Display panel and preparation method thereof, flexible display module and display device

Abstract

The invention discloses a display panel and a preparation method thereof, a flexible display module and a display device. The display panel comprises a first body, a second body and a bending part, the second body and the first body are arranged at an interval along the thickness direction of the display panel; the bending part is connected between the first body and the second body, and the section, in the thickness direction of the display panel, of the bending part comprises a plurality of arc sections which are formed by bending in sequence in the direction away from the first body and have different curvature radiuses; in at least two adjacent arc sections, the curvature radius of the arc section away from the first body is smaller than that of the arc section close to the first body. The curvature radius of the arc section located at the high-risk position is relatively large, so that the risk of line breakage is reduced; in addition, the curvature radius of the arc section located at the low-risk position is relatively small, so that the overall size of the bent part is reduced, the frame of the display module can be further reduced, and the purpose of narrow frame is achieved.

Description

Technical Field

[0001] The present application relates to the field of displays, and particularly to a display panel, a preparation method thereof, a flexible display module, and a display device. Background Art

[0002] Organic Light Emitting Diode (OLED) display panels have advantages such as high color gamut, flexibility, and fast response speed, and their market share has been increasing year by year. Flexible display screens are currently the mainstream trend in the development of the display industry. Relying on the development of the curved surface fitting technology, the borders of display screens of mobile terminal devices such as mobile phones and smart watches have been further reduced, greatly improving the screen-to-body ratio and thus enhancing the visual experience.

[0003] Currently, in the process of developing curved surface display technology, it has always been a difficulty to bend the control circuit to the back of the display panel by using the curved surface bending technology. In the prior art, problems such as circuit breakage and pulling in the bending area are likely to occur in the bent display panel, making it difficult to ensure the service life of the display panel. Summary of the Invention

[0004] Embodiments of the present application provide a display panel, a preparation method thereof, a flexible display module, and a display device, aiming to improve the service life of the display module.

[0005] In a first aspect of the embodiments of the present application, a display panel is provided. The display panel includes a first body, a second body, and a bending portion; the second body is disposed at an interval from the first body along the thickness direction of the display panel; the bending portion is connected between the first body and the second body, and a cross-section of the bending portion in the thickness direction of the display panel includes a plurality of arc segments with different curvature radii that are sequentially bent along a direction away from the first body; wherein, among at least two adjacent arc segments, the curvature radius of the arc segment farther from the first body is smaller than the curvature radius of the arc segment closer to the first body.

[0006] According to an embodiment of the first aspect of the present application, the curvature radius of the arc segment connected to the first body is not less than the curvature radius of any other arc segment.

[0007] According to any of the foregoing embodiments of the first aspect of the present application, the film layer thickness of the arc segment connected to the first body is not less than the film layer thickness of any other arc segment.

[0008] According to any of the foregoing embodiments of the first aspect of the present application, the bending portion is disposed on one side of the first body in a first direction, and the bending portion has a bending vertex that is the farthest from the first body along the first direction, and the first direction is perpendicular to the thickness direction; wherein, among two arc segments adjacent to the arc segment where the bending vertex is located, along the direction away from the first body, the curvature radii of the respective arc segments are arranged in a decreasing manner.

[0009] According to any of the foregoing embodiments of the first aspect of the present application, along the direction away from the first body, the radii of curvature of at least three successively connected arc segments are arranged in a decreasing manner.

[0010] According to any of the foregoing embodiments of the first aspect of the present application, along the direction away from the first body, the film layer thicknesses of at least three successively connected arc segments are arranged in a decreasing manner.

[0011] According to any of the foregoing embodiments of the first aspect of the present application, the multiple arc segments include a first arc, a second arc, a third arc, and a fourth arc that are successively connected. The first arc is connected to the first body, and the radii of curvature of the first arc, the second arc, the third arc, and the fourth arc decrease in sequence.

[0012] According to any of the foregoing embodiments of the first aspect of the present application, the radius of curvature of the first arc ranges from 0.28 mm to 0.32 mm, the radius of curvature of the second arc ranges from 0.23 mm to 0.27 mm, the radius of curvature of the third arc ranges from 0.18 mm to 0.22 mm, and the radius of curvature of the fourth arc ranges from 0.13 mm to 0.17 mm.

[0013] According to any of the foregoing embodiments of the first aspect of the present application, the radius of curvature of the first arc is 0.3 mm, the radius of curvature of the second arc is 0.25 mm, the radius of curvature of the third arc is 0.2 mm, and the radius of curvature of the fourth arc is 0.15 mm.

[0014] According to any of the foregoing embodiments of the first aspect of the present application, the fourth arc is connected to the second body.

[0015] According to any of the foregoing embodiments of the first aspect of the present application, the multiple arc segments further include a fifth arc, which is connected between the fourth arc and the second body, and the radius of curvature of the fifth arc is greater than that of the fourth arc.

[0016] According to any of the foregoing embodiments of the first aspect of the present application, the radius of curvature of the fifth arc ranges from 0.18 mm to 0.32 mm.

[0017] According to any of the foregoing embodiments of the first aspect of the present application, the radius of curvature of the fifth arc is 0.3 mm.

[0018] According to any of the foregoing embodiments of the first aspect of the present application, the bent portion has a turning point. Along the direction from the first body to the turning point, the radii of curvature of the multiple arc segments are arranged in a decreasing manner. Along the direction from the turning point to the second body, the radii of curvature of the multiple arc segments are arranged in an increasing manner.

[0019] According to any of the foregoing embodiments of the first aspect of the present application, the display panel includes a display side and a non-display side, the first body is located on the display side, and the second body is located on the non-display side; alternatively, the display panel includes a first display side and a second display side, the first body is located on the first display side, and the second body is located on the second display side.

[0020] An embodiment of the second aspect of the present application provides a method for manufacturing a display panel, which is used to manufacture the display panel of any of the foregoing embodiments. The manufacturing method includes:

[0021] Perform bending simulation analysis on the display panel according to a specified bending radius to obtain the partial stress of each sub-segment of the pre-bending part of the display panel and the total stress of the pre-bending part;

[0022] Compare the partial stress with the total stress, increase the pre-bending radius of the sub-segment with the partial stress greater than the total stress to obtain the first bending radius, and decrease the pre-bending radius of the sub-segment with the partial stress less than the total stress to obtain the second bending radius;

[0023] Perform segmented bending on the display panel according to the first bending radius and the second bending radius to form a bending part.

[0024] According to the foregoing embodiment of the second aspect of the present application, the cross-section of the bending part in the thickness direction of the display panel includes a plurality of arc segments with different curvature radii bent in sequence along the direction away from the first body. The stress formula of the arc segment is σ = Eε = Ey / p, where σ is the stress, ε is the strain, E is the elastic modulus, p is the curvature radius of the neutral layer of the arc segment, and y is the distance between a certain point of the arc segment and the neutral layer. Along the direction away from the neutral layer, the stress of the arc segment gradually increases.

[0025] An embodiment of the third aspect of the present application provides a flexible display module, which includes the display panel of any of the foregoing embodiments of the first aspect, and further includes a cover plate and a support assembly. The cover plate is at least disposed on one side of the first body facing away from the second body; the support assembly includes a first support part and a second support part. The first support part is disposed on one side of the first body facing the second body, and the second support part is disposed on one side of the second body facing the first body.

[0026] An embodiment of the fourth aspect of the present application provides a display device, which includes the display panel of any of the foregoing embodiments of the first aspect or the flexible display module of the third aspect.

[0027] According to the display panel of the embodiment of the present application, the display panel includes a first body, a second body, and a bending portion. The first body is used to implement the display function of the display panel. The stacked structure of the first body is relatively complex. As the stacked structure of the first body extends towards the bending portion, the stacked structure of the bending portion becomes relatively simple, but there are also multiple stepped structures therein. Therefore, in the arc segment close to the first body, the bending risk is higher at the position where the stacked structure is more complex, and the bending risk is relatively lower at the position where the stacked structure is simple. In the present application, by setting different bending radii on the bending path of the bending portion, in at least two adjacent arc segments, the curvature radius of the arc segment located at the high-risk position is relatively large, so as to reduce the bending stress in this area, avoid the concentration of bending stress at the stacked junction position, and reduce the risk of circuit breakage; the curvature radius of the arc segment located at the low-risk position is relatively small, which can disperse the bending stress of the screen body and can reduce the distance from the boundary of the first body to the bending vertex, thereby reducing the overall size of the bending portion, and can further reduce the frame of the display module to achieve the purpose of a narrow frame. Description of the Drawings

[0028] By reading the following detailed description of non-limiting embodiments with reference to the accompanying drawings, other features, objects, and advantages of the present application will become more apparent. Among them, the same or similar reference numerals represent the same or similar features, and the drawings are not drawn to actual scale.

[0029] Figure 1 is a schematic structural diagram of a flexible display module provided by an embodiment of the present application;

[0030] Figure 2 is a schematic structural diagram of stress and strain calculation of a bending portion provided by an embodiment of the present application;

[0031] Figure 3 is a schematic diagram of the bending path structure of the bending portion in a display panel provided by an embodiment of the present application;

[0032] Figure 4 is a schematic diagram of the bending path structure of the bending portion in a display panel provided by an embodiment of the present application;

[0033] Figure 5 is a schematic diagram of the bending path structure of the bending portion in a display panel provided by an embodiment of the present application;

[0034] Figure 6 is a schematic flowchart of a manufacturing method of a display panel provided by an embodiment of the present application.

[0035] Description of the Reference Numerals:

[0036] 1. First body;

[0037] 2. Second body;

[0038] 3. Bending part; 30. Arc segment; 301. Bending vertex; 31. First arc; 32. Second arc; 33. Third arc; 34. Fourth arc; 35. Fifth arc; 36. Turning point;

[0039] 110. Display side; 120. Non-display side;

[0040] 130. First display side; 140. Second display side;

[0041] 200. Cover plate;

[0042] 300. Support assembly; 310. First support part; 320. Second support part;

[0043] 400. Bending fixing glue; 500. Optical glue; 600. Polarizer;

[0044] X. First direction; Z. Thickness direction. Detailed implementation manners

[0045] The features and exemplary embodiments of each aspect of the present application will be described in detail below. For the purpose of making the objectives, technical solutions and advantages of the present application clearer, the present application will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only configured to explain the present application and are not configured to limit the present application. For those skilled in the art, the present application can be implemented without some of these specific details. The following description of the embodiments is only intended to provide a better understanding of the present application by showing examples of the present application.

[0046] It should be noted that, in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device. Without further limitation, elements defined by the statement "including..." do not exclude the existence of additional identical elements in the process, method, article or device including the said elements.

[0047] It should be understood that when describing the structure of a component, when a layer or a region is referred to as being "above" or "over" another layer or another region, it may mean directly above the other layer or another region, or there may be other layers or regions between it and the other layer or another region. And if the component is flipped, this layer or region will be "below" or "beneath" the other layer or another region.

[0048] Organic Light Emitting Diode (OLED) display modules have advantages such as high color gamut, flexibility, and fast response speed, and their market share has been increasing year by year. Users' requirements for the display effect of OLED panels are also getting higher and higher.

[0049] Optionally, in this application, the display panel is a flexible display panel, which includes a display side and a non-display side extending from the display side. Specifically, the display side is the side for displaying images, and the display content of the display panel can be observed from the display side. The non-display side is the area where no images are displayed. Further, components for displaying images such as light-emitting elements and pixel array layers are distributed on the display side. Integrated circuits for functions such as signal transmission and driving the light-emitting components to emit light are arranged on the non-display side. It should be noted that the non-display side can extend outward from one side edge of the display side, but it is not limited to this. The non-display side can also extend outward from multiple side edges of the display side.

[0050] Optionally, the display side includes a display surface for displaying images and a back surface disposed opposite to the display surface. In order to achieve full-screen display of the flexible display panel, the non-display side that does not display images can be bent towards the back surface, and the non-display side is bent to the back surface of the display side, thereby hiding the non-display side and increasing the area ratio of the display side on the front surface of the flexible display panel, thus increasing the screen-to-body ratio of the flexible display panel.

[0051] With the development of AMOLED full-screen technology, double-curved and even quadruple-curved products have become a development trend in mobile phone displays. In a curved screen, in order to achieve full-screen display, the flexible display screen needs to be bent. And in order to achieve a higher screen-to-body ratio, it is necessary to further reduce the width of the border of the flexible display module, such as reducing the bending radius of the bending area. However, this method is likely to cause relatively large bending stress and the circuit to break, resulting in problems such as poor display.

[0052] To solve the above problems, the embodiments of this application provide a display panel, a preparation method thereof, a flexible display module, and a display device. The following will describe each embodiment of the display panel, its preparation method, the flexible display module, and the display device with reference to the accompanying drawings.

[0053] Please refer to Figures 1 to 5 , Figure 1It is a schematic structural diagram of a flexible display module provided by an embodiment of the present application. A display panel is disposed within the flexible display module.

[0054] An embodiment of the present application provides a display panel, and the display panel may be an Organic Light Emitting Diode (OLED) display panel.

[0055] As Figures 1 to 5 shown, an embodiment of the first aspect of the present application provides a display panel, and the display panel includes a first body 1, a second body 2, and a bending portion 3; the second body 2 is disposed at an interval from the first body 1 along the thickness direction Z of the display panel; the bending portion 3 is connected between the first body 1 and the second body 2, and a cross-section of the bending portion 3 in the thickness direction Z of the display panel includes a plurality of arc segments 30 sequentially bent in a direction away from the first body 1 and having different radii of curvature; wherein, among at least two adjacent arc segments 30, the radius of curvature of the arc segment 30 away from the first body 1 is smaller than the radius of curvature of the arc segment 30 close to the first body 1.

[0056] Optionally, as Figure 1 shown, the display panel includes a display side 110 and a non-display side 120, the first body 1 is located on the display side 110 of the display panel, the second body 2 is located on the non-display side 120 of the display panel, and the second body 2 may not be used for display, but an integrated circuit for realizing functions such as signal transmission and driving a light-emitting component to emit light is disposed on the second body 2, and then the second body 2 is bent to the back of the display surface of the first body 1 through the bending portion 3, so as to reduce the width of the border of the display surface and improve the screen-to-body ratio.

[0057] Optionally, the radius of curvature of the arc segment 30 may refer to the radius of curvature of each position on the neutral axis of the arc segment 30, or may refer to the radius of curvature of the surface of the arc segment close to the bending center. Optionally, on the same side of the bending portion 3, the radii of curvature at various places in the same arc segment 30 are the same.

[0058] Optionally, the second body 2 may also be used for display, the display panel includes a first display side 130 and a second display side 140, the first body 1 is located on the first display side 130, and the second body 2 is located on the second display side 140. For example, two display screen bodies forming a folding screen with the first body 1 can have the advantages of portability and large-size display through bending or unfolding.

[0059] In the embodiments of the present application, the case where the second body 2 is not used for display is mainly described. Those skilled in the art can understand that even if the second body 2 is used for display, by correspondingly setting different bending radii in high-risk areas and low-risk areas, the risk of wire breakage can be reduced while the size of the bending portion 3 can also be reduced.

[0060] According to the display panel of the embodiment of the present application, the display panel includes a first body 1, a second body 2, and a bending portion 3. The first body 1 is used to implement the display function of the display panel. The stacked structure of the first body 1 is relatively complex. As the stacked structure of the first body 1 extends toward the bending portion 3, the stacked structure of the bending portion 3 becomes relatively simple. This results in a step structure on one side of the film layer structure near the connection position between the first body 1 and the bending portion 3. This leads to a relatively high bending risk near the connection position between the first body 1 and the bending portion 3, and a relatively low bending risk away from the first body 1. In the present application, different bending radii are set on the bending path of the bending portion 3, that is, when designing the screen body, the screen body is bent with multiple different curvature radii. Among at least two adjacent arc segments 30, the curvature radius of the arc segment 30 close to the first body 1 is larger, that is, the curvature radius of the arc segment 30 located at the high-risk position is relatively larger, so as to reduce the bending stress in this area, avoid the concentration of bending stress at the stacked junction position, and reduce the risk of circuit breakage. The curvature radius of the arc segment 30 away from the first body 1 is smaller, that is, the curvature radius of the arc segment 30 located at the low-risk position is relatively smaller, which can disperse the bending stress of the screen body and can reduce the distance H from the boundary of the first body 1 to the bending vertex 301, thereby reducing the overall size of the bending portion 3 and further reducing the border of the display module to achieve the purpose of a narrow border.

[0061] Wherein, each part of the same arc segment 30 has the same curvature center, and the bending radii of different arc segments 30 are different. That is, the change in the curvature radius of the bending portion 3 in the embodiment of the present application is not continuous, but changes at the junction of two adjacent arc segments 30. Specifically, the design of the bending radius can be set according to the risk level of the screen body stress of the display panel.

[0062] The relationship between the bending radius and the stress has the following characteristics:

[0063] 1. The normal stress at each point on the neutral axis is zero.

[0064] 2. For the same homogeneous material, the stress strain is inversely proportional to the curvature radius, that is, the larger the curvature radius, the smaller the stress strain; the stress strain is proportional to the radial distance from the stress point to the neutral layer, that is, the larger the distance, the larger the stress strain.

[0065] 3. For the bending of the screen body, the smaller the bending radius, the larger the stress strain, and the higher the risk of screen body fracture.

[0066] The stress formula for the arc segment is σ = Eε = Ey / p, where σ is the stress, ε is the strain, E is the elastic coefficient, p is the curvature radius of the neutral layer of the arc segment, and y is the distance between a certain point of the arc segment and the neutral layer. Along the direction away from the neutral layer, the stress of the arc segment gradually increases. With reference to Figure 3, when in pure bending, the longitudinal "fibers" of the beam change from straight lines to arcs, and two adjacent cross-sections 1'-1' and 2'-2' rotate relative to the neutral axis, as Figure 3 shown. The cross-sections 1'-1' and 2'-2' extend and intersect at point O, which is the center of curvature of the neutral layer. Let the radius of curvature of the neutral layer be ρ, and the angle between these two cross-sections be dθ. Then, the normal strain of the longitudinal "fiber" ab at a distance y from the neutral layer is:

[0067]

[0068] where ab is the straight-line distance between points a and b before bending, and a'b' is the arc length between points a and b after bending.

[0069] According to the longitudinal fiber hypothesis, each longitudinal "fiber" is in a state of unidirectional tension or compression. Therefore, when the normal stress does not exceed the proportional limit of the material, Hooke's law holds. Thus, the normal stress at a distance y from the neutral axis on the cross-section is:

[0070]

[0071] where E is the elastic coefficient of the material. This formula is the distribution law of the normal stress on the cross-section during the bending of the beam-column. From this formula, it can be seen that the normal stress at any point on the cross-section is proportional to the distance of this point from the neutral axis, and the normal stresses at points on the same horizontal line equidistant from the neutral axis are equal.

[0072] Optionally, the bending portion 3 is provided on one side of the first body 1 in the first direction X. The bending portion 3 has a bending vertex 301 that is the farthest from the first body 1 in the first direction X. The first direction X is perpendicular to the thickness direction Z. Among the two arc segments 30 adjacent to the arc segment 30 where the bending vertex 301 is located, along the direction away from the first body 1, the radius of curvature of each arc segment 30 is set to decrease.

[0073] In the related art, the bending portion 3 can be compressed into an "elliptical" shape. However, its radius of curvature changes gradually, which is quite different from the different bending radii set according to different risk areas in this application.

[0074] In these embodiments, the bending vertex 301 itself can be on an arc segment 30 or at the intersection of two adjacent arc segments 30. In this area, setting the radius of curvature of each arc segment 30 to decrease along the direction away from the first body 1 can effectively reduce the distance from the bending vertex 301 to the first body 1, realizing a narrow border of the display panel.

[0075] Optionally, referring to Figure 1, the flexible display module includes a support assembly 300. The support assembly 300 includes a first support portion 310 and a second support portion 320. The first support portion 310 is disposed on one side of the first body 1 facing the second body 2, and the second support portion 320 is disposed on one side of the second body 2 facing the first body 1. The boundary of the first support portion 310 extends toward the bending portion 3. At the position where the first support portion 310 intersects with the bending portion 3, the bending risk of the display panel is relatively high. A relatively large bending radius is set in this area to reduce the risk of wire breakage.

[0076] In some alternative embodiments, referring to Figures 3 to 5 , the curvature radius of the arc segment 30 connecting the first body 1 is not less than the curvature radius of any other arc segment 30. Optionally, the film layer thickness of the arc segment 30 connecting the first body 1 is not less than the film layer thickness of any other arc segment 30.

[0077] In these embodiments, the laminated structure of the arc segment 30 closest to the first body 1 is the most complex, and the film layer thickness is also the thickest, making the bending risk in this area the highest. Bending stress concentration at the laminated junction position should be avoided. For example, at the junction of the first support portion 310 and the bending portion 3. In order to reduce the overall size of the bending portion 3, the curvature radius R1 of the arc segment 30 connected to the first body 1 is set to be the largest. The bending radii of other areas can be less than or equal to R1, and at least one arc segment 30 has a curvature radius less than R1. By reducing the bending radii of other areas, the size of the bending path formed by the bending portion 3 can be made smaller than the size of the semi-circular bending path formed by R1, achieving the effect of a narrow border while reducing the risk of wire breakage.

[0078] Optionally, referring to Figure 3 and Figure 4 , along the direction away from the first body 1, the curvature radii of at least three successively connected arc segments 30 are set to decrease. Optionally, along the direction away from the first body, the film layer thicknesses of at least three successively connected arc segments 30 are set to decrease.

[0079] The arc segments 30 with successively decreasing curvature radii can smoothly change the bending radius, reducing the possibility of mutation points and stress concentration caused by large size changes, thereby reducing the risk of wire breakage; at the same time, this implementation can further reduce the size of the bending path, achieve a narrower border display effect, and increase the screen-to-body ratio.

[0080] Optionally, referring to Figure 3 and Figure 4, the multiple arc segments 30 include a first arc 31, a second arc 32, a third arc 33, and a fourth arc 34 that are sequentially connected. The first arc 31 is connected to the first body 1, and the curvature radii of the first arc 31, the second arc 32, the third arc 33, and the fourth arc 34 decrease sequentially. As the multiple arc segments 30 gradually move away from the first body 1, the bending risk gradually decreases. By designing the bending path of the bending portion 3 into multiple segments and setting different bending radius trajectory schemes for each segment, the bending radius in the high-stress risk areas such as the laminated junction position is larger, and the bending radius in the low-risk areas is smaller, thereby reducing the risk of line breakage at the bending portion 3 of the screen body and reducing the problem of display defects related to the line. Optionally, the value range of the curvature radius R1 of the first arc 31 is 0.28 mm to 0.32 mm. For example, R1 can be 0.28 mm, 0.29 mm, 0.3 mm, 0.31 mm, or 0.32 mm; the value range of the curvature radius R2 of the second arc 32 is 0.23 mm to 0.27 mm. For example, R2 can be 0.23 mm, 0.24 mm, 0.25 mm, 0.26 mm, or 0.27 mm; the value range of the curvature radius R3 of the third arc 33 is 0.18 mm to 0.22 mm. For example, R3 can be 0.18 mm, 0.19 mm, 0.2 mm, 0.21 mm, or 0.22 mm; the value range of the curvature radius R4 of the fourth arc 34 is 0.13 mm to 0.17 mm. For example, R4 can be 0.13 mm, 0.14 mm, 0.15 mm, 0.16 mm, or 0.17 mm.

[0081] Optionally, the curvature radius R1 of the first arc 31 is 0.3 mm, the curvature radius R2 of the second arc 32 is 0.25 mm, the curvature radius R3 of the third arc 33 is 0.2 mm, and the curvature radius R4 of the fourth arc 34 is 0.15 mm. The curvature radii of the first arc 31 to the fourth arc 34 decrease by 0.05 mm in sequence, realizing a smooth transition of the curvature radii between different arc segments 30.

[0082] Optionally, referring to Figure 3 , the fourth arc 34 is connected to the second body 2. In this embodiment, a total of 4 arc segments 30 are provided. From the direction of the first body 1 to the second body 2, the size of each arc segment 30 decreases sequentially, so that the distance between the first body 1 and the second body 2 is less than 2*R1 to achieve a narrower border.

[0083] Or, referring to Figure 4, the plurality of arc segments 30 further includes a fifth arc 35. The fifth arc 35 is connected between the fourth arc 34 and the second body 2. The radius of curvature R5 of the fifth arc 35 can be greater than the radius of curvature R4 of the fourth arc 34. In this embodiment, a total of 5 arc segments 30 are provided. Near the position of the second body 2, the laminated structure at the fifth arc 35 may be relatively more complex than that of the fourth arc 34, and the risk of fracture is relatively high. By setting the radius of curvature R5 of the fifth arc 35 to be larger, the risk of wire breakage at this position can be reduced. Optionally, the value range of the radius of curvature R5 of the fifth arc 35 is 0.18 mm to 0.32 mm. For example, R5 can be 0.18 mm, 0.20 mm, 0.25 mm, 0.30 mm or 0.32 mm.

[0084] Alternatively, the radius of curvature R5 of the fifth arc 35 can also be less than the radius of curvature R4 of the fourth arc 34. If the laminated structure at the fifth arc 35 is relatively simpler than that of the fourth arc 34, such a design is more conducive to the narrow border design of the display panel. Referring to Table 1, it can be seen that as the arc segment 30 moves away from the first body 1, the risk of bending and wire breakage of the display panel gradually decreases.

[0085] Table 1: Influence of different curling radii on risk

[0086]

[0087] In addition, with reference to Figure 1 and Figure 4 , the boundary of the second support portion 320 extends toward the bending portion 3. At the position where the second support portion 320 intersects with the bending portion 3, the bending risk of the display panel is also relatively high. A relatively large bending radius is set in this area to reduce the risk of wire breakage. Optionally, the radius of curvature R5 of the fifth arc 35 is 0.3 mm. The radius of curvature R5 of the fifth arc 35 can be the same as the radius of curvature R1 of the first arc 31, but not greater than the radius of curvature R1 of the first arc 31.

[0088] In some alternative embodiments, with reference to Figure 5 , the bending portion 3 has a turning point 36. Along the direction from the first body 1 to the turning point 36, the radii of curvature of the plurality of arc segments 30 are set to decrease. Along the direction from the turning point 36 to the second body 2, the radii of curvature of the plurality of arc segments 30 are set to increase.

[0089] Optionally, in the Figure 5 shown viewing direction, the tangent slope of the arc segment 30 between the turning point 36 and the first body 1 can be less than 0, and the tangent slope of the arc segment 30 between the turning point 36 and the second body 2 can be greater than 0.

[0090] In these alternative embodiments, the turning point 36 is located in the middle of the bending path. The laminated structures of the bending portions 3 near the positions of the first body 1 and the second body 2 are relatively complex, and the bending stress received is relatively large. Therefore, a larger curvature radius is set to reduce the risk of wire breakage. As the distance from the first body 1 and the second body 2 increases, the bending risk gradually decreases, and the curvature radius of the arc segment 30 in the middle of the bending portion 3 gradually decreases. While achieving a narrow border effect, the stress can be relatively smoothly dispersed on the arc segment 30 at the middle position.

[0091] Figure 6 The flow schematic diagram of a manufacturing method of a display panel provided by an embodiment of the present application is shown.

[0092] With reference to Figures 1 to 6 , an embodiment of the second aspect of the present application provides a manufacturing method of a display panel, which is used to manufacture and form the display panel of any of the above embodiments. The manufacturing method includes:

[0093] S10, performing bending simulation analysis on the display panel according to a specified bending radius to obtain the partial stress of each sub-segment of the pre-bending portion of the display panel and the total stress of the pre-bending portion.

[0094] S20, comparing the partial stress with the total stress, increasing the pre-bending radius of the sub-segment with the partial stress greater than the total stress to obtain the first bending radius, and decreasing the pre-bending radius of the sub-segment with the partial stress less than the total stress to obtain the second bending radius.

[0095] S30, performing segmented bending on the display panel according to the first bending radius and the second bending radius to form a bending portion.

[0096] The cross-section of the bending portion in the thickness direction of the display panel includes a plurality of arc segments with different curvature radii sequentially bent along the direction away from the first body. The stress formula of the arc segment is σ = Eε = Ey / p, where σ is the stress, ε is the strain, E is the elastic coefficient, p is the curvature radius of the neutral layer of the arc segment, and y is the distance between a certain point of the arc segment and the neutral layer. Along the direction away from the neutral layer, the stress of the arc segment gradually increases. Therefore, at the position where the film layer structure of the display panel is complex / the film layer is thick, increasing its bending radius can effectively reduce its stress. In S20, the film layer thickness and material of the arc segment are considered in combination, such as the junction of the twisted wires.

[0097] With reference to Figure 1, an embodiment of the third aspect of the present application provides a flexible display module, which includes the display panel of any embodiment of the first aspect described above, and further includes a cover plate 200 and a support assembly 300. The cover plate 200 is at least disposed on one side of the first body 1 away from the second body 2; the support assembly 300 includes a first support portion 310 and a second support portion 320. The first support portion 310 is disposed on one side of the first body 1 facing the second body 2, and the second support portion 320 is disposed on one side of the second body 2 facing the first body 1. Since the flexible display module provided by the embodiment of the third aspect of the present application includes the display panel of any embodiment of the first aspect, the flexible display module provided by the embodiment of the third aspect of the present application has the beneficial effects of the display panel of any embodiment of the first aspect, which will not be elaborated herein.

[0098] In the flexible display module of the embodiment of the third aspect of the present application, the boundary of the first support portion 310 extends toward the bending portion 3. At the position where the first support portion 310 intersects with the bending portion 3, the bending risk of the display panel is relatively high. A relatively large bending radius is set in this area to reduce the risk of wire breakage.

[0099] Optionally, the flexible display module further includes a bending fixing adhesive 400. The bending fixing adhesive 400 is coated on the side of the bending portion 3 away from the support assembly 300, which can play a role in fixing and protecting the bent bending portion 3.

[0100] Optionally, the flexible display module further includes an optical adhesive 500 and a polarizer 600. In the thickness direction Z of the flexible display module, the cover plate 200, the optical adhesive 500, the polarizer 600, and the first body 1 are stacked in sequence. The optical adhesive 500 can be an OCA (Optically Clear Adhesive). OCA is made by making optical acrylic glue into a substrate-free form, and then laminating a release film on each of the upper and lower bottom layers to obtain a double-sided adhesive tape without a matrix material. Since OCA is generally shipped in the form of a double-sided tape, it is also called an optical adhesive 500 tape or an optical double-sided tape, and it is a better adhesive used in display modules.

[0101] An embodiment of the fourth aspect of the present application provides a display device, which includes the display panel of any embodiment of the first aspect or the flexible display module of the third aspect.

[0102] The display device in the embodiments of the present application includes, but is not limited to, devices with display functions such as mobile phones, personal digital assistants (Personal Digital Assistant, abbreviated as: PDA), tablet computers, e-books, televisions, access control systems, smart landline telephones, and consoles.

[0103] According to the embodiments of the present application as described above, these embodiments do not describe all the details in detail, nor do they limit the invention to the specific embodiments described. Obviously, many modifications and variations can be made according to the above description. These embodiments are selected and specifically described in this specification in order to better explain the principles and practical applications of the present application, so that those skilled in the art can make good use of the present application and its modifications based on the present application. The present application is only limited by the claims and their full scope and equivalents.

Claims

1. A display panel, characterized in that: include: first ontology; A second body, spaced apart from the first body along a thickness direction of the display panel; a bending portion connected between the first body and the second body, wherein a cross section of the bending portion in the thickness direction of the display panel includes a plurality of arc segments with different curvature radii formed by sequentially bending in a direction away from the first body; Among them, in at least two adjacent arc segments, the curvature radius of the arc segment far away from the first body is smaller than the curvature radius of the arc segment close to the first body.

2. The display panel according to claim 1, characterized in that: The bending portion is disposed on one side of the first body in a first direction, the bending portion has a bending vertex farthest from the first body along the first direction, and the first direction is perpendicular to the thickness direction; Among the two arc segments adjacent to the arc segment where the bending vertex is located, the curvature radius of each arc segment is arranged to decrease gradually along the direction away from the first body.

3. The display panel according to claim 1, characterized in that: The curvature radius of the arc segment connecting the first body is not less than the curvature radius of any other arc segment; Preferably, the film thickness of the arc segment connected to the first body is not less than the film thickness of any other arc segment.

4. The display panel according to claim 1, characterized in that: Along the direction away from the first body, the curvature radii of at least three sequentially connected arc segments are arranged to decrease; Preferably, along the direction away from the first body, the film thickness of at least three sequentially connected arc segments is arranged to decrease.

5. The display panel according to claim 4, characterized in that: The plurality of arc segments include a first arc, a second arc, a third arc and a fourth arc connected in sequence, the first arc is connected to the first body, and the curvature radii of the first arc, the second arc, the third arc and the fourth arc decrease in sequence; Preferably, the radius of curvature of the first arc is in the range of 0.28 mm to 0.32 mm, the radius of curvature of the second arc is in the range of 0.23 mm to 0.27 mm, the radius of curvature of the third arc is in the range of 0.18 mm to 0.22 mm, and the radius of curvature of the fourth arc is in the range of 0.13 mm to 0.17 mm; Preferably, the radius of curvature of the first circular arc is 0.3 mm, the radius of curvature of the second circular arc is 0.25 mm, the radius of curvature of the third circular arc is 0.2 mm, and the radius of curvature of the fourth circular arc is 0.15 mm.

6. The display panel according to claim 5, characterized in that: The fourth arc is connected to the second body.

7. The display panel according to claim 5, characterized in that: The plurality of arc segments further include a fifth arc, the fifth arc is connected between the fourth arc and the second body, and the curvature radius of the fifth arc is greater than the curvature radius of the fourth arc; Preferably, the curvature radius of the fifth arc ranges from 0.18 mm to 0.32 mm; Preferably, the curvature radius of the fifth circular arc is 0.3 mm.

8. The display panel according to claim 1, characterized in that: The bending portion has a turning point, and along the direction from the first body to the turning point, the curvature radii of the plurality of arc segments are arranged in a decreasing manner, and along the direction from the turning point to the second body, the curvature radii of the plurality of arc segments are arranged in an increasing manner.

9. The display panel according to any one of claims 1 to 8, characterized in that: The display panel includes a display side and a non-display side, the first body is located on the display side, and the second body is located on the non-display side; Alternatively, the display panel includes a first display side and a second display side, the first body is located on the first display side, and the second body is located on the second display side.

10. A method for preparing a display panel, characterized in that: Used to prepare a display panel as claimed in any one of claims 1 to 9, the preparation method comprising: Performing a bending simulation analysis on the display panel according to a specified bending radius to obtain the partial stress of each sub-segment of the pre-bending portion of the display panel and the total stress of the pre-bending portion; Comparing the partial stress with the total stress, increasing the pre-bending radius of the sub-segment where the partial stress is greater than the total stress to obtain a first bending radius, and reducing the pre-bending radius of the sub-segment where the partial stress is less than the total stress to obtain a second bending radius; The display panel is bent in sections according to the first bending radius and the second bending radius to form a bending portion.

11. The method for preparing a display panel according to claim 10, characterized in that: The cross-section of the bent portion in the thickness direction of the display panel includes a plurality of arc segments with different curvature radii formed by bending in sequence along a direction away from the first body. The stress formula of the arc segment is σ=Eε=Ey / p, wherein σ is stress, ε is strain, E is elastic coefficient, p is the curvature radius of the neutral layer of the arc segment, y is the distance between a certain point of the arc segment and the neutral layer, and the stress of the arc segment gradually increases along the direction away from the neutral layer.

12. A flexible display module, characterized in that: The display panel according to any one of claims 1 to 9, further comprising: a cover plate, at least disposed on a side of the first body facing away from the second body; The support assembly includes a first support portion and a second support portion, wherein the first support portion is arranged on a side of the first body facing the second body, and the second support portion is arranged on a side of the second body facing the first body.

13. A display device, characterized in that: The invention comprises the display panel according to any one of claims 1 to 9 or the flexible display module according to claim 12.

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