Protective film, inner folding display module and electronic device

Abstract

The embodiment of the application provides a protective film, an inner folding display module and electronic equipment. The protective film is applied to the inner folding display module. The protective film comprises: a transparent adhesive layer, a base film layer and a surface layer which are sequentially stacked; the upper surface of the base film layer close to the surface layer has a base film layer recess; part of the surface layer is located in the base film layer recess, and the surface layer away from the upper surface of the base film layer has a surface layer recess; the base film layer recess and the surface layer recess are both located in a predicted pair wear area of the protective film; the predicted pair wear area is located in a first non-rotation shaft area and / or a second non-rotation shaft area of the protective film; in an inner folding state of the protective film, the first non-rotation shaft area and the second non-rotation shaft area are stacked and distributed. The protective film reduces the wear damage of the predicted pair wear area, slows down the wear of the predicted pair wear area, improves the wear resistance of the predicted pair wear area, improves the clarity and the aesthetic degree of the inner folding display screen, and thus improves the user experience.

Description

Technical Field

[0001] This application relates to the field of accessories for electronic devices, and in particular to a protective film, an inward-folding display module, and electronic devices. Background Technology

[0002] Currently, foldable electronic devices that bend inward, such as inward-folding mobile phones, include an inward-folding display screen that includes a stacked display panel and a protective film that protects the inward-folding display screen.

[0003] When foldable electronic devices fold inwards, the inward-folding display undergoes slight deformation. A portion of the protective film outside the hinge area will bulge slightly, and this bulge will rub against its corresponding area. Over prolonged use, this friction causes wear and tear on the protective film. Because the protective film has relatively poor abrasion resistance, it suffers significant wear and tear over extended periods, affecting the clarity and aesthetics of the inward-folding display and resulting in a poor user experience. Summary of the Invention

[0004] This application provides a protective film, an inward-folding display module, and an electronic device to improve the wear resistance of the predicted wear area in the protective film, reduce wear damage in the predicted wear area in the protective film, and improve the clarity and aesthetics of the inward-folding display module, thereby enhancing the user experience.

[0005] To achieve the above objectives, this application provides the following technical solution:

[0006] In a first aspect, this application provides a protective film applied to an inwardly folded display module; the protective film includes: a transparent adhesive layer, a base film layer, and a surface layer stacked sequentially; wherein, the upper surface of the base film layer near the surface layer has a base film layer recess; a portion of the surface layer is located within the base film layer recess, and the upper surface of the surface layer away from the base film layer has a surface layer recess; both the base film layer recess and the surface layer recess are located within the predicted wear area of ​​the protective film; the predicted wear area is located within a first non-rotation axis region and / or a second non-rotation axis region of the protective film; in the inwardly folded state of the protective film, the first non-rotation axis region and the second non-rotation axis region are stacked and distributed.

[0007] As can be seen from the above, in the protective film, the upper surface of the base film layer has a base film layer recess; the surface layer is located within the base film layer recess, and the upper surface of the surface layer has a surface layer recess. Thus, the base film layer recess provides space to accommodate part of the surface layer. With the surface layer recess on the upper surface of the surface layer, thinning of the surface layer is avoided, which helps to ensure the mechanical and light properties of the protective film. The surface layer recess is located within the predicted wear area. Therefore, when the inward-folding phone is in the folded state, the recess can prevent the predicted wear area from bulging (or reduce the degree of bulging) in the predicted wear area, thus ensuring that the two opposing predicted wear areas... The recessed portion prevents contact and friction between the two predicted wear areas (or reduces the degree of friction between the two opposing predicted wear areas); for the predicted wear area opposite the slightly raised predicted wear area, the recessed portion can provide clearance space for the slightly raised predicted wear area. This clearance space can be understood as extra non-contact space, so that the two opposing predicted wear areas cannot contact and rub against each other (or can reduce the degree of friction between the two opposing predicted wear areas). Based on this, the protective film reduces wear damage to the predicted wear area and slows down the wear of the predicted wear area, effectively improving the wear resistance of the predicted wear area, enhancing the clarity and aesthetics of the inward folding display, and thus improving the user experience.

[0008] As can be seen from the above, the protective film can improve the wear resistance of the predicted abrasion area while ensuring its mechanical and light performance, and enhance the clarity and aesthetics of the inward-folding display screen, thereby improving the user experience.

[0009] In one possible implementation, a first hardening layer is disposed within the recess of the base film layer. The hardness of the first hardening layer is greater than that of the base film layer, and the thickness of the first hardening layer is less than the depth of the recess of the base film layer. A surface layer is stacked on the base film layer and the first hardening layer.

[0010] As can be seen from the above, since the hardness of the first hardened layer is greater than that of the base film layer, the addition of the first hardened layer effectively increases the hardness of the predicted wear area in the protective film. This reduces the degree of protrusion in the predicted wear area due to the creep of the inward-folding display screen, and also reduces the degree of protrusion due to protruding components. This effectively reduces wear damage in the predicted wear area, slows down wear, and improves the wear resistance of the predicted wear area, enhancing the clarity and aesthetics of the inward-folding display screen, thereby improving the user experience. Based on this, the combined effect of the first hardened layer and the surface recess further reduces and slows down wear damage in the predicted wear area, further improves the wear resistance of the predicted wear area, further enhances the clarity and aesthetics of the inward-folding display screen, and further improves the user experience. Simultaneously, because the first hardened layer reduces the protrusion of the predicted wear area, the depth of the surface recess can be reduced, and correspondingly, the depth of the base film recess can be reduced.

[0011] In one possible implementation, the surface layer includes a functional layer, which is stacked in the base film layer on the side away from the transparent adhesive layer, and the upper surface of the functional layer away from the base film layer is the upper surface of the surface layer.

[0012] As can be seen from the above, the functional layer can realize the specific optical functions of the protective film and improve the display quality of the inward folding display module.

[0013] In one possible implementation, the functional layer includes a first sub-functional layer and a second sub-functional layer; wherein the first sub-functional layer is located in the predicted wear area and corresponds to the base film layer recess, and the second sub-functional layer is located in other areas of the protective film besides the predicted wear area, and the first sub-functional layer and the second sub-functional layer cooperate to form the surface recess; the upper surfaces of the first sub-functional layer and the second sub-functional layer that are away from the base film layer are both planar.

[0014] As can be seen from the above, a fault structure can appear at the connection between the first sub-functional layer and the second sub-functional layer, which facilitates the setting of the first and second sub-functional layers and also makes it easier to ensure the formation of surface depressions in the predicted wear area.

[0015] In one possible implementation, the upper surface of the first sub-functional layer away from the base film layer and the lower surface of the second sub-functional layer near the base film layer are flush; or, the upper surface of the first sub-functional layer away from the base film layer and the lower surface of the second sub-functional layer near the base film layer are distributed sequentially along the stacking direction.

[0016] As can be seen from the above, the upper surface of the first sub-functional layer that is far from the base film layer and the lower surface of the second sub-functional layer that is close to the base film layer are set flush, which makes it easy to ensure that the depth of the surface recess meets the requirements. By adjusting the relative positional relationship between the upper surface of the first sub-functional layer and the lower surface of the second sub-functional layer in the stacking direction, the depth of the surface recess can be adjusted to ensure that the depth of the surface recess meets the requirements.

[0017] In one possible implementation, the surface layer further includes a second hardened layer, which is stacked between the base film layer and the functional layer; wherein a portion of the second hardened layer is located within a recess in the base film layer, and the second hardened layer has a hardened layer recess near the upper surface of the functional layer, the hardened layer recess being located within the predicted wear area; a portion of the functional layer is located within the hardened layer recess.

[0018] As can be seen from the above, the second hardened layer is attached to the upper surface of the base film layer and can serve as the base layer for the functional layer. This improves the adhesion of the functional layer to the surface of the base film layer, prevents easy peeling between the functional layer and the base film layer, improves the reliability of the protective film, and also helps to ensure the light performance of the protective film. Moreover, the second hardened layer can ensure the hardness of the protective film, so as to ensure the mechanical properties of the protective film.

[0019] In one possible implementation, the second hardened layer includes a first sub-hardened layer and a second sub-hardened layer; wherein the first sub-hardened layer is located within the predicted wear area and corresponds to the recess of the base film layer, and the second sub-hardened layer is located in other areas of the protective film besides the predicted wear area, and the first sub-hardened layer and the second sub-hardened layer cooperate to form the hardened layer recess; the upper surfaces of the first sub-hardened layer and the second sub-hardened layer that are away from the base film layer are both planar.

[0020] As can be seen from the above, a fault structure can appear at the junction of the first sub-hardening layer and the second sub-hardening layer, which facilitates the setting of the first sub-hardening layer and the second sub-hardening layer, and also makes it easier to ensure the formation of hardening layer depressions in the predicted wear area.

[0021] In one possible implementation, the upper surface of the first sub-hardening layer away from the base film layer and the lower surface of the second sub-hardening layer near the base film layer are flush; or, the upper surface of the first sub-hardening layer away from the base film layer and the lower surface of the second sub-hardening layer near the base film layer are distributed sequentially along the stacking direction.

[0022] As can be seen from the above, the upper surface of the first sub-hardening layer that is far from the base film layer and the lower surface of the second sub-hardening layer that is close to the base film layer are set flush, which makes it easy to ensure that the depth of the hardening layer recess meets the requirements. By adjusting the relative positional relationship between the upper surface of the first sub-hardening layer and the lower surface of the second sub-hardening layer in the stacking direction, the depth of the hardening layer recess can be adjusted to ensure that the depth of the hardening layer recess meets the requirements.

[0023] In one possible implementation, the transparent adhesive layer is one layer; or, the transparent adhesive layer is at least two layers stacked sequentially, with an elastic layer stacked between adjacent transparent adhesive layers, and the transparent adhesive layer and the elastic layer are located on the same side of the base film layer.

[0024] In one possible implementation, the base film layer is a cast film.

[0025] As can be seen from the above, the base film layer is a cast film. Therefore, using the casting process to process the base film layer makes it easier to set the base film layer recesses, which simplifies the processing of the base film layer.

[0026] Secondly, this application provides another protective film, which is applied to an inwardly folded display module. The protective film includes: a transparent adhesive layer, a base film layer, and a surface layer stacked sequentially. The base film layer has a recessed portion near the upper surface of the surface layer, and a first hardened layer is disposed within the recessed portion. The hardness of the first hardened layer is greater than that of the base film layer. Both the recessed portion and the first hardened layer are located within the predicted wear area of ​​the protective film. The surface layer is located on the same side as the base film layer and the first hardened layer. The predicted wear area is located within a first non-rotational axis region and / or a second non-rotational axis region of the protective film. In the inwardly folded state of the protective film, the first and second non-rotational axis regions are stacked and distributed.

[0027] As can be seen from the above, the upper surface of the base film layer has a base film layer recess; the first hardening layer is located within the base film layer recess. This provides space for the first hardening layer, avoiding or reducing its impact on the surface layer, thus ensuring the mechanical and optical properties of the protective film. Since the hardness of the first hardening layer is greater than that of the base film layer, the addition of the first hardening layer effectively increases the hardness of the predicted wear area in the protective film, reducing the degree of protrusion caused by the creep of the inward-folding display screen and also reducing the degree of protrusion caused by protruding components. This effectively reduces wear damage in the predicted wear area and slows down wear, effectively improving the wear resistance of the predicted wear area, enhancing the clarity and aesthetics of the inward-folding display screen, and thus improving the user experience.

[0028] As can be seen from the above, the protective film can improve the wear resistance of the predicted abrasion area while ensuring its mechanical and light performance, and enhance the clarity and aesthetics of the inward-folding display screen, thereby improving the user experience.

[0029] In one possible implementation, the thickness of the first hardened layer is equal to the depth of the recess in the base film layer; and / or, the upper surface of the surface layer away from the base film layer is planar.

[0030] As can be seen from the above, the thickness of the first hardened layer is equal to the depth of the recessed portion of the base film layer, which facilitates the setting of the surface layer and avoids the first hardened layer from affecting the surface layer, thus ensuring the mechanical and optical properties of the protective film.

[0031] In one possible implementation, the surface layer includes a functional layer, which is stacked on the base film layer and the first hardened layer, and the upper surface of the functional layer away from the base film layer is the upper surface of the surface layer away from the base film layer.

[0032] As can be seen from the above, the functional layer can realize the specific optical functions of the protective film and improve the display quality of the inward folding display module.

[0033] In one possible implementation, the surface layer further includes a second hardening layer, which is stacked on the same side as the base film layer and the first hardening layer, and the functional layer is stacked on the side of the second hardening layer away from the transparent adhesive layer.

[0034] As can be seen from the above, the second hardened layer is attached to the upper surface of the base film layer and the first hardened layer. It can serve as the base layer for the functional layer, improve the adhesion of the functional layer to the surface of the base film layer, prevent easy peeling between the functional layer and the base film layer, improve the reliability of the protective film, and also help ensure the light performance of the protective film. Moreover, the second hardened layer can ensure the hardness of the protective film, so as to ensure the mechanical properties of the protective film.

[0035] In one possible implementation, the hardness of the first hardened layer is not less than the hardness of the second hardened layer; and / or, the upper surface of the second hardened layer near the functional layer is planar.

[0036] As can be seen from the above, the hardness of the first hardened layer is not less than that of the second hardened layer, effectively improving the hardness of the predicted wear zone. The upper surface of the second hardened layer near the functional layer is planar, facilitating the installation of the functional layer and ensuring its performance, thereby ensuring the mechanical and optical properties of the protective film.

[0037] In one possible implementation, the transparent adhesive layer is one layer; or, the transparent adhesive layer is at least two layers stacked sequentially, with an elastic layer stacked between adjacent transparent adhesive layers, and the elastic layer and the transparent adhesive layer are located on the same side of the base film layer.

[0038] In one possible implementation, the base film layer is a cast film.

[0039] As can be seen from the above, the base film layer is a cast film. Therefore, using the casting process to process the base film layer makes it easier to set the base film layer recesses, which simplifies the processing of the base film layer.

[0040] Thirdly, this application provides an inwardly folding display module, which includes: a display panel, and a protective film as proposed in the first aspect, the second aspect, or any possible implementation thereof; wherein the protective film is connected to the display side of the display panel.

[0041] As can be seen from the above, the inward folding display module in this application includes the protective film proposed in the first aspect, the second aspect, or any possible implementation. Therefore, the inward folding display module with the protective film also has all the above-mentioned technical effects, which will not be repeated here.

[0042] Fourthly, this application provides an electronic device, which includes: a housing, and the inwardly folding display module as described in the third aspect; wherein the inwardly folding display module is connected to the housing.

[0043] As can be seen from the above, the electronic device in this application includes the inward folding display module proposed in the third aspect. Therefore, the electronic device with the inward folding display module also has all the above-mentioned technical effects, which will not be repeated here. Attached Figure Description

[0044] Figure 1 This is a front view of the protective film in its unfolded state in conventional technology.

[0045] Figure 2 This is a schematic diagram of the structure of a protective film in conventional technology;

[0046] Figure 3 An isometric view of an inwardly folding mobile phone in its unfolded state, as provided in an embodiment of this application.

[0047] Figure 4 This is a schematic diagram of an inwardly folding display screen provided in an embodiment of this application;

[0048] Figure 5 A front view of the protective film provided in the embodiments of this application in an unfolded state;

[0049] Figure 6 This is a schematic diagram of a single-layer membrane structure provided in the embodiments of this application;

[0050] Figure 7 A schematic diagram of a method for producing a protective film according to an embodiment of this application;

[0051] Figure 8 This is a schematic diagram of the structure of the cooling roller in the production method of the protective film provided in the embodiments of this application;

[0052] Figure 9 This is a schematic diagram of a cooling roller with a diaphragm provided in an embodiment of this application;

[0053] Figure 10 A schematic diagram of a multilayer film structure provided in the embodiments of this application;

[0054] Figure 11 This is another schematic diagram of a single-layer membrane structure provided in the embodiments of this application;

[0055] Figure 12 Another schematic diagram illustrating a method for producing the protective film provided in an embodiment of this application;

[0056] Figure 13 This application provides an embodiment of a protective film that is a multilayer film structure, which is another structural schematic diagram.

[0057] Figure 14 This is another schematic diagram of a single-layer membrane structure provided in the embodiments of this application. Detailed Implementation

[0058] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. The terminology used in the following embodiments is for the purpose of describing specific embodiments only and is not intended to be a limitation of this application. As used in the specification and appended claims of this application, the singular expressions "a," "an," "the," "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 embodiments of this application, "one or more" refers to one, two, or more; "and / or" describes the relationship between related objects, indicating that three relationships may exist; for example, A and / or B can represent: 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.

[0059] 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.

[0060] The term "multiple" in this application refers to two or more. It should be noted that in the description of this application, terms such as "first" and "second" are used only for descriptive purposes and should not be construed as indicating or implying relative importance or order.

[0061] The “plane” referred to in this application is a “plane that is substantially parallel to the horizontal plane” in actual operation.

[0062] Foldable electronic devices, such as foldable phones, are becoming increasingly popular due to their large screens and other advantages. Currently, foldable phones are mainly divided into two types: inward-folding phones (which can be understood as the screen bending inwards) and outward-folding phones (which can be understood as the screen bending outwards).

[0063] In an inward-folding phone, the inward-folding display screen includes a stacked display panel and a protective film. The protective film can protect the display screen from damage caused by external stress impacts and scratches from external foreign objects.

[0064] Please see Figure 1 , Figure 1 This is a front view of the protective film 01 in the unfolded state in conventional technology.

[0065] like Figure 1 As shown, the protective film 01 includes a first non-rotating axis region 011, a second non-rotating axis region 012, and a rotating axis region 013, wherein the rotating axis region 013 corresponds to the rotating axis assembly of the inward-folding mobile phone.

[0066] When an inward-folding phone is folded, the display screen will creep, causing the first sub-region 0111 of the first non-rotating region 011 and / or the second sub-region 0121 of the second non-rotating region 012 in the protective film 01 to bulge slightly. The first sub-region 0111 and the second sub-region 0121 are relatively distributed and rub against each other. During prolonged use by the user, the first sub-region 0111 and the second sub-region 0121 will experience some wear and tear from this friction.

[0067] In inward-folding phones, certain components protrude along the thickness of the display screen. These protruding components lift the display screen, causing the third, fourth, and fifth sub-regions 0112, 0113, and 0114 of the first non-hinge area 011 to bulge slightly. The sixth and third sub-regions 0122 of the second non-hinge area 012 are relatively distributed and rub against each other; the seventh and fourth sub-regions 0113 of the second non-hinge area 012 are relatively distributed and rub against each other; and the eighth and fifth sub-regions 0124 of the second non-hinge area 012 are relatively distributed and rub against each other. During prolonged use, these sub-regions will experience some wear and tear from this friction.

[0068] For example, the third sub-region 0112 corresponds to the phone box of the mobile phone, the fourth sub-region 0113 corresponds to the through-axis FPC (Flexible Printed Circuit) of the mobile phone, and the fifth sub-region 0114 corresponds to the back adhesive of the display screen of the mobile phone.

[0069] It should be noted that, Figure 1 In the diagram, the positions and shapes of the first sub-region 0111, the second sub-region 0121, the third sub-region 0112, the fourth sub-region 0113, the fifth sub-region 0114, the sixth sub-region 0122, the seventh sub-region 0123, and the eighth sub-region 0124 are only illustrative. Each region can also be located in other positions outside the rotation axis region or have other shapes.

[0070] Please see Figure 2 , Figure 2 This is a schematic diagram of the structure of the protective film 01 in conventional technology.

[0071] like Figure 2 As shown, the protective film 01 includes: a transparent adhesive layer 014, a base film layer 015, a hardening layer 016, and a functional layer 017 stacked sequentially along its thickness direction; wherein, the transparent adhesive layer 014 is stacked on the display panel; the functional layer 017 and the hardening layer 016 are both integral coatings, and the base film layer 015 has a flat design.

[0072] In order to meet the high and low temperature and room temperature bending performance requirements of the pivot area 013 of the protective film 01, the hardness of the hardened layer 016 and the functional layer 017 cannot be too high, and the functional layer 017 cannot contain high wear-resistant particles (if high wear-resistant particles are added to the functional layer 017, cracks will appear in the protective film 01 when it is bent at high and low temperatures and room temperature, reducing the high and low temperature and room temperature bending performance of the protective film 01), thus reducing the wear resistance (friction resistance) of the hardened layer 016 and the functional layer 017.

[0073] As mentioned earlier, during prolonged use, some areas of the protective film 01 will experience wear and tear from friction, primarily affecting the functional layer 017. Due to the relatively low wear resistance of the hardened layer 016 and the functional layer 017, the functional layer 017 suffers more wear and damage, which can even extend to the hardened layer 016. Therefore, prolonged use results in significant wear and tear on the protective film 01, impacting the clarity and aesthetics of the display screen and reducing the user experience.

[0074] In view of the above problems, this application provides a protective film, an inward folding display screen, and an electronic device to improve the wear resistance of the wear-resistant areas in the protective film, reduce wear damage in the wear-resistant areas of the protective film, improve the clarity and aesthetics of the inward folding display screen, and thus enhance the user experience.

[0075] The electronic device provided in this application is a type of electronic device including an inward-folding display screen. This electronic device can be a mobile phone, tablet computer, wearable device, in-vehicle device, augmented reality (AR) / virtual reality (VR) device, laptop computer, ultra-mobile personal computer (UMPC), netbook, personal digital assistant (PDA), digital camera, SLR / mirrorless camera, action camera, gimbal camera, drone, or other electronic devices with inward-folding functionality. This application does not limit the specific type of electronic device. For ease of understanding, the following description uses an inward-folding mobile phone as an example.

[0076] Please see Figure 3 , Figure 3 This is an isometric view of an inward-folding mobile phone 100 in its unfolded state, according to some embodiments of this application. The inward-folding mobile phone 100 is approximately rectangular. Based on this, for the convenience of the following description of the embodiments, an XYZ coordinate system is established, defining the width direction of the inward-folding mobile phone 100 as the X-axis, the length direction as the Y-axis, and the thickness direction as the Z-axis. The X, Y, and Z axes are mutually perpendicular. It should be noted that the coordinate system settings of the inward-folding mobile phone 100 can be flexibly set according to actual needs, and are not specifically limited here.

[0077] like Figure 3 As shown, the inward-folding phone 100 includes a housing 2 and an inward-folding display screen 1, which is connected to the housing 2. The inward-folding display screen 1 can be understood as a form of inward-folding display module.

[0078] The housing 2 is a foldable structure and may include a first housing 201, a second housing 202, and a pivot assembly 203. The first housing 201 and the second housing 202 are located on both sides of the pivot assembly 203, and the first housing 201, the pivot assembly 203, and the second housing 202 are distributed sequentially along the X-axis. Of course, the first housing 201, the pivot assembly 203, and the second housing 202 may be distributed sequentially along the Y-axis, and are not limited to this arrangement. Figure 3 The structure shown.

[0079] The first housing 201 and the second housing 202 are respectively connected to the pivot assembly 203. The first housing 201 and the second housing 202 can rotate relative to each other through the pivot assembly 203, so that the housing 2 (inward folding phone 100) can be in a folded state and an unfolded state. When the inward folding phone 100 is in the folded state, the first housing 201 and the second housing 202 are stacked and present a two-layer structure.

[0080] The inward-folding display screen 1 is used to display images, videos, etc. The inward-folding display screen 1 includes a first display area 101, a second display area 102, and a third display area 103. The first display area 101 is correspondingly arranged with the first housing 201, the second display area 102 is correspondingly arranged with the second housing 202, and the third display area 103 is correspondingly arranged with the hinge assembly 203.

[0081] The inward-folding display screen 1 can be understood as a flexible display screen. The inward-folding display screen 1 itself has bendable properties and can deform under external force. When the housing 2 is in the folded state, the inward-folding display screen 1 is also folded, with the first display area 101 and the second display area 102 stacked, and the third display area 103 can be bent into an arc shape. When the housing 2 is in the unfolded state, the inward-folding display screen 1 is also unfolded, and the first display area 101, the second display area 102, and the third display area 103 are in a flat state.

[0082] Foldable phone 100 Figure 3 The unfolded state shown enables a large-screen display, providing users with richer information and a better user experience. When the inward-folding phone 100 is in the folded state, its size is reduced, making it easier to carry.

[0083] Please see Figure 4 , Figure 4 This is a schematic diagram illustrating the structure of an inwardly folding display screen provided in some embodiments of this application. It should be noted that... Figure 4 Only a portion of the inward-folding display 1 is shown; the entire inward-folding display 1 is not shown.

[0084] like Figure 4As shown, the inward-folding display screen 1 includes a display panel 12 and a protective film 11 stacked sequentially along the Z-axis. The Z-axis can be understood as the thickness direction of the inward-folding display screen 1. In practice, the inward-folding display screen 1 may also include other components or structures, and is not limited to these. Figure 4 The display panel 12 and protective film 11 are shown.

[0085] Display panel 12 is the main component for displaying images and videos. Specifically, display panel 12 can be an organic light-emitting diode (OLED) display panel, a micro-organic light-emitting diode (Micro-OLED) display panel, or a quantum dot light-emitting diode (QLED) display panel. Display panel 12 has a display side and a back side opposite to the display side. The display side of display panel 12 refers to the side of display panel 12 that displays images or videos, and the user can view the images or videos displayed on display panel 12 from this display side.

[0086] The protective film 11 is located on the display side of the display panel 12. The protective film 11 can protect the inward folding display screen 1 to prevent damage to the inward folding display screen 1 during use.

[0087] The structure of the protective film 11 is described in detail below. Please refer to [link / reference]. Figure 5 , Figure 5 A front view of the protective film 11 provided in some embodiments of this application in an unfolded state.

[0088] like Figure 5 As shown, the protective film 11 includes a first non-rotational region 1101, a second non-rotational region 1102, and a rotational region 1103. The first non-rotational region 1101 and the second non-rotational region 1102 can both be understood as non-rotational regions.

[0089] The first non-rotating hinge area 1101 corresponds to the first display area 101 of the inward-folding display screen 1, and also to the first housing 201 of the housing 2; the second non-rotating hinge area 1102 corresponds to the second display area 102 of the inward-folding display screen 1, and also to the second housing 202 of the housing 2; the hinge area 1103 corresponds to the third display area 103 of the inward-folding display screen 1, and also to the hinge assembly 203 of the housing 2. In the inward-folded state of the protective film 11, the first non-rotating hinge area 1101 and the second non-rotating hinge area 1102 are stacked. It should be noted that the inward-folded state of the protective film 11 refers to the state of the protective film 11 when the inward-folding phone 100 is in the folded state.

[0090] In order to improve the wear resistance of the wear-resistant area in the protective film 11, some embodiments of this application provide specific structures of the protective film 11.

[0091] Please see Figure 6 , Figure 6 This is a schematic diagram of the structure of the protective film 11 provided in some embodiments of this application. It should be noted that... Figure 6 Only a portion of the protective film 11 is shown; the entire protective film 11 is not shown. Figure 6 The protective film 11 shown is a single-layer film structure, which can be understood as a film structure including a layer of transparent adhesive.

[0092] like Figure 6 As shown, the protective film 11 includes: a first transparent adhesive layer 111, a base film layer 112, a hardening layer 113, and a functional layer 114, which are sequentially stacked along the Z-axis direction; wherein, the Z-axis direction can be understood as the thickness direction of the protective film 11, the thickness direction of the first transparent adhesive layer 111, the thickness direction of the base film layer 112, the thickness direction of the hardening layer 113, and the thickness direction of the functional layer 114; the first transparent adhesive layer 111 is stacked on the display side of the display panel 12.

[0093] The first transparent adhesive layer 111 is used to bond the entire protective film 11 to the display panel 12. The first transparent adhesive layer 111 can be OCA (Optically Clear Adhesive) optical adhesive, or OCR (Optical Clear Resin) liquid optical adhesive, etc. The type of the first transparent adhesive layer 111 is not limited in this application embodiment.

[0094] It should be noted that the first transparent adhesive layer 111 can be understood as a manifestation of the transparent adhesive layer.

[0095] The base film layer 112 can improve the hardness and smoothness of the protective film 11 and enhance the surface damage resistance of the protective film 11. Therefore, the base film layer 112 affects the mechanical properties of the protective film 11.

[0096] The base film layer 112 can be made of PET (polyethylene glycol terephthalate), PC (polycarbonate), or PMMA (polymethyl methacrylate). PET, as the substrate layer of the protective film 11, has high hardness, providing the protective film 11 with high abrasion resistance and scratch resistance. Of course, the material of the base film layer 112 is not limited to the above; it can also be other materials suitable for thin films that possess the aforementioned properties.

[0097] The hardened layer 113 adheres to the surface of the base film layer 112 and also serves as the underlayer for the functional layer 114, improving the adhesion of the functional layer 114 to the surface of the base film layer 112 and preventing easy peeling between the functional layer 114 and the base film layer 112. This enhances the reliability of the protective film 11 and helps ensure the light performance of the protective film 11. Furthermore, the hardened layer 113 ensures the hardness of the protective film 11, thus guaranteeing its mechanical properties. Therefore, the hardened layer 113 affects both the optical and mechanical properties of the protective film 11.

[0098] The hardened layer 113 can be an HC (Hard, Coating) coating or other types. The material of the hardened layer 113 can be an acrylic ester material, a PUA-based material, a silane-modified acrylic ester material, or a silane-modified PUA-based material, etc., and this application embodiment does not limit this. The hardened layer 113 can be set by coating or other methods. To facilitate the setting of the hardened layer 113, it can be set by coating, which can be understood as the hardened layer 113 being a coating layer.

[0099] It should be noted that the hardened layer 113 can be understood as a manifestation of the second hardened layer.

[0100] The functional layer 114 affects the optical and mechanical properties of the protective film 11. The functional layer 114 can achieve specific optical functions, improving the display quality of the inward-folding display screen 1. For example, the functional layer may include one or more of an anti-reflective layer, an anti-glare layer, an anti-fingerprint layer, and an antistatic layer. The anti-reflective layer can increase the transmittance of light on the surface of the protective film 11 and reduce the reflectivity of light on the surface of the protective film 11, ensuring the anti-reflective effect of the protective film 11, reducing the impact of the protective film 11 on the display clarity of the inward-folding display screen 1, and improving the user experience. For example, the anti-reflective layer is an AR / LR (Anti-Reflection / Low-Reflective) optical coating. The anti-glare layer can reduce the adverse effects of glare. The anti-fingerprint layer can prevent the inward-folding display screen 1 from being contaminated by dust and grease, reducing fingerprint adhesion and improving product cleanliness. The antistatic layer has antistatic properties, ensuring the antistatic properties of the protective film 11, preventing the adsorption of dust and impurities on the surface of the protective film 11, thereby improving the display quality of the inward-folding display screen 1.

[0101] Functional layer 114 can be set by coating or other methods. To facilitate the setting of functional layer 114, functional layer 114 can be set by coating, which can be understood as functional layer 114 being a coating layer.

[0102] Both the functional layer 114 and the hardening layer 113 can be understood as part of the surface structure of the protective film 11.

[0103] In the protective film 11, the surface of the base film layer 112 furthest from the first transparent adhesive layer 111 can be referred to as the upper surface, and the surface of the base film layer 112 closest to the first transparent adhesive layer 111 can be referred to as the lower surface; the surface of the hardened layer 113 closest to the functional layer 114 (the surface of the hardened layer 113 furthest from the first transparent adhesive layer 111 and the surface of the hardened layer 113 furthest from the base film layer 112) can be referred to as the upper surface; the surface of the hardened layer 113 furthest from the functional layer 114 (the surface of the hardened layer 113 furthest from the first transparent adhesive layer 111 and the surface of the hardened layer 113 furthest from the base film layer 112) can be referred to as the lower surface. The surface of layer 11 (the surface of the hardened layer 113 near the base film layer 112) can be called the lower surface; the surface of the functional layer 114 away from the hardened layer 113 (the surface of the functional layer 114 away from the base film layer 112, the surface of the functional layer 114 away from the first transparent adhesive layer 111) can be called the upper surface; the surface of the functional layer 114 near the hardened layer 113 (the surface of the functional layer 114 near the base film layer 112, the surface of the functional layer 114 near the first transparent adhesive layer 111) can be called the lower surface.

[0104] The surface of the protective film 11 closest to the first transparent adhesive layer 111 can be referred to as the lower surface, and the surface of the protective film 11 furthest from the first transparent adhesive layer 111 can also be referred to as the lower surface. The lower surface of the first transparent adhesive layer 111 can be understood as the lower surface of the protective film 11, and the upper surface of the functional layer 114 can be understood as the upper surface of the protective film 11, or as a manifestation of the upper surface of the surface layer. It should be noted that the upper surface of the surface layer is the same as the upper surface of the protective film 11.

[0105] The upper surface of the base film layer 112 has a base film layer recess 115; a portion of the hardened layer 113 is located within the base film layer recess 115, and the upper surface of the hardened layer 113 has a hardened layer recess 116; a portion of the functional layer 114 is located within the hardened layer recess 116, and the upper surface of the functional layer 114 has a functional layer recess 117. It should be noted that the functional layer recess 117 can be understood as a manifestation of a surface layer recess.

[0106] The base film layer recess 115, the hardened layer recess 116, and the functional layer recess 117 are all located within the predicted wear region of the protective film 11. These recesses are sequentially distributed along the Z-axis within the predicted wear region. The predicted wear region is located within the first non-rotational region 1101 and / or the second non-rotational region 1102 of the protective film 11.

[0107] It should be noted that the predicted wear area can be the wear area of ​​the protective film 11 identified based on the wear test of the inner screen of the inward-folding phone 100. The wear test of the inner screen of the inward-folding phone 100 can be understood as the wear test of the folding of the inward-folding phone 100, which is a test well known to those skilled in the art and will not be described in detail here. For example, by conducting a limited number of folding wear tests, areas in the protective film 11 with relatively severe wear (areas with wear exceeding a set wear level) are obtained, and these areas with relatively severe wear can be called the predicted wear area.

[0108] The wear regions mentioned above can be understood as predicted wear regions. Based on this, the first sub-region 0111, the second sub-region 0121, the third sub-region 0112, the fourth sub-region 0113, the fifth sub-region 0114, the sixth sub-region 0122, the seventh sub-region 0123, and the eighth sub-region 0124 mentioned above can all be understood as a manifestation of the predicted wear regions.

[0109] The projection of any one of the base film layer recess 115, the hardened layer recess 116, and the functional layer recess 117 onto the upper surface of the protective film 11 can be the same as or different from the projection of the predicted wear area onto the upper surface of the protective film 11. To maximize the wear resistance of the predicted wear area in the protective film 11, the projection of the recess (any one of the base film layer recess 115, the hardened layer recess 116, and the functional layer recess 117) onto the upper surface of the protective film 11 can be chosen to cover the projection of the predicted wear area onto the upper surface of the protective film 11. For example, the recess and the projection of the predicted wear area onto the upper surface of the protective film 11 can have the same shape and size. Alternatively, the projection of the recess onto the upper surface of the protective film 11 can be chosen not to cover the projection of the predicted wear area onto the upper surface of the protective film 11, as long as the projection of the recess onto the upper surface of the protective film 11 falls within the projection of the predicted wear area onto the upper surface of the protective film 11.

[0110] In the aforementioned protective film 11, the upper surface of the base film layer 112 has a base film layer recess 115; a portion of the hardened layer 113 is located within the base film layer recess 115, and the upper surface of the hardened layer 113 has a hardened layer recess 116; a portion of the functional layer 114 is located within the hardened layer recess 116. Thus, the base film layer recess 115 provides space for accommodating a portion of the hardened layer, and the hardened layer recess 116 provides space for accommodating a portion of the functional layer. With the functional layer recess 117 on the upper surface of the functional layer 114, the thinning of the hardened layer 113 and the functional layer 114 is avoided, thus ensuring the mechanical and optical properties of the protective film 11.

[0111] It should be noted that the base film layer 112 is thicker than the hardened layer 113 and the functional layer 114. The base film layer recess 115 has little effect on the base film layer 112, and the effect of the base film layer recess 115 on the mechanical and optical properties of the protective film 11 can be ignored.

[0112] In the aforementioned protective film 11, the upper surface of the functional layer 114 has a functional layer recess 117, which is located within the predicted wear area. Thus, when the inward-folding phone 100 is in the folded state, the recess can prevent the predicted wear area from bulging (or reduce the degree of bulging) of the slightly raised predicted wear area, preventing the two opposing predicted wear areas from contacting and rubbing against each other (or reducing the degree of rubbing between the two opposing predicted wear areas). For the predicted wear area opposite to the slightly raised predicted wear area, the recess can provide clearance space for the slightly raised predicted wear area. This clearance space can be understood as extra non-contact space, preventing the two opposing predicted wear areas from contacting and rubbing against each other (or reducing the degree of rubbing between the two opposing predicted wear areas). Therefore, the protective film 11 reduces wear damage in the predicted wear area and slows down wear in the predicted wear area, effectively improving the wear resistance of the predicted wear area, enhancing the clarity and aesthetics of the inward folding display screen 1, and thus improving the user experience.

[0113] It should be noted that the above-mentioned protective film 11 can maintain the hardness of the hardened layer 113 and the functional layer 114 without increasing the hardness of the hardened layer 113 and the functional layer 114. It can meet the high and low temperature and room temperature bending performance of the rotating area 1103 of the protective film 11, thereby ensuring the mechanical properties of the protective film 11.

[0114] Therefore, the aforementioned protective film 11 can improve the wear resistance of the predicted abrasion area while ensuring its mechanical and optical properties, thereby enhancing the clarity and aesthetics of the inward-folding display screen 1 and improving the user experience. The depths of the base film layer recess 115, the hardened layer recess 116, and the functional layer recess 117 in the protective film 11 can be selected according to actual conditions, and this embodiment does not limit this. It should be noted that the depth direction of the base film layer recess 115, the hardened layer recess 116, and the functional layer recess 117 is the Z-axis direction.

[0115] In some embodiments, the hardened layer 113 includes a first sub-hardened layer 1131 and a second sub-hardened layer 1132. The first sub-hardened layer 1131 is located within the predicted wear region and corresponds to the base film layer recess 115, while the second sub-hardened layer 1132 is located within the unpredicted wear region. The first sub-hardened layer 1131 and the second sub-hardened layer 1132 cooperate to form a hardened layer recess 116. The upper surfaces of both the first sub-hardened layer 1131 and the second sub-hardened layer 1132 that are away from the base film layer 112 are planar. This allows for a discontinuous structure at the junction of the first sub-hardened layer 1131 and the second sub-hardened layer 1132, facilitating the installation of both layers and ensuring the formation of the hardened layer recess 116 within the predicted wear region.

[0116] It should be noted that the upper surface of the first sub-hardening layer 1131 and the upper surface of the second sub-hardening layer 1132 form the upper surface of the hardening layer 113, and the lower surface of the first sub-hardening layer 1131 and the lower surface of the second sub-hardening layer 1132 form the lower surface of the hardening layer 113.

[0117] The upper surface of the first sub-hardening layer 1131, which is away from the base film layer 112, and the lower surface of the second sub-hardening layer 1132, which is close to the base film layer 112, can be flush. This makes it easier to ensure that the depth of the hardening layer recess 116 meets the requirements.

[0118] Of course, the upper surface of the first sub-hardening layer 1131 away from the base film layer 112 and the lower surface of the second sub-hardening layer 1132 near the base film layer 112 can be sequentially distributed along the Z-axis direction (lamination direction). For example, the upper surface of the first sub-hardening layer 1131 is closer to the first transparent adhesive layer 111 than the lower surface of the second sub-hardening layer 1132, or the upper surface of the first sub-hardening layer 1131 is farther away from the first transparent adhesive layer 111 than the lower surface of the second sub-hardening layer 1132.

[0119] In practice, the upper surface of the first sub-hardening layer 1131 can be closer to the first transparent adhesive layer 111 than the lower surface of the second sub-hardening layer 1132, and the upper surface of the first sub-hardening layer 1131 can be farther away from the first transparent adhesive layer 111 than the lower surface of the second sub-hardening layer 1132.

[0120] In the aforementioned protective film 11, by adjusting the relative positional relationship between the upper surface of the first sub-hardening layer 1131 and the lower surface of the second sub-hardening layer 1132 in the Z-axis direction, the depth of the hardening layer recess 116 can be adjusted, so that the depth of the hardening layer recess 116 meets the requirements.

[0121] To facilitate the fabrication of the hardened layer 113, it can be selected as a structure of uniform thickness, which can be understood as the first sub-hardened layer 1131 and the second sub-hardened layer 1132 having equal thicknesses. This also facilitates the formation of the hardened layer recess 116. Of course, the hardened layer 113 can also be selected as a structure of non-uniform thickness, and this embodiment does not limit this.

[0122] In some embodiments, the functional layer 114 includes a first sub-functional layer 1141 and a second sub-functional layer 1142; wherein the first sub-functional layer 1141 is located within the predicted wear region and corresponds to the base film layer recess 115 and the hardened layer recess 116; the second sub-functional layer 1142 is located within the unpredicted wear region; wherein the unpredicted wear region can be understood as other regions in the protective film 11 besides the predicted wear region; the first sub-functional layer 1141 and the second sub-functional layer 1142 cooperate to form a functional layer recess 117, and the upper surfaces of the first sub-functional layer 1141 and the second sub-functional layer 1142 away from the base film layer 112 are both planar. In this way, a discontinuous structure can appear at the connection between the first sub-functional layer 1141 and the second sub-functional layer 1142, which facilitates the setting of the first sub-functional layer 1141 and the second sub-functional layer 1142, and also facilitates the formation of the functional layer recess 117 within the predicted wear region.

[0123] It should be noted that the upper surface of the first sub-functional layer 1141 and the upper surface of the second sub-functional layer 1142 form the upper surface of the functional layer 114, and the lower surface of the first sub-functional layer 1141 and the lower surface of the second sub-functional layer 1142 form the lower surface of the functional layer 114. To ensure that the protective film 11 has a recessed portion, the sum of the thicknesses of the first sub-hardening layer 1131 and the first sub-functional layer 1141 is less than the depth of the recessed portion 115 of the base film layer, and the sum of the thicknesses of the second sub-hardening layer 1132 and the second sub-functional layer 1142.

[0124] The upper surface of the first sub-functional layer 1141, which is away from the base film layer 112, and the lower surface of the second sub-functional layer 1142, which is close to the base film layer 112, can be flush. This makes it easier to ensure that the depth of the functional layer recess 117 meets the requirements.

[0125] Of course, the upper surface of the first sub-functional layer 1141 away from the base film layer 112 and the lower surface of the second sub-functional layer 1142 near the base film layer 112 can be sequentially distributed along the Z-axis direction (lamination direction). For example, the upper surface of the first sub-functional layer 1141 is closer to the first transparent adhesive layer 111 than the lower surface of the second sub-functional layer 1142, or the upper surface of the first sub-functional layer 1141 is farther away from the first transparent adhesive layer 111 than the lower surface of the second sub-functional layer 1142.

[0126] In practice, the upper surface of the first sub-functional layer 1141 can be closer to the first transparent adhesive layer 111 than the lower surface of the second sub-functional layer 1142, and the upper surface of the first sub-functional layer 1141 can be farther away from the first transparent adhesive layer 111 than the lower surface of the second sub-functional layer 1142.

[0127] In the aforementioned protective film 11, by adjusting the relative positional relationship between the upper surface of the first sub-functional layer 1141 and the lower surface of the second sub-functional layer 1142 in the Z-axis direction, the depth of the functional layer recess 117 can be adjusted so that the depth of the functional layer recess 117 meets the requirements.

[0128] To facilitate the fabrication of functional layers 114, all functional layers 114 can be of uniform thickness, which can be understood as the first sub-functional layer 1141 and the second sub-functional layer 1142 having equal thicknesses. This also facilitates the formation of functional layer recesses 117, thereby ensuring that the entire protective film 11 has recesses. Of course, functional layers 114 can also be of non-uniform thickness, and this embodiment does not limit this.

[0129] The production method of the protective film 11 is described in detail below. Please refer to [link / reference needed]. Figure 7 , Figure 7 This is a schematic diagram of a method for producing the protective film 11 provided in some embodiments of this application.

[0130] like Figure 7 As shown, the method for producing the protective film 11 includes:

[0131] S11: Process the base film layer 112 so that the base film layer 112 has a base film layer recess 115 corresponding to the predicted wear area, the base film layer recess 115 being located on the upper surface of the base film layer 12.

[0132] S12: A hardening layer 113 is stacked on the upper surface of the base film layer 112 having a base film layer recess 115. A portion of the hardening layer 113 is located within the base film layer recess 115, and the upper surface of the hardening layer 113 has a hardening layer recess 116 at the corresponding base film layer recess 115.

[0133] S13: A functional layer 114 is stacked on the upper surface of the hardened layer 113 having a hardened layer recess 116. A portion of the functional layer 114 is located within the hardened layer recess 116, and the upper surface of the functional layer 114 has a functional layer recess 117 at the corresponding hardened layer recess 116.

[0134] S14: A first transparent adhesive layer 111 is stacked on the lower surface of the base film layer 112 away from the hardened layer 113 to obtain a protective film 11.

[0135] In S11, the predicted wear area is obtained in advance. Of course, it is optional that the predicted wear area is obtained by this method. In some embodiments, the method for producing the protective film 11 further includes S10 before S11: obtaining the predicted wear area of ​​the protective film 11 based on the folding wear test of the inward-folding mobile phone 100.

[0136] In S11, the base film layer 112 can be processed using a casting method (casting process), which can be understood as the base film layer 112 being a cast film. The casting process is a plastic film production process where an extruder plasticizes and melts the raw material and extrudes it into sheet material through a forming die. The sheet material is cast onto the surface of a rotating cooling roller, where it is cooled and shaped into a film. This film sheet can then be cut to form the base film layer 112.

[0137] Please see Figure 8 and Figure 9 , Figure 8 This is a schematic diagram of the structure of a cooling roller provided in some embodiments of this application. Figure 9 This is a schematic diagram of a cooling roller with a diaphragm provided in some embodiments of this application.

[0138] like Figure 8 and Figure 9 As shown, in order to achieve a base film layer 112 with a base film layer recess 115, the roller surface 210 of the cooling roller 200 is provided with a boss 220, and the diaphragm 300 is located on the roller surface 210. A film recess is formed in the diaphragm 300 at a position corresponding to the boss 220. The diaphragm 300 can be cut into the base film layer 112, and the film recess is the base film layer recess 115.

[0139] To ensure that the recessed portion 115 of the base film layer is located within the predicted wear area of ​​the protective film 11, the position of the protrusion 220 on the roller surface 210 is designed according to the location of the predicted wear area in the protective film 11. The shape, size, and number of the protrusion 220 are designed according to the predicted wear area in the protective film 11, and are not limited in this embodiment. The height of the protrusion 220 can be adjusted as needed to meet the mechanical and optical performance requirements of the base film layer 112, and is not limited in this embodiment either.

[0140] It should be noted that the height of the boss 220 is parallel to the radial direction of the cooling roller. Figure 8 and Figure 9 The shape, number, and distribution of the central boss 220 are merely illustrative and not the only embodiment.

[0141] The thickness of the base film layer 112 and the depth of the base film layer recess 115 are selected according to the actual situation, and the embodiments of this application do not limit this.

[0142] As can be seen from the above, the base film layer 112 is a cast film, which makes it easier to set the base film layer recess 115 on the base film layer 112 and simplifies the processing of the base film layer 112.

[0143] In S12, the hardening layer 113 can be formed by coating. Therefore, the hardening layer 113 is formed over the entire surface of the base film layer 112 containing the base film layer recess 115. This can be understood as coating the entire surface of the base film layer 112 containing the base film layer recess 115 with the hardening layer 113. Of course, other methods can be chosen to form the hardening layer 113, and this embodiment does not limit this approach.

[0144] The thickness of the hardened layer 113 can be selected according to the actual situation, and this application embodiment does not limit it.

[0145] In S13, the functional layer 114 can be formed by coating. Based on this, the functional layer 114 is stacked on the upper surface of the hardened layer 113 having the hardened layer recess 116. This can be understood as: the functional layer 114 is coated on the upper surface of the hardened layer 113 having the hardened layer recess 116. Of course, other methods can be chosen to form the functional layer 114, and this embodiment does not limit this.

[0146] The thickness of the functional layer 114 can be selected according to the actual situation, and this application embodiment does not limit it.

[0147] In S14, the specific arrangement and thickness of the first transparent adhesive layer 111 can be selected according to the actual situation, and this application embodiment does not limit this.

[0148] In the production method of protective film 11, S14 can also be selected between S11 and S12, or between S12 and S13, depending on the actual situation, and is not limited to the above embodiments.

[0149] As mentioned above, Figure 6 The protective film 11 shown is a single-layer film structure. In practice, the protective film 11 can also be a multi-layer film structure, which can be understood as a film structure including at least two transparent adhesive layers. Please refer to [link / reference]. Figure 10 , Figure 10 The protective film 11 provided in some embodiments of this application is a schematic diagram of a multilayer film structure. It should be noted that... Figure 10 Only a portion of the protective film 11 is shown; the entire protective film 11 is not shown.

[0150] like Figure 10As shown, the protective film 11 includes: a second transparent adhesive layer 119, an elastic layer 118, a first transparent adhesive layer 111, a base film layer 112, a hardening layer 113, and a functional layer 114, which are sequentially stacked along the Z-axis direction; wherein, the second transparent adhesive layer 119 is disposed on the display side of the display panel 12. It should be noted that the second transparent adhesive layer 119 can also be understood as a manifestation of the transparent adhesive layer.

[0151] For details regarding the first transparent adhesive layer 111, the base film layer 112, the hardening layer 113, and the functional layer 114, please refer to the preceding text; they will not be repeated here. For details regarding the second transparent adhesive layer 119, please refer to the first transparent adhesive layer 111; they will not be repeated here.

[0152] The aforementioned elastic layer 118 possesses a certain degree of elasticity. When the inward-folding display screen 1 is subjected to an external impact, the elastic layer 118 can buffer the impact, thereby protecting the inward-folding display screen 1 and preventing it from being damaged under the impact. In some embodiments, the elastic layer 118 is a TPU (thermoplastic polyurethane elastomer) component or a silicone component, etc. Among them, TPU has good elasticity, low cost, and good mechanical strength. TPU can be processed by injection, extrusion, calendering, and dissolving into solution resin, etc., and has good processing performance.

[0153] based on Figure 10 The protective film 11 shown, in the production method of the protective film 11, S4 further includes: stacking an elastic layer 118 on the lower surface of the first transparent adhesive layer 111 away from the base film layer 112, and stacking a second transparent adhesive layer 119 on the lower surface of the elastic layer 118 away from the first transparent adhesive layer 111.

[0154] In practice, multilayer membrane structures are not limited to Figure 10 The structure shown can also be modified so that the protective film 11 includes at least three layers of transparent adhesive layers stacked sequentially in the Z-circumferential direction; an elastic layer 118 is disposed between two adjacent transparent adhesive layers, and the elastic layer 118 and the transparent adhesive layer are located on the same side of the base film layer 112. The production method of the protective film 11 can be adaptively adjusted according to the number of transparent adhesive layers.

[0155] The structure of the protective film 11 described above can improve the wear resistance of the protective film 11 in the predicted abrasion-resistant areas. In practice, other protective film 11 structures can also improve the wear resistance of the predicted abrasion-resistant areas. Below, we will specifically describe another structure of the protective film 11 provided in some embodiments of this application.

[0156] Please see Figure 11 , Figure 11 This is another structural schematic diagram of the protective film 11 provided in some embodiments of this application. It should be noted that... Figure 11Only a portion of the protective film 11 is shown; the entire protective film 11 is not shown.

[0157] like Figure 11 As shown, the protective film 11 includes: a first transparent adhesive layer 111, a base film layer 112, a hardening layer 113, a functional layer 114, and a reinforcing hardening layer 110; wherein, the first transparent adhesive layer 111, the base film layer 112, the hardening layer 113, and the functional layer 114 are sequentially stacked along the Z-axis direction; the first transparent adhesive layer 111 is disposed on the display side of the display panel; the base film layer 112 has a base film layer recess 115 on the side near the hardening layer 113 (the side of the base film layer 112 away from the first transparent adhesive layer 111), and the reinforcing hardening layer 110 is located within the base film layer recess 115. The hardness of the reinforcing hardening layer 110 is greater than the hardness of the base film layer 112. Both the base film layer recess 115 and the reinforcing hardening layer 110 are located in the predicted wear area of ​​the protective film 11; the hardening layer 113 is located on the same side as the base film layer 112 and the reinforcing hardening layer 110.

[0158] The first transparent adhesive layer 111, the base film layer 112, the hardened layer 113, the functional layer 114, and the predicted wear zone can be referred to the previous text and will not be repeated here. The reinforced hardened layer 110 can be understood as a manifestation of the first hardened layer.

[0159] To ensure the mechanical and optical properties of the protective film 11, the upper surface of the functional layer 114 away from the base film layer 112 is planar. This can be understood as the upper surface of the surface layer away from the base film layer 112 being planar, i.e., the upper surface of the protective film 11 being planar. Of course, the upper surface of the functional layer 114 can also be other shapes, and this embodiment does not limit this.

[0160] To facilitate the configuration of the functional layer 114, the upper surface of the hardened layer 113 near the functional layer 114 can be selected as a plane. This also helps to ensure the performance of the functional layer, thereby facilitating the guarantee of the mechanical and optical properties of the protective film. Of course, the upper surface of the hardened layer 113 can also be other shapes, and this embodiment does not limit this.

[0161] The upper surfaces of the reinforcing hardening layer 110 near the hardening layer 113 and the upper surfaces of the base film layer 112 near the hardening layer 113 can be flush. This can be understood as the thickness of the reinforcing hardening layer 110 being equal to the depth of the recess 115 in the base film layer. This facilitates the placement of the hardening layer 113 and prevents the reinforcing hardening layer 110 from affecting the hardening layer 113 and the functional layer 114, thus ensuring the mechanical and optical properties of the protective film 11.

[0162] It should be noted that the thickness direction of the hardening layer 110 is the Z-axis direction.

[0163] Alternatively, the upper surfaces of the reinforcing hardening layer 110 and the base film layer 112 can be sequentially distributed along the lamination direction. For example, the upper surface of the reinforcing hardening layer 110 is closer to the first transparent adhesive layer 111 than the upper surface of the base film layer 112. This can be understood as the thickness of the reinforcing hardening layer 110 being less than the depth of the recessed portion 115 of the base film layer. In this case, a portion of the hardening layer 113 is located within the recessed portion 115 of the base film layer, so that the upper surface of the hardening layer 113 can be planar, avoiding the reinforcing hardening layer 110 from affecting the functional layer 114. Alternatively, the upper surface of the reinforcing hardening layer 110 is farther from the first transparent adhesive layer 111 than the upper surface of the base film layer 112. This can be understood as the thickness of the reinforcing hardening layer 110 being greater than the depth of the recessed portion 115 of the base film layer. In this case, the reinforcing hardening layer 110 protrudes from the base film layer 112, and the portion of the hardening layer 113 opposite to the reinforcing hardening layer 110 is recessed. In this way, the upper surface of the hardened layer 113 near the functional layer 114 can be a plane, so as to avoid the hardened layer 110 from affecting the functional layer 114.

[0164] The materials of the reinforcing hardening layer 110 and the hardening layer 113 can be the same or different. The hardness of the reinforcing hardening layer 110 and the hardening layer 113 can be the same or different. In some embodiments, the hardness of the reinforcing hardening layer 110 can be greater than that of the hardening layer 113, thus effectively improving the hardness of the predicted wear zone. Of course, the hardness of the reinforcing hardening layer 110 can be less than or equal to the hardness of the hardening layer 113.

[0165] The reinforcing and hardening layer 110 can be of equal thickness or non-equal thickness. To facilitate the setting of the reinforcing and hardening layer 110 and the hardening layer 113, the reinforcing and hardening layer 110 can be selected as an equal thickness structure.

[0166] The reinforcing and hardening layer 110 can be set by coating or other methods. To facilitate the setting of the reinforcing and hardening layer 110, it can be set by coating. This can be understood as the reinforcing and hardening layer 110 being a coating layer.

[0167] In the aforementioned protective film 11, the upper surface of the base film layer 112 has a base film layer recess 115; the reinforcing hardening layer 110 is located within the base film layer recess 115. In this way, the base film layer recess 115 provides space to accommodate the reinforcing hardening layer 110, avoiding affecting the hardening layer 113 and the functional layer 114 (or reducing the impact on the hardening layer 113 and the functional layer 114), and facilitating the guarantee of the mechanical and optical properties of the protective film 11.

[0168] It should be noted that the base film layer 112 is thicker than the hardened layer 113 and the functional layer 114. The base film layer recess 115 has little effect on the base film layer 112, and the effect of the base film layer recess 115 on the mechanical and optical properties of the protective film 11 can be ignored.

[0169] In the protective film 11, since the hardness of the reinforced hardening layer 110 is greater than that of the base film layer 112, the addition of the reinforced hardening layer 110 effectively improves the hardness of the predicted wear area of ​​the protective film 11, reduces the degree of protrusion of the predicted wear area of ​​the protective film 11 due to the creep of the inward folding display screen 1, and also reduces the degree of protrusion of the predicted wear area of ​​the protective film 11 due to the protruding components. This effectively reduces wear damage in the predicted wear area and slows down wear, effectively improving the wear resistance of the predicted wear area, enhancing the clarity and aesthetics of the inward folding display screen 1, and thus improving the user experience.

[0170] It should be noted that the protective film 11 can maintain the hardness of the hardened layer 113 and the functional layer 114 without increasing the hardness of the hardened layer 113 and the functional layer 114. This can meet the high and low temperature and room temperature bending performance of the pivot area 1103 of the protective film 11, thereby ensuring the mechanical properties of the protective film 11.

[0171] Therefore, the aforementioned protective film 11 can improve the wear resistance of the predicted wear area while ensuring its mechanical and light performance, thereby enhancing the clarity and aesthetics of the inward-folding display screen 1 and improving the user experience.

[0172] The production method of the protective film 11 is described in detail below. Please refer to [link / reference needed]. Figure 12 , Figure 12 This is a schematic diagram of a method for producing the protective film 11 provided in some embodiments of this application.

[0173] like Figure 12 As shown, the method for producing the protective film 11 includes:

[0174] S21: Process the base film layer 112 so that the base film layer 112 has a base film layer recess 115 corresponding to the predicted wear area, the base film layer recess 115 being located on the upper surface of the base film layer 12.

[0175] S22: A reinforcing hardening layer 110 is provided in the recessed portion 115 of the base film layer;

[0176] S23: A hardening layer 113 is stacked on the same side of the base film layer 112 and the reinforcing hardening layer 110, and the hardening layer 113 covers the base film layer 112 and the reinforcing hardening layer 110.

[0177] S24: A functional layer 114 is stacked on the upper surface of the hardened layer 113 away from the base film layer 112;

[0178] S25: A first transparent adhesive layer 111 is stacked on the lower surface of the base film layer 112 away from the hardened layer 113 to obtain a protective film 11.

[0179] In S21, the predicted wear area is obtained in advance. Of course, it is optional that the predicted wear area is obtained by this method. In some embodiments, the method for producing the protective film 11 further includes S20 before S21: obtaining the predicted wear area of ​​the protective film 11 based on the inner screen folding wear test of the inward-folding mobile phone 100.

[0180] For S20, please refer to S21 above; for S21, please refer to S11 above. It will not be repeated here.

[0181] In S22, the reinforcing hardening layer 110 and the base film layer 112 can be flush. This can be understood as the upper surface of the reinforcing hardening layer 110 that contacts the hardening layer 113 and the upper surface of the base film layer 112 that contacts the hardening layer 113 are flush. In S22, the reinforcing hardening layer 110 can be formed by coating. Therefore, forming the reinforcing hardening layer 110 within the recess 115 of the base film layer can be understood as coating the recess 115 of the base film layer with the reinforcing hardening layer 110. Of course, other methods can be chosen to form the reinforcing hardening layer 110, and this embodiment does not limit this.

[0182] In S23, the surface of the hardened layer 113 that is far from the base film layer 112 and the reinforcing hardened layer 110 can be a flat surface. Regarding the setting method and thickness of the hardened layer 113 in S23, please refer to the previous text, which will not be repeated here.

[0183] In S24, the surface of the functional layer 114 that is far from the hardened layer 113 can be a flat surface. Regarding the setting method and thickness of the functional layer 114 in S24, please refer to the previous text, which will not be repeated here.

[0184] Regarding the setting method and thickness of the first transparent adhesive layer 111 in S25, please refer to the previous text, and it will not be repeated here.

[0185] In the production method of the protective film 11, S25 can also be selected between S21 and S22, between S22 and S23, or between S23 and S24, depending on the actual situation, and is not limited to the above embodiments.

[0186] Figure 11 and Figure 12 The protective film 11 shown is a single-layer film structure. In practice, the protective film 11 can also be a multi-layer film structure. Please refer to [link / reference]. Figure 13 , Figure 13 The protective film 11 provided in some embodiments of this application is another structural schematic diagram of a multilayer film structure. It should be noted that... Figure 13 Only a portion of the protective film 11 is shown; the entire protective film 11 is not shown.

[0187] like Figure 13 As shown, the protective film 11 includes: a second transparent adhesive layer 119, an elastic layer 118, a first transparent adhesive layer 111, a base film layer 112, a hardening layer 113, a functional layer 114, and a reinforcing hardening layer 110; wherein, the second transparent adhesive layer 119, the elastic layer 118, the first transparent adhesive layer 111, the base film layer 112, the hardening layer 113, and the functional layer 114 are stacked sequentially along the Z-axis direction.

[0188] The second transparent adhesive layer 119 is disposed on the display side of the display panel; the base film layer 112 has a base film layer recess 115 on the side near the hardening layer 113, the base film layer recess 115 is located in the predicted wear area of ​​the protective film 11, the reinforcing hardening layer 110 is located in the base film layer recess 115, and the reinforcing hardening layer 110 is in contact with the hardening layer 113; the surface of the reinforcing hardening layer 110 that is in contact with the hardening layer 113 and the surface of the base film layer 112 that is in contact with the hardening layer 113 are disposed flush.

[0189] For an explanation of each layer in the protective film 11, please refer to the previous text; it will not be repeated here.

[0190] based on Figure 13 The protective film 11 shown above, in the production method of the above-mentioned protective film 11, S25 further includes: stacking an elastic layer 118 on the lower surface of the first transparent adhesive layer 111 away from the base film layer 112, and stacking a second transparent adhesive layer 119 on the lower surface of the elastic layer 118 away from the first transparent adhesive layer 111.

[0191] For details regarding the elastic layer 118 and the second transparent adhesive layer 119, please refer to the previous text; they will not be repeated here.

[0192] Apart from Figure 13 The multilayer film structure shown can also be replaced with other structures. For example, the protective film 11 includes at least three transparent adhesive layers stacked sequentially in the Z-axis direction; an elastic layer 118 is disposed between adjacent transparent adhesive layers, and the elastic layer 118 and the transparent adhesive layer are located on the same side of the base film layer 112. The production method of the protective film 11 can be adaptively adjusted according to the number of transparent adhesive layers.

[0193] In practice, other protective films 11 with different structures can also improve the wear resistance of the predicted abrasion-resistant areas. The following describes another structure of the protective film 11 provided in some embodiments of this application.

[0194] Please refer to Figure 14 , Figure 14 This is another structural schematic diagram of the protective film 11 provided in some embodiments of this application. It should be noted that... Figure 14 Only a portion of the protective film 11 is shown; the entire protective film 11 is not shown.

[0195] like Figure 14 As shown, in the protective film 11, the thickness of the reinforcing hardening layer 110 is less than the depth of the base film layer recess 115. In this case, a portion of the hardening layer 113 is located within the base film layer recess 115, and the upper surface of the hardening layer 113 away from the base film layer 112 has a hardening layer recess 116; a portion of the functional layer 114 is located within the hardening layer recess 116, and the upper surface of the functional layer 114 away from the hardening layer 113 has a functional layer recess 117. Thus, under the dual action of the reinforcing hardening layer 110 and the functional layer recess 117, the wear damage in the predicted wear area is further reduced and mitigated, the wear resistance of the predicted wear area is further improved, the clarity and aesthetics of the inward-folding display screen 1 are further enhanced, and the user experience is further improved; at the same time, because the reinforcing hardening layer 110 reduces the protrusion of the predicted wear area, the depth of the functional layer recess 117 can be reduced, and correspondingly, the depth of the base film recess 115 can be reduced.

[0196] based on Figure 14 The protective film 11 shown above, in the production method of the protective film 11, in S22 the thickness of the reinforcing hardening layer 110 is less than the depth of the base film layer recess 115; in S23, a portion of the hardening layer 113 is located within the base film layer recess 115, and the upper surface of the hardening layer 113 has a hardening layer recess 116; in S24, a portion of the functional layer 114 is located within the hardening layer recess 116, and the upper surface of the functional layer 114 has a functional layer recess 117.

[0197] Figure 14 The protective film 11 shown is a single-layer film structure. In practice, it can be... Figure 14 On the single-layer membrane structure shown, corresponding elastic layers and transparent adhesive layers are added to form a multi-layer membrane structure. The production method of the protective film 11 is adaptively adjusted according to the number of transparent adhesive layers.

[0198] As mentioned above, both the hardened layer 113 and the functional layer 114 can be understood as part of the surface layer of the protective film 11. In practice, the surface layer may only include the functional layer 114 and not the hardened layer 113, or it may include other layers, not limited to the hardened layer 113 and the functional layer 114 mentioned above. If one or more layers of the surface layer change, it is sufficient to ensure that the upper surface of the surface layer meets the corresponding requirements.

Claims

1. A protective film, characterized in that, The protective film is applied to the inward folding display module, and the protective film includes: a transparent adhesive layer, a base film layer and a surface layer stacked in sequence; Wherein, the upper surface of the base film layer near the surface layer has a base film layer recess; a portion of the surface layer is located within the base film layer recess, and the upper surface of the surface layer away from the base film layer has a surface layer recess; Both the base film layer depression and the surface layer depression are located within the predicted wear area of ​​the protective film. The predicted wear area is located within the first non-rotating axis region and / or the second non-rotating axis region of the protective film; in the inward folded state of the protective film, the first non-rotating axis region and the second non-rotating axis region are stacked.

2. The protective film according to claim 1, characterized in that, A first hardening layer is disposed within the recessed portion of the base film layer. The hardness of the first hardening layer is greater than that of the base film layer, and the thickness of the first hardening layer is less than the depth of the recessed portion of the base film layer. The surface layer is stacked on the base film layer and the first hardening layer.

3. The protective film according to claim 1 or 2, characterized in that, The surface layer includes a functional layer, which is stacked in the base film layer on the side away from the transparent adhesive layer, and the upper surface of the functional layer away from the base film layer is the upper surface of the surface layer.

4. The protective film according to claim 3, characterized in that, The functional layer includes a first sub-functional layer and a second sub-functional layer; Wherein, the first sub-functional layer is located in the predicted wear area and corresponds to the base film layer recess, and the second sub-functional layer is located in other areas of the protective film besides the predicted wear area. The first sub-functional layer and the second sub-functional layer cooperate to form the surface recess. The upper surfaces of both the first and second sub-functional layers that are away from the base film layer are planar.

5. The protective film according to claim 4, characterized in that, The upper surface of the first sub-functional layer away from the base film layer and the lower surface of the second sub-functional layer near the base film layer are flush; or, the upper surface of the first sub-functional layer away from the base film layer and the lower surface of the second sub-functional layer near the base film layer are distributed sequentially along the stacking direction.

6. The protective film according to claim 3, characterized in that, The surface layer further includes a second hardening layer, which is stacked between the base film layer and the functional layer; Wherein, a portion of the second hardened layer is located within the recess of the base film layer, and the second hardened layer has a hardened layer recess near the upper surface of the functional layer, the hardened layer recess being located within the predicted wear area; a portion of the functional layer is located within the hardened layer recess.

7. The protective film according to claim 6, characterized in that, The second hardening layer includes a first sub-hardening layer and a second sub-hardening layer; Wherein, the first sub-hardening layer is located within the predicted wear area and corresponds to the recessed portion of the base film layer, and the second sub-hardening layer is located in other areas of the protective film besides the predicted wear area. The first sub-hardening layer and the second sub-hardening layer cooperate to form the hardening layer recessed portion. The upper surfaces of both the first and second sub-hardening layers that are away from the base film layer are planar.

8. The protective film according to claim 7, characterized in that, The upper surface of the first sub-hardening layer away from the base film layer and the lower surface of the second sub-hardening layer near the base film layer are flush; or, the upper surface of the first sub-hardening layer away from the base film layer and the lower surface of the second sub-hardening layer near the base film layer are distributed sequentially along the stacking direction.

9. The protective film according to claim 6, characterized in that, The hardness of the first hardened layer of the protective film is not less than the hardness of the second hardened layer.

10. The protective film according to claim 1 or 2, characterized in that, The transparent adhesive layer is one layer; or, the transparent adhesive layer is at least two layers stacked sequentially, with an elastic layer stacked between adjacent transparent adhesive layers, and the transparent adhesive layer and the elastic layer are located on the same side of the base film layer.

11. The protective film according to claim 1 or 2, characterized in that, The base film layer is a cast film.

12. An inwardly folding display module, characterized in that, include: The display panel, with a protective film as described in any one of claims 1-11; wherein the protective film is attached to the display side of the display panel.

13. An electronic device, characterized in that, include: The housing, as described in claim 12, comprises an inwardly folding display module connected to the housing.

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