Display module and display device

Abstract

The present disclosure provides a display module and a display device, and relates to the technical field of display, which comprises a display area, a bending area located at one side of the display area, and a step area located at a side of the bending area away from the display area; the display module comprises: a display panel having opposite light-emitting surfaces and backlight surfaces; a functional film layer assembly arranged on the light-emitting surface and / or the backlight surface of the display panel; wherein the functional film layer assembly comprises a first film layer part corresponding to the display area and a second film layer part corresponding to the step area, and the elastic modulus of the second film layer part is greater than that of the first film layer part. In this way, the physical deformation of the step area in the display product when subjected to external force is reduced, and the generation of cracks is reduced or avoided, thereby improving the reliability and production yield of the display product.

Description

Technical Field

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

[0002] With the continuous development of science and technology, more and more display products, such as mobile phones, tablets, laptops and smart wearable devices, are being widely used in people's daily lives and work, bringing great convenience to people's daily lives and work, and becoming an indispensable tool for people today.

[0003] Currently, flexible display products are increasingly widely used. In the structural design of flexible display products, the deflection of the bending area decreases when bending, making the portion of the display panel bent towards its backlight surface prone to twisting or shearing deformation. Especially in the design of wearable devices (such as smartwatches and wristbands), in order to achieve a high screen-to-body ratio or a specific appearance, the width of its bending area (often called the "neck area") is significantly narrower than the display area. The deflection in this area is greatly reduced, making the module prone to cracking during assembly and significantly reducing product yield. Summary of the Invention

[0004] To address the aforementioned technical problems, this disclosure provides a display module and display device, which aim to reduce the physical deformation of display products when subjected to external forces, reduce or avoid the generation of cracks, and improve the reliability and production yield of display products.

[0005] In a first aspect, this disclosure provides a display module, which includes a display area, a bent area located on one side of the display area, and a stepped area located on the side of the bent area away from the display area; the display module includes: The display panel has a light-emitting surface and a backlight surface; Functional film layer assembly, disposed on the light-emitting surface and / or backlight surface of the display panel; The functional film layer component includes a first film layer portion corresponding to the display area and a second film layer portion corresponding to the step area, wherein the elastic modulus of the second film layer portion is greater than that of the first film layer portion.

[0006] Secondly, based on the same inventive concept, this disclosure also provides a display device, including the display panel provided in the first aspect of this disclosure.

[0007] The technical solution provided in this disclosure has the following advantages compared with the prior art: This disclosure introduces a second film layer in the stepped area. By increasing the elastic modulus of the second film layer (greater than the elastic modulus of the first film layer corresponding to the display area), the second film layer in the stepped area forms a high-rigidity protective structure. This design utilizes the principle of stress distribution in physics: when the module is subjected to torsional or shear forces, the deformation of the high-modulus region is minimal, thereby preventing cracks from forming in the stepped area due to assembly torque, and effectively protecting the display panel from cracking. When the display module is a wearable device, considering that wearable devices have limited space, narrow bending areas, and low deflection, the high-modulus second film layer can provide strong support for the display panel in the stepped area during assembly pressing or shearing, reducing the physical deformation of the stepped area under external forces. Cracks typically occur on one side of the light-emitting surface of the panel. The high-modulus second film layer not only reduces overall displacement but also acts as a "stress barrier layer" or "sacrificial layer," absorbing energy first during severe torsion. Its rigid structure can prevent microcracks from propagating further from the surface layer to the circuit layer inside the panel, protecting the circuitry within the display panel from damage. Therefore, by introducing a second film layer with a high elastic modulus in the step region, mechanical damage during assembly can be significantly reduced, improving the reliability and production yield of the display module. Attached Figure Description

[0008] The accompanying drawings, which are incorporated in and form a part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure.

[0009] To more clearly illustrate the technical solutions in the embodiments of this disclosure or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0010] Figure 1 The image shown is a schematic diagram of a wearable device. Figure 2 The figure shown is a schematic diagram of a planar structure of a display module provided in an embodiment of this disclosure; Figure 3 The diagram shown is a schematic diagram of another planar structure of the display module provided in an embodiment of this disclosure; Figure 4 As shown Figure 2 A BB'-direction cross-sectional view of the display module; Figure 5 The diagram shown is a schematic diagram of another planar structure of the display module provided in an embodiment of this disclosure; Figure 6 The diagram shown is a schematic representation of an embodiment of this disclosure in which the first and second film layers are formed using the same material. Figure 7 The diagram shown is a schematic representation of an embodiment of this disclosure in which a first membrane layer and a second membrane layer are formed using different materials. Figure 8 The diagram shown is a schematic diagram of another planar structure of the display module provided in an embodiment of this disclosure; Figure 9 As shown Figure 8 A cross-sectional view of the display module along the CC' direction; Figure 10 The diagram shown is a schematic representation of an embodiment of the present disclosure in which a first film layer, a second film layer, and a third film layer are attached to a display panel. Figure 11 The diagram shown is a schematic diagram of another planar structure of the display module provided in an embodiment of this disclosure; Figure 12 The diagram shown is a schematic diagram of another planar structure of the display module provided in an embodiment of this disclosure; Figure 13 As shown Figure 2 Another BB' section view of the display module; Figure 14 As shown Figure 2 Another BB' section view of the display module; Figure 15 The diagram shown is a schematic diagram of another planar structure of the display module provided in an embodiment of this disclosure; Figure 16 As shown Figure 15 A DD'-direction cross-sectional view of the display module; Figure 17 As shown Figure 15 Another DD' section view of the display module; Figure 18 The diagram shown is a schematic diagram of another planar structure of the display module provided in an embodiment of this disclosure; Figure 19 As shown Figure 2 Another BB' section view of the display module; Figure 20 The diagram shown is a planar structural schematic of a display device provided in an embodiment of this disclosure. Detailed Implementation

[0011] To better understand the above-mentioned objectives, features, and advantages of this disclosure, the solutions disclosed herein will be further described below. It should be noted that, unless otherwise specified, the embodiments and features described herein can be combined with each other.

[0012] Numerous specific details are set forth in the following description in order to provide a full understanding of this disclosure, but this disclosure may also be implemented in other ways different from those described herein; obviously, the embodiments in the specification are only some, and not all, of the embodiments of this disclosure.

[0013] In the structural design of flexible display products, such as wearable devices (e.g., smartwatches, wristbands), to achieve a high screen-to-body ratio or a specific aesthetic shape, the width of the bending region WQ (often called the "neck area") is significantly narrower than the display region XQ. For example, please refer to... Figure 1 The deflection of the bending zone WQ is significantly reduced, making the module prone to large torsional or shear deformation during assembly. Figure 1 The diagram shows a planar schematic of a wearable device 00. Under assembly stress, the display panel is highly susceptible to developing internal radius (R) corner cracks (LW), resulting in a high defect rate. These internal radius (R) corner cracks are panel breakage caused by uneven stress or excessive deformation at the bending radius (R-angle).

[0014] Therefore, this disclosure provides a display module, Figure 2 The figure shown is a schematic diagram of a planar structure of a display module provided in an embodiment of this disclosure. Figure 3 The diagram shown is a schematic representation of another planar structure of the display module provided in this embodiment. Figure 4 As shown Figure 2 Please refer to the BB' section view of the display module. Figure 2 , Figure 3 and Figure 4 The display module 100 provided in this embodiment includes a display area A1, a bent area A2 located on one side of the display area A1, and a stepped area A3 located on the side of the bent area A2 away from the display area A1. The display area A1 of the display module 100 is provided with sub-pixels actually used for displaying the image, while the bent area A2 and the stepped area A3 do not display the image. By bending the bent area A2, the stepped area A3 can be bent to one side of the backlight surface M2 of the display module. Figure 2 The diagram shows the planar structure of the display module 100 before the stepped area A3 bends to the backlight side. Figure 3 The planar structure of the display module 100 is shown after bending the stepped area A3 to the backlight side. Please refer to... Figure 2 and Figure 4The display module 100 includes a display panel 10 and a functional film layer assembly 20. The display panel 10 has a light-emitting surface M1 and a backlight surface M2. The light-emitting surface M1 can be understood as the display surface of the display panel 10, and the backlight surface M2 can be understood as the non-display surface of the display panel 10, i.e., the back side. Optionally, the display panel 10 mentioned in the embodiments of this disclosure can be, for example, an OLED display panel, or other types of display panels with a certain degree of flexibility and bendability. It should be noted that... Figure 2 and Figure 3 The illustration uses only a circular display module (e.g., a wearable device) as an example, but this disclosure is not limited thereto. In other embodiments of this disclosure, the display module may also be, for example... Figure 5 The rectangular structure or other shapes shown, such as ellipse, etc., are examples of such structures. Figure 5 The diagram shown is a schematic diagram of another planar structure of the display module provided in an embodiment of this disclosure.

[0015] In this disclosure, the functional film layer assembly 20 is disposed on the light-emitting surface M1 and / or the backlight surface M2 of the display panel 10; Figure 4 The illustrated embodiment is only used as an example of placing the functional film layer assembly 20 on one side of the backlight surface M2, but it is not limited thereto. Subsequent embodiments will describe other placement positions of the functional film layer assembly 20. The functional film layer assembly 20 includes a first film layer portion 21 corresponding to the display area A1 and a second film layer portion 22 corresponding to the step area A3. The elastic modulus of the second film layer portion 22 is greater than the elastic modulus of the first film layer portion 21.

[0016] This disclosure provides a modular customization of the functional film layer assembly 20 for different functional areas of the display module 100. The first film layer portion 21 located in the display area A1 can be made of a material with a relatively low elastic modulus to ensure the flexibility of the screen and basic support. The bending area A2 is used to connect the display area A1 and the step area A3 and is the area with the highest stress concentration. The step area A3 is located at the end of the display module. When the bending area A2 of the display module bends, the step area A3 will be affected by a large assembly torque. Therefore, the step area A3 uses a second film layer portion 22 with a relatively high elastic modulus.

[0017] When the display module is a wearable device, the bending area A2 and the step area A3 are narrower than the display area A1, making the step area A3 most susceptible to the effects of assembly torque. To address this, this disclosure introduces a second film layer 22 in the step area A3. By increasing the elastic modulus of the second film layer 22 (greater than the elastic modulus of the first film layer 21 corresponding to the display area A1), the second film layer 22 in the step area A3 forms a highly rigid protective structure. This design utilizes the principle of stress distribution in physics: when the module is subjected to torsional or shear forces, the deformation of the high-modulus region is minimal, thereby preventing cracks from forming in the step area A3 due to assembly torque, and effectively protecting the display panel 10 from cracking. When the display module 100 is a wearable device, considering that the bending area A2 is narrow and has low deflection due to space constraints, the high-modulus second film layer 22 can provide strong support for the display panel 10 in the step area A3 during assembly pressing or when subjected to shear forces, reducing the physical deformation of the step area A3 under external forces. Inner radius (R) corner cracks typically occur on one side of the light-emitting surface M1 of the panel. The second film layer 22, with its high elastic modulus, not only reduces overall displacement but also acts as a "stress barrier layer" or "sacrificial layer," absorbing energy first during severe bending. Its rigid structure prevents or reduces the generation of microcracks and prevents them from propagating further from the surface layer into the circuit layers inside the panel, protecting the circuitry within the display panel 10 from damage. Therefore, by introducing the second film layer 22 with a high elastic modulus in the step region A3, mechanical damage during assembly can be significantly reduced, improving the reliability and production yield of the display module.

[0018] Please continue to refer to this. Figure 4 In one optional embodiment of this disclosure, the elastic modulus of the first film layer 21 is T1, and the elastic modulus of the second film layer 22 is T2, wherein T2 ≥ 2 × T1.

[0019] Considering that wearable devices experience a significant reduction in deflection due to the narrowing of the bending zone A2, the torsional forces during assembly are extremely concentrated. If the increase in the elastic modulus T2 of the second film layer 22 is insufficient (e.g., T2 < 2 × T1), the rigidity of the material in the second film layer 22 will be insufficient to provide effective support. Under compression or shear forces, the step zone A3 will still undergo significant physical deformation, failing to protect the fragile display panel 10, resulting in insignificant improvement in the inner R-corner crack. If the elastic modulus T2 of the second film layer 22 is low, its ability to absorb energy and prevent crack propagation will be greatly reduced. When the surface is subjected to stress, the second film layer 22 with a lower modulus will undergo large-curvature bending synchronously with the panel, and the stress will be directly transferred to the functional layers of the panel (such as the circuit layer), leading to structural damage.

[0020] When the elastic modulus T2 of the second film layer 22 is significantly greater than the elastic modulus T1 of the first film layer 21, for example, when T2 ≥ 2 × T1, the step region A3 physically exhibits a locally rigid state. During assembly, this region behaves like a rigid backing plate, forcibly constraining the deformation of the panel, so that stress is intercepted and dispersed by the high-modulus material before entering the step region A3. In addition, the high-modulus second film layer 22 has higher fracture toughness requirements. When microcracks attempt to propagate from the edge inward, the high-modulus interface can change the transmission path of stress waves, thereby protecting the core display function from damage. Moreover, when a high-modulus second film layer 22 is set in the step region A3, the second film layer 22 not only plays a role during assembly, but also ensures that the relative displacement between the protective layer and the display panel 10 remains within a very small range during daily wear and bending by the user, effectively extending the service life of the flexible circuit.

[0021] Optionally, the first film layer portion 21 corresponding to the display area A1 can maintain a conventional elastic modulus, such as 4 GPa-5 GPa. This ensures the flexibility of the display area A1 during normal use and bending, avoiding poor feel or brittleness due to excessive rigidity. Considering that the step area A3 is the area where the driver chip is bonded and the circuit is concentrated, and is also the "weak point" most vulnerable to damage in wearable devices due to space constraints, this disclosure can set the elastic modulus of the second film layer portion 22 corresponding to the step area A3 to 10 GPa-15 GPa or higher.

[0022] Please continue to refer to this. Figure 4 In one optional embodiment of this disclosure, the functional film layer assembly 20 includes a first support layer Z1 located on the backlight surface M2 of the display panel 10. The first support layer Z1 includes the aforementioned first film layer portion 21 and second film layer portion 22.

[0023] In this embodiment, the first support layer Z1 serves as the core support structure attached to the backlight surface M2 (bottom side) of the flexible panel. Internally, it is divided into two functional structures. The first film layer 21 corresponds to the display area A1 and typically maintains a low elastic modulus to ensure the flexibility of the display area A1 during bending and use, while also providing a flat support surface for the display area A1 without affecting the display effect. The second film layer 22 corresponds to the stepped area A3 and has a higher elastic modulus. Addressing the issue of low deflection in the "narrow neck" area of ​​wearable devices, the first support layer Z1 is locally hardened (increasing the hardness of the second film layer 22), thereby enhancing the bending resistance of the stepped area A3.

[0024] During the assembly and lamination of the display module, the bonding of the driver chip or flexible circuit board, or the assembly of the mid-frame, the stepped area A3 is subjected to complex shear stress. The high elastic modulus of the second film layer 22 makes it exhibit stronger rigidity under stress, significantly reducing the physical displacement of the stepped area A3, thereby preventing the panel from cracking due to excessive deformation. When the first support layer Z1 is made of a single material, this disclosure can improve local mechanical reliability without significantly increasing the overall thickness of the module by changing the local properties of the same layer material. This is crucial for wearable devices where internal space is extremely limited.

[0025] When the first support layer Z1 includes both the aforementioned first film layer 21 and second film layer 22, in an optional embodiment of this disclosure, the first film layer 21 and the second film layer 22 are formed using the same material, and the second film layer 22 is a region in the first support layer Z1 that has undergone specific light treatment, while the first film layer 21 is a region in the first support layer Z1 that has not undergone specific light treatment. For example, please refer to... Figure 6 , Figure 6 The diagram shown is a schematic representation of an embodiment of this disclosure in which the first film layer 21 and the second film layer 22 are formed using the same material.

[0026] In this embodiment, the first support layer Z1 is initially made of the same photosensitive or modified material (such as a specific polyimide or a polymer containing a photosensitizer), and its initial modulus is at a low level. In practical applications, the same film material can be cut into a portion located in the display area A1 and a portion located in the step area A3. Then, by masking with a mask or scanning with a laser, only the first support layer Z1 in the step area A3 is irradiated with specific light. In the step area A3, the light excites further molecular chain crosslinking or polymerization reactions within the material of the first support layer Z1, making the molecular chain structure of the first support layer Z1 in this region more compact and the network structure stronger, forming a second film layer 22 with a higher elastic modulus. For example, the elastic modulus of the first support layer Z1 in the step area A3 can jump from the initial 4Gpa-5Gpa to 10Gpa-15Gpa, while the unirradiated display area A1 (first film layer 21) retains its original flexibility.

[0027] Furthermore, when the first film layer 21 and the second film layer 22 in the first support layer Z1 are made of the same material, micron-level precise partitioning can be achieved through cutting and photomask technology, which is very suitable for the extremely narrow "neck area" space requirements in wearable devices. After light treatment, the hardness and rigidity of the step area A3 are greatly improved. During the assembly and pressing process, this area can effectively resist torsional deformation, thereby protecting the display panel 10 from internal R-corner cracks. Moreover, homogeneous materials exhibit more consistent performance during thermal expansion and contraction (thermal shock test), preventing the step area A3 from warping or the display panel 10 from being damaged by tensile stress due to the different expansion coefficients of the two materials.

[0028] Of course, in one alternative embodiment of this disclosure, the first film layer 21 and the second film layer 22 may also be formed using different materials. For example, please refer to... Figure 7 , Figure 7 The diagram shows a first film layer 21 and a second film layer 22 formed using different materials in an embodiment of this disclosure. Exemplarily, in practical applications, a first film layer 21 located in the display area A1 can be formed by cutting a film material, and then the first film layer 21 and a second film layer 22 made of a different material from the first film layer 21 can be respectively attached to the display area A1 and the step area A3.

[0029] In this embodiment, materials with completely different physicochemical properties are selected for the first film layer 21 and the second film layer 22 to achieve customized protection for different regions, based on the stress characteristics of each region. Since the first film layer 21 and the second film layer 22 use different materials, designers can completely break free from the limitations of a single material and can choose an extremely high-rigidity material for the step area A3 (low deflection, easy to twist). This embodiment, without affecting the normal bending performance of the display area A1, forcibly reduces the deflection of the step area A3 during assembly by introducing a heterogeneous high-modulus material. The high-modulus material is not only resistant to deformation itself, but also significantly improves the interfacial strength of the composite structure after being bonded to the panel. When microscopic cracks appear at the edge of the panel, the high-modulus layer can absorb most of the shear stress, thereby reducing or preventing crack formation.

[0030] Optionally, the first film layer 21 can be made of materials such as PET (Polyethylene terephthalate), thin PI (Polyimide), or low-modulus PEN (Polyethylene Naphthalate). PET has an elastic modulus of approximately 4-5 GPa, is low in cost, and has a mature manufacturing process. PI has excellent heat resistance and mechanical stability. PEN has better dimensional stability.

[0031] Optionally, the second film layer 22 can be made of high-modulus PI (special polyimide), PE (polyethylene), or high-modulus PEN. High-modulus PI, through its molecular chain design, enhances rigidity, achieving a modulus of over 10 GPa, and exhibits good compatibility with the display panel 10 and the underlying PI. PE film possesses extremely high tensile modulus and abrasion resistance. High-modulus PEN can, for example, be PEN reinforced through a stretching process.

[0032] Please refer to Figure 4 and Figure 5 In one alternative embodiment of this disclosure, the second membrane layer 22 covers the step region A3.

[0033] In flexible display modules, the stepped area A3 is typically the region where driver chips are bonded, flexible circuit boards are connected, and signal lines converge. When the second film layer 22, with its high elastic modulus, covers the stepped area A3, it ensures that every inch of space in the stepped area A3 is reinforced with high-rigidity material. Because the bending area A2 of the wearable device narrows, the stepped area A3 experiences a lever-like amplification effect when subjected to assembly torque. The design of the second film layer 22 fully covering the stepped area A3 enhances the bending stiffness of the entire stepped area A3, transforming it from a "deformable body" into a "quasi-rigid body." When assembly stress (shear or torsional force) is transmitted to the stepped area A3, because the high elastic modulus of the second film layer 22 covers the entire stepped area A3, the stress cannot find a weak point within the stepped area A3 for release; instead, it is evenly distributed across the entire second film layer 22, thus preventing localized stress concentration that could lead to panel cracking. Inner corner cracks typically originate at the panel edge. The second film layer 22 covering the stepped area A3 means it also covers the panel edge. The second film layer 22 with high elastic modulus can lock the degree of freedom of the panel edge like a "clamp", physically preventing the initiation of microcracks.

[0034] By fully covering the step region A3 with the second film layer 22, the deflection of the step region A3 in the assembled state is compressed to a minimum. This design effectively addresses the failure risk caused by reduced deflection in wearable devices, significantly reducing the defect rate. Furthermore, the high-elastic-modulus second film layer 22 fully covering the step region A3 provides a more stable base for the driver chip. During the lamination of the driver chip or bonding of the flexible circuit board, the strong support on the back ensures uniform force distribution, preventing bonding displacement due to excessive softness in the step region A3. This implementation method is simple and clear in its positioning, making it easily achievable in automated bonding processes.

[0035] The above embodiments illustrate a method in which the second film layer 22 fully covers the step region A3. This disclosure is not limited thereto. In some other embodiments of this disclosure, the second film layer 22 may also partially cover the step region A3. For example, please refer to... Figure 8 and Figure 9 , Figure 8 The diagram shown is a schematic representation of another planar structure of the display module provided in this embodiment. Figure 9 As shown Figure 8 The image shows a cross-sectional view of the module along the CC' direction. In one optional embodiment of this disclosure, the step region A3 includes a first region A31 and a second region A32. The first region A31 is located between the second region A32 and the bending region A2. The second film layer 22 is located in the first region A31. The first support layer Z1 also includes a third film layer 23 disposed in the second region A32. The elastic modulus of the third film layer 23 is less than the elastic modulus of the second film layer 22.

[0036] In this embodiment, the structure of the step region A3 is divided into two core parts. The first region A31 is located between the bending region A2 and the second region A32, and is the first station for stress transmission from the bending part to the rigid step part. This region is provided with a second membrane layer 22 with a larger elastic modulus. The second region A32 is located at the farthest end of the step region A3. The second region A32 is provided with a third membrane layer 23 with a lower elastic modulus, which is less than the elastic modulus of the second membrane layer 22.

[0037] In wearable devices, the most likely location for internal radius (R) corner cracks is not the entire stepped area A3, but rather the boundary between the bending area A2 and the stepped area A3 (i.e., the first area A31). This is the abrupt point where the "flexible" nature transitions to "rigid," resulting in the most drastic change in deflection. By applying a high-modulus film layer to the first area A31, a protective structure is directly installed at the most vulnerable crack source. Considering that high-modulus materials are typically expensive and difficult to process, confining them to the first area A31 (the core stress area) solves the cracking problem while controlling material costs.

[0038] This embodiment establishes a rigid buffer zone between the bending zone A2 (extremely flexible) and the second zone A32 (constant modulus) by placing a high-modulus layer in the first zone A31. This effectively smooths the stress curve and prevents the panel from tearing due to a sudden stress burst at the entrance of the step zone A3 during assembly twisting. Failures mostly occur in the area near the bending zone A2 (i.e., the first zone A31). This solution concentrates reinforcement resources in the first zone A31, achieving maximum crack prevention with less material change and significantly improving production yield. The second zone A32 (third film layer 23) maintains a lower modulus, allowing the end of the step zone A3 to retain a certain degree of toughness. During driver chip lamination or flexible circuit board attachment, this "rigid-flexible" base better adapts to assembly tolerances and reduces mechanical damage.

[0039] Optionally, in this disclosure, when the elastic modulus of the second film layer 22 is greater than that of the third film layer 23, the elastic modulus of the third film layer 23 can be equal to or close to the elastic modulus of the first film layer 21. This structure forms a "flexible-rigid-flexible" mechanical gradient. In the assembled state, the high-rigidity area in the middle (first area A31) plays a role in strengthening protection, locking the most vulnerable neck position of the display panel 10, while the flexible areas on both sides are responsible for absorbing excess vibration and deformation energy.

[0040] Figure 10 The diagram shown is a schematic of a first film layer 21, a second film layer 22, and a third film layer 23 attached to a display panel 10 in an embodiment of this disclosure. Taking the first film layer 21 and the third film layer 23 as examples of using the same material, the first film layer 21 and the third film layer 23 can be formed by cutting the same film material, and then the first film layer 21, the second film layer 22, and the third film layer 23 are attached. When the second film layer 22 is attached to the first area A31 of the bending area A2 and the step area A3, the second film layer 22 needs to be further cut to remove the part located in the bending area A2 and only retain the part located in the first area A31.

[0041] It should be noted that, Figure 8 The illustration shows a scheme in which the second membrane layer 22 covers the first region A31 of the step region A3, but this disclosure is not limited thereto. In many other embodiments of this disclosure, the second membrane layer 22 may also cover only a portion of the first region A31, for example, please refer to [reference needed]. Figure 11 , Figure 11 The diagram shows another planar structure of the display module provided in this embodiment. The second film layer 22 is located in the central region of the first region A31. The second film layer 22 is located in the second region A32 and in the regions of the first region A31 where the second film layer 22 is not provided. Considering that the central region Q0 of the first region A31 may be a region subject to large assembly torque, the second film layer 22 with a large elastic modulus is specifically provided in the central region Q0 of the first region A31, while the third film layer 23 with a smaller elastic modulus is provided in other regions of the step region A3. This can achieve the maximum anti-cracking effect with minimal material changes, significantly improve production yield, and at the same time help reduce the amount of the more expensive second film layer 22 used, thereby reducing the overall manufacturing cost. Optionally, for Figure 11 In the embodiment, the elastic modulus of the second film layer 22 may exhibit a gradual change, for example, from the center to both sides ( Figure 11In the direction of the two side waists of the trapezoid (middle finger), the elastic modulus can gradually increase, thus making the elastic modulus largest in the area near the two edges. This results in a larger elastic modulus in the second membrane layer 22 located in areas with greater torsional or shear forces, adapting to the stress characteristics of different areas. It should be noted that... Figure 11 The description uses only the trapezoidal second membrane layer 22 as an example, but this disclosure is not limited thereto. In some other embodiments of this disclosure, the side waist of the trapezoid can be modified into a curved shape, for example, please refer to Figure 12 The curved shape causes a change in the elastic modulus of the edge region, which may provide some support while alleviating localized stress concentration. Among these, Figure 12 The diagram shown is a schematic diagram of another planar structure of the display module provided in an embodiment of this disclosure.

[0042] Figure 13 As shown Figure 2 Please refer to another BB' section view of the display module. Figure 13 In one optional embodiment of this disclosure, the functional film layer assembly 20 includes a second support layer Z2 and a first reinforcing component 51. The second support layer Z2 and the first reinforcing component 51 are located on the backlight surface M2 of the display panel 10. The second support layer Z2 includes a first support portion 41 and a second support portion 42. The first support portion 41 is correspondingly disposed with respect to the display area A1, and the second support portion 42 is correspondingly disposed with respect to the step area A3. The first reinforcing component 51 is located in the step area A3 and on the side of the second support portion 42 away from the display panel 10. The elastic modulus of the first reinforcing component 51 is greater than that of the first support portion 41. The first film layer portion 21 provided in this disclosure includes the aforementioned first support portion 41, and the second film layer portion 22 includes the aforementioned first reinforcing component 51.

[0043] In this embodiment, the first support portion 41 is disposed corresponding to the display area A1, providing basic flexible support (e.g., an elastic modulus of 4 GPa-5 GPa). The second support portion 42 is disposed corresponding to the step area A3, and the first reinforcing component 51 is located only in the step area A3 and is attached to the outer side of the second support portion 42 (the side away from the display panel 10). The elastic modulus of the first reinforcing component 51 is significantly greater than the elastic modulus of the first support portion 41 in the display area A1. Optionally, the modulus of the reinforcing component is 10 GPa-15 GPa or higher.

[0044] In this embodiment, the first film layer 21 provided in the display area A1 includes a single base support layer (first support 41), while the support structure of the step area A3 includes a base support layer (second support 42) and a first reinforcing component 51. The second support 42 and the first reinforcing component 51 together constitute a composite support structure.

[0045] In this embodiment, an additional high-elasticity modulus first reinforcing component 51 is adhered to the step area A3. According to the principles of material mechanics, the equivalent bending stiffness of this area is significantly increased. This provides a support structure with high rigidity for the step area A3, greatly resisting compression and torsion during assembly. The bottom second support layer Z2 is responsible for adhesion and flat support to the panel. The first reinforcing component 51 is responsible for resisting external mechanical impacts and large deformations. This division of labor effectively absorbs assembly stress and prevents cracks from being transmitted vertically to the panel.

[0046] Thus, the most vulnerable first area A31 of the display panel 10 (such as the "neck" area in wearable devices) receives double-layer protection. The high-modulus reinforcing component locks the geometry of the step area A3, ensuring that the curvature change of the panel is strictly limited within a safe range when subjected to assembly forces, thereby solving the pain point of high defect rates in related technologies. In actual production, after attaching the second support layer Z2, the first reinforcing component 51 can be introduced to locally reinforce the step area A3 through a precision attachment process. This process is relatively easy to automate. The first reinforcing component 51 is located on the outermost side and can be made of scratch-resistant and wear-resistant high-elastic modulus materials (such as high-modulus PI or PET reinforcing plates), which enhances rigidity and provides additional physical protection for the driver chip and circuit area.

[0047] Please continue to refer to this. Figure 13 In one optional embodiment of this disclosure, the first support portion 41 and the second support portion 42 have the same elastic modulus.

[0048] When the first support portion 41 (located in the display area A1) and the second support portion 42 (located in the step area A3) have the same modulus, the entire second support layer Z2 can be made of a single, integral material of the same material and thickness. Optionally, the second support layer Z2 can be made of conventional PET or PI with a modulus of 4 GPa-5 GPa. Furthermore, a high-modulus first reinforcing component 51 can be additionally attached to the side of the second support portion 42 facing away from the display panel 10.

[0049] Since the first support part 41 and the second support part 42 are made of the same material, the thermal expansion and contraction behavior of the display area A1 and the step area A3 is completely consistent. In reliability tests (such as high temperature and high humidity environments), uneven stress on the panel or delamination will not occur due to local expansion differences.

[0050] Although the first support portion 41 and the second support portion 42 at the bottom layer have the same elastic modulus, by superimposing a first reinforcing component 51 with a higher elastic modulus on the second support portion 42, the second support layer Z2 as a whole is responsible for flat support, while the first reinforcing component 51 is responsible for resisting torsion. This "composite structure" not only retains the consistency of the thermal expansion and contraction behavior of the bottom layer, but also achieves local high rigidity in the step area A3. When assembling the narrow-neck wearable device, the step area A3 supported by the first reinforcing component 51 can still maintain minimal deformation, thereby protecting the display panel 10 from internal R-corner cracks.

[0051] Figure 14 As shown Figure 2 The image shows another BB' cross-sectional view of the display module. In one optional embodiment of this disclosure, the second support 42 covers the stepped area A3; the stepped area A3 includes a first area A31 and a second area A32, with the first area A31 located between the second area A32 and the bending area A2. Please refer to [reference needed]. Figure 14 The first reinforcing component 51 is located in the first area A31, or, please refer to... Figure 13 The first reinforcing component 51 covers the step area A3.

[0052] When a second support portion 42 covering the stepped area A3 is introduced into the display panel 10, the arrangement of the further introduced first reinforcing component 51 can be in two feasible ways, for example, the first way is as follows: Figure 14 The first reinforcement component 51 is set only in the first area A31, while the second method is as follows: Figure 13 The first reinforcing component 51 is provided throughout the entire stepped area A3. Considering that in the display panel 10 provided in this embodiment, the first area A31 is a critical stress area, located at the junction of the bending area A2 and the main body of the stepped area A3 (e.g., the second area A32). When the first reinforcing component 51 is attached only to the first area A31, the first area A31 is the place where the stress change is most severe. Concentrating the high elastic modulus material (the first reinforcing component 51) here can achieve the maximum crack resistance with the minimum material area. The second area A32 is used, for example, for bonding a driver chip or a flexible circuit board. When the second area A32 (the end of the stepped area A3 away from the bending area A2) is not provided with a reinforcing component, this retains a certain degree of flexibility at the end, which helps to absorb minor mechanical vibrations during driver chip pressing or flexible circuit board bonding, avoids the entire stepped area A3 from being too rigid and causing brittle damage, and reduces the amount of high-cost material (the high elastic modulus first reinforcing component 51) used.

[0053] When the first reinforcing component 51 completely covers the entire step area A3, please refer to... Figure 13The first reinforcing component 51 completely covers the first area A31 and the second area A32, thus constructing the entire stepped area A3 into a highly rigid region. When subjected to torsional forces during assembly, the entire stepped area A3 hardly bends, minimizing deflection. This full coverage not only solves the cracking problem but also provides a complete physical barrier for the driving chip or flexible circuit board and related wiring on the stepped area A3, preventing scratches or pressure damage during assembly. The full coverage solution simplifies alignment logic during automated attachment, and the first reinforcing component 51 can be integrally cut with the shape of the display panel 10, resulting in neat edges and more uniform effective support.

[0054] The above embodiments illustrate a scheme in which a first reinforcing component 51 is introduced into the backlight surface M2 of the display panel 10, but this disclosure is not limited thereto. Figure 15 The diagram shown is a schematic representation of another planar structure of the display module provided in this embodiment. Figure 16 As shown Figure 15 Please refer to the DD' section view of the display module. Figure 15 and Figure 16 In one optional embodiment of this disclosure, the functional film layer assembly 20 includes a third support layer Z3 and a second reinforcing assembly 52. ​​The third support layer Z3 is located on the backlight surface M2 of the display panel 10, and the second reinforcing assembly 52 is located on the light-emitting surface M1 of the display panel 10. The third support layer Z3 includes a third support portion 43 and a fourth support portion 44. The third support portion 43 is correspondingly disposed with respect to the display area A1, and the fourth support portion 44 is correspondingly disposed with respect to the step area A3. The second reinforcing assembly 52 is located in the step area A3. The elastic modulus of the second reinforcing assembly 52 is greater than the elastic modulus of the third support portion 43. The first film layer portion 21 includes the aforementioned third support portion 43, and the second film layer portion 22 includes the aforementioned second reinforcing assembly 52.

[0055] In this embodiment, the third support portion 43 is disposed in the display area A1 and located on the backlight surface M2 of the display panel 10, and is used to provide basic flexible support for the display area A1 of the display panel 10. The fourth support portion 44 is disposed in the step area A3, and is used to maintain the flatness of the display panel 10 in the step area A3. The second reinforcing component 52 is located in the step area A3 and on the light-emitting surface M1 of the display panel 10, and its elastic modulus is significantly greater than that of the third support portion 43. In the actual product, the first film layer portion 21 located in the display area A1 includes the third support portion 43, and the second film layer portion 22 located in the step area A3 includes the second reinforcing component 52.

[0056] When flexible display panels 10 (especially wearable devices) are twisted, inner radius cracks often occur on one side of the light-emitting surface M1. By directly setting a high-modulus second reinforcing component 52 on the light-emitting surface M1, deformation can be directly locked from the "crack initiation side," preventing the surface material from tearing due to excessive tensile stress. A third support layer Z3 is provided at the bottom (backlight surface M2) of the display panel 10 as a basic support layer, and a high-modulus second reinforcing component 52 is provided at the top (light-emitting surface M1). This structure greatly improves the bending stiffness of the stepped area A3 in both the vertical and horizontal torsional directions, preventing excessive deformation of the stepped area A3 during assembly. At the same time, placing the second reinforcing component 52 on the light-emitting surface M1 provides scratch protection for the front of the stepped area A3.

[0057] Since the second reinforcing component 52 in this embodiment is located in the stepped area A3 of the light-emitting surface M1, where cracks are prone to occur, it can directly share the tensile stress on that side. Experiments have shown that the rigid support of the light-emitting surface M1 has an immediate effect on preventing surface cracks from propagating to the functional layer of the display panel 10. In addition to providing rigid support, the second reinforcing component 52 can also act as a non-functional sacrificial layer under extreme stress. When severe assembly twisting occurs, the second reinforcing component 52 absorbs energy first, and its high elastic modulus ensures that the displacement of the display panel 10 below it is minimal, thereby ensuring the integrity of the display function. This design allows for local reinforcement in the later stages of the production line (such as the polarizer attachment stage), increasing the flexibility of the process. Compared to changing the material of the entire underlying support layer, adding a reinforcing component locally located on the light-emitting surface M1 requires less modification to the original production line process and is more conducive to rapid mass production.

[0058] Please continue to refer to this. Figure 15 and Figure 16 In one alternative embodiment of this disclosure, the third support portion 43 and the fourth support portion 44 have the same elastic modulus.

[0059] Since the third support layer Z3 includes a third support portion 43 and a fourth support portion 44, when the third support portion 43 and the fourth support portion 44 have the same elastic modulus, the entire third support layer Z3 can be made of the same material (such as PET with an elastic modulus of 4Gpa-5Gpa). This helps ensure that the mechanical environment at the bottom of the display panel 10 is completely consistent, avoiding flatness differences or stress abrupt changes caused by bottom material splicing. The actual rigidity enhancement is provided by the second reinforcing component 52 located on the light-emitting surface M1 (upper side). Thus, since the bottom third support layer Z3 is homogeneous, the panel will not produce micro-wrinkles due to sudden changes in the hardness of the support film during the bonding process. This is crucial for ensuring the integrity of the circuit in the step area A3. During reliability tests such as high temperature and high humidity, the panel will not warp due to uneven distribution of the thermal expansion coefficients of the third support portion 43 and the fourth support portion 44.

[0060] Furthermore, the backlight surface M2 does not require complex laser splicing or local modification; it can be directly attached using large sheets of roll material. When the bending area A2 does not have a third support layer, the large sheets of roll material can be cut and attached to the display area A1 and the step area A3 respectively. This significantly reduces the complexity and defect rate of the backlight surface M2 process, thereby improving the module's first-pass yield. Considering that cracks mostly occur on one side of the light-emitting surface M1, when the elastic modulus of the bottom third support layer Z3 is the same, the top second reinforcing component 52 can precisely target and reinforce areas prone to cracking. This structure, which is hard on top and stable on the bottom, can effectively absorb the assembly shear force of the display panel 10.

[0061] In this embodiment, the third support layer and the second reinforcing component 52 together form a stable mechanical envelope. When subjected to assembly torque, the bottom layer with equal elastic modulus provides a uniform reaction force, which, together with the strong support of the top second reinforcing component 52, makes the display panel 10 more evenly stressed. In the assembly environment of the narrow bending area A2, this design allows the step area A3 to have a certain overall toughness while having extremely high local rigidity, thereby absorbing the mechanical energy generated by assembly tolerances without damaging the display panel 10.

[0062] The above embodiments illustrate the design scheme of the third support part 43 and the fourth support part 44 using equal elastic modulus, but this disclosure is not limited thereto. Figure 17 As shown Figure 15 Please refer to another DD' section view of the display module. Figure 17 In one optional embodiment of this disclosure, the elastic modulus of the fourth support portion 44 is greater than that of the third support portion 43, and the second film layer portion 22 includes the aforementioned fourth support portion 44 and the second reinforcing component 52. That is, a portion of the second film layer portion 22 is located on the light-emitting surface M1 of the display panel 10, and a portion is located on the backlight surface M2 of the display panel 10.

[0063] In this embodiment, a second reinforcing component 52 with a relatively large elastic modulus (e.g., 10 GPa-15 GPa) is provided in the step region A3 of the light-emitting surface M1. The third support portion 43 in the third support layer Z3 is located in the display area A1, and its elastic modulus is relatively small, for example, approximately 4 GPa-5 GPa. A fourth support portion 44 in the third support layer is located in the step region A3, and its elastic modulus is larger than that of the third support portion 43. This means that the underlying support film has also undergone material upgrades or reinforcement treatment at the step region A3.

[0064] In this embodiment, the first film layer 21 disposed in the display area A1 includes a third support portion 43 with a low elastic modulus. The second film layer 22 disposed in the step area A3 is a double-sided reinforced composite, including a second reinforcing component 52 at the top and a fourth support portion 44 at the bottom. In flexible electronic design, if only one side is reinforced, the neutral layer will shift to the stronger side during bending, which may cause excessive stress on the other side. By making the elastic modulus of the fourth support portion 44 greater than that of the third support portion 43, and in conjunction with the second reinforcing component 52, the step area A3 forms a symmetrical or nearly high-rigidity sandwich structure. The display panel 10 is sandwiched between the upper and lower high-elastic-modulus layers. During assembly and twisting, since the materials on both sides are extremely difficult to deform, the display panel 10 is firmly locked in the middle, and the physical deformation is compressed to the limit. Therefore, this structure not only solves the risk of cracking on the light-emitting surface M1 of the display panel 10, but also prevents panel sagging or micro-cracks on the backlight surface M2 due to insufficient support by increasing the elastic modulus of the bottom fourth support part 44, which helps to greatly reduce the defect rate of the display panel 10. Considering that the bending area A2 of the wearable device is extremely narrow and the shear force generated is extremely large, this double-sided high elastic modulus design can ensure sufficient torque resistance in a very small space, protect the precision circuits and driver chips in the step area A3, and help to significantly reduce functional failures after assembly and ensure yield.

[0065] Please continue to refer to this. Figures 15 to 17 In one optional embodiment of this disclosure, the functional film layer assembly 20 includes a third support layer and a second reinforcing assembly 52. ​​The third support layer is located on the backlight surface M2 of the display panel 10, and the second reinforcing assembly 52 is located on the light-emitting surface M1 of the display panel 10. The third support layer Z3 includes a third support portion 43 and a fourth support portion 44. The third support portion 43 is correspondingly disposed with respect to the display area A1, and the fourth support portion 44 is correspondingly disposed with respect to the step area A3. The second reinforcing assembly 52 is located in the step area A3. The elastic modulus of the second reinforcing assembly 52 is greater than the elastic modulus of the third support portion 43. The first film layer portion 21 includes the aforementioned third support portion 43, and the second film layer portion 22 includes the aforementioned second reinforcing assembly 52, or the second film layer portion 22 includes the aforementioned second reinforcing assembly 52 and the fourth support portion 44. The step area A3 is provided with bonding pads 80. The step area A3 includes a first area A31 and a second area A32. The first area A31 is located between the second area A32 and the bending area A2. The second reinforcing component 52 is located in the first area A31, and the bonding pads 80 are located in the second area A32.

[0066] In this disclosure, the first region A31, adjacent to the bending region A2 (e.g., the neck area in a wearable device), is the first point where stress transitions from flexible bending to a rigid step. The first region A31 is provided with a second reinforcing component 52 with a high elastic modulus. The high-rigidity material can lock the deflection in this region, preventing stress from inducing panel cracks near the red line boundary of the bending region A2 during assembly twisting.

[0067] The second zone A32 (electrical bonding zone / end zone) is the end of the stepped zone A3, away from the bending zone A2, and is equipped with bonding pads 80 for connecting driver chips or flexible circuit boards. Without the second reinforcing component 52 in the second zone A32, a normal process environment can be maintained, ensuring uniform stress during the thermoforming process.

[0068] Considering that the internal radius cracks mainly occur at the edge of the step area A3 near the bending area A2, the second reinforcing component 52 is precisely placed in the first area A31, which is equivalent to attaching a reinforcing plate at the crack source, directly offsetting the torsional stress. The bonding process requires the gold ball to undergo appropriate deformation through hot pressing to achieve conductivity. If the reinforcing component directly covers the bonding pad 80 below or above, excessive hardness may lead to uneven pressure absorption during hot pressing, causing excessive or insufficient breakage of the gold ball, affecting the electrical connection. By placing the reinforcing component in the first area A31, the original film modulus is retained in the second area A32, ensuring the reliability of the bonding process.

[0069] This embodiment addresses the mechanical risks at the most prone-to-cracking locations, reduces panel cracking and scrapping during assembly, avoids the area where the bonding pads 80 are located, and eliminates the risk of poor conductivity that may result from the introduction of high-elasticity modulus materials. In this embodiment, a stepped stress transition is formed from the bending zone A2 (extremely flexible) to the first zone A31 (high-rigidity reinforcement) and then to the second zone A32 (medium-rigidity support), avoiding extreme stress accumulation at a single point.

[0070] Please refer to Figure 15 and Figure 16 In one optional embodiment of this disclosure, along the arrangement direction of the first region A31 and the second region A32, the distance between the second reinforcing component 52 and the bonding pad 80 is D0, where D0 ≥ 1 mm.

[0071] In this embodiment, distance D0 refers to the horizontal distance within the step region A3, from the edge of the high-modulus second reinforcing component 52 to the edge of the bonding pad 80. In micron-level display module processes, 1 mm is a significant macroscopic span. It not only includes the process attachment tolerance (typically ±0.1~0.2 mm) but also reserves space for stress attenuation. The bonding process requires precise hot press head pressure to ensure that the anisotropic conductive adhesive between the gold ball of the driver chip or flexible circuit board and the bonding pad 80 is fully stressed. If the aforementioned distance D0 is too small (the second reinforcing component 52 is tightly attached to the bonding pad 80), the high-modulus second reinforcing component 52 will form a locally protruding hard platform. When the press head is pressed down, the pressure will be unbalanced due to uneven hardness. Therefore, the setting of D0≥1 mm ensures that when the press head is stressed in the bonding pad 80 area, the substrate below has a consistent deformation response, ensuring the consistency of gold ball breakage and thus avoiding poor conductivity.

[0072] Furthermore, the edge of the second reinforcing component 52 is a stress concentration point. If this edge is close to the precision bonding pad 80, the stress generated by assembly twisting will directly act on the root of the fragile signal line. The 1mm gap acts as a stress relief zone. From the high elastic modulus area to the normal elastic modulus area, the stress can be smoothly released within this 1mm range, preventing stress peaks from directly damaging the stability of the bonding interface. When attaching the second reinforcing component 52 or performing driver chip encapsulation, the 1mm distance can effectively prevent the adhesive from overflowing and contaminating the bonding pad 80, or prevent the encapsulant from being blocked, ensuring cleanliness and production yield during the production process.

[0073] In this embodiment, the use of a second reinforcing component 52 with a high elastic modulus in the first region A31 effectively suppresses cracks at the inner R-angle near the bending region A2. The second reinforcing component 52 in the second region A32 has a distance D0 between it and the bonding pad 80, ensuring the stability of the bonding resistor. This solution, through physical isolation, not only prevents cracks but also prevents secondary pressure damage caused by excessively hard reinforcement, comprehensively improving the module's production yield. In daily use of wearable devices (such as wrist swinging and squeezing), the 1mm buffer zone can absorb minor alternating stresses, preventing fatigue peeling of the bonding pad 80 under long-term vibration.

[0074] Please refer to Figure 17 In one optional embodiment of this disclosure, the thickness of the second reinforcing component 52 is H0, wherein 10μm≤H0≤20μm.

[0075] According to the formulas of mechanics of materials, the bending stiffness of an object is proportional to the cube of its thickness. If the thickness is less than 10μm, even if the material modulus is as high as 15Gpa, its overall mechanical support will be insufficient due to its thinness, making it difficult to resist the severe torsional stress generated during the assembly of wearable devices. 10μm is the basic thickness to ensure that the film layer can generate enough strain energy to absorb when it breaks under stress, preventing stress from directly penetrating to the panel. The internal space of wearable devices (such as smartwatches) is extremely compressed. If the thickness of the second reinforcing component exceeds 20μm, it will significantly increase the total thickness of the step area A3, which may lead to interference with the mid-frame or pose a height difference challenge to the subsequent bonding and sealing processes of the driver chip. If the thickness of the second reinforcing component 52 is too large (e.g., >20μm), the step area A3 may become too rigid. Under impact, the overly rigid film layer may undergo brittle fracture due to a lack of toughness, resulting in a sharp fracture surface that damages the panel.

[0076] Setting the thickness of the second reinforcing component 52 to 10μm~20μm, combined with a material with a high elastic modulus, can increase the local rigidity of the step area A3 several times. This is sufficient to control the deformation during assembly within the elastic range that the panel can withstand, thereby effectively suppressing the generation of internal R-corner cracks. The film in this thickness range has good adhesion conformability and is not prone to bubbles or edge lifting. Moreover, the height difference of 10μm~20μm is within the compensable range of the bonding process and will not have a fatal impact on the uniformity of the pressure head, ensuring the pass rate of electrical performance.

[0077] Figure 18 The diagram shows another planar structure of the display module provided in this embodiment. In an optional embodiment of this disclosure, the step area A3 includes a central area Q0 and peripheral areas Q1 located on both sides of the central area Q0 along a first direction D1. The first direction D1 is perpendicular to the direction from the bending area A2 to the step area A3 and parallel to the light-emitting surface M1 of the display panel 10. The second film layer 22 includes a first sub-part 221 located in the central area Q0 and a second sub-part 222 located in the peripheral area Q1. The elastic modulus of the second sub-part 222 is greater than that of the first sub-part 221.

[0078] The direction from the bending area A2 to the step area A3 is usually called the longitudinal direction (the main direction of stress transfer), while the first direction D1 defined in this scheme is its perpendicular direction (i.e., the width direction of the step area A3). The central area Q0 is the middle region of the step area A3 in the transverse direction, which is usually an area where signal lines are relatively dense and the compression from structural components is relatively uniform. The outer area Q1 is located on both sides of the central area Q0, that is, the area near the left and right edges of the panel. The elastic modulus of the second sub-part 222 located in the outer area Q1 is greater than that of the first sub-part 221 located in the central area Q0, which is equivalent to rigidly reinforcing the two sides of the step area A3.

[0079] During the assembly or bending of wearable devices, stress often concentrates most at the edges of the panel. Cracks typically initiate at the edge stress points and propagate inward. By increasing the modulus of the outer perimeter region Q1, a high-strength defensive wall can be built at the panel edge, directly preventing the generation of microcracks. Due to their narrow "neck," wearable devices are prone to minor lateral torsion during assembly. According to mechanics of materials, increasing the modulus on the outer side of the cross-section can significantly improve the torsional stiffness of the entire structure. Strengthening the outer perimeter region Q1 is like adding two "reinforcing ribs" to the stepped region A3, making it less prone to warping and lateral deformation under asymmetric shear forces. The edge of the stepped region A3 usually has frame traces (such as power lines, gate drive lines, etc.). The high-modulus film layer of the outer perimeter region Q1 can effectively protect these edge traces from mechanical compression damage during assembly. This "strong on both sides, stable in the middle" structure can effectively offset the edge stress concentration caused by the reduced deflection of the wearable device. When stress attempts to penetrate from the red line boundary (edge), the high-modulus second sub-section 222 can quickly absorb and disperse it. Due to the increased edge rigidity, the module is more resistant to impact when installed in the mid-frame, reducing edge cracking caused by misalignment. The central region Q0 maintains a relatively low elastic modulus (first sub-section 221), which provides better pressure buffer space for the bonding of the central driver chip, avoiding the bonding effect due to excessive overall rigidity.

[0080] Please continue to refer to this. Figure 18 In one optional embodiment of this disclosure, the elastic modulus of the second membrane layer 22 increases along the direction from the central region Q0 to the peripheral region Q1.

[0081] In the stepped region A3 of the flexible display module, the stress distribution is not uniform. Due to the narrowing of the bending region A2 of the wearable device, when the module is subjected to torsion or compression, the strain energy borne by the edge positions (left and right boundaries) is much higher than that of the central region Q0. Traditional heterogeneous material splicing will produce a modulus jump at the interface. This jump point often becomes a new weak point, leading to film peeling or instantaneous stress burst at the interface. This embodiment guides the stress to diffuse and dilute gently from the center to the edge by making the elastic modulus gradually increase (e.g., from the relatively low elastic modulus in the central region Q0 to the relatively high elastic modulus at the edge red line). In the actual process, ultraviolet irradiation can be used, and by controlling the transmittance of the mask (gradient mask), the light intensity received at the edge of the stepped region A3 is higher than that at the center, resulting in a higher polymer crosslinking density and a larger modulus in the edge region.

[0082] Inner radius (R) corner cracks most commonly originate at the physical boundaries of the panel. This solution ensures that the modulus reaches its maximum near the boundaries of the display panel 10 (the two red lines on the left and right). This "edge reinforcement" strategy in this embodiment can accurately pinpoint the crack source, preventing the crack from propagating inward, thereby significantly reducing the defect rate of the display panel 10. Wearable devices are prone to lateral twisting during assembly. The high-modulus layer at the edge acts like two rigid edge seals for the stepped area A3, greatly improving the structure's torsional resistance and reducing mechanical damage during assembly. Because the modulus is gradual, the stress change along the path of the cutting head is smaller during laser cutting or integrated cutting, resulting in smoother edge cutting quality and reducing secondary damage caused by edge chipping. The gradual structure can alleviate the internal stress within the film layer, making the adhesion between the support film and the panel tighter and less prone to bubbles or wrinkles due to thermal expansion and contraction, ensuring the long-term reliability of the display module.

[0083] Alternatively, please refer to Figure 2 and Figure 4 The display module also includes a polarizer 90, which is located on the light-emitting surface M1 of the display panel 10 and overlaps with the display area A1. The polarizer 90 is responsible for controlling the polarization state of the light and eliminating ambient reflected light.

[0084] Figure 19 As shown Figure 2 Please refer to another BB' section view of the display module. Figure 19 In one optional embodiment of this disclosure, the display module further includes a polarizer 90 and a color-changing functional layer 60 disposed on the light-emitting surface M1 of the display panel 10, wherein the polarizer 90 and the color-changing functional layer 60 cover the display area A1, and the color-changing functional layer 60 is located between the polarizer 90 and the display panel 10; the color-changing functional layer 60 is configured to present a transparent state in a first state of the display module and a black state in a second state of the display module.

[0085] In this embodiment, the polarizer 90 is responsible for controlling the polarization state of light and eliminating ambient reflected light. The color-changing functional layer 60 is the core functional layer, sandwiched between the polarizer 90 and the display panel 10. In the first state, it has high transmittance, allowing light to pass through almost without loss. In normal display mode, the colors are vibrant, and the contrast is determined by the sub-pixels in the display panel 10. Application scenarios include daily viewing of notifications, sports data, and switching between color dials.

[0086] The second state has lower transmittance, presenting a deep or black color, such as in the ultimate black mode, where the background is completely hidden and blends seamlessly with the bezel. It can be applied to always-on display, low-power mode, privacy masking, and can also improve contrast under strong light.

[0087] In wearable devices, users seek a seamless integration between the screen and the metal / ceramic bezel. When the color-changing layer switches to its black state, it absorbs most of the ambient light entering the panel, completely eliminating reflections from the internal metal circuitry (even in strong light, the dark red photosensitive area is not visible), achieving true screen-off aesthetics. In bright outdoor environments, even though the polarizer 90 filters out some stray light, panel reflections still exist. Activating the black (or semi-black) state of the color-changing layer significantly reduces background brightness, thereby physically improving ambient contrast without drastically increasing the power consumption of the display panel. Color-changing layers (especially electrochromic materials) typically possess bistable or low sustaining current characteristics. In its second state (black state), it covers inactive pixel areas, reducing background light leakage, which is particularly effective in always-on display mode, extending the battery life of wearable devices.

[0088] The color-changing functional layer 60, as a new functional layer on the light-emitting surface M1, is typically made of a material with a certain degree of elasticity. Together with the polarizer 90, it forms a physical protective film, further helping to alleviate the pressure from the inner radius corner cracks mentioned in the aforementioned embodiments. The introduction of the color-changing functional layer 60 increases the thickness of the light-emitting surface M1, which mechanically alters the position of the neutral layer of the panel. If designed properly, the neutral layer can be pulled closer to the fragile circuit layer, thereby reducing bending stress. By introducing the combination of the polarizer 90 and the color-changing functional layer 60, this disclosure not only solves the mechanical reliability problems of wearable devices (such as inner radius corner cracks) but also upgrades the user experience through color-changing technology. This design allows the screen to freely switch between vibrant color displays and pure, deep black screens.

[0089] Please continue to refer to this. Figure 19 In one optional embodiment of this disclosure, the color-changing functional layer 60 is an electrochromic functional layer or a photochromic functional layer.

[0090] Electrochromism refers to the phenomenon where a material undergoes a reversible change in color or transparency due to a redox reaction under the influence of an applied electric field. It typically consists of an electrochromic material sandwiched between two transparent conductive layers, an ion-conducting layer, and an ion-storage layer. By changing the polarity of the voltage, ions are driven to insert into or detach from the color-changing layer, thus achieving a transition from a "transparent" to a "black" state. Users can manually trigger the color change via software algorithms or physical buttons. Many electrochromic materials retain their current state (transparent or black) even after power is turned off, resulting in extremely low power consumption. It allows for continuous adjustment of different grayscale levels, not just on / off functionality. Applications include "privacy mode" in smartwatches, one-click "ultra-black" always-on display aesthetics, or proactive adjustment of screen contrast based on ambient light sensors. Optionally, the electrochromic functional layer includes tungsten trioxide.

[0091] Photochromism refers to the color change of a material when its molecular structure changes upon exposure to light of a specific wavelength (usually ultraviolet light), and it returns to its original state when the light exposure stops. The functional layer contains photosensitive molecules (such as silver halide or specific organic dyes). In strong outdoor light (including ultraviolet light), the molecules absorb energy and undergo isomerization, causing the film to rapidly darken (black state); upon returning to a low-light indoor environment, the molecules spontaneously revert to their initial configuration (transparent state). The color-changing process is entirely dependent on ambient light, requiring neither battery power nor complex circuitry. Automatic "blackening" under strong sunlight naturally provides shading and enhances contrast, protecting eyesight and improving readability in bright light. The absence of conductive electrodes and complex control circuits allows for a thinner and lighter module. Application scenario: Outdoor sports wearable devices. When the user moves from indoors to sunlight, the watch face background automatically darkens, enhancing text readability while reducing the panel's absorption of ultraviolet light.

[0092] Based on the same inventive concept, this disclosure also provides a display device. Figure 20 The diagram shown is a planar structural schematic of a display device provided in an embodiment of this disclosure. Please refer to it. Figure 20 The display device 200 includes the display module 100 provided in any of the foregoing embodiments of this disclosure.

[0093] The display device 200 provided in this embodiment can be any electronic device with display function, such as a touch screen, mobile phone, tablet computer, laptop computer, e-reader, or television. It can also be a large-size splicing display device, such as a command center screen. The display device 200 provided in this embodiment has the beneficial effects of the display module 100 provided in this embodiment. For details, please refer to the specific descriptions of the display module in the above embodiments. These descriptions will not be repeated here.

[0094] It is understood that the accompanying drawings only illustrate one shape of the display device 200 by using a circular structure as an example. In some other embodiments of this disclosure, the display device 200 may also be square, elliptical, fan-shaped or any other feasible shape, and this disclosure does not specifically limit it in this regard.

[0095] 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 one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0096] The above description is merely a specific embodiment of this disclosure, enabling those skilled in the art to understand or implement it. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this disclosure. Therefore, this disclosure is not to be limited to the embodiments described herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A display module, characterized in that, The display module includes a display area, a bent area located on one side of the display area, and a stepped area located on the side of the bent area away from the display area; the display module includes: The display panel has a light-emitting surface and a backlight surface; A functional film layer assembly is disposed on the light-emitting surface and / or backlight surface of the display panel; The functional film layer component includes a first film layer portion corresponding to the display area and a second film layer portion corresponding to the step area, wherein the elastic modulus of the second film layer portion is greater than that of the first film layer portion.

2. The display module according to claim 1, characterized in that, The elastic modulus of the first membrane layer is T1, and the elastic modulus of the second membrane layer is T2, wherein T2 ≥ 2 × T1.

3. The display module according to claim 1, characterized in that, The functional film layer assembly includes a first support layer located on the backlight surface of the display panel, and the first support layer includes a first film layer portion and a second film layer portion.

4. The display module according to claim 3, characterized in that, The first film layer and the second film layer are formed using the same material, and the second film layer is the area in the first support layer that has been treated with specific light, while the first film layer is the area in the first support layer that has not been treated with specific light.

5. The display module according to claim 3, characterized in that, The first membrane layer and the second membrane layer are formed using different materials.

6. The display module according to claim 3, characterized in that, The second membrane layer covers the stepped area.

7. The display module according to claim 3, characterized in that, The stepped area includes a first area and a second area, the first area being located between the second area and the bending area, and the second film layer being located in the first area; the first support layer also includes a third film layer disposed in the second area, the elastic modulus of the third film layer being less than that of the second film layer.

8. The display module according to claim 1, characterized in that, The functional film layer assembly includes a second support layer and a first reinforcing component. The second support layer and the first reinforcing component are located on the backlight surface of the display panel. The second support layer includes a first support portion and a second support portion. The first support portion is disposed corresponding to the display area, and the second support portion is disposed corresponding to the stepped area. The first reinforcing component is located in the stepped area and on the side of the second support portion away from the display panel. The elastic modulus of the first reinforcing component is greater than the elastic modulus of the first support portion. The first film layer portion includes the first support portion, and the second film layer portion includes the first reinforcing component.

9. The display module according to claim 8, characterized in that, The first support portion and the second support portion have the same elastic modulus.

10. The display module according to claim 8, characterized in that, The second support covers the stepped area; the stepped area includes a first area and a second area, the first area is located between the second area and the bending area, the first reinforcing component is located in the first area, or the first reinforcing component covers the stepped area.

11. The display module according to claim 1, characterized in that, The functional film layer assembly includes a third support layer and a second reinforcement component. The third support layer is located on the backlight surface of the display panel, and the second reinforcement component is located on the light-emitting surface of the display panel. The third support layer includes a third support portion and a fourth support portion. The third support portion is disposed corresponding to the display area, and the fourth support portion is disposed corresponding to the step area. The second reinforcing component is located in the step area. The elastic modulus of the second reinforcing component is greater than the elastic modulus of the third support portion. The first film layer includes the third support portion, and the second film layer includes the second reinforcing component.

12. The display module according to claim 11, characterized in that, The third support and the fourth support have the same elastic modulus.

13. The display module according to claim 11, characterized in that, The elastic modulus of the fourth support portion is greater than that of the third support portion, and the second membrane layer portion also includes the fourth support portion.

14. The display module according to claim 11, characterized in that, The step area is provided with bonding pads. The step area includes a first area and a second area. The first area is located between the second area and the bending area. The second reinforcing component is located in the first area, and the bonding pads are located in the second area.

15. The display module according to claim 14, characterized in that, Along the arrangement direction of the first and second regions, the distance between the second reinforcing component and the bonding pad is D0, where D0 ≥ 1 mm.

16. The display module according to claim 11, characterized in that, The thickness of the second reinforcing component is H0, where 10μm≤H0≤20μm.

17. The display module according to claim 1, characterized in that, The stepped area includes a central area and peripheral areas located on both sides of the central area along a first direction, the first direction being perpendicular to the direction from the bending area to the stepped area and parallel to the light-emitting surface of the display panel; the second film layer includes a first sub-part located in the central area and a second sub-part located in the peripheral area, the elastic modulus of the second sub-part being greater than the elastic modulus of the first sub-part.

18. The display module according to claim 17, characterized in that, Along the direction from the central region to the peripheral region, the elastic modulus of the second membrane layer tends to increase.

19. The display module according to claim 1, characterized in that, It also includes a polarizer and a color-changing functional layer disposed on the light-emitting surface of the display panel, wherein the polarizer and the color-changing functional layer cover the display area, and the color-changing functional layer is located between the polarizer and the display panel; the color-changing functional layer is configured to present a transparent state in a first state of the display module and a black state in a second state of the display module.

20. The display module according to claim 19, characterized in that, The color-changing functional layer is an electrochromic functional layer or a photochromic functional layer.

21. A display device, characterized in that, Includes the display module described in any one of claims 1 to 20.

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