Flexible display device

Abstract

A device according to an exemplary embodiment of the present invention includes a flexible display device. The flexible display device may include: a display panel including an active area, an inactive area, and a curved area, wherein the display panel has one edge curved in a rearward direction with 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 a coating layer disposed on the exposed rear edge of the metal plate. Therefore, device assembly time can be shortened and alignment accuracy can be improved.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of and priority to Korean Patent Application No. 10-2021-0131073, 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 invention relates to a flexible display device, and more particularly, to a flexible display device that allows for reducing the width of a frame. Background Art

[0004] As today's society enters an information-oriented society, the field of display devices that visually present electrical information signals is rapidly developing. Accordingly, various display devices having excellent properties such as thin thickness, light weight, and low power consumption are being developed.

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

[0006] Electroluminescent display devices, represented by organic light-emitting display devices, are self-luminous display devices. Unlike liquid crystal display devices, which have a separate light source, they do not require a separate light source and can be made light and thin. In addition, electroluminescent display devices have advantages in power consumption due to low-voltage driving and are excellent in color realization, response speed, viewing angle, and contrast ratio (CR). Therefore, electroluminescent display devices are expected to be used in various fields.

[0007] In an electroluminescent display device, a light-emitting layer is provided between two electrodes, 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 react with each other, so that the host generates excitons from electrons and holes and transfers energy to the dopant; the dopant is a small amount of dye-based organic material added, and receives energy from the host and converts it into light.

[0009] The electroluminescent display device is encapsulated by 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 light-emitting layer or electrode and protecting it from external mechanical or physical impact. Summary of the Invention

[0010] The present invention continues to focus on reducing the bezel area, which is the peripheral portion of the active area, in order to increase the size of an effective display screen in a display device of the same area.

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

[0012] Regarding a flexible electroluminescent display device that maintains display performance even when bent, the inventors have employed a flexible substrate formed from a flexible material such as plastic, and have attempted to reduce the bezel area while ensuring sufficient area for wiring and driver circuits. This is achieved by bending the inactive area of the flexible substrate to reduce the bezel area. For convenience, this display device will be referred to as a curved-bezel display device.

[0013] Therefore, the inventors of the present invention 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 needs to ensure flexibility of wires and various insulating layers 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 provided over the insulating layer and the wire in the bending region to prevent cracks from occurring and to protect the wire from external impurities. The protective layer may be coated to a predetermined thickness and is used to adjust the neutral plane of the bending region.

[0016] In a recently developed electroluminescent display device for minimizing a bezel area and allowing a reduction in thickness of the display device, a bent area of a flexible substrate has an extreme curvature and the thickness of a micro coating layer is minimized.

[0017] Meanwhile, in a display device with a curved bezel (hereinafter, referred to as a "curved bezel display device with curvature" for convenience), when the curved area has a curvature and is bent, a pressure sensitive adhesive (PSA) of a soft foam material is used to fix the curved portion.

[0018] In addition, when the metal plate is attached to the upper part of the display panel by an adhesive, a cut-out is formed in the side surface of the metal plate so that the alignment mark for alignment can be visually identified. In addition, the cut-out edge is identified by recognizing the object on the visual camera screen by adjusting the intensity and input angle of the light source for alignment. However, due to the taper collapse and abnormal straightness of the cut-out edge, it is difficult to accurately identify it. In addition, due to the aggregation of adhesive or impurities in the cut-out area, the alignment mark is covered, making it difficult to perform the bonding process.

[0019] Therefore, the inventors of the present invention have invented a flexible display device that increases reflectivity in a specific wavelength band in a visual device by applying a coating layer to a surface edge of a metal plate, thereby improving edge recognition accuracy.

[0020] The objects of the present invention are not limited to the above objects, and those skilled in the art can clearly understand other objects not mentioned above based on the following description.

[0021] A device according to an exemplary embodiment of the present invention includes a flexible display device, which may include: a display panel, the display panel including an active area, an inactive area, and a bending area, and the display panel having one edge bent in a rear direction, the one edge having a predetermined curvature; a first back plate and a second back plate arranged on a rear surface of the display panel; a metal plate arranged on the rear surface of the first back plate; and a coating layer arranged on the exposed rear edge of the metal plate.

[0022] A flexible display device according to an exemplary embodiment of the present invention may include: a display panel divided into 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 provided on a rear surface of the display panel; a metal plate provided on the rear surface of the first back plate; and a coating layer provided on an exposed rear edge of the metal plate.

[0023] Additional details of exemplary embodiments are included in the detailed description and accompanying drawings.

[0024] The flexible display device according to the exemplary embodiment of the present invention may provide an effect of improving aesthetics and enhancing practicality by reducing a bezel width.

[0025] In the flexible display device according to an exemplary embodiment of the present invention, by applying a coating layer to the surface edge of a metal plate, the reflectivity in a specific wavelength band is increased, thereby improving edge recognition accuracy. This also reduces the installation difficulty associated with conventional visual devices, shortening device assembly time and improving alignment accuracy.

[0026] The flexible display device according to the exemplary embodiment of the present invention prevents moisture from being introduced from the side surface thereof, thereby providing an effect of improving the reliability of the flexible display device since the existing alignment mark and the cut-off portion region can be eliminated.

[0027] The flexible display device according to the exemplary embodiment of the present invention provides an effect of applying a coating layer reflecting information such as a serial number or the like to a portion to which it is difficult to apply an engraved seal due to concerns about appearance defects.

[0028] The effects of the flexible display device according to the exemplary embodiment of the present invention are not limited to the above-exemplified contents, and more various effects are included in the present application.

[0029] The details described in the above problems to be solved, means for solving the problems, and effects do not specify essential features of the claims, and thus the scope of protection of the claims is not limited by these details. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 is a block diagram of a flexible display device according to a first exemplary embodiment of the present invention.

[0031] 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 invention.

[0032] Figure 3 is a plan view of a flexible display device according to a first exemplary embodiment of the present invention.

[0033] Figure 4A It is along Figure 3 A cross-sectional view taken along line II'.

[0034] Figure 4B It is along Figure 3 A sectional view taken along line II-II'.

[0035] Figure 5 is a plan view of a flexible display device according to a first exemplary embodiment of the present invention.

[0036] Figure 6 It is along Figure 5 A cross-sectional view taken along line IIIa-IIIa'.

[0037] Figure 7It is along Figure 5 A cross-sectional view taken along line IIIb-IIIb'.

[0038] Figure 8A and 8B yes Figure 7 An enlarged view of part A of FIG.

[0039] Figure 9 is a plan view of a flexible display device according to a second exemplary embodiment of the present invention.

[0040] Figure 10 It is along Figure 9 A sectional view taken along line IV-IV'.

[0041] Figure 11 and 12 yes Figure 10 An enlarged view of part B. DETAILED DESCRIPTION

[0042] The advantages and features of the present invention and the methods for achieving these advantages and features are described in detail below and in the accompanying drawings. Figure 1 The following detailed description of the exemplary embodiments will become apparent. However, the present invention is not limited to the exemplary embodiments disclosed herein, but may be implemented in various forms. The exemplary embodiments are provided by way of example only so that those skilled in the art can fully understand the disclosure and scope of the present invention. Therefore, the present invention shall be limited only by the scope of the appended claims.

[0043] The shapes, sizes, proportions, angles, quantities, etc. shown in the drawings for the purpose of describing exemplary embodiments of the present invention are merely examples, and the present invention is not limited thereto. Similar reference numerals denote similar elements throughout the application. In addition, in the following description of the present invention, detailed explanations of known related arts may be omitted to avoid unnecessarily obscuring the subject matter of the present invention. 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."

[0044] Even if not explicitly stated, the components are interpreted as including the usual error range.

[0045] When terms such as "on," "above," "below," and "after" are used to describe the positional relationship between two parts, one or more parts may be set between the two parts unless these terms are used together with the terms "immediately" or "directly."

[0046] When an element or layer is referred to as being “on” another element or layer, the element or layer can be directly on the other element or layer or other elements or layers may be interposed therebetween.

[0047] Although the terms "first," "second," etc. are used to describe various components, these components are not limited by these terms. These terms are merely used to distinguish one component from other components. Therefore, within the technical concept of the present invention, the first component mentioned below may be the second component.

[0048] Like reference numbers generally refer to like elements throughout the application.

[0049] The size and thickness of each component shown in the drawings are shown for convenience of explanation, and the present invention is not limited to the sizes and thicknesses of the components shown in the drawings.

[0050] The features of the various embodiments of the present invention may be combined or combined with each other in part or in whole, and may be technically interlocked and operated in various ways, and these embodiments may be implemented independently of each other, or in association with each other.

[0051] Hereinafter, various embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0052] Figure 1 is a block diagram of a flexible display device according to a first exemplary embodiment of the present invention.

[0053] Reference Figure 1 , the flexible display device 100 according to the first exemplary embodiment of the present invention may include an image processor 151 , a timing controller 152 , a data driver 153 , a gate driver 154 , and a display panel 110 .

[0054] The image processor 151 may output a data signal DATA and a data enable signal DE through a data signal DATA provided from the outside.

[0055] 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.

[0056] The timing controller 152 receives a data signal DATA from the image processor 151 along with a data enable signal DE or a driving signal including a vertical synchronization signal, a horizontal synchronization signal, and a clock signal. 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.

[0057] The data driver 153 samples and latches the data signal DATA provided from the timing controller 152 in response to the data timing control signal DDC provided from the timing controller 152, converts the data signal DATA into a gamma reference voltage, and outputs the gamma reference voltage. The data driver 153 may output the data signal DATA through the data lines DL1 to DLn.

[0058] 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 provided from the timing controller 152. The gate driver 154 may output the gate signal through the gate lines GL1 to GLm.

[0059] The display panel 110 may display an image while the sub-pixels P emit light in response to the data signal DATA and the gate signal supplied from the data driver 153 and the gate driver 154. Figure 2 as well as Figure 4A and 4B The specific structure of the sub-pixel P is described in detail.

[0060] 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 invention.

[0061] Reference Figure 2 , the sub-pixel of the flexible display device 100 according to the first exemplary embodiment of the present invention may include a switching transistor ST, a driving transistor DT, a compensation circuit 135 , and a light emitting element 130 .

[0062] The light emitting element 130 may operate to emit light according to a driving current formed by the driving transistor DT.

[0063] The switching transistor ST may perform a switching operation so that a data signal supplied through the data line 117 in response to a gate signal supplied through the gate line 116 is stored as a data voltage in the capacitor.

[0064] The driving transistor DT may operate in response to the data voltage stored in the capacitor so that a constant driving current flows between the high potential power line VDD and the low potential power line GND.

[0065] 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 depending on the compensation method.

[0066] Figure 2The illustrated sub-pixel is configured to have a 2T (transistor) 1C (capacitor) structure including a switching transistor ST, a driving transistor DT, a capacitor C, and a light-emitting element 130. However, when a compensation circuit 135 is added, the sub-pixel may have various structures such as 3T1C, 4T2C, 5T2C, 6T1C, 6T2C, 7T1C, and 7T2C structures.

[0067] Figure 3 is a plan view of a flexible display device according to a first exemplary embodiment of the present invention.

[0068] Figure 3 An example is illustrated in which the flexible substrate 111 is not bent in the flexible display device 100 according to the first exemplary embodiment of the present invention.

[0069] Reference Figure 3 The flexible display device 100 may include an active area AA in which pixels that actually emit light via thin film transistors and light emitting elements are provided on the flexible substrate 111 ; and a non-active area NA that is a frame area surrounding the edge of the active area AA.

[0070] In the non-active area NA of the flexible substrate 111 , circuits such as a gate driver 154 for driving the flexible display device 100 and various signal lines such as a scan line SL may be provided.

[0071] A circuit for driving the flexible display device 100 is provided on the substrate 111 in a gate-in-panel (GIP) method or may be connected to the flexible substrate 111 according to a tape carrier package (TCP) or chip-on-film (COF) method.

[0072] 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.

[0073] 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 indicated by an arrow. As an example, the display panel 110 may be divided into (or include) an active area AA, a non-active area NA, and a bending area BA, and have one edge bent in a rearward direction to have a predetermined curvature.

[0074] The non-active area NA of the flexible substrate 111 is where the wires and driver circuits used to drive the screen are located. Since the non-active area NA does not display images, it does not need to be visible from the top surface of the flexible substrate 111. Therefore, by bending a portion of the non-active area NA of the flexible substrate 111, the bezel area BA can be reduced while ensuring area for the wires and driver circuits.

[0075] Various lines may be formed on the flexible substrate 111. Lines may be formed in the active area AA of the flexible substrate 111, or the circuit lines 140 formed in the non-active area NA may connect driving circuits or gate drivers, data drivers, etc. to each other to transmit signals.

[0076] The circuit line 140 is formed of a conductive material and can be formed of a conductive material with excellent ductility to reduce the occurrence of cracks when the flexible substrate 111 is bent. The circuit line 140 can be formed of a conductive material with excellent ductility, such as gold (Au), silver (Ag), or aluminum (Al), or can be formed of one of the various conductive materials used in the active area AA. The circuit line 140 can 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).

[0077] For example, the circuit line 140 may be formed of a multi-layer structure including various conductive materials, and may be formed of a three-layer structure of titanium (Ti) / aluminum (Al) / titanium (Ti), but the present invention is not limited thereto.

[0078] The circuit lines 140 formed in the bending area BA receive tensile force generated during bending. The circuit lines 140 extending in the same direction as the bending direction on the flexible substrate 111 receive the greatest tensile force, and thus may be cracked or broken. Therefore, in addition to forming the circuit lines 140 extending in the bending direction, at least a portion of the circuit lines 140 provided 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), thereby minimizing tensile force.

[0079] The circuit line 140 provided in the region including the bending area BA may be formed in various shapes, and may be formed in shapes such as a trapezoidal waveform, a triangular waveform, a sawtooth waveform, a sine waveform, an Ω shape, a diamond shape, and the like.

[0080] Figure 4A It is along Figure 3 A cross-sectional view taken along line II'.

[0081] Figure 4B It is along Figure 3 A sectional view taken along line II-II'.

[0082] Figure 4A It is along Figure 3 A detailed cross-sectional view taken along line II' of the active area AA is described.

[0083] First, refer to Figure 4A The substrate 111 is used to support and protect the components of the flexible display device 100 disposed thereon.

[0084] Recently, the flexible substrate 111 may be formed of a ductile material having flexible characteristics, such as plastic.

[0085] 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.

[0086] For example, the flexible substrate 111 may be formed of at least one of polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polysilane, polysiloxane, polysilazane, polycarbosilane, polyacrylate, polymethacrylate, polymethylacrylate, polymethylmethacrylate, polyethyl acrylate, polyethyl methacrylate, cyclic olefin copolymer (COC), cyclic olefin polymer (COP), polyethylene (PE), polypropylene (PP), polyimide (PI), polymethyl methacrylate (PMMA), polystyrene (PS), polyacetal (POM), polyetheretherketone (PEEK), polyester sulfone (PES), polytetrafluoroethylene (PTFE), polyvinyl chloride (PVC), polycarbonate (PC), polyvinylidene fluoride (PVDF), perfluoroalkyl polymer (PFA), styrene-acrylonitrile copolymer (SAN), and combinations thereof.

[0087] A buffer layer may be further provided on the flexible substrate 111. The buffer layer prevents moisture or other impurities from penetrating from the outside through the flexible substrate 111 and may flatten the surface of the flexible substrate 111. The buffer layer is not necessarily an essential component and may be omitted depending on the type of thin film transistor 120 provided on the flexible substrate 111.

[0088] The thin film transistor 120 may be provided 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 .

[0089] In this case, the semiconductor layer 124 may be formed of amorphous silicon or polycrystalline silicon, but is not limited thereto. Polycrystalline silicon has better mobility than amorphous silicon, and has low power consumption and excellent reliability. Therefore, polycrystalline silicon can be applied to the driving thin film transistor in the pixel.

[0090] The semiconductor layer 124 may be formed of an oxide semiconductor. Oxide semiconductors have excellent mobility and uniformity characteristics. The oxide semiconductor may be formed of a quaternary metal oxide such as an indium zinc tin gallium zinc oxide (InSnGaZnO)-based material; a ternary metal oxide such as an indium zinc gallium zinc oxide (InGaZnO)-based material, an indium tin zinc oxide (InSnZnO)-based material, a tin gallium zinc oxide (SnGaZnO)-based material, an aluminum gallium zinc oxide (AlGaZnO)-based material, an indium aluminum zinc oxide (InAlZnO)-based material, and a tin aluminum zinc oxide (SnAlZnO)-based material; a binary metal oxide such as an indium zinc oxide (InZnO)-based material, a zinc tin oxide (SnZnO)-based material, an aluminum zinc oxide (AlZnO)-based material, a magnesium zinc oxide (ZnMgO)-based material, a tin magnesium oxide (SnMgO)-based material, an indium magnesium oxide (InMgO)-based material, and an indium gallium oxide (InGaO)-based material; or a monometallic oxide such as an indium oxide (InO)-based material, a tin oxide (SnO)-based material, and a zinc oxide (ZnO)-based material. The composition ratio of each element is not limited.

[0091] The semiconductor layer 124 may include a source region having p-type or n-type impurities, a drain region, and a channel region between the source and drain regions. The semiconductor layer 124 may further include a low-concentration doped region between the source and drain regions adjacent to the channel region.

[0092] The source region and the drain region are doped with high-concentration impurities and may be connected to the source 122 and the drain 123 of the thin film transistor 120 , respectively.

[0093] 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).

[0094] 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. The thin film transistor included in the flexible display device 100 according to the first exemplary embodiment of the present invention may be an NMOS or PMOS thin film transistor.

[0095] 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 121. In this case, silicon oxide has weaker ductility than metal but stronger ductility than silicon nitride, and may be formed as a single layer or a multilayer according to its characteristics.

[0096] The gate electrode 121 functions as a switch that turns the thin film transistor 120 on or off based on an electrical signal transmitted from the outside via a gate line, and may be formed 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 invention is not limited thereto.

[0097] The source electrode 122 and the drain electrode 123 are connected to the data line and can enable an externally transmitted electrical signal 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 formed 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.

[0098] In this case, in order to insulate the gate 121 from the source 122 and the drain 123 from each other, a second insulating layer 115 b composed of a single layer or multiple layers of silicon oxide (SiOx) or silicon nitride (SiNx) may be provided between the gate 121 and the source 122 and the drain 123 .

[0099] A passivation layer formed of an inorganic insulating material such as silicon oxide (SiOx) or silicon nitride (SiNx) may be disposed on the thin film transistor 120 .

[0100] The passivation layer can 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 can be omitted.

[0101] The structure of the thin film transistor 120 can be classified 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 is provided at a position opposite to a source and a drain based on a semiconductor layer. Figure 4A As shown in FIG, the thin film transistor 120 having a coplanar structure refers to a thin film transistor having a structure in which the gate electrode 121 and the source electrode 122 and the drain electrode 123 are located on the same side based on the semiconductor layer 124.

[0102] 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 invention may also include a thin film transistor having an inverse staggered structure.

[0103] For ease of description, only a driving thin film transistor is illustrated among various thin film transistors that may be included in the flexible display device 100. Switching thin film transistors, capacitors, etc. may also be included in the flexible display device 100.

[0104] 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 of the driving thin film transistor. The driving thin film transistor can transmit the current transmitted via the power line to the anode 131 by the signal transmitted from the switching thin film transistor, and control the light emission by the current transmitted to the anode 131.

[0105] Planarization layers 115 c and 115 d may be disposed on the thin film transistor 120 to protect the thin film transistor 120 , alleviate steps caused by the thin film transistor 120 , and reduce parasitic capacitance generated between the thin film transistor 120 , the gate line, the data line, and the light emitting element 130 .

[0106] The planarization layers 115 c and 115 d 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 styrene-propylcyclobutene, but are not limited thereto.

[0107] The flexible display device 100 according to the first exemplary embodiment of the present invention may include a first planarization layer 115c and a second planarization layer 115d stacked in sequence. 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.

[0108] A buffer layer may be provided on the first planarization layer 115c. The buffer layer may be composed of multiple layers of silicon oxide (SiOx) to protect components provided on the first planarization layer 115c, and may be omitted depending on the configuration and characteristics of the thin film transistor 120 and the light emitting element 130.

[0109] The intermediate electrode 125 may be connected to the thin film transistor 120 via a contact hole formed in the first planarization layer 115c. The intermediate electrode 125 is stacked in such a manner as to be connected to the thin film transistor 120, and the data line may also be formed in a multi-layer structure.

[0110] 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 as a structure in which two layers are connected in parallel to each other, and in this case, the line resistance of the data line may be reduced.

[0111] Meanwhile, a passivation layer formed of an inorganic insulating layer such as silicon oxide (SiOx) or silicon nitride (SiNx) may be further provided on the first planarization layer 115c and the intermediate electrode 125. The passivation layer may be used to protect unnecessary electrical connections between components and prevent contamination or damage from the outside, and the passivation layer may be omitted depending on the configuration and characteristics of the thin film transistor 120 and the light emitting element 130.

[0112] 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 .

[0113] The anode 131 may be disposed on the second planarization layer 115 d .

[0114] The anode 131 is used to provide holes to the light emitting unit 132 and may be connected to the intermediate electrode 125 via a contact hole in the second planarization layer 115 d , thereby being electrically connected to the thin film transistor 120 .

[0115] 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.

[0116] When the flexible display device 100 is a top emission type display device that emits light toward an 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 so as to be smoothly emitted in a direction toward an upper portion where the cathode 133 is disposed.

[0117] The anode 131 may be a double-layer structure in which a transparent conductive layer and a reflective layer formed of a transparent conductive material are stacked in sequence, or a triple-layer structure in which a transparent conductive layer, a reflective layer, and a transparent conductive layer are stacked in sequence. The reflective layer may be formed of silver (Ag) or an alloy containing silver.

[0118] The embankment 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 forming a photoresist on the anode 131, the embankment 115e can be formed by photolithography. 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 whose solubility in the developer increases due to exposure. When the positive photoresist is developed, a pattern in which the exposed portion is removed is obtained. A negative photoresist is a photoresist whose solubility in the developer is significantly reduced due to exposure. When the negative photoresist is developed, a pattern in which the non-exposed portion is removed is obtained.

[0119] The light emitting unit 132 of the light emitting element 130 may be formed using a fine metal mask (FMM) as a deposition mask.

[0120] In addition, in order to prevent damage due to contact with the 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, photo acryl, and styrene as transparent organic materials may be set on the embankment 115e.

[0121] The light emitting unit 132 may be disposed between the anode 131 and the cathode 133 .

[0122] 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.

[0123] A hole injection layer is provided on the anode 131 to facilitate injection of holes.

[0124] The hole transport layer is provided on the hole injection layer to smoothly transport holes to the light emitting layer.

[0125] The light emitting layer is provided on the hole transport layer and may include a material capable of emitting light of a specific color, thereby emitting light of a specific color. In addition, the light emitting material may be formed using a phosphorescent material or a fluorescent material.

[0126] The electron transport layer is disposed on the light emitting layer, and the electron injection layer may be further disposed on the electron transport layer. The electron injection layer is an organic layer that helps inject electrons from the cathode 133 and may be omitted depending on the structure and characteristics of the flexible display device 100.

[0127] At the same time, an electron blocking layer or a hole blocking layer is further provided at a position adjacent to the light-emitting layer to block the flow of electrons or holes, thereby preventing the phenomenon that when electrons are injected into the light-emitting layer, electrons migrate from the light-emitting layer and are transferred to the adjacent hole transport layer, or preventing the phenomenon that when holes are injected into the light-emitting layer, holes migrate from the light-emitting layer and are transferred to the adjacent electron transport layer, thereby improving the luminous efficiency.

[0128] The cathode 133 is provided on the light emitting unit 132 and is used 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, or the like, which is a conductive material having a low work function, but is not limited thereto.

[0129] 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).

[0130] The encapsulation portion 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 portion 115g may be formed by stacking a plurality of encapsulation layers, an impurity compensation layer, and a plurality of barrier films.

[0131] The encapsulation layer may be provided 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) and aluminum oxide (AlYOz) as an inorganic material. However, the present invention is not limited thereto. The encapsulation layer may be further provided on the impurity compensation layer.

[0132] An impurity compensation layer is provided on the encapsulation layer and may be made of an organic material such as silicon oxycarbide (SiOCz), acryl, or epoxy resin. However, the present invention is not limited thereto. When defects occur due to cracking caused by impurities or particles that may be generated during the process, the defects can be compensated by covering the curve and impurities with the impurity compensation layer.

[0133] A barrier film may be provided on the encapsulation layer and the impurity compensation layer, thereby preventing the penetration of oxygen and moisture from the outside of the flexible display device 100. The barrier film is constructed in the form of a light-transmitting double-sided adhesive film and may be composed of any one of olefin-based, acrylic-based, and silicon-based insulating materials. Alternatively, a barrier film composed of any one of COP (cyclic olefin polymer), COC (cyclic olefin copolymer), and PC (polycarbonate) may be further stacked, but is not limited thereto.

[0134] Then, Figure 4B It is along Figure 3 A detailed cross-sectional view taken along line II-II' of the bending area BA is shown.

[0135] Figure 4B Some components of Figure 4A Those described are substantially the same or similar, so description thereof will be omitted.

[0136] Reference Figures 1 to 3 The described gate signal and data signal are externally transmitted to the pixels provided in the active area AA via the circuit lines provided in the non-active area NA of the flexible display apparatus 100, thereby allowing light emission.

[0137] When the wires arranged in the non-active area NA within the bending area BA of the flexible display device 100 are formed into a single-layer structure, a large amount of space is required to arrange the wires therein. After depositing the conductive material, the conductive material is patterned into the desired linear shape through a process such as etching. However, due to limitations in the fineness of the etching process, there are restrictions on narrowing the gaps between the wires. This requires a large amount of space, resulting in an increase in the area of the non-active area NA, which can make it difficult to achieve a narrow bezel.

[0138] Furthermore, in the case of transmitting one signal using one line, when the corresponding line is broken, the corresponding signal is not transmitted.

[0139] In the process of bending the substrate 111, cracks may occur in the wire itself, or cracks may occur in other layers and propagate into the wire. In this way, when cracks occur in the wire, the signal to be transmitted is not transmitted.

[0140] Therefore, the line provided in the bending area BA of the flexible display apparatus 100 according to the exemplary embodiment of the present invention may be provided as a double line of the first line 141 and the second line 142 .

[0141] The first and second lines 141 and 142 are formed of a conductive material, and may be formed of a conductive material having excellent ductility in order to reduce the occurrence of cracks when the flexible substrate 11 is bent.

[0142] 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 molybdenum (Mo), chromium (Cr), titanium (Ti), nickel (Ni), neodymium (Nd), copper (Cu), and an alloy of 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 invention is not limited thereto.

[0143] To protect the first and second lines 141 and 142, a buffer layer formed of an inorganic insulating layer may be provided below 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.

[0144] The first and second wires 141 and 142 formed in the bending area BA are subjected to tension when being bent. Figure 3As shown, the wires extending on the substrate 111 in the same direction as the bending direction are subject to the greatest tension and may crack therein. If the cracks are severe, they may break. Therefore, instead of forming the wires to extend in the bending direction, at least a portion of the wires disposed in the region including the bending area BA is formed to extend in an oblique direction (the oblique direction is a direction different from the bending direction), thereby minimizing the tension and reducing the incidence of cracks. The wires may be formed in shapes such as, but are not limited to, diamonds, triangular waveforms, sinusoidal waveforms, trapezoidal waveforms, and the like.

[0145] 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 styrene-propylcyclobutene, but are not limited thereto.

[0146] A micro-coating layer 145 may be disposed on the second planarization layer 115 d .

[0147] 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 a resin having a small thickness at a bent position.

[0148] Figure 5 is a plan view of a flexible display device according to a first exemplary embodiment of the present invention.

[0149] Figure 6 It is along Figure 5 A cross-sectional view taken along line IIIa-IIIa'.

[0150] Figure 7 It is along Figure 5 A cross-sectional view taken along line IIIb-IIIb'.

[0151] Figure 8A and 8B yes Figure 7 An enlarged view of part A of FIG.

[0152] Figures 5 to 7 For the sake of convenience, the middle frame is omitted in the illustration.

[0153] Figure 6 A cross section of a lower edge of the flexible display device 100 according to the first exemplary embodiment of the present invention is illustrated as an example.

[0154] Figure 7 A cross section of a left edge of the flexible display apparatus 100 according to the first exemplary embodiment of the present invention is illustrated as an example.

[0155] Figure 8A and 8B It shows Figure 7 A view of a state in which a portion A of the flexible display device 100 is flipped, Figure 8A The cross section is shown in the case where the cut-out CO is not formed. Figure 8B The cross section is shown in the case where the cut portion CO is formed. Therefore, for convenience, Figure 7 The upper surface is Figure 8A and 8B The rear surface of Figure 7 The rear surface is Figure 8A and 8B The upper surface of .

[0156] Figures 5 to 8A The flexible display device 100 of 8B illustrates a case where a hole H for a camera, an optical sensor, a receiver, or a fingerprint sensor is formed on the upper side of the flexible display device 100, but is not limited thereto and may not include a hole.

[0157] Reference Figures 5 to 8A 8B, the flexible display device 100 according to the first exemplary embodiment of the present invention may include a display panel 110 , a polarizing plate 162 , and a cover glass 164 .

[0158] The display panel 110 may include a first flat portion, a second flat portion, and a curved portion therebetween. The first flat portion corresponds to the active area AA having a plurality of sub-pixels and a portion of the non-active area NA, and is a region maintained in a flat state.

[0159] The non-active area NA may be a bezel area surrounding the edge of the active area AA.

[0160] The non-active area NA may include a pad portion defined outside the active area AA. A plurality of sub-pixels may be provided in the active area AA. The sub-pixels may be arranged in the active area AA in an R (red), G (green), and B (blue) pattern, or an R, G, B, and W (white) pattern, thereby achieving full color. The sub-pixels may be divided by gate lines and data lines that intersect each other.

[0161] The second flat portion is a region facing the first flat portion, corresponds to a pad portion having a pad bonded to a circuit element, and is a region maintained in a flat state.

[0162] The circuit element may include a protrusion (or terminal).

[0163] Although not shown, the raised portions of the circuit element may be bonded to the pads of the pad portion via an anisotropic conductive film (ACF), respectively. The circuit element may be a chip on film (COF) in which a driver integrated circuit (IC) is mounted on a flexible film. In addition, the circuit element may be implemented as a COG type that is directly bonded to the pads on the substrate via a chip on glass (COG) process. In addition, the circuit element may be a flexible circuit such as a flexible flat cable (FFC) or a flexible printed circuit (FPC). In the following embodiments, COF is mainly described as an example of a circuit element, but is not limited thereto.

[0164] Driving signals, such as gate signals and data signals, provided via circuit elements may be provided to gate lines and data lines of the active area AA via circuit lines such as routing lines.

[0165] In the flexible display device 100, in addition to the active area AA where an input image is realized, sufficient space must be secured for placement of pads, circuit elements, and the like. This space corresponds to a bezel area, which is a non-active area NA. The bezel area is recognized by a user positioned in front of the flexible display device 100, and may degrade aesthetics and practicality to some extent.

[0166] Therefore, the flexible display device 100 according to the first exemplary embodiment of the present invention may be bent in a rearward direction so that the lower edge of the display panel 110 has a predetermined curvature.

[0167] 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 positioned. When the display panel 110 is bent, the pad portion may be positioned so as to overlap the non-active area NA in the rearward direction of the non-active area NA. Therefore, the border area visible from the front surface of the flexible display device 100 can be minimized. Consequently, the border width is reduced, thereby improving both aesthetics and practicality.

[0168] To this end, the substrate of the display panel 110 may be formed of a bendable, flexible material. For example, the substrate may be formed of a plastic material such as polyimide (PI). In addition, the circuit lines may be formed of a flexible material. The circuit lines may be formed of materials such as metal nanowires, metal meshes, or carbon nanotubes (CNTs), but are not limited thereto.

[0169] Meanwhile, the curved portion is a curved area BA maintained in a curved state with a predetermined curvature.

[0170] In this case, for example, the bending zone may have That is, the curved portion extends from the first flat portion and may be bent in the rear direction, for example, at an angle of 180°. Therefore, the second flat portion extending from the curved portion may be placed to overlap the first flat portion at the rear of the first flat portion. Therefore, the circuit element bonded to the display panel 110 at the second flat portion may be placed in the rear direction of the first flat portion of the display panel 110. However, the present invention is not limited thereto, and the curved 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; at the same time, The entirety of the shaped curved portion may be bent downward while having a curvature.

[0171] In addition, although not shown, a blocking film may be provided on the display panel 110 .

[0172] The barrier film is a component for protecting the components of the display panel 100 and can be provided to correspond to at least the active area AA of the display panel 110. The barrier film is not required and can be removed according to the structure of the flexible display device 100. The barrier film can be constructed to include an adhesive material. The adhesive material can be a thermosetting or self-curing adhesive and can be formed of a material such as a pressure-sensitive adhesive (PSA), so that it can be used to fix the polarizing plate 162 to the barrier film.

[0173] Polarizing plate 162, disposed on the blocking film, suppresses reflection of external light from display panel 110. When flexible display device 100 is used outdoors, natural external light may be introduced and reflected by the reflective layer included in the anode of the electroluminescent element, or by the metal electrode disposed below the electroluminescent element. The image of flexible display device 100 may not be well recognized due to the reflected light. Polarizing plate 162 polarizes the externally introduced light in a specific direction and prevents the reflected light from being re-emitted outside of display device 100.

[0174] The polarizing plate 162 may be a polarizing plate composed of a polarizer and a protective film for protecting the polarizer, and may be formed by coating a polarizing material to achieve flexibility.

[0175] An adhesive layer 163 may be provided on the polarizing plate 162, whereby a cover glass 164 for protecting the appearance of the display panel 110 may be bonded and provided over the polarizing plate 162 with the adhesive layer 163 interposed therebetween. 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.

[0176] The adhesive layer 163 may include an optically clear adhesive (OCA).

[0177] Light blocking patterns 167 may be formed on four edges of the cover glass 164 .

[0178] A light blocking pattern 167 may be formed on an edge of the rear surface of the cover glass 164 .

[0179] The light-blocking pattern 167 may extend to overlap a portion of each of the adhesive layer 163 , the polarizing plate 162 , and the display panel 110 disposed below the light-blocking pattern 167 .

[0180] The light blocking pattern 167 may be coated with black ink.

[0181] 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 provided above the touch screen panel. When the touch screen panel is included, a glass cover 164 may be provided to cover at least a portion of the touch screen panel.

[0182] The touch screen panel may include a plurality of touch sensors. The touch sensors may be provided 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.

[0183] A mutual capacitance sensor forms a mutual capacitance between two touch electrodes. A mutual capacitance sensing circuit applies a drive signal (or excitation signal) to either electrode and senses touch input through the other electrode based on the charge change in the mutual capacitance. When a conductor approaches the mutual capacitance, the charge in the mutual capacitance decreases, enabling the detection of a touch input or gesture.

[0184] A self-capacitance sensor includes self-capacitance formed in each sensor electrode. A self-capacitance sensing circuit provides charge to each sensor electrode and senses touch input based on the charge change in the self-capacitance. When a conductor approaches the self-capacitance, the sensor's capacitance connects in parallel with the conductor's capacitance, increasing the capacitance. Therefore, in the case of self-capacitance, the sensor's capacitance increases when a touch input is sensed.

[0185] A plurality of holes (or openings) H may be provided on 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).

[0186] The back plates 101a and 101b may be provided 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 made of glass provided on the rear surface of the display panel 110. After the manufacturing process is completed, the support substrate may be separated and released.

[0187] Since components for supporting the display panel 110 are required even after the support substrate is released, back plates 101a and 101b 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.

[0188] The back plates 101 a and 101 b may prevent foreign matter from being attached to the lower portion of the substrate and may serve to buffer impact from the outside.

[0189] In this case, the back plates 101a and 101b may be composed of a first back plate 101a and a second back plate 101b located on the rear surfaces of the first and second flat portions, respectively. The first back plate 101a reinforces the rigidity of the first flat portion, thereby maintaining the first flat portion in a flat state. The second back plate 101b reinforces the rigidity of the second flat portion, thereby maintaining the second flat portion in a flat state. At the same time, in order to ensure the flexibility of the curved portion and facilitate control of the neutral plane using the micro-coating layer 145, it is preferable not to place the back plates 101a and 101b on the rear surfaces of a portion of the curved portion.

[0190] The back sheets 101 a and 101 b 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.

[0191] The metal plate 168 may be disposed on the rear surface of the first back plate 101 a .

[0192] The metal plate 168 may be attached to the rear surface of the first back plate 101a using an adhesive 169, that is, the adhesive 169 may be interposed between the metal plate 168 and the first back plate 101a. The metal plate 168 may be set back a predetermined distance from the end of the first back plate 101, but is not limited thereto.

[0193] The adhesive 169 may have an embossing pattern, but is not limited thereto.

[0194] The adhesive 169 may be formed of a pressure sensitive adhesive (PSA).

[0195] The metal plate 168 may be formed of a metal material such as stainless steel (SUS) and may be used to radiate heat, connect to the ground, and protect the rear surface. That is, the metal plate 168 may be a composite heat sink.

[0196] The adhesive member 165 may be attached to the rear surface of the metal plate 168 at the lower side of the flexible display device 100. The coating layer 170 may be in contact with the side surface of the adhesive member 165.

[0197] The adhesive member 165 may be disposed between the metal plate 168 and the second back plate 101 b and attached to the rear surface of the metal plate 168 and the upper surface of the second back plate 101 b .

[0198] The adhesive member 165 may be disposed to be retracted a predetermined distance from the ends of the first and second back plates 101a and 101b. In addition, the adhesive member 165 may be disposed to be retracted a predetermined distance from the ends of the metal plate 168, but is not limited thereto.

[0199] An end portion of the adhesive member 165 may be disposed in the non-active area NA between the bending area BA and the active area AA.

[0200] The light blocking pattern 167 may overlap a portion of the adhesive member 165 .

[0201] Meanwhile, the 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.

[0202] The micro coating layer 145 may be formed to partially overlap the first back plate 101 a on one side and bend along with the curved portion of the display panel 110 to partially overlap the second back plate 101 b on the other side, but the present invention is not limited thereto.

[0203] One side of the micro coating layer 145 may extend to the polarizing plate 162 and contact the side surface of the polarizing plate 162. In this case, an adhesive layer 163 may be provided between the polarizing plate 162 and the cover glass 164 to cover the one side of the micro coating layer 145.

[0204] Since tension is applied to circuit lines disposed on the display panel 110 when the display panel 110 is bent so that cracks occur in the lines, the micro coating layer 145 may serve to protect the lines by coating a small thickness of resin at a bent position.

[0205] The micro coating layer 145 may be formed of an acrylic material such as an acrylate polymer, but is not limited thereto.

[0206] The micro coating layer 145 can adjust the neutral plane of the bending area BA.

[0207] As mentioned above, the neutral plane refers to a virtual surface that is unstressed when a structure is bent, as the compressive and tensile forces applied to the structure cancel each other out. When two or more structures are stacked, a virtual neutral plane can be formed between the structures. When the entire structure is bent in one direction, structures positioned in the direction of the bend relative to the neutral plane are compressed by the bending, thus experiencing compressive forces. Conversely, structures positioned in the direction opposite to the bending direction relative to the neutral plane are stretched by the bending, thus experiencing tensile forces. Furthermore, since structures experiencing tension are more fragile when subjected to the same levels of compressive and tensile forces, the likelihood of fracture is higher when subjected to tension.

[0208] The flexible substrate of the display panel 110 disposed below the neutral plane is compressed and thus subjected to pressure. The circuit lines disposed above the neutral plane may be subjected to tension, and cracks may occur in the circuit lines due to the tension. Therefore, in order to minimize the tension received by the circuit lines, the micro-coating layer 145 may be located above the neutral plane.

[0209] By providing the micro coating layer 145 on the bending area BA, the neutral plane can be raised upward and formed at the same position as the circuit line, or the circuit line is located at a position higher than the neutral plane. Therefore, the circuit line is not stressed or subjected to pressure during bending, thereby suppressing the occurrence of cracks.

[0210] The circuit element may be connected to the end portion of the second planar portion of the display panel 110 .

[0211] Various lines for transmitting signals to pixels disposed in the active area AA may be formed on the circuit elements.

[0212] The circuit element may be formed of a material having flexibility so as to be bendable.

[0213] The driving IC may be mounted on the second planar portion of the display panel 110 and connected to lines formed on the circuit elements, thereby providing driving signals and data to the sub-pixels disposed in the active area AA.

[0214] The micro coating layer 145 of the first exemplary embodiment of the present invention may be formed to cover one side of the barrier film on the curved area BA of the display panel 110 and may extend to cover the side surface of the polarizing plate 162, thereby further suppressing the occurrence of cracks. However, the present invention is not limited thereto.

[0215] At the same time, one feature of the present invention is that by applying a coating layer 170 to the surface of the metal plate 168, that is, the rear edge of the metal plate 168, the reflectivity in a specific wavelength band in the visual device is increased, thereby improving edge recognition accuracy. The coating layer 170 may be provided in the non-active area NA located between the bending area BA and the active area AA at one edge of the display panel 110 that is bent in the rear direction to have a predetermined curvature, and in the non-active area NA at the remaining edges.

[0216] Conventionally, when a metal plate is attached to the upper portion of a display panel via an adhesive, a cutout is formed in the side surface of the metal plate so that an alignment mark for alignment can be visually identified. In addition, the cutout edge is identified by identifying the real object on the visual camera screen by adjusting the intensity and input angle of the light source used for alignment. However, due to the cone collapse and abnormal straightness of the cutout edge, accurate identification is difficult. In addition, due to the adhesive aggregation or impurities in the cutout area, the alignment mark is covered, making it difficult to perform the bonding process. That is, the alignment mark is covered due to the adhesive loss of the adhesive present in the cutout area, thereby causing defects in the attachment process of the metal plate. In addition, the current cannot leave the cutout area, thereby causing defects such as color gradient and greening in the driving screen. In addition, when identifying the edge, it is difficult to accurately identify the edge due to the aggregation of the adhesive, abnormal blanking straightness and cone change,

[0217] Therefore, the inventors of the present invention invented a flexible display device that increases reflectivity in a specific wavelength band in a visual device by applying a coating layer 170 to the exposed rear edge of a metal plate 168 , thereby improving edge recognition accuracy.

[0218] The visual device may be an electron microscope, and can be used to identify the edge of the metal plate 168 by using a specific wavelength band. In this case, one wavelength band with high reflectivity can be used, or two wavelength bands can be used. That is, by applying the coating layer 170 to the edge line of the surface of the metal plate 168, the reflectivity in the specific wavelength band is increased, so that the edge line of the coating layer 170 can be accurately identified by a visual device such as an electron microscope.

[0219] Therefore, the difficulty of installing conventional visual devices is eliminated, the device assembly time is shortened, and the alignment accuracy can be improved. At the same time, the camera can adjust the resolution by adjusting the wavelength based on the same principle as in electron microscopes.

[0220] Meanwhile, conventionally, information such as a serial number cannot be visually recognized through appearance inspection. However, as in the present invention, when the coating layer 170 is formed by excluding (i.e., by engraving) information to be reflected, such as a serial number, that is, by engraving information on the coating layer 170, an effect of identifying information can be provided due to the difference in reflection characteristics of corresponding portions during reflection of a specific wavelength.

[0221] Meanwhile, similar to the mirror coating technology, silicon monoxide (SiO) may be coated on the coating layer 170 , and the coating layer 170 may have wear-resistant properties.

[0222] The coating layer 170 may be formed on the edge surface of the metal plate 168 in the shape of a quadrangular frame, but is not limited thereto.

[0223] In the case of the first exemplary embodiment of the present invention, alignment is performed by identifying the edge of the surface of the metal plate 168 on which the coating layer 170 is formed, so that the existing alignment mark and the cut-off portion area can be removed, as shown in FIG. Figure 8A In this case, the reliability of the flexible display device can be improved by preventing moisture from being introduced from the side surface thereof. However, the present invention is not limited thereto, and a cut-off portion CO region may be formed in a portion of the side surface of the metal plate 168 and the side surface of the adhesive 169, as shown in FIG. Figure 8B In this case, a portion of the side surface of the metal plate 168 and the side surface of the adhesive 169 may be removed to provide a cut-off region, so that the metal plate 168 and the adhesive 169 may be set back a predetermined distance from the ends of the display panel 110 and the first back plate 101a.

[0224] The coating layer of the present invention may be formed not only on the surface of the metal plate but also on the side surface of the metal plate and the side surface of the adhesive, which will be described in detail below through a second exemplary embodiment.

[0225] Figure 9 is a plan view of a flexible display device according to a second exemplary embodiment of the present invention.

[0226] Figure 10 It is along Figure 9 A sectional view taken along line IV-IV'.

[0227] Figure 11 and 12 yes Figure 10 An enlarged view of part B.

[0228] Figures 9 to 10 For the sake of convenience, the middle frame is omitted in the illustration.

[0229] Figure 10A cross section of a left edge of the flexible display apparatus 200 according to the second exemplary embodiment of the present invention is illustrated as an example.

[0230] Figure 11 It shows Figure 10 FIG. 2 is a diagram showing a state in which a portion B of the flexible display device 200 is flipped. Therefore, for convenience, Figure 10 The upper surface is Figure 11 The rear surface of Figure 10 The rear surface is Figure 11 The upper surface of .

[0231] also, Figure 12 When viewed from the rear Figure 10 View of portion B.

[0232] Figures 9 to 12 The flexible display device 200 exemplifies a case where a hole H for a camera, an optical sensor, a receiver, or a fingerprint sensor is formed on the upper side of the flexible display device 200 , but is not limited thereto and may not include a hole.

[0233] Figures 9 to 12 The flexible display device 200 of the second exemplary embodiment of the present invention has the same Figures 5 to 8A 8B has substantially the same configuration as the flexible display device 100 according to the first exemplary embodiment of the present invention, except for the coating layer 270. Therefore, the same reference numerals are used to refer to the same components.

[0234] Reference Figures 9 to 12 , the flexible display device 200 according to the second exemplary embodiment of the present invention may include a display panel 110 , a polarizing plate 162 , and a cover glass 164 .

[0235] As described above, the display panel 110 may include a first flat portion, a second flat portion, and a curved portion between the first and second flat portions. The first flat portion corresponds to the active area AA having a plurality of sub-pixels and a portion of the non-active area NA, and is a region maintained in a flat state.

[0236] In addition, the flexible display device 200 according to the second exemplary embodiment of the present invention may be bent in a rearward direction so that the lower edge of the display panel 110 has a predetermined curvature.

[0237] A plurality of holes (or openings) H may be provided on the upper side of the flexible display device 200. 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).

[0238] The back plate 101 a may be disposed on a rear surface of the display panel 110 .

[0239] In this case, the back plate 101 a may be composed of a first back plate 101 a and a second back plate located on the rear surface of the first flat portion and the rear surface of the second flat portion, respectively.

[0240] The metal plate 268 may be disposed on the rear surface of the first back plate 101 a .

[0241] The metal plate 268 may be attached to the rear surface of the first backplate 101 a using an adhesive 269 .

[0242] The adhesive 269 may have an embossed pattern, but is not limited thereto.

[0243] The adhesive 269 may be formed of a pressure sensitive adhesive (PSA).

[0244] The metal plate 268 may be formed of a metal material such as stainless steel (SUS) and may be used to radiate heat, connect to the ground, and protect the rear surface. That is, the metal plate 268 may be a composite heat sink.

[0245] Meanwhile, a feature of the second exemplary embodiment of the present invention is that by applying a coating layer 270 from the surface edge (i.e., rear edge) of the metal plate 268 to the side surfaces of the metal plate 268 and the side surfaces of the adhesive 269, the reflectivity in a specific wavelength band in the visual device can be increased, thereby improving edge recognition accuracy; and at the same time, corrosion can be prevented by reducing the exposure of the display panel 110 to moisture. Furthermore, the coating layer 270 of the second exemplary embodiment of the present invention can be formed from the surface edge or rear edge of the metal plate 268 to the side surfaces of the metal plate 268 and the side surfaces of the adhesive 269, as well as a portion of the surface or rear surface of the first backplane 101a. However, the present invention is not limited to this, and the coating layer 270 of the present invention can be formed not only from the surface edge or rear edge of the metal plate 268 to the side surfaces of the metal plate 268 and the side surfaces of the adhesive 269, but also all the way to the rear surface of the first backplane 101a, the side surfaces of the first backplane 101a, and the side surfaces of the display panel 110.

[0246] The visual device may be an electron microscope and may be used to identify the edge of the metal plate 268 by using a specific wavelength band. In this case, one wavelength band having high reflectivity may be used, or two wavelength bands may be used.

[0247] Therefore, the difficulty of installing conventional visual devices is eliminated, the device assembly time is shortened, and the alignment accuracy can be improved. At the same time, the camera can adjust the resolution by adjusting the wavelength based on the same principle as in electron microscopes.

[0248] Meanwhile, conventionally, information such as a serial number cannot be visually recognized through appearance inspection. However, as in the present invention, when the coating layer 270 is formed by excluding (i.e., by engraving) information INF to be reflected, such as the serial number S / N 20210617, the effect of identifying information can be provided due to the difference in reflection characteristics of corresponding portions during reflection of a specific wavelength.

[0249] Meanwhile, similar to the mirror coating technology, silicon monoxide (SiO) may be coated on the coating layer 270 , and the coating layer 270 may have wear-resistant properties.

[0250] In the case of the second exemplary embodiment of the present invention, a cut-off portion CO region may be formed in a portion of the side surface of the metal plate 268 and the side surface of the adhesive 269. In this case, the above-mentioned portion of the side surface of the metal plate 268 and the side surface of the adhesive 269 may be removed so that the metal plate 268 and the adhesive 269 can be set back a predetermined distance from the ends of the display panel 110 and the first back plate 101a. The cut-off portion CO region may have a trapezoidal shape, but is not limited thereto, and may have a triangular, quadrilateral, or semicircular shape.

[0251] The cut-off portions CO may be provided one by one at the left end, the right end, the upper end, and the lower end of the flexible display device 200, but are not limited thereto.

[0252] Exemplary embodiments of the present invention can also be described as follows.

[0253] According to one aspect of the present invention, a flexible display device is provided. The flexible display device includes: a display panel, the display panel being divided into an active area, an inactive area, and a bending area, and having an edge bent in a rearward direction to have a predetermined curvature; a first backplane and a second backplane provided on a rear surface of the display panel; a metal plate provided on the rear surface of the first backplane; and a coating layer provided on the exposed rear edge of the metal plate.

[0254] The display panel may include: a first flat portion; a second flat portion facing the first flat portion; and a curved portion located between the first flat portion and the second flat portion, the curved portion extending from the first flat portion and bending in a rearward direction, wherein the first back plate and the second back plate may be located on the rear surface of the first flat portion and the rear surface of the second flat portion, respectively.

[0255] The flexible display device may further include: a polarizing plate disposed on the display panel; a cover glass disposed on the polarizing plate, wherein an adhesive layer is interposed between the cover glass and the polarizing plate; and an adhesive member disposed between the metal plate and the second back plate.

[0256] Information may be engraved on the coating.

[0257] The coating layer may be made of silicon monoxide (SiO).

[0258] The coating layer may be provided on the edge surface of the metal plate in a quadrangular frame shape.

[0259] The flexible display device may further include an adhesive interposed between the metal plate and the first back plate.

[0260] A portion of a side surface of the metal plate and a side surface of the adhesive may be removed to provide a cut-off region.

[0261] The cut-off portion region may have a triangle, a quadrangle, a trapezoid, or a semicircle.

[0262] The cut-off regions may be disposed one by one at a left end, a right end, an upper end, and a lower end of the flexible display device.

[0263] The coating layer may be provided from a rear edge of the metal plate to a side surface of the metal plate and a side surface of the adhesive.

[0264] The coating layer may be provided from a rear edge of the metal plate to a side surface of the metal plate and a side surface of the adhesive and a rear surface of the first back plate.

[0265] The coating layer may be provided from a rear edge of the metal plate to side surfaces of the metal plate and the adhesive, a rear surface of the first back plate, and side surfaces of the first back plate and the display panel.

[0266] The coating layer may be in contact with a side surface of the adhesive member.

[0267] The coating layer may be disposed in a non-active region between the bending region and the active region at the one edge, and may be disposed in the non-active region at the remaining edges.

[0268] Although the exemplary embodiments of the present invention have been described in detail with reference to the accompanying drawings, the present invention is not limited thereto. Without departing from the technical concept of the present invention, the present invention can be implemented in many different forms. Therefore, the exemplary embodiments of the present invention are provided only for the purpose of illustration and are not intended to limit the technical concept of the present invention. The scope of the technical concept of the present invention is not limited thereto. Therefore, it should be understood that the above exemplary embodiments are merely illustrative in all aspects and do not limit the present invention. The scope of protection of the present invention should be interpreted based on the appended claims, and all technical concepts within their equivalent scope should be interpreted as falling within the scope of the present invention.

Claims

1. A device comprising a flexible display device, the flexible display device comprising: a display panel including an active area, an inactive area, and a bending area, wherein the display panel has one edge bent in a rearward direction, the one edge having a predetermined curvature; a first back plate and a second back plate disposed on the rear surface of the display panel; a metal plate disposed on the rear surface of the first back plate; as well as a coating layer disposed on the exposed rear edge of the metal sheet between the first backing plate and the second backing plate, The coating layer is disposed in a non-active region between the bending region and the active region at the one edge, and is disposed in the non-active region at the remaining edges.

2. The device according to claim 1, wherein the display panel further comprises: a first flat portion; a second flat portion facing the first flat portion; as well as a curved portion located between the first flat portion and the second flat portion, the curved portion extending from the first flat portion and curving in the rearward direction, The first back plate and the second back plate are respectively located on the rear surface of the first flat portion and the rear surface of the second flat portion.

3. The apparatus according to claim 1, further comprising: a polarizing plate disposed on the display panel; a glass cover disposed on the polarizing plate; an adhesive layer between the polarizing plate and the glass cover; as well as An adhesive member is provided between the metal plate and the second back plate. The device of claim 1 , wherein the coating layer comprises engraved information. The device of claim 1 , wherein the coating layer is silicon monoxide (SiO). The device according to claim 1 , wherein the coating layer is provided on the edge surface of the metal plate in a quadrangular frame shape.

7. The apparatus according to claim 1, further comprising: An adhesive is interposed between the metal plate and the first backing plate. 8 . The apparatus according to claim 7 , wherein the metal plate includes a cutout region defined by removing a portion of a side surface of the metal plate. 9 . The device according to claim 8 , wherein the cut-off portion region has a triangle, a quadrangle, a trapezoid, or a semicircle. 10 . The device of claim 8 , wherein the cutout regions are provided at a left end, a right end, an upper end, and a lower end of the flexible display device. 11 . The apparatus according to claim 7 , wherein the coating layer is provided from a rear edge of the metal plate to a side surface of the metal plate and a side surface of the adhesive. 12 . The device of claim 7 , wherein the coating layer is provided from a rear edge of the metal plate to a side surface of the metal plate and a side surface of the adhesive and a rear surface of the first back plate.

13. The device according to claim 7, wherein the coating layer is provided from the rear edge of the metal plate to the side surface of the metal plate and the side surface of the adhesive, the rear surface of the first back plate, and the side surface of the first back plate and the side surface of the display panel. The device according to claim 3 , wherein the coating layer is in contact with a side surface of the adhesive member.

15. The device according to claim 2 , wherein the first flat portion corresponds to the active region and a portion of the inactive region and remains in a flat state. The second flat portion corresponds to a pad portion provided in the non-active region and is maintained in a flat state. 16 . The device of claim 15 , wherein the pad portion is positioned to overlap the non-active region in a rearward direction of the non-active region in response to bending of the display panel.

17. The apparatus according to claim 3, further comprising: A light-blocking pattern is positioned on four edges of the cover glass and overlaps a portion of each of the display panel, the adhesive layer, and the polarizing plate disposed below the light-blocking pattern. 18 . The device of claim 17 , wherein an end portion of the adhesive member is disposed in an inactive region between the bending region and the active region, and the light-blocking pattern overlaps a portion of the adhesive member.

19. The device according to claim 2, further comprising a micro coating layer disposed on the bending region, One side of the micro coating layer partially overlaps with the first backing plate, and is configured to bend together with the bent portion so that the other side of the micro coating layer partially overlaps with the second backing plate.

20. The device of claim 19, wherein the micro-coating layer is disposed above a neutral plane of the curved portion.

21. The device according to claim 19, further comprising a polarizing plate disposed on the display panel, One side of the micro coating layer extends to the polarizing plate and contacts the side surface of the polarizing plate.

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