Display module, assembling method thereof and electronic equipment

Abstract

The embodiment of the invention provides a display module, an assembling method thereof and electronic equipment, relates to the technical field of display, and is used for considering the thickness performance of the electronic equipment on the basis of meeting the back extrusion impact performance of a display screen. The display module comprises a screen protection layer, a first connecting layer, a display screen, a second connecting layer and a back film. The screen protection layer is located on the light-emitting side of the display screen. The first connector is located between the display screen and the screen protection layer and used for connecting the display screen and the screen protection layer. The back film is located on the back face of the display screen, and the modulus of the material of the back film ranges from 10 GPa to 500 GPa. The second connecting layer is located between the display screen and the back film and used for connecting the back film and the display screen. Compared with a PI (or PET) back film, the thickness of the back film can be obviously reduced under the same rigidity. And under the same thickness, the rigidity can be obviously improved. Therefore, the back film with the rigidity meeting the requirement and small thickness can be obtained, and the back extrusion impact performance of the display module is effectively improved.

Description

Technical Field

[0001] This application relates to the field of display technologies, and particularly to a display module, an assembly method thereof, and an electronic device. Background Art

[0002] With the continuous development of display technologies, foldable electronic devices have gradually become a development trend of future mobile electronic products. When in the unfolded state, a foldable electronic device can obtain a larger display area, improving the viewing effect. When in the folded state, a foldable electronic device can obtain a smaller volume, facilitating user carrying.

[0003] A flexible display screen is an important component of a foldable electronic device. Due to the special nature of its material, the display screen is vulnerable to damage under external forces. Based on this, a back protective layer is usually provided on the back of the display screen. Since the overall electronic device needs to have the first bendable property, the back protective layer also needs to have the first bendable property, which results in the inability of the electronic device to balance the back extrusion impact performance of the display screen and the thickness performance of the back protective layer on the basis of having the first bendable property. Summary of the Invention

[0004] Embodiments of this application provide a display module, an assembly method thereof, and an electronic device, which are used to balance the thickness performance of the electronic device on the basis of meeting the back extrusion impact performance of the display screen.

[0005] To achieve the above object, this application adopts the following technical solutions:

[0006] In a first aspect of the embodiments of this application, a display module is provided. The display module is a foldable display module. The display module includes: a screen protective layer, a first connection layer, a display screen, a second connection layer, and a back film. The display screen is located in a first non-bendable area, a second non-bendable area, and a first bendable area. The screen protective layer is located on the light-emitting side of the display screen. The first connection layer is located between the display screen and the screen protective layer and is used to connect the display screen and the screen protective layer. The back film is located on the back of the display screen. The back film has a single-film layer structure, and the modulus of the material of the back film is 10 GPa - 500 GPa. 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.

[0007] The foldable display module provided by the embodiment of the present application uses a high-rigidity material with a modulus of 10 GPa - 500 GPa for the back film, and the modulus of the back film material is much greater than that of materials such as PI and PET. Therefore, compared with the PI (or PET) back film in the embodiment of the present application: at the same rigidity, the thickness can be significantly reduced. At the same thickness, the rigidity can be significantly improved. Therefore, a back film with a stiffness meeting the requirements and a relatively thin thickness can be obtained, thereby effectively improving the extrusion and impact reliability of the display screen in the first foldable area and enhancing the back extrusion and impact performance of the display module. Moreover, through simulation, it is found that when the display screen is supported by a single-layer back film, the creases of the display module are smoother, the overall fineness (crease and large-area light and shadow) is higher, and the anti-rear arching ability during the unfolded state drop is stronger.

[0008] In a possible implementation, the back film is formed of the same material. In this way, the structure and process of the back film are simple.

[0009] In a possible implementation, in the flattened state, the display module has a first non-foldable area, a second non-foldable area, and a first foldable area connecting the first non-foldable area and the second non-foldable area in the horizontal direction. The display module provided by the present application can be applied to a two-fold electronic device.

[0010] In a possible implementation, the display module further includes a functional layer, the functional layer is located on the back of the display screen and is stacked with the back film, and the projection of the functional layer on the display screen overlaps with the first non-foldable area, the second non-foldable area, and the first foldable area. In the embodiment of the present application, the back film can carry the cross-axis functional layer, and there is no need to set the cross-axis functional layer under the bamboo book, so as to simplify the architecture of the display module.

[0011] In a possible implementation, the display module further has a second foldable area and a third non-foldable area, and the second foldable area connects the second non-foldable area and the third non-foldable area. The display module provided by the present application can also be applied to a multi-fold electronic device.

[0012] In a possible implementation, the projection of the functional layer on the display screen also overlaps with the third non-foldable area and the second foldable area. In the embodiment of the present application, the back film can carry the cross-axis functional layer, and there is no need to set the cross-axis functional layer under the bamboo book, so as to simplify the architecture of the display module.

[0013] In a 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 arranged on the middle frame and passes through the inside of the first rotating shaft mechanism, there will be a problem of pushing against the rotating shaft door panel during the bending process. If it crosses the upper part of the first rotating shaft mechanism, there will be a problem of pushing against the display screen during the bending process. Moreover, it increases the design difficulty of the first rotating shaft mechanism and reduces the utilization rate of the overall space of the machine. However, in this application, the cross-axis wiring layer is integrated inside the display module, which can improve the above problems and simplify the design.

[0014] In a possible implementation, the surface of the back film away from the display screen has grooves, and the wiring layer is arranged in the grooves. This can improve the film printing problem caused by the wiring layer.

[0015] In a possible implementation, the functional layer includes a heat-conducting layer, and the heat-conducting layer is located on the side of the back film away from the display screen. By integrating the cross-axis heat dissipation functional layer inside the display module, the concentration of heat generated by the system-level chip in the electronic device can be effectively reduced, the heat dissipation uniformity can be increased, and the heat dissipation capacity of the electronic device can be further enhanced.

[0016] In a possible implementation, the material of the heat-conducting layer includes graphene. This is a material with good heat-conducting effect and low cost.

[0017] In a possible implementation, the functional layer includes a light-absorbing layer, and the light-absorbing layer is located on the side of the back film facing the display screen. By setting the light-absorbing layer on the back of the display screen, on the one hand, the large-surface light and shadow effect of the display module can be improved, and the overall delicacy of the display module can be enhanced. On the other hand, it can serve as a connection transition layer between the back film and the second connection layer, and improve the connection effect between the back film and the display screen.

[0018] In a possible implementation, the material of the light-absorbing layer includes ink, epoxy resin, polyester or acrylic acid. This is a material with good light-absorbing effect and low cost.

[0019] In a possible implementation, the functional layer includes a connection transition layer, and the connection transition layer is located on the side of the back film away from the display screen. By setting a 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.

[0020] In a possible implementation, the material of the connection transition layer includes a polar material containing hydrogen bonds. This is a material with good connection effect and low cost.

[0021] In a possible implementation, a slit is formed on the back film, and the slit is arranged close to the first foldable area. By forming a slit on the back film, the first foldable performance of the back film can be improved.

[0022] In a possible implementation, the thickness of the back film is 15 μm-45 μm. In the embodiment of the present application, the modulus of the back film is relatively high, and the ability to resist back extrusion and impact is relatively strong. Therefore, it is not necessary to increase the thickness of the back film to improve the ability of the back film to resist back extrusion and impact. The thickness of the back film can be 15 μm-45 μm, which is conducive to realizing the thinness of the display module while ensuring the ability to resist back extrusion and impact.

[0023] 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.

[0024] In a possible implementation, the material of the back film includes a conductive material, 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. By connecting the conductive back film to the ground conductive layer through the transition portion, the back film can meet the ESD requirements and has a simple structure.

[0025] In a 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 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 arranged in sequence; the rigidity of the second part is greater than the rigidity of the third part and less than the rigidity of the first part, and the rigidity of the fourth part is greater than the rigidity of the third part and less than the rigidity of the fifth part. The first bendable portion in the bamboo book includes at least five parts, and the rigidity gradually increases from the third part to the second part, then to the first part, and then to the first non-bending portion. The rigidity gradually increases from the third part to the fourth part, then to the fifth part, and then to the second non-bending portion. The stiffness of the first bendable portion is smoothly transitioned and continuous, thereby increasing the anti-arch radius and reducing the anti-arch height, which can effectively reduce the anti-arch height of the display module at the first bendable area during the drop of the unfolded state, and improve the anti-arch ability of the display module. At the same time, due to the smooth transition of the stiffness change of the bamboo book, the smoothness of the water drop shape of the display module can also be further improved. Moreover, the tensile force of the bamboo book is decomposed by the hole, and after the display module changes from the folded state to the unfolded state, the bamboo book can completely or almost completely return to the initial state.

[0026] In a possible implementation, holes are provided in the first part, the second part, the third part, the fourth part, and the fifth part. 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. By means of opening holes, the stiffness of each part in the first bendable part is adjusted, and the structure is simple and easy to implement.

[0027] In a possible implementation, the shapes of the holes in the first part, the second part, and the third part are different. The shapes of the holes in the first part and the fifth part are the same. The shapes of the holes in the second part and the fourth part are the same. In this way, the symmetry of the first bendable part is good, which helps to absorb the symmetry of the bending force.

[0028] In a possible implementation, the bamboo book further includes a second bendable part and a third non-bendable part; the second bendable part is located in the second bendable area, and the third non-bendable part is located in the third non-bendable area; along the direction from the second non-bendable part to the third non-bendable part, the second bendable part 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. The bamboo book designed in this way can be applied to an electronic device with an inner fold plus an inner fold.

[0029] In a possible implementation, 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 part, a second non-bendable part, and a first bendable part. The first non-bendable part is located in the first non-bendable area, the second non-bendable part is located in the second non-bendable area, and the first bendable part is located in the first bendable area; the stiffness of the first bendable part is less than that of the first non-bendable part and the second non-bendable part. The bamboo book designed in this way can be applied to a single outer fold electronic device.

[0030] In a possible implementation, the bamboo book further includes a second bendable part and a third non-bendable part; the second bendable part is located in the second bendable area, and the third non-bendable part is located in the third non-bendable area; the stiffness of the second bendable part is less than that of the second non-bendable part and the third non-bendable part. The bamboo book designed in this way can be applied to an electronic device with an outer fold plus an outer fold or an inner fold plus an outer fold.

[0031] In a 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 material of the anti-extrusion layer is 10 GPa - 500 GPa. By using a material with a high modulus to form the anti-extrusion layer, the anti-extrusion, anti-impact, and anti-creep properties of the screen protection layer can be improved, and the requirements for thinning can be met while improving the crease and extrusion impact reliability of the display module.

[0032] 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 anti-impact effect, and thin thickness.

[0033] In a possible implementation, the material of the anti-extrusion layer includes metal, and the thickness of the anti-extrusion layer is less than 50um. The metal with a thickness less than 50um has the first bendability, which can not only meet the trend of thinning the film layer but also improve the anti-impact and anti-extrusion capabilities of the screen protection layer.

[0034] In a possible implementation, the thickness of the first connection layer and the second connection layer is 10um - 75um. The thickness of the first connection layer and the second connection layer is limited within the range of 10um - 75um, and still can ensure the anti-impact and anti-extrusion performance of the display module.

[0035] In the second aspect of the embodiments of the present application, an electronic device is provided. 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 the first aspects.

[0036] In the third aspect of the embodiments of the present application, an assembly method of a display module is provided, 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 bending portion, and a bonding portion; the back film covers the display portion, the bending portion, and the bonding portion; 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, and the projection of the mark on the display screen is located in the display portion; aligning the mark to form a bamboo book that is stacked with the display portion. When the back film is made of a light-blocking material, the mark on the display screen cannot be recognized when forming the bamboo book. Therefore, forming a mark on the surface of the back film can realize the process feasibility of fitting the bamboo book with the back film.

[0037] In a possible implementation, 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: placing the display screen stack on the carrier of the transfer device, with the light-emitting side of the display screen facing the carrier; grasping the display portion of the display screen through the grasping probe of the transfer device; forming a mark on the surface of the back film away from the display screen through the laser probe at the bottom of the transfer device; removing the portions of the back film and the connection layer that are stacked with the bending portion through the laser. This is a simple implementation principle. Description of the Drawings

[0038] Figure 1A It is a schematic structural diagram of an electronic device provided by the embodiments of the present application;

[0039] Figure 1B and Figure 1CSchematic diagram of the folded state of an electronic device provided by an embodiment of the present application;

[0040] Figure 2 Architecture diagram of a display module provided by an embodiment of the present application;

[0041] Figure 3A Side view of a bamboo book provided by an embodiment of the present application;

[0042] Figure 3B Top view of a bamboo book provided by an embodiment of the present application;

[0043] Figure 3C Cross-sectional view of a bamboo book provided by an embodiment of the present application;

[0044] Figure 3D Schematic diagram of the reverse arch of a display module provided by an embodiment of the present application;

[0045] Figure 4A Cross-sectional view of a display module and a middle frame provided by an embodiment of the present application;

[0046] Figure 4B Top view of an under-screen buffer layer and a middle frame provided by an embodiment of the present application;

[0047] Figure 5A Cross-sectional view of a display module and a middle frame provided by an embodiment of the present application;

[0048] Figure 5B Top view of a cross-axis functional layer and a middle frame provided by an embodiment of the present application;

[0049] Figure 6 Schematic diagram of the structure of a display module provided by an embodiment of the present application;

[0050] Figure 7 Schematic diagram of the structure of a screen protection layer provided by an embodiment of the present application;

[0051] Figure 8 Schematic diagram of the structure of a display screen in the unfolded state provided by an embodiment of the present application;

[0052] Figure 9A Schematic diagram of the structure of a display module provided by an embodiment of the present application;

[0053] Figure 9B Simulation effect diagram of the crease of a display module provided by an embodiment of the present application;

[0054] Figure 10A and Figure 10B Schematic diagram of the structure of a display module provided by an embodiment of the present application;

[0055] Figure 11 Schematic diagram of the structure of a display module provided by an embodiment of the present application;

[0056] Figure 12A Top view of a bamboo book provided by an embodiment of the present application;

[0057] Figure 12B Side view of a bamboo book provided by an embodiment of the present application;

[0058] Figure 12C Relative relationship diagram of a bamboo book and a rotating shaft door panel provided by an embodiment of the present application;

[0059] Figure 12D Top view of a bamboo book provided by an embodiment of the present application;

[0060] Figure 13A Schematic diagram of the structure of a display module provided by an embodiment of the present application;

[0061] Figure 13B Schematic diagram of the structure of a display module provided by an embodiment of the present application;

[0062] Figure 14A Top view schematic diagram of a functional layer provided by an embodiment of the present application;

[0063] Figure 14B Another top view schematic diagram of a functional layer provided by an embodiment of the present application;

[0064] Figure 15 Schematic diagram of the relative relationship between a wiring layer and a back film provided by an embodiment of the present application;

[0065] Figure 16 Schematic diagram of the structure of a display module provided by an embodiment of the present application;

[0066] Figure 17 Schematic diagram of the structure of a display module provided by an embodiment of the present application;

[0067] Figure 18 Flowchart of an assembling method of a display module provided by an embodiment of the present application;

[0068] Figure 19 Schematic diagram of a partial assembling process of a display module provided by an embodiment of the present application;

[0069] Figure 20A Schematic diagram of the unfolded state of an electronic device provided by an embodiment of the present application;

[0070] Figure 20B Cross-sectional view of an electronic device provided by an embodiment of the present application;

[0071] Figure 21A Schematic diagram of the folded state of an electronic device provided by an embodiment of the present application;

[0072] Figure 21B Top view schematic diagram of a bamboo book provided by an embodiment of the present application;

[0073] Figure 22A Schematic diagram of the folded state of an electronic device provided by an embodiment of the present application;

[0074] Figure 22B Top view schematic diagram of a bamboo book provided by an embodiment of the present application;

[0075] Figure 23A Schematic diagram of the folded state of an electronic device provided by an embodiment of the present application;

[0076] Figure 23B Top view schematic diagram of a bamboo book provided by an embodiment of the present application. Detailed implementation manners

[0077] Next, the technical solutions in the embodiments of the present application will be described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments.

[0078] Hereinafter, terms such as "second" and "first" are only for convenience of description, and cannot be construed as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, features defined with "second", "first", etc. may explicitly or implicitly include one or more of such features. In the description of the present application, unless otherwise specified, the meaning of "a plurality" is two or more.

[0079] In addition, in the embodiments of the present application, orientation terms such as "upper", "lower", "left", "right", etc. may include, but are not limited to, being defined relative to the schematic placement orientation of the components in the drawings. It should be understood that these directional terms may be relative concepts, which are used for relative description and clarification, and they may change accordingly with the change of the orientation of the components in the drawings.

[0080] In the embodiments of the present application, unless otherwise clearly defined and limited, the term "connection" should be understood in a broad sense. For example, "connection" may be a fixed connection, a detachable connection, or an integral body; it may be directly connected, or indirectly connected through an intermediate medium. In addition, the term "coupled" may be a direct electrical connection, or an indirect electrical connection through an intermediate medium. The term "contact" may be direct contact, or indirect contact through an intermediate medium.

[0081] In the embodiments of the present application, "and / or" describes the association relationship between associated objects, indicating that there can be three relationships. For example, A and / or B can represent the cases of A existing alone, A and B existing simultaneously, and B existing alone, where A and B can be singular or plural. The character " / " generally indicates that the associated objects before and after are in an "or" relationship.

[0082] The embodiments of the present application provide an electronic device, which can be a foldable electronic device, for example. The electronic device can be a consumer electronic product, a home electronic product, a vehicle-mounted electronic product, or a financial electronic product. Among them, consumer electronic products such as mobile phones, tablets, laptop computers, e-readers, personal computers (PCs), personal digital assistants (PDAs), desktop monitors, smart wearable products (such as smart watches, smart bracelets), virtual reality (VR) electronic devices, augmented reality (AR) electronic devices, drones, etc. Home electronic products such as smart door locks, TVs, refrigerators, small household appliances for charging (such as soymilk makers, floor sweeping robots), etc. Vehicle-mounted electronic products such as vehicle-mounted navigators, vehicle-mounted DVDs, etc. Financial electronic products such as ATMs, electronic devices for self-service business handling, etc.

[0083] Figure 1A It is a schematic structural diagram of an electronic device provided by the embodiments of the present application. Figure 1B and Figure 1C It is a schematic diagram of the folded state of an electronic device provided by the embodiments of the present application.

[0084] To facilitate the understanding of the electronic device provided by the embodiments of the present application, in combination with the attached Figure 1A , a two-fold electronic device is introduced as follows:

[0085] As Figure 1A shown, the electronic device 1 includes a display module 10, a middle frame 20, and a rear cover (or called a back shell, a battery cover, etc., Figure 1A not shown in the figure). The display module 10 is disposed on the middle frame 20, and the middle frame 20 is used to carry the display module 10. The rear cover is covered on the middle frame 20 and forms an accommodation space with the side of the middle frame 20 away from the display module 10.

[0086] The middle frame 20 includes a first frame body 201, a second frame body 202, and a first rotating shaft mechanism 203. The first frame body 201 and the second frame body 202 are disposed on both sides of the first rotating shaft mechanism 203, and the first rotating shaft mechanism 203 is respectively connected to the first frame body 201 and the second frame body 202. 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 is kept as flat as possible during use and the non-display surface of the flexible display module 10 is protected. Exemplarily, a part of the display module 10 is fixed to the first frame body 201 through an adhesive layer, and a part is fixed to the second frame body 202 through an adhesive layer. The adhesive layer can be a thin film layer formed after applying glue, and the specific form of the adhesive layer in the embodiments of the present application is not limited.

[0087] In addition, other electronic components can be provided on the sides of the first frame body 201 and the second frame body 202 away from the display module 10. For example, a printed circuit board (PCB), a battery, a receiver, a speaker, a camera, etc. can be provided. The PCB can integrate electronic components such as the main controller, storage unit, antenna module, and power management module of the electronic device, and the battery can supply power to electronic components such as the display module 10, the circuit board, the receiver, the speaker, and the camera. Of course, the electronic components provided on the first frame body 201 and the second frame body 202 in the embodiments of the present application are not limited.

[0088] Exemplarily, 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, along the horizontal direction, the display module 10 has a first non-bendable area 101, a second non-bendable area 102, and a first bendable area 103 connecting the first non-bendable area 101 and the second non-bendable area 102. For example, the display module 10 can include a first non-bendable area 101 corresponding to the first frame body 201, a second non-bendable area 102 corresponding to the second frame body 202, and a first bendable area 103 corresponding to the first rotating shaft mechanism 203. The first non-bendable area 101 can be connected to the first frame body 201, and the second non-bendable area 102 can be connected to the second frame body 202.

[0089] Under the action of the first rotating shaft mechanism 203, the first frame body 201 and the second frame body 202 can approach or move away from each other. Correspondingly, the first non-bendable area 101 of the display module 10 and the second non-bendable area 102 of the display module 10 can approach or move away from each other, so that the display module 10 can be folded or unfolded.

[0090] In the embodiments of the present application, the direction from the first non-bending region 101 to the second non-bending region 102 is defined as the first direction X, and the first direction X is perpendicular to the first rotating shaft mechanism 203. The extending direction of the first rotating shaft mechanism 203 is defined as the second direction Y, and the second direction Y intersects (for example, is perpendicular to) the first direction X. The first direction X is the above-mentioned horizontal direction. The thickness direction of the electronic device 1 is defined as the third direction Z, and the third direction Z intersects (for example, is perpendicular to) both the first direction X and the second direction Y.

[0091] As Figure 1B and Figure 1C shown, in the folded state, the angle α between the first housing 201 and the second housing 202 can rotate from 180° to the first housing 201 and the second housing 202 being parallel and oppositely arranged, and the distance between the first housing 201 and the second housing 202 is the smallest. At this time, the first non-bending region 101 and the second non-bending region 102 can be regarded as being arranged on different planes. Figure 1B In Figure 1C an example is schematically shown where the display module 10 faces inward when the electronic device 1 is folded, and the first non-bending region 101 and the second non-bending region 102 face each other (inward folding).

[0092] As Figure 1A shown, in the unfolded state, the angle α between the first housing 201 and the second housing 202 can be approximately 180°.

[0093] Figure 2 This is an architecture diagram of a display module provided by the embodiments of the present application.

[0094] Different from a straight-board electronic device, since a foldable electronic device needs to have the first bendable characteristic, the display module 10 is mainly composed of multiple layers of flexible materials with relatively low stiffness. As Figure 2 shown, the display module 10 can be roughly divided into five layers: a protective film layer 11, a cover plate (cover) 12, a display screen (or called a display panel, panel) 13, a back film 14, and a bracket (BKT) 15.

[0095] The protective film layer 11 protects the display screen 13 and prevents the cover plate 12 from cracking. The cover plate 12 provides a protective function, similar to the glass cover plate of a straight electronic device. The display screen 13 is used to implement functions such as touch control and light emission. The back film 14 is used to support and protect the display screen 13. 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. 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 OCA, for example. The display screen 13 and the back film can be connected by a pressure sensitive adhesive (PSA), for example. The back film 14 and the bamboo book 15 can be connected by OCA, for example.

[0096] To achieve flexibility, the display screen 13 can be a self-luminous display screen, for example, without the need to provide a backlight module (BLM). Exemplarily, 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 diodes (QLED) display screen, etc. In the embodiments of the present application, the surface of the display screen 13 for displaying an 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.

[0097] In order to achieve flexibility, the materials of the protective film layer 11, the cover plate 12, the back film 14, and the bamboo book 15 are mostly polymer materials. When the display screen 13 is subjected to force scenes such as falling impact and pointed extrusion, the display screen 13 is very likely to fail due to black spots, broken bright spots, etc., resulting in the display and touch functions being affected, and its reliability is not as good as that of a straight display screen. At the same time, because the display module 10 needs to have a specific first bendable performance, it is usually necessary to perform a shaft area opening process on the bamboo book 15, and the rigidity of its rotating shaft area will be smaller than that of the large surface area, so the extrusion impact performance of the back of the shaft area will be worse. At the same time, as the thickness of the folding electronic device is further reduced, the thickness of the display module 10 will be less and less. After the thickness of the display module 10 is reduced, the performance of extrusion and impact, the risk of the display screen 13 back arching when the electronic device 1 falls, and the delicacy of the display module 10 (such as 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 be a challenge.

[0098] Several structures of the display module 10 are exemplified below.

[0099] In some embodiments, the cover plate 12 is made of polyethylene terephthalate (PET) with a thickness of about 50 um or colorless polyimide (CPI) with a thickness of about 50 um.

[0100] 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.

[0101] In order to enhance the protective performance of the cover plate 12, in some embodiments, a plurality of protective layers are stacked as the cover plate 12, and the protective layers are connected by OCAs of different thicknesses. This can improve the ability of the cover plate 12 to absorb impact or extrusion. However, with the current trend of the thickness of the display module 10 gradually decreasing, the number of protective layers is continuously reduced, and the thickness of the OCA is continuously reduced. This results in the limited ability of the cover plate 12 to absorb impact or extrusion, and this problem has been waiting to be improved.

[0102] Figure 3A A side view of a bamboo book provided in an embodiment of the present application, Figure 3B A top view of a bamboo book provided in an embodiment of the present application, Figure 3C A cross-sectional view of a bamboo book provided in an embodiment of the present application, Figure 3D A schematic diagram of a reverse arch of a display module provided in an embodiment of the present application.

[0103] In some embodiments, the material of the bamboo book 15 includes carbon fiber. As Figure 3A shown, when the electronic device is in a bent state, the bamboo book 15 needs to be bent into a "water droplet" shape in cooperation with the display screen 13. The bamboo book 15 includes a first non-bendable portion 151, a second non-bendable portion 152, and a first bendable portion 153, and the first bendable portion 153 is bent into a "water droplet" shape. A hole is formed in the first bendable portion 153.

[0104] The first non-bendable portion 151 is located in the first non-bendable area 101, the second non-bendable portion 152 is located in the second non-bendable area 102, and the first bendable portion 153 is located in the first bendable area 103. A hole is formed in the first bendable portion 153 to reduce the stiffness and achieve the bending function.

[0105] 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 portion 1531 and the third portion 1533, and a fourth portion 1534 located between the first portion 1531 and the fifth portion 1535. Holes are formed in the first portion 1531, the third portion 1533, and the fifth portion 1535, and no holes are formed in the second portion 1532 and the fourth portion 1534. The second portion 1532 and the fourth portion 1534 are connected to the rotating shaft door panel of the first rotating shaft mechanism 203 by dotting glue to realize the connection between the first rotating shaft mechanism 203 and the bamboo book 15. The top view of the bamboo book 15 is as Figure 3B shown, the first non-bendable portion 151, the first bendable portion 153, and the second non-bendable portion 152 are arranged along the first direction X. The first portion 1531 can be understood as the "inner R area" commonly referred to in the art, and the third portion 1533 and the fifth portion 1535 can be understood as the "outer R area" commonly referred to in the art.

[0106] As Figure 3C shown, no hole needs to be formed in the second portion 1532, and holes are formed in the first portion 1531 and the third portion 1533, 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.

[0107] Since there are unperforated second part 1532 and fourth part 1534 in the bamboo book 15 of the first bendable part, stiffness mutations occur at the junctions of the first part 1531 and the second part 1532, and the second part 1532 and the third part 1533. There are two stiffness mutations between the first part 1531 and the third part 1533, where the stiffness first increases and then decreases. Similarly, there are also two stiffness mutations between the third part 1533 and the fifth part 1535. Hindered by the second part 1532 and the fourth part 1534, when the bamboo book 15 drops in the unfolded state, the arching deformation generated by the third part 1533 cannot spread to the left and right, and the third part 1533 alone bears the reverse arch. The radius of the reverse arch is the length corresponding to the third part 1533, resulting in a relatively high reverse arch bulge and poor reverse arch strain of the bamboo book 15. As Figure 3D shown, the reverse arch bulge of the bamboo book 15 will deteriorate the reverse arch performance of the display module 10 in the unfolded state when dropped, causing the display screen 13 to fail due to excessive strain. In addition, since there is no smooth connection of stiffness between the first part 1531 and the third part 1533, the "water droplet" screen in the folded state is not smooth enough at the first bendable part. Moreover, in the first bendable area 103, due to the perforation of the bamboo book 15 to ensure bending, there are obvious shortcomings in the extrusion impact on the shaft area on the back below the display screen 13.

[0108] Figure 4A The figure is a cross-sectional view of a display module and a middle frame provided by an embodiment of the present application. Figure 4B The figure is a top view of an under-screen buffer layer and a middle frame provided by an embodiment of the present application.

[0109] In some embodiments, as Figure 4A shown, the material of the back film 14 includes PET or polyimide (PI).

[0110] Since the stiffness of PET and PI is relatively small, only about 3 GPa, the anti-impact and extrusion performance on the back of the display screen 13 is relatively poor.

[0111] In some embodiments, the thickness of the back film 14 is 50 μm or more.

[0112] By increasing the thickness of the back film 14, the stiffness of the back film 14 is increased to improve the support for the display screen 13 and the reliability of the display screen 13. However, this will cause the thickness of the display module 10 to be too thick, which is not conducive to the realization of thin and light. Moreover, the problem of the reverse arch of the bamboo book 15 still has not been solved.

[0113] In some embodiments, as Figure 4A shown, the electronic device further includes an under-screen buffer layer.

[0114] The under-screen buffer layer is located below the bamboo book 15 and above the first rotating shaft mechanism 203, asFigure 4B As shown, the under-screen buffer layer can cover the first rotating shaft mechanism 203. The under-screen buffer layer is used to absorb external extrusion and impact, thereby improving the reliability of the display module 10 in the first bendable area 103.

[0115] However, setting the under-screen buffer layer, on the one hand, increases the complexity of the architecture of the display module 10. On the other hand, since the gap space between the display module 10 and the first rotating shaft mechanism 203 is filled, it couples the uncertain factors with the middle frame 20, and some new problems will be introduced during the bending process, such as the under-screen buffer layer is prone to interfere with the first rotating shaft mechanism 203 resulting in abnormal noise, wear of the first rotating shaft mechanism 203 or the under-screen buffer layer, etc. On the other hand, it will sacrifice the thickness allocated to the first rotating shaft mechanism 203 in the overall design dimension of the electronic device 1, increasing the gap between the bamboo book 15 and the middle frame 20.

[0116] Figure 5A A cross-sectional view of a display module and a middle frame provided by an embodiment of the present application, Figure 5B A top view of a cross-axis functional layer and a middle frame provided by an embodiment of the present application.

[0117] In some embodiments, as Figure 5A shown, a cross-axis functional layer is provided below the bamboo book 15.

[0118] As Figure 5B shown, the so-called cross-axis means that the functional layer is located above the first frame body 201 and extends across the first rotating shaft mechanism 203 to above the second frame body 202.

[0119] For example, when the cross-axis functional layer is a wiring layer, the cross-axis functional layer is respectively coupled to the first circuit board corresponding to the first non-bendable area 101 and the second circuit board corresponding to the second non-bendable area 102 through a flexible printed circuit (FPC) to realize the connection between the first circuit board and the second circuit board.

[0120] Or, 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 realized through the cross-axis functional layer.

[0121] A cross-axis functional layer is disposed below 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 region 103. However, the cross-axis functional layer occupies the space in the thickness direction of the entire electronic device 1 and also squeezes 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 (not fully covered in the entire horizontal plane), it will cause a visual effect problem of die stamping due to the step difference in the horizontal unfolded state. At the same time, during the bending process, the coupling between the cross-axis functional layer and the display screen 13 and the first rotating shaft mechanism 203 is relatively large, which will cause problems such as the cross-axis functional layer supporting the screen, pushing against the screen, and interference between the cross-axis functional layer and the first rotating shaft mechanism 203 during bending, deteriorating the bending reliability of the display module 10.

[0122] Since the bamboo book 15 of the foldable display module 10 needs to open holes through the first bendable portion 153 to achieve the water droplet-shaped bending, as the requirement for reducing the rebound force of the entire machine architecture increases, it is inevitable that the porosity of the first bendable portion 153 increases. At the same time, the display module 10 is continuously iterated in the ultra-thin design, resulting in no high-rigidity support solution for the display module 10 in the first bendable region 103, and it is impossible to protect the display screen 13 from the back. Moreover, when the water droplet bending radius shows a decreasing trend, the crease will deteriorate further. Based on the above description, although the display module 10 is constantly improving, there are still various problems that need to be improved.

[0123] Figure 6 Schematic structural diagram of a display module provided by an embodiment of the present application.

[0124] An embodiment of the present application provides a display module 10, as Figure 6 shown, the display module 10 has a first non-bendable region 101, a second non-bendable region 102, and a first bendable region 103. The first bendable region 103 connects the first non-bendable region 101 and the second non-bendable region 102. When the display module 10 is applied to the electronic device 1, the display module 10 is disposed on the middle frame 20. The first non-bendable region 101 corresponds to the first frame 201, the second non-bendable region 102 corresponds to the second frame 202, and the first bendable region 103 corresponds to the first rotating shaft mechanism 203.

[0125] 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.

[0126] The embodiment of the present application does not limit the structure of the screen protection layer 16, and the screen protection layers in related technologies are applicable to the embodiment of the present application.

[0127] Figure 7 Schematic structural diagram of a screen protection layer provided by an embodiment of the present application.

[0128] In some embodiments, such as Figure 7 shown, the screen protection layer 16 includes a surface layer 161, at least one anti-extrusion layer 162, and at least one connection layer 163. Figure 7 Taking the screen protection layer 16 including three anti-extrusion layers 162 as an example for illustration, a connection layer 163 is provided between the surface layer 161 and the uppermost anti-extrusion layer 162, and the surface layer 161 and the uppermost anti-extrusion layer 162 are connected through the connection layer 163. A connection layer 163 is provided between adjacent anti-extrusion layers 162, and adjacent anti-extrusion layers 162 are connected through the connection layer 163.

[0129] The surface layer 161 is located on the side of at least one anti-extrusion layer 162 away from the display screen 13. In the electronic device 1, the surface layer 161 is a film layer that can be touched by the user, and functions to prevent scratching and explosion-proof. Exemplarily, the material of the surface layer 161 includes high-modulus transparent polymer materials such as PET, CPI, glass fiber, and CPI composite materials. The anti-extrusion layer 162 that is farthest from the surface layer 161 among the at least one anti-extrusion layer 162 is connected to the display screen 13 through a first connection layer 191.

[0130] In some embodiments, the material of the anti-extrusion layer 162 includes low-modulus polymer materials such as PET and CPI.

[0131] In some other embodiments, the material of the anti-extrusion layer 162 includes high-modulus materials.

[0132] Exemplarily, 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, etc.

[0133] For example, the material of the anti-extrusion layer 162 includes ultra-thin glass (UTG) or high-entropy glass.

[0134] Using a high-modulus material to form the anti-extrusion layer 162 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.

[0135] In some embodiments, the anti-extrusion layer 162 is bonded to the surface layer 161 and does not need to be connected through the connection layer 163.

[0136] UTG and high-entropy glass have good elastic recoverability. Adopting this screen protection layer 16 architecture with multiple UTGs or high-entropy glasses can also greatly improve the recoverability of creases.

[0137] Alternatively, for example, the material of the anti-extrusion layer 162 includes metal, and the thickness of the anti-extrusion layer 162 is less than 50 um. For example, the thickness of the anti-extrusion layer 162 is 50 um, 45 um, 40 um, 35 um, 30 um, 25 um, 20 um, 15 um, 10 um, or 5 um, etc.

[0138] The metal with a thickness less than 50 um has a first bendability, which can not only meet the trend of thinning the film layer but also improve the impact resistance and anti-extrusion ability of the screen protection layer 16.

[0139] The material of the connection layer 163 may include, for example, high-viscosity and high-recovery adhesives with energy absorption and light transmission properties such as OCA, thermoplastic polyurethanes (TPU), nylon elastomer, and silicone gel.

[0140] In the embodiment of the present application, the connection layer 163 is used to connect the high-modulus "hard" layers such as the surface layer 161 and the anti-extrusion layer 162, and at the same time, the bendability of dislocation and the repairability of creases are realized.

[0141] Exemplarily, the thickness of the connection layer 163 is 10 um - 75 um. For example, the thickness of the connection layer 163 is 10 um, 15 um, 20 um, 25 um, 30 um, 35 um, 40 um, 45 um, 50 um, 55 um, 60 um, 65 um, 70 um, or 75 um, etc.

[0142] In the embodiment of the present application, when the thickness of the connection layer 163 is limited within the range of 10 um - 75 um, the impact resistance and anti-extrusion performance of the display module 10 can still be guaranteed.

[0143] In some embodiments, the material of the first connection layer 191 may include, for example, energy absorption and light transmission materials such as OCA, TPU, nylon elastomer, and silicone gel.

[0144] Exemplarily, the thickness of the first connection layer 191 is 10 um - 75 um. For example, the thickness of the first connection layer 191 is 10 um, 15 um, 20 um, 25 um, 30 um, 35 um, 40 um, 45 um, 50 um, 55 um, 60 um, 65 um, 70 um, or 75 um, etc.

[0145] In the embodiment of the present application, when the thickness of the first connection layer 191 is limited within the range of 10 um - 75 um, the impact resistance and anti-extrusion performance of the display module 10 can still be guaranteed.

[0146] As Figure 6As shown, the display screen 13 is used to display images. The display screen 13 can be, for example, a flexible display screen with touch function. Exemplarily, 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 implement the display function of the display screen 13. The bonding portion 133 is bent to the back of the display portion 131 through the bending portion 132. The bonding portion 133 can be located, for example, below the first non-bending area 101. The display portion 131 can include, for example, 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.

[0147] The screen protection layer 16 is located on the 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 to connect the display screen 13 and the screen protection layer 16. Exemplarily, the screen protection layer 16 and the first connection layer 191 at least cover the display portion 131 of the display screen 13.

[0148] In some embodiments, the back film 14 is located on the back of the display screen 13. The second connection layer 192 is located between the display screen 13 and the back film 14 and is used to connect the display screen 13 and the back film 14.

[0149] Exemplarily, the back of the display screen 13 is in contact connection with the second connection layer 192, and the surface of the back film 14 facing the display screen 13 is in contact connection with the second connection layer 192.

[0150] In the embodiments of the present application, the back film 14 has a single-layer structure, and the modulus of the material of the back film 14 is 10 GPa - 500 GPa.

[0151] Exemplarily, 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, etc.

[0152] 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 material, etc. The selection of materials for the back film 14 is rich and the applicable range is wide. 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 changes from the folded state to the unfolded state, the high-modulus back film 14 can completely or almost completely return to the initial state.

[0153] For example, the back film 14 is a single film layer structure in a flat state made of the same material. That is, the materials at each position of the back film 14 are the same. The aforementioned material is not limited to a single element material and can also be a mixed material. The single film layer back film 14 covers at least the display portion 131 of the display screen 13.

[0154] In some embodiments, the material of the second connection layer 192 may include energy-absorbing and light-transmitting materials such as OCA, TPU, nylon elastomer, and silicone gel.

[0155] Exemplarily, the thickness of the second connection layer 192 is 10um - 75um. For example, the thickness of the second connection layer 192 is 10um, 15um, 20um, 25um, 30um, 35um, 40um, 45um, 50um, 55um, 60um, 65um, 70um, or 75um, etc.

[0156] In the embodiments of the present application, the thickness of the second connection layer 192 is limited within the range of 10um - 75um, and the impact resistance and extrusion resistance of the display module 10 can still be ensured.

[0157] Figure 8 It is a schematic structural diagram of a display screen in an unfolded state provided by the embodiments of the present application.

[0158] In some embodiments, as Figure 8 shown, when the display screen 13 is in an unfolded state, the display portion 131 and the bonding portion 133 of the display screen 13 are laminated and connected with a back film 14. Or it can be understood that a back film 14 is correspondingly arranged below the display portion 131 and the bonding portion 133 of the display screen 13, and no back film 14 is arranged below the bending portion 132 of the display screen 13.

[0159] In some embodiments, when the display screen 13 is in an unfolded state, a screen protection layer 16 is laminated and connected to the display portion 131 of the display screen 13. Or it can be understood that a screen protection layer 16 is correspondingly arranged above the display portion 131 of the display screen 13, and no screen protection layer 16 is arranged above the bending portion 132 and the bonding portion 133 of the display screen 13.

[0160] No first connection layer 191 and screen protection layer 16 are arranged above the bending portion 132 of the display screen 13, and no second connection layer 192 and back film 14 are arranged below the bending portion 132, which helps the display screen 13 to bend at the bending portion 132.

[0161] For the display module 10 provided by the embodiments of the present application, the modulus of the material of the back film 14 is a high-rigidity material of 10 GPa - 500 GPa, and the modulus of the material of the back film 14 is much greater than that of materials such as PI and PET. Therefore, compared with the PI (or PET) back film in the embodiments of the present application: at the same rigidity, the thickness can be significantly reduced, thereby effectively reducing the thickness of the display module 10. At the same thickness, the rigidity can be significantly improved. Therefore, a back film 14 with a rigidity meeting the requirements and a relatively thin thickness can be obtained, thereby effectively improving the extrusion and impact reliability of the display screen 13 in the first bendable area 103 and enhancing the back extrusion and impact performance of the display module 10. Moreover, through simulation, it is found that with the single-layer back film 14 supporting the display screen 13, the creases of the display module 10 are smoother, the overall refinement (crease and large-surface light and shadow) is higher, and the anti-reverse arch ability during the unfolded state drop is stronger.

[0162] Figure 9A It is a schematic structural diagram of a display module provided by the embodiments of the present application; Figure 9B It is a crease simulation effect diagram of a display module provided by the embodiments of the present application.

[0163] For example, as Figure 9A shown, an example of a display module 10 is given. The material of the surface layer 161 is PET with a thickness of 53 um, the material of the connection layer 163 is OCA with a thickness of 35 um, the material of the anti-extrusion layer 162 is UTG with a thickness of 30 um. The material of the first connection layer 191 is OCA with a thickness of 35 um. The material of the bamboo book 15 is carbon fiber with a thickness of 150 um. Taking the material of the second connection layer 192 as OCA with a thickness of 15 um and the material of the back film 14 as PET with a thickness of 50 um, and the total thickness of the display module 10 being 435 um as an example for simulation. And taking the material of the second connection layer 192 as OCA with a thickness of 25 um and the material of the back film 14 as a steel sheet with a thickness of 20 um, and the total thickness of the display module 10 being 415 um as an example for simulation. As Figure 9BAs shown, the horizontal axis represents the dimension of the display module 10 in the first direction X, the vertical axis represents the dimension of the display module 10 in the third direction Z, and the curve represents the degree of protrusion at each position in the first direction X when the display module 10 is bent. When the material of the back film 14 is a steel sheet with a thickness of 20 μm, on the premise of reducing the total thickness of the display module 10 (thinning by 20 μm), the crease of the display module 10 provided by the embodiment of the present application is smoother (the crease effect is improved by about 36%), the degree of protrusion is significantly reduced, and when the bending radius of the water droplet is reduced, the effect of crease optimization is more obvious. Moreover, both the extrusion and impact resistance capabilities 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 increased by more than about 60%, and the impact resistance of the display screen 13 is increased by more than about 40%). Furthermore, the effect of large-area light and shadow is also improved after the material of the back film 14 is changed to metal.

[0164] In some embodiments, the thickness of the back film 14 is 15 μm - 45 μm. For example, the thickness of the back film 14 is 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, or 45 μm, etc.

[0165] In the embodiment of the present application, the modulus of the back film 14 is relatively high, and the anti-back extrusion and impact resistance capabilities are relatively strong. Therefore, it is not necessary to increase the thickness of the back film 14 to improve the anti-back extrusion and impact resistance capabilities of the back film 14. The thickness of the back film 14 can be made 15 μm - 45 μm, which is beneficial to realizing the lightness and thinness of the display module 10 while ensuring the anti-back extrusion and impact resistance capabilities.

[0166] Figure 10A and Figure 10B is a schematic structural diagram of a display module provided by an embodiment of the present application.

[0167] In some embodiments, a gap is formed in the back film 14, and the gap is disposed close to the first bendable area 103. For example, the back film 14 includes a first gap located at the junction of the first non-bendable area 101 and the first bendable area 103, or the first gap straddles the junction of the first non-bendable area 101 and the first bendable area 103. The back film 14 further includes a second gap located at the junction of the second non-bendable area 102 and the first bendable area 103, or the second gap straddles the junction of the second non-bendable area 102 and the first bendable area 103.

[0168] Exemplarily, the gap is Figure 10A the gap shown. Or, exemplarily, the gap is a groove, and the opening of the groove can face the display screen 13, and the opening of the groove can also face away from the display screen 13. One of the above gaps can be formed in the back film 14, or multiple of the above gaps can be formed in the back film 14. The structures of the multiple gaps can be the same, and the structures of the multiple gaps can also be different.Figure 10A The structure in the figure is only an example and is not intended to be limiting.

[0169] For example, Figure 10A As shown, the second connection layer 192 does not fill the gap on the back film 14. For example, at the position where the back film 14 has a gap, the second connection layer 192 also has a corresponding gap. Or, for example, the second connection layer 192 covers the opening of the gap but does not fill the gap.

[0170] In the embodiment of the present application, by opening a gap on the back film 14 , the rigidity at the gap can be reduced to improve the first bendability of the back film 14 .

[0171] In some embodiments, Figure 10A As shown, 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 include a single layer.

[0172] In other embodiments, Figure 10B As shown, 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 multiple layers of back films 14 is a single layer structure that at least covers the display part 131 of the display screen 13.

[0173] The display module 10 includes a multi-layer back film 14, and 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 light and shadow performance of the back film 14, and can also improve the first bendability of the back film 14 stack.

[0174] Figure 11 A schematic diagram of the structure of a display module provided in an embodiment of the present application.

[0175] In some embodiments, the material of the back film 14 includes a conductive material. Figure 11 As shown, 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 through the transition portion.

[0176] The embodiment of the present application does not limit the location of the grounding conductive layer, and the grounding conductive layer may be any grounding component in the display module 10 .

[0177] For example, Figure 6 As shown, 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 connection 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 through the third connection layer 193.

[0178] For example, the bamboo book 15 is connected to the middle frame 20 through the adhesive backing, so as to realize the connection between the display module 10 and the middle frame 20. The embodiment of the present application does not limit the setting position of the adhesive backing, and only needs to realize the connection between the display module 10 and the middle frame 20. The embodiment of the present 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.

[0179] In some embodiments, Figure 8 As shown, when the display screen 13 is in the unfolded state, the back film 14 laminated and connected to the display portion 131 of the display screen 13 is laminated with the bamboo book 15. Alternatively, it can be understood that the bamboo book 15 is correspondingly arranged below the display portion 131 of the display screen 13, and the bamboo book 15 is not arranged below the bending portion 132 and the binding portion 133 of the display screen 13.

[0180] For example, Figure 11 As shown, a grounding 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 penetrates the third connecting layer 193 and the bamboo book 15, and the back film 14 is connected to the grounding conductive layer through the transition part.

[0181] For example, the material of the transition portion includes metals such as copper and silver.

[0182] The grounding conductive layer is arranged on the back of the bamboo book 15, so that the bamboo book 15 can meet the requirements of electrostatic discharge (ESD). In the case where the material of the back film 14 is a conductive material, the back film 14 also needs to meet the requirements of ESD. The conductive back film 14 is connected to the grounding conductive layer through the transition part, so that the back film 14 can meet the requirements of ESD without adding a grounding layer, and the structure is simple.

[0183] In some embodiments, Figure 11 As shown, 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.

[0184] Figure 12A A top view of a bamboo book provided in an embodiment of the present application, Figure 12B A side view of a bamboo book provided in an embodiment of the present application, Figure 12C A diagram showing the relative relationship between a bamboo book and a hinge door panel provided in an embodiment of the present application.

[0185] In some embodiments, the display module 10 is applied to Figure 1B An inward-folding electronic device is shown.

[0186] like Figure 12AAs shown, along the direction from the first non-bending region 101 to the second non-bending region 102 (the first direction X), the first bendable portion 153 includes a first part 1531, a second part 1532, a third part 1533, a fourth part 1534, and a fifth part 1535 arranged in sequence. The stiffness of the second part 1532 is greater than that of the third part 1533 and less than that of the first part 1531. The stiffness of the fourth part 1534 is greater than that of the third part 1533 and less than that of the fifth part 1535.

[0187] Exemplarily, the stiffness of the third part 1533 is the smallest, followed by the stiffness of the second part 1532 and the fourth part 1534, and then the stiffness of the first part 1531 and the fifth part 1535. The stiffness of the second part 1532 and the fourth part 1534 may be equal or unequal. The stiffness of the first part 1531 and the fifth part 1535 may be equal or unequal. From the third part 1533 to the second part 1532, then to the first part 1531, and then to the first non-bending part 151, the stiffness shows a gradually increasing trend. From the third part 1533 to the fourth part 1534, then to the fifth part 1535, and then to the second non-bending part 152, the stiffness shows a gradually increasing trend.

[0188] The embodiments of the present application do not limit the manner of changing the stiffness of each part of the bamboo book 15. For example, the stiffness of each part of the bamboo book 15 can be changed by means such as changing the thickness, changing the material, forming holes, etc. Of course, the embodiments of the present application do not limit that the first bendable portion 153 of the bamboo book 15 only includes the first part 1531, the second part 1532, the third part 1533, the fourth part 1534, and the fifth part 1535. The first bendable portion 153 may further include more parts to further refine the stiffness division of the first bendable portion 153 and improve the bending effect of the bamboo book 15.

[0189] In the bamboo book 15 provided by the embodiments of the present application, the first bendable portion 153 includes at least five parts, and realizes that from the third part 1533 to the second part 1532, then to the first part 1531, and then to the first non-bending part 151, the stiffness shows a gradually increasing trend. From the third part 1533 to the fourth part 1534, then to the fifth part 1535, and then to the second non-bending part 152, the stiffness shows a gradually increasing trend. This makes the stiffness of the first bendable portion 153 transition smoothly and the stiffness has continuity, thereby increasing the camber range. As Figure 12BAs shown, the radius of the reverse arch changes from the third part 1533 to the entire first bendable part 153, effectively increasing the reverse arch radius and reducing the reverse arch height. This can effectively reduce the reverse arch height of the display module 10 at the first bendable area 103 during the drop process in the unfolded state, and improve the anti-reverse arch ability of the display module 10. At the same time, since the stiffness change of the bamboo book 15 is smooth, the smoothness of the water droplet shape of the display module 10 can be further improved. Moreover, the tensile force of the bamboo book 15 is decomposed by the holes, 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 initial state.

[0190] In some embodiments, as Figure 12A shown, holes are provided in the first part 1531, the second part 1532, the third part 1533, the fourth part 1534, and the fifth part 1535. The hole density of the second part 1532 is greater than that of the first part 1531 and less than that of the third part 1533. The hole density of the fourth part 1534 is greater than that of the fifth part 1535 and less than that of the third part 1533.

[0191] That is, the greater the hole density, the smaller the stiffness of this part. Based on this, the hole density of the third part 1533 is the largest, followed by the hole densities of the second part 1532 and the fourth part 1534, and then the hole densities of the first part 1531 and the fifth part 1535. As Figure 12B shown, the first bendable part 153 is non-uniformly provided with holes, and there is no longer a dispensing area without holes. Then, for example, as Figure 12C shown, no dispensing is provided between the first bendable part 153 and the rotating shaft door panel.

[0192] The ways to change the hole density include various ways such as changing the shape of the holes, changing the depth of the holes, changing the gap between the holes, and changing the arrangement rule of the holes. The embodiments of the present application do not limit this. For example, Figure 12A shown, the third part 1533 is provided with strip-shaped large holes of a fixed length, the second part 1532 and the fourth part 1524 are provided with strip-shaped holes with alternating lengths, and the first part 1531 and the fifth part 1535 are provided with strip-shaped small 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.

[0193] 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.

[0194] Exemplarily, 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.

[0195] This can improve the symmetry of the bamboo book 15, help with stress dispersion when the display module 10 is bent, and reduce the camber.

[0196] In the embodiments of the present application, the holes included in the bamboo book 15 can be blind holes or through holes, and can be holes of various shapes such as circular holes, rectangular holes, strip holes, trapezoidal holes, etc. This is only an illustration in the embodiments of the present application.

[0197] In some embodiments, the display module 10 further includes a support layer, which is arranged between the bamboo book 15 and the back film 14. The support layer can be, for example, a double-sided PI tape. The support layer plays a role in enhancing the energy absorption of the back extrusion impact to improve the support effect on the display screen 13. Of course, the display module 10 may not include a support layer to reduce the thickness of the display module 10.

[0198] In some embodiments, the dimensions of the second part 1532 and the fourth part 1534 along the first direction X are greater than or equal to 2.5 mm. For example, the dimensions of the second part 1532 and the fourth part 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, etc. The second part 1532 and the fourth part 1534 with holes are used to replace the traditional dispensing area, and there is no dispensing area in the bamboo book 15.

[0199] Figure 12D This is a top view of a bamboo book provided by the embodiments of the present application.

[0200] In other embodiments, the display module 10 is applied to Figure 1C the externally foldable electronic device shown.

[0201] As Figure 12D shown, the stiffness of the first bendable part 153 is less than the stiffness of the first non-bendable part 151 and the second non-bendable part 152. That is, the first bendable part 153 can be regarded as a whole area and is no longer divided into multiple parts with different stiffnesses.

[0202] Exemplarily, the stiffness of the first bendable part 153 is adjusted by setting holes in the first bendable part 153.

[0203] Figure 13A and Figure 13B This is a structural schematic diagram of a display module provided by the embodiments of the present application.

[0204] In some embodiments, as Figure 13A shown, the display module 10 further 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.

[0205] Or it can be understood that the functional layer 17 extends from the first non-bending area 101 across the first bendable area 103 to the second non-bending area 102. The functional layer 17 can be understood as a cross-axis functional layer. The functions implemented by the functional layer 17 in the embodiments of the present application are not limited, and the functional layer 17 can be carried by the back film 14 with a higher modulus.

[0206] The functional layer 17 can be disposed on the side of the back film 14 facing the display screen 13, or the functional layer 17 can also be disposed on the side of the back film 14 facing away from the display screen 13 to reduce the influence of the functional layer 17 on the flatness of the display screen 13. The functional layer 17 can be directly disposed on the surface of the back film 14, or the functional layer 17 can also be connected to the back film 14 through a connection layer. Figure 13A This is only a schematic illustration and is not subject to any limitation.

[0207] In the embodiments of the present application, as Figure 13A shown, the functional layer 17 can be disposed only on the back film 14 connected to the display portion 131. As Figure 13B shown, the functional layer 17 can also be disposed on both the back film 14 connected to the display portion 131 and the back film 14 connected to the bonding portion 133.

[0208] Figure 14A This is a top view of a functional layer provided by an embodiment of the present application, Figure 14B This is another top view schematic illustration of a functional layer provided by an embodiment of the present application.

[0209] In some embodiments, as Figure 14A shown, 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, but does not cover the first non-bending area 101, the second non-bending area 102, and the first bendable area 103. By way of example, a partial area of the first non-bending area 101 is provided with the functional layer 17, a partial area of the second non-bending area 102 is provided with the functional layer 17, and a partial area of the first bendable area 103 is provided with the functional layer 17. Or, the functional layer 17 passes through the first bendable area 103 from the first non-bending area 101 and extends to the second non-bending area 102. The dimension of the functional layer 17 in the second direction Y is smaller than the dimension of the display screen 13 in the second direction Y, and the dimension of the functional layer 17 in the first direction X is smaller than or equal to the dimension of the display screen 13 in the second direction Y.

[0210] In some other embodiments, as Figure 14B shown, 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.

[0211] In the embodiments of the present application, the functional layer 17 can be carried by the back film 14 and integrated in the display module 10, without the need to arrange the functional layer 17 below the bamboo book 15, so as to simplify the architecture of the display module 10.

[0212] In some embodiments, the functional layer 17 includes a wiring layer.

[0213] 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.

[0214] The surface of the back film 14 can be a plane, and the wiring layer is arranged 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 connection layer. In this way, the process is simple and the cost is low.

[0215] The back film 14 can also include a groove, and the wiring layer is arranged in the groove. The opening of the groove can face the display screen 13, and the opening of the groove can also be away from the display screen. This can improve the film printing problem caused by the wiring layer.

[0216] The wiring layer can include a single metal wire layer, or the wiring layer can include multiple metal wire layers, and a dielectric layer is arranged between adjacent metal wire layers. The gap between the metal wire layer and the groove can be filled, for example, through an insulating layer or OCA.

[0217] Figure 15 It is a schematic diagram of the relative relationship between a wiring layer and a back film provided by the embodiments of the present application.

[0218] Exemplarily, as Figure 15 shown, 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.

[0219] The first non-bending area 101 and the second non-bending area 102 are respectively provided with flexible printed circuits (FPCs). The wiring layer is coupled to the first main board in the first non-bending area 101 through the FPC in the first non-bending area 101 (for example, coupled in a board-to-board (BTB) connection manner), and the wiring layer is also coupled to the second main board in the second non-bending area 102 through the FPC in the second non-bending area 102, realizing the interconnection of the first main board and the second main board, thereby realizing cross-axis signal transmission. The first main board can be installed on the first frame 201, and the second main board can be installed on the second frame 202, for example.

[0220] If the wiring layer is arranged on the middle frame 20 and is arranged inside the first rotating shaft mechanism 203, there will be a problem that the wiring layer presses against the rotating shaft door panel during the bending process. If it crosses over the upper part of the first rotating shaft mechanism 203, there will be a problem that the wiring layer presses against the display screen 13 during the bending process. Moreover, it increases the design difficulty of the first rotating shaft mechanism 203 and reduces the utilization rate of the overall space of the machine. However, in this application, integrating the wiring layer inside the display module 10 can improve the above problems and simplify the design.

[0221] Figure 16 It is a schematic structural diagram of a display module provided by an embodiment of this application.

[0222] 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.

[0223] Exemplarily, the materials of the heat-conducting layer include high heat-conducting materials such as graphene and copper.

[0224] In some embodiments, graphene sheets can be directly integrated on the back film 14. For example, graphene is directly integrated on the back film 14 by processes such as pressing graphene with the back film 14, electromagnetic deposition of graphene onto the back film, and geometric combination of graphene and the back film through powder metallurgy.

[0225] In some other embodiments, as Figure 16 shown, the heat-conducting layer (functional layer 17) can be connected to the back film 14 through the fourth connection layer 194.

[0226] By integrating a cross-axis heat dissipation functional layer inside the display module 10, the concentration of heat generated by the system on chip (SOC) in the electronic device can be effectively reduced, the heat dissipation uniformity can be increased, and the heat dissipation ability of the electronic device can be further enhanced. It is found through simulation that the temperature in the large surface area of the middle frame is reduced by about 10 °C, and the temperature at the SOC is reduced by about 10 °C.

[0227] Figure 17Schematic diagram of the structure of a display module provided by an embodiment of the present application.

[0228] In some embodiments, the functional layer 17 includes a light-absorbing layer.

[0229] For example, as Figure 17 shown, 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, etc.

[0230] By providing a light-absorbing layer on the back of the display screen 13, on the one hand, the effect of the large-area light and shadow of the display module 10 can be improved, and the overall refinement of the display module 10 can be enhanced. On the other hand, it can serve as a connection transition layer between the back film 14 and the second connection layer 192, and improve the connection effect between the back film 14 and the display screen 13.

[0231] 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 provided on the surface of the back film 14 away from the display screen 13.

[0232] For example, the material of the connection transition layer includes polar materials containing hydrogen bonds. For example, the material of the connection transition layer includes ink, epoxy resin, polyester, or acrylic acid, etc.

[0233] 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.

[0234] In some embodiments, the materials of the connection layers in the display module 10 are all OCA. Except for the surface layer 161 in the screen protection layer 16, the display screen 13, and various connection layers, the other film layers in the display module 10 are all film layers with high modulus and low creep (or no creep). For example, the anti-extrusion layer 162, the back film 14, and the bamboo book 15 are all film layers with high modulus and low creep (or no creep).

[0235] Figure 18 Flowchart of an assembly method of a display module provided by an embodiment of the present application, Figure 19 Schematic diagram of a partial assembly process of a display module provided by an embodiment of the present application.

[0236] The embodiment of the present application also provides an assembly method of a display module. As Figure 18 shown, the assembly method of the display module includes:

[0237] S10, as Figure 19As shown, a display stack is provided. The display stack includes a display screen 13, a connection layer (second connection layer 192), and a back film 14. The back film 14 is connected to the back of the display screen 13 through the connection layer. The display screen 13 includes a display portion 131, a bending portion 132, and a bonding portion 133. The back film 14 covers the display portion 131, the bending portion 132, and the bonding portion 133.

[0238] S20, as Figure 19 shown, form a mark on the side of the back film 14 away from the display screen 13, and remove the portions of the back film 14 and the connection layer that are stacked with the bending portion 132.

[0239] The projection of the above mark on the display screen 13 is located on the display portion 131. Of course, marks may also be formed in the corresponding areas of the bending portion 132 and the bonding portion 133.

[0240] Exemplarily, step S20 includes:

[0241] S21. Place the display stack on the carrier of the transfer device, with the light-emitting side of the display screen 13 facing the carrier.

[0242] S22. Grasp the display portion 131 of the display screen 13 through the grasping probe of the transfer device.

[0243] S23. Form a mark on the surface of the back film 14 away from the display screen 13 through the laser probe at the bottom of the transfer device.

[0244] S24. Remove the portions of the back film 14 and the connection layer that are stacked with the bending portion 132 through the laser.

[0245] S30, as Figure 19 shown, align the above mark to form a bamboo book 15 that is stacked with the display portion 131.

[0246] 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 other film layers.

[0247] After the back film 14 is made of an opaque material, when the bamboo book 15 is formed, the mark on the display screen 13 cannot be recognized. Therefore, forming a mark on the surface of the back film 14 can achieve the process feasibility of the fitting of the bamboo book 15 and the back film 14.

[0248] Figure 20A It is a schematic diagram of the unfolded state of an electronic device provided by an embodiment of the present application. Figure 20B It is a cross-sectional view of an electronic device provided by an embodiment of the present application.

[0249] An embodiment of the present application further provides an electronic device 1, and the electronic device 1 is a multi-fold electronic device. In combination with Figure 20AA three-fold electronic device is introduced as follows: As Figure 20A shown, the electronic device 1 includes a display module 10 and a middle frame 20.

[0250] In some embodiments, the middle frame 20 includes a first frame body 201, a second frame body 202, a first rotating shaft mechanism 203, a third frame body 204, and a second rotating shaft mechanism 205. The first frame body 201 and the second frame body 202 are disposed on both sides of the first rotating shaft mechanism 203, and the first rotating shaft mechanism 203 is respectively connected to the first frame body 201 and the second frame body 202. The second frame body 202 and the third frame body 204 are disposed on both sides of the second rotating shaft mechanism 205, and the second rotating shaft mechanism 205 is respectively connected to the second frame body 202 and the third frame body 204.

[0251] In some embodiments, in the flattened state, along the horizontal direction, the display module 10 has a first non-bendable area 101, a second non-bendable area 102, a first bendable area 103 connecting the first non-bendable area 101 and the second non-bendable area 102, a third non-bendable area 104, and a second bendable area 105 connecting the third non-bendable area 104 and the second non-bendable area 102. For example, the display module 10 may include a first non-bendable area 101 corresponding to the first frame body 201, a second non-bendable area 102 corresponding to the second frame body 202, a first bendable area 103 corresponding to the first rotating shaft mechanism 203, a third non-bendable area 104 corresponding to the third frame body 204, and a second bendable area 105 corresponding to the second rotating shaft mechanism 205.

[0252] In some embodiments, as Figure 20B shown, 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.

[0253] The display screen 13 is located in the first non-bendable area 101, the first bendable area 103, the second non-bendable area 102, the second bendable area 105, and the third non-bendable area 104.

[0254] 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 may refer to the above related descriptions and will not be elaborated here.

[0255] Figure 21A This is a schematic diagram of the folded state of an electronic device provided by an embodiment of the present application. Figure 21B This is a top view schematic diagram of a bamboo book provided by an embodiment of the present application.

[0256] In some embodiments, the electronic device 1 may include a folding device with an inner-fold screen and an outer-fold screen. As Figure 21AAs shown, the electronic device 1 includes an "S"-shaped folding device composed of one inward folding form and one outward folding form.

[0257] In some embodiments, as Figure 21B shown, the bamboo book 15 includes a first non-bendable portion 151, a second non-bendable portion 152, a first bendable portion 153, a third non-bendable portion 154, and a second bendable portion 155.

[0258] The first non-bendable portion 151 is located in the first non-bendable area 101, the second non-bendable portion 152 is located in the second non-bendable area 102, the first bendable portion 153 is located in the first bendable area 103, the third non-bendable portion 154 is located in the third non-bendable area 104, and the second bendable portion 155 is located in the second bendable area 105.

[0259] The first bendable portion 153 corresponds to the inward folding use of the electronic device 1. The structures of the first non-bendable portion 151, the second non-bendable portion 152, and the first bendable portion 153 can refer to the above description regarding Figure 12A this.

[0260] The second bendable portion 155 corresponds to the outward folding use of the electronic device 1. The stiffness of the second bendable portion 155 is less than the stiffness of the second non-bendable portion 152 and the third non-bendable portion 154. That is, the second bendable portion 155 can be regarded as a whole area and is no longer divided into multiple parts with different stiffnesses.

[0261] For example, by setting holes in the second bendable portion 155, the stiffness of the second bendable portion 155 can be adjusted.

[0262] Figure 22A This is a schematic diagram of the folding state of an electronic device provided by an embodiment of the present application. Figure 22B This is a top view schematic diagram of a bamboo book provided by an embodiment of the present application.

[0263] In some other embodiments, the electronic device 1 may include a folding device with all inward folding screens. This inward folding screen is formed by an inward folding form. As Figure 22A shown, the electronic device 1 includes a "G"-shaped folding device with two inward folding forms.

[0264] In some embodiments, as Figure 22B shown, the bamboo book 15 includes a first non-bendable portion 151, a second non-bendable portion 152, a first bendable portion 153, a third non-bendable portion 154, and a second bendable portion 155.

[0265] The first bendable portion 153 corresponds to the inward folding use of the electronic device 1. The structures of the first non-bendable portion 151, the second non-bendable portion 152, and the first bendable portion 153 can refer to the above description regarding Figure 12A this.

[0266] The second bendable portion 155 corresponds to the inward folding use of the electronic device 1. Along the direction from the second non-bendable portion 152 to the third non-bendable 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 that of the eighth portion 1553 and less than that of the sixth portion 1551, and the stiffness of the ninth portion 1554 is greater than that of the eighth portion 1553 and less than that of the tenth portion 1555.

[0267] Exemplarily, the stiffness 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 can be made to the relevant description regarding the first bendable portion 153 above.

[0268] Figure 23A Schematic diagram of the folded state of an electronic device provided by an embodiment of the present application, Figure 23B Top view schematic diagram of a bamboo book provided by an embodiment of the present application.

[0269] In some other embodiments, the electronic device 1 can be a folding device including multiple outward folding screens. The outward folding screen is formed in an outward folding form. As Figure 23A shown, the electronic device 1 includes two "G"-shaped folding devices in an outward folding form.

[0270] In some embodiments, as Figure 23B shown, the bamboo book 15 includes a first non-bendable portion 151, a second non-bendable portion 152, a first bendable portion 153, a third non-bendable portion 154, and a second bendable portion 155.

[0271] The first bendable portion 153 corresponds to the outward folding use of the electronic device 1, and the stiffness of the first bendable portion 153 is less than that of the first non-bendable portion 151 and the second non-bendable portion 152. That is, the first bendable portion 153 can be regarded as a whole area and is no longer divided into multiple parts with different stiffnesses.

[0272] 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 that of the second non-bendable portion 152 and the third non-bendable portion 154. That is, the second bendable portion 155 can be regarded as a whole area and is no longer divided into multiple parts with different stiffnesses. The electronic device 1 provided by the embodiment of the present application can be a multi-fold electronic device, and the above is only an illustration taking a three-fold electronic device as an example. When the electronic device includes more folds on the basis of three folds, the design of the bamboo book 15 at the inward folding part and the design of the bamboo book 15 at the outward folding part can refer to the above relevant description.

[0273] The above is only the specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions within the technical scope disclosed in the present application shall be covered by the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope 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, characterized in that 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, characterized in that, 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, 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; 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 assembling 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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