Display module, assembly method therefor and electronic device

Abstract

A display module (10), an assembly method therefor, and an electronic device (1). The display module (10) comprises a screen protection layer (16), a first connection layer (191), a display screen (13), a second connection layer (192) and a back film (14). The screen protection layer (16) is located on a light emitting side of the display screen (13). The first connection layer (191) is located between the display screen (13) and the screen protection layer (16) and is used for connecting the display screen (13) and the screen protection layer (16). The back film (14) is located on the back surface of the display screen (13), the modulus of the material of the back film (14) being 10GPa-500GPa. The second connection layer (192) is located between the display screen (13) and the back film (14) and is used for connecting the back film (14) and the display screen (13). Compared with a PI (or PET) back film, the back film (14) has an obviously reduced thickness at the same stiffness, and an obviously improved stiffness at the same thickness. Therefore, the back film (14) having a less thickness and a stiffness meeting a requirement can be obtained, thereby effectively improving the back pressing impact resistance of the display module (10).

Description

Display module, assembly method thereof, and electronic device

[0001] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office on January 5, 2024, with application number 202410029179.7 and invention name “Display module, assembly method thereof, and electronic device”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of display technology, and in particular to a display module and an assembly method thereof, and an electronic device. Background Art

[0003] With the continuous development of display technology, foldable electronic devices are becoming a trend in future mobile electronic products. When unfolded, these devices can provide a larger display area, improving viewing experience. When folded, they can also be compact, making them easier to carry.

[0004] Flexible displays are a key component of foldable electronic devices. Due to the special properties of their materials, they are susceptible to damage from external forces. For this reason, a backside protective layer is typically placed on the backside of the display. Because the electronic device as a whole must possess the primary bendability, the backside protective layer also needs to exhibit primary bendability. This results in the electronic device being unable to balance primary bendability with both the display's backside impact resistance and the thickness of the backside protective layer.

[0005] Summary of the Invention

[0006] The embodiments of the present application provide a display module and an assembly method thereof, and an electronic device, which are used to meet the back compression impact performance of the display screen while taking into account the thickness performance of the electronic device.

[0007] To achieve the above objectives, this application adopts the following technical solutions:

[0008] According to a first aspect of an embodiment of the present application, a display module is provided, which is a foldable display module. The display module includes: a screen protection layer, a first connection layer, a display screen, a second connection layer, and a back film. The display screen is located in the first non-bending area, the second non-bending area, and the first bendable area, and the screen protection layer is located on the light-emitting side of the display screen. The first connection is located between the display screen and the screen protection layer, and is used to connect the display screen and the screen protection layer. The back film is located on the back of the display screen, and the back film is a single-film structure. The modulus of the material of the back film is 10GPa-500GPa. The second connection layer is located between the display screen and the back film, and is used to connect the back film and the display screen.

[0009] The foldable display module provided in the embodiment of the present application has a back film material with a modulus of 10GPa-500GPa and a high-rigidity material, and the modulus of the back film material is much greater than that of materials such as PI and PET. Therefore, the back film of the embodiment of the present application is compared with the PI (or PET) back film: at the same stiffness, the thickness can be significantly thinned. At the same thickness, the stiffness can be significantly improved. Therefore, a back film with a stiffness that meets the requirements and a thinner thickness can be obtained, thereby effectively improving the extrusion impact reliability of the display screen in the first bendable area and improving the back extrusion impact performance of the display module. Moreover, it was found through simulation that the display screen is supported by a back film of a single film layer, and the creases of the display module are smoother, the overall refinement (creases and large-surface light and shadow) is higher, and the anti-rebound ability of the unfolded state is stronger.

[0010] In a possible implementation, the back film is formed of the same material, which makes the back film structure simple and the process simple.

[0011] In one possible implementation, in the flattened state, the display module has a first non-bending area, a second non-bending area, and a first bendable area connecting the first non-bending area and the second non-bending area along the horizontal direction. The display module provided in this application can be applied to a two-fold electronic device.

[0012] In one possible implementation, the display module further includes a functional layer located on the back of the display screen and laminated with the backing film. The projection of the functional layer on the display screen overlaps the first non-bending area, the second non-bending area, and the first bendable area. In this embodiment of the present application, the backing film can support the cross-axis functional layer, eliminating the need to position the cross-axis functional layer beneath the bamboo book, thereby simplifying the display module architecture.

[0013] In one possible implementation, the display module further comprises a second bendable region and a third non-bending region, wherein the second bendable region connects the second non-bending region and the third non-bending region. The display module provided in this application can also be applied to multi-fold electronic devices.

[0014] In one possible implementation, the projection of the functional layer on the display screen also overlaps with both the third non-bending area and the second bendable area. In this embodiment of the present application, the cross-axis functional layer can be carried by the back film, eliminating the need to place the cross-axis functional layer under the bamboo book, thereby simplifying the display module architecture.

[0015] In one possible implementation, the functional layer includes a wiring layer; the wiring layer is located on the side of the back film away from the display screen. If the cross-axis wiring layer is set on the middle frame, if it is arranged inside the first hinge mechanism, there will be a problem of the hinge door panel being pushed up during the bending process. If it crosses the upper part of the first hinge mechanism, there will be a problem of pushing up the display screen during the bending process. In addition, the design difficulty of the first hinge mechanism is increased and the utilization rate of the entire machine space is reduced. However, the present application integrates the cross-axis wiring layer inside the display module, which can improve the above problems and simplify the design.

[0016] In one possible implementation, the surface of the back film away from the display screen has a groove, and the wiring layer is arranged in the groove, which can improve the film printing problem caused by the wiring layer.

[0017] In one possible implementation, the functional layer includes a heat-conducting layer located on the side of the back film away from the display screen. By integrating a cross-axis heat dissipation functional layer within the display module, it is possible to effectively reduce the concentration of heat generated by the system-on-chip in electronic devices, increase heat dissipation uniformity, and further enhance the heat dissipation capacity of electronic devices.

[0018] In one possible implementation, the heat-conducting layer is made of graphene, which is a material with good heat conductivity and low cost.

[0019] In one possible implementation, the functional layer includes a light-absorbing layer located on the side of the backing film facing the display. This layer can enhance the lighting and shadow effects across the display module, improving its overall sophistication. It also serves as a transition layer between the backing film and the second connecting layer, improving the connection between the backing film and the display.

[0020] In a possible implementation, the light absorbing layer is made of ink, epoxy resin, polyester, or acrylic acid, which are materials with good light absorbing effects and low costs.

[0021] In one possible implementation, the functional layer includes a connection transition layer, which is located on the side of the back film away from the display screen. By providing the connection transition layer on the side of the back film away from the display screen, the connection effect between the back film and the third connection layer can be improved.

[0022] In one possible implementation, the material of the connecting transition layer includes a polar material containing hydrogen bonds, which is a material with good connection effect and low cost.

[0023] In a possible implementation, a slit is provided on the back film, and the slit is arranged near the first bendable area. By providing the slit on the back film, the first bendability of the back film can be reduced and enhanced.

[0024] In one possible implementation, the back film has a thickness of 15 μm to 45 μm. The back film in the embodiment of the present application has a relatively high modulus and is highly resistant to back compression and impact. Therefore, rather than increasing the thickness of the back film to improve its resistance to back compression and impact, the back film can be made 15 μm to 45 μm thick, which, while ensuring resistance to back compression and impact, facilitates achieving a thinner and lighter display module.

[0025] In a possible implementation, the material of the back film includes SUS, copper, aluminum, copper alloy, aluminum alloy, UTG, glass fiber, carbon fiber, ceramic or polymer material, etc. These are materials with high modulus and low cost.

[0026] In one possible implementation, the back film comprises a conductive material, the display module further comprises a grounded conductive layer and a transition portion, and the back film is coupled to the grounded conductive layer via the transition portion. Connecting the conductive back film to the grounded conductive layer via the transition portion enables the back film to meet ESD requirements and maintains a simple structure.

[0027] In one possible implementation, the display module further includes a bamboo book, which is located on the side of the back film away from the display screen. The bamboo book includes a first non-bending portion, a second non-bending portion, and a first bendable portion. The first non-bending portion is located in the first non-bending region, the second non-bending portion is located in the second non-bending region, and the first bendable portion is located in the first bendable region. The first bendable portion includes, in order from the first non-bending portion to the second non-bending portion, a first portion, a second portion, a third portion, a fourth portion, and a fifth portion. The second portion has a stiffness greater than that of the third portion and less than that of the first portion, and the fourth portion has a stiffness greater than that of the third portion and less than that of the fifth portion. The first bendable portion in the bamboo book includes at least five portions, and the stiffness gradually increases from the third portion to the second portion, to the first portion, and then to the first non-bending portion. The stiffness gradually increases from the third portion to the fourth portion, to the fifth portion, and then to the second non-bending portion. This creates a smooth transition and continuity in the stiffness of the first bendable portion, thereby increasing the arch radius and reducing the arch height. This effectively reduces the arch height of the display module at the first bendable area during a drop from the unfolded state, improving the display module's ability to resist arching. Furthermore, the bamboo book's smooth transition in stiffness further enhances the smoothness of the display module's water droplet shape. Furthermore, the tensile force of the bamboo book is dissipated by the holes, allowing it to fully or nearly fully return to its original state after the display module transitions from a folded state to an unfolded state.

[0028] In one possible implementation, the first, second, third, fourth, and fifth portions are all provided with holes. The hole density of the second portion is greater than that of the first portion and less than that of the third portion. The hole density of the fourth portion is greater than that of the fifth portion and less than that of the third portion. Adjusting the stiffness of each portion of the first bendable portion by providing holes is structurally simple and easy to implement.

[0029] In one possible implementation, the holes in the first, second, and third portions have different shapes, the holes in the first and fifth portions have the same shape, and the holes in the second and fourth portions have the same shape. This improves the symmetry of the first bendable portion, facilitating symmetrical absorption of bending forces.

[0030] In one possible implementation, the bamboo book also includes a second bendable portion and a third non-bendable portion; the second bendable portion is located in the second bendable region, and the third non-bendable portion is located in the third non-bendable region; along the direction from the second non-bendable portion to the third non-bendable portion, the second bendable portion includes a sixth portion, a seventh portion, an eighth portion, a ninth portion, and a tenth portion, arranged in sequence; the stiffness of the seventh portion is greater than that of the eighth portion and less than that of the sixth portion, and the stiffness of the ninth portion is greater than that of the eighth portion and less than that of the tenth portion. This bamboo book design can be used in electronic devices that fold inward and outward.

[0031] In one possible implementation, the display module also includes a bamboo book, located on the side of the back film away from the display screen. The bamboo book includes a first non-bending portion, a second non-bending portion, and a first bendable portion. The first non-bending portion is located in the first non-bending region, the second non-bending portion is located in the second non-bending region, and the first bendable portion is located in the first bendable region. The stiffness of the first bendable portion is less than that of the first non-bending portion and the second non-bending portion. This bamboo book design can be used in single-folding electronic devices.

[0032] In one possible implementation, the bamboo book further includes a second bendable portion and a third non-bendable portion; the second bendable portion is located in the second bendable region, and the third non-bendable portion is located in the third non-bendable region; the second bendable portion has a lower stiffness than the second and third non-bendable portions. This bamboo book design can be used in electronic devices with either external-folding or internal-folding configurations.

[0033] In one possible implementation, the screen protection layer includes a surface layer and at least one anti-extrusion layer; the surface layer is located on the side of the at least one anti-extrusion layer away from the display screen, and the modulus of the anti-extrusion layer is 10GPa-500GPa. Using a high-modulus material to form the anti-extrusion layer can improve the screen protection layer's anti-extrusion, impact, and creep resistance, thereby meeting the demand for thinness and lightweight while improving the display module's reliability against creases and extrusion impacts.

[0034] In a possible implementation, the material of the anti-extrusion layer includes UTG or high entropy glass. These materials can form an anti-extrusion layer with good bending effect, good impact resistance and thin thickness.

[0035] In one possible implementation, the anti-extrusion layer comprises metal, and the thickness of the anti-extrusion layer is less than 50 μm. Metal with a thickness less than 50 μm has a first bendability, which can meet the trend of thinner and lighter film layers while improving the impact and extrusion resistance of the screen protection layer.

[0036] In one possible implementation, the thickness of the first connection layer and the second connection layer is 10 μm-75 μm. The thickness of the first connection layer and the second connection layer is limited to the range of 10 μm-75 μm, which can still ensure the impact resistance and compression resistance of the display module.

[0037] According to a second aspect of an embodiment of the present application, an electronic device is provided. The electronic device includes a display module and a middle frame, where the display module is arranged on the middle frame; the display module includes any display module of the first aspect.

[0038] A third aspect of the embodiments of the present application provides a method for assembling a display module, comprising: providing a display screen laminate, the display screen laminate comprising a display screen, a connecting layer, and a backing film, the backing film being connected to the back of the display screen via the connecting layer; the display screen comprising a display portion, a bending portion, and a binding portion; the backing film covering the display portion, the bending portion, and the binding portion; forming a mark on the side of the backing film away from the display screen, removing the portion of the backing film and the connecting layer that overlaps with the bending portion, such that the projection of the mark on the display screen is located on the display portion; and aligning the mark to form a bamboo book that overlaps with the display portion. Since the backing film is made of an opaque material, the mark on the display screen cannot be recognized when the bamboo book is formed. Therefore, forming the mark on the surface of the backing film allows for the feasibility of laminating the bamboo book to the backing film.

[0039] In one possible implementation, a mark is formed on the side of the backing film away from the display screen, and the portion of the backing film and connecting layer that overlaps the bend is removed. This method includes: placing the display screen stack on a carrier of a transfer device, with the light-emitting side of the display screen facing the carrier; using a gripper probe of the transfer device to grasp the display portion of the display screen; using a laser probe at the bottom of the transfer device to form a mark on the surface of the backing film away from the display screen; and using a laser to remove the portion of the backing film and connecting layer that overlaps the bend. This is a simple implementation method. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] FIG1A is a schematic structural diagram of an electronic device provided in an embodiment of the present application;

[0041] 1B and 1C are schematic diagrams of an electronic device in a folded state provided by an embodiment of the present application;

[0042] FIG2 is a structural diagram of a display module provided in an embodiment of the present application;

[0043] FIG3A is a side view of a bamboo book provided in an embodiment of the present application;

[0044] FIG3B is a top view of a bamboo book provided in an embodiment of the present application;

[0045] FIG3C is a cross-sectional view of a bamboo book provided in an embodiment of the present application;

[0046] FIG3D is a schematic diagram of an inverted arch of a display module provided in an embodiment of the present application;

[0047] FIG4A is a cross-sectional view of a display module and a middle frame provided in an embodiment of the present application;

[0048] FIG4B is a top view of an under-screen buffer layer and a middle frame provided in an embodiment of the present application;

[0049] FIG5A is a cross-sectional view of a display module and a middle frame provided in an embodiment of the present application;

[0050] FIG5B is a top view of a cross-axis functional layer and a middle frame provided in an embodiment of the present application;

[0051] FIG6 is a schematic structural diagram of a display module provided in an embodiment of the present application;

[0052] FIG7 is a schematic structural diagram of a screen protection layer provided in an embodiment of the present application;

[0053] FIG8 is a schematic structural diagram of a display screen in an unfolded state provided by an embodiment of the present application;

[0054] FIG9A is a schematic structural diagram of a display module provided in an embodiment of the present application;

[0055] FIG9B is a crease simulation effect diagram of a display module provided in an embodiment of the present application;

[0056] 10A and 10B are schematic structural diagrams of a display module provided in an embodiment of the present application;

[0057] FIG11 is a schematic structural diagram of a display module provided in an embodiment of the present application;

[0058] FIG12A is a top view of a bamboo book provided in an embodiment of the present application;

[0059] FIG12B is a side view of a bamboo book provided in an embodiment of the present application;

[0060] FIG12C is a diagram showing the relative relationship between a bamboo book and a hinged door panel provided in an embodiment of the present application;

[0061] FIG12D is a top view of a bamboo book provided in an embodiment of the present application;

[0062] FIG13A is a schematic structural diagram of a display module provided in an embodiment of the present application;

[0063] FIG13B is a schematic structural diagram of a display module provided in an embodiment of the present application;

[0064] FIG14A is a schematic top view of a functional layer provided in an embodiment of the present application;

[0065] FIG14B is a schematic top view of another functional layer provided in an embodiment of the present application;

[0066] FIG15 is a schematic diagram of the relative relationship between a wiring layer and a back film provided in an embodiment of the present application;

[0067] FIG16 is a schematic structural diagram of a display module provided in an embodiment of the present application;

[0068] FIG17 is a schematic structural diagram of a display module provided in an embodiment of the present application;

[0069] FIG18 is a flow chart of a method for assembling a display module according to an embodiment of the present application;

[0070] FIG19 is a schematic diagram of a partial assembly process of a display module provided in an embodiment of the present application;

[0071] FIG20A is a schematic diagram of an electronic device in an unfolded state provided by an embodiment of the present application;

[0072] FIG20B is a cross-sectional view of an electronic device provided in an embodiment of the present application;

[0073] FIG21A is a schematic diagram of an electronic device in a folded state provided by an embodiment of the present application;

[0074] FIG21B is a schematic top view of a bamboo book provided in an embodiment of the present application;

[0075] FIG22A is a schematic diagram of an electronic device in a folded state provided by an embodiment of the present application;

[0076] FIG22B is a schematic top view of a bamboo book provided in an embodiment of the present application;

[0077] FIG23A is a schematic diagram of an electronic device in a folded state provided by an embodiment of the present application;

[0078] FIG23B is a schematic top view of a bamboo book provided in an embodiment of the present application. DETAILED DESCRIPTION

[0079] The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments.

[0080] Hereinafter, the terms "second," "first," etc., are used for descriptive convenience only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature qualified as "second," "first," etc., may explicitly or implicitly include one or more of such features. In the description of this application, unless otherwise specified, "plurality" means two or more.

[0081] In addition, in the embodiments of the present application, directional terms such as "up", "down", "left", and "right" may be defined including but not limited to the orientation relative to the schematic placement of the components in the drawings. It should be understood that these directional terms may be relative concepts, which are used for relative descriptions and clarifications, and may change accordingly according to changes in the orientation of the components in the drawings.

[0082] In the embodiments of this application, unless otherwise specified or limited, the term "connection" should be understood in a broad sense. For example, "connection" can mean fixed connection, detachable connection, or integration; it can mean direct connection or indirect connection through an intermediate medium. In addition, the term "coupling" can mean direct electrical connection or indirect electrical connection through an intermediate medium. The term "contact" can mean direct contact or indirect contact through an intermediate medium.

[0083] In the embodiments of the present application, "and / or" describes the relationship between associated objects, indicating that three possible relationships exist. For example, "A and / or B" can represent: A exists alone, A and B exist simultaneously, and B exists alone. A and B can be singular or plural. The character " / " generally indicates that the associated objects are in an "or" relationship.

[0084] An embodiment of the present application provides an electronic device, which may be, for example, a foldable electronic device. The electronic device may be, for example, a consumer electronic product, a home electronic product, a vehicle-mounted electronic product, or a financial electronic product. Among them, consumer electronic products include mobile phones, tablet computers, laptop computers, e-readers, personal computers (PCs), personal digital assistants (PDAs), desktop displays, smart wearable products (for example, smart watches, smart bracelets), virtual reality (VR) electronic devices, augmented reality (AR) electronic devices, drones, etc. Home electronic products include smart door locks, televisions, refrigerators, rechargeable small household appliances (for example, soymilk machines, sweeping robots), etc. Vehicle-mounted electronic products include car navigation systems, car DVDs, etc. Financial electronic products include ATM machines, electronic devices for self-service transactions, etc.

[0085] FIG1A is a schematic structural diagram of an electronic device provided in an embodiment of the present application, and FIG1B and FIG1C are schematic diagrams of a folded state of an electronic device provided in an embodiment of the present application.

[0086] To facilitate understanding of the electronic device provided in the embodiments of the present application, a bifold electronic device is described below with reference to FIG. 1A :

[0087] As shown in Figure 1A, electronic device 1 includes a display module 10, a middle frame 20, and a back cover (also known as a rear shell, battery cover, etc., not shown in Figure 1A). The display module 10 is disposed on the middle frame 20, which is used to support the display module 10. The back cover is disposed on the middle frame 20, forming a storage space with the side of the middle frame 20 away from the display module 10.

[0088] The middle frame 20 includes a first frame body 201, a second frame body 202, and a first hinge mechanism 203. The first frame body 201 and the second frame body 202 are arranged on both sides of the first hinge mechanism 203, and the first hinge mechanism 203 is connected to the first frame body 201 and the second frame body 202, respectively. The first frame body 201 and the second frame body 202 can be used to carry the flexible display module 10, so that the flexible display module 10 remains as flat as possible during use, and the non-display surface of the flexible display module 10 is protected. For example, a portion of the display module 10 is fixed to the first frame body 201 by an adhesive layer, and a portion is fixed to the second frame body 202 by an adhesive layer. The adhesive layer can be a thin film layer formed after applying glue, and the embodiment of the present application does not limit the specific form of the adhesive layer.

[0089] In addition, other electronic components may be disposed on the side of the first frame 201 and the second frame 202 away from the display module 10, such as a printed circuit board (PCB), a battery, a receiver, a speaker, a camera, etc. The PCB may integrate electronic components such as the main controller, storage unit, antenna module, and power management module of the electronic device, while the battery may power the display module 10, the circuit board, the receiver, the speaker, the camera, and other electronic components. Of course, the embodiments of the present application do not limit the electronic components disposed on the first frame 201 and the second frame 202.

[0090] For example, the electronic device 1 is a foldable electronic device, and the display module 10 is a foldable display module. In some embodiments, in the flattened state, the display module 10 has a first non-bending area 101, a second non-bending area 102, and a first bendable area 103 connecting the first non-bending area 101 and the second non-bending area 102 along the horizontal direction. For example, the display module 10 may include a first non-bending area 101 corresponding to the first frame 201, a second non-bending area 102 corresponding to the second frame 202, and a first bendable area 103 corresponding to the first hinge mechanism 203. The first non-bending area 101 can be connected to the first frame 201, and the second non-bending area 102 can be connected to the second frame 202.

[0091] Under the action of the first hinge mechanism 203, the first frame 201 and the second frame 202 can move closer to or farther from each other. Accordingly, the first non-bending area 101 and the second non-bending area 102 of the display module 10 can move closer to or farther from each other, allowing the display module 10 to be folded or unfolded.

[0092] In the embodiment of the present application, the direction from the first non-bending region 101 to the second non-bending region 102 is defined as a first direction X, which is perpendicular to the first hinge mechanism 203. The extension direction of the first hinge mechanism 203 is defined as a second direction Y, which intersects (e.g., is perpendicular to) the first direction X. The first direction X is the horizontal direction described above. The thickness direction of the electronic device 1 is defined as a third direction Z, which intersects (e.g., is perpendicular to) both the first direction X and the second direction Y.

[0093] As shown in Figures 1B and 1C, in the folded state, the angle α between the first frame 201 and the second frame 202 can be rotated from 180° to the first frame 201 and the second frame 202 being parallel to each other and opposite to each other, and the spacing between the first frame 201 and the second frame 202 is minimized. At this time, the first non-bending area 101 and the second non-bending area 102 can be considered to be arranged on different planes. Figure 1B illustrates the electronic device 1 when the display module 10 faces inward and the first non-bending area 101 and the second non-bending area 102 face each other (inward folding) as an example. Figure 1C illustrates the electronic device 1 when the display module 10 faces outward and the first frame 201 and the second frame 202 face each other (outward folding) as an example. In the folded state, the first non-bending area 101 and the second non-bending area 102 can be parallel to each other and opposite to each other, and the spacing height between the first non-bending area 101 and the second non-bending area 102 is minimized.

[0094] As shown in FIG. 1A , in the unfolded state, the angle α between the first frame body 201 and the second frame body 202 may be approximately 180°.

[0095] FIG2 is an architecture diagram of a display module provided in an embodiment of the present application.

[0096] Unlike standard electronic devices, foldable electronic devices require the primary bendability feature. Therefore, the display module 10 is primarily composed of multiple layers of relatively low-rigidity flexible materials. As shown in Figure 2, the display module 10 can be roughly divided into five layers: a protective film 11, a cover 12, a display screen (or display panel) 13, a backing film 14, and a bamboo bracket (BKT) 15.

[0097] The protective film layer 11 protects the display screen 13 and prevents the cover plate 12 from bursting. The cover plate 12 plays a protective role, just like the glass cover plate of a straight-screen electronic device. The display screen 13 is used to realize functions such as touch and lighting, the back film 14 is used to support and protect the display screen 13, and the bamboo book 15 is used to support the back of the display screen 13. The protective film layer 11 and the cover plate 12 are located on the light-emitting side of the display screen 13, and the back film 14 and the bamboo book 15 are located on the back of the display screen 13. The protective film layer 11 and the cover plate 12 can be connected by an optically clear adhesive (OCA), the cover plate 12 and the display screen 13 can be connected by, for example, OCA, the display screen 13 and the back film can be connected by, for example, pressure sensitive adhesives (PSA), and the back film 14 and the bamboo book 15 can be connected by, for example, OCA.

[0098] In order to achieve flexibility, the display screen 13 can be, for example, a self-luminous display screen, without the need for a backlight module (BLM). For example, the display screen 13 is a self-luminous display screen such as an organic light emitting diode (OLED) display screen, an active-matrix organic light-emitting diode (AMOLED) display screen, a mini organic light-emitting diode (Mini-OLED) display screen, a micro light-emitting diode (Micro-LED) display screen, a micro organic light-emitting diode (Micro-OLED) display screen, a quantum dot light emitting diode (QLED) display screen, etc. In the embodiment of the present application, the surface of the display screen 13 used to display the image is the light-emitting surface of the display screen 13, the surface opposite to the light-emitting surface is the back of the display screen 13, and the side where the light-emitting surface of the display screen 13 is located is the light-emitting side of the display screen 13.

[0099] To achieve flexibility, the materials of the protective film layer 11, cover plate 12, back film 14, and bamboo book 15 are mostly polymer materials. When the display screen 13 is subjected to stress scenarios such as drop impact, pointed extrusion, etc., the display screen 13 is very likely to fail due to black spots, broken bright spots, etc., which affects the display and touch functions, and its reliability is not as good as a straight-screen display. At the same time, because the display module 10 needs to have the first bendable performance, it is usually necessary to perform a hole opening process on the axis area of ​​the bamboo book 15. The rigidity of the hinge area will be smaller than that of the large surface area, so the extrusion and impact performance of the back of the axis area will be worse. At the same time, as the thickness of the foldable electronic device is further reduced, the thickness of the display module 10 will be reduced. After the thickness of the display module 10 is reduced, the extrusion and impact performance, the risk of the display screen 13 arching when the electronic device 1 falls, and the refinement of the display module 10 (for example, the light and shadow performance of the first non-bending area 101 and the second non-bending area 102 and the crease of the first bendable area 103) will all be challenges.

[0100] Several structures of the display module 10 are exemplified below.

[0101] In some embodiments, the cover plate 12 is made of polyethylene terephthalate (PET) with a thickness of about 50 μm or colorless polyimide (CPI) with a thickness of about 50 μm.

[0102] Although PET and CPI can meet the first bendability, due to the relatively small modulus of PET and CPI, when the display module 10 is squeezed or impacted, they cannot absorb or dissipate enough energy like the glass cover in a straight-screen electronic device, and their protective performance is poor.

[0103] To enhance the protective performance of the cover plate 12, some embodiments employ a stacked arrangement of multiple protective layers, connected by OCAs of varying thicknesses. This improves the cover plate 12's ability to absorb impact or compression. However, with the current trend of decreasing thickness of display modules 10, the number of protective layers and the thickness of OCAs are decreasing. This results in a limited ability of the cover plate 12 to absorb impact or compression, a problem that remains to be addressed.

[0104] Figure 3A is a side view of a bamboo book provided in an embodiment of the present application, Figure 3B is a top view of a bamboo book provided in an embodiment of the present application, Figure 3C is a cross-sectional view of a bamboo book provided in an embodiment of the present application, and Figure 3D is a schematic diagram of an inverted arch of a display module provided in an embodiment of the present application.

[0105] In some embodiments, the bamboo book 15 is made of carbon fiber. As shown in Figure 3A , when the electronic device is bent, the bamboo book 15 needs to bend into a "teardrop" shape in conjunction with the display screen 13. The bamboo book 15 includes a first non-bending portion 151, a second non-bending portion 152, and a first bendable portion 153. The first bendable portion 153 is bent into a "teardrop" shape. The first bendable portion 153 has a hole.

[0106] The first non-bending portion 151 is located in the first non-bending area 101, the second non-bending portion 152 is located in the second non-bending area 102, and the first bendable portion 153 is located in the first bendable area 103. The first bendable portion 153 has a hole to reduce rigidity and achieve bending function.

[0107] The first bendable portion 153 includes a first portion 1531, a third portion 1533, a fifth portion 1535, a second portion 1532 located between the first and third portions 1533, and a fourth portion 1534 located between the first and fifth portions 1531, 1535. The first, third, and fifth portions 1531, 1533, and 1535 all have holes, while the second and fourth portions 1532, 1534 do not. The second and fourth portions 1532, 1534 are connected to the hinge door panel of the first hinge mechanism 203 via adhesive dispensing, thereby connecting the first hinge mechanism 203 to the bamboo book 15. A top view of the bamboo book 15 is shown in FIG3B . The first non-bending portion 151, the first bendable portion 153, and the second non-bending portion 152 are arranged along the first direction X. The first portion 1531 may be understood as what is commonly referred to in the art as the “inner R zone”, and the third portion 1533 and the fifth portion 1535 may be understood as what is commonly referred to in the art as the “outer R zone”.

[0108] As shown in FIG3C , the second portion 1532 does not need to be opened, but the first portion 1531 and the third portion 1533 have holes, so there is a sudden change in stiffness in the second portion 1532. Similarly, there is also a sudden change in stiffness in the fourth portion 1534.

[0109] Because the first bendable portion of the bamboo book 15 contains an unperforated second portion 1532 and fourth portion 1534, sudden stiffness changes occur at the junctions of the first and second portions 1531 and 1532, and at the junctions of the second and third portions 1532 and 1533. There are two sudden stiffness changes between the first and third portions 1531 and 1533, with the stiffness increasing from small to large and then decreasing from large to small. Similarly, there are two sudden stiffness changes between the third and fifth portions 1533 and 1535. Hindered by the second and fourth portions 1532 and 1534, the arching deformation of the third portion 1533 when the bamboo book 15 falls in its unfolded state cannot propagate to the left or right. Instead, the third portion 1533 bears the entire arching force, with a radius equal to the length of the third portion 1533. This results in a relatively high arching bulge and poor arching strain. As shown in Figure 3D, the arching protrusion of the bamboo book 15 deteriorates the arching performance of the display module 10 when dropped in its unfolded state, leading to failure of the display screen 13 due to excessive strain. Furthermore, the lack of a smooth, rigid connection between the first portion 1531 and the third portion 1533 results in a less than smooth transition in the folded "waterdrop" screen's first bendable section. Furthermore, in the first bendable region 103, the perforation in the bamboo book 15 ensures bending, resulting in a significant weakness in the axial compression impact area below and behind the display screen 13.

[0110] 4A is a cross-sectional view of a display module and a middle frame provided in an embodiment of the present application, and FIG. 4B is a top view of an under-screen buffer layer and a middle frame provided in an embodiment of the present application.

[0111] In some embodiments, as shown in FIG. 4A , the material of the backing film 14 includes PET or polyimide (PI).

[0112] Since the stiffness of PET and PI is relatively low, only about 3 GPa, the impact and extrusion resistance of the back of the display screen 13 is relatively poor.

[0113] In some embodiments, the thickness of the backing film 14 is greater than 50 μm.

[0114] By increasing the thickness of the backing film 14, the rigidity of the backing film 14 can be increased, thereby improving the support for the display screen 13 and improving the reliability of the display screen 13. However, this will make the display module 10 too thick, which is not conducive to achieving lightweight and thinness. Moreover, the problem of the bamboo book 15 being bent backward remains unresolved.

[0115] In some embodiments, as shown in FIG4A , the electronic device further includes an under-screen buffer layer.

[0116] The under-screen buffer layer is located below the bamboo book 15 and above the first hinge mechanism 203. As shown in FIG4B , the under-screen buffer layer can cover the first hinge mechanism 203. The under-screen buffer layer is used to absorb external pressure and impact, thereby improving the reliability of the display module 10 in the first bendable area 103.

[0117] However, the provision of an under-screen buffer layer, on the one hand, increases the complexity of the display module 10 architecture. Furthermore, since the gap between the display module 10 and the first hinge mechanism 203 is filled, the uncertainty of the middle frame 20 is coupled, introducing new problems during the bending process. For example, the under-screen buffer layer may easily interfere with the first hinge mechanism 203, causing abnormal noise, and wear and tear of the first hinge mechanism 203 or the under-screen buffer layer. Furthermore, the thickness of the first hinge mechanism 203 is sacrificed in the overall design of the electronic device 1, increasing the gap between the bamboo book 15 and the middle frame 20.

[0118] FIG5A is a cross-sectional view of a display module and a middle frame provided in an embodiment of the present application, and FIG5B is a top view of a cross-axis functional layer and the middle frame provided in an embodiment of the present application.

[0119] In some embodiments, as shown in FIG5A , a cross-axis functional layer is disposed below the bamboo book 15 .

[0120] As shown in FIG. 5B , the so-called cross-axis means that the functional layer is located above the first frame 201 and extends across the first rotating shaft mechanism 203 to above the second frame 202 .

[0121] For example, by using the cross-axis functional layer as a wiring layer, the cross-axis functional layer is coupled to the first circuit board corresponding to the first non-bending area 101 and the second circuit board corresponding to the second non-bending area 102 through a flexible printed circuit (FPC) to achieve connectivity between the first circuit board and the second circuit board.

[0122] Alternatively, for example, the cross-axis functional layer is a graphite sheet, and heat conduction between the first frame body 201 and the second frame body 202 can be achieved through the cross-axis functional layer.

[0123] A cross-axis functional layer is provided under the bamboo book 15. Although the cross-axis functional layer can absorb external extrusion and impact, thereby improving the reliability of the display module 10 in the first bendable area 103. However, the cross-axis functional layer occupies the space in the thickness direction of the entire electronic device 1, and also occupies the space in the horizontal direction. In addition, since the cross-axis functional layer does not cover the first frame 201 and the second frame 202 (it is not fully covered in the entire horizontal plane), it will cause a visual effect problem of the mold due to the step difference in the horizontal expansion state. At the same time, during the bending process, the cross-axis functional layer is highly coupled with the display screen 13 and the first rotating shaft mechanism 203, which will cause the cross-axis functional layer to support the screen, top the screen, and interfere with the first rotating shaft mechanism 203 during bending, thereby worsening the bending reliability of the display module 10.

[0124] Because the bamboo book 15 of the foldable display module 10 requires a hole in the first bendable portion 153 to achieve a teardrop-shaped bend, the increasing demand for reduced rebound force in the overall device architecture inevitably leads to an increase in the porosity of the first bendable portion 153. Furthermore, the continuous iteration of ultra-thinning solutions for the display module 10 has resulted in a lack of a high-rigidity support solution in the first bendable region 103 of the display module 10, making it impossible to protect the display screen 13 from the back. Furthermore, as the teardrop-shaped bend radius continues to decrease, the crease will be further exacerbated. Based on the above description, it can be seen that while the display module 10 is constantly being improved, it still has various issues that need to be addressed.

[0125] FIG6 is a schematic structural diagram of a display module provided in an embodiment of the present application.

[0126] The present embodiment provides a display module 10. As shown in FIG6 , the display module 10 comprises a first non-bending region 101, a second non-bending region 102, and a first bendable region 103. The first bendable region 103 connects the first non-bending region 101 and the second non-bending region 102. When the display module 10 is used in an electronic device 1, the display module 10 is disposed on a middle frame 20. The first non-bending region 101 corresponds to the first frame 201, the second non-bending region 102 corresponds to the second frame 202, and the first bendable region 103 corresponds to the first hinge mechanism 203.

[0127] The display module 10 includes a screen protection layer 16 , a first connection layer 191 , a display screen 13 , a second connection layer 192 , and a back film 14 .

[0128] The embodiment of the present application does not limit the structure of the screen protection layer 16 , and all screen protection layers in related technologies are applicable to the embodiment of the present application.

[0129] FIG7 is a schematic structural diagram of a screen protection layer provided in an embodiment of the present application.

[0130] In some embodiments, as shown in FIG7 , the screen protection layer 16 includes a surface layer 161, at least one anti-extrusion layer 162, and at least one connecting layer 163. FIG7 illustrates an example in which the screen protection layer 16 includes three anti-extrusion layers 162. A connecting layer 163 is provided between the surface layer 161 and the topmost anti-extrusion layer 162, and the surface layer 161 and the topmost anti-extrusion layer 162 are connected via the connecting layer 163. A connecting layer 163 is provided between adjacent anti-extrusion layers 162, and adjacent anti-extrusion layers 162 are connected via the connecting layer 163.

[0131] Surface layer 161 is located on the side of at least one anti-extrusion layer 162 away from display screen 13. In electronic device 1, surface layer 161 is a touchable layer that provides scratch and explosion protection. Exemplary materials for surface layer 161 include high-modulus transparent polymer materials such as PET, CPI, fiberglass, and CPI composite materials. The anti-extrusion layer 162 furthest from surface layer 161 of the at least one anti-extrusion layer 162 is connected to display screen 13 via a first connecting layer 191.

[0132] In some embodiments, the material of the anti-extrusion layer 162 includes low modulus polymer materials such as PET and CPI.

[0133] In other embodiments, the material of the anti-extrusion layer 162 includes a high modulus material.

[0134] For example, the modulus of the material of the anti-extrusion layer 162 is 10 GPa-500 GPa. For example, the modulus of the material of the anti-extrusion layer 162 is 10 GPa, 50 GPa, 100 GPa, 150 GPa, 200 GPa, 250 GPa, 300 GPa, 350 GPa, 400 GPa, 450 GPa, or 500 GPa.

[0135] For example, the material of the anti-extrusion layer 162 includes ultra-thin glass (UTG) or high entropy glass.

[0136] The anti-extrusion layer 162 is formed of a high modulus material, which can improve the anti-extrusion, anti-impact, and anti-creep properties of the screen protection layer 16 , and improve the crease and extrusion impact reliability of the display module 10 .

[0137] In some embodiments, the anti-extrusion layer 162 is bonded to the surface layer 161 without being connected via the connection layer 163 .

[0138] UTG and high-entropy glass have good elasticity and recoverability. By adopting this multi-UTG or high-entropy glass screen protection layer 16 structure, the recoverability of creases is also greatly improved.

[0139] Alternatively, for example, the anti-extrusion layer 162 includes metal, and the thickness of the anti-extrusion layer 162 is less than 50 μm. For example, the thickness of the anti-extrusion layer 162 is 50 μm, 45 μm, 40 μm, 35 μm, 30 μm, 25 μm, 20 μm, 15 μm, 10 μm, or 5 μm.

[0140] Metal with a thickness of less than 50 μm has a first bendability, which can not only meet the trend of thinner and lighter film layers, but also improve the impact resistance and extrusion resistance of the screen protection layer 16 .

[0141] The material of the connection layer 163 may include, for example, OCA, thermoplastic polyurethanes (TPU), nylon elastomer, silicone gel, or other high-viscosity and high-recovery rubber materials with energy-absorbing and light-transmitting properties.

[0142] The embodiment of the present application uses a connecting layer 163 to achieve the connection between the high-modulus "hard" layers such as the surface layer 161 and the anti-extrusion layer 162, while achieving the flexibility of bending and the repairability of creases.

[0143] For example, the thickness of the connecting layer 163 is 10 μm to 75 μm. For example, the thickness of the connecting layer 163 is 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, 50 μm, 55 μm, 60 μm, 65 μm, 70 μm, or 75 μm.

[0144] In the embodiment of the present application, the thickness of the connection layer 163 is limited to the range of 10 μm-75 μm, which can still ensure the impact resistance and extrusion resistance of the display module 10.

[0145] In some embodiments, the material of the first connection layer 191 may include, for example, OCA, TPU, nylon elastomer, silicone gel, or other energy-absorbing and light-transmitting materials.

[0146] For example, the thickness of the first connection layer 191 is 10 μm to 75 μm. For example, the thickness of the first connection layer 191 is 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, 50 μm, 55 μm, 60 μm, 65 μm, 70 μm, or 75 μm.

[0147] In the embodiment of the present application, the thickness of the first connection layer 191 is limited to the range of 10 μm-75 μm, which can still ensure the impact resistance and extrusion resistance of the display module 10.

[0148] As shown in FIG6 , the display screen 13 is used to display images. The display screen 13 can be, for example, a flexible display screen with a touch function. For example, the display screen 13 includes a display portion 131, a bending portion 132, and a bonding portion 133. The display portion 131 of the display screen 13 is used to realize the display function of the display screen 13. The binding portion 133 is bent to the back of the display portion 131 through the bending portion 132. The binding portion 133 can be located, for example, below the first non-bending area 101. The display portion 131 can, for example, include a first display area, a second display area, and a first bendable display area. The first display area is located in the first non-bending area 101, the second display area is located in the second non-bending area 102, and the first bendable display area is located in the first bendable area 103.

[0149] The screen protection layer 16 is located on the light-emitting side of the display screen 13, and the first connection layer 191 is located between the display screen 13 and the screen protection layer 16 for connecting the display screen 13 and the screen protection layer 16. For example, the screen protection layer 16 and the first connection layer 191 at least cover the display portion 131 of the display screen 13.

[0150] In some embodiments, the back film 14 is located on the back of the display screen 13 , and the second connecting layer 192 is located between the display screen 13 and the back film 14 for connecting the display screen 13 and the back film 14 .

[0151] For example, the back surface of the display screen 13 is in contact with and connected to the second connection layer 192 , and the surface of the back film 14 facing the display screen 13 is in contact with and connected to the second connection layer 192 .

[0152] In the embodiment of the present application, the back film 14 is a single-layer structure, and the modulus of the material of the back film 14 is 10 GPa-500 GPa.

[0153] For example, the modulus of the material of the back film 14 is 10 GPa, 50 GPa, 100 GPa, 150 GPa, 200 GPa, 250 GPa, 300 GPa, 350 GPa, 400 GPa, 450 GPa, or 500 GPa.

[0154] For example, the material of the back film 14 includes stainless steel (SUS), copper, aluminum, copper alloy, aluminum alloy, UTG, glass fiber, carbon fiber, ceramic, or polymer materials. The back film 14 has a rich selection of materials and a wide range of applications. Moreover, the modulus of the material of the back film 14 is relatively large. After the display module 10 is stretched and deformed, the recovery rate of the back film 14 is higher than that of PI (or PET). After the display module 10 is changed from the folded state to the unfolded state, the high-modulus back film 14 can completely or almost completely recover to its original state.

[0155] For example, the backing film 14 is a flat, single-layer structure made of the same material. That is, the material at each location on the backing film 14 is the same. The aforementioned material is not limited to a single substance; a mixture of materials is also possible. The single-layer backing film 14 covers at least the display portion 131 of the display screen 13.

[0156] In some embodiments, the material of the second connection layer 192 may include, for example, OCA, TPU, nylon elastomer, silicone gel, or other energy-absorbing and light-transmitting materials.

[0157] For example, the thickness of the second connection layer 192 is 10 μm to 75 μm. For example, the thickness of the second connection layer 192 is 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, 50 μm, 55 μm, 60 μm, 65 μm, 70 μm, or 75 μm.

[0158] In the embodiment of the present application, the thickness of the second connection layer 192 is limited to the range of 10 μm-75 μm, which can still ensure the impact resistance and extrusion resistance of the display module 10.

[0159] FIG8 is a schematic structural diagram of a display screen in an unfolded state provided by an embodiment of the present application.

[0160] In some embodiments, as shown in FIG8 , when the display screen 13 is in the unfolded state, the display portion 131 and the binding portion 133 of the display screen 13 are laminated and connected with a backing film 14. Alternatively, the backing film 14 is disposed below the display portion 131 and the binding portion 133 of the display screen 13, but not below the bent portion 132 of the display screen 13.

[0161] In some embodiments, when the display screen 13 is in the unfolded state, the display portion 131 of the display screen 13 is laminated with a screen protection layer 16. Alternatively, the screen protection layer 16 is disposed above the display portion 131 of the display screen 13, while the screen protection layer 16 is not disposed above the bent portion 132 and the binding portion 133 of the display screen 13.

[0162] The first connection layer 191 and the screen protection layer 16 are not provided above the bending portion 132 of the display screen 13 , and the second connection layer 192 and the back film 14 are not provided below the bending portion 132 , which helps the display screen 13 to bend at the bending portion 132 .

[0163] The display module 10 provided in the embodiment of the present application has a back film 14 of a high-rigidity material with a modulus of 10GPa-500GPa, and the modulus of the back film 14 is much greater than that of materials such as PI and PET. Therefore, the back film 14 in the embodiment of the present application is compared with the PI (or PET) back film: at the same stiffness, the thickness can be significantly thinned, thereby effectively reducing the thickness of the display module 10. At the same thickness, the stiffness can be significantly improved. Therefore, a back film 14 with a stiffness that meets the requirements and a thinner thickness can be obtained, thereby effectively improving the extrusion impact reliability of the display screen 13 in the first bendable area 103 and improving the back extrusion impact performance of the display module 10. Moreover, it was found through simulation that the display screen 13 is supported by the back film 14 of a single film layer, and the creases of the display module 10 are smoother, the overall refinement (creases and large-surface light and shadow) is higher, and the anti-rebound ability of the unfolded state is stronger.

[0164] FIG9A is a schematic structural diagram of a display module provided in an embodiment of the present application; FIG9B is a crease simulation effect diagram of a display module provided in an embodiment of the present application.

[0165] For example, as shown in Figure 9A , a display module 10 is illustrated. The surface layer 161 is made of PET and has a thickness of 53 μm. The connection layer 163 is made of OCA and has a thickness of 35 μm. The anti-extrusion layer 162 is made of UTG and has a thickness of 30 μm. The first connection layer 191 is made of OCA and has a thickness of 35 μm. The bamboo book 15 is made of carbon fiber and has a thickness of 150 μm. A simulation is performed using an example where the second connection layer 192 is made of OCA and has a thickness of 15 μm, the back film 14 is made of PET and has a thickness of 50 μm, and the total thickness of the display module 10 is 435 μm. Another simulation is performed using an example where the second connection layer 192 is made of OCA and has a thickness of 25 μm, the back film 14 is made of steel sheet and has a thickness of 20 μm, and the total thickness of the display module 10 is 415 μm. As shown in Figure 9B, the horizontal axis represents the size of the display module 10 in the first direction X, and the vertical axis represents the size of the display module 10 in the third direction Z. The curve represents the degree of convexity at various locations in the first direction X when the display module 10 is bent. When the back film 14 is made of steel sheet and has a thickness of 20 μm, while reducing the total thickness of the display module 10 (thinning by 20 μm), the display module 10 provided by the embodiment of the present application has a smoother crease (the crease effect is improved by approximately 36%) and the degree of convexity is significantly reduced. When the water droplet bending radius is reduced, the crease optimization effect is even more obvious. Moreover, the extrusion and impact resistance of the display module 10 are greatly improved (for example, at the weak point of the first bendable area 103, the extrusion resistance of the display screen 13 is improved by approximately 60%, and the impact resistance of the display screen 13 is improved by approximately 40%. Furthermore, the large-scale light and shadow effect is also improved after the back film 14 is replaced with metal.

[0166] In some embodiments, the thickness of the backing film 14 is 15 μm-45 μm, for example, the thickness of the backing film 14 is 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm or 45 μm.

[0167] In the embodiment of the present application, the back film 14 has a relatively high modulus and is highly resistant to back compression and impact. Therefore, it is not necessary to increase the thickness of the back film 14 to improve the back compression and impact resistance. The thickness of the back film 14 can be reduced to 15 μm-45 μm, which is conducive to achieving a thinner and lighter display module 10 while ensuring the back compression and impact resistance.

[0168] 10A and 10B are schematic structural diagrams of a display module provided in an embodiment of the present application.

[0169] In some embodiments, a slit is provided on the backing film 14, and the slit is disposed near the first bendable region 103. For example, the backing film 14 includes a first slit, and the first slit is located at the junction of the first non-bending region 101 and the first bendable region 103, or the first slit spans the junction of the first non-bending region 101 and the first bendable region 103. The backing film 14 also includes a second slit, and the second slit is located at the junction of the second non-bending region 102 and the first bendable region 103, or the second slit spans the junction of the second non-bending region 102 and the first bendable region 103.

[0170] For example, the gap is the gap shown in FIG10A . Alternatively, for example, the gap is a groove, the opening of which can face the display screen 13 or face away from the display screen 13 . The backing film 14 can have one or more of the above-mentioned gaps, and the structures of the multiple gaps can be the same or different. The structure shown in FIG10A is merely an example and is not intended to be limiting.

[0171] For example, as shown in FIG10A , the second connection layer 192 does not fill the gaps in the backing film 14. For example, where the backing film 14 has gaps, the second connection layer 192 also has corresponding gaps. Alternatively, for example, the second connection layer 192 covers the openings of the gaps but does not fill them.

[0172] In the embodiment of the present application, by providing a slit on the back film 14 , the rigidity at the slit can be reduced, thereby improving the first bendability of the back film 14 .

[0173] In some embodiments, as shown in FIG10A , the display module 10 includes a layer of any of the above-mentioned backing films 14 . The structure of the display module 10 can be simplified by configuring the backing film 14 to be a single layer.

[0174] In other embodiments, as shown in Figure 10B, the display module 10 includes multiple layers of any of the above-mentioned back films 14, the multiple layers of back films 14 are stacked, the multiple layers of back films 14 can be connected by a connecting layer, and each layer of the multi-layer back film 14 is a single film layer structure that at least covers the display part 131 of the display screen 13.

[0175] The display module 10 includes a multi-layer back film 14. The thickness of each layer of the back film 14 can be reduced without affecting the impact resistance of the back film 14 stack. It can even improve the extrusion impact, crease and light and shadow performance of the back film 14, and can also improve the first bendability of the back film 14 stack.

[0176] FIG11 is a schematic structural diagram of a display module provided in an embodiment of the present application.

[0177] In some embodiments, the material of the back film 14 includes a conductive material. As shown in FIG11 , the display module 10 further includes a ground conductive layer and a transition portion; the back film 14 is coupled to the ground conductive layer via the transition portion.

[0178] The embodiment of the present application does not limit the location of the ground conductive layer, and the ground conductive layer can be any ground component in the display module 10 .

[0179] For example, as shown in FIG6 , the display module 10 further includes a bamboo book 15 , which is disposed on the side of the back film 14 away from the display screen 13 . For example, the display module 10 further includes a third connecting layer 193 , which is located between the back film 14 and the bamboo book 15 , and the back film 14 and the bamboo book 15 are connected via the third connecting layer 193 .

[0180] For example, the bamboo book 15 is connected to the middle frame 20 via adhesive backing, thereby achieving a connection between the display module 10 and the middle frame 20. The present embodiment of the application does not limit the location of the adhesive backing; it only needs to achieve a connection between the display module 10 and the middle frame 20. The present embodiment of the application does not limit the material of the bamboo book 15. For example, the material of the bamboo book 15 includes stainless steel, titanium alloy, or carbon fiber.

[0181] In some embodiments, as shown in FIG8 , when the display screen 13 is in the unfolded state, the back film 14, which is laminated and connected to the display portion 131 of the display screen 13, is laminated with a bamboo book 15. Alternatively, the bamboo book 15 is disposed below the display portion 131 of the display screen 13, while no bamboo book 15 is disposed below the bent portion 132 and the binding portion 133 of the display screen 13.

[0182] For example, as shown in Figure 11, a ground conductive layer is provided on the side of the bamboo book 15 away from the back film 14, the transition part is located on the side of the back film 14 away from the display screen 13, the transition part passes through the third connecting layer 193 and the bamboo book 15, and the back film 14 is connected to the ground conductive layer through the transition part.

[0183] For example, the material of the transition portion includes metals such as copper and silver.

[0184] A grounding conductive layer is provided on the back of the bamboo book 15, ensuring that the bamboo book 15 meets electrostatic discharge (ESD) requirements. If the backing film 14 is made of a conductive material, the backing film 14 must also meet ESD requirements. By connecting the conductive backing film 14 to the grounding conductive layer via a transition, the backing film 14 can meet ESD requirements without adding a grounding layer, resulting in a simple structure.

[0185] In some embodiments, as shown in Figure 11, the bamboo book 15 includes a first non-bending portion 151, a second non-bending portion 152 and a first bendable portion 153. The first non-bending portion 151 is located in the first non-bending area 101, the second non-bending portion 152 is located in the second non-bending area 102, and the first bendable portion 153 is located in the first bendable area 103.

[0186] Figure 12A is a top view of a bamboo book provided in an embodiment of the present application, Figure 12B is a side view of a bamboo book provided in an embodiment of the present application, and Figure 12C is a relative relationship diagram of a bamboo book and a rotating shaft door panel provided in an embodiment of the present application.

[0187] In some embodiments, the display module 10 is applied to an inward-folding electronic device as shown in FIG. 1B .

[0188] As shown in FIG12A , along the direction from first non-bending zone 101 to second non-bending zone 102 (first direction X), first bendable portion 153 includes, in order, first portion 1531, second portion 1532, third portion 1533, fourth portion 1534, and fifth portion 1535. The stiffness of second portion 1532 is greater than that of third portion 1533, but less than that of first portion 1531. The stiffness of fourth portion 1534 is greater than that of third portion 1533, but less than that of fifth portion 1535.

[0189] For example, the stiffness of the third portion 1533 is the smallest, followed by the stiffness of the second portion 1532 and the fourth portion 1534, and then the stiffness of the first portion 1531 and the fifth portion 1535. The stiffness of the second portion 1532 and the fourth portion 1534 may be equal or unequal. The stiffness of the first portion 1531 and the fifth portion 1535 may be equal or unequal. The stiffness gradually increases from the third portion 1533 to the second portion 1532, to the first portion 1531, and then to the first non-bending portion 151. The stiffness gradually increases from the third portion 1533 to the fourth portion 1534, to the fifth portion 1535, and then to the second non-bending portion 152.

[0190] The embodiment of the present application does not limit the method for changing the stiffness of the various parts of the bamboo book 15. For example, the stiffness of the various parts of the bamboo book 15 can be changed by changing the thickness, changing the material, forming holes, etc. Of course, the embodiment of the present application does not limit the first bendable portion 153 of the bamboo book 15 to only include the first portion 1531, the second portion 1532, the third portion 1533, the fourth portion 1534, and the fifth portion 1535. The first bendable portion 153 can also include more parts to further refine the stiffness of the first bendable portion 153 and improve the bending effect of the bamboo book 15.

[0191] In the bamboo book 15 provided in the embodiment of the present application, the first bendable portion 153 comprises at least five sections, and the stiffness gradually increases from the third section 1533 to the second section 1532, to the first section 1531, and finally to the first non-bending section 151. The stiffness also gradually increases from the third section 1533 to the fourth section 1534, to the fifth section 1535, and finally to the second non-bending section 152. This results in a smooth and continuous transition in the stiffness of the first bendable portion 153, thereby increasing the range of the arch. As shown in Figure 12B, the arch radius changes from the third section 1533 to the entire first bendable portion 153, effectively increasing the arch radius and reducing the arch height. This effectively reduces the arch height of the display module 10 at the first bendable region 103 during a drop in the unfolded state, thereby improving the display module 10's anti-arching capability. Furthermore, due to the smooth transition in the stiffness of the bamboo book 15, the smoothness of the teardrop shape of the display module 10 is further improved. Moreover, the stretching force of the bamboo book 15 is decomposed by the hole, and after the display module 10 changes from the folded state to the unfolded state, the bamboo book 15 can completely or almost completely return to the original state.

[0192] In some embodiments, as shown in Figure 12A, the first part 1531, the second part 1532, the third part 1533, the fourth part 1534 and the fifth part 1535 are all provided with holes, the hole density of the second part 1532 is greater than the hole density of the first part 1531 and less than the hole density of the third part 1533, the hole density of the fourth part 1534 is greater than the hole density of the fifth part 1535 and less than the hole density of the third part 1533.

[0193] That is, the greater the hole density, the lower the stiffness of that section. Based on this, the third section 1533 has the highest hole density, followed by the second section 1532 and the fourth section 1534, and then the first section 1531 and the fifth section 1535. As shown in Figure 12B , the first bendable section 153 is unevenly distributed with holes, eliminating any undistributed glue spots. For example, as shown in Figure 12C , no glue spots are provided between the first bendable section 153 and the hinged door panel.

[0194] There are many ways to change the hole density, including changing the shape of the holes, changing the depth of the holes, changing the gap between the holes, changing the arrangement of the holes, etc., which are not limited in the embodiments of the present application. For example, as shown in Figure 12A, the third part 1533 is provided with large strip-shaped holes of a fixed length, the second part 1532 and the fourth part 1524 are provided with strip-shaped holes of alternating lengths, and the first part 1531 and the fifth part 1535 are provided with small strip-shaped holes of a fixed length. Of course, the second part 1532 and the fourth part 1524 can also be provided with strip-shaped holes of a fixed length, and the length of the holes is between the length of the holes in the third part 1533 and the length of the holes in the first part 1531.

[0195] In some embodiments, the shapes of the holes in the first part 1531, the second part 1532 and the third part 1533 are different, the shapes of the holes in the first part 1531 and the fifth part 1535 are the same, and the shapes of the holes in the second part 1532 and the fourth part 1534 are the same.

[0196] For example, with the axis of the first rotating shaft mechanism 203 (the midline of the third part 1533 along the second direction Y) as the axis of symmetry, the second part and the fourth part 1534 are symmetrically arranged on both sides of the third part 1533, and the first part 1531 and the fifth part 1535 are symmetrically arranged on both sides of the third part 1533.

[0197] This can improve the symmetry of the bamboo book 15, help disperse the stress when the display module 10 is bent, and reduce the back arch.

[0198] In the embodiment of the present application, the holes included in the bamboo book 15 can be blind holes or through holes, can be circular holes, or holes of various shapes such as rectangular holes, strip holes, trapezoidal holes, etc. The embodiment of the present application is only an illustration.

[0199] In some embodiments, the display module 10 further includes a support layer disposed between the bamboo book 15 and the backing film 14. The support layer may be, for example, double-sided PI tape. The support layer absorbs the impact energy of the back surface, thereby enhancing support for the display screen 13. Of course, the display module 10 may also not include a support layer to reduce its thickness.

[0200] In some embodiments, the dimensions of the second portion 1532 and the fourth portion 1534 along the first direction X are greater than or equal to 2.5 mm. For example, the dimensions of the second portion 1532 and the fourth portion 1534 along the first direction X are 2.5 mm, 2.7 mm, 3 mm, 3.2 mm, 3.5 mm, 3.7 mm, or 4 mm. The second portion 1532 and the fourth portion 1534, each having holes, are used to replace the traditional glue dispensing area, and the bamboo book 15 no longer has a glue dispensing area.

[0201] FIG12D is a top view of a bamboo book provided in an embodiment of the present application.

[0202] In other embodiments, the display module 10 is applied to an outward-folding electronic device as shown in FIG. 1C .

[0203] 12D , the stiffness of the first bendable portion 153 is less than that of the first non-bending portion 151 and the second non-bending portion 152. That is, the first bendable portion 153 can be considered as a whole area rather than being divided into multiple parts with different stiffnesses.

[0204] For example, the rigidity of the first bendable portion 153 can be adjusted by providing a hole in the first bendable portion 153 .

[0205] 13A and 13B are schematic structural diagrams of a display module provided in an embodiment of the present application.

[0206] In some embodiments, as shown in Figure 13A, the display module 10 also includes a functional layer 17, which is located on the back of the display screen 13 and is stacked with the back film 14. The projection of the functional layer 17 on the display screen 13 overlaps with the first non-bending area 101, the second non-bending area 102 and the first bendable area 103.

[0207] Alternatively, functional layer 17 extends from first non-bending region 101 across first bendable region 103 to second non-bending region 102. Functional layer 17 can be considered a cross-axis functional layer. The present embodiment does not limit the function of functional layer 17; the functional layer 17 can be supported by backing film 14 having a higher modulus.

[0208] The functional layer 17 can be disposed on the side of the back film 14 facing the display screen 13, or on the side of the back film 14 facing away from the display screen 13 to reduce the impact of the functional layer 17 on the flatness of the display screen 13. The functional layer 17 can be disposed directly on the surface of the back film 14, or it can be connected to the back film 14 via a connecting layer. Figure 13A is merely illustrative and does not constitute a limitation.

[0209] In the embodiment of the present application, as shown in FIG13A , the functional layer 17 may be provided only on the back film 14 connected to the display portion 131. As shown in FIG13B , the functional layer 17 may also be provided on both the back film 14 connected to the display portion 131 and the back film 14 connected to the binding portion 133.

[0210] FIG14A is a top view of a functional layer provided in an embodiment of the present application, and FIG14B is a schematic top view of another functional layer provided in an embodiment of the present application.

[0211] In some embodiments, as shown in FIG14A , the projection of functional layer 17 on display screen 13 overlaps with first non-bending zone 101, second non-bending zone 102, and first bendable zone 103, but does not cover first non-bending zone 101, second non-bending zone 102, and first bendable zone 103. For example, functional layer 17 is disposed in a portion of first non-bending zone 101, a portion of second non-bending zone 102, and a portion of first bendable zone 103. Alternatively, functional layer 17 extends from first non-bending zone 101 through first bendable zone 103 to second non-bending zone 102. The dimension of functional layer 17 along second direction Y is smaller than the dimension of display screen 13 along second direction Y, and the dimension of functional layer 17 along first direction X is smaller than or equal to the dimension of display screen 13 along second direction Y.

[0212] In other embodiments, as shown in FIG. 14B , the projection of the functional layer 17 on the display screen 13 covers the first non-bending area 101 , the second non-bending area 102 , and the first bendable area 103 .

[0213] In the embodiment of the present application, the back film 14 can carry the functional layer 17 and be integrated into the display module 10 . There is no need to place the functional layer 17 under the bamboo book 15 , thereby simplifying the structure of the display module 10 .

[0214] In some embodiments, the functional layer 17 includes a wiring layer.

[0215] For example, the wiring layer is located on the side of the back film 14 away from the display screen 13 , or the wiring layer is located on the side of the back film 14 facing the display screen 13 .

[0216] The surface of the back film 14 can be flat, and the wiring layer is provided on the surface of the back film 14. The wiring layer can be directly formed on the surface of the back film 14, or can be connected to the back film 14 through a connecting layer. This process is simple and low in cost.

[0217] The back film 14 may also include a groove, and the wiring layer is arranged in the groove, and the opening of the groove may face the display screen 13 or may be away from the display screen. This can improve the film printing problem caused by the wiring layer.

[0218] The wiring layer may include a metal wire layer, or may include multiple metal wire layers, with a dielectric layer disposed between adjacent metal wire layers. The gap between the metal wire layer and the groove may be filled with, for example, an insulating layer or OCA.

[0219] FIG15 is a schematic diagram of the relative relationship between a wiring layer and a back film provided in an embodiment of the present application.

[0220] For example, as shown in FIG15 , the back film 14 is bent along the second direction Y of the electronic device 1 to the back of the bamboo book 15 , and the wiring layer (functional layer 17 ) is arranged in the groove on the lower surface of the back film 14 and bends along with the back film 14 .

[0221] The first non-bending region 101 and the second non-bending region 102 are each provided with a flexible printed circuit (FPC). The wiring layer is coupled to the first mainboard of the first non-bending region 101 via the FPC of the first non-bending region 101 (for example, via a board-to-board (BTB) connection). The wiring layer is also coupled to the second mainboard of the second non-bending region 102 via the FPC of the second non-bending region 102, thereby interconnecting the first and second mainboards and achieving cross-axis signal transmission. The first mainboard can be mounted on the first frame 201, for example, and the second mainboard can be mounted on the second frame 202, for example.

[0222] If the wiring layer is placed on the middle frame 20 and routed through the interior of the first hinge mechanism 203, there will be a problem of the wiring layer hitting the hinge door during bending. If it is placed across the top of the first hinge mechanism 203, the wiring layer will hit the display screen 13 during bending. This also increases the design difficulty of the first hinge mechanism 203 and reduces the overall space utilization of the device. However, the present application integrates the wiring layer within the display module 10, which can alleviate these problems and simplify the design.

[0223] FIG16 is a schematic structural diagram of a display module provided in an embodiment of the present application.

[0224] In some embodiments, the functional layer 17 includes a heat-conducting layer. For example, the heat-conducting layer is located on the side of the back film 14 away from the display screen 13.

[0225] For example, the material of the heat-conducting layer includes graphene, copper and other high thermal conductivity materials.

[0226] In some embodiments, the graphene sheet can be directly integrated onto the backing film 14. For example, the graphene sheet can be directly integrated onto the backing film 14 by laminating the graphene to the backing film 14, electromagnetically depositing the graphene onto the backing film, or integrating the graphene directly onto the backing film 14 through powder metallurgy and backing film geometry.

[0227] In other embodiments, as shown in FIG. 16 , the heat conductive layer (functional layer 17 ) may be connected to the back film 14 via a fourth connecting layer 194 .

[0228] By integrating a cross-axis heat dissipation layer within the display module 10, the heat concentration generated by the system-on-chip (SOC) in electronic devices can be effectively reduced, heat dissipation can be more uniform, and the heat dissipation capacity of electronic devices can be further enhanced. Simulations have shown that the temperature of the large area of ​​the midframe has dropped by approximately 10°C, and the temperature at the SOC has also dropped by approximately 10°C.

[0229] FIG17 is a schematic structural diagram of a display module provided in an embodiment of the present application.

[0230] In some embodiments, the functional layer 17 includes a light absorbing layer.

[0231] 17 , the light absorbing layer (functional layer 17) is located on the side of the back film 14 facing the display screen 13. For example, the light absorbing layer is located on the surface of the back film 14 facing the display screen 13. The material of the light absorbing layer includes, for example, ink, epoxy resin, polyester or acrylic acid.

[0232] By providing a light-absorbing layer on the back of the display screen 13, on the one hand, the light and shadow effects of the large surface of the display module 10 can be improved, and the overall refinement of the display module 10 can be improved. On the other hand, it can serve as a connecting transition layer between the back film 14 and the second connecting layer 192, thereby improving the connection between the back film 14 and the display screen 13.

[0233] In some embodiments, the functional layer 17 includes a connection transition layer, and the connection transition layer is located on the side of the back film 14 away from the display screen 13. For example, the connection transition layer is disposed on the surface of the back film 14 away from the display screen 13.

[0234] For example, the material of the connecting transition layer includes a polar material containing hydrogen bonds, such as ink, epoxy resin, polyester, or acrylic acid.

[0235] By providing a connection transition layer on the side of the back film 14 away from the display screen 13 , the connection effect between the back film 14 and the third connection layer 193 can be improved.

[0236] In some embodiments, the connecting layers in the display module 10 are all made of OCA. Except for the surface layer 161 of the screen protection layer 16, the display screen 13, and various connecting layers, all other film layers in the display module 10 are high-modulus, low-creep (or no-creep) film layers. For example, the anti-extrusion layer 162, the back film 14, and the bamboo book 15 are all high-modulus, low-creep (or no-creep) film layers.

[0237] FIG18 is a flow chart of an assembly method of a display module provided in an embodiment of the present application, and FIG19 is a schematic diagram of a partial assembly process of a display module provided in an embodiment of the present application.

[0238] The present application also provides an assembly method for a display module. As shown in FIG18 , the assembly method for a display module includes:

[0239] S10. As shown in FIG19 , a display screen laminate is provided. The display screen laminate includes a display screen 13, a connecting layer (second connecting layer 192), and a backing film 14. The backing film 14 is connected to the back of the display screen 13 via the connecting layer. The display screen 13 includes a display portion 131, a bent portion 132, and a binding portion 133. The backing film 14 covers the display portion 131, the bent portion 132, and the binding portion 133.

[0240] S20, as shown in FIG19, a mark is formed on the side of the back film 14 away from the display screen 13, and the portion of the back film 14 and the connecting layer that is overlapped with the bending portion 132 is removed.

[0241] The projection of the above mark on the display screen 13 is located on the display portion 131. Of course, marks can also be formed in the areas corresponding to the bending portion 132 and the binding portion 133.

[0242] For example, step S20 includes:

[0243] S21 , placing the display screen stack on a carrier of a transfer device, with the light-emitting side of the display screen 13 facing the carrier.

[0244] S22 , grabbing the display portion 131 of the display screen 13 by using a grabbing probe of the transfer device.

[0245] S23 , forming a mark on the surface of the back film 14 away from the display screen 13 by using a laser probe at the bottom of the transfer device.

[0246] S24 , removing the portion of the back film 14 and the connection layer that is stacked with the bent portion 132 by laser.

[0247] S30: As shown in FIG. 19 , the above-mentioned marks are aligned to form the bamboo book 15 stacked with the display portion 131 .

[0248] Of course, when other film layers are provided between the bamboo book 15 and the back film 14 , steps similar to step S30 can be performed to form the other film layers.

[0249] When the back film 14 is made of opaque material, the mark on the display screen 13 cannot be recognized when the bamboo book 15 is formed. Therefore, forming the mark on the surface of the back film 14 can realize the process feasibility of bonding the bamboo book 15 to the back film 14.

[0250] FIG20A is a schematic diagram of an electronic device in an expanded state according to an embodiment of the present application, and FIG20B is a cross-sectional view of an electronic device according to an embodiment of the present application.

[0251] The present application also provides an electronic device 1 , which is a multi-fold electronic device. A tri-fold electronic device is described below with reference to FIG. 20A : As shown in FIG. 20A , the electronic device 1 includes a display module 10 and a middle frame 20 .

[0252] In some embodiments, the middle frame 20 includes a first frame body 201, a second frame body 202, a first hinge mechanism 203, a third frame body 204, and a second hinge mechanism 205. The first frame body 201 and the second frame body 202 are disposed on either side of the first hinge mechanism 203, and the first hinge mechanism 203 is connected to the first frame body 201 and the second frame body 202, respectively. The second frame body 202 and the third frame body 204 are disposed on either side of the second hinge mechanism 205, and the second hinge mechanism 205 is connected to the second frame body 202 and the third frame body 204, respectively.

[0253] In some embodiments, in the flattened state, the display module 10 has, along the horizontal direction, a first non-bending region 101, a second non-bending region 102, a first bendable region 103 connecting the first non-bending region 101 and the second non-bending region 102, a third non-bending region 104, and a second bendable region 105 connecting the third non-bending region 104 and the second non-bending region 102. For example, the display module 10 may include a first non-bending region 101 corresponding to the first frame 201, a second non-bending region 102 corresponding to the second frame 202, a first bendable region 103 corresponding to the first hinge mechanism 203, a third non-bending region 104 corresponding to the third frame 204, and a second bendable region 105 corresponding to the second hinge mechanism 205.

[0254] In some embodiments, as shown in FIG. 20B , the display module 10 includes a screen protection layer 16 , a first connection layer 191 , a display screen 13 , a second connection layer 192 , a back film 14 , and a bamboo book 15 .

[0255] The display screen 13 is located in the first non-bending area 101 , the first bendable area 103 , the second non-bending area 102 , the second bendable area 105 and the third non-bending area 104 .

[0256] The structures of the screen protection layer 16 , the first connection layer 191 , the display screen 13 , the second connection layer 192 and the back film 14 can be referred to the above related descriptions and will not be repeated here.

[0257] FIG21A is a schematic diagram of a folded state of an electronic device provided in an embodiment of the present application, and FIG21B is a schematic diagram of a top view of a bamboo book provided in an embodiment of the present application.

[0258] In some embodiments, the electronic device 1 may include a folding device with an inner folding screen and an outer folding screen. As shown in FIG21A , the electronic device 1 includes an S-shaped folding device consisting of an inner folding form and an outer folding form.

[0259] In some embodiments, as shown in FIG. 21B , the bamboo book 15 includes a first non-bending portion 151 , a second non-bending portion 152 , a first bendable portion 153 , a third non-bending portion 154 , and a second bendable portion 155 .

[0260] The first non-bending portion 151 is located in the first non-bending zone 101, the second non-bending portion 152 is located in the second non-bending zone 102, the first bendable portion 153 is located in the first bendable zone 103, the third non-bending portion 154 is located in the third non-bending zone 104, and the second bendable portion 155 is located in the second bendable zone 105.

[0261] The first bendable portion 153 corresponds to the inward folding use of the electronic device 1. The structures of the first non-bending portion 151, the second non-bending portion 152, and the first bendable portion 153 can refer to the above description of Figure 12A.

[0262] The second bendable portion 155 corresponds to the outward folding of the electronic device 1. The rigidity of the second bendable portion 155 is less than the rigidity of the second non-bendable portion 152 and the third non-bendable portion 154. In other words, the second bendable portion 155 can be considered as a single integral area, rather than being divided into multiple portions with different rigidities.

[0263] For example, the rigidity of the second bendable portion 155 can be adjusted by providing a hole in the second bendable portion 155 .

[0264] Figure 22A is a schematic diagram of a folded state of an electronic device provided in an embodiment of the present application, and Figure 22B is a schematic diagram of a top view of a bamboo book provided in an embodiment of the present application.

[0265] In other embodiments, the electronic device 1 may include foldable devices each having an inward-folding screen. The inward-folding screen is formed in an inward-folding configuration. As shown in FIG22A , the electronic device 1 includes two inward-folding "G"-shaped foldable devices.

[0266] In some embodiments, as shown in FIG. 22B , the bamboo book 15 includes a first non-bending portion 151 , a second non-bending portion 152 , a first bendable portion 153 , a third non-bending portion 154 , and a second bendable portion 155 .

[0267] The first bendable portion 153 corresponds to the inward folding use of the electronic device 1. The structures of the first non-bending portion 151, the second non-bending portion 152, and the first bendable portion 153 can refer to the above description of Figure 12A.

[0268] The second bendable portion 155 corresponds to the inward folding use of the electronic device 1. Along the direction from the second non-bending portion 152 to the third non-bending portion 154 (the first direction X), the second bendable portion 155 includes a sixth portion 1551, a seventh portion 1552, an eighth portion 1553, a ninth portion 1554 and a tenth portion 1555 arranged in sequence; the stiffness of the seventh portion 1552 is greater than the stiffness of the eighth portion 1553 and less than the stiffness of the sixth portion 1551, and the stiffness of the ninth portion 1554 is greater than the stiffness of the eighth portion 1553 and less than the stiffness of the tenth portion 1555.

[0269] For example, the rigidity can be changed by providing holes in the sixth portion 1551 , the seventh portion 1552 , the eighth portion 1553 , the ninth portion 1554 , and the tenth portion 1555 . Reference may be made to the above description regarding the first bendable portion 153 .

[0270] Figure 23A is a schematic diagram of a folded state of an electronic device provided in an embodiment of the present application, and Figure 23B is a schematic diagram of a top view of a bamboo book provided in an embodiment of the present application.

[0271] In some other embodiments, the electronic device 1 may be a foldable device including multiple outward-folding screens. The outward-folding screens are formed in an outward-folding configuration. As shown in FIG23A , the electronic device 1 includes two outward-folding "G"-shaped foldable devices.

[0272] In some embodiments, as shown in FIG. 23B , the bamboo book 15 includes a first non-bending portion 151 , a second non-bending portion 152 , a first bendable portion 153 , a third non-bending portion 154 , and a second bendable portion 155 .

[0273] The first bendable portion 153 corresponds to the outward folding of the electronic device 1. The rigidity of the first bendable portion 153 is less than that of the first non-bending portion 151 and the second non-bending portion 152. In other words, the first bendable portion 153 can be considered as a single integral area, rather than being divided into multiple portions with different rigidities.

[0274] The second bendable portion 155 corresponds to the outward folding use of the electronic device 1, and the stiffness of the second bendable portion 155 is less than the stiffness of the second non-bend portion 152 and the third non-bend portion 154. That is, the second bendable portion 155 can be regarded as an integral area, and is no longer divided into multiple parts with different stiffness. The electronic device 1 provided in the embodiment of the present application can be a multi-fold electronic device, and the above is only an example of a three-fold electronic device. When the electronic device includes more folds on the basis of the three folds, the design of the bamboo book 15 at the inner fold and the design of the bamboo book 15 at the outer fold can refer to the above-mentioned relevant description.

[0275] The above are only specific embodiments of the present application, but the scope of protection of the present application is not limited thereto. Any changes or replacements within the technical scope disclosed in this application should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A display module, characterized in that, The display module is a foldable display module, and the display module comprises: Display screen; A screen protection layer, located on the light-emitting side of the display screen; A first connecting layer, located between the display screen and the screen protection layer, and used to connect the display screen and the screen protection layer; A back film, located on the back of the display screen; the back film is a single film layer structure, and the modulus of the material of the back film is 10GPa-500GPa; The second connecting layer is located between the display screen and the back film and is used to connect the back film and the display screen.

2. The display module according to claim 1, wherein In the flattened state, the display module has a first non-bending area, a second non-bending area, and a first bendable area connecting the first non-bending area and the second non-bending area along the horizontal direction; The display module also includes a functional layer, which is located on the back of the display screen and is stacked with the back film. The projection of the functional layer on the display screen overlaps with the first non-bending area, the second non-bending area and the first bendable area.

3. The display module according to claim 2, wherein, The functional layer includes a wiring layer; the wiring layer is located on a side of the back film away from the display screen.

4. The display module according to claim 2 or 3, characterized in that, The functional layer comprises a heat-conducting layer, and the heat-conducting layer is located on a side of the back film away from the display screen.

5. The display module according to claim 4, wherein The material of the heat conducting layer includes graphene.

6. The display module according to any one of claims 2-5, characterized in that, The functional layer comprises a light absorbing layer, and the light absorbing layer is located on a side of the back film facing the display screen.

7. The display module according to claim 6, wherein The material of the light absorbing layer includes ink, epoxy resin, polyester or acrylic acid.

8. The display module according to any one of claims 2-7, characterized in that, The functional layer comprises a connection transition layer, and the connection transition layer is located on a side of the back film away from the display screen.

9. The display module according to claim 6, wherein The material of the connection transition layer includes a polar material containing hydrogen bonds.

10. The display module according to any one of claims 1-9, characterized in that The back film is provided with a slit, and the slit is arranged close to the first bendable area.

11. The display module according to any one of claims 1-10, characterized in that, The thickness of the back film is 15 μm-45 μm.

12. The display module according to any one of claims 1-11, characterized in that, The material of the backing film includes SUS, copper, aluminum, copper alloy, aluminum alloy, UTG, glass fiber, carbon fiber, ceramic or polymer material, etc.

13. The display module according to any one of claims 1-12, characterized in that, The material of the back film includes a conductive material, and the display module also includes a ground conductive layer and a transition portion; the back film is coupled to the ground conductive layer through the transition portion.

14. The display module according to any one of claims 1-13, characterized in that, In the flattened state, the display module has a first non-bending area, a second non-bending area, and a first bendable area connecting the first non-bending area and the second non-bending area along the horizontal direction; The display module further comprises a bamboo book, and the bamboo book is located on a side of the back film away from the display screen; The bamboo book comprises a first non-bending portion, a second non-bending portion and a first bendable portion, wherein the first non-bending portion is located in the first non-bending area, the second non-bending portion is located in the second non-bending area, and the first bendable portion is located in the first bendable area; Along the direction from the first non-bending portion to the second non-bending portion, the first bendable portion includes a first part, a second part, a third part, a fourth part and a fifth part which are arranged in sequence; the stiffness of the second part is greater than the stiffness of the third part and less than the stiffness of the first part, and the stiffness of the fourth part is greater than the stiffness of the third part and less than the stiffness of the fifth part.

15. The display module according to claim 14, wherein The first part, the second part, the third part, the fourth part, and the fifth part are all provided with holes. The hole density of the second part is greater than that of the first part and less than that of the third part. The hole density of the fourth part is greater than that of the fifth part and less than that of the third part.

16. The display module according to claim 14 or 15, wherein The display module further includes a second bendable region and a third non-bendable region, and the second bendable region connects the second non-bendable region and the third non-bendable region; The bamboo book further includes a second bendable portion and a third non-bendable portion; the second bendable portion is located in the second bendable region, and the third non-bendable portion is located in the third non-bendable region; Along the direction from the second non-bendable portion to the third non-bendable portion, the second bendable portion includes a sixth part, a seventh part, an eighth part, a ninth part, and a tenth part arranged in sequence; the stiffness of the seventh part is greater than that of the eighth part and less than that of the sixth part, and the stiffness of the ninth part is greater than that of the eighth part and less than that of the tenth part.

17. The display module according to any one of claims 1-13, characterized in that, In the flattened state, the display module has a first non-bendable region, a second non-bendable region, and a first bendable region connecting the first non-bendable region and the second non-bendable region in the horizontal direction; The display module further includes a bamboo book, and the bamboo book is located on the side of the back film away from the display screen; The bamboo book includes a first non-bendable portion, a second non-bendable portion, and a first bendable portion. The first non-bendable portion is located in the first non-bendable region, the second non-bendable portion is located in the second non-bendable region, and the first bendable portion is located in the first bendable region; The stiffness of the first bendable portion is less than that of the first non-bendable portion and the second non-bendable portion.

18. The display module according to claim 14, 15 or 17, characterized in that, The display module further includes a second bendable region and a third non-bendable region, and the second bendable region connects the second non-bendable region and the third non-bendable region; The bamboo book further includes a second bendable portion and a third non-bendable portion; the second bendable portion is located in the second bendable region, and the third non-bendable portion is located in the third non-bendable region; The stiffness of the second bendable portion is less than that of the second non-bendable portion and the third non-bendable portion.

19. The display module according to any one of claims 1-18, characterized in that, The screen protection layer includes a surface layer and at least one anti-extrusion layer; the surface layer is located on the side of the at least one anti-extrusion layer away from the display screen, and the modulus of the material of the anti-extrusion layer is 10 GPa - 500 GPa.

20. The display module according to claim 19, wherein, The material of the anti-extrusion layer includes UTG or high-entropy glass.

21. The display module according to any one of claims 1-20, characterized in that, The thickness of the first connection layer and the second connection layer is 10 μm - 75 μm.

22. An electronic device, characterized in that, The electronic device includes a display module and a middle frame, and the display module is disposed on the middle frame; the display module includes the display module according to any one of claims 1 - 21.

23. An assembly method of a display module, characterized in that, Including: Providing a display screen stack, the display screen stack includes a display screen, a connection layer, and a back film, and the back film is connected to the back of the display screen through the connection layer; the display screen includes a display portion, a bendable portion, and a bonding portion; the back film covers the display portion, the bendable portion, and the bonding portion; Form a mark on the side of the back film away from the display screen, and remove the portions of the back film and the connection layer that are stacked with the bending portion. The projection of the mark on the display screen is located in the display portion; Align the mark to form a bamboo book that is stacked with the display portion.

24. The assembly method according to claim 23, wherein Forming a mark on the side of the back film away from the display screen and removing the portions of the back film and the connection layer that are stacked with the bending portion includes: Stack the display screen on the carrier of the transfer device, with the light-emitting side of the display screen facing the carrier; Grab the display portion of the display screen through the grasping probe of the transfer device; Form the mark on the surface of the back film away from the display screen through the laser probe at the bottom of the transfer device; Remove the portions of the back film and the connection layer that are stacked with the bending portion by laser.

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