Foldable display module and foldable electronic device

Abstract

This application relates to the field of display technology, disclosing a foldable display module and a foldable electronic device. The foldable display module includes: a display panel with a bending area and a non-bending area; a second support layer disposed on the side of the first support layer opposite to the display panel; the second support layer includes a first surface and a second surface disposed opposite to each other; in the bending area, at least one of the first surface and the second surface includes at least one groove; the elastic modulus of the first support layer is greater than 10 GPa. This eliminates creases in the display panel when flattened, improving the user experience.

Description

Technical Field

[0001] This invention relates to the field of display technology, and in particular to a foldable display module and a foldable electronic device. Background Technology

[0002] Flexible display panel design is seen as a future development direction, and with the advancement of flexible display technology, flexible display panels are increasingly being used in foldable terminal devices. In foldable terminal devices, flexible display panels and supporting structures are typically combined. The supporting structure enables the folding and unfolding of the flexible display panel, thus forming the foldable screen in the foldable terminal device. Compared to traditional display panels, flexible display panels have significant advantages, such as being thinner and lighter, consuming less power, and their applications are becoming increasingly widespread due to their bendability and flexibility.

[0003] However, the existing support structure at the bottom of the flexible display panel is not strong enough, which leads to creases after the flexible display panel is folded. Summary of the Invention

[0004] To address the issue of creases appearing after flexible display panels are folded, this application provides a foldable display module, comprising: Display panel, including bent and non-bent areas; A first support layer is disposed on the backlight side of the display panel; A second support layer is disposed on the side of the first support layer opposite to the display panel; the second support layer includes a first surface and a second surface disposed opposite to each other; In the bending region, at least one of the first surface and the second surface includes at least one groove; and the elastic modulus of the first support layer is greater than 10 GPa.

[0005] In one possible implementation, the first surface is located on the side of the second support layer closer to the first support layer, and the second surface is located on the side of the second support layer away from the first support layer. In the bending area, the first surface includes a plurality of first grooves, and the second surface includes a plurality of second grooves. The first grooves and the second grooves extend along a first direction and are arranged alternately along a second direction, wherein the first direction and the second direction intersect.

[0006] In one possible implementation, in the bending region, the second support layer includes a plurality of first connecting plates and a plurality of second connecting plates, the first surface includes the surfaces of the plurality of first connecting plates close to the first support layer, and the second surface includes the surfaces of the plurality of second connecting plates away from the first support layer. The first connecting plate overlaps with the adjacent ends of two adjacent second connecting plates to form the second groove, and the second connecting plate overlaps with the adjacent ends of two adjacent first connecting plates to form the first groove. Preferably, the material of the second support layer includes: stainless steel, titanium alloy, or carbon fiber; Preferably, a first transparent optical adhesive layer is provided on the side of the second support layer close to the first support layer, and the first transparent optical adhesive layer is in contact with the first connecting plate in the bending area; Preferably, the first transparent optical adhesive layer fills the first groove.

[0007] In one possible implementation, in the second direction, the width D of the first connecting plate and the second connecting plate is equal, and the width D of the first connecting plate and the second connecting plate is greater than or equal to 0.1 mm and less than or equal to 0.3 mm. In the second direction, the first distance between two adjacent first connecting plates is greater than or equal to D / 4 of the first dimension, and less than or equal to D; the second distance between two adjacent second connecting plates is greater than or equal to D / 4, and less than or equal to D. Preferably, the thickness of the first connecting plate and the second connecting plate is less than 0.08 mm.

[0008] Preferably, the thickness of the first connecting plate and the second connecting plate is greater than 0.03 mm.

[0009] In one possible implementation, the first surface is located on the side of the second support layer close to the first support layer, and the second surface is located on the side of the second support layer away from the first support layer. In the bending region, the first surface or the second surface includes a third groove.

[0010] In one possible implementation, the first support layer includes a third surface located on the side of the first support layer away from the display panel, and the thickness of the first support layer gradually decreases from the bending area to the non-bending area, forming a fourth groove on the third surface. Preferably, the cross-section of the fourth groove perpendicular to the first direction is trapezoidal.

[0011] In one possible implementation, the fourth groove is filled with a highly elastic material; Preferably, the elastic modulus of the high-elasticity material is greater than 0.1 MPa and less than or equal to 100 MPa; Preferably, the elastic modulus of the first support layer is less than 260 GPa; Preferably, the material of the first support layer includes stainless steel or ultra-thin flexible glass; Preferably, the thickness of the first support layer is less than or equal to 60 μm.

[0012] In one possible implementation, a back film layer is disposed on the side of the first support layer near the display panel, and a second transparent optical adhesive layer is disposed between the back film layer and the first support layer.

[0013] In one possible implementation, the light-emitting side of the display panel is provided with a cover plate, the cover plate comprising ultra-thin flexible glass.

[0014] This application also provides a foldable electronic device, including a foldable display module as described in any of the foregoing aspects.

[0015] To enable the foldable display module to bend in the bending area, this application involves patterning the second support layer in the bending area. This involves creating multiple strip-shaped grooves on the second support layer in the bending area, reducing its stiffness and allowing for bending. The grooves in the bending area reduce stiffness, making it flexible and effectively releasing bending stress. The groove structure significantly reduces stress concentration during folding, preventing plastic deformation or breakage of the second support layer due to excessive bending, thus extending the lifespan of the display panel and improving folding reliability. It also improves display quality by reducing the stress impact of bending on the display panel, effectively preventing uneven display, black spots, bright lines, and other defects caused by stress. Furthermore, the use of a first support layer with a high elastic modulus (greater than 10 GPa) provides rigid support, ensuring flatness in both the non-bending and bending areas when unfolded, preventing creases in the display body in the bending area, and improving the user experience. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a cross-sectional schematic diagram of a foldable display module provided in an embodiment of this application; Figure 2 This is a partial structural diagram of a second support layer provided in an embodiment of this application; Figure 3a This is a comparison diagram of the screen flatness of a prior art solution and the screen flatness of the solution provided in this application. Figure 3bThis is a comparison diagram of the screen stress in a prior art solution and the screen stress in the solution of this application, provided in an embodiment of this application. Figure 4 This is a cross-sectional schematic diagram of another foldable display module provided in an embodiment of this application; Figure 5 This is a cross-sectional schematic diagram of another foldable display module provided in an embodiment of this application; Figure 6 This is a cross-sectional schematic diagram of another foldable display module provided in an embodiment of this application; Figure 7 This is a cross-sectional schematic diagram of another foldable display module provided in an embodiment of this application; Figure 8 This is a cross-sectional schematic diagram of another foldable display module provided in an embodiment of this application.

[0018] Explanation of reference numerals in the attached figures: Display panel 100, bending area 110, non-bending area 120; First support layer 200, third surface 210, fourth groove 211; Second support layer 300, first surface 310, second surface 320, first connecting plate 330, second connecting plate 340, first groove 311, second groove 321, third groove 302; First transparent optical adhesive layer 400; Backing layer 500; Second transparent optical adhesive layer 600; Cover plate 700; High elastomer material 800. Detailed Implementation

[0019] The features and exemplary embodiments of various aspects of this application will now be described in detail. To make the objectives, technical solutions, and advantages of this application clearer, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only configured to explain this application and are not configured to limit this application. For those skilled in the art, this application can be implemented without some of these specific details. The following description of the embodiments is merely to provide a better understanding of this application by illustrating examples of this application.

[0020] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes the element.

[0021] It should be understood that when describing the structure of a component, when referring to a layer or region as being "above" or "on top of" another layer or region, it can mean that it is directly above the other layer or region, or that it contains other layers or regions between it and the other layer or region. Furthermore, if the component is flipped over, that layer or region will be located "below" or "under" the other layer or region.

[0022] In related technologies, flexible displays typically consist of a multi-layered structure composed of a cover plate, display panel, touch layer, and support layer. During the use of foldable terminal devices, the flexible display is repeatedly bent. Research by the inventors revealed that in a multi-layered screen, each layer has a different bending radius and deformation capacity, resulting in relative displacement and compression between layers. When stacked together, these layers restrain each other. When the hinge bends, the inner layer is compressed, and the outer layer is stretched. During folding, stress and strain (deformation) are generated under external force. When the stress does not exceed the material's elastic limit, the deformation is completely eliminated after the external force is removed, and the material returns to its original shape; this deformation is reversible elastic deformation. However, when the stress exceeds the material's elastic limit, the deformation cannot be fully recovered after the external force is removed, leaving residual deformation. The material cannot return to its original shape; this residual deformation is irreversible plastic deformation. Therefore, creases easily form in the folding area of ​​the display, affecting the user experience.

[0023] To address the aforementioned technical problems, embodiments of this application provide a foldable display module, such as... Figure 1 As shown, Figure 1 A cross-sectional schematic diagram of a foldable display module provided in this application embodiment includes: Display panel 100 includes a bent area 110 and a non-bent area 120; A first support layer 200 is disposed on the backlight side of the display panel 100; The second support layer 300 is disposed on the side of the first support layer 200 away from the display panel 100; the second support layer includes a first surface 310 and a second surface 320 disposed opposite to each other; In the bending region 110, at least one of the first surface 310 and the second surface 320 includes at least one groove; and the elastic modulus of the first support layer is greater than 10 GPa.

[0024] The display panel 100 has a bending region 110 and two non-bending regions 120 located on both sides of the bending region 110. The bending region 110 is the area where the display panel 100 undergoes bending deformation during the folding process. The display panel 100 is a flexible organic light-emitting diode display panel, which specifically includes a flexible substrate, an array layer, a light-emitting layer, and an encapsulation layer, etc. The display panel 100 can be repeatedly bent in the bending region.

[0025] The array layer is formed on a flexible substrate and may include a driving circuit layer, which includes pixel driving circuits connected to corresponding light-emitting devices to control the light-emitting state of the light-emitting devices 210. The driving circuit layer includes a transistor layer, which comprises an active layer, a gate insulating layer, a gate layer, an interlayer dielectric layer, source / drain electrode layers, and a planarization layer. The active layer, gate layer, and source / drain electrode layers are structures found in thin-film transistors (TFTs). The gate insulating layer, interlayer dielectric layer, and planarization layer define the film positions of the active layer, gate layer, and source / drain electrode layers, as well as the film positions between these structures and other components (e.g., anodes). For example, the transistor layer may also include capacitors, wiring, and other structures.

[0026] A light-emitting device may include a first electrode, a light-emitting functional layer, and a second electrode stacked sequentially on an array layer. The encapsulation structure can encapsulate and protect the film layers of the light-emitting device. For example, the first electrode can be an anode, and the second electrode can be a cathode.

[0027] In the embodiments of this application, Figure 1 Both the first surface 310 and the second surface 320 shown have grooves. Figure 1 For illustrative purposes only, in the actual display module structure, the second support layer 300 may only have grooves on the first surface 310 or only on the second surface 320. The number of grooves can also be set according to actual needs, and may be one or more.

[0028] Furthermore, the display panel in this application embodiment may also be any one of, for example, liquid crystal display (LCD), organic light-emitting diode (OLED), active-matrix organic light-emitting diode (AMOLED), flexible light-emitting diode (FLED), quantum dot light-emitting diodes (QLED), etc., and this application embodiment does not limit it in this way.

[0029] To enable the foldable display module to bend in the bending area 110, this application patterns the second support layer 300 in the bending area 110 by forming multiple strip-shaped grooves on the second support layer 300 in the bending area 110. This reduces the stiffness of the second support layer in the bending area 110, allowing it to bend. The grooves in the bending area 100 of the second support layer 300 further reduce the stiffness of this area, making it flexible and effectively releasing bending stress. The groove structure significantly reduces stress concentration in the bending area 100 during folding, preventing the second support layer 300 from undergoing plastic deformation or breakage due to excessive bending, thereby extending the service life of the display panel 100 and improving folding reliability. It also improves display performance: by reducing the stress impact of bending on the display panel, it effectively prevents uneven display, black spots, bright lines, and other defects caused by stress, ensuring display quality. Meanwhile, by using a first support layer 200 with a high elastic modulus (greater than 10 GPa) to provide rigid support, the flatness of the non-bending area and the bending area in the flattened state is guaranteed, avoiding creases in the display screen body in the bending area and improving the user experience.

[0030] In another embodiment of this application, based on the above embodiments, such as Figure 2 As shown, Figure 2 This is a partial structural diagram of the second support layer 300 provided in an embodiment of this application. The first surface 310 of the second support layer 300 is located on the side of the second support layer 300 close to the first support layer 200, and the second surface 320 is located on the side of the second support layer 300 away from the first support layer 200. In the bending area 110, the first surface 310 includes a plurality of first grooves 311, and the second surface 320 includes a plurality of second grooves 321. The first grooves 311 and the second grooves 321 extend along a first direction X and are arranged alternately along a second direction Y. The first direction X and the second direction Y intersect.

[0031] The first groove 311 and the second groove 321 both extend along the first direction X (parallel to the bending axis), that is, in the direction parallel to the bending axis, the first groove 311 and the second groove 321 are continuous strip structures.

[0032] By forming a first groove 311 and a second groove 321 on the first surface 310 and the second surface 320 on both sides of the second support 300, the first groove 311 and the second groove 321 are staggered in the second direction Y, which can ensure the continuity of the bending state of the display panel 100 after bending, avoid large bending and twisting in local positions, and thus avoid stress concentration in local positions, which could lead to film detachment and breakage.

[0033] Based on the above embodiments, please continue to refer to Figure 2 In the bending area 110, the second support layer 300 includes a plurality of first connecting plates 330 and a plurality of second connecting plates 340, the first surface 310 includes the surface of the plurality of first connecting plates 330 close to the first support layer 200, and the second surface 320 includes the surface of the plurality of second connecting plates 340 away from the first support layer 200. The first connecting plate 330 overlaps with the adjacent ends of two adjacent second connecting plates 340 to form the second groove 321, and the second connecting plate 340 overlaps with the adjacent ends of two adjacent first connecting plates 330 to form the first groove 311.

[0034] In the bending zone 110, the second support layer 300 includes a plurality of first connecting plates 330 and a plurality of second connecting plates 340. The first connecting plates 330 and the second connecting plates 340 are arranged alternately in the second direction Y (i.e., the direction perpendicular to the bending axis, i.e., the width direction of the bending zone) and extend continuously in the first direction X (i.e., the direction parallel to the bending axis). The first connecting plate 330 overlaps with the adjacent ends of two adjacent second connecting plates 340, thereby forming a second groove 321 on the second surface 320 (lower surface). Specifically, when viewed from below, a recessed space is formed between two adjacent second connecting plates 340 due to the overlap of the first connecting plate 330, and this space is the second groove 321. The bottom surface of the second groove 321 is the lower surface of the first connecting plate 330.

[0035] Similarly, the second connecting plate 340 overlaps the adjacent ends of the two adjacent first connecting plates 330, thereby forming a first groove 311 on the first surface 310 (upper surface). When viewed from above, an upwardly recessed space is formed between the two adjacent first connecting plates 330 due to the overlap of the second connecting plate 340, and this space is the first groove 311. The bottom surface of the first groove 311 is the upper surface of the second connecting plate.

[0036] The first groove 311 and the second groove 321 are arranged alternately in the second direction Y; that is, along the second direction Y, they are arranged in the following order: first connecting plate 330, first groove 311 (formed by overlapping second connecting plate 340), second connecting plate 340, second groove 321 (formed by overlapping first connecting plate), and first connecting plate 330. This arrangement sequence is used to form the patterned structure on the second support layer 300.

[0037] The second support 300 in this embodiment includes a first connecting plate 330 and a second connecting plate 340. The first connecting plate 330 and the second connecting plate 340 are alternately overlapped to form a first groove 311 and a second groove 321, respectively. The first groove 311 and the second groove 321 are staggered in the second direction Y, which can ensure the continuity of the bending state of the display panel after bending, avoid large bending and torsion in local positions, and thus avoid stress concentration in local positions, which could lead to film detachment and breakage.

[0038] Furthermore, in the prior art, foldable display modules typically include a back film layer. The foldable display module provided in this application replaces the back film layer by adding an additional high-rigidity first support layer, without increasing the thickness of the display module, thus ensuring the lightweight requirements of the foldable display module.

[0039] In a preferred embodiment of this application, the material of the second support layer 300 includes stainless steel, titanium alloy, or carbon fiber.

[0040] For example, the second support layer 300 is made entirely of titanium alloy, so the first connecting plate 330 and the second connecting plate 340 can be an integral structure, and the above-mentioned overlapping structure is formed by etching or stamping processes.

[0041] In another preferred embodiment of this application, a first transparent optical adhesive layer 400 is provided on the side of the second support layer 300 near the first support layer 200, and the first transparent optical adhesive layer 400 and the first connecting plate 330 are in contact in the bending area 110.

[0042] In this embodiment, a first transparent optical adhesive layer 400 is disposed between the second support layer 300 and the first support layer 200, for attaching the second support layer 300 to the lower surface of the first support layer 200. For example, the first transparent optical adhesive layer 400 can be an acrylic optical transparent adhesive. In the bending region 110, the first transparent optical adhesive layer 400 can also fill the first groove 311 and contact the upper surface of the first connecting plate 330. Due to the presence of the first groove 311, the first transparent optical adhesive layer 400 can also form a protruding structure in the bending region 110 that matches the shape of the first groove 311, increasing the bonding area and improving bonding reliability.

[0043] In another embodiment of this application, in the second direction Y, the width D of the first connecting plate 330 and the second connecting plate 340 is equal, and the width D of the first connecting plate 330 and the second connecting plate 340 is greater than or equal to 0.1 mm and less than or equal to 0.3 mm. The inventors have found that the value of the width D is related to the number of first connecting plates and second connecting plates and the connection stability. When the value of D is greater than 0.3 mm, since the width of the bending area is fixed, the number of first connecting plates and second connecting plates that can be set is small, the number of first grooves and second grooves is small, and the bending performance of the second support layer in the bending area will be worse. When the value of the width D is less than 0.1 mm, it becomes difficult for the first connecting plate and the second connecting plate to overlap, the stability of the overlap of the first connecting plate and the second connecting plate is poor, the width of the first groove and the second groove formed is narrow, and the bending performance of the second support layer in the bending area will also be worse.

[0044] And / or, the first distance between two adjacent first connecting plates 330 is greater than or equal to D / 4 and less than or equal to D; the second distance between two adjacent second connecting plates is greater than or equal to D / 4 and less than or equal to D. Similar to the range of the width value D, the inventors found that the setting of the first distance and the second distance also relates to the connection stability between the first connecting plates and the second connecting plates, as well as the bendability of the second support layer in the bending area. The connection stability and bendability are optimal when the values ​​of the first distance and the second distance are between D / 4 and D.

[0045] In one implementation, the width D of the first connecting plate 330 and the second connecting plate 340 in the second direction Y is equal, for example, both are 0.2mm, but it can also be 0.1mm or 0.3mm. The specific value of the first dimension can be set within the range of 0.1-0.3mm according to actual needs.

[0046] In this embodiment of the application, in the second direction Y, the first distance between two adjacent first connecting plates 330 (i.e., the opening width of the first groove 311) and the second distance between two adjacent second connecting plates 340 (i.e., the opening width of the second groove 321) may be equal or unequal. For example, when the first dimension is 0.2 mm, both the first distance and the second distance can be 0.12 mm. This distance is equal to 0.6 times the first dimension, falling within the range of being greater than or equal to one-quarter of the first dimension (0.05 mm) and less than or equal to the first dimension (0.2 mm). In other implementations, the first distance and the second distance can also be 0.05 mm or 0.2 mm. The specific value of the first distance can be set within the range defined by this application based on the value of the first dimension.

[0047] In one alternative implementation, the thickness of the first connecting plate 330 and the second connecting plate 340 is less than 0.08 mm.

[0048] In another alternative implementation, the thickness of the first connecting plate 330 and the second connecting plate 340 is greater than 0.03 mm. For example, the thickness of the first connecting plate 330 and the second connecting plate 340 is the thickness of the second support layer, which is 0.04mm, 0.05mm, 0.06mm or 0.07mm, less than 0.08mm.

[0049] In the above embodiment, when the display panel 100 is in a flattened state, the first support layer 200 provides rigid support for the entire display panel 100 with its high elastic modulus, ensuring the flatness of the display panel 100. The alternating groove structure of the second support layer 300 also remains stable when flattened. When the display panel 100 is folded along the bending axis (first direction), the bending area 110 bends. At this time, the alternating groove structure of the second support layer 300 allows the first connecting plate 330 and the second connecting plate 340 to undergo slight relative rotation around the overlap point, thereby significantly reducing the bending stiffness of the second support layer 300 in the bending area 110. The presence of the first groove 311 and the second groove 321 provides deformation space for bending, allowing the tensile and compressive stresses generated by bending to be released at the grooves, preventing stress transmission to the first support layer 200 and the display panel 100. Due to its high elastic modulus, the first support layer 200 mainly bears compressive stress during bending. However, since the second support layer 300 has released most of the stress, the stress borne by the first support layer 200 is relatively small, making it less prone to plastic deformation or fracture. Through the above structure, this embodiment of the application effectively reduces bending stress in the bending area while ensuring rigid support in the non-bending area, improving folding reliability, eliminating creases, and enhancing display quality.

[0050] According to simulation experiments, the proposed solution can effectively reduce the stress on the screen during the unfolding process, decreasing the stress from 8.059 MPa to 2.042 MPa, thus significantly reducing the risk of screen bending failure. Figure 3a and Figure 3b As shown, Figure 3a and Figure 3b The diagram shows a comparison of the surface curvature (flatness) and normal stress of the bend area screen during the unfolding process of the existing second support layer (Base) and the improved second support (BAT) scheme of this application. It can be seen from the diagram that the scheme of this application can effectively improve the surface curvature (flatness) of the screen and reduce the stress on the screen.

[0051] like Figure 4 and Figure 5 As shown, Figure 4 and Figure 5This is a cross-sectional schematic diagram of another foldable display module provided in an embodiment of this application. Figure 4 In the bending region 110, the first surface 310 is located on the side of the second support layer 300 close to the first support layer 200, and the second surface 320 is located on the side of the second support layer 300 away from the first support layer 200. In the bending region 110, either the first surface 310 or the second surface 320 includes a third groove 302. Figure 2 The second surface 320 of the second support layer 300 shown in FIG. 3 includes a third groove 302, and the first surface 310 of the second support layer 300 shown in FIG. 3 includes a third groove 302.

[0052] In this embodiment, the second support layer 300 has a third groove 302 provided on the first surface 310 (upper surface) or the second surface 320 (lower surface) of the bending region 100. The third groove 302 extends along the first direction X (parallel to the bending axis), the cross-section of the third groove 302 is rectangular, and the depth is less than or equal to the thickness of the second support layer 300. When the third groove 302 is provided on the first surface 310, the second surface 320 (lower surface) remains flat without grooves. When the third groove 302 is provided on the second surface 320, the first surface 310 remains flat without grooves.

[0053] The second support layer 300 can be made of titanium alloy. The first transparent optical adhesive layer 400 is disposed between the second support layer 300 and the first support layer 200. When the third groove 302 is located on the first surface 320, the first transparent optical adhesive layer can also fill the third groove 302.

[0054] When the display panel 100 is folded, the third groove 302 on the second support layer 300 can effectively reduce the bending stiffness of the bending area 100. Since the third groove 302 is only provided on the first surface 310 or the second surface 320, the second support layer 300 exhibits asymmetrical mechanical properties when bent, which is suitable for specific bending directions (e.g., folding inward or outward). Moreover, the structure of this embodiment is relatively simple, easy to process, and suitable for products with moderate bending performance requirements.

[0055] In another embodiment of this application, based on any of the above embodiments, such as Figure 6 , Figure 7 and Figure 8 As shown, Figure 6 , Figure 7 and Figure 8 Cross-sectional schematic diagrams of three other foldable display modules provided in the embodiments of this application are shown in [the diagram]. Figure 6 , Figure 7 and Figure 8In the folding display module shown, the first support layer 200 includes a third surface 210, which is located on the side of the first support layer 200 away from the display panel 100. At the junction of the bending area 110 and the non-bending area 120, the thickness of the first support layer gradually decreases, and a fourth groove 211 is formed on the third surface 210.

[0056] In one implementation, the cross-section of the fourth groove 211 perpendicular to the first direction X is trapezoidal.

[0057] The fourth groove 211 extends along the first direction X (parallel to the bending axis). Furthermore, the cross-section of the fourth groove 211 perpendicular to the first direction X is an isosceles trapezoid. The two sides of the trapezoid form an angle with the vertical direction. This design avoids stress concentration at right angles or sharp corners, allowing for a smoother transition and release of bending stress. Additionally, it ensures a smooth transition in stiffness between the bending region 110 and the non-bending region 120 of the first support layer 200, preventing potential fracture problems caused by abrupt changes in stiffness.

[0058] The fourth groove 211 is filled with a high-elasticity material 800. The filling process can be spraying or dispensing to completely fill the fourth groove 211 with silicone rubber and then cure it.

[0059] In a preferred embodiment, the elastic modulus of the high elastomer material 800 is greater than 0.1 MPa and less than or equal to 100 MPa; for example, the elastic modulus of the high elastomer material 800 can be 0.2 MPa, 10 MPa, 20 MPa, 30 MPa, 40 MPa, 50 MPa, 60 MPa, 70 MPa, 80 MPa, 90 MPa or 100 MPa.

[0060] In a preferred implementation, the elastic modulus of the first support layer is less than 260 GPa. For example, the elastic modulus of the first support layer can be 15 GPa, 20 GPa, 50 GPa, 100 GPa, 150 GPa, 200 GPa, 250 GPa, etc.

[0061] In a preferred implementation, the material of the first support layer 200 includes stainless steel or ultra-thin flexible glass.

[0062] In a preferred implementation, the thickness of the first support layer 200 is less than or equal to 60 μm. For example, the thickness of the first support layer 200 can be 30 μm, 40 μm, 50 μm or 55 μm, etc. The thickness of the first support layer can be determined according to the material actually selected and the thickness of other film layers.

[0063] The first support layer 200 is made of stainless steel or can provide rigid support for the entire display panel 100, ensuring the flatness of the display panel 100 in the flattened state.

[0064] When the display panel 100 is folded, the alternating groove structure of the second support layer 300 first comes into play, releasing most of the bending stress. Simultaneously, the first support layer 200 also undergoes a slight bend. At this time, the presence of the fourth groove 211 reduces the local stiffness of the first support layer 200 in the bending area 110, making it easier to bend. The trapezoidal groove design avoids stress concentration. The highly elastic material 800 filled in the fourth groove 211 acts as a buffer and distributes stress during bending. When the first support layer 200 bends, the highly elastic material 800 undergoes elastic deformation, absorbing some energy and preventing fatigue damage to the first support layer 200 during repeated bending. Simultaneously, since the elastic modulus of the highly elastic material 800 is much lower than that of the first support layer 200, its filling does not significantly increase the overall stiffness of the bending area, thus not affecting the overall bending performance. By simultaneously providing stress-relieving structures on the first support layer 200 and the second support layer 300, this embodiment forms a multi-level stress-relieving mechanism, further improving folding reliability and the lifespan of the display panel.

[0065] In another embodiment of this application, to further increase the impact resistance of the back of the foldable display module, as shown in Figure 3- Figure 7 As shown, a back film layer 500 is provided on the side of the first support layer 200 near the display panel 100, and a second transparent optical adhesive layer 600 is provided between the back film layer 500 and the first support layer 200.

[0066] The backsheet layer 500 can be made of polyimide, polyethylene terephthalate or other polymer materials, and its thickness can be adjusted according to the cushioning requirements.

[0067] A back film layer 500 is disposed on the backlight side of the display panel 100, i.e., the non-light-emitting surface of the display panel 100. The back film layer 500 is made of polyimide material. The back film layer 500 provides back protection for the display panel 100, buffers external impacts, and absorbs some bending stress. The back film layer 500 is bonded to the first support layer 200 via a second transparent optical adhesive layer 600. The second transparent optical adhesive layer 600 can be an acrylic optically transparent adhesive.

[0068] In another embodiment of this application, a cover plate 700 is provided on the light-emitting side of the display panel 100, and the cover plate 700 includes ultra-thin flexible glass.

[0069] A cover plate 700 is disposed on the light-emitting side of the display panel 100 to protect the display panel 100. In this embodiment, the cover plate 700 is made of ultra-thin flexible glass with a thickness of 30 μm. Ultra-thin flexible glass has high hardness, high light transmittance, and good bendability, which can provide effective protection for the display panel without affecting its folding performance. The cover plate is bonded to the display panel with optically transparent adhesive.

[0070] In another implementation, the cover plate 700 may also include ultra-thin flexible glass with local thinning treatment in the bending area. The thickness of the ultra-thin flexible glass in the bending area 100 is less than or equal to 30 μm, and the thickness in the non-bending area 120 is greater than 30 μm. For example, the thickness in the non-bending area 120 is 70 μm. This can ensure both the folding performance of the cover plate 700 in the bending area 110 and the impact resistance of the cover plate 700 in the non-bending area 120.

[0071] This application also provides a foldable electronic device, including the foldable display module as described in any of the above embodiments. The foldable electronic device in this application can be a foldable smartphone, a foldable tablet, or other electronic device.

[0072] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0073] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A foldable display module, characterized in that, include: Display panel, including bent and non-bent areas; A first support layer is disposed on the backlight side of the display panel; A second support layer is disposed on the side of the first support layer opposite to the display panel; the second support layer includes a first surface and a second surface disposed opposite to each other; In the bending region, at least one of the first surface and the second surface includes at least one groove; and the elastic modulus of the first support layer is greater than 10 GPa.

2. The display module according to claim 1, characterized in that, The first surface is located on the side of the second support layer that is close to the first support layer, and the second surface is located on the side of the second support layer that is away from the first support layer. In the bending area, the first surface includes a plurality of first grooves, and the second surface includes a plurality of second grooves. The first grooves and the second grooves extend along a first direction and are arranged alternately along a second direction, wherein the first direction and the second direction intersect.

3. The display module according to claim 2, characterized in that, In the bending area, the second support layer includes a plurality of first connecting plates and a plurality of second connecting plates, the first surface includes the surfaces of the plurality of first connecting plates close to the first support layer, and the second surface includes the surfaces of the plurality of second connecting plates away from the first support layer. The first connecting plate overlaps with the adjacent ends of two adjacent second connecting plates to form the second groove, and the second connecting plate overlaps with the adjacent ends of two adjacent first connecting plates to form the first groove. Preferably, the material of the second support layer includes: stainless steel, titanium alloy, or carbon fiber; Preferably, a first transparent optical adhesive layer is provided on the side of the second support layer close to the first support layer, and the first transparent optical adhesive layer is in contact with the first connecting plate in the bending area; Preferably, the first transparent optical adhesive layer fills the first groove.

4. The display module according to claim 3, characterized in that, In the second direction, the width D of the first connecting plate and the second connecting plate is equal, and the width D of the first connecting plate and the second connecting plate is greater than or equal to 0.1 mm and less than or equal to 0.3 mm; And / or, in the second direction, the first distance between two adjacent first connecting plates is greater than or equal to D / 4 and less than or equal to D; the second distance between two adjacent second connecting plates is greater than or equal to D / 4 and less than or equal to D; Preferably, the thickness of the first connecting plate and the second connecting plate is less than 0.08 mm; Preferably, the thickness of the first connecting plate and the second connecting plate is greater than 0.03 mm.

5. The display module according to claim 1, characterized in that, The first surface is located on the side of the second support layer close to the first support layer, and the second surface is located on the side of the second support layer away from the first support layer. In the bending area, the first surface or the second surface includes a third groove.

6. The display module according to any one of claims 1-5, characterized in that, The first support layer includes a third surface located on the side of the first support layer away from the display panel. The thickness of the first support layer gradually decreases from the bending area to the non-bending area, and a fourth groove is formed on the third surface. Preferably, the cross-section of the fourth groove perpendicular to the first direction is trapezoidal.

7. The display module according to claim 6, characterized in that, The fourth groove is filled with a highly elastic material; Preferably, the elastic modulus of the high-elasticity material is greater than 0.1 MPa and less than or equal to 100 MPa; Preferably, the elastic modulus of the first support layer is less than 260 GPa; Preferably, the material of the first support layer includes stainless steel or ultra-thin flexible glass; Preferably, the thickness of the first support layer is less than or equal to 60 μm.

8. The display module according to claim 1, characterized in that, A back film layer is provided on the side of the first support layer near the display panel, and a second transparent optical adhesive layer is provided between the back film layer and the first support layer.

9. The display module according to claim 1, characterized in that, The display panel has a cover plate on its light-emitting side, and the cover plate includes ultra-thin flexible glass.

10. A foldable electronic device, characterized in that, Includes the foldable display module as described in any one of claims 1-9.

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