Flexible display device

Abstract

A flexible display device according to an exemplary embodiment of the present disclosure may include: a display panel including an active area, an inactive area, and a bending area, and having an edge bent in a rear direction to have a predetermined curvature; a first backplane and a second backplane disposed on a rear surface of the display panel; a metal plate disposed on a rear surface of the first backplane; and an adhesive member disposed between the metal plate and the second backplane, and including a support layer, a first adhesive layer and a third adhesive layer disposed on an upper portion of the support layer, and a second adhesive layer disposed on a lower portion of the support layer, wherein the third adhesive layer may include a conductive material and may have conductivity. Therefore, the fixing force of the bent portion may be increased, thereby preventing cracks in the bent portion that may occur during the drop evaluation.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of and priority to Korean Patent Application No. 10-2021-0131105 filed in Korea on October 1, 2021, which is hereby expressly incorporated by reference into this application in its entirety. Technical Field

[0003] The present disclosure relates to a flexible display device, and more particularly, to a flexible display device that allows a bezel width to be reduced. Background Art

[0004] As our society develops toward an information-oriented society, the field of display devices for visually expressing electrical information signals has rapidly developed. Accordingly, various display devices having excellent performance in terms of thinness, lightness, and low power consumption are being developed.

[0005] Representative display devices include a liquid crystal display device (LCD), a field emission display device (FED), an electrowetting display device (EWD), an organic light emitting display device (OLED), and the like.

[0006] The electroluminescent display device represented by the organic light-emitting display device is a self-luminous display device, and since it does not require a separate light source, unlike a liquid crystal display device having a separate light source, it can be manufactured to be light and thin. In addition, the electroluminescent display device has an advantage in power consumption due to low voltage driving, and is excellent in color realization, response speed, viewing angle, and contrast (CR). Therefore, it is expected that the electroluminescent display device is used in various fields.

[0007] In an electroluminescent display device, a light-emitting layer is provided between two electrodes formed by an anode and a cathode. When holes from the anode are injected into the light-emitting layer and electrons from the cathode are injected into the light-emitting layer, the injected electrons and holes recombine with each other to form excitons in the light-emitting layer and emit light.

[0008] The light-emitting layer contains a host material and a dopant material. The two materials interact with each other so that the host generates excitons from electrons and holes and transfers energy to the dopant, and the dopant is a small amount of dye-based organic material added, receives energy from the host, and converts the energy into light.

[0009] The electroluminescent display device is encapsulated with glass, metal, or film to block moisture or oxygen from being introduced into the interior of the electroluminescent display device from the outside, thereby preventing oxidation of the emission layer or electrode and protecting it from external mechanical or physical impact. Summary of the invention

[0010] As display devices are miniaturized, efforts aimed at reducing a bezel area, which is a peripheral portion of an active area, are continuing in order to increase the size of an effective display screen in the same area of ​​the display device.

[0011] However, since lines and driving circuits for driving the screen are disposed in a bezel area corresponding to a non-active area, there is a limitation in reducing the bezel area.

[0012] Regarding a flexible electroluminescent display device capable of maintaining display performance even when bent by applying a flexible substrate formed of a flexible material such as plastic, efforts are made to reduce a frame area by bending a non-active area of ​​the flexible substrate to reduce the frame area while ensuring an area for wires and a driving circuit. Hereinafter, for convenience, such a display device will be referred to as a frame-bending display device.

[0013] Therefore, the inventors of the present disclosure have recognized the above limitations and invented a flexible display device with a reduced bezel width.

[0014] An electroluminescent display device using a flexible substrate such as plastic or the like needs to ensure flexibility of various insulating layers and wires formed of a metal material provided on the substrate and prevent defects such as cracks that may be caused by bending.

[0015] A protective layer, such as a micro coating layer, is disposed over the insulating layer and the wire in the bending region to prevent cracks from occurring and to protect the wire from external foreign matter. The protective layer may be coated to have a predetermined thickness and is used to adjust a neutral plane of the bending region.

[0016] In an electroluminescent display device recently developed to minimize a bezel area and allow a reduction in thickness of the display device, a bending area of ​​a flexible substrate has a large curvature and minimizes the thickness of a micro coating layer.

[0017] In particular, in a frame bending display device (hereinafter, referred to as a frame bending display device having curvature for convenience), in the case where the bending area has a curvature and is bent, a pressure sensitive adhesive (PSA) of a soft foam material is used to fix the bent portion. At this time, when evaluating the impact (drop) of the flexible display device, cracks may occur in the bent portion due to interference between the bent portion and the components, and in the case of the soft foam material, the movement (flow) of the bent portion may increase.

[0018] Therefore, the inventors of the present disclosure invented a flexible display device that implements a frame bending structure with a curvature that enhances the grounding force while increasing the fixing force of the bent portion.

[0019] The objects of the present disclosure are not limited to the objects mentioned above, and other objects not mentioned above may be clearly understood by those skilled in the art from the following description.

[0020] A flexible display device according to an exemplary embodiment of the present disclosure may include: a display panel, which includes an active area, an inactive area and a bending area, and has an edge bent in a rear direction to have a predetermined curvature; a first back plate and a second back plate arranged on the rear surface of the display panel; a metal plate arranged on the rear surface of the first back plate; and an adhesive member, which is arranged between the metal plate and the second back plate and includes a supporting layer, a first adhesive layer and a third adhesive layer arranged on an upper portion of the supporting layer, and a second adhesive layer arranged on a lower portion of the supporting layer, wherein the third adhesive layer may include a conductive material and has conductivity.

[0021] A flexible display device according to another exemplary embodiment of the present disclosure may include: a display panel, the display panel including: a first flat portion, a second flat portion facing the first flat portion, and a curved portion, the curved portion extending from the first flat portion and bending in a rear direction and located between the first flat portion and the second flat portion; a first back plate located on a rear surface of the first flat portion and a second back plate located on a rear surface of the second flat portion; a metal plate disposed on the rear surface of the first back plate; and an adhesive member disposed between the metal plate and the second back plate and including a supporting layer, a first adhesive layer attached to an upper surface of the supporting layer, and a second adhesive layer attached to a lower surface of the supporting layer, wherein the supporting layer is made of a metal material.

[0022] Additional details of exemplary embodiments are included in the detailed description and the accompanying drawings.

[0023] The flexible display device according to the exemplary embodiment of the present disclosure may provide an effect of improving aesthetics by reducing a bezel width.

[0024] The flexible display device according to the exemplary embodiment of the present disclosure may provide an effect of improving the quality of the flexible display device by preventing cracks in the bent portion that may occur during the drop evaluation through an increase in the fixing force of the bent portion.

[0025] The flexible display device according to the exemplary embodiment of the present disclosure provides an effect of providing a flexible display device that allows a grounding force to be enhanced by increasing a grounding path.

[0026] Effects of the flexible display device according to the exemplary embodiment of the present disclosure are not limited to the above-mentioned exemplifications, and more various effects thereof are included in the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a block diagram of a flexible display device according to a first exemplary embodiment of the present disclosure.

[0028] Figure 2 is a circuit diagram of a sub-pixel included in the flexible display device according to the first exemplary embodiment of the present disclosure.

[0029] Figure 3 is a plan view of a flexible display device according to a first exemplary embodiment of the present disclosure.

[0030] Figure 4A is along Figure 3 A cross-sectional view taken along line II'.

[0031] Figure 4B is along Figure 3 A cross-sectional view taken along line II-II'.

[0032] Figure 5 is a plan view of a flexible display device according to a first exemplary embodiment of the present disclosure.

[0033] Figure 6 is along Figure 5 A cross-sectional view taken along line III-III'.

[0034] Figure 7 is a perspective view of a flexible display device according to a first exemplary embodiment of the present disclosure.

[0035] Fig. 8A is a plan view of an adhesive member according to a first exemplary embodiment of the present disclosure.

[0036] Figure 8B is along Fig. 8A A cross-sectional view taken along line AA'.

[0037] Fig. 9 is a plan view of an adhesive member according to a second exemplary embodiment of the present disclosure.

[0038] Fig.10 is a plan view of an adhesive member according to a third exemplary embodiment of the present disclosure. DETAILED DESCRIPTION

[0039] By referring to the following and attached Figure 1The advantages and features of the present disclosure and the methods for achieving the advantages and features will become clear from the exemplary embodiments described in detail. However, the present disclosure is not limited to the exemplary embodiments disclosed herein, but will be implemented in various forms. The exemplary embodiments are provided only by way of example so that those skilled in the art can fully understand the disclosure of the present disclosure and the scope of the present disclosure. Therefore, the present disclosure will be limited only by the scope of the appended claims.

[0040] The shapes, sizes, ratios, angles, numbers, etc. shown in the accompanying drawings for describing the exemplary embodiments of the present disclosure are merely examples, and the present disclosure is not limited thereto. Throughout the specification, similar reference numerals generally represent similar elements. In addition, in the following description of the present disclosure, detailed descriptions of known related technologies may be omitted to avoid unnecessarily obscuring the subject matter of the present disclosure. Terms such as "including", "having" and "comprising" used herein are generally intended to allow the addition of other components unless these terms are used together with the term "only". Unless otherwise expressly stated, any reference to a singular form may include a plural form.

[0041] Even if not explicitly stated, the components should be construed as including the ordinary error range.

[0042] When terms such as "on," "over," "below," and "adjacent" are used to describe the positional relationship between two parts, unless these terms are used together with the terms "immediately" or "directly," one or more parts may be located between the two parts.

[0043] When an element or layer is referred to as being “on” another element or layer, the other layer or element may be directly on the other element or between them.

[0044] Although the terms "first", "second", etc. are used to describe various components, these components are not limited by these terms. These terms are only used to distinguish one component from another component. Therefore, in the technical concept of the present disclosure, the first component to be mentioned below may be the second component.

[0045] Like reference numbers generally refer to like elements throughout the specification.

[0046] The size and thickness of each component shown in the drawings are illustrated for convenience of description, and the present disclosure is not limited to the size and thickness of the components shown.

[0047] The features of the various embodiments of the present disclosure may be partially or completely adhered or combined with each other, and may be interlocked and operated in technically different ways, and the embodiments may be performed independently or in association with each other.

[0048] Hereinafter, exemplary embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0049] Figure 1 is a block diagram of a flexible display device according to a first exemplary embodiment of the present disclosure.

[0050] Reference Figure 1 , the flexible display device 100 according to the first exemplary embodiment of the present disclosure may include an image processor 151 , a timing controller 152 , a data driver 153 , a gate driver 154 , and a display panel 110 .

[0051] The image processor 151 may output a data signal DATA and a data enable signal DE by a data signal DATA supplied from the outside.

[0052] The image processor 151 may also output one or more of a vertical synchronization signal, a horizontal synchronization signal, and a clock signal in addition to the data enable signal DE.

[0053] The timing controller 152 receives a data signal DATA and a data enable signal DE or a driving signal including a vertical synchronization signal, a horizontal synchronization signal, and a clock signal from the image processor 151. The timing controller 152 may output a gate timing control signal GDC for controlling the operation timing of the gate driver 154 and a data timing control signal DDC for controlling the operation timing of the data driver 153 based on the driving signal.

[0054] The data driver 153 samples and latches the data signal DATA supplied from the timing controller 152 in response to the data timing control signal DDC supplied from the timing controller 152 and converts the data signal DATA into a gamma reference voltage to output it. The data driver 153 may output the data signal DATA through the data lines DL1 to DLn.

[0055] The gate driver 154 may output a gate signal while shifting a level of a gate voltage in response to a gate timing control signal GDC supplied from the timing controller 152. The gate driver 154 may output the gate signal through the gate lines GL1 to GLm.

[0056] In response to the data signal DATA supplied from the data driver 153 and the gate signal supplied from the gate driver 154, the display panel 110 may display an image while the sub-pixel P emits light. Figure 2 as well as Figure 4A and Figure 4B The detailed structure of the sub-pixel P is described in detail in .

[0057] Figure 2is a circuit diagram of a sub-pixel included in the flexible display device according to the first exemplary embodiment of the present disclosure.

[0058] Reference Figure 2 , the sub-pixel of the flexible display device 100 according to the first exemplary embodiment of the present disclosure may include a switching transistor ST, a driving transistor DT, a compensation circuit 135 , and a light emitting element 130 .

[0059] The light emitting element 130 may operate to emit light according to a driving current formed by the driving transistor DT.

[0060] The switching transistor ST may perform a switching operation so that a data signal supplied through the data line 117 is stored in the capacitor as a data voltage in response to a gate signal supplied through the gate line 116 .

[0061] The driving transistor DT may operate such that a constant driving current flows between the high potential power line VDD and the low potential power line GND in response to the data voltage stored in the capacitor.

[0062] The compensation circuit 135 is a circuit for compensating for a threshold voltage of the driving transistor DT, etc., and the compensation circuit 135 may include one or more thin film transistors and capacitors. The configuration of the compensation circuit 135 may vary according to a compensation method.

[0063] Shows Figure 2 The sub-pixel shown is configured to have a 2T (transistor) 1C (capacitor) structure including a switching transistor ST, a driving transistor DT, a capacitor, and a light emitting element 130. However, when a compensation circuit 135 is added thereto, the sub-pixel may have various structures, such as a 3T1C structure, a 4T2C structure, a 5T2C structure, a 6T1C structure, a 6T2C structure, a 7T1C structure, and a 7T2C structure.

[0064] Figure 3 is a plan view of a flexible display device according to a first exemplary embodiment of the present disclosure.

[0065] Figure 3 An example is shown in which the flexible substrate 111 is not bent in the flexible display device 100 according to the first exemplary embodiment of the present disclosure.

[0066] Reference Figure 3 The flexible display device 100 may include: an active area AA, in which pixels that actually emit light through thin film transistors and light emitting elements are disposed on the flexible substrate 111; and a non-active area NA, which serves as a frame area surrounding the edge of the active area AA.

[0067] In the non-active area NA of the flexible substrate 111 , a circuit for driving the flexible display device 100 , such as a gate driver 154 and various signal lines, such as a scan line SL, may be disposed.

[0068] A circuit for driving the flexible display device 100 is disposed on the substrate 111 in a gate in panel (GIP) method, or may be connected to the flexible substrate 111 in a tape carrier package (TCP) or chip on film (COF) method.

[0069] A pad 155 as a metal pattern may be provided on one side of the substrate 111 in the non-active area NA so that an external module may be bonded.

[0070] The bending area BA may be formed by bending a portion of the non-active area NA of the flexible substrate 111 in a bending direction as indicated by an arrow.

[0071] The non-active area NA of the flexible substrate 111 is an area where lines and driving circuits for driving the screen are provided. Since the non-active area NA is not an area for displaying an image, it is not necessary to be viewed from the upper surface of the flexible substrate 111. Therefore, by bending a portion of the non-active area NA of the flexible substrate 111, the frame area can be reduced while ensuring an area for the lines and driving circuits.

[0072] Various lines may be formed on the flexible substrate 111. These lines may be formed in the active area AA of the flexible substrate 111, or the circuit line 140 formed in the non-active area NA may connect driving circuits or gate drivers, data drivers, etc. to each other to transmit signals.

[0073] The circuit line 140 is formed of a conductive material, and may be formed of a conductive material having excellent ductility to reduce the occurrence of cracks when the flexible substrate 111 is bent. The circuit line 140 may be formed of a conductive material having excellent ductility, such as gold (Au), silver (Ag), or aluminum (Al), or may be formed of one of the various conductive materials used in the active area AA. The circuit line 140 may also be formed of molybdenum (Mo), chromium (Cr), titanium (Ti), nickel (Ni), neodymium (Nd), copper (Cu), and an alloy of silver (Ag) and magnesium (Mg).

[0074] For example, the circuit line 140 may be formed of a multi-layer structure including various conductive materials, and may be formed of a triple-layer structure of titanium (Ti) / aluminum (Al) / titanium (Ti), but the present disclosure is not limited thereto.

[0075] The circuit line 140 formed in the bending area BA receives tension when bent. The circuit line 140 extending in the same direction as the bending direction on the flexible substrate 111 receives the greatest tension, so that cracks or disconnections may occur therein. Therefore, instead of forming the circuit line 140 to extend in the bending direction, at least a portion of the circuit line 140 disposed in the area including the bending area BA is formed to extend in a diagonal direction, which is a direction different from the bending direction, so that the tension can be minimized.

[0076] The circuit line 140 disposed in the region including the bending area BA may have various shapes and may be formed in shapes such as a trapezoidal wave shape, a triangle wave shape, a sawtooth wave shape, a sine wave shape, an omega (Ω) shape, a diamond shape, or the like.

[0077] Figure 4A is along Figure 3 A cross-sectional view taken along line II'.

[0078] Figure 4B is along Figure 3 A cross-sectional view taken along line II-II'.

[0079] Figure 4A is along Figure 3 Detailed cross-sectional view taken along line II′ of the active area AA described in FIG.

[0080] First, refer to Figure 4A The flexible substrate 111 is used to support and protect the components of the flexible display device 100 disposed thereon.

[0081] Recently, the flexible substrate 111 may be formed of a ductile material having a flexible property, such as plastic.

[0082] The flexible substrate 111 may be in the form of a film including one of the group consisting of a polyester-based polymer, a silicone-based polymer, an acrylic polymer, a polyolefin-based polymer, and copolymers thereof.

[0083] For example, the flexible substrate 111 may be formed of at least one of the following: polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polysilane, polysiloxane, polysilazane, polycarbosilane, polyacrylate, polymethacrylate, polymethylacrylate, polymethylmethacrylate, polyethylacrylate, polyethylmethacrylate, cyclic olefin copolymer (COC), cyclic olefin polymer (COP), polyethylene (PE), polypropylene (PP), polyimide (PI), polymethylmethacrylate (PMMA), polystyrene (PS), polyacetal (POM), polyetheretherketone (PE), polyimide (PI), polymethylmethacrylate (PMMA), polystyrene (PS), polyacetal (POM), polyetheretherketone (PE), polyimide (PI), polymethylmethacrylate (PMMA), polystyrene (PS), polyimide (PI), polymethylmethacrylate (PMMA ... ketone (PEEK), polyester sulfone (PES), polytetrafluoroethylene (PTFE), polyvinyl chloride (PVC), polycarbonate (PC), polyvinylidene fluoride (PVDF), perfluoroalkyl polymer (PFA), styrene acrylonitrile copolymer (SAN), and combinations thereof.

[0084] A buffer layer may be further provided on the flexible substrate 111. The buffer layer prevents moisture or other impurities from penetrating through the flexible substrate 111 from the outside and may planarize the surface of the flexible substrate 111. The buffer layer is not necessarily a necessary component and may be deleted according to the type of the thin film transistor 120 provided on the flexible substrate 111.

[0085] The thin film transistor 120 may be disposed on the flexible substrate 111 and may include a gate electrode 121 , a source electrode 122 , a drain electrode 123 , and a semiconductor layer 124 .

[0086] In this case, the semiconductor layer 124 may be formed of amorphous silicon or polycrystalline silicon, but is not limited thereto. Polycrystalline silicon has superior mobility than amorphous silicon, and has low power consumption and excellent reliability, and thus may be applied to a driving thin film transistor within a pixel.

[0087] The semiconductor layer 124 may be formed of an oxide semiconductor. The oxide semiconductor has excellent mobility and uniformity characteristics. The oxide semiconductor may be formed of a quaternary metal oxide such as a material based on indium tin gallium zinc oxide (InSnGaZnO), a material based on indium gallium zinc oxide (InGaZnO), a material based on indium tin zinc oxide (InSnZnO), a material based on tin gallium zinc oxide (SnGaZnO), a material based on aluminum gallium zinc oxide (AlGaZnO), a material based on indium aluminum zinc oxide (InAlZnO), and a material based on tin aluminum zinc oxide (SnAlZnO), or a ternary metal oxide such as a material based on The present invention relates to a binary metal oxide based on indium zinc oxide (InZnO), a material based on tin zinc oxide (SnZnO), a material based on aluminum zinc oxide (AlZnO), a material based on zinc magnesium oxide (ZnMgO), a material based on tin magnesium oxide (SnMgO), a material based on indium magnesium oxide (InMgO), a material based on indium gallium oxide (InGaO), a material based on indium oxide (InO), a material based on tin oxide (SnO), and a material based on zinc oxide (ZnO). The composition ratio of each element is not limited.

[0088] The semiconductor layer 124 may include: a source region including p-type impurities or n-type impurities; a drain region; and a channel region between the source region and the drain region. The semiconductor layer 124 may also include a low-concentration doped region between the source region and the drain region adjacent to the channel region.

[0089] The source region and the drain region are doped with impurities at a high concentration and may be connected to a source electrode 122 and a drain electrode 123 of the thin film transistor 120 , respectively.

[0090] As the impurity ions, p-type impurities or n-type impurities can be used. The p-type impurity can be one of boron (B), aluminum (Al), gallium (Ga) and indium (In), and the n-type impurity can be one of phosphorus (P), arsenic (As) and antimony (Sb).

[0091] The channel region of the semiconductor layer 124 may be doped with n-type impurities or p-type impurities according to an NMOS or PMOS thin film transistor structure, and the thin film transistor included in the flexible display device 100 according to the first exemplary embodiment of the present disclosure may be an NMOS or PMOS thin film transistor.

[0092] The first insulating layer 115a is an insulating layer composed of a single layer or a multilayer of silicon oxide (SiOx) or silicon nitride (SiNx), and may be provided on the semiconductor layer 124 so that current flowing through the semiconductor layer 124 does not flow to the gate electrode 121. In this case, silicon oxide has lower ductility than metal but better ductility than silicon nitride, and may be formed as a single layer or a multilayer according to its characteristics.

[0093] The gate electrode 121 is used as a switch for turning on or off the thin film transistor 120 based on an electrical signal transmitted from the outside through a gate line, and may be composed of a single layer or multiple layers of a conductive metal such as copper (Cu), aluminum (Al), molybdenum (Mo), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), and neodymium (Nd), or an alloy thereof. However, the present disclosure is not limited thereto.

[0094] The source electrode 122 and the drain electrode 123 are connected to the data line, and may enable an electrical signal transmitted from the outside to be transmitted from the thin film transistor 120 to the light emitting element 130. The source electrode 122 and the drain electrode 123 may be composed of a single layer or multiple layers of a conductive metal such as copper (Cu), aluminum (Al), molybdenum (Mo), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), and neodymium (Nd), or an alloy thereof, but are not limited thereto.

[0095] In this case, in order to insulate the gate electrode 121 from the source electrode 122 and the drain electrode 123 from each other, a second insulating layer 115 b consisting of a single layer or multiple layers of silicon oxide (SiOx) or silicon nitride (SiNx) may be disposed between the gate electrode 121 and the source electrode 122 and the drain electrode 123 .

[0096] A passivation layer formed of an inorganic insulating layer such as silicon oxide (SiOx) or silicon nitride (SiNx) may be disposed on the thin film transistor 120 .

[0097] The passivation layer may prevent unnecessary electrical connection between components disposed above and below the passivation layer, and prevent contamination or damage from the outside. Depending on the configuration and characteristics of the thin film transistor 120 and the light emitting element 130, the passivation layer may be omitted.

[0098] The structure of the thin film transistor 120 can be divided into an inverted staggered structure and a coplanar structure according to the positions of the elements constituting the thin film transistor 120. For example, a thin film transistor having an inverted staggered structure refers to a thin film transistor having a structure in which a gate electrode is positioned opposite to a source electrode and a drain electrode based on a semiconductor layer. Figure 4A In the embodiment, the thin film transistor 120 having a coplanar structure refers to a thin film transistor having a structure in which a gate electrode 121 is positioned on the same side as a source electrode 122 and a drain electrode 123 based on a semiconductor layer 124 .

[0099] exist Figure 4A , the thin film transistor 120 having a coplanar structure is illustrated, but the flexible display device 100 according to the first exemplary embodiment of the present disclosure may further include a thin film transistor having an inverted staggered structure.

[0100] For the convenience of description, only a driving thin film transistor is shown among various thin film transistors that may be included in the flexible display device 100. In addition, a switching thin film transistor, a capacitor, etc. may also be included in the flexible display device 100.

[0101] In addition, when a signal is applied from the gate line to the switching thin film transistor, the switching thin film transistor transmits the signal from the data line to the gate electrode of the driving thin film transistor. The driving thin film transistor can transmit the current transmitted through the power line to the anode 131 through the signal transmitted from the switching thin film transistor, and control the light emission through the current transmitted to the anode 131.

[0102] The planarization layers 115 c and 115 d may be disposed on the thin film transistor 120 to protect the thin film transistor 120 , to mitigate a step caused by the thin film transistor 120 , and to reduce parasitic capacitance generated between the thin film transistor 120 , the gate and data lines, and the light emitting element 130 .

[0103] The planarization layers 115 c and 115 d may be formed of one or more of acrylic resin, epoxy resin, phenol resin, polyamide resin, polyimide resin, unsaturated polyester resin, polyphenylene resin, polyphenylene sulfide resin, and benzocyclobutene, but are not limited thereto.

[0104] The flexible display device 100 according to the first exemplary embodiment of the present disclosure may include a first planarization layer 115c and a second planarization layer 115d sequentially stacked. That is, the first planarization layer 115c may be disposed on the thin film transistor 120, and the second planarization layer 115d may be disposed on the first planarization layer 115c.

[0105] A buffer layer may be disposed on the first planarization layer 115c. The buffer layer may be composed of multiple layers of silicon oxide (SiOx) to protect components disposed on the first planarization layer 115c, and may be omitted according to the configuration and characteristics of the thin film transistor 120 and the light emitting element 130.

[0106] The intermediate electrode 125 may be connected to the thin film transistor 120 through a contact hole formed in the first planarization layer 115c. The intermediate electrode 125 is stacked to be connected to the thin film transistor 120, and the data line may also be formed in a multi-layer structure.

[0107] The data line may be formed to have a structure in which a lower layer formed of the same material as the source electrode 122 and the drain electrode 123 and an upper layer formed of the same material as the intermediate electrode 125 are connected to each other. That is, the data line may be implemented in a structure in which two layers are connected to each other in parallel, and in this case, the line resistance of the data line may be reduced.

[0108] Meanwhile, a passivation layer formed of an inorganic insulating layer such as silicon oxide (SiOx) or silicon nitride (SiNx) may be further disposed on the first planarization layer 115c and the intermediate electrode 125. The passivation layer may be used to prevent unnecessary electrical connection between components and to prevent contamination or damage from the outside, and may be omitted according to the configuration and characteristics of the thin film transistor 120 and the light emitting element 130.

[0109] The light emitting element 130 disposed on the second planarization layer 115 d may include an anode 131 , a light emitting unit 132 , and a cathode 133 .

[0110] The anode 131 may be disposed on the second planarization layer 115 d .

[0111] The anode 131 is used to supply holes to the light emitting unit 132 and may be connected to the intermediate electrode 125 through a contact hole in the second planarization layer 115 d , thereby being electrically connected to the thin film transistor 120 .

[0112] The anode 131 may be formed of a transparent conductive material such as indium tin oxide (ITO), indium zinc oxide (IZO), etc., but is not limited thereto.

[0113] When the flexible display device 100 is a top emission type display device that emits light toward its upper portion where the cathode 133 is disposed, it may further include a reflective layer so that the emitted light is reflected from the anode 131 to be smoothly emitted in a direction toward the upper portion where the cathode 133 is disposed.

[0114] The anode 131 may be a two-layer structure in which a transparent conductive layer and a reflective layer formed of a transparent conductive material are sequentially stacked, or a three-layer structure in which a transparent conductive layer, a reflective layer, and a transparent conductive layer are sequentially stacked. The reflective layer may be formed of silver (Ag) or an alloy including silver.

[0115] The bank 115e provided on the anode 131 and the second planarization layer 115d can define sub-pixels by dividing the area where light is actually emitted. After a photoresist is formed on the anode 131, the bank 115e can be formed by photolithography. A photoresist refers to a photosensitive resin whose solubility in a developer is changed by the action of light, and a specific pattern can be obtained by exposing and developing the photoresist. The types of photoresists can be divided into positive photoresists and negative photoresists. A positive photoresist is a photoresist that increases the solubility of its exposed portion in a developer by exposure. When the positive photoresist is developed, a pattern from which the exposed portion is removed is obtained. A negative photoresist is a photoresist that significantly reduces the solubility of its exposed portion in a developer by exposure. When the negative photoresist is developed, a pattern from which the unexposed portion is removed is obtained.

[0116] A fine metal mask (FMM) as a deposition mask may be used to form the light emitting unit 132 of the light emitting element 130 .

[0117] In addition, in order to prevent damage that may occur due to contact with a deposition mask set on the embankment 115e, and to maintain a constant distance between the embankment 115e and the deposition mask, a spacer 115f formed of one of polyimide (which is a transparent organic material), photo acrylic and benzocyclobutene can be set on the embankment 115e.

[0118] The light emitting unit 132 may be disposed between the anode 131 and the cathode 133 .

[0119] The light emitting unit 132 is used to emit light, and may include at least one of a hole injection layer (HIL), a hole transport layer (HTL), a light emitting layer, an electron transport layer (ETL), and an electron injection layer (EIL), and some components may be omitted according to the structure or characteristics of the flexible display device 100. Here, an electroluminescent layer and an inorganic light emitting layer may be used as the light emitting layer.

[0120] A hole injection layer is provided on the anode 131 to facilitate injection of holes.

[0121] The hole transport layer is disposed on the hole injection layer to smoothly transport holes to the light emitting layer.

[0122] The light emitting layer is disposed on the hole transport layer and may include a material capable of emitting light of a specific color so as to emit light of a specific color. In addition, a phosphorescent material or a fluorescent material may be used to form the light emitting material.

[0123] An electron injection layer may be further disposed on the electron transport layer. The electron injection layer is an organic layer that facilitates injection of electrons from the cathode 133 and may be omitted according to the structure and characteristics of the flexible display device 100.

[0124] At the same time, an electron blocking layer or a hole blocking layer is further arranged at a position adjacent to the light-emitting layer to block the flow of holes or electrons, thereby preventing the following phenomenon: when electrons are injected into the light-emitting layer, the electrons move from the light-emitting layer and are transferred to the adjacent hole transport layer, or preventing the following phenomenon: when holes are injected into the light-emitting layer, the holes move from the light-emitting layer and are transferred to the adjacent electron transport layer, so that the light-emitting efficiency can be improved.

[0125] The cathode 133 is disposed on the light emitting unit 132 and serves to supply electrons to the light emitting unit 132. Since the cathode 133 needs to supply electrons, it may be formed of a metal material such as magnesium (Mg), silver-magnesium, which is a conductive material having a low work function, but is not limited thereto.

[0126] When the flexible display device 100 is a top emission type display device, the cathode 133 may be a transparent conductive oxide such as indium tin oxide (ITO), indium zinc oxide (IZO), indium tin zinc oxide (ITZO), zinc oxide (ZnO), and tin oxide (TO).

[0127] The encapsulation part 115g may be provided on the light emitting element 130 to prevent the thin film transistor 120 and the light emitting element 130, which are components of the flexible display device 100, from being oxidized or damaged due to moisture, oxygen or impurities introduced from the outside. The encapsulation part 115g may be formed by stacking a plurality of encapsulation layers, a foreign matter compensation layer and a plurality of barrier films.

[0128] The encapsulation layer may be disposed on the entire surface of the upper portion of the thin film transistor 120 and the light emitting element 130, and may be formed of one of silicon nitride (SiNx) or aluminum oxide (AlyOz) as an inorganic material. However, the present disclosure is not limited thereto. The encapsulation layer may be further disposed on the foreign matter compensation layer.

[0129] A foreign matter compensation layer is disposed on the encapsulation layer, and an organic material such as silicon carbon oxide (SiOCz), acrylic acid (propylene) or epoxy resin may be used for the foreign matter compensation layer. However, the present disclosure is not limited thereto. When defects occur due to cracks caused by foreign matter or particles that may be generated during the process, the defects can be compensated by covering the curve and foreign matter with the foreign matter compensation layer.

[0130] The barrier film may be disposed on the encapsulation layer and the foreign matter compensation layer, whereby the flexible display device 100 may delay the penetration of oxygen and moisture from the outside. The barrier film is configured in the form of a light-transmitting and double-sided adhesive film, and may be composed of any one of an olefin-based insulating material, an acrylic-based insulating material, and a silicon-based insulating material. Alternatively, a barrier film composed of any one of COP (cycloolefin polymer), COC (cycloolefin copolymer), and PC (polycarbonate) may also be stacked, but is not limited thereto.

[0131] Then, Figure 4B is along Figure 3 Detailed cross-sectional view taken along line II-II' of the bending area BA described in FIG.

[0132] Figure 4B Some of the components in Figure 4A Those components described in are substantially the same or similar, and thus description thereof will be omitted.

[0133] Reference Figures 1 to 3 The described gate signal and data signal are externally transmitted to the pixels disposed in the active area AA through the circuit lines disposed in the non-active area NA of the flexible display device 100, thereby allowing light emission.

[0134] When the wires disposed in the non-active area NA including the bending area BA of the flexible display device 100 are formed into a single-layer structure, a large amount of space is required for disposing the wires therein. After depositing the conductive material, the conductive material is patterned into a desired line shape by a process such as an etching process. However, since there is a limitation in the fineness of the etching process, a large amount of space is required due to the narrowing of the gap between the lines, and the area of ​​the non-active area NA increases, which may make it difficult to achieve a narrow frame.

[0135] In addition, in the case of transmitting one signal using one line, when the corresponding line is broken, the corresponding signal may not be transmitted.

[0136] In the process of bending the substrate 111, cracks may occur in the wire itself, or cracks may occur in other layers and propagate to the wire. In this way, when cracks occur in the wire, the signal to be transmitted may not be transmitted.

[0137] Therefore, the line provided in the bending area BA of the flexible display device 100 according to the exemplary embodiment of the present disclosure may be provided as a double line of the first line 141 and the second line 142 .

[0138] The first wire 141 and the second wire 142 are formed of a conductive material, and may be formed of a conductive material having excellent ductility to reduce the occurrence of cracks when the flexible substrate 111 is bent.

[0139] The first wire 141 and the second wire 142 may be formed of a conductive material having excellent ductility, such as gold (Au), silver (Ag), or aluminum (Al). The first wire 141 and the second wire 142 may be formed of one of the various conductive materials used in the active area AA, and may be formed of an alloy of molybdenum (Mo), chromium (Cr), titanium (Ti), nickel (Ni), neodymium (Nd), copper (Cu), and silver (Ag) and magnesium (Mg). In addition, the first wire 141 and the second wire 142 may be formed of a multilayer structure including various conductive materials, and may be formed of a three-layer structure of titanium (Ti) / aluminum (Al) / titanium (Ti). However, the present disclosure is not limited thereto.

[0140] In order to protect the first and second lines 141 and 142, a buffer layer formed of an inorganic insulating layer may be disposed under the first and second lines 141 and 142. A passivation layer formed of an inorganic insulating layer is formed to surround upper and side portions of the first and second lines 141 and 142, thereby preventing the first and second lines 141 and 142 from reacting with moisture or the like and being corroded.

[0141] The first wire 141 and the second wire 142 formed in the bending area BA are subjected to tension when bent. Figure 3 As described in , the wire extending in the same direction as the bending direction on the substrate 111 is subjected to the greatest tension, and cracks may occur therein. If the cracks are severe, disconnection may occur. Therefore, instead of forming the wire to extend in the bending direction, at least a portion of the wire provided in the area including the bending area BA is formed to extend in a diagonal direction (the diagonal direction is a direction different from the bending direction), so that the tension can be minimized to reduce the occurrence of cracks. The wire can be formed into shapes such as a rhombus shape, a triangular wave shape, a sine wave shape, a trapezoidal wave shape, etc., but is not limited thereto.

[0142] The first line 141 may be disposed on the substrate 111, and the first planarization layer 115c may be disposed on the first line 141. The second line 142 may be disposed on the first planarization layer 115c, and the second planarization layer 115d may be disposed on the second line 142. The first planarization layer 115c and the second planarization layer 115d may be formed of one or more of acrylic resin, epoxy resin, phenolic resin, polyamide resin, polyimide resin, unsaturated polyester resin, polyphenylene resin, polyphenylene sulfide resin, and benzocyclobutene, but are not limited thereto.

[0143] A micro coating layer 145 may be disposed on the second planarization layer 115 d .

[0144] Since tension is applied to a wire portion disposed on the substrate 111 when the substrate is bent, thereby causing cracks in the wire, the micro coating layer 145 may serve to protect the wire by coating the resin with a small thickness at the bent position.

[0145] Figure 5 is a plan view of a flexible display device according to a first exemplary embodiment of the present disclosure.

[0146] Figure 6 is along Figure 5 A cross-sectional view taken along line III-III'.

[0147] Figure 7 is a perspective view of a flexible display device according to a first exemplary embodiment of the present disclosure.

[0148] Figure 5 and Figure 6 An illustration in which the middle frame is omitted is provided for convenience.

[0149] Figure 6 A cross section of a lower edge of the flexible display device 100 according to the first exemplary embodiment of the present disclosure is shown as an example.

[0150] Figure 7 It is shown Figure 6 1 is a perspective view of a cross section of the flexible display device 100.

[0151] Figures 5 to 7 The flexible display device 100 illustrates a case where a hole H for a camera, an optical sensor, a receiver, or a fingerprint sensor is formed at an upper side of the flexible display device 100, but the present disclosure is not limited thereto and may not include a hole.

[0152] Reference Figures 5 to 7 , the flexible display device 100 according to the first exemplary embodiment of the present disclosure may include a display panel 110 , a polarizing plate 162 , and a cover glass 164 .

[0153] The display panel 110 may include a first flat portion, a second flat portion, and a curved portion positioned between the first flat portion and the second flat portion. The first flat portion corresponds to a portion of the non-active area NA and the active area AA having a plurality of sub-pixels, and is an area maintained in a flat state. The curved portion corresponds to the bent area BA.

[0154] The non-active area NA may be a frame area surrounding the edge of the active area AA.

[0155] The non-active area NA may include a pad portion defined outside the active area AA. A plurality of sub-pixels may be disposed in the active area AA. The sub-pixels may be arranged in the active area AA in the form of R (red), G (green), and B (blue), or in the form of R, G, B, and W (white), thereby achieving full color. The sub-pixels may be divided by gate lines and data lines intersecting each other.

[0156] The second flat portion is a region facing the first flat portion, corresponds to a pad portion having a pad bonded to the circuit element 150 , and is a region maintained in a flat state.

[0157] The circuit element 150 may include bumps (or terminals) 161 .

[0158] The protrusions 161 of the circuit element 150 can be respectively bonded to the pads of the pad portion through an anisotropic conductive film (ACF). The circuit element 150 can be a chip on film (COF) in which the driver integrated circuit (IC) 165 is mounted on a flexible film. In addition, the circuit element 150 can be implemented as a COG type that is directly bonded to the pads on the substrate through a chip on glass (COG) process. In addition, the circuit element 150 can be a flexible circuit, such as a flexible flat cable (FFC) or a flexible printed circuit (FPC). In the following embodiments, COF is mainly used as an example of the circuit element 150 for description, but it is not limited to this. The driver IC 165 can be covered and protected by a cover shield 166, but it is not limited to this.

[0159] Driving signals, such as gate signals and data signals, supplied through the circuit element 150 may be supplied to gate lines and data lines of the active area AA through circuit lines such as routing lines.

[0160] In the flexible display device 100, in addition to the active area AA for implementing the input image, it is necessary to ensure a sufficient space in which the pad portion, the circuit element 150, etc. can be positioned. This space corresponds to the bezel area which is the non-active area NA, and the bezel area is recognized by the user located in front of the flexible display device 100 and may be a factor that slightly reduces the aesthetics.

[0161] Therefore, the flexible display device 100 according to the first exemplary embodiment of the present disclosure may be bent in the rear direction such that the lower edge of the display panel 110 has a predetermined curvature.

[0162] The lower edge of the display panel 110 may correspond to the outside of the active area AA and may correspond to the area where the pad portion is located. As the display panel 110 is bent, the pad portion may be located to overlap the non-active area NA in the rear direction of the non-active area NA. Therefore, the bezel area recognized from the front surface of the flexible display device 100 may be minimized. Therefore, the bezel width is reduced, thereby providing an effect of improving aesthetics.

[0163] To this end, the substrate of the display panel 110 may be formed of a flexible material that can be bent. For example, the substrate may be formed of a plastic material such as polyimide (PI). In addition, the circuit line may be formed of a flexible material. The circuit line may be formed of a material such as a metal nanowire, a metal mesh, or a carbon nanotube (CNT), but is not limited thereto.

[0164] Meanwhile, the bent portion is a bent area BA maintained in a bent state having a predetermined curvature.

[0165] In this case, for example, the bending area BA may have shape. That is, the bent portion extends from the first flat portion and can be bent at an angle of 180° in the rear direction. Therefore, the second flat portion extending from the bent portion can be positioned to overlap the first flat portion at the rear of the first flat portion. Therefore, the circuit element 150 bonded to the display panel 110 at the second flat portion of the display panel 110 can be positioned in the rear direction of the first flat portion of the display panel 110. However, the present disclosure is not limited thereto, and the bent area BA may have That is, the bent portion extends from the first flat portion, bends at an angle of 180° in the rear direction and has shape, and also has The entire curved portion of the shape can bend downward while having curvature.

[0166] In addition, although not shown, a barrier film may be disposed on the display panel 110 .

[0167] The barrier film is a component for protecting various components of the display panel 110, and may be provided to correspond to at least the active area AA of the display panel 110. The barrier film is not necessary and may be deleted according to the structure of the flexible display device 100. The barrier film may be configured to include an adhesive material. The adhesive material may be a thermosetting adhesive or a self-curing adhesive, and may be formed of a material such as a pressure sensitive adhesive (PSA), so that it may be used to fix the polarizing plate 162 on the barrier film.

[0168] The polarizing plate 162 disposed on the barrier film can suppress the reflection of external light on the display panel 110. When the flexible display device 100 is used externally, external natural light may be introduced and may be reflected by the reflective layer included in the anode of the electroluminescent element, or by the electrode formed of metal disposed under the electroluminescent element. The reflected light may not be able to recognize the image of the flexible display device 100 well. The polarizing plate 162 polarizes the light introduced from the outside in a specific direction and prevents the reflected light from being re-emitted to the outside of the display device 100.

[0169] The polarizing plate 162 may be a polarizing plate composed of a polarizing plate and a protective film for protecting the polarizing plate, and may be formed by coating a polarizing material with respect to flexibility.

[0170] An adhesive layer 163 may be disposed on the polarizing plate 162 so that a cover glass 164 for protecting the outside of the display panel 110 may be bonded and disposed on the polarizing plate 162. That is, the cover glass 164 may be provided to cover the entire surface of the display panel 110 and to protect the display panel 110.

[0171] The adhesive layer 163 may include an optically clear adhesive (OCA).

[0172] Light blocking patterns 167 may be formed on four edges of the cover glass 164 .

[0173] The light blocking pattern 167 may be formed on an edge of the rear surface of the cover glass 164 .

[0174] The light blocking pattern 167 may extend to overlap the polarizing plate 162 , the adhesive layer 163 , and a portion of the display panel 110 disposed under the light blocking pattern 167 .

[0175] The light blocking pattern 167 may be applied with black ink.

[0176] Although not shown, a touch screen panel may be further included on the display panel 110. In this case, a polarizing plate 162 may be positioned above the touch screen panel. When the touch screen panel is included, a cover glass 164 may be provided to cover at least a portion of the touch screen panel.

[0177] The touch screen panel may include a plurality of touch sensors. The touch sensors may be disposed at positions corresponding to the active area AA of the display panel 110. The touch sensors may include at least one of a mutual capacitance sensor and a self capacitance sensor.

[0178] A mutual capacitance sensor includes a mutual capacitance formed between two touch electrodes. A mutual capacitance sensing circuit may apply a drive signal (or stimulus signal) to either of the two electrodes and sense a touch input based on a change in charge in the mutual capacitance through the other electrode. When a conductor approaches the mutual capacitance, the amount of charge in the mutual capacitance decreases, allowing a touch input or gesture to be detected.

[0179] The self-capacitance sensor includes a self-capacitance formed in each of the sensor electrodes. The self-capacitance sensing circuit can supply charge to each sensor electrode and sense touch input based on the change in charge in the self-capacitance. When a conductor approaches the self-capacitance, the capacitance of the sensor is connected in parallel to the capacitance of the conductor, thereby increasing the capacitance value. Therefore, in the case of self-capacitance, the capacitance value of the sensor increases when a touch input is sensed.

[0180] A plurality of holes (or openings) H may be provided in the upper side of the flexible display device 100. For example, the holes H may include an optical sensor hole, a receiver hole, a camera hole, and a fingerprint sensor hole (or a home button hole).

[0181] The back plate may be disposed on the rear surface of the display panel 110. When the substrate of the display panel 110 is formed of a plastic material such as polyimide, the manufacturing process of the flexible display device 100 is performed with a support substrate formed of glass disposed on the rear surface of the display panel 110. After the manufacturing process is completed, the support substrate may be separated and peeled off.

[0182] Since a member for supporting the display panel 110 is required even after the support substrate is peeled off, a back plate for supporting the display panel 110 may be disposed on the rear surface of the display panel 110 except for a portion of the bending area BA.

[0183] The back plate may prevent foreign matter from being attached to the lower portion of the base plate, and may serve to buffer impact from the outside.

[0184] In this case, the back plate can be composed of a first back plate 101a and a second back plate 101b, the first back plate 101a is located on the rear surface of the first flat portion, and the second back plate 101b is located on the rear surface of the second flat portion. The first back plate 101a enhances the rigidity of the first flat portion so that the first flat portion can be maintained in a flat state. The second back plate 101b enhances the rigidity of the second flat portion so that the second flat portion can be maintained in a flat state. At the same time, in order to ensure the flexibility of the curved portion and facilitate the use of the micro-coating layer 145 to control the neutral plane, it is preferred that the first back plate 101a and the second back plate 101b are not positioned on the rear surface of a portion of the curved portion.

[0185] The first back plate 101a and the second back plate 101b may be formed of a plastic film formed of polyimide (PI), polyethylene naphthalate (PEN), polyethylene terephthalate (PET), a polymer, or a combination of these polymers.

[0186] The metal plate 168 may be disposed on the rear surface of the first back plate 101 a .

[0187] The metal plate 168 may be attached to the rear surface of the first back plate 101a using an adhesive 169. The metal plate 168 may be disposed to be retracted a predetermined distance from an end of the first back plate 101a, but is not limited thereto.

[0188] The adhesive 169 may have an embossed pattern, but is not limited thereto.

[0189] The adhesive 169 may be formed of a pressure sensitive adhesive (PSA).

[0190] The metal plate 168 may be formed of a metal material, such as stainless steel (SUS), and may be used for radiating heat, grounding, and protecting the rear surface. The metal plate 168 may be a composite heat sink.

[0191] The adhesive member 170 of the present disclosure may be attached to the rear surface of the metal plate 168 .

[0192] For example, the adhesive member 170 according to the first exemplary embodiment of the present disclosure may include a support layer 171, a first adhesive layer 172 attached to an upper surface of the support layer 171, and a second adhesive layer 173 attached to a lower surface of the support layer 171. However, the present disclosure is not limited thereto.

[0193] The first adhesive layer 172 may be attached to the rear surface of the metal plate 168 , and the second adhesive layer 173 may be attached to the upper surface of the second back plate 101 b .

[0194] The support layer 171 may be formed of a metal material, for example, stainless steel (SUS).

[0195] The adhesive member 170 according to the first exemplary embodiment of the present disclosure includes the support layer 171 formed of a hard metal material instead of PSA which is a conventional soft foam, so that the fixing force is increased, thereby preventing cracks in the bent portion that may occur during the drop evaluation. Therefore, the quality of the flexible display device 100 can be improved.

[0196] The adhesive member 170 according to the first exemplary embodiment of the present disclosure may further optionally include a third adhesive layer 174 attached to the upper surface of the support layer 171 .

[0197] The first adhesive layer 172 and the third adhesive layer 174 are located on the same plane and may have a predetermined gap formed therebetween, but the present disclosure is not limited thereto.

[0198] The third adhesive layer 174 may have an adhesive strength lower than those of the first adhesive layer 172 and the second adhesive layer 173. The third adhesive layer 174 may include a conductive material and have conductivity.

[0199] The adhesive member 170 may be disposed to be retracted a predetermined distance from the ends of the first back plate 101a and the second back plate 101b. In addition, the adhesive member 170 may be disposed to be retracted a predetermined distance from the ends of the metal plate 168, but is not limited thereto.

[0200] The first adhesive layer 172 and the third adhesive layer 174 may be disposed to be retracted a predetermined distance from the ends of the support layer 171 and the second adhesive layer 173 , but is not limited thereto.

[0201] An end portion of the adhesive member 170 may be disposed in the non-active area NA between the bending area BA and the active area AA.

[0202] The light blocking pattern 167 may overlap a portion of the adhesive member 170 .

[0203] In addition, in the adhesive member 170 according to the first exemplary embodiment of the present disclosure, a third adhesive layer 174 having conductivity is provided on the supporting layer 171 formed of a metal material, and thus the adhesive member 170 is made conductive together with the metal plate 168, so that the grounding path is increased and the grounding force can be enhanced.

[0204] Will refer to Fig. 8A and Figure 8B The detailed structure of the adhesive member 170 is described in detail.

[0205] Meanwhile, a micro-coating layer 145 may be disposed on the bending area BA of the display panel 110. The micro-coating layer 145 may be formed to cover one side of the barrier film.

[0206] The micro coating layer 145 may be formed such that one side thereof partially overlaps the first back plate 101 a and is bent together with the curved portion of the display panel 110 such that the other side thereof partially overlaps the second back plate 101 b , but the present disclosure is not limited thereto.

[0207] One side of the micro coating layer 145 may extend to the polarizing plate 162 and may be in contact with a side surface of the polarizing plate 162. In this case, an adhesive layer 163 may be disposed between the polarizing plate 162 and the cover glass 164 to cover one side of the micro coating layer 145.

[0208] One end portion of the micro coating layer 145 may be disposed between the support layer 171 and the third adhesive layer 174 .

[0209] Since a tensile force is applied to a circuit line disposed on the display panel 110 when the display panel 110 is bent so that cracks occur in the line, the micro coating layer 145 may be used to protect the line by coating a resin having a small thickness at a bent position.

[0210] The micro coating layer 145 may be formed of an acrylic material, such as an acrylate polymer, but is not limited thereto.

[0211] The micro coating layer 145 can adjust the neutral plane of the bending area BA.

[0212] As described above, the neutral plane may mean a virtual surface that is not stressed because the compressive force and the tensile force applied to the structure when the structure is bent cancel each other out. When two or more structures are stacked, a virtual neutral plane may be formed between the structures. When the entire structure is bent in one direction, the structure arranged in the bending direction relative to the neutral plane is compressed by bending and is thus subjected to a compressive force. On the contrary, the structure arranged in the direction opposite to the bending direction relative to the neutral plane is stretched by bending and is thus subjected to a tensile force. In addition, since the structure is more vulnerable when it is subjected to a tensile force among the compressive force and the tensile force at the same level, the probability of cracks occurring when it is subjected to a tensile force is higher.

[0213] The flexible substrate of the display panel 110 disposed below the neutral plane is compressed and thus subjected to a compressive force. The circuit line disposed above the neutral plane may be subjected to a tensile force, and cracks may occur in the circuit line due to the tensile force. Therefore, in order to minimize the tensile force to be received by the circuit line, the micro coating layer 145 may be located above the neutral plane.

[0214] By providing the micro coating layer 145 on the bending area BA, the neutral plane can be raised upward, and the neutral plane is formed at the same position as the position of the circuit line, or the circuit line is located at a position higher than the neutral plane. Therefore, during bending, the circuit line is not stressed or subjected to compression force, so that the occurrence of cracks can be suppressed.

[0215] The circuit element 150 may be connected to an end portion of the second planar portion of the display panel 110 .

[0216] Various lines for transmitting signals to pixels disposed in the active area AA may be formed on the circuit element 150 .

[0217] The circuit element 150 may be formed of a material having flexibility so that it can be bent.

[0218] The driving IC 165 may be mounted on the second planar portion of the display panel 110 and may be connected to lines formed on the circuit element 150 to provide driving signals and data to sub-pixels disposed in the active area AA.

[0219] The circuit element 150 may be a flexible printed circuit board (FPCB).

[0220] The micro coating layer 145 of the first exemplary embodiment of the present disclosure may be formed to cover one side of the barrier film on the bending area BA of the display panel 110 and may extend to cover the side surface of the polarizing plate 162 to further suppress the occurrence of cracks. However, the present disclosure is not limited thereto.

[0221] Fig. 8A is a plan view of an adhesive member according to a first exemplary embodiment of the present disclosure.

[0222] Figure 8B is along Fig. 8A A cross-sectional view taken along line AA'.

[0223] Fig. 8A is a plan view of the adhesive member 170 according to the first exemplary embodiment of the present disclosure viewed from the cover glass side, and illustrates a state in which the second adhesive layer 173 disposed under the adhesive member 170 is covered by the support layer 171 .

[0224] Reference Fig. 8A and Figure 8B For example, the adhesive member 170 according to the first exemplary embodiment of the present disclosure may include a support layer 171 , a first adhesive layer 172 attached to an upper surface of the support layer 171 , and a second adhesive layer 173 attached to a lower surface of the support layer 171 .

[0225] The support layer 171 may be formed of a metal material, for example, stainless steel (SUS).

[0226] For example, the support layer 171 may have a thickness of about 45 μm to 55 μm, but is not limited thereto.

[0227] The adhesive member 170 according to the first exemplary embodiment of the present disclosure includes the support layer 171 formed of a hard metal material instead of PSA which is a conventional soft foam, so that the fixing force is increased, thereby preventing cracks in the bent portion that may occur during the drop evaluation. Therefore, the quality of the flexible display device 100 can be improved.

[0228] The support layer 171 and the second adhesive layer 173 may have the same width by attaching the second adhesive layer 173 to the rear surface of the support layer 171 and then cutting them at the same time, but the present disclosure is not limited thereto.

[0229] The adhesive member 170 according to the first exemplary embodiment of the present disclosure may further optionally include a third adhesive layer 174 attached to the upper surface of the support layer 171 .

[0230] The first adhesive layer 172 and the third adhesive layer 174 are located on the same plane and may have a predetermined gap formed therebetween, but the present disclosure is not limited thereto.

[0231] The third adhesive layer 174 may be disposed in the central portion of the support layer 171. In addition, the third adhesive layer 174 may be disposed in the form of an island at a portion of the front end of the central portion of the support layer 171. In this case, in the first adhesive layer 172, a portion of the front end of the central portion of the first adhesive layer 172 where the third adhesive layer 174 is disposed may be removed, and in this case, the first adhesive layer 172 and the third adhesive layer 174 may be disposed to have a predetermined gap therebetween. However, the present disclosure is not limited thereto. Here, the front end portion of the third adhesive layer 174 refers to a portion adjacent to the bent portion where the display panel is bent.

[0232] The first adhesive layer 172 and the third adhesive layer 174 may be disposed to be retracted a predetermined distance from the ends of the support layer 171 and the second adhesive layer 173 , but is not limited thereto.

[0233] For example, the first adhesive layer 172, the third adhesive layer 174, and the second adhesive layer 173 may have a thickness of about 30 μm to 40 μm, but the present disclosure is not limited thereto. For example, in the adhesive member 170 according to the first exemplary embodiment of the present disclosure, the support layer 171 may have a thickness of 50 μm, and the first adhesive layer 172, the third adhesive layer 174, and the second adhesive layer 173 may have a thickness of 35 μm, respectively, and therefore, the adhesive member 170 may have a total thickness of 120 μm. As another example, in the adhesive member 170 according to the first exemplary embodiment of the present disclosure, the support layer 171 may have a thickness of 45 μm, and the first adhesive layer 172, the third adhesive layer 174, and the second adhesive layer 173 may have a thickness of 70 μm and 35 μm, respectively, and therefore, the adhesive member 170 may have a total thickness of 150 μm. However, the present disclosure is not limited thereto.

[0234] The first adhesive layer 172 , the second adhesive layer 173 , and the third adhesive layer 174 may be formed of a pressure sensitive adhesive (PSA), but the present disclosure is not limited thereto.

[0235] The third adhesive layer 174 may include a conductive material and have conductivity. Therefore, the third adhesive layer 174 may have an adhesive strength lower than that of the first adhesive layer 172 and the second adhesive layer 173 .

[0236] In the adhesive member 170 according to the first exemplary embodiment of the present disclosure, the third adhesive layer 174 having conductivity is provided at the surface to which the metal plate 168 is attached above the support layer 171 of the metal material, and thus, conducts electricity together with the metal plate 168, so that the grounding path increases and the grounding force can be enhanced. That is, the grounding path connected to the third adhesive layer 174 and the support layer 171 through the metal plate 168 can be formed in the display panel, and thus, the grounding force can be enhanced.

[0237] As described above, the third adhesive layer 174 may be provided on a portion of the front end of the central portion of the surface bonded to the metal plate 168, and the third adhesive layer 174 has an adhesive strength lower than the adhesive strengths of the first adhesive layer 172 and the second adhesive layer 173. Therefore, the attachment area of ​​the third adhesive layer 174 may be set in consideration of the total adhesive strength of the first adhesive layer 172 and the third adhesive layer 174.

[0238] However, the present disclosure is not limited thereto, and the third adhesive layer of the present disclosure may be disposed at the center of the support layer, or may be disposed at a portion of the front end of the left and right sides of the support layer. Fig. 9 and Fig.10Describe this in detail.

[0239] Fig. 9 is a plan view of an adhesive member according to a second exemplary embodiment of the present disclosure.

[0240] In addition to the placement of the adhesive member 270, Fig. 9 The adhesive member 270 according to the second exemplary embodiment of the present disclosure has Fig. 8A and Figure 8B The adhesive member 170 according to the first exemplary embodiment of the present disclosure has substantially the same configuration. Therefore, the same reference numerals are used for the same components.

[0241] Fig. 9 is a plan view of an adhesive member 270 according to the second exemplary embodiment of the present disclosure viewed from the cover glass side, and illustrates a state in which a second adhesive layer disposed under the adhesive member 270 is covered with a support layer 271 .

[0242] Reference Fig. 9 For example, the adhesive member 270 according to the second exemplary embodiment of the present disclosure may include a support layer 271 , a first adhesive layer 272 attached to an upper surface of the support layer 271 , and a second adhesive layer attached to a lower surface of the support layer 271 .

[0243] The support layer 271 may be formed of a metal material, for example, stainless steel (SUS).

[0244] The adhesive member 270 according to the second exemplary embodiment of the present disclosure may further optionally include a third adhesive layer 274 attached to the upper surface of the support layer 271 .

[0245] The first adhesive layer 272 and the third adhesive layer 274 are located on the same plane and may have a predetermined gap formed therebetween, but the present disclosure is not limited thereto.

[0246] The third adhesive layer 274 may be disposed at the center of the support layer 271. Specifically, the third adhesive layer 274 may be disposed in the form of an island at the center spaced apart from the upper and lower ends of the support layer 271 by a predetermined distance. In this case, the central portion of the first adhesive layer 272 provided with the third adhesive layer 274 may be removed, and the first adhesive layer 272 and the third adhesive layer 274 may have a predetermined gap therebetween. However, the present disclosure is not limited thereto.

[0247] As described above, when the third adhesive layer 274 is provided at the center of the support layer 271 , it can be more strongly bonded to the metal plate than in the first exemplary embodiment.

[0248] The first adhesive layer 272 may be disposed to be retracted a predetermined distance from the support layer 271 and the end portions of the second adhesive layer, but the present disclosure is not limited thereto.

[0249] The first adhesive layer 272 , the second adhesive layer, and the third adhesive layer 274 may be formed of PSA, but the present disclosure is not limited thereto.

[0250] The third adhesive layer 274 may include a conductive material and have conductivity. Therefore, the third adhesive layer 274 may have an adhesive strength lower than that of the first adhesive layer 272 and the second adhesive layer.

[0251] Fig.10 is a plan view of an adhesive member according to a third exemplary embodiment of the present disclosure.

[0252] In addition to the placement of the adhesive member 370, Fig.10 The adhesive member 370 according to the third exemplary embodiment of the present disclosure has Fig. 8A and Figure 8B The adhesive member 170 according to the first exemplary embodiment of the present disclosure has substantially the same configuration. Therefore, the same reference numerals are used for the same components.

[0253] Fig.10 is a plan view of an adhesive member 370 according to the third exemplary embodiment of the present disclosure viewed from the cover glass side, and illustrates a state in which a second adhesive layer disposed under the adhesive member 370 is covered with a support layer 371 .

[0254] Reference Fig.10 , the adhesive member 370 according to the third exemplary embodiment of the present disclosure may include a support layer 371 , a first adhesive layer 372 attached to an upper surface of the support layer 371 , and a second adhesive layer attached to a lower surface of the support layer 371 .

[0255] The support layer 371 may be formed of a metal material, for example, stainless steel (SUS).

[0256] The adhesive member 370 according to the third exemplary embodiment of the present disclosure may further optionally include third adhesive layers 374 a and 374 b attached to the upper surface of the support layer 371 .

[0257] In this case, the first adhesive layer 372 and the third adhesive layers 374 a and 374 b are located on the same plane and a predetermined gap may be formed therebetween, but the present disclosure is not limited thereto.

[0258] The third adhesive layers 374a and 374b may be disposed on the left and right sides of the support layer 371. That is, the third adhesive layers 374a and 374b may include: a first third adhesive layer 374a disposed on the left side of the support layer 371 in an island shape; and a second third adhesive layer 374b disposed on the right side of the support layer 371 in an island shape. In this case, in the first adhesive layer 372, portions of the left and right sides thereof where the third adhesive layers 374a and 374b are disposed may be removed, and the first adhesive layer 372 and the third adhesive layers 374a and 374b may be formed to have a predetermined gap therebetween. However, the present disclosure is not limited thereto.

[0259] As described above, when the third adhesive layers 374 a and 374 b are disposed on the left and right sides of the support layer 371 , the ground path increases compared to the first and second exemplary embodiments, so that the ground force may be enhanced.

[0260] The first adhesive layer 372 and the third adhesive layers 374 a and 374 b may be disposed to be retracted by a predetermined distance from the end portions of the support layer 371 and the second adhesive layer, but is not limited thereto.

[0261] The first adhesive layer 372 , the second adhesive layer, and the third adhesive layers 374 a and 374 b may be formed of PSA, but are not limited thereto.

[0262] The third adhesive layers 374a and 374b may include a conductive material and have conductivity. Therefore, the third adhesive layers 374a and 374b may have an adhesive strength lower than that of the first adhesive layer 372 and the second adhesive layer.

[0263] Exemplary embodiments of the present disclosure may also be described as follows:

[0264] According to one aspect of the present disclosure, a flexible display device is provided. The flexible display device includes: a display panel including an active area, an inactive area, and a bending area, and having an edge bent in a rear direction to have a predetermined curvature; a first backplane and a second backplane disposed on the rear surface of the display panel; a metal plate disposed on the rear surface of the first backplane; and an adhesive member disposed between the metal plate and the second backplane, and including a support layer, a first adhesive layer and a third adhesive layer disposed on an upper portion of the support layer, and a second adhesive layer disposed on a lower portion of the support layer, wherein the third adhesive layer may include a conductive material and has conductivity.

[0265] The display panel may include: a first flat portion, the first flat portion corresponding to a portion of the inactive area and the active area; a second flat portion facing the first flat portion; and a curved portion extending from the first flat portion and bending in a rear direction and located between the first flat portion and the second flat portion, wherein the curved portion corresponds to the bending area, wherein the first back panel is located on the rear surface of the first flat portion and the second back panel is located on the rear surface of the second flat portion.

[0266] The adhesive member may be disposed to be retracted a predetermined distance from ends of the first back plate and the second back plate.

[0267] The support layer may be made of a metallic material.

[0268] The first adhesive layer and the third adhesive layer may be located on the same plane, and a predetermined gap may be formed between the first adhesive layer and the third adhesive layer.

[0269] The third adhesive layer may be provided in an island shape at a portion of the front end of the central portion of the support layer.

[0270] In the first adhesive layer, a portion of a front end of a central portion of the first adhesive layer where the third adhesive layer is provided may be removed so that a predetermined gap may be provided between the first adhesive layer and the third adhesive layer.

[0271] The third adhesive layer may be provided in the form of an island at the center spaced apart from the upper and lower ends of the support layer by a predetermined distance.

[0272] In the first adhesive layer, a central portion of the first adhesive layer where the third adhesive layer is disposed may be removed so that a predetermined gap may be provided between the first adhesive layer and the third adhesive layer.

[0273] The third adhesive layer may include a first third adhesive layer disposed in an island shape on a left side of the support layer, and a second third adhesive layer disposed in an island shape on a right side of the support layer.

[0274] In the first adhesive layer, portions on the left and right sides of the first adhesive layer where the third adhesive layer is disposed may be removed so that a predetermined gap may be provided between the first adhesive layer and the third adhesive layer.

[0275] The first adhesive layer and the third adhesive layer may be disposed to be retracted from ends of the support layer and the second adhesive layer by a predetermined distance.

[0276] The first adhesive layer, the second adhesive layer, and the third adhesive layer may be made of a pressure sensitive adhesive (PSA).

[0277] The third adhesive layer may have an adhesive strength lower than those of the first adhesive layer and the second adhesive layer.

[0278] A ground path connected to the third adhesive layer and the support layer through the metal plate may be formed in the display panel.

[0279] According to one aspect of the present disclosure, a flexible display device is provided. The flexible display device includes: a display panel, the display panel includes: a first flat portion, a second flat portion facing the first flat portion, and a curved portion, the curved portion extending from the first flat portion and bending in the rear direction, and located between the first flat portion and the second flat portion; a first backplane located on the rear surface of the first flat portion and a second backplane located on the rear surface of the second flat portion; a metal plate disposed on the rear surface of the first backplane; and an adhesive member disposed between the metal plate and the second backplane and including a support layer, a first adhesive layer attached to the upper surface of the support layer, and a second adhesive layer attached to the lower surface of the support layer, wherein the support layer is made of a metal material.

[0280] Although the exemplary embodiments of the present disclosure have been described in detail with reference to the accompanying drawings, the present disclosure is not limited thereto, and the present disclosure can be implemented in many different forms without departing from the technical concept of the present disclosure. Therefore, the exemplary embodiments of the present disclosure are provided for illustrative purposes only and are not intended to limit the technical concept of the present disclosure. The scope of the technical concept of the present disclosure is not limited thereto. Therefore, it should be understood that the above exemplary embodiments are illustrative in all aspects and do not limit the present disclosure. The scope of protection of the present disclosure should be interpreted based on the attached claims, and all technical concepts within their equivalent scope should be interpreted as falling within the scope of the present disclosure.

Claims

1. A flexible display device, comprising: A display panel including an active area, an inactive area, and a bending area, and having one edge bent in a rear direction to have a predetermined curvature; A first back plate and a second back plate disposed on a rear surface of the display panel; a metal plate disposed on the rear surface of the first backplane; as well as an adhesive member disposed between the metal plate and the second back plate and including a support layer, a first adhesive layer and a third adhesive layer disposed on an upper portion of the support layer, and a second adhesive layer disposed on a lower portion of the support layer, Wherein, the third adhesive layer includes a conductive material and has conductivity, Wherein, the supporting layer is made of metal material, and The first adhesive layer and the third adhesive layer are located on the same plane, and a predetermined gap is formed between the first adhesive layer and the third adhesive layer.

2. The flexible display device according to claim 1, wherein: The display panel comprises: a first flat portion, the first flat portion corresponding to a portion of the inactive region and the active region; a second flat portion facing the first flat portion; and a bent portion extending from the first flat portion and bent in the rear direction and located between the first flat portion and the second flat portion, wherein the bent portion corresponds to the bent region, The first back plate is located on the rear surface of the first flat portion and the second back plate is located on the rear surface of the second flat portion.

3. The flexible display device according to claim 1 or 2, wherein: The adhesive member is disposed to be retracted a predetermined distance from ends of the first back plate and the second back plate.

4. The flexible display device according to claim 1, wherein: The third adhesive layer is provided in an island shape at a portion of a front end of a central portion of the support layer.

5. The flexible display device according to claim 4, wherein: In the first adhesive layer, a portion of a front end of a central portion of the first adhesive layer where the third adhesive layer is provided is removed so that a predetermined gap exists between the first adhesive layer and the third adhesive layer.

6. The flexible display device according to claim 1, wherein: The third adhesive layer is provided in the form of an island at the center spaced apart from the upper and lower ends of the support layer by a predetermined distance.

7. The flexible display device according to claim 6, wherein: In the first adhesive layer, a central portion of the first adhesive layer where the third adhesive layer is provided is removed so that a predetermined gap exists between the first adhesive layer and the third adhesive layer.

8. The flexible display device according to claim 1, wherein: The third adhesive layer includes a first third adhesive layer disposed in an island shape on a left side of the support layer, and a second third adhesive layer disposed in an island shape on a right side of the support layer.

9. The flexible display device according to claim 8, wherein: In the first adhesive layer, portions on the left and right sides of the first adhesive layer where the third adhesive layer is provided are removed so that a predetermined gap exists between the first adhesive layer and the third adhesive layer.

10. The flexible display device according to claim 1 or 2, wherein: The first adhesive layer and the third adhesive layer are disposed to be retracted a predetermined distance from ends of the support layer and the second adhesive layer.

11. The flexible display device according to claim 1, wherein: The first adhesive layer, the second adhesive layer, and the third adhesive layer are made of a pressure sensitive adhesive (PSA).

12. The flexible display device according to claim 11, wherein: The third adhesive layer has an adhesive strength lower than adhesive strengths of the first adhesive layer and the second adhesive layer.

13. The flexible display device according to claim 1 or 2, wherein: A ground path connected to the third adhesive layer and the support layer through the metal plate is formed in the display panel.

14. A flexible display device, comprising: A display panel, the display panel comprising: a first flat portion, a second flat portion facing the first flat portion, and a curved portion extending from the first flat portion and bent in a rear direction and located between the first flat portion and the second flat portion; a first back plate located on a rear surface of the first flat portion and a second back plate located on a rear surface of the second flat portion; a metal plate disposed on a rear surface of the first back plate; and an adhesive member disposed between the metal plate and the second back plate and comprising a support layer, a first adhesive layer and a third adhesive layer attached to an upper surface of the support layer, and a second adhesive layer attached to a lower surface of the support layer, Wherein, the third adhesive layer includes a conductive material and has conductivity, Wherein, the supporting layer is made of metal material, and The first adhesive layer and the third adhesive layer are located on the same plane, and a predetermined gap is formed between the first adhesive layer and the third adhesive layer.

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