Patent ID: 12260786

DETAILED DESCRIPTION

The disclosure may be variously modified and realized in many different forms, and thus specific embodiments will be exemplified in the drawings and described in detail hereinbelow. However, the disclosure should not be limited to the specific disclosed forms, and be construed to include all modifications, equivalents, or replacements included in the spirit and scope of the disclosure.

In the 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 may be directly on, connected or coupled to the other element or layer or intervening elements or layers may be present.

Like numerals refer to like elements throughout. In the drawings, the thickness, ratio, and dimension of components are exaggerated for effective description of the technical content.

As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.

It will be understood that, although the terms first, second, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another region, layer or section. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the disclosure. As used herein, the singular forms, “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise.

Spatially relative terms, such as “beneath”, “below”, “lower”, “above”, “upper” and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as shown in the drawing figures.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

It will be further understood that the terms “includes” and/or “including”, when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

“About” or “approximately” as used herein is inclusive of the stated value and means within an acceptable range of deviation for the particular value as determined by one of ordinary skill in the art, considering the measurement in question and the error associated with 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.

Hereinafter, a display device according to the invention will be explained in detail with reference to the accompanying drawings.

FIGS.1A and2Aare perspective views showing an embodiment of display devices DD and DD-1according to the invention.FIG.1Bis a perspective view showing the display device DD ofFIG.1Ain a folded state.FIG.2Bis a perspective view showing the display device DD-1ofFIG.2Ain a folded state.

Referring toFIGS.1A,1B,2A, and2B, the display devices DD and DD-1may be foldable display devices. In an embodiment, the display devices DD and DD-1may be applied to a large-sized electronic item, such as a television set, a monitor, and the like, or a small and medium-sized electronic item, such as a mobile phone, a tablet computer, a game unit, a navigation unit, and the like.

An upper surface of each of the display devices DD and DD-1may be defined as a display surface DS. The display surface DS may correspond to a plane defined by a first directional axis DR1and a second directional axis DR2when the display devices DD and DD-1are in an unfolded state.

The display surface DS may include a display area DA and a non-display area NDA defined around the display area DA. An image IM is displayed through the display area DA, and the image IM is not displayed through the non-display area NDA. The image IM may include a still image or a motion image.FIGS.1A and2Ashow a plurality of application icons as representative examples of the image IM.

The display area DA may have a quadrangular shape. The non-display area NDA may surround the display area DA. However, they should not be limited thereto or thereby, and the shape of the display area DA and the shape of the non-display area NDA may be designed to have other shapes.

The display device DD may include a first non-folding area NFA1, a folding area FA, and a second non-folding area NFA2, which are defined therein and sequentially arranged in one direction. That is, the folding area FA may be defined between the first non-folding area NFA1and the second non-folding area NFA2. The display device DD-1may include a first non-folding area NFAT-1, a folding area FA-1, and a second non-folding area NFA2-1, which are defined therein and sequentially arranged in one direction. That is, the folding area FA-1may be defined between the first non-folding area NFAT-1and the second non-folding area NFA2-1.

The display devices DD and DD-1may be folded about folding axes FX and FX-1, respectively. That is, the folding areas FA and FA-1may be folded about the folding axes FX and FX-1, respectively. The folding areas FA and FA-1are portions where deformation may occur when the display devices DD and DD-1are folded or bent and correspond to bending portions of the display devices DD and DD-1.

Referring toFIGS.1A and1B, the folding axis FX may extend in the first directional axis DRT. The folding axis FX may be a short axis substantially parallel to short sides of the display device DD. Referring toFIGS.2A and2B, the folding axis FX-1may extend in the second directional axis DR2. The folding axis FX-1may be a long axis substantially parallel to long sides of the display device DD-1.

When the display devices DD and DD-1are folded, the display surfaces corresponding to the first non-folding areas NFA1and NFAT-1may face the display surfaces corresponding to the second non-folding areas NFA2and NFA2-1. Accordingly, the display surface DS may not be exposed to the outside in the folded state of the display devices DD and DD-1, however, the invention is not limited thereto. When the display devices DD and DD-1are folded, the display surfaces corresponding to the first non-folding areas NFAT and NFAT-1may be opposite to the display surfaces corresponding to the second non-folding areas NFA2and NFA2-1. Accordingly, the display surface DS may be exposed to the outside in the folded state of the display devices DD and DD-1.

FIGS.1A and1Bshow one folding area FA, one first non-folding area NFA1and one second non-folding area NFA2, andFIGS.2A and2Bshow one folding area FA-1, one first non-folding area NFAT-1, and one second non-folding area NFA2-1, however, the number of the folding areas and the number of the non-folding areas should not be limited thereto or thereby. In an embodiment, each of the display devices DD and DD-1may include more than two non-folding areas and may include folding areas disposed between the non-folding areas, for example.

Hereinafter, the structure of the display device DD folded about the short axis shown inFIGS.1A and1Bwill be described as a representative example, however, the invention should not be limited thereto or thereby, and details described hereinafter may be applied to the display device DD-1folded about the long axis.

FIG.3is an exploded perspective view showing an embodiment of the display device DD according to the invention. The display device DD may include a display module DM, and a lower module UM disposed under the display module DM. The lower module UM may include a support member SP, a heat dissipation member HD, and a cover member CV. The heat dissipation member HD may be disposed between the support member SP and the cover member CV. Although not shown in drawing figures, the display device DD may further include a case (or housing) to accommodate the display module DM and the cover member CV.

The display module DM may display the image IM (refer toFIG.1A) and may sense an external input TC (refer toFIG.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 the user's body, light, heat, pen, or pressure. InFIG.1A, the external input TC is shown as a user's hand being applied to the display surface DS, however, the invention is not limited thereto. The display module DM may sense the external input TC applied to a side or rear surface of the display device DD depending on its structure, and, it should not be limited to a specific embodiment.

The display module DM may have a quadrangular (e.g., rectangular) shape with short sides extending in the first directional axis DR1and long sides extending in the second directional axis DR2. The display module DM may include the folding area FA folded about the folding axis FX extending in the first directional axis DR1. The display module DM may include the first non-folding area NFA1, the folding area FA, and the second non-folding area NFA2, which are sequentially arranged in the second directional axis DR2. The first non-folding area NFA1and the second non-folding area NFA2may be spaced apart from each other with the folding area FA interposed therebetween.

The support member SP may be disposed under the display module DM. The support member SP may support a rear surface of the display module DM and may protect the display module DM. The support member SP may include a barrier portion that protects the display module DM and has an elasticity advantageous to restore deformation, an impact absorbing portion that absorbs impacts, or a support portion that supports the display module DM and prevents the deformation.

The display device DD may include the heat dissipation member HD disposed under the support member SP. A first opening OP1and a second opening OP2may be defined through the heat dissipation member HD. The first opening OP1may be defined to overlap the first non-folding area NFA1, and the second opening OP2may be defined to overlap the second non-folding area NFA2.

The display device DD may include a first adhesive member AM1and a second adhesive member AM2. The first adhesive member AM1may be disposed in the first opening OP1, and the second adhesive member AM2may be disposed in the second opening OP2. The bending deformation may occur in an area corresponding to the folding area FA due to repeated folding and unfolding operations of the display device DD by the user, however, the first and second adhesive members AM1and AM2may reduce a degree of the bending deformation by controlling the bending deformation.

The cover member CV may be disposed under the heat dissipation member HD to cover the display module DM and the lower module UM. In an embodiment, the cover member CV may have a unitary plate shape. However, they should not be limited thereto or thereby, and the cover member CV may include a plurality of cover portions spaced apart from each other in the folding area FA. The cover member CV may include a metal or plastic material.

FIG.4is a cross-sectional view showing an embodiment of the display module DM according to the invention.FIG.4shows the cross-section defined by the second directional axis DR2and a third directional axis DR3. The third directional axis DR3may be a direction substantially perpendicular to the plane defined by the first directional axis DR1and the second directional axis DR2.

Referring toFIG.4, the display module DM may include a display panel DP. The display panel DP may include the folding area FA folded about the folding axis FX extending in the first directional axis DR1. The display panel DP may include the first non-folding area NFA1and the second non-folding area NFA2spaced apart from each other with the folding area FA interposed therebetween in the second directional axis DR2.

The display panel DP may be a light emission display panel, however, it should not be particularly limited. In an embodiment, the display panel DP may include a liquid crystal display panel, an organic light emitting display panel, or a quantum dot light emitting display panel, for example.

An input sensing layer (not shown) may be disposed on the display panel DP. The input sensing layer (not shown) may be disposed directly on the display panel DP through successive processes. The input sensing layer (not shown) may include a plurality of insulating layers and a plurality of conductive layers. The conductive layers may form a sensing electrode sensing the external input, a sensing line connected to the sensing electrode, and a sensing pad connected to the sensing line.

As shown inFIG.4, the display module DM may further include a protective layer PL, a window WM, an anti-reflective layer POL, and a protective film PF. However, the display module DM should not be limited to the structure shown inFIG.4, and some components included in the display module DM may be omitted.

The anti-reflective layer POL may be disposed on the display panel DP The anti-reflective layer POL may reduce a reflectance of an external light incident thereto from the above of the window WM. The anti-reflective layer POL in the embodiment of the invention may include a retarder and a polarizer. Each of the retarder and the polarizer may be a film type or liquid crystal coating type. The retarder and the polarizer may further include a protective film.

The anti-reflective layer POL may include color filters. The color filters may have a predetermined alignment. The alignment of the color filters may be determined by taking into account emission colors of pixels included in the display panel DP. The anti-reflective layer POL may further include a black matrix disposed adjacent to the color filters.

The anti-reflective layer POL may include a destructive interference structure. In an embodiment, the destructive interference structure may include a first reflection layer and a second reflection layer, which are disposed on different layers from each other, for example. A first reflection light and a second reflection light, which are respectively reflected by the first reflection layer and the second reflection layer, may interfere destructively with each other, and thus, the reflectance of the external light may be reduced.

The window WM may be disposed on the anti-reflective layer POL. The window WM may protect the display panel DP from external scratch and impact. The image generated by the display panel DP may be provided to the user after passing through the window WM.

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-reflective layer, and a hard coating layer, however, the functional coating layer included in the window WM should not be limited thereto or thereby.

A shape of the window WM may be changed to correspond to a change in shape of the foldable display device DD and may protect the display panel DP even though the shape of the window WM is changed. In an embodiment, the window WM may include a glass material, e.g., an ultra-thin glass (“UTG”).

The protective layer PL may be disposed on the window WM. The impact resistance of the display device DD may be improved by the protective layer PL. In an embodiment, the protective layer PL may be a polymer film or a tempered glass film, for example. In another embodiment, the protective layer PL may be omitted.

The protective film PF may be disposed under the display panel DP. The protective film PF may protect a rear surface of the display panel DP. The protective film PF may be a synthetic resin film. In an embodiment, the protective film PF may be a polyimide film or a polyethylene terephthalate film, for example. However, the protective film PF should not be limited thereto or thereby.

The display module DM may further include adhesive layers disposed between the components thereof. The adhesive layers may be disposed between the components, such as the protective layer PL, the window WM, the anti-reflective layer POL, the display panel DP, and the protective film PF, and each adhesive layer may attach components corresponding to each other among the components. InFIG.4, the display module DM in the embodiment includes an adhesive layer AD1disposed between the protective layer PL and the window WM and an adhesive layer AD2disposed between the window WM and the anti-reflective layer POL. However, the display module DM should not be limited thereto or thereby and may further include the adhesive layers, and one of the adhesive layers AD1and AD2may be omitted.

Some components included in the display module DM may be provided through successive processes and may be directly disposed without using the adhesive layers. As shown inFIG.4, the protective film PF and the display panel DP may be successively disposed without using the adhesive layers. In addition, the anti-reflective layer POL may be disposed on the display panel DP without using the adhesive layers. Further, in another embodiment, one of the adhesive layers AD1and AD2shown inFIG.4may be omitted.

The adhesive layers AD1and AD2may include a conventional adhesive. In an embodiment, each of the adhesive layers AD1and AD2may include a pressure sensitive adhesive (“PSA”), an optical clear adhesive (“OCA”), or an optical clear resin (“OCR”), for example.

FIG.5is a cross-sectional view showing an embodiment of the lower module UM according to the invention, andFIG.6is a graph showing a degree of bending deformation of a display device in an embodiment example and a comparative example. For the convenience of explanation, the folding area FA, the first non-folding area NFA1, and the second non-folding area NFA2of the display panel DP shown inFIGS.5to14(exceptFIG.10) are illustrated.

Referring toFIG.5, the lower module UM may include the support member SP, the heat dissipation member HD, and the cover member CV. The lower module UM may further include an adhesive layer AD4that attaches the support member SP to the heat dissipation member HD. The lower module UM may further include a step-difference compensation member SM.

The heat dissipation member HD may be disposed between the support member SP and the cover member CV. The first and second openings OP1and OP2may be defined through the heat dissipation member HD. The first opening OP1may overlap the first non-folding area NFA1, and the second opening OP2may overlap the second non-folding area NFA2.

The lower module UM may include the first adhesive member AM1and the second adhesive member AM2. The first adhesive member AM1may be disposed in the first opening OP1, and the second adhesive member AM2may be disposed in the second opening OP2. The first adhesive member AM1may overlap the first non-folding area NFA1, and the second adhesive member AM2may overlap the second non-folding area NFA2.

The first adhesive member AM1and the second adhesive member AM2may reduce the degree of the bending deformation in the folding area FA. Referring toFIG.6, the graph of the comparative example shows a bending deformation shape of the display device that does not include the first adhesive member AM1and the second adhesive member AM2. The graph of the embodiment example shows a bending deformation shape of the display device that includes the first adhesive member AM1and the second adhesive member AM2.

The bending deformation shape of the comparative example that does not include the first and second adhesive members AM1and AM2may have a seagull shape in which both ends of an area corresponding to the folding area FA are convex upward and a point corresponding to a center of the folding area FA is convex downward. The first adhesive member AM1and the second adhesive member AM2may reduce the degree of bending deformation while closely adhering the deformed portion, which is convex upward, toward the cover member CV.

The degree of bending deformation is a gap difference between the point convex upward and the point convex downward. Hereinafter, the degree of bending deformation is also referred to as a deformation degree. The deformation degree BF′ of the comparative example may be greater than the deformation degree BF of the embodiment example. As represented by the graphs, the deformation degree of the display device DD may be reduced by disposing the first and second adhesive members AM1and AM2between the support member SP and the cover member CV.

The bending deformation shape of the embodiment example that includes the first and second adhesive members AM1and AM2may have a shape in which both ends of the area corresponding to the folding area FA are convex downward since the portions that are convex upward of the bending deformation shape in the comparative example are lowered. Accordingly, the area corresponding to the portion that is convex downward in the bending deformation of the comparative example becomes convex upward, and the point corresponding to the center of the folding area becomes convex downward. Accordingly, there are three points that are convex downward in the bending deformation of the embodiment example.

The phenomenon in which the bending deformation is viewed from the outside may be improved by adjusting a curvature value of the convexly deformed point as well as the deformation degree. When the curvature value is substantially large, it means that the bending deformation has occurred steeply, and when the curvature value is substantially small, it means that the bending deformation is relatively gentle. Therefore, when the curvature value is substantially large, the bending deformation may be easily viewed from the outside.

The deformation degree and the curvature value may be controlled by adjusting an interval at which each of the first adhesive member AM1and the second adhesive member AM2is disposed. When the interval between the first and second adhesive members AM1and AM2increases, the deformation degree increases, and the curvature value decreases. Accordingly, the degree of visual recognition of the bending deformation of the display device DD may be adjusted depending on whether the first and second adhesive members AM1and AM2are included and depending on the interval between the first and second adhesive members AM1and AM2.

Referring toFIG.5, the first adhesive member AM1may be spaced apart from the folding axis FX by a first distance D1in the second directional axis DR2. The second adhesive member AM2may be spaced apart from the folding axis FX by a second distance D2in the second directional axis DR2. The first adhesive member AM1and the second adhesive member AM2may not overlap the folding area FA.

The first non-folding area NFA1and the second non-folding area NFA2, which are included in the display panel DP (refer toFIG.4), have centers C1and C2, respectively. For the convenience of explanation, the centers C1and C2of the first and second non-folding areas NFA1and NFA2are respectively shown above the support member SP inFIG.5.

The first distance D1may have a maximum value corresponding to a minimum distance D3between the folding axis FX and the center C1of the first non-folding area NFA1. The second distance D2may have a maximum value corresponding to a minimum distance D4between the folding axis FX and the center C2of the second non-folding area NFA2.

The first adhesive member AM1and the second adhesive member AM2may be spaced apart from each other by a sum of the first distance D1and the second distance D2. A maximum value of the sum of the first distance D1and the second distance D2may correspond to a minimum distance between the center C1of the first non-folding area NFA1and the center C2of the second non-folding area NFA2.

The first adhesive member AM1and the second adhesive member AM2may be symmetrical with each other with respect to the folding axis FX. Accordingly, the first distance D1and the second distance D2may be substantially the same as each other, however, they should not be limited thereto or thereby. That is, the first distance D1may be different from the second distance D2.

The degree of bending deformation and the curvature of the bending area may be controlled by adjusting the minimum distances D1and D2from the folding axis FX to the first and second adhesive members AM1and AM2, respectively. As the first and second distances D1and D2from the folding axis FX increase, the degree of bending deformation increases, and the curvature of the bending area decreases. Accordingly, the degree of bending deformation and the curvature of the bending area may be controlled by adjusting the distances D1and D2of the first and second adhesive members AM1and AM2, and thus, the phenomenon in which the bending deformation is viewed from the outside may be improved.

Each of the first and second adhesive members AM1and AM2may include a conventional adhesive. Each of the first and second adhesive members AM1and AM2may include an acrylic-based resin or a silicon-based resin. In an embodiment, each of the first and second adhesive members AM1and AM2may include a PSA, an OCA, or an OCR, for example.

The heat dissipation member HD may be disposed under the support member SP to disperse and dissipate heat generated in the display device DD. The heat dissipation member HD may include a heat dissipation sheet. The heat dissipation sheet may include graphite or a graphitized polymer film. In an embodiment, the polymer film may be a polyimide film, for example.

The lower module UM may include the impact absorbing member SA (refer toFIG.14), which will be described later, rather than the heat dissipation member HD. The impact absorbing member SA (refer toFIG.14) may absorb impacts applied to the display device DD. The impact absorbing member SA (refer toFIG.14) may include a sponge, a foam, or a urethane resin.

The support member SP may include a flexible material to increase flexibility of an area corresponding to the folding area FA. In addition, the support member SP may have a folding pattern obtained by patterning the area corresponding to the folding area FA or may include a plurality of support portions spaced apart from each other in the folding area FA.

The lower module UM may include the cover member CV disposed under the support member SP. The cover member CV may cover the display module DM and the lower module UM. The cover member CV may be accommodated in the case (not shown) of the display device DD. The cover member CV may include a plastic or metal material.

The lower module UM may further include the step-difference compensation member SM. The step-difference compensation member SM may be disposed between the support member SP and the cover member CV. The step-difference compensation member SM may be disposed around the heat dissipation member HD.

The step-difference compensation member SM may include a step-difference compensation film or a step-difference compensation adhesive. One surface of the step-difference compensation film may have an adhesion lower than the other surface of the step-difference compensation film. The step-difference compensation film may be a synthetic resin film. The step-difference compensation adhesive may be a PSA. In an embodiment, the step-difference compensation adhesive may include an acrylic-based resin or a silicon-based resin, for example, however, it should not be limited thereto or thereby. The step-difference compensation adhesive may be, but not limited to, a step-difference compensation tape.

The step-difference compensation member SM may have a thickness, in a third direction DR3, that is substantially the same as a sum of a thickness of the adhesive layer AD4and a thickness of the heat dissipation member HD. The thickness of the heat dissipation member HD may be substantially the same as the thickness of the first and second adhesive members AM1and AM2. In an embodiment, the thickness of the step-difference compensation member SM may be about 75 micrometers, the thickness of the adhesive layer AD4may be about 15 micrometers, and the thickness of each of the heat dissipation member HD and the first and second adhesive members AM1and AM2may be about 60 micrometers, for example. However, each thickness should not be limited to the above values.

FIGS.7and8are cross-sectional views respectively showing embodiments of lower modules UM1aand UM1baccording to the invention.FIG.9is a cross-sectional view showing an embodiment of a display device DD according to the invention.FIG.10is a graph showing variations in a degree of bending deformation of a display device (hereinafter, also referred to as bending deformation degree) and a curvature value in a bending area as a function of a distance at one side of the adhesive member (hereinafter, also referred to as one side distance of the adhesive member).

Referring toFIG.7, a support member SP1of the lower module UM1amay include an impact absorbing portion CL and support portions SL1and SL2. The impact absorbing portion CL may be disposed on the support portions SL1and SL2.

The support portions SL1and SL2included in the support member SP1may prevent or reduce the bending deformation of the display module DM due to external force. That is, although the external force is applied to the support portions SL1and SL2, the display module DM may maintain a relatively flat state.

The support member SP1may include a first support portion SL1that overlaps the first non-folding area NFA1and a second support portion SL2that overlaps the second non-folding area NFA2. Each of the first and second support portions SL1and SL2may overlap a portion of the folding area FA.

The first support portion SL1may be spaced apart from the second support portion SL2in the second directional axis DR2. The first and second support portions SL1and SL2may be spaced apart from each other in the folding area FA. As the first support portion SL1is spaced apart from the second support portion SL2in the folding area FA, when the display device DD is folded, the first and second support portions SL1and SL2are less affected by stress or tensile force caused by folding the display device DD. Accordingly, the bending deformation degree may be reduced.

Each of the first support portion SL1and the second support portion SL2may be a metal plate. In an embodiment, each of the first support portion SL1and the second support portion SL2may include stainless steel, aluminum, or alloys thereof, for example.

A heat dissipation member HD may include a first heat dissipation portion HD1and a second heat dissipation portion HD2. The first heat dissipation portion HD1may be disposed under the first support portion SL1and may overlap the first non-folding area NFA1. The second heat dissipation portion HD2may be disposed under the second support portion SL2and may overlap the second non-folding area NFA2.

A first opening OP1may be defined through the first heat dissipation portion HD1, and a second opening OP2may be defined through the second heat dissipation portion HD2. A first adhesive member AM1may be disposed in the first opening OP1, and a second adhesive member AM2may be disposed in the second opening OP2.

The first adhesive member AM1and the second adhesive member AM2may be spaced apart from a folding axis FX by a first distance D1and a second distance D2, respectively. Details on the first and second distances D1and D2described with reference toFIGS.5and6may be applied to the first and second distances D1and D2shown inFIG.7.

The first heat dissipation portion HD1may be in contact with the first support portion SL1by an adhesive layer AD4-1, and the second heat dissipation portion HD2may be in contact with the second support portion SL2by an adhesive layer AD4-2. However, the invention is not limited thereto, and the adhesive layers AD4-1and AD4-2may be omitted.

A cover member CV may include a first cover portion CV1disposed under the first support portion SL1and a second cover portion CV2disposed under the second support portion SL2. The first cover portion CV1may cover a lower portion of the first support portion SL1, and the second cover portion CV2may cover a lower portion of the second support portion SL2. Each of the first and second cover portions CV1and CV2may include a metal or plastic material.

The support member SP1may include the impact absorbing portion CL. The impact absorbing portion CL may be disposed on the first and second support portions SL1and SL2. The impact absorbing portion CL may absorb impacts applied to the support member SP1. The impact absorbing portion CL may be a cushion layer. In an embodiment, the impact absorbing portion CL may include a sponge, a foam, or a urethane resin, for example. The impact absorbing portion CL may be in contact with the support portions SL1and SL2by an adhesive layer AD3. However, the invention is not limited thereto, and the adhesive layer AD3may be omitted.

The adhesive layers AD3, AD4-1and AD4-2may include an acrylic-base resin or a silicon-based resin. In an embodiment, the adhesive layers AD3, AD4-1and AD4-2may be a PSA, an OCA, or an OCR, for example.

Referring toFIG.8, a support member SP2of the lower module UM1bmay include an impact absorbing portion CL and a support portion SLa. Details on the impact absorbing portion CL, the adhesive layers AD3, AD4-1, and AD4-2, and the first and second adhesive members AM1and AM2shown inFIG.7may be applied to the impact absorbing portion CL, adhesive layers AD3, AD4-1, and AD4-2, and adhesive members AM1and AM2shown inFIG.8,

The support portion SLa included in the support member SP2may prevent or reduce the bending deformation of the display module DM due to external force. That is, although the external force is applied to the support portion SLa, the display module DM may maintain a relatively flat state.

A plurality of openings OP may be defined through the support portion SLa in the folding area FA. The openings OP may be spaced apart from each other at a predetermined interval. Accordingly, the support portion SLa may have a folding pattern in the folding area FA. The support portion SLa may be flexibly folded by the openings OP The support portion SLa may be, but not limited to, a metal plate. In an embodiment, the support portion SLa may include stainless steel, aluminum, or alloys thereof, for example.

The support portion SLa may further include an adhesive AD5and a capping layer CA in the folding area FA. The adhesive AD5may be disposed between the capping layer CA and the support portion SLa to attach the capping layer CA to a rear surface of the support portion SLa.

The capping layer CA may cover the openings OP defined through the support portion SLa. The capping layer CA may prevent a foreign substance from entering the openings OP.

A heat dissipation member HD may include a first heat dissipation portion HD1and a second heat dissipation portion HD2. Each of the first heat dissipation portion HD1and the second heat dissipation portion HD2may be disposed under the support portion SLa. The first heat dissipation portion HD1may overlap a first non-folding area NFA1, and the second heat dissipation portion HD2may overlap a second non-folding area NFA2. Each of the first heat dissipation portion HD1and the second heat dissipation portion HD2may not overlap the folding area FA, however, it should not be limited thereto or thereby.

A first opening OP1may be defined through the first heat dissipation portion HD1, and a second opening OP2may be defined through the second heat dissipation portion HD2. A first adhesive member AM1may be disposed in the first opening OP1, and a second adhesive member AM2may be disposed in the second opening OP2.

A cover member CV may include a first cover portion CV1that at least partially overlaps the first non-folding area NFA1and a second cover portion CV2that at least partially overlaps the second non-folding area NFA2. The first cover portion CV1may cover the first non-folding area NFA1of the support portion SLa and a portion of the folding area FA, and the second cover portion CV2may cover the second non-folding area NFA2of the support portion SLa and a portion of the folding area FA. Each of the first and second cover portions CV1and CV2may include a metal or plastic material.

Referring toFIG.9, the display device DD may include a display module DM and a lower module UM1b. The display module DM may include a display panel DP (refer toFIG.4) in which a first non-folding area NFA1, a folding area FA, and a second non-folding area NFA2are defined. The lower module UM1bmay include a support member SP2including an impact absorbing portion CL and a support portion SLa, a plurality of heat dissipation portions HD1and HD2, and a plurality of cover portions CV1and CV2. Hereinafter, descriptions of the same components included in the display device as those ofFIGS.3to8will be omitted, and inFIG.9, the following description focuses on differences between the current and previous embodiments.

Each of the first heat dissipation portion HD1and the second heat dissipation portion HD2may include a heat dissipator GS, and a first gap adhesive (e.g., first gap tape) GL1disposed adjacent to the heat dissipator GS, and a second gap adhesive (e.g., second gap tape) GL2disposed under the heat dissipator GS. The first gap adhesive GL1of the first heat dissipation portion HD1may be disposed between adhesive layer AD4-1and the second gap adhesive GL2disposed on the first cover portion CV1. The first gap adhesive GL1of the second heat dissipation portion HD2may be disposed between adhesive layer AD4-2and the second gap adhesive GL2disposed on the second cover portion CV2.

Each of the first gap adhesive GL1and the second gap adhesive GL2may include a plurality of layers. The first and second gap adhesives GL1and GL2may include a base, an upper adhesive disposed on an upper surface of the base, and a lower adhesive disposed on a lower surface of the base.

The first gap adhesive GL1may be disposed around the heat dissipator GS. The heat dissipator GS may be sealed by the adhesive layers AD4-1and AD4-2disposed on the heat dissipator GS, the first gap adhesive GL1, and the second gap adhesive GL2.

The heat dissipator GS may include graphite or graphitized polymer film. In an embodiment, the polymer film may be a polyimide film, for example, however, it should not be limited thereto or thereby.

The display device DD may have the bending deformation degree and the curvature value of the bending area, which are varied depending on the first and second distances D1and D2corresponding to the one side distance of adhesive members AM1and AM2.FIG.10shows a relation between the one side distance of the first and second adhesive members AM1and AM2, the bending deformation degree, and the curvature value.

The one side distance of the first and second adhesive members AM1and AM2(refer toFIG.9) ofFIG.10may correspond to the first distance D1or the second distance D2ofFIG.9. The first distance D1may be a minimum distance between the folding axis FX and the first adhesive member AM1spaced apart from the folding axis FX in the second directional axis DR2. The second distance D2may be a minimum distance between the folding axis FX and the second adhesive member AM2spaced apart from the folding axis FX in the second directional axis DR2.

Referring toFIG.10, as the one side distance of the first and second adhesive members AM1and AM2(refer toFIG.9) increases, the bending deformation degree increases, and the curvature of the bending area decreases. When the one side distance is equal to or greater than about 40 millimeters (mm), the bending deformation degree steeply increases, and when the one side distance is equal to or smaller than about 10 mm, the curvature steeply increases. When the bending deformation degree and the curvature increase, the degree of visibility of the bending deformation from the outside increases. Accordingly, it is necessary to adjust the one side distance of the first and second adhesive members AM1and AM2to an appropriate range.

The first and second adhesive members AM1and AM2may not overlap the folding area FA. This is because it is difficult to effectively prevent the display device DD from being deformed to be upwardly convex at a boundary between the folding area FA and the first and second non-folding areas NFA1and NFA2when the first and second adhesive members AM1and AM2overlap the folding area FA.

When the first and second adhesive members AM1and AM2are distant from the folding area FA and are arranged close to an end of the display device DD, the bending deformation degree may significantly increase. Accordingly, as described with reference toFIG.5, a maximum value of the first distance D1may correspond to a minimum distance D3between the folding axis FX and a center C1of the first non-folding area NFA1, and a maximum value of the second distance D2may correspond to a minimum distance D4between the folding axis FX and a center C2of the second non-folding area NFA2.

In an embodiment, each of the first and second distances D1and D2may be equal to or greater than about 15 mm and equal to or smaller than about 35 mm. When each of the first and second distances D1and D2is smaller than about 15 mm, the curvature value of the bending area significantly increases, and thus, the bending deformation of the folding area FA may be easily viewed. When each of the first and second distances D1and D2is greater than about 35 mm, the bending deformation degree significantly increases, and thus, the difference in the degree of protrusion and depression of the bending portion corresponding to the folding area FA of the display device may increase, so that the bending deformation may be easily viewed.

The distance between the first adhesive member AM1and the second adhesive member AM2, which corresponds to a sum of the one side distance of the first adhesive member AM1and the one side distance of the second adhesive member AM2, may affect the bending deformation. The distance between the first adhesive member AM1and the second adhesive member AM2may be the sum of the first distance D1and the second distance D2.

A maximum value of the distance between the first adhesive member AM1and the second adhesive member AM2may be the minimum distance between the center C1of the first non-folding area NFA1and the center C2of the second non-folding area NFA2. The distance between the first adhesive member AM1and the second adhesive member AM2may be equal to or greater than about 35 mm and equal to or smaller than about 65 mm, and the phenomenon in which the bending deformation is viewed may be effectively improved in the above range.

Table 1 below shows the deformation degree (refer toFIG.6) and the curvature value of the display device DD shown inFIG.9according to the one side distance of the first and second adhesive members AM1and AM2. The comparative example corresponds to a display device in which the first and second adhesive members AM1and AM2are not included.

TABLE 1One side distance ofadhesive members (mm)Comparative81012152030exampleDeformation27.627.828.029.831.534.7125.9degree (μm)Curvature10.59.18.06.25.04.41.6(m−1)

According to Table 1, as the one side distance of the adhesive member increases, the deformation degree increases, but the curvature decreases. The expression “the degree deformation increases” means that a difference between the convex upward portion and the convex downward portion becomes larger. The expression “the curvature decreases” means that the bending deformation occurs with more gentle slope.

The deformation degree of the display device of the comparative example is about 125.9 micrometers, and the deformation degree of the display device of the comparative example is substantially greater than that of the display device with the adhesive members. Although the curvature is about 1.6 m−1, which is relatively small, the deformation degree is substantially large, so that the bending deformation of the display device may be easily viewed, and reliability of the display device may be lowered.

When the one side distance of the adhesive members decreases, the deformation degree decreases. However, since the curvature increases, the bending deformation of the display device may be easily viewed. When the one side distance of the adhesive members significantly increases, the deformation degree increases, and thus, the bending deformation of the display device may be easily viewed. Accordingly, the adhesive members is desired to have the one side distance in the appropriate range.

Referring to Table 1, when the one side distance of the adhesive members is equal to or greater than about 15 mm and equal to or smaller than about 30 mm, the deformation degree significantly decreases when compared with that of the comparative example, and the curvature does not increase significantly. Accordingly, the bending deformation of the display device may be effectively prevented from being viewed from the outside.

FIGS.11A to11Dare plan views showing embodiments of heat dissipation members HD-1, HD-2, HD-3, and HD-4according to the invention.FIGS.11A to11Dshow the plan views in the plane defined by the first directional axis DR1and the second directional axis DR2. Each ofFIGS.11A to11Dshows an area overlapping the folding area FA, the first non-folding area NFA1, and the second non-folding area NFA2.

Referring toFIGS.11A to11D, the first adhesive member AM1may be spaced apart from the folding axis FX by a first distance D1, and the second adhesive member AM2may be spaced apart from the folding axis FX by a second distance D2. Descriptions on the first and second distances D1and D2with reference toFIGS.5to10may be applied to the first and second distances D1and D2ofFIGS.11A to11D.

The first and second openings OP1and OP2may be defined through the heat dissipation members HD-1, HD-2, HD-3, and HD-4to respectively overlap the first and second non-folding areas NFA1and NFA2.

Referring toFIG.11A, the openings OP1and OP2defined through the heat dissipation member HD-1may have a quadrangular shape. In an embodiment, the openings OP1and OP2defined through the heat dissipation member HD-1may have a rectangular shape extending in the first directional axis DR1substantially parallel to the folding axis FX, for example. The openings OP1and OP2defined through the heat dissipation member HD-1may have the rectangular shape with long sides extending in the first directional axis DR1and short sides extending in the second directional axis DR2.

The first and second adhesive members AM1and AM2disposed in the openings OP1and OP2may fill at least a portion of the openings OP1and OP2. As the embodiment shown inFIG.11A, the first and second adhesive members AM1and AM2may fill an entire space of the openings OP1and OP2, respectively, however, they should not be limited thereto or thereby. That is, the first and second adhesive members AM1and AM2may fill only a portion of the openings OP1and OP2, respectively.

Referring toFIG.11B, the first and second openings OP1and OP2defined through the heat dissipation member HD-2may extend in the first directional axis DR1substantially parallel to the folding axis FX to both ends of the heat dissipation member HD-2, which are substantially parallel to the second directional axis DR2. Accordingly, an area of the heat dissipation member HD-2, which overlaps the first non-folding area NFA1, may be divided into two areas spaced apart from each other by the first opening OP1. In addition, an area of the heat dissipation member HD-2, which overlaps the second non-folding area NFA2, may be divided into two areas spaced apart from each other by the second opening OP2.

The first and second adhesive members AM1and AM2disposed in the openings OP1and OP2may fill at least a portion of the openings OP1and OP2. As the embodiment shown inFIG.11B, the first and second adhesive members AM1and AM2may fill an entire space of the openings OP1and OP2, respectively. In an embodiment, the first and second adhesive members AM1and AM2may be filled to the both ends of the heat dissipation member HD-2, which are substantially parallel to the second directional axis DR2, for example, however, they should not be limited thereto or thereby. That is, the first and second adhesive members AM1and AM2may fill only a portion of the openings OP1and OP2, respectively.

Referring toFIGS.11A and11B, each of the first and second adhesive members AM1and AM2may have a bar shape. The first and second adhesive members AM1and AM2having the bar shape may be disposed such that long sides of the bar shape are substantially parallel to the first directional axis DR1.

The first adhesive member AM1may have a first width H1in the second directional axis DR2, and the second adhesive member AM2may have a second width H2in the second directional axis DR2. The first width H1may be the same as or different from the second width H2. Each of the first and second widths H1and H2may be in a range from about 5 mm to about 10 mm, however, the first and second widths H1and H2should not be limited thereto or thereby.

Referring toFIG.11C, each of the first and second openings OP1and OP2defined through the heat dissipation member HD-3may be provided in plural. Each of the first openings OP1and the second openings OP2may be arranged in the first directional axis DR1substantially parallel to the folding axis FX.

The first openings OP1may be spaced apart from each other at regular intervals, and the second openings OP2may be spaced apart from each other at regular intervals. However, the first openings OP1and the second openings OP2do not necessarily have to be spaced apart at regular intervals from each other. In another embodiment, the first openings OP1may be spaced apart from each other at different intervals, and the second openings OP2may be spaced apart from each other at different intervals.

The first openings OP1may have the same shape as each other or may have different shapes from each other. The second openings OP2may have the same shape as each other or may have different shapes from each other. As the embodiment shown inFIG.11C, the first openings OP1and the second openings OP2may have substantially the same shape as each other.

Each of the first openings OP1and the second openings OP2may have a quadrangular shape, e.g., a square shape, in a plan view. However, the shape of the first openings OP1and the second openings OP2should not be limited thereto or thereby.

The first adhesive member AM1may include a plurality of first adhesive portions AM1-1spaced apart from each other. The second adhesive member AM2may include a plurality of second adhesive portions AM2-1spaced apart from each other. The first adhesive portions AM1-1may be respectively disposed in the first openings OP1. The second adhesive portions AM2-1may be respectively disposed in the second openings OP2. The first adhesive portions AM1-1may be disposed in all or some of the first openings OP1. The second adhesive portions AM2-1may be disposed in all or some of the second openings OP2.

Each first adhesive portion AM1-1may have the same shape as or a different shape from that of a corresponding first opening in which the first adhesive portion AM1-1is disposed among the first openings OP1. Each second adhesive portion AM2-1may have the same shape as or a different shape from that of a corresponding second opening in which the second adhesive portion AM2-1is disposed among the second openings OP2. Each of the first adhesive portions AM1-1and each of the second adhesive portions AM2-1may have a quadrangular shape, e.g., a square shape, in a plan view. However, the shape of the first adhesive portions AM1-1and the second adhesive portions AM2-1should not be limited thereto or thereby.

Referring toFIG.11D, the first and second openings OP1and OP2defined through the heat dissipation member HD-4may extend in the first directional axis DR1substantially parallel to the folding axis FX to both ends of the heat dissipation member HD-4, which are substantially parallel to the second directional axis DR2.

The first adhesive member AM1may include a plurality of first adhesive portions AM1-1spaced apart from each other. The second adhesive member AM2may include a plurality of second adhesive portions AM2-1spaced apart from each other. The first adhesive portions AM1-1may be arranged in some portions of the first openings OPT. The second adhesive portions AM2-1may be arranged in some portions of the second openings OP2.

The first adhesive portions AM1-1may be arranged in the first directional axis DR1substantially parallel to the folding axis FX. The second adhesive portions AM2-1may be arranged in the first directional axis DR1substantially parallel to the folding axis FX.

The first adhesive portions AM1-1may be spaced apart from each other at regular intervals, and the second adhesive portions AM2-1may be spaced apart from each other at regular intervals. However, it is not necessary that the first adhesive portions AM1-1are arranged at regular intervals and the second adhesive portions AM2-1are arranged at regular intervals. In another embodiment, the first adhesive portions AM1-1may be spaced apart from each other at different intervals, and the second adhesive portions AM2-1may be spaced apart from each other at different intervals.

The first adhesive portions AM1-1may have the same shape as each other or may have different shapes from each other. The second adhesive portions AM2-1may have the same shape as each other or may have different shapes from each other. Each of the first adhesive portions AM1-1and each of the second adhesive portions AM2-1may have a quadrangular shape, e.g., a square shape, in a plan view. As the embodiment shown in FIG.11D, each of the first adhesive portions AM1-1and each of the second adhesive portions AM2-1may have the square shape.

Referring toFIGS.11C and11D, each first adhesive portion AM1-1may have the square shape with one side length that is a first length L1, and each second adhesive portion AM2-1may have the square shape with one side length that is a second length L2. The first length L1may be the same as or different from the second length L2. Each of the first length L1and the second length L2may be in a range from about 5 mm to about 10 mm. However, the first and second lengths L1and L2should not be limited thereto or thereby.

The first adhesive member AM1and the second adhesive member AM2may be symmetrical with each other with respect to the folding axis FX. The first adhesive portions AM1-1included in the first adhesive member AM1and the second adhesive portions AM2-1included in the second adhesive member AM2may be symmetrical with each other with respect to the folding axis FX.

Although the first and second openings OP1and OP2and the first and second adhesive members AM1and AM2defined in various forms have been described with reference toFIGS.11A to11D, the shapes of the first and second openings OP1and OP2and the first and second adhesive members AM1and AM2should not be limited thereto or thereby.

Descriptions on the heat dissipation members HD-1, HD-2, HD-3, and HD-4with reference toFIG.11A to11Dmay be applied to the impact absorbing member SA (refer toFIG.14). Descriptions described with reference toFIGS.11A to11Dmay be applied to the first adhesive member AM1disposed in the first opening OP1and the second adhesive member AM2disposed in the second opening OP2, which are defined through the impact absorbing member SA (refer toFIG.14).

FIG.12is a cross-sectional view showing an embodiment of a display device DD-2according to the invention, andFIGS.13and14are cross-sectional views respectively showing embodiments of lower modules UM2aand UM2baccording to the invention.

Referring toFIG.12, the display device DD-2may include a display panel DP The display panel DP may include a folding area FA folded about a folding axis FX extending in the first directional axis DR1and first and second non-folding areas NFA1and NFA2spaced apart from each other with the folding area FA interposed therebetween in the second directional axis DR2.

The display device DD-2may include a cover member CV disposed under the display panel DP to cover the display panel DP. The cover member CV may include a metal or plastic material.

A support member SP may be disposed under the display panel DP The support member SP may prevent the bending deformation of the display panel DP due to a folding operation or external force. Although not shown inFIG.12, the display device DD-2may further include a protective film (not shown) disposed between the display panel DP and the support member SP.

A lower module UM2of the display device DD-2may include first and second adhesive members AM1and AM2disposed between the support member SP and the cover member CV. The first adhesive member AM1may overlap the first non-folding area NFA1. The second adhesive member AM2may overlap the second non-folding area NFA2. The first and second adhesive members AM1and AM2included in the display device DD-2may reduce a bending deformation degree of the display device DD-2.

The first adhesive member AM1may be spaced apart from the second adhesive member AM2by a first gap G1in the second directional axis DR2. A degree in reduction of the bending deformation and a curvature value of a bending portion may be affected by the first gap G1. As the first gap G1increases, the degree in reduction of the bending deformation may decrease. Accordingly, a maximum value of the first gap G1may correspond to a minimum distance G2between a center C1of the first non-folding area NFA1and a center C2of the second non-folding area NFA2.

The display device DD-2may further include a step-difference compensation member SM. The step-difference compensation member SM may include a step-difference compensation film or a step-difference compensation adhesive. The step-difference compensation member SM may be disposed between the support member SP and the cover member CV. The step-difference compensation member SM may be spaced apart from the first and second adhesive members AM1and AM2and may be disposed on an upper surface of the cover member CV to correspond to an edge of the cover member CV.

Referring toFIGS.13and14, the lower modules UM2aand UM2bmay further include the impact absorbing member SA. The impact absorbing member SA may absorb impacts applied to the display device DD-2. The impact absorbing member SA may include the sponge, the foam, or the urethane resin.

Referring toFIG.13, the impact absorbing member SA may be disposed under the support member SP. The impact absorbing member SA may be disposed between the support member SP and the first and second adhesive members AM1and AM2. That is, the first and second adhesive members AM1and AM2disposed on the same layer may be disposed under the impact absorbing member SA.

Referring toFIG.14, first and second openings OP1and OP2may be defined through the impact absorbing member SA. The first opening OP1may be defined to overlap the first non-folding area NFA1. The second opening OP2may be defined to overlap the second non-folding area NFA2. The first adhesive member AM1may be disposed in the first opening OP1, and the second adhesive member AM2may be disposed in the second opening OP2.

The support member SP may include a support portion and an impact absorbing portion disposed on the support portion. Although not shown inFIG.14, The support portion may include the first support portion SL1and the second support portion SL2spaced apart from the first support portion SL1as the lower module UM1ashown inFIG.7. The support portion may be the support portion SLa through which the openings OP are defined in an area overlapping the folding area FA as the lower module UM1bshown inFIG.8.

The cover member CV may include a first cover portion CV1overlapping at least a portion of the first non-folding area NFA1and a second cover portion CV2overlapping at least a portion of the second non-folding area NFA2. The first cover portion CV1may cover the first non-folding area NFA1and a portion of the folding are a FA of the impact absorbing member SA, and the second cover portion CV2may cover the second non-folding area NFA2and a portion of the folding area FA of the impact absorbing member SA.

Although not shown inFIG.14, the impact absorbing member SA may include a plurality of impact absorbing portions. One impact absorbing portions may be disposed under the support member SP and may overlap the first non-folding area NFA1. The other impact absorbing portions may be disposed under the support member SP and may overlap the second non-folding area NFA2. The impact absorbing portions may be spaced apart from each other in the folding area FA.

Each of the first and second adhesive members AM1and AM2may include an acrylic-based resin or a silicon-based resin. In an embodiment, each of the first and second adhesive members AM1and AM2may include a PSA, an OCA, or an OCR, for example.

Although not shown inFIG.14, similar to the embodiments shown inFIGS.11C and11D, the first adhesive member AM1may include a plurality of first adhesive portions AM1-1, and the second adhesive member AM2may include a plurality of second adhesive portions AM2-1. The first adhesive portions AM1-1may be disposed under the impact absorbing member SA or may be disposed in the first opening OP1defined through the impact absorbing member SA. The second adhesive portions AM2-1may be disposed under the impact absorbing member SA or may be disposed in the second opening OP2defined through the impact absorbing member SA.

The lower modules UM2aand UM2bmay further include an adhesive layer AD4disposed between the impact absorbing member SA and the support member SP. The adhesive layer AD4may attach the impact absorbing member SA to the support member SP.

When compared with the display device that does not include the first and second adhesive members AM1and AM2, the bending deformation degree of the display device in the embodiment may be reduced. However, the curvature of the bending area may increase depending on positions of the first and second adhesive members AM1and AM2included in the display device DD-2. Accordingly, the bending deformation degree may significantly decrease and the curvature of the bending area may not remarkably increase by adjusting the first gap G1. The first gap G1may be equal to or greater than about 35 mm and equal to or smaller than about 65 mm.

The display device in the embodiment may include the adhesive members disposed under the support member and spaced apart from each other, and thus, the bending deformation degree of the bending area of the display device may decrease. The bending deformation degree of the bending area and the curvature of the bending area may be controlled by adjusting the intervals between the adhesive members, and thus, the phenomenon in which the bending deformation is viewed from the outside of the display device may be improved.

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

Therefore, the disclosed subject matter should not be limited to any single embodiment described herein, and the scope of the invention shall be determined according to the attached claims.