Display device

Abstract

To provide a display device that improves the phenomena of wrinkles and buckling in a display device having a display panel capable of being folded and wound, or bent, and in a manufacturing method of the display device.SOLUTION: A display device includes: a display panel having a bending region, and a lower protection member which is disposed on a first surface of the display panel and contains a first substance. The first substance contains: an alloy of titanium (Ti)-niobium (Nb)-tantalum (Ta)-zirconium (Zr)-oxygen (O); or a crystal alloy of copper (Cu)-aluminum (Al)-manganese (Mn).SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a display device. [Background technology]

[0002] With the development of the information society, the demands for display devices for displaying images are becoming more and more diverse. The display devices may be flat (panel-shaped) display devices such as liquid crystal displays, field emission displays, light emitting displays, etc. The light emitting display devices may include organic light emitting display devices including organic light emitting diode elements as light emitting elements, or light emitting diode display devices including inorganic light emitting diode elements such as LEDs (Light Emitting Diodes) as light emitting elements.

[0003] Recently, in order to increase the portability of display devices and provide a wide display screen at the same time, bendable display devices whose display area can be bent or foldable display devices whose display area can be folded have been released. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Korean Patent Publication 2023-0011853 (KR10-2023-0011853A) [Patent Document 2] Korean Patent Publication 2022-0000014 (KR10-2022-0000014A) Summary of the Invention [Problem to be solved by the invention]

[0005] An object of the present invention is to provide a display device in which the phenomena of wrinkles and buckling are improved.

[0006] Another problem to be solved by the present invention is to provide a display device having improved impact resistance.

[0007] The object of the present invention is not limited to the above-mentioned objects, and other technical objects not mentioned will be clearly understood by those skilled in the art from the following description. [Means for solving the problem]

[0008] According to one embodiment of the present invention, a display device includes a display panel including a bending region, and a lower protective member disposed on a first surface of the display panel and including a first material, the first material including a titanium (Ti)-niobium (Nb)-tantalum (Ta)-zirconium (Zr)-oxygen (O) alloy or a copper (Cu)-aluminum (Al)-manganese (Mn) crystalline alloy.

[0009] The lower protection member may have an elastic deformation rate of 2.0% or more.

[0010] The lower protection member may have an elastic deformation rate of 4.0% or more.

[0011] The lower protection member may have a Young's modulus of 20 GPa to 80 GPa.

[0012] The lower protection member may have a Young's modulus of 20 GPa to 50 GPa.

[0013] The lower protective member may have a thickness of 10 μm to 50 μm.

[0014] The lower protective member may have a thickness of 10 μm to 30 μm.

[0015] The base may further include a panel support member disposed on one surface of the lower protection member and including a folded portion overlapping the folded region, and the panel support member may be directly attached onto the lower protection member via an adhesive member.

[0016] The bent portion may include a plurality of horizontal bars, a plurality of vertical bars intersecting the plurality of horizontal bars, and a plurality of slits disposed between the plurality of vertical bars, and the plurality of horizontal bars may connect the plurality of vertical bars.

[0017] The bent portion may include a plurality of vertical bars and a plurality of slits disposed between the plurality of vertical bars, the plurality of vertical bars being spaced apart from one another.

[0018] The panel support member may include a first non-folded portion and a second non-folded portion disposed on either side of the folded portion, the folded portion including a resin disposed between the first non-folded portion and the second non-folded portion, the resin may completely fill a space between the first non-folded portion and the second non-folded portion.

[0019] The display panel may include a second surface located opposite the first surface, and the display device may further include a wrinkled portion disposed in the folding region, the wrinkled portion extending toward the first surface on the second surface.

[0020] The wrinkles may have a vertical height of less than 5 μm.

[0021] The display device may further include a lower protection film disposed between the display panel and the lower protection member, the lower protection film including polyimide or polyethylene terephthalate.

[0022] A display device according to another embodiment for solving the above problem includes a display panel and a lower protective member arranged on one surface of the display panel, wherein the elastic deformation rate of the lower protective member may be 2.0% or more and the Young's modulus of the lower protective member may be 20 GPa to 80 GPa.

[0023] The lower protective member includes a titanium (Ti)-niobium (Nb)-tantalum (Ta)-zirconium (Zr)-oxygen (O) alloy or a copper (Cu)-aluminum (Al)-manganese (Mn) crystalline alloy.

[0024] The lower protective member may have a thickness of 10 μm to 50 μm.

[0025] A display device according to another embodiment for solving the above problem includes a display panel including a first surface and a second surface located opposite to the first surface, a first upper protective member arranged on the first surface of the display panel, a window member arranged on the first upper protective member, a second upper protective member arranged on the window member, a lower protective member arranged on the second surface of the display panel, and a panel support member arranged on the lower protective member, wherein the lower protective member includes a titanium (Ti)-niobium (Nb)-tantalum (Ta)-zirconium (Zr)-oxygen (O) alloy or a copper (Cu)-aluminum (Al)-manganese (Mn) crystalline alloy.

[0026] The lower protection member may have an elastic deformation rate of 2.0% or more.

[0027] The lower protection member may have a Young's modulus of 20 GPa to 80 GPa. Effect of the Invention

[0028] According to a display device according to an embodiment of the present invention, the phenomenon of wrinkles and buckling can be improved.

[0029] According to the display device according to the embodiment of the present invention, the impact resistance can be improved.

[0030] The effects of the embodiments are not limited to the above-mentioned examples, and more diverse effects are included in the present specification. [Brief description of the drawings]

[0031] [Figure 1]1 is a perspective view showing a display device according to an embodiment in an unfolded state; [Diagram 2] 1 is a perspective view illustrating a display device according to an embodiment in a folded state; [Diagram 3] FIG. 11 is a perspective view showing a display device according to another embodiment in an unfolded state. [Figure 4] FIG. 11 is a perspective view illustrating a display device according to another embodiment in a folded state. [Diagram 5] 1 is a cross-sectional view showing a display device according to an embodiment. [Figure 6] FIG. 2 is a cross-sectional view illustrating an example of a display panel according to an embodiment. [Figure 7] FIG. 2 is a plan view illustrating a panel support member according to one embodiment. [Figure 8] 8 is a cross-sectional view taken along the line X1-X1' in FIG. 7. [Figure 9] 1 is a graph showing a stress-strain curve of a lower protection member according to an embodiment. [Figure 10] 13 is a graph showing a stress-strain curve of a lower protection member according to another embodiment. [Figure 11] FIG. 2 is a perspective view showing a wrinkled portion of the display device according to the embodiment. [Figure 12] FIG. 4 is a side view showing a wrinkled portion of the display device according to the embodiment. [Figure 13] 4 is a side view illustrating a ball drop test process of a display device according to an embodiment; [Figure 14] FIG. 11 is a cross-sectional view showing a display device according to another embodiment. [Figure 15] FIG. 11 is a plan view showing a panel support member according to still another embodiment. [Figure 16] 16 is a cross-sectional view taken along the line X2-X2' in FIG. 15. [Figure 17] FIG. 11 is a plan view showing a panel support member according to still another embodiment. [Figure 18] 18 is a cross-sectional view taken along the line X3-X3' in FIG. 17. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0032] The advantages and features of the present invention, as well as the methods for achieving the same, will become clearer with reference to the following detailed embodiments in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, and may be realized in various different forms. The present embodiments are provided merely to complete the disclosure of the present invention and to fully inform those skilled in the art of the invention of the scope of the invention, and the present invention is defined only by the scope of the claims.

[0033] When elements or layers are referred to as "on" another element or layer, this includes either directly on top of the other elements or with other layers or elements intervening. Similarly, when elements or layers are referred to as "below," "left," and "right," this includes either directly adjacent to the other elements or with other layers or materials intervening. Like reference numbers refer to like elements throughout the specification.

[0034] Hereinafter, specific embodiments will be described with reference to the accompanying drawings.

[0035] Fig. 1 is a perspective view showing a display device according to an embodiment in an unfolded state, and Fig. 2 is a perspective view showing a display device according to an embodiment in a folded state.

[0036] Referring to Figures 1 and 2, Figure 1 shows a first state of the display device 10 unfolded and unfolded along the fold lines FL1 and FL2, and Figure 2 shows a second state of the display device 10 folded along the fold lines FL1 and FL2.

[0037] The display device 10 according to an embodiment is a device for displaying moving or still images, and can be used as a display screen for a variety of products, including portable electronic devices such as mobile phones, smart phones, tablet personal computers (PCs), smart watches, watch phones, mobile communication terminals, electronic organizers, electronic books, portable multimedia players (PMPs), navigation systems, and Ultra Mobile PCs (UMPCs), as well as televisions, notebook computers, monitors, billboards, and Internet of Things (IOT).

[0038] In the drawings, the first direction DR1 is a direction along one side of the display device 10 when viewed in a plan view, and may be, for example, the horizontal direction of the display device 10. The second direction DR2 is a direction along the other side that is in contact with the one side of the display device 10 when viewed in a plan view, and may be the vertical direction of the display device 10. The third direction DR3 may be the thickness direction of the display device 10.

[0039] The planar shape of the display device 10 may have a quadrangular shape, such as a rectangle. Each of the corners of the display device 10 may have a planar shape of a right angle or a rounded or chamfered corner. The front surface of the display device 10 may include two short sides arranged in a first direction DR1 and two long sides arranged in a second direction DR2.

[0040] The display device 10 may include a display area DA and a non-display area NDA. The planar shape of the display area DA may conform to the shape of the display device 10. For example, if the planar shape of the display device 10 is rectangular, the planar shape of the display area DA may also be rectangular.

[0041] The display area DA may be an area including a plurality of pixels and displaying an image. The non-display area NDA may be an area including no pixels and therefore not displaying an image. The non-display area NDA may be disposed around the display area DA. The non-display area NDA is disposed to surround the display area DA, but the embodiment of the present specification is not limited thereto. The display area DA may be partially surrounded by the non-display area NDA.

[0042] The display device 10 can maintain both a first state, which is an unfolded state, and a second state, which is a folded state. In one embodiment, the display device 10 can be folded in an in-folding manner such that the display areas DA face each other as shown in FIG. 2. In this case, the front faces of the display devices 10 can face each other when folded. In another embodiment, the display device 10 can be folded in an out-folding manner such that the rear faces face each other.

[0043] The display device 10 may include a folding region FDA, a first non-folding region NFA1, and a second non-folding region NFA2. The folding region FDA may be an area where the display device 10 is bent or folded, and the first non-folding region NFA1 and the second non-folding region NFA2 may be areas where the display device 10 is not bent or folded. In one embodiment, the first non-folding region NFA1 and the second non-folding region NFA2 may be flat areas of the display device 10.

[0044] The first non-folding area NFA1 may be disposed on one side of the folding area FDA, for example, on the left side. The second non-folding area NFA2 may be disposed on the other side of the folding area FDA, for example, on the right side. The folding area FDA is an area whose range is defined by the first folding line FL1 and the second folding line FL2, and may be an area where the display device 10 is bent with a predetermined curvature. The first folding line FL1 may be a boundary between the folding area FDA and the first non-folding area NFA1, and the second folding line FL2 may be a boundary between the folding area FDA and the second non-folding area NFA2.

[0045] 1 and 2, the first fold line FL1 and the second fold line FL2 extend in the second direction DR2, in which case the display device 10 can be folded based on the second direction DR2. This reduces the length of the display device 10 in the first direction DR1 to approximately half, making it convenient for users to carry the display device 10.

[0046] The first non-folding area NFA1 may be disposed on one side of the folding area FDA, e.g., the left side, and the second non-folding area NFA2 may be disposed on the other side of the folding area FDA, e.g., the right side, where the left side refers to one side in the first direction DR1, and the right side refers to the other side in the first direction DR1.

[0047] 1 and 2, when the first fold line FL1 and the second fold line FL2 extend in the second direction DR2, the length of the folding region FDA in the second direction DR2 may be longer than the length of the first direction DR1. Also, the length of the first non-folding region NFA1 in the second direction DR2 may be longer than the length of the first non-folding region NFA1 in the first direction DR1. The length of the second non-folding region NFA2 in the second direction DR2 may be longer than the length of the second non-folding region NFA2 in the first direction DR1.

[0048] Each of the display area DA and the non-display area NDA may overlap at least one of the folding area FDA, the first non-folding area NFA1, and the second non-folding area NFA2. In Fig. 1 and Fig. 2, each of the display area DA and the non-display area NDA overlaps with the folding area FDA, the first non-folding area NFA1, and the second non-folding area NFA2.

[0049] Fig. 3 is a perspective view showing a display device according to another embodiment in an unfolded state, and Fig. 4 is a perspective view showing a display device according to another embodiment in a folded state.

[0050] Referring to Figures 3 and 4, Figure 3 shows a first state of the display device 10 unfolded and unfolded along the fold lines FL1 and FL2, and Figure 2 shows a second state of the display device 10 folded along the fold lines FL1 and FL2.

[0051] In a first state in which the display device 10 is unfolded, the long sides of the display device 10 may extend along a second direction DR2, and the short sides of the display device 10 may extend along a first direction DR1.

[0052] The first fold line FL1 and the second fold line FL2 extend in a first direction DR1 as shown in FIG. 3 and FIG. 4, and in this case, the display device 10 can be folded based on the first direction DR1.

[0053] The first non-folding area NFA1 may be disposed on one side, e.g., the lower side, of the folding area FDA, and the second non-folding area NFA2 may be disposed on the other side, e.g., the upper side, of the folding area FDA, where the upper side refers to one side in the second direction DR2, and the lower side refers to the other side in the second direction DR2.

[0054] 3 and 4, the length of the folding area FDA in the first direction DR1 may be longer than the length of the second direction DR2. Also, the length of the first non-folding area NFA1 in the second direction DR2 may be longer than the length of the first non-folding area NFA1 in the first direction DR1. The length of the second non-folding area NFA2 in the second direction DR2 may be longer than the length of the second non-folding area NFA2 in the first direction DR1.

[0055] For convenience of explanation, the embodiment of FIG. 1 and FIG. 2 will be described below as an example. However, the present invention is not limited to this, and the following content can be similarly applied to the embodiment of FIG. 3 and FIG.

[0056] FIG. 5 is a cross-sectional view showing a display device according to an embodiment.

[0057] Referring to FIG. 5, a display device 10 according to one embodiment may include a first upper protection member 100, a first adhesive member ADH1, a window member 200, a second adhesive member ADH2, a second upper protection member 300, a third adhesive member ADH3, a display panel 400, a fourth adhesive member ADH4, a lower protection member 600, a fifth protection member ADH5, and a panel support member 700.

[0058] The display panel 400 may be a panel for displaying an image. The display panel 400 may be at least one of an organic light-emitting display panel including an organic light-emitting layer, a quantum dot light-emitting display panel including a quantum dot light-emitting layer, an inorganic light-emitting display panel using inorganic semiconductor elements as light-emitting elements, and a micro light-emitting display panel using micro light-emitting diodes as light-emitting elements. The following description will be focused on the case where the display panel 400 is an organic light-emitting display panel, but is not limited thereto.

[0059] The display panel 400 may include a light-transmitting area LTA overlapping the optical device OPD in the third direction DR3. The optical device OPD is an optical sensor that detects light, and may be, for example, a camera sensor, a proximity sensor, and an illuminance sensor. The light-transmitting area LTA may be a part of the display area DA.

[0060] The light-transmitting region LTA may include a transmissive region that can transmit light. Alternatively, the light-transmitting region LTA may be a region that includes a through-hole penetrating the display panel. The light transmittance of the light-transmitting region LTA may be higher than the light transmittance of the display region DA excluding the light-transmitting region LTA. In addition, due to the transmissive region of the light-transmitting region LTA, the density or integration of pixels in the light-transmitting region LTA may be lower than the density or integration of pixels in the display region DA excluding the light-transmitting region LTA. For example, the number of pixels per unit area in the light-transmitting region LTA may be smaller than the number of pixels per unit area in the display region DA excluding the light-transmitting region LTA. Alternatively, the PPI (Pixels Per Inch) in the light-transmitting region LTA may be smaller than the PPI in the display region DA excluding the light-transmitting region LTA.

[0061] The second upper protection member 300 may be disposed on the front surface of the display panel 400. The second upper protection member 300 may perform an impact absorbing function for protecting the display panel 400 from external impact. The second upper protection member 300 may include a material having high flexibility and high rigidity. For example, the second upper protection member 300 may include flexible plastic materials such as polyimide (PI) and polyethyleneterephthalte (PET).

[0062] In another embodiment, the second upper protection member 300 may have an anti-reflection function. The second upper protection member 300 may reduce the reflectance of external light incident from the upper side of the window member 200. In one embodiment, the second upper protection member 300 may include a phase retarder, a polarizer, and a destructive interference structure. For example, the phase retarder and the polarizer may be a film type or a liquid crystal coating type. The destructive interference structure may include a first reflective layer and a second reflective layer disposed on different layers. The first reflected light and the second reflected light reflected by the first reflective layer and the second reflective layer, respectively, may destructively interfere with each other, thereby reducing the reflectance of the external light.

[0063] The third adhesive member ADH3 may be disposed on the rear surface of the second upper protection member 300. For example, the third adhesive member ADH3 may be disposed between the second upper protection member 300 and the display panel 400. The second upper protection member 300 and the display panel 400 may be bonded to each other via the third adhesive member ADH3. The third adhesive member ADH3 may include a transparent adhesive such as a pressure sensitive adhesive (PSA) or an optically clear adhesive (OCA). The third adhesive member ADH3 may include an acrylic adhesive material.

[0064] The window member 200 may be attached onto the front surface of the second upper protection member 300. The window member 200 may be made of a transparent material, such as glass or plastic. For example, the window member 200 may be an ultra-thin glass (UTG) having a thickness of 0.1 mm or less, or a transparent polyimide film.

[0065] The second adhesive member ADH2 may be disposed on the back surface of the window member 200. For example, the second adhesive member ADH2 may be disposed between the window member 200 and the second upper protection member 300. The window member 200 and the second upper protection member 300 may be bonded to each other via the second adhesive member ADH2. The second adhesive member ADH2 may include a transparent adhesive such as a pressure sensitive adhesive (PSA) or an optically clear adhesive (OCA). The second adhesive member ADH2 may include an acrylic adhesive material.

[0066] The first upper protection member 100 may be disposed on the front surface of the window member 200. The first upper protection member 100 may perform at least one of the functions of shock absorption, scratch prevention, fingerprint prevention, glare prevention, and shatter prevention of the window member 200. The first upper protection member 100 may include a material that is highly flexible and scratch resistant. For example, the first upper protection member 100 may be a polymer film or a tempered glass film.

[0067] The first adhesive member ADH1 may be disposed on the back surface of the first upper protection member 100. For example, the first adhesive member ADH1 may be disposed between the first upper protection member 100 and the window member 200. The first upper protection member 100 and the window member 200 may be bonded to each other via the first adhesive member ADH1. The first adhesive member ADH1 may include a transparent adhesive such as a pressure sensitive adhesive (PSA) or an optically clear adhesive (OCA). The first adhesive member ADH1 may include an acrylic adhesive material.

[0068] The lower protection member 600 may be disposed on the rear surface of the display panel 400. The lower protection member 600 may have high elasticity and high flexibility. The display device 10 according to the present embodiment includes the lower protection member 600 having high elasticity and high flexibility on the rear surface of the display panel 400, so that the degree of bending deformation of the display device may be reduced even when the display device 10 is repeatedly folded and unfolded, which is advantageous for deformation restoration. In addition, the display device 10 according to the present embodiment may be minimised in terms of wrinkles and buckling, and may have improved impact resistance.

[0069] The lower protection member 600 will be described in more detail below with reference to FIGS.

[0070] The fourth adhesive member ADH4 may be disposed on the front surface of the lower protection member 600. For example, the fourth adhesive member ADH4 may be disposed between the display panel 400 and the lower protection member 600. The display panel 400 and the lower protection member 600 may be bonded to each other via the fourth adhesive member ADH4. The fourth adhesive member ADH4 may include a transparent adhesive such as a pressure sensitive adhesive (PSA) or an optically clear adhesive (OCA). The fourth adhesive member ADH4 may include an acrylic adhesive material.

[0071] The panel support member 700 may be disposed on the rear surface of the lower protection member 600. The panel support member 700 may be a rigid member whose shape and volume do not easily change due to external pressure. The panel support member 700 is disposed on the rear surface of the display panel 400 and is a rigid member whose shape and volume do not easily change due to external pressure, so that it can support the display panel 400.

[0072] In one embodiment, the panel support member 700 may be a metal plate. For example, the panel support member 700 may be made of a metal or a metal alloy as a metal plate. The panel support member 700 may include, but is not limited to, copper (Cu), aluminum (Al), stainless steel (SUS), and / or alloys thereof.

[0073] In another embodiment, the panel support member 700 may be a polymer containing carbon fiber or glass fiber. In this case, since the panel support member 700 is formed of a polymer containing carbon fiber or glass fiber, when the display device 10 includes a digitizer member, the electromagnetic signal of the digitizer member can pass through. Therefore, a panel support member 700 that can support the display panel 400 without reducing the touch sensitivity of the digitizer member can be provided.

[0074] The panel support member 700 may include a through hole STH overlapping with the optical device OPD in the third direction DR3. The through hole STH may overlap with the light-transmitting region LTA of the display panel 400 in the third direction DR3. The area of ​​the through hole STH may be greater than or equal to the area of ​​the light-transmitting region LTA. The optical device OPD may sense light incident from the front surface of the display device 10 through the light-transmitting region LTA and the through hole STH.

[0075] The panel support member 700 may include a lattice pattern disposed in the folding region FDA so as to be easily bent in the folding region FDA. By including the lattice pattern disposed in the folding region FDA, the panel support member 700 may be easily bent when the display device 10 is folded.

[0076] The panel support member 700 will be described in detail later with reference to FIGS.

[0077] The fifth adhesive member ADH5 may be disposed on the front surface of the panel support member 700. For example, the fifth adhesive member ADH5 may be disposed between the lower protection member 600 and the panel support member 700. The lower protection member 600 and the panel support member 700 may be bonded to each other via the fifth adhesive member ADH5. The fifth adhesive member ADH5 may include a transparent adhesive such as a pressure sensitive adhesive (PSA) or an optically clear adhesive (OCA). The fifth adhesive member ADH5 may include an acrylic adhesive material.

[0078] FIG. 6 is a cross-sectional view illustrating an example of a display panel according to an embodiment.

[0079] 6, the display panel 400 may include a substrate SUB, a display layer DISL disposed on the substrate SUB, and a touch sensing layer TDL disposed on the display layer DISL. The display layer DISL may include a thin film transistor layer TFTL, a light emitting element layer EML, and an encapsulation layer TFEL.

[0080] A thin film transistor layer TFTL may be disposed on the substrate SUB. The thin film transistor layer TFTL may include a barrier film BR, a thin film transistor TFT1, a first capacitor electrode CAE1, a second capacitor electrode CAE2, a first anode connecting electrode ANDE1, a second anode connecting electrode ANDE2, a gate insulating film 130, a first interlayer insulating film 141, a second interlayer insulating film 142, a first planarization film 160, and a second planarization film 180.

[0081] The substrate SUB may be made of an insulating material such as a polymer resin. For example, the substrate SUB may be made of polyimide. The substrate SUB may be a flexible substrate that is capable of bending, folding, rolling, and the like.

[0082] A barrier film BR may be disposed on the substrate SUB. The barrier film BR is a film for protecting the thin film transistors of the thin film transistor layer TFTL and the light emitting layer 172 of the light emitting element layer EML from moisture that may penetrate through the substrate SUB, which is susceptible to moisture permeation. The barrier film BR is made of a plurality of inorganic films that are alternately laminated. For example, the barrier film BR may be formed of a multi-film (laminate film) in which one or more inorganic films selected from the group consisting of a silicon nitride layer, a silicon oxynitride layer, a silicon oxide layer, a titanium oxide layer, and an aluminum oxide layer are alternately laminated.

[0083] A thin film transistor TFT1 may be disposed on the barrier film BR. An active layer ACT1 of the thin film transistor TFT1 may be disposed on the barrier film BR. The active layer ACT1 of the thin film transistor TFT1 may include polycrystalline silicon, single crystal silicon, low-temperature polycrystalline silicon, amorphous silicon, or an oxide semiconductor.

[0084] The active layer ACT1 may include a channel region CHA1, a source region TS1, and a drain region TD1. The channel region CHA1 may be a region overlapping with the gate electrode TG1 in a third direction DR3 that is a thickness direction of the substrate SUB. The source region TS1 may be disposed on one side of the channel region CHA1, and the drain region TD1 may be disposed on the other side of the channel region CHA1. The source region TS1 and the drain region TD1 may be regions that do not overlap with the gate electrode TG1 in the third direction DR3. The source region TS1 and the drain region TD1 may be regions in which ions or impurities are doped into a silicon semiconductor or an oxide semiconductor to have conductivity.

[0085] A gate insulating film 130 may be disposed on the active layer ACT1 of the thin film transistor TFT1. The gate insulating film 130 may be formed of an inorganic film, for example, a silicon nitride layer, a silicon oxynitride layer, a silicon oxide layer, a titanium oxide layer, or an aluminum oxide layer.

[0086] A gate electrode TG1 of the thin film transistor TFT1 and a first capacitor electrode CAE1 may be disposed on the gate insulating film 130. The gate electrode TG1 may overlap the channel region CHA1 in the third direction DR3. Although FIG. 6 illustrates a case in which the gate electrode TG1 and the first capacitor electrode CAE1 are disposed apart from each other, the gate electrode TG1 and the first capacitor electrode CAE1 may be connected to each other and formed as one piece. The gate electrode TG1 and the first capacitor electrode CAE1 may be formed as a single layer or multiple layers (stacked film) made of any one of molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd), and copper (Cu), or an alloy thereof.

[0087] A first interlayer insulating film 141 may be disposed on the gate electrode TG1 of the thin film transistor TFT1 and the first capacitor electrode CAE1. The first interlayer insulating film 141 may be formed of an inorganic film, for example, a silicon nitride layer, a silicon oxynitride layer, a silicon oxide layer, a titanium oxide layer, or an aluminum oxide layer. The first interlayer insulating film 141 may be formed of a plurality of inorganic films.

[0088] A second capacitor electrode CAE2 may be disposed on the first interlayer insulating film 141. The second capacitor electrode CAE2 may overlap the first capacitor electrode CAE1 of the thin film transistor TFT1 in the third direction DR3. In addition, when the gate electrode TG1 and the first capacitor electrode CAE1 are integrally formed, the second capacitor electrode CAE2 may overlap the gate electrode TG1 in the third direction DR3. Since the first interlayer insulating film 141 has a predetermined dielectric constant, a capacitor may be formed by the first capacitor electrode CAE1, the second capacitor electrode CAE2, and the first interlayer insulating film 141 disposed therebetween. The second capacitor electrode CAE2 may be formed of a single layer or multiple layers made of any one of molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd), and copper (Cu), or an alloy thereof.

[0089] A second interlayer insulating film 142 may be disposed on the second capacitor electrode CAE2. The second interlayer insulating film 142 may be formed of an inorganic film, for example, a silicon nitride layer, a silicon oxynitride layer, a silicon oxide layer, a titanium oxide layer, or an aluminum oxide layer. The second interlayer insulating film 142 may be formed of a plurality of inorganic films.

[0090] A first anode connecting electrode ANDE1 may be disposed on the second interlayer insulating film 142. The first anode connecting electrode ANDE1 may be connected to the drain region TD1 of the thin film transistor TFT1 through a first connecting contact hole ANCT1 penetrating the gate insulating film 130, the first interlayer insulating film 141, and the second interlayer insulating film 142. The first anode connecting electrode ANDE1 may be formed of a single layer or multiple layers made of any one of molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd), and copper (Cu), or an alloy thereof.

[0091] A first planarization film 160 for planarizing a step caused by the thin film transistor TFT1 may be disposed on the first anode connecting electrode ANDE1. The first planarization film 160 may be formed of an organic film such as an acrylic resin, an epoxy resin, a phenolic resin, a polyamide resin, or a polyimide resin.

[0092] A second anode connecting electrode ANDE2 may be disposed on the first planarization film 160. The second anode connecting electrode ANDE2 may be connected to the first anode connecting electrode ANDE1 through a second connecting contact hole ANCT2 penetrating the first planarization film 160. The second anode connecting electrode ANDE2 may be formed of a single layer or multiple layers made of any one of molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd), and copper (Cu), or an alloy thereof.

[0093] A second planarization film 180 may be disposed on the second anode connecting electrode ANDE2. The second planarization film 180 may be formed of an organic film such as an acrylic resin, an epoxy resin, a phenolic resin, a polyamide resin, or a polyimide resin.

[0094] A light emitting element layer EML including a light emitting element LEL and a bank 190 may be disposed on the second planarization film 180. Each of the light emitting elements LEL includes a pixel electrode 171, a light emitting layer 172, and a common electrode 173.

[0095] The pixel electrode 171 may be disposed on the second planarization layer 180. The pixel electrode 171 may be connected to the second anode connecting electrode ANDE2 through a third connecting contact hole ANCT3 penetrating the second planarization layer 180.

[0096] The pixel electrode 171 has a top emission structure that emits light from the light emitting layer 172 toward the common electrode 173, and may be made of a metal material with high reflectivity, such as a laminated structure of aluminum (Al) and titanium (Ti) (Ti / Al / Ti), a laminated structure of aluminum (Al) and ITO (indium tin oxide) (ITO / Al / ITO), a laminated structure of silver (Ag) and ITO (indium tin oxide) (ITO / Ag / ITO), an APC alloy, and a laminated structure of an APC alloy and ITO (ITO / APC / ITO). The APC alloy is an alloy of silver (Ag), palladium (Pd), and copper (Cu).

[0097] The bank 190 may be formed on the second planarization film 180 to define the pixel electrodes 171 in order to define the light emitting portions EA1 and EA2. The bank 190 may be disposed to cover the edges of the pixel electrodes 171. The bank 190 may be formed of an organic film such as an acrylic resin, an epoxy resin, a phenolic resin, a polyamide resin, or a polyimide resin.

[0098] Each of the first light-emitting section EA1 and the second light-emitting section EA2 represents an area in which a pixel electrode 171, a light-emitting layer 172, and a common electrode 173 are sequentially stacked, and light is emitted by holes from the pixel electrode 171 and electrons from the common electrode 173 recombining in the light-emitting layer 172.

[0099] An emitting layer 172 may be disposed on the pixel electrode 171 and the bank 190. The emitting layer 172 may include an organic material and emit a predetermined color. For example, the emitting layer 172 may include a hole transporting layer, an organic material layer, and an electron transporting layer.

[0100] The common electrode 173 may be disposed on the light emitting layer 172. The common electrode 173 may be disposed so as to cover the light emitting layer 172. The common electrode 173 may be a common layer formed in common to the first light emitting unit EA1 and the second light emitting unit EA2.

[0101] In the upper light emitting structure, the common electrode 173 may be made of a transparent metal material (TCO, Transparent Conductive Material) such as ITO or IZO that can transmit light, or a semi-transmissive metal material such as magnesium (Mg), silver (Ag), or an alloy of magnesium (Mg) and silver (Ag). When the common electrode 173 is made of a semi-transmissive metal material, the light output efficiency may be increased due to micro cavities.

[0102] A spacer 191 may be disposed on the bank 190. The spacer 191 may play a role in supporting a mask during a manufacturing process for manufacturing the light emitting layer 172. The spacer 191 may be formed of an organic film such as an acrylic resin, an epoxy resin, a phenolic resin, a polyamide resin, or a polyimide resin.

[0103] In some embodiments, the display panel 400 may further include a capping layer CPL disposed on the common electrode 173. The capping layer CPL may include an inorganic material. For example, the capping layer CPL may include at least one of silicon nitride, aluminum nitride, zirconium nitride, titanium nitride, hafnium nitride, tantalum nitride, silicon oxide, aluminum oxide, titanium oxide, tin oxide, cerium oxide, and silicon oxynitride.

[0104] An encapsulation layer TFEL may be disposed on the common electrode 173. The encapsulation layer TFEL may include at least one inorganic film to prevent oxygen or moisture from penetrating into the light-emitting element layer EML. The encapsulation layer TFEL may also include at least one organic film to protect the light-emitting element layer EML from foreign matter such as dust. For example, the encapsulation layer TFEL may include a first encapsulation inorganic film TFE1, a encapsulation organic film TFE2, and a second encapsulation inorganic film TFE3.

[0105] The first sealing inorganic film TFE1 may be disposed on the common electrode 173, the sealing organic film TFE2 may be disposed on the first sealing inorganic film TFE1, and the second sealing inorganic film TFE3 may be disposed on the sealing organic film TFE2. The first sealing inorganic film TFE1 and the second sealing inorganic film TFE3 may be formed of a multi-layer in which one or more inorganic films selected from a silicon nitride layer, a silicon oxynitride layer, a silicon oxide layer, a titanium oxide layer, and an aluminum oxide layer are alternately laminated. The sealing organic film TFE2 may be an organic film such as an acrylic resin, an epoxy resin, a phenolic resin, a polyamide resin, or a polyimide resin.

[0106] A touch sensing layer TDL may be disposed on the encapsulation layer TFEL. The touch sensing layer TDL includes a first touch insulating film TINS1, a connecting electrode BE, a second touch insulating film TINS2, a driving electrode TE, a sensing electrode RE, and a third touch insulating film TINS3.

[0107] The first touch insulating film TINS1 may be disposed on the encapsulation layer TFEL. The first touch insulating film TINS1 may be formed of an inorganic film, for example, a silicon nitride layer, a silicon oxynitride layer, a silicon oxide layer, a titanium oxide layer, or an aluminum oxide layer.

[0108] A connecting electrode BE may be disposed on the first touch insulating film TINS1. The connecting electrode BE may be formed of a single layer or multiple layers made of any one of molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd), and copper (Cu), or an alloy thereof.

[0109] A second touch insulating film TINS2 may be disposed on the connecting electrode BE. The second touch insulating film TINS2 may be formed of an inorganic film, for example, a silicon nitride layer, a silicon oxynitride layer, a silicon oxide layer, a titanium oxide layer, or an aluminum oxide layer. Alternatively, the second touch insulating film TINS2 may be formed of an organic film such as an acrylic resin, an epoxy resin, a phenolic resin, a polyamide resin, or a polyimide resin.

[0110] A driving electrode TE and a sensing electrode RE may be disposed on the second touch insulating film TINS2. The driving electrode TE and the sensing electrode RE may be formed of a single layer or multiple layers made of any one of molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd), and copper (Cu), or an alloy thereof.

[0111] The driving electrodes TE and the sensing electrodes RE may overlap with the connecting electrodes BE in a third direction DR3. The driving electrodes TE may be connected to the connecting electrodes BE through touch contact holes TCNT1 penetrating the first touch insulating film TINS1.

[0112] A third touch insulating film TINS3 may be formed on the driving electrode TE and the sensing electrode RE. The third touch insulating film TINS3 may play a role in planarizing steps formed by the driving electrode TE, the sensing electrode RE, and the connecting electrode BE. The third touch insulating film TINS3 may be formed of an organic film such as an acrylic resin, an epoxy resin, a phenolic resin, a polyamide resin, or a polyimide resin.

[0113] Fig. 7 is a plan view showing a panel support member according to an embodiment, and Fig. 8 is a cross-sectional view taken along line X1-X1' in Fig. 7.

[0114] 7 and 8, panel support member 700 may include a folding portion 710, a first non-folding portion 720, and a second non-folding portion 730. The folding portion 710 may be disposed in the folding area FDA, the first non-folding portion 720 may be disposed in the first non-folding area NFA1, and the second non-folding portion 730 may be disposed in the second non-folding area NFA2.

[0115] The first non-bending portion 720 and the second non-bending portion 730 may be portions that are not folded when the display device 10 is folded. The first non-bending portion 720 may be disposed on one side of the bending portion 710 in the first direction DR1, and the second non-bending portion 730 may be disposed on the other side of the bending portion 710 in the first direction DR1. A through hole STH penetrating the panel support member 700 may be disposed in the first non-bending portion 720. The through hole STH may be disposed adjacent to one side of the first non-bending portion 720 in the second direction DR2.

[0116] The folding portion 710 may be a portion that is folded when folding the display device 10. The folding portion 710 may be disposed between the first non-folding portion 720 and the second non-folding portion 730 in the first direction DR1.

[0117] The bent portion 710 may include a lattice pattern. For example, the bent portion 710 may include a plurality of slits SLT disposed between the plurality of bars BAR.

[0118] The multiple bars BAR may include multiple horizontal bars HBAR each extending in a first direction DR1, and multiple vertical bars VBAR each extending in a second direction DR2.

[0119] The vertical bars VBAR may be disposed between the slits SLT in the first direction DR1. The vertical bars VBAR may be disposed between the horizontal bars HBAR in the first direction DR1. The vertical bars VBAR may be connected to the horizontal bars HBAR on one side and the other side. The vertical bars VBAR may extend across the entire bent portion 710 in the second direction DR2.

[0120] The horizontal bars HBAR may be disposed between the slits SLT in the second direction DR2, respectively. The horizontal bars HBAR may be disposed between the vertical bars VBAR in the first direction DR1, respectively.

[0121] A plurality of horizontal bars HBAR adjacent to each other along the first direction DR1 do not overlap each other in the first direction DR1. For example, horizontal bars HBAR arranged in odd-numbered rows overlap each other in the first direction DR1, and horizontal bars HBAR arranged in even-numbered rows overlap each other in the first direction DR1, but horizontal bars HBAR arranged in odd-numbered rows and horizontal bars HBAR arranged in even-numbered rows do not overlap each other in the first direction DR1.

[0122] Each of the slits SLT may be a hole penetrating the panel support member 700 in the third direction DR3. Each of the slits SLT may extend in the second direction DR2. For example, the length of each of the slits SLT in the second direction DR2 may be longer than the length of each of the slits SLT in the first direction DR1.

[0123] The multiple slits SLT adjacent to each other in the first direction DR1 may be arranged alternately in the second direction DR2. For example, the multiple slits SLT arranged in odd-numbered rows have their second direction ends overlapping each other in the first direction DR1, and the multiple slits SLT arranged in even-numbered rows have their second direction ends overlapping each other in the first direction DR1, and the ends of the multiple slits SLT arranged in odd-numbered rows and the ends of the slits SLT arranged in even-numbered rows do not overlap each other in the first direction DR1.

[0124] In the display device 10 according to the present embodiment, the folding portion 710 may have flexibility by including a plurality of slits SLT, that is, the folding portion 710 may be stretched in a first direction DR1 when the display device 10 is folded.

[0125] 9 and 10 are graphs showing stress-strain curves of a lower protection member according to one embodiment and another embodiment, respectively.

[0126] 9 and 10 in addition to FIG. 5, in the display device 10 according to the present embodiment, the lower protection member 600 may have high elasticity and high flexibility. The display device 10 according to the present embodiment includes the lower protection member 600 having high elasticity and high flexibility on the rear surface of the display panel 400, so that even when the display device 10 is repeatedly folded and unfolded, the degree of bending deformation of the display device may be reduced, which is advantageous for deformation restoration. In addition, the wrinkles and buckling phenomenon of the display device 10 according to the present embodiment may be minimized, and impact resistance may be improved.

[0127] For example, the display device 10 according to the present embodiment may not crack or buckle even after repeated folding and unfolding about 100,000 times or more. In addition, the wrinkle phenomenon may be improved due to the restoring force of the lower protection member 600 having high elasticity and flexibility.

[0128] In some embodiments, the thickness of the lower protection member 600, that is, the length (dimension) in the third direction DR3, may be approximately 10 μm to 50 μm. Preferably, the thickness of the lower protection member 600 may be approximately 10 μm to 30 μm.

[0129] In some embodiments, the elastic strain of the lower protection member 600 may be approximately 2.0% or more. Preferably, the elastic strain of the lower protection member 600 may be approximately 4.0% or more. In the display device 10 according to the present embodiment, the lower protection member 600 has an elastic strain of 2.0% or more, so that the phenomenon of wrinkles and buckling of the display device 10 can be minimized.

[0130] In some embodiments, the Young's modulus value of the lower protection member 600 may be approximately 20 GPa to 80 GPa. Preferably, the Young's modulus of the lower protection member 600 may be approximately 20 GPa to 50 GPa. In the display device 10 according to the present embodiment, the lower protection member 600 has a Young's modulus of 20 GPa to 80 GPa, so that the impact resistance of the display device 10 may be improved.

[0131] The elastic deformation rate and Young's modulus in the above can be values ​​measured by a standard tensile test ISO527-1 or JIS K 7161-1.

[0132] In order to achieve the above elastic deformation rate and Young's modulus, the lower protection member 600 may include a titanium (Ti)-niobium (Nb)-tantalum (Ta)-zirconium (Zr)-oxygen (O) alloy or a copper (Cu)-aluminum (Al)-manganese (Mn) crystalline alloy as a highly elastic and flexible material.

[0133] A first graph G1 in Fig. 9 is a graph showing a stress-strain curve (SS curve) according to tension when the lower protection member 600 contains a titanium (Ti)-niobium (Nb)-tantalum (Ta)-zirconium (Zr)-oxygen (O) alloy. A second graph G2 in Fig. 10 is a graph showing a stress-strain curve according to tension when the lower protection member 600 contains a copper (Cu)-aluminum (Al)-manganese (Mn) crystalline alloy.

[0134] As shown in FIG. 9, when the lower protection member 600 includes a titanium (Ti)-niobium (Nb)-tantalum (Ta)-zirconium (Zr)-oxygen (O) alloy, the lower protection member 600 can maintain a maximum elastic deformation state at a first elastic limited point (ELP1) where a vertical line of a first tensile deformation rate (strain, STA1) intersects with a horizontal line of a first tensile stress (stress, STE1).

[0135] The tensile deformation rate indicates the degree to which a material is deformed in response to tensile stress as a percentage, and may be the same indicator as the elastic deformation rate described above. The elastic limit point refers to the point where the line of the maximum stress at which the material can maintain an elastic deformation state intersects with the line of the maximum deformation rate. The elastic deformation state refers to the deformation state to which the material can return to its original state when the applied stress is removed. When the stress gradually increases and exceeds the elastic limit point, the material can no longer maintain the elastic deformation state and undergoes plastic deformation.

[0136] When the lower protection member 600 includes a titanium (Ti)-niobium (Nb)-tantalum (Ta)-zirconium (Zr)-oxygen (O) alloy, the first tensile deformation rate STA1 at the first elastic limit point ELP1 may be approximately 2.5% or more. Also, when the lower protection member 600 includes a titanium (Ti)-niobium (Nb)-tantalum (Ta)-zirconium (Zr)-oxygen (O) alloy, the first Young's modulus M1 may be approximately 40 GPa or more.

[0137] Young's modulus means the slope of the elastic region, and the elastic region means the section from the origin to the tensile deformation rate of the elastic limit point. For example, the first Young's modulus M1 means the slope of the line connecting the origin and the first elastic limit point ELP1, and the elastic region of the first graph G1 means the section from the origin to the first tensile deformation rate STA1.

[0138] On the other hand, as shown in FIG. 10, when the lower protection member 600 includes a copper (Cu)-aluminum (Al)-manganese (Mn) crystalline alloy, the lower protection member 600 can maintain a maximum deformation state at a second elastic limit point ELP2 where the second tensile deformation rate STA2 and the second tensile stress STE2 intersect.

[0139] When the lower protection member 600 includes a copper (Cu)-aluminum (Al)-manganese (Mn) crystal alloy, the second tensile deformation rate STA2 at the second elastic limit point ELP2 may be approximately 4.0% or more. Also, when the lower protection member 600 includes a copper (Cu)-aluminum (Al)-manganese (Mn) crystal alloy, the second Young's modulus M2 may be approximately 15 GPa or more.

[0140] As described above, Young's modulus means the slope of the elastic region, and the elastic region means the section from the origin to the tensile deformation rate of the elastic limit point. Therefore, the second Young's modulus M2 means the slope of the line connecting the origin and the second elastic limit point ELP2, and the elastic region of the second graph G2 means the section from the origin to the second tensile deformation rate STA2.

[0141] In the display device 10 according to the present embodiment, the lower protection member 600 has a high elastic deformation rate and an appropriate level of Young's modulus, thereby having high elasticity and high flexibility. Therefore, the wrinkles and buckling phenomena of the display device 10 can be minimized, and the impact resistance can be improved. This will be described with reference to FIGS. 11 to 13.

[0142] Fig. 11 is a perspective view illustrating a wrinkled portion of a display device according to an embodiment, Fig. 12 is a side view illustrating a wrinkled portion of a display device according to an embodiment, and Fig. 13 is a side view illustrating a ball drop test process of a display device according to an embodiment.

[0143] 11 to 13, in some embodiments, the display device 10 may include a wrinkled portion CRS as shown in FIGS. 11 and 12. The wrinkled portion CRS may be located in the folding region FDA. The wrinkled portion CRS may extend along the second direction DR2. The wrinkled portion CRS may be shaped to be concave toward the center in the first direction DR1. The wrinkled portion CRS may be formed by repeatedly folding and unfolding the display device 10. The height of the wrinkled portion CRS may be a first height H1.

[0144] 13, a ball drop test may be performed to test the impact resistance of the display device 10. The height at which the ball is dropped may be a second height H2. The second height H2 may be the distance between the bottom of the ball and the top of the display device 10.

[0145] Table 1 below shows comparative experimental data on the first height H1, which is the height of the wrinkled portion CRS of the display device 10, the second height H2, which is the height at which a ball falls, and the limit number of bending times, in each application example and comparative example according to the material, thickness, Young's modulus, and elastic deformation rate of the lower protection member 600 of the display device 10. The limit number of bending times means the maximum number of bending times at which cracks or buckling occur in the display device 10.

[0146] The material, thickness, Young's modulus, and elastic deformation rate values ​​of the lower protection member 600 are not limited to the experimental data values ​​in Table 1 below, and the first height H1, second height H2, and limit number of bending times are measured under conditions of room temperature and normal pressure and are not limited thereto.

[0147] [Table 1]

[0148] The lower protective member 600 in the display device 10 according to the first application example may include a copper (Cu)-aluminum (Al)-manganese (Mn) crystalline alloy. The lower protective member 600 in the display device 10 according to the second application example may include a titanium (Ti)-niobium (Nb)-tantalum (Ta)-zirconium (Zr)-oxygen (O) alloy. The display device 10 according to the first comparative example may not include the lower protective member 600. The lower protective member 600 in each of the display devices 10 according to the second to fourth comparative examples may include polyimide (PI), ultra thin glass (UTG), nano stainless steel (Nano SUS), and stainless steel (SUS), respectively.

[0149] The thickness of the lower protective member 600 in the display device 10 according to the first application example, the second application example, and the third comparative example was measured as an example when it was about 30 μm. In the display device 10 according to the second comparative example, the lower protective member 600 includes polyimide having a relatively low Young's modulus value, and in order to achieve a minimum Young's modulus value, the thickness of the lower protective member 600 in the display device 10 according to the second comparative example was measured as an example when it was about 35 μm. In the display device 10 according to the fourth comparative example and the fifth comparative example, the lower protective member 600 includes nano SUS or SUS having a relatively high Young's modulus value, and in order to lower the Young's modulus value, the thickness of the lower protective member 600 in the display device 10 according to the fourth comparative example and the fifth comparative example was measured as an example when it was about 22 μm and 10 μm, respectively.

[0150] The Young's modulus values ​​of the lower protection member 600 in the display devices 10 according to the first application example, the second application example, the second comparative example, the third comparative example, the fourth comparative example, and the fifth comparative example may be approximately 23 GPa, 70 GPa, 4 GPa, 68 GPa, 170 GPa, and 180 GPa, respectively.

[0151] The lower protection member 600 in the display device 10 according to the first and second application examples may have a Young's modulus value of 20 GPa to 80 GPa. Therefore, the impact resistance of the display device 10 according to the first and second application examples may be improved. For example, the second height H2, which is the height at which a ball (BAL) falls in a ball drop test, may be larger in the display device 10 according to the first and second application examples than in the other first to fifth comparative examples. The second height H2 in the display device 10 according to the first and second application examples may be approximately 20 cm and 25 cm, respectively, and the second height H2 in the display device 10 according to the first to fifth comparative examples may be 20 cm or less.

[0152] In addition, the display devices 10 according to the first and second application examples did not crack or buckle even after being folded 200,000 times or more and 100,000 times or more, respectively. On the other hand, the display devices 10 according to the third to fifth comparative examples may crack or buckle even after being folded less than 100 times.

[0153] On the other hand, the elastic deformation rates of the lower protection member 600 in the display devices 10 according to the first application example, the second application example, the second comparative example, the third comparative example, the fourth comparative example, and the fifth comparative example may be approximately 4.3%, 2.5%, 2%, less than 0.2%, less than 0.2%, and less than 0.2%, respectively.

[0154] The lower protection member 600 in the display device 10 according to the first and second application examples may have an elastic deformation rate of 2.0% or more. Therefore, the display device 10 according to the first and second application examples may minimize the phenomenon of wrinkles and buckling. For example, the first height H1, which is the height of the wrinkled portion CRS, may be smaller in the display device 10 according to the first and second application examples than in the other first to fifth comparative examples. The first height H1 in the display device 10 according to the first and second application examples may be approximately 2.6 μm and 3.1 μm, respectively, and the first height H1 in the display device 10 according to the first to fifth comparative examples may be 5 μm or more.

[0155] Meanwhile, in the display device 10 according to the present embodiment, as shown in Fig. 5, the lower protection member 600 having high elasticity and high flexibility is directly attached onto the panel support member 700, thereby improving the shear characteristics. For example, as shown in Fig. 11, when the first shear force F1 acts on one side of the second direction DR2 of the first non-folding area NFA1 and the second shear force F2 acts on the other side of the second direction DR2 of the second non-folding area NFA2, the impact resistance due to the first and second shear forces F1 and F2 can be improved. Such shear characteristics can be improved by directly attaching the panel support member 700 having high rigidity and the lower protection member 600 having high elasticity and high flexibility.

[0156] In the following, another embodiment of the display device according to the embodiment will be described. In the following embodiment, the same reference numerals are used for the same components as those in the above-described embodiment, and the description will be omitted or simplified, focusing on the differences.

[0157] FIG. 14 is a cross-sectional view showing a display device according to another embodiment.

[0158] 14, the display device 10 according to the present embodiment differs from the display device 10 according to the embodiment described with reference to FIG. 5 and the like in that it further includes a lower protective film 500. As shown in FIG.

[0159] More specifically, the display device 10 may further include a lower protective film 500 .

[0160] The lower protective film 500 may be disposed on the rear surface of the display panel 400. For example, the lower protective film 500 may be disposed between the display panel 400 and the lower protective member 600. The lower protective film 500 may be a layer that protects the rear surface of the display panel 400. The lower protective film 500 may include a synthetic resin film. For example, the lower protective film 500 may be a polyimide film or a polyethylene terephthalate film.

[0161] The sixth adhesive member ADH6 may be disposed on the front surface of the lower protection film 500. For example, the sixth adhesive member ADH6 may be disposed between the display panel 400 and the lower protection film 500. The display panel 400 and the lower protection film 500 may be bonded to each other via the sixth adhesive member ADH6. The sixth adhesive member ADH6 may include a transparent adhesive such as a pressure sensitive adhesive (PSA) or an optically clear adhesive (OCA). The sixth adhesive member ADH6 may include an acrylic adhesive material.

[0162] The display device 10 according to the present embodiment includes a lower protective film 500 on the rear surface of the display panel 400, thereby minimizing damage to the display panel 400 when the highly flexible display panel 400 is moved or when a process of attaching the display panel 400 to other components is performed.

[0163] Fig. 15 is a plan view showing a panel support member according to another embodiment. Fig. 16 is a cross-sectional view taken along the line X2-X2' in Fig. 15.

[0164] 15 and 16 in addition to FIG. 5, the display device 10 according to this embodiment differs from the display device 10 according to the embodiment described with reference to FIG. 7 etc. in that the lattice pattern shape of the folding portion 710 of the panel support member 700 is different.

[0165] More specifically, the bent portion 710 may include a lattice pattern. For example, the bent portion 710 may include a plurality of bars BAR and a plurality of slits SLT disposed between the plurality of bars BAR.

[0166] The multiple bars BAR may include multiple vertical bars VBAR extending in the second direction DR2.

[0167] The vertical bars VBAR may be spaced apart from one another in the first direction DR1. The vertical bars VBAR may not be connected to one another and may be physically separated from one another. Each of the vertical bars VBAR separated from one another may be fixed onto the rear surface of the lower protection member 600 by a fifth adhesive member ADH5 disposed on the panel support member 700.

[0168] A plurality of slits SLT may be arranged between the plurality of vertical bars VBAR spaced apart from one another. Each of the plurality of vertical bars VBAR may extend across the entire bent portion 710 in the second direction DR2.

[0169] The vertical bars VBAR may be disposed between the first unfolded portion 720 and the second unfolded portion 730 in the first direction DR1. The vertical bars VBAR may be disposed apart from the first unfolded portion 720 and the second unfolded portion 730 in the first direction DR1. The vertical bars VBAR may be configured to be physically separated from the first unfolded portion 720 and the second unfolded portion 730 without being connected thereto.

[0170] In the display device 10 according to this embodiment, a plurality of vertical bars VBAR that are spaced apart and not connected to each other are attached to the rear surface of the lower protection member 600, thereby improving the impact resistance of the display device 10 and increasing elasticity to minimize wrinkles and buckling phenomena.

[0171] Fig. 17 is a plan view showing a panel support member according to still another embodiment, and Fig. 18 is a cross-sectional view taken along line X3-X3' in Fig. 17.

[0172] 17 and 18 in addition to FIG. 5, the display device 10 according to this embodiment differs from the display device 10 according to the embodiment described above with reference to FIG. 7 and FIG. 15, etc. in that the bending portion 710 includes a resin RSN.

[0173] More specifically, the folded portion 710 may include a resin RSN. For example, the folded portion 710 may include a resin RSN disposed between a first unfolded portion 720 and a second unfolded portion 730.

[0174] The resin RSN may fill the space of the folded portion 710 located between the first unfolded portion 720 and the second unfolded portion 730. In one embodiment, the resin RSN may be disposed over the entire folded area FDA. The resin RSN may be fixed onto the back surface of the lower protection member 600 by a fifth adhesive member ADH5.

[0175] The resin RSN may include a material that absorbs external shocks, such as, but not limited to, a urethane resin, an epoxy resin, an acrylic resin, a silicone resin, or an inorganic sealant.

[0176] The display device 10 according to the present embodiment includes the resin RSN on the rear surface of the lower protection member 600, thereby minimizing the repulsive force applied to the display panel 400 when the display device 10 is folded. As a result, the buckling phenomenon of the display device 10 is minimized, and the impact resistance of the display device 10 is improved. In addition, by filling the space between the first non-folding portion 720 and the second non-folding portion 730 with the resin RSN, it is possible to prevent the display panel 400 from entering the space between the first non-folding portion 720 and the second non-folding portion 730 and forming wrinkles.

[0177] Although the embodiment of the present invention has been described above with reference to the accompanying drawings, those skilled in the art will understand that the present invention can be embodied in other specific forms without changing the technical idea or essential features of the present invention. Therefore, it should be understood that the above embodiment is illustrative in all respects and is not limiting.

[0178] According to one preferred embodiment, the following is true:

[0179] The background and issues of this case are as follows (i) to (iv). (i) Display panels used in mobile devices such as smartphones are now commercially available that can be folded in half widthwise or lengthwise in order to "increase portability while providing a wide display screen." Research, development, and production are also underway for panels that can be folded in three, etc., and panels that can be rolled up.

[0180] (ii) Various studies have been conducted to prevent wrinkles and breakage even when the display is repeatedly folded. Among these, attempts have been made to place a window member or the like on the front surface of a flexible display substrate and to place a bendable protective (support) plate on the back surface (Patent Documents 1 and 2).

[0181] (iii) Patent Document 1 also discloses using a metal having a composition of 55-70% Zr, 15-20% Cu, 10-15% Ni, 2-6% Al, and 1-5% Ti as a protective (support) plate (

[0521] ), and also discloses configuring the folded parts of this metal plate in a kind of mesh shape (Figures 6a-6b).

[0182] (iv) The demand for durability against repeated folding is becoming higher, and further improvements are needed to meet this demand.

[0183] Therefore, in particularly preferred embodiments, A1 to A4 are as follows. A1 A Cu-Al-Mn crystalline alloy (Application Example 1 of the present application) or a Ti-Nb-Ta-Zr-O alloy (Application Example 2 of the present application) is used as the material for the protective (support) plate (the "panel support member 700" of the present application).

[0184] A2 The protective (supporting) plate has a Young's modulus of 20 GPa to 50 GPa, a thickness of 10 μm to 30 μm, and an elastic deformation rate of 4.0% or more.

[0185] A3 The belt-shaped folded portion (700) of the protective (support) plate (the "panel support member 700" of the present application) is configured in a mesh shape so that it can easily expand and contract in the left-right direction (the direction crossing the folded portion) when folded (FIGS. 7-8 of the present application). In particular, they are configured in a staggered lattice as shown in Fig. 7 of the present application. That is, strip-shaped (long, narrow rectangular) slits are arranged so that adjacent ones in the left-right direction are staggered.

[0186] A4: Instead of A3, the bent portion (700) is made up of multiple rod-shaped parts separated from each other in the left-right direction (direction across the bent portion), and these rod-shaped parts are connected with adhesive, pressure sensitive adhesive, or resin. (Figure 15 of the present application) [Explanation of symbols]

[0187] 10 Display device FDA Bend Area NFA1,NFA2 First and second non-folding regions FL1,FL2 1st and 2nd fold curves 100 First upper protective member 200 Window Materials 300 Second upper protective member 400 Display Panel 500 Bottom protection film 600 Lower protection member 700 Panel support member ADH1 to ADH6: First to sixth adhesive members LTA light transmission area OPD optical device STH through hole 710 Bending part 720,730 First and second non-folding portions BAR VBAR Vertical Bar HBAR Horizontal Bar SLT Slit ELP1,ELP2 First and second elastic limit points STA1, STA2 First and second tensile deformation ratios STE1, STE2 First and second tensile stresses M1,M2 First and second Young's modulus CRS wrinkle section H1,H2 First and second heights BAL Ball RSN Resin

Claims

1. A display panel including a fold region; and a lower protective member disposed on a first surface of the display panel and including a first material; The display device, wherein the first material comprises a titanium (Ti)-niobium (Nb)-tantalum (Ta)-zirconium (Zr)-oxygen (O) alloy or a copper (Cu)-aluminum (Al)-manganese (Mn) crystalline alloy.

2. The display device according to claim 1 , wherein the lower protection member has an elastic deformation rate of 2.0% or more.

3. The display device according to claim 2 , wherein the lower protection member has an elastic deformation rate of 4.0% or more.

4. 2. The display device according to claim 1, wherein the lower protection member has a Young's modulus of 20 GPa to 80 GPa.

5. 5. The display device according to claim 4, wherein the lower protection member has a Young's modulus of 20 GPa to 50 GPa.

6. 2. The display device according to claim 1, wherein the lower protection member has a thickness of 10 μm to 50 μm.

7. 7. The display device according to claim 6, wherein the lower protection member has a thickness of 10 μm to 30 μm.

8. a panel support member disposed on one surface of the lower protection member and including a folding portion overlapping the folding region; The display device according to claim 1 , wherein the panel support member is directly attached onto the lower protection member via an adhesive member.

9. The bent portion is Multiple horizontal bars, a plurality of vertical bars intersecting the plurality of horizontal bars; and a plurality of slits disposed between the plurality of vertical bars; The display device of claim 8 , wherein the plurality of horizontal bars connect the plurality of vertical bars.

10. The bent portion is Multiple vertical bars, and a plurality of slits disposed between the plurality of vertical bars; The display device of claim 8 , wherein the vertical bars are spaced apart from one another.

11. the panel support member includes a first non-bending portion and a second non-bending portion disposed on either side of the bending portion, the bent portion includes a resin disposed between the first non-bent portion and the second non-bent portion, The display device of claim 8 , wherein the resin completely fills a space between the first unfolded portion and the second unfolded portion.

12. the display panel includes a second surface opposite the first surface; The display device according to claim 1 , further comprising a wrinkled portion disposed in the folding region and indented on the second surface toward the first surface.

13. The display device of claim 12 , wherein the wrinkles have a vertical height of less than 5 μm.

14. A display panel; and a lower protection member disposed on one surface of the display panel, The elastic deformation rate of the lower protection member is 2.0% or more, The display device, wherein the lower protection member has a Young's modulus of 20 GPa to 80 GPa.

15. 15. The display device of claim 14, wherein the lower protective member comprises a titanium (Ti)-niobium (Nb)-tantalum (Ta)-zirconium (Zr)-oxygen (O) alloy or a copper (Cu)-aluminum (Al)-manganese (Mn) crystalline alloy.

16. The display device according to claim 14, wherein the lower protection member has a thickness of 10 μm to 50 μm.

17. The display device according to claim 16, wherein the lower protection member has a thickness of 10 μm to 30 μm.

18. a display panel including a first surface and a second surface opposite the first surface; a first upper protection member disposed on the first surface of the display panel; a window member disposed on the first upper protective member; a second upper protective member disposed on the window member; a lower protection member disposed on the second surface of the display panel; and a panel support member disposed on the lower protection member; The display device, wherein the lower protective member comprises a titanium (Ti)-niobium (Nb)-tantalum (Ta)-zirconium (Zr)-oxygen (O) alloy or a copper (Cu)-aluminum (Al)-manganese (Mn) crystalline alloy.

19. The display device according to claim 18 , wherein the lower protection member has an elastic deformation rate of 2.0% or more.

20. The display device according to claim 18, wherein the lower protection member has a Young's modulus of 20 GPa to 80 GPa.

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