Composite layer, flexible display screen and terminal
By filling the hollow areas of the metal layer with anisotropic films, the flatness and reliability issues caused by stress and strain during the rolling process of flexible display panels are solved, resulting in a flexible display screen with high flatness and high reliability.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- HUAWEI TECH CO LTD
- Filing Date
- 2021-03-29
- Publication Date
- 2026-06-16
Smart Images
Figure CN115128861B_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of display technology, and in particular to a composite layer, a flexible display screen, and a terminal. Background Technology
[0002] Electronic display products have evolved from fixed shapes to foldable and rollable forms, achieving both large-screen viewing and portability. Rollable devices combine flexible displays with cylindrical scrolls, offering the advantages of a large unfolded screen area and easy portability when rolled up.
[0003] Because flexible display panels are made of flexible plastic materials, creep occurs when these materials are under stress and deformation for extended periods. Creep causes the length of the plastic material to increase compared to its unstressed length, affecting the flatness of the screen surface when the flexible display panel is unrolled. A rollable rigid support structure can be used at the bottom of the flexible display panel to increase the flatness of the screen surface after unfolding. As shown in Figure 1, the support structure 20 is located at the bottom of the flexible display panel 10. The support structure 20 includes multiple support members 21, adjacent support members 21 are connected as a whole by a connecting shaft 22. When the flexible display panel 10 and the support structure 20 are in the unrolled state, the flexible display panel 10 is not subjected to stress or strain at the location of the connecting shaft 22. Figure 2 As shown, when the flexible display panel 10 and the support structure 20 enter a rolled state around the scroll 30, the adjacent support member 21 will undergo a certain angular deflection at the connecting shaft 22 position, thereby causing the flexible display panel 10 above the support structure 20 to also experience stress tension. The magnitude of the stress strain tension varies with the number of turns the flexible display panel 10 makes on the scroll.
[0004] Currently, to reduce the stress and tension caused by the supporting structure, a graphic cutout design is usually made at the bottom of the flexible display panel corresponding to the connecting shaft position. However, the cutout design at the bottom of the flexible display panel increases the risk of unevenness on the surface of the flexible display panel and is prone to curling and wrinkling problems, thus affecting the curling reliability of the rollable device. Summary of the Invention
[0005] This application provides a composite layer, a flexible display screen, and a terminal to improve the rollability of the flexible display screen and the terminal.
[0006] In a first aspect, this application provides a composite layer comprising a patterned metal layer and an anisotropic film. The patterned metal layer has at least one hollow region, and the anisotropic film fills the at least one hollow region. The elastic modulus of the anisotropic film along a first direction is less than that along a second direction, the first direction being parallel to the curling direction of the composite layer, and the second direction being perpendicular to the first direction. This application does not limit the number, shape, or position of the hollow regions.
[0007] It is understandable that if the first direction is the X-axis, and the directions perpendicular to the X-axis are the Y-axis and Z-axis, then the second direction is the Y-axis and Z-axis, with the Y-axis and Z-axis being perpendicular to each other. For example, if the curling direction of the composite layer is the length direction of the composite layer, then the first direction is along the length, and the second direction is along the thickness and width.
[0008] The composite layer provided in this application has an anisotropic membrane disposed in the hollow area of the metal layer. The anisotropic membrane has a small elastic modulus in the curling direction (e.g., length), which can absorb the stress and strain caused by curling to achieve the curling characteristics. The anisotropic membrane has a large elastic modulus in the thickness and width directions, which can achieve the function of rigid support.
[0009] Optionally, in this application, the elastic modulus of the anisotropic membrane along the first direction can be set to 0.1 MPa to 10 MPa, for example: 0.1 MPa, 0.5 MPa, 1 MPa, 5 MPa, 10 MPa, etc.; the elastic modulus of the anisotropic membrane layer along the second direction can be set to 1 GPa to 20 GPa, for example: 1 GPa, 5 GPa, 10 GPa, 15 GPa, 20 GPa, etc., and is not limited here.
[0010] In specific implementation, the anisotropic membrane can be made of polyacrylate or polyurethane, or other materials whose elastic modulus meets the above requirements, which are not limited here.
[0011] This application does not limit the thickness of the metal layer and the anisotropic film in the composite layer, and the design can be tailored to the actual product. For example, the thickness of the anisotropic film can be controlled between 20 μm and 100 μm, such as 20 μm, 50 μm, 80 μm, 100 μm, etc., and the thickness of the metal layer can be controlled between 20 μm and 150 μm, such as 20 μm, 50 μm, 80 μm, 100 μm, 130 μm, 150 μm, etc., and is not limited here. Furthermore, in this application, the thickness of the anisotropic film and the thickness of the metal layer can be set to be the same. Of course, the thickness of the anisotropic film and the thickness of the metal layer can also be different, and this is not limited here.
[0012] In specific implementations, the metal layer is made of an alloy, such as stainless steel, nickel-titanium (Ni / Ti) alloy, titanium-copper (Ti / Cu) alloy, etc., and is not limited here. The anisotropic film can be bonded to the metal layer by inkjet printing or hot pressing, and of course, it can also be bonded by other processes, which are not limited here.
[0013] Secondly, this application provides a flexible display screen, comprising a flexible display panel, a composite layer provided in the first aspect, and a rollable support structure stacked together. The flexible display panel has a display surface and a back surface. The support structure and the composite layer are both disposed on the back surface of the flexible display panel to support it. The composite layer is located between the support structure and the flexible display panel. The composite layer includes a patterned metal layer and an anisotropic film. The patterned metal layer has multiple hollow areas, and the anisotropic film fills the multiple hollow areas. The elastic modulus of the anisotropic film along a first direction is less than that along a second direction. The first direction is parallel to the roll-up direction of the composite layer, and the second direction is perpendicular to the first direction. The roll-up direction of the composite layer is parallel to the roll-up direction of the flexible display screen.
[0014] For example, if the rolling direction of the flexible display screen is the length direction of the flexible display screen, then the first direction is along the length, and the second direction is along the thickness and width.
[0015] The flexible display screen provided in this application has a composite layer between the rollable support structure and the flexible display panel. The patterned metal layer in the composite layer supports the flexible display panel and ensures the flatness of the display surface. An anisotropic film is set in the hollow area. The anisotropic film has a small elastic modulus in the rolling direction (e.g., the length direction), thereby absorbing the stress and strain caused by rolling to achieve the rolling characteristics. The anisotropic film has a large elastic modulus in the thickness and width directions, thereby achieving rigid support for the flexible display panel and reducing the deformation of the display surface.
[0016] In practical implementation, the supporting structure, composite layer, and flexible display panel can be bonded together by an adhesive layer. The composite layer and supporting structure provide support for the flexible display panel. Specifically, the adhesive layer can be optically clear adhesive (OCA) or an adhesive layer containing materials such as polyurethane, polyethylene, or polypropylene. In practical implementation, the shape and size of the supporting structure and composite layer can be the same as or different from the shape and size of the flexible display panel. For example, in one embodiment provided in this application, the supporting structure, composite layer, and flexible display panel are rectangular structures of the same size.
[0017] The support structure includes multiple support members and connecting shafts for connecting adjacent support members, with each hollowed-out area in the metal layer corresponding to one connecting shaft. In this application, the metal layer graphically forms the hollowed-out areas at positions corresponding to the connecting shafts, ensuring that the composite layer is easily bent at the connecting shaft positions. This application does not limit the shape of the hollowed-out areas; for example, they can be regular shapes such as rectangles, rhombuses, or ellipses, or of course, irregular shapes.
[0018] For example, the support structure includes multiple support members and connecting shafts for connecting adjacent support members, with at least one of the hollowed-out areas in the metal layer corresponding to one connecting shaft. Preferably, each hollowed-out area in the metal layer corresponds to one connecting shaft. In this application, the hollowed-out area is graphically formed in the metal layer at the position corresponding to the connecting shaft, ensuring that the composite layer is easy to bend at the position of the connecting shaft. This application does not limit the shape of the hollowed-out area; for example, it can be a regular shape such as a rectangle, rhombus, or ellipse, or it can be an irregular shape.
[0019] In actual products, the tensile stress on a flexible display panel varies depending on the number of turns it makes on the spool. The closer the turns are to the spool (i.e., the innermost turns), the greater the tensile stress on the flexible display panel. Therefore, the composite layer can be divided into multiple regions along the first direction, i.e., the winding direction of the flexible display screen: L1 to LN (N is an integer greater than 1, and the length of each region Ln (n is any integer from 1 to N) along the first direction is nC, where C is the circumference of the composite layer after one turn around the spool, and n is an integer greater than 0. The farther away from the spool a region is, the greater the elastic modulus of the anisotropic film along the first direction, while the elastic modulus of the anisotropic film in the same region is consistent along the first direction. For example, region L1 of the composite layer is the first turn around the spool, and region Ln of the composite layer is the first turn around the spool. Region L2 is the second turn around the spool, and region L3 of the composite layer is the third turn around the spool. The elastic modulus of the anisotropic film in region L1 along the first direction X is E1, the elastic modulus of the anisotropic film in region L2 along the first direction is E2, and the elastic modulus of the anisotropic film in region L3 along the first direction is E3. The elastic modulus of the anisotropic film in each region along the first direction satisfies E1 < E2 < E3. For example, E1 is between 0.1 MPa and 1 MPa, E2 is between 1 MPa and 5 MPa, and E3 is between 5 MPa and 10 MPa.
[0020] It should be noted that, for each region Ln in the composite layer, the length of region Ln along the first direction is an integer number of turns that can be made around the spool, such as the length of 1 turn, 2 turns, 3 turns, etc., which is not limited here. The number of turns that different regions Ln in the composite layer make around the spool can be the same or different. In addition, the length of one turn of the composite layer located on different turns of the spool will be slightly different, with the length of one turn being longer on turns farther away from the spool.
[0021] In specific implementation, the flexible display panel can be any flexible display device capable of display, such as any one of electrophoretic display panel, electrowetting display panel, organic light-emitting diode (OLED) display panel, quantum dot light-emitting diode (QLED) display panel or micro-light-emitting diode (Micro-LED) display panel, without limitation.
[0022] This application does not limit the shape of the flexible display panel. For example, the flexible display panel may have a substantially rectangular shape, or any other suitable shape.
[0023] In practical implementation, some display products also have camera functions. To achieve a full-screen effect, the camera needs to be placed below the flexible display panel. For flexible displays, such as those using OLED, QLED, or Micro-LED panels, a liquid crystal polarizing structure needs to be set on the display surface. The liquid crystal coating layer in the polarizing structure has a significant impact on light transmittance, typically only reaching >40%. To improve the light transmittance of the flexible display at the camera location, a physical aperture solution can be used, creating an opening in the liquid crystal polarizing structure at the camera position. However, the reflectivity at the aperture location changes significantly, affecting the display effect of the flexible display. Furthermore, the aperture location is prone to stress concentration, leading to decreased mechanical reliability. Additionally, the manufacturing process requires extra steps such as alignment, drilling, cleaning, and visual inspection.
[0024] To improve the light transmittance of the flexible display screen at the camera location without affecting the display effect or the mechanical reliability of the camera location, a liquid crystal polarizing structure is located on one side of the display surface of the flexible display panel, and the camera is located on the backlight side of the flexible display panel. The liquid crystal polarizing structure includes a substrate and a liquid crystal coating layer located on the side of the substrate facing away from the flexible display panel. The liquid crystal coating layer has a coating avoidance area, i.e., an opening area, in the region corresponding to the camera. The orthographic projection of the camera onto the liquid crystal polarizing structure at least partially overlaps with the coating avoidance area.
[0025] It is understandable that when the orthographic projection of the camera onto the liquid crystal polarizing structure completely overlaps with the coating avoidance area, both the light transmittance of the area corresponding to the camera and the normal display of other areas besides the camera can be guaranteed. Of course, in specific implementations, a certain alignment error between the camera and the coating avoidance area is permissible.
[0026] In the flexible display screen of this application, since the liquid crystal polarizing structure does not require physical openings, the design only involves coating the liquid crystal coating layer in the liquid crystal polarizing structure to avoid coating avoidance areas, thus preventing the liquid crystal coating layer from blocking the camera and ensuring the camera's light transmittance. Other film layers in the liquid crystal polarizing structure that do not affect transmittance remain unchanged, so the reflectivity at the camera location does not change significantly, and the display effect of the flexible display screen is not affected visually. Furthermore, since the liquid crystal polarizing structure eliminates the need for a perforation process, stress is less likely to concentrate at the camera location, significantly enhancing the optical and mechanical reliability of the flexible display screen. In addition, during the module assembly process, the liquid crystal polarizing structure can be bonded according to the marked positions, eliminating the need for perforation, cleaning, and visual inspection processes.
[0027] In practical implementation, the liquid crystal polarizing structure can exist independently of the composite layer. That is, the flexible display screen provided in this application may include only one of the liquid crystal polarizing structure and the composite layer, or it may include both the liquid crystal polarizing structure and the composite layer simultaneously; this is not limited here. Preferably, the flexible display screen includes both the liquid crystal polarizing structure and the composite layer, which can maximize the reliability of the flexible display screen.
[0028] It should be noted that the liquid crystal polarizing structure includes other functional film layers in addition to the liquid crystal coating layer. The specific settings of these other functions are the same as those in the prior art and will not be described in detail here.
[0029] In this application, the position of the camera's orthographic projection on the flexible display panel is not limited and can be designed according to the actual product.
[0030] In one feasible implementation, the camera and the support structure can be placed on the same layer, i.e., an opening is made in the support structure, and the camera is placed in the opening. The composite layer also has an opening at the corresponding position of the camera to prevent the composite layer from obstructing the camera. Furthermore, when a high-transmittance material is used for the anisotropic film, the anisotropic film can be filled into the openings of the composite layer.
[0031] For example, the substrate in the liquid crystal polarizing structure includes a pressure-sensitive adhesive layer, a quarter-wavelength retardation layer, an ultraviolet light cutoff layer, a half-wavelength retardation layer, and a dielectric layer stacked sequentially; the pressure-sensitive adhesive layer is located near the flexible display panel, and the liquid crystal coating layer is disposed on the dielectric layer. Further, the thickness of the liquid crystal polarizing structure can be controlled between 25 μm and 60 μm, and is not limited thereto.
[0032] In practical implementation, the liquid crystal polarizing structure can be combined with the flexible display panel via OCA.
[0033] The flexible display screen of this application may further include a cover plate located on the side of the liquid crystal polarizing structure opposite to the flexible display panel; the cover plate serves to protect the liquid crystal polarizing structure and the flexible display panel. In a specific implementation, the cover plate can be combined with the liquid crystal polarizing structure via an OCA (Optical Coefficient of Motion).
[0034] In the actual production of flexible displays, the cover plate, liquid crystal polarizing structure, flexible display panel, composite layer, support structure, and camera can all be manufactured separately. After each component is manufactured, the cover plate, liquid crystal polarizing structure, flexible display panel, composite layer, support structure, and camera are aligned and bonded together. For example, in one embodiment, the cover plate is bonded to the liquid crystal polarizing structure via a first OCA layer, the liquid crystal polarizing structure is bonded to the flexible display panel via a second OCA layer, the flexible display panel is bonded to the composite layer via a third OCA layer, and the composite layer is bonded to the support structure via an adhesive layer.
[0035] Alternatively, the fabrication of the cover plate, flexible display panel, support structure, and camera can be the same as in the prior art, and will not be described in detail here.
[0036] The liquid crystal polarizing structure can be prepared by the following two methods, but is not limited to these two methods; the following two methods are only used as examples for illustration.
[0037] The first method
[0038] Step 1: Clean the surface of the substrate and activate the surface energy.
[0039] In a specific implementation, the substrate can be any of the film layers located below the liquid crystal coating layer in the liquid crystal polarizing structure.
[0040] Step 2: Place a shielding mold at the position corresponding to the camera to ensure that the coating avoidance area is effectively shielded, and place a support plate on the bottom side of the substrate.
[0041] Step 3: Coat the substrate with shear stress coating liquid crystal solution. Except for the coating avoidance area, the liquid crystal solution is uniformly coated on the substrate. The concentration of the liquid crystal solution is controlled between 10% and 15%.
[0042] Step 4: Heat-cur the coated liquid crystal solution to form a liquid crystal coating layer.
[0043] The thickness of the liquid crystal coating layer can be controlled between 1μm and 2μm, and is not limited here.
[0044] For example, the curing temperature can be controlled between 50℃ and 55℃, and the curing time can be controlled between 10min and 15min.
[0045] The liquid crystal coating layer can be aligned by the initial coating force and the intermolecular forces of liquid crystal molecules during the curing process, without the need for an additional alignment layer.
[0046] Step 5: Remove the blocking mold and support plate to form a liquid crystal polarizing structure.
[0047] In a specific implementation, after step 1 and before step 2, the process may further include: applying a primer layer to the surface of the substrate and then performing thermal curing. For example, the curing temperature can be controlled between 50°C and 55°C, and the curing time can be controlled between 10 minutes and 15 minutes.
[0048] The primer layer can be made of silane, and its main function is to isolate the liquid crystal coating layer from the substrate surface, thereby reducing the interaction between the liquid crystal in the substrate (e.g., the liquid crystal in the half-wavelength retardation layer and the quarter-wavelength retardation layer) and the liquid crystal in the liquid crystal coating layer.
[0049] The second method
[0050] Step 1: Clean the surface of the substrate and activate the surface energy.
[0051] In a specific implementation, the substrate can be any of the film layers located below the liquid crystal coating layer in the liquid crystal polarizing structure.
[0052] Step 2: Coat a high contact angle development layer on the surface of the substrate.
[0053] The contact angle of the developing layer is greater than 90 degrees, and the material of the developing layer may include fluorinated alkyl silane, with a thickness that is the same as that of the subsequently coated liquid crystal coating layer.
[0054] Step 3: Place an ultraviolet (UV) shielding mold at the location corresponding to the camera. After UV irradiation, only the development layer of the coated avoidance area is retained, while the development layer of other areas is removed by photolithography.
[0055] Step 4: Coat the substrate with shear stress coating liquid crystal solution. Except for the coating avoidance area, the liquid crystal solution is uniformly coated on the substrate. The concentration of the liquid crystal solution is controlled between 10% and 15%.
[0056] Step 5: The liquid crystal solution after thermal curing is used to form a liquid crystal coating layer, thereby forming a liquid crystal polarization structure.
[0057] The thickness of the liquid crystal coating layer can be controlled between 1μm and 2μm, and is not limited here.
[0058] For example, the curing temperature can be controlled between 50℃ and 55℃, and the curing time can be controlled between 10min and 15min.
[0059] The liquid crystal coating layer can be aligned by the initial coating force and the intermolecular forces of liquid crystal molecules during the curing process, without the need for an additional alignment layer.
[0060] In a specific implementation, after step 1 and before step 2, the process may further include: applying a primer layer to the surface of the substrate and then performing thermal curing. For example, the curing temperature can be controlled between 50°C and 55°C, and the curing time can be controlled between 10 minutes and 15 minutes.
[0061] The primer layer can be made of silane, and its main function is to isolate the liquid crystal coating layer from the substrate surface, thereby reducing the interaction between the liquid crystal in the substrate (e.g., the liquid crystal in the half-wavelength retardation layer and the quarter-wavelength retardation layer) and the liquid crystal in the liquid crystal coating layer.
[0062] Both methods described above can be used to prepare liquid crystal polarizing structures for use in the flexible display screen of this application. Structurally, the liquid crystal polarizing structure prepared by the second method has an additional developing layer located within the coating avoidance area. This developing layer serves to prevent the liquid crystal coating layer from being applied to the coating avoidance area during its formation. Since the contact angle of the developing layer is greater than 90 degrees, it prevents the liquid crystal solution from accumulating at the edge of the coating avoidance area, thus avoiding a thicker liquid crystal coating at the edge of the avoidance area compared to other areas. Therefore, the liquid crystal polarizing structure prepared by the second method exhibits better uniformity of liquid crystal coating thickness at the edge of the avoidance area, which is beneficial for maintaining consistent optical properties around the avoidance area. In terms of manufacturing process, the second method offers higher photolithography precision and better treatment of the liquid crystal coating at the edge of the avoidance area.
[0063] In this application, an OCA layer and a release film can also be attached to the side of the liquid crystal polarizing structure facing the flexible display panel. When the liquid crystal polarizing structure is bonded to the flexible display panel, the release film is removed, thereby the OCA layer bonds the liquid crystal polarizing structure to the flexible display panel.
[0064] In this application, the flexible display screen can be used for an inward roll design, that is, after the flexible display screen is rolled up, the cover plate is located on the side closer to the roll shaft, and the support structure is located on the side away from the roll shaft; of course, the flexible display screen can also be used for an outward roll design, that is, after the flexible display screen is rolled up, the support structure is located on the side closer to the roll shaft, and the cover plate is located on the side away from the roll shaft.
[0065] Thirdly, embodiments of this application also provide a terminal, including: a housing and the flexible display screen provided in the first aspect; the housing has a scroll and an opening; a first end of the flexible display screen is wound around the scroll, and a second end enters and exits the housing through the opening as the scroll rotates. The flexible display screen can be rolled up and / or unfolded relative to the scroll in the housing. Attached Figure Description
[0066] Figure 1 A schematic diagram of a cross-sectional structure of a terminal provided for related technologies;
[0067] Figure 2 for Figure 1 The diagram shown illustrates the structure of the terminal in a curled-up state.
[0068] Figure 3 A cross-sectional structural diagram of another terminal provided for related technologies;
[0069] Figure 4 This is a schematic diagram of the structure of a composite layer provided in one embodiment of this application;
[0070] Figure 5 for Figure 4 The cross-sectional structure of the composite layer along the AA' direction is shown in the diagram.
[0071] Figure 6 This is a schematic diagram of the structure of a flexible display screen provided in one embodiment of this application;
[0072] Figure 7 This is a schematic diagram of the structure of a flexible display screen provided in another embodiment of this application;
[0073] Figure 8 This is a schematic diagram of the structure of a flexible display screen in a rolled-up state according to an embodiment of this application;
[0074] Figure 9 for Figure 8 The diagram shown is a schematic diagram of the composite layer structure of the flexible display screen in its flattened state.
[0075] Figure 10 This is a schematic diagram of the structure of a flexible display screen provided in another embodiment of this application;
[0076] Figure 11 This is a schematic diagram of a liquid crystal polarizing structure provided in one embodiment of this application;
[0077] Figure 12 This is a schematic diagram of the structure of a flexible display screen provided in another embodiment of this application;
[0078] Figure 13a and Figure 13b This is an example diagram illustrating the fabrication of the liquid crystal polarizing structure in the first method of this application.
[0079] Figures 14a to 14c This is an example diagram illustrating the fabrication of the liquid crystal polarizing structure using the second method in this application.
[0080] Figure 15 This is a schematic diagram of the structure of a bendable device provided in an embodiment of this application. Detailed Implementation
[0081] To make the objectives, technical solutions, and advantages of this application clearer, the application will now be described in further detail with reference to the accompanying drawings.
[0082] To facilitate understanding of the flexible display screen provided in the embodiments of this application, its application scenarios will be introduced first below.
[0083] The flexible display screen provided in this application can be applied to terminals, such as rollable phones, foldable phones, rollable e-readers, foldable e-readers, rollable tablets, or foldable tablets. The flexible display screen has a certain degree of rollability; therefore, it can be rolled up in some cases and unfolded in others. For example, when the terminal is rolled up, the flexible display screen can be rolled up accordingly, thereby reducing the terminal's area and improving portability. When the terminal is unfolded, the flexible display screen can be unfolded accordingly, thereby providing a larger display area and improving user convenience.
[0084] See Figure 1 and Figure 2 In the terminal, a rollable support structure 20 is provided at the bottom of the flexible display panel 10. The support structure 20 includes multiple support members 21, which are connected as a whole by a connecting shaft 22. When the flexible display panel 10 and the support structure 20 are in a flattened state, the flexible display panel 10 is not subjected to stress or strain at the position of the connecting shaft 22. When the flexible display panel 10 and the support structure 20 are rolled up around the scroll 30, the adjacent support members 21 will undergo a certain angular deflection at the position of the connecting shaft 22, resulting in stress and tension on the flexible display panel 10 above the support structure 20. The magnitude of the stress and strain varies with the number of times the flexible display panel 10 is rolled up on the scroll 30.
[0085] See Figure 3 To reduce the stress and tension caused by the support structure 20, a graphic hollow design is made at the bottom of the flexible display panel 10 corresponding to the position of the connecting shaft 22. However, the graphic hollow design at the bottom of the flexible display panel 10 will increase the risk of unevenness of the surface of the flexible display panel 10 and is prone to curling and wrinkling problems.
[0086] Therefore, embodiments of this application provide a flexible display screen and a terminal using the flexible display screen, which reduces the impact of misalignment and tension of the support structure without affecting the flatness of the display screen, improves the stress and strain of the film layer, and enhances the roll-up reliability of the terminal.
[0087] To facilitate understanding of the technical solution of this application, the flexible screen provided in this application will be described in detail below with reference to the accompanying drawings and specific embodiments.
[0088] The terminology used in the following embodiments is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. As used in the specification and appended claims of this application, the singular expressions “a,” “an,” “the,” “the,” and “this” are intended to also include expressions such as “one or more,” unless the context clearly indicates otherwise. It should also be understood that in the following embodiments of this application, “at least one” and “one or more” refer to one, two, or more than two. The term “and / or” is used to describe the relationship between related objects, indicating that three relationships may exist; for example, A and / or B can indicate: A alone, A and B simultaneously, or B alone, where A and B can be singular or plural. The character “ / ” generally indicates that the preceding and following related objects are in an “or” relationship.
[0089] References to "one embodiment" or "some embodiments" as described in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.
[0090] See Figure 4 and Figure 5 , Figure 4 This is a top view of the composite layer provided in an embodiment of this application. Figure 5 for Figure 4 The diagram shows a cross-sectional view of the composite layer along the AA' direction. The composite layer 120 includes a patterned metal layer 121 and an anisotropic film 122. The patterned metal layer 121 has at least one hollow region S1, and the anisotropic film 122 fills the at least one hollow region S1. This application does not limit the number, shape, or position of the hollow regions S1. Figure 5 The number, shape, and position of the hollowed-out areas S1 are only for illustration.
[0091] Optionally, continue to refer to Figure 4 and Figure 5 The elastic modulus of the anisotropic membrane 122 along the first direction X is less than that along the second directions Y and Z. The first direction X is parallel to the curling direction of the composite layer 120, and the second directions Y and Z are perpendicular to the first direction X.
[0092] It is understandable that, such as Figure 4 and Figure 5 As shown, if the first direction is the X-axis, the directions perpendicular to the X-axis are: Figure 4 Y-axis direction and Figure 5 In this context, the Z-axis direction, i.e., the second direction, is the Y-axis direction and the Z-axis direction, which are perpendicular to each other. For example, if the curling direction of the composite layer is the length direction of the composite layer, then the first direction is along the length, and the second direction is along the thickness and width.
[0093] The composite layer provided in this application has an anisotropic membrane 122 disposed in the hollow area S1 of the metal layer 121. The anisotropic membrane 122 has a small elastic modulus in the curling direction (e.g., length), so it can absorb the stress and strain caused by curling to achieve curling characteristics. The anisotropic membrane 122 has a large elastic modulus in the thickness and width directions, so it can achieve the function of rigid support.
[0094] Optionally, in this application, the elastic modulus of the anisotropic membrane along the first direction can be set to 0.1 MPa to 10 MPa, for example: 0.1 MPa, 0.5 MPa, 1 MPa, 5 MPa, 10 MPa, etc.; the elastic modulus of the anisotropic membrane layer along the second direction can be set to 1 GPa to 20 GPa, for example: 1 GPa, 5 GPa, 10 GPa, 15 GPa, 20 GPa, etc., and is not limited here.
[0095] In specific implementation, the anisotropic membrane can be made of polyacrylate or polyurethane, or other materials whose elastic modulus meets the above requirements, which are not limited here.
[0096] This application does not limit the thickness of the metal layer and the anisotropic film in the composite layer, and the design can be tailored to the actual product. For example, the thickness of the anisotropic film can be controlled between 20 μm and 100 μm, such as 20 μm, 50 μm, 80 μm, 100 μm, etc., and the thickness of the metal layer can be controlled between 20 μm and 150 μm, such as 20 μm, 50 μm, 80 μm, 100 μm, 130 μm, 150 μm, etc., and is not limited here. Furthermore, in this application, the thickness of the anisotropic film and the thickness of the metal layer can be set to be the same. Of course, the thickness of the anisotropic film and the thickness of the metal layer can also be different, and this is not limited here.
[0097] In specific implementations, the metal layer is made of an alloy, such as stainless steel, nickel-titanium (NiTi) alloy, titanium-copper (Ti / Cu) alloy, etc., and is not limited here. The anisotropic film can be bonded to the metal layer by inkjet printing or hot pressing, or by other processes, and is not limited here.
[0098] In practical applications, the composite layer can be used in flexible displays. See also... Figure 6 , Figure 6 This is a schematic diagram of the structure of a flexible display screen provided in one embodiment of this application. The flexible display screen 100 includes a flexible display panel 110, a composite layer 120, and a rollable support structure 130 stacked together. The flexible display panel 110 has a display surface and a back surface; the support structure 130 and the composite layer 120 are both disposed on the back surface of the flexible display panel 110 to support it; the composite layer 120 is located between the support structure 130 and the flexible display panel 110. In this flexible display screen, combined with... Figure 4 and Figure 5 The anisotropic film 122 has an elastic modulus along the first direction X that is less than that along the second directions Y and Z. The first direction X is parallel to the curling direction of the composite layer, and the second directions Y and Z are perpendicular to the first direction X. The curling direction of the composite layer is parallel to the curling direction of the flexible display screen.
[0099] It is understandable that, such as Figure 6 As shown, if the first direction is the X-axis, and the directions perpendicular to the X-axis are the Y-axis and Z-axis, then the second direction is the Y-axis and Z-axis, which are perpendicular to each other. For example, if the flexible display screen's rolling direction is its length direction, then the first direction is along the length, and the second direction is along the thickness and width.
[0100] The flexible display screen provided in this application has a composite layer 120 between the rollable support structure 130 and the flexible display panel 110. The patterned metal layer 121 in the composite layer 120 is used to support the flexible display panel 110, ensuring the flatness of the display surface of the flexible display panel 110. An anisotropic film 122 is provided in the hollow area S1. The anisotropic film 122 has a small elastic modulus in the rolling direction (e.g., length), thereby absorbing the stress and strain caused by rolling to achieve the rolling characteristics. The anisotropic film 122 has a large elastic modulus in the thickness and width directions, thereby achieving rigid support for the flexible display panel 110 and reducing the deformation of the display surface.
[0101] In practical implementation, the supporting structure, composite layer, and flexible display panel can be bonded together by an adhesive layer. The composite layer and supporting structure provide support for the flexible display panel. Specifically, the adhesive layer can be optically clear adhesive (OCA) or an adhesive layer containing materials such as polyurethane, polyethylene, or polypropylene. In practical implementation, the shape and size of the supporting structure and composite layer can be the same as or different from the shape and size of the flexible display panel. For example, in one embodiment provided in this application, the supporting structure, composite layer, and flexible display panel are rectangular structures of the same size.
[0102] See Figure 7 The support structure 130 includes a plurality of support members 131 and a connecting shaft 132 for connecting adjacent support members 131. At least one of the hollowed-out areas S1 in the metal layer 121 corresponds to one connecting shaft 132. Preferably, each hollowed-out area S1 in the metal layer 121 corresponds to one connecting shaft 132. In this application, the hollowed-out area S1 is graphically formed in the metal layer 121 at the position corresponding to the connecting shaft 132, ensuring that the composite layer 120 is easy to bend at the position of the connecting shaft 132. This application does not limit the shape of the hollowed-out area S1. For example, it can be a regular shape such as a rectangle, rhombus, or ellipse, or it can be an irregular shape.
[0103] In actual products, the magnitude of tensile stress on a flexible display panel varies depending on the number of turns it makes on the spool. The closer the turns are to the spool (i.e., the innermost turns), the greater the tensile stress on the flexible display panel. See also Figure 8 and Figure 9 , Figure 8 This is a schematic diagram of the flexible display screen being rolled up around a roller in an embodiment of this application; Figure 9 for Figure 8 The schematic diagram of the composite layer in the flexible display screen after being flattened shows that, along the first direction X, i.e., the rolling direction of the flexible display screen 100, the composite layer 120 can be divided into multiple regions: L1~LN (N is an integer greater than 1). Figure 8 and Figure 9 (Taking N=3 as an example for illustration), the length of each region Ln (n is any integer from 1 to N) along the first direction X is nC, where C is the circumference of the composite layer 120 rolled around the spool once, and n is an integer greater than 0. The farther the region is from the spool, the greater the elastic modulus of the anisotropic membrane 122 along the first direction (X direction), while the elastic modulus of the anisotropic membrane 122 located in the same region is consistent along the first direction. For example... Figure 8In this structure, region L1 of the composite layer 120 is the first turn around the spool, region L2 of the composite layer 120 is the second turn around the spool, and region L3 of the composite layer 120 is the third turn around the spool. The elastic modulus of the anisotropic membrane 122 in region L1 along the first direction X is E1, the elastic modulus of the anisotropic membrane 122 in region L2 along the first direction X is E2, and the elastic modulus of the anisotropic membrane 122 in region L3 along the first direction X is E3. The elastic modulus of the anisotropic membrane 122 in each region along the first direction X satisfies E1 < E2 < E3. For example, E1 is between 0.1 MPa and 1 MPa, E2 is between 1 MPa and 5 MPa, and E3 is between 5 MPa and 10 MPa.
[0104] It should be noted that, for each region Ln in the composite layer 120, the length of region Ln along the first direction X is an integer number of turns that can be wound around the spool, such as the length of 1 turn, 2 turns, 3 turns, etc., which is not limited here. The number of turns that different regions Ln in the composite layer 120 are wound around the spool can be the same or different. In addition, the length of one turn of the composite layer 120 located on different turns of the spool will be slightly different, with the length of one turn being longer on turns farther away from the spool.
[0105] In specific implementation, the flexible display panel can be any flexible display device capable of display, such as any one of electrophoretic display panel, electrowetting display panel, organic light-emitting diode (OLED) display panel, quantum dot light-emitting diode (QLED) display panel or micro-light-emitting diode (Micro-LED) display panel, without limitation.
[0106] The flexible display panel may include a substrate and a display functional layer, the display functional layer being disposed on the substrate for displaying images. The substrate may be a transparent insulating substrate, but is not limited to this. The substrate may include at least one of polycarbonate (PC), polyethylene terephthalate (PET), polyethylene (PE), polypropylene (PP), polysulfone (PSF), polymethyl methacrylate (PMMA), cellulose triacetate (TAC), cyclic olefin polymer (COP), and cyclic olefin copolymer (COC).
[0107] This application does not limit the shape of the flexible display panel. For example, the flexible display panel may have a substantially rectangular shape, or any other suitable shape.
[0108] In practical implementation, some display products also have camera functions. To achieve a full-screen effect, the camera needs to be placed below the flexible display panel. For flexible displays, such as those using OLED, QLED, or Micro-LED panels, a liquid crystal polarizing structure needs to be set on the display surface. The liquid crystal coating layer in the polarizing structure has a significant impact on light transmittance, typically only reaching >40%. To improve the light transmittance of the flexible display at the camera location, a physical aperture solution can be used, creating an opening in the liquid crystal polarizing structure at the camera position. However, the reflectivity at the aperture location changes significantly, affecting the display effect of the flexible display. Furthermore, the aperture location is prone to stress concentration, leading to decreased mechanical reliability. Additionally, the manufacturing process requires extra steps such as alignment, drilling, cleaning, and visual inspection.
[0109] To improve the light transmittance of the flexible display at the camera location without affecting the display effect or the mechanical reliability of the camera location, see [reference needed]. Figure 10 , Figure 10 This is a schematic diagram of another flexible display screen in an embodiment of this application; in the flexible display screen 100, the liquid crystal polarizing structure 150 is located on one side of the display surface of the flexible display panel 110, and the camera 140 is located on one side of the backlight surface of the flexible display panel 110. See also Figure 11 , Figure 11 This is a top view schematic diagram of a liquid crystal polarizing structure in one embodiment of this application; the liquid crystal polarizing structure 150 includes: a substrate 151 and a liquid crystal coating layer 152 located on the side of the substrate 151 facing away from the flexible display panel 110, the liquid crystal coating layer 152 being adjacent to the camera 140 (… Figure 11 The area corresponding to the unseen region has a coating avoidance area C1, i.e., an opening area, and the orthographic projection of the camera 140 onto the liquid crystal polarizing structure 150 at least partially overlaps with the coating avoidance area C1.
[0110] It is understandable that when the orthographic projection of the camera 140 onto the liquid crystal polarizing structure 150 completely overlaps with the coating avoidance area C1, both the light transmittance of the area corresponding to the camera and the normal display of other areas besides the camera 140 can be guaranteed. Of course, in specific implementations, a certain alignment error between the camera 140 and the coating avoidance area C1 is permissible.
[0111] In the flexible display screen of this application, since the liquid crystal polarizing structure does not require physical openings, the design only involves coating the liquid crystal coating layer in the liquid crystal polarizing structure to avoid coating avoidance areas, thus preventing the liquid crystal coating layer from blocking the camera and ensuring the camera's light transmittance. Other film layers in the liquid crystal polarizing structure that do not affect transmittance remain unchanged, so the reflectivity at the camera location does not change significantly, and the display effect of the flexible display screen is not affected visually. Furthermore, since the liquid crystal polarizing structure eliminates the need for a perforation process, stress is less likely to concentrate at the camera location, significantly enhancing the optical and mechanical reliability of the flexible display screen. In addition, during the module assembly process, the liquid crystal polarizing structure can be bonded according to the marked positions, eliminating the need for perforation, cleaning, and visual inspection processes.
[0112] In practical implementation, the liquid crystal polarizing structure can exist independently of the composite layer. That is, the flexible display screen provided in this application may include only one of the liquid crystal polarizing structure and the composite layer, or it may include both the liquid crystal polarizing structure and the composite layer simultaneously; this is not limited here. Preferably, the flexible display screen includes both the liquid crystal polarizing structure and the composite layer, which can maximize the reliability of the flexible display screen.
[0113] It should be noted that the liquid crystal polarizing structure includes other functional film layers in addition to the liquid crystal coating layer. The specific settings of these other functions are the same as those in the prior art and will not be described in detail here.
[0114] In this application, the position of the camera's orthographic projection on the flexible display panel is not limited and can be designed according to the actual product.
[0115] See Figure 10 The camera 140 and the support structure 130 can be placed on the same layer, that is, an opening is provided in the support structure 130, and the camera 140 is placed in the opening. Similarly, the composite layer 120 has an opening at the position corresponding to the camera 140 to prevent the composite layer 120 from obstructing the camera 140. Furthermore, when the anisotropic film 122 is made of a high-transmittance material, the anisotropic film 122 can be filled into the opening of the composite layer 120.
[0116] The substrate can be any of the functional film layers located below the liquid crystal coating layer in the liquid crystal polarizing structure 150. For example, such as... Figure 12As shown, the substrate 151 includes a pressure-sensitive adhesive layer 1511, a quarter-wavelength retardation layer 1512, an ultraviolet light cutoff layer 1513, a half-wavelength retardation layer 1514, and a dielectric layer 1515, which are sequentially stacked. The pressure-sensitive adhesive layer 1511 is located near the flexible display panel 110, and the liquid crystal coating layer 152 is disposed on the dielectric layer 1515. Further, the thickness of the liquid crystal polarizing structure 150 can be controlled between 25 μm and 60 μm, and is not limited thereto.
[0117] In a specific implementation, the liquid crystal polarizing structure 150 can be combined with the flexible display panel 110 via an OCA.
[0118] See also Figure 10 and Figure 12 The flexible display screen 100 of this application may also include a cover plate 160 located on the side of the liquid crystal polarizing structure 150 away from the flexible display panel 110; the cover plate 160 is used to protect the liquid crystal polarizing structure 150 and the flexible display panel 110.
[0119] In a specific implementation, the cover plate 160 can be combined with the liquid crystal polarizing structure 150 via OCA.
[0120] In the actual production of flexible displays, the cover plate, liquid crystal polarizing structure, flexible display panel, composite layer, support structure, and camera can all be manufactured separately. After each component is manufactured, the cover plate, liquid crystal polarizing structure, flexible display panel, composite layer, support structure, and camera are then aligned and bonded together. For example... Figure 10 As shown, the cover plate 160 is bonded to the liquid crystal polarizing structure 150 through the first OCA layer 171, the liquid crystal polarizing structure 150 is bonded to the flexible display panel 110 through the second OCA layer 172, the flexible display panel 110 is bonded to the composite layer 120 through the third OCA layer 173, and the composite layer 120 is bonded to the support structure 130 through the adhesive layer 174.
[0121] Alternatively, the fabrication of the cover plate, flexible display panel, support structure, and camera can be the same as in the prior art, and will not be described in detail here.
[0122] The liquid crystal polarizing structure can be prepared by the following two methods, but is not limited to these two methods; the following two methods are only used as examples for illustration.
[0123] The first method
[0124] Step 1: Clean the surface of the substrate and activate the surface energy.
[0125] In a specific implementation, the substrate can be any of the film layers located below the liquid crystal coating layer in the liquid crystal polarizing structure.
[0126] Step 2: See Figure 13a A shielding mold is placed at the position corresponding to the camera to ensure that the coating avoidance area is effectively shielded, and a support plate is placed on the bottom side of the substrate 151.
[0127] Step 3: See also Figure 13a A shear stress coating liquid crystal solution is coated on the substrate 151. Except for the coating avoidance area, the liquid crystal solution is uniformly coated on the substrate 151, and the concentration of the liquid crystal solution is controlled between 10% and 15%.
[0128] Step 4: Heat-cur the coated liquid crystal solution to form a liquid crystal coating layer 152.
[0129] The thickness of the liquid crystal coating layer can be controlled between 1μm and 2μm, and is not limited here.
[0130] For example, the curing temperature can be controlled between 50℃ and 55℃, and the curing time can be controlled between 10min and 15min.
[0131] The liquid crystal coating layer can be aligned by the initial coating force and the intermolecular forces of liquid crystal molecules during the curing process, without the need for an additional alignment layer.
[0132] Step 5: Remove the shielding mold and support plate to form a shape like... Figure 13b The liquid crystal polarizing structure 150 shown is illustrated.
[0133] In a specific implementation, after step 1 and before step 2, the process may further include: applying a primer layer to the surface of the substrate and then performing thermal curing. For example, the curing temperature can be controlled between 50°C and 55°C, and the curing time can be controlled between 10 minutes and 15 minutes.
[0134] The primer layer can be made of silane, and its main function is to isolate the liquid crystal coating layer from the substrate surface, thereby reducing the interaction between the liquid crystal in the substrate (e.g., the liquid crystal in the half-wavelength retardation layer and the quarter-wavelength retardation layer) and the liquid crystal in the liquid crystal coating layer.
[0135] The second method
[0136] Step 1: Clean the surface of the substrate and activate the surface energy.
[0137] In a specific implementation, the substrate can be any of the film layers located below the liquid crystal coating layer in the liquid crystal polarizing structure.
[0138] Step 2: See Figure 14a A high contact angle developing layer 153 is coated on the surface of the substrate 151.
[0139] The contact angle of the developing layer is greater than 90 degrees, and the material of the developing layer may include fluorinated alkyl silane, with a thickness that is the same as that of the subsequently coated liquid crystal coating layer.
[0140] Step 3: See Figure 14b An ultraviolet (UV) shielding mold is placed at the position corresponding to the camera. After UV irradiation, only the developing layer 153 of the coating avoidance area C1 is retained, while the developing layer 153 of other areas is removed by photolithography.
[0141] Step 4: Coat the substrate with shear stress coating liquid crystal solution. Except for the coating avoidance area, the liquid crystal solution is uniformly coated on the substrate. The concentration of the liquid crystal solution is controlled between 10% and 15%.
[0142] Step 5: The liquid crystal solution after thermal curing is applied to form a liquid crystal coating layer 152, thereby forming a liquid crystal coating layer 152. Figure 14c The liquid crystal polarizing structure 150 shown is illustrated.
[0143] The thickness of the liquid crystal coating layer 152 can be controlled between 1μm and 2μm, and is not limited here.
[0144] For example, the curing temperature can be controlled between 50℃ and 55℃, and the curing time can be controlled between 10min and 15min.
[0145] The liquid crystal coating layer can be aligned by the initial coating force and the intermolecular forces of liquid crystal molecules during the curing process, without the need for an additional alignment layer.
[0146] In a specific implementation, after step 1 and before step 2, the process may further include: applying a primer layer to the surface of the substrate and then performing thermal curing. For example, the curing temperature can be controlled between 50°C and 55°C, and the curing time can be controlled between 10 minutes and 15 minutes.
[0147] The primer layer can be made of silane, and its main function is to isolate the liquid crystal coating layer from the substrate surface, thereby reducing the interaction between the liquid crystal in the substrate (e.g., the liquid crystal in the half-wavelength retardation layer and the quarter-wavelength retardation layer) and the liquid crystal in the liquid crystal coating layer.
[0148] Both of the liquid crystal polarizing structures prepared by the above two methods can be applied to the flexible display screen of this application. Structurally, the liquid crystal polarizing structure prepared by the second method has an additional developing layer 153 located within the coating avoidance area C1. The developing layer 153 serves to prevent the liquid crystal coating layer 152 from being coated onto the coating avoidance area C1 during the formation of the liquid crystal coating layer 152. Since the contact angle of the developing layer 153 is greater than 90 degrees, it can prevent the liquid crystal solution from accumulating at the edge of the coating avoidance area C1, thereby preventing the thickness of the liquid crystal coating layer 152 at the edge of the coating avoidance area C1 from being thicker than in other areas. Therefore, the liquid crystal polarizing structure 150 prepared by the second method exhibits good uniformity in the thickness of the liquid crystal coating layer 152 at the edge of the coating avoidance area C1, which is beneficial for maintaining consistent optical properties around the coating avoidance area C1. In terms of process, the second method has higher photolithography precision and better treatment of the liquid crystal coating layer 152 at the edge of the coating avoidance area C1.
[0149] In this application, an OCA layer and a release film can also be attached to the side of the liquid crystal polarizing structure facing the flexible display panel. When the liquid crystal polarizing structure is bonded to the flexible display panel, the release film is removed, thereby the OCA layer bonds the liquid crystal polarizing structure to the flexible display panel.
[0150] In this application, the flexible display screen can be used for an inward roll design, that is, after the flexible display screen is rolled up, the cover plate is located on the side closer to the roll shaft, and the support structure is located on the side away from the roll shaft; of course, the flexible display screen can also be used for an outward roll design, that is, after the flexible display screen is rolled up, the support structure is located on the side closer to the roll shaft, and the cover plate is located on the side away from the roll shaft.
[0151] See Figure 15 This application also provides a terminal, including: a housing 200 and any of the flexible display screens 100 described in this application embodiment; the housing 200 has a scroll 300 and an opening 2001, wherein the scroll extends along the Y direction; a first end of the flexible display screen 100 is wound around the scroll 300, and a second end enters and exits the housing 200 through the opening 2001 as the scroll 300 rotates. The flexible display screen 100 can be rolled up and / or unfolded relative to the scroll 300 in the housing 200. The flexible display screen 100 can be exposed to the outside of the housing 200 by applying an external force to its second end. For example, once an external force is applied, the flexible display screen 100, rolled up and held within the housing 200, can be exposed to the outside of the housing 200 after passing through the opening 2001 in the housing 200.
[0152] The housing 200 is used to house the flexible display screen 100 rolled up on the reel 300. The housing 200 may have a substantially cylindrical shape, but the shape of the housing 200 is not limited to this. For example, the housing 200 may have any suitable shape, as long as the flexible display screen 100 can be rolled up and held within the housing 200.
[0153] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the scope of protection of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.
Claims
1. A composite layer, characterized in that, It includes a patterned metal layer and an anisotropic film, wherein the patterned metal layer has at least one hollow area, and the anisotropic film fills the at least one hollow area; The elastic modulus of the anisotropic membrane along the first direction is less than that along the second direction, the first direction is parallel to the curling direction of the composite layer, and the second direction is perpendicular to the first direction.
2. The composite layer as described in claim 1, characterized in that, The anisotropic membrane has an elastic modulus of 0.1 MPa to 10 MPa along the first direction, and the anisotropic membrane layer has an elastic modulus of 1 GPa to 20 GPa along the second direction.
3. The composite layer as described in claim 1 or 2, characterized in that, The anisotropic membrane is made of polyacrylate or polyurethane.
4. The composite layer as described in claim 3, characterized in that, The thickness of the anisotropic film is 20 μm to 100 μm, and the thickness of the metal layer is 20 μm to 150 μm.
5. The composite layer as described in claim 1 or 2, characterized in that, The thickness of the anisotropic film is 20 μm to 100 μm, and the thickness of the metal layer is 20 μm to 150 μm.
6. The composite layer as described in claim 1 or 2, characterized in that, The metal layer is made of an alloy.
7. The composite layer as described in claim 3, characterized in that, The metal layer is made of an alloy.
8. The composite layer as described in claim 4, characterized in that, The metal layer is made of an alloy.
9. The composite layer as described in claim 5, characterized in that, The metal layer is made of an alloy.
10. A flexible display screen, characterized in that, The invention comprises: a flexible display panel, a rollable support structure, and a composite layer as described in any one of claims 1 to 9, all stacked together. The flexible display panel has a display surface and a back surface. The composite layer and the support structure are both located on the back surface of the flexible display panel, and the composite layer is located between the flexible display panel and the support structure.
11. The flexible display screen as described in claim 10, characterized in that, Along the first direction, the composite layer is divided into multiple regions, and the length of each region along the first direction is nC, where C is the circumference of the composite layer when it is rolled around a spool, and n is an integer greater than 0. The greater the region is from the spool, the greater the elastic modulus of the anisotropic membrane along the first direction; the anisotropic membranes located in the same region have the same elastic modulus along the first direction.
12. The flexible display screen as described in claim 10 or 11, characterized in that, The support structure includes multiple support members and a connecting shaft for connecting adjacent support members; At least one of the hollowed-out areas in the metal layer corresponds to one of the connecting shafts.
13. The flexible display screen as described in claim 10 or 11, characterized in that, Also includes: Liquid crystal polarizing structure and camera; wherein: The liquid crystal polarizing structure is disposed on one side of the display surface of the flexible display panel; The camera is located on one side of the back of the flexible display panel; The liquid crystal polarizing structure includes: a substrate and a liquid crystal coating layer located on the side of the substrate opposite to the flexible display panel; the liquid crystal coating layer has a coating avoidance area in the region corresponding to the camera, and the orthographic projection of the camera onto the liquid crystal polarizing structure at least partially overlaps with the coating avoidance area.
14. The flexible display screen as described in claim 13, characterized in that, The liquid crystal polarizing structure further includes: a developing layer located within the coating avoidance area, wherein the contact angle of the developing layer is greater than 90 degrees; The developing layer is used to prevent the liquid crystal coating layer from being coated in the coating avoidance area during the formation of the liquid crystal coating layer.
15. The flexible display screen as described in claim 14, characterized in that, The material of the developing layer includes fluorinated alkylsilanes.
16. The flexible display screen as described in claim 13, characterized in that, The substrate in the liquid crystal polarization structure includes a pressure-sensitive adhesive layer, a quarter-wavelength retardation layer, an ultraviolet light cutoff layer, a half-wavelength retardation layer, and a dielectric layer stacked sequentially. The pressure-sensitive adhesive layer is located on the side close to the flexible display panel, and the liquid crystal coating layer is disposed on the dielectric layer.
17. The flexible display screen as described in claim 16, characterized in that, The liquid crystal polarizing structure further includes a primer layer located between the dielectric layer and the liquid crystal coating layer, wherein the primer layer is made of silane.
18. The flexible display screen as described in claim 13, characterized in that, It also includes a cover plate located on the side of the liquid crystal polarizing structure opposite to the flexible display panel.
19. A terminal, characterized in that, include: The housing and the flexible display screen as described in any one of claims 10 to 18; The housing contains a spool and an opening. The first end of the flexible display screen is wound around the spool, and the second end enters and exits the housing through the opening as the spool rotates.