Display Devices

Abstract

The present application relates to a display device. The display device comprises: a display module, comprising a first non-folding area, a folding area, and a second non-folding area; a support plate, arranged below the display module; a foam coating, comprising a base part and a foaming agent contained in the base part, the foam coating being arranged on the support plate; and a barrier layer, arranged between the display module and the foam coating and comprising an elastic material.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to and the benefit of Korean Patent Application No. 10-2020-0077169 filed in the Korean Intellectual Property Office on June 24, 2020, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present disclosure relates to a display device and a foldable display device. Background Art

[0004] The display device displays various images through a display screen to provide information to a user. The display device can be applied to various electronic items such as smart phones, notebook computers, televisions, etc. to display images.

[0005] In recent years, flexible display devices including flexible display panels are being developed, and the flexible display panels may be foldable. Unlike rigid display devices, flexible display devices may be foldable, rollable, or bendable. Flexible display devices that can be transformed into various shapes are easy to carry and improve user convenience.

[0006] Meanwhile, bending deformation may occur or be seen in a folding region of a foldable flexible display device, and thus, research aimed at preventing the bending deformation is required.

[0007] It should be understood that the background of the technical section is intended, in part, to provide a useful background for understanding the technology. However, the background of the technical section may also include ideas, concepts, or understandings that were not known or understood by a person skilled in the relevant art before the corresponding effective filing date of the subject matter disclosed herein. Summary of the invention

[0008] The present disclosure provides a display device capable of improving bending deformation in a folding area thereof.

[0009] An embodiment provides a display device, which may include: a display module, including a first non-folding area, a folding area, and a second non-folding area; a support plate, arranged below the display module; a foam coating, including a base part and a foaming agent contained in the base part, the foam coating being directly arranged on the support plate; and a barrier layer, arranged between the display module and the foam coating and including an elastic material.

[0010] The blowing agent of the foam coating may have a substantially spherical shape and may include a shell portion and a core portion.

[0011] The shell portion of the blowing agent of the foam coating may include a thermoplastic resin.

[0012] The weight of the foaming agent may be equal to or greater than about 3 wt % and equal to or less than about 15 wt % of the total weight of the base part.

[0013] The base part of the foam coating may include a polymer resin having a weight average molecular weight equal to or greater than about 1,000 and equal to or less than about 15,000.

[0014] The foam coating may have a Young's modulus equal to or greater than about 1 MPa and equal to or less than about 100 MPa at room temperature.

[0015] The foam coating may have a g / cm 3 and equal to or less than about 0.7 g / cm 3 density.

[0016] The barrier layer may have a yield strain equal to or greater than about 1.0% and equal to or less than about 2.5%.

[0017] The barrier layer may include ultra-thin glass, fiberglass, or stainless steel.

[0018] The barrier layer may have a Young's modulus equal to or greater than about 2 GPa and equal to or less than about 200 GPa at room temperature.

[0019] An embodiment provides a display device, which may include: a display module, including: a folding area that can be folded relative to a folding axis extending in a first direction; a first non-folding area adjacent to one side of the folding area; and a second non-folding area adjacent to the other side of the folding area; a barrier layer, arranged below the display module and including an elastic material; a first support plate, arranged below the first non-folding area; a second support plate, arranged below the second non-folding area and spaced apart from the first support plate in a second direction, the second direction being substantially perpendicular to the first direction; a first foam coating, arranged on the first support plate; and a second foam coating, arranged on the second support plate and spaced apart from the first foam coating in the second direction.

[0020] Each of the first foam coating layer and the second foam coating layer may include a base portion and a foaming agent contained in the base portion, the foaming agent having a substantially spherical shape.

[0021] The barrier layer may have a yield strain equal to or greater than about 1.0% and equal to or less than about 2.5%.

[0022] Each of the first foam coating and the second foam coating may include a plurality of sub-coatings.

[0023] The first foam coating may include: a first sub-coating, arranged on a first supporting plate; and a second sub-coating, arranged on the first sub-coating, and the second foam coating may include: a third sub-coating, arranged on the second supporting plate; and a fourth sub-coating, arranged on the third sub-coating, and the minimum spacing distance between the first sub-coating and the third sub-coating adjacent to the first sub-coating is smaller than the minimum spacing distance between the second sub-coating and the fourth sub-coating adjacent to the second sub-coating.

[0024] The minimum spacing distance (D3) between a line extending from one end of the first support plate overlapping with the folding area and a line extending from one end of the second sub-coating can satisfy the following equation: DP+RC≤D3≤DP+3RC, and the minimum spacing distance (D4) between a line extending from one end of the second support plate overlapping with the folding area and a line extending from one end of the fourth sub-coating can satisfy the following equation: DP+RC≤D4≤DP+3RC, wherein DP represents the minimum spacing distance between the first support plate and the second support plate, and RC represents the curvature radius of the folding area.

[0025] The display device may further include: a first pad layer disposed under the first support plate and including a first hole; and a second pad layer disposed under the second support plate and including a second hole, and each of the first hole of the first pad layer and the second hole of the second pad layer may be substantially parallel to the first direction.

[0026] The display device may further include an adhesive portion filled in each of the first hole of the first cushion layer and the second hole of the second cushion layer.

[0027] The thickness of the bonding portion may be smaller than a thickness of each of the first cushion layer and the second cushion layer.

[0028] The shortest distance between the first hole of the first cushion layer and the second hole of the second cushion layer in the second direction may be equal to or greater than about 25 mm and equal to or less than about 35 mm.

[0029] According to the above, the bending deformation in the folding area of ​​the display device can be reduced, and thus, the phenomenon that the user perceives the bending deformation of the display device can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The above and other advantages of the present disclosure will become apparent by reference to the following detailed description when considered in conjunction with the accompanying drawings, in which:

[0031] Figure 1A is a perspective view showing a display device according to an embodiment;

[0032] Figure 1B It is shown Figure 1A A perspective view of a folded or foldable state of a display device as shown in ;

[0033] Figure 2A is a perspective view showing a display device according to an embodiment;

[0034] Figure 2B It is shown Figure 2A A perspective view of a folded or foldable state of a display device as shown in ;

[0035] Figure 3 is an exploded perspective view showing a display device according to an embodiment;

[0036] Figure 4 is a schematic cross-sectional view showing a display module according to an embodiment;

[0037] Figure 5 is a schematic cross-sectional view showing a covering member according to an embodiment;

[0038] Fig. 6A is a schematic cross-sectional view showing a foaming agent before foaming according to an embodiment;

[0039] Figure 6B It shows the foaming Fig. 6A A schematic cross-sectional view of the blowing agent shown in ;

[0040] Fig. 7A is a schematic cross-sectional view showing a covering member according to an embodiment;

[0041] Figure 7B is a schematic cross-sectional view showing a covering member according to a comparative example;

[0042] Figure 8 is a graph showing the degree of deformation of display devices according to an embodiment example and a comparative example;

[0043] Fig. 9 is a schematic cross-sectional view showing a covering member according to an embodiment;

[0044] Fig.10 is a schematic cross-sectional view showing a folded or foldable state of a display device according to an embodiment;

[0045] Fig.11A is a schematic cross-sectional view showing a covering member according to an embodiment;

[0046] Fig. 11B is a schematic cross-sectional view showing a covering member according to an embodiment;

[0047] Fig.12 is a plan view showing a cushion layer according to an embodiment;

[0048] Fig.13is a schematic cross-sectional view showing a covering member according to a comparative example. DETAILED DESCRIPTION

[0049] The present disclosure can be variously modified and implemented in many different forms, and therefore, embodiments will be shown in the drawings and described in detail below. However, the present disclosure should not be limited to the disclosed forms, but should be interpreted as including all modifications, equivalents or substitutions included in the spirit and scope of the present disclosure.

[0050] In the present disclosure, it will be understood that when an element or layer is referred to as being “on,” “connected to” or “coupled to” another element or layer, it can be directly on, connected to or coupled to the other element or layer, or intervening elements or layers may be present.

[0051] The same reference numerals refer to the same elements throughout. In the drawings, in order to effectively describe the technical contents, the thickness, proportion, and size of components may be exaggerated.

[0052] As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0053] The terms "and" and "or" may be used in a conjunctive or disjunctive sense and may be understood to be equivalent to "and / or". In the specification and claims, for the purpose of its meaning and interpretation, the phrase "at least one of..." is intended to include the meaning of "at least one selected from the set...". For example, "at least one of A and B" may be understood to mean "A, B, or A and B".

[0054] It will be understood that, although the terms "first", "second" etc. can be used in this article to describe various elements, components, regions, layers and / or parts, these elements, components, regions, layers and / or parts should not be limited by these terms. These terms are only used to distinguish an element, component, region, layer or part from another element, component, region, layer or part. Therefore, without departing from the teaching of the present disclosure, the first element, first component, first area, first layer or first part discussed below can be referred to as the second element, second component, second area, second layer or second part. Unless the context clearly indicates otherwise, as used herein, the singular forms "one", "an" and "the" are intended to include plural forms.

[0055] For ease of description, spatially relative terms such as "below," "below," "down," "above," "upper," etc. may be used herein to describe the relationship of one element or component to another element or component as shown in the drawings. It will be understood that the spatially relative terms are intended to cover different orientations of the device in use or operation in addition to the orientations depicted in the drawings. For example, where the device shown in the drawings is flipped, a device positioned "below" or "below" another device may be placed "above" the other device. Thus, the schematic term "below" may include both lower and upper positioning. The device may also be oriented in other directions, and thus the spatially relative terms may be interpreted accordingly depending on the orientation.

[0056] In addition, the term "overlap" or "overlapping" means that the first object can be above or below the second object or on one side of the second object, or vice versa. In addition, the term "overlap" can include layers, stacks, facing or facing, extending on, covering or partially covering or any other suitable terms that a person of ordinary skill in the art will appreciate and understand. The terms "facing" and "facing" mean that the first element can be directly or indirectly opposite to the second element. In the case where the third element is between the first element and the second element, the first element and the second element can be understood to be indirectly opposite to each other, although still facing each other. When an element is described as "non-overlapping" or "without overlapping" another element, this can include elements spaced apart from each other, offset from each other or separated from each other or any other suitable terms that a person of ordinary skill in the art will appreciate and understand.

[0057] The phrase "in a plan view" means observing an object from the top, and the phrase "in a schematic cross-sectional view" means observing a section of an object cut vertically from the side.

[0058] As used herein, "about" or "approximately" includes the stated value and the mean within an acceptable deviation range of the particular value as determined by one of ordinary skill in the art taking into account the measurement in question and the errors associated with the measurement of the particular quantity (i.e., the limitations of the measurement system). For example, "about" can mean within one or more standard deviations, or within ±30%, ±20%, ±10%, ±5% of the stated value.

[0059] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as those commonly understood by those skilled in the art to which the present disclosure belongs. It will also be understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology and should not be interpreted in an idealized or overly formal sense unless explicitly defined as such herein.

[0060] It will also be understood that when used in this specification, the terms "comprises" and / or "comprising", "includes" and / or "including", "has", "has" and / or "having" and variations thereof specify the presence of stated features, integers, steps, operations, elements and / or parts, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, parts and / or combinations thereof.

[0061] Hereinafter, a display device according to the present disclosure will be described in detail with reference to the accompanying drawings.

[0062] Figure 1A and Figure 2A is a perspective view showing display devices DD and DD-1 according to an embodiment. Figure 1B It is shown Figure 1A 0 is a perspective view of a folded or foldable state of the display device DD shown in . Figure 2B It is shown Figure 2A A perspective view of a folded or foldable state of the display device DD-1 shown in FIG.

[0063] Reference Figure 1A , Figure 1B , Figure 2A ,and Figure 2B The display devices DD and DD-1 may be foldable display devices. Within the spirit and scope of the present disclosure, the display devices DD and DD-1 may be applied to large electronic items such as televisions, monitors, etc., as well as small and medium-sized electronic items such as mobile phones, tablet computers, game units, navigation units, etc.

[0064] An upper surface of each of the display devices DD and DD-1 may be defined as a display surface DS. When the display devices DD and DD-1 are in an unfolded state, the display surface DS may correspond to a plane defined by the first direction axis DR1 and the second direction axis DR2.

[0065] The display surface DS may include a display area DA and a non-display area NDA, which is defined or formed around or near the display area DA. An image IM may be displayed through the display area DA, and the image IM may not be displayed through the non-display area NDA. The image IM may include one or more still images, or one or more moving images. Figure 1A and Figure 2A A plurality of application icons are shown as representative examples of the image IM.

[0066] The display area DA may have a substantially quadrilateral shape. The non-display area NDA may surround the display area DA or be adjacent to the display area DA. However, they should not be limited thereto or thereby, and the display area DA and the non-display area NDA may be designed to have other shapes. For example, the non-display area NDA may be defined or formed to be adjacent to only one side of the display area DA, or may be omitted. The display devices DD and DD-1 may include various embodiments, and they should not be particularly limited.

[0067] The display device DD may include a first non-folding area NFA1, a folding area FA, and a second non-folding area NFA2, which may be defined or formed in the display device DD and sequentially arranged or set on the second direction axis DR2. For example, the folding area FA may be defined or formed between the first non-folding area NFA1 and the second non-folding area NFA2. The display device DD-1 may include a first non-folding area NFA1-1, a folding area FA-1, and a second non-folding area NFA2-1, which may be defined or formed in the display device DD and sequentially arranged or set on the first direction axis DR1. For example, the folding area FA-1 may be defined or formed between the first non-folding area NFA1-1 and the second non-folding area NFA2-1.

[0068] The display devices DD and DD-1 may be foldable or foldable around folding axes FX and FX-1, respectively. For example, the folding areas FA and FA-1 may be foldable or foldable around folding axes FX and FX-1, respectively. The folding areas FA and FA-1 may be portions where deformation occurs when the display devices DD and DD-1 are folded or foldable or bent, and may correspond to bent portions of the display devices DD and DD-1.

[0069] Reference Figure 1A and Figure 1B , the folding axis FX may extend on the first direction axis DR1. The folding axis FX may be a short axis substantially parallel to the short side of the display device DD. Figure 2A and Figure 2B , the folding axis FX-1 may extend on the second direction axis DR2. The folding axis FX-1 may be a long axis substantially parallel to a long side of the display device DD-1.

[0070] When the display device DD is folded or foldable, the display surface corresponding to the first non-folding area NFA1 and the display surface corresponding to the second non-folding area NFA2 may face each other. When the display device DD-1 is folded or foldable, the display surface corresponding to the first non-folding area NFA1-1 and the display surface corresponding to the second non-folding area NFA2-1 may face each other. Therefore, in the folded or foldable state of the display devices DD and DD-1, the display surface DS may not be exposed to the outside, however, this is only an example. Although not shown in the figure, when the display devices DD and DD-1 are folded or foldable, respectively, the display surfaces corresponding to the first non-folding areas NFA1 and NFA1-1 and the display surfaces corresponding to the second non-folding areas NFA2 and NFA2-1 may be opposite to each other. Therefore, in the folded or foldable state of the display devices DD and DD-1, the display surface DS may be exposed to the outside.

[0071] According to Figure 1A and Figure 2A Each of the display devices DD and DD-1 of the embodiments shown in the drawings includes one folding area and two non-folding areas. However, the number of folding areas and the number of non-folding areas should not be limited thereto or thereby. For example, each of the display devices DD and DD-1 may include more than two non-folding areas and a folding area disposed between the non-folding areas.

[0072] In the following, the Figure 1A and Figure 1B The structure of the display device DD foldable or foldable about a short axis shown in is taken as a representative example, however, the present disclosure should not be limited to or thereby, and the description provided below can be applicable to the display device DD-1 foldable or foldable about a long axis.

[0073] Figure 3 is an exploded perspective view showing a display device DD according to an embodiment. The display device DD may include a display module DM and a cover member CV disposed below or under the display module DM. Although not shown in the figure, the display device DD may also include a housing (or shell) for accommodating the display module DM and the cover member CV.

[0074] The display module DM can display the image IM (refer to Figure 1A ) and can sense the external input TC (refer to Figure 1A ). The external input TC may be a user input. The user input may include various types of external inputs, such as a part of a user's body, light, heat, a pen, or pressure. Figure 1AIn the figure, the external input TC is shown as the user's hand applied to the display surface DS, however, this is only an example. For example, the display module DM can sense the external input TC applied to the side or rear surface of the display device DD according to its structure, and it should not be limited to a specific embodiment.

[0075] The display module DM may have a substantially rectangular shape having a short side extending on a first direction axis DR1 and a long side extending on a second direction axis DR2. The display module DM may include a folding area FA, a first non-folding area NFA1 that is folded or foldable about a folding axis FX extending on the first direction axis DR1, and a second non-folding area NFA2 that is defined or formed adjacent to one side of the folding area FA and adjacent to the other side of the folding area FA.

[0076] The cover member CV may be disposed under or below the display module DM. The cover member CV may support the rear surface of the display module DM and may protect the display module DM. The cover member CV may include a blocking portion BR and a supporting portion SL, wherein the blocking portion BR has an elastic force that is conducive to restoring deformation while protecting the display module DM, and the supporting portion SL supports the display module DM and has impact resistance.

[0077] Figure 4 is a schematic cross-sectional view showing a display module DM according to an embodiment. Figure 4 A cross-sectional view corresponding to a plane defined by the second direction axis DR2 and the third direction axis DR3 is shown. The third direction axis DR3 may be perpendicular to a plane defined by the first direction axis DR1 and the second direction axis DR2.

[0078] Reference Figure 4 The display module DM may include a protective layer PL, a window WM, an anti-reflection layer POL, a display panel DPN, and a protective film PF. The display module DM may also include adhesive layers AD1, AD2, AD3, and AD4 disposed between its components. The display module DM should not be limited to Figure 4 , and some components included in the display module DM may be formed by a continuous process and may be provided without being attached to each other by an adhesive layer. In this case, some of the adhesive layers AD1, AD2, AD3, and AD4 may be omitted.

[0079] The display panel DPN may be a light-emitting display panel, however, it should not be particularly limited. For example, the display panel DPN may be a liquid crystal display panel, an organic light-emitting display panel, or a quantum dot light-emitting display panel.

[0080] The anti-reflection layer POL may be disposed on the display panel DPN. The anti-reflection layer POL may reduce the reflectivity of external light incident thereon from above the window WM. The anti-reflection layer POL according to an embodiment may include a retarder and a polarizer. Each of the retarder and the polarizer may be a thin film type or a liquid crystal coating type. The retarder and the polarizer may further include a protective film.

[0081] The anti-reflection layer POL may include a color filter. The color filter may have a predetermined orientation. The orientation of the color filter may be determined by considering the emission color of the pixels included in the display panel DPN. The anti-reflection layer POL may further include a black matrix disposed adjacent to the color filter.

[0082] The anti-reflection layer POL may include a destructive interference structure. For example, the destructive interference structure may include a first reflective layer and a second reflective layer, and the first reflective layer and the second reflective layer may be disposed on different layers from each other. The first reflected light and the second reflected light, which may be respectively reflected by the first reflective layer and the second reflective layer, may destructively interfere with each other, and thus, the reflectivity of the external light may be reduced.

[0083] The window WM may be disposed on the anti-reflection layer POL. The window WM may protect the structure disposed thereunder from external scratches and impacts. The window WM may include an optically transparent material. Therefore, an image generated by the display panel DPN may be provided to a user after passing through the window WM.

[0084] The window WM may further include a functional coating layer. The functional coating layer may include at least one of an anti-fingerprint layer, an anti-reflection layer, and a hard coating layer, however, the functional coating layer included in the window WM should not be limited thereto or thereby.

[0085] The shape of the window WM can be easily changed to match the foldable display device DD (see Figure 3 ), and the display panel DPN may be protected even if the shape of the window WM may be changed. The window WM may include ultra-thin glass (UTG).

[0086] The protective layer PL may be disposed on the window WM. The display device DD may be improved by the protective layer PL (see Figure 3 ) impact resistance. The protective layer PL may be a polymer film or a tempered glass film. According to an embodiment, the protective layer PL may be omitted.

[0087] The protective film PF may be disposed under or below the display panel DPN. The protective film PF may protect the rear surface of the display panel DPN. The protective film PF may be a synthetic resin film. For example, the protective film PF may be a polyimide film or a polyethylene terephthalate film. However, the protective film PF should not be limited thereto or thereby.

[0088] Meanwhile, the display module DM may further include an input sensing layer (not shown) disposed on the display panel DPN. The input sensing layer (not shown) may be directly disposed on the display panel DPN through a continuous process. The input sensing layer (not shown) may include a plurality of insulating layers and a plurality of conductive layers. The conductive layer may form a sensing electrode for sensing an external input, a sensing line electrically connected to the sensing electrode, and a sensing pad electrically connected to the sensing line.

[0089] Adhesive layers AD1, AD2, AD3, and AD4 may be disposed between the protective layer PL, the window WM, the anti-reflection layer POL, the display panel DPN, and the protective film PF to attach the protective layer PL, the window WM, the anti-reflection layer POL, the display panel DPN, and the protective film PF to each other. Some of the adhesive layers AD1, AD2, AD3, and AD4 may be omitted. The adhesive layers AD1, AD2, AD3, and AD4 may include conventional adhesives. For example, each of the adhesive layers AD1, AD2, AD3, and AD4 may include a pressure-sensitive adhesive (PSA), an optically clear adhesive (OCA), or an optically clear resin (OCR).

[0090] Figure 5 2 is a schematic cross-sectional view showing a cover member CV-a according to an embodiment. The cover member CV-a may include a support portion SL-a and a blocking portion BR. The blocking portion BR may be provided on the support portion SL-a.

[0091] The blocking portion BR may include a blocking layer BRL and adhesive layers AD5 and AD6 disposed on and below or under the blocking layer BRL, respectively. One of the adhesive layers AD5 and AD6 may be omitted.

[0092] The barrier layer BRL including an elastic material may be provided on the display module DM (refer to Figure 4 ) below or below. By providing a barrier layer BRL, the display device DD (refer to Figure 3 ) and can help restore the deformation of the display device DD even if the display device DD is repeatedly folded or foldable and unfolded by the user.

[0093] The barrier layer BRL may include a highly elastic material. The barrier layer BRL having the highly elastic material may have a yield strain equal to or greater than about 1.0% and equal to or less than about 2.5%. Since the barrier layer BRL has a wide elastic limit region, the barrier layer BRL may be advantageous in recovering deformation caused by an external force.

[0094] The barrier layer BRL may include a material having strong rigidity. For example, the barrier layer BRL may include a material that can resist deformation. The barrier layer BRL may have a Young's modulus equal to or greater than about 2 GPa and equal to or less than or less than about 200 GPa at room temperature.

[0095] The barrier layer BRL may include a polymer material, a glass material, or a metal material having relatively strong rigidity. For example, the barrier layer BRL may include polyimide, polycarbonate, polyethylene terephthalate, ultra-thin glass (UTG), fiberglass, stainless steel (SUS), or nano stainless steel.

[0096] The support portion SL-a may be disposed under or below the barrier portion BR including the barrier layer BRL. The support portion SL-a may include a support plate SP and a foam coating FC disposed directly on the support plate SP. Within the spirit and scope of the present disclosure, the foam coating FC may be directly coated on the support plate SP using a slit coating method, a screen printing coating method, or the like. Therefore, an adhesive layer for attaching the support plate SP to the foam coating FC may not be required.

[0097] The foam coating FC directly disposed on the support plate SP may include a base portion RS and a foaming agent BA. Properties such as elasticity and impact resistance of the foam coating FC may be controlled by adjusting the type of the base portion RS, the type of the foaming agent BA, or the content of the foaming agent BA. Therefore, the foam coating FC may have a predetermined elastic force and may absorb impact applied thereto.

[0098] The foaming agent BA included in the foam coating FC may be distributed in the base portion RS. The foaming agent BA may have a substantially spherical shape with a size in the micrometer order. Fig. 6A and Figure 6B The blowing agent BA included in the foam coating FC is described in detail.

[0099] Fig. 6A is a schematic cross-sectional view showing a blowing agent P-BA before foaming according to an embodiment. Figure 6B It shows the foaming Fig. 6A Schematic cross-sectional view of the blowing agent BA shown in FIG. Figure 6B , the blowing agent BA may include a shell portion SH and a core portion CO.

[0100] The foam coating FC can be formed by adding a foaming agent P-BA before foaming to the base part RS and foaming the added foaming agent P-BA. Fig. 6A, the blowing agent P-BA before foaming may have a shape in which the shell part P-SH may surround the core part P-CO. The shell part P-SH may be a thermoplastic resin. The core part P-CO may include an organic solvent, and the organic solvent may be a liquid hydrocarbon. For example, the blowing agent P-BA before foaming may be, but is not limited to, a microcapsule in which a thermoplastic resin may surround a liquid hydrocarbon.

[0101] When heat is applied to the foaming agent P-BA before foaming, the shell part P-SH begins to soften, and substantially simultaneously, the foaming material contained in the core part P-CO is vaporized. Therefore, the internal pressure of the core part P-CO increases, and the core part P-CO begins to expand. When a certain temperature is reached, the pressure inside the foaming agent, the surface tension of the shell part, and the external pressure applied to the foaming agent are balanced, and the expansion volume of the foaming agent can be maximized. When the foaming agent is continuously heated, the external pressure applied to the foaming agent increases, and the foaming agent can shrink again.

[0102] The foamed blowing agent BA included in the foam coating FC may have a substantially spherical shape in which the shell portion SH may surround the core portion CO, and the final volume may increase when compared with the volume of the blowing agent P-BA before foaming. The volume of the core portion CO of the foamed blowing agent BA may be larger than the volume of the core portion P-CO of the foaming agent P-BA before foaming, and the thickness of the shell portion SH of the foamed blowing agent BA may be smaller than the thickness of the shell portion P-SH of the foaming agent P-BA before foaming. Due to the volume expansion of the blowing agent BA, the density of the foam coating FC containing the blowing agent BA decreases.

[0103] The size of the foaming agent P-BA before foaming, the size of the foaming agent BA after foaming, and the temperature at which foaming of the foaming agent P-BA occurs may vary depending on the type of the foaming agent. The temperature at which foaming occurs may be used to dry the foam coating FC during the foaming process, however, this is only an example. The foaming process and the drying process of the foam coating FC may be performed separately from each other.

[0104] The degree of volume increase of the blowing agent BA can be changed by adjusting the type or content of the blowing agent BA contained in the foam coating FC. The density of the foam coating FC can be changed according to the degree of volume increase of the blowing agent BA. For example, the density of the foam coating FC can be equal to or greater than about 0.3 g / cm 3 and equal to or less than or less than about 0.7 g / cm 3 .

[0105] By adjusting the content of the blowing agent BA contained in the foam coating FC, the foam coating FC may have a predetermined elastic force and a predetermined impact resistance. In the case where the content of the blowing agent BA is small, the impact applied to the foam coating FC may not be easily absorbed and the elastic force may be reduced, and in the case where the content of the blowing agent BA is large, the durability of the foam coating FC may be reduced. Therefore, it may be necessary to adjust the content of the blowing agent BA within an appropriate range. In the case where the total weight of the base part RS is about 100wt%, the blowing agent BA contained in the foam coating FC may have a weight equal to or greater than about 3wt% and equal to or less than about 15wt%.

[0106] The foam coating FC may more easily absorb impact by the expanded volume of the core portion CO. The foam coating FC may have a Young's modulus equal to or greater than about 1 MPa and equal to or less than or less than about 100 MPa at room temperature. Therefore, the support plate SP having the foam coating FC directly disposed thereon may have improved impact resistance.

[0107] The type of base part RS included in the foam coating FC can be controlled. The base part RS can be a polymer resin. For example, the base part RS can be a polyurethane resin or a polyurethane acrylate resin. The polymer resin can have a flexibility that varies according to the type of reactants. For example, in the case of a polyurethane resin, a hard polyurethane resin or a soft polyurethane resin can be formed by using different types of polyols and isocyanates.

[0108] The base part RS may be, but is not limited to, a polymer resin having a weight average molecular weight equal to or greater than about 1000 and equal to or less than or less than about 15000. In the case where the weight average molecular weight of the polymer resin is less than or less than about 1000, the viscosity of the base part RS decreases, and thus, the foam coating layer FC may not be coated on the support plate SP to closely adhere to the support plate SP. In the case where the weight average molecular weight of the polymer resin is greater than about 15000, the pressure applied to the foaming agent BA distributed in the base part RS increases, and as a result, the foaming agent BA may not maintain a substantially spherical shape and may be deformed.

[0109] Reference Figure 5 The support portion SL-a may include a support plate SP. The support plate SP may prevent or mitigate the display module DM (refer to Figure 3 Therefore, although external force may be applied to the support plate SP, the display module DM can still maintain a relatively flat state.

[0110] The support plate SP may include a flexible material or a folding pattern in a region corresponding to the folding region FA to reduce the display module DM (refer to FIG. Figure 3). As another example, Fig. 7A As shown in FIG. 1 , the support plate SP may be provided as a plurality of support plates SP- 1 and SP- 2 spaced apart from each other in the folding area FA. Figure 3 ) should not be limited to or thereby.

[0111] The support plate SP may be a metal plate. For example, the support plate SP may include stainless steel, aluminum, or an alloy thereof.

[0112] The support portion SL-a and the barrier layer BRL may be attached to each other by an adhesive layer AD6 (referred to as a “sixth adhesive layer”) provided on the lower surface of the barrier layer BRL. The cover member CV-a may be attached to the display module DM (refer to FIG. 2 ) by an adhesive layer AD5 (referred to as a “fifth adhesive layer”) provided on the upper surface of the barrier layer BRL. Figure 3 )'s rear surface.

[0113] Adhesive layers AD5 and AD6 may include conventional adhesives. Each of adhesive layers AD5 and AD6 may include an acrylic resin or a silicon resin. For example, each of adhesive layers AD5 and AD6 may include a pressure sensitive adhesive (PSA), an optically clear adhesive (OCA), or an optically clear resin (OCR).

[0114] The adhesive layers AD5 and AD6 may have different thicknesses. The barrier layer BRL is attached to the display module DM (see Figure 3 ) may be thicker than the sixth adhesive layer AD6 attaching the barrier layer BRL to the support portion SL-a. For example, the fifth adhesive layer AD5 may have a thickness of about 25 μm, and the sixth adhesive layer AD6 may have a thickness of about 10 μm. However, the thickness of the fifth adhesive layer AD5 and the sixth adhesive layer AD6 should not be limited thereto or thereby.

[0115] The display device DD according to the embodiment (refer to Figure 3 ) may include a barrier layer BRL and a foam coating FC, the barrier layer BRL including an elastic material and disposed on the display module DM (refer to Figure 3 ), the foam coating FC comprises a base portion RS directly disposed on the support plate SP and a foaming agent BA distributed in the base portion RS. By comprising a barrier layer BRL of elastic material, the folding area FA (refer to FIG. 1 ) of the display device DD can be reduced. Figure 3). By including the foam coating layer FC of the base portion RS and the foaming agent BA distributed in the base portion RS, the display device DD can have impact resistance. When the foam coating layer FC is directly disposed on the support plate SP and the foam coating layer FC is coated to have a thickness of less than or less than about 100 μm, there is no need to provide an adhesive layer between the support plate SP and the foam coating layer FC. Therefore, the thickness of the stacked structure of the display device DD, which is deformed during the folding operation, can be reduced. Therefore, the impact resistance of the display device DD can be enhanced without significantly increasing the deformation in the folding area FA of the display device DD.

[0116] Fig. 7A is a schematic cross-sectional view showing a covering member CV-b according to an embodiment. The covering member CV-b may include a supporting portion SL-b including supporting plates SP-1 and SP-2 spaced apart from each other on a second direction axis DR2. The supporting plates SP-1 and SP-2 may be spaced apart from each other in a folding area FA. The supporting plates SP-1 and SP-2 may include a first supporting plate SP-1 and a second supporting plate SP-2. The first supporting plate SP-1 may overlap with a first non-folding area NFA1, and the second supporting plate SP-2 may overlap with a second non-folding area NFA2.

[0117] The covering member CV-b may include a blocking portion BR. Figure 5 The description of the blocking portion BR shown in FIG. 2 may be applied to the blocking portion BR of the cover member CV-b.

[0118] The support portion SL-b may include a first foam coating FC-1 directly disposed on the first support plate SP-1 and a second foam coating FC-2 directly disposed on the second support plate SP-2. The first foam coating FC-1 and the second foam coating FC-2 may be spaced apart from each other on the second direction axis DR2. Figure 5 , Fig. 6A ,and Figure 6B The description of the foam coating FC provided may be applicable to the first foam coating FC-1 and the second foam coating FC-2. Therefore, a detailed description of the first foam coating FC-1 and the second foam coating FC-2 will be omitted, and different features will be mainly described.

[0119] The first foam coating layer FC-1 and the second foam coating layer FC-2 may be spaced apart from each other in the folding area FA. Since the first foam coating layer FC-1 and the second foam coating layer FC-2 may be spaced apart from each other, in the display device DD (refer to Figure 3) is folded or foldable, the first foam coating layer FC-1 and the second foam coating layer FC-2 may not be subjected to tension or stress. Therefore, even if the first foam coating layer FC-1 and the second foam coating layer FC-2 have Young's modulus and restoring force relatively lower than those of the foam coating formed in a single piece, the first foam coating layer FC-1 and the second foam coating layer FC-2 spaced apart from each other may be designed to enhance impact resistance. For example, the base portions RS-1 and RS-2 respectively included in the first foam coating layer FC-1 and the second foam coating layer FC-2 may be relatively harder than the hardness of the base portions included in the foam coating formed in a single piece, and may have a relatively larger modulus than the modulus of the base portions included in the foam coating formed in a single piece.

[0120] The first foam coating FC-1 and the second foam coating FC-2 can be directly coated on the support plates SP-1 and SP-2 spaced apart from each other, respectively, without being attached through an adhesive layer. For example, since the adhesive layer is not interposed between the first foam coating FC-1 and the first support plate SP-1, and is not interposed between the second foam coating FC-2 and the second support plate SP-2, the process of attaching the first foam coating FC-1 and the second foam coating FC-2 to the first support plate SP-1 and the second support plate SP-2 is omitted, and thus the manufacturing process of the covering member CV-b can be simplified.

[0121] The base part RS-1 included in the first foam coating layer FC-1 and the base part RS-2 included in the second foam coating layer FC-2 may be the same type as each other or different types from each other. The blowing agent BA-1 included in the first foam coating layer FC-1 and the blowing agent BA-2 included in the second foam coating layer FC-2 may be the same type as each other or different types from each other, and may have the same content as each other or different contents from each other.

[0122] Figure 7B 1 is a schematic cross-sectional view showing a covering member CV' according to a comparative example. Fig. 7A The covering member CV-b shown in Figure 7B The difference between the covering members CV' shown in FIG.

[0123] The cover member CV' according to the comparative example may include a cushion layer CS and an adhesive layer AD8 (referred to as an "eighth adhesive layer"), and the adhesive layer AD8 may be disposed on the support plates SP-1 and SP2 spaced apart from each other. The cushion layer CS may be attached to the support plates SP-1 and SP-2 spaced apart from each other through the eighth adhesive layer AD8. The cushion layer CS may be attached to a component disposed above the cushion layer CS, for example, a display module, through an adhesive layer AD7 (referred to as a "seventh adhesive layer").

[0124] The seventh adhesive layer AD7 and the eighth adhesive layer AD8 may include a conventional adhesive, such as an acrylic-based resin or a silicon-based resin. Each of the seventh adhesive layer AD7 and the eighth adhesive layer AD8 may include a pressure-sensitive adhesive, an optically transparent adhesive, or an optically transparent resin.

[0125] The difference between the covering member CV' according to the comparative example and the covering member CV-b according to the embodiment is whether a barrier layer BRL is included. Since the barrier layer BRL including an elastic material is included in the covering member CV-b, the deformation recovery force of the display device DD can be improved and the degree of deformation of the display device DD can be reduced.

[0126] Another difference between the covering member CV' according to the comparative example and the covering member CV-b according to the embodiment is the stacked structure that is deformed by the folding operation. The blocking portion BR included in the covering member CV-b according to the embodiment, and the adhesive layers AD7 and AD8 and the cushion layer CS included in the covering member CV' according to the comparative example can be deformed while being bent by the folding operation of the display device.

[0127] Due to the difference in stacking structures, the thickness of the stacking structure that is deformed in the folding area FA during the folding operation may be different. The thickness of the stacking structure that is deformed in the covering member CV-b according to the embodiment may be less than or less than the thickness of the stacking structure that is deformed in the comparative example. The thickness of the barrier layer BRL may be less than or less than the thickness of the cushion layer CS of the comparative example. For example, the thickness of the barrier layer BRL may be in the range from about 10 μm to about 30 μm, and the thickness of the cushion layer CS may be about 100 μm. However, the thickness of each of the barrier layer BRL and the cushion layer CS should not be limited to the above values. In the case where the thickness of the stacking structure that is deformed due to repeated folding and unfolding operations is reduced, the bending deformation in the folding area can be reduced.

[0128] Another difference between the cover member CV′ according to the comparative example and the cover member CV-b according to the embodiment is whether foam coatings FC-1 and FC-2 directly provided on the support plates SP-1 and SP-2 may be included.

[0129] The foam coatings FC-1 and FC-2 may be directly disposed on the support plates SP-1 and SP-2, however, the cushion layer CS of the comparative example is attached to the support plates SP-1 and SP-2 by the eighth adhesive layer AD8. The foam coatings FC-1 and FC-2 directly coated on the support plates SP-1 and SP-2 may have a relatively thin thickness compared to the thickness of the cushion layer CS of the comparative example. For example, the foam coatings FC-1 and FC-2 may have a thickness equal to or greater than about 30 μm and equal to or less than or less than about 80 μm, and the cushion layer CS may have a thickness of about 100 μm. However, the thickness of each of the foam coatings FC-1 and FC-2, and the cushion layer CS should not be limited to the above values.

[0130] The foam coatings FC-1 and FC-2 according to the embodiment and the cushion layer CS according to the comparative example can allow the display device to have impact resistance. The foam coatings FC-1 and FC-2 according to the embodiment can easily absorb impacts by the foaming agents BA-1 and BA-2 included in the foam coatings FC-1 and FC-2, and can absorb impacts with the same strength even if they have a relatively thinner thickness than the cushion layer CS according to the comparative example.

[0131] The single-piece cushion layer CS of the comparative example is disposed on the support plates SP-1 and SP-2 spaced apart from each other, however, the foam coatings FC-1 and FC-2 of the embodiment may be directly disposed on the support plates SP-1 and SP-2, respectively, and may be spaced apart from each other in the folding area FA. Therefore, the cushion layer CS of the comparative example is deformed in the folding area FA during the folding operation, so that the deformation recovery force of the cushion layer CS has an effect on the degree of deformation of the display device. However, the foam coatings FC-1 and FC-2 of the embodiment may not be deformed during the folding operation, and therefore, the effect of the foam coatings FC-1 and FC-2 on the deformation of the display device may be less than or less than the effect of the cushion layer CS. Therefore, compared with the cushion layer CS of the comparative example, the foam coatings FC-1 and FC-2 of the embodiment may be designed to enhance impact resistance.

[0132] Figure 8 is a graph showing the degree of deformation of the display device according to the embodiment example and the comparative example. Fig. 7A The display device of the cover member CV-b shown in FIG. 1 indicates a display device according to an embodiment example, and includes Figure 7B The display device of the cover member CV′ shown in indicates a display device according to a comparative example.

[0133] The graph shows the degree of deformation of the display device when viewed from a plane defined by the second direction axis DR2 and the third direction axis DR3. The center of the horizontal axis may correspond to the center of the folding area FA. When the display device is viewed from a plane defined by the third direction axis DR3 and the second direction axis DR2, the upward convex portion of the graph may indicate a protruding shape of the upper surface of the display device, and the downward convex portion of the graph may indicate a concave shape of the upper surface of the display device.

[0134] The degree of deformation means the height difference between the highest point protruding upward in the graph and the lowest point protruding downward in the graph. As the degree of deformation becomes larger, the degree to which the user perceives the deformation of the display device in the folding area increases. Therefore, by reducing the degree of deformation, the phenomenon that the user perceives the bending deformation of the display device can be reduced.

[0135] It can be seen that, when the degree of deformation BF of the embodiment example is compared with the degree of deformation BF' of the comparative example, the degree of deformation BF' of the comparative example is greater than the degree of deformation BF of the embodiment example. For example, the degree of deformation BF' of the comparative example is in the range from about 15 μm to about 20 μm, and the degree of deformation BF of the embodiment example may be about 5 μm. For example, the degree of deformation BF of the embodiment example may be less than or less than the degree of deformation BF' of the comparative example, and the phenomenon that the user perceives the bending deformation of the display device is reduced.

[0136] Display device DD (refer to Figure 3 ) can be affected by the deformation degree set in the display module DM (refer to Figure 3 ) is affected by the structure and thickness of the covering member CV below or under the embodiment example. Since the thickness of the blocking portion BR of the embodiment example may be less than or less than the thickness of the cushion layer CS and the adhesive layers AD7 and AD8 of the comparative example, the degree of deformation of the display device DD is reduced. For example, since the covering member CV-b of the embodiment example may include a barrier layer BRL including an elastic material, it may be beneficial to restore deformation. When the display device DD of the embodiment example is compared with the display device DD of the comparative example, the degree of deformation of the display device DD of the embodiment example in the folding area FA may be reduced, and the impact resistance of the display device DD of the embodiment example may be maintained by the foam coatings FC-1 and FC-2 directly provided on the support plates SP-1 and SP-2.

[0137] Fig. 9 : is a schematic cross-sectional view showing a covering member CV-c according to an embodiment. Figure 5 The description of the blocking portion BR provided may be applicable to the blocking portion BR included in the cover member CV-c.

[0138] The support portion SL-2 included in the cover member CV-c may include a first foam coating FC-1 and a second foam coating FC-2, which are spaced apart from each other and include a plurality of sub-coatings CL1, CL2, CL3, and CL4. The number of sub-coatings should not be limited to Fig. 9 The number shown in , and three or more sub-coating layers may be provided on each of the first support plate SP-1 and the second support plate SP-2. For example, the sub-coating layers may be formed by a plurality of processes using a screen printing method, and a foam coating layer including a plurality of sub-coating layers may be formed.

[0139] Reference Fig. 9 , the first foam coating FC-1 may include a first sub-coating CL1 directly disposed on the first support plate SP-1, and the second foam coating FC-2 may include a third sub-coating CL3 directly disposed on the second support plate SP-2. The first foam coating FC-1 may include a second sub-coating CL2 disposed on the first sub-coating CL1, and the second foam coating FC-2 may include a fourth sub-coating CL4 disposed on the third sub-coating CL3.

[0140] In the case of forming sub-coatings CL1, CL2, CL3, and CL4, the elastic force, density, and impact resistance of each of the sub-coatings CL1, CL2, CL3, and CL4 can be controlled. The base parts RS1, RS2, RS3, and RS4 respectively included in the sub-coatings CL1, CL2, CL3, and CL4 can be the same type as each other or different types from each other, and can have the same molecular weight as each other or different molecular weights from each other. As another example, the foaming agents BA1, BA2, BA3, and BA4 respectively included in the sub-coatings CL1, CL2, CL3, and CL4 can be the same type as each other or different types from each other, and can have the same molecular weight as each other or different molecular weights from each other. For example, by adjusting the type of the base part, the molecular weight of the base part, the type of the foaming agent, or the content of the foaming agent relative to the base part, the properties of the sub-coatings CL1, CL2, CL3, and CL4 can be the same as each other or different from each other.

[0141] The shapes of the foam coatings FC-1 and FC-2 corresponding to the folding area FA can be changed by adjusting the thickness or spacing distance of the sub-coatings CL1, CL2, CL3, and CL4 included in the foam coatings FC-1 and FC-2. For example, there can be a step difference between the sub-coatings stacked on the third direction axis DR3. As another example, by adjusting the spacing distances D1 and D2 between the sub-coatings adjacent to each other on the second direction axis DR2, the spacing distance between the sub-coatings can increase as the distance from the support plates SP-1 and SP-2 increases, for example, as the distance from the blocking portion BR decreases. For example, the bending deformation in the folding area FA can be reduced by adjusting the spacing distance and stacking structure of the sub-coatings CL1, CL2, CL3, and CL4.

[0142] A minimum spacing distance D1 between the first sub-coating layer CL1 and the third sub-coating layer CL3 adjacent to the first sub-coating layer CL1 may be smaller than or less than a minimum spacing distance D2 between the second sub-coating layer CL2 and the fourth sub-coating layer CL4 adjacent to the second sub-coating layer CL2.

[0143] The second sub-coating CL2 and the fourth sub-coating CL4 may be formed to satisfy the following equations. In the case where the minimum spacing distance between the line L1 extending from the end of the first support plate SP-1 that may overlap with the folding area FA and the line L2 extending from the end of the second sub-coating CL2 is referred to as "D3", and the minimum spacing distance between the line L3 extending from the end of the second support plate SP-2 that may overlap with the folding area FA and the line L4 extending from the end of the fourth sub-coating CL4 is referred to as "D4", D3 and D4 satisfy the following equations 1 and 2, respectively.

[0144] Equation 1

[0145] DP+RC≤D3≤DP+3RC

[0146] Equation 2

[0147] DP+RC≤D4≤DP+3RC

[0148] In Equation 1 and Equation 2, "DP" represents the minimum spacing distance between the first support plate SP-1 and the second support plate SP-2, and "RC" represents the curvature radius RC of the folding area FA (refer to Fig.10 ).

[0149] Fig.10is a schematic cross-sectional view showing a folded or foldable state of a display device DD according to an embodiment. When the display device DD is folded or foldable, the portion of the display module DM and the blocking portion BR corresponding to the folding area FA may be folded or foldable. Even if the display device DD is foldable or foldable, the support plates SP-1 and SP-2 spaced apart from each other and the foam coatings FC-1 and FC-2 spaced apart from each other may not be folded or foldable. Therefore, the foam coatings FC-1 and FC-2 may improve the impact resistance of the display device DD without significantly changing the degree of deformation of the folding area FA of the display device DD.

[0150] Despite Fig.10 , but the foam coating FC-1 may include a base portion RS (see Figure 5 ) and the blowing agent BA distributed in the base part RS (refer to Figure 5 ). For example, the foam coatings FC-1 and FC-2 may include a plurality of sub-coatings CL1, CL2, CL3, and CL4. By adjusting the spacing distance between adjacent sub-coatings among the sub-coatings CL1, CL2, CL3, and CL4, the shapes of the foam coatings FC-1 and FC-2 in the curved portion corresponding to the folding area FA may be changed.

[0151] Fig.11A and Fig. 11B 2 is a schematic cross-sectional view showing covering members CV-d1 and CV-d2 according to the embodiment. Regarding the description of components denoted by the same reference numerals, the above description can be equally applied.

[0152] The supporting portions SL-d1 and SL-d2 may further include a first cushion layer CS-1 and a second cushion layer CS-2 disposed under or below the first supporting plate SP-1 and the second supporting plate SP-2, respectively. The first cushion layer CS-1 may be disposed under or below the first supporting plate SP-1, and the second cushion layer CS-2 may be disposed under or below the second supporting plate SP-2. The first cushion layer CS-1 and the second cushion layer CS-2 may be spaced apart from each other.

[0153] The first cushion layer CS-1 may support the first support plate SP-1, and the second cushion layer CS-2 may support the second support plate SP-2. When the display device DD is not folded or foldable, the first cushion layer CS-1 and the second cushion layer CS-2 may prevent the folding area FA from being squeezed or deformed due to external impact. Each of the first cushion layer CS-1 and the second cushion layer CS-2 may include sponge, foam, or polyurethane resin.

[0154] Reference Fig.11A and Fig. 11B, the first cushion layer CS-1 may be provided with a first hole HA1 defined or formed therethrough, and the second cushion layer CS-2 may be provided with a second hole HA2 defined or formed therethrough. Fig.12 1 is a plan view showing the first cushion layer CS-1 and the second cushion layer CS-2 in a plane substantially parallel to a plane defined by the first direction axis DR1 and the second direction axis DR2. Fig.12 , each of the first hole HA1 and the second hole HA2 may have a substantially quadrilateral shape in which a long side extends on the first direction axis DR1 and a short side extends on the second direction axis DR2.

[0155] Reference Fig. 11B and Fig.12 , the first hole HA1 and the second hole HA2 may be filled with adhesive parts AD-H1 and AD-H2, respectively. The adhesive parts AD-H1 and AD-H2 may include conventional adhesives. Each of the adhesive parts AD-H1 and AD-H2 may include a pressure-sensitive adhesive (PSA), an optically clear adhesive (OCA), or an optically clear resin (OCR). For example, each of the adhesive parts AD-H1 and AD-H2 may include an acrylic-based resin or a silicone-based resin, however, the adhesive parts AD-H1 and AD-H2 should not be limited thereto or thereby.

[0156] Reference Fig. 11B , the thickness DAD1 of the adhesive portion AD-H1 filled in the first hole HA1 of the first cushion layer CS-1 may be less than or less than the thickness DCS1 of the first cushion layer CS-1. The thickness DAD2 of the adhesive portion AD-H2 filled in the second hole HA2 of the second cushion layer CS-2 may be less than or less than the thickness DCS2 of the second cushion layer CS-2. For example, in the case where the thickness of each of the first cushion layer CS-1 and the second cushion layer CS-2 is about 100 μm, the thickness of each of the adhesive portions AD-H1 and AD-H2 may be about 90 μm. However, the thickness of each of the first cushion layer CS-1 and the second cushion layer CS-2 and the thickness of each of the adhesive portions AD-H1 and AD-H2 should not be limited thereto or thereby.

[0157] like Fig. 11B As shown in , the adhesive portions AD-H1 and AD-H2 may have a substantially quadrilateral shape in their cross-section and may be inserted into the first hole HA1 and the second hole HA2 of the cushion layers CS-1 and CS-2, respectively, to have a substantially flat surface, however, they should not be limited thereto or thereby. The adhesive portions AD-H1 and AD-H2 may be inserted into the first hole HA1 and the second hole HA2 of the cushion layers CS-1 and CS-2, respectively, to have a concave surface.

[0158] The shortest distance DH between the first hole HA1 and the second hole HA2 may have an influence on the degree of deformation in the folding area FA. The shortest distance DH may be equal to or greater than about 25 mm and equal to or less than or less than about 35 mm. For example, the shortest distance DH may be about 30 mm. Therefore, the shortest distance DH between the adhesive portions AD-H1 and AD-H2 filled in the first hole HA1 and the second hole HA2, respectively, may be equal to or greater than about 25 mm and equal to or less than or less than about 35 mm.

[0159] The degree of deformation in the folding area FA may be changed according to the configuration of the first cushion layer CS-1 and the second cushion layer CS-2 respectively disposed under or below the support plates SP-1 and SP-2. In the case where the value corresponding to the height change of the portion where the deformation occurs and the curvature value indicating the degree of deformation of the bent portion may be relatively large, the deformation of the display device DD may be easily observed from the outside.

[0160] The first hole HA1 and the second hole HA2 may be defined or formed through the first cushion layer CS-1 and the second cushion layer CS-2 and the degree of deformation and curvature of the embodiment in which the adhesive portions AD-H1 and AD-H2 may be filled in the first hole HA1 and the second hole HA2 may be less than or less than the degree of deformation and curvature of the embodiment in which the adhesive portions AD-H1 and AD-H2 may not be filled in the first hole HA1 and the second hole HA2. Therefore, in the case where the adhesive portions AD-H1 and AD-H2 are provided or arranged under or below the support plates SP-1 and SP2, the phenomenon of observed bending deformation can be improved.

[0161] Fig.13 is a schematic cross-sectional view showing a covering member CV-d according to a comparative example. The covering member CV-d' may include a blocking portion BR' and a support portion SL-d' disposed under or below the blocking portion BR'. The blocking portion BR' may include adhesive layers AD5 and AD7 disposed on and under or below the barrier layer BRL, respectively. The adhesive layer AD7 disposed under or below the barrier layer BRL attaches the cushion layer CS disposed at the upper portion of the support portion SL-d' to the barrier layer BRL.

[0162] The support portion SL-d' of the comparative example may include support plates SP-1 and SP-2 spaced apart from each other, and a cushion layer CS disposed above the support plates SP-1 and SP-2. The support portion SL-d' of the comparative example may include an adhesive layer AD8 disposed between the support plates SP-1 and SP-2 and the cushion layer CS. The support portion SL-d' of the comparative example may include a first cushion layer CS-1 disposed under or below the first support plate SP-1 and a second cushion layer CS-2 disposed under or below the second support plate SP-2. The first cushion layer CS-1 and the second cushion layer CS-2 include adhesive portions AD-H1 and AD-H2 filled in the holes HA1 and HA2, respectively.

[0163] Table 1 below shows the deformation degree and curvature value of the comparative example and embodiment examples 1 to 3. Figure 8 As described, the expression "degree of deformation" means Figure 8 The expression "curvature" is a value obtained by measuring the degree of curvature of the highest point of the upwardly convex portion and the lowest point of the downwardly convex portion in the graph shown in .

[0164] Compare examples with included Fig.13 , and Embodiment Examples 1 to 3 correspond to a display device including a cover member shown in Fig. 11B The display device of the cover member shown in FIG.

[0165] As a common experimental condition of the comparative example and the embodiment examples 1 to 3, the thickness of the support plates SP-1 and SP-2 may be about 150 μm, and the shortest distance DH between the adhesive portions AD-H1 and AD-H2 disposed under or below the support plates SP-1 and SP-2 may be about 30 mm. The adhesive layers AD5, AD6, AD7, and AD8 of the comparative example and the embodiment examples 1 to 3 may be pressure-sensitive adhesives. The fifth adhesive layer AD5 disposed on the barrier layer BRL may have a thickness of about 25 μm.

[0166] The sixth adhesive layer AD6 of Embodiment Examples 1 to 3 has a thickness of about 10 μm. The foam coatings FC-1 and FC-2 directly provided on the support plates SP-1 and SP-2 have a thickness of about 30 μm.

[0167] The barrier layers BR1 of Embodiment Examples 1 to 3 have different thicknesses and include materials different from each other. The barrier layer BRL of Embodiment Example 1 is ultra-thin glass and has a thickness of about 30 μm. The barrier layer BRL of Embodiment Example 2 is nano stainless steel and has a thickness of about 22 μm. The barrier layer BRL of Embodiment Example 3 is stainless steel and has a thickness of about 10 μm.

[0168] Unlike Implementation Examples 1 to Implementation Examples 3, in the covering member CV-d' of the comparative example, the eighth adhesive layer AD8 is provided on the support plates SP-1 and SP-2, and the cushion layer CS is provided on the eighth adhesive layer AD8. The eighth adhesive layer AD8 has a thickness of about 10 μm, and the cushion layer CS has a thickness of about 100 μm. The thickness of the seventh adhesive layer AD7 attaching the barrier layer BRL to the support portion SL-d' may vary. The seventh adhesive layer AD7 has a thickness of about 25 μm. The barrier layer BRL of the comparative example is ultra-thin glass and has a thickness of about 30 μm.

[0169] Table 1

[0170]

[0171] In the case where the deformation degree is relatively large, the deformation in the folding area can be easily observed from the outside. Referring to Table 1, the deformation degree of the comparative example may be about 12.7 μm, and the deformation degree of embodiment examples 1 to 3 may be about 5.1 μm or about 6.5 μm, and the deformation degree of the comparative example is relatively greater than the deformation degree of embodiment examples 1 to 3.

[0172] This is because the foam coatings FC-1 and FC-2 can be directly disposed on the support plates SP-1 and SP-2 of embodiment examples 1 to 3. The foam coatings FC-1 and FC-2 improve the impact resistance, as does the cushion layer CS of the comparative example, however, the foam coatings FC-1 and FC-2 can be directly coated on the support plates SP-1 and SP-2 and have a relatively thin thickness than the cushion layer CS of the comparative example. Therefore, in the embodiment examples, the degree of deformation in the folding area FA can be less than or less than that in the comparative example.

[0173] For example, the foam coatings FC-1 and FC-2 of the embodiment examples 1 to 3 may be directly disposed on the support plates SP-1 and SP-2 spaced apart from each other, and therefore, the foam coatings FC-1 and FC-2 of the embodiment examples 1 to 3 may be spaced apart from each other in the folding area FA. Therefore, the portions of the foam coatings FC-1 and FC-2 that may overlap with the folding area FA may not be affected by the tension caused by the folding operation. Therefore, the extent to which the foam coatings FC-1 and FC-2 affect the degree of deformation of the covering member CV-d2 may be less than or less than the extent to which the cushion layer CS of the comparative example affects the covering member CV-d'.

[0174] In Embodiment Examples 1 to 3, the structure that is deformed during the folding operation is the blocking portion BR. In the comparative example, the structure that is deformed during the folding operation is the blocking portion BR', the cushion layer CS, and the adhesive layer AD8. Therefore, when the thickness of the structure that is deformed during the folding operation of Embodiment Examples 1 to 3 is compared with the thickness of the structure that is deformed during the folding operation of the comparative example, the thickness of Embodiment Examples 1 to 3 may be less than or less than the thickness of the comparative example, and therefore, in Embodiment Examples 1 to 3, the degree of deformation in the folding area is reduced.

[0175] When compared with Embodiment Examples 1 to 3, in the comparative examples, the cushion layer CS is not directly disposed on the support plates SP-1 and SP-2, and the adhesive layer AD8 is further disposed between the support plates SP-1 and SP-2 and the cushion layer CS. In Embodiment Examples 1 to 3, in which the foam coatings FC-1 and FC-2 may be directly disposed on the support plates SP-1 and SP-2, the adhesive layer is not disposed between the support plates SP-1 and SP-2 and the foam coatings FC-1 and FC-2, and the lamination process of attaching the components to the adhesive layer may be omitted.

[0176] The curvature obtained by measuring the degree of bending of the highest point of the upward protrusion shows how much bending deformation occurs in the folding area. Therefore, in the case where the curvature value is relatively large, the bending deformation can be easily observed from the outside. According to the comparative example and embodiment examples 1 to 3, the curvature value may vary according to the material and thickness of the barrier layer BRL and the structure under or below the barrier layer BRL. The curvature values ​​of the comparative example and embodiment examples 1 to 3 may be relatively small, ranging from about 1.1 to about 4.8. Therefore, since the barrier layer BRL including an elastic material is provided on the display module DM (refer to Figure 3 ), so it can be beneficial to recover the deformation and the degree of deformation becomes gentle.

[0177] The display device according to the embodiment may include a barrier layer and a foam coating, the barrier layer being disposed under or below the display module and including an elastic material, the foam coating including a base portion disposed directly on a support plate and a foaming agent distributed in the base portion. Due to the barrier layer that can facilitate recovery of deformation and the foam coating having a predetermined elastic force and enhanced impact resistance, the degree of deformation of a bent portion after the display device is folded or foldable can be improved.

[0178] A display device according to an embodiment may include a foam coating layer directly disposed on a support plate that may be spaced apart from each other to be spaced apart from each other. Since the foam coating layers may be spaced apart from each other, when the display device is folded or foldable, the foam coating layer may not be affected by external forces. Therefore, the foam coating layer may improve the impact resistance of the display device without significantly changing the degree of bending deformation of the display device.

[0179] Although the embodiments have been described, it should be understood that the present disclosure should not be limited to these embodiments, but various changes and modifications may be made by one of ordinary skill in the art within the spirit and scope of the present disclosure as hereinafter claimed.

[0180] Therefore, the disclosed subject matter should not be limited to any single embodiment described herein, and the scope of the present disclosure should be determined in accordance with the following claims.

Claims

1. A display device, comprising: The display module comprises a first non-folding area, a folding area, and a second non-folding area; A support plate, disposed below the display module, wherein the support plate comprises stainless steel, aluminum, or an alloy thereof; a foam coating, comprising a base portion and a foaming agent contained in the base portion, wherein the foam coating is directly disposed on the support plate between the display module and the support plate in the first non-folding region, the second non-folding region, and the folding region; as well as The barrier layer is disposed between the display module and the foam coating and includes an elastic material.

2. The display device according to claim 1, wherein: The weight of the foaming agent is equal to or greater than 3 wt % of the total weight of the base part and equal to or less than 15 wt % of the total weight of the base part.

3. The display device according to claim 1, wherein: The base part of the foam coating layer includes a polymer resin having a weight average molecular weight of 1,000 or more and 15,000 or less.

4. The display device according to claim 1, wherein: The foam coating has a Young's modulus equal to or greater than 1 MPa and equal to or less than 100 MPa at room temperature.

5. The display device according to claim 1, wherein: The foam coating has a g / cm 3 and equal to or less than 0.7 g / cm 3 density.

6. The display device according to claim 1, wherein: The barrier layer has a yield strain equal to or greater than 1.0% and equal to or less than 2.5%.

7. The display device according to claim 1, wherein: The barrier layer includes ultra-thin glass, fiberglass, or stainless steel.

8. The display device according to claim 1, wherein: The barrier layer has a Young's modulus equal to or greater than 2 GPa and equal to or less than 200 GPa at room temperature.

9. A display device, comprising: Display module, including: a folding region capable of being folded relative to a folding axis extending in a first direction; a first unfolded region adjacent to one side of the folded region; and a second unfolded region, adjacent to the other side of the folded region; a barrier layer, disposed below the display module and comprising an elastic material; A first support plate, disposed below the first unfolded area, wherein the first support plate comprises stainless steel, aluminum, or an alloy thereof; A second support plate, disposed below the second unfolded area and spaced apart from the first support plate in a second direction, the second direction being perpendicular to the first direction, the second support plate comprising stainless steel, aluminum, or an alloy thereof; a first foam coating disposed on the first support plate directly between the first support plate and the first unfolded region of the display module; and A second foam coating layer is directly disposed on the second supporting plate between the second supporting plate and the second non-folding area of ​​the display module, and the second foam coating layer is spaced apart from the first foam coating layer in the second direction.

10. The display device according to claim 9, wherein: The barrier layer has a yield strain equal to or greater than 1.0% and equal to or less than 2.5%.

11. The display device according to claim 9, wherein: Each of the first foam coating and the second foam coating includes a plurality of sub-coatings.

12. The display device according to claim 11, wherein The first foam coating comprises: a first sub-coating layer disposed on the first support plate; as well as a second sub-coating layer, disposed on the first sub-coating layer, The second foam coating comprises: a third sub-coating layer disposed on the second support plate; and a fourth sub-coating layer, disposed on the third sub-coating layer; and A minimum spacing distance between the first sub-coating and the third sub-coating adjacent to the first sub-coating is smaller than a minimum spacing distance between the second sub-coating and the fourth sub-coating adjacent to the second sub-coating.

13. The display device according to claim 12, wherein The minimum spacing distance D3 between a line extending from one end of the first support plate overlapping the folding area and a line extending from one end of the second sub-coating layer satisfies the following equation: DP+RC≤D3≤DP+3RC, The minimum spacing distance D4 between a line extending from one end of the second support plate overlapping the folding area and a line extending from one end of the fourth sub-coating layer satisfies the following equation: DP+RC≤D4≤DP+3RC, in, DP denotes a minimum spacing distance between the first support plate and the second support plate, and RC denotes a radius of curvature of the folding region.

14. The display device according to claim 9, further comprising: a first cushion layer disposed below the first support plate and comprising a first hole; and a second cushion layer, disposed below the second support plate and comprising a second hole, Wherein, each of the first hole of the first pad layer and the second hole of the second pad layer is parallel to the first direction. 15 . The display device of claim 14 , further comprising an adhesive portion filled in each of the first hole of the first cushion layer and the second hole of the second cushion layer.

16. The display device according to claim 14, wherein: The shortest distance between the first hole of the first cushion layer and the second hole of the second cushion layer in the second direction is equal to or greater than 25 mm and equal to or less than 35 mm.

Images