Display device

Abstract

A display device according to the present disclosure comprises a flexible display panel (DP) including: a flexion region (BF); a first fixed region (A1) fixed to a first support substrate (S1); a second fixed region (A2) fixed to a second support substrate (S2); a first free region (F1) located between the flexion region (BF) and the first fixed region (A1) and not fixed to the first support substrate (S1); and a second free region (F2) located between the flexion region (BF) and the second fixed region (A2) and not fixed to the second support substrate (S2).

Description

display device

[0001] The present disclosure relates to a display device.

[0002] Patent Document 1 discloses the configuration of a bendable electronic device.

[0003] US 2020 / 0319672 A1

[0004] In the configuration disclosed in Patent Document 1, the flexible display panel is adhesively fixed to the plate up to the edge of the bending region. This makes it easy for peeling stress to act on the display panel, making it easy for peeling to occur inside the flexible display panel. Peeling tends to progress between layers with the weakest bonding.

[0005] A display device according to one aspect of the present disclosure is a foldable display device that includes a first support substrate, a second support substrate, and a flexible display panel and can be in an open state and a closed state, wherein the display panel has a bending region, a first fixing region fixed to the first support substrate, a second fixing region fixed to the second support substrate, a first free region located between the bending region and the first fixing region and not fixed to the first support substrate, and a second free region located between the bending region and the second fixing region and not fixed to the second support substrate.

[0006] According to the configuration of the present disclosure, it is possible to reduce the occurrence of peeling inside the display device.

[0007] 11 is a cross-sectional view showing an example of a configuration of a display device according to an embodiment of the present disclosure in an open state. FIG. 12 is a cross-sectional view showing an example of a configuration of a display device according to an embodiment of the present disclosure in a closed state. FIG. 13 is a diagram showing an external force and internal stress in a bonding direction according to the present disclosure. FIG. 14 is a diagram showing an external force and internal stress in a displacement direction according to the present disclosure. FIG. 15 is a cross-sectional view showing an example of a configuration of a display panel according to an embodiment of the present disclosure. FIG. 16 is a cross-sectional view showing an example of a configuration of a display device according to an embodiment of the present disclosure in a closed state. FIG. 17 is a cross-sectional view showing an example of a configuration of a display device according to an embodiment of the present disclosure in a closed state. FIG. 18 is a cross-sectional view showing an example of a configuration of a display device according to an embodiment of the present disclosure in a closed state. FIG. 19 is a cross-sectional view showing an example of a configuration of a display device according to an embodiment of the present disclosure in an open state. FIG. 19 is a plan view showing an example of a configuration of the flexible substrate shown in FIGS. 9 and 10. FIG. 19 is a cross-sectional view showing a modified configuration of a display device according to an embodiment of the present disclosure in an open state. FIG. 19 is a cross-sectional view showing a modified configuration of a display device according to an embodiment of the present disclosure in an open state. FIG. 1 is a graph showing simulation results of compressive stress and tensile stress generated in the display panel in the closed state. FIG. 2 is a diagram showing simulation results of compressive stress and tensile stress generated in the display panel according to Comparative Example 1 in the closed state superimposed on a cross-sectional view. FIG. 3 is a diagram showing simulation results of compressive stress and tensile stress generated in the display panel according to Example 1 in the closed state superimposed on a cross-sectional view. FIG. 4 is a diagram showing simulation results of shear stress generated in the display panel according to Comparative Example 1 in the closed state superimposed on a cross-sectional view. FIG. 5 is a diagram showing simulation results of shear stress generated in the display panel according to Example 1 in the closed state superimposed on a cross-sectional view. FIG. 6 is a cross-sectional view showing simulation results of deformation and movement of the display panel according to Example 1 in the closed state.

[0008] [Embodiment 1] Fig. 1 is a cross-sectional view showing an example of the configuration of a display device according to an embodiment of the present disclosure in an open state. Fig. 2 is a cross-sectional view showing an example of the configuration of a display device according to an embodiment of the present disclosure in a closed state. As shown in Figs. 1 and 2, a display device 10 according to embodiment 1 of the present disclosure is a foldable display device that includes a first support substrate S1, a second support substrate S2, and a flexible display panel DP and can be in an open state or a closed state. The display panel DP has a bending region BF, a first fixing region A1 fixed to the first support substrate S1, a second fixing region A2 fixed to the second support substrate S2, a first free region F1 located between the bending region BF and the first fixing region A1 and not fixed to the first support substrate S1, and a second free region F2 located between the bending region BF and the second fixing region A2 and not fixed to the second support substrate S2.

[0009] In this disclosure, the direction in which the display panel DP is located relative to the first support substrate S1 is defined as the z direction, the direction in which the second support substrate S2 is located relative to the first support substrate S1 in the open state is defined as the x direction, and the direction perpendicular to the x direction and z direction is defined as the y direction.

[0010] Fig. 3 is a diagram showing external forces and internal stresses in the bonding direction according to the present disclosure. As shown in Fig. 3, when a tensile force is applied to the display panel, a tensile stress acts to peel the objects 1 and 2 from the bonding surface. Furthermore, when a compressive force is applied to the display panel, a compressive stress acts to press the objects 1 and 2 against the bonding surface. The tensile force and tensile stress shown on the left side of Fig. 3 are defined as positive directions, and the compressive force and compressive stress shown on the right side of Fig. 3 are defined as negative directions.

[0011] Fig. 4 is a diagram showing external forces and internal stresses in the shear direction according to the present disclosure. As shown in Fig. 4, when a force in the shear direction is applied to the bonded body, shear stress acts to displace objects 1 and 2 from the bonded surface. The force and shear stress in the shear direction shown on the left side of Fig. 4 are defined as positive directions, and the force and shear stress in the shear direction shown on the right side of Fig. 4 are defined as negative directions.

[0012] In actual experiments, when the tensile stress and shear stress acting on the bonding surface exceed the bonding strength, objects 1 and 2 peel from the bonding surface. In this disclosure, tensile stress and shear stress that can cause peeling are collectively referred to as "peeling stress." Note that the simulations described below (see FIGS. 18 to 23) are not actual experiments but numerical experiments performed on a computer. For simplicity, the stress simulations (see FIGS. 18 to 22) used a model in which peeling does not occur, i.e., a model in which the bonding strength of the bonding surface is infinite.

[0013] 1 and 2 , according to the configuration of the present disclosure, the display panel DP has a bending region BF, a first fixing region A1 fixed to the first support substrate S1, a second fixing region A2 fixed to the second support substrate S2, a first free region F1 located between the bending region BF and the first fixing region A1 and not fixed to the first support substrate S1, and a second free region F2 located between the bending region BF and the second fixing region A2 and not fixed to the second support substrate S2. Therefore, even if an external force is applied to the first free region F1 by opening or closing the display device 10, peel stress is unlikely to act on the bonding surface between the first free region F1 and the first support substrate S1 or on the bonding surface within the first free region F1. Even if an external force is applied to the second free region F2, peel stress is unlikely to act on the bonding surface between the second free region F2 and the second support substrate S2 or on the bonding surface within the second free region F2.

[0014] Therefore, the configuration according to the present disclosure can reduce the occurrence of peeling inside the display device 10 compared to a configuration in which there is no free region between the fixed region and the bending region. In the configuration according to the present disclosure, it is beneficial for the widths of the first free region F1 and the second free region F2 to be sufficiently large so that opening and closing the display device 10 does not affect the first fixed region A1 and the second fixed region A2. For example, if the distance of the gap G1 between the first fixed region F1 and the second fixed region F2 in the closed state is 3 mm, the widths of the first free region F1 and the second free region F2 may each be 1 to 20 mm. In this disclosure, "width" refers to the size in the x direction in the open state unless otherwise specified.

[0015] The bending region BF is located between the first free region F1 and the second free region F2 and is continuously connected to the first free region F1 and the second free region F2. The first free region F1 is continuously connected to the first fixed region A1, and the second free region F2 is continuously connected to the second fixed region A2. The first fixed region A1 and the first free region F1 are located on the same plane as each other, and the second free region F2 and the second fixed region A2 are located on the same plane as each other.

[0016] In the closed state, the first support substrate S1 and the first free region F1 may be in contact with each other, and the second support substrate S2 and the second free region F2 may be in contact with each other. The first free region F1 may be in contact with the first support substrate S1 even in the open state, and the second free region F2 may be in contact with the second support substrate S2 even in the open state. On the other hand, in the closed state, the bending region BF may not be in contact with either the first support substrate S1 or the second support substrate S2. In the closed state, the bending region BF may be located between the first support substrate S1 and the second support substrate S2 in a cross-sectional view.

[0017] The first fixing region A1 is fixed to the first support substrate S1 via a first fixing material B1, and the second fixing region A2 is fixed to the second support substrate S2 via a second fixing material B2. The thickness of the first support substrate S1 at a portion overlapping the first free region F1 may be greater than the thickness of the portion overlapping the first fixing material B1, and the thickness of the second support substrate S2 at a portion overlapping the second free region F2 may be greater than the thickness of the portion overlapping the second fixing material B2. The difference in thickness between the portion overlapping the first free region F1 and the portion overlapping the first fixing material B1 may be equal to the thickness of the first fixing material B1, and the difference in thickness between the portion overlapping the second free region F2 and the portion overlapping the second fixing material B2 may be equal to the thickness of the second fixing material B2. "Thickness" refers to the size in the z direction in the open state.

[0018] In the present disclosure, when the difference between the first size and the second size is 10% or less of the first size, or 10 μm or less, the first size is said to be equal to the second size.

[0019] In the closed state, the gap G1 between the first fixing region A1 and the second fixing region A2 may be equal to the gap G2 between the first free region F1 and the second free region F2. In the closed state, the bent region BF may be bent, for example, U-shaped, so that the gap G3 between the bent regions BF is smaller than the gap G2 between the first free region F1 and the second free region F2 (see FIG. 2).

[0020] Referring to FIG. 1 , the display panel DP includes a cushion material BA as a layer closest to the first support substrate S1 and the second support substrate S2. For example, the display panel DP includes the cushion material BA adhered to a flexible substrate 1 via an adhesive layer M1, and the cushion material BA is fixed to the first support substrate S1 and the second support substrate S2 via a first fixing material B1 and a second fixing material B2. The first support substrate S1 and the second support substrate S2 are each one of a metal plate, a resin plate, and a fiber-reinforced resin plate. The fiber-reinforced resin plate includes a carbon plate containing carbon fiber. The first support substrate S1 and the second support substrate S2 may be movably mechanically connected by a hinge device HD. A first end of the hinge device HD may be directly or indirectly fixed to the first support substrate S1, and a second end of the hinge device HD may be directly or indirectly fixed to the second support substrate S2.

[0021] FIG. 5 is a cross-sectional view showing an example of the configuration of a display panel according to an embodiment of the present disclosure. As shown in FIG. 5, the display panel DP may include a light-emitting element ED including an organic light-emitting layer or a quantum dot light-emitting layer as the light-emitting layer EM. For example, the display panel DP may include a flexible substrate 1, a transistor layer 2 including circuit elements such as transistors Tr and wiring, a display layer 3 including the light-emitting element ED, and a sealing layer 4 for preventing oxygen and moisture from entering the light-emitting element ED. The light-emitting element ED may include an anode E1, a cathode E2, and an light-emitting layer EM located between the anode E1 and the cathode E2. For example, the light-emitting element ED may further include an electron injection layer EIL and an electron transport layer ETL for facilitating electron injection into the light-emitting layer EM, and a hole injection layer HIL and a hole transport layer HTL for facilitating hole injection into the light-emitting layer EM. For example, the display panel DP may include, in this order above the sealing layer 4, an adhesive layer M2, a touch panel layer 5, an adhesive layer M3, a polarizing film 6, an adhesive layer M4, and a flexible cover 7.

[0022] Quantum dots refer to dots with a maximum width of 100 nm or less. The shape of the quantum dots is not particularly limited as long as it satisfies the above maximum width, and is not limited to a spherical three-dimensional shape (circular cross-sectional shape). For example, they may have a polygonal cross-sectional shape, a rod-like three-dimensional shape, a branch-like three-dimensional shape, a three-dimensional shape with an uneven surface, or a combination thereof. In this embodiment, the quantum dots are semiconductor microparticles having a particle size of, for example, 100 nm or less, and may include II-VI group semiconductor compounds such as MgS, MgSe, MgTe, CaS, CaSe, CaTe, SrS, SrSe, SrTe, BaS, BaSe, BaTe, ZnS, ZnSe, ZnTe, CdS, CdSe, CdTe, HgS, HgSe, and HgTe, and / or crystals of III-V group semiconductor compounds such as GaAs, GaP, InN, InAs, InP, and InSb, and / or crystals of Group IV semiconductor compounds such as Si and Ge. Furthermore, the quantum dots may have a core / shell structure in which the above-mentioned semiconductor crystal serves as a core and the core is overcoated with a shell material having a large band gap. The shell does not necessarily need to completely cover the core; it may be formed on at least a portion of the core.

[0023] The cushioning material BA may include multiple layers, and may include an adhesive layer. Materials included in the cushioning material BA include polyethylene terephthalate (PET) resin, acrylic resin, urethane resin, polyester resin, stainless steel, aluminum, titanium, copper, and the like.

[0024] [Embodiment 2] Another embodiment of the present disclosure will be described below. For ease of explanation, the same reference numerals will be used to designate components having the same functions as those described in the above embodiment, and the description thereof will not be repeated.

[0025] 6 is a cross-sectional view showing an example of the configuration of a display device according to an embodiment of the present disclosure in a closed state. As shown in FIG. 6 , the display device 10 may have a first gap C1 adjacent to a first fixing member B1 and located between a first support substrate S1 and a first free region F1 of the display panel DP, and a second gap C2 adjacent to a second fixing member B2 and located between a second support substrate S2 and a second free region F2 of the display panel DP. The width of the first gap C1 may be smaller than the width of the first fixing member B1, and the width of the second gap C2 may be smaller than the width of the second fixing member B2.

[0026] In this disclosure, "a member adjacent to another member" includes a case where there is a gap between the two members and the member is adjacent to the other member via the gap, and a case where the member is in contact with the other member and adjacent to it with no gap. In this disclosure, "adjacent to a member with a gap" means a case where there is no other member between the gap and the member and the member is in contact with the member with the gap and adjacent to it.

[0027] [Embodiment 3] Fig. 7 is a cross-sectional view showing an example of the configuration of a display device according to an embodiment of the present disclosure in a closed state. As shown in Fig. 7, the display device 10 may have a first step adjustment material D1 adjacent to a first fixing material B1 and located between a first support substrate S1 and a first free region F1 of the display panel DP, and a second step adjustment material D2 adjacent to a second fixing material B2 and located between a second support substrate S2 and a second free region F2 of the display panel DP. The first fixing material B1 and the first step adjustment material D1 may be in contact with each other, and the second fixing material B2 and the second step adjustment material D2 may be in contact with each other.

[0028] The thickness of the first support substrate S1 at a portion overlapping with the first free region F1 may be equal to the thickness of the portion overlapping with the first fixing material B1, and the thickness of the second support substrate S2 at a portion overlapping with the second free region F2 may be equal to the thickness of the portion overlapping with the second fixing material B2. The thickness of the first step adjustment material D1 may be equal to the thickness of the first fixing material B1, and the thickness of the second step adjustment material D2 may be equal to the thickness of the second fixing material B2.

[0029] In the closed state, the first step adjustment material D1 and the first free region F1 of the display panel DP may be in contact with each other, and the second step adjustment material D2 and the second free region F2 of the display panel DP may be in contact with each other.

[0030] [Embodiment 4] Fig. 8 is a cross-sectional view showing an example of the configuration of a display device according to an embodiment of the present disclosure in a closed state. As shown in Fig. 8, the display device 10 has a first step adjustment material D1 and a second step adjustment material D2, and may further have a first gap C1 located between the first fixing material B1 and the first step adjustment material D1, and a second gap C2 located between the second fixing material B2 and the second step adjustment material D2.

[0031] [Embodiment 5] Fig. 9 is a cross-sectional view showing an example of the configuration of a display device according to an embodiment of the present disclosure in an open state. Fig. 10 is a cross-sectional view showing an example of the configuration of a display device according to an embodiment of the present disclosure in a closed state. As shown in Figs. 9 and 10, the display device 10 may include a flexible substrate S3 that is continuously connected to the first support substrate S1 and the second support substrate S2 and is integrated with the first support substrate S1 and the second support substrate S2.

[0032] 11 is a plan view showing an example of the configuration of the flexible substrate shown in FIGS. 9 and 10. As shown in FIG. 11, the flexible substrate S3 may be a portion that has been shaped to reduce the second moment of area of ​​the rigid substrate S4, and each of the first support substrate S1 and the second support substrate S2 may be a portion that has not been shaped to reduce the second moment of area of ​​the rigid substrate S4. The shaping to reduce the second moment of area of ​​the portion of the rigid substrate S4 includes processing to form an opening K in that portion. Therefore, the flexible substrate S3 may include one or more openings K. The opening K may or may not be a through opening.

[0033] 9 and 10, the bent region BF of the display panel DP may be in contact with the flexible substrate S3, and the first free region F1 and the second free region F2 may be in contact with the flexible substrate S3.

[0034] 12 to 14 are cross-sectional views showing modified examples of the configuration of the display device according to an embodiment of the present disclosure in an open state. As shown in FIGS. 12 to 14, the configuration according to embodiment 5 can be combined with the configurations according to embodiments 2 to 4 described above.

[0035] [Embodiment 6]

[0036] 15 is a cross-sectional view showing an example of the configuration of a display device according to an embodiment of the present disclosure in an open state. As shown in FIG. 15, a bending region BF of a display panel DP may be adhered to a flexible substrate S3 via an adhesive layer M5. The display device 10 may have a first gap C1 located between a first fixing material B1 and the adhesive layer M5, and a second gap C2 located between a second fixing material B2 and the adhesive layer M5.

[0037] An example of the present disclosure will be described below. As Example 1 of the present disclosure, a display device 10 having the configuration shown in Figures 1 and 2 was produced. In addition, display devices 100 and 200 according to Comparative Examples 1 and 2 were also produced.

[0038] FIG. 16 is a cross-sectional view showing the configuration of a display device according to Comparative Example 1 in an open state. As shown in FIG. 16 , the display device 100 according to Comparative Example 1 was a foldable display device that included a first support substrate 101, a second support substrate 102, and a flexible display panel 103 and could be in an open or closed state. The display panel 103 had a bending region 110, a first fixing region 111 fixed to the first support substrate 101 by a first fixing member 104, and a second fixing region 112 fixed to the second support substrate 102 by a second fixing member 105. The bending region 110 was directly connected to the first fixing region 111 and the second fixing region 112. The width of the bending region 110 according to Comparative Example 1 was approximately the same as the width of the bending region BF according to Example 1 of the present disclosure.

[0039] FIG. 17 is a cross-sectional view showing the configuration of a display device according to Comparative Example 2 in an open state. As shown in FIG. 17 , the display device 200 according to Comparative Example 1 was a foldable display device that included a first support substrate 201, a second support substrate 202, and a flexible display panel 203 and could be in an open or closed state. The display panel 203 had a bending region 210, a first fixing region 211 fixed to the first support substrate 201 by a first fixing member 204, and a second fixing region 212 fixed to the second support substrate 202 by a second fixing member 205. The bending region 210 was continuously connected to the first fixing region 211 and the second fixing region 212. The width of the bending region 210 according to Comparative Example 2 was the same as the combined width of the first free region F1, the bending region BF, and the second free region F2 according to Example 1 of the present disclosure.

[0040] In all of Example 1, Comparative Example 1, and Comparative Example 2, the display panel DP, 103, 203 was flat in the open state, and the distance of the gap G1 between the first fixing area A1, 111, 211 and the second fixing area A2, 112, 212 was 3.0 mm in the closed state.

[0041] FIG. 18 is a graph showing the results of a simulation of compressive stress and tensile stress generated in the display panel in the closed state. On the vertical axis, positive indicates compressive stress, and negative indicates tensile stress. As shown in FIG. 18, the graphs for Comparative Example 1 and Example 1 almost overlap, and the peak tensile stress value for Comparative Example 1 was 0.43 times that of Comparative Example 2, and for Example 1 it was 0.42 times that of Comparative Example 2. Peeling typically occurs between layers with the weakest adhesive strength. Typically, the adhesive strength between the display panel DP and the first and second support substrates S1 and S2 is stronger than the adhesive strength within the display panel DP, and peeling tends to occur within the display panel DP. Therefore, compared to the display panel 203 of Comparative Example 2, peeling within the display panel DP is less likely to occur in Example 1.

[0042] The distance from the bending center CP to the boundary between the bending region BF and the first free region F1 in Example 1 was 2.4 mm to 3.2 mm. The distance from the bending center 115 to the boundary between the bending region 110 and the first fixing region 111 in Comparative Example 1 was 2.4 mm to 3.2 mm. The distance from the bending center 215 to the boundary between the bending region 210 and the first fixing region 211 in Comparative Example 2 was 4.8 mm to 6.2 mm.

[0043] The peak positions of the tensile stress were in the first and second fixing regions 111, 112, 211, and 212 in Comparative Examples 1 and 2, and in the first and second free regions F1 and F2 in Example 1. Therefore, in the actual experiment, it is expected that the display panel DP in Example 1 will be less likely to peel off from the first and second support substrates S1 and S2 than in Comparative Examples 1 and 2.

[0044] 19 is a diagram superimposed on a cross-sectional view showing the results of a simulation of compressive stress and tensile stress generated in the display panel according to Comparative Example 1 in the closed state. Fig. 20 is a diagram superimposed on a cross-sectional view showing the results of a simulation of compressive stress and tensile stress generated in the display panel according to Example 1 in the closed state. In graphs 120 and 20, the length of a line segment extending from the central surface of the display panel 103 (DP) indicates the magnitude of tensile stress or compressive stress. The support substrate side of the central surface of the display panel 103 (DP) indicates tensile stress, and the opposite side of the support substrate indicates compressive stress.

[0045] FIG. 21 is a diagram superimposed on a cross-sectional view showing the results of a simulation of shear stress generated in a display panel according to Comparative Example 1 in the closed state. FIG. 22 is a diagram superimposed on a cross-sectional view showing the results of a simulation of shear stress generated in a display panel according to Example 1 in the closed state. In graphs 130 and 30, the length of a line extending from the central surface of the display panel 103 (DP) indicates the magnitude of shear stress. The support substrate side of the central surface of the display panel 103 (DP) indicates negative shear stress, and the side opposite the support substrate indicates positive shear stress. In this simulation, the direction from the bending center toward the edge of the display panel was defined as positive, and the opposite direction was defined as negative.

[0046] 19 and 21 , in Comparative Example 1, the range in which tensile stress and positive shear stress occur was included in the first fixing region 111. Because the display panel 103 is fixed to the first support substrate 101 by the first fixing region 111, it is expected that the display panel 103 will be easily peeled off from the first support substrate 101 due to the tensile stress and positive shear stress in the actual experiment. On the other hand, as shown in FIGS. 20 and 22 , in Example 1, the range in which tensile stress and positive shear stress occur was included in the first free region F1. Because the display panel DP is not fixed in the first free region F1, it is expected that the display panel DP will deform and move, thereby relieving the tensile stress and positive shear stress, making it difficult for the display panel DP to peel off from the first support substrate S1 in the actual experiment.

[0047] 23 is a cross-sectional view showing the results of a simulation of deformation and movement of the display panel in the closed state according to Example 1. As shown in Fig. 23, in Example 1, the display panel DP rose above the first support substrate S1 in a range R. Note that the distance of the rise was very small.

[0048] The present disclosure is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present disclosure. Furthermore, new technical features can be formed by combining the technical means disclosed in each embodiment.

[0049] 10 Display device A1 1st fixing area A2 2nd fixing area B1 1st fixing material B2 2nd fixing material BA Cube material BF Flexing area C1 1st gap C2 2nd gap CP, 115, 215 Flexing center D1 1st step adjustment material D2 2nd step adjustment material DP, 103, 203 Display pannel ED Light emitting element F1 1st free area F2 2nd free area G1, G2, G3 Gaps K Openings M1, M2, M3, M4, M5 Adhesive layer S1 1st supporting substrate S2 2nd supporting substrate S3 Flexible substrate S4 Rigid substrate

Claims

1. A foldable display device comprising a first support substrate, a second support substrate, and a flexible display panel, and capable of being in an open state and a closed state, wherein the display panel has a bending region, a first fixing region fixed to the first support substrate, a second fixing region fixed to the second support substrate, a first free region located between the bending region and the first fixing region and not fixed to the first support substrate, and a second free region located between the bending region and the second fixing region and not fixed to the second support substrate.

2. The display device according to claim 1, wherein the bending region is connected to the first free region and the second free region.

3. A display device according to claim 1 or 2, wherein the first fixed region and the first free region are located on the same plane.

4. A display device according to any one of claims 1 to 3, wherein in the closed state, the first support substrate and the first free area are in contact, and the second support substrate and the second free area are in contact.

5. The display device according to claim 4, wherein in the closed state, the bending region is not in contact with the first support substrate and the second support substrate.

6. The display device according to claim 4 or 5, wherein in the closed state, the bending region is located between the first support substrate and the second support substrate.

7. The display device according to claim 4, wherein the first free area contacts the first support substrate in the open state, and the second free area contacts the second support substrate in the open state.

8. A display device according to any one of claims 1 to 7, wherein the first fixing region is fixed to the first support substrate via a first fixing material, and the second fixing region is fixed to the second support substrate via a second fixing material.

9. The display device described in claim 8, wherein the first support substrate has a portion that overlaps with the first free region that is thicker than the portion that overlaps with the first fixing material, and the second support substrate has a portion that overlaps with the second free region that is thicker than the portion that overlaps with the second fixing material.

10. The display device of claim 9, comprising: a first gap adjacent to the first fixing material and located between the first support substrate and the first free area; and a second gap adjacent to the second fixing material and located between the second support substrate and the second free area.

11. The display device according to claim 10, wherein the width of the first gap is smaller than the width of the first fixing material, and the width of the second gap is smaller than the width of the second fixing material.

12. A display device as described in claim 8, comprising: a first step adjustment material adjacent to the first fixing material and located between the first support substrate and the first free area; and a second step adjustment material adjacent to the second fixing material and located between the second support substrate and the second free area.

13. The display device according to claim 12, wherein the first fixing material and the first step adjustment material are in contact with each other, and the second fixing material and the second step adjustment material are in contact with each other.

14. The display device according to claim 12, further comprising a first gap located between the first fixing material and the first step adjustment material, and a second gap located between the second fixing material and the second step adjustment material.

15. A display device according to any one of claims 12 to 14, wherein in the closed state, the first step adjustment material and the first free area are in contact, and the second step adjustment material and the second free area are in contact.

16. The display device according to any one of claims 1 to 15, further comprising a flexible substrate connected to the first support substrate and the second support substrate and integral with the first support substrate and the second support substrate.

17. The display device of claim 16, wherein the flexible substrate includes one or more apertures.

18. The display device according to any one of claims 16 to 17, wherein the bending region is in contact with the flexible substrate.

19. The display device of claim 18, wherein the first free area and the second free area are in contact with the flexible substrate.

20. The display device according to any one of claims 15 to 17, wherein the bending region is adhered to the flexible substrate via an adhesive layer.

21. A display device according to any one of claims 1 to 20, wherein in the closed state, the gap distance between the first fixed area and the second fixed area is equal to the gap distance between the first free area and the second free area.

22. The display device according to any one of claims 1 to 21, wherein in the closed state, the bent region is U-shaped.

23. The display device according to any one of claims 1 to 22, wherein the display panel comprises a cushioning material as a layer closest to the first support substrate and the second support substrate.

24. The display device according to any one of claims 1 to 23, wherein the first support substrate and the second support substrate are any one of a metal plate, a resin plate, and a fiber-reinforced resin plate.

25. The display device according to any one of claims 1 to 24, wherein the display panel has light-emitting elements including an organic light-emitting layer or a quantum dot light-emitting layer.

Images