Display apparatus and method for manufacturing the same

Abstract

The present invention provides a display device comprising a display panel including a display element and an upper organic layer including a first organic layer disposed on the upper portion of the display panel and a second organic layer interposed between the first organic layer and the display panel, wherein the upper organic layer comprises a first non-folding portion and a second non-folding portion disposed spaced apart from each other, a first foldable portion disposed between the first non-folding portion and the second non-folding portion and extending in a direction intersecting a virtual straight line connecting the first non-folding portion and the second non-folding portion and having a thickness greater than the thickness of the first non-folding portion, and a plurality of second foldable portions disposed on both sides of the first foldable portion and extending in a direction intersecting a virtual straight line connecting the first non-folding portion and the second non-folding portion and having a thickness thinner than the thickness of the first non-folding portion.

Description

Technology Field

[0001] Embodiments of the present invention relate to a display device, and more specifically, to a display device capable of increasing the flatness of the display surface. Background Technology

[0002] Display devices can be utilized in various electronic devices. For example, a display device can be a mobile electronic device such as a smartphone. To reduce its overall size while expanding the display surface area, such an electronic device may be a foldable electronic device in which a portion of the display surface is folded. The problem to be solved

[0003] However, these conventional display devices had a problem in that the display surface might not be flat when unfolded after being folded.

[0004] The present invention aims to solve various problems, including those mentioned above, by providing a display device capable of increasing the flatness of the display surface. However, this problem is exemplary and does not limit the scope of the present invention. means of solving the problem

[0005] According to one aspect of the present invention, a display device is provided comprising a display panel including a display element and an upper organic layer including a first organic layer disposed on top of the display panel and a second organic layer interposed between the first organic layer and the display panel, wherein the upper organic layer comprises a first non-folding portion and a second non-folding portion disposed spaced apart from each other, a first foldable portion disposed between the first non-folding portion and the second non-folding portion and extending in a direction intersecting a virtual straight line connecting the first non-folding portion and the second non-folding portion and having a thickness greater than the thickness of the first non-folding portion, and a plurality of second foldable portions disposed on both sides of the first foldable portion and extending in a direction intersecting a virtual straight line connecting the first non-folding portion and the second non-folding portion and having a thickness thinner than the thickness of the first non-folding portion.

[0006] The thickness of the first foldable portion may increase from the outer edge of the first foldable portion toward the center of the first foldable portion, and the thickness of the second foldable portion may decrease from the outer edge of the second foldable portion toward the center of the second foldable portion.

[0007] The thickness of the first foldable portion may increase as it moves away from the second foldable portion, the thickness of a part of the second foldable portion may decrease as it moves away from the first foldable portion, the thickness of another part of the second foldable portion may decrease as it moves away from the first non-folding portion, and the thickness of yet another part of the second foldable portion may decrease as it moves away from the second non-folding portion.

[0008] The first non-folding portion includes a first-1 non-folding portion which is part of the first organic layer and a second-1 non-folding portion which is part of the second organic layer, and the second non-folding portion includes a first-2 non-folding portion which is part of the first organic layer and a second-2 non-folding portion which is part of the second organic layer, and the first foldable portion includes a first-1 foldable portion which is part of the first organic layer and a second-1 foldable portion which is part of the second organic layer, and the second foldable portion may include a first-2 foldable portion which is part of the first organic layer and a second-2 foldable portion which is part of the second organic layer.

[0009] The second organic layer has a uniform thickness, the thickness of the first-1 foldable portion is thicker than the thickness of the first-1 non-foldable portion, and the thickness of the first-2 foldable portion may be thinner than the thickness of the first-1 non-foldable portion.

[0010] The thickness of the first-1 foldable portion may increase from the outer edge of the first-1 foldable portion toward the center of the first-1 foldable portion, and the thickness of the second-1 foldable portion may decrease from the outer edge of the second-1 foldable portion toward the center of the second-1 foldable portion.

[0011] The thickness of the first-1 foldable portion may increase as it moves away from the first-2 foldable portion, the thickness of a part of the first-2 foldable portion may decrease as it moves away from the first-1 foldable portion, the thickness of another part of the first-2 foldable portion may decrease as it moves away from the first-1 non-folding portion, and the thickness of yet another part of the first-2 foldable portion may decrease as it moves away from the first-2 non-folding portion.

[0012] The first organic layer has a uniform thickness, the thickness of the second-1 foldable portion is thicker than the thickness of the second-1 non-foldable portion, and the thickness of the second-2 foldable portion may be thinner than the thickness of the second-1 non-foldable portion.

[0013] The thickness of the above 2-1 foldable portion may increase from the outer edge of the above 2-1 foldable portion toward the center of the above 2-1 foldable portion, and the thickness of the above 2-2 foldable portion may decrease from the outer edge of the above 2-2 foldable portion toward the center of the above 2-2 foldable portion.

[0014] The thickness of the above 2-1 foldable portion increases as it moves away from the above 2-2 foldable portion, the thickness of a part of the above 2-2 foldable portion decreases as it moves away from the above 2-1 foldable portion, the thickness of another part of the above 2-2 foldable portion decreases as it moves away from the above 2-1 non-folding portion, and the thickness of yet another part of the above 2-2 foldable portion decreases as it moves away from the above 2-2 non-folding portion.

[0015] The sum of the thickness of the first-1 foldable portion and the thickness of the second-1 foldable portion is greater than the sum of the thickness of the first-1 non-foldable portion and the thickness of the second-1 non-foldable portion, and the sum of the thickness of the first-2 foldable portion and the thickness of the second-2 foldable portion may be smaller than the sum of the thickness of the first-1 non-foldable portion and the thickness of the second-1 non-foldable portion.

[0016] The first organic layer may have a higher modulus than the second organic layer.

[0017] The modulus of the first organic layer may be 1 GPa or more and less than 10 GPa, and the modulus of the second organic layer may be 0.1 GPa or more and less than 1 GPa.

[0018] According to one aspect of the present invention, a method for manufacturing a display device is provided, comprising the steps of preparing a display panel including a display element and forming an upper organic layer including a first organic layer and a second organic layer on the display panel, wherein the step of forming the upper organic layer comprises a first non-folding portion and a second non-folding portion spaced apart from each other, a first foldable portion disposed between the first non-folding portion and the second non-folding portion and extending in a direction intersecting a virtual straight line connecting the first non-folding portion and the second non-folding portion and having a thickness greater than the thickness of the first non-folding portion, and a plurality of second foldable portions disposed on both sides of the first foldable portion and extending in a direction intersecting a virtual straight line connecting the first non-folding portion and the second non-folding portion and having a thickness thinner than the thickness of the first non-folding portion.

[0019] The step of forming the upper organic layer may include the step of applying a second organic layer composition to the display panel, the step of forming a second organic layer by irradiating ultraviolet rays onto the second organic layer composition, the step of applying a first organic layer composition onto the second organic layer, and the step of forming a first organic layer by irradiating ultraviolet rays onto the first organic layer composition while applying pressure to the first organic layer composition using a jig.

[0020] The lower surface of the above jig can be treated as a non-stick surface.

[0021] The step of forming the first organic layer may be a step of forming the first organic layer such that the upper surface of the first organic layer has a shape that interlocks with the lower surface of the jig.

[0022] The step of forming the upper organic layer may include the step of applying a second organic layer composition onto the display panel, the step of forming a second organic layer by applying ultraviolet rays to the second organic layer composition while applying pressure to the second organic layer composition using a jig, the step of applying a first organic layer composition to the second organic layer, and the step of forming a first organic layer by irradiating ultraviolet rays to the first organic layer composition.

[0023] The lower surface of the above jig can be treated as a non-stick surface.

[0024] The step of forming the second organic layer may be a step of forming the second organic layer such that the upper surface of the second organic layer has a shape that interlocks with the lower surface of the jig.

[0025] Other aspects, features, and advantages other than those described above will become clear from the following specific details, claims, and drawings for implementing the invention. Effects of the invention

[0026] According to one embodiment of the present invention as described above, a display device capable of increasing the flatness of the display surface can be implemented. Of course, the scope of the present invention is not limited by this effect. Brief explanation of the drawing

[0027] FIG. 1 is a perspective view schematically illustrating a display device according to one embodiment of the present invention. FIG. 2 is a cross-sectional view schematically illustrating a display device according to one embodiment of the present invention. FIG. 3 is a cross-sectional view schematically illustrating a cross-section taken along the line I-I' of the display device (1) of FIG. 1. FIG. 4a is a cross-sectional view schematically illustrating an enlarged view of part A of the display device (1) of FIG. 3. Figures 4b, 4c, and 4d are drawings to illustrate the thickness of the upper organic layer of Figure 4a. FIG. 5a is a cross-sectional view schematically illustrating a display device according to one embodiment of the present invention. Figures 5b, 5c, and 5d are drawings to explain the thickness of the upper organic layer of Figure 5a. FIG. 6 is a cross-sectional view schematically illustrating a part of a display device according to a comparative example. Figure 7 is a drawing for explaining the deformation of the foldable area of ​​a display device according to a comparative example. FIG. 8 is a drawing for explaining a deformation of a foldable area of ​​a display device according to an embodiment of the present invention. FIG. 9 is a cross-sectional view schematically illustrating a part of a display panel included in a display device according to one embodiment of the present invention. FIGS. 10 to 13 are drawings for explaining a method of manufacturing a display device according to an embodiment of the present invention. FIGS. 14 to 16 are drawings for explaining a method of manufacturing a display device according to an embodiment of the present invention. Specific details for implementing the invention

[0028] The present invention is capable of various modifications and may have various embodiments; specific embodiments are illustrated in the drawings and described in detail in the detailed description. The effects and features of the present invention, and the methods for achieving them, will become clear by referring to the embodiments described below in detail together with the drawings. However, the present invention is not limited to the embodiments disclosed below but can be implemented in various forms.

[0029] Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings. When describing with reference to the drawings, identical or corresponding components are given the same reference numerals, and redundant descriptions thereof will be omitted.

[0030] In the following embodiments, when various components such as layers, films, regions, and plates are described as being "on" another component, this includes not only cases where they are "directly on" another component, but also cases where other components are interposed between them. Furthermore, for convenience of explanation, the size of components in the drawings may be exaggerated or reduced. For example, the size and thickness of each component shown in the drawings are depicted arbitrarily for convenience of explanation, and therefore the present invention is not necessarily limited to what is illustrated.

[0031] In the following embodiments, the x-axis, y-axis, and z-axis are not limited to three axes in an orthogonal coordinate system and can be interpreted in a broader sense that includes them. For example, the x-axis, y-axis, and z-axis may be orthogonal to each other, but they may also refer to different directions that are not orthogonal to each other.

[0032] In the following examples, terms such as first, second, etc. are used not in a limiting sense, but for the purpose of distinguishing one component from another component.

[0033] In the following examples, singular expressions include plural expressions unless the context clearly indicates otherwise.

[0034] In the following embodiments, terms such as "comprising" or "having" mean that the features or components described in the specification are present, and do not preclude the possibility that one or more other features or components may be added.

[0035] In this specification, "A and / or B" indicates the case where it is A, B, or both A and B. And, "at least one of A and B" indicates the case where it is A, B, or both A and B.

[0036] FIG. 1 is a perspective view schematically illustrating a display device (1) according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view schematically illustrating a display device (1) according to an embodiment of the present invention. Specifically, FIG. 1 illustrates a display device (1) before being folded, and FIG. 2 illustrates a folded display device (1). In this specification, the expression “before being folded” means a case in which the display device (1) is not folded and at least a part of the display device (1) is not deformed by folding.

[0037] The display device (1) may have a polygonal shape including a rectangle. For example, the display device (1) may have a rectangular shape in which the horizontal length is longer than the vertical length, a rectangular shape in which the horizontal length is shorter than the vertical length, or a square shape. Alternatively, the display device (1) may have various shapes such as an ellipse or a circle. Although FIG. 1 illustrates the display device (1) having a rectangular shape in which the horizontal length is longer than the vertical length, the present invention is not limited thereto.

[0038] The display device (1) may include a first surface (S1) and a second surface (S2) opposite to the first surface (S1). The display device (1) may display an image on the first surface (S1). That is, the first surface (S1) may include a display surface. In one embodiment, the first surface (S1) may be the upper surface (in the +z direction) of the display device (1). The second surface (S2) may be the lower surface (in the -z direction) of the display device (1). In some embodiments, the display device (1) may also display an image on the second surface (S2).

[0039] The display device (1) can be folded. That is, at least a portion of the display device (1) may have flexibility, and the display device (1) can be folded as the flexible portion bends. Accordingly, it may include a folding area and a non-folding area provided on at least one side of the folding area. In this specification, "non-folding" means not being folded, and this includes not only cases where it is rigid and not flexible and therefore not folded, but also cases where it is flexible but not folded. The display device (1) can display an image in the folding area as well as in the non-folding area.

[0040] As illustrated in FIG. 1, the display device (1) may include a first non-folding area (NFA1), a second non-folding area (NFA2), and a foldable area (FA). The first non-folding area (NFA1) and the second non-folding area (NFA2) may be non-folding areas, and the foldable area (FA) may be a flexible area that can be folded.

[0041] The foldable area (FA) may be extended in a direction that intersects a virtual straight line connecting the first non-folding area (NFA1) and the second non-folding area (NFA2). Specifically, when the display device (1) is in a state before being folded, the first non-folding area (NFA1) and the second non-folding area (NFA2) may be spaced apart from each other along a first direction (e.g., the x-direction or the -x-direction). The foldable area (FA) may be positioned between the first non-folding area (NFA1) and the second non-folding area (NFA2). Specifically, the first non-folding area (NFA1) may be adjacent to one side of the foldable area (FA), and the second non-folding area (NFA2) may be adjacent to the other side of the foldable area (FA). When the display device (1) is in a state before being folded, the foldable area (FA) may be extended in a second direction (e.g., y direction or -y direction) that intersects the first direction.

[0042] A folding line (FL) may be provided within the foldable area (FA) along a second direction (e.g., the y-direction or the -y-direction) which is the extension direction of the foldable area (FA). Accordingly, the display device (1) may be folded in the foldable area (FA). The foldable area (FA) and the folding line (FL) of the foldable area (FA) may overlap with the area where an image of the display device (1) is displayed, and when the display device (1) is folded, the portion displaying the image may be folded.

[0043] In FIG. 1, for convenience of explanation, the first non-folding area (NFA1) and the second non-folding area (NFA2) are shown having the same or similar area, and the display device (1) is shown having one foldable area (FA); however, the present invention is not limited thereto. For example, the first non-folding area (NFA1) and the second non-folding area (NFA2) may have different areas. In addition, the display device (1) may have a plurality of foldable areas (FA). In this case, the plurality of non-folding areas are spaced apart from each other, and each of the plurality of foldable areas (FA) may be placed between the non-folding areas. Each foldable area (FA) may be folded along a folding line (FL), and the folding line (FL) may be provided in multiple numbers.

[0044] Meanwhile, in FIG. 1, the folding line (FL) passes through the center of the foldable region (FA) and the foldable region (FA) is shown as being symmetric with respect to the folding line (FL), but the present invention is not limited thereto. For example, the folding line (FL) may be provided asymmetrically within the foldable region (FA).

[0045] As illustrated in FIG. 2, the display device (1) can be folded so that the first surface (S1) of the first non-folding area (NFA1) and the first surface (S1) of the second non-folding area (NFA2) face each other with respect to the folding line (FL). In other words, as the foldable area (FA) of the display device (1) bends, the first surface (S1) of the first non-folding area (NFA1) and the first surface (S1) of the second non-folding area (NFA2) can be positioned to face each other. Even when the display device (1) is folded, the foldable area (FA) can be extended in a direction that intersects with an imaginary straight line connecting the first non-folding area (NFA1) and the second non-folding area (NFA2). Specifically, when the display device (1) is folded, it may be extended in a second direction (e.g., y direction or -y direction) that intersects a virtual straight line (e.g., a straight line parallel to the z-axis direction) connecting the first non-folding area (NFA1) and the second non-folding area (NFA2).

[0046] Meanwhile, the foldable area (FA) can be unfolded again after being bent. Accordingly, the display device (1) can be unfolded. In this specification, "unfolding" means the case where the display device (1) is unfolded after being folded. That is, the display device (1) may be a foldable display device.

[0047] Meanwhile, the term "folded" in this specification means that the shape is not fixed but is transformed from the original shape into a different shape, and includes being folded, curved, or bent along one or more specific lines, namely folding lines (FL). Accordingly, FIG. 2 illustrates a state in which the first surface (S1) of the first non-folding area (NFA1) and the first surface (S1) of the second non-folding area (NFA2) are arranged parallel to each other and folded to face each other, but the present invention is not limited thereto. For example, the first surface (S1) of the first non-folding area (NFA1) and the first surface (S1) of the second non-folding area (NFA2) may be folded at a predetermined angle (e.g., acute angle, right angle, or obtuse angle) with the foldable area (FA) in between.

[0048] FIG. 3 is a schematic cross-sectional view taken along the line I-I' of the display device (1) of FIG. 1, and FIG. 4a is a schematic cross-sectional view showing an enlarged view of part A of the display device (1) of FIG. 3. FIG. 4b, FIG. 4c, and FIG. 4d are drawings for explaining the thickness of the upper organic layer (20) of FIG. 4a. FIG. 4b and FIG. 4c also show the first-third thickness (t1-3) for convenience of explanation.

[0049] As illustrated in FIGS. 3 and 4a, the display device (1) may include a display panel (10) and an upper organic layer (20). The display panel (10) may display an image. To this end, the display panel (10) may include a plurality of display elements, and the plurality of display elements may emit light. Thus, the display panel (10) may display an image through the light emitted from the plurality of display elements. In one embodiment, the display element may be an organic light-emitting diode (OLED) including an organic light-emitting layer. Alternatively, the display element may be a light-emitting diode (LED). The size of the light-emitting diode (LED) may be micro-scale or nano-scale. For example, the light-emitting diode may be a micro-light-emitting diode. Alternatively, the light-emitting diode may be a nanorod light-emitting diode. The nanorod light-emitting diode may include gallium nitride (GaN). In one embodiment, a color conversion layer may be placed on the nanorod light-emitting diode. The color conversion layer may include quantum dots. Alternatively, the display element may be a quantum dot light-emitting diode (QD) including a quantum dot light-emitting layer. Alternatively, the display element may be an inorganic light-emitting diode including an inorganic semiconductor. A detailed description of the components included in the display panel (10) will be provided later.

[0050] As described above, the display device (1) may include a first non-folding area (NFA1), a second non-folding area (NFA2), and a foldable area (FA). Of course, since the display device (1) includes a display panel (10), it may be said that the display panel (10) has the first non-folding area (NFA1), the second non-folding area (NFA2), and the foldable area (FA) as described above. For convenience, the following description will assume that the display panel (10) has the first non-folding area (NFA1), the second non-folding area (NFA2), and the foldable area (FA).

[0051] Meanwhile, as illustrated in FIG. 4a, the foldable region (FA) may include a first foldable region (FA1) and a second foldable region (FA2). The first foldable region (FA1) may be positioned between the first non-foldable region (NFA1) and the second non-foldable region (NFA2). In one embodiment, the second foldable region (FA2) may be provided in multiple numbers, and the multiple second foldable regions (FA2) may be positioned on both sides of the first foldable region (FA1). That is, one second foldable region (FA2) may be positioned on one side of the first foldable region (FA1), and another second foldable region (FA2) may be positioned on the other side of the first foldable region (FA1). In other words, one second foldable area (FA2) may be positioned between the first foldable area (FA1) and the first non-foldable area (NFA1), and another second foldable area (FA2) may be positioned between the first foldable area (FA1) and the second non-foldable area (NFA2). For convenience, the following description will focus on the case where one second foldable area (FA2) is positioned on one side of the first foldable area (FA1) and the other second foldable area (FA2) is positioned on the other side of the first foldable area (FA1).

[0052] The upper organic layer (20) can protect the display panel (10). The upper organic layer (20) may include an optically transparent region. Accordingly, the display panel (10) can display an image through the optically transparent region of the upper organic layer (20). In one embodiment, this transparent region may be surrounded by a bezel region, and the shape of the transparent region may be defined by the bezel region. The light transmittance of this bezel region may be lower than the light transmittance of the transparent region. In one embodiment, the bezel region may include an opaque material that blocks light. In one embodiment, the bezel region may have a predetermined color. The bezel region may be defined by a bezel layer provided separately from the transparent organic layer that defines the light-transmitting region, or by an ink layer formed by being inserted into or colored in the transparent organic layer.

[0053] The upper organic layer (20) may include a first non-folding portion (20NF1), a second non-folding portion (20NF2), and a foldable portion (20F), and the foldable portion (20F) may include a first foldable portion (20F1) and a second foldable portion (20F2). The first non-folding portion (20NF1) may be placed on a first non-folding region (NFA1), and the second non-folding portion (20NF2) may be placed on a second non-folding region (NFA2). The first foldable portion (20F1) may be placed on a first foldable region (FA1), and the second foldable portion (20F2) may be placed on a second foldable region (FA2).

[0054] The above description regarding the positional relationship between the first non-folding area (NFA1), the second non-folding area (NFA2), the first foldable area (FA1), and the second foldable area (FA2) of the display panel (10) can also be applied to the positional relationship between the first non-folding portion (20NF1), the second non-folding portion (20NF2), the first foldable portion (20F1), and the second foldable portion (20F2) of the upper organic layer (20), so redundant descriptions in this regard are omitted. Specifically, before the display device (1) is folded, the first non-folding portion (20NFA1) and the second non-folding portion (20NFA2) may be spaced apart from each other along a first direction (e.g., the x-direction or the -x-direction). When the display device (1) is folded, the first non-folding portion (20NFA1) and the second non-folding portion (20NFA2) may be arranged to face each other. The first foldable portion (20F1) and the second foldable portion (20F2) included in the foldable portion (20F) may be extended in a direction that intersects with an imaginary straight line connecting the first non-folding portion (20NF1) and the second non-folding portion (20NF2). The first foldable portion (20F1) may be placed between the first non-folding portion (20NF1) and the second non-folding portion (20NF2), and a plurality of second non-folding portions (20NFA2) may be placed on both sides of the first foldable portion (20F1).

[0055] Meanwhile, the upper organic layer (20) may include a first organic layer (21) and a second organic layer (22). The first organic layer (21) may be placed on the upper part of the display panel (10). The first organic layer (21) may have high strength and hardness to protect the display panel (10) from external impact. Specifically, the first organic layer (21) may have a large modulus. Preferably, the modulus of the first organic layer (21) may be 1 GPa or more and less than 10 GPa, and more preferably, the modulus of the first organic layer (21) may be 1 GPa to 2 GPa.

[0056] The first organic layer (21) may include at least one of an acryl-based compound, a siloxane-based compound, and a carbonate-based compound. For example, the first organic layer (21) may include at least one of polyacrylate, polydimethylsiloxanes, and polycarbonate.

[0057] The first organic layer (21) may include a first-1 non-folding portion (21NF1), a first-2 non-folding portion (21NF2), and a first organic foldable portion (21F), and the first organic foldable portion (21F) may include a first-1 foldable portion (21F1) and a first-2 foldable portion (21F2). The first-1 non-folding portion (21NF1) may be placed on a first non-folding region (NFA1), and the first-2 non-folding portion (21NF2) may be placed on a second non-folding region (NFA2). The first-1 foldable portion (21F1) may be placed on a first foldable region (FA1), and the first-2 foldable portion (21F2) may be placed on a second foldable region (FA2).

[0058] The second organic layer (22) may be interposed between the display panel (10) and the first organic layer (21). Specifically, the first organic layer (21) may be placed on the second organic layer (22). The second organic layer (22) can prevent or reduce damage to the display panel (10) caused by external impact by absorbing external impact applied to the display panel (10). Specifically, the second organic layer (22) may have a small modulus. Preferably, the modulus of the second organic layer (22) may be 0.1 GPa or more and less than 1 GPa, and more preferably, the modulus of the first organic layer (21) may be 0.1 GPa or more and less than 0.5 GPa.

[0059] The second organic layer (22) may include a urethane-based compound. For example, the second organic layer (22) may include polyurethane.

[0060] The second organic layer (22) may include a second-1 non-folding portion (22NF1), a second-2 non-folding portion (22NF2), and a second organic foldable portion (22F), and the second organic foldable portion (22F) may include a second-1 foldable portion (22F1) and a second-2 foldable portion (22F2). The second-1 non-folding portion (22NF1) may be placed on a first non-folding region (NFA1), and the second-2 non-folding portion (22NF2) may be placed on a second non-folding region (NFA2). The second-1 foldable portion (22F1) may be placed on a first foldable region (FA1), and the second-2 foldable portion (22F2) may be placed on a second foldable region (FA2). That is, the 2-1 non-folding portion (22NF1) can be placed between the 1-1 non-folding area (NFA1) and the 1-1 non-folding portion (21NF1), and the 2-2 non-folding portion (22NF2) can be placed between the 2-2 non-folding area (NFA2) and the 1-2 non-folding portion (21NF2). The 2-1 foldable portion (22F1) can be placed between the 1-1 foldable area (FA1) and the 1-1 foldable portion (21F1), and the 2-2 foldable portion (22F2) can be placed between the 2-2 foldable area (FA2) and the 1-2 foldable portion (21F2).

[0061] In other words, the first non-folding portion (20NF1) of the upper organic layer (20) may be composed of a first-1 non-folding portion (21NF1) and a second-1 non-folding portion (22NF1), and the second non-folding portion (20NF2) of the upper organic layer (20) may be composed of a first-2 non-folding portion (21NF2) and a second-2 non-folding portion (22NF2). The foldable portion (20F) of the upper organic layer (20) may be composed of a first organic foldable portion (21F) and a second organic foldable portion (22F).

[0062] The foldable portion (20F) of the upper organic layer (20) may include a first foldable portion (20F1) and a second foldable portion (20F2). Specifically, the first foldable portion (20F1) of the upper organic layer (20) may be composed of a first-1 foldable portion (21F1) and a second-1 foldable portion (22F1), and the second foldable portion (20F2) of the upper organic layer (20) may be composed of a first-2 foldable portion (21F2) and a second-2 foldable portion (22F2).

[0063] As illustrated in FIG. 4a, the upper organic layer (20) may have different thicknesses depending on its location. In this specification, "thickness" of one part refers to the distance from the upper surface of one part to the lower surface of one part in a direction perpendicular to the display panel (10) (e.g., z-axis direction). As described above, the upper organic layer (20) may include a first non-folding part (20NF1), a second non-folding part (20NF2), and a foldable part (20F), and the foldable part (20F) may include a first foldable part (20F1) and a second foldable part (20F2). The thickness of the first foldable part (20F1) may be thicker than the thickness of the first non-folding part (20NF1), and the thickness of the second foldable part (20F2) may be thinner than the thickness of the first non-folding part (20NF1). Meanwhile, the thickness of the second non-folding portion (20NF2) may be the same as or similar to the thickness of the first non-folding portion (20NF1).

[0064] Meanwhile, the first non-folding portion (20NF1) may have a uniform thickness within the first non-folding portion (20NF1), and the second non-folding portion (20NF2) may have a uniform thickness within the second non-folding portion (20NF2). Accordingly, the first non-folding portion (20NF1) and the second non-folding portion (20NF2) may have a flat upper surface.

[0065] The thickness of the first foldable portion (20F1) may vary depending on the location within the first foldable portion (20F1). Specifically, the thickness of the first foldable portion (20F1) may increase as it moves from the outer edge of the first foldable portion (20F1) toward the center of the first foldable portion (20F1). In other words, since the second foldable portions (20F2) are arranged on both sides of the first foldable portion (20F1), the thickness of the first foldable portion (20F1) may increase as it moves further away from the second foldable portion (20F2). For example, the thickest part of the first foldable portion (20F1) may have a first thickness (t1). If the first non-folding portion (20NF1) has a third thickness (t3), the difference between the first thickness (t1) and the third thickness (t3) may be 100 μm or less. In other words, the first foldable portion (20F1) may be 100 μm or less thicker than the first non-foldable portion (20NF1). Even in this case, the thickness of the first foldable portion (20F1) may be thicker than the thickness of the first non-foldable portion (20NF1). That is, the thickness of the thinnest part of the first foldable portion (20F1) may be thicker than the thickness of the first non-foldable portion (20NF1).

[0066] Accordingly, as illustrated in FIG. 4a, the first foldable portion (20F1) before the display device (1) is folded may protrude in the opposite direction to the display panel (10) (e.g., +z direction). That is, the first foldable portion (20F1) may have a convexly curved shape.

[0067] The thickness of the second foldable portion (20F2) may vary depending on the location within the second foldable portion (20F2). Specifically, the thickness of the second foldable portion (20F2) may decrease as it moves from the outer edge of the second foldable portion (20F2) toward the center of the second foldable portion (20F2). In other words, since the second foldable portions (20F2) are positioned between the first foldable portion (20F1) and the first non-foldable portion (20NF1) or between the first foldable portion (20F1) and the second non-foldable portion (20NF2), the thickness of the second foldable portion (20F2) may decrease as it moves further away from the first foldable portion (20F1), the first non-foldable portion (20NF1), or the second non-foldable portion (20NF2). Specifically, a portion of the second foldable portion (20F2) adjacent to the first foldable portion (20F1) may have its thickness reduced as it moves further away from the first foldable portion (20F1), another portion of the second foldable portion (20F2) adjacent to the first non-foldable portion (20NF1) may have its thickness reduced as it moves further away from the first non-foldable portion (20NF1), and yet another portion of the second foldable portion (20F2) adjacent to the second non-foldable portion (20NF2) may have its thickness reduced as it moves further away from the second non-foldable portion (20NF2).

[0068] For example, the thinnest part of the second foldable portion (20F2) may have a second thickness (t2). If the first non-foldable portion (20NF1) has a third thickness (t3), the difference between the second thickness (t2) and the third thickness (t3) may be 100 μm or less. In other words, the second foldable portion (20F2) may be thinner than the first non-foldable portion (20NF1) by 100 μm or less. Even in this case, the thickness of the second foldable portion (20F2) may be thinner than the thickness of the first non-foldable portion (20NF1). That is, the thickness of the thickest part of the second foldable portion (20F2) may be thinner than the thickness of the first non-foldable portion (20NF1).

[0069] Accordingly, as illustrated in FIG. 4a, the second foldable portion (20F2) before the display device (1) is folded can be recessed in the direction of the display panel (10) (e.g., -z direction). That is, the second foldable portion (20F2) can have a concave curved shape. Since the second foldable portions (20F2) are arranged on both sides of the first foldable portion (20F1), the upper surface (in the +z direction) of the foldable portion (20F) of the upper organic layer (20) before the display device (1) is folded can have an approximate W shape.

[0070] Meanwhile, as described above, the second foldable portion (20F2) may be placed between the first foldable portion (20F1) and the first non-foldable portion (20NF1). The thickness of the first foldable portion (20F1) is thicker than the thickness of the first non-foldable portion (20NF1), and the thickness of the second foldable portion (20F2) may be thinner than the thickness of the first non-foldable portion (20NF1). Since the first foldable portion (20F1) and the second foldable portion (20F2) are connected without being disconnected, there may exist a point between the first foldable portion (20F1) and the second foldable portion (20F2) that has the same thickness as the first non-foldable portion (20NF1).

[0071] Meanwhile, as shown in FIG. 4b, the thickness of the first foldable portion (20F1) may be equal to the sum of the thickness of the first-1 foldable portion (21F1) and the thickness of the second-1 foldable portion (22F1). As shown in FIG. 4c, the thickness of the second foldable portion (20F2) may be equal to the sum of the thickness of the first-2 foldable portion (21F2) and the thickness of the second-2 foldable portion (22F2). As illustrated in FIG. 4d, the thickness of the first non-folding portion (20NF1) may be equal to the sum of the thickness of the first-1 non-folding portion (21NF1) and the thickness of the second-1 non-folding portion (22NF1), and the thickness of the second non-folding portion (20NF2) may be equal to the sum of the thickness of the first-2 non-folding portion (21NF2) and the thickness of the second-2 non-folding portion (22NF2). Accordingly, the sum of the thickness of the first-1 foldable portion (21F1) and the thickness of the second-1 foldable portion (22F1) may be greater than the sum of the thickness of the first-1 non-folding portion (21NF1) and the thickness of the second-1 non-folding portion (22NF1). The sum of the thickness of the first-2 foldable portion (21F2) and the thickness of the second-2 foldable portion (22F2) may be smaller than the sum of the thickness of the first-1 non-foldable portion (21NF1) and the thickness of the second-1 non-foldable portion (22NF1).

[0072] In one embodiment, the second organic layer (22) may have a uniform thickness, and the second organic layer (22) may be flat. Specifically, as shown in FIGS. 4a to 4d, the second organic foldable portion (22F) disposed below the first organic foldable portion (21F) may have a uniform thickness, and the second organic foldable portion (22F) may be flat. That is, the thickness of the second-1 foldable portion (22F1) and the thickness of the second-2 foldable portion (22F2) may be the same or similar. The second-1 foldable portion (22F1) may have a second-1 thickness (t2-1), the second-2 foldable portion (22F2) may have a second-2 thickness (t2-2), and the second-1 non-foldable portion (22NF1) may have a second-3 thickness (t2-3). Meanwhile, the thickness of the second-2 non-foldable portion (22NF2) may be the same as or similar to the thickness of the second-1 non-foldable portion (22NF1). For example, the second-1 thickness (t2-1), the second-2 thickness (t2-2), and the second-3 thickness (t2-3) may be the same or similar.

[0073] In this case, the first organic layer (21) may have different thicknesses depending on its location. As described above, the first organic layer (21) may include a first-1 non-folding portion (21NF1), a first-2 non-folding portion (21NF2), and a first organic foldable portion (21F), and the first organic foldable portion (21F) may include a first-1 foldable portion (21F1) and a first-2 foldable portion (21F2). As illustrated in FIGS. 4a to 4d, the thickness of the first-1 foldable portion (21F1) is thicker than the thickness of the first-1 non-folding portion (21NF1), and the thickness of the first-2 foldable portion (21F2) may be thinner than the thickness of the first-1 non-folding portion (21NF1). Meanwhile, the thickness of the first-2 non-folding portion (21NF2) may be the same as or similar to the thickness of the first-1 non-folding portion (21NF1).

[0074] Meanwhile, the first-1 non-folding portion (21NF1) may have a uniform thickness within the first-1 non-folding portion (21NF1), and the first-2 non-folding portion (21NF2) may have a uniform thickness within the first-2 non-folding portion (21NF2). Accordingly, the first-1 non-folding portion (21NF1) and the first-2 non-folding portion (21NF2) may have a flat upper surface.

[0075] The thickness of the first-1 foldable portion (21F1) may vary depending on the location within the first-1 foldable portion (21F1). Specifically, the thickness of the first-1 foldable portion (21F1) may increase as it moves from the outer edge of the first-1 foldable portion (21F1) toward the center of the first-1 foldable portion (21F1). In other words, since the first-2 foldable portions (21F2) are arranged on both sides of the first-1 foldable portion (21F1), the thickness of the first-1 foldable portion (21F1) may increase as it moves further away from the first-2 foldable portions (21F2). For example, the thickest part of the first-1 foldable portion (21F1) may have a first-1 thickness (t1-1). If the 1-1 non-folding portion (21NF1) has a 1-3 thickness (t1-3), the difference between the 1-1 thickness (t1-1) and the 1-3 thickness (t1-3) may be 100㎛ or less. In other words, the 1-1 foldable portion (21F1) may be 100㎛ or less thicker than the 1-1 non-folding portion (21NF1). Even in this case, the thickness of the 1-1 foldable portion (21F1) may be thicker than the thickness of the 1-1 non-folding portion (21NF1). That is, the thickness of the thinnest portion of the 1-1 foldable portion (21F1) may be thicker than the thickness of the 1-1 non-folding portion (21NF1).

[0076] Accordingly, as illustrated in FIG. 4a, the first-1 foldable portion (21F1) before the display device (1) is folded may protrude in the opposite direction to the display panel (10) (e.g., +z direction). That is, the first-1 foldable portion (21F1) may have a convexly curved shape.

[0077] The thickness of the first-2 foldable portion (21F2) may vary depending on the location within the first-2 foldable portion (21F2). Specifically, the thickness of the first-2 foldable portion (21F2) may decrease as it moves from the outer edge of the first-2 foldable portion (21F2) toward the center of the first-2 foldable portion (21F2). In other words, since the first-2 foldable portions (21F2) are positioned between the first-1 foldable portion (21F1) and the first-1 non-foldable portion (21NF1) or between the first-1 foldable portion (21F1) and the first-2 non-foldable portion (21NF2), the thickness of the first-2 foldable portion (21F2) can be reduced as it moves further away from the first-1 foldable portion (21F1), the first-1 non-foldable portion (21NF1), or the first-2 non-foldable portion (21NF2). Specifically, a portion of the first-2 foldable portion (21F2) adjacent to the first-1 foldable portion (21F1) may have its thickness reduced as it moves further away from the first-1 foldable portion (21F1), another portion of the first-2 foldable portion (21F2) adjacent to the first-1 non-foldable portion (21NF1) may have its thickness reduced as it moves further away from the first-1 non-foldable portion (21NF1), and yet another portion of the first-2 foldable portion (21F2) adjacent to the first-2 non-foldable portion (21NF2) may have its thickness reduced as it moves further away from the first-2 non-foldable portion (21NF2).

[0078] For example, the thinnest part of the first-2 foldable portion (21F2) may have a first-2 thickness (t1-2). If the first-1 non-foldable portion (21NF1) has a first-3 thickness (t1-3), the difference between the first-2 thickness (t1-2) and the first-3 thickness (t1-3) may be 100 μm or less. In other words, the first-2 foldable portion (21F2) may be thinner than the first-1 non-foldable portion (21NF1) by 100 μm or less. Even in this case, the thickness of the first-2 foldable portion (21F2) may be thinner than the thickness of the first-1 non-foldable portion (21NF1). That is, the thickness of the thickest part of the first-2 foldable portion (21F2) may be thinner than the thickness of the first-1 non-foldable portion (21NF1).

[0079] Accordingly, as illustrated in FIG. 4a, the first-second foldable portion (21F2) before the display device (1) is folded may be recessed in the direction of the display panel (10) (e.g., -z direction). That is, the first-second foldable portion (21F2) may have a concave curved shape. Since the first-second foldable portions (21F2) are arranged on both sides of the first-first foldable portion (21F1), the upper surface (in the +z direction) of the first organic foldable portion (21F) of the first organic layer (21) before the display device (1) is folded may have an approximate W shape.

[0080] Meanwhile, as described above, the first-2 foldable portion (21F2) may be placed between the first-1 foldable portion (21F1) and the first-1 non-foldable portion (21NF1). The thickness of the first-1 foldable portion (21F1) is thicker than the thickness of the first-1 non-foldable portion (21NF1), and the thickness of the first-2 foldable portion (21F2) may be thinner than the thickness of the first-1 non-foldable portion (21NF1). Since the first-1 foldable portion (21F1) and the first-2 foldable portion (21F2) are connected without being disconnected, there may exist a point between the first-1 foldable portion (21F1) and the first-2 foldable portion (21F2) that has the same thickness as the first-1 non-foldable portion (21NF1).

[0081] Even in this case, the upper surface (in the +z direction) of the foldable portion (20F) of the upper organic layer (20) before the display device (1) is folded may have an approximate W shape. That is, the sum of the thickness of the first-1 foldable portion (21F1) and the thickness of the second-1 foldable portion (22F1) is greater than the sum of the thickness of the first-1 non-foldable portion (21NF1) and the thickness of the second-1 non-foldable portion (22NF1), and the sum of the thickness of the first-2 foldable portion (21F2) and the thickness of the second-2 foldable portion (22F2) may be smaller than the sum of the thickness of the first-1 non-foldable portion (21NF1) and the thickness of the second-1 non-foldable portion (22NF1). For example, the sum of the first-1 thickness (t1-1) and the second-1 thickness (t2-1) may be greater than the sum of the first-3 thickness (t1-3) and the second-3 thickness (t2-3), and the sum of the first-2 thickness (t1-2) and the second-2 thickness (t2-2) may be less than the sum of the first-3 thickness (t1-3) and the second-3 thickness (t2-3).

[0082] In FIG. 4a, the second organic layer (22) is shown to have a uniform thickness and the first organic layer (21) has a different thickness depending on its position, but the present invention is not limited thereto. For example, the second organic layer (22) may have a different thickness depending on its position and the first organic layer (21) may have a uniform thickness.

[0083] FIG. 5a is a cross-sectional view schematically illustrating a display device (1) according to an embodiment of the present invention. FIG. 5b, FIG. 5c, and FIG. 5d are drawings for explaining the thickness of the upper organic layer (20) of FIG. 5a. For convenience of explanation, the second-third thickness (t2-3) is also shown in FIG. 5b and FIG. 5c. Since the display device (1) according to the present embodiment is similar to the display device (1) described above with reference to FIG. 1 to FIG. 4d, the following description will focus on the differences from the display device (1) described above with reference to FIG. 1 to FIG. 4d. In FIG. 5a to FIG. 5d, reference numerals identical to those in FIG. 1 to FIG. 4d denote identical components, so redundant descriptions will be omitted.

[0084] With reference to FIG. 4a, etc., the display device (1) described above includes a display panel (10) and an upper organic layer (20), and the upper organic layer (20) may include a first organic layer (21) and a second organic layer (22). As shown in FIG. 5a, in the case of the display device (1) according to the present embodiment, the display device (1) includes a display panel (10) and an upper organic layer (20), and the upper organic layer (20) may include a first organic layer (21) and a second organic layer (22).

[0085] However, as illustrated in FIGS. 5a to 5d, the second organic layer (22) may have different thicknesses depending on its location. As described above, the second organic layer (22) may include a second-1 non-folding portion (22NF1), a second-2 non-folding portion (22NF2), and a second organic foldable portion (22F), and the second organic foldable portion (22F) may include a second-1 foldable portion (22F1) and a second-2 foldable portion (22F2). For example, the thickness of the second-1 foldable portion (22F1) may be thicker than the thickness of the second-1 non-folding portion (22NF1), and the thickness of the second-2 foldable portion (22F2) may be thinner than the thickness of the second-1 non-folding portion (22NF1). Meanwhile, the thickness of the 2-2 non-folding portion (22NF2) may be the same as or similar to the thickness of the 2-1 non-folding portion (22NF1).

[0086] Meanwhile, the 2-1 non-folding portion (22NF1) may have a uniform thickness within the 2-1 non-folding portion (22NF1), and the 2-2 non-folding portion (22NF2) may have a uniform thickness within the 2-2 non-folding portion (22NF2). Accordingly, the 2-1 non-folding portion (22NF1) and the 2-2 non-folding portion (22NF2) may have a flat upper surface.

[0087] The thickness of the second-1 foldable portion (22F1) may vary depending on the location within the second-1 foldable portion (22F1). Specifically, the thickness of the second-1 foldable portion (22F1) may increase as it moves from the outer edge of the second-1 foldable portion (22F1) toward the center of the second-1 foldable portion (22F1). In other words, since the second-2 foldable portions (22F2) are arranged on both sides of the second-1 foldable portion (22F1), the thickness of the second-1 foldable portion (22F1) may increase as it moves further away from the second-2 foldable portion (22F2). For example, the thickest part of the second-1 foldable portion (22F1) may have a second-1 thickness (t2-1). If the 2-1 non-folding portion (22NF1) has a 2-3 thickness (t2-3), the difference between the 2-1 thickness (t2-1) and the 2-3 thickness (t2-3) may be 100㎛ or less. In other words, the 2-1 foldable portion (22F1) may be 100㎛ or less thicker than the 2-1 non-folding portion (22NF1). Even in this case, the thickness of the 2-1 foldable portion (22F1) may be thicker than the thickness of the 2-1 non-folding portion (22NF1). That is, the thickness of the thinnest portion of the 2-1 foldable portion (22F1) may be thicker than the thickness of the 2-1 non-folding portion (22NF1).

[0088] Accordingly, as illustrated in FIG. 5a, the second-1 foldable portion (22F1) before the display device (1) is folded may protrude in the opposite direction to the display panel (10) (e.g., +z direction). That is, the second-1 foldable portion (22F1) may have a convexly curved shape.

[0089] The thickness of the second-2 foldable portion (22F2) may vary depending on the location within the second-2 foldable portion (22F2). Specifically, the thickness of the second-2 foldable portion (22F2) may decrease as it moves from the outer edge of the second-2 foldable portion (22F2) toward the center of the second-2 foldable portion (22F2). In other words, since the second-2 foldable portions (22F2) are positioned between the second-1 foldable portion (22F1) and the second-1 non-foldable portion (22NF1) or between the second-1 foldable portion (22F1) and the second-2 non-foldable portion (22NF2), the thickness of the second-2 foldable portion (22F2) can be reduced as it moves further away from the second-1 foldable portion (22F1), the second-1 non-foldable portion (22NF1), or the second-2 non-foldable portion (22NF2). Specifically, a portion of the second-2 foldable portion (22F2) adjacent to the second-1 foldable portion (22F1) may have its thickness reduced as it moves further away from the second-1 foldable portion (22F1), another portion of the second-2 foldable portion (22F2) adjacent to the second-1 non-foldable portion (22NF1) may have its thickness reduced as it moves further away from the second-1 non-foldable portion (22NF1), and yet another portion of the second-2 foldable portion (22F2) adjacent to the second-2 non-foldable portion (22NF2) may have its thickness reduced as it moves further away from the second-2 non-foldable portion (22NF2).

[0090] For example, the thinnest part of the second-2 foldable portion (22F2) may have a second-2 thickness (t2-2). If the second-1 non-foldable portion (22NF1) has a second-3 thickness (t2-3), the difference between the second-2 thickness (t2-2) and the second-3 thickness (t2-3) may be 100 μm or less. In other words, the second-2 foldable portion (22F2) may be 100 μm or less thinner than the second-1 non-foldable portion (22NF1). Even in this case, the thickness of the second-2 foldable portion (22F2) may be thinner than the thickness of the second-1 non-foldable portion (22NF1). That is, the thickness of the thickest part of the second-2 foldable portion (22F2) may be thinner than the thickness of the second-1 non-foldable portion (22NF1).

[0091] Accordingly, as illustrated in FIG. 5a, the second-2 foldable portion (22F2) before the display device (1) is folded may be recessed in the direction of the display panel (10) (e.g., -z direction). That is, the second-2 foldable portion (22F2) may have a concave curved shape. Since the second-2 foldable portions (22F2) are arranged on both sides of the second-1 foldable portion (22F1), the upper surface (in the +z direction) of the second organic foldable portion (22F) of the second organic layer (22) before the display device (1) is folded may have an approximate W shape.

[0092] Meanwhile, as described above, the second-2 foldable portion (22F2) may be placed between the second-1 foldable portion (22F1) and the second-1 non-foldable portion (22NF1). The thickness of the second-1 foldable portion (22F1) is thicker than the thickness of the second-1 non-foldable portion (22NF1), and the thickness of the second-2 foldable portion (22F2) may be thinner than the thickness of the second-1 non-foldable portion (22NF1). Since the second-1 foldable portion (22F1) and the second-2 foldable portion (22F2) are connected without being disconnected, there may exist a point between the second-1 foldable portion (22F1) and the second-2 foldable portion (22F2) that has the same thickness as the second-1 non-foldable portion (22NF1).

[0093] In this case, the first organic layer (21) may have a uniform thickness. Specifically, the first organic foldable portion (21F) positioned on top of the second organic foldable portion (22F) may have a uniform thickness. That is, the thickness of the first-1 foldable portion (21F1) and the thickness of the first-2 foldable portion (21F2) may be the same or similar. For example, the first-1 thickness (t1-1), the first-2 thickness (t1-2), and the first-3 thickness may be the same or similar. Since the upper surface (in the +z direction) of the second organic foldable portion (22F) of the second organic layer (22) has an approximate W shape, the upper surface (in the +z direction) of the first organic foldable portion (21F) of the first organic layer (21) may also have an approximate W shape.

[0094] Therefore, even in this case, the upper surface (in the +z direction) of the foldable portion (20F) of the upper organic layer (20) before the display device (1) is folded may have an approximate W shape. That is, the sum of the thickness of the first-1 foldable portion (21F1) and the thickness of the second-1 foldable portion (22F1) is greater than the sum of the thickness of the first-1 non-foldable portion (21NF1) and the thickness of the second-1 non-foldable portion (22NF1), and the sum of the thickness of the first-2 foldable portion (21F2) and the thickness of the second-2 foldable portion (22F2) may be smaller than the sum of the thickness of the first-1 non-foldable portion (21NF1) and the thickness of the second-1 non-foldable portion (22NF1). For example, the sum of the first-1 thickness (t1-1) and the second-1 thickness (t2-1) may be greater than the sum of the first-3 thickness (t1-3) and the second-3 thickness (t2-3), and the sum of the first-2 thickness (t1-2) and the second-2 thickness (t2-2) may be less than the sum of the first-3 thickness (t1-3) and the second-3 thickness (t2-3).

[0095] FIG. 6 is a cross-sectional view schematically illustrating a part of a display device (2) according to a comparative example, and FIG. 7 is a drawing for explaining the deformation of the foldable area (FA) of the display device (2) according to a comparative example. Specifically, FIG. 6 illustrates the state of the display device (2) according to a comparative example before folding, and FIG. 7 illustrates the state of the display device (2) according to a comparative example after unfolding. Since the display device (2) according to the comparative example is similar to the display device (1) according to an embodiment of the present invention, the following description will focus on the differences from the display device (1) according to an embodiment of the present invention.

[0096] As illustrated in FIG. 6, a display device (2) according to a comparative example may also include a display panel (10) and an upper organic layer (20), and the upper organic layer (20) may include a first organic layer (21) and a second organic layer (22). Compared to a display device (1) according to an embodiment of the present invention, the upper organic layer (20) of the display device (2) according to a comparative example may have a uniform thickness. For example, the first organic layer (21) may have a uniform thickness, and the second organic layer (22) may have a uniform thickness. That is, the thickness of the first-1 foldable portion (21F1), the thickness of the first-2 foldable portion (21F2), the thickness of the first-1 non-foldable portion (21NF1), and the thickness of the first-2 non-foldable portion (21NF2) may be the same or similar. The thickness of the 2-1 foldable portion (22F1), the thickness of the 2-2 foldable portion (22F2), the thickness of the 2-1 non-foldable portion (22NF1), and the thickness of the 2-2 non-foldable portion (22NF2) may be the same or similar. In other words, the first thickness (t1), the second thickness (t2), and the third thickness (t3) may be the same or similar.

[0097] When the display device is folded, the foldable area (FA) of the display device may be deformed. Specifically, when the display device is folded, the foldable area (FA) of the display device bends, and accordingly, compressive stress or tensile stress may be applied to the foldable area (FA). The foldable area (FA) may be deformed by such compressive stress or tensile stress. The deformed foldable area (FA) may not recover to its original shape even if the display device is unfolded again.

[0098] As shown in FIG. 7, which is a cross-sectional view schematically illustrating a display device (2) in an unfolded state, when the upper organic layer (20) has a uniform thickness, the first foldable portion (20F1) of the upper organic layer (20) may be recessed in the direction of the display panel (10) (e.g., -z direction), and the second foldable portion (20F2) of the upper organic layer (20) may protrude in the opposite direction to the display panel (10) (e.g., +z direction). That is, when the display device (2) is unfolded after being folded, the upper surface (in the +z direction) of the foldable portion (20F) of the upper organic layer (20) may have an approximate M-shape. That is, when the display device (2) is unfolded after being folded, the first surface (S1) of the foldable area (FA) of the display device (2) may not be flat. That is, the display surface of the display device (2) may not be flat.

[0099] However, in the case of the display device (1) according to the present invention, the upper organic layer (20) may have different thicknesses depending on its position. Specifically, the thickness of the first foldable portion (20F1) may be thicker than the thickness of the first non-foldable portion (20NF1), and the thickness of the second foldable portion (20F2) may be thinner than the thickness of the first non-foldable portion (20NF1).

[0100] Accordingly, before the display device (1) is folded, the first foldable portion (20F1) of the upper organic layer (20) may protrude in the opposite direction to the display panel (10) (e.g., +z direction), and the second foldable portion (20F2) may be recessed in the direction of the display panel (10) (e.g., -z direction). In other words, the upper surface (in the +z direction) of the foldable portion (20F) of the display device (1) before folding may have an inverse image of the upper surface (in the +z direction) of the foldable portion (20F) of the unfolded display device (2).

[0101] In this case, as illustrated in FIG. 8, which is a drawing for explaining the deformation of the foldable region (FA) of the display device (1) according to one embodiment of the present invention, the first surface (S1) of the foldable region (FA) of the display device (1) may be flat. That is, the display surface of the display device (1) may be flat. Specifically, the first foldable portion (20F1) of the display device (1) before folding may protrude in the opposite direction to the display panel (10) (e.g., +z direction). Accordingly, even if the display device (1) is unfolded after folding, the degree to which the first foldable portion (20F1) is indented in the direction of the display panel (10) (e.g., -z direction) may be reduced. Meanwhile, the second foldable portion (20F2) of the display device (1) before folding may be indented in the direction of the display panel (10) (e.g., -z direction). Accordingly, even if the display device (1) is unfolded after being folded, the degree to which the second foldable portion (20F2) protrudes in the opposite direction to the display panel (10) (e.g., +z direction) can be reduced. Therefore, the display surface of the display device (1) can be flat. That is, the flatness of the display surface of the unfolded display device (1) can be increased.

[0102] Meanwhile, if the difference between the first thickness (t1) and the third thickness (t3) or the difference between the second thickness (t2) and the third thickness (t3) exceeds 100 μm, the degree to which the first foldable portion (20F1) is indented in the direction of the display panel (10) (e.g., -z direction) may be excessively reduced, or the degree to which the second foldable portion (20F2) protrudes in the opposite direction to the display panel (10) (e.g., +z direction) may be excessively reduced. Therefore, the display surface of the display device (1) may not be flat. However, as described above, the difference between the first thickness (t1) and the third thickness (t3) and the difference between the second thickness (t2) and the third thickness (t3) of the display device (1) according to one embodiment of the present invention may each be 100 μm or less. Therefore, the display surface of the display device (1) may be flat.

[0103] Although not illustrated, a protective film may be disposed on the lower part of the display panel (10) so as to face the lower surface (in the -z direction) of the display panel (10). Specifically, the protective film may be disposed on the lower part of the substrate (100, see FIG. 9) so as to face the lower surface (in the -z direction) of the substrate (100). The protective film may serve to protect the display panel (10) during the manufacturing process of the display device. An adhesive layer may be interposed between the protective film and the substrate (100), and by means of this adhesive layer, the protective film may be attached to the lower part of the substrate (100). The adhesive layer interposed between the protective film and the substrate (100) may include at least one of an optical clear resin (OCR), an optical clear adhesive (OCA), and a pressure sensitive adhesive (PSA).

[0104] FIG. 9 is a cross-sectional view schematically illustrating a portion of a display panel (10) included in a display device (1) according to an embodiment of the present invention. As shown in FIG. 9, the display panel (10) may include a substrate (100), a pixel circuit layer (200), a display element layer (300), and an encapsulation layer (400). A pixel circuit layer (200) may be disposed on the substrate (100). The substrate (100) may include various materials having flexible or bendable characteristics. For example, the substrate (100) may include glass, metal, or polymer resin. Additionally, the substrate (100) may include a polymer resin such as polyethersulphone, polyacrylate, polyetherimide, polyethylene naphthalate, polyethylene terephthalate, polyphenylene sulfide, polyarylate, polyimide, polycarbonate, or cellulose acetate propionate. Of course, the substrate (100) may have a multilayer structure including two layers each containing such a polymer resin and a barrier layer containing an inorganic material (such as silicon oxide, silicon nitride, silicon oxynitride, etc.) interposed between the layers, and various modifications are possible.

[0105] The pixel circuit layer (200) may include a thin film transistor (TFT), an insulating layer (IL), and a planarization layer (240). As shown in FIG. 9, the thin film transistor (TFT) may include a semiconductor layer (Act) comprising amorphous silicon, polycrystalline silicon, an oxide semiconductor material, or an organic semiconductor material, a gate electrode (GE), a source electrode (SE), and a drain electrode (DE). The insulating layer (IL) may include a gate insulating layer (210), a first interlayer insulating layer (220), and a second interlayer insulating layer (230). To ensure insulation between the semiconductor layer (Act) and the gate electrode (GE), a gate insulating layer (210) comprising an inorganic material such as silicon oxide, silicon nitride, and / or silicon oxynitride may be interposed between the semiconductor layer (Act) and the gate electrode (GE). In addition, a first interlayer insulating layer (220) containing inorganic materials such as silicon oxide, silicon nitride, and / or silicon oxynitride may be disposed on the upper surface of the gate electrode (GE), and a second interlayer insulating layer (230) may be disposed to cover the source electrode (SE) and the drain electrode (DE). Insulating layers (IL) containing inorganic materials in this manner may be formed through CVD or ALD. Furthermore, a planarization layer (240) may be disposed on the thin-film transistor (TFT). The planarization layer (240) may serve to generally planarize the upper surface of the thin-film transistor (TFT). This planarization layer (240) may include organic materials such as, for example, acrylic, BCB (Benzocyclobutene), or HMDSO (hexamethyldisiloxane). Although the planarization layer (240) is shown as a single layer in FIG. 9, various variations are possible, such as it being a multilayer.

[0106] A display element layer (300) may be disposed on a pixel circuit layer (200). The display element layer (300) may include a display element (310) electrically connected to a thin-film transistor (TFT) and a pixel defining film (320). The display element (310) may be, for example, an organic light-emitting diode having a pixel electrode (311), a counter electrode (313), and an intermediate layer (312) interposed between them and including a light-emitting layer. The fact that the display element (310) is electrically connected to the thin-film transistor (TFT) can be understood as the pixel electrode (311) of the display element (310) being electrically connected to the thin-film transistor (TFT).

[0107] As shown in FIG. 9, the pixel electrode (311) is electrically connected to a thin-film transistor (TFT) by contacting either the source electrode (SE) or the drain electrode (DE) through an opening formed in the planarization layer (240), etc. This pixel electrode (311) includes a transparent conductive layer formed of a transparent conductive oxide such as ITO, In2O3, or IZO, and a reflective layer formed of a metal such as Al or Ag. For example, the pixel electrode (311) may have a three-layer structure of ITO / Ag / ITO.

[0108] A pixel defining film (320) may be placed on top of a flattening layer (240). This pixel defining film (320) serves to define pixels by having openings corresponding to each pixel, that is, openings that expose at least the central part of the pixel electrode (311). In addition, as shown in FIG. 9, the pixel defining film (320) serves to prevent arcs from occurring at the edge of the pixel electrode (311) by increasing the distance between the edge of the pixel electrode (311) and the opposing electrode (313) above the pixel electrode (311). Such a pixel defining film (320) may include, for example, an organic material such as polyimide or HMDSO (hexamethyldisiloxane).

[0109] The intermediate layer (312) of the display element (310) may include a low-molecular-weight or high-molecular-weight material. If the intermediate layer (312) includes a low-molecular-weight material, the intermediate layer (312) may have a structure in which a hole injection layer (HIL), a hole transport layer (HTL), an emission layer (EML), an electron transport layer (ETL), and an electron injection layer (EIL) are stacked in a single or composite structure, and may be formed by a vacuum deposition method. If the intermediate layer (312) includes a high-molecular-weight material, the intermediate layer (312) may have a structure including a hole transport layer (HTL) and an emission layer (EML). In this case, the hole transport layer may include PEDOT, and the emission layer may include a high-molecular-weight material such as a PPV (polyphenylene vinylene) system and a polyfluorene system. This intermediate layer (312) can be formed by screen printing, inkjet printing, laser induced thermal imaging (LITI), etc. Of course, the intermediate layer (312) is not necessarily limited to this and can have various structures. Also, the intermediate layer (312) may include a layer that is integral across a plurality of pixel electrodes (311), or may include a layer patterned to correspond to each of the plurality of pixel electrodes (311).

[0110] The counter electrode (313) may be integrally formed in a plurality of display elements (310) and may correspond to a plurality of pixel electrodes (311). This counter electrode (313) may include a transparent conductive layer formed of ITO, In2O3, or IZO, and may also include a semi-transparent film containing a metal such as Al or Ag. For example, the counter electrode (313) may be a semi-transparent film containing Mg or Ag.

[0111] An encapsulation layer (400) may be disposed on the display element layer (300). Since the display element (310) can be easily damaged by moisture or oxygen from the outside, the encapsulation layer (400) may cover and protect the display element (310). The encapsulation layer (400) may include a first inorganic encapsulation layer (410), an organic encapsulation layer (420), and a second inorganic encapsulation layer (430), as shown in FIG. 9.

[0112] The first inorganic sealing layer (410) covers the counter electrode (313) and may include silicon oxide, silicon nitride and / or silicon oxynitride, etc. Of course, other layers such as a capping layer may be interposed between the first inorganic sealing layer (410) and the counter electrode (313) as needed. Since this first inorganic sealing layer (410) is formed along the structure below it, its upper surface is not flat as shown in FIG. 9. The organic sealing layer (420) covers this first inorganic sealing layer (410), and unlike the first inorganic sealing layer (410), its upper surface can be made approximately flat. These organic encapsulation layers (420) may include one or more materials selected from the group consisting of polyethylene terephthalate, polyethylene naphthalate, polycarbonate, polyimide, polyethylene sulfonate, polyoxymethylene, polyarylate, and hexamethyldisiloxane. The second inorganic encapsulation layer (430) covers the organic encapsulation layer (420) and may include silicon oxide, silicon nitride and / or silicon oxynitride, etc.

[0113] In this way, the sealing layer (400) includes a first inorganic sealing layer (410), an organic sealing layer (420), and a second inorganic sealing layer (430). Through this multilayer structure, even if a crack occurs within the sealing layer (400), such cracks can be prevented from connecting between the first inorganic sealing layer (410) and the organic sealing layer (420), or between the organic sealing layer (420) and the second inorganic sealing layer (430). This prevents or minimizes the formation of a path through which moisture or oxygen from the outside penetrates into the interior of the display panel (10).

[0114] The upper organic layer (20) can be placed on the display panel (10). The upper organic layer (20) can be placed to cover the upper surface of the display panel (10). This upper organic layer (20) can function to protect the upper surface of the display panel (10).

[0115] The upper organic layer (20) may have a high transmittance to transmit light emitted from the display panel (10) and may have a thin thickness to minimize the weight of the display device (1). In addition, the upper organic layer (20) may have high strength and hardness to protect the display panel (10) from external impact. The upper organic layer (20) can protect the display panel (10) by easily bending according to external force without the occurrence of cracks, etc.

[0116] Although not illustrated, a protective film may be disposed below the display panel (10) so as to face the lower surface (in the -z direction) of the display panel (10). Specifically, the protective film may be disposed below the substrate (100) so as to face the lower surface (in the -z direction) of the substrate (100). The protective film may serve to protect the display panel (10) during the manufacturing process of the display device. An adhesive layer may be interposed between the protective film and the substrate (100), and by means of this adhesive layer, the protective film may be attached to the underside of the substrate (100). The adhesive layer interposed between the protective film and the substrate (100) may include at least one of an optical clear resin (OCR), an optical clear adhesive (OCA), and a pressure sensitive adhesive (PSA).

[0117] Up to this point, the display device (1) has been described, but the present invention is not limited thereto. A method for manufacturing such a display device is also considered to be within the scope of the present invention. Below, a method for manufacturing such a display device (1) will be described.

[0118] FIGS. 10 to 13 are drawings for explaining a method of manufacturing a display device according to an embodiment of the present invention. Specifically, FIGS. 10 to 13 are cross-sectional views schematically illustrating the process of forming an upper organic layer (20) including a first organic layer (21) and a second organic layer (22) among the processes of manufacturing a display device (1).

[0119] First, as illustrated in FIG. 10, a second organic layer forming layer (22FL) can be formed on the display panel (10). In this specification, "second organic layer forming layer" may refer to a layer that has not been irradiated with ultraviolet light after applying the second organic layer composition. The second organic layer composition may include a urethane-based compound. For example, the second organic layer composition may include polyurethane. Meanwhile, the second organic layer composition may further include a photocuring agent. The photocuring agent may include any that can be used to photocur a urethane-based compound and is not particularly limited. Additionally, the second organic layer composition may further include a solvent. That is, the second organic layer composition may be a solution in which a urethane-based compound and a photocuring agent are dissolved in a solvent.

[0120] The second organic layer composition can be applied to the display panel (10). By doing so, the second organic layer forming layer (22FL) can be formed. The second organic layer composition can be applied to the display panel (10) using various methods. For example, the second organic layer composition can be applied to the entire surface of the display panel (10) using an inkjet device. Alternatively, the second organic layer composition can be coated onto the display panel (10) by a dip coating method. In one embodiment, the applied second organic layer composition can be heat-treated to remove at least a portion of the solvent.

[0121] Next, as illustrated in FIG. 11, ultraviolet light can be irradiated onto the second organic layer forming layer (22FL). By doing so, the second organic layer (22) can be formed. Specifically, ultraviolet light having a light intensity of 100 mJ / cm² to 1000 mJ / cm² can be irradiated onto the second organic layer forming layer (22FL). For photocuring, ultraviolet light having a wavelength of about 300 nm to about 400 nm can be used. An LED or a metal halide can be used as the ultraviolet source.

[0122] Next, as illustrated in FIG. 12, a first organic layer forming layer (21FL) may be formed on the second organic layer (22). In this specification, "first organic layer forming layer" may refer to a layer that has not been irradiated with ultraviolet light after applying the first organic layer composition. The first organic layer composition may include at least one of an acrylic compound, a siloxane compound, and a carbonate compound. For example, the first organic layer composition may include at least one of polyacrylate, polydimethylsiloxanes, and polycarbonate. Meanwhile, the first organic layer composition may further include a photocuring agent. The photocuring agent may include any that can be used to photocur an acrylic compound, a siloxane compound, or a carbonate compound, and is not particularly limited. Additionally, the first organic layer composition may further include a solvent. That is, the first organic layer composition may be a solution in which at least one of an acrylic compound, a siloxane compound, and a carbonate compound and a photocuring agent are dissolved in a solvent.

[0123] The first organic layer composition can be applied onto the second organic layer (22). By doing so, the first organic layer forming layer (21FL) can be formed. The first organic layer composition can be applied onto the display panel (10) using various methods. For example, the first organic layer composition can be applied to the entire surface of the display panel (10) using an inkjet device. Alternatively, the first organic layer composition can be coated onto the display panel (10) by a dip coating method. In one embodiment, the applied first organic layer composition can be heat-treated to remove at least a portion of the solvent.

[0124] Next, as illustrated in FIG. 13, ultraviolet rays can be irradiated onto the first organic layer forming layer (21FL) while applying pressure using a jig. That is, by applying pressure to the first organic layer forming layer (21FL) with a jig, the upper surface of the first organic layer forming layer (21FL) can have a shape that interlocks with the lower surface of the jig. Accordingly, the upper surface of the first organic layer (21), which is formed by curing the first organic layer forming layer (21FL), can have a shape that interlocks with the lower surface of the jig.

[0125] Meanwhile, the lower surface of the jig may be flat overall. However, in order for the portion of the first organic layer forming layer (21FL) corresponding to the first organic foldable portion (21F) to have a curve, the lower surface of the jig may include a portion that is recessed in the direction opposite to the display panel (10) (e.g., +z direction) and other portions that are arranged on both sides of this portion and protrude in the direction of the display panel (10). The upper surface of the jig may be approximately flat as shown in FIG. 13, but the present invention is not limited thereto. For example, the upper surface of the jig may have a shape similar to the lower surface of the jig.

[0126] Meanwhile, the lower surface of the jig may be treated as non-adhesive. Specifically, the entire lower surface of the jig may be coated with a fluorine-based compound. As a result, even if ultraviolet rays are irradiated onto the first organic layer forming layer (21FL) while the lower surface of the jig is in contact with the upper surface of the first organic layer forming layer (21FL), the first organic layer (21) may not adhere to the jig. For example, the fluorine-based compound may include at least one of polytetrafluoroethylene (PTFE) and polyvinylidene fluoride (PVDF).

[0127] The first organic layer forming layer (21FL) is deformed by being pressed by an external force (e.g., a force such as compression) and may have a pre-set flat surface and curved surface. Specifically, when pressure is applied to the jig in the direction of the display panel (10), the upper surface of the first organic layer forming layer (21FL) adheres to the lower surface of the jig, and the upper surface of the first organic layer forming layer (21FL) may be deformed according to the shape of the lower surface of the jig. That is, the upper surface of the first organic layer forming layer (21FL) may have a shape that interlocks with the lower surface of the jig.

[0128] Ultraviolet light may be irradiated onto the first organic layer forming layer (21FL). This irradiation of ultraviolet light may be performed together with pressurization of the first organic layer forming layer (21FL) using a jig. Specifically, ultraviolet light having a light intensity of 100 mJ / cm² to 1000 mJ / cm² may be irradiated onto the first organic layer forming layer (21FL). For photocuring, ultraviolet light having a wavelength of about 300 nm to about 400 nm may be used. An LED or a metal halide may be used as the ultraviolet light source.

[0129] Through this process, as described above with reference to FIG. 4a, the first organic layer (21) may have different thicknesses depending on its position. Specifically, the thickness of the first-1 foldable portion (21F1) may be thicker than the thickness of the first-1 non-foldable portion (21NF1), and the thickness of the first-2 foldable portion (21F2) may be thinner than the thickness of the first-1 non-foldable portion (21NF1). Accordingly, the upper organic layer (20) including the first organic layer (21) and the second organic layer (22) may have different thicknesses depending on its position. Specifically, the thickness of the first foldable portion (20F1) may be thicker than the thickness of the first non-foldable portion (20NF1), and the thickness of the second foldable portion (20F2) may be thinner than the thickness of the first non-foldable portion (20NF1).

[0130] FIGS. 14 to 16 are drawings for explaining a method for manufacturing a display device according to an embodiment of the present invention. Since this corresponds to a modified embodiment of the method for manufacturing a display device described above with reference to FIGS. 10 to 13, the following description will focus on the differences from the method for manufacturing a display device described above with reference to FIGS. 10 to 13.

[0131] The manufacturing method of the display device according to the present embodiment may also form a second organic layer forming layer (22FL) on the display panel (10). Since this process is identical to the manufacturing method of the display device described above with reference to FIGS. 10 to 13, a redundant description in relation thereto is omitted.

[0132] However, in the case of the manufacturing method of the display device according to the present embodiment, as shown in FIG. 14, ultraviolet rays can be irradiated onto the second organic layer forming layer (22FL) while pressing the second organic layer forming layer (22FL) using a jig. That is, by pressing the second organic layer forming layer (22FL) with the jig, the upper surface of the second organic layer forming layer (22FL) can have a shape that interlocks with the lower surface of the jig. Accordingly, the upper surface of the second organic layer (22) formed by curing the second organic layer forming layer (22FL) can have a shape that interlocks with the lower surface of the jig.

[0133] The above description regarding the jig used to press the first organic layer forming layer (21FL) can also be applied to the jig used to press the second organic layer forming layer (22FL), so redundant explanations regarding this are omitted.

[0134] The second organic layer forming layer (22FL) is deformed by being pressed by an external force (e.g., a compressive force) and may have a pre-set flat surface and a curved surface. Specifically, when pressure is applied to the jig in the direction of the display panel (10), the upper surface of the second organic layer forming layer (22FL) adheres to the lower surface of the jig, and the upper surface of the second organic layer forming layer (22FL) may be deformed according to the shape of the lower surface of the jig. That is, the upper surface of the second organic layer forming layer (22FL) may have a shape that interlocks with the lower surface of the jig. Ultraviolet light may be irradiated onto this second organic layer forming layer (22FL).

[0135] Through this process, as described above with reference to FIG. 5a, the second organic layer (22) may have different thicknesses depending on its location. Specifically, the thickness of the second-1 foldable portion (22F1) is thicker than the thickness of the second-1 non-foldable portion (22NF1), and the thickness of the second-2 foldable portion (22F2) may be thinner than the thickness of the second-1 non-foldable portion (22NF1).

[0136] Next, as shown in FIG. 15, a first organic layer forming layer (21FL) can be formed on the second organic layer (22). Since the first organic layer forming layer (21FL) is formed along the second organic layer below it, its upper surface may have a shape that interlocks with the lower surface of the jig as shown in FIG. 15.

[0137] Next, as illustrated in FIG. 16, ultraviolet light can be irradiated onto the first organic layer forming layer (21FL). Accordingly, as described above with reference to FIG. 5a, the upper organic layer (20), which includes the first organic layer (21) and the second organic layer (22), may have different thicknesses depending on its location. Specifically, the thickness of the first foldable portion (20F1) may be thicker than the thickness of the first non-foldable portion (20NF1), and the thickness of the second foldable portion (20F2) may be thinner than the thickness of the first non-foldable portion (20NF1).

[0138] As such, the present invention has been described with reference to the embodiments illustrated in the drawings, but this is merely illustrative, and those skilled in the art will understand that various modifications and equivalent alternative embodiments are possible therefrom. Accordingly, the true technical scope of protection of the present invention should be determined by the technical spirit of the appended claims. Explanation of the symbols

[0139] 1: Display device 10: Display panel 20: Upper organic layer 21: First organic layer 22: Second organic layer 20NF1: 1st non-folding part 20NF2: 2nd non-folding part 20F1: 1st foldable part 20F2: Second foldable part 310: Display element

Claims

Claim 1 A display device comprising: a display panel including a display element; and an upper organic layer including a first organic layer disposed on the upper portion of the display panel and a second organic layer interposed between the first organic layer and the display panel; wherein the upper organic layer comprises: a first non-folding portion and a second non-folding portion disposed spaced apart from each other; a first foldable portion disposed between the first non-folding portion and the second non-folding portion, extending in a direction intersecting a virtual straight line connecting the first non-folding portion and the second non-folding portion, and having a thickness greater than the thickness of the first non-folding portion; and a plurality of second foldable portions disposed on both sides of the first foldable portion, extending in a direction intersecting a virtual straight line connecting the first non-folding portion and the second non-folding portion, and having a thickness thinner than the thickness of the first non-folding portion. Claim 2 A display device according to claim 1, wherein the thickness of the first foldable portion increases from the outer edge of the first foldable portion toward the center of the first foldable portion, and the thickness of the second foldable portion decreases from the outer edge of the second foldable portion toward the center of the second foldable portion. Claim 3 A display device according to claim 1, wherein the thickness of the first foldable portion increases as it moves away from the second foldable portion, the thickness of a part of the second foldable portion decreases as it moves away from the first foldable portion, the thickness of another part of the second foldable portion decreases as it moves away from the first non-folding portion, and the thickness of yet another part of the second foldable portion decreases as it moves away from the second non-folding portion. Claim 4 A display device according to claim 1, wherein the first non-folding portion comprises a first-1 non-folding portion which is part of the first organic layer and a second-1 non-folding portion which is part of the second organic layer, the second non-folding portion comprises a first-2 non-folding portion which is part of the first organic layer and a second-2 non-folding portion which is part of the second organic layer, the first foldable portion comprises a first-1 foldable portion which is part of the first organic layer and a second-1 foldable portion which is part of the second organic layer, and the second foldable portion comprises a first-2 foldable portion which is part of the first organic layer and a second-2 foldable portion which is part of the second organic layer. Claim 5 A display device according to claim 4, wherein the second organic layer has a uniform thickness, the thickness of the first-1 foldable portion is thicker than the thickness of the first-1 non-foldable portion, and the thickness of the first-2 foldable portion is thinner than the thickness of the first-1 non-foldable portion. Claim 6 A display device according to claim 5, wherein the thickness of the first-1 foldable portion increases from the outer edge of the first-1 foldable portion toward the center of the first-1 foldable portion, and the thickness of the first-2 foldable portion decreases from the outer edge of the first-2 foldable portion toward the center of the first-2 foldable portion. Claim 7 A display device according to claim 5, wherein the thickness of the first-1 foldable portion increases as it moves away from the first-2 foldable portion, the thickness of a part of the first-2 foldable portion decreases as it moves away from the first-1 foldable portion, the thickness of another part of the first-2 foldable portion decreases as it moves away from the first-1 non-folding portion, and the thickness of yet another part of the first-2 foldable portion decreases as it moves away from the first-2 non-folding portion. Claim 8 A display device according to claim 4, wherein the first organic layer has a uniform thickness, the thickness of the second-1 foldable portion is thicker than the thickness of the second-1 non-foldable portion, and the thickness of the second-2 foldable portion is thinner than the thickness of the second-1 non-foldable portion. Claim 9 A display device according to claim 8, wherein the thickness of the 2-1 foldable portion increases from the outer edge of the 2-1 foldable portion toward the center of the 2-1 foldable portion, and the thickness of the 2-2 foldable portion decreases from the outer edge of the 2-2 foldable portion toward the center of the 2-2 foldable portion. Claim 10 A display device according to claim 8, wherein the thickness of the 2-1 foldable portion increases as it moves away from the 2-2 foldable portion, the thickness of a part of the 2-2 foldable portion decreases as it moves away from the 2-1 foldable portion, the thickness of another part of the 2-2 foldable portion decreases as it moves away from the 2-1 non-folding portion, and the thickness of yet another part of the 2-2 foldable portion decreases as it moves away from the 2-2 non-folding portion. Claim 11 A display device according to claim 4, wherein the sum of the thickness of the first-1 foldable portion and the thickness of the second-1 foldable portion is greater than the sum of the thickness of the first-1 non-foldable portion and the thickness of the second-1 non-foldable portion, and the sum of the thickness of the first-2 foldable portion and the thickness of the second-2 foldable portion is smaller than the sum of the thickness of the first-1 non-foldable portion and the thickness of the second-1 non-foldable portion. Claim 12 A display device according to claim 1, wherein the first organic layer has a higher modulus than the modulus of the second organic layer. Claim 13 A display device according to claim 12, wherein the modulus of the first organic layer is 1 GPa or more and less than 10 GPa, and the modulus of the second organic layer is 0.1 GPa or more and less than 1 GPa. Claim 14 A method for manufacturing a display device, comprising: a step of preparing a display panel including a display element; and a step of forming an upper organic layer including a first organic layer and a second organic layer on the display panel; wherein the step of forming the upper organic layer comprises a first non-folding portion and a second non-folding portion spaced apart from each other, a first foldable portion disposed between the first non-folding portion and the second non-folding portion and extending in a direction intersecting a virtual straight line connecting the first non-folding portion and the second non-folding portion and having a thickness greater than the thickness of the first non-folding portion, and a plurality of second foldable portions disposed on both sides of the first foldable portion and extending in a direction intersecting a virtual straight line connecting the first non-folding portion and the second non-folding portion and having a thickness thinner than the thickness of the first non-folding portion. Claim 15 In claim 14, the step of forming the upper organic layer comprises: a step of applying a second organic layer composition to the display panel; a step of forming a second organic layer by irradiating ultraviolet rays onto the second organic layer composition; a step of applying a first organic layer composition onto the second organic layer; and a step of forming a first organic layer by irradiating ultraviolet rays onto the first organic layer composition while applying pressure to the first organic layer composition using a jig; a method for manufacturing a display device. Claim 16 A method for manufacturing a display device according to claim 15, wherein the lower surface of the above jig is treated with a non-adhesive process. Claim 17 A method for manufacturing a display device according to claim 15, wherein the step of forming the first organic layer is a step of forming the first organic layer such that the upper surface of the first organic layer has a shape that engages with the lower surface of the jig. Claim 18 In claim 14, the step of forming the upper organic layer comprises: applying a second organic layer composition onto the display panel; forming a second organic layer by applying ultraviolet rays to the second organic layer composition while applying pressure to the second organic layer composition using a jig; applying a first organic layer composition to the second organic layer; and forming a first organic layer by irradiating ultraviolet rays to the first organic layer composition. Claim 19 In claim 18, a method for manufacturing a display device wherein the lower surface of the above jig is treated with a non-adhesive process. Claim 20 A method for manufacturing a display device according to claim 18, wherein the step of forming the second organic layer is a step of forming the second organic layer such that the upper surface of the second organic layer has a shape that engages with the lower surface of the jig.

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