Protective film and folding terminal

Abstract

The embodiment of the application provides a protective film and a folding terminal. The protective film comprises a main body layer and a first adhesive layer, the first adhesive layer comprises a first adhesive surface, a second adhesive surface and an edge side surface, wherein the first adhesive surface is bonded with the main body layer, the second adhesive surface is used for bonding with the surface of a folding screen of the folding terminal, and the edge side surface comprises a first edge side surface, and the orthographic projection of the first edge side surface on the main body layer is located on the inner side of the contour edge of the main body layer. According to the technical scheme of the embodiment of the application, the protection effect of the protective film can be improved, and then the product quality of the folding terminal is improved.

Description

Technical Field

[0001] This application relates to the field of foldable terminal technology, and in particular to a protective film and a foldable terminal. Background Technology

[0002] With the continuous advancement of technology, mobile terminals have been widely applied to all aspects of people's lives due to their rich functionality, ease of use, small size, and light weight. Foldable mobile terminals, referred to as foldable terminals in this article, offer users a large-screen experience when unfolded, and are compact, portable, and easy to operate with one hand when folded. As a significant innovation in the field of smart terminals in recent years, foldable terminals have gradually become a market hotspot thanks to their unique design and functionality.

[0003] In foldable devices, the protective film, as a functional structural component attached to the screen surface, plays a role in resisting minor scratches and wear, inhibiting crack propagation, and optimizing tactile and optical performance. How to improve the protective effect of the film, thereby enhancing the product quality of foldable devices, is a technical problem that urgently needs to be solved by those skilled in the art. Utility Model Content

[0004] This application provides a protective film and a folding terminal to improve the protective effect of the protective film and thus improve the product quality of the folding terminal.

[0005] According to one aspect of this application, a protective film is provided for use in a foldable terminal. The protective film includes a main body layer and a first adhesive layer. The first adhesive layer includes a first adhesive surface, a second adhesive surface, and an edge side surface. The first adhesive surface is bonded to the main body layer, the second adhesive surface is bonded to the surface of the foldable screen of the foldable terminal, and the edge side surface includes a first edge side surface located inside the contour edge of the main body layer.

[0006] According to the technical solution of the embodiment of this application, since the first edge side of the first adhesive surface is located inside the outline edge of the main body layer and there is a certain gap between it and the outline edge of the main body layer, after the protective film is attached to the folding screen, the main body layer can cover and protect the first edge side, which can reduce dust adhesion to the first edge side, thereby improving the protective effect of the protective film and improving the product quality of the folding terminal.

[0007] In some embodiments, the orthographic projection of the second adhesive surface onto the main body layer coincides with or is offset from the first adhesive surface. The first adhesive layer typically has a certain degree of elasticity, and under the action of external force, the relative position of the edge of the second adhesive surface and the edge of the first adhesive surface may change, thus potentially exhibiting the aforementioned state.

[0008] In some embodiments, the edge side also includes a second edge side, which is flush with the contour edge of the main body layer. In these embodiments, the first edge side can be a partial section of the edge side of the first adhesive layer, and the location of the first edge side can be flexibly designed according to the specific structure of the folding terminal.

[0009] In some embodiments, a first gap exists between the intersection line of the first edge side and the first adhesive surface and the contour edge of the main body layer. The first gap is greater than 0 and not greater than 2 mm. The first gap is selected within this range to take into account both the adhesion effect and the protective effect of the protective film on the foldable screen surface.

[0010] In some embodiments, the main layer is a single-layer base film layer. As the outer layer of the protective film, the base film layer primarily provides mechanical protection, such as resistance to scratches, impacts, and abrasion. In some embodiments, the surface of the base film layer facing away from the first adhesive layer may undergo surface treatments such as anti-glare and anti-fingerprint treatments. Furthermore, a hardening coating or anti-reflective coating may be added to enhance the functionality and protective properties of the protective film.

[0011] In some embodiments, the main body layer includes multiple sub-layers, including a base film layer and at least one of a second adhesive layer or a buffer layer. The sub-layer furthest from the first adhesive layer is the base film layer. The base film layer primarily provides mechanical protection. The second adhesive layer, as a connecting layer, possesses a certain degree of flexibility and elasticity, and can also serve as an intermediate stress buffer, helping to absorb and disperse stress between different sub-layers. The buffer layer can absorb external impact energy, effectively reducing the possibility of functional failures such as screen breakage, bright spots, or black spots caused by external impacts.

[0012] In some embodiments, the base film layer is made of polyethylene terephthalate, polyimide, polyetheretherketone, polyethylene naphthalate, thermoplastic polyurethane elastomer, or thermoplastic polyester elastomer; or, the buffer layer is made of thermoplastic polyurethane elastomer, silicone gel, acrylic gel, or ethylene-vinyl acetate copolymer; or, the first adhesive layer and the second adhesive layer are made of acrylic adhesive, epoxy adhesive, polyurethane adhesive, or silicone. The material selection and design of this embodiment allows the overall protective film to possess good flexibility, protective performance, and adhesion.

[0013] In some embodiments, the material modulus of the base film layer is not less than 0.1 GPa and not more than 100 GPa; or, the material modulus of the buffer layer is not less than 10 kPa and not more than 2 GPa; or, the material modulus of the first adhesive layer and the second adhesive layer is not less than 10 kPa and not more than 10 MPa. The material design of this embodiment enables the protective film as a whole to have good flexibility, protective performance and adhesion.

[0014] According to one aspect of this application, a foldable terminal is provided, comprising: a foldable mid-frame, a foldable screen connected to one side of the foldable mid-frame, and a protective film according to the foregoing embodiment, the protective film being adhered to the surface of the foldable screen by a first adhesive layer.

[0015] In this embodiment, the protective film can be a factory-installed or replaceable configuration for the folding terminal. The main layer of the protective film can effectively cover and protect the first edge side of the first adhesive layer, thus effectively reducing dust adhesion and providing better protection. This improves the product quality of the folding terminal.

[0016] In some embodiments, the folding terminal further includes a pressure frame, which is disposed on the periphery of the folding screen and connected to the folding mid-frame; wherein, the orthographic projection of the intersection line of the first edge side and the first adhesive surface on the folding screen has a second distance between it and the orthographic projection of the inner edge of the pressure frame on the folding screen, and the orthographic projection of the main body layer on the folding screen has a third distance between it and the orthographic projection of the inner edge of the pressure frame on the folding screen, wherein the second distance is greater than 0.3 mm and less than 0.5 mm, and the third distance is greater than 0 and less than the second distance.

[0017] The design of these embodiments helps to reduce the gap between the protective film and the bezel, thus reducing the exposed area of ​​the folding screen at the gap and enhancing the edge protection effect of the protective film on the folding screen, which can reduce the mechanical damage that the folding screen may suffer at the edges.

[0018] In some embodiments, at least a portion of the outline edge of the main body layer is located inside the outline edge of the foldable screen; or, at least a portion of the outline edge of the main body layer is located outside the outline edge of the foldable screen; or, at least a portion of the outline edge of the main body layer coincides with the outline edge of the foldable screen. Depending on the specific structural design differences of different products or the structural design differences of the same product at different edge positions, the outline edge of the main body layer and the outline edge of the foldable screen can present various relative positional states. Attached Figure Description

[0019] Figure 1A The diagram shows a partial cross-sectional view of the protective film of a foldable terminal in the product's factory condition and after the product has been used for a period of time.

[0020] Figure 1B This diagram illustrates the operation of applying a protective film to the surface of a foldable screen in the related technology;

[0021] Figure 2 A three-dimensional structural schematic diagram of a folding terminal according to some embodiments of this application is shown, wherein the folding screen is in a flattened state;

[0022] Figure 3The foldable terminal shown in some embodiments of this application is in Figure 2 A schematic diagram of the local cross-sectional structure at point A;

[0023] Figure 4 A partial cross-sectional structural diagram of the folding terminal at the edge of some embodiments of this application is shown;

[0024] Figure 5 A schematic diagram showing the deformation of the first edge side of the protective film according to some embodiments of this application is shown;

[0025] Figure 6 A top view of the protective film of some embodiments of this application is shown;

[0026] Figure 7 A top view of the protective film of some embodiments of this application is shown;

[0027] Figures 8A to 8F This paper shows a partial cross-sectional structural diagram of the protective film at the edge of some embodiments of the present application;

[0028] Figure 9 The illustration shows a schematic diagram of the operation of attaching a protective film to the surface of a foldable screen in some embodiments of this application.

[0029] Figure label:

[0030] Related technical aspects:

[0031] 052-Foldable screen; 054-Protective film; 041-Main body layer; 042-Adhesive layer; 053-Frame pressing; 056-Dust; 003-Scroll wheel; a'-Gap.

[0032] Part of the embodiments of this application:

[0033] 500 - Foldable terminal; 510 - Foldable mid-frame; 520 - Foldable screen; 521 - Flexible display panel; 522 - Cover plate; 530 - Bezel; 540 - Protective film;

[0034] 210 - Folded / bent area; 211 - Non-folded / bent area; 41 - Main layer; 42 - First adhesive layer; 421 - First adhesive surface;

[0035] 422 - Second bonding surface; 423 - Edge side surface; 231 - First edge side surface; 232 - Second edge side surface; 10 - Base film layer;

[0036] 11-Second adhesive layer; 12-Buffer layer; 222-At least a portion of the edge of the second adhesive surface; 300-Roller; 43-Release film; c-First spacing;

[0037] a - Second spacing; b - Third spacing; S - Folding axis. Detailed Implementation

[0038] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of this application. Therefore, the drawings and description are considered to be exemplary in nature and not restrictive.

[0039] The terminology used in the following embodiments is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. As used in the specification and appended claims of this application, the singular expressions “a,” “an,” “the,” “the,” “the,” and “this” are intended to also include expressions such as “one or more” unless the context clearly indicates otherwise.

[0040] References to “an embodiment” or “a specific embodiment” as used in this specification mean that one or more embodiments of this application include a particular feature, structure, or characteristic described in connection with that embodiment. The terms “comprising,” “including,” “having,” and variations thereof mean “including, but not limited to,” unless otherwise specifically emphasized.

[0041] In related technologies, the main structure of a foldable terminal may include: a foldable mid-frame, a foldable screen connected to one side of the foldable mid-frame, a back cover connected to the other side of the foldable mid-frame, some electronic components such as batteries, motherboards and camera modules disposed between the foldable mid-frame and the back cover and / or between the foldable mid-frame and the foldable screen, a protective film attached to the surface of the foldable screen, and a pressure frame disposed around the perimeter of the foldable screen and connected to the foldable mid-frame.

[0042] The folding frame enables the folding function via hinges. It supports, limits, and mounts the flexible folding screen and some electronic components. Furthermore, the folding frame, when connected to the back cover, also provides structural reinforcement to the back cover. The pressure frame, often called the "small A-frame," primarily prevents the edges of the folding screen from warping during folding and unfolding. The protective film, attached to the surface of the folding screen, protects against minor scratches and wear, inhibits crack propagation, and optimizes tactile and optical performance. Typically, the side of the protective film closest to the folding screen has an adhesive layer, usually made of transparent optical adhesive, to ensure adhesion and meet optical performance requirements.

[0043] like Figure 1A The diagram illustrates a partial cross-sectional view of the protective film 054 of a folding terminal in the related art, both in its factory condition and after a period of use. In this related art, the protective film 054 includes a main body layer 041 and an adhesive layer 042. (As shown...) Figure 1AAs shown in the upper middle figure, in the product's factory condition, the edges of the main body layer 041 and the adhesive layer 042 of the protective film 054 are flush.

[0044] The technical problem with this technology is that, at the edge of the protective film 054, the adhesive layer 042 is exposed on the side, making it prone to dust accumulation 056. With the increasing use of foldable terminals, such as... Figure 1A As shown in the lower part of the image, the edges of the adhesive layer 042 may be deformed by the folding screen 052, resulting in a larger exposed area and more and more dust 056 adhering to it. This not only affects the appearance but also easily causes the protective film 054 to peel off from the edge of the folding screen 052, ultimately leading to the failure of protection.

[0045] like Figure 1B The diagram illustrates the process of applying a protective film 054 to the surface of a foldable screen 052 in the relevant art. The protective film 054 is typically applied to the surface of the foldable screen 052 using a roller 003. This application process is generally performed after the frame 053 is assembled. To prevent mechanical damage to the frame 053 caused by the roller 003, a sufficient gap a' is usually maintained between the edge of the protective film 054 and the inner edge of the frame 053; for example, gap a' should not be less than 0.3 mm. This results in the edge of the foldable screen 052 being exposed at gap a', making it susceptible to mechanical damage due to the lack of protection from the protective film 054.

[0046] In view of this, embodiments of this application provide a protective film and a folding terminal to improve the protective effect of the protective film, thereby improving the product quality of the folding terminal. The embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0047] In this application embodiment, the product type of the foldable terminal may include, but is not limited to, foldable mobile phones, foldable tablets, foldable personal computers, or foldable wearable devices.

[0048] like Figure 2 As shown, it illustrates a perspective structural diagram of a foldable terminal 500 according to some embodiments of this application, wherein the foldable terminal 500 is exemplified by a foldable mobile phone, and its foldable screen 520 is in a flattened state. Referring to this... Figure 2As shown, the main structure of the foldable terminal 500 may include a folding frame 510, a rear shell connected to one side of the folding frame 510 (not shown in the figure due to viewing angle), a foldable screen 520 connected to the other side of the folding frame 510, a protective film 540 attached to the surface of the foldable screen 520, and a pressing frame 530 disposed on the periphery of the foldable screen 520 and connected to the folding frame 510. Electronic components may be disposed between the folding frame 510 and the rear shell and / or between the folding frame 510 and the foldable screen 520. These electronic components may include, but are not limited to, batteries, motherboards, and camera modules. The basic functions of the folding frame 510, the protective film 540, and the pressing frame 530 in the foldable terminal 500 can be referred to the description of the aforementioned related technologies, and will not be repeated here. To alleviate the aforementioned technical problems in the related technologies, in the embodiments of this application, the protective film 540 of the foldable terminal 500 may adopt the design schemes of some embodiments described below.

[0049] like Figure 3 As shown, it illustrates a foldable terminal 500 according to some embodiments of this application. Figure 2 The attached figure shows a partial cross-sectional view of the protective film 540 in some embodiments of this application. In these embodiments, the protective film 540 may include a main body layer 41 and a first adhesive layer 42. The first adhesive layer 42 includes a first adhesive surface 421, a second adhesive surface 422, and an edge side surface 423. The first adhesive surface 421 is bonded to the main body layer 41, the second adhesive surface 422 is used to bond to the surface of the folding screen 520 of the folding terminal, and the edge side surface 423 includes a first edge side surface 231, which is located inside the contour edge of the main body layer 41.

[0050] In some embodiments of this application, the main body layer 41 can be a single-layer base film layer, that is, the main body layer 41 can be designed as a single-layer base film layer. In other embodiments of this application, the main body layer 41 can also be a composite layer, which includes multiple sub-layers, so that the materials of adjacent sub-layers can be different. The embodiments of this application do not limit the specific structure of the main body layer 41.

[0051] The module structure of the foldable screen 520 typically includes a flexible display panel 521 and a cover plate 522. The cover plate 522 is disposed on the display side of the flexible display panel 521, and the two can be connected by a transparent optical adhesive layer (not shown in the figure). The cover plate 522 can protect and structurally reinforce the flexible display panel 521, and also provide some flatness support for the flexible display panel 521. In this embodiment, the second adhesive surface 422 of the first adhesive layer 42 can be used to bond with the cover plate 522 of the foldable screen 520.

[0052] The first adhesive layer 42 can be a transparent optical adhesive layer. Transparent optical adhesive (OCA) has a certain degree of flexibility and elasticity, and also has advantages such as high light transmittance, low haze, good environmental tolerance, process-friendly, and few defects.

[0053] The first adhesive layer 42 can be formed on the surface of the main body layer 41 facing the foldable screen 520 by coating. After the first adhesive layer 42 is fabricated on the main body layer 41, the side of it that is bonded to the main body layer 41 is the first adhesive surface 421, and the side that is bonded to the surface of the foldable screen 520 is the second adhesive surface 422. Since the first adhesive layer 42 has a certain thickness, it also includes an edge side surface 423 located at the edge. Because the first adhesive layer 42 usually has a certain degree of elasticity, its edge side surface 423 may have different shapes depending on the manufacturing process or its usage in the foldable terminal. For example, the edge side surface 423 may be flat or curved, and may be perpendicular to the first adhesive surface 421, form an acute angle, or form an obtuse angle, etc. In some embodiments, the second adhesive surface 422 of the first adhesive layer 42 may be stretched in a certain direction during the folding operation of the folding screen 520, so that the edge side 423 of the first adhesive layer 42 may be a sloping surface, thus forming an obtuse angle with the first adhesive surface 421.

[0054] In the embodiments of this application, geometric terms such as "perpendicular" and "coincident" are to be understood within the allowable error range and should not be interpreted as absolutely limiting. In the embodiments of this application, the orthographic projection of "one structure" onto "another planar structure" can be understood as the graphic obtained by projecting all points on "one structure" onto "another planar structure" in a direction perpendicular to the projection plane.

[0055] In this embodiment, the edge side 423 of the first adhesive layer 42 includes a first edge side 231, meaning that at least a portion of the edge side 423 of the first adhesive layer 42 is the first edge side 231. This first edge side 231 is located inside the contour edge of the main body layer 41, thus, the orthographic projection of the first edge side 231 onto the main body layer 41 has a certain distance from the contour edge of the main body layer 41. In other words, the first edge side 231 of the first adhesive layer 42 adopts a design that is recessed compared to the main body layer 41. The first edge side 231 can be the entire edge side of the first adhesive layer 42, or a portion of the edge side of the first adhesive layer 42. The edge side 423 of the first adhesive surface 421 may include one or more such first edge sides 231, which is not specifically limited in this embodiment.

[0056] According to the technical solution of the embodiment of this application, since the first edge side 231 of the first adhesive surface 421 is located inside the outline edge of the main body layer 41 and has a certain distance between it and the outline edge of the main body layer 41, after the protective film 540 is attached to the folding screen 520, the main body layer 41 can cover and protect the first edge side 231, which can reduce dust adhesion to the first edge side 231, thereby improving the protective effect of the protective film 540 and thus improving the product quality of the folding terminal.

[0057] In this embodiment, depending on the specific structural design differences of different products or the structural design differences of the same product at different edge positions, the outline edge of the main body layer 41 and the outline edge of the foldable screen 520 can present various relative positional states. For example... Figure 3 As shown, in these embodiments, at least a portion of the outline edge of the main body layer 41 is located inside the outline edge of the foldable screen 520. This design is applicable to situations where the foldable terminal 500 includes a pressure bezel 530, and this design scheme can be adopted in the area where the pressure bezel 530 is set.

[0058] like Figure 4 The diagram illustrates a partial cross-sectional view of the foldable terminal 500 at its edge, representing some other embodiments of this application. In these embodiments, at least a portion of the outline edge of the main body layer 41 is located outside the outline edge of the foldable screen 520, that is, extending beyond the outline edge of the foldable screen 520. This embodiment can be applied to situations where the foldable terminal 500 includes or does not include a bezel. When the foldable terminal 500 includes a bezel, this design can be used in the edge area where no bezel is provided.

[0059] In some other embodiments not illustrated in the accompanying drawings, at least a portion of the outline edge of the main body layer 41 may also coincide with the outline edge of the foldable screen 520.

[0060] like Figure 3 or Figure 4 As shown, in some embodiments of this application, the orthographic projection of the second adhesive surface 422 on the main body layer 41 coincides with the first adhesive surface 421. This state may exist in the factory state of the protective film 540, the state after the protective film 540 is initially attached to the folding screen 520, the factory state of the folding terminal 500, or the state in which the folding terminal 500 is folded by operation.

[0061] In some embodiments of this application, the orthographic projection of the second adhesive surface 422 onto the main body layer 41 may also be offset from the first adhesive surface 421, meaning that the orthographic projection of the second adhesive surface 422 onto the main body layer 41 does not completely coincide with the first adhesive surface 421. This state may exist in the factory state of the protective film 540, the state after the protective film 540 is initially attached to the foldable screen 520, the factory state of the foldable terminal 500, or the state in which the foldable terminal 500 is folded.

[0062] like Figure 5 The diagram illustrates a deformation of the first edge side 231 of the protective film 540 according to some embodiments of this application. In some embodiments, reference is made to this... Figure 5 As shown in the upper middle figure, in the factory state, in the state after initial application to the foldable screen 520, or in the factory state of the foldable terminal, the orthographic projection of the second adhesive surface 422 on the main body layer 41 coincides with the first adhesive surface 421; referring to this... Figure 5 As shown in the lower figure, when the folding terminal is folded, the orthographic projection of at least a portion of the edge 222 of its second adhesive surface 422 onto the main body layer 41 may be located outside the edge of the first adhesive surface 421, thus the orthographic projection of the second adhesive surface 422 onto the main body layer 41 is offset from the first adhesive surface 421. In other words, the first edge side 231 may undergo some adaptive state changes as the folding terminal is folded, for example, it may change from a vertical surface to a sloping surface, but since it is still covered and protected by the main body layer 41, dust adhesion can still be reduced compared to related technologies.

[0063] like Figure 6 The diagram shows a top view of the protective film 540 according to some embodiments of this application. In these embodiments of this application, the first edge side 231 can be the entire edge side of the first adhesive layer 42, thus the entire edge side of the first adhesive layer 42 adopts a design that is recessed relative to the main body layer 41, and the orthographic projection of the first adhesive surface 421 on the main body layer 41 is located entirely inside the contour edge of the main body layer 41.

[0064] like Figure 7 The diagram shows a top view of the protective film 540 according to some embodiments of this application. In these embodiments of this application, the edge side 423 of the first adhesive surface 421 may include a second edge side 232 in addition to the first edge side 231, and the second edge side 232 is flush with the contour edge of the main body layer 41. For example, the edge side 423 of the first adhesive surface 421 is composed of two first edge sides 231 and two second edge sides 232, wherein the two first edge sides 231 avoid the folding bending region 210 of the folding screen 520, and the two second edge sides 232 are located in the folding bending region 210 of the folding screen 520.

[0065] Understandably, when the folding screen 520 folds or unfolds from its folded state, the further away from the folding axis S the area is from the folding axis, the longer the "distance" it needs to travel, and the greater the potential for misalignment or displacement between layers. Since the folding bending area 210 of the folding screen 520 is fixed to the hinge structure, it will bend when the hinge structure moves. In this area, the relative misalignment between the first adhesive layer 42 and the folding screen 520 is relatively small. The non-folding bending area 211 of the folding screen 520 is further away from the folding axis S than the folding bending area 210; therefore, the relative misalignment between the first adhesive layer 42 and the folding screen 520 is larger in this non-folding bending area 211.

[0066] exist Figure 7 In the illustrated embodiment, two first edge sides 231 are disposed in the non-folding bending area 211 of the foldable screen 520. When the foldable screen 520 folds or flattens out from a folded state, the first edge sides 231 may be "pulled" by the foldable screen 520 and deformed, thus, as Figure 5 As shown, it may be a sloping surface, but since it is still covered and protected by the main layer 41, it can still reduce dust adhesion compared to related technologies, and the protective film 540 still has a good protective effect.

[0067] Reference Figure 3 As shown, in some embodiments of this application, a first spacing c exists between the intersection line of the first edge side 231 and the first adhesive surface 421 and the contour edge of the main body layer 41. This first spacing c can be designed to be greater than 0 and not greater than 2 mm. This balances the adhesion and protective effects of the protective film 540 on the surface of the foldable screen 520. The first spacing c can be selected based on the specifications and dimensions of the foldable screen 520, the specifications and dimensions of the bezel 530, etc., and its specific design value is not limited. For example, in some embodiments, the first spacing c can be 0.5 mm, 0.8 mm, 1 mm, 1.2 mm, 1.5 mm, 1.8 mm, or 2 mm, etc., and is not limited to these specific values. In these embodiments, the distance between the intersection of the first edge side 231 and the first adhesive surface 421 and the outline edge of the main body layer 41 is defined as the first distance c because the first adhesive surface 421 is bonded to the main body layer 41, and the main body layer 41 does not have a "pulling" effect on the first adhesive surface 421. Therefore, the edge position of the first adhesive surface 421 is relatively fixed and is less likely to undergo displacement under external force compared to the edge of the second adhesive surface 422.

[0068] In some embodiments, when the protective film 540 is in its factory state, the orthographic projection of its second adhesive surface 422 onto the main body layer 41 coincides with the first adhesive surface 421. Therefore, the distance between the orthographic projection of the intersection line of the first edge side surface 231 and the second adhesive surface 422 onto the main body layer 41 and the outline edge of the main body layer 41 is equal to the aforementioned first distance c. However, with the use of the folding terminal, the intersection line of the first edge side surface 231 and the second adhesive surface 422 may shift or displace. In this case, the distance between the orthographic projection of the intersection line of the first edge side surface 231 and the second adhesive surface 422 onto the main body layer 41 and the outline edge of the main body layer 41 is no longer equal to the aforementioned first distance c.

[0069] The embodiments of this application do not limit the specific structural design scheme of the main layer 41. Figures 8A to 8F The diagram shows partial cross-sectional structural schematics of the protective film 540 at its edge in some embodiments of this application.

[0070] like Figure 8A As shown, in some embodiments of this application, the main body layer 41 can be a single-layer base film layer 10. The base film layer 10, as the outer layer of the protective film 540, mainly provides mechanical protection, such as resistance to scratches, impacts, and abrasion. In some embodiments, the surface of the base film layer 10 facing away from the first adhesive layer 42 can be treated with anti-glare, anti-fingerprint, or other surface treatments. A hardened coating or an anti-reflective coating can also be added to enhance the functionality and protective properties of the protective film 540.

[0071] like Figures 8B to 8E As shown, in some other embodiments of this application, the main body layer 41 can be a composite layer, which includes multiple sub-layers. Among the multiple sub-layers, there is a base film layer 10 and at least one of a second adhesive layer 11 or a buffer layer 12. The sub-layer furthest from the first adhesive layer 42 among the multiple sub-layers is the base film layer 10.

[0072] The base film layer 10 primarily provides mechanical protection. The second adhesive layer 11, as a connecting layer, also serves as an intermediate stress buffer due to its flexibility and elasticity, helping to absorb and disperse stress between different sublayers. The buffer layer 12 can absorb external impact energy, effectively reducing the possibility of functional failures such as screen breakage, bright spots, or black spots caused by external impacts.

[0073] like Figure 8B As shown, in these embodiments, the protective film 540 is structurally designed to include a first base film layer 10, a second adhesive layer 11, a second base film layer 10, and a first adhesive layer 42 arranged sequentially. The first base film layer 10 is the outermost layer of the protective film 540. The first base film layer 10, the second adhesive layer 11, and the second base film layer 10 serve as the main body layer 41 of the protective film 540. The first adhesive layer 42 can adopt the design scheme of the above embodiments of this application.

[0074] like Figure 8C As shown, in some other embodiments, the protective film 540 is designed to include a base film layer 10, a buffer layer 12 and a first adhesive layer 42 arranged sequentially. The base film layer 10 is the outermost layer of the protective film 540, and the base film layer 10 and the buffer layer 12 serve as the main body layer 41 of the protective film 540. The first adhesive layer 42 can adopt the design scheme of the above embodiments of this application.

[0075] like Figure 8D As shown, in some other embodiments, the protective film 540 is designed to include a first base film layer 10, a buffer layer 12, a second adhesive layer 11, a second base film layer 10, and a first adhesive layer 42 arranged sequentially. The first base film layer 10 is the outermost layer of the protective film 540. The first base film layer 10, the buffer layer 12, the second adhesive layer 11, and the second base film layer 10 serve as the main body layer 41 of the protective film 540. The first adhesive layer 42 can adopt the design scheme of the above embodiments of this application.

[0076] like Figure 8E As shown, in some embodiments, the protective film 540 is designed to include a base film layer 10, a second adhesive layer 11, a buffer layer 12 and a first adhesive layer 42 arranged sequentially. The base film layer 10 is the outermost layer of the protective film 540, and the base film layer 10, the second adhesive layer 11 and the buffer layer 12 serve as the main body layer 41 of the protective film 540. The first adhesive layer 42 can adopt the design scheme of the above embodiments of this application.

[0077] The embodiments of this application do not limit the specific material types that can be used for the base film layer 10, buffer layer 12, first adhesive layer 42 and second adhesive layer 11.

[0078] In some embodiments, exemplarily, the material of the base film layer 10 may include, but is not limited to, polyethylene terephthalate (PET), polyimide (PI), polyether ether ketone (PEEK), polyethylene naphthalate (PEN), thermoplastic polyurethane (TPU), or thermoplastic polyester elastomer (TPEE).

[0079] In some embodiments, the material of the buffer layer 12 may include, but is not limited to, thermoplastic polyurethane elastomer, silicone gel, acrylic gel, or ethylene-vinylacetate (EVA).

[0080] In some embodiments, the materials of the first adhesive layer 42 and the second adhesive layer 11 may include, but are not limited to, acrylic adhesive, epoxy adhesive, polyurethane adhesive, or silicone adhesive.

[0081] In some embodiments, exemplarily, the material modulus of the base film layer 10 is not less than 0.1 gigapascals and not greater than 100 gigapascals. Material modulus generally refers to Young's modulus, a physical quantity that measures the "stiffness" or "resistance to elastic deformation" of a material. Generally, a higher material modulus means the material is harder and stiffer; a lower material modulus means the material is softer and more flexible.

[0082] In some embodiments, for example, the material modulus of the buffer layer 12 is not less than 10 kPa and not more than 2 GPa.

[0083] In some embodiments, exemplarily, the material modulus of the first adhesive layer 42 and the second adhesive layer 11 is not less than 10 kPa and not greater than 10 MPa.

[0084] like Figure 8F As shown, in some embodiments of this application, the protective film 540 may include a release film 43, which is bonded to the second adhesive surface 422 of the first adhesive layer 42. During use, the release film 43 can be automatically peeled off by the equipment or manually peeled off by the operator. The release film 43 protects the first adhesive layer 42 from contamination and maintains its adhesiveness before use, and also ensures that the protective film 540 can be easily, smoothly, and without residue applied to the folding screen 520.

[0085] like Figure 2 and Figure 3 As shown, this application embodiment also provides a foldable terminal 500, which includes a foldable frame 510, a foldable screen 520 connected to one side of the foldable frame 510, and a protective film 540 of any of the foregoing embodiments. The protective film 540 is bonded to the surface of the foldable screen 520 through its first adhesive layer 42.

[0086] In this embodiment, when the foldable terminal 500 is in a folded state, the foldable screen 520 can be located on the outside or inside of the folded structure. This embodiment does not specifically limit this.

[0087] The specific product type of the foldable terminal 500 is not limited, such as a foldable mobile phone, a foldable tablet computer, a foldable personal computer, or a foldable wearable device, etc. The main structure of the foldable terminal 500 may also include a back cover (not shown in the figure) connected to one side of the folding frame 510, and some electronic components (not shown in the figure) disposed between the folding frame 510 and the back cover and / or between the folding frame 510 and the folding screen 520. These electronic components may include, but are not limited to, a battery, a motherboard, and a camera module.

[0088] In this embodiment, the protective film 540 can be a factory-installed or replaceable configuration of the folding terminal 500. The main body layer 41 of the protective film 540 can effectively cover and protect the first edge side 231 of the first adhesive layer 42, thus effectively reducing dust adhesion and providing better protection. This improves the product quality of the folding terminal 500.

[0089] Continue to refer to Figure 2 and Figure 3 As shown, in some embodiments, the folding terminal 500 may further include a pressure frame 530 disposed on the periphery of the folding screen 520 and connected to the folding frame 510. As described above, the main function of the pressure frame 530 is to prevent the edges of the folding screen 520 from warping during folding and unfolding. The pressure frame 530 is typically made of high-strength metal, alloy, or plastic materials. Typically, the protective film is applied in the final stage of assembly, before final packaging and shipment, or when the user requests a replacement. Therefore, when the protective film 540 is applied, the folding terminal 500 is already in the assembled state, and the pressure frame 530, folding frame 510, and folding screen 520 are all assembled.

[0090] In some embodiments, the application process of the protective film 540 may include:

[0091] Lay the foldable terminal flat on the fixture and clean the surface of the foldable screen. For example, you can first use an ionizing air gun to blow away large dust particles from the surface, and then use a dust roller or a special cleaning cloth with a cleaning solvent to thoroughly clean the surface of the foldable screen.

[0092] The protective film 540 is applied manually or using fully automated application equipment. The release liner of the protective film 540 can be automatically peeled off by the equipment or manually peeled off by the operator. Figure 9The diagram illustrates the operation of applying a protective film 540 to the surface of a foldable screen 520 in some embodiments of this application. During the application process, the protective film 540 is rolled from the center to the edge by a roller 300, ensuring that the first adhesive layer 42 of the protective film 540 adheres tightly to the foldable screen 520 and simultaneously expelling air and air bubbles towards the edges. Understandably, the rolling stroke of the roller 300 during the application of the protective film 540 is related to the edge position of the first adhesive layer 42.

[0093] like Figure 1B As shown, in the related technology, the edges of the main body layer 041 and the adhesive layer 042 of the protective film 054 are flush. To prevent the roller 003 from causing mechanical damage to the pressure frame 053 when it rolls against the edge of the protective film 054, a sufficient gap a' is usually designed between the edge of the protective film 054 and the pressure frame 053. For example, the gap a' should not be less than 0.3 mm, so that the roller 003 stops rolling against the edge of the protective film 054 in time. It can be seen that a part of the surface of the folding screen 052 will be exposed at the gap a', and thus, this exposed surface is susceptible to mechanical damage due to the lack of protection from the protective film 054.

[0094] like Figure 9 As shown, to alleviate this problem in the related technology, in the embodiment of this application, the orthographic projection of the intersection line of the first edge side 231 of the first adhesive layer 42 and the first adhesive surface 421 on the folding screen 520 and the orthographic projection of the inner edge of the pressure frame 530 on the folding screen 520 have a second distance a, and the orthographic projection of the main body layer 41 on the folding screen 520 and the orthographic projection of the inner edge of the pressure frame 530 on the folding screen 520 have a third distance b, wherein the second distance a is greater than 0.3 mm and less than 0.5 mm, and the third distance b is greater than 0 and less than the second distance a.

[0095] contrast Figure 1B and Figure 9 As can be seen, in this embodiment, the protective film 540 has a smaller gap (i.e., the third gap b) between it and the frame 530. This reduces the exposed area of ​​the folding screen 520 at the gap, enhances the edge protection effect of the protective film 540 on the folding screen 520, and reduces the mechanical damage that the folding screen 520 may suffer at the edge.

[0096] For example, in related technologies, the crush resistance test of the folding screen 052 of a folding terminal at its edge was measured to be 24.5 Newtons; the crush resistance test of the folding screen 520 of the folding terminal 500 in this application embodiment was measured to be 34.3 Newtons, which is a significant improvement compared to related technologies. Crushing resistance can be understood as the ability of a material or structure to resist external compressive forces and prevent permanent deformation, damage, or failure; it is usually quantified through mechanical testing.

[0097] In this embodiment, depending on the specific structural design differences of different products or the structural design differences of the same product at different edge positions, the outline edge of the main body layer 41 and the outline edge of the foldable screen 520 can present various relative positional states. For example... Figure 3 As shown, in these embodiments, at least a portion of the outline edge of the main body layer 41 is located inside the outline edge of the foldable screen 520. This design is applicable to situations where the foldable terminal 500 includes a pressure bezel 530, and this design scheme can be adopted in the area where the pressure bezel 530 is set. Figure 4 As shown, in these embodiments, at least a portion of the outline edge of the main body layer 41 is located outside the outline edge of the foldable screen 520. This embodiment can be applied to situations where the foldable terminal 500 includes or does not include a pressure frame. When the foldable terminal 500 includes a pressure frame, this design can be adopted in the edge area where no pressure frame is provided. In some embodiments not illustrated in the drawings, at least a portion of the outline edge of the main body layer 41 may also coincide with the outline edge of the foldable screen 520.

[0098] It should be understood that some terms that may appear in this application, such as “center,” “longitudinal,” “transverse,” “length,” “width,” “thickness,” “upper,” “lower,” “front,” “rear,” “left,” “right,” “vertical,” “horizontal,” “top,” “bottom,” “inner,” “outer,” “clockwise,” “counterclockwise,” “axial,” “radial,” and “circumferential,” indicate the orientation or positional relationship or dimensions based on the orientation or positional relationship or dimensions shown in the accompanying drawings. The use of these terms is merely for the convenience of description and does not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this application.

[0099] Furthermore, some terms that may appear in this application, such as "first," "second," and "third," are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first," "second," "third," etc., may explicitly or implicitly include one or more of that feature. In this application, "multiple" means two or more, unless otherwise explicitly specified.

[0100] In this application, unless otherwise explicitly specified and limited, some terms that may appear, such as "installation," "connection," "linking," and "fixing," should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integrally formed connection; they can refer to a mechanical connection, an electrical connection, an electromagnetic coupling connection, or a communication connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0101] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0102] This specification provides many different implementations or examples that can be used to implement this application. It should be understood that these different implementations or examples are entirely exemplary and are not intended to limit the scope of protection of this application in any way. Those skilled in the art will be able to conceive of various variations or substitutions based on the disclosure of this specification, and these should all be covered within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope defined in the appended claims.

Claims

1. A protective film applied to a folding terminal, characterized in that, The protective film includes: Main body layer; and The first adhesive layer includes a first adhesive surface, a second adhesive surface, and an edge side surface. The first adhesive surface is bonded to the main body layer, the second adhesive surface is bonded to the surface of the foldable screen of the foldable terminal, and the edge side surface includes a first edge side surface located inside the contour edge of the main body layer.

2. The protective film according to claim 1, characterized in that, The orthographic projection of the second adhesive surface onto the main body layer coincides with or is offset from the first adhesive surface.

3. The protective film according to claim 1, characterized in that, The edge side also includes a second edge side, which is flush with the contour edge of the main body layer.

4. The protective film according to claim 1, characterized in that, The intersection of the first edge side and the first adhesive surface has a first gap with the outline edge of the main body layer, the first gap being greater than 0 and not greater than 2 mm.

5. The protective film according to any one of claims 1 to 4, characterized in that, The main body layer is a single-layer base film layer.

6. The protective film according to any one of claims 1 to 4, characterized in that, The main body layer includes multiple sub-layers, which include a base film layer and at least one of a second adhesive layer or a buffer layer. The sub-layer furthest from the first adhesive layer is the base film layer.

7. The protective film according to claim 6, characterized in that, The base film layer is made of polyethylene terephthalate, polyimide, polyetheretherketone, polyethylene naphthalate, thermoplastic polyurethane elastomer, or thermoplastic polyester elastomer; or The material of the buffer layer includes thermoplastic polyurethane elastomer, silicone gel, acrylic gel, or ethylene-vinyl acetate copolymer; or The materials of the first adhesive layer and the second adhesive layer include acrylic adhesive, epoxy adhesive, polyurethane adhesive, or silicone adhesive.

8. The protective film according to claim 6, characterized in that, The material modulus of the base film layer is not less than 0.1 GPa and not greater than 100 GPa; or The material modulus of the buffer layer is not less than 10 kPa and not greater than 2 GPa; or The material modulus of the first adhesive layer and the second adhesive layer is not less than 10 kPa and not greater than 10 MPa.

9. A foldable terminal, characterized in that, include: Folded mid-frame; A foldable screen is connected to one side of the foldable frame; as well as The protective film according to any one of claims 1 to 8 is bonded to the surface of the folding screen by the first adhesive layer.

10. The folding terminal according to claim 9, characterized in that, Also includes: A pressure frame is provided on the periphery of the foldable screen and connected to the foldable middle frame; Wherein, the orthographic projection of the intersection line of the first edge side and the first adhesive surface on the folding screen and the orthographic projection of the inner edge of the pressing frame on the folding screen have a second distance, and the orthographic projection of the main body layer on the folding screen and the orthographic projection of the inner edge of the pressing frame on the folding screen have a third distance, wherein the second distance is greater than 0.3 mm and less than 0.5 mm, and the third distance is greater than 0 and less than the second distance.

11. The folding terminal according to claim 9, characterized in that, At least a portion of the outline edge of the main body layer is located inside the outline edge of the foldable screen; or At least a portion of the outline edge of the main body layer is located outside the outline edge of the foldable screen; or At least a portion of the outline edge of the main body layer coincides with the outline edge of the foldable screen.

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