Foldable display device, method for manufacturing the same, and electronic device

Abstract

The present application discloses a foldable display device, a preparation method thereof, and an electronic device. The foldable display device includes: a screen body and a support structure. The screen body includes two non-bending regions and a bending region located between adjacent non-bending regions. In a flattened state, the adjacent non-bending regions are located on both sides of the bending region in a first direction; the support structure includes two sets of support components, and the two sets of support components are respectively located on both sides of the bending axis of the bending region. Each set of support components includes a first support portion and a second support portion arranged at intervals; the support structure is designed according to a predetermined empirical formula, and the empirical formula includes a first characteristic parameter and a second characteristic parameter. The first characteristic parameter includes the distance between the first support portion and the second support portion in the flattened state and / or the deflection angle of the second support portion relative to the first support portion in the folded state; the second characteristic parameter is determined according to the morphological design requirements of the screen body. According to the embodiments of the present application, it is beneficial to improve the reliability of the foldable display device.

Description

Technical Field

[0001] The present application relates to the field of display technology, and in particular to a foldable display device, a preparation method thereof, and an electronic device. Background Art

[0002] Flexible displays, with their unique form factors, such as folding, wide-angle bending, and curling, are finding increasing application. For example, foldable displays, when flattened, offer a larger display area; when folded, they are compact and portable, garnering widespread attention.

[0003] In related art, a foldable display device may include a support and a flexible screen. The flexible screen is fixed on the support. The support has mechanical strength and can support the flexible screen.

[0004] Foldable display devices are bent repeatedly during use, so the reliability of foldable display devices becomes a major challenge faced by those skilled in the art. Summary of the Invention

[0005] The embodiments of the present application provide a foldable display device and a manufacturing method thereof, and an electronic device, which are beneficial to improving the reliability of the foldable display device and the electronic device.

[0006] In a first aspect, embodiments of the present application provide a foldable display device having a flattened state and a folded state, including:

[0007] The screen body includes two non-bending areas and a bending area located between adjacent non-bending areas, wherein in a flattened state, the adjacent non-bending areas are located on both sides of the bending area in a first direction;

[0008] The support structure includes two groups of support assemblies, the two groups of support assemblies are respectively located on both sides of the bending axis of the bending zone, each group of support assemblies includes a first support portion and a second support portion arranged at intervals, at least part of the first support portion is arranged corresponding to the non-bending zone, and the second support portion is arranged on the side of the bending zone away from the bending axis;

[0009] The support structure is designed according to an established empirical formula, which includes a first characteristic parameter and a second characteristic parameter. The first characteristic parameter is a design parameter of the support structure, including at least the distance between the first support part and the second support part in the flattened state and / or the deflection angle of the second support part relative to the first support part in the folded state; the second characteristic parameter is determined according to the morphological design requirements of the screen body.

[0010] In a possible implementation of the first aspect, the first support portion includes a transition area, the transition area of the first support portion is close to the second support portion, and a surface of the first support portion in the transition area facing the screen body is an arc-shaped surface;

[0011] In the flattened state, the distance between the first support portion and the second support portion in the same set of support components in the first direction is X. The first characteristic parameter includes X, and X is determined based on X' calculated according to the established empirical formula (1), and X and X' conform to the first preset relationship:

[0012]

[0013] Wherein, the second characteristic parameters include θ, b, d, L, f0, p, R2. In the folded state, the light-emitting surface of the bending area forms a semi-elliptical cylindrical surface and two inclined surfaces located on both sides of the semi-elliptical cylindrical surface. At least part of the second support portion is correspondingly arranged with the inclined surface. θ represents the angle between the light-emitting surface of the non-bending area and the inclined surface in the folded state, b represents the semi-minor axis of the semi-elliptical cylindrical surface formed by the light-emitting surface of the bending area in the folded state, d represents half of the distance between the light-emitting surfaces of the two non-bending areas in the folded state; L represents half of the length of the bending area in the first direction, f0 represents the length of the transition area of the first support portion in the first direction, R2 represents the minimum curvature radius of the semi-elliptical cylindrical surface formed by the bending area in the folded state, and P is the correction coefficient corresponding to the minimum curvature radius; b is equal to half of the distance between the two opposite ends of the semi-elliptical cylindrical surface formed by the light-emitting surface of the bending area in the first direction in the folded state;

[0014] And / or, the deflection angle in the first characteristic parameter is determined based on θ. The second characteristic parameters include X, b, d, L, f0, p, R2. θ is determined based on θ' calculated according to the established empirical formula (2), and θ and θ' conform to the second preset relationship:

[0015]

[0016] In a possible implementation manner of the first aspect, the first preset relationship includes: X is less than or equal to (1 + 10%) X', and X is greater than or equal to (1 - 10%) X'.

[0017] In a possible implementation manner of the first aspect, the second preset relationship includes: θ is less than or equal to (1 + 10%) θ', and θ is greater than or equal to (1 - 10%) θ'.

[0018] In a possible implementation manner of the first aspect, p is greater than or equal to 1.1 and less than or equal to 1.2.

[0019] In a possible implementation manner of the first aspect, R2 conforms to the following formula:

[0020]

[0021] Wherein, a represents the semi-major axis of the semi-elliptical cylindrical surface formed by the light-emitting surface of the bending area in the folded state.

[0022] In a possible implementation manner of the first aspect, R2 is greater than or equal to 0.8b and less than or equal to 0.9b.

[0023] In a possible implementation manner of the first aspect, in the folded state, the light-emitting surface of the screen body is located inside the non-light-emitting surface of the screen body opposite to the light-emitting surface.

[0024] In a possible implementation manner of the first aspect, in the folded state, the deflection angle of the second support portion relative to the first support portion is θ1, the first characteristic parameter includes θ1, and the included angle between the light-emitting surface of the non-bending area and the light-emitting surface of the bending area in the folded state is θ;

[0025] The relationship between θ and θ1 conforms to the following formula (4):

[0026] θ1 = -t1θ 2 +t2θ - t3 (4)

[0027] Wherein, t1, t2, and t3 are all positive numbers.

[0028] In a possible implementation manner of the first aspect, the deflection angle θ1 of the second support portion is equal to the included angle between the light-emitting surface of the non-bending area and the side surface of the second support portion facing the screen body.

[0029] In a possible implementation manner of the first aspect, t1 < t2 and t2 < t3.

[0030] In a possible implementation manner of the first aspect, t1 = 0.032, t2 = 2.1553, and t3 = 5.6217.

[0031] In a possible implementation manner of the first aspect, the foldable display device further includes a first flipping mechanism and a second flipping mechanism. The support portion corresponding to the non-bending area is the first support portion, and the support portion corresponding to the bending area is the second support portion. The first flipping mechanism controls the flipping of the first support portion, and the second flipping mechanism controls the flipping of the second support portion relative to the first support portion. At least a part of the second flipping mechanism is disposed on the first support portion.

[0032] In a possible implementation manner of the first aspect, the first flipping mechanism includes a first rotating shaft and a first bracket. The first bracket is fixedly connected to the first support portion, and one end of the first bracket is connected to the first rotating shaft.

[0033] In a possible implementation of the first aspect, the second flipping mechanism includes a second rotating shaft, a second bracket, and a connection structure. The second bracket is fixedly connected to the first supporting portion, one end of the second bracket is connected to the connection structure, the connection structure is fixedly connected to the second supporting portion, and the connection structure is connected to the second rotating shaft.

[0034] In a possible implementation of the first aspect, the second rotating shaft includes a sliding rail, and one end of the connection structure is movably disposed within the sliding rail of the second rotating shaft.

[0035] In a possible implementation of the first aspect, the first supporting portion includes a transition region. The transition region of the first supporting portion is close to the second supporting portion, and the surface of the first supporting portion facing the screen body in the transition region is an arc surface;

[0036] In the flattened state, adjacent non-bending regions are located on both sides of the bending region in the first direction. The length of the second supporting portion in the first direction is d0,

[0037] d0 and e' calculated using the following formula (5) conform to a third preset relationship:

[0038]

[0039] wherein, L represents half of the length of the bending region in the first direction, F = f0 + 0.5X, f0 represents the length of the transition region of the first supporting portion in the first direction, X represents the spacing distance between the first supporting portion and the second supporting portion in the first direction in the same set of supporting components in the flattened state. In the folded state, the light-emitting surface of the bending region forms a semi-elliptical cylinder surface and inclined surfaces located on both sides of the semi-elliptical cylinder surface. The second supporting portion is correspondingly arranged with the inclined surface. a represents the semi-major axis of the semi-elliptical cylinder surface formed by the light-emitting surface of the bending region in the folded state, and b represents the semi-minor axis of the semi-elliptical cylinder surface formed by the light-emitting surface of the bending region in the folded state; b is equal to half of the spacing distance between the relatively two ends of the semi-elliptical cylinder surface formed by the light-emitting surface of the bending region in the folded state along the first direction.

[0040] In a possible implementation of the first aspect, the third preset relationship includes: d0 is less than or equal to (1 + 10%)e', and d0 is greater than or equal to (1 - 10%)e'.

[0041] In a possible implementation of the first aspect, both the first supporting portion and the second supporting portion include a transition region. The transition region of the first supporting portion is close to the second supporting portion, the transition region of the second supporting portion is close to the first supporting portion, the surface of the first supporting portion facing the screen body in the transition region is an arc surface; the surface of the second supporting portion facing the screen body in the transition region is an arc surface; the radius of the arc surface of the first supporting portion in the transition region is R4, and the radius of the arc surface of the second supporting portion in the transition region is R3;

[0042] In the folded state, the screen body further includes a reverse folding area, the reverse folding area corresponds to the transition area, and the radius of the reverse folding area is R1;

[0043] R3 ≤ R1.

[0044] In a possible implementation manner of the first aspect, R4 ≤ R1.

[0045] In a possible implementation manner of the first aspect, R3 is less than or equal to 10 millimeters.

[0046] In a possible implementation manner of the first aspect, R4 is less than or equal to 10 millimeters.

[0047] In a possible implementation manner of the first aspect, R3 = R4.

[0048] In a possible implementation manner of the first aspect, in the flattened state, adjacent non-bending areas are located on both sides of the bending area in the first direction. The length of the second support part in the first direction is d0, and the length of the transition area of the second support part in the first direction is d1.

[0049] In a possible implementation manner of the first aspect,

[0050] In a possible implementation manner of the first aspect, the arc surface protrudes towards the screen body; the foldable display device includes a flattened state and a folded state. In the flattened state, among the same set of support components, in the direction along the approach to the other support part, the gap between the arc surface of the support part and the screen body gradually increases.

[0051] In a possible implementation manner of the first aspect, the support structure is located on the non-light-emitting surface side of the screen body opposite to the light-emitting surface.

[0052] In a possible implementation manner of the first aspect, the foldable display device further includes an adhesive layer, and the adhesive layer is located between the support part and the screen body.

[0053] In a possible implementation manner of the first aspect, the orthographic projection of the adhesive layer on the screen body is smaller than the orthographic projection of the support part on the screen body.

[0054] In a possible implementation manner of the first aspect, the orthographic projection of the adhesive layer on the screen body is located outside the orthographic projection of the transition area of the support part on the screen body.

[0055] Based on the same inventive concept, in the second aspect, an embodiment of the present application provides a method for manufacturing a foldable display device. The foldable display device has a flattened state and a folded state, and the foldable display device includes:

[0056] The screen body includes two non-bending areas and a bending area located between adjacent non-bending areas, wherein in a flattened state, the adjacent non-bending areas are located on both sides of the bending area in a first direction;

[0057] The support structure includes two groups of support assemblies, the two groups of support assemblies are respectively located on both sides of the bending axis of the bending zone, each group of support assemblies includes a first support portion and a second support portion arranged at intervals, at least part of the first support portion is arranged corresponding to the non-bending zone, and the second support portion is arranged on the side of the bending zone away from the bending axis;

[0058] The preparation method comprises:

[0059] Obtaining an empirical formula, where the empirical formula includes a first characteristic parameter and a second characteristic parameter, where the first characteristic parameter is a design parameter of the support structure, including at least a distance between the first support portion and the second support portion in a flattened state and / or a deflection angle of the second support portion relative to the first support portion in a folded state;

[0060] Determine the second characteristic parameter according to the screen shape design requirements;

[0061] Substitute the second characteristic parameter into the empirical formula to determine the first characteristic parameter.

[0062] In a possible implementation of the second aspect, the first support portion includes a transition area, the transition area is close to the second support portion, and a surface of the first support portion in the transition area facing the screen body is an arc-shaped surface;

[0063] In the flattened state, adjacent non-bending areas are located on both sides of the bending area in the first direction. In the flattened state, the spacing between the first support portion and the second support portion in the same group of support components in the first direction is X. The first characteristic parameter includes X. Substituting the second characteristic parameter into the empirical formula to determine the first characteristic parameter includes:

[0064] Substitute the second characteristic parameter into the empirical formula (1) and determine X according to X′;

[0065]

[0066] Among them, the second characteristic parameters include θ, b, d, L, f0, p, R2. In the folded state, the light-emitting surface of the bending area forms a semi-elliptical cylindrical surface and inclined surfaces on both sides of the semi-elliptical cylindrical surface. At least part of the second support part is arranged corresponding to the inclined surface. θ represents the angle between the light-emitting surface of the non-bending area and the inclined surface in the folded state. The angle between the light-emitting surface of the non-bending area and the inclined surface in the folded state is the deflection angle. b represents the semi-minor axis of the semi-elliptical cylindrical surface formed by the light-emitting surface of the bending area in the folded state. d represents half of the distance between the light-emitting surfaces of the two non-bending areas in the folded state; L represents half of the length of the bending area in the first direction. f0 represents the length of the transition area of the first support part in the first direction. R2 represents the minimum curvature radius of the semi-elliptical cylindrical surface formed by the bending area in the folded state. P is the correction coefficient corresponding to the minimum curvature radius; b is equal to half of the distance between the opposite ends of the semi-elliptical cylindrical surface formed by the light-emitting surface of the bending area in the first direction;

[0067] And / or, the first characteristic parameter includes the deflection angle θ1 of the second support part relative to the first support part in the folded state. The first characteristic parameter includes θ1, and the second characteristic parameters include X, b, d, L, f0, p, R2. Substituting the second characteristic parameters into the empirical formula to determine the first characteristic parameter, including:

[0068] Substitute the second characteristic parameters into the empirical formula (2), and determine θ according to θ';

[0069] Determine θ1 according to θ;

[0070]

[0071] In a possible implementation manner of the second aspect, X is less than or equal to (1 + 10%) X', and X is greater than or equal to (1 - 10%) X'.

[0072] In a possible implementation manner of the second aspect, θ is less than or equal to (1 + 10%) θ', and θ is greater than or equal to (1 - 10%) θ'.

[0073] In a possible implementation manner of the second aspect, p is greater than or equal to 1.1 and less than or equal to 1.2.

[0074] In a possible implementation manner of the second aspect, R2 conforms to the following formula:

[0075]

[0076] Among them, a represents the semi-major axis of the semi-elliptical cylindrical surface formed by the light-emitting surface of the bending area in the folded state.

[0077] In a possible implementation of the second aspect, R2 is greater than or equal to 0.8b and less than or equal to 0.9b.

[0078] In a possible implementation of the second aspect, in the folded state, the light-emitting surface of the screen body is located inside the non-light-emitting surface of the screen body opposite to the light-emitting surface.

[0079] In a possible implementation of the second aspect, determining θ1 according to θ includes:

[0080] Determining θ1 degrees according to formula (4):

[0081] θ1 = -t1θ 2 +t2θ - t3 (4)

[0082] Wherein, t1, t2, and t3 are all positive numbers.

[0083] In a possible implementation of the second aspect, the deflection angle θ1 of the second support portion is equal to the included angle between the light-emitting surface of the non-bending area and the surface of the second support portion facing the screen body.

[0084] In a possible implementation of the second aspect, t1 < t2 and t2 < t3.

[0085] In a possible implementation of the second aspect, t1 = 0.032, t2 = 2.1553, and t3 = 5.6217.

[0086] In a possible implementation of the second aspect, the second support portion includes a transition area. The transition area of the second support portion is close to the first support portion, and the surface of the second support portion facing the screen body in the transition area is an arc surface;

[0087] The length of the second support portion in the first direction is d0, and the method further includes:

[0088] Determining d0 according to e' in formula (5):

[0089]

[0090] In a possible implementation of the second aspect, d0 is less than or equal to (1 + 10%)e' and greater than or equal to (1 - 10%)e'.

[0091] The length of the transition area of the second support portion in the first direction is d1,

[0092] In a possible implementation of the second aspect,

[0093] Based on the same inventive concept, in a third aspect, an embodiment of the present application provides an electronic device, including the foldable display device provided in any one of the embodiments of the first aspect.

[0094] According to the foldable display device provided in the embodiment of the present application, its preparation method, and the electronic device, instead of randomly setting the parameters of the support structure, the morphological parameters of the foldable display device are controllably designed according to a given empirical formula. In this way, the sizes of the key parameters of the foldable display device can be optimized, which is beneficial to achieving the optimal water droplet stress state, thus helping to avoid stress concentration in the screen body, optimizing the stress in the water droplet bending area, and improving the problems of peeling of the adhesive layer and fracture of the inorganic film layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0095] 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.

[0096] Figure 1 FIG. 1 shows a schematic structural diagram of a foldable display device provided by the related art in a folded state;

[0097] Figure 2 FIG. 2 shows a schematic structural diagram of a foldable display device provided by an embodiment of the present application in an unfolded state;

[0098] Figure 3 FIG. 3 shows a schematic structural diagram of a foldable display device provided by an embodiment of the present application in a folded state;

[0099] Figure 4 FIG. 4 shows a schematic parameter diagram of a two-stage free-state water droplet in a folded state provided by an embodiment of the present application;

[0100] Figure 5 FIG. 5 shows a schematic relationship diagram of two angles in a foldable display device provided by an embodiment of the present application;

[0101] Figure 6 FIG. 6 shows another schematic structural diagram of a foldable display device provided by an embodiment of the present application in an unfolded state;

[0102] Figure 7 FIG. 7 shows another schematic structural diagram of a foldable display device provided by an embodiment of the present application;

[0103] Figure 8 FIG. 8 shows a schematic flow diagram of a preparation method of a foldable display device provided by an embodiment of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0104] The features and exemplary embodiments of various aspects of the present application will be described in detail below. In order to make the purpose, technical solutions and advantages of the present application more clear, the following further describes the present application in combination 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 to provide a better understanding of the present application by showing examples of the present application.

[0105] 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 such 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 elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "including..." does not exclude the existence of additional identical elements in the process, method, article or device including the said element.

[0106] 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 region.

[0107] It should be understood that the term "and / or" used herein is only a relational term describing the relationship between associated objects, indicating that three relationships may exist. For example, A and / or B may mean: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0108] Without departing from the spirit or scope of the present application, various modifications and changes can be made to the present application, which are obvious to those skilled in the art. Therefore, the present application is intended to cover modifications and changes of the present application that fall within the scope of the corresponding claims (the claimed technical solutions) and their equivalents. It should be noted that the embodiments provided by the embodiments of the present application can be combined with each other without contradiction.

[0109] Before presenting the technical solutions provided by the embodiments of the present application, for the convenience of understanding the embodiments of the present application, the present application first specifically describes the problems existing in the related technologies:

[0110] To improve the flatness of the screen body, as Figure 1 shown, support portions can be provided corresponding to the non-bending area and the bending area of the screen body. For the convenience of distinction, the support portion provided corresponding to the non-bending area of the screen body is marked as support portion 11, and the support portion provided corresponding to the bending area of the screen body is marked as support portion 12. The support portions 11 and 12 can be flipped around the rotation axis ( Figure 1 not shown in the figure) of the foldable display device, and the screen body will be bent as the support portions are flipped. For example, the screen body is folded into a water droplet shape. The inventors have found that during the flipping process of the support portions 11 and 12, one end of the support portion 11 close to the support portion 12 will squeeze the screen body, and / or one end of the support portion 12 close to the support portion 11 will squeeze the screen body. And the support portion has a certain mechanical strength. As mentioned in the background art, the foldable display device will be repeatedly bent during use. In this way, one end of the support portion 11 close to the support portion 12 and / or one end of the support portion 12 close to the support portion 11 will repeatedly squeeze the screen body, affecting the reliability of the screen body and possibly causing damage to the screen body or poor display.

[0111] To solve the above problems, the embodiments of the present application provide a foldable display device, a preparation method thereof, and an electronic device. The following will describe the embodiments of the foldable display device, the preparation method thereof, and the electronic device with reference to the accompanying drawings.

[0112] First, the foldable display device provided by the embodiments of the present application will be introduced below.

[0113] Figure 2 The structural schematic diagram of a foldable display device provided by the embodiments of the present application shown in the unfolded state. Figure 3 The structural schematic diagram of a foldable display device provided by the embodiments of the present application shown in the folded state. As Figure 1 and Figure 2 shown, the foldable display device 200 provided by the embodiments of the present application may include a screen body 20 and a support structure 30. The support structure 30 is used to support the screen body 20. The screen body 20 may include a light-emitting surface and a non-light-emitting surface opposite to the light-emitting surface, and the support structure 30 may be provided on the non-light-emitting surface of the screen body 20.

[0114] The screen body 20 includes two non-bending areas 21 and a bending area 22 located between adjacent non-bending areas 21. In the flattened state, the adjacent non-bending areas 21 are located on both sides of the bending area 22 in the first direction. The support structure 30 may include two sets of support components 301. The two sets of support components 301 are respectively located on both sides of the bending axis Z of the bending area 22. In other words, the two sets of support components 301 may be correspondingly arranged corresponding to the bending area 22 and the two non-bending areas on both sides of the bending area 22. Specifically, each set of support components 301 may include two support parts arranged at intervals, one of the support parts is arranged corresponding to the non-bending area 21, and the other support part is arranged corresponding to the bending area 22. At least one of the two support parts of the same set of support components 301 includes a transition area, the transition area is close to the other support part, and the surface of the support part facing the screen body 20 in the transition area is an arc surface.

[0115] For the convenience of understanding, in this article, the support part arranged corresponding to the non-bending area 21 is called the first support part 31, and the support part arranged corresponding to the bending area 22 is called the second support part 32. At least one of the first support part 31 and the second support part 32 may include a transition area. In the accompanying drawings of this article, it is taken as an example that both the first support part 31 and the second support part 32 include a transition area, which is not used to limit this application. In addition, for the convenience of distinction, the transition area of the first support part 31 is called the first transition area 311, and the first transition area 311 is close to the second support part 32. The transition area of the second support part 32 is called the second transition area 321, and the second transition area 321 is close to the first support part 31. The surfaces of the support parts facing the screen body 20 in the first transition area 311 and the second transition area 321 are arc surfaces.

[0116] According to the foldable display device provided by the embodiment of the present application, since at least one of the first support part 31 and the second support part 32 may include a transition area, and the surface of the support part facing the screen body 20 in the transition area is an arc surface, in the process of folding the foldable display device, the possibility of contact between one end of the first support part 31 close to the second support part 32 and / or one end of the second support part 32 close to the first support part 31 and the screen body 20 can be reduced. Furthermore, the possibility of extrusion of one end of the first support part 31 close to the second support part 32 and / or one end of the second support part 32 close to the first support part 31 to the screen body 20 can be reduced, which is beneficial to improving the reliability of the screen body 20 and avoiding damage to the screen body or poor display.

[0117] In some optional embodiments, the surface of the support part facing the screen body 20 in the transition area is an arc surface, and the arc surface protrudes towards the screen body 20.

[0118] Exemplarily, the region of the first support portion 31 outside the first transition region 311 is referred to as the first non-transition region 312, and the surface of the first support portion 31 facing the screen body 20 in the first non-transition region 312 may be a plane. It can be understood that the first support portion 31 can smoothly transition between the first transition region 311 and the first non-transition region 312, and there is no tip at the connection between the first transition region 311 and the first non-transition region 312. The first transition region 311 may correspond to the bending region 22 of the screen body 20, and the first non-transition region 312 may correspond to the non-bending region 21 of the screen body.

[0119] The region of the second support portion 32 outside the second transition region 321 is referred to as the second non-transition region 322, and the surface of the second support portion 32 facing the screen body 20 in the second non-transition region 322 may be a plane. It can be understood that the second support portion 32 can smoothly transition between the second transition region 321 and the second non-transition region 322, and there is no tip at the connection between the second transition region 321 and the second non-transition region 322.

[0120] Exemplarily, the surface of the first support portion 31 facing away from the screen body 20 in the first transition region 311 may be a plane, and the surface of the second support portion 32 facing away from the screen body 20 in the second transition region 321 may be a plane. Additionally, the surface of the first support portion 31 facing away from the screen body 20 in the first non-transition region 312 may be a plane, and the surface of the second support portion 32 facing away from the screen body 20 in the second non-transition region 322 may be a plane.

[0121] Exemplarily, in the flattened state, the surface of the first support portion 31 facing away from the screen body 20 and the surface of the second support portion 32 facing away from the screen body 20 may be in the same plane.

[0122] In the embodiments of the present application, the arc surface of the support portion in the transition region protrudes towards the screen body, so that the support portion can smoothly transition between the transition region and the non-transition region connected to the transition region, avoiding the existence of a tip at the connection between the transition region and the non-transition region of the support portion, and further reducing the possibility of the support portion squeezing the screen body.

[0123] Please continue to refer to Figure 2, the arc surface protrudes towards the screen body 20. The foldable display device includes a flattened state and a folded state. In the flattened state, among the same set of support components, in the direction along which the support part with a transition area approaches another support part, the gap between the arc surface of the support part and the screen body gradually increases. Taking the first support part 31 having a transition area as an example, in the flattened state, along the direction in which the first support part 31 approaches the second support part 32, the gap between the arc surface of the first support part 31 and the screen body 20 can gradually increase. Taking the second support part 32 having a transition area as an example, in the flattened state, along the direction in which the second support part 32 approaches the first support part 31, the gap between the arc surface of the second support part 32 and the screen body 20 can also gradually increase. In this way, the possibility of the support part squeezing the screen body during the folding process can be further reduced.

[0124] In the embodiment of the present application, the foldable display device can be an inward-foldable display device, and the support structure 30 is located on the non-light-emitting surface side of the screen body 20 opposite to the light-emitting surface. In the folded state, the light-emitting surface of the screen body 20 is located inside the non-light-emitting surface of the screen body 20 opposite to the light-emitting surface.

[0125] The inventors also found that a flexible display screen with foldability is prone to the risk of fracture after undergoing long-term periodic folding. In the folded state, by setting the bending area of the screen body in a water droplet shape in the folded state, the radius of the bending area is increased, which can effectively reduce the risk of the screen body breaking during the folding process and improve the folding performance of the foldable display device. In the related art, for the morphological parameters of the specified radius of the water droplet bending area, it can only be achieved through simulation and mechanism design, which is time-consuming and laborious. Moreover, if the mechanism operation trajectory is not designed well, the morphological parameters of the specified radius of the water droplet bending area cannot achieve better or optimal control. And the morphological parameters of the water droplet bending area directly determine the stress release of each layer of the screen body bending area. If the morphological parameters cannot achieve better or optimal control, problems such as peeling of the adhesive layer in the bending area and fracture of the inorganic film layer in the bending center area are likely to occur.

[0126] After long-term research, the inventors derived an empirical formula for the relationship between the morphological parameters of the water droplet shape of the bending area of the screen body in the folded state, and the support structure can be designed according to the established empirical formula. Specifically, the empirical formula can include a first characteristic parameter and a second characteristic parameter. Among them, the first characteristic parameter is a design parameter of the support structure, at least including the distance between the first support part and the second support part in the flattened state and / or the deflection angle of the second support part relative to the first support part in the folded state; the second characteristic parameter is determined according to the morphological design requirements of the screen body.

[0127] In the embodiment of the present application, the parameters of the support structure are no longer set arbitrarily. Instead, the morphological parameters of the foldable display device are controllably designed according to established empirical formulas. This allows for optimized design of the dimensions of key parameters of the foldable display device, which is beneficial for achieving the optimal water droplet stress form, thereby helping to avoid stress concentration on the screen body, optimize the stress in the water droplet bending zone, and improve the peeling problem of the glue layer and the fracture problem of the inorganic film layer.

[0128] The specific derivation process of the empirical formula is described below.

[0129] For example, a water droplet having support parts only in the non-bending area of the screen is called a two-stage free-state water droplet, and a water droplet having support parts in both the non-bending area and the bending area of the screen is called a four-stage constrained-state water droplet.

[0130] Figure 4 Schematic diagram showing the parameters of a two-segment free-state water droplet in a folded state. Figure 4 The first support portion 31 is provided only in the non-bending region of the screen 20. When folded, the bending region of the screen is teardrop-shaped. The first support portion 31 may include a transition region, located on the side of the first support portion 31 closest to the bending region of the screen. The transition region of the first support portion 31 may at least partially correspond to the bending region of the screen 20. At least a portion of the first support portion 31 corresponds to the non-bending region. The second support portion 32 is provided on the side of the bending region facing away from the bending axis Z.

[0131] In the folded state, the bending area forms a semi-elliptical cylinder and inclined surfaces on both sides of the semi-elliptical cylinder, and part or all of the second support portion 32 is arranged corresponding to the inclined surfaces. Figure 4 In the equation ( θ ) , θ represents the angle between the light-emitting surface of the non-bending region of the screen 20 and the slant-like surface formed by the light-emitting surface of the bending region of the screen 20 in the folded state, a represents the semi-major axis of the slant-like semi-elliptical cylinder formed by the light-emitting surface of the bending region of the screen 20 in the folded state, b represents the semi-minor axis of the slant-like semi-elliptical cylinder formed by the light-emitting surface of the bending region of the screen 20 in the folded state, c represents the length of a water droplet, d represents half the distance between the light-emitting surfaces of the two non-bending regions of the screen 20 in the folded state, e represents the approximate length of the slant side of the water droplet formed by the bending region of the screen 20 in the folded state, f0 represents the length of the transition region of the first support portion 31, and R2 represents the minimum radius of curvature of the slant-like semi-elliptical cylinder formed by the bending region of the screen 20 in the folded state. b is equal to half the distance between the two opposite ends of the slant-like semi-elliptical cylinder formed by the light-emitting surface of the bending region in the folded state along the first direction.

[0132] In addition, if Figure 4 As shown, in the folded state, the bending area of the screen body is teardrop-shaped, and part of the area is convex toward the inside. This part of the area can be called the inflection area of the screen body 20, and R1 represents the radius of the inflection area of the screen body 20 in the folded state.

[0133] For example, half of the length of the bending area of the screen body 20 is L. As Figure 4 shown, the two ends of the bending area of the screen body 20 are marked as N1 and N2, and it can be understood that the length from N1 to N2 is 2L.

[0134] The ellipse perimeter formula is L0 = 2πb + 4(a - b). The lower part of the water droplet formed by the bending area of the screen body 20 is half of the ellipse. Therefore, 2L = 2e + 2f0 + L0 / 2, and further the relational expression (1.1) can be obtained:

[0135] 2e = 2L - 2f0 - L0 / 2 = 2L - 2f0 - πb - 2(a - b) (1.1)

[0136] That is

[0137] Therefore, the included angle θ can be obtained according to the relational expression to find the included angle θ.

[0138] Furthermore, the relational expression (1.2) can be obtained:

[0139]

[0140] Of course, e 2 = (c - f0 - a) 2 + (b - d) 2 , and further the included angle θ can also be obtained according to the relational expression to find the included angle θ, but the inventor's research found that there will be a large error in this way.

[0141] In the relational expression (1.2), the semi-major axis a can be expressed by the semi-minor axis b and the minimum curvature radius R2.

[0142] For example, for the curve function y(x), the curvature radius is And R2 can be approximately regarded as the minimum curvature radius of the quasi-ellipse formed by the bending area of the screen body 20 in the folded state. Therefore

[0143] For a flexible screen, it is mainly composed of a film material and an adhesive material stacked. The inventor also found through research that there is a certain degree of compression deformation in the final state of the water droplet morphology of the bending area in the folded state, and there is a certain error from the theoretical value. So there is a certain difference between the approximate value of the minimum curvature radius R2 and the theoretical value. The inventor performs fitting through simulation means and corrects the formula of the minimum curvature radius R2 to obtain the relational expression (3):

[0144]

[0145] Among them, p is the correction coefficient corresponding to the minimum curvature radius R2.

[0146] Substituting relational expression (3) into relational expression (1.2), relational expression (1.3) can be obtained:

[0147]

[0148] Relational expression (1.3) is the relational expression corresponding to the derived two-segment free-state water droplet morphology parameters.

[0149] As introduced above, the free-state water droplet morphology refers to the control of the bending area of the screen body without a support part. For the four-segment constrained-state water droplet, support parts are correspondingly arranged in both the bending area and the non-bending area of the screen body. The support part arranged in the non-bending area of the screen body can control the distance between the screen bodies in the folded state, and the water droplet shape presented by the bending area of the screen body in the folded state can be controlled by the deflection angle of the support part corresponding to the bending area.

[0150] The four-segment constrained-state water droplet morphology can be approximated to the two-segment free-state water droplet morphology. The relational expression (1.3) can be corrected to obtain the relational expression corresponding to the four-segment constrained-state water droplet morphology parameters. For the four-segment constrained-state water droplet, since support parts are correspondingly arranged in both the bending area and the non-bending area of the screen body, f0 in relational expression (1.3) can be corrected to F, and then relational expression (1) can be obtained:

[0151]

[0152] Among them, F = f0 + 0.5X, as Figure 2 shown, X represents the interval distance between the first support part 31 and the second support part 32 in the first direction in the same set of support components 301 in the flattened state, and f0 represents the length of the transition area of the first support part 31 in the first direction.

[0153] The inventor's research found that in F = f0 + 0.5X, when the coefficient of X is set to 0.5, it can correspond to the starting point of the ideal water droplet morphology, which is more in line with the ideal formula design and can make the design deviation smaller.

[0154] p is related to the film stack structure and material selection of the foldable display device. As an example, p can take values in the range of 1.1 to 1.2. Through a large number of simulations and verifications by the inventor, when p is greater than or equal to 1.1 and p is less than or equal to 1.2, using the above relational expression (1) to controllably design the morphology parameters of the foldable display device can achieve a better or optimal water droplet force state.

[0155] R2 is also related to the film layer structure and material selection of the foldable display device. The inventors found through research that the minimum radius of curvature R2 can determine the failure risk of the inorganic film layer. As an example, R2 is greater than or equal to 0.8b and R2 is less than or equal to 0.9b. Similarly, through a large number of simulations, the inventors verified that when R2 is greater than or equal to 0.8b and R2 is less than or equal to 0.9b, using the above relationship (1) to controllably design the morphological parameters of the foldable display device can achieve a better or optimal water droplet force state.

[0156] In addition, through the theoretical formula, when the deflection angle of the second support portion 32 is θ, the force on the screen body can reach the optimum. However, θ in formula (1) is determined based on the light-emitting surface of the screen body, that is, based on the inside of the water droplet. For the inward-foldable foldable display device, in the folded state, the second support portion 32 is located outside the water droplet. Therefore, there is an error between the actual deflection angle θ1 of the second support portion 32 and θ in formula (1). Figure 5 The relationship between θ1 and θ obtained by simulation is shown. Figure 5 In the figure, the horizontal axis represents θ, the vertical axis represents θ1, and the actual deflection angle θ1 of the second support portion 32 and θ in formula (1) conform to a polynomial relationship. Specifically, the relationship between θ and θ1 conforms to the following formula (4):

[0157] θ1 = -t1θ 2 +t2θ - t3 (4)

[0158] Wherein, t1, t2, and t3 are all positive numbers.

[0159] In this way, the error caused by directly using θ as the actual deflection angle of the second support portion 32 can be improved or avoided.

[0160] As Figure 3 shown, the deflection angle θ1 of the second support portion 32 can be understood as the included angle between the light-emitting surface of the non-bending area 21 and the surface of the second support portion 32 facing the screen body 20.

[0161] As an example, t1 < t2 and t2 < t3. For example, t1 = 0.032, t2 = 2.1553, and t3 = 5.6217.

[0162] Of course, the specific values of t1, t2, and t3 can be obtained by fitting according to the actual product, and the present application does not limit this.

[0163] The inventors not only derived the above relationship, but also verified the accuracy of the above relationship and the force effect under the parameters determined based on the above relationship.

[0164] Referring to Table 1 and Table 2, Table 1 shows the design values of key parameters determined based on the above formula (1) when b = 1.5, and Table 2 shows the simulation results of the key parameters based on Table 1. From the simulation results, the simulated b value is relatively well matched with the target b value, verifying that the θ value derived from the modified formula (1) is relatively reasonable, that is, the accuracy of formula (1) is relatively good. Among them, as Figure 4 shown, e represents the approximate length of the water droplet hypotenuse formed by the bending area of the screen body 20 in the folded state of the two-stage structure. As Figure 2 shown, d0 represents the length of the second support portion 32 in the first direction in the four-stage structure. d0 can be approximately equal to e. In addition, in Table 1 and Table 2, the unit of each numerical value is millimeter.

[0165] Table 1

[0166]

[0167] Table 2

[0168]

[0169]

[0170] Referring to Table 3, the schematic illustration of some parameters in Table 3 can be referred to Figure 3 . Among them, X = 1.8 is deduced according to formula (1), and the values of X equal to 0.2, 0.5, 1.0, 1.5 and the values in their columns are several design schemes listed. For each scheme in Table 3, the force conditions of the adhesive layer are obtained through simulation. The inventor found that for the foldable display device with an inner fold structure, the failure of the optical adhesive (OCA) is relatively common. In Table 3, the force conditions of two optical adhesive layers (OCA1 and OCA2), the back support film layer (BPF), and the pressure-sensitive adhesive layer (PSA) are taken as examples. As an example, on one side of the light-emitting surface of the screen body of the foldable display device and in the direction away from the light-emitting surface of the screen body, there may be a polarizing layer, a second optical adhesive layer, a second cover plate, a first optical adhesive layer, and a first cover plate arranged in layers. OCA1 is the first optical adhesive layer, and OCA2 is the second optical adhesive layer.

[0171] By listing several design schemes, the optimal force result is found and compared with the design scheme derived from the design formula (1) of the present application. From the simulation results, it can be seen that reasonable design of the key dimension parameters of the second support portion and the gap X value between the first support portion and the second support portion can make the force of the adhesive layer in the foldable display device relatively optimal. Comparing the gap X value deduced from the formula with the ideal gap value with the minimum force of the adhesive material (the ideal gap value X in Table 3 is 1.5), although there are some deviations, the differences are small, indicating that the controllable design scheme of the water droplet morphology using formula (1) in the present application is close to the most ideal adhesive material force scheme and can provide effective guidance for the design of the support portion.

[0172] Table 3

[0173]

[0174]

[0175] It should be noted that Tables 1 to 3 only list some examples in the simulation process and do not represent the number of simulation examples.

[0176] It can be seen that by using the above relationship formula (1) to controllably design the morphological parameters of the foldable display device, and the dimensions of the key parameters of the foldable display device can be designed and optimized to achieve the optimal water droplet force state, effectively avoiding stress concentration in the screen body, optimizing the force in the water droplet bending area, and improving the peeling problem of the adhesive layer and the fracture problem of the inorganic film layer.

[0177] Exemplarily, the key parameters of the foldable display device may include the spacing distance X between the first support portion 31 and the second support portion 32 in the first direction, the deflection angle of the second support portion 32, etc.

[0178] Optionally, the first characteristic parameter includes X, and X is determined according to X' calculated by a given empirical formula (1), and X and X' conform to a first preset relationship:

[0179]

[0180] Among them, the second characteristic parameters include θ, b, d, L, f0, p, R2.

[0181] As an example, the above relationship formula (1) can be used to design the spacing distance X between the first support portion 31 and the second support portion 32 in the first direction. For example, some or all of the parameters θ, L, b, d, f0, p, R2 are set to fixed known values, and let F = f0 + 0.5X' be substituted into the above relationship formula (1), the value of X' can be obtained, and then the spacing distance X between the first support portion 31 and the second support portion 32 in the first direction can be determined according to the value of X'.

[0182] Exemplarily, X and X' calculated by using formula (1) may conform to a first preset relationship. The first preset relationship may include: X is less than or equal to (1 + 10%)X', and X is greater than or equal to (1 - 10%)X'.

[0183] Optionally, the deflection angle in the first characteristic parameter is determined according to θ, the second characteristic parameters include X, b, d, L, f0, p, R2, and θ is determined according to θ' calculated by a given empirical formula (2), and θ and θ' conform to a second preset relationship:

[0184]

[0185] Similarly, as another example, the included angle θ can be designed according to θ' obtained from the relational expression (2).

[0186]

[0187] For example, some or all of the parameters L, b, d, f0, X, p, R2 are set to fixed known values, and F = f0 + 0.5X is substituted into the above relational expression (2) to obtain the value of θ', and then the included angle θ can be determined according to the value of θ'.

[0188] Exemplarily, θ and θ' calculated using Equation (2) conform to a second preset relationship. The second preset relationship includes: θ is less than or equal to (1 + 10%)θ', and θ is greater than or equal to (1 - 10%)θ'.

[0189] Optionally, in the folded state, the deflection angle of the second support portion relative to the first support portion is θ1, the first characteristic parameter includes θ1, and the included angle between the light-emitting surface of the non-bending area and the light-emitting surface of the bending area that form a bevel surface in the folded state is θ;

[0190] The relationship between θ and θ1 conforms to the following formula (4):

[0191] θ1 = -t1θ 2 +t2θ - t3 (4)

[0192] It should be noted that if the first characteristic parameter includes θ1 and X, one of the parameters can be preset within a small range according to design experience, and the other parameter can be obtained through the above formula, and optimization can be performed by means of simulation to obtain the optimal values of θ1 and X.

[0193] Exemplarily, the key parameters of the foldable display device may further include the length of the second support portion 32 in the first direction. As introduced above, e can be approximately equal to the length d0 of the second support portion in the first direction. For the four-segment constrained-state water droplet, since the support portions are correspondingly arranged in both the bending area and the non-bending area of the screen body, the relational expression in which f0 is corrected to F, and then the relational expression (5) can be obtained. The value of e' can be calculated using the following formula (5), and then d0 can be determined according to the value of e'.

[0194]

[0195] wherein, F = f0 + 0.5X.

[0196] In the embodiments of the present application, the better or optimal length parameter of the second support portion can be quickly and accurately determined according to the relational expression (5).

[0197] In this text, the first direction may be the arrangement direction of the non-bending area and the bending area in the unfolded state. As Figure 2 shown, in the unfolded state, adjacent non-bending areas 21 are located on both sides of the bending area 22 in the first direction.

[0198] Exemplarily, d0 and e' calculated using Equation (5) conform to a third preset relationship. The third preset relationship includes: d0 is less than or equal to (1 + 10%)e', and d0 is greater than or equal to (1 - 10%)e'.

[0199] With reference to Figure 2 and Figure 3 , the radius of the arc surface of the first support portion 31 in the first transition region 311 is R4, and the radius of the arc surface of the second support portion 32 in the second transition region 321 is R3. In the folded state, the screen body 20 further includes a reverse folding area, the position of the reverse folding area corresponds to the position of the transition area, and the radius of the reverse folding area is R1.

[0200] It can be understood that the smaller the value of the radius R3, the less likely the second support portion 32 is to contact the screen body 20 in the second transition region 321 during the folding process. Exemplarily, R3 ≤ R1. In this way, the possibility of the second transition region 321 of the second support portion 32 squeezing the screen body 20 can be further reduced, thereby further improving the reliability of the foldable product.

[0201] Similarly, the smaller the value of the radius R4, the less likely the first support portion 31 is to contact the screen body 20 in the first transition region 311 during the folding process. Exemplarily, R4 ≤ R1. In this way, the possibility of the first transition region 311 of the first support portion 31 squeezing the screen body 20 can be further reduced, thereby further improving the reliability of the foldable product.

[0202] As an example, R3 may be less than or equal to 10 millimeters, and R4 may be less than or equal to 10 millimeters.

[0203] As another example, R3 and R4 may be equal.

[0204] Of course, the values of R3 and R4 can also be designed according to the actual product requirements.

[0205] In addition, the radius R1 of the reverse folding area can determine the risk of the adhesive material failing under force. Therefore, the value of R1 can also be designed according to the actual product requirements.

[0206] As Figure 2 shown, the length of the second transition region 321 of the second support portion 32 in the first direction is d1. It can be understood that there may be no connection relationship between the second transition region 321 of the second support portion 32 and the screen body 20, and the second non-transition region 322 of the second support portion 32 and the screen body 20 can be connected through an adhesive layer.

[0207] To ensure that the second support portion 32 has sufficient support performance for the screen body 20,

[0208] As an example,

[0209] such as Figure 6 shown, the foldable display device may further include an adhesive layer 40. The adhesive layer 40 is located between the support portion 30 and the screen body 20. The orthographic projection of the adhesive layer 40 on the screen body 20 is smaller than the orthographic projection of the support portion 30 on the screen body 20. That is to say, the area of the adhesive layer 40 is smaller than the area of the support portion 30.

[0210] For example, the adhesive layer 40 may include a first adhesive sub-portion 41 and a second adhesive sub-portion 42. The first adhesive sub-portion 41 is located between the first support portion 31 and the screen body 20, and the second adhesive sub-portion 42 is located between the second support portion 32 and the screen body 20. The orthographic projection of the first adhesive sub-portion 41 on the screen body 20 may be smaller than the orthographic projection of the first support portion 31 on the screen body 20, and the orthographic projection of the second adhesive sub-portion 42 on the screen body 20 may be smaller than the orthographic projection of the second support portion 32 on the screen body 20.

[0211] In the folded state, the light-emitting surface corresponding to the area where the bending area is bonded to the second support portion 32 is a quasi-inclined surface. The bending area includes two quasi-inclined surfaces and a quasi-semi-elliptical cylindrical surface located between the two quasi-inclined surfaces.

[0212] It can be understood that the screen body at the position of the adhesive layer is equivalent to being fixed, and the larger the area of the adhesive layer, the larger the area of the screen body being fixed. During the folding process, the support portion can pull the screen body through the adhesive layer, which is likely to cause stress concentration. In the embodiments of the present application, by setting the area of the adhesive layer to be smaller than the area of the support portion, it is equivalent to reducing the area of the screen body being fixed, thereby improving the phenomenon that the screen body is pulled during the folding process.

[0213] As an example, the orthographic projection of the adhesive layer 40 on the screen body 20 is located outside the orthographic projection of the transition area of the support portion 30 on the screen body 20. The orthographic projection of the adhesive layer 40 on the screen body 20 and the orthographic projection of the transition area of the support portion 30 on the screen body 20 have no overlap. In this way, there is no adhesive layer 40 between the transition area of the support portion 30 and the screen body 20, which can further reduce the phenomenon that the transition area of the support portion 30 squeezes the screen body 20.

[0214] Exemplarily, the orthographic projection of the first bonding part 41 on the screen body 20 is located outside the orthographic projection of the first transition area 311 of the first support part 31 on the screen body 20. The orthographic projection of the first bonding part 41 on the screen body 20 and the orthographic projection of the first transition area 311 of the first support part 31 on the screen body 20 do not overlap. Exemplarily, the orthographic projection of the second bonding part 42 on the screen body 20 is located outside the orthographic projection of the second transition area 321 of the second support part 32 on the screen body 20. The orthographic projection of the second bonding part 42 on the screen body 20 and the orthographic projection of the second transition area 321 of the second support part 32 on the screen body 20 do not overlap.

[0215] In some alternative embodiments, as Figure 7 shown, the foldable display device may further include a first flipping mechanism 61 and a second flipping mechanism 62. The support part corresponding to the non-bending area is the first support part 31, and the support part corresponding to the bending area is the second support part 32. For the sake of clearly showing the flipping mechanism, Figure 7 only one first support part 31 is shown in []. The first flipping mechanism 31 can be used to control the flipping of the first support part 31, the second flipping mechanism 62 can be used to control the flipping of the second support part 32 relative to the first support part 31, and at least a partial area of the second flipping mechanism 62 can be arranged on the first support part 31. In this way, when the first support part 31 flips around the rotation axis, the second support part 32 can be driven to flip by the second flipping structure 62.

[0216] Exemplarily, the first flipping mechanism 61 may include a first rotation axis 611 and a first bracket 612. The first bracket 612 is fixedly connected to the first support part 31, and one end of the first bracket 612 is connected to the first rotation axis 611.

[0217] For example, the first rotation axis 611 can be a gear structure, and one end of the first bracket 612 and the first rotation axis 611 can be hinged. The first flipping mechanism 61 may further include a fixing structure 613. The first rotation axis 611 is connected to the fixing structure 613. The fixing structure 613 is used to fix the first rotation axis 611 and does not limit the rotational freedom of the first rotation axis 611. Fixing structures 613 can be arranged on both sides of the first rotation axis 611. The first support part 31 can be manually flipped. Since the first support part 31 is fixed to the first bracket 612 and the first bracket 612 and the first rotation axis 611 are rotatable (that is, one end of the first bracket 612 and the first rotation axis 611 are rotatably connected), when the first support part 31 is manually flipped, the first support part 31 can flip around the first rotation axis 611. Of course, the rotation of the first rotation axis 611 can also be controlled by a motor. The first rotation axis 611 can drive the first bracket 612 to rotate, and the first bracket 612 can drive the first support part 31.

[0218] Exemplarily, the second flipping mechanism 62 may include a second rotating shaft 621, a second bracket 622, and a connecting structure 623. The second bracket 622 is fixedly connected to the first supporting portion 31, and one end of the second bracket 622 is connected to the connecting structure 623 (e.g., rotatably connected). The connecting structure 623 is fixedly connected to the second supporting portion 32, and the connecting structure 623 is connected to the second rotating shaft 621 (e.g., rotatably connected). Thus, when the first supporting portion 31 flips, the second bracket 622 fixed to the first supporting portion 31 can flip, the second bracket 622 drives the connecting structure 623 to flip, and further the connecting structure 623 drives the second supporting portion 32 to flip.

[0219] Exemplarily, the second rotating shaft 621 may include a slide rail (not shown in the figure), and one end of the connecting structure 6 can be movably disposed in the slide rail of the second rotating shaft 621. In this way, the slide rail of the second rotating shaft 621 can provide a flipping trajectory for the second supporting portion 32. The flipping angle of the second supporting portion 32 can be controlled by the slide rail of the second rotating shaft 621. Exemplarily, the optimal flipping angle of the second supporting portion 32 relative to the first supporting portion 31 can be determined first, and then the slide rail of the second rotating shaft 621 can be designed based on the optimal flipping angle.

[0220] The connecting structure 623 may include a pin structure, and the pin structure of the connecting structure 623 can be movably disposed in the slide rail of the second rotating shaft 621.

[0221] Figure 7 The flipping structure shown is only an example and is not used to limit the present application.

[0222] Based on the same inventive concept, an embodiment of the present application provides a preparation method of a foldable display device, which can be used to prepare the foldable display device as in the embodiment of the first aspect. The foldable display device has a flattened state and a folded state. As Figure 8 shown, the preparation method of the foldable display device provided by the embodiment of the present application may include S801 to S803.

[0223] S801, obtain an empirical formula, the empirical formula includes a first characteristic parameter and a second characteristic parameter, the first characteristic parameter is a design parameter of the support structure, at least including the distance between the first supporting portion and the second supporting portion in the flattened state and / or the deflection angle of the second supporting portion relative to the first supporting portion in the folded state;

[0224] S802, determine the second characteristic parameter according to the morphological design requirements of the screen body;

[0225] S803, substitute the second characteristic parameter into the empirical formula to determine the first characteristic parameter.

[0226] According to the manufacturing method of the foldable display device provided by the embodiments of the present application, instead of randomly setting the parameters of the support structure, the morphological parameters of the foldable display device are controllably designed according to established empirical formulas. In this way, the sizes of the key parameters of the foldable display device can be optimized, which is beneficial to achieving the optimal water droplet force-bearing form, thus helping to avoid stress concentration on the screen body, optimizing the force on the water droplet bending area, and improving the problems of adhesive layer peeling and inorganic film layer fracture.

[0227] Exemplarily, the first support portion includes a transition region close to the second support portion, and the surface of the first support portion facing the screen body in the transition region is an arc surface;

[0228] In the flattened state, adjacent non-bending regions are located on both sides of the bending region in the first direction. In the flattened state, the distance between the first support portion and the second support portion in the first direction in the same set of support components is X, and the first characteristic parameter includes X. S803 may specifically include:

[0229] Substitute the second characteristic parameter into the empirical formula (1), and determine X according to X';

[0230]

[0231] Wherein, the second characteristic parameters include θ, b, d, L, f0, p, R2. In the folded state, the light-emitting surface of the bending region forms a semi-elliptical cylindrical surface and inclined surfaces on both sides of the semi-elliptical cylindrical surface. Part or all of the second support portions are correspondingly arranged with the inclined surfaces. θ represents the angle between the light-emitting surface of the non-bending region and the inclined surface in the folded state. The angle between the light-emitting surface of the non-bending region and the inclined surface in the folded state is the deflection angle. b represents the semi-minor axis of the semi-elliptical cylindrical surface formed by the light-emitting surface of the bending region in the folded state. d represents half of the distance between the light-emitting surfaces of the two non-bending regions in the folded state; L represents half of the length of the bending region in the first direction. f0 represents the length of the transition region of the first support portion in the first direction. R2 represents the minimum curvature radius of the semi-elliptical cylindrical surface formed by the bending region in the folded state. P is the correction coefficient corresponding to the minimum curvature radius; b is equal to half of the distance between the opposite ends of the semi-elliptical cylindrical surface formed by the light-emitting surface of the bending region in the first direction in the folded state;

[0232] And / or, the first characteristic parameter includes the deflection angle θ1 of the second support portion relative to the first support portion in the folded state. The deflection angle in the first characteristic parameter is determined according to θ. The second characteristic parameters include X, b, d, L, f0, p, R2. S803 may specifically include:

[0233] Substitute the second characteristic parameter into the empirical formula (2), and determine θ according to θ';

[0234] Determine θ1 according to θ;

[0235]

[0236] Exemplarily, X is less than or equal to (1 + 10%)X′, and X is greater than or equal to (1 - 10%)X′.

[0237] Exemplarily, θ is less than or equal to (1 + 10%)θ′, and θ is greater than or equal to (1 - 10%)θ′.

[0238] Exemplarily, p is greater than or equal to 1.1, and p is less than or equal to 1.2.

[0239] Exemplarily, R2 conforms to the following formula (3):

[0240]

[0241] Wherein, a represents the semi-major axis of the semi-elliptical cylindrical surface formed by the light-emitting surface of the bending area in the folded state.

[0242] Exemplarily, R2 is greater than or equal to 0.8b, and R2 is less than or equal to 0.9b.

[0243] Exemplarily, in the folded state, the light-emitting surface of the screen body is located inside the non-light-emitting surface of the screen body opposite to the light-emitting surface.

[0244] Exemplarily, determining θ1 according to θ includes:

[0245] Determining the degree of θ1 according to formula (4):

[0246] θ1 = -t1θ 2 +t2θ - t3 (4)

[0247] Wherein, t1, t2, and t3 are all positive numbers.

[0248] Exemplarily, the deflection angle θ1 of the second support part is equal to the included angle between the light-emitting surface of the non-bending area and the side surface of the second support part facing the screen body.

[0249] Exemplarily, t1 < t2, t2 < t3.

[0250] Exemplarily, t1 = 0.032, t2 = 2.1553, t3 = 5.6217.

[0251] Exemplarily, the second support part includes a transition area. The transition area of the second support part is close to the first support part, and the surface of the second support part facing the screen body in the transition area is an arc surface;

[0252] The length of the second support part in the first direction is d0, and the method further includes:

[0253] Determine d0 according to e’ in formula (5):

[0254]

[0255] Exemplarily, d0 is less than or equal to (1 + 10%)e’ and d0 is greater than or equal to (1 - 10%)e’.

[0256] The length of the transition region of the second support part in the first direction is d1,

[0257] Exemplarily,

[0258] In the preparation method of the foldable display device provided by the embodiments of the present application, the derivation process of each formula can be seen in detail in the above introduction to the embodiments in the foldable display device, and will not be elaborated here.

[0259] Based on the same inventive concept, the present application also provides an electronic device, including the foldable display device provided by any one of the above embodiments of the present application. It can be understood that the electronic device provided by the embodiments of the present application can be a mobile phone, a tablet computer, a computer, a television or other electronic devices with a display function, and the present application does not make specific limitations thereto. The electronic device provided by the embodiments of the present application has the beneficial effects of the foldable display device provided by the embodiments of the present application, and for details, reference can be made to the specific descriptions of the foldable display device in the above embodiments, which will not be elaborated in this embodiment.

[0260] In accordance with the embodiments of the present application as described above, these embodiments do not describe all the details in detail, nor do they limit the application to only 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 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 foldable display device having a flattened state and a folded state, characterized in that, include: The screen body comprises two non-bending areas and a bending area located between adjacent non-bending areas, wherein in the flattened state, adjacent non-bending areas are located on both sides of the bending area in the first direction; a support structure comprising two groups of support assemblies, the two groups of support assemblies being respectively located on either side of a bending axis of the bending zone, each group of support assemblies comprising a first support portion and a second support portion spaced apart from each other, at least a portion of the first support portion being disposed corresponding to the non-bending zone, and the second support portion being disposed on a side of the bending zone away from the bending axis; The support structure is designed according to a predetermined empirical formula, which includes a first characteristic parameter and a second characteristic parameter, wherein the first characteristic parameter is a design parameter of the support structure, including at least a distance between the first support portion and the second support portion in a flattened state and / or a deflection angle of the second support portion relative to the first support portion in a folded state; and the second characteristic parameter is determined according to the morphological design requirements of the screen body. In the flattened state, the spacing between the first support portion and the second support portion in the same group of the support assembly in the first direction is X, and the first characteristic parameter includes X, which is determined by X′ calculated according to the established empirical formula (1): X and X′ meet the first preset relationship; Wherein, the second characteristic parameter includes θ, b, d, L, f0, p, and R2. In the folded state, the light-emitting surface of the bending zone constitutes a semi-elliptical cylinder and slant-like surfaces on both sides of the semi-elliptical cylinder. At least part of the second support portion is arranged corresponding to the slant-like surfaces. θ represents the angle between the light-emitting surface of the non-bending zone and the slant-like surface in the folded state. b represents the semi-minor axis of the semi-elliptical cylinder constituted by the light-emitting surface of the bending zone in the folded state. d represents half of the distance between the light-emitting surfaces of the two non-bending zones in the folded state. L represents half of the length of the bending zone in the first direction. f0 represents the length of the transition zone of the first support portion in the first direction. R2 represents the minimum curvature radius of the semi-elliptical cylinder constituted by the bending zone in the folded state. P is the correction coefficient corresponding to the minimum curvature radius. b is equal to half of the distance between the two opposite ends of the semi-elliptical cylinder constituted by the light-emitting surface of the bending zone in the folded state along the first direction. The transition zone of the first support portion is close to the second support portion. And / or, the deflection angle in the first characteristic parameter is determined based on θ, and the second characteristic parameter includes X, b, d, L, f0, p, and R2, and θ is determined based on θ' calculated according to the established empirical formula (2): And θ and θ' comply with the second preset relationship.

2. The foldable display device according to claim 1, wherein The surface of the first supporting portion in the transition area facing the screen body is an arc-shaped surface.

3. The foldable display device according to claim 1, wherein The first preset relationship includes: X is less than or equal to (1+10%)X′, and X is greater than or equal to (1-10%)X′.

4. The foldable display device according to claim 1, wherein The second preset relationship includes: θ is less than or equal to (1+10%)θ', and θ is greater than or equal to (1-10%)θ'.

5. The foldable display device according to claim 1, wherein, p is greater than or equal to 1.1 and less than or equal to 1.

2.

6. The foldable display device according to claim 1, wherein, R2 satisfies the following formula: where a represents the semi-major axis of the semi-elliptic cylindrical surface formed by the light-emitting surface of the bending region in the folded state.

7. The foldable display device according to claim 6, wherein R2 is greater than or equal to 0.8b and less than or equal to 0.9b.

8. The foldable display device according to claim 1, wherein, In the folded state, the light-emitting surface of the screen body is located inside the non-light-emitting surface of the screen body opposite to the light-emitting surface.

9. The foldable display device according to claim 1, wherein In the folded state, the deflection angle of the second support portion relative to the first support portion is θ1, and the first characteristic parameter includes θ1; The relationship between θ and θ1 satisfies the following formula (4): θ1 = -t1θ 2 +t2θ - t3 (4) where t1, t2, and t3 are all positive numbers.

10. The foldable display device according to claim 9, wherein, The deflection angle θ1 of the second support portion is equal to the angle between the light-emitting surface of the non-bending region and the surface of the second support portion facing the screen body.

11. The foldable display device according to claim 9, wherein, t1 < t2, t2 < t3.

12. The foldable display device according to claim 9, wherein, t1 = 0.032, t2 = 2.1553, t3 = 5.6217.

13. The foldable display device according to claim 1, wherein, The foldable display device further includes a first flipping mechanism and a second flipping mechanism. The support portion corresponding to the non-bending region is the first support portion, and the support portion corresponding to the bending region is the second support portion. The first flipping mechanism controls the flipping of the first support portion, and the second flipping mechanism controls the flipping of the second support portion relative to the first support portion. At least a partial region of the second flipping mechanism is disposed on the first support portion.

14. The foldable display device according to claim 13, wherein, The first flipping mechanism includes a first rotating shaft and a first bracket. The first bracket is fixedly connected to the first support portion, and one end of the first bracket is connected to the first rotating shaft.

15. The foldable display device according to claim 13, wherein The second flipping mechanism includes a second rotating shaft, a second bracket, and a connecting structure. The second bracket is fixedly connected to the first support portion, and one end of the second bracket is connected to the connecting structure. The connecting structure is fixedly connected to the second support portion and is connected to the second rotating shaft.

16. The foldable display device according to claim 15, wherein The second rotating shaft includes a slide rail, and one end of the connecting structure is movably disposed in the slide rail of the second rotating shaft.

17. The foldable display device according to claim 1, wherein, The length of the second support portion in the first direction is d0, d0 and e' calculated by the following formula (5) satisfy a third preset relationship: where F = f0 + 0.5X.

18. The foldable display device according to claim 17, wherein The third preset relationship includes: d0 is less than or equal to (1 + 10%)e' and greater than or equal to (1 - 10%)e'.

19. The foldable display device according to claim 1, wherein, Both the first support portion and the second support portion include a transition region. The transition region of the first support portion is close to the second support portion, and the transition region of the second support portion is close to the first support portion. The surface of the first support portion facing the screen body in the transition region is an arc surface; The surface of the second support portion facing the screen body in the transition region is an arc surface; The radius of the arc surface of the first support portion in the transition region is R4, and the radius of the arc surface of the second support portion in the transition region is R3; In the folded state, the screen body further includes a reverse folding region corresponding to the transition region, and the radius of the reverse folding region is R1.

20. The foldable display device according to claim 19, wherein, R3 ≤ R1.

21. The foldable display device according to claim 19, wherein, R4 ≤ R1.

22. The foldable display device according to claim 19, wherein R3 is less than or equal to 10 millimeters.

23. The foldable display device according to claim 19, wherein R4 is less than or equal to 10 millimeters.

24. The foldable display device according to claim 19, wherein R3 = R4.

25. The foldable display device according to claim 19, wherein The length of the second support portion in the first direction is d0, and the length of the transition region of the second support portion in the first direction is d1.

26. The foldable display device according to claim 25, wherein, 27. The foldable display device according to claim 2 or 19, characterized in that, The arc surface protrudes towards the screen body; the foldable display device includes a flattened state and a folded state. In the flattened state, among the same set of the support components, in the direction of approaching another support component, the gap between the arc surface of the support part with the transition area and the screen body gradually increases.

28. The foldable display device according to claim 1, wherein The support structure is located on the non-light-emitting surface side of the screen body opposite to the light-emitting surface.

29. The foldable display device according to claim 1, wherein, The foldable display device further includes an adhesive layer, and the adhesive layer is located between the support part and the screen body.

30. The foldable display device according to claim 29, wherein, The orthographic projection of the adhesive layer on the screen body is smaller than the orthographic projection of the support part on the screen body.

31. The foldable display device according to claim 29, wherein The orthographic projection of the adhesive layer on the screen body is located outside the orthographic projection of the transition area of the support part on the screen body.

32. A method for preparing a foldable display device, characterized in that, The foldable display device has a flattened state and a folded state, and the foldable display device includes: A screen body, including two non-bending areas and a bending area located between the adjacent non-bending areas. In the flattened state, the adjacent non-bending areas are located on both sides of the bending area in a first direction; A support structure, the support structure includes two sets of support components, the two sets of support components are respectively located on both sides of the bending axis of the bending area, each set of the support components includes a first support part and a second support part arranged at intervals, at least part of the first support part is arranged corresponding to the non-bending area, and the second support part is arranged on the side of the bending area away from the bending axis; The method includes: Obtaining an empirical formula, the empirical formula includes a first characteristic parameter and a second characteristic parameter, the first characteristic parameter is a design parameter of the support structure, at least including the distance between the first support part and the second support part in the flattened state and / or the deflection angle of the second support part relative to the first support part in the folded state; Determining the second characteristic parameter according to the morphological design requirements of the screen body; Substituting the second characteristic parameter into the empirical formula to determine the first characteristic parameter; In the flattened state, the interval distance between the first support part and the second support part in the same set of the support components in the first direction is X, the first characteristic parameter includes X, and substituting the second characteristic parameter into the empirical formula to determine the first characteristic parameter includes: Substituting the second characteristic parameter into empirical formula (1) to determine X according to X'; Among them, the second characteristic parameters include θ, b, d, L, f0, p, R2. In the folded state, the light-emitting surface of the bending area forms a semi-elliptical cylinder surface and inclined surfaces on both sides of the semi-elliptical cylinder surface. At least a part of the second support part is correspondingly arranged with the inclined surfaces. θ represents the angle between the light-emitting surface of the non-bending area and the inclined surface in the folded state. The angle between the light-emitting surface of the non-bending area and the inclined surface in the folded state is the deflection angle. b represents the semi-minor axis of the semi-elliptical cylinder surface formed by the light-emitting surface of the bending area in the folded state. d represents half of the distance between the light-emitting surfaces of the two non-bending areas in the folded state. L represents half of the length of the bending area in the first direction. f0 represents the length of the transition area of the first support part in the first direction. R2 represents the minimum curvature radius of the semi-elliptical cylinder surface formed by the bending area in the folded state. P is the correction coefficient corresponding to the minimum curvature radius. b is equal to half of the distance between the opposite ends of the semi-elliptical cylinder surface formed by the light-emitting surface of the bending area in the first direction. The transition area of the first support part is close to the second support part; And / or, the first characteristic parameter includes the deflection angle θ1 of the second support part relative to the first support part in the folded state. The first characteristic parameter includes θ1. The second characteristic parameters include X, b, d, L, f0, p, R2. Substituting the second characteristic parameters into the empirical formula to determine the first characteristic parameter includes: Substitute the second characteristic parameters into the empirical formula (2), and determine θ according to θ'; Determine θ1 according to θ.

33. The method according to claim 32, wherein The surface of the first support part facing the screen body in the transition area is an arc surface.

34. The method according to claim 32, characterized in that, X is less than or equal to (1 + 10%)X', and X is greater than or equal to (1 - 10%)X'.

35. The method according to claim 32, wherein θ is less than or equal to (1 + 10%)θ', and θ is greater than or equal to (1 - 10%)θ'.

36. The method according to claim 32, wherein p is greater than or equal to 1.1 and less than or equal to 1.

2.

37. The method according to claim 32, wherein R2 conforms to the following formula: Among them, a represents the semi-major axis of the semi-elliptical cylinder surface formed by the light-emitting surface of the bending area in the folded state.

38. The method according to claim 37, wherein R2 is greater than or equal to 0.8b and less than or equal to 0.9b.

39. The method according to claim 37, wherein In the folded state, the light-emitting surface of the screen body is located inside the non-light-emitting surface of the screen body opposite to the light-emitting surface.

40. The method according to claim 32, characterized in that, The determining θ1 according to θ includes: Determine θ1 degrees according to formula (4): θ1 = -t1θ 2 +t2θ - t3 (4) Among them, t1, t2, and t3 are all positive numbers.

41. The method according to claim 40, wherein The deflection angle θ1 of the second support part is equal to the angle between the light-emitting surface of the non-bending area and the surface of the second support part facing the screen body.

42. The method according to claim 40, characterized in that, t1 < t2, t2 < t3.

43. The method according to claim 40, wherein t1 = 0.032, t2 = 2.1553, t3 = 5.6217.

44. The method according to claim 32, wherein The second support part includes a transition area. The transition area of the second support part is close to the first support part. The surface of the second support part facing the screen body in the transition area is an arc surface; The length of the second support part in the first direction is d0. The method further includes: Determine d0 according to e’ in formula (5):

45. The method according to claim 44, wherein, d0 is less than or equal to (1 + 10%)e’, and d0 is greater than or equal to (1 - 10%)e’.

46. The method according to claim 44, wherein The length of the transition region of the second support portion in the first direction is d1, 47. The method according to claim 44, wherein 48. An electronic device, characterized in that, Comprising the foldable display device according to any one of claims 1 to 31.

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