Display device

Abstract

A display device is provided. The display device includes a display panel; and a cover window on the display panel, wherein the cover window includes a glass cover, a flame retardant layer, and a functional coating layer. A cover window having a flame retardant property and an anti-diffusion property by using a flame retardant layer is used to improve durability and heat resistance of a display device.

Description

[0001] This application is a divisional application of the application patent application with the application number 202210403496.1 and the application name “Display device” filed on April 18, 2022.

[0002] Cross Reference to Related Applications

[0003] This application claims priority to Korean Patent Application No. 10-2021-0051399 filed in Korea on April 20, 2021, the disclosure of which is incorporated herein by reference. TECHNICAL FIELD

[0004] The present application relates to a display device, and more particularly, to a display device having a flame retardant property and a diffusion preventing property. BACKGROUND

[0005] With the advent of the information age, the display field that visually presents an electric information signal is rapidly developing, and accordingly, various display devices having excellent properties such as a thin thickness, a light weight, and a low power consumption are being developed. Specific examples of such display devices include a liquid crystal display device (LCD), a plasma display panel device (PDP), a field emission display device (FED), and an organic light emitting display device (OLED).

[0006] Meanwhile, a display device installed in a public place used by random people must satisfy various regulations. For example, since the spread of a flame or a toxic smoke caused by a burning at the time of a fire can cause damage to a human life, a display device used in a closed space such as a car, a subway, a ship, and an airplane needs to satisfy legal regulations.

[0007] In general, an optical film such as a polarizing film for the outermost part of a display device is formed of a polymer material that is easily affected by heat and fire. Therefore, at the time of a fire, the optical film is burned to spread a flame or a toxic smoke, which can cause damage to a human life. In addition, a small flame generated outside the display device not only burns the outside of the display device, but also burns a component of the display device such as a display panel inside the display device, thereby causing material damage to the display device and surrounding objects.

[0008] When a glass cover is used to protect a display panel, the glass is broken or damaged due to an external impact, and glass fragments are diffused to cause damage to a human body.

[0009] Therefore, there is a need for a method for protecting a display panel by providing a high-strength cover window on the surface of the display panel and minimizing damage due to various accidents and fires that can occur in a closed space or a public place. SUMMARY

[0010] An object to be achieved by the present application is to provide a display device including a cover window having flame retardant properties and anti-scattering properties.

[0011] Another object to be achieved by the present application is to provide a display device for a transportation facility such as a car, a subway, and an airplane, which satisfies a regulation of a domestic law and an international standard related to fire.

[0012] Still another object to be achieved by the present application is to provide a display device that minimizes damage due to various accidents and fires that can occur in a closed space or a public place.

[0013] The objects of the present application are not limited to the above-mentioned objects, and other objects not mentioned above will be clearly understood by those skilled in the art from the following description.

[0014] According to an aspect of the present application, a display device includes a display panel; and a cover window on the display panel, the cover window including a glass cover, a flame retardant layer, and a functional coating layer. The cover window having flame retardant properties and anti-scattering properties by employing the flame retardant layer is used to improve the durability and heat resistance of the display device.

[0015] According to a further aspect of the present application, a display device includes a display panel; at least one glass cover disposed on the display panel; an adhesive layer joining the display panel and the at least one glass cover; at least one flame retardant layer disposed on the at least one glass cover; and at least one functional coating layer disposed on the at least one flame retardant layer, wherein the functional coating layer functions as one or more of an anti-scattering layer, a hard coating layer, an anti-fingerprint layer, an anti-reflection layer, an anti-fouling layer, an anti-glare layer, a viewing angle control layer, and an anti-static layer.

[0016] Further specific matters of the exemplary embodiments include those described in the detailed description and the drawings.

[0017] According to the present application, a cover window having flame retardant properties and anti-scattering properties is provided to improve the durability and heat resistance of a display device.

[0018] According to the present application, an adhesive layer performing a bonding function and a flame retardant function is used to join a plurality of thin glass covers to achieve a thin thickness having excellent flame retardant properties and rigidity.

[0019] According to the present application, a display device satisfying a domestic law and an international standard related to fire can be provided.

[0020] Effects according to the present application are not limited to those exemplified above, and include more diverse effects in the present application. BRIEF DESCRIPTION OF DRAWINGS

[0021] The above and other aspects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

[0022] Figure 1A is a schematic cross-sectional view of a display device according to an exemplary embodiment of the present invention;

[0023] Figure 1A is a cross-sectional view illustrating an example of a rear cover structure of a display device according to an exemplary embodiment of the present invention;

[0024] Figure 2 is a schematic cross-sectional view of a display device according to another exemplary embodiment of the present invention;

[0025] Figure 3 is a schematic cross-sectional view of a display device according to yet another exemplary embodiment of the present invention;

[0026] Figure 4 is a schematic cross-sectional view of a display device according to yet another exemplary embodiment of the present invention;

[0027] Figure 5 is a schematic cross-sectional view of a display device according to yet another exemplary embodiment of the present invention;

[0028] Figures 6 to 8 is a view for explaining an example of employing a display device according to an exemplary embodiment of the present invention;

[0029] Figure 9 is a graph illustrating evaluation results of flame retardant properties of cover windows according to the exemplary embodiment and comparative examples;

[0030] Figure 10 is a graph illustrating evaluation results of impact resistance and anti-diffusion properties of cover windows according to exemplary embodiments and comparative examples. DETAILED DESCRIPTION

[0031] The advantages and features of the present invention and methods for achieving these advantages and features will become apparent by referring to the exemplary embodiments described in detail below in conjunction with the accompanying drawings. 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.

[0032] The shapes, sizes, proportions, angles, numbers, and the like shown in the drawings for describing exemplary embodiments of the present application are merely examples, and the present application is not limited thereto. Like reference numerals refer to like elements throughout the specification. Also, in the following description of the present application, detailed explanations of known related technologies can be omitted to avoid unnecessarily obscuring the subject matter of the present application. The terms such as "include," "have," and "comprise" used herein are generally intended to allow for addition of other components, unless the terms are used with the term "only."

[0033] Components are interpreted to include generally accepted ranges of error even if not expressly stated.

[0034] When a positional relationship between two parts is described using terms such as "on," "above," "below," and "behind," one or more parts can be disposed therebetween unless the terms are used with the term "immediately" or "directly."

[0035] When an element or a layer is disposed "on" another element or layer, the element or layer can be disposed directly on the other element or layer or other elements or other layers can be interposed therebetween.

[0036] Although various components are described using the terms "first," "second," and the like, the components are not limited by the terms. The terms are used only to distinguish one component from another component. Thus, the first component mentioned below can be the second component within the technical idea of the present application.

[0037] The same reference numerals generally refer to the same elements throughout the specification.

[0038] The sizes and thicknesses of each component shown in the drawings are shown for convenience of explanation, and the present application is not limited to the sizes and thicknesses of the components shown in the drawings.

[0039] The features of the respective embodiments of the present application can be combined or integrated with each other partially or entirely, and can be technically interlocked and operated in various ways, and the embodiments can be implemented independently of each other or in association with each other.

[0040] Hereinafter, a display device according to an exemplary embodiment of the present application will be described in detail with reference to the accompanying drawings.

[0041] Figure 1A and 1B are views for explaining a display device according to an exemplary embodiment of the present application. Figure 1A is a schematic cross-sectional view of a display device according to an exemplary embodiment of the present application. Figure 1B is a cross-sectional view illustrating an example of a back cover structure of a display device according to an exemplary embodiment of the present application

[0042] Referring to Figure 1A The display device 100 according to an exemplary embodiment of the present application includes a cover plate 110, a back cover 120, a display panel 130, a first adhesive layer ADH1, and a cover window CW. Hereinafter, each component will be described in greater detail.

[0043] First, the cover plate 110 is a case member that accommodates and protects the display panel 130 and each component of the display device 100.

[0044] The cover plate 110 can be formed of a plastic or metal material having high strength to protect the display panel 130. For example, the cover plate 110 can be a metal material such as stainless steel (SUS) or nickel-iron alloy, and can be formed of a plastic material such as polymethyl methacrylate (PMMA), polycarbonate (PC), polyvinyl alcohol (PVA), acrylonitrile diethylene butadiene (ABS), polyethylene terephthalate (PET), silicone, or polyurethane (PU), but is not limited thereto.

[0045] The cover plate 110 can be an integrated cover plate having a rectangular frame shape with edges vertically curved. Also, the cover plate 110 can be a separable cover plate including a lower plate positioned below the display panel 130 and a side plate disposed to surround a side portion of the display panel 130. In the separable cover plate, the lower plate and the cover plate are joined together. Hereinafter, a more specific shape of the cover plate 110 will be described with reference to Figure 5

[0046] The back cover 120 is disposed on the cover plate 110. The back cover 120 is disposed on a rear surface of the display panel 130 to support the display panel 130 and performs a heat dissipation function to smoothly spread heat from the display panel 130 to the outside. The back cover 120 can include a material having high thermal conductivity and rigidity to perform a support function and a heat dissipation function. For example, the back cover 120 can be manufactured by a metal plate such as aluminum, aluminum nitride (AlN), electrogalvanized zinc steel plate (EGI), stainless steel (SUS), hot-dipped aluminum zinc steel plate (SGLC), aluminum-plated steel plate (ALCOSTA), tin-plated steel plate (SPTE), but is not limited thereto.

[0047] The back cover 120 can be formed of an advanced composite material (ACM) to secure rigidity and heat dissipation characteristics. Hereinafter, a structure of the back cover 120 formed of an advanced composite material (ACM) will be described in greater detail with reference to Figure 1B

[0048] Referring to Figure 1B ​​The rear cover 120 formed of an advanced composite material (ACM) includes a first metal layer 120a, a polymer layer 120c, and a second metal layer 120b. The first metal layer 120a and the second metal layer 120b can be formed of a metal material such as aluminum, aluminum nitride (AlN), electrogalvanized steel sheet (EGI), stainless steel (SUS), hot-dipped aluminum-zinc steel sheet (SGLC), plated aluminum steel sheet (ALCOSTA), or plated tin steel sheet (SPTE). The polymer layer 120c is filled between the first metal layer 120a and the second metal layer 120b to absorb external impact. The polymer layer 120c can be formed of a fiber material such as carbon fiber, silicon carbide fiber, aramid fiber, or boron fiber, or a heat-resistant resin such as epoxy resin or polyimide resin, but is not limited thereto.

[0049] In Figure 1B , the first metal layer 120a and the second metal layer 120b are shown to be disposed on the lower surface and the upper surface of the polymer layer 120c, respectively. However, the first metal layer 120a and the second metal layer 120b are disposed to completely surround the side surface of the polymer layer 120c, such that the polymer layer 120c is sealed by the first metal layer 120a and the second metal layer 120b used to fill the inside.

[0050] An oxide layer 120d can be formed on one surface of the first metal layer 120a. The oxide layer 120d can be formed by anodizing one surface of the first metal layer 120a, which is exposed to the outside and is another surface other than the contact surface of the first metal layer 120a and the polymer layer 120c. The oxide layer 120d can be disposed on the upper surface of the cover plate 110 and located at opposite sides of the upper surface of the cover plate 110. The oxide layer 120d can improve the durability and rigidity of the first metal layer 120a. For example, when the first metal layer 120a and the second metal layer 120b are formed of aluminum, the oxide layer 120d on the first metal layer 120a is composed of aluminum oxide. Aluminum oxide has strong mechanical properties and excellent chemical resistance to help protect the rear cover 120.

[0051] Although the oxide layer 120d is shown to be formed only on the surface of the first metal layer 120a in Figure 1B , the oxide layer 120d can additionally be formed on the surface of the second metal layer 120b. When the oxide layer is formed on the surfaces of the first metal layer 120a and the second metal layer 120b exposed to the outside, the rigidity and durability of the rear cover 120 can be significantly improved.

[0052] The rear cover 120 can be attached to the display panel 130 or the cover plate 110 by an optical clear adhesive (OCA) or a pressure sensitive adhesive (PAS) or a foam tape, but is not limited thereto.

[0053] The display panel 130 is disposed on the back cover 120. The display panel 130 is a panel for displaying an image to a user. The display panel 130 includes a display area and a non-display area. The display area is an area in which a plurality of pixels displaying an image are disposed. In the display area, pixels including a light emitting area for displaying an image and a driving circuit for driving the pixels can be disposed. The pixels can include a plurality of sub-pixels. The sub-pixel is the smallest unit constituting the display area, and each sub-pixel can be configured to emit light of a specific wavelength band. For example, each sub-pixel can be configured to emit red light, green light, blue light, or white light. The non-display area is disposed to surround the display area. The non-display area is an area in which an image is not displayed and various wiring, a driving IC, and a printed circuit board for driving the pixels and the driving circuit located in the display area are disposed. In the non-display area, various ICs such as a gate driver IC and a data driver IC can be disposed.

[0054] For example, the display panel 130 can be a liquid crystal display panel including a liquid crystal layer and adjusting the light transmittance of the liquid crystal to display an image. As another example, the display panel 130 can be an organic light emitting display panel including an organic light emitting layer displaying an image using light emitted from the organic light emitting layer. Unlike the liquid crystal display panel, the organic light emitting display panel is a self-emitting device that does not require a separate light source, and has a slim profile and excellent flexibility. Hereinafter, the display device according to an exemplary embodiment of the present application will be described assuming that the display panel 130 is an organic light emitting display panel, but is not limited thereto. Further, the display panel 130 can be a flexible display panel.

[0055] Specifically, the display panel 130 includes a substrate, a thin film transistor, and an organic light emitting diode.

[0056] The substrate supports various elements constituting the display panel 130. The substrate can be a plastic or a glass substrate having flexibility. For example, the plastic substrate can be selected from the group consisting of polyimide, polyamide-imide, polyphenyl ether sulfone, polyethylene terephthalate, and polycarbonate, but is not limited thereto. The plastic substrate has relatively weak barrier properties against moisture or oxygen, and thus, in order to compensate for this, the plastic substrate can have a structure in which a plastic film and an inorganic layer are laminated. For example, the flexible substrate can have a multi-layer structure in which a first plastic film, an inorganic layer, and a second plastic film are sequentially laminated, but is not limited thereto.

[0057] The thin film transistor is disposed on the flexible substrate to drive the organic light emitting diode. The thin film transistor can be disposed in each of a plurality of pixel areas. For example, the driving thin film transistor includes a gate, an active layer, a source, and a drain. Further, the thin film transistor can further include a gate insulating layer insulating the gate from the active layer and an interlayer insulating layer insulating the gate from the source and the drain.

[0058] A planarization layer can be disposed on the thin film transistor to planarize the upper surface.

[0059] An organic light emitting diode is disposed on the planarization layer. The organic light emitting diode can include an anode, a cathode, and an organic light emitting layer disposed between the anode and the cathode. In the organic light emitting diode, holes injected from the anode and electrons injected from the cathode combine on the organic light emitting layer to emit light. An image is displayed using the light emitted as described above.

[0060] An encapsulation layer can be disposed on the organic light emitting diode. The encapsulation layer seals the organic light emitting diode of the pixel unit. The encapsulation layer can protect the organic light emitting diode from moisture, oxygen, or impact from the outside. The encapsulation layer can be formed by alternately layering a plurality of inorganic layers and a plurality of organic layers. For example, the inorganic layers can be formed of inorganic materials such as silicon nitride SiNx, silicon oxide SiOx, and aluminum oxide AlOx, and the organic layers can use epoxy resin or acrylic polymer, but are not limited thereto.

[0061] An optical control layer can be disposed on the encapsulation layer. The optical control layer uniformly transmits light to the outside of the display panel 130 under conditions that do not degrade the brightness of light emitted by the organic light emitting diode, and reduces external light reflection to improve display quality. For example, the optical control layer can be a polarizing film.

[0062] A first adhesive layer ADH1 is disposed between the display panel 130 and the cover window CW. The display panel 130 and the cover window CW are bonded to each other by the first adhesive layer ADH1. The first adhesive layer ADH1 can be an optically clear adhesive (OCA) or an optically clear resin (OCR), but is not limited thereto.

[0063] Advantageously, the first adhesive layer ADH1 has high tensile strength and shear strength compared to a general transparent adhesive. For example, the tensile strength of the first adhesive layer ADH1 can be 3 Kgf / cm 2 or more, or 5 Kgf / cm 2 to 20 Kgf / cm 2 ; the shear strength of the first adhesive layer ADH1 can be 3 Kgf / cm 2 or more, or 3 Kgf / cm 2 to 6 Kgf / cm 2 .

[0064] The cover window CW is disposed on the display panel 130 and the first adhesive layer ADH1. The cover window CW protects the display panel 130 from external impact and scratches, and inhibits deterioration of the display elements due to external air such as moisture or oxygen. Meanwhile, the display device 100 according to an exemplary embodiment of the present application can be used in transportation facilities such as cars, subways, and airplanes. As described above, when the display device is installed in public places or densely installed in enclosed spaces, the display device needs to satisfy strict legal and regulatory conditions related to safety in order to protect passengers in the event of an accident. Accordingly, the cover window CW for the display device 100 according to an exemplary embodiment of the present application can have flame retardation and diffusion prevention properties.

[0065] The cover window includes at least one cover glass, at least one flame retardant layer, and at least one functional coating layer. Referring to Figure 1A In the display device 100 according to an exemplary embodiment of the present application, the cover window CW includes a cover glass 140, a second adhesive layer ADH2, a flame retardant layer 150, and a functional coating layer 160.

[0066] The cover glass 140 has the following advantages over a plastic cover formed of a transparent resin: excellent optical properties, high strength and impact resistance, and superior surface hardness.

[0067] The thickness of the cover glass 140 can be 1 mm or less, or 0.5 mm or less. When the display device 100 according to an exemplary embodiment of the present application is a flexible display device, the cover glass 140 can be a thin cover glass (TCG) having a thickness of 0.1 mm or less, 90 µm or less, 50 µm to 0.1 mm, 50 µm to 90 µm, or 70 µm to 90 µm. As described above, the thin cover glass having a limited thickness can effectively alleviate stress applied when the display device 100 is folded or bent.

[0068] The cover glass 140 can be a chemically strengthend glass. The chemically strengthend glass is a glass that is strengthened by a chemical strengthening method. The chemical strengthening method is a process of enhancing the strength of the glass by ion exchange in which sodium ions contained in the glass are replaced with ions having a larger ionic radius than that of the sodium ions. With the penetration of the ions having a larger ionic radius than that of the sodium ions constituting the cover glass 140, a compressive stress layer is formed on the surface of the cover glass 140 to enhance the strength. For example, the chemically strengthend glass can be prepared by a process of immersing the glass in a potassium salt solution such as potassium nitride, and replacing the sodium ions of the glass with potassium ions while heating at a temperature of 200°C to 450°C for a predetermined time. 200°C to 450°C is a temperature equal to or lower than the glass transition temperature.

[0069] The flame retardant layer 150 is disposed on the glass cover 140. When the display device 100 catches fire, the flame retardant layer 150 suppresses the spread of fire and the generation of smoke. Also, when the display device 100 is broken due to an external impact, the flame retardant layer 150 can suppress the diffusion of fragments.

[0070] In Figure 1A In the illustrated display device 100, the flame retardant layer 150 disposed on the glass cover 140 is constructed of a flame retardant film. The flame retardant film can be a single layer film formed by forming a film of a polymer material having a flame retardant property, or a multi-layer film in which a flame retardant coating layer including a flame retardant agent is formed on a base film.

[0071] First, the flame retardant film having a single layer structure can be formed of a transparent resin. For example, the flame retardant film having a single layer structure can be formed of one or more resins selected from the group consisting of polyimide (PI), polycarbonate (PC), polyester (PE), polyethylene terephthalate (PET), polymethyl methacrylate (PMMA), polyethylene naphthalate (PEN), polyethylene sulfone (PES), acryl, and polystyrene (PS). Also, the film to be employed is not limited as long as it has a flame retardant property and excellent transparency.

[0072] At this time, as the flame retardant film, colorless polyimide (CPI) can be easily employed. Polyimide has excellent flame retardant properties and excellent mechanical strength. Also, polyimide has high toughness and thus can impart a diffusion-preventing property to the flame retardant film. Also, colorless polyimide has high light transmittance, and thus when the colorless polyimide is disposed on the display panel 130, degradation of luminance can be minimized.

[0073] The colorless polyimide can include units derived from a fluorine-based aromatic diamine and units derived from an aromatic dianhydride, or units derived from an aromatic diamine and units derived from a fluorine-based aromatic dianhydride. Also, the colorless polyimide can include units derived from an aromatic diamine and units derived from an alicyclic dianhydride, or units derived from an alicyclic diamine and units derived from an aromatic dianhydride.

[0074] Also, the colorless polyimide can have a polyamide-imide structure further including units derived from an aromatic acid dichloride.

[0075] The aromatic dianhydride can use any one selected from the group consisting of 4,4'-hexafluoroisopropyl phthalic anhydride (6FDA), biphenyl tetracarboxylic dianhydride (BPDA), diphenyl ether dianhydride (ODPA), sulfur-based bisphthalic anhydride (SO2DPA), (isopropylidene diphenyl) bis(phthalic anhydride) (6HDBA), 4-(2,5-dioxotetrahydrofuran-3-yl)-1,2,3,4-tetrahydronaphthalene-1,2-dicarboxylic acid dianhydride (TDA), 1,2,4,5-benzene tetracarboxylic dianhydride (PMDA), benzophenone tetracarboxylic dianhydride (BTDA), bis(carboxyphenyl)dimethylsilane dianhydride (SiDA), bis(dicarboxyphenoxy)diphenyl sulfide dianhydride (BDSDA), and derivatives thereof, or a mixture of two or more thereof, but is not limited thereto.

[0076] The alicyclic dianhydride, for example, can use any one selected from the group consisting of 1,2,3,4-cyclobutane tetracarboxylic dianhydride (CBDA), 5-(2,5-dioxotetrahydrofuranyl)-3-methylcyclohexene-1,2-dicarboxylic acid dianhydride (DOCDA), bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxylic dianhydride (BTA), bicyclooctene-2,3,5,6-tetracarboxylic dianhydride (BODA), 1,2,3,4-cyclopentane tetracarboxylic dianhydride (CPDA), 1,2,4,5-cyclohexane tetracarboxylic dianhydride (CHDA), 1,2,4-tricarboxy-3-methylcarboxy cyclopentane dianhydride (TMDA), 1,2,3,4-tetracarboxy cyclopentane dianhydride (TCDA), and derivatives thereof, or a mixture of two or more thereof, but is not limited thereto.

[0077] For example, the colorless polyimide can include a repeating unit represented by the following Chemical Formula 1:

[0078]

Chemical Formula 1

[0079]

[0080] In Chemical Formula 1, A is a tetravalent organic group, and is an aryl group having 6 to 42 carbon atoms or a cycloalkane group having 4 to 30 carbon atoms; B is a divalent organic group, and is an aryl group having 6 to 30 carbon atoms or a cycloalkane group having 4 to 30 carbon atoms. n can be an integer of 10 to 1000, but is not limited thereto.

[0081] At this time, at least one of the organic groups A and B can further include a fluorine-based substituent such as a trifluoromethyl group (-CF3).

[0082] Next, a flame-retardant film having a multi-layer structure can be constructed by a base film and a flame-retardant coating layer provided on at least one surface of the base film.

[0083] The base film can be formed of a thermoplastic colorless resin. For example, the thermoplastic colorless resin can be selected from the group consisting of polyimide (PI), polycarbonate (PC), polyphenylene ether sulfone (PES), polyarylate (PAR), polyethylene naphthalate, polyethylene terephthalate (PET), and cyclic olefin copolymer.

[0084] The flame retardant coating layer can be formed of a base resin and a flame retardant.

[0085] The base resin can be formed of a polymer having transparency, for example, one or more selected from the group consisting of acrylic resin, polyester resin, polyimide resin, polyethylene resin, polyurethane resin, and polyphenylene sulfide resin, but is not limited thereto.

[0086] The flame retardant can use one or more selected from the group consisting of halogen-based flame retardants, phosphorus (P)-based flame retardants, nitrogen-based flame retardants, metal-based flame retardants, melamine-based flame retardants, antimony-based flame retardants, and graphite material-based flame retardants. More specifically, the flame retardant can use a chlorine (Cl)-based flame retardant such as chlorinated paraffin, chlorinated polyethylene, chlorinated polyphenyl, perchlorocamphane; a bromine (Br)-based flame retardant such as ethylene dipentylbenzene, ethylene dipentyl diphenyl, tetrabromoethane, tetrabromobisphenol A, hexabromobenzene, decabromodiphenyl ether, tetrabromophthalic anhydride, polydibromophenyl oxide, hexabromocamphane, ammonium bromide; a phosphate ester or phosphorus compound such as tripropylene phosphate, alkyl propylene phosphate, alkyl phosphate, dimethyl phosphite, polyphosphate ester, halogenated polyphosphate ester, trimethyl phosphate, phosphoric acid tributyl ester, phosphoric acid trioctyl ester, phosphoric acid tributoxyethyl ester, octyl diphenyl phosphate, tritolyl phosphate, chlorophenyl phosphate, triphenyl phosphate, tris(chloroethyl)phosphate, tris(2-chloropropyl)phosphate, tris(2,3-dichloropropyl)phosphate, tris(2,3-dibromopropyl)phosphate, tris(bromochloropropyl)phosphate, s(2,3-dibromopropyl)2,3-dichloropropyl phosphate, bis(chloropropyl)phosphate monooctyl ester, polyphosphate, polyphosphate ester, aromatic polyphosphate, dibromoneopentyl glycol, aluminum tris(diethyl phosphinate); a polyol such as a phosphate ester polyol, a phosphate polyol, a halogen-containing polyol; a metal powder or inorganic compound such as aluminum hydroxide, magnesium hydroxide, magnesium carbonate, antimony trioxide, antimony trichloride, zinc borate, antimony borate, boric acid, antimony molybdenum butenoic acid, molybdenum butene oxide, phosphorus-nitrogen compound, calcium aluminum silicate, titanium dioxide, zirconium compound, tin compound, dawsonite, hydrated calcium aluminate, copper oxide, metallic copper powder, calcium carbonate, barium metaborate; or a nitrogen-based flame retardant such as melamine cyanurate, triazine, isocyanurate, urea, guanidine, but is not limited thereto.

[0087] The flame retardant can contain an amount of 5 to 50 weight percent based on the total weight of the flame retardant coating layer, but is not limited thereto. Depending on the properties of the flame retardant to be used, the flame retardant can contain an amount in a range that has an effect of improving the flame retardant properties, while not significantly deteriorating the light transmittance.

[0088] In the display device 100 according to the exemplary embodiment of the present application, the flame retardant layer 150 is a flame retardant film manufactured in advance. Accordingly, the flame retardant film is attached on the upper surface of the glass cover 140 using a separate adhesive layer to form the flame retardant layer 150. That is, a second adhesive layer ADH2 is provided between the glass cover 140 and the flame retardant layer 150 to join the glass cover 140 and the flame retardant layer 150 to each other. The second adhesive layer ADH2 can be an optical clear adhesive (OCA), but is not limited thereto. As long as the adhesive satisfies the adhesive properties and optical properties, any adhesive can be used without limitation. The flame retardant layer 150 constructed of the flame retardant film can be joined to the glass cover 140 using the second adhesive layer ADH2 between the flame retardant film 150 and the glass cover 140 through a lamination process.

[0089] A functional coating layer 160 is provided on the flame retardant layer 150. The functional coating layer 160 includes one or more of a diffusion prevention layer, a hard coating layer, a fingerprint prevention layer, an anti-reflection layer, a contamination prevention layer, an anti-glare layer, a viewing angle control layer, and an anti-static layer. The functional coating layer 160 can be provided above, below, or above and below the cover window CW.

[0090] For example, the diffusion prevention layer can be provided on the upper surface of the flame retardant layer 150. The diffusion prevention layer serves as a buffer to protect a component located thereunder, such as the glass cover 140, from external impact, and can inhibit the spread of fragments when damaged. For example, the diffusion prevention layer can be formed of polyurethane, silicone, or polybutanol, but is not limited thereto. For example, the diffusion prevention layer can be formed by forming a diffusion prevention coating agent on the glass cover 140 or the flame retardant layer 150. As another example, the diffusion prevention layer can be formed by attaching a diffusion prevention film on the glass cover 140 or the flame retardant layer 150.

[0091] The display device according to the exemplary embodiment of the present application includes a cover window including a glass cover, a flame retardant layer, and a functional coating layer. The cover window including the flame retardant layer is used to improve the flame retardant properties. Accordingly, when the display device catches fire, the spread of fire and the generation of smoke can be minimized. Further, in the display device according to the exemplary embodiment of the present application, the flame retardant layer of the cover window can be a flame retardant film manufactured in the form of a film. The flame retardant film manufactured in advance is provided on the glass cover to improve the diffusion prevention properties. Thereby, when an external impact is applied to the cover window, the breakage can be inhibited, and even if the cover window is broken, the diffusion of fragments can be minimized.

[0092] In particular, when the display apparatus according to the exemplary embodiment of the present application is installed in public places such as cars, subways, and airplanes or densely installed in enclosed spaces, the display apparatus needs to satisfy strict legal and regulatory conditions to address problems due to the outbreak of fire and the spread of fire and smoke. Therefore, the display apparatus according to the exemplary embodiment of the present application uses a cover window having a flame retardant property and a diffusion-preventing property, thereby providing a display apparatus satisfying the specifications required by domestic laws and international standards.

[0093] Figure 2 is a schematic cross-sectional view of a display apparatus according to another exemplary embodiment of the present application. Referring to Figure 2 , a display apparatus 200 according to another exemplary embodiment of the present application is substantially the same as the display apparatus 100 shown in Figure 1A , except that a cover window is provided without a separate adhesive layer, in which a flame retardant layer 250 is disposed on a glass cover 140. Therefore, a description of repeated components will be omitted.

[0094] Referring to Figure 2 , the cover window includes the glass cover 140, the flame retardant layer 250, and the functional coating layer 160. At this time, the flame retardant layer 250 is constructed by a flame retardant film disposed on the glass cover 140 and directly contacting the glass cover 140 without using an adhesive layer. In the display apparatus 200 shown in Figure 2 , the flame retardant layer 250 is a single layer film formed by manufacturing a film of a polymer material having a flame retardant property.

[0095] First, as described with reference to Figure 1A , the flame retardant film having a single layer structure can be formed of a thermoplastic colorless resin. The thermoplastic colorless resin is flexible, easy to process, and has excellent optical properties. For example, the flame retardant film having a single layer structure can be formed of one or more resins including polyimide (PI), polycarbonate (PC), polyester (PE), polyethylene terephthalate (PET), polymethyl methacrylate (PMMA), polyethylene naphthalate (PEN), polyethylene sulfone (PES), acrylic, and polystyrene (PS). Further, the flame retardant film having a single layer structure can be used without limitation as long as it has a flame retardant property and excellent transparency.

[0096] In the display apparatus 100 shown in Figure 1A , the flame retardant film constituting the flame retardant layer 150 is formed through a separate process and then disposed on the glass cover 140 using a second adhesive layer ADH2. In contrast to this, in the display apparatus 200 shown in Figure 2 , the flame retardant film constituting the flame retardant layer 250 is directly formed on the glass cover 140 to be disposed in contact with the glass cover 140.

[0097] Specifically, the flame-retardant layer 250 can be formed by applying a precursor composition of a resin constituting a flame-retardant film onto the glass cover 140, and then directly forming the flame-retardant film on the glass cover 140 through a polymerization reaction. For example, when the flame-retardant film constituting the flame-retardant layer 250 is polyimide, a polyimide precursor composition containing dianhydride and diamine is applied to the glass cover 140, and then heated at a high temperature under an inert atmosphere for thermal imidization, thereby forming a polyimide film on the glass cover 140.

[0098] In addition, when the resin component constituting the flame retardant film is prepared by powdering the resin and dissolving it in an organic solvent, the resin component is applied to the glass cover 140 and then dried to form the flame retardant film. For example, when the flame retardant film constituting the flame retardant layer 250 is polyimide, after first synthesizing the polyimide from a precursor, the homogeneous reaction mixture is poured into methanol, water, etc. to precipitate the polyimide, and then a filtration, washing, and drying process is performed to obtain the powdered polyimide. A polyimide solution is prepared by dissolving the powdered polyimide in an organic solvent, and then the polyimide solution is applied to the glass cover 140 and dried to form a polyimide film on the glass cover 140.

[0099] The thickness of the flame-retardant layer 250 formed by the flame-retardant film having a single-layer structure formed by the above-mentioned coating process may be 20 μm or more, and may be 30 μm to 100 μm. When the thickness of the flame-retardant layer 250 formed by the coating process satisfies the above-mentioned range, sufficient flame-retardant properties can be ensured, and the upper surface can be formed uniformly.

[0100] like Figure 2 As shown, when the flame retardant layer 250 is formed by the above coating process, the flame retardant film can be provided on the glass cover 140 so as to be in direct contact with the glass cover 140 without using a separate adhesive layer. Thus, not only the flame retardant property is imparted to the cover window, but also a thin thickness can be achieved.

[0101] Figure 3 is a schematic cross-sectional view of a display device according to another exemplary embodiment of the present invention. Figure 3 According to another exemplary embodiment of the present invention, a display device 300 and Figure 1A The display device 100 shown is substantially the same except that the cover window includes a plurality of glass covers 340, and in the cover window, a flame retardant layer 350 is disposed between the plurality of glass covers 340. Therefore, descriptions of duplicate components will be omitted.

[0102] Reference Figure 3The cover window includes a first glass cover 341, a flame retardant layer 350, a second glass cover 342, and a functional coating layer 160. Descriptions of the first glass cover 341 and the second glass cover 342 are substantially the same as those of the glass cover 140 of the display device 100 shown in FIG. 1, and thus redundant descriptions will be omitted. Figure 1A The descriptions of the first glass cover 341 and the second glass cover 342 are substantially the same as those of the glass cover 140 of the display device 100 shown in FIG. 1, and thus redundant descriptions will be omitted. Figure 3 In the display device 300 shown in FIG. 3, when a plurality of glass covers 340 are provided, the rigidity of the cover window is maintained, and the flexibility can be improved.

[0103] When a plurality of glass covers 340 are configured in the cover window, the first glass cover 341 and the second glass cover 342 can be thin glass covers (TCG). For example, the thickness of the first glass cover 341 and the second glass cover 342 can be 0.1 mm or less, 90 µm or less, 50 µm to 0.1 mm, 50 µm to 90 µm, or 70 µm to 90 µm. When the display device 300 shown in FIG. 3 is implemented as a flexible display device, stress applied when the flexible display device is folded or bent can be effectively alleviated. Figure 3 When the display device 300 shown in FIG. 3 is implemented as a flexible display device, stress applied when the flexible display device is folded or bent can be effectively alleviated.

[0104] The flame retardant layer 350 is disposed between the first glass cover 341 and the second glass cover 342. In the display device 300 shown in FIG. 3, the flame retardant layer 350 can have an adhesive property of bonding the first glass cover 341 and the second glass cover 342 to each other and a flame retardant property of suppressing the spread of fire and the generation of smoke in the case of a fire. That is, in the display device 300 shown in FIG. 3, the flame retardant layer 350 can also function as an adhesive layer. Figure 3 In the display device 300 shown in FIG. 3, the flame retardant layer 350 can have an adhesive property of bonding the first glass cover 341 and the second glass cover 342 to each other and a flame retardant property of suppressing the spread of fire and the generation of smoke in the case of a fire. Figure 3 In the display device 300 shown in FIG. 3, the flame retardant layer 350 can also function as an adhesive layer.

[0105] The flame retardant layer 350 can be formed of a coating composition including an adhesive property and a flame retardant property.

[0106] The flame retardant layer 350 can be formed of an adhesive satisfying a light transmittance, an adhesive degree, and a flame retardant property. For example, the flame retardant layer 350 can include a silicon-based optically clear adhesive, but is not limited thereto.

[0107] Further, the flame retardant layer 350 can be formed of a mixture of an adhesive and a flame retardant agent. The adhesive can include an adhesive selected from among known optically clear adhesives, optically clear resins, and pressure sensitive adhesives. Further, the adhesive can include a polymer resin. For example, the polymer resin can use one or more selected from among a set consisting of a polyester resin, a polyimide resin, a polyethylene resin, a polyurethane resin, and a polyphenylene sulfide resin, but any polymer resin can be used without limitation as long as the polymer resin satisfies a sufficient adhesive degree and a light transmittance. The flame retardant agent can use one or more selected from among a set consisting of a halogen-based flame retardant agent, a phosphorus (P)-based flame retardant agent, a nitrogen-based flame retardant agent, a metal-based flame retardant agent, a melamine-based flame retardant agent, an antimony-based flame retardant agent, and a graphite material-based flame retardant agent.Figure 3 The flame retardant included in the flame retardant layer 350 of the display device 300 shown is substantially the same as the flame retardant included in the flame retardant layer 150 of the display device 100 shown in FIG. 1, and thus a repeated description will be omitted. Figure 1A The flame retardant included in the flame retardant layer 150 of the display device 100 shown is substantially the same as the flame retardant included in the flame retardant layer 150 of the display device 100 shown in FIG. 1, and thus a repeated description will be omitted.

[0108] In the display device 300 according to still another exemplary embodiment of the present application, the cover window includes a plurality of glass covers 340, and a flame retardant layer 350 having adhesion and flame retardant properties is disposed between the plurality of glass covers 340. The flexibility of the cover window can be improved by the plurality of glass covers 340. Further, by imparting the flame retardant properties to the adhesive layer disposed between the plurality of glass covers 340, a separate flame retardant layer 350 can be omitted, and thus the thickness of the cover window or the display device 300 can be reduced.

[0109] Figure 4 is a schematic cross-sectional view of a display device according to still another exemplary embodiment of the present application. Referring to Figure 4 , the display device 400 according to still another exemplary embodiment of the present application is substantially the same as the display device 300 shown in FIG. 3, except that a separate flame retardant layer is further disposed on the second glass cover 342. Thus, a description of repeated components will be omitted. Figure 3 Referring to

[0110] , the cover window includes a first glass cover 341, a first flame retardant layer 451, a second glass cover 342, a second flame retardant layer 452, and a functional coating layer 160. Figure 4 The first flame retardant layer 451 is disposed between the first glass cover 341 and the second glass cover 342, and has adhesion and flame retardant properties. The first flame retardant layer 451 is substantially the same as the flame retardant layer 150 of the display device 100 shown in FIG. 1, and thus a repeated description will be omitted.

[0111] Figure 1A The second flame retardant layer 452 is disposed on the second glass cover 342. The second flame retardant layer 452 imparts a flame retardant function and a diffusion prevention function to the cover window. The second flame retardant layer 452 can be constructed by a flame retardant film. The flame retardant film can be a single layer film formed by forming a film of a polymer material having flame retardant properties, or a multi-layer film in which a flame retardant coating layer including a flame retardant agent is formed on a base film. The second flame retardant layer 452 is substantially the same as the flame retardant layer 150 of the display device 100 shown in FIG. 1, and thus a repeated description will be omitted.

[0112] The second flame retardant layer 452 is disposed on the second glass cover 342. The second flame retardant layer 452 imparts a flame retardant function and a diffusion prevention function to the cover window. The second flame retardant layer 452 can be constructed by a flame retardant film. The flame retardant film can be a single layer film formed by forming a film of a polymer material having flame retardant properties, or a multi-layer film in which a flame retardant coating layer including a flame retardant agent is formed on a base film. The second flame retardant layer 452 is substantially the same as the flame retardant layer 150 of the display device 100 shown in FIG. 1, and thus a repeated description will be omitted. Figure 1A

[0113] ​​In the display device 400 according to the still another exemplary embodiment of the present application, the cover window includes a plurality of glass covers 340, and a first flame retardant layer 451 having an adhesive property and a flame retardant property is disposed between the plurality of glass covers 340. In addition, a second flame retardant layer 452 having a flame retardant property and a diffusion-preventing property is disposed on a surface of the glass cover 340 located at an outermost portion. The flexibility of the cover window can be improved by the plurality of glass covers 340. In addition, the adhesive layer disposed between the plurality of glass covers 340 is imparted with the flame retardant property, so that the flame retardant performance of the cover window can be further improved.

[0114] Figure 5 is a schematic cross-sectional view of a display device according to still another exemplary embodiment of the present application. Referring to Figure 5 , a display device 500 according to still another exemplary embodiment of the present application is substantially the same as the display device 100 shown in Figure 1A , except that the display device 500 has a structure in which a cover plate 510 includes a horizontal portion 511, a vertical portion 512, and a protruding portion 513, and the display device 500 further includes a top cover 570 surrounding an upper corner portion of the cover plate 510. Thus, a description of repeated components will be omitted.

[0115] Referring to Figure 5 , the cover plate 510 protects the display panel 130 from a side surface, and supports the display panel 130. The cover plate 510 includes the horizontal portion 511, the vertical portion 512, and the protruding portion 513.

[0116] The horizontal portion 511 is disposed below the display panel 130 and the back cover 120, and is opposite to a rear surface of the back cover 120. The vertical portion 512 extends from a section of the horizontal portion 511 to a vertical direction or a front direction or a front direction. That is, the vertical portion 512 has a shape protruding to the front direction from the horizontal portion 511. The vertical portion 512 is disposed to surround and be opposite to side surfaces of the display panel 130 and the back cover 120. The back cover 120, the display panel 130, and the cover window CW are accommodated in an internal space provided by the horizontal portion 511 and the vertical portion 512.

[0117] The protruding portion 513 supports the display panel 130 below. The protruding portion 513 protrudes into the cover plate 510 from the vertical portion 512. The protruding portion 513 can protrude from the vertical portion 512 to support the display panel 130. Specifically, the protruding portion 513 protrudes between the display panel 130 and the back cover 120, and is parallel to the display panel 130. The display panel 130 is disposed on an upper surface of the protruding portion 513, and the back cover 120 is disposed on a lower surface of the protruding portion 513.

[0118] Meanwhile, the display panel 130 and the back cover 120 can be spaced apart from each other by the protrusion 513 located between the display panel 130 and the back cover 120. In this case, the foam tape can be disposed into the protrusion 513 between the display panel 130 and the back cover 120 to fill a gap between the display panel 130 and the back cover 120 and to join the display panel 130 and the back cover 120.

[0119] Although the integrated cover plate 510 (in which the horizontal portion 511, the vertical portion 512, and the protrusion 513 are formed to be connected together) is illustrated in Figure 5 , the horizontal portion 511 and the vertical portion 512 can be separated. For example, the vertical portion and the protrusion can be formed as a side plate fastened together with a lower plate including the horizontal portion.

[0120] The top cover 570 is disposed to surround the upper corner portion of the cover plate 510. The top cover 570 protects the display panel 130 from the outside. When the outside of the display device 500 catches fire, the top cover 570 can suppress the fire from entering between the cover window CW and the cover plate 510 to affect the display panel 130.

[0121] The top cover 570 is disposed to cover the edge of the side surface of the cover window CW and the upper surface and portions of the side surface of the vertical portion 512 of the cover plate 510. That is, the top cover 570 includes a horizontal portion covering the upper edge of the cover window CW and a vertical portion covering the side surface of the cover plate 510. The top cover 570 has a frame shape. The top cover 570 can be formed of a plastic or metal material having high strength so as to protect the display panel 130 from a physical impact and can also be formed of a material having a flame retardant property so as to protect the display panel 130 from a fire.

[0122] Figures 6 to 8 is a view for explaining an example in which a display device according to an exemplary embodiment of the present application is employed. Referring to Figures 6 to 8 , the display device according to an exemplary embodiment of the present application can be used in a transportation facility such as a car, a subway, and an airplane.

[0123] More specifically, referring to Figure 6 , the display device according to an exemplary embodiment of the present application can be used as a navigation device 600a or an instrument panel 600b of a vehicle. Further, referring to Figure 7 , the display device according to an exemplary embodiment of the present application can be used as a signboard 700a or an infotainment guide 700b of a subway. Further, referring to Figure 8 , the display device according to an exemplary embodiment of the present application can be used as a large-size display 800a or a personal display 800b in an airplane.

[0124] Transportation facilities such as cars, subways, and airplanes are used by a large number of people in a closed space. Therefore, when a display device is installed in a transportation facility or a closed public place, it is necessary to use a display device that satisfies various regulations to suppress the outbreak of fire and minimize the spread of fire and smoke. The display device according to an exemplary embodiment of the present application provides a cover window including a flame retardant layer on a display panel, thereby improving flame retardant properties and diffusion prevention properties. Thus, a display device capable of satisfying the regulations required by domestic laws and international standards can be provided.

[0125] Specifically, the display device according to an exemplary embodiment of the present application needs to satisfy the vertical burning regulation, the smoke density regulation, and the smoke toxicity regulation required by international standards.

[0126] Hereinafter, the effects of the present application will be described in greater detail with reference to exemplary embodiments and comparative examples. However, the exemplary embodiments below are set forth merely for illustrative purposes, and the scope of the present application is not limited thereto.

[0127] Example 1

[0128] A cover window was prepared in which a 0.5 mm glass cover, a 25 μm OCA, and a 50 μm colorless polyimide film were sequentially stacked.

[0129] Example 2

[0130] A cover window was prepared in substantially the same manner as in Exemplary Embodiment 1, except that a hard coat layer composed of a 5 μm acrylic resin component including silsesquioxane (SSQ) was additionally stacked on the colorless polyimide film.

[0131] Example 3

[0132] A cover window was prepared in substantially the same manner as in Exemplary Embodiment 1, except that a hard coat layer composed of a 10 μm acrylic resin component was additionally stacked on the colorless polyimide film.

[0133] Comparative Example 1

[0134] A cover window was prepared in which a 0.5 mm glass cover, a 25 μm OCA, and a 200 μm polarizing film were sequentially stacked.

[0135] Experimental Example 1 - Evaluation of Flame Retardant Properties

[0136] The length of the carbonized cover window was measured after ignition for 60 seconds on the cover windows manufactured through Exemplary Embodiments 1 to 3 and Comparative Example 1. The results are shown in Table 1. Figure 9

[0137] ​After preparing cover window samples (size: 2 inches x 12 inches) according to Example Embodiments 1 to 3 and Comparative Example 1, the front of the sample was placed at a point 2 cm apart from a flame (temperature: 843.3°C) having a size of 1.5 inches and exposed for 60 seconds to ignite it. Thereafter, the length of the carbonized cover window was measured. The results are shown in Table 1 (when the sample combustion height exceeds 6 inches, the result is failure; when the sample combustion time exceeds 15 seconds, the result is failure; when the flame drops from the sample after 3 seconds or more, the result is failure). Figure 9

[0138] Referring to Figure 9 , the polarizing film for the display device of the related art generally includes TAC, PVA, and acrylic, and is very vulnerable to heat and fire to easily burn. In Comparative Example 1 in which the polarizing film is disposed on the cover window, it was confirmed that most of the film burned and scorched. In contrast, it was confirmed that when the flame-retardant layer formed of the colorless polyimide film is disposed on the glass cover, the length of the carbonized cover window is 2 inches or less. That is, it was confirmed that the flame-retardant properties of Example Embodiments 1 to 3 are superior to those of Comparative Example 1.

[0139] Example 4

[0140] A cover window having a structure in which a 28-μm-thick colorless polyimide film is directly formed on the cover window without using an adhesive layer was prepared by a film forming process in which a colorless polyimide component was coated on a 1.0-mm-thick glass cover and then heated.

[0141] Example 5

[0142] A cover window having a structure in which a 18-μm-thick colorless polyimide film is directly formed on the cover window without using an adhesive layer was prepared by a film forming process in which a colorless polyimide component was coated on a 0.7-mm-thick glass cover and then heated.

[0143] Example 6

[0144] A cover window was prepared in which a 0.7-mm-thick first glass cover, a 25-μm-thick OCA, a 0.5-mm-thick second glass cover, and a 7-μm-thick colorless polyimide film were sequentially stacked.

[0145] Example 7

[0146] A cover window was prepared in which a 1.0-mm-thick glass cover, a 25-μm-thick OCA, a 50-μm-thick colorless polyimide film, and a hard coating layer composed of a 5-μm-thick acrylic resin component including silsesquioxane (SSQ) were sequentially stacked.

[0147] Comparative Example 2 ​

[0148] A cover window was prepared in which a first glass cover of 0.7 mm, an OCA of 25 μm, and a second glass cover of 0.5 mm were sequentially stacked.

[0149] Experimental Example 2 - Evaluation of Impact Resistance and Diffusion Resistance Properties

[0150] To identify the impact resistance and diffusion prevention properties of the display devices of Example 4 to 7 and Comparative Example 2, a ball drop test was performed on the cover windows by the method prescribed in ASTM F3007. Whether or not a crack appeared in the cover window and whether or not diffusion of fragments occurred were examined by freely falling a 260-gram metal ball from a height of 2.1 meters from the cover window. The results are shown in Table 1. Figure 10

[0151] Referring to Table 1, Figure 10 When the flame retardant layer formed of the transparent polyimide film was provided on the cover window, it was confirmed through the ball drop test that even if the cover glass was cracked, no fragments were splashed. In addition, in the case of Example 6, it was confirmed that when a double-layer glass cover was used, the degree of cracking was mitigated.

[0152] The exemplary embodiments of the present application can also be described as follows.

[0153] According to an aspect of the present application, there is provided a display device. The display device includes a display panel; and a cover window on the display panel, wherein the cover window includes a glass cover, a flame retardant layer, and a functional coating layer.

[0154] The flame retardant layer can be a flame retardant film positioned between the glass cover and the functional coating layer.

[0155] The flame retardant film can be a flame retardant film having a single layer structure formed of one or more resins selected from the group consisting of polyimide (PI), polycarbonate (PC), polyester (PE), polyethylene terephthalate (PET), polymethyl methacrylate (PMMA), polyethylene naphthalate (PEN), polyethylene sulfone (PES), acrylic, and polystyrene (PS).

[0156] The flame retardant film can be provided on the glass cover in direct contact with the glass cover by a coating process, and the thickness of the flame retardant film can be 30 μm to 100 μm.

[0157] The flame retardant film can have a multi-layer structure including a base film and a flame retardant coating layer provided on the base film.

[0158] ​The flame retardant coating layer can include a base resin and a flame retardant, wherein the base resin can include one or more selected from the group consisting of acrylic resin, polyester resin, polyimide resin, polyethylene resin, polyurethane resin, and polyphenylene sulfide resin, and the flame retardant can include one or more selected from the group consisting of halogen-based flame retardant, phosphorus (P)-based flame retardant, nitrogen-based flame retardant, metal-based flame retardant, melamine-based flame retardant, antimony-based flame retardant, and graphite material-based flame retardant.

[0159] The flame retardant layer can include a colorless polyimide.

[0160] The colorless polyimide can include units derived from a fluorine-based aromatic diamine and units derived from an aromatic dianhydride, or units derived from an aromatic diamine and units derived from a fluorine-based aromatic dianhydride, or units derived from an aromatic diamine and units derived from an alicyclic dianhydride, or units derived from an alicyclic diamine and units derived from an aromatic dianhydride.

[0161] The glass cover can include a first glass cover and a second glass cover, and the flame retardant layer can include a first flame retardant layer between the first glass cover and the second glass cover.

[0162] The first flame retardant layer can include an adhesive and a flame retardant.

[0163] The first flame retardant layer can be a silicon-based optically transparent adhesive.

[0164] The display device can further include a second flame retardant layer on the second glass cover, wherein the second flame retardant layer can be a flame retardant film having a single layer structure formed of one or more resins selected from the group consisting of polyimide (PI), polycarbonate (PC), polyester (PE), polyethylene terephthalate (PET), polymethyl methacrylate (PMMA), polyethylene naphthalate (PEN), polyethylene sulfone (PES), acrylic, and polystyrene (PS).

[0165] The functional coating layer can be a diffusion prevention layer.

[0166] The display device can further include a back cover under the display panel, and a cover plate surrounding side surfaces of the back cover and the display panel to accommodate the back cover and the display panel.

[0167] The back cover can include a first metal layer, a second metal layer, and a polymer layer filled between the first metal layer and the second metal layer, and the polymer layer can be formed of carbon fiber, silicon carbide fiber, aramid fiber, boron fiber, epoxy resin, or polyimide resin.

[0168] The back cover can further include an oxide layer formed on a surface of at least one of the first metal layer and the second metal layer, and the oxide layer can be disposed opposite an upper surface of the back cover.

[0169] The first metal layer and the second metal layer can be formed of aluminum.

[0170] The cover plate can include a horizontal portion located below the cover plate and opposite a rear surface of the back cover, a vertical portion protruding from the horizontal portion toward a front direction, and a protruding portion protruding inward from the vertical portion to support the display panel.

[0171] The display device can further include a top cover covering an upper edge of the cover window and an upper surface and portions of side surfaces of the vertical portion of the cover plate to surround an upper corner portion of the cover plate.

[0172] Although the exemplary embodiments of the present application have been described in detail with reference to the accompanying drawings, the present application is not limited thereto and can be implemented in various forms. Therefore, the exemplary embodiments of the present application are provided only for illustrative purposes, and are not intended to limit the technical idea of the present application. The scope of the technical idea of the present application is not limited to this. Therefore, it should be understood that the above-described exemplary embodiments are merely illustrative in all aspects and do not limit the present application. The scope of protection of the present application should be interpreted based on the appended claims, and all technical ideas within the equivalent scope thereof should be interpreted as falling within the scope of the present application.

Claims

1. A display device comprising: Display panel; and a cover window on the display panel; as well as a polarizing layer on the display panel, The cover window comprises a glass cover, a flame retardant layer and a functional coating layer. The flame retardant layer is a flame retardant film between the glass tube and the functional coating layer. The flame retardant film has a single-layer structure formed of colorless polyimide (PI) or a mixture of an adhesive and a flame retardant. The glass cover is chemically strengthened glass, The cover window has a thickness of 0.5 mm to 1 mm, and An optically clear adhesive layer (OCA) is disposed between the display panel and the cover window. 2 . The display device according to claim 1 , wherein a thickness of the flame retardant film is 30 μm to 100 μm.

3. The display device according to claim 1 , wherein the adhesive comprises a polymer resin selected from the group consisting of a polyester resin, a polyimide resin, a polyethylene resin, a polyurethane resin, and a polyphenylene sulfide resin, and the flame retardant is selected from the group consisting of a halogen-based flame retardant, a phosphorus (P)-based flame retardant, a nitrogen-based flame retardant, a metal-based flame retardant, a melamine-based flame retardant, an antimony-based flame retardant, and a graphite material-based flame retardant.

4. The display device according to claim 1, wherein the colorless polyimide includes units derived from a fluorine-based aromatic diamine and units derived from an aromatic dianhydride, includes units derived from an aromatic diamine and units derived from a fluorine-based aromatic dianhydride, includes units derived from an aromatic diamine and units derived from an alicyclic dianhydride, or includes units derived from an alicyclic diamine and units derived from an aromatic dianhydride. The display device according to claim 4 , wherein the colorless polyimide further comprises a unit derived from aromatic diacid dichloride.

6. The display device according to claim 4, wherein the colorless polyimide comprises a repeating unit represented by the following Chemical Formula 1: 【Chemical Formula 1】 wherein A is a tetravalent organic group and is an aryl group having 6 to 42 carbon atoms or a cycloalkane group having 4 to 30 carbon atoms; B is a divalent organic group and is an aryl group having 6 to 30 carbon atoms or a cycloalkane group having 4 to 30 carbon atoms; and n is an integer from 10 to 1000. 7 . The display device according to claim 1 , wherein the cover glass comprises a first cover glass and a second cover glass, and the flame retardant layer comprises a first flame retardant layer between the first cover glass and the second cover glass. The display device according to claim 1 , wherein the flame retardant layer is on and / or under the glass cover. 9 . The display device according to claim 1 , wherein the glass cover is on and / or under the flame retardant layer.

10. The display device of claim 1, wherein the flame retardant layer comprises a silicon-based optically clear adhesive.

11. The display device according to claim 1, wherein the functional coating layer is provided on the flame retardant layer and comprises at least one of an anti-diffusion layer, a hard coating layer, an anti-fingerprint layer, an anti-reflection layer, an anti-pollution layer, an anti-glare layer, a viewing angle control layer, and an antistatic layer.

12. The display device according to claim 1, further comprising: a back cover below the display panel; as well as A cover plate surrounds side surfaces of the back cover and the display panel to accommodate the back cover and the display panel.

13. The display device according to claim 12, wherein the back cover comprises a first metal layer, a second metal layer, and a polymer layer filled between the first metal layer and the second metal layer, and The polymer layer is formed of carbon fiber, silicon carbide fiber, aramid fiber, boron fiber, epoxy resin or polyimide resin.

14. The display device according to claim 13, wherein the back cover further includes an oxide layer formed on a surface of at least one of the first metal layer and the second metal layer, and the oxide layer is provided on the upper surface of the cover plate and located on opposite sides of the upper surface of the cover plate. 15 . The display device according to claim 14 , wherein the first metal layer and the second metal layer are formed of aluminum.

16. The display device according to claim 15, wherein the cover plate comprises: a horizontal portion, the horizontal portion being located below the cover plate and opposite to the rear surface of the rear cover; a vertical portion protruding forward from the horizontal portion; as well as A raised portion protrudes from the vertical portion to support the display panel.

17. The display device according to claim 16, further comprising: A top cover is formed of a flame-retardant material and covers an upper edge of the cover window and portions of an upper surface and side surfaces of the vertical portion of the cover plate to surround an upper corner portion of the cover plate. 18 . The display device of claim 16 , wherein the rear cover, the display panel, and the cover window are accommodated in an inner space provided by the horizontal portion and the vertical portion.

19. The display device according to claim 16, wherein the display panel and the back cover are spaced apart from each other by the protrusion located between the display panel and the back cover, and a foam tape is used to fill the gap between the display panel and the back cover and to join the display panel and the back cover.

20. The display device according to claim 1, wherein the tensile strength of the optically transparent adhesive layer is 5 Kgf / cm 2 Up to 20Kgf / cm 2 , and the shear strength of the optically clear adhesive layer is 3Kgf / cm 2 Up to 6Kgf / cm 2 .

Images