Display module

Abstract

The application provides a display module, comprising: a flexible display panel, comprising: a first flat part having an outlight surface; a second flat part located at the back side of the outlight surface of the first flat part; and a curved part connecting the first flat part and the second flat part, the inner curved surface of the curved part is connected with the back surface of the outlight surface of the first flat part, the inner curved surface comprises a bending starting point and a bending ending point, the bending starting point is located at the connection between the curved part and the first flat part, the bending ending point is located at the connection between the curved part and the second flat part, the distance between the bending starting point and the bending ending point is D1, the distance between the midpoint of the line connecting the bending starting point and the bending ending point and the inner curved surface vertex of the inner curved surface is D2; wherein D1 and D2 satisfy the following formula: D2<(D1) / 2.

Description

Technical Field

[0001] This application relates to the field of display technology, and more particularly to a display module. Background Technology

[0002] In the development of smart terminals, in order to pursue a high screen-to-body ratio, it is necessary to minimize the bezels of the display module to improve the user experience.

[0003] Therefore, a technical solution is needed to reduce the bezel of flexible display modules. Summary of the Invention

[0004] The purpose of this application is to provide a display module that reduces the bezel of the display module.

[0005] In a first aspect, this application provides a display module, comprising:

[0006] Flexible display panels, including:

[0007] The first straight section has a light-emitting surface;

[0008] The second straight section is located on the back side of the light-emitting surface of the first straight section; and

[0009] A curved section connects the first straight section and the second straight section. The inner curved surface of the curved section is connected to the back side of the light-emitting surface of the first straight section. The inner curved surface includes a bending start point and a bending end point. The bending start point is located at the connection between the curved section and the first straight section, and the bending end point is located at the connection between the curved section and the second straight section. The distance between the bending start point and the bending end point is D1, and the distance from the midpoint of the line connecting the bending start point and the bending end point to the vertex of the inner curved surface is D2.

[0010] Wherein, D1 and D2 satisfy the following formula: D2 < (D1) / 2.

[0011] Beneficial effects: The distance between the starting point and the ending point of the bend in the flexible display panel is D1, and the distance from the midpoint of the line connecting the starting point and the ending point to the vertex of the inner curved surface is D2, where D2 < (D1) / 2. With this design, D1 can remain unchanged or be reduced slightly, so as not to reduce or only slightly reduce the thickness of the module stack below the flexible display panel. This essentially does not reduce the mechanical performance of the display module, while simultaneously reducing the distance D2 from the midpoint of the line connecting the starting and ending points to the vertex of the inner curved surface. This reduces the size of the lower bezel occupied by the bend in the flexible display panel, thereby reducing the size of the lower bezel of the display module. Attached Figure Description

[0012] Figure 1This is a cross-sectional schematic diagram of the display module according to an embodiment of this application;

[0013] Figure 2 for Figure 1 The diagram shows the second end face of the second back plate of the module near the bend relative to the first end face of the first back plate near the bend.

[0014] Figure 3 for Figure 1 The diagram shows the second end face of the second back plate of the module near the bend relative to the first end face of the first back plate near the bend.

[0015] Figure 4 for Figure 1 The diagram shows a partial view of the display module when the flexible display panel and the back panel are both in a flattened state.

[0016] Figure 5 Experimental test diagrams showing the stress on the traces of the source and drain metal layers in the flexible display panel at different locations when the curved part of the flexible display panel is bent in a semi-circular arc shape with a bending radius of 0.23 mm, and the second back plate of the display module is aligned with the first back plate, misaligned to the left, and misaligned to the right.

[0017] Figure 6 Experimental test diagrams showing the stress on the traces of the source and drain metal layers in the flexible display panel at different locations when the curved part of the flexible display panel is bent in a semi-circular arc shape with a bending radius of 0.17 mm, and the second back plate of the display module is aligned with the first back plate, misaligned to the left, and misaligned to the right.

[0018] Figure 7 The curved portion of the flexible display panel is Figure 1 The diagram shows the experimental test results of the stress on the traces of the source and drain metal layers in the flexible display panel at different positions under the conditions of alignment, left misalignment, and right misalignment of the second back plate and the first back plate of the display module, with (D1) / 2 being 0.23 mm and D2 being 0.17 mm.

[0019] Figure 8 The curved portion of the flexible display panel is Figure 1 The diagram shows the experimental test results of the stress on the traces of the source and drain metal layers in the flexible display panel at different locations, under the conditions of alignment, left misalignment, and right misalignment of the second back plate and the first back plate of the display module, with (D1) / 2 being 0.20 mm and D2 being 0.17 mm.

[0020] Attached image labels:

[0021] 100, Display module; 100a, Display area; 100b, Non-display area; 100b1, Curved area;

[0022] 10, Flexible display panel; 101, First flat section; 101a, Light-emitting surface; 102, Second flat section; 103, Curved section; 103a, Inner curved surface; 103b, Outer curved surface; A, Curved start point; B, Curved end point; O, Midpoint; P, Vertex of inner curved surface;

[0023] First direction x; Second direction y;

[0024] 12, back plate; 121, first back plate; 121a, first end face; 122, second back plate; 122a, second end face; 123, groove; 123a, initial groove;

[0025] 14, Protective layer; 14a, First region; 14b, Second region; 141, Initial protective layer;

[0026] 15, Functional layer; 15a, Third end face;

[0027] 18. Protective cover plate;

[0028] 20, Support component; 201, Rigid support layer;

[0029] 221, First adhesive layer; 222, Second adhesive layer; 223, Third adhesive layer; 224, Fourth adhesive layer; 225, Fifth adhesive layer; 226, Sixth adhesive layer. Detailed Implementation

[0030] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0031] Please refer to Figure 1 As shown, this application provides a display module 100. The display module 100 has a display area 100a and a non-display area 100b arranged adjacent to each other along a first direction x, and the non-display area 100b includes a curved area 100b1. The display module 100 includes a flexible display panel 10 and a back plate 12, and the flexible display panel 10 is located on the back plate 12.

[0032] The flexible display panel 10 includes a driving substrate (not shown) and a light-emitting device layer (not shown) disposed on the driving substrate. The driving substrate is located in the display area 100a and the non-display area 100b, and the light-emitting device layer is located in the display area 100a. The driving substrate includes a substrate and a driving circuit layer disposed on the substrate, and the light-emitting device layer is disposed on the driving circuit layer. Specifically, the flexible display panel 10 is a flexible organic light-emitting diode display panel, but is not limited thereto.

[0033] The flexible display panel 10 includes a first flat portion 101, a second flat portion 102, and a curved portion 103. The first flat portion 101 includes a light-emitting device layer and has a light-emitting surface 101a, which is located in the display area 100a, with a first direction x parallel to the light-emitting surface 101a. The second flat portion 102 is located on the back side of the light-emitting surface 101a of the first flat portion 101. The curved portion 103 connects the first flat portion 101 and the second flat portion 102. A driving circuit layer is located in the first flat portion 101, the second flat portion 102, and the curved portion 103.

[0034] Both the first straight portion 101 and the second straight portion 102 are straight. The first straight portion 101 and the second straight portion 102 are arranged parallel to each other. It can be understood that the second straight portion 102 may also be arranged at an angle relative to the first straight portion 101.

[0035] The curved portion 103 is located in the curved area 100b1. The curved portion 103 is in a curved state, so that the second straight portion 102 is located on the back side of the light-emitting surface 101a of the first straight portion 101, reducing the size of the non-display area 100b, thereby narrowing the lower bezel of the display module 100.

[0036] The curved portion 103 includes an inner curved surface 103a and an outer curved surface 103b, with the outer curved surface 103b facing away from the inner curved surface 103a. The inner curved surface 103a is connected to the back side of the light-emitting surface 101a of the first straight portion 101. The inner curved surface 103a includes a bending start point A, a bending end point B, and an inner curved surface vertex P. The bending start point A is located at the connection between the curved portion 103 and the first straight portion 101, the bending end point B is located at the connection between the curved portion 103 and the second straight portion 102, and the inner curved surface vertex P is located at the vertex of the inner curved surface 103a. The distance between the bending start point A and the bending end point B is D1. The distance from the midpoint O of the line connecting the bending start point A and the bending end point B to the inner curved surface vertex P is D2.

[0037] The line connecting the bend start point A and the bend end point B is parallel to the second direction y, which intersects the first direction x. In other words, the bend start point A and the bend end point B are aligned in the second direction y. Specifically, the second direction y is perpendicular to the first direction x, but it is not limited to this. It can be understood that the angle between the second direction y and the first direction x can also be acute or obtuse.

[0038] Wherein, D1 and D2 satisfy the following formula: D2 < (D1) / 2. Due to this design, D1 can remain unchanged or be reduced slightly, so as not to reduce the thickness of the module stack below the flexible display panel, thereby basically not reducing the mechanical performance of the display module, while making the distance D2 from the midpoint O of the line connecting the bending start point A and the bending end point B to the vertex P of the inner curved surface 103a smaller, so as to reduce the space occupied by the bending part 103 of the bending area 100b1 in the first direction x, thereby reducing the size of the non-display area 100b, in other words, reducing the size of the lower bezel of the display module 100, thereby increasing the screen ratio of the display module.

[0039] Specifically, the cross-section of the curved portion 103 along the second direction y is a semi-elliptical arc or approximately a semi-elliptical arc. The starting point A and the ending point B of the curve are the two vertices of the major axis of the semi-elliptical arc, respectively, and the vertex P of the inner curved surface is a vertex of the minor axis of the semi-elliptical arc. At the same time, both the inner curved surface 103a and the outer curved surface 103b include elliptical arc surfaces. In the direction extending from the starting point A to the ending point B of the curve on the inner curved surface 103a, the distance between the point and the midpoint O in the region between the starting point A and the vertex P of the inner curved surface decreases, while the distance between the point and the midpoint O in the region between the vertex P of the inner curved surface and the ending point B increases.

[0040] It should be noted that in some related technologies, the curved portion of the flexible display panel is a semi-circular arc. When the bending radius of the curved portion is large, it results in a large bottom bezel of the display module, which is not conducive to achieving a narrow bezel design. On the other hand, when the bending radius of the curved portion is small to reduce the size of the bottom bezel of the display module, on the one hand, it leads to a large stress value at the bending apex of the curved portion, increasing the risk of circuit breakage in the curved portion; on the other hand, it also leads to a significant reduction in the thickness of the display module. A significant reduction in the thickness of the display module leads to a decrease in its mechanical properties, making it difficult for the display module to pass mechanical performance tests such as extrusion resistance and drop ball resistance.

[0041] In this application, the cross-section of the curved portion 103 along the second direction y is a semi-elliptical arc or approximately a semi-elliptical arc. The distance between the bending start point A and the bending end point B is D1, and the distance from the midpoint O of the line connecting the bending start point A and the bending end point B to the vertex P of the inner curved surface is D2, where D2 < (D1) / 2. This design reduces the space occupied by the curved portion 103 in the first direction x, thereby reducing the size of the lower bezel of the display module. Simultaneously, since the size of the curved portion 103 in the second direction y can remain unchanged or be reduced slightly, it helps to maintain the thickness of the display module, thus improving the problem of reduced mechanical performance caused by significant thinning of the display module in related technologies. Furthermore, the reduction in the size of the curved portion 103 in the first direction x, while maintaining or slightly reducing its size in the second direction y, also improves the problem of excessive stress due to the small bending radius of the curved portion in related technologies. Therefore, compared with related technologies, this application achieves a narrow bezel design for the bottom bezel of the display module while taking into account the mechanical performance of the display module as a whole, and reduces the risk of internal circuit breakage caused by high stress in the bending part of the flexible display panel.

[0042] Please refer to Figure 1 As shown, the back plate 12 protects the back of the flexible display panel 10. The back plate 12 includes a first back plate 121, a second back plate 122, and a groove 123. The first back plate 121 is connected to the first straight portion 101. The second back plate 122 is connected to the second straight portion 102. The groove 123 overlaps with the curved portion 103. The material of the back plate 12 includes organic insulating materials such as polyimide and polyethylene terephthalate.

[0043] In this embodiment, the first back plate 121 has a first end face 121a near the bend 103, which overlaps with the bend start point A. The second back plate 122 has a second end face 122a near the bend 103, which overlaps with the bend end point B. The first end face 121a and the second end face 122a are aligned in the second direction y.

[0044] In other embodiments, please refer to Figure 2 and Figure 3 As shown, the first end face 121a and the second end face 122a can also be offset, and in the first direction x, the offset distance between the first end face 121a and the second end face 122a is less than or equal to 200 micrometers. Figure 2 As shown, the second end face 122a is located on the side of the first end face 121a away from the bend 103, and is referred to as the left misalignment of the second back plate 122. Figure 3 As shown, the second end face 122a is located on the side of the first end face 121a near the bend 103, and is referred to as the right misalignment of the second back plate 122.

[0045] It should be noted that in some embodiments of this application, in order to meet assembly requirements, or due to deviations in assembly processes or other processes, the first end face 121a and the second end face 122a may be offset.

[0046] In this embodiment, please also refer to Figure 1 and Figure 4 As shown, when the flexible display panel 10 is in a flattened state, the back plate 12 is also in a flattened state. The surface of the first back plate 121 of the flattened back plate 12 near the flexible display panel 10 and the surface of the second back plate 122 near the flexible display panel are located on the same plane, and this plane is perpendicular to the thickness direction of the flexible display panel. The distance L between the first back plate 121 and the second back plate 122 of the flattened back plate 12 satisfies the following formula: L=π(D2+kh)+2((D1) / 2-D2), k is greater than 0 and less than 1, and h is the thickness of the flexible display panel 10.

[0047] By controlling the distance L between the first back plate 121 and the second back plate 122 using the above formula, the second straight portion 102 of the flexible display panel 10 is bent to the back side of the light-emitting surface 101a of the first straight portion 101 via the bending portion 103. When the second back plate 122 is located on the side of the first back plate 121 away from the first straight portion 101, the cross section of the bending portion 103 along the second direction y is semi-elliptical or approximately semi-elliptical. Moreover, the design of D2+kh in the formula is used to adjust the neutral surface of the bending portion 103 of the flexible display panel 10 to be located between the inner curved surface 103a and the outer curved surface 103b, thereby reducing the stress on the internal wiring of the bending portion 103 and reducing the risk of breakage of the internal wiring of the bending portion 103 due to excessive stress. Furthermore, the design of the above formula L=π(D2+kh)+2((D1) / 2-D2), where k is greater than 0 and less than 1, also makes the adjustable range of the distance L between the first back plate 121 and the second back plate 122 larger.

[0048] It should be noted that, Figure 1 The manufacturing process of the first back panel 121 and the second back panel 122 shown includes, after bonding the flexible display panel 10 in a flattened state to the initial back panel (not shown) with an adhesive layer, grooving the initial back panel and the adhesive layer to obtain... Figure 4The initial groove 123a shown is followed by two initial back plates: a first back plate 121 and a second back plate 122, which are coplanar and spaced apart. Next, the portion of the flexible display panel 10 in its flattened state that overlaps with the initial groove 123a is bent. After forming the bent portion 103, the initial groove 123a is transformed into the groove 123. Therefore, by adjusting the size of the initial groove 123a, i.e., adjusting the distance L between the first back plate 121 and the second back plate 122, the shape of the bent portion 103 of the flexible display panel 10 can be adjusted.

[0049] It should also be noted that in related technologies, to ensure that the curved portion is semi-circular, a small groove needs to be prepared on the initial back plate. Correspondingly, the distance between the first back plate and the second back plate is small. However, preparing a small groove on the initial back plate increases the difficulty of die-cutting the initial back plate. In this application, to ensure that the cross-section of the curved portion 103 along the second direction y is semi-elliptical or approximately semi-elliptical, the design value of the distance L between the first back plate 121 and the second back plate 122 is larger, which can improve the problem of the high difficulty in die-cutting the initial back plate in related technologies.

[0050] In this embodiment, k is greater than or equal to 0.2 and less than or equal to 0.8, so that the neutral surface of the curved portion 103 of the flexible display panel 10 is closer to the middle position between the inner curved surface 103a and the outer curved surface 103b, thereby reducing the stress on the middle portion between the inner curved surface 103a and the outer curved surface 103b.

[0051] For example, k can be 0.1, 0.2, 0.3, 0.4, 0.5, 0.7, 0.8, 0.9, or 0.95.

[0052] Specifically, k = 0.5, so that the neutral surface of the curved portion 103 of the flexible display panel 10 is located in the middle position between the inner curved surface 103a and the outer curved surface 103b, thereby reducing the stress on the middle portion of the curved portion 103 of the flexible display panel 10 located between the inner curved surface 103a and the outer curved surface 103b.

[0053] In this embodiment, D1 and D2 also satisfy the following formula: 0.7 ≤ D2 / ((D1) / 2). Due to this design, when the second end face 122a of the second back plate 122 is misaligned with the first end face 121a of the first back plate 121, it helps to reduce the stress on either the second end face 122a of the second back plate 122 or the first end face 121a of the first back plate 121 compared to the stress at the vertex P of the inner curved surface. This reduces the stress on the second end face 122a of the second back plate 122 and the first end face 121a of the first back plate 121, thereby reducing the risk of collapse of the second back plate 122 or the first back plate 121 due to excessive stress.

[0054] In this embodiment, 0.85≤D2 / ((D1) / 2)≤0.95, so as to further reduce the size of the lower bezel of the display module 100, and at the same time, when the second end face 122a of the second back plate 122 is misaligned with the first end face 121a of the first back plate 121, the stress on the second end face 122a of the second back plate 122 and the first end face 121a of the first back plate 121 is further reduced.

[0055] For example, the value of D2 / ((D1) / 2) can be 0.7, 0.75, 0.8, 0.85, 0.9 or 0.95.

[0056] In this embodiment, please refer to Figure 1 As shown, the display module 100 also includes a protective layer 14. Part of the protective layer 14 is located on the outer curved surface 103b of the curved portion 103 facing away from the inner curved surface 103a, and the opposite ends of the protective layer 14 are located on the first straight portion 101 and the second straight portion 102, respectively, to protect the curved portion 103. The material of the protective layer 14 includes a UV-curable adhesive.

[0057] In the extending direction of the protective layer 14, the protective layer 14 has a first region 14a and a second region 14b disposed adjacent to each other. The thickness of the protective layer 14 in the first region 14a is gradually changing. The thickness of the protective layer 14 in the second region 14b is constant; in other words, the thickness of the protective layer 14 in the second region 14b is the same or substantially the same at all points. The minimum thickness of the protective layer 14 in the first region 14a is greater than the thickness of the protective layer 14 in the second region 14b. The first region 14a overlaps with the bending start point A and / or the bending end point B. With this design, the protective layer 14 is thicker at the locations where it overlaps with the bending start point A and / or the bending end point B, increasing the stiffness of the bent portion 103 of the flexible display panel 10 at the bending start point A and / or the bending end point B, thereby reducing the stress at the bending start point A and / or the bending end point B.

[0058] In addition, in the extending direction of the protective layer 14, at least one of the second end face 122a of the second back plate 122 and the first end face 121a of the first back plate 121 overlaps with the first region 14a to reduce the stress on at least one of the second end face 122a of the second back plate 122 and the first end face 121a of the first back plate 121.

[0059] Specifically, such as Figure 1As shown, the protective layer 14 located in the first region 14a includes a first portion and a second portion. The first portion is located on a first straight portion 101 of the non-display area 100b, and the second portion is located in the curved area 100b1 and connected to the first portion. In the first region 14a, and along the direction extending from one end of the protective layer 14 located on the first straight portion 101 to one end of the protective layer 14 located on the second straight portion 102, the thickness of the protective layer 14 decreases. The protective layer 14 located in the second region 14b includes a third portion, which is located in the curved area 100b1 and connected to the second portion. In the second region 14b, the thickness of the protective layer 14 remains constant, and correspondingly, the thickness of the third portion remains constant.

[0060] In this embodiment, the first region 14a overlaps with the bending start point A and the first end face 121a of the first back plate 121, increasing the stiffness of the bent portion 103 of the flexible display panel 10 at the bending start point A, thereby reducing the stress at the bending start point A and reducing the stress on the first end face 121a of the first back plate 121.

[0061] In other embodiments, in the extending direction of the protective layer 14, the first region 14a may overlap with the bending endpoint B and the second end face 122a of the second back plate 122, or the first region 14a may overlap with the bending start point A, the bending endpoint B, the second end face 122a and the first end face 121a.

[0062] In this embodiment, the maximum thickness of the protective layer 14 in the first region 14a is greater than or equal to 120 micrometers and less than or equal to 160 micrometers. This increases the stiffness of the portion where the flexible display panel 10 overlaps with the first region 14a while ensuring the flexibility of the protective layer 14 in the first region 14a. When the maximum thickness of the protective layer 14 is less than 120 micrometers, it is difficult to ensure sufficient stiffness in the portion where the flexible display panel 10 overlaps with the first region 14a. When the maximum thickness of the protective layer 14 is greater than 160 micrometers, the flexibility of the protective layer 14 decreases.

[0063] The protective layer 14 has a thickness greater than or equal to 60 micrometers and less than or equal to 80 micrometers in the second region 14b, so that the protective layer 14 has good flexibility.

[0064] For example, the maximum thickness of the protective layer 14 in the first region 14a is 120 micrometers, 130 micrometers, 140 micrometers, 150 micrometers, or 160 micrometers. The thickness of the protective layer 14 in the second region 14b is 60 micrometers, 70 micrometers, or 80 micrometers.

[0065] Please refer to Figure 1As shown, the display module 100 also includes a functional layer 15. The functional layer 15 is located on the side of the first flat portion 101 away from the second flat portion 102. The functional layer 15 is fixed to the light-emitting surface 101a of the first flat portion 101 by an adhesive layer, and the functional layer 15 is in contact with one end of the protective layer 14 located on the first flat portion 101.

[0066] The functional layer 15 includes at least one of a polarizer and a protective film. The material of the protective film includes, but is not limited to, polyethylene terephthalate. Specifically, the functional layer 15 includes a polarizer.

[0067] In this embodiment, the distance D3 between the third end face 15a of the functional layer 15 in contact with the protective layer 14 in the first direction x and the first end face 121a of the bending start point A and the first back plate 121 is smaller than the size of the first region 14a in the extension direction of the protective layer 14, so as to ensure that the first region 14a of the protective layer 14 overlaps with the bending start point A and the first end face 121a of the first back plate 121 in the extension direction of the protective layer 14.

[0068] Specifically, the dimension of the first region 14a in the extension direction of the protective layer 14 is greater than or equal to 250 micrometers and less than or equal to 500 micrometers.

[0069] Please refer to Figure 4 As shown, Figure 1 The manufacturing process of the protective layer 14 shown includes applying an initial adhesive layer (not shown) to the flexible display panel 10 in a flattened state. The initial adhesive layer is located on the surface of the flexible display panel 10 in the flattened state away from the second back plate 122. The initial adhesive layer is in contact with the functional layer 15. After the initial adhesive layer is irradiated with ultraviolet light, an initial protective layer 141 is obtained. The initial protective layer 141 is bent to become Figure 1 Protective layer 14 is shown.

[0070] Before the initial adhesive layer is irradiated with ultraviolet light, due to the interaction force between the initial adhesive layer and the functional layer 15, the thickness of the initial adhesive layer decreases within a distance d1 from the third end face 15a, and the initial adhesive layer is thicker closer to the third end face 15a. Within a distance greater than d1 and less than or equal to d1+d2 from the third end face 15a, the thickness of the initial adhesive layer is the same.

[0071] After the initial adhesive layer is irradiated with ultraviolet light, it cures to form an initial protective layer 141. Within a distance d1 from the third end face 15a, the thickness of the initial protective layer 141 decreases, with a greater thickness closer to the third end face 15a. Within a distance greater than d1 and less than or equal to d1+d2 from the third end face 15a, the thickness of the initial protective layer 141 remains constant. After the initial protective layer 141 is bent into a protective layer 14, in the first region 14a, the thickness of the protective layer 14 decreases from the direction closer to the third end face 15a to the direction farther away from the third end face 15a.

[0072] Wherein, d1 is greater than or equal to 250 micrometers and less than or equal to 500 micrometers. By controlling the distance D3 between the third end face 15a of the functional layer 15 and the first end face 121a of the first back plate 121, the thickness gradient region of the protective layer 14 can overlap with the bending region 100b1, thereby making the first region 14a of the protective layer 14 overlap with the bending start point A and the first end face 121a of the first back plate 121, improving the stiffness of the flexible display panel at the bending start point A and reducing the stress on the bending start point A and the first end face 121a of the first back plate 121.

[0073] In this embodiment, the display module 100 further includes a support component 20, which is disposed between the first back plate 121 and the second back plate 122. The support component 20 includes, but is not limited to, at least one of a rigid support layer and a buffer layer.

[0074] Specifically, such as Figure 1 As shown, the support assembly 20 includes a rigid support layer 201, which is fixed to the surface of the first back plate 121 away from the first flat portion 101 by an adhesive layer. The material of the rigid support layer 201 includes metal, including but not limited to steel.

[0075] In other embodiments, the display module 100 may also exclude support components 20 such as rigid support layers and buffer layers.

[0076] In this embodiment, the display module 100 further includes a first adhesive layer 221, which adheres to the rigid support layer 201 and the second back plate 122 to fix the second back plate 122 onto the rigid support layer 201.

[0077] In this embodiment, when the functional layer 15 is a polarizer, the display module 100 also includes a protective cover plate 18, which is fixed to the side of the functional layer 15 away from the light-emitting surface 101a by an adhesive layer.

[0078] It should be noted that when the functional layer 15 is a protective film, the display module 100 does not include the protective cover plate 18.

[0079] Please refer to Figure 1 As shown, the display module 100 also includes a second adhesive layer 222. The second adhesive layer 222 is located between the second straight portion 102 and the second back plate 122, and bonds the second straight portion 102 and the second back plate 122.

[0080] The display module 100 also includes a third adhesive layer 223. The third adhesive layer 223 is located between the rigid support layer 201 and the first back plate 121, and bonds the rigid support layer 201 and the first back plate 121.

[0081] The display module 100 also includes a fourth adhesive layer 224. The fourth adhesive layer 224 is located between the first back plate 121 and the first flat portion 101, and bonds the first back plate 121 and the first flat portion 101. The fourth adhesive layer 224 has the same thickness as the second adhesive layer 222.

[0082] The materials of the second adhesive layer 222, the third adhesive layer 223, and the fourth adhesive layer 224 include, but are not limited to, pressure-sensitive adhesives.

[0083] In this embodiment, the display module 100 further includes a fifth adhesive layer 225. The fifth adhesive layer 225 is located between the functional layer 15 and the first flat portion 101, and bonds the functional layer 15 to the first flat portion 101.

[0084] In this embodiment, the display module 100 further includes a sixth adhesive layer 226. The sixth adhesive layer 226 is located between the functional layer 15 and the protective cover plate 18.

[0085] The materials of the fifth adhesive layer 225 and the sixth adhesive layer 226 include, but are not limited to, optical adhesives.

[0086] It should be noted that the distance D1 between the bending start point A and the bending end point B is also equal to the thickness of the module stack located between the second straight portion 102 and the first straight portion 101. For example, the distance D1 is equal to the sum of the thicknesses of the fourth adhesive layer 224, the first back plate 121, the third adhesive layer 223, the rigid support layer 201, the first adhesive layer 221, the second back plate 122, and the second adhesive layer 222.

[0087] Please refer to Figures 5 to 8 As shown, this is an experimental test diagram of the stress on the traces of the source and drain metal layers in the flexible display panel at different positions under different conditions, with the second back plate and the first back plate of the display module aligned, misaligned to the left, and misaligned to the right.

[0088] in, Figure 5Experimental test diagram for a flexible display panel with a semi-circular curved section and a bending radius of 0.23 mm. Figure 6 Experimental test diagram for a flexible display panel with a semi-circular curved section and a bending radius of 0.17 mm. Figure 7 The curved portion of the flexible display panel is Figure 1 The experimental test diagram shows a semi-elliptical arc with (D1) / 2 of 0.23 mm and D2 of 0.17 mm. Figure 8 The curved portion of the flexible display panel is Figure 1 The experimental test diagram shows a semi-elliptical arc with (D1) / 2 of 0.20 mm and D2 of 0.17 mm.

[0089] in addition, Figures 5 to 8 In the diagram, line 1 represents the stress curve under left misalignment, line 2 represents the stress curve under alignment, and line 3 represents the stress curve under right misalignment. Dashed line 4 corresponds to the starting point of the bending of the source / drain metal layer, which corresponds to and overlaps with the bending start point A. Dashed line 5 corresponds to the ending point of the bending of the source / drain metal layer, which corresponds to the bending end point B. Point a represents the stress of the source / drain metal layer at the starting point of its bending. Point b represents the stress of the source / drain metal layer at the bending vertex, which corresponds to and overlaps with the bending vertex P.

[0090] Under alignment conditions, the second end face of the second back plate near the bend is aligned with the first end face of the first back plate near the bend, as detailed in the following reference. Figure 1 The positional relationship between the second backplate and the first backplate is shown. Under the left misalignment condition, the second end face of the second backplate near the bend is located on the side of the first end face of the first backplate away from the bend, and the distance between the second end face and the first end face in the first direction x is 160 micrometers. (See reference for details.) Figure 2 The positional relationship between the second backplate and the first backplate is shown. Under the right misalignment condition, the second end face of the second backplate near the bend is located on the side of the first end face of the first backplate near the bend, and the distance between the second end face and the first end face in the first direction x is 160 micrometers. (See reference for details.) Figure 3 The positional relationship between the second backplate and the first backplate is shown.

[0091] Please refer to Table 1 below, which shows the experimental test results of the maximum stress on the traces of the source and drain metal layers in the flexible display panel at the starting position and the apex position of the bend under the conditions of alignment, left misalignment and right misalignment of the second back plate and the first back plate of the display module.

[0092] Table 1

[0093]

[0094] As shown in Table 1, when the curved portion of the flexible display panel in the display module is semi-circular, directly reducing the bending radius of the curved portion of the flexible display panel from 0.23 mm to 0.17 mm, thereby reducing the bottom bezel of the display module by 0.06 mm, will cause the maximum stress on the traces of the source and drain metal layers in the flexible display panel at the bending apex to increase by 45.9%. Furthermore, since the thickness of the module stack beneath the flexible display panel is twice the bending radius when the curved portion is semi-circular, directly reducing the bending radius of the curved portion of the flexible display panel from 0.23 mm to 0.17 mm will require a 0.12 mm reduction in the thickness of the module stack beneath the flexible display panel, thus significantly reducing the mechanical properties of the display module.

[0095] In this application, the curved portion is semi-elliptical arc, (D1) / 2 is 0.23 mm and D2 is 0.17 mm. The lower bezel of the display module is reduced by 0.06 mm, which can ensure that the thickness of the display module does not need to be thinned, thereby ensuring the mechanical performance of the display module. Moreover, the maximum stress on the traces of the source and drain metal layers in the flexible display panel at the bending apex only increases by 6.1%.

[0096] Furthermore, in this application, when the curved portion is a semi-elliptical arc with (D1) / 2 of 0.20 mm and D2 of 0.17 mm, the thickness of the display module is reduced by 0.06 mm, which makes the mechanical properties of the display module basically unchanged or slightly reduced. It also reduces the bottom bezel of the display module by 0.06 mm, and the maximum stress on the traces of the source and drain metal layers in the flexible display panel at the bending apex only increases by 17.5%.

[0097] In addition, in conjunction with Table 1, Figures 4 to 8 It can be seen that when the bend is a semi-elliptical arc, with (D1) / 2 being 0.23 mm and D2 being 0.17 mm, and with (D1) / 2 being 0.20 mm and D2 being 0.17 mm, the maximum stress at the bend apex of the source / drain metal layer is significantly less than the maximum stress at the bend apex of the source / drain metal layer when the bend is a semi-circular arc and the bend radius is 0.17 mm.

[0098] Therefore, the design of the display module in this application reduces the size of the bottom bezel of the display module while maintaining or slightly reducing the thickness of the display module, thereby ensuring the mechanical properties of the display module and improving the problem of high stress on the bending part of the flexible display panel of the display module.

[0099] In addition, combined Figure 7 and Figure 8It is understood that, in this application, when the curved part is a semi-elliptical arc, the stress at the start of the bend, the apex of the bend, and the end of the bend is relatively small under the alignment condition compared with the conditions of left misalignment and right misalignment.

[0100] Furthermore, as mentioned above, for the problem that the stress at the start and end of bending is relatively large under left and right misalignment conditions, this application reduces the stress at the start and end of bending under left and right misalignment conditions by having the first region 14a of the protective layer 14 overlap with the bending start point A and / or bending end point B, and by using 0.7≤D2 / ((D1) / 2).

[0101] It should be noted that left misalignment and right misalignment are phenomena that may be caused by certain actual process deviations. This application proposes the design of the above embodiments while taking into account both the alignment conditions without process deviations and the forces under the conditions of left or right misalignment with process deviations.

[0102] In summary, in this application, regardless of whether the lower bezel of the display module is aligned, misaligned to the left, or misaligned to the right, the thickness of the display module is not reduced or only slightly reduced while the lower bezel of the display module is narrowed, thereby ensuring the mechanical performance of the display module. Furthermore, the bending portion of the flexible display panel of the display module experiences less stress at the beginning and end of the bending.

[0103] The above description of the embodiments is only for the purpose of helping to understand the technical solutions and core ideas of this application; those skilled in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A display module, characterized by include: Flexible display panels, including: The first straight section has a light-emitting surface; The second straight section is located on the back side of the light-emitting surface of the first straight section; and A curved section connects the first straight section and the second straight section. The inner curved surface of the curved section is connected to the back side of the light-emitting surface of the first straight section. The inner curved surface includes a bending start point and a bending end point. The bending start point is located at the connection between the curved section and the first straight section, and the bending end point is located at the connection between the curved section and the second straight section. The distance between the bending start point and the bending end point is D1, and the distance from the midpoint of the line connecting the bending start point and the bending end point to the vertex of the inner curved surface is D2. Wherein, D1 and D2 satisfy the following formula: D2 < (D1) / 2, 0.7 ≤ D2 / ((D1) / 2).

2. The display module of claim 1, wherein, D1 and D2 also satisfy the following formula: 0.85≤D2 / ((D1) / 2)≤0.

95.

3. The display module of claim 1, wherein, The display module further includes a back panel, and the flexible display panel is located on the back panel. The back panel includes: The first back plate is connected to the first straight portion; The second back plate is connected to the second straight portion; and The groove overlaps with the curved portion; When the flexible display panel is in a flattened state, the back plate is also in a flattened state. The surfaces of the first back plate and the second back plate near the flexible display panel in the flattened state are located on the same plane, and this plane is perpendicular to the thickness direction of the flexible display panel. The distance L between the first and second back plates in the flattened state satisfies the following formula: L = π(D2 + kh) + 2((D1) / 2 - D2), where k is greater than 0 and less than 1, and h is the thickness of the flexible display panel.

4. The display module of claim 3, wherein, The value of k is greater than or equal to 0.2 and less than or equal to 0.

8.

5. The display module of claim 1, wherein, The display module also includes: A protective layer, a portion of which is located on the outer curved surface of the curved portion facing away from the inner curved surface, and the opposite ends of the protective layer are located on the first straight portion and the second straight portion, respectively; In the extension direction of the protective layer, the protective layer has adjacent first and second regions, the thickness of the protective layer in the first region is gradually changing, the thickness of the protective layer in the second region is constant, the minimum thickness of the protective layer in the first region is greater than the thickness of the protective layer in the second region, and the first region overlaps with the bending start point and / or the bending end point.

6. The display module of claim 5, wherein, The display module also includes: A functional layer is located on the side of the first flat portion away from the second flat portion. The functional layer and the protective layer are in contact at one end on the first flat portion. The distance between the end face of the functional layer and the protective layer in contact with the bending start point in the direction intersecting the thickness direction of the first flat portion is smaller than the size of the first region in the extension direction of the protective layer.

7. The display module of claim 5, wherein, The first region has a dimension greater than or equal to 250 micrometers and less than or equal to 500 micrometers in the direction of extension of the protective layer.

8. The display module of claim 5, wherein, The maximum thickness of the protective layer in the first region is greater than or equal to 120 micrometers and less than or equal to 160 micrometers.

9. The display module of claim 1, wherein, The curved portion includes an elliptical arc surface.

10. The display module of claim 1, wherein, In the direction in which the inner curved surface extends from the starting point of the bend to the ending point of the bend, the distance between the points in the region between the starting point of the bend and the vertex of the inner curved surface and the midpoint decreases, while the distance between the points in the region between the vertex of the inner curved surface and the ending point of the bend and the midpoint increases.

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