Folding display module and display device

Abstract

According to the folding display module and the display device, the buffer layer is arranged between the back supporting layer and the metal layer, the buffer layer comprises the first adhesive layer making contact with the metal layer, and the first adhesive layer is provided with the at least one opening part, so that the integrity of the back supporting layer, the buffer layer and the metal layer is guaranteed; the module centroid is reduced, and the defect that in the prior art, bending and anti-arching are prone to being generated by sectional glue can be effectively improved; at least one opening part is at least partially overlapped with the through hole penetrating through the side surface of the metal layer, so that a closed space formed by the whole-surface adhesive design and an adhesive tape subsequently attached to the back surface of the metal layer in a folding area can be effectively avoided; and the influence on the yield of the module due to the appearance deformation of the adhesive tape and the bad impression on the front surface of the module caused by the volume change of gas in a closed space in a module production defoaming process and a reliability test high-temperature and high-humidity environment is avoided.

Description

Technical Field

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

[0002] Foldable display modules, made of flexible materials, are deformable and bendable display devices. Typically, a buffer layer is placed between the back support layer and the metal layer (usually made of SUS, titanium alloy, or carbon fiber). This buffer layer consists of PET or PI with adhesive on both sides, appearing black and providing light-blocking and cushioning functions. Currently, the adhesive surface in contact with the back support layer in the buffer layer structure is generally designed as a single layer of adhesive, while the adhesive surface in contact with the metal layer has two designs: a single layer of adhesive and a segmented adhesive design. A single layer of adhesive creates a sealed space in the folding area with the tape subsequently applied to the back of the metal layer. During the degassing process in foldable display module production and the high-temperature, high-humidity environment of reliability testing, the gas volume in this sealed space changes, causing deformation of the tape and poor imprinting on the front of the module, affecting module yield. A segmented adhesive design effectively avoids the defects caused by a sealed space formed by a single layer of adhesive; however, when the user's overall hinge bending axis is close to or below the centroid of the foldable display module, the segmented adhesive design is more likely to cause the screen to arch during bending.

[0003] To address the problems caused by the aforementioned full-surface adhesive design and segmented adhesive design, this application proposes a foldable display module and display device that can effectively solve these problems. Summary of the Invention

[0004] This application provides a foldable display module and display device, which can solve the technical problems that the prior art cannot simultaneously solve the problems of poor printing on the front of the module and screen arching during the bending process.

[0005] This application provides a foldable display module, including a foldable area and a first non-foldable area and a second non-foldable area located on both sides of the foldable area;

[0006] The foldable display module also includes:

[0007] The display panel and the back support layer, buffer layer, and metal layer sequentially disposed on the backlight side of the display panel;

[0008] The buffer layer includes a first adhesive layer that contacts the metal layer, the first adhesive layer including at least one opening in the folded area;

[0009] The metal layer includes a plurality of through holes located in the folded region, the plurality of through holes including at least one first through hole, the at least one first through hole penetrating the side of the metal layer, and the projection of the at least one opening portion on the metal layer at least partially overlaps with the at least one first through hole.

[0010] According to the foldable display module provided in this application, the folding area includes a folding center line, the size of the at least one opening portion in the direction of the folding center line is smaller than the size of the first adhesive layer in the direction of the folding center line, and the size of the at least one opening portion in the direction perpendicular to the folding center line is smaller than the size of the first adhesive layer in the direction perpendicular to the folding center line.

[0011] According to the foldable display module provided in this application, the plurality of through holes includes a plurality of first through holes, the minimum distance between the end of the plurality of first through holes away from the side of the metal layer and the side of the metal layer is a first distance, the opening portion of the at least one opening portion near the side of the metal layer includes an opening edge near the side of the buffer layer, the distance from the opening edge to the side of the buffer layer is a second distance, and the second distance is less than the first distance.

[0012] According to the folding display module provided in this application, the at least one opening portion includes a plurality of opening portions spaced apart, wherein the projection of the opening portion near the side of the buffer layer on the metal layer at least partially overlaps with at least one of the first through holes.

[0013] According to the folding display module provided in this application, the opening near the side of the buffer layer in the plurality of openings penetrates the side of the first adhesive layer, and a non-opening portion is provided between every two openings.

[0014] According to the folding display module provided in this application, the at least one opening portion includes a plurality of opening portions spaced apart, and a non-opening portion is provided between every two opening portions. The plurality of through holes also includes a plurality of second through holes, the second through holes not penetrating the side of the metal layer. The projection of the opening portion near the side of the buffer layer on the metal layer of the plurality of opening portions at least partially overlaps with each first through hole. The non-opening portion covers at least a portion of the second through hole, and the second through hole covered by the non-opening portion does not at least partially overlap with the corresponding non-opening portion.

[0015] According to the foldable display module provided in this application, the plurality of through holes further includes a plurality of second through holes, the second through holes do not penetrate the side of the metal layer, the second through holes are symmetrically arranged about the folding center line, the distance between the two opposite edges of the two second through holes that are farthest from the folding center line and are symmetrically arranged is a third distance; the maximum width of the at least one opening portion in the direction perpendicular to the folding center line is a first width, and the third distance is less than the first width.

[0016] According to the folding display module provided in this application, the at least one opening portion is symmetrically arranged along the folding center line and a vertical center line perpendicular to the folding center line.

[0017] According to the folding display module provided in this application, the non-opening portion is symmetrically arranged along the folding center line and the vertical center line perpendicular to the folding center line.

[0018] According to the foldable display module provided in this application, the buffer layer further includes a second adhesive layer near the back support layer and a substrate layer located between the first adhesive layer and the second adhesive layer. The second adhesive layer is continuously disposed across the entire surface, and the substrate layer is at least one of polyethylene terephthalate and polyimide.

[0019] According to the foldable display module provided in this application, the buffer layer includes only the first adhesive layer, and the first adhesive layer is a black adhesive layer.

[0020] According to the folding display module provided in this application, an adhesive tape is provided on the side of the metal layer away from the first adhesive layer, and the projection of the plurality of through holes on the adhesive tape is located within the range of the adhesive tape.

[0021] This application provides a display device including the above-described foldable display module.

[0022] Beneficial effects:

[0023] In the foldable display module and display device provided in this application embodiment, by providing at least one opening in the first adhesive layer of the folding area, external air is allowed to communicate with the first adhesive layer located in the buffer layer through the at least one first through hole penetrating the side of the metal layer. This avoids the entire adhesive layer design from forming a sealed space in the folding area with the tape subsequently bonded to the back of the metal layer. This prevents tape deformation and poor imprints on the front of the module caused by gas volume changes in the sealed space during the degassing process of module production and high temperature and humidity environment during reliability testing, thus affecting the module yield. At the same time, the projection of the first adhesive layer on the metal layer overlaps with at least one of the first through holes. Unlike the traditional segmented adhesive design, this module has adhesive connections on both sides of the opening. This design ensures the integrity of the back support layer, buffer layer and metal layer, lowers the module centroid, and can effectively improve the bending and arching defects that are easily caused by segmented adhesive. Attached Figure Description

[0024] The accompanying drawings, which are incorporated herein and form part of the specification, illustrate embodiments of the invention and, together with the specification, further serve to explain the principles of the invention and enable those skilled in the art to practice and use the invention.

[0025] Figure 1 This is a schematic diagram of the planar structure of the foldable display module;

[0026] Figure 2 A schematic diagram of at least one opening in the folding area of ​​the buffer layer of a foldable display module;

[0027] Figure 3 A schematic diagram showing multiple openings spaced apart in the buffer layer of a foldable display module;

[0028] Figure 4 A schematic diagram of the opening portion of the buffer layer of the foldable display module;

[0029] Figure 5 for Figure 4 A magnified design diagram of region A in the diagram. 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] In the description of this application, it should be understood that the terms "length," "width," "thickness," "upper," "lower," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are used only for the convenience of describing this application and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified.

[0032] In this application, unless otherwise expressly specified and limited, the term "above" or "below" a second feature may include direct contact between the first and second features, or contact between the first and second features not in direct contact but through another feature between them.

[0033] Optionally, some embodiments of this application provide a foldable display module and display device. (See reference) Figure 3 The foldable display module includes a foldable area and non-foldable areas located on both sides of the foldable area (not marked in the figure). For example... Figure 1 As shown, the foldable display module also includes a display panel and a back support layer 1, a buffer layer 3, and a metal layer 4 sequentially disposed on the backlight side of the display panel. Figure 2As shown, the buffer layer 3 includes a first adhesive layer 6 that contacts the metal layer 4. The first adhesive layer 6 includes at least one opening 11 located in the folding area, which can be cut using a die-cutting method. The thickness of the first adhesive layer 6 is set to 15 μm. The buffer layer 3 also includes a second adhesive layer 2 that contacts the back support layer 1. The second adhesive layer 2 is continuously disposed across the entire surface without any openings. Between the first adhesive layer 6 and the second adhesive layer 2 of the buffer layer 3 is a base material 13, which is at least one of polyethylene terephthalate and polyimide. The thickness of the second adhesive layer is set to 25 μm. This adhesive layer design balances the thinness of the module with the ability to achieve folding functionality. (Reference) Figure 1 The metal layer 4 is provided with an adhesive tape 5 on the side away from the first adhesive layer. The projection of the plurality of through holes on the adhesive tape 5 is located within the range of the adhesive tape 5. The design of the adhesive tape can not only prevent water and oxygen from entering the display module through the through holes and causing abnormal display effect, but also make the stress release of the module more uniform when it is bent by completely covering the through holes, thus preventing warping.

[0034] It should be noted that in some embodiments, the buffer layer 3 only includes the first adhesive layer 6, and the first adhesive layer 6 is a black adhesive layer, thereby achieving the buffering and light-blocking function through the black adhesive layer; in other embodiments, the buffer layer may also include other structures, which are not specifically limited in this application.

[0035] refer to Figure 2 , Figure 4 and Figure 5 The metal layer 4 includes multiple through holes located in the folded area. Each through hole includes at least one first through hole 9, which penetrates the side of the metal layer 4, allowing it to communicate with the outside. The projection of the first adhesive layer 6 onto the metal layer 4 partially overlaps with the projection of the first through hole 9. This allows air within the buffer layer 3 to flow directly to the outside through the first through hole without being blocked by the adhesive overlapping the through hole, thus avoiding the problems associated with traditional full-surface adhesive designs that would affect subsequent bonding. Figure 1The tape 5 forms a sealed space in the folding area, which causes deformation of the tape appearance and poor imprint on the front of the module due to changes in the gas volume in the sealed space during the degassing process of the production assembly and the high temperature and high humidity environment of the reliability test, affecting the module yield. The folding area includes a folding center line 7. The size of at least one opening 11 in the direction of the folding center 7 is smaller than the size of the first adhesive layer 6 in the direction of the folding center line 7, and the size of at least one opening 11 in the direction perpendicular to the folding center line 7 is smaller than the size of the first adhesive layer 6 in the direction perpendicular to the folding center line 7. That is, the first adhesive layer 6 has adhesive connections on both sides of at least one opening 11. This not only ensures that the buffer layer 3 and the metal layer 4 can be bonded together through the first adhesive layer 6, but also, unlike the traditional segmented adhesive design, since there are adhesive connections on both sides of at least one opening 11, the metal layer 4 and the tape 5 in the folding area are provided with corresponding stress by the adhesive, ensuring the integrity of the whole and preventing the arching phenomenon when bending.

[0036] refer to Figure 2 The plurality of through holes includes a plurality of first through holes 9. The minimum distance between the end of the plurality of first through holes 9 away from the side of the metal layer 4 and the side of the metal layer 4 is a first distance D. The opening portion 11 of the at least one opening portion 11 near the side of the metal layer 4 includes an opening edge near the side of the buffer layer 3. The distance from the opening edge to the side of the buffer layer 3 is a second distance d. The second distance d is less than the first distance D, that is, d < D. Considering material cutting tolerances and equipment bonding tolerances, the Dd difference is set to 300mm in this embodiment. This ensures that the projection of the at least one opening portion 11 on the metal layer 4 at least partially overlaps with the at least one first through hole 9, so that the at least one first through hole 9 is not completely covered by the first adhesive layer 6. The at least one opening portion 11 is connected to the outside through the first through hole, so that the gas between the first adhesive layer 6 and the tape 5 can be connected to the outside under the design of the at least one opening portion 11 and the first through hole 9 to avoid the buffer layer 3 forming a sealed space with the metal layer 4 and the tape 5 on the back of the metal layer 4 after bonding, thus ensuring the breathability of the folding display module in the folding area.

[0037] Optionally, in some embodiments, reference is made to Figure 3 The opening of the first adhesive layer 6 is not limited to one, but also includes multiple openings 11 spaced apart. The openings 11 near the side of the buffer layer 3 penetrate the side of the first adhesive layer 6, so that the openings 11 of the first adhesive layer 6 in the buffer layer 3 are connected to the outside, so as to avoid the buffer layer 3 forming a sealed space with the metal layer 4 and the adhesive tape 5 on the back of the metal layer 4 after being attached, thus ensuring the breathability of the folding display module in the folding area. A non-opening part 12 is provided between every two openings 11. This design not only ensures breathability, but also makes the bonding effect better and can better meet the stress requirements when bending.

[0038] In some embodiments, at least one opening portion 11 includes a plurality of opening portions 11 spaced apart, with a non-opening portion 12 disposed between every two opening portions 11. The plurality of through holes also includes a plurality of second through holes 10, the second through holes 10 not penetrating the side surface of the metal layer 4. Figure 3 As shown, unlike the previous embodiment, the projection of the opening portion 11 near the side of the buffer layer 3 on the metal layer 4 at least partially overlaps with each of the first through holes 9, that is, there is no adhesive covering the at least one first through hole 9, while there is adhesive covering the multiple second through holes 10. The second through hole 10 covered by the non-opening portion 12 does not overlap with the corresponding non-opening portion 12 at least partially. This ensures that the adhesive of the non-opening portion 12 of the first adhesive layer 6 will not completely cover the multiple second through holes 10. The spacing of the multiple opening portions 11 can make the adhesion between the buffer layer 3 and the metal layer 4 better, and will not produce peeling when the module is bent, thus preventing the arching phenomenon.

[0039] refer to Figure 2 The second through hole is symmetrically arranged about the folding center line 7. The distance between the two opposite edges of the two second through holes 10 that are farthest from the folding center line 7 and symmetrically arranged is the third distance H. The maximum width of the at least one opening portion 11 in the direction perpendicular to the folding center line 7 (the direction shown by the vertical center line 8 in the figure) is the first width h. The third distance H is less than the first width h, that is, h>H. Considering the material cutting tolerance and the equipment bonding tolerance, the hH difference is set to 600μm in this embodiment (300μm on one side, 600μm on both sides). After setting h>H, since the projection of the non-opening part of the first adhesive layer on the metal layer 4 will not completely overlap with the first through hole 9 and the second through hole 10, the at least first through hole and the second through hole corresponding to the opening portion will not be completely covered by the first adhesive layer. This makes the opening portion of the first adhesive layer in the buffer layer 3 connected to the outside, so as to avoid the buffer layer 3 forming a sealed space with the metal layer 4 and the tape 5 after bonding, and to ensure the air permeability of the folding display module in the folding area.

[0040] refer to Figure 2 The at least one open portion 11 is symmetrically arranged along the folding center line 7 and the vertical center line 8 perpendicular to the folding center line; the non-open portion 12 is symmetrically arranged along the folding center line 7 and the vertical center line 8 perpendicular to the folding center line 7. This design of open and non-open portions facilitates more uniform stress release when the display module is folded, preventing warping.

[0041] To address the aforementioned problems, the present invention provides a foldable display device, comprising: the foldable display module described in the present invention.

[0042] In some embodiments, the foldable display module includes a foldable region and a first non-foldable region and a second non-foldable region located on both sides of the foldable region, and the foldable display module further includes:

[0043] The display panel and the back support layer 1, buffer layer 3, and metal layer 4 are sequentially disposed on the backlight side of the display panel;

[0044] The buffer layer 3 includes a first adhesive layer 6 that contacts the metal layer 4, and the first adhesive layer 6 includes at least one opening portion 11 located in the stacked area;

[0045] The metal layer 4 includes a plurality of through holes located in the folded area, the plurality of through holes including at least one first through hole 9, the at least one first through hole 9 penetrating the side of the metal layer 4, and the projection of at least one opening portion 11 on the metal layer 4 at least partially overlaps with the at least one first through hole 9.

[0046] In some embodiments, the folding area includes a folding center line 7, at least one opening portion 11 has a smaller dimension in the direction of the folding center line 7 than the dimension of the first adhesive layer 6 in the direction of the folding center line 7, and at least one opening portion 11 has a smaller dimension in the direction perpendicular to the folding center line 7 than the dimension of the first adhesive layer 6 in the direction perpendicular to the folding center line 7.

[0047] In the folding display device provided in this application embodiment, by providing at least one opening in the first adhesive layer of the folding area, external air can communicate with the first adhesive layer located in the buffer layer through the at least one first through hole penetrating the side of the metal layer. This avoids the entire adhesive layer design from forming a sealed space in the folding area with the tape subsequently bonded to the back of the metal layer. This prevents tape deformation and poor imprints on the front of the module caused by gas volume changes in the sealed space during the degassing process of module production and the high temperature and high humidity environment of reliability testing, which would affect the module yield. At the same time, the projection of the first adhesive layer on the metal layer overlaps with at least one of the first through holes. Unlike the traditional segmented adhesive design, this module has adhesive connecting the two sides of the opening. This design ensures the integrity of the back support layer, buffer layer and metal layer, lowers the module centroid, and can effectively improve the bending and arching defects that are easily caused by segmented adhesive.

[0048] This invention should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the invention to those skilled in the art.

[0049] Although the invention has been specifically shown and described with reference to embodiments thereof, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit or scope of the invention as defined by the appended claims.

Claims

1. A foldable display module, comprising a foldable area and a first non-foldable area and a second non-foldable area respectively located on both sides of the foldable area, characterized in that: The foldable display module comprises: A display panel and a back support layer, a buffer layer, and a metal layer sequentially arranged on a backlight side of the display panel; The buffer layer includes a first glue layer contacting the metal layer, and the first glue layer includes at least one opening portion located in the folding area; The metal layer includes a plurality of through holes located in the folding area, the plurality of through holes include at least one first through hole, the at least one first through hole passes through the side surface of the metal layer, and the projection of the at least one opening portion on the metal layer at least partially overlaps with the at least one first through hole.

2. The foldable display module according to claim 1, characterized in that: The folding area includes a folding center line, the size of the at least one opening portion in the direction of the folding center line is smaller than the size of the first adhesive layer in the direction of the folding center line, and the size of the at least one opening portion in a direction perpendicular to the folding center line is smaller than the size of the first adhesive layer in a direction perpendicular to the folding center line.

3. The foldable display module according to claim 2, characterized in that: The multiple through holes include multiple first through holes, and the minimum distance between one end of the multiple first through holes away from the side of the metal layer and the side of the metal layer is a first distance. The opening portion close to the side of the metal layer in the at least one opening portion includes an opening edge close to the side of the buffer layer, and the distance from the opening edge to the side of the buffer layer is a second distance, and the second distance is smaller than the first distance.

4. The foldable display module according to claim 3, characterized in that: The at least one opening portion includes a plurality of opening portions arranged at intervals, and a projection of an opening portion of the plurality of opening portions close to a side surface of the buffer layer on the metal layer at least partially overlaps with at least one of the first through holes.

5. The foldable display module according to claim 4, characterized in that: The opening portions close to the side surface of the buffer layer among the plurality of opening portions penetrate the side surface of the first adhesive layer, and a non-opening portion is arranged between every two of the opening portions.

6. The foldable display module according to claim 2, characterized in that: The at least one opening portion includes a plurality of opening portions arranged at intervals, a non-opening portion is arranged between every two of the opening portions, the plurality of through holes also include a plurality of second through holes, the second through holes do not penetrate the side surface of the metal layer, the projection of the opening portion close to the side surface of the buffer layer among the plurality of opening portions on the metal layer at least partially overlaps with each of the first through holes, the non-opening portion covers at least a portion of the second through hole, and the second through hole covered by the non-opening portion does not at least partially overlap with the corresponding non-opening portion.

7. The foldable display module according to claim 2, characterized in that: The multiple through holes also include multiple second through holes, which do not penetrate the side surfaces of the metal layer, and are symmetrically arranged about the folding center line. The distance between two opposite edges of two second through holes that are farthest from the folding center line and symmetrically arranged is a third distance. The maximum width of the at least one opening portion in a direction perpendicular to the folding center line is the first width, and the third distance is smaller than the first width.

8. The foldable display module according to claim 2, characterized in that: The at least one opening portion is symmetrically arranged along the folding center line and a vertical center line perpendicular to the folding center line.

9. The foldable display module according to claim 5 or 6, characterized in that: The non-opening portion is symmetrically arranged along the folding center line and a vertical center line perpendicular to the folding center line.

10. The foldable display module according to claim 1, characterized in that: The buffer layer also includes a second adhesive layer close to the back support layer and a base material layer located between the first adhesive layer and the second adhesive layer, the second adhesive layer is continuously arranged on the entire surface, and the base material layer is at least one of polyethylene terephthalate and polyimide.

11. The foldable display module according to claim 1, characterized in that: The buffer layer only includes the first glue layer, and the first glue layer is a black glue layer.

12. The foldable display module according to claim 1, characterized in that: An adhesive tape is disposed on a side of the metal layer away from the first adhesive layer, and projections of the plurality of through holes on the adhesive tape are located within a range where the adhesive tape is located.

13. A display device, characterized in that: A folding display module comprising any one of claims 1-12.

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