Display device

Abstract

A display device is provided. The display device includes a display panel, a support substrate supporting the display panel below the display panel and including a plurality of opening patterns, and an adhesive layer disposed on the support substrate and including a plurality of first regions disposed to respectively correspond to the plurality of opening patterns, and a second region surrounding the plurality of first regions and having a Young's modulus lower than a Young's modulus of the plurality of first regions. Each of the first regions is larger than a corresponding opening pattern.

Description

[0001] Cross-references to related applications

[0002] This application claims priority to Korean Patent Application No. 10-2021-0184262, filed with the Korean Intellectual Property Office on December 21, 2021, the disclosure of which is incorporated herein by reference. Technical Field

[0003] This disclosure relates to display devices, and more particularly, to flexible display devices having superior mechanical properties, improved appearance quality, and improved folding reliability. Background Technology

[0004] In recent years, with the advent of the information age, the field of displays that visually express electrical information signals has developed rapidly, and in response, various display devices with excellent performance (such as thinness, light weight, and low power consumption) have been developed. Specific examples of such display devices include liquid crystal displays (LCDs), plasma display panels (PDPs), field emission displays (FEDs), and organic light-emitting diode displays (OLEDs).

[0005] Meanwhile, efforts continue to diversify the shapes and sizes of display devices. For example, display devices with various shapes are being developed, such as curved display devices with curved surfaces, or flexible display devices that maintain their display performance even when bent or folded. Flexible display devices use flexible substrates for their display panels, allowing support substrates, such as back panels, to be positioned below the display panel to prevent sagging and protect it from foreign objects and external impacts. Summary of the Invention

[0006] The purpose of this disclosure is to provide a display panel that solves the problem of the opening pattern of the support substrate being visible from the display panel and minimizes folding stress.

[0007] Another objective of this disclosure is to provide a display device that improves the appearance quality caused by leakage of the adhesive layer through the opening pattern of the support substrate.

[0008] The purpose of this disclosure is not limited to the purposes mentioned above, and other purposes not mentioned above will be clearly understood by those skilled in the art from the following description.

[0009] According to an aspect of the disclosure, a display device includes a display panel, a support substrate supporting the display panel below the display panel and including a plurality of opening patterns, and an adhesive layer disposed on the support substrate and including a plurality of first regions disposed to respectively correspond to the plurality of opening patterns, and a second region surrounding the plurality of first regions and having a Young's modulus lower than a Young's modulus of the plurality of first regions, and each of the first regions being larger than a corresponding opening pattern.

[0010] Other matters of detail of the exemplary embodiments include those described in the DETAILED DESCRIPTION and the drawings.

[0011] According to the disclosure, the adhesive layer is partially re-cured to form first regions having a high Young's modulus in the adhesive layer to correspond to the opening patterns of the support substrate, to minimize a transfer of the opening patterns to the display panel that causes a shape of the opening patterns to be visible to a user, and to relieve a folding stress by a second region having a low Young's modulus.

[0012] According to the disclosure, the first regions having a high Young's modulus in the adhesive layer are disposed to correspond to the opening patterns to solve a problem of leakage of the adhesive layer through the opening patterns.

[0013] Effects according to the disclosure are not limited to those exemplified above, and include more various effects in the present specification. BRIEF DESCRIPTION OF DRAWINGS

[0014] The above and other aspects, features, and other advantages of the disclosure will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

[0015] Figure 1 is a schematic plan view of a display device according to an exemplary embodiment of the disclosure;

[0016] Figure 2 is a schematic cross-sectional view taken along line II-II' of Figure 1

[0017] Figure 3 is an enlarged plan view of an adhesive layer and a support substrate of a display device according to an exemplary embodiment of the disclosure;

[0018] Figure 4 is a cross-sectional view for explaining an adhesive layer and a support substrate of a display device according to an exemplary embodiment of the disclosure;

[0019] Figure 5 is a schematic cross-sectional view of a display device according to another exemplary embodiment of the disclosure; ​

[0020] Figure 6 is a schematic cross-sectional view of a display device according to yet another exemplary embodiment of the present disclosure;

[0021] Figure 7 is a schematic cross-sectional view of a display device according to yet another exemplary embodiment of the present disclosure; and

[0022] Figure 8 is a schematic cross-sectional view of a display device according to yet another exemplary embodiment of the present disclosure. DETAILED DESCRIPTION

[0023] Advantages and features of the present disclosure and methods of accomplishing the same will become apparent by reference to the following exemplary embodiments described in detail in conjunction with the accompanying drawings. However, the present disclosure is not limited to the exemplary embodiments disclosed herein and can be implemented in various forms. The exemplary embodiments are provided by way of example only, so that one skilled in the art can fully understand the disclosure and the scope of the present disclosure. Therefore, the present disclosure will be limited only by the scope of the claims attached hereto.

[0024] The shapes, sizes, ratios, angles, numbers, and the like shown in the drawings for describing the exemplary embodiments of the present disclosure are merely examples and the present disclosure is not limited thereto. Throughout the specification, like reference numerals generally refer to like elements. Also, in the following description of the present disclosure, detailed descriptions of known related technologies can be omitted to avoid unnecessarily obscuring the subject matter of the present disclosure. The terms such as "include," "have," and "consist of" used herein are generally intended to allow the addition of other components, unless the terms are used with the term "only." Unless explicitly stated otherwise, any reference to a singular can include a plural.

[0025] Components are interpreted to include ordinary error ranges even if not explicitly stated.

[0026] When terms such as "on," "above," "below," and "adjacent" are used to describe the positional relationship between two parts, unless these terms are used with the term "immediately" or "directly," one or more parts can be located between the two parts.

[0027] When an element or layer is disposed "on" another element or layer, the other layer or the other element can be directly placed on the other element or placed therebetween.

[0028] Although the terms "first", "second", and the like are used to describe various components, the components are not limited by these terms. The terms are only used to distinguish one component from another. Thus, a first component mentioned below can be a second component in the technical idea of the disclosure.

[0029] Throughout the specification, like reference numerals will be used to designate like elements throughout the specification.

[0030] For ease of description, the size and thickness of each component shown in the drawings are shown, but the disclosure is not limited to the size and thickness of the components shown.

[0031] The features of various embodiments of the disclosure can be partially or wholly dependent on or combined with each other, and can be technically interlocked and operated in various ways, and the embodiments can be executed independently of or in association with each other.

[0032] Hereinafter, a display device according to an exemplary embodiment of the disclosure will be described in detail with reference to the accompanying drawings.

[0033] Figure 1 is a schematic plan view of a display device according to an exemplary embodiment of the disclosure. Figure 2 is a schematic cross-sectional view taken along line II-II' of Figure 1

[0034] Referring to Figure 1 and Figure 2 , a display device 100 according to an exemplary embodiment of the disclosure includes a support substrate 110, a display panel 120, and a cover member 130. Hereinafter, for ease of description, it is assumed that the display device 100 according to an exemplary embodiment of the disclosure is an organic light emitting display device, but is not limited thereto.

[0035] The display panel 120 includes a display area DA and a non-display area NDA. In addition, the display panel 120 includes a folding area FA and non-folding areas NFA1 and NFA2. The display panel 120 can be divided into the display area DA and the non-display area NDA according to whether an image is displayed, and can be divided into the folding area FA and the non-folding areas NFA according to whether it is foldable. Thus, a part of the display panel 120 can be the display area DA and the folding area FA, and the other part of the display panel 120 can be the non-display area NDA and the non-folding area NFA.

[0036] ​Meanwhile, for convenience of description, it is assumed that the display device 100 according to the exemplary embodiment of the disclosure is a foldable display device in which the folding area FA is disposed in only a part of the display area DA. However, the display device 100 according to the exemplary embodiment of the disclosure can be a flexible or rollable display device in which the display area DA of the display panel 120 is the folding area FA, but is not limited thereto.

[0037] The display area DA is an area in which a plurality of pixels are disposed to substantially display an image. In the display area DA, a plurality of pixels including a light emitting area for displaying an image, a thin film transistor for driving the pixels, and a capacitor can be disposed. One pixel can include a plurality of sub-pixels SP. The sub-pixel SP is the smallest unit configuring the display area DA, and each sub-pixel SP can be configured to emit light of a specific waveband. For example, each of the sub-pixels SP can be configured to emit red light, green light, blue light, or white light.

[0038] The non-display area NDA is disposed to surround the display area DA. The non-display area NDA is an area in which an image is not substantially displayed, and in which various wirings and a driving IC for driving the pixels and driving elements disposed in the display area DA are disposed.

[0039] As described above, the display panel 120 can be defined as the folding area FA and the non-folding areas NFA1 and NFA2 according to whether it is foldable. The display panel 120 includes one foldable folding area FA and non-folding areas NFA1 and NFA2 that do not include the folding area. The folding area FA is an area that is folded when the flexible display device 100 is folded, and is folded with a certain radius of curvature with respect to a folding axis. For example, the folding axis of the folding area FA can be formed in the X-axis direction, and the non-folding areas NFA1 and NFA2 can extend from the folding area FA in the Y-axis direction perpendicular to the folding axis. When the folding area FA is folded with respect to the folding axis, the folding area FA can form a part of a circular or elliptical shape. At this time, the radius of curvature of the folding area FA can refer to the radius of the circular or elliptical shape formed by the folding area FA.

[0040] The non-folded areas NFA1 and NFA2 are areas that are not folded when the flexible display apparatus 100 is folded. That is, the non-folded areas NFA1 and NFA2 maintain a flat state when the flexible display apparatus 100 is folded. The non-folded areas NFA1 and NFA2 can be located on both sides of the folded area FA. That is, the non-folded areas NFA1 and NFA2 can be areas extending in a Y-axis direction perpendicular to the folding axis. At this time, the folded area FA can be defined between the non-folded areas NFA1 and NFA2. Furthermore, the non-folded areas NFA1 and NFA2 can overlap each other when the flexible display apparatus 100 is folded with respect to the folding axis.

[0041] The display panel 120 includes a flexible substrate 121 and a display element 122.

[0042] The flexible substrate 121 supports various elements configuring the display panel 120. The flexible substrate 121 can be a plastic substrate having flexibility. For example, the plastic substrate can be a polymer material selected from polyimide, polyamide-imide, polyether sulfone, polyethylene terephthalate, and polycarbonate, but is not limited thereto.

[0043] The plastic substrate has a relatively weak barrier property against moisture or oxygen, and thus, in order to compensate for this, the plastic substrate can have a structure in which a plastic film and an inorganic layer are laminated. For example, the flexible substrate 121 can have a multi-layer structure in which a first plastic film, an inorganic layer, and a second plastic film are sequentially laminated, but is not limited thereto.

[0044] The flexible substrate 121 has excellent folding properties, but has a thin thickness and has a lower rigidity than that of a glass substrate or a metal substrate, making it difficult to maintain a constant shape during folding, and thus, a sag phenomenon can occur. Therefore, in order to support the flexible substrate 121 and improve impact resistance, the support substrate 110 is disposed under the display panel 120.

[0045] The support substrate 110 is disposed under the display panel 120 to support the display panel 120 and protect the display panel 120 from moisture or foreign substances penetrating from the outside and external impact. The support substrate 110 will be described in greater detail below.

[0046] A driving thin film transistor (not shown) for driving the display element 122 can be disposed on the flexible substrate 121. The driving thin film transistor can be disposed in each of a plurality of pixel areas. For example, the driving thin film transistor includes a gate electrode, an active layer, a source electrode, and a drain electrode. The driving thin film transistor can further include a gate insulating layer insulating the gate electrode from the active layer, and an interlayer insulating layer insulating the gate electrode from the source electrode and the drain electrode.

[0047] A planarization layer (not shown) can be provided on the thin film transistor to planarize the upper surface.

[0048] The display element 122 can be provided on the planarization layer. The display element 122 can be an organic light emitting diode. The organic light emitting diode can include an anode, a cathode, and an organic light emitting layer provided between the anode and the cathode. In the organic light emitting diode, holes injected from the anode and electrons injected from the cathode are coupled on the organic light emitting layer to emit light. The emitted light can be used to display an image as described above.

[0049] The cover member 130 is provided on the display element 122. The cover member 130 protects the display panel 120 from external impact and scratches. Accordingly, the cover member 130 can be formed of a material that is transparent and has excellent impact resistance and scratch resistance. In addition, the cover member 130 protects the display panel 120 from moisture that permeates from the outside. When moisture permeates from the outside, the display panel 120 deteriorates, so that the display quality can decrease.

[0050] For example, the cover member 130 can be a film formed of a polymer such as polyimide, polyamide-imide, polyethylene terephthalate, polymethyl methacrylate, polypropylene glycol, and polycarbonate. As another example, the cover member can be a film formed of a phototropic polymer such as a cyclic olefin (co)polymer, a phototropic polycarbonate, or a phototropic polymethyl methacrylate.

[0051] In addition, the cover member 130 can have a multi-layer structure in which various functional layers are laminated. For example, the cover member 130 can include various functional layers such as an external light reflection reduction layer, a UV blocking layer, or a hard coating layer.

[0052] Hereinafter, the support substrate 110 and the adhesive layer Adh will be described in detail with reference to Figure 3 and Figure 4 together.

[0053] Figure 3 is an enlarged plan view of an adhesive layer and a support substrate of a display device according to an exemplary embodiment of the present disclosure. Figure 4 is a cross-sectional view for explaining an adhesive layer and a support substrate of a display device according to an exemplary embodiment of the present disclosure. For convenience of description, in Figure 3 , only the support substrate 110 and the adhesive layer Adh among the components of the display device 100 are shown, and in Figure 4 , the support substrate 110, the adhesive layer Adh, and the flexible substrate 121 among the components of the display device 100 are shown. At this time, in Figure 4In this regard, reference numeral A denotes a distance between one open pattern 111 in the support substrate 110 and another adjacent open pattern 111, B denotes a width of the first region Adh1 overlapping the support substrate 110, and C denotes a width of the second region Adh2 disposed between the plurality of first regions Adh1. Further, D denotes a thickness of the adhesive layer Adh.

[0054] Referring to FIG. 1, a flexible display device 100 according to an embodiment of the present disclosure includes a display panel 120 and a support substrate 110 disposed below the display panel 120 to support the display panel 120. Figure 2 and Figure 3 The support substrate 110 is disposed on a rear surface of the flexible substrate 121 to suppress sagging or deformation of the flexible substrate 121 and to protect the display panel 120 from external impact or foreign substances.

[0055] The support substrate 110 can be joined to the display panel 120 by means of an adhesive layer Adh to be described below. That is, the support substrate 110 is attached to the rear surface of the flexible substrate 121 by the adhesive layer Adh. The support substrate 110 serves to substantially support the display panel 120. The support substrate 110 can be a foldable plate having excellent rigidity. The support substrate 110 can be formed of a material having greater rigidity than that of the flexible substrate 121 to support the display panel 120.

[0056] For example, the support substrate 110 can be a metal plate including a metal such as stainless steel (SUS), invar, aluminum, or magnesium. The metal plate has excellent rigidity and impact resistance as well as excellent restoring force. When the support substrate 110 is formed of a metal material having excellent rigidity as described above, mechanical properties such as rigidity are maintained even if the thickness thereof is reduced to firmly support the display panel 120. Accordingly, the thickness can be significantly smaller compared to a support substrate formed of a polymer material of the related art. The thickness of the support substrate 110 is minimized to reduce stress applied to the support substrate 110 or the display panel 120 during folding, thus improving folding reliability and folding characteristics. Further, a flexible display device having a greater curvature compared to the related art can be implemented, and a multi-foldable display device or a rollable display device can also be implemented. Further, the support substrate 110 formed of a metal material as described above has excellent restoring force such that deformation such as plastic deformation does not occur even during repeated folding, so that appearance defects can be improved.

[0057] For example, the thickness of the support substrate 110 can be 90 μm to 220 μm. When the thickness of the support substrate 110 is less than 90 μm, the support substrate is too thin to effectively support the sag of the display panel 120. In addition, if the thickness of the support substrate 111 is greater than 220 μm, when the flexible display apparatus 100 is folded, the stress applied to the display panel 120 increases, which causes a crack and reduces the restoring force to cause plastic deformation, and the folding reliability is not satisfied.

[0058] The support substrate 110 includes a plurality of opening patterns 111. For convenience of description, although four opening patterns 111 are shown as being formed in Figure 2 , the present application is not limited thereto.

[0059] The plurality of opening patterns 111 can be formed on the support substrate 110 to correspond to the folding area FA. That is, the plurality of opening patterns 111 can be holes that pass through the support substrate 110 in the thickness direction. When the display apparatus 100 is folded, stress is concentrated on the folding area FA. The plurality of opening patterns 111 can disperse the stress concentrated on the folding area FA during folding. As described above, since the plurality of opening patterns 111 are formed at positions corresponding to the folding area FA, it is advantageous that the display apparatus 100 is easily foldable and the restoring force is excellent.

[0060] Referring to Figure 3 , each of the plurality of opening patterns 111 can be formed to be elongated in a direction parallel to the folding axis. That is, each of the plurality of opening patterns 111 can be formed to be elongated in the same direction as the folding axis. Accordingly, each of the plurality of opening patterns 111 can be formed to be parallel to the folding axis in a bar shape in a plan view.

[0061] Each of the plurality of opening patterns 111 can continuously extend to the non-display area without interruption from the display area FA in a direction parallel to the folding axis, but the present application is not limited thereto.

[0062] Although in Figure 3 , the plurality of opening patterns 111 are shown to have an elliptical cross-section, the present application is not limited thereto. The cross-sectional shape of each of the plurality of opening patterns 111 can be formed in various shapes, such as a polygonal shape other than a semicircular shape or a quadrangular shape.

[0063] An adhesive layer Adh is disposed on the support substrate 110 to join the support substrate 110 and the flexible substrate 121. Accordingly, the adhesive layer Adh can join the support substrate 110 and the display panel 120.

[0064] Although in Figure 2 and Figure 4In the middle, the flexible substrate 121 is shown disposed on the adhesive layer Adh, but a back plate can also be disposed on the adhesive layer Adh. The back plate can also be disposed between the display panel 120 and the support substrate 110, that is, between the flexible substrate 121 disposed on the rear surface of the display panel 120 and the adhesive layer Adh disposed on the support substrate 110. Thus, the adhesive layer Adh is disposed to join the support substrate 110 and the back plate, but is not limited thereto.

[0065] A back plate can be included between the display panel 120 and the support substrate 110 so as to support the display panel 120 together with the support substrate 110, and the back plate can be referred to as a top plate. When the display device 100 is folded, the back plate maintains the curvature of the display panel 120 constant and suppresses generation of a crease on the top surface of the display panel 120. In addition, the back plate is disposed between the display panel 120 and the support substrate 110 to suppress a shift of a boundary of the opening pattern 111, which is visible to a user due to the shape of the opening pattern 111, onto the display panel 120, which is disposed to correspond to the folding area FA of the support substrate 110.

[0066] The adhesive layer Adh can be formed of a photocurable material. For example, the adhesive layer Adh is a layer formed of a polymer, and is formed using an ultraviolet (UV) curable resin, but is not limited thereto.

[0067] Referring to Figure 2 and Figure 3 , the adhesive layer Adh includes a first area Adh1 and a second area Adh2.

[0068] The first area Adh1 can be an area formed by further partially curing the adhesive layer Adh. At this time, the Young's modulus of the first area can be 1 × 10 8 or more.

[0069] Referring to Figure 2 to Figure 4 , the first area Adh1 can be disposed in the adhesive layer Adh to correspond to each of the plurality of opening patterns 111. The first area Adh1 can be greater than the opening pattern 111, and a lower surface of the first area Adh1 can have the same shape as the opening pattern 111.

[0070] Referring to Figure 2 to Figure 4 , the second area Adh2 is disposed to surround the plurality of first areas Adh1. The second area Adh2 is a remaining portion in the adhesive layer Adh that is not cured when the first areas Adh1 are formed. Thus, the Young's modulus of the second area Adh2 can be lower than the Young's modulus of the first area Adh1. Specifically, the Young's modulus of the second area Adh2 can be 1 × 10 4 Pa to 9 × 10 6 Pa.

[0071] For example, the first region Adh1 can be a region formed by curing the adhesive layer Adh by means of light passing through the opening pattern 111 from below the support substrate 110 and being irradiated onto the adhesive layer Adh. Accordingly, the lower surface of the first region Adh1 can have the same shape as the opening pattern 111. At this time, the UV light irradiated onto the adhesive layer Adh from below the opening pattern 111 is diffracted by the opening pattern 111, so that a region larger than the opening pattern 111 can be cured. Accordingly, the first region Adh1 can be formed larger than the opening pattern 111.

[0072] Referring to Figure 2 to Figure 4 At least a portion of the lower surface of the first region Adh1 can overlap the support substrate 110. The upper surface of the first region Adh1 is disposed on the same plane as the upper surface of the adhesive layer Adh, and the area of the lower surface of the first region Adh1 can be greater than the corresponding opening pattern 111. The lower surface of the first region Adh1 can have the same size as the upper surface of the first region Adh1. That is, the first region Adh1 can be disposed to completely cover the opening pattern 111 of the support substrate 110. Accordingly, the first region Adh1 is disposed on the support substrate 110 as a division shape, so that the second region Adh2 can be configured to be limited between the plurality of first regions Adh1 on the support substrate 110.

[0073] In the display device 100 according to the exemplary embodiment of the disclosure, desirably, the width B of the first region Adh1 overlapping the support substrate 110 can be equal to or greater than the thickness D of the adhesive layer Adh, and equal to or less than 40% of the distance A between one opening pattern 111 and another adjacent opening pattern 111 in the support substrate 110. Accordingly, the first region Adh1 can be disposed to stably completely cover the opening pattern 111 of the support substrate 110.

[0074] In the display device 100 according to the exemplary embodiment of the disclosure, the first region Adh1 having a higher Young's modulus than other portions is formed on the adhesive layer Adh at positions corresponding to the plurality of opening patterns 111. Accordingly, the phenomenon in which the opening pattern 111 is visible from the display surface is improved, and the folding stress is also minimized.

[0075] In the related art, in order to disperse the folding stress concentrated on the folding region, an opening pattern, i.e., a plurality of holes, is formed on the support substrate. However, in this case, the folding stress is dispersed to satisfy the folding reliability, but the visibility of the opening pattern increases, so that the appearance quality is deteriorated.

[0076] In the display device 100 according to the exemplary embodiment of the present disclosure, a first region Adh1 having a higher Young's modulus than other portions is formed on the adhesive layer Adh at positions corresponding to the plurality of opening patterns 111. The transfer of the opening patterns 111 onto the display panel 120 can be minimized. That is, the plurality of opening patterns 111 formed in the folding area FA can not be visible to a user. Accordingly, the appearance quality deterioration problem in which the opening patterns 111 are visible from the display panel can be addressed.

[0077] In the display device 100 according to the exemplary embodiment of the present disclosure, a second region Adh2 having a lower Young's modulus than the first region Adh1 is disposed to surround the plurality of first regions Adh1 of the adhesive layer Adh. Accordingly, when the display device 100 is folded, the folding stress applied to the first region Adh1 having a higher Young's modulus can be alleviated. Thus, the concentration of the folding stress can be alleviated by the first region Adh1 configured to have a higher Young's modulus, to minimize the transfer of the opening patterns 111 onto the display panel 120 in the display device 100 according to the exemplary embodiment of the present disclosure.

[0078] In the display device 100 according to the exemplary embodiment of the present disclosure, a first region Adh1 having a higher Young's modulus than other portions is formed on the adhesive layer Adh at positions corresponding to the plurality of opening patterns 111. Accordingly, the phenomenon in which the opening patterns 111 are visible from the display panel is improved and the folding stress is also alleviated, so that the appearance quality of the display device 100 is improved.

[0079] Meanwhile, in the display device 100 according to the exemplary embodiment of the present disclosure, the first region Adh1 is disposed to correspond to the opening patterns 111, so that the leakage of the adhesive layer Adh through the opening patterns 111 can be improved.

[0080] In the related art display device, when the display device is folded, stress is concentrated on the adhesive layer and the adhesive layer leaks through the opening patterns, so that the appearance quality of the display device can be deteriorated.

[0081] Accordingly, in the display device 100 according to the exemplary embodiment of the present disclosure, the first region Adh1 having a higher Young's modulus is disposed in the adhesive layer Adh at positions corresponding to the opening patterns 111. Further, as Figure 2 to Figure 4As illustrated, the first regions Adh1 are disposed to completely cover the opening pattern 111, such that the second regions Adh2 are confined between the first regions Adh1. Accordingly, in the adhesive layer Adh, the flow of the second regions Adh2 having a lower Young's modulus is restricted, and the second regions Adh2 can be configured not to leak through the opening pattern 111. Accordingly, in the display device 100 according to the exemplary embodiment of the disclosure, the first regions Adh1 having a higher Young's modulus are disposed to correspond to the opening pattern 111, such that leakage of the adhesive layer Adh through the opening pattern 111 can be improved. Accordingly, the defective appearance quality of the display device 100 can be improved.

[0082] Meanwhile, the display device 100 according to the disclosure can be implemented as a display device having a folding area FA of a large curvature of 3R or less (and further 1.5R or less). Further, even if the curvature increases, the folding reliability is satisfied, such that it can be implemented as a multi-foldable display device. In the present specification, a curvature radius 1R means that a radius of a curved surface of the folding area during folding is 1 mm.

[0083] Figure 5 is a schematic cross-sectional view of a display device according to an exemplary embodiment of the disclosure. For convenience of description, in Figure 5 in the components of the display device 500, only the support substrate 110, the adhesive layer Adh, and the flexible substrate 121 are illustrated. Figure 5 The display device 500 of Figure 1 The only difference between the display device 100 of

[0084] The adhesive layer Adh includes the first regions Adh1 and the second regions Adh2.

[0085] The first regions Adh1 can be regions formed by further partially curing the adhesive layer Adh. The first regions Adh1 can be disposed in the adhesive layer Adh1 to correspond to each of the plurality of opening patterns 111. The first regions Adh1 can be larger than the opening patterns 111, and a lower surface of the first regions Adh1 can have the same shape as the opening patterns 111.

[0086] The second regions Adh2 are disposed to surround the plurality of first regions Adh1. The second regions Adh2 are the remaining portions in the adhesive layer Adh that are not cured when the first regions Adh1 are formed. Accordingly, the Young's modulus of the second regions Adh2 can be lower than the Young's modulus of the first regions Adh1.

[0087] Referring to Figure 5In the display device 500 according to another exemplary embodiment of the present disclosure, a lower surface of the first area Adh1 can be greater than an upper surface of the first area Adh1. The cross-sectional shape of the first area Adh1 can be a semi-circular shape as shown, but can also be a trapezoidal shape, and is not limited thereto. Figure 5

[0088] In the display device 500 according to another exemplary embodiment of the present disclosure, a first area Adh1 having a higher Young's modulus than other portions is formed on the adhesive layer Adh at positions corresponding to the plurality of opening patterns 111. Accordingly, a phenomenon in which the opening patterns 111 are visible from the display surface is improved, and a folding stress is also alleviated.

[0089] In the related art, in order to disperse a folding stress concentrated on a folding area, an opening pattern, i.e., a plurality of holes, is formed on a support substrate. In this case, the folding stress is dispersed to satisfy folding reliability, but visibility of the opening pattern increases, such that appearance quality is deteriorated.

[0090] In the display device 500 according to another exemplary embodiment of the present disclosure, a first area Adh1 having a higher Young's modulus than other portions is formed on the adhesive layer Adh at positions corresponding to the plurality of opening patterns 111. The transfer of the opening patterns 111 onto the display panel 120 can be minimized. That is, the plurality of opening patterns 111 formed in the folding area FA can not be visible to a user. Accordingly, a problem of appearance quality deterioration in which the opening patterns 111 are visible from the display panel can be solved.

[0091] Further, in the display device 500 according to another exemplary embodiment of the present disclosure, a second area Adh2 having a lower Young's modulus than the first area Adh1 is disposed to surround the plurality of first areas Adh1 of the adhesive layer, and a lower surface of the first area Adh1 is configured to be greater than an upper surface of the first area. Accordingly, when the display device 500 is folded, a folding stress applied to the first area Adh1 having a higher Young's modulus can be further effectively alleviated. Thus, concentration of the folding stress can be minimized by the first area Adh1 configured to have a higher Young's modulus to minimize the transfer of the opening patterns 111 onto the display panel 120 in the display device 500 according to another exemplary embodiment of the present disclosure.

[0092] ​In the display device 500 according to another exemplary embodiment of the present disclosure, a first area Adh1 having a higher Young's modulus than other portions is formed on the adhesive layer Adh at positions corresponding to the plurality of opening patterns 111. Accordingly, the phenomenon that the opening patterns 111 are visible from the display panel is improved and the folding stress is also more effectively alleviated, so that the appearance quality of the display device 500 is improved.

[0093] Figure 6 is a schematic cross-sectional view of a display device according to still another exemplary embodiment of the present disclosure. For convenience of description, only the support substrate 110, the adhesive layer Adh, and the flexible substrate 121 are illustrated among the components of the display device 600. Figure 6 Figure 6 The display device 600 of Figure 1 The only difference between the display device 100 of

[0094] Referring to Figure 6 In the display device 600 according to another exemplary embodiment of the present disclosure, an upper surface of the first area Adh1 can be disposed lower than an upper surface of the adhesive layer Adh. That is, a second area Adh2 having a lower Young's modulus than a Young's modulus of the first area Adh1 can be disposed above the first area Adh1.

[0095] In the display device 600 according to still another exemplary embodiment of the present disclosure, a first area Adh1 having a higher Young's modulus than other portions is formed on the adhesive layer Adh at positions corresponding to the plurality of opening patterns 111. Accordingly, the phenomenon that the opening patterns 111 are visible from the display surface is improved and the folding stress is also alleviated.

[0096] In the related art, in order to disperse the folding stress concentrated on the folding area, an opening pattern, i.e., a plurality of holes, is formed on the support substrate. In this case, the folding stress is dispersed to satisfy the folding reliability, but the visibility of the opening pattern increases, so that the appearance quality is deteriorated.

[0097] In the display device 600 according to still another exemplary embodiment of the present disclosure, a first area Adh1 having a higher Young's modulus than other portions is formed on the adhesive layer Adh at positions corresponding to the plurality of opening patterns 111. The transfer of the opening patterns 111 onto the display panel 120, which causes the shape of the opening patterns 111 to be visible to a user, can be minimized. That is, the plurality of opening patterns 111 formed in the folding area FA can not be visible to a user. Accordingly, the appearance quality deterioration problem that the opening patterns 111 are visible from the display panel can be solved.​

[0098] Further, in the display device 600 according to the still another exemplary embodiment of the present disclosure, the second regions Adh2 having a Young's modulus lower than that of the first regions Adh1 are disposed to surround the plurality of first regions Adh1 of the adhesive layer. Further, the second regions Adh2 having a Young's modulus lower than that of the first regions Adh1 are disposed above the first regions Adh1. Thus, when the display device 600 is folded, the folding stress applied to the first regions Adh1 having a higher Young's modulus can be further effectively alleviated. Thus, the concentration of the folding stress can be alleviated by the first regions Adh1 configured to have a higher Young's modulus to minimize the transfer of the opening patterns 111 on the display panel 120 in the display device 600 according to the still another exemplary embodiment of the present disclosure.

[0099] Thus, in the display device 600 according to the still another exemplary embodiment of the present disclosure, the first regions Adh1 having a higher Young's modulus than other portions are formed on the adhesive layer Adh at positions corresponding to the plurality of opening patterns 111. Thus, the phenomenon that the opening patterns 111 are visible from the display panel is improved and the folding stress is also more effectively alleviated, so that the appearance quality of the display device 600 is improved.

[0100] Figure 7 is a schematic cross-sectional view of a display device according to the still another exemplary embodiment of the present disclosure. For convenience of description, in Figure 7 In the display device 700, among the components of the display device 700, only the support substrate 110, the adhesive layer Adh, and the flexible substrate 121 are illustrated. Figure 7 The display device 700 of Figure 1 The only difference between the display device 100 of

[0101] Referring to Figure 7 In the display device 700 according to the other exemplary embodiment of the present disclosure, the Young's modulus of the first regions Adh1 can increase from the support substrate 110 toward the display panel 120.

[0102] Specifically, the first area Adh1 can include a plurality of areas Adh11, Adh12, and Adh13 having different Young's moduli. The first area Adh1 includes a first Young's modulus area Adh11, a second Young's modulus area Adh12, and a third Young's modulus area Adh13. The first Young's modulus area Adh11 is disposed closest to the support substrate 110 and has the lowest Young's modulus. The second Young's modulus area Adh12 is disposed on the first Young's modulus area Adh11 and has the second highest Young's modulus. The third Young's modulus area Adh13 is disposed on the second Young's modulus area Adh12 and has the highest Young's modulus. Accordingly, the Young's modulus of the first area Adh1 can increase from the support substrate 110 toward the display panel 120.

[0103] In the display device 700 according to still another exemplary embodiment of the disclosure, a first area Adh1 having a higher Young's modulus than other portions is formed on the adhesive layer Adh at positions corresponding to the plurality of opening patterns 111. Accordingly, a phenomenon in which the opening patterns 111 are visible from the display surface is improved, and a folding stress is also reduced.

[0104] In the related art, in order to disperse a folding stress concentrated on a folding area, an opening pattern, i.e., a plurality of holes, is formed on a support substrate. In this case, the folding stress is dispersed to satisfy folding reliability, but visibility of the opening pattern increases, so that appearance quality is deteriorated.

[0105] In the display device 700 according to still another exemplary embodiment of the disclosure, a first area Adh1 having a higher Young's modulus than other portions is formed on the adhesive layer Adh at positions corresponding to the plurality of opening patterns 111. It is possible to minimize a transfer of the opening patterns 111 onto the display panel 120. That is, the plurality of opening patterns 111 formed in the folding area FA can not be visible to a user. Accordingly, it is possible to solve a problem of appearance quality deterioration in which the opening patterns 111 are visible from the display panel.

[0106] Further, in the display device 700 according to the still another exemplary embodiment of the present disclosure, a second region Adh2 having a Young's modulus lower than that of the first regions Adh1 is disposed to surround the plurality of first regions Adh1 of the adhesive layer. The Young's modulus of the first regions Adh1 can increase from the support substrate 110 toward the display panel 120, so that the folding stress applied to the first regions Adh1 having a higher Young's modulus can be further effectively alleviated when the display device 700 is folded. Accordingly, the concentration of the folding stress can be addressed by the first regions Adh1 configured to have a higher Young's modulus to minimize the transfer of the opening pattern 111 onto the display panel 120 in the display device 700 according to the still another exemplary embodiment of the present disclosure.

[0107] Accordingly, in the display device 700 according to the still another exemplary embodiment of the present disclosure, the first regions Adh1 having a higher Young's modulus than other portions are formed on the adhesive layer Adh at positions corresponding to the plurality of opening patterns 111. Accordingly, the phenomenon that the opening patterns 111 are visible from the display panel is improved and the folding stress is also effectively alleviated, so that the appearance quality of the display device 700 is improved.

[0108] Figure 8 is a schematic cross-sectional view of a display device according to the still another exemplary embodiment of the present disclosure. For convenience of description, in Figure 8 , among the components of the display device 800, only the support substrate 110, the adhesive layer Adh, and the flexible substrate 121 are illustrated. Figure 8 The display device 800 of Figure 1 is substantially the same as the display device 100 of , except for the first regions Adh1 of the adhesive layer Adh, so that a redundant description will be omitted.

[0109] Figure 8 Referring to , in the display device 800 according to the still another exemplary embodiment of the present disclosure, the upper surface of the first regions Adh1 can be greater than the lower surface of the first regions Adh1. That is, the cross-section of the first regions Adh1 can have an inverted conical shape.

[0110] In the display device 800 according to the still another exemplary embodiment of the present disclosure, the first regions Adh1 having a higher Young's modulus than other portions are formed on the adhesive layer Adh at positions corresponding to the plurality of opening patterns 111. Accordingly, the phenomenon that the opening patterns 111 are visible from the display surface is improved, and the folding stress is also alleviated.

[0111] In the related art, in order to disperse the folding stress concentrated on the folding area, an opening pattern, i.e., a plurality of holes, is formed on the support substrate. In this case, the folding stress is dispersed to satisfy folding reliability, but the visibility of the opening pattern increases, so that the appearance quality deteriorates.

[0112] In the display device 800 according to the still another exemplary embodiment of the present disclosure, a first area Adh1 having a higher Young's modulus than other portions is formed on the adhesive layer Adh at positions corresponding to the plurality of opening patterns 111. The transfer of the opening patterns 111 onto the display panel 120 can be minimized. That is, the plurality of opening patterns 111 formed in the folding area FA can not be visible to a user. Accordingly, the appearance quality deterioration problem in which the opening patterns 111 are visible from the display panel can be solved.

[0113] In the display device 800 according to the still another exemplary embodiment of the present disclosure, a second area Adh2 having a lower Young's modulus than the first area Adh1 is disposed to surround the plurality of first areas Adh1 of the adhesive layer. Accordingly, when the display device 800 is folded, the folding stress applied to the first area Adh1 having a higher Young's modulus can be alleviated. Thus, the concentration of the folding stress can be alleviated by the first area Adh1 configured to have a higher Young's modulus, to minimize the transfer of the opening patterns 111 onto the display panel 120 in the display device 800 according to the still another exemplary embodiment of the present disclosure.

[0114] Thus, in the display device 800 according to the still another exemplary embodiment of the present disclosure, a first area Adh1 having a higher Young's modulus than other portions is formed on the adhesive layer Adh at positions corresponding to the plurality of opening patterns 111. Accordingly, the phenomenon in which the opening patterns 111 are visible from the display panel is improved and the folding stress is also alleviated, so that the appearance quality of the display device 800 is improved.

[0115] The exemplary embodiments of the present disclosure can also be described as follows:

[0116] According to an aspect of the present disclosure, a display device is provided. The display device includes: a display panel; a support substrate supporting the display panel below the display panel and including a plurality of opening patterns; and an adhesive layer disposed on the support substrate and including: a plurality of first areas disposed to respectively correspond to the plurality of opening patterns; and a second area surrounding the plurality of first areas and having a lower Young's modulus than a Young's modulus of the plurality of first areas. Each of the first areas is larger than a corresponding one of the opening patterns.

[0117] The lower surface of each first region can be larger than the corresponding opening pattern, and at least a portion of the lower surface of the first region overlaps the support substrate.

[0118] The upper surface of the first region can be disposed on the same plane as the upper surface of the adhesive layer.

[0119] The lower surface of the first region can have the same size as the upper surface of the first region.

[0120] The lower surface of the first region can be larger than the upper surface of the first region.

[0121] The upper surface of the first region can be larger than the lower surface of the first region.

[0122] The first region can have a semi-spherical shape.

[0123] The Young's modulus of the first region can increase from the support substrate toward the display panel.

[0124] The upper surface of the first region can be disposed lower than the upper surface of the adhesive layer.

[0125] The lower surface of the first region of the adhesive layer disposed on the support substrate can have the same shape as the opening pattern.

[0126] The width of the portion of the first region overlapping the support substrate can be equal to or greater than the thickness of the adhesive layer, and can be equal to or less than 40% of the distance between one opening pattern and another adjacent opening pattern in the support substrate.

[0127] The Young's modulus of the first region can be 1×10 8 , and the Young's modulus of the second region can be 1×10 4 to 9×10 6 .

[0128] The adhesive layer can be formed of a light-curable material.

[0129] The first region can be formed by curing the adhesive layer by light passing through the opening pattern from below the support substrate and being irradiated onto the adhesive layer.

[0130] The display panel can include a folding region and a non-folding region, and the opening pattern of the support substrate can be disposed to correspond to the folding region of the display panel.

[0131] The display device can further include a back plate disposed between the display panel and the support substrate. The adhesive layer bonds the support substrate and the back plate.

[0132] Although exemplary embodiments of the present disclosure have been described in detail with reference to the accompanying drawings, the present disclosure is not limited thereto and can be embodied in various forms without departing from the technical concept of the present disclosure. Therefore, the exemplary embodiments of the present disclosure are provided only for illustrative purposes, not intended to limit the technical concept of the present disclosure. The scope of the technical concept of the present disclosure is not limited thereto. Therefore, it should be understood that the above-described exemplary embodiments are illustrative in all aspects and do not limit the present disclosure. The scope of protection of the present disclosure should be interpreted based on the claims and all technical concepts within the equivalent scope thereof should be interpreted as falling within the scope of the present disclosure.

Claims

1. A display device, comprising: Display panel; A support substrate that supports the display panel below the display panel and includes a plurality of opening patterns; as well as An adhesive layer disposed on the support substrate includes: a plurality of first regions configured to correspond respectively to the plurality of opening patterns; and a second region surrounding the plurality of first regions and having a Young's modulus lower than that of the plurality of first regions. Each of the first regions is larger than the corresponding opening pattern.

2. The display device according to claim 1, wherein, The area of ​​the lower surface of each of the first regions is larger than the corresponding opening pattern, and at least a portion of the lower surface of the first region overlaps with the support substrate.

3. The display device according to claim 2, wherein, The upper surface of the first region is disposed on the same plane as the upper surface of the adhesive layer.

4. The display device according to claim 3, wherein, The lower surface of the first region has the same dimensions as the upper surface of the first region.

5. The display device according to claim 3, wherein, The lower surface of the first region is larger than the upper surface of the first region.

6. The display device according to claim 3, wherein, The upper surface of the first region is larger than the lower surface of the first region.

7. The display device according to claim 2, wherein, The first region has a hemispherical shape.

8. The display device according to claim 1, wherein, The Young's modulus of the first region increases from the support substrate toward the display panel.

9. The display device according to claim 1, wherein, The upper surface of the first region is configured to be lower than the upper surface of the adhesive layer.

10. The display device according to claim 1, wherein, The lower surface of the first region of the adhesive layer disposed on the support substrate has the same shape as the opening pattern.

11. The display device according to claim 1, wherein, The width of the portion of the first region that overlaps with the support substrate is equal to or greater than the thickness of the adhesive layer, and equal to or less than 40% of the distance between one opening pattern and another adjacent opening pattern in the support substrate.

12. The display device according to claim 1, wherein, The Young's modulus of the first region is 1×10⁻⁶. 8 Furthermore, the Young's modulus of the second region is 1×10⁻⁶. 4 Up to 9×10 6 .

13. The display device according to claim 1, wherein, The adhesive layer is formed of a photocurable material.

14. The display device according to claim 13, wherein, The first region is formed by curing the adhesive layer with light that passes through the opening pattern from below the support substrate and shines onto the adhesive layer.

15. The display device according to claim 1, wherein, The display panel includes a folded area and a non-folded area, and the opening pattern of the support substrate is configured to correspond to the folded area of ​​the display panel.

16. The display device according to claim 15, further comprising: A backplate is disposed between the display panel and the supporting substrate. The adhesive layer bonds the support substrate to the back plate.

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