The Young's modulus of the material of the sixth film layer 133 is greater than or equal to 1 GPa and less than or equal to 80 GPa.

[0059] In some embodiments, the Young's modulus of the material of the sixth film layer 133 is greater than or equal to 1 GPa and less than or equal to 10 GPa, that is, the sixth film layer 133 can be a medium stiffness material film layer. For example, the Young's modulus of the material of the sixth film layer 133 can be 1 GPa, 3 GPa, 5 GPa, 7 GPa, 10 GPa, etc., but is not limited thereto.

[0060] In some embodiments, the Young's modulus of the material of the sixth film layer 133 is greater than or equal to 10 GPa and less than or equal to 80 GPa, that is, the sixth film layer 133 can be a high-stiffness material film layer. For example, the Young's modulus of the material of the sixth film layer 133 can be 10 GPa, 15 GPa, 20 GPa, 25 GPa, 30 GPa, 35 GPa, 40 GPa, 45 GPa, 50 GPa, 55 GPa, 60 GPa, 65 GPa, 70 GPa, 75 GPa, 80 GPa, etc., but is not limited thereto.

[0061] In some embodiments, when the Young's modulus of the material of the sixth film layer 133 is greater than or equal to 10 GPa, the thickness of the sixth film layer 133 is greater than the thickness of the fourth film layer 131; furthermore, the thickness of the sixth film layer 133 may be less than the thickness of the fifth film layer 132 to ensure the bending reliability of the display module 10.

[0062] It is understood that the material of the sixth film layer 133 can be a medium stiffness material or a high stiffness material, and the specific design can be made according to the actual performance requirements of the display module 10. This application does not impose any restrictions.

[0063] In some embodiments, the thickness of the sixth film layer 133 is greater than 0 μm and less than or equal to 100 μm; for example, the thickness of the sixth film layer 133 may be 10 μm, 30 μm, 50 μm, 70 μm, 100 μm, etc., but is not limited thereto.

[0064] It should be noted that the second stacked structure 130 may also exclude the sixth film layer 133 in order to reduce the overall thickness of the display module 10.

[0065] In some embodiments, the display module 10 of this application is a foldable display module 10, which includes a first state (flattened state) and a second state (folded state). Please refer to... Figure 2 , Figure 2 This is a schematic diagram of the first state of the display module 10. The display module 10 includes a bending area AA1 and non-bending areas AA2 located on opposite sides of the bending area AA1. In the flattened state, on the same side of the display module 10 (e.g., the second side 112), the maximum distance h in the thickness direction of the display module 10 between the surface of the display module 10 located in the bending area AA1 and the surface of the display module 10 located in the non-bending area AA2 is less than 100 μm. In existing folding display modules, the maximum distance h' in the thickness direction between the surface of the display module located in the bending area AA1 and the surface of the display module located in the non-bending area AA2 is typically greater than 150 μm. However, in the display module 10 of this application, h is less than 100 μm after multiple bends, which significantly reduces the deformation and creases of the bending area AA1 of the display module 10 compared to the prior art.

[0066] For details, please refer to Figure 2 The display module 10 has a surface B on the second side 112, where h is the distance in the thickness direction between the lowest point of the surface B of the bent area AA1 and the surface B of the non-bent area AA2.

[0067] In some embodiments, the thickness of the first film layer 121 in the bending region AA1 can be equal to the thickness of the non-bending region AA2, that is, the first film layer 121 is a film layer with uniform thickness.

[0068] In some embodiments, the thickness of the first film layer 121 in the bending region AA1 may be less than the thickness of the non-bending region AA2. By differentiating the thickness of the first film layer 121 in the bending region AA1 and the non-bending region AA2, the bending resistance can be reduced, deformation accumulation can be reduced, and crease morphology defects can be reduced; the non-bending region AA2 is thickened, which on the one hand increases the rigidity of the flat area, and on the other hand forms a rigid boundary constraint on both sides of the bending region AA1 to prevent deformation from spreading to both sides, making the surface of the display module 10 flatter and weakening the visual crease.

[0069] In some embodiments, the thickness of the second film layer 122 in the bending region AA1 can be equal to the thickness of the non-bending region AA2, that is, the second film layer 122 is a film layer with uniform thickness.

[0070] In some embodiments, the thickness of the second film layer 122 in the bending region AA1 may be less than the thickness of the non-bending region AA2. By differentiating the thickness of the second film layer 122 in the bending region AA1 and the non-bending region AA2, the bending resistance can be reduced, deformation accumulation can be reduced, and crease morphology defects can be reduced; the straight area AA2 can be thickened, which on the one hand increases the rigidity of the straight area, and on the other hand forms a rigid boundary constraint on both sides of the bending region AA1 to prevent deformation from spreading to both sides, making the surface of the display module 10 flatter and weakening the visual crease.

[0071] In some embodiments, the thickness of the third film layer 123 in the bending region AA1 may be less than or equal to the thickness of the non-bending region AA2. The principle is the same as that of the first film layer 121 or the second film layer 122 described above, and will not be repeated here.

[0072] In some embodiments, the thickness of the fourth film layer 131, the fifth film layer 132, and the sixth film layer 133 in the bending region AA1 may be equal to or unequal to the thickness in the non-bending region AA2, and this application does not impose any restrictions.

[0073] In some embodiments, the materials of the first film layer 121 and the second film layer 122 are selected from polyimide (PI) or ultra-thin glass (UTG), etc. When the materials of the film layers are selected from polyimide, colorless polyimide (CPI) can be selected, but is not limited thereto.

[0074] The materials of the first film layer 121 and the second film layer 122 may be the same or different, and this application does not impose any restrictions.

[0075] In some embodiments, the material of the third film layer 123 is selected from, but is not limited to, aromatic polyamide (aramid), polyimide (PI), ultrathin flexible glass (UTG), polyethylene terephthalate (PET), polymethyl methacrylate (PMMA), polycarbonate (PC), cellulose triacetate (TAC), etc.

[0076] It is understandable that the first film layer 121, the second film layer 122, and the third film layer 123 are located on the first side 111 (i.e. the light-emitting side) of the display panel 110, requiring each film layer to have good light transmittance. Modified polyimide (CPI) and ultra-thin flexible glass (UTG) have good light transmittance and can meet the light transmittance requirements of the first stacked structure 120.

[0077] In some embodiments, the materials of the fourth film layer 131, the fifth film layer 132, and the sixth film layer 133 are selected from aromatic polyamide (aramid), polyimide (PI), ultrathin flexible glass (UTG), metal, or carbon fiber, etc. When the material of the film layer is selected from polyimide, self-modified polyimide (CPI) may be selected; when the material of the film layer is selected from metal, it may be selected from Ti alloy, stainless steel (SUS), etc., but is not limited thereto.

[0078] The materials of the fourth membrane layer 131, the fifth membrane layer 132, and the sixth membrane layer 133 may be the same or different, and this application does not impose any restrictions.

[0079] It is understandable that the fourth film layer 131, the fifth film layer 132, and the sixth film layer 133 are located on the second side 112 (i.e., the back side) of the display panel 110, requiring each film layer to have good support and stiffness. Ultra-thin flexible glass (UTG), metal, or carbon fiber have good mechanical properties and can meet the support and stiffness requirements of the second laminated structure 130.

[0080] The display module 10 structure of this application can not only meet the bending requirements of the folding module, but also reduce the unevenness of the bending area AA1 through the high stiffness film layer and reduce the deformation after multiple bends. At the same time, it can also improve the strength of the display module 10 and increase the reliability of the folding product.

[0081] In some embodiments, please refer to Figure 1The first laminated structure 120 further includes a first adhesive layer 124, which is disposed between any two adjacent film layers among the display panel 110, the first film layer 121, the second film layer 122, and the third film layer 123. For example, the first adhesive layer 124 may be disposed between the first film layer 121 and the display panel 110, and / or between the first film layer 121 and the second film layer 122, and / or between the second film layer 122 and the third film layer 123. The creep recovery rate of the first adhesive layer 124 is greater than or equal to 95%, and the material of the first adhesive layer 124 has good resilience, resulting in smaller deformation after bending, further reducing creases and improving the overall reliability of the display module 10.

[0082] In some embodiments, the material of the first adhesive layer 124 is selected from optically clear adhesive (OCA), acrylic adhesive, or polyurethane adhesive, but is not limited thereto.

[0083] For details, please refer to Figure 1 A first adhesive layer 124a is disposed between the first film layer 121 and the display panel 110, a first adhesive layer 124b is disposed between the first film layer 121 and the second film layer 122, and a first adhesive layer 124c is disposed between the second film layer 122 and the third film layer 123. The materials of the first adhesive layers 124a, 124b, and 124c may be the same or different. For example, the first adhesive layers 124a, 124b, and 124c may all be selected from optically transparent adhesive (OCA), but are not limited to this.

[0084] In some embodiments, please refer to Figure 1 The second laminated structure 130 further includes a second adhesive layer 134, which is disposed between any two adjacent film layers among the display panel 110, the fourth film layer 131, the fifth film layer 132, and the sixth film layer 133. For example, the second adhesive layer 134 may be disposed between the fourth film layer 131 and the display panel 110, and / or between the fourth film layer 131 and the sixth film layer 133, and / or between the fifth film layer 132 and the sixth film layer 133. The creep recovery rate of the second adhesive layer 134 is greater than or equal to 95%, and the material of the second adhesive layer 134 has good resilience, resulting in smaller deformation after bending, further reducing creases and improving the overall reliability of the display module 10.

[0085] In some embodiments, the material of the second adhesive layer 134 is selected from pressure-sensitive adhesive (PSA), acrylic adhesive, or polyurethane adhesive, but is not limited thereto.

[0086] For details, please refer to Figure 1 A second adhesive layer 134a is disposed between the fourth film layer 131 and the sixth film layer 133, and a second adhesive layer 134b is disposed between the fifth film layer 132 and the sixth film layer 133. The materials of the second adhesive layers 134a and 134b may be the same or different. For example, both the second adhesive layers 134a and 134b may be selected from pressure-sensitive adhesives (PSA), but are not limited thereto.

[0087] The display module 10 of this application will be further described below through specific embodiments, but this application is not limited to the following embodiments.

[0088] Comparison Example Please refer to Figure 3 The display module includes a display panel 110, a first stacked structure located on a first side 111 of the display panel 110, and a second stacked structure located on a second side 112 of the display panel 110. The first stacked structure includes a first adhesive layer 107a, a first protective layer 101, a first adhesive layer 107b, a second protective layer 102, a first adhesive layer 107c, and a third protective layer 103, which are stacked sequentially in a direction away from the display panel 110. The second stacked structure includes a fourth protective layer 104, a second adhesive layer 108a, a fifth protective layer 105, a second adhesive layer 108b, and a sixth protective layer 106, which are stacked sequentially in a direction away from the display panel 110.

[0089] The first adhesive layers 107a, 107b, and 107c are made of OCA, with an OCA creep recovery rate of 94%. The first protective layer 101 is made of PET (Young's modulus of 4 GPa) and has a thickness of 50 μm. The second protective layer 102 is made of UTG (Young's modulus of 70 GPa) and has a thickness of 50 μm. The third protective layer 103 is made of PET (Young's modulus of 4 GPa) and has a thickness of 50 μm. The surface of the third protective layer 103 contains a hard coating with a thickness of 5 μm. The second adhesive layer 108a and the second adhesive layer 108b are made of PSA, and the creep recovery rate of PSA is 92%; the fourth protective layer 104 is made of PET (Young's modulus of 4 GPa) and has a thickness of 50 μm; the fifth protective layer 105 is made of PI (Young's modulus of 4.5 GPa) and has a thickness of 25 μm; the sixth protective layer 106 is made of Ti alloy (Young's modulus of 110 GPa) and has a thickness of 120 μm.

[0090] Example 1 Please refer to Figure 4The display module 10 includes a display panel 110, a first stacked structure 120 located on a first side 111 of the display panel 110, and a second stacked structure 130 located on a second side 112 of the display panel 110. The first stacked structure 120 includes a first adhesive layer 124a, a first film layer 121, a first adhesive layer 124b, a second film layer 122, a first adhesive layer 124c, and a third film layer 123, which are stacked sequentially in a direction away from the display panel 110. The second stacked structure 130 includes a fourth film layer 131, a second adhesive layer 134a, and a fifth film layer 132, which are stacked sequentially in a direction away from the display panel 110.

[0091] The first adhesive layers 124a, 124b, and 124c are made of acrylic OCA with a creep recovery rate of 96%. The first film layer 121 is made of UTG (Young's modulus of 70 GPa) with a thickness of 30 μm. The second film layer 122 is made of UTG (Young's modulus of 70 GPa) with a thickness of 60 μm. The third film layer 123 is made of PET (Young's modulus of 4 GPa) with a thickness of 50 μm. The second adhesive layer 134a is made of acrylic PSA with a creep recovery rate of 95%. The fourth film layer 131 is made of Ti alloy (Young's modulus of 110 GPa) with a thickness of 20 μm. The fifth film layer 132 is made of Ti alloy (Young's modulus of 110 GPa) with a thickness of 120 μm.

[0092] Example 2 Please refer to Figure 4 The display module 10 includes a display panel 110, a first stacked structure 120 located on a first side 111 of the display panel 110, and a second stacked structure 130 located on a second side 112 of the display panel 110. The first stacked structure 120 includes a first adhesive layer 124a, a first film layer 121, a first adhesive layer 124b, a second film layer 122, a first adhesive layer 124c, and a third film layer 123, which are stacked sequentially in a direction away from the display panel 110. The second stacked structure 130 includes a fourth film layer 131, a second adhesive layer 134a, and a fifth film layer 132, which are stacked sequentially in a direction away from the display panel 110.

[0093] The first adhesive layers 124a, 124b, and 124c are made of acrylic OCA with a creep recovery rate of 96%. The first film layer 121 is made of aramid (Young's modulus of 15 GPa) with a thickness of 25 μm. The second film layer 122 is made of UTG (Young's modulus of 70 GPa) with a thickness of 60 μm. The third film layer 123 is made of PET (Young's modulus of 4 GPa) with a thickness of 50 μm. The second adhesive layer 134a is made of acrylic PSA with a creep recovery rate of 95%. The fourth film layer 131 is made of UTG (Young's modulus of 70 GPa) with a thickness of 30 μm. The fifth film layer 132 is made of carbon fiber (Young's modulus of 290 GPa) with a thickness of 150 μm.

[0094] Example 3 Please refer to Figure 5 The display module 10 includes a display panel 110, a first stacked structure 120 located on a first side 111 of the display panel 110, and a second stacked structure 130 located on a second side 112 of the display panel 110. The first stacked structure 120 includes a first adhesive layer 124a, a first film layer 121, a first adhesive layer 124b, and a second film layer 122, which are stacked sequentially in a direction away from the display panel 110. The second stacked structure 130 includes a fourth film layer 131, a second adhesive layer 134a, and a fifth film layer 132, which are stacked sequentially in a direction away from the display panel 110.

[0095] The first adhesive layer 124a and 124b are made of acrylic OCA with a creep recovery rate of 96.5%. The first film layer 121 is made of UTG (Young's modulus of 70 GPa) and has a thickness of 30 μm. The second film layer 122 is made of UTG (Young's modulus of 70 GPa) and has a thickness of 55 μm. The second adhesive layer 134a is made of acrylic PSA with a creep recovery rate of 95.5%. The fourth film layer 131 is made of UTG (Young's modulus of 70 GPa) and has a thickness of 40 μm. The fifth film layer 132 is made of Ti alloy (Young's modulus of 110 GPa) and has a thickness of 120 μm.

[0096] Example 4 Please refer to Figure 5The display module 10 includes a display panel 110, a first stacked structure 120 located on a first side 111 of the display panel 110, and a second stacked structure 130 located on a second side 112 of the display panel 110. The first stacked structure 120 includes a first adhesive layer 124a, a first film layer 121, a first adhesive layer 124b, and a second film layer 122, which are stacked sequentially in a direction away from the display panel 110. The second stacked structure 130 includes a fourth film layer 131, a second adhesive layer 134a, and a fifth film layer 132, which are stacked sequentially in a direction away from the display panel 110.

[0097] The first adhesive layer 124a and 124b are made of acrylic OCA with a creep recovery rate of 95.5%. The first film layer 121 is made of UTG (Young's modulus of 70 GPa) with a thickness of 30 μm. The second film layer 122 is made of unequal-thickness UTG (Young's modulus of approximately 70 GPa), with a thickness of 150 μm in the non-bending region AA2 and 60 μm in the bending region AA1. The second adhesive layer 134a is made of acrylic PSA with a creep recovery rate of 95.5%. The fourth film layer 131 is made of UTG (Young's modulus of 70 GPa) with a thickness of 40 μm. The fifth film layer 132 is made of carbon fiber (Young's modulus of 290 GPa) with a thickness of 150 μm.

[0098] The display modules 10 corresponding to the above comparative examples, Example 1, Example 2, Example 3, and Example 4 were subjected to bending performance tests. Under the same test conditions, each of the above display modules 10 was bent the same number of times and then unfolded. The maximum distance h between the bending area AA1 surface and the non-bending area AA2 surface of the second side 112 of each display module 10 was measured. The measurement results are shown in Table 1.

[0099] Table 1

[0100] As can be seen from the measurement results of the comparative example, Example 1, Example 2, Example 3, and Example 4, the height difference h of the bending area AA1 of the display module 10 of this application is less than 100 μm after multiple bends. Compared with the comparative example, the deformation and creases of the bending area AA1 of the display module 10 of this application are significantly reduced. This proves that the structure of the display module 10 of this application can effectively improve the crease problem of the foldable display module 10 and improve the reliability of the foldable product.

[0101] This application also provides a display device, which includes the display module 10 as described above. The display device can be applied to mobile phones, tablet computers, smart displays, and other fields, but is not limited thereto.

[0102] This application provides a display module and a display device. The display module includes a display panel, a first stacked structure located on a first side of the display panel, and a second stacked structure located on a second side of the display panel. The display module is bent toward the first side. At least two film layers in the first stacked structure have a Young's modulus greater than or equal to 10 GPa, and at least one film layer in the second stacked structure has a Young's modulus greater than or equal to 10 GPa. This application improves the undulation defects caused by unevenness in the bending area by increasing the proportion of high stiffness material (Young's modulus greater than or equal to 10 GPa) film layers in the display module structure, while reducing permanent deformation caused by multiple bends. While ensuring the bending characteristics of the display module, it significantly improves the crease problem and enhances the reliability of the foldable display product.

[0103] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0104] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0105] The embodiments, implementation methods, and related technical features of this application can be combined and substituted for each other without conflict.

[0106] The above are merely preferred embodiments of this application and are not intended to limit this application in any way. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of this application without departing from the scope of the technical solution of this application shall still fall within the scope of the technical solution of this application.

Claims

1. A display module, characterized in that, The display module is configured in a first state and a second state. In the first state, the display module is in a flattened state, and in the second state, the display module is in a bent state. The display module includes: The display panel includes a first side and a second side opposite to each other, and in the second state, the display module is bent toward the first side; A first stacked structure is disposed on the first side of the display panel, and the first stacked structure includes a plurality of film layers stacked together. A second stacked structure is disposed on the second side of the display panel, and the second stacked structure includes a plurality of film layers stacked together. Wherein, the Young's modulus of the material of at least two films in the first stacked structure is greater than or equal to 10 GPa, and the Young's modulus of the material of at least one film in the second stacked structure is greater than or equal to 10 GPa.

2. The display module according to claim 1, characterized in that, The first stacked structure includes: The first film layer is disposed on the side of the display panel away from the second laminated structure; The second film layer is disposed on the side of the first film layer away from the display panel; Wherein, the Young's modulus of the material of the second film layer is greater than or equal to the Young's modulus of the material of the first film layer.

3. The display module according to claim 2, characterized in that, In the thickness direction of the display module, the thickness of the second film layer is greater than the thickness of the first film layer.

4. The display module according to claim 2, characterized in that, The Young's modulus of the material of the first film layer is greater than or equal to 10 GPa and less than or equal to 80 GPa; the Young's modulus of the material of the second film layer is greater than or equal to 10 GPa and less than or equal to 80 GPa.

5. The display module according to claim 2, characterized in that, The first stacked structure further includes: A third film layer is disposed on the side of the second film layer away from the first film layer, wherein the Young's modulus of the material of the third film layer is greater than or equal to 1 GPa and less than or equal to 80 GPa.

6. The display module according to claim 5, characterized in that, The materials of the first film layer and the second film layer are selected from at least one of polyimide and ultrathin flexible glass; The material of the third membrane layer is selected from at least one of aromatic polyamide, polyimide, ultrathin flexible glass, polyethylene terephthalate, polymethyl methacrylate, polycarbonate, and cellulose triacetate.

7. The display module according to claim 5, characterized in that, The first laminated structure further includes a first adhesive layer, which is disposed between any two adjacent film layers among the display panel, the first film layer, the second film layer and the third film layer, wherein the creep recovery rate of the first adhesive layer is greater than or equal to 95%.

8. The display module according to claim 2, characterized in that, The second laminated structure includes at least one of a fourth film layer and a fifth film layer; Wherein, when the second stacked structure includes both the fourth film layer and the fifth film layer, the fourth film layer is disposed on the side of the display panel away from the first stacked structure, the fifth film layer is disposed on the side of the fourth film layer away from the display panel, and the Young's modulus of the material of the fifth film layer is greater than or equal to the Young's modulus of the material of the fourth film layer.

9. The display module according to claim 8, characterized in that, In the thickness direction of the display module, the thickness of the fifth film layer is greater than the thickness of the fourth film layer.

10. The display module according to claim 8, characterized in that, The Young's modulus of the material of the fourth film layer is greater than or equal to 10 GPa and less than or equal to 80 GPa; the Young's modulus of the material of the fifth film layer is greater than or equal to 10 GPa and less than or equal to 400 GPa.

11. The display module according to claim 8, characterized in that, The second stacked structure further includes: A sixth film layer is disposed between the fourth film layer and the fifth film layer, wherein the Young's modulus of the material of the sixth film layer is greater than or equal to 1 GPa and less than or equal to 80 GPa.

12. The display module according to claim 11, characterized in that, The materials of the fourth film layer, the fifth film layer, and the sixth film layer are selected from at least one of aromatic polyamide, polyimide, ultrathin flexible glass, metal, and carbon fiber.

13. The display module according to claim 11, characterized in that, The second laminated structure further includes a second adhesive layer, which is disposed between any two adjacent film layers among the display panel, the fourth film layer, the fifth film layer, and the sixth film layer, wherein the creep recovery rate of the second adhesive layer is greater than or equal to 95%.

14. The display module according to any one of claims 2-13, characterized in that, The display module includes a bent area and non-bent areas located on opposite sides of the bent area; The thickness of the first film layer in the bending region is less than or equal to the thickness of the non-bending region, and / or the thickness of the second film layer in the bending region is less than or equal to the thickness of the non-bending region.

15. The display module according to any one of claims 2-13, characterized in that, The display module includes a bent area and non-bent areas located on opposite sides of the bent area; In the first state, on the same side of the display module, the maximum distance h between the surface of the display module located in the bending area and the surface of the display module located in the non-bending area in the thickness direction of the display module is less than 100 μm.

16. A display device, characterized in that, Includes the display module as described in any one of claims 1 to 15.

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