Display device

Abstract

A display device is provided. The display device includes a display module including a first non-folded area, a second non-folded area, and a folding area disposed between the first folding area and the second non-folded area, a first body disposed on the first non-folded area, a second body disposed on the second non-folded area, a plurality of rotation pin units connected to the first body and the second body to provide a dual-axis rotation axis superimposed with the folding area to the first body and the second body, and a plurality of gears rotated in cooperation with the rotation pin units. The plurality of gears is disposed on the rotation pin units.

Description

[0001] This application claims priority to Korean Patent Application No. 10-2020-0107981, filed on August 26, 2020, and Korean Patent Application No. 10-2020-0146722, filed on November 5, 2020, and all benefits accruing therefrom, the contents of which are incorporated herein in their entirety by reference. TECHNICAL FIELD

[0002] Embodiments of the present application relate to a display device, and more particularly, to a foldable display device. BACKGROUND

[0003] Electronic products such as smartphones, digital cameras, laptop computers, navigation systems, and smart TVs include display devices for displaying images to users. The display devices generate images and provide the images to users through screens.

[0004] With the development of display technology, various display devices are being recently developed. For example, flexible display devices that can be bendably deformed, foldable, or rollable are being developed. Since the shape of the flexible display device can be variously changed, the flexible display device has advantages of portability and user convenience.

[0005] A foldable display device, which is one of the flexible display devices, includes a display module that can be folded along a folding axis extending in a predetermined direction. The display module can be folded or unfolded along the folding axis. The display module includes a folding area that can be folded by a folding operation. SUMMARY

[0006] Embodiments of the present application provide a display device including a hinge for folding a display module into a dumbbell shape.

[0007] In an embodiment of the present application, a display device includes a display module including a first non-folding area, a second non-folding area, and a folding area disposed between the first non-folding area and the second non-folding area; a first body disposed on the first non-folding area; a second body disposed on the second non-folding area; a plurality of rotation pin units connected to the first body and the second body to provide the first body and the second body with a dual-axis rotation axis superimposed with the folding area; and a plurality of gears that rotate in cooperation with the plurality of rotation pin units. The plurality of gears are disposed on the plurality of rotation pin units.

[0008] In an embodiment of the application, a display device can include a display module including a first non-folded area, a second non-folded area, and a folded area disposed between the first non-folded area and the second non-folded area; a first body disposed on the first non-folded area; a second body disposed on the second non-folded area; a hinge connected to the first body and the second body to provide a dual-axis rotation axis to the first body and the second body; a first wing plate rotatably coupled to a portion of the first body adjacent to a side of the first body facing the second body; and a second wing plate rotatably coupled to a portion of the second body adjacent to a side of the second body facing the first body. Surfaces of the first body and the first wing plate facing the display module adjacent to each other and surfaces of the second body and the second wing plate facing the display module adjacent to each other can have curved surfaces.

[0009] In an embodiment of the application, a display device can include a display module; a first body disposed on the display module; a second body disposed on the display module and spaced apart from the first body; a plurality of rotation pin units providing a dual-axis rotation axis to the first body and the second body; a plurality of bracket bodies connecting the plurality of rotation pin units to the first body and the second body; a first frame to which the plurality of rotation pin units are coupled; a plurality of gears disposed on the plurality of rotation pin units, rotating in cooperation with the plurality of rotation pin units, and coupled to the first frame; and a plurality of bracket cams including sides coupled to some gears of the plurality of gears. When the display module is folded, opposite sides of the plurality of bracket cams move along guide grooves defined in the bracket bodies. BRIEF DESCRIPTION OF DRAWINGS

[0010] The embodiments will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

[0011] Figure 1 is a perspective view illustrating an embodiment of a display device according to the present application.

[0012] Figure 2 is a perspective view illustrating a folded state of the display device of Figure 1

[0013] Figure 3 is a plan view of the display device of Figure 1

[0014] Figure 4 is a schematic cross-sectional view of the display device of Figure 1

[0015] Figure 5 is a cross-sectional view of a display panel of Figure 4 ​​​​

[0016] Figure 6 is a plan view showing a detailed structure of the display device of Figure 1 .

[0017] Figure 7 is an exploded perspective view of the display device of Figure 6 .

[0018] Figure 8 is a plan view of the folding apparatus of Figure 7 .

[0019] Figure 9 is an exploded perspective view of the folding apparatus of Figure 8 .

[0020] Figure 10 is an exploded perspective view of the first hinge of Figure 9 .

[0021] Figure 11 is a front view of the first frame of Figure 10 in a first direction.

[0022] Figure 12 is a perspective view showing an internal structure of the second frame of Figure 10 .

[0023] Figure 13 is an exploded perspective view of the torque control unit of Figure 10 .

[0024] Figure 14 is a diagram showing a structure in which the first hinge of Figure 9 and Figure 10 is coupled to the first body and the second body.

[0025] Figure 15 is a diagram showing components provided in the first frame and the second frame of Figure 14 .

[0026] Figure 16A and Figure 16B are perspective views showing operations of the first rotation cam and the first movement cam shown in Figure 15 .

[0027] Figure 17A is a perspective view showing an unfolded state of the folding apparatus of Figure 8 .

[0028] Figure 17B is a perspective view showing a folded state of the folding apparatus of Figure 17A .

[0029] Figure 18A is a sectional view taken along line I-I' of Figure 14 .

[0030] Figure 18B and Figure 18C is a cross-sectional view showing a folding operation of the folding apparatus of Figure 18A

[0031] Figure 19A is a cross-sectional view taken along line II-II' of Figure 14

[0032] Figure 19B and Figure 19C is a cross-sectional view showing a folding operation of the folding apparatus of Figure 19A

[0033] Figure 20 is an enlarged cross-sectional view of a display module of Figure 19C

[0034] Figure 21 is an enlarged cross-sectional view of a first area Al of Figure 19C

[0035] Figure 22 is an enlarged cross-sectional view showing an unfolded state of a second reverse curvature portion of Figure 21

[0036] Figure 23 is a cross-sectional view taken along line III-III' of Figure 14

[0037] Figure 24 is an enlarged cross-sectional view showing a folded state of a second reverse curvature portion of Figure 23

[0038] Figure 25 is a diagram showing an embodiment of a folding apparatus according to the present invention.

[0039] Figure 26A is a cross-sectional view taken along line IV-IV' of Figure 25

[0040] Figure 26B to Figure 26E is a cross-sectional view showing a folding operation of the folding apparatus of Figure 26A

[0041] ​​​​​​​​​​It should be noted that the drawings are intended to show the general characteristics of methods, structures and / or materials used in the predetermined embodiments and to supplement the written description provided below. However, the drawings are not drawn to scale and can not accurately reflect the precise structural or performance characteristics of any given embodiment, and should not be interpreted as limiting or restricting the scope or nature of the values or properties encompassed by the embodiments. In the embodiments, the relative thicknesses and positioning of the microparticles, layers, regions and / or structural elements can be reduced or exaggerated for clarity. The use of similar or identical reference numerals in various drawings is intended to indicate the presence of similar or identical elements or features. DETAILED DESCRIPTION

[0042] Embodiments of the application will now be described more fully with reference to the accompanying drawings, in which embodiments are shown. The application may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the inventive concept to those skilled in the art. In the drawings, the thicknesses of layers and regions are exaggerated for clarity. Like reference numerals in the various drawings indicate like elements, and thus their description will be omitted.

[0043] It will be understood that when an element is referred to as being "connected" or "coupled" to another element, it can be directly connected or coupled to the other element or intervening elements can be present. In contrast, when an element is referred to as being "directly connected" or "directly coupled" to another element, there are no intervening elements present. Like reference numerals designate like elements throughout. As used herein the term "and / or" includes any and all combinations of one or more of the associated listed items. Other words used to describe the relationship between elements or layers should be interpreted in the same way (e.g., "between" versus "directly between", "adjacent" versus "directly adjacent", "on" versus "directly on").

[0044] It will be understood that, although the terms "first", "second", etc. can 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 element, component, 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 embodiments.

[0045] For purposes of the description hereinafter, spatial or directional terms, such as "below," "lower," "bottom," "above," "upper," and the like, can be used with reference to the illustrated embodiment. Unless otherwise specified, these terms are intended to encompass different orientations of the device in use or operation, in addition to the orientation depicted in the figures. In addition, terms such as "first," "second," and the like, can be used for purposes of description, but do not connote or require any ordinal nature or sequence. For example, a "first" element could occur before or after a "second" element. Terms such as "front," "back," "top," "bottom," and the like, can be used for purposes of description, but are not intended to be limiting. For example, a "front" surface can become a "back" surface when the device is reversed.

[0046] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of embodiments. 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. It will be further understood that the terms "comprises" and / or "comprising," 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.

[0047] Embodiments of the application are described herein with reference to schematic cross-sectional illustrations of idealized embodiments (and intermediate structures) of the application as examples. As such, variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and / or tolerances, are to be expected. Thus, embodiments of the application should not be construed as limited to the particular shapes of regions illustrated herein but are to include deviations in shapes that result, for example, from manufacturing. Thus, the regions illustrated in the figures are schematic in nature and their shapes are not intended to illustrate the precise shape of a region of a device and are not intended to limit the scope of the application.

[0048] "About" or "approximately," as used herein, includes the recited value and means within a reasonable range considering the measurement discussed and the error associated with measuring the particular quantity (i.e., 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.

[0049] 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 embodiments of the application belong. 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.

[0050] Figure 1 is a perspective view illustrating an embodiment of a display device according to the present invention. Figure 2 is a perspective view illustrating a folded state of the display device of Figure 1 .

[0051] Referring to Figure 1 , the display device DD in the embodiments of the invention can have a quadrangular (e.g., rectangular) shape including a long side parallel to a first direction DR1 and a short side parallel to a second direction DR2 intersecting the first direction DR1. However, the invention is not limited to this example, and in embodiments, the display device DD can have one of various shapes (e.g., a circular shape and a polygonal shape). The display device DD can be a flexible display device.

[0052] Hereinafter, a direction perpendicular to both the first direction DR1 and the second direction DR2 will also be referred to as a third direction DR3. Also, in the specification, the expression "in a plan view" will be used to describe a structure observed in the third direction DR3.

[0053] The display device DD can include a folding area FA and a plurality of non-folding areas NFA1 and NFA2. The non-folding areas NFA1 and NFA2 can include a first non-folding area NFA1 and a second non-folding area NFA2. The folding area FA can be disposed between the first non-folding area NFA1 and the second non-folding area NFA2. The folding area FA, the first non-folding area NFA1, and the second non-folding area NFA2 can be arranged in the second direction DR2.

[0054] Although one folding area FA and two non-folding areas NFA1 and NFA2 are illustrated, the number of folding areas FA and non-folding areas NFA1 and NFA2 is not limited to this example. In embodiments, for example, the display device DD can include two or more non-folding areas and a plurality of folding areas disposed between the non-folding areas.

[0055] A top surface of the display device DD can include a display surface DS, and the display surface DS can have a flat surface defined by the first direction DR1 and the second direction DR2. An image IM generated by the display device DD can be provided to a user through the display surface DS.

[0056] An edge portion EG can be disposed near or around the display surface DS. The edge portion EG can not be used for displaying an image. The edge portion EG can surround the display surface DS and define an edge of the display device DD printed with a predetermined color.

[0057] The display apparatus DD can include a plurality of sensors SN and at least one camera CM. The sensors SN and the camera CM can be disposed in a portion of the display surface DS adjacent to the edge portion EG. As Figure 3 The sensors SN and the camera CM can be disposed in the display area DA adjacent to the non-display area NDA, as shown in FIG. 1B. The sensors SN and the camera CM can be disposed in the first non-fold area NFA1 and the second non-fold area NFA2.

[0058] In an embodiment, the sensors SN can include optical proximity sensors, but the kind of the sensors SN is not limited thereto. The camera CM can obtain an image of an external object.

[0059] Referring to Figure 2 , the display apparatus DD can be a foldable display apparatus that can be folded or unfolded. In an embodiment, for example, when the display apparatus DD is folded, the folding area FA can be bent along a folding axis FX parallel to the first direction DR1. The folding axis FX can be defined as a long axis parallel to the long side of the display apparatus DD.

[0060] When the display apparatus DD is folded, the display apparatus DD can be folded in an inner folding manner in which the first non-fold area NFA1 and the second non-fold area NFA2 face each other and the display surface DS is not exposed to the outside.

[0061] Figure 3 is a plan view of the display apparatus of Figure 1 .

[0062] Referring to Figure 3 , the display apparatus DD can include a display panel DP, a scan driver SDV, a data driver DDV, and an emission driver EDV.

[0063] The display panel DP can include a first area AA1, a second area AA2, and a bending area BA between the first area AA1 and the second area AA2. The bending area BA can extend in the first direction DR1, and the first area AA1, the bending area BA, and the second area AA2 can be arranged in the second direction DR2.

[0064] The first area AA1 can include a display area DA and a non-display area NDA adjacent to the display area DA. The non-display area NDA can surround the display area DA. The display area DA can be an area for displaying an image IM, and the non-display area NDA can be an area not for displaying the image IM. The second area AA2 and the bending area BA can not be used for displaying the image IM.

[0065] The first area AA1 can include a first non-folded area NFA1, a second non-folded area NFA2, and a folded area FA between the first non-folded area NFA1 and the second non-folded area NFA2 in the second direction DR2.

[0066] The display panel DP can include a plurality of pixels PX, a plurality of scan lines SL1 to SLm, a plurality of data lines DL1 to DLn, a plurality of emission lines EL1 to ELm, a first control line CSL1 and a second control line CSL2, a power line PL, a connection line CNL, and a plurality of pads PD (also referred to as "bonding pads"). Here, m and n can be natural numbers greater than 1. The pixels PX can be disposed in the display area DA and can be connected to the scan lines SL1 to SLm, the data lines DL1 to DLn, and the emission lines EL1 to ELm.

[0067] The scan driver SDV and the emission driver EDV can be disposed in the non-display area NDA. The scan driver SDV and the emission driver EDV can be disposed in two areas of the non-display area NDA that are opposite each other in the first direction DR1 and disposed at two opposite sides of the first area AA1, respectively. The data driver DDV can be disposed in the second area AA2. The data driver DDV can be manufactured in the form of an integrated circuit ("IC") chip and can be disposed (e.g., mounted) in the second area AA2.

[0068] The scan lines SL1 to SLm can extend in the first direction DR1 and can be connected to the scan driver SDV. The data lines DL1 to DLn can extend in the second direction DR2 and can be connected to the data driver DDV via the bending area BA. The emission lines EL1 to ELm can extend in the first direction DR1 and can be connected to the emission driver EDV.

[0069] The power line PL can extend in the second direction DR2 and can be disposed in the non-display area NDA. The power line PL can be disposed between the display area DA and the emission driver EDV, but the invention is not limited to this example, and the power line PL can be disposed between the display area DA and the scan driver SDV.

[0070] The power line PL can extend into the second area AA2 through the bending area BA. In a plan view, the power line PL can extend toward a lower end of the second area AA2. The power line PL can be used to receive a driving voltage.

[0071] The connection line CNL can extend in the first direction DR1 and can be arranged in the second direction DR2. The connection line CNL can be connected to the power line PL and the pixel PX. A driving voltage can be applied to the pixel PX through the power line PL and the connection line CNL connected to the power line PL.

[0072] The first control line CSL1 can be connected to the scan driver SDV and can extend toward the lower end of the second area AA2 via the bending area BA. The second control line CSL2 can be connected to the emission driver EDV and can extend toward the lower end of the second area AA2 via the bending area BA. The data driver DDV can be disposed between the first control line CSL1 and the second control line CSL2.

[0073] In a plan view, the pad PD can be disposed adjacent to the lower end of the second area AA2. The data driver DDV, the power line PL, the first control line CSL1, and the second control line CSL2 can be connected to the pad PD.

[0074] The data lines DL1 to DLn can be connected to corresponding ones of the pads PD by the data driver DDV. In an embodiment, for example, the data lines DL1 to DLn can be connected to the data driver DDV, and the data driver DDV can be connected to the pads PD corresponding to the data lines DL1 to DLn, respectively.

[0075] Although not shown, a printed circuit board ("PCB") connected to the pads PD can be disposed. A timing controller and a voltage generator can be disposed on the PCB. The timing controller can be manufactured in the form of an IC chip and can be disposed (e.g., mounted) on the PCB. The timing controller and the voltage generator can be connected to the pads PD through the PCB.

[0076] The timing controller can control operations of the scan driver SDV, the data driver DDV, and the emission driver EDV. The timing controller can generate scan control signals, data control signals, and emission control signals in response to a control signal to be transmitted from the outside. The voltage generator can generate a driving voltage.

[0077] The scan control signals can be provided to the scan driver SDV through the first control line CSL1. The emission control signals can be provided to the emission driver EDV through the second control line CSL2. The data control signals can be provided to the data driver DDV. The timing controller can receive an image signal from the outside, can convert the image signal into a data format suitable for an interface specification required by the data driver DDV, and can provide the converted data to the data driver DDV.

[0078] The scan driver SDV can generate a plurality of scan signals in response to the scan control signals. The scan signals can be applied to the pixels PX through the scan lines SL1 to SLm. The scan signals can be sequentially applied to the pixels PX.

[0079] The data driver DDV can generate a plurality of data voltages corresponding to the image signal in response to a data control signal. The data voltages can be applied to the pixel PX through data lines DL1 to DLn. The emission driver EDV can generate a plurality of emission signals in response to an emission control signal. The emission signals can be applied to the pixel PX through emission lines EL1 to ELm.

[0080] The pixel PX can receive the data voltages in response to the scan signal. The pixel PX can emit light having a luminance level (gradation) corresponding to the data voltages in response to the emission signal, thereby displaying the image. The light emission time of the pixel PX can be controlled by the emission signal.

[0081] Although not shown, the bending area BA can be bent such that the second area AA2 is located below the first area AA1. Accordingly, the data driver DDV can be disposed below the first area AA1, and can be prevented from being recognized by the user.

[0082] Figure 4 is a schematic cross-sectional view of a display apparatus. Figure 1

[0083] Figure 4 A cross section of the display apparatus DD viewed in the first direction DR1 is shown, but for convenience of explanation, cross sections of the bending area BA and the second area AA2 are omitted in Figure 4

[0084] Referring to Figure 4 , the display apparatus DD can include a display module DM. The display module DM can be a flexible display module. The display apparatus DD can include a folding set for supporting and folding the display module DM. The structure of the folding set will be described in more detail with reference to Figure 7

[0085] Like the display apparatus DD, the display module DM can include a first non-folded area NFA1, a folding area FA, and a second non-folded area NFA2 arranged in a second direction DR2. The folding area FA can include a curved surface portion CSP, a first extension portion EX1 between the curved surface portion CSP and the first non-folded area NFA1, and a second extension portion EX2 between the curved surface portion CSP and the second non-folded area NFA2. The first extension portion EX1 and the second extension portion EX2 can extend from the curved surface portion CSP.

[0086] The display module DM can include a display panel DP, an anti-reflection layer RPL, a window WIN, a window protection layer WP, a panel protection layer PPL, a printing layer PIT, a support plate SPT, a buffer layer CUL, and a coating layer BCT.

[0087] ​​​In an embodiment, the display panel DP can be a light emitting type display panel. In an embodiment, the display panel DP can be, for example, an organic light emitting display panel or a quantum dot light emitting display panel. The light emitting layer of the organic light emitting display panel can include an organic light emitting material. The light emitting layer of the quantum dot light emitting display panel can include quantum dots and / or quantum rods. For the sake of brevity, the following description will refer to the example in which the display panel DP is an organic light emitting display panel.

[0088] The display panel DP can be a flexible display panel. Like the display module DM, the display panel DP can include the first non-folded area NFA1, the folded area FA, and the second non-folded area NFA2 arranged in the second direction DR2. Also, like the display module DM, the folded area FA of the display panel DP can include the curved surface portion CSP, the first extension portion EX1, and the second extension portion EX2. The display panel DP can include a plurality of pixels PX for displaying an image IM. The pixels PX can include organic light emitting devices.

[0089] The anti-reflection layer RPL can be disposed on the display panel DP. The anti-reflection layer RPL can be directly disposed on the top surface of the display panel DP. However, the invention is not limited to this example, and in an embodiment, the anti-reflection layer RPL can be manufactured as a separate panel, which can then be attached to the display panel DP by an adhesive layer.

[0090] The anti-reflection layer RPL can be defined as an anti-reflection film against external light. The anti-reflection layer RPL can reduce the reflectance of external light incident from the outside of the display device DD into the display panel DP.

[0091] When the display panel DP reflects external light like a mirror to a user, the user can recognize the external light. In an embodiment, the anti-reflection layer RPL can include a plurality of color filters for displaying the same color as that of the pixels PX, and in this case, the reflection phenomenon can be prevented.

[0092] The color filters can filter external light having a color different from that of the pixels PX. In this case, the external light is not recognized by the user. However, the invention is not limited to this example, and in an embodiment, the anti-reflection layer RPL can include a phase retarder and / or a polarizer for reducing the reflectance of external light.

[0093] The window WIN can be disposed on the anti-reflection layer RPL. The window WIN can protect the display panel DP and the anti-reflection layer RPL from external scratches. The window WIN can be optically transparent. The window WIN can be composed of or include glass. In an embodiment, for example, the window WIN can also be referred to as ultra-thin glass ("UTG"). However, the invention is not limited to this example, and in an embodiment, the window WIN can be composed of or include a synthetic resin film.

[0094] A window protection layer WP can be disposed on the window WIN. The window protection layer WP can protect the window WIN. In an embodiment, the window protection layer WP can be composed of or include at least one of a flexible plastic material, for example, polyimide ("PI") or polyethylene terephthalate ("PET"). Although not shown, a hard coating layer can be further disposed on the window protection layer WP. In an embodiment, at least one functional layer, for example, an anti-fingerprint layer or an anti-shatter layer, can be further disposed on the window protection layer WP.

[0095] A panel protection layer PPL can be disposed under the display panel DP. The panel protection layer PPL can protect the bottom of the display panel DP. The panel protection layer PPL can include a flexible plastic material. In an embodiment, for example, the panel protection layer PPL can be composed of or include PET.

[0096] A support plate SPT can be disposed under the panel protection layer PPL. The support plate SPT can be composed of or include a metal material, for example, stainless steel. In an embodiment, for example, the support plate SPT can be composed of or include STS 316, but the disclosure is not limited to this example, and the support plate SPT can be composed of or include at least one of various metal materials.

[0097] The support plate SPT can support the display panel DP. In an embodiment, for example, the support plate SPT can have a thickness equal to or less than about 40 micrometers (µm). Heat dissipation properties of the display device DD can be improved by the support plate SPT.

[0098] The support plate SPT can include a first support plate SPT1 disposed in the first non-fold area NFA1 and a second support plate SPT2 disposed in the second non-fold area NFA2. The support plate SPT can not be disposed in the fold area FA.

[0099] A cushion layer CUL can be disposed under the support plate SPT. The cushion layer CUL can absorb external impact applied on the lower portion of the display module DM, thereby protecting the display module DM. The cushion layer CUL can include a foam plate having elastic properties. The cushion layer CUL can be composed of or include at least one of foam, sponge, and polyurethane, for example, thermoplastic polyurethane, thermosetting polyurethane.

[0100] The buffer layer CUL can include a first buffer layer CUL1 disposed under the first support plate SPT1 and a second buffer layer CUL2 disposed under the second support plate SPT2. The buffer layer CUL can not be disposed in the folding area FA.

[0101] The coating layer BCT can be disposed between the panel protection layer PPL and the support plate SPT. The coating layer BCT can be coated on a top surface of the first support plate SPT1 and a top surface of the second support plate SPT2. The coating layer BCT can be composed of or include a black material. The coating layer BCT can prevent an element disposed under the coating layer BCT from being identified by a user.

[0102] The display device DD can include first to fourth adhesive layers AL1 to AL4. The first adhesive layer AL1 can be disposed between the window protection layer WP and the window WIN. The second adhesive layer AL2 can be disposed between the window WIN and the anti-reflection layer RPL.

[0103] The third adhesive layer AL3 can be disposed between the display panel DP and the panel protection layer PPL. The fourth adhesive layer AL4 can be disposed between the panel protection layer PPL and the support plate SPT. In detail, the fourth adhesive layer AL4 can be disposed between the panel protection layer PPL and the coating layer BCT.

[0104] The first to fourth adhesive layers AL1 to AL4 can include a transparent adhesive (e.g., a pressure sensitive adhesive ("PSA") or an optically clear adhesive ("OCA")).

[0105] The window protection layer WP and the window WIN can be attached to each other by the first adhesive layer AL1. The window WIN and the anti-reflection layer RPL can be attached to each other by the second adhesive layer AL2.

[0106] The display panel DP and the panel protection layer PPL can be attached to each other by the third adhesive layer AL3. The panel protection layer PPL and the support plate SPT can be attached to each other by the fourth adhesive layer AL4. In detail, the panel protection layer PPL can be attached to the coating layer BCT by the fourth adhesive layer AL4.

[0107] The printed layer PIT can be disposed on a bottom surface of the window protection layer WP. In a plan view, the printed layer PIT can overlap the non-display area NDA. The first adhesive layer AL1 can be disposed under the window protection layer WP to cover the printed layer PIT. In an embodiment, the printed layer PIT can be black, but the invention is not limited to this example. In an embodiment, for example, the printed layer PIT can have various colors.

[0108] In a plan view, the fourth adhesive layer AL4 can overlap the first non-folded area NFA1 and the second non-folded area NFA2. Also, in a plan view, the fourth adhesive layer AL4 can overlap the first extended portion EX1 and the second extended portion EX2, but can not overlap the curved surface portion CSP. Accordingly, the first support plate SPT1 and the second support plate SPT2 can be attached to the panel protection layer PPL in the first non-folded area NFA1 and the second non-folded area NFA2 and the first extended portion EX1 and the second extended portion EX2, but not in the curved surface portion CSP.

[0109] In an embodiment, for example, the window WIN can have a thickness greater than about 30 μm and less than or equal to about 80 μm when measured in the third direction DR3, and the window protection layer WP can have a thickness in a range of about 55 μm to about 100 μm. In an embodiment, for example, the support plate SPT can have a thickness in a range of about 80 μm to about 150 μm when measured in the third direction DR3.

[0110] The width of the window protection layer WP can be greater than the width of the window WIN when measured in the first direction DR1 and the second direction DR2. Here, the width of an element can mean a length measured in a direction perpendicular to a main length extension direction of the element. Each of the display panel DP, the anti-reflection layer RPL, and the panel protection layer PPL can have substantially the same width when measured in the first direction DR1 and the second direction DR2.

[0111] The display panel DP, the anti-reflection layer RPL, and the panel protection layer PPL can have substantially the same width when measured in the first direction DR1 and the second direction DR2. The width of the first adhesive layer AL1 can be equal to the width of the window protection layer WP, and the width of the second adhesive layer AL2 can be less than the width of the window WIN when measured in the first direction DR1 and the second direction DR2.

[0112] A step structure can be provided between the window protection layer WP and the display panel DP due to the width difference between the window WIN and the second adhesive layer AL2. The window protection layer WP can have a thickness capable of preventing the step structure from being recognized by a user. In an embodiment, for example, the step structure can not be recognized by a user in a case where the window protection layer WP has a thickness of about 55 μm to about 100 μm.

[0113] In a plan view, the first support plate SPT1 and the second support plate SPT2 and the first cushion layer CUL1 and the second cushion layer CUL2 can be disposed in an inner (inside) area of the display panel DP, which is inside (on an inner side of) an edge of the display panel DP.

[0114] Figure 5 is Figure 4 a cross-sectional view of a display panel.

[0115] Referring to Figure 5 , the display panel DP can include a substrate SUB, a circuit device layer DP-CL on the substrate SUB, a display device layer DP-OLED on the circuit device layer DP-CL, a thin encapsulation layer TFE on the display device layer DP-OLED, and an input sensing portion ISP on the thin encapsulation layer TFE.

[0116] The substrate SUB can include a display area DA and a non-display area NDA near the display area DA. The substrate SUB can include a flexible plastic material. In an embodiment, the substrate SUB can be composed of or include PI. For example, the display device layer DP-OLED can be disposed in the display area DA.

[0117] The circuit device layer DP-CL can include an insulating layer, a semiconductor pattern, a conductive pattern, and a signal line. The insulating layer, the semiconductor layer, and the conductive layer can be disposed on the substrate SUB by a coating or deposition process. Thereafter, the insulating layer, the semiconductor layer, and the conductive layer can be selectively patterned by performing a photolithography and etching process a plurality of times, as a result, the insulating pattern, the semiconductor pattern, the conductive pattern, and the signal line can be provided.

[0118] The circuit device layer DP-CL can include a transistor including the semiconductor pattern, the conductive pattern, and the signal line. The display device layer DP-OLED can include a light emitting device connected to the transistor. The pixel PX can include the transistor and the light emitting device.

[0119] The thin encapsulation layer TFE can be disposed on the circuit device layer DP-CL to cover the display device layer DP-OLED. The thin encapsulation layer TFE can include inorganic layers, organic layers, and inorganic layers stacked in sequence. The inorganic layers can be composed of or include inorganic materials, and can protect the pixel PX from moisture and / or oxygen. The organic layers can be composed of or include organic materials, and can protect the pixel PX from contaminant substances such as dust particles.

[0120] The input sensing portion ISP can include a plurality of sensors (not shown) for sensing an external input. The sensors can capacitively sense the external input. The external input can include various types of external inputs such as a part of a user's body, a pen, light, heat, or pressure.

[0121] When the display panel DP is manufactured, the input sensing portion ISP can be directly manufactured on the thin encapsulation layer TFE. However, the invention is not limited to this example, and in an embodiment, the input sensing portion ISP can be manufactured as a different panel from the display panel DP, and then can be attached to the display panel DP through an adhesive layer.

[0122] Figure 6 is a plan view showing a detailed structure of the display device of Figure 1 . Figure 7 is an exploded perspective view of the display device of Figure 6 .

[0123] Referring to Figure 6 and Figure 7 , the display device DD can include a display module DM, a bezel cover BZC disposed adjacent to the display module DM, and a folding apparatus FST disposed under the display module DM and the bezel cover BZC.

[0124] The bezel cover BZC can be disposed adjacent to the first non-folded area NFA1 and the second non-folded area NFA2 of the display module DM. The bezel cover BZC can surround the first non-folded area NFA1 and the second non-folded area NFA2 of the display module DM. The bezel cover BZC can be black, and the color of the bezel cover BZC is not limited to this example. Figure 1 The edge portion EG of the display device DD shown in

[0125] The folding apparatus FST can be disposed under the display module DM and the bezel cover BZC to support the display module DM and the bezel cover BZC. When the display module DM is folded, the folding apparatus FST can be parallel to the first direction DR1, and can be folded along a biaxial folding axis superposed with the folding area FA in a plan view. This will be described in more detail below.

[0126] Although not shown in Figure 7 , the display module DM and the bezel cover BZC can be attached to the folding apparatus FST through an adhesive layer.

[0127] Figure 8 is a plan view of the folding apparatus of Figure 7 .

[0128] Referring to Figure 8, the folding device FST can include a first body BD1, a second body BD2, a hinge module HGM, a first wing plate WPT1, and a second wing plate WPT2. The first body BD1 and the second body BD2 can be arranged in a second direction DR2. The first body BD1 and the second body BD2 can have a flat surface defined by the first direction DR1 and the second direction DR2. The shapes of the first body BD1 and the second body BD2 can be symmetrical to each other in the second direction DR2.

[0129] The hinge module HGM can be disposed between the first body BD1 and the second body BD2. The hinge module HGM can be connected to two opposite sides of the first body BD1 opposite to each other in the first direction DR1, and connected to two opposite sides of the second body BD2 opposite to each other in the first direction DR1. The hinge module HGM can be connected to the first body BD1 and the second body BD2 to provide biaxial rotation axes RX1 and RX2 to the first body BD1 and the second body BD2, respectively.

[0130] The biaxial rotation axes RX1 and RX2 can extend in the first direction DR1. The biaxial rotation axes RX1 and RX2 can include a first rotation axis RX1 and a second rotation axis RX2 extending in the first direction DR1 and spaced apart from each other in the second direction DR2. The biaxial rotation axes RX1 and RX2 can define a folding axis FX as shown in FIG. 1. Figure 2

[0131] The first wing plate WPT1 and the second wing plate WPT2 can be arranged in the second direction DR2 and can extend in the first direction DR1. The shapes of the first wing plate WPT1 and the second wing plate WPT2 can be symmetrical to each other in the second direction DR2.

[0132] Each of the first wing plate WPT1 and the second wing plate WPT2 can have a flat surface defined by the first direction DR1 and the second direction DR2. The first wing plate WPT1 can be adjacent to the hinge module HGM and can be connected to the first body BD1. The second wing plate WPT2 can be adjacent to the hinge module HGM and can be connected to the second body BD2.

[0133] Figure 9 is an exploded perspective view of a folding device of Figure 8

[0134] Referring to Figure 9 ​​The top surface of the first body BD1 adjacent to the side OS1 of the first body BD1 can have a first inclined surface SLP1. The height of the first inclined surface SLP1 can decrease toward the side OS1 of the first body BD1. The first inclined surface SLP1 can have a height difference with the top surface of the first body BD1 near the first inclined surface SLP1.

[0135] The top surface of the second body BD2 adjacent to the side OS2 of the second body BD2 can have a second inclined surface SLP2. The side OS2 of the second body BD2 can face the side OS1 of the first body BD1. The height of the second inclined surface SLP2 can decrease toward the side OS2 of the second body BD2. The second inclined surface SLP2 can have a height difference with the top surface of the second body BD2 near the second inclined surface SLP2.

[0136] The first wing plate WPT1 can be provided on the first body BD1 and can be coupled to the first body BD1. The first wing plate WPT1 can be provided on the first inclined surface SLP1. The first wing plate WPT1 can be rotatably coupled to a portion of the first body BD1 adjacent to the side OS1 of the first body BD1. In an embodiment, for example, the first wing plate WPT1 can be rotatably coupled to an upper side of the first inclined surface SLP1 farthest from the side OS1 of the first body BD1.

[0137] A plurality of first rotation surfaces RTS1 can be defined in a portion on the first inclined surface SLP1. The portion on the first inclined surface SLP1 can be defined as a first boundary BA1 between the first inclined surface SLP1 and the top surface of the first body BD1 adjacent to each other. The first rotation surface RTS1 can be a recessed area defined in the first body BD1. The first rotation surface RTS1 can be arranged in the first direction DR1 along the portion on the first inclined surface SLP1.

[0138] The first wing plate WPT1 can include a plurality of first coupling portions CUP1 extending outward from opposite sides of the first wing plate WPT1, and here, the opposite sides of the first wing plate WPT1 are opposite to the side of the first wing plate WPT1 facing the second wing plate WPT2. The first coupling portions CUP1 can be arranged in the first direction DR1. The first coupling portions CUP1 can be respectively provided in (e.g., on) the first rotation surfaces RTS1.

[0139] The first wing plate WPT1 can be rotatable about a wing rotation axis adjacent to the opposite sides of the first wing plate WPT1 and parallel to the first direction DR1. In an embodiment, for example, when the first coupling portions CUP1 are rotated about the wing rotation axis, the first coupling portions CUP1 can be coupled to the first rotation surfaces RTS1. The wing rotation axis will be described in detail with reference to FIG. 4.Figure 23 and Figure 24 are shown in FIGS.

[0140] The second wing plate WPT2 can be provided on the second body BD2 and can be coupled to the second body BD2. The second wing plate WPT2 can be provided on the second inclined surface SLP2. The second wing plate WPT2 can be rotatably coupled to a portion of the second body BD2 adjacent to the side OS2 of the second body BD2. In an embodiment, for example, the second wing plate WPT2 can be rotatably coupled to an upper side of the second inclined surface SLP2 farthest from the side OS2 of the second body BD2.

[0141] A plurality of second rotation surfaces RTS2 can be defined in a portion of the second inclined surface SLP2. The portion of the second inclined surface SLP2 can be defined as a second boundary BA2 between the second inclined surface SLP2 and the top surface of the second body BD2 adjacent to each other (refer to FIG. Figure 19A ) The second rotation surface RTS2 can be a recessed area defined in the second body BD2. The second rotation surface RTS2 can be arranged in the first direction DR1 along the portion of the second inclined surface SLP2.

[0142] The second wing plate WPT2 can include a plurality of second coupling portions CUP2 extending outward from opposite sides of the second wing plate WPT2, and here, the opposite sides of the second wing plate WPT2 are opposite to the side of the second wing plate WPT2 facing the first wing plate WPT1. The second coupling portions CUP2 can be arranged in the first direction DR1. The second coupling portions CUP2 can be respectively provided in (e.g., on) the second rotation surfaces RTS2.

[0143] The second wing plate WPT2 can be rotatable about a wing rotation axis adjacent to the opposite sides of the second wing plate WPT2 and parallel to the first direction DR1. In an embodiment, for example, when the second coupling portions CUP2 are rotated about the wing rotation axis, the second coupling portions CUP2 can be coupled to the second rotation surfaces RTS2.

[0144] The hinge module HGM can include a first hinge HIG1, a second hinge HIG2, a center frame CFM, and a hinge cover HGC. The first hinge HIG1 and the second hinge HIG2 can be arranged in the first direction DR1. The shapes of the first hinge HIG1 and the second hinge HIG2 can be symmetrical to each other in the first direction DR1. The first hinge HIG1 and the second hinge HIG2 can be connected to the first body BD1 and the second body BD2 to provide the first rotation axis RX1 and the second rotation axis RX2 to the first body BD1 and the second body BD2.

[0145] The first hinge HIG1 can be disposed between the first body BD1 and the second body BD2. The first hinge HIG1 can be connected to one side of the two opposite sides of the first body BD1 along the first direction DR1 opposite to each other and one side of the two opposite sides of the second body BD2 along the first direction DR1 opposite to each other.

[0146] The second hinge HIG2 can be disposed between the first body BD1 and the second body BD2. The second hinge HIG2 can be connected to the other side of the two opposite sides of the first body BD1 along the first direction DR1 opposite to each other and the other side of the second body BD2 along the first direction DR1 opposite to each other.

[0147] A plurality of first holes H1 can be defined in the first hinge HIG1 and the second hinge HIG2. A plurality of first connection grooves CG1 can be defined in the first body BD1 and the second body BD2. The first hinge HIG1 and the second hinge HIG2 can be connected to the first body BD1 and the second body BD2 by inserting a plurality of screws (not shown) through the first holes H1 into the first connection grooves CG1.

[0148] The center frame CFM can extend in the first direction DR1 and can be disposed between the first hinge HIG1 and the second hinge HIG2. The center frame CFM can be disposed between the first body BD1 and the second body BD2. The center frame CFM can be disposed between the first wing plate WPT1 and the second wing plate WPT2.

[0149] The hinge cover HGC can be disposed below the first hinge HIG1, the second hinge HIG2, and the center frame CFM. The first hinge HIG1, the second hinge HIG2, and the center frame CFM can be connected to the hinge cover HGC.

[0150] In an embodiment, for example, a plurality of second holes H2 can be defined in the first hinge HIG1, the second hinge HIG2, and the center frame CFM. A plurality of second connection grooves CG2 can be defined in the hinge cover HGC. The first hinge HIG1, the second hinge HIG2, and the center frame CFM can be connected to the hinge cover HGC by inserting a plurality of screws (not shown) through the second holes H2 into the second connection grooves CG2.

[0151] The first groove GV1 can be defined in upper portions of two opposite sides of the center frame CFM opposite to each other in the second direction DR2. The first groove GV1 can extend in the first direction DR1. When the hinge module HGM is connected to the first body BD1 and the second body BD2, the sides of the first wing plate WPT1 and the second wing plate WPT2 facing each other can be disposed in the first groove GV1, respectively.

[0152] Figure 10 is an exploded perspective view of a first hinge of Figure 9 Figure 11 is a front view of a first frame of Figure 10 Figure 12 is a perspective view illustrating an internal structure of a second frame of Figure 10

[0153] Since the second hinge HIG2 has the same structure as that of the first hinge HIG1, only the structure of the first hinge HIG1 will be described in more detail below, and the description of the second hinge HIG2 will be omitted. In the following description, Figure 9 will be mentioned together with Figure 10 , Figure 11 and Figure 12 .

[0154] Referring to Figure 9 and Figure 10 , the first hinge HIG1 can include a plurality of bracket bodies BBD1 and BBD2, a plurality of rotation pin units RPN1 and RPN2, a plurality of bracket cams BCM1 and BCM2, a first frame FM1, a plurality of gears GR1 and GR2, a plurality of cams CAM1 and CAM2, a plurality of springs SPR1 and SPR2, a second frame FM2, and a plurality of ring units RG. Some of the gears GR1 and GR2, the cams CAM1 and CAM2, and the springs SPR1 and SPR2 can be defined as a torque control unit TQC.

[0155] The bracket bodies BBD1 and BBD2 can be connected to the first body BD1 and the second body BD2 and the rotation pin units RPN1 and RPN2. The rotation pin units RPN1 and RPN2 can be connected to the first body BD1 and the second body BD2 through the bracket bodies BBD1 and BBD2.

[0156] The bracket bodies BBD1 and BBD2 can include a first bracket body BBD1 connected to the first body BD1 and a second bracket body BBD2 connected to the second body BD2. The first bracket body BBD1 and the second bracket body BBD2 can be arranged in the second direction DR2 and can be symmetrical to each other in the second direction DR2. A first hole H1 can be defined in the first bracket body BBD1 and the second bracket body BBD2.​​​

[0157] The rotation pin units RPN1 and RPN2 can include a first rotation pin unit RPN1 connected to the first bracket body BBD1 and a second rotation pin unit RPN2 connected to the second bracket body BBD2. The first rotation pin unit RPN1 and the second rotation pin unit RPN2 can be spaced apart from each other in the second direction DR2 and can extend in the first direction DR1. The first rotation pin unit RPN1 and the second rotation pin unit RPN2 can define first and second rotation axes RX1 and RX2, respectively.

[0158] The first rotation pin unit RPN1 and the second rotation pin unit RPN2 can be connected to side portions of the first bracket body BBD1 and the second bracket body BBD2, respectively, which face each other in the second direction DR2. The first rotation pin unit RPN1 and the second rotation pin unit RPN2 can be separately manufactured and then connected to the first bracket body BBD1 and the second bracket body BBD2, respectively. However, the invention is not limited to this example, and in an embodiment, each of the first rotation pin unit RPN1 and the second rotation pin unit RPN2 can be integrated with the first bracket body BBD1 and the second bracket body BBD2 and can extend from the first bracket body BBD1 and the second bracket body BBD2.

[0159] The first frame FM1, the second frame FM2, and the center frame CFM can be arranged in the first direction DR1. The second frame FM2 can be disposed between the first frame FM1 and the center frame CFM. The first frame FM1 can be disposed between the first and second bracket bodies BBD1 and BBD2 and the second frame FM2.

[0160] Referring to Figure 10 and Figure 11 The first rotation pin unit RPN1 and the second rotation pin unit RPN2 can be inserted into the first frame FM1 to be connected to the first frame FM1. In an embodiment, for example, a third hole H3 extending in the first direction DR1 can be defined in a portion of the first frame FM1 adjacent to an upper portion of the first frame FM1. The first rotation pin unit RPN1 and the second rotation pin unit RPN2 can be inserted into the third hole H3, respectively, to be connected to the first frame FM1.

[0161] The gears GR1 and GR2 can extend in the first direction DR1. The gears GR1 and GR2 can include a plurality of first gears GR1 and a plurality of second gears GR2. Although a pair of first gears GR1 and a pair of second gears GR2 are illustrated, the number of the first gears GR1 and the second gears GR2 is not limited thereto. The first gears GR1 can extend in the first direction DR1 and can rotate while being engaged with each other in the second direction DR2.

[0162] The second gears GR2 can extend in the first direction DR1 and can be spaced apart from each other in the second direction DR2. The first gear GR1 can be disposed between the second gears GR2. The second gears GR2 can rotate while being engaged with the first gear GR1 in the second direction DR2. The first gear GR1 and the second gears GR2 can rotate about a gear rotation axis (not shown) parallel to the first direction DR1.

[0163] The first gear GR1 can include a plurality of first protruding portions PT1 disposed on an outer circumferential surface of the first gear GR1 adjacent to an opposite side among two opposite sides of the first gear GR1 facing each other in the first direction DR1. The first protruding portions PT1 can define a gear shape. The first protruding portions PT1 of the first gear GR1 can move while being engaged with each other, and thus, the first gear GR1 can rotate together.

[0164] Among two opposite sides of the second gear GR2 facing each other in the first direction DR1, a side of the second gear GR2 can be adjacent to a side of the first gear GR1. The second gear GR2 can include a plurality of second protruding portions PT2 disposed on an outer circumferential surface of the second gear GR2 adjacent to an opposite side among two opposite sides of the second gear GR2 facing each other in the first direction DR1 to define a gear shape. The second protruding portions PT2 can move while being engaged with the first protruding portions PT1, and thus, the second gear GR2 can rotate together with the first gear GR1.

[0165] The first gear GR1 can be inserted into the cams CAM1 and CAM2 and the springs SPR1 and SPR2, and thus, the cams CAM1 and CAM2 and the springs SPR1 and SPR2 can be disposed on the first gear GR1. Opposite sides of the first gear GR1 can be inserted into the cams CAM1 and CAM2 and the springs SPR1 and SPR2. The cams CAM1 and CAM2 and the springs SPR1 and SPR2 can be disposed between the first protruding portions PT1 and the opposite sides of the first gear GR1.

[0166] The sides of the first gear GR1 and the sides of the second gear GR2 can be directed toward the first frame FM1, and the opposite sides of the first gear GR1 and the opposite sides of the second gear GR2 can be directed toward the second frame FM2. The sides of the first gear GR1 and the sides of the second gear GR2 can be inserted into the first frame FM1, and the opposite sides of the first gear GR1 and the opposite sides of the second gear GR2 can be inserted into the second frame FM2.

[0167] A plurality of fourth holes H4 and fifth holes H5 extending in the first direction DR1 can be defined in a portion of the first frame FM1 adjacent to the lower portion of the first frame FM1. The fourth holes H4 and the fifth holes H5 can be defined below the third holes H3. The fourth holes H4 can correspond to the first gear GR1. The fifth holes H5 can correspond to the second gear GR2.

[0168] The side portions of the first gear GR1 can be respectively inserted into the fourth holes H4, and thus the first gear GR1 can be coupled to the first frame FM1. The side portions of the second gear GR2 can be respectively inserted into the fifth holes H5, and thus the second gear GR2 can be coupled to the first frame FM1.

[0169] A portion of the first frame FM1 between the third holes H3 and the fourth holes H4 can be defined as a flat portion PP, and can be shaped like a flat plate defined by the first direction DR1 and the second direction DR2.

[0170] The accommodation grooves SGV can be defined in the upper portions of two opposite side portions of the second frame FM2 facing each other in the first direction DR1. The end portions of the flat portion PP can be disposed in the accommodation grooves SGV of the second frame FM2 adjacent to the first frame FM1. The upper portions of the side portions of the center frame CFM can be disposed in the accommodation grooves SGV of the second frame FM2 adjacent to the center frame CFM.

[0171] Referring to Figure 10 and Figure 12 , an inner space SPC and a plurality of insertion holes IGV can be defined in the second frame FM2. The inner space SPC can be defined to correspond to the first gear GR1. The insertion holes IGV can be defined to correspond to the second gear GR2. Opposite side portions of the first gear GR1 can be inserted into the inner space SPC. Opposite side portions of the second gear GR2 can be respectively inserted into the insertion holes IGV.

[0172] Two holes (not labeled) can be defined in the end portions of the inner space SPC, and opposite side portions of the first gear GR1 can be respectively disposed in the two holes. The first cam CAM1 and the second cam CAM2 and the first spring SPR1 and the second spring SPR2 can be disposed in the inner space SPC of the second frame FM2.

[0173] Referring to Figure 10 , the bracket cams BCM1 and BCM2 can include a first bracket cam BCM1 coupled with the first bracket body BBD1 and a second bracket cam BCM2 coupled with the second bracket body BBD2. The first bracket cam BCM1 and the second bracket cam BCM2 can be arranged in the second direction DR2, and can have shapes symmetrical to each other in the second direction DR2.

[0174] The groove GV can be defined in two opposite side portions of the first frame FM1 opposite to each other in the second direction DR2. The first bracket cam BCM1 and the second bracket cam BCM2 can be disposed in the groove GV. The side portions of the first bracket cam BCM1 and the second bracket cam BCM2 facing each other in the second direction DR2 can be disposed in the groove GV.

[0175] The side portion of the second gear GR2 can be inserted into the side portions of the first bracket cam BCM1 and the second bracket cam BCM2. Accordingly, the side portions of the first bracket cam BCM1 and the second bracket cam BCM2 can be coupled to the second gear GR2. The side portion of the second gear GR2 can be inserted into the hole H defined in the side portions of the first bracket cam BCM1 and the second bracket cam BCM2, and accordingly, the first bracket cam BCM1 and the second bracket cam BCM2 can be coupled to the second gear GR2.

[0176] The opposite side portions of the first bracket cam BCM1 and the second bracket cam BCM2 can protrude in the first direction DR1 and can be disposed in guide grooves GG defined in the first bracket body BBD1 and the second bracket body BBD2, respectively. The ring-shaped unit RG can be disposed on the opposite side portions of the first bracket cam BCM1 and the second bracket cam BCM2 protruding in the first direction DR1.

[0177] The guide grooves GG can be defined on surfaces of the first bracket body BBD1 and the second bracket body BBD2 facing the first bracket cam BCM1 and the second bracket cam BCM2. The guide grooves GG can extend in the second direction DR2.

[0178] When the first rotation pin unit RPN1 and the second rotation pin unit RPN2 rotate, the first bracket cam BCM1 and the second bracket cam BCM2 can rotate together with the second gear GR2 and can move along the guide grooves GG. This operation will be described in more detail below.

[0179] The second groove GV2 can be defined in upper portions of two opposite side portions of the second frame FM2 opposite to each other in the second direction DR2. The second groove GV2 can extend in the first direction DR1. When the hinge module HGM is connected to the first body BD1 and the second body BD2, the side portions of the first wing plate WPT1 and the second wing plate WPT2 facing each other can be disposed in the second groove GV2.

[0180] Figure 13 is Figure 10 An exploded perspective view of a torque control unit.

[0181] In the following description, Figure 10 will be described withFigure 13 are mentioned together.

[0182] Referring to Figure 10 and Figure 13 , the torque control unit TQC can include a plurality of first gears GR1, a plurality of cams CAM1 and CAM2, and a plurality of springs SPR1 and SPR2. The cams CAM1 and CAM2 can include a first cam CAM1 and a second cam CAM2 spaced apart from each other in the first direction DR1.

[0183] The first cam CAM1 can include a first moving cam MVC1 and a first rotating cam RCM1. The second cam CAM2 can include a second moving cam MVC2 and a second rotating cam RCM2. The springs SPR1 and SPR2 can include a first spring SPR1 and a second spring SPR2, each of which extends in the first direction DR1.

[0184] The first gear GR1 can be inserted into the first moving cam MVC1 and the second moving cam MVC2. The first gear GR1 can be commonly inserted into each of the first moving cam MVC1 and the second moving cam MVC2. The first gear GR1 can be inserted into a hole penetrating each of the first moving cam MVC1 and the second moving cam MVC2 in the first direction DR1, although the reference numerals of the holes are not shown. Opposite sides of the first gear GR1 can pass through the holes defined in the first moving cam MVC1 and the second moving cam MVC2, and thus, the first moving cam MVC1 and the second moving cam MVC2 can be disposed on an outer circumferential surface of a portion of the first gear GR1.

[0185] The first gear GR1 can be inserted into the first rotating cam RCM1 and the second rotating cam RCM2. The first gear GR1 can be inserted into the first rotating cam RCM1 and the second rotating cam RCM2, respectively, in a one-to-one correspondence.

[0186] The first gear GR1 can be inserted into holes each defined to penetrate a corresponding one of the first rotating cam RCM1 and the second rotating cam RCM2 in the first direction DR1, although the reference numerals of the holes are not shown. Opposite sides of the first gear GR1 can pass through the holes defined in the first rotating cam RCM1 and the second rotating cam RCM2, and thus, the first rotating cam RCM1 and the second rotating cam RCM2 can be disposed on an outer circumferential surface of a portion of the first gear GR1.

[0187] The first gear GR1 can be inserted into the first spring SPR1 and the second spring SPR2. The first gear GR1 can be inserted into the first spring SPR1 and the second spring SPR2, respectively, in a one-to-one correspondence.

[0188] Each of the first moving cam MVC1 and the second moving cam MVC2 can be disposed between a corresponding pair of the rotary cam and the spring among the first rotary cam RCM1 and the second rotary cam RCM2 and the first spring SPR1 and the second spring SPR2. The corresponding pair of the rotary cam and the spring can be disposed on the same one of the first gears GR1. Accordingly, each of the first moving cam MVC1 and the second moving cam MVC2 can be disposed between a pair of the rotary cam and the spring disposed on a corresponding one of the first gears GR1.

[0189] The first moving cam MVC1 can be disposed between the first rotary cam RCM1 and the first spring SPR1, the first rotary cam RCM1 and the first spring SPR1 being disposed on one of the first gears GR1. The second moving cam MVC2 can be disposed between the second rotary cam RCM2 and the second spring SPR2, the second rotary cam RCM2 and the second spring SPR2 being disposed on another one of the first gears GR1.

[0190] The surfaces of the moving cam and the surfaces of the rotary cam disposed on the same one of the first gears GR1 to face each other can include protruding portions. The protruding portions of the surfaces of the moving cam and the protruding portions of the surfaces of the rotary cam disposed on the same one of the first gears GR1 can be staggered with each other.

[0191] In an embodiment, for example, the surfaces of the first moving cam MVC1 and the surfaces of the first rotary cam RCM1 disposed on one of the first gears GR1 to face each other can include protruding portions, although reference numerals of the protruding portions are not shown. The protruding portions of the surfaces of the first moving cam MVC1 and the protruding portions of the surfaces of the first rotary cam RCM1 can be staggered with each other.

[0192] The surfaces of the second moving cam MVC2 and the surfaces of the second rotary cam RCM2 disposed on another one of the first gears GR1 to face each other can include protruding portions, although reference numerals of the protruding portions are not shown. The protruding portions of the surfaces of the second moving cam MVC2 and the protruding portions of the surfaces of the second rotary cam RCM2 can be staggered with each other.

[0193] Figure 14 is a view showing a structure in which Figure 9 and is a view showing a structure in which a first hinge of Figure 10 is a view showing a structure in which a first hinge of Figure 15 is a view showing a structure in which a first hinge of Figure 14 is a view showing a structure in which a first hinge of

[0194] In order to reduce complexity in the drawings, fromFigure 15 The first frame FM1 and the second frame FM2 are omitted. In the following description, if necessary, Figure 10 will be mentioned together with Figure 14 and Figure 15 .

[0195] Referring to Figure 10 , Figure 14 and Figure 15 , the first bracket body BBD1 and the second bracket body BBD2 can be connected to the first body BD1 and the second body BD2 by screws inserted into the first holes H1.

[0196] The first rotation pin unit RPN1 and the second rotation pin unit RPN2 can be inserted into the first frame FM1 and can be rotatably coupled to the first frame FM1. The first rotation pin unit RPN1 can define a first rotation axis RX1, and the second rotation pin unit RPN2 can define a second rotation axis RX2.

[0197] The first bracket cam BCM1 and the second bracket cam BCM2 can be coupled to the first bracket body BBD1 and the second bracket body BBD2. The first bracket cam BCM1 and the second bracket cam BCM2 can be disposed near the first frame FM1, and the second gear GR2 can be inserted into the first bracket cam BCM1 and the second bracket cam BCM2 such that the first bracket cam BCM1 and the second bracket cam BCM2 are coupled to the first frame FM1. The first bracket cam BCM1 and the second bracket cam BCM2 can be coupled to the second gear GR2 to rotate together with the second gear GR2.

[0198] Ends of the flat portions PP can be disposed in receiving grooves SGV defined in side portions of the second frame FM2, and the first frame FM1 and the second frame FM2 can be connected to each other by fastening units (e.g., screws) (not shown).

[0199] The first gear GR1 and the second gear GR2 can be inserted into the first frame FM1 and the second frame FM2, thereby can be coupled to the first frame FM1 and the second frame FM2. The first protrusion portion PT1 and the second protrusion portion PT2 can be engaged with each other, and in this case, the first protrusion portion PT1 and the second protrusion portion PT2 engaged with each other can rotate together.

[0200] The first moving cam MVC1 and the second moving cam MVC2, the first rotation cam RCM1 and the second rotation cam RCM2, and the first spring SPR1 and the second spring SPR2 can be coupled to the first gear GR1 and can be disposed in the second frame FM2. The first rotation cam RCM1 and the second rotation cam RCM2 can be coupled to the first gear GR1 to rotate together with the first gear GR1.

[0201] The side of the first wing plate WPT1 and the side of the second wing plate WPT2 can be disposed on the first groove GV1 and the second groove GV2. The first coupling portion CUP1 and the second coupling portion CUP2 of the first wing plate WPT1 and the second wing plate WPT2 can be rotatably coupled to the first rotation surface RTS1 and the second rotation surface RTS2 defined in the first body BD1 and the second body BD2.

[0202] Figure 16A and Figure 16B is a perspective view showing the operation of the first rotation cam and the first moving cam shown in FIG. 1. Figure 15

[0203] The following description will refer to the operation of the first rotation cam RCM1 and the first moving cam MVC1, but the operation of the second rotation cam RCM2 and the second moving cam MVC2 can be substantially the same as the operation of the first rotation cam RCM1 and the first moving cam MVC1.

[0204] Referring to Figure 16A , the first protrusion portion PRT1 of the first rotation cam RCM1 can be disposed between the second protrusion portions PRT2 of the first moving cam MVC1. Due to the restoring force applied by the first spring SPR1, it can be possible to maintain the state of the first protrusion portion PRT1 disposed between the second protrusion portions PRT2. Figure 16A The first rotation cam RCM1 and the first moving cam MVC1 are shown when the display device DD is in the unfolded state. Since the state of the first protrusion portion PRT1 disposed between the second protrusion portions PRT2 is maintained, it can be possible to more easily maintain the display device DD in the unfolded state.

[0205] Referring to Figure 16B , the display device DD can be folded by an external force (e.g., an external force from a user). In the case where the first rotation cam RCM1 is rotated by the external force, the first protrusion portion PRT1 can pass over the protrusion top surface of the second protrusion portion PRT2 and can move in the counterclockwise direction. In the case where the external force from the user becomes greater than the force required to maintain the state of the first protrusion portion PRT1 disposed between the second protrusion portions PRT2, the first protrusion portion PRT1 can move to pass over the top surface of the second protrusion portion PRT2, and in this case, the display device DD can be folded.

[0206] ​As a result of the foregoing operation, in a case in which the user unfolds the display device DD, the unfolded state can be easily maintained, and in a case in which the user wants to fold the display device DD, the display device DD can be folded by applying a force to the display device DD. To implement this operation, a torque control unit TQC including the first cam CAM1 and the second cam CAM2 can be provided in the hinge module HGM.

[0207] Figure 17A is a perspective view illustrating an unfolded state of the folding apparatus of Figure 8 . Figure 17B is a perspective view illustrating a folded state of the folding apparatus of Figure 17A .

[0208] Referring to Figure 17A and Figure 17B , the folding apparatus FST can be folded by rotating about first and second rotation axes RX1 and RX2 defined by first and second rotation pin units RPN1 and RPN2. A display module DM provided on the folding apparatus FST can be folded or unfolded by the folding operation of the folding apparatus FST.

[0209] Figure 18A is a cross-sectional view taken along line I-I' of Figure 14 . Figure 18B and Figure 18C are cross-sectional views illustrating a folding operation of the folding apparatus of Figure 18A .

[0210] In the following description, Figure 14 will be mentioned with Figure 18A , Figure 18B and Figure 18C .

[0211] Referring to Figure 14 , Figure 18A , Figure 18B and Figure 18C , the first and second rotation pin units RPN1 and RPN2 can rotate about the first and second rotation axes RX1 and RX2 such that the folding apparatus FST is folded. As the first and second rotation pin units RPN1 and RPN2 rotate, the first and second bracket bodies BBD1 and BBD2 can rotate about the first and second rotation axes RX1 and RX2, and such rotation can cause the first and second bracket bodies BBD1 and BBD2 to move (e.g., rotate).

[0212] When the first and second bracket bodies BBD1 and BBD2 rotate, the first and second bodies BD1 and BD2 connected to the first and second bracket bodies BBD1 and BBD2 can rotate about the first and second rotation axes RX1 and RX2, and such rotation can move the first and second bodies BD1 and BD2. In other words, the first and second rotation pin units RPN1 and RPN2 can provide the first and second bodies BD1 and BD2 with the first and second rotation axes RX1 and RX2, and the first and second bodies BD1 and BD2 can rotate about the first and second rotation axes RX1 and RX2. In an embodiment, the first and second bodies BD1 and BD2 can face each other, and thus, the folding device FST can be folded in an inward folding manner.

[0213] The first and second gears GR1 and GR2 can be disposed below the first and second rotation pin units RPN1 and RPN2. When the first and second rotation pin units RPN1 and RPN2 rotate, the first and second gears GR1 and GR2 can rotate in cooperation with the first and second rotation pin units RPN1 and RPN2.

[0214] In detail, due to the movement of the first and second bracket bodies BBD1 and BBD2 that rotate together with the first and second rotation pin units RPN1 and RPN2, the first and second bracket cams BCM1 and BCM2 combined with the first and second bracket bodies BBD1 and BBD2 can move. Due to the movement of the first and second bracket cams BCM1 and BCM2, the second gear GR2 combined with the first and second bracket cams BCM1 and BCM2 can rotate.

[0215] Due to the rotation of the second gear GR2, the first gear GR1 engaged with the second gear GR2 can rotate. In other words, when the first and second bracket cams BCM1 and BCM2 move by rotation, the first and second gears GR1 and GR2 can rotate together with the first and second bracket cams BCM1 and BCM2. The first and second gears GR1 and GR2 can rotate about a gear rotation axis GRX, respectively, which is parallel to the first direction DR1 and is defined at the center of the first and second gears GR1 and GR2 in the first direction DR1.

[0216] When the first bracket cam BCM1 and the second bracket cam BCM2 rotate, the end portions of the first bracket cam BCM1 and the second bracket cam BCM2 can move along the guide grooves GG defined in the first bracket body BBD1 and the second bracket body BBD2. The first bracket cam BCM1 and the second bracket cam BCM2 can move in a direction away from each other when the folding apparatus FST is folded. Since the first bracket cam BCM1 and the second bracket cam BCM2 move along the guide grooves GG, the first bracket body BBD1 and the second bracket body BBD2 can more easily move.

[0217] Figure 19A is a cross-sectional view taken along Figure 14 line II-II' of Figure 19B and Figure 19C is a cross-sectional view illustrating a folding operation of the folding apparatus of Figure 19A .

[0218] In order to provide a better understanding of the folded state of the display module DM, Figure 19A , Figure 19B and Figure 19C not only illustrate the folding apparatus FST, but also illustrate the display module DM.

[0219] Referring to Figure 19A , the display module DM can be disposed on the folding apparatus FST. The first body BD1 can be disposed under the first non-folding area NFA1, and the second body BD2 can be disposed under the second non-folding area NFA2. In a plan view, the first rotation axis RX1 and the second rotation axis RX2 can be superposed with the folding area FA. The first rotation axis RX1 and the second rotation axis RX2 can be disposed at a level lower than a top surface of the display module DM.

[0220] The center frame CFM can be disposed under the folding area FA. Although not illustrated, the first frame FM1 and the second frame FM2 arranged in the first direction DR1 and close to the center frame CFM can also be disposed under the folding area FA.

[0221] The first body BD1 can extend to an area under the first extension portion EX1 and the curved surface portion CSP, and the second body BD2 can extend to an area under the second extension portion EX2 and the curved surface portion CSP. The first body BD1 and the second body BD2 can be adjacent to each other under the curved surface portion CSP in the second direction DR2.

[0222] A top surface of the first body BD1 facing the first extension portion EX1 can be defined as a first inclined surface SLP1. A top surface of the first body BD1 under the first wing plate WPT1 can function as the first inclined surface SLP1. A top surface of the second body BD2 facing the second extension portion EX2 can be defined as a second inclined surface SLP2. A top surface of the second body BD2 under the second wing plate WPT2 can function as the second inclined surface SLP2. Heights of the first inclined surface SLP1 and the second inclined surface SLP2 can decrease toward side portions OS1 of the first body BD1 and side portions OS2 of the second body BD2.

[0223] The first inclined surface SLP1 and the second inclined surface SLP2 can form a stepwise structure with respect to top surfaces of the first body BD1 and the second body BD2 disposed under the first non-folded area NFA1 and the second non-folded area NFA2. A boundary between the first body BD1 disposed under the first non-folded area NFA1 and the first inclined surface SLP1 can be defined as a first boundary BA1. A boundary between the second body BD2 disposed under the second non-folded area NFA2 and the second inclined surface SLP2 can be defined as a second boundary BA2.

[0224] The first wing plate WPT1 can be disposed between the first inclined surface SLP1 and the first extension portion EX1. The first wing plate WPT1 can be adjacent to the first boundary BA1. The second wing plate WPT2 can be disposed between the second inclined surface SLP2 and the second extension portion EX2. The second wing plate WPT2 can be adjacent to the second boundary BA2.

[0225] Side portions of the first wing plate WPT1 and side portions of the second wing plate WPT2 facing each other can be disposed on two opposite side portions of the center frame CFM. The side portions of the first wing plate WPT1 and the side portions of the second wing plate WPT2 facing each other can be disposed on (e.g., in) first grooves GV1 defined in the two opposite side portions of the center frame CFM. Although not shown in FIG. 1A, the side portions of the first wing plate WPT1 and the side portions of the second wing plate WPT2 can be disposed on (e.g., in) second grooves GV2 defined in the second frame FM2. Figure 19A

[0226] The display device DD can further include an adhesive layer ADH. The adhesive layer ADH can be disposed between the first non-folded area NFA1 and the first body BD1 and between the second non-folded area NFA2 and the second body BD2. In addition, the adhesive layer ADH can be disposed between the first extension portion EX1 and the first wing plate WPT1 and between the second extension portion EX2 and the second wing plate WPT2.

[0227] ​The display module DM can be attached to the first and second bodies BD1 and BD2 and the first and second wing plates WPT1 and WPT2 through an adhesive layer ADH. In an embodiment, the adhesive layer ADH can be a double-sided tape, but the kind of the adhesive layer ADH is not limited thereto.

[0228] Referring to Figure 19B and Figure 19C , the folding apparatus FST can be folded with respect to the first and second rotation axes RX1 and RX2 such that the display module DM is folded. The folding area FA can be bent such that the display module DM is folded. The display module DM can be folded in an inner folding manner in which the first and second non-folding areas NFA1 and NFA2 face each other.

[0229] When the display module DM is folded, the curved portion CSP can be bent to have a predetermined curvature. In other words, the curved portion CSP can be bent to have a predetermined radius of curvature. In an embodiment, for example, such a radius of curvature can be set to be in a range of about 1.5 millimeters (mm) to about 5.0 mm (particularly, about 2.5 mm).

[0230] A portion of the display module DM adjacent to a boundary between the first extension portion EX1 and the first non-folding area NFA1 can be bent. The first extension portion EX1 can be bently extended from the first non-folding area NFA1 to the curved portion CSP. The first extension portion EX1 attached to the first wing plate WPT1 of a flat shape can be maintained as the flat shape.

[0231] A portion of the display module DM adjacent to a boundary between the second extension portion EX2 and the second non-folding area NFA2 can be bent. The second extension portion EX2 can be bently extended from the second non-folding area NFA2 to the curved portion CSP. The second extension portion EX2 attached to the second wing plate WPT2 of a flat shape can be maintained as the flat shape.

[0232] When the display module DM is folded, the first wing plate WPT1 can be moved toward the first inclined surface SLP1 by a stress of the folding area FA, and thus can come into contact with the first inclined surface SLP1. When the display module DM is folded, the second wing plate WPT2 can be moved toward the second inclined surface SLP2 by a stress of the folding area FA, and thus can come into contact with the second inclined surface SLP2.

[0233] According to the foregoing folding structure, the first distance GP1 between the first non-folding area NFA1 and the second non-folding area NFA2 can be smaller than the second distance GP2 between the first extension part EX1 and the second extension part EX2 in the case where the display module DM is folded. The second distance GP2 can gradually increase toward the curved surface part CSP. Accordingly, the display module DM can be folded to have a shape like a dumbbell when the display module DM is folded.

[0234] Referring to Figure 19C In the case where the first body BD1 and the second body BD2 are rotated by about 90 degrees (°) in the clockwise direction and the counterclockwise direction, respectively, to fold the display apparatus DD in the unfolded state, the folding area FA can not be in contact with the center frame CFM. In an embodiment, for example, the curved surface part CSP of the folding area FA can not be in contact with the center frame CFM even when the display apparatus DD is folded.

[0235] Referring to Figure 18C and Figure 19C Since the first gear GR1 and the second gear GR2 are disposed below the rotation pin units RPN1 and RPN2, the first rotation axis RX1 and the second rotation axis RX2 can be disposed at a higher level than the gear rotation axis GRX.

[0236] The position of the curved surface part CSP changes according to the positions of the first rotation axis RX1 and the second rotation axis RX2. When the first rotation axis RX1 and the second rotation axis RX2 are disposed at a lower level to be adjacent to the gear rotation axis GRX or the folding apparatus FST is implemented to overlap the gear rotation axis GRX, the position of the curved surface part CSP changes to a lower position such that the curved surface part CSP is in contact with the center frame CFM. In this case, the curved surface part CSP can be damaged by repeated folding and unfolding operations of the display apparatus DD.

[0237] However, in an embodiment, since the first rotation axis RX1 and the second rotation axis RX2 are disposed at a higher level than the gear rotation axis GRX, the curved surface part CSP can not be in contact with the center frame CFM when the display apparatus DD is folded. As a result, the curved surface part CSP can be prevented from being damaged.

[0238] Figure 20 is Figure 19C An enlarged cross-sectional view of the display module.

[0239] Figure 20 The first wing plate WPT1 and the second wing plate WPT2, the adhesive layer ADH, and the display module DM are shown in FIG. 1. In addition, for convenience of description, the adhesive layer ADH is shown as being thicker than the thickness of the adhesive layer ADH in Figure 19A , Figure 19B and Figure 19C .

[0240] Referring to Figure 20 , the display module DM can include a first inverse curvature portion ICV1 defined as a portion of the display module DM adjacent to a boundary between the first non-folded area NFA1 and the first extension portion EX1, and a second inverse curvature portion ICV2 defined as a portion of the display module DM adjacent to a boundary between the second non-folded area NFA2 and the second extension portion EX2. The first inverse curvature portion ICV1 and the second inverse curvature portion ICV2 can be bent in an opposite manner to the curved portion CSP when the display module DM is folded.

[0241] The adhesive layer ADH can not be disposed in areas below the curved portion CSP and below the first inverse curvature portion ICV1 and the second inverse curvature portion ICV2. The areas below the curved portion CSP and below the first inverse curvature portion ICV1 and the second inverse curvature portion ICV2 can be defined as areas disposed below a bottom surface of the display module DM, the bottom surface of the display module DM being opposite to a front surface (e.g., the display surface DS) of a display image of the display module DM.

[0242] Since the adhesive layer ADH is not disposed below the curved portion CSP, the curved portion CSP can be bent more easily. Also, since the adhesive layer ADH is not disposed below the first inverse curvature portion ICV1 and the second inverse curvature portion ICV2, the first inverse curvature portion ICV1 and the second inverse curvature portion ICV2 can be bent more easily.

[0243] Figure 21 is an enlarged sectional view of the first area A1 of Figure 19C Figure 22 is an enlarged sectional view showing a deployed state of the second inverse curvature portion of Figure 21

[0244] In particular, Figure 21 shows a structure near the second inverse curvature portion ICV2 during a folding operation of the display device DD, Figure 22 shows a structure near the second inverse curvature portion ICV2 during a deployment operation of the display device DD.

[0245] Figure 21 and Figure 22 The structure near the second inverse curvature portion ICV2 is shown in Figure 21 but the structure near the first inverse curvature portion ICV1, which is not shown in

[0246] Referring to Figure 21 and Figure 22 ​​The top surfaces of the adjacent second body BD2 and the second wing WPT2 can have curved surfaces. In an embodiment, for example, the first top surface US1 of the second wing WPT2 adjacent to the second boundary BA2 and the second top surface US2 of the second body BD2 disposed below the second non-folded region NFA2 and adjacent to the second boundary BA2 can have curved surfaces.

[0247] Although not shown, the top surfaces of the first body BD1 and the first wing plate WPT1, which are adjacent to each other, may be curved. In an embodiment, for example, the first top surface of the first wing plate WPT1 adjacent to the first boundary BA1 and the second top surface of the first body BD1 disposed below the first non-folded region NFA1 and adjacent to the first boundary BA1 may be curved.

[0248] The side portion WOS of the second boundary BA2 and the second wing WPT2 adjacent to the second boundary BA2 may be adjacent to the central portion of the second inverse curvature portion ICV2. Although not shown, the side portions of the first boundary BA1 and the first wing WPT1 adjacent to the first boundary BA1 may be adjacent to the central portion of the first inverse curvature portion ICV1.

[0249] like Figure 21 As shown, when the display module DM is folded, the curved surfaces of the first top surface US1 and the second top surface US2 can have curved surfaces corresponding to the curved surfaces of the second inverse curvature portion ICV2. The curved surfaces of the first top surface US1 and the second top surface US2 can have curvatures that are substantially the same as the curvatures of the curved surfaces of the second inverse curvature portion ICV2. The curved surfaces of the first top surface US1 and the second top surface US2 can have curvatures that are substantially the same as the curvatures of the bottom surface of the second inverse curvature portion ICV2.

[0250] Although not shown, when the display module DM is folded, the first top surface of the first wing plate WPT1 adjacent to the first boundary BA1 and the second top surface of the first body BD1 adjacent to the first boundary BA1 may have a surface corresponding to the surface of the first inverse curvature portion ICV1.

[0251] Since the first top surface US1 and the second top surface US2 are curved, the second inverse curvature portion ICV2 can bend more easily along the first top surface US1 and the second top surface US2.

[0252] Figure 23 It is along Figure 14 The sectional view taken from line III-III'. Figure 24 It is shown Figure 23 An enlarged cross-sectional view of the folded state of the second inverse curvature section.

[0253] Specifically,Figure 23 structures near the second inverse curvature portion ICV2 during a folding operation of the display device DD are shown. Figure 24 structures near the second inverse curvature portion ICV2 during a folding operation of the display device DD are shown. In order to provide a better understanding of the invention, in Figure 23 and Figure 24 the display module DM is also shown.

[0254] Some elements disposed near the second inverse curvature portion ICV2 in the display module DM are briefly shown in the circular dotted line of Figure 24 Although structures near the second inverse curvature portion ICV2 are shown in Figure 23 and Figure 23 and Figure 24 structures near the first inverse curvature portion ICV1, which are not shown in Figure 23 and Figure 24 may be substantially the same as the structures near the second inverse curvature portion ICV2.

[0255] In the following description, when necessary, Figure 9 and Figure 14 will be referred to together with Figure 23 and Figure 24 .

[0256] Referring to Figure 9 , Figure 14 , Figure 23 and Figure 24 , the second rotation surface RTS2 defined in the second body BD2 can have a concave curvature. Although not shown, the first rotation surface RTS1 defined in the first body BD1 can also have a concave curvature.

[0257] The second coupling portion CUP2 of the second wing plate WPT2 can have a convex curvature and can be in contact with the second rotation surface RTS2. The curvature of the second coupling portion CUP2 can be substantially equal to the curvature of the second rotation surface RTS2. Although not shown, the first coupling portion CUP1 of the first wing plate WPT1 can also have a convex curvature and can be in contact with the first rotation surface RTS1.

[0258] The center of the circle defined by the curvature of the second coupling portion CUP2 can be defined as a wing rotation axis WRX. The second coupling portion CUP2 can be rotated by moving along the curvature of the second rotation surface RTS2 when the display module DM is folded. In other words, the second coupling portion CUP2 can be rotated about the wing rotation axis WRX when the display module DM is folded.

[0259] Although not shown, when the display module DM is folded, the first coupling portion CUP1 can rotate along the wing rotation axis WRX adjacent to the first rotation surface RTS1, thereby rotating along the curved surface of the first rotation surface RTS1.

[0260] The display module DM and the aforementioned bezel cover BZC can be disposed on the first wing plate WPT1 and the second wing plate WPT2 to fasten the first wing plate WPT1 and the second wing plate WPT2. Accordingly, the first coupling portion CUP1 and the second coupling portion CUP2 can be easily disposed on the first rotation surface RTS1 and the second rotation surface RTS2 without being separated from the first rotation surface RTS1 and the second rotation surface RTS2.

[0261] Due to the aforementioned structure, even when the first coupling portion CUP1 and the second coupling portion CUP2 are not coupled to the first body BD1 and the second body BD2 using a pin, the first coupling portion CUP1 and the second coupling portion CUP2 can easily rotate while being in contact with the first rotation surface RTS1 and the second rotation surface RTS2.

[0262] The wing rotation axis WRX can be set by the following method.

[0263] The wing rotation axis WRX adjacent to the second inverse curvature portion ICV2 can be set in such a manner that a length of a neutral plane NTL of the second inverse curvature portion ICV2 when the second inverse curvature portion ICV2 is bent (shown in the middle) becomes equal to a length of the second inverse curvature portion ICV2 in the second direction DR2 when the second inverse curvature portion ICV2 is unfolded. Figure 24

[0264] Specifically, a portion of the display module DM corresponding to the second inverse curvature portion ICV2 can be bent to have a desired curvature. Hereinafter, the portion of the display module DM corresponding to the second inverse curvature portion ICV2 is referred to as a curvature portion. A top surface of the curvature portion can be widened when the curvature portion is bent than when the curvature portion is flat, and a bottom surface of the curvature portion can be contracted when bent than when flat. Accordingly, a tensile stress can be generated on the top surface of the curvature portion, and a compressive stress can be generated on the bottom surface of the curvature portion.

[0265] The tensile stress and the compressive stress can be compensated for in the curvature portion, and there can be a portion in which a net stress is zero. The portion of the curvature portion in which the net stress is zero can be defined as a neutral plane NTL of the curvature portion.

[0266] The tensile stress and the compressive stress can be compensated for in the curvature portion, and there can be a portion in which a net stress is zero. The portion of the curvature portion in which the net stress is zero can be defined as a neutral plane NTL of the curvature portion. Figure 24 ​The length of the neutral plane NTL indicated by the double arrow in the middle. The length of the neutral plane NTL can be equal to the length of the second inverse curvature portion ICV2 in the second direction DR2 when the curvature portion is unfolded. That is, Figure 23 The straight line length LT of the second inverse curvature portion ICV2 shown in the middle can be set to Figure 24 The length of the neutral plane NTL shown in the middle.

[0267] The rotation axis can be set in such a way that the straight line length LT of the second inverse curvature portion ICV2 is equal to the length of the neutral plane NTL, and a circle can be defined to have a center point on the rotation axis. The curved surface of the second coupling portion CUP2 and the curved surface of the second rotating surface RTS2 can be determined based on the defined circle. The rotation axis can be the aforementioned wing rotation axis WRX. That is, when the display module DM is bent along the predetermined rotation axis, the straight line length LT of the second inverse curvature portion ICV2 can become equal to the length of the neutral plane NTL.

[0268] Similarly, the wing rotation axis WRX adjacent to the first inverse curvature portion ICV1 can be set in such a way that the length of the neutral plane of the first inverse curvature portion ICV1 when the first inverse curvature portion ICV1 is bent becomes equal to the length of the first inverse curvature portion ICV1 in the second direction DR2 when the first inverse curvature portion ICV1 is unfolded.

[0269] Figure 25 is a view showing an embodiment of a folding apparatus according to the present application.

[0270] In detail, in Figure 25 the corresponding perspective view is shown in the middle. Figure 14

[0271] In the following description of the folding apparatus FST' of Figure 25 , features different from the folding apparatus FST will be mainly explained, and the same reference numerals will be used to identify the same elements. Figure 14

[0272] Referring to Figure 25 , the folding apparatus FST' can include a plurality of protruding guides PG1 and PG2 protruding from the first wing plate WPT1' and the second wing plate WPT2'. The protruding guides PG1 and PG2 can protrude from the side portions of the first wing plate WPT1' and the second wing plate WPT2' facing each other. The protruding guides PG1 and PG2 can protrude toward the center frame CFM'.

[0273] ​​The protruding guides PG1 and PG2 can include a first protruding guide PG1 protruding from a side of the first wing plate WPT1' and a second protruding guide PG2 protruding from a side of the second wing plate WPT2'. Although one first protruding guide PG1 and one second protruding guide PG2 are shown, a plurality of first protruding guides PG1 and a plurality of second protruding guides PG2 can be provided.

[0274] Figure 26A is a cross-sectional view taken along the line IV-IV' of Figure 25 .

[0275] To provide a better understanding of the application, a display module DM and a folding apparatus FST' are shown in Figure 26A . For ease of explanation, Figure 26A a first body BD1 and a second body BD2, a center frame CFM', a hinge cover HGC, and a first wing plate WPT1' and a second wing plate WPT2' are shown in

[0276] Referring to Figure 26A , the hinge cover HGC can be provided under the center frame CFM'. The center frame CFM' can include a guide portion GDP and an upper protruding portion UPT protruding from the guide portion GDP toward the folding area FA. The guide portion GDP can be included in the center frame CFM'. Two opposite sides of the guide portion GDP opposite each other in the second direction DR2 can be disposed adjacent to an upper portion of the center frame CFM'. The upper protruding portion UPT can protrude upward more than the guide portion GDP.

[0277] The first protruding guide PG1 and the second protruding guide PG2 can be provided on the guide portion GDP. The upper protruding portion UPT can be disposed between the first protruding guide PG1 and the second protruding guide PG2. A top surface of the guide portion GDP can have a curved surface. In an embodiment, for example, a top surface of the guide portion GDP adjacent to the hinge cover HGC can have a curved surface.

[0278] The adhesive layer ADH can be provided under the first non-folding area NFA1 and the second non-folding area NFA2. The adhesive layer ADH can not be provided under the folding area FA. Thus, unlike the structure of Figure 19A , the adhesive layer ADH can not be provided between the first and second extension portions EX1 and EX2 and the first and second wing plates WPT1' and WPT2'. Thus, the first and second wing plates WPT1' and WPT2' can not be attached to the first and second extension portions EX1 and EX2.

[0279] Figure 26B to Figure 26E is a cross-sectional view showing a folding operation of the folding apparatus of Figure 26A .

[0280] Referring to Figure 26B to Figure 26E , the folding apparatus FST' can be folded so that the display device DD' is folded. When the folding apparatus FST' is folded, the first protruding guide PG1 and the second protruding guide PG2 can move along the top surface of the guide portion GDP. The top surface of the guide portion GDP can guide the movement of the first protruding guide PG1 and the movement of the second protruding guide PG2. When the folding apparatus FST' is folded, the first protruding guide PG1 and the second protruding guide PG2 can move in a direction away from the upper protruding portion UPT.

[0281] Because the first protruding guide PG1 and the second protruding guide PG2 move along the top surface of the guide portion GDP, even when the first wing plate WPT1' and the second wing plate WPT2' are attached to the first extension portion EX1 and the second extension portion EX2, the first wing plate WPT1' and the second wing plate WPT2' can easily move.

[0282] In the inventive embodiment, the display module can be easily folded in a dumbbell shape, and the folding area of the display module can be prevented from being damaged.

[0283] While the inventive embodiments have been particularly shown and described, those of ordinary skill in the art will understand that various changes in form and details can be made herein.

Claims

1. A display apparatus comprising: a display module including a first non-folded area, a second non-folded area, and a folded area disposed between the first non-folded area and the second non-folded area; a first body disposed in the first non-folded area; a second body disposed in the second non-folded area; a plurality of rotation pin units connected to the first body and the second body to provide a biaxial rotation axis superimposed with the folded area to the first body and the second body; and a plurality of gears rotated in cooperation with the plurality of rotation pin units, wherein, when the display module is unfolded, the plurality of gears are disposed below the plurality of rotation pin units in a direction toward the display module and are spaced apart from the plurality of rotation pin units. the biaxial rotation axis, the plurality of rotation pin units, and the plurality of gears extend in a first direction, and 2. The display device according to claim 1, wherein the first non-folded area, the folded area, and the second non-folded area extend in a second direction crossing the first direction. the plurality of gears include:

3. The display device of claim 2, wherein, a plurality of first gears extending in the first direction and meshing with each other in the second direction; and a plurality of second gears extending in the first direction and spaced apart from each other, and the plurality of first gears are interposed between the plurality of second gears in the second direction, wherein the plurality of first gears and the plurality of second gears mesh with each other in the second direction to rotate about a gear rotation axis parallel to the first direction. 4.The display apparatus of claim 3, further comprising: a first frame into which sides of the plurality of rotation pin units and sides of the plurality of first gears and the plurality of second gears are inserted; and a second frame into which opposite sides of the plurality of first gears and the plurality of second gears are inserted. 5.The display apparatus of claim 4, further comprising: a plurality of bracket bodies connected to first and second rotation pin units of the plurality of rotation pin units and the first and second bodies; and a plurality of bracket cams disposed in grooves defined in sides of the first frame opposite to each other in the second direction, wherein the sides of the plurality of second gears are inserted into sides of the plurality of bracket cams disposed in the grooves, and when the plurality of rotation pin units rotate, opposite sides of the plurality of bracket cams move along guide grooves defined in the bracket bodies and extending in the second direction. 6.The display apparatus of claim 4, further comprising: a plurality of moving cams spaced apart from each other in the first direction and into which the plurality of first gears are respectively inserted; a plurality of rotating cams into which the plurality of first gears are respectively inserted and adjacent to the plurality of moving cams; and a plurality of springs into which the plurality of first gears are respectively inserted, ​ ​ ​ wherein the plurality of moving cams, the plurality of rotating cams, and the plurality of springs are disposed in the second frame, each of the plurality of moving cams is disposed between a pair of rotating cams of the plurality of rotating cams and a spring of the plurality of springs, the pair of rotating cams and the spring being disposed on a corresponding first gear of the plurality of first gears, surfaces of the moving cams of the plurality of moving cams and surfaces of the rotating cams of the plurality of rotating cams disposed on a same first gear of the plurality of first gears face each other, and the plurality of surfaces of the moving cams and the plurality of surfaces of the rotating cams disposed on the same first gear are interleaved with each other.

7. The display device according to claim 2, wherein the folding area includes: a curved portion that is curved to have a predetermined curvature when the display module is folded; a first extension portion between the first non-folding area and the curved portion; and a second extension portion between the second non-folding area and the curved portion.

8. The display device of claim 7, wherein, a distance between the first non-folding area and the second non-folding area is smaller than a distance between the first extension portion and the second extension portion when the display module is folded.

9. The display device according to claim 7, wherein the first body extends to an area located on the first extension portion, the second body extends to an area located on the second extension portion, a surface of the first body that faces the display module and that faces the first extension portion has a first inclined surface, a surface of the second body that faces the display module and that faces the second extension portion has a second inclined surface, the first inclined surface and the second inclined surface have a stepped structure with respect to surfaces of the first body and the second body that face the display module and that are disposed in the first non-folding area and the second non-folding area, and heights of the first inclined surface and the second inclined surface decrease toward side portions of the first body and the second body that face each other. 10.The display device of claim 9, further comprising: a first wing disposed between the first extension portion and the first inclined surface and rotatably coupled to a first rotation surface of the first body, the first rotation surface being superposed with a first boundary between a surface of the first body that faces the display module and that is disposed in the first non-folding area and the first inclined surface; a second wing disposed between the second extension portion and the second inclined surface and rotatably coupled to a second rotation surface of the second body, the second rotation surface being superposed with a second boundary between a surface of the first body that faces the display module and that is disposed in the second non-folding area and the second inclined surface; and a center frame disposed between the first wing and the second wing. ​ wherein the side portions of the first wing plate and the second wing plate facing each other are disposed in a groove defined in portions of the side portions of the center frame facing the display module and opposite to each other in the second direction.

11. The display device of claim 10, further comprising: an adhesive layer disposed between the first and second non-folded regions and the first and second bodies and between the first and second extension portions and the first and second wing plates.

12. The display device of claim 11, wherein, when the display module is folded, a first reverse curvature portion defined in a portion of the display module adjacent to a boundary between the first non-folded region and the first extension portion and curved in a manner opposite to the curved portion, and a second reverse curvature portion defined in a portion of the display module adjacent to a boundary between the second non-folded region and the second extension portion and curved in a manner opposite to the curved portion.

13. The display device of claim 12, wherein, the adhesive layer is not disposed on the curved portion and the first and second reverse curvature portions.

14. The display device of claim 12, wherein, first surfaces of the first and second wing plates facing the display module and disposed adjacent to the first and second boundaries and second surfaces of the first and second bodies facing the display module and disposed in the first and second non-folded regions and adjacent to the first and second boundaries have curved surfaces.

15. The display device of claim 12, wherein, side portions of the first and second boundaries and the first and second wing plates adjacent to the first and second boundaries are adjacent to central portions of the first and second reverse curvature portions.

16. The display device of claim 12, wherein, when the display module is folded, the first and second surfaces of the first and second wing plates facing the display module have curved surfaces corresponding to curved surfaces of the first and second reverse curvature portions.

17. The display device of claim 12, wherein, the first and second rotation surfaces have concave curved surfaces, the first wing plate includes a first coupling portion having a convex curved surface in contact with the first rotation surface, and the second wing plate includes a second coupling portion having a convex curved surface in contact with the second rotation surface.

18. The display device of claim 17, wherein, a center point of a circle defined by the curved surfaces of the first and second coupling portions is set in such a manner that lengths of neutral planes of the first and second reverse curvature portions when the first and second reverse curvature portions are curved are respectively equal to lengths of the first and second reverse curvature portions in the second direction when the first and second reverse curvature portions are unfolded, and the first and second coupling portions are respectively rotated about wing rotation axes defined at the center point. 19.The display device of claim 10, further comprising: a center frame disposed in the folding area, the center frame including a guide portion and a protruding portion protruding from the guide portion toward the folding area; and a plurality of protruding guides disposed on the guide portion, the plurality of protruding guides protruding from the first wing panel and the second wing panel toward the center frame, wherein the protruding portion is disposed between a first protruding guide of the first wing panel and a second protruding guide of the second wing panel, and when the display module is folded, the first protruding guide and the second protruding guide move along a surface of the guide portion facing the display module and in a direction away from the protruding portion.

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