Organic light emitting diode display device

Abstract

To provide an organic light emitting diode display device capable of improving heat dissipation speed.SOLUTION: The present invention relates to an organic light emitting diode display device that can improve the heat dissipation speed, the display device includes a display panel (10) including organic light emitting diodes; and a heat dissipating member (60) disposed opposite the display panel, and the heat dissipating member includes a plurality of heat dissipating layers (650) having different thicknesses and different thermal conductivities from each other.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a display device, and more particularly to an organic light emitting diode display device capable of improving the heat dissipation rate.

Background Art

[0002] An organic light emitting diode display has self-emitting characteristics and, unlike a liquid crystal display, does not require a separate light source, so the thickness and weight can be reduced. In addition, since the organic light emitting diode display exhibits high-quality characteristics such as low power consumption, high brightness, and high response speed, it has attracted attention as a next-generation display device for TVs, monitors, and portable electronic devices.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0004] An object of the present invention is to provide an organic light emitting diode display device capable of improving the heat dissipation rate.

[0005] The problems of the present invention are not limited to the problems mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art from the following description.

Means for Solving the Problems

[0006] A display device according to an embodiment of the present invention for achieving the above object includes a display panel 10 including an organic light-emitting diode; and a heat radiating member 60 disposed to face the display panel, and the heat radiating member includes a plurality of heat radiating layers 650 having different thicknesses from each other and different thermal conductivities from each other.

[0007] The plurality of heat radiating layers include a first heat radiating layer 651; and a second heat radiating layer 652 between the first heat radiating layer and the display panel.

[0008] The second heat radiating layer has a higher thermal conductivity than the first heat radiating layer, and the second heat radiating layer has a smaller thickness than the first heat radiating layer.

[0009] The ratio between the thickness of the first heat radiating layer and the thickness of the second heat radiating layer is 19:1.

[0010] The first heat radiating layer has a thickness of 820 μm and a thermal conductivity of 240 W / m·k (the thermal conductivity in the direction along the heat radiating layer at 25°C. The same applies hereinafter.), and the second heat radiating layer has a thickness of 100 μm and a thermal conductivity of 1000 W / m·k.

[0011] The first heat radiating layer includes natural graphite, and the second heat radiating layer includes artificial graphite.

[0012] The plurality of heat radiating layers include a first heat radiating layer; a second heat radiating layer between the first heat radiating layer and the display panel; and a third heat radiating layer 653 between the first heat radiating layer and the second heat radiating layer.

[0013] The third heat radiating layer has a thickness larger than that of the second heat radiating layer and smaller than that of the first heat radiating layer, and the first heat radiating layer has a thermal conductivity larger than that of the third heat radiating layer and smaller than that of the second heat radiating layer.

[0014] The ratio among the thickness of the first heat radiating layer, the thickness of the third heat radiating layer, and the thickness of the second heat radiating layer is 16:3:1.

[0015] The first heat dissipation layer has a thickness of 500 μm or 820 μm and a thermal conductivity of 240 W / m·k, the second heat dissipation layer has a thickness of 100 μm and a thermal conductivity of 1000 W / m·k, and the third heat dissipation layer has a thickness of 300 μm and a thermal conductivity of 202 W / m·k.

[0016] The first heat dissipation layer includes natural graphite, the third heat dissipation layer includes a metal, and the second heat dissipation layer includes artificial graphite.

[0017] The third heat dissipation layer includes aluminum.

[0018] It further includes a housing 600 surrounding the plurality of heat dissipation layers.

[0019] The housing has exhaust holes 601c passing through the housing.

[0020] Of one surface and the other surface of the housing facing each other, the other surface is arranged closer to the display panel than the one surface, and the exhaust holes penetrate the other surface of the housing.

[0021] It further includes a housing selectively surrounding at least one of the plurality of heat dissipation layers.

[0022] The plurality of heat dissipation layers includes a first heat dissipation layer and a second heat dissipation layer between the first heat dissipation layer and the display panel, and the housing surrounds the first heat dissipation layer.

[0023] The plurality of heat dissipation layers includes a first heat dissipation layer, a second heat dissipation layer between the first heat dissipation layer and the display panel, and a third heat dissipation layer between the first heat dissipation layer and the second heat dissipation layer, and the housing surrounds the first heat dissipation layer.

[0024] The total thickness of the plurality of heat dissipation layers is 50% to 150% of the thickness of the display panel.

[0025] The total thickness of the plurality of heat dissipation layers is from 0.5 mm to 1.5 mm.

[0026] Specific contents of other embodiments are included in the detailed description and the drawings.

Advantages of the Invention

[0027] According to the organic light-emitting diode display device of the present invention, the heat dissipation rate can be improved. Furthermore, afterimages can be minimized to improve image quality.

[0028] Note that the effects obtained by the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those of ordinary skill in the technical field to which the present invention pertains from the following description.

Brief Description of the Drawings

[0029]

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Embodiments for Carrying Out the Invention

[0030] The advantages, features, and methods for achieving them of the present invention will become clear by referring to the embodiments described in detail below together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below and can be realized in various different forms. These embodiments are merely provided to complete the disclosure of the present invention and to fully inform those with ordinary knowledge in the technical field to which the present invention pertains of the scope of the invention. The present invention is defined only by the scope of the claims.

[0031] When an element or layer is referred to as being "on" another element or layer, it includes all cases where another layer or element is interposed immediately above or in the middle of the other element. Throughout the specification, the same reference numerals shall refer to the same components. Since the shapes, sizes, ratios, angles, numbers, etc. disclosed in the drawings for explaining the embodiments are exemplary, the present invention is not limited to the illustrations.

[0032] First, second, etc. are used to describe various components, but of course these components are not limited by these terms. These terms are merely used to distinguish one component from another. Thus, it goes without saying that the first component referred to below can be the second component within the technical idea of the present invention.

[0033] The respective features of the various embodiments of the present invention can be combined or combined with each other, either partially or wholly, enabling various technical linkages and drives, and each embodiment can be implemented independently of each other or in cooperation with each other.

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

[0035] FIG. 1 is an exploded perspective view of a display device according to an embodiment.

[0036] Referring to FIG. 1, a display device 1 according to an embodiment can be applied to various household appliances such as smartphones, mobile phones, tablet PCs, PDAs (Personal Digital Assistants), PMPs (Portable Multimedia Players), televisions, game consoles, wristwatch-type electronic devices, head-mounted displays, monitors of personal computers, notebook computers, automotive navigation systems, vehicle instrument panels, digital cameras, camcorders, external billboards, electro-optical panels, medical devices, inspection devices, refrigerators, washing machines, or Internet-of-Things devices.

[0037] In this specification, as an example of the display device 1, a large display device such as a television (for example, a large organic light-emitting diode display device) will be described. The TV can have a high resolution or an ultra-high resolution such as HD, UHD, 4K, 8K, etc.

[0038] Also, the display device 1 according to an embodiment can be classified in various ways according to the display method. For example, the classification of the display device can include an organic light-emitting display device (OLED), an inorganic light-emitting display device (inorganic EL), a quantum dot light-emitting display device (QED), a micro-LED display device (micro-LED), a nano-LED display device (nano-LED), a plasma display device (PDP), a field emission display device (FED), a cathode ray tube display device (CRT), a liquid crystal display device (LCD), an electrophoretic display device (EPD), and the like. Hereinafter, an organic light-emitting display device will be described as an example of the display device. Unless otherwise specifically distinguished, the organic light-emitting display device applied to the embodiment will be simply abbreviated as the display device. However, the embodiment is not limited to the organic light-emitting display device, and other display devices listed above or known in the technical field can also be applied within the scope of sharing the technical idea.

[0039] The display device 1 may include a heat dissipation member 60, a display panel 10, and a front cover 40. The heat dissipation member 60, the display panel 10, and the front cover 40 may be arranged, for example, along the third direction DR3. The display panel 10 may be arranged between the heat dissipation member 60 and the front cover.

[0040] The display panel 10 may be a self-emitting display panel 10. The display panel 10 may be an organic light-emitting display panel 10 as a self-emitting display panel 10. However, it is not limited thereto, and different types of display panels 10 such as a liquid crystal display panel, a quantum dot organic light-emitting display panel 10, a quantum dot liquid crystal display, a quantum nano light-emitting display panel 10, and a micro-LED can also be applied.

[0041] The display panel 10 may include a substrate (SUB; see FIG. 4) and a display layer (DU; see FIG. 4) disposed on the substrate SUB. The description of the detailed structure of the display panel 10 will be described later with reference to FIG. 4 and the like.

[0042] The heat radiating member 60 may be disposed to face the display panel 10. The heat radiating member 60 can radiate the heat generated by the display panel 10 and the driving board (30; see FIG. 4) to other spaces inside the display device 1 or to the outside. For example, the heat radiating member 60 can radiate the heat generated by the display panel 10 and the driving board 30 to the internal space of the front cover 40 or to the outside of the display device 1.

[0043] At least a part of the heat radiating member 60 may surround the display panel 10. For example, at least a part of the heat radiating member 60 may surround the side surface of the display panel 10. Therefore, the heat radiating member 60 can protect the side surface of the display panel 10. According to one embodiment, the heat radiating member 60 may include a side wall SW surrounding the side surface of the display panel 10. Such a side wall SW may include a first side wall SW1, a second side wall SW2, a third side wall SW3, and a fourth side wall SW4 respectively disposed at four edges of the heat radiating member 60. The first to fourth side walls SW1 - SW4 are integral with the heat radiating member 60. As in the example shown in FIG. 1, when the display panel 10 has a rectangular shape including four side surfaces (for example, a first side surface, a second side surface, a third side surface, and a fourth side surface), the plurality of side walls SW1 - SW4 of the heat radiating member 60 may be disposed to face the plurality of side surfaces of the display panel 10. For example, the first side wall SW1 may face the first side surface of the display panel 10, the second side wall SW2 may face the second side surface of the display panel 10, the third side wall SW3 may face the third side surface of the display panel 10, and the fourth side wall SW4 may face the fourth side surface of the display panel 10.

[0044] According to one embodiment, the first to fourth side walls SW1 - SW4 are integral.

[0045] According to one embodiment, the first to fourth side walls SW1 - SW4 and the heat radiating member 60 may include a metal such as aluminum.

[0046] The display device 1 can rapidly disperse or release the heat generated by the driving board 30 by including a heat dissipation member or part such as a heat dissipation member 60 made of a sheet-like heat conductive material.

[0047] The front cover 40 and the heat dissipation member 60 can surround the display panel 10 and the driving board 30. The front cover 40 can protect the display panel 10 and the driving board 30 from external impacts.

[0048] The front cover 40 may include a highly transparent substance so that the light emitted from the display panel 10 can pass through. As an example, the front cover 40 may include a polymer resin such as polyimide, or glass. In other embodiments, the front cover 40 may also include an opening where the area overlapping the display area (DPA; see FIG. 2) is open.

[0049] The heat dissipation member 60, the display panel 10, and the front cover 40 may each include a long side extending in the first direction DR1 and a short side extending in the second direction DR2.

[0050] At least a part of the heat dissipation member 60 can surround the side surface of the front cover 40. For example, the side wall SW of the heat dissipation member 60 can surround the side surface of the front cover 40. As shown in the example of FIG. 1, when the front cover 40 has a rectangular shape including four side surfaces (for example, the first side surface, the second side surface, the third side surface, and the fourth side surface), a plurality of side walls SW1 - SW4 of the heat dissipation member 60 can be arranged to face the plurality of side surfaces of the front cover 40 respectively. For example, the first side wall SW1 faces the first side surface of the front cover 40, the second side wall SW2 faces the second side surface of the front cover 40, the third side wall SW3 faces the third side surface of the front cover 40, and the fourth side wall SW4 can face the fourth side surface of the front cover 40.

[0051] Note that the front cover 40 can be omitted.

[0052] According to one embodiment, the heat radiating member 60 can function as a cover (e.g., side cover and rear cover) of the display device 1 in addition to its heat radiating function. Therefore, the size of the bezel of the display device 1 can be reduced, enabling a slim structure. Further, according to one embodiment, since a separate rear cover and side cover are not required, the manufacturing cost of the display device 1 can be saved. Also, since the heat radiating member 60 is exposed to the outside without being covered by a rear cover, the heat radiating effect of the heat radiating member 60 can be improved.

[0053] FIG. 2 is a plan view of the display device 1 according to one embodiment.

[0054] Referring to FIG. 2, the display device 1 according to one embodiment may have a square shape in a plan view. For example, it may have a rectangular shape, but is not limited thereto.

[0055] In some embodiments, when the display device 1 is a television, it is arranged such that the long side is positioned in the horizontal direction. However, it is not limited thereto, and the long side may be positioned in the vertical direction, and it may be installed rotatably so that the long side can be variably positioned in the horizontal or vertical direction.

[0056] The display device 1 may include a display area DPA and a non-display area NDA. The display area DPA may be an active area where an image is displayed. The display area DPA may have a rectangular shape in a plan view, similar to the overall shape of the display device 1, but is not limited thereto.

[0057] The display area DPA may include a plurality of pixels PX. The plurality of pixels PX may be arranged in a matrix direction. The shape of each pixel PX may be rectangular or square in a plan view, but is not limited thereto, and may be a rhombus shape in which each side is inclined with respect to the direction of one side of the display device 1. The plurality of pixels PX may include pixels PX that provide light of different colors (or wavelengths). For example, the plurality of pixels PX may include, but are not limited to, a red pixel that provides red light, a green pixel PX that provides green light, and a blue pixel that provides blue light. Each color pixel PX may be alternately arranged in a stripe shape or a pentile shape.

[0058] A non-display area NDA may be arranged around the display area DPA. The non-display area NDA may constitute a bezel of the display device 1. The non-display area NDA may entirely or partially surround the display area DPA.

[0059] In some embodiments, the display area DPA has a rectangular shape, and the non-display area NDA may be arranged adjacent to the four sides of the display area DPA. For example, a first non-display area NDA1 arranged adjacent to the first long side (the lower side in FIG. 2) of the display device 1, a second non-display area NDA2 arranged adjacent to the second long side (the upper side in FIG. 2), a third non-display area NDA3 arranged adjacent to the first short side (the left side in FIG. 2), and a fourth non-display area NDA4 arranged adjacent to the second short side (the right side in FIG. 2) may be included.

[0060] A driving circuit and driving elements for driving the display area DPA may be arranged in the non-display area NDA. As an example, pad portions are provided on the substrate of the display panel 1 in the first non-display area NDA1 and the second non-display area NDA2, and an external device EXD may be mounted on the pad electrodes of the pad portions. The external device EXD may include circuit members (CCM; see FIG. 4) described later. Examples of the circuit member CCM include a connection film, a printed circuit board, a driving chip (DIC), a connector, a wiring connection film, and the like. As another example, a scan driving unit SDR directly formed on the substrate of the display panel 1 may be arranged in the third non-display area NDA3.

[0061] Figure 3 is a circuit diagram of the display device 1 according to an embodiment.

[0062] Referring to FIG. 3, a plurality of wirings can be arranged on the substrate of the display device 1. The plurality of wirings may include a scan line SCL, a sensing signal line SSL, a data line DTL, a reference voltage line RVL, a first power line ELVDL, and the like.

[0063] The scan line SCL and the sensing signal line SSL can extend in the first direction DR1. The scan line SCL and the sensing signal line SSL can be connected to the scan driving unit SDR. The scan driving unit SDR may include a driving circuit composed of a circuit layer. The scan driving unit SDR can be arranged in the third non-display area NDA3, but is not limited thereto, and may be arranged in the fourth non-display area NDA4, or may be arranged in both the third non-display area NDA3 and the fourth non-display area NDA4. The scan driving unit SDR is connected to the signal connection wiring CWL, and at least one end of the signal connection wiring CWL can form a pad WPD_CW on the first non-display area NDA1 and / or the second non-display area NDA2 and be connected to an external device ("EXD" in FIG. 2).

[0064] In the illustrated drawing, the first direction DR1 and the second direction DR2 intersect each other in the horizontal direction. For example, the first direction DR1 and the second direction DR2 can be perpendicular to each other. Also, the third direction DR3 can be a direction intersecting the first direction DR1 and the second direction DR2, for example, a perpendicular direction perpendicular thereto. In this specification, the direction indicated by the arrows of the first to third directions DR1, DR2, DR3 is referred to as one side, and the opposite direction is referred to as the other side.

[0065] The data line DTL and the reference voltage line RVL can extend in a second direction DR2 intersecting the first direction DR1. The first power line ELVDL may include a portion extending in the second direction DR2. The first power line ELVDL may further include a portion extending in the first direction DR1. The first power line ELVDL may have a mesh structure, but is not limited thereto.

[0066] A wiring pad WPD may be disposed at at least one end of the data line DTL, the reference voltage line RVL, and the first power supply line ELVDL. Each wiring pad WPD may be disposed in the pad portion PDA of the non-display area NDA. In one embodiment, the wiring pad (WPD_DT, hereinafter referred to as the "data pad") of the data line DTL is disposed in the pad portion PDA of the first non-display area NDA1, and the wiring pad (WPD_RV, hereinafter referred to as the "reference voltage pad") of the reference voltage line RVL and the wiring pad (WPD_ELVD, hereinafter referred to as the "first power supply pad") of the first power supply line ELVDL may be disposed in the pad portion PDA of the second non-display area NDA2. As another example, the data pad WPD_DT, the reference voltage pad WPD_RV, and the first power supply pad WPD_ELVD may all be disposed in the same area, for example, the first non-display area NDA1. An external device (the "EXD" in FIG. 1) may be mounted on the wiring pad WPD as described above. The external device EXD may be mounted on the wiring pad WPD by an anisotropic conductive film, ultrasonic bonding, or the like.

[0067] Each pixel PX on the substrate of the display panel 10 may include a pixel driving circuit. The above-described wiring passes through each pixel PX or its periphery and can apply a driving signal to each pixel driving circuit. The pixel driving circuit may include a transistor and a capacitor. The number of transistors and capacitors in each pixel driving circuit can be variously modified.

[0068] FIG. 4 is a side view of a display device according to an embodiment, and FIG. 5 is a rear view of a display device according to an embodiment.

[0069] Referring to FIGS. 4 and 5, the display panel 10 may include a substrate SUB and a display layer DU.

[0070] The substrate SUB can be a base substrate or a base member. The substrate SUB can be a flexible substrate that can be bent, folded, rolled, etc. For example, the substrate SUB can include, but is not limited to, a polymer resin such as polyimide (PI). In other embodiments, the substrate SUB can include a glass material or a metal material.

[0071] The display layer DU can include a thin film transistor layer (not shown), a light emitting element layer (not shown), and a thin film encapsulation layer (not shown).

[0072] The thin film transistor layer can include a plurality of thin film transistors that constitute the pixel circuits of the pixels and various wirings described in FIG. 2. The light emitting element layer can include a plurality of light emitting elements that emit light by including a first electrode, a light emitting layer, and a second electrode. The thin film encapsulation layer covers the upper surface and the side surface of the light emitting element layer and can protect the light emitting element layer. The thin film encapsulation layer can include at least one inorganic film and at least one organic film.

[0073] The circuit member CCM can be a connection film, a driving IC chip, a connector, a printed circuit board (PCB), or a flexible printed circuit board (FPCB). In one embodiment, when the circuit member CCM is a flexible member, the circuit member CCM can be bent so that at least a part thereof can face the rear surface of the substrate SUB.

[0074] The circuit member CCM can be mounted on the substrate SUB via a pad portion. In one embodiment, one end portion of the circuit member CCM can be connected to the substrate SUB, and the other end portion can be connected to the driving board 30. In other embodiments, when a plurality of circuit members CCM are connected, both end portions of the circuit member CCM can be connected to other circuit members CCM.

[0075] In some embodiments, the circuit member CCM may include a first circuit member CCM1, a second circuit member CCM2, and a third circuit member CCM3.

[0076] A plurality of the first circuit members CM1 may be formed and connected to the substrate SUB and the second circuit member CCM2. In one embodiment, the first circuit member CM1 may be a flexible member and may be either a connecting film or a flexible circuit board. The first circuit member CM1 may be bent to position the second circuit member CCM2, the third circuit member CCM3, and the driving board 30 on the rear surface of the substrate SUB.

[0077] The second circuit member CCM2 may have a shape extending in the second direction DR2. The second circuit member CCM2 may include a protruding portion protruding in the third direction DR3. The second circuit member CCM2 may be connected to the first circuit member CCM1 at an end opposite to the protruding portion, and may be connected to the third circuit member CCM3 at the protruding portion. In one embodiment, the second circuit member CCM2 may be a printed circuit board.

[0078] The third circuit member CCM3 may have a shape extending in the third direction DR3. The third circuit member CCM3 may be connected to the second circuit member CCM2 and the driving board 30 at both side ends, respectively. In one embodiment, the third circuit member CCM3 may be a wiring connection film. The position of the driving board 30 can be adjusted by adjusting the length of the third circuit member CCM3.

[0079] The driving board 30 may be disposed behind the substrate SUB by bending the circuit member CCM. In one embodiment, the driving board 30 may be disposed at a distance from the display panel 10. In a non-limiting embodiment, the driving board 30 may be parallel to the display panel 10.

[0080] The drive board 30 can be located on the opposite side of the display panel 10 so as to sandwich the heat dissipation member 60. In one embodiment, the drive board 30 can be arranged so as to overlap the center of the heat dissipation member 60. The drive board 30 can be supported and fixed by a support part SPT arranged between the heat dissipation member 60 and the drive board 30.

[0081] The drive board 30 may include a processor, a memory, and / or an interface. In one embodiment, the drive board 30 may include various electronic components such as an integrated circuit chip (IC).

[0082] In the drawings, a chip-on-film (COF) structure in which the substrate SUB - circuit member CCM - drive board 30 are connected in this order is shown, but this is merely an example. In other embodiments, the drive board 30 may be directly mounted on the substrate SUB without the circuit member CCM, and the substrate SUB itself may be bent, which may be a chip-on-plastic (COP) structure. As long as the drive board 30 is arranged on the rear surface of the display panel 10 and the heat dissipation member 60 is arranged between the display panel 10 and the drive board 30, it is not limited to any one embodiment.

[0083] The heat dissipation member 60 can be arranged between the display panel 10 and the drive board 30. The heat dissipation member 60 can be arranged behind the display panel 10 and in front of the drive board 30.

[0084] In this specification and the drawings, the front means the direction pointed to by the third direction DR3, and the rear means the direction pointed to by the reverse direction of the third direction DR3 (hereinafter, the third reverse direction).

[0085] In some embodiments, the heat dissipation member 60 can be in direct contact with the rear surface of the display panel 10. Therefore, the heat generated in the display panel 10 can be transmitted to the heat dissipation member 60.

[0086] As shown in the drawings, the heat radiating member 60 can be spaced apart from the drive board 30 so as to sandwich the support portion SPT. However, it is not limited thereto. In order to reduce the thickness of the display device 1 and increase the heat radiation efficiency, the heat radiating member 60 can be in direct contact with the drive board 30 without the support portion SPT, or even if there is a support portion SPT, the separation distance can be minimized. Therefore, the heat generated in the drive board 30 can be transmitted to the heat radiating member 60.

[0087] The heat radiating member 60 can radiate the heat generated in the display panel 10 and the drive board 30 to other spaces inside or outside the display device 1.

[0088] FIG. 5 is a cross-sectional view of a display device according to an embodiment.

[0089] A display device according to an embodiment may include a rear cover 50, a display panel 10, a heat radiating member 60, and an adhesive layer 750, as shown in FIG. 5.

[0090] The display panel 10 may include a light shielding layer BM disposed in a non-display area. For example, the light shielding layer BM may be disposed at the edge of the display panel 10. When viewed in plan, the light shielding layer BM may have a closed curve shape surrounding the heat radiating layer 650. For example, when viewed in plan, the light shielding layer BM may have a square ring shape.

[0091] The adhesive layer 750 may be disposed between the edge of the rear cover 50 and the edge of the display panel 10. When viewed in plan, the adhesive layer 750 may have a closed curve shape surrounding the heat radiating member 60 between the peripheral portion of the rear cover 50 and the peripheral portion of the display panel 10. For example, when viewed in plan, the adhesive layer 750 may have a square ring shape surrounding the heat radiating member 60. One surface of the adhesive layer 750 may be adhered to the rear cover 50, and the other surface of the adhesive layer 750 may be adhered to the display panel (10; for example, the substrate of the display panel 10).

[0092] The heat radiating member 60 can be disposed between the rear cover 50 and the display panel 10. When viewed in plan, the heat radiating member 60 can have a quadrangular shape. The heat radiating member 60 can include a housing 600 and a heat radiating layer 650. For example, the heat radiating member 60 can be disposed within a first space S1 defined and surrounded by the rear cover 50, the display panel 10, and the adhesive layer 750.

[0093] The housing 600 can define a second space (or internal space) in which the heat radiating layer 650 is disposed. The housing 600 can include a first housing plate 601 and a second housing plate 602 that are disposed to face each other in a third direction DR3. The first housing plate 601 and the second housing plate 602 can be spaced apart in the third direction DR3. The first housing plate 601 and the second housing plate 602 can be joined to each other at their peripheral edges. For example, the peripheral edge of the first housing plate 601 can have a shape that is bent toward the peripheral edge of the second housing plate 602, and the peripheral edge of the second housing plate 602 can have a shape that is bent toward the edge of the first housing plate 601. The second space S2 of the housing 600 can be sealed by the contact (and / or joining) of the peripheral edge of the first housing plate 601 and the peripheral edge of the second housing plate 602 with each other. The portion where the peripheral edge of the first housing plate 601 and the peripheral edge of the second housing plate 602 are joined can function as a flange 603 for sealing the housing 600. The adhesive layer 750, the flange 603 of the housing 600, and the bent portion adjacent to this flange 603 can be hidden by the light shielding layer BM. That is, the adhesive layer 750, the flange 603 of the housing 600, and the bent portion adjacent to the flange 603 can overlap the light shielding layer BM.

[0094] The first housing plate 601 may include a first inner plate 601a and a first outer plate 601b. The first inner plate 601a and the first outer plate 601b can have substantially the same shape. For example, the first inner plate 601a and the first outer plate 601b can have the same shape as the aforementioned first housing plate 601. The first inner plate 601a and the first outer plate 601b can be in contact (and / or joined) with each other. The first inner plate 601a and the first outer plate 601b can have the same thickness. For example, the first inner plate 601a and the first outer plate 601b can each have a thickness of 25 μm (e.g., the dimension in the third direction DR3). Since the first inner plate 601a can contain polyurethane, the first outer plate 601b can contain polyethylene terephthalate.

[0095] The second housing plate 602 may include a second inner plate 602a and a second outer plate 602b. The second inner plate 602a and the second outer plate 602b can have substantially the same shape. For example, the second inner plate 602a and the second outer plate 602b can have the same shape as the aforementioned second housing plate 602. The second inner plate 602a and the second inner plate 602a can be in contact (and / or joined) with each other. The second inner plate 602a and the second outer plate 602b can have the same thickness. For example, the second inner plate 602a and the second outer plate 602b can each have a thickness of 25 μm (e.g., the dimension in the third direction DR3). Since the second inner plate 602a can contain polyurethane, the second outer plate 602b can contain polyethylene terephthalate.

[0096] The first inner plate 601a and the second inner plate 602a can be in contact (and / or joined) with each other at the peripheral portion.

[0097] The heat dissipation layer 650 can be disposed in the second space S2 defined by the housing 600. For example, the heat dissipation layer 650 can be disposed between the first housing plate 601 and the second housing plate 602. As a specific example, the heat dissipation layer 650 can be disposed between the first inner plate 601a and the second inner plate 602a.

[0098] The heat dissipation layer 650 may include a plurality of heat dissipation layers 651, 652. For example, the heat dissipation layer 650 can include a first heat dissipation layer 651 and a second heat dissipation layer 652 laminated along the third direction DR3 within the second space S2 defined by the housing 600. The first heat dissipation layer 651 and the second heat dissipation layer 652 may contain different substances from each other. Also, the first heat dissipation layer 651 and the second heat dissipation layer 652 may have different thicknesses from each other. Here, the thickness of the heat dissipation layer 650 means the size of the heat dissipation layer 650 in the third direction DR3. Also, the first heat dissipation layer 651 and the second heat dissipation layer 652 may have a thermal conductivity with respect to each other.

[0099] The first heat dissipation layer 651 can be disposed on the first housing plate 601. For example, the first heat dissipation layer 651 can be disposed between the first housing plate 601 and the second heat dissipation layer 652 within the housing 600. As a specific example, the first heat dissipation layer 651 can be disposed between the first inner plate 601a and the second heat dissipation layer 652. One surface of the first heat dissipation layer 651 can be in contact with the first inner plate 601a of the housing 600, and the other surface of the first heat dissipation layer 651 can be in contact with the second heat dissipation layer 652. The first heat dissipation layer 651 can have the characteristic of anisotropic heat diffusion that diffuses more heat in the area direction (for example, the first direction DR1 and the second direction DR2 that define the area of the first heat dissipation layer 651 when viewed in plan) than in the thickness direction (for example, the third reverse direction). The first heat dissipation layer 651 can have a thermal conductivity of 240 W / m·k. The first heat dissipation layer 651 may contain natural graphite.

[0100] The second heat dissipation layer 652 can be disposed on the first heat dissipation layer 651. For example, the second heat dissipation layer 652 can be disposed between the first heat dissipation layer 651 and the second housing plate 602 within the housing 600. As a specific example, the second heat dissipation layer 652 can be disposed between the first heat dissipation layer 651 and the second inner plate 602a. One surface of the second heat dissipation layer 652 can be in contact with the first heat dissipation layer 651, and the other surface of the second heat dissipation layer 652 can be in contact with the second inner plate 602a of the housing 600. The second heat dissipation layer 652 can have the characteristic of anisotropic heat diffusion that diffuses more heat in the area direction (for example, the first direction DR1 and the second direction DR2 that define the area of the second heat dissipation layer 652 when viewed in plan) than in the thickness direction (for example, the third reverse direction). The second heat dissipation layer 652 can have a thermal conductivity of 1000 W / m·k. The second heat dissipation layer 652 can include artificial graphite.

[0101] The total thickness (T1 + T2; for example, the sum of the thickness T1 of the first heat dissipation layer 651 and the thickness T2 of the second heat dissipation layer 652) of the heat dissipation layer 650 can be 50% to 200% of the thickness T3 of the display panel 10. Here, the thickness T3 of the display panel 10 means the thickness from the substrate SUB of this display panel 10 to the sealing layer of this display panel 10. For example, the thickness T3 of the display panel 10 means the distance from the lower surface of the substrate SUB in the third direction DR3 to the upper surface of the sealing layer. According to one embodiment, the total thickness of the heat dissipation layer 650 can be 0.5 mm to 1.5 mm.

[0102] According to one embodiment, when the heat dissipation layer 650 includes a plurality of heat dissipation layers 650, the thicknesses between the heat dissipation layers 650 may be different from each other. For example, the thickness T1 of the first heat dissipation layer 651 may be greater than the thickness T2 of the second heat dissipation layer 652. According to one embodiment, the ratio of the thickness of the first heat dissipation layer 651 made of natural graphite material to the thickness of the second heat dissipation layer 652 made of artificial graphite material may be 19:1. That is, when the thickness T1 of the first heat dissipation layer 651 is 19, the thickness T2 of the second heat dissipation layer 652 may be 1. According to one embodiment, the ratio of the thicknesses between the first heat dissipation layer 651 and the second heat dissipation layer 652 described above may be greater than 19:1. For example, when the thickness T1 of the first heat dissipation layer 651 is 820 μm, the thickness T2 of the second heat dissipation layer 652 may be 100 μm.

[0103] According to one embodiment, the thermal conductivity of the first heat dissipation layer 651 may be lower than the thermal conductivity of the second heat dissipation layer 652. For example, the thermal conductivity of the first heat dissipation layer 651 may be 240 W / m·k, and the thermal conductivity of the second heat dissipation layer 652 may be 1000 W / m·k. At this time, as described above, the thickness T1 of the first heat dissipation layer 651 may be greater than the thickness T2 of the second heat dissipation layer 652. That is, according to one embodiment, in terms of thermal conductivity, the first heat dissipation layer 651 made of natural graphite material has a smaller value than the second heat dissipation layer 652 made of artificial graphite material, but in terms of thickness, the first heat dissipation layer 651 may have a larger value than the second heat dissipation layer 652 (T1>T2).

[0104] According to one embodiment, when viewed in plan view, the area of the first heat dissipation layer 651 and the area of the second heat dissipation layer 652 may be the same. For example, the area of the first heat dissipation layer 651 based on the size in the first direction DR1 and the size in the second direction DR2, and the area of the second heat dissipation layer 652 based on the size in the first direction DR1 and the size in the second direction DR2 may be the same. Here, the edge (or end) of the first heat dissipation layer 651 and the edge (end) of the second heat dissipation layer 652 may overlap in the third direction DR3 so that the entire area of the first heat dissipation layer 651 and the entire area of the second heat dissipation layer 652 overlap each other.

[0105] FIG. 6 is a cross-sectional view of a display device according to an embodiment.

[0106] The display device in FIG. 6 has differences from the display device in FIG. 5 described above in that it further includes an exhaust hole 601c. Therefore, the following is an explanation centered on the differences.

[0107] As shown in FIG. 6, the display device may further include an exhaust hole (601c; or an air hole). The exhaust hole 601c may be disposed in the housing 600. For example, the exhaust hole 601c may be disposed on one surface of the housing 600 so as to be located on the opposite surface of the contact surface between the housing 600 and the display panel 10. The exhaust hole 601c may penetrate that one surface of the housing 600. For example, the exhaust hole 601c may penetrate the first housing plate 601 of the housing 600 in the third direction DR3. A plurality of exhaust holes 601c may be provided. When viewed in plan, the exhaust hole 601c can have a circular shape. By discharging the heated air inside the housing 600 through the exhaust hole 601c to the outside of the housing 600, the heat dissipation effect of the heat dissipation member 60 can be further improved.

[0108] FIG. 7 is a cross-sectional view of a display device according to an embodiment.

[0109] The display device in FIG. 7 has differences from the display device in FIG. 5 described above in that it further includes a third heat dissipation layer 653. Therefore, the following is an explanation centered on the differences.

[0110] As shown in FIG. 7, the display device may further include a third heat dissipation layer 653. For example, the heat dissipation layer 650 may include a first heat dissipation layer 651, a third heat dissipation layer 653, and a second heat dissipation layer 652 that are sequentially stacked along the third direction DR3 on the first inner plate 601a.

[0111] The third heat dissipation layer 653 can be disposed between the first heat dissipation layer 651 and the second heat dissipation layer 652. One surface of the third heat dissipation layer 653 can be in contact with the first heat dissipation layer 651, and the other surface of the third heat dissipation layer 653 can be in contact with the second heat dissipation layer 652. The third heat dissipation layer 653 can have the property of isotropic heat diffusion that diffuses heat uniformly in its thickness direction (e.g., the third reverse direction) and its area direction (e.g., the first direction DR1 and the second direction DR2 that define the area of the third heat dissipation layer 653 when viewed in plan). The third heat dissipation layer 653 can have a thickness T3 that is larger than the second heat dissipation layer 652 and smaller than the first heat dissipation layer 651 (T2 < T3 < T1). The third heat dissipation layer 653 can have a thermal conductivity of 202 W / m·k. The third heat dissipation layer 653 can contain a metal. For example, the third heat dissipation layer 653 can contain aluminum (Al).

[0112] The ratio of the thicknesses between the first heat dissipation layer 651, the third heat dissipation layer 653, and the second heat dissipation layer 652 can be, for example, 16:3:1. For example, when the thickness T1 of the first heat dissipation layer 651 is 16, the thickness T3 of the third heat dissipation layer 653 can be 3, and the thickness T2 of the second heat dissipation layer 652 can be 1. According to one embodiment, the thickness T1 of the first heat dissipation layer 651 can be 820 μm (or 500 μm), the thickness T3 of the third heat dissipation layer 653 can be 300 μm, and the thickness T2 of the second heat dissipation layer 652 can be 100 μm.

[0113] According to one embodiment, when viewed in plan, the area of the first heat dissipation layer 651, the area of the third heat dissipation layer 653, and the area of the second heat dissipation layer 652 can be the same as each other. For example, the area of the first heat dissipation layer 651 based on the size in the first direction DR1 and the size in the second direction DR2, the area of the third heat dissipation layer 653 based on the size in the first direction DR1 and the size in the second direction DR2, and the area of the second heat dissipation layer 652 based on the size in the first direction DR1 and the size in the second direction DR2 can be the same as each other. Here, the periphery (or end) of the first heat dissipation layer 651, the periphery (or end) of the third heat dissipation layer 653, and the periphery (end) of the second heat dissipation layer 652 can overlap each other in the third direction DR3 so that the entire areas of the first heat dissipation layer 651, the third heat dissipation layer 653, and the second heat dissipation layer 652 overlap each other.

[0114] Figure 8 is a cross-sectional view of a display device according to an embodiment.

[0115] Since the display device in FIG. 8 further includes an exhaust hole 601c and thus has a difference from the display device in FIG. 7 described above, the description will focus on this difference as follows.

[0116] As shown in FIG. 8, the display device may further include an exhaust hole 601c. The exhaust hole 601c may be disposed in the housing 600. Note that since the exhaust hole 601c in FIG. 8 is substantially the same as the exhaust hole 601c in FIG. 6 described above, for the specific description of the exhaust hole 601c in FIG. 8, refer to FIG. 6 described above and the related description.

[0117] Figure 9 is a cross-sectional view of a display device according to an embodiment.

[0118] Since the display device in FIG. 9 has a difference from the display device in FIG. 5 described above in the arrangement position of the second heat dissipation layer 652, the description will focus on this difference as follows.

[0119] As illustrated in FIG. 9, when the heat dissipation layer 650 includes a plurality of heat dissipation layers 650, at least one heat dissipation layer 650 may be disposed outside the housing 600. For example, the second heat dissipation layer 652 made of artificial graphite material among the first heat dissipation layer 651 and the second heat dissipation layer 652 may be disposed outside the housing 600. As a specific example, the second heat dissipation layer 652 may be disposed between the housing 600 and the display panel 10. As a more specific example, the second heat dissipation layer 652 may be disposed between the second housing plate 602 and the display panel 10. For example, the second heat dissipation layer 652 may be disposed between the second outer plate 602b and the substrate SUB of the display panel 10 within the first space S1.

[0120] One surface of the second heat dissipation layer 652 may contact the housing (600; for example, the second outer plate 602b of the housing 600), and the other surface of the second heat dissipation layer 652 may contact the display panel (10; for example, the substrate SUB of the display panel 10).

[0121] Note that one surface of the first heat dissipation layer 651 may contact the first inner plate 601a of the housing 600, and the other surface of the first heat dissipation layer 651 may contact the second inner plate 602a of the housing 600.

[0122] FIG. 10 is a cross-sectional view of a display device according to an embodiment.

[0123] The display device in FIG. 10 has differences from the display device in FIG. 9 described above in that it further includes an exhaust hole 601c. Therefore, the description centered on the differences is as follows.

[0124] As shown in FIG. 10, the display device may further include an exhaust hole 601c. The exhaust hole 601c may be disposed in the housing 600. Note that since the exhaust hole 601c in FIG. 10 is substantially the same as the exhaust hole 601c in FIG. 6 described above, for the specific description of the exhaust hole 601c in FIG. 10, refer to FIG. 6 described above and related descriptions.

[0125] FIG. 11 is a cross-sectional view of a display device according to an embodiment.

[0126] The display device in FIG. 11 has differences from the display device in FIG. 8 described above in the arrangement positions of the third heat dissipation layer 653 and the second heat dissipation layer 652. Therefore, the description centered on the differences is as follows.

[0127] As shown in FIG. 11, when the heat dissipation layer 650 includes a plurality of heat dissipation layers 651, 653, 652, at least one heat dissipation layer may be disposed outside the housing 600. For example, among the first heat dissipation layer 651, the third heat dissipation layer 653, and the second heat dissipation layer 652, the third heat dissipation layer 653 made of a metal material and the second heat dissipation layer 652 made of an artificial graphite material may be disposed outside the housing 600.

[0128] The third heat dissipation layer 653 can be disposed between the housing 600 and the second heat dissipation layer 652. For example, the third heat dissipation layer 653 can be disposed between the second housing plate 602 and the second heat dissipation layer 652. That is, the third heat dissipation layer 653 can be disposed between the second outer plate 602b and the second heat dissipation layer 652 within the first space S1. One surface of the third heat dissipation layer 653 can be in contact with the second outer plate 602b, and the other surface of the third heat dissipation layer 653 can be in contact with the second heat dissipation layer 652.

[0129] The second heat dissipation layer 652 can be disposed between the third heat dissipation layer 653 and the display panel 10. For example, the second heat dissipation layer 652 can be disposed between the third heat dissipation layer 653 and the display panel 10. That is, the second heat dissipation layer 652 can be disposed between the third heat dissipation layer 653 and the substrate SUB of the display panel 10 within the first space S1. One surface of the second heat dissipation layer 652 can be in contact with the third heat dissipation layer 653, and the other surface of the second heat dissipation layer 652 can be in contact with the substrate SUB of the display panel 10.

[0130] Note that one surface of the first heat dissipation layer 651 can be in contact with the first inner plate 601a of the housing 600, and the other surface of the first heat dissipation layer 651 can be in contact with the second inner plate 602a of the housing 600.

[0131] FIG. 12 is a cross-sectional view of a display device according to an embodiment.

[0132] The display device in FIG. 12 further includes an exhaust hole 601c, so it has differences from the display device in FIG. 11 described above. Therefore, the differences will be described as follows with the differences as the center.

[0133] As shown in FIG. 12, the display device can further include an exhaust hole 601c. The exhaust hole 601c can be disposed in the housing 600. Note that the exhaust hole 601c in FIG. 12 is substantially the same as the exhaust hole 601c in FIG. 6 described above. Therefore, for the specific description of the exhaust hole 601c in FIG. 12, refer to FIG. 6 described above and related descriptions.

[0134] Note that since the light-emitting element of the pixel included in the display device according to one embodiment may have a tandem structure, the description thereof with reference to FIGS. 13 to 20 is as follows.

[0135] FIGS. 13 to 17 are cross-sectional views showing the structure of the light-emitting element according to one embodiment.

[0136] Referring to FIG. 13, the light-emitting element (for example, an organic light-emitting diode) according to one embodiment may include a pixel electrode 201, a common electrode 205, and an intermediate layer 203 between the pixel electrode 201 and the common electrode 205 described above.

[0137] The pixel electrode 201 may include a light-transmissive conductive oxide such as indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), indium oxide (In2O3), indium gallium oxide (IGO), or aluminum zinc oxide (AZO). The pixel electrode 201 may include a reflective layer containing silver (Ag), magnesium (Mg), aluminum (Al), platinum (Pt), palladium (Pd), gold (Au), nickel (Ni), neodymium (Nd), iridium (Ir), chromium (Cr), or a compound thereof. For example, the pixel electrode 201 may have a three-layer structure of ITO / Ag / ITO.

[0138] The common electrode 205 can be disposed on the intermediate layer 203. The common electrode 205 can include a metal, an alloy, an electrically conductive compound, or any combination thereof having a low work function. For example, the common electrode 205 can include lithium (Li), silver (Ag), magnesium (Mg), aluminum (Al), aluminum-lithium (Al-Li), calcium (Ca), magnesium-indium (Mg-In), magnesium-silver (Mg-Ag), ytterbium (Yb), silver-ytterbium (Ag-Yb), ITO, IZO, or any combination thereof. The common electrode 205 can be a transmissive electrode, a semi-transmissive electrode, or a reflective electrode.

[0139] The intermediate layer 203 can include a polymer or a small molecule organic substance that emits light of a predetermined hue. In addition to various organic substances, the intermediate layer 203 can further include a metal-containing compound such as an organometallic compound, an inorganic substance such as a quantum dot, and the like.

[0140] In one embodiment, the intermediate layer 203 can include a single light-emitting layer, and a first functional layer and a second functional layer disposed below and above the single light-emitting layer, respectively. The first functional layer can include, for example, a hole transport layer (HTL), or can include a hole transport layer and a hole injection layer (HIL). The second functional layer is a component disposed on the light-emitting layer and is optional. For example, the intermediate layer 203 may or may not include the second functional layer. The second functional layer can include an electron transport layer (ETL) and / or an electron injection layer (EIL).

[0141] In one embodiment, the intermediate layer 203 may include two or more emitting units stacked in order between the pixel electrode 201 and the common electrode 205, and a charge generation layer (CGL) disposed between the two emitting units. When the intermediate layer 203 includes the emitting units and the charge generation layer, the light-emitting element (e.g., an organic light-emitting diode) may be a tandem light-emitting element. By having a stacked structure of a plurality of emitting units, the light-emitting element (e.g., an organic light-emitting diode) can improve color purity and light-emitting efficiency.

[0142] One emitting unit may include a light-emitting layer, and a first functional layer and a second functional layer disposed below and above the light-emitting layer, respectively. The charge generation layer CGL may include a negative charge generation layer and a positive charge generation layer. The negative charge generation layer and the positive charge generation layer can further increase the light-emitting efficiency of an organic light-emitting diode which is a tandem light-emitting element including a plurality of light-emitting layers.

[0143] The negative charge generation layer may be an n-type charge generation layer. The negative charge generation layer can supply electrons. The negative charge generation layer may include a host and a dopant. The host may include an organic substance. The dopant may include a metal substance. The positive charge generation layer may be a p-type charge generation layer. The positive charge generation layer can supply holes. The positive charge generation layer may include a host and a dopant. The host may include an organic substance. The dopant may include a metal substance.

[0144] In one embodiment, as shown in FIG. 14, a light-emitting element (e.g., an organic light-emitting diode) may include a first light-emitting unit EU1 including a first light-emitting layer EL1, and a second light-emitting unit EU2 including a second light-emitting layer EL2, which are stacked in this order. A charge generation layer CGL may be disposed between the first light-emitting unit EU1 and the second light-emitting unit EU2. For example, the light-emitting element (e.g., an organic light-emitting diode) may include a pixel electrode 201, a first light-emitting layer EL1, a charge generation layer CGL, a second light-emitting layer EL2, and a common electrode 205, which are stacked in this order. A first functional layer and a second functional layer may be disposed below and above the first light-emitting layer EL1, respectively. A first functional layer and a second functional layer may be included below and above the second light-emitting layer EL2, respectively. The first light-emitting layer EL1 may be a blue light-emitting layer, and the second light-emitting layer EL2 may be a yellow light-emitting layer.

[0145] In one embodiment, as shown in FIG. 15, a light-emitting element (e.g., an organic light-emitting diode) may include a first light-emitting unit EU1 including a first light-emitting layer EL1, a third light-emitting unit EU3, and a second light-emitting unit EU2 including a second light-emitting layer EL2. A first charge generation layer CGL1 may be disposed between the first light-emitting unit EU1 and the second light-emitting unit EU2, and a second charge generation layer CGL2 may be disposed between the second light-emitting unit EU2 and the third light-emitting unit EU3. For example, the light-emitting element (e.g., an organic light-emitting diode) may include a pixel electrode 201, a first light-emitting layer EL1, a first charge generation layer CGL1, a second light-emitting layer EL2, a second charge generation layer CGL2, a first light-emitting layer EL1, and a common electrode 205, which are stacked in this order. A first functional layer and a second functional layer may be disposed below and above the first light-emitting layer EL1, respectively. A first functional layer and a second functional layer may be disposed below and above the second light-emitting layer EL2, respectively. The first light-emitting layer EL1 may be a blue light-emitting layer, and the second light-emitting layer EL2 may be a yellow light-emitting layer.

[0146] In one embodiment, a light-emitting element (e.g., an organic light-emitting diode) may further include a third light-emitting layer EL3 and / or a fourth light-emitting layer EL4 that are in direct contact with the second light-emitting layer EL2 directly below and / or above the second light-emitting unit EU2 in addition to the second light-emitting layer EL2. Here, direct contact means that no other layer is disposed between the second light-emitting layer EL2 and the third light-emitting layer EL3 and / or between the second light-emitting layer EL2 and the fourth light-emitting layer EL4. The third light-emitting layer EL3 may be a red light-emitting layer, and the fourth light-emitting layer EL4 may be a green light-emitting layer.

[0147] For example, as illustrated in FIG. 16, a light-emitting element (e.g., an organic light-emitting diode) may include a pixel electrode 201, a first light-emitting layer EL1, a first charge generation layer CGL1, a third light-emitting layer EL3, a second light-emitting layer EL2, a second charge generation layer CGL2, a first light-emitting layer EL1, and a common electrode 205 that are stacked in this order. Alternatively, as illustrated in FIG. 17, a light-emitting element (e.g., an organic light-emitting diode) may include a pixel electrode 201, a first light-emitting layer EL1, a first charge generation layer CGL1, a third light-emitting layer EL3, a second light-emitting layer EL2, a fourth light-emitting layer EL4, a second charge generation layer CGL2, a first light-emitting layer EL1, and a common electrode 205 that are stacked in this order.

[0148] FIG. 18 is a cross-sectional view showing an example of the organic light-emitting diode of FIG. 16, and FIG. 19 is a cross-sectional view showing an example of the organic light-emitting diode of FIG. 17.

[0149] Referring to FIG. 18, a light-emitting element (e.g., an organic light-emitting diode) may include a first light-emitting unit EU1, a second light-emitting unit EU2, and a third light-emitting unit EU3 that are stacked in sequence. A first charge generation layer CGL1 may be disposed between the first light-emitting unit EU1 and the second light-emitting unit EU2, and a second charge generation layer CGL2 may be disposed between the second light-emitting unit EU2 and the third light-emitting unit EU3. The first charge generation layer CGL1 and the second charge generation layer CGL2 may each include a negative charge generation layer nCGL and a positive charge generation layer pCGL.

[0150] The first light-emitting unit EU1 may include a blue light-emitting layer BEML. The first light-emitting unit EU1 may further include a hole injection layer HIL and a hole transport layer HTL between the pixel electrode 201 and the blue light-emitting layer BEML. In one embodiment, a p-doped layer may be further included between the hole injection layer HIL and the hole transport layer HTL. The p-doped layer may be formed by doping the hole injection layer HIL with a p-type dopant. In one embodiment, at least one of a blue light assisting layer, an electron blocking layer, and a buffer layer may be further included between the blue light-emitting layer BEML and the hole transport layer HTL. The blue light assisting layer can increase the light extraction efficiency of the blue light-emitting layer BEML. The blue light assisting layer can adjust the hole charge balance to increase the light extraction efficiency of the blue light-emitting layer BEML. The electron blocking layer can prevent electron injection into the hole transport layer HTL. The buffer layer can compensate for the resonance distance according to the wavelength of the light emitted from the light-emitting layer.

[0151] The second light-emitting unit EU2 may include a yellow light-emitting layer YEML and a red light-emitting layer REML that is directly in contact with the yellow light-emitting layer YEML under the yellow light-emitting layer YEML. The second light-emitting unit EU2 may further include a hole transport layer HTL between the positive charge generation layer pCGL of the first charge generation layer CGL1 and the red light-emitting layer REML, and may further include an electron transport layer ETL between the yellow light-emitting layer YEML and the negative charge generation layer nCGL of the second charge generation layer CGL2.

[0152] The third light-emitting unit EU3 may include a blue light-emitting layer BEML. The third light-emitting unit EU3 may further include a hole transport layer HTL between the positive charge generation layer pCGL of the second charge generation layer CGL2 and the blue light-emitting layer BEML. The third light-emitting unit EU3 may further include an electron transport layer ETL and an electron injection layer EIL between the blue light-emitting layer BEML and the common electrode 205. The electron transport layer ETL may be a single layer or a multilayer. In one embodiment, at least one of a blue light auxiliary layer, an electron blocking layer, and a buffer layer may be further included between the blue light-emitting layer BEML and the hole transport layer HTL. At least one of a hole blocking layer and a buffer layer may be further included between the blue light-emitting layer BEML and the electron transport layer ETL. The hole blocking layer can prevent hole injection into the electron transport layer ETL.

[0153] The light-emitting element (e.g., an organic light-emitting diode) shown in FIG. 19 has a stacked structure of the second light-emitting unit EU2 different from that of the light-emitting element (e.g., an organic light-emitting diode) shown in FIG. 17, and other configurations are the same. Referring to FIG. 19, the second light-emitting unit EU2 may include a yellow light-emitting layer YEML, a red light-emitting layer REML that is in direct contact with the yellow light-emitting layer YEML under the yellow light-emitting layer YEML, and a green light-emitting layer GEML that is in direct contact with the yellow light-emitting layer YEML above the yellow light-emitting layer YEML. The second light-emitting unit EU2 may further include a hole transport layer HTL between the positive charge generation layer pCGL of the first charge generation layer CGL1 and the red light-emitting layer REML, and may further include an electron transport layer ETL between the green light-emitting layer GEML and the negative charge generation layer nCGL of the second charge generation layer CGL2.

[0154] FIG. 20 is a cross-sectional view showing the structure of a pixel of a display device 1000 according to an embodiment.

[0155] Referring to FIG. 20, the display panel 400 of the display device 1000 may include a plurality of pixels. The plurality of pixels may include a first pixel PX1, a second pixel PX2, and a third pixel PX3. The first pixel PX1, the second pixel PX2, and the third pixel PX3 may each include a pixel electrode 201, a common electrode 205, and an intermediate layer 203. In one embodiment, the first pixel PX1 may be a red pixel, the second pixel PX2 may be a green pixel, and the third pixel PX3 may be a blue pixel.

[0156] The pixel electrode 201 may be provided independently for each of the first pixel PX1, the second pixel PX2, and the third pixel PX3.

[0157] The intermediate layer 203 of each of the first pixel PX1, the second pixel PX2, and the third pixel PX3 may include a first light-emitting unit EU1, a second light-emitting unit EU2, and a charge generation layer CGL between the first light-emitting unit EU1 and the second light-emitting unit EU2, which are stacked in order. The charge generation layer CGL may include a negative charge generation layer nCGL and a positive charge generation layer pCGL. The charge generation layer CGL may be a common layer formed continuously across the first pixel PX1, the second pixel PX2, and the third pixel PX3.

[0158] The first light-emitting unit EU1 of the first pixel PX1 may include a hole injection layer HIL, a hole transport layer HTL, a red light-emitting layer REML, and an electron transport layer ETL, which are stacked in order on the pixel electrode 201. The first light-emitting unit EU1 of the second pixel PX2 may include a hole injection layer HIL, a hole transport layer HTL, a green light-emitting layer GEML, and an electron transport layer ETL, which are stacked in order on the pixel electrode 201. The first light-emitting unit EU1 of the third pixel PX3 may include a hole injection layer HIL, a hole transport layer HTL, a blue light-emitting layer BEML, and an electron transport layer ETL, which are stacked in order on the pixel electrode 201. Each of the hole injection layer HIL, the hole transport layer HTL, and the electron transport layer ETL of the first light-emitting unit EU1 may be a common layer formed continuously across the first pixel PX1, the second pixel PX2, and the third pixel PX3.

[0159] The second light-emitting unit EU2 of the first pixel PX1 may include a hole transport layer HTL, an auxiliary layer AXL, a red light-emitting layer REML, and an electron transport layer ETL, which are sequentially stacked on the charge generation layer CGL. The second light-emitting unit EU2 of the second pixel PX2 may include a hole transport layer HTL, a green light-emitting layer GEML, and an electron transport layer ETL, which are sequentially stacked on the charge generation layer CGL. The second light-emitting unit EU2 of the third pixel PX3 may include a hole transport layer HTL, a blue light-emitting layer BEML, and an electron transport layer ETL, which are sequentially stacked on the charge generation layer CGL. Each of the hole transport layer HTL and the electron transport layer ETL of the second light-emitting unit EU2 may be a common layer that is continuously formed across the first pixel PX1, the second pixel PX2, and the third pixel PX3. In one embodiment, at least one of a hole blocking layer and a buffer layer may be further included between the light-emitting layer and the electron transport layer ETL in the second light-emitting units EU2 of the first pixel PX1, the second pixel PX2, and the third pixel PX3.

[0160] The thickness H1 of the red light-emitting layer REML, the thickness H2 of the green light-emitting layer GEML, and the thickness H3 of the blue light-emitting layer BEML may be determined according to the resonance distance. The auxiliary layer AXL is a layer added to adjust the resonance distance and may include a resonance auxiliary substance. For example, the auxiliary layer AXL may include the same substance as the hole transport layer HTL.

[0161] In FIG. 20, the auxiliary layer AXL is disposed only in the first pixel PX1, but embodiments of the present invention are not limited thereto. For example, the auxiliary layer AXL may be disposed in at least one of the first pixel PX1, the second pixel PX2, and the third pixel PX3 to adjust the resonance distance of each of the first pixel PX1, the second pixel PX2, and the third pixel PX3.

[0162] The display panel 400 of the display device 1000 may further include a capping layer 207 disposed outside the common electrode 205. The capping layer 207 can play a role in improving the light emission efficiency by the principle of constructive interference. Thereby, the light extraction efficiency of the light-emitting element (for example, an organic light-emitting diode) increases, and the light emission efficiency of the light-emitting element (for example, an organic light-emitting diode) can be improved.

[0163] FIG. 21 is a diagram for explaining the effect of the display device according to an embodiment. For example, FIG. 21 is a diagram for explaining the heat dissipation effect of the display device of FIG. 5 described above.

[0164] Previously, the second heat dissipation layer 652 in FIG. 21 includes a artificial graphite material, the thickness T2 of this second heat dissipation layer 652 is 100 μm, and the thermal conductivity of this second heat dissipation layer 652 can be 1000 W / m·k. Also, the first heat dissipation layer 651 in FIG. 21 includes a natural graphite material, the thickness T1 of the first heat dissipation layer 651 is 820 μm, and the thermal conductivity of this first heat dissipation layer 651 can be 240 W / m·k.

[0165] In FIG. 21, the arrow indicating the third reverse direction indicates the heat dissipation direction of the display panel 10.

[0166] As shown in FIG. 21, a rectangular video pattern IMP can be displayed at the center of the display area of the display panel 10. This video pattern IMP may include, for example, pixels that provide light with the highest gradation of luminance. That is, the pixels that display the video pattern IMP may include OLEDs (Organic Light Emitting Diodes) that emit light with a full white luminance.

[0167] With the all-white video pattern IMP, high heat can be generated in the area (AR1; for example, the video pattern area AR1) of the display panel 10 corresponding to this video pattern IMP. The heat in the video pattern area AR1 can be transferred to the second heat dissipation layer 652. Then, heat can diffuse centering on the area of the second heat dissipation layer 652 corresponding to the video pattern area AR1. Here, in the area AR2 of the second heat dissipation layer 652 corresponding to the video pattern area AR1, the central part of this area AR2 can have the highest temperature, and the temperature becomes lower as it gets farther from the central part of the area AR2. Here, since the second heat dissipation layer 652 has a smaller thickness than the first heat dissipation layer 651, compared with the first heat dissipation layer 651, the second heat dissipation layer 652 can diffuse more heat in the area direction (for example, the first direction DR1 and the second direction DR2) of the second heat dissipation layer 652 than in its thickness direction (for example, the third reverse direction).

[0168] The heat from the second heat dissipation layer 652 can be transferred to the first heat dissipation layer 651. Then, heat can diffuse centering on the area of the first heat dissipation layer 651 corresponding to the video pattern area AR1. Here, in the area AR3 of the first heat dissipation layer 651 corresponding to the video pattern area AR1, the central part of this area AR3 can have the highest temperature, and the temperature becomes lower as it gets farther from the central part of the area AR3. At this time, since the second heat dissipation layer 652 has a smaller thickness than the first heat dissipation layer 651, compared with the second heat dissipation layer 652, the first heat dissipation layer 651 can diffuse more heat in its thickness direction (for example, the third reverse direction) than in its area direction (for example, the first direction DR1 and the second direction DR2).

[0169] Since the first heat dissipation layer 651 and the second heat dissipation layer 652 have different thermal conductivities from each other and also have different thicknesses from each other, in the second heat dissipation layer 652 made of artificial graphite material, more heat diffuses in the first and second directions DR1, DR2, while in the first heat dissipation layer 651 made of natural graphite material, more heat can diffuse in the third reverse direction. Therefore, the heat evenly diffused in the area direction (for example, the first and second directions DR1, DR2 that define the area of the second heat dissipation layer 652 when viewed in plan) in the second heat dissipation layer 652 can be dissipated in the thickness direction (for example, the third reverse direction) through the first heat dissipation layer 651. That is, the heat transferred to the second heat dissipation layer 652 does not concentrate in the area corresponding to the video pattern area AR1 and evenly diffuses in the area direction of the second heat dissipation layer 652, so that the heat of the second heat dissipation layer 652 can be dissipated through the first heat dissipation layer 651 at a faster speed. Therefore, the heat in the display panel 10 can be dissipated more effectively. In addition, the afterimage (for example, thermal transient afterimage) of the screen generated when heat concentrates in a more specific area AR1 for a specific video pattern IMP can be removed, and the image quality of the display device can be improved.

[0170] <Equation 1> Qcond=-kA(ΔT / Δx)

[0171] The above Equation 1 is an equation regarding the thermal conductivity (Qcond). In the above Equation 1, k means the thermal conductivity of the heat dissipation layer (thermal conductivity; the thermal conductivity of the material used as the heat dissipation layer 650), A means the area of the heat dissipation layer (for example, the area of the heat dissipation layer defined by the first direction DR1 and the second direction DR2), and (ΔT / Δx) means the temperature gradient. Here, ΔT means the temperature difference between the temperature of the heat provided to the heat dissipation layer and the heat that has passed through the heat dissipation layer, and Δx means the thickness of the heat dissipation layer 650.

[0172] Since the second heat dissipation layer 652 has an area (A) that is large compared to its thickness, heat evenly diffuses in the area direction of the second heat dissipation layer 652, whereby the heat transfer amount of heat diffusion by the second heat dissipation layer 652 and the first heat dissipation layer 651 can be increased.

[0173] The display device according to an embodiment shown in FIG. 21 may have a low numerical value of the just noticeable difference (JND). For example, based on 2.6 JND, the display device according to an embodiment of FIG. 21 may have an improved just noticeable difference of 7.3.

[0174] The just noticeable difference means the difference in physical stimuli that causes the minimum sensory difference. That is, the just noticeable difference means the minimum difference in luminance, chroma, and hue that a person can recognize a residual image, and the lower this numerical value, the more the residual image of the display device decreases and the image quality of the display device can be improved.

[0175] FIG. 22 is a diagram for explaining the effect of the display device according to an embodiment. For example, FIG. 22 is a diagram for explaining the heat dissipation effect of the display device of FIG. 7 described above.

[0176] Previously, the second heat dissipation layer 652 in FIG. 22 includes a artificial graphite material, the thickness T2 of the second heat dissipation layer 652 is 100 μm, and the thermal conductivity of the second heat dissipation layer 652 may be 1000 W / m·k. Further, the third heat dissipation layer 653 in FIG. 22 includes an aluminum material, the thickness T3 of the third heat dissipation layer 653 is 300 μm, and the thermal conductivity of the third heat dissipation layer 653 may be 202 W / m·k. Further, the first heat dissipation layer 651 in FIG. 22 includes a natural graphite material, the thickness T1 of the first heat dissipation layer 651 is 820 μm, and the thermal conductivity of the first heat dissipation layer 651 may be 240 W / m·k.

[0177] The arrow indicating the third reverse direction in FIG. 22 indicates the heat dissipation direction of the display panel 10.

[0178] As shown in FIG. 22, a video pattern IMP can be displayed in a rectangular shape at the center of the display area of the display panel 10. This video pattern IMP may include, for example, pixels that provide light with the highest gradation of brightness. That is, the pixels that display the video pattern IMP may include OLEDs (Organic Light Emitting Diodes) that emit light with a full white brightness.

[0179] Due to the full white video pattern IMP, high heat can be generated in the area AR1 of the display panel 10 corresponding to this video pattern IMP. The heat in this video pattern area AR1 can be transmitted to the second heat dissipation layer 652. Then, heat can diffuse centering on the area of the second heat dissipation layer 652 corresponding to the video pattern area AR1. Here, in the area AR2 of the second heat dissipation layer 652 corresponding to the video pattern area AR1, the center part of this area AR2 can have the highest temperature, and the temperature becomes lower as it gets farther from the center part of that area AR2. Here, since the second heat dissipation layer 652 is relatively thin, more heat can diffuse in the area direction (for example, the first direction DR1 and the second direction DR2) of this second heat dissipation layer 652 than in the thickness direction (for example, the third reverse direction) of this second heat dissipation layer 652.

[0180] The heat from the second heat dissipation layer 652 can be transmitted to the third heat dissipation layer 653. Then, heat can diffuse centering on the area AR3 of the third heat dissipation layer 653 corresponding to the video pattern area AR1. Here, in the area AR3 of the third heat dissipation layer 653 corresponding to the video pattern area AR1, the center part of this area AR3 can have the highest temperature, and the temperature becomes lower as it gets farther from the center part of that area AR3. Here, the third heat dissipation layer 653 is a metal layer, and heat can diffuse evenly in the thickness direction and the area direction of the third heat dissipation layer 653.

[0181] Heat from the third heat dissipation layer 653 can be transferred to the first heat dissipation layer 651. Then, heat can diffuse around the region AR4 corresponding to the video pattern region AR1 in the first heat dissipation layer 651. Here, in the region AR4 corresponding to the video pattern region AR1 in the first heat dissipation layer 651, the central portion of this region AR4 can have the highest temperature, and the temperature becomes lower as it gets farther from the central portion of the region AR4. Here, since the first heat dissipation layer 651 is relatively thick, more heat can diffuse in the thickness direction (e.g., the third reverse direction) of the second heat dissipation layer 652 than in the area direction (e.g., the first direction DR1 and the second direction DR2) of this first heat dissipation layer 651.

[0182] In this way, since the first heat dissipation layer 651, the third heat dissipation layer 653, and the second heat dissipation layer 652 have different thermal conductivities from each other, and the first heat dissipation layer 651 and the second heat dissipation layer 652 have different thicknesses from each other, in the first heat dissipation layer 651 made of artificial graphite material, more heat diffuses in the first and second directions DR1, DR2, while in the first heat dissipation layer 651 made of natural graphite material, more heat can diffuse in the third reverse direction. Also, since the third heat dissipation layer 653 made of a metal material is disposed between the second heat dissipation layer 652 and the first heat dissipation layer 651, the heat of the second heat dissipation layer 652 can be evenly diffused to the first heat dissipation layer 651. Therefore, the heat evenly diffused in the area direction (e.g., the first and second directions DR1, DR2) in the second heat dissipation layer 652 can be dissipated in the thickness direction (e.g., the third reverse direction) through the third heat dissipation layer 653 and the first heat dissipation layer 651. That is, the heat transferred to the first heat dissipation layer 651 does not concentrate in the region AR2 corresponding to the video pattern region AR1, but evenly diffuses in the area direction of the second heat dissipation layer 652, so that the heat of the second heat dissipation layer 652 can be dissipated at a faster speed through the third heat dissipation layer 653 and the first heat dissipation layer 651. Therefore, the heat in the display panel 10 can be dissipated more effectively. Also, the afterimage (e.g., thermal instantaneous afterimage) of the screen that occurs when heat concentrates in a specific region AR1 due to a specific video pattern IMP can be removed, and the image quality of the display device can be improved.

[0183] The display device according to an embodiment shown in FIG. 22 may have a low numerical minimum perceptible difference. For example, based on 2.6 JND, the display device according to an embodiment in FIG. 22 can have an improved minimum perceptible difference of 7.6.

[0184] Those of ordinary skill in the art to which this specification pertains can understand that this specification can be implemented in other specific forms without changing its technical idea and essential features. Therefore, it must be understood that the above-described embodiments are exemplary in all aspects and not restrictive. The scope of this specification is determined by the claims described below rather than the detailed description above, and all changes or modified forms derived from the meaning and scope of the claims and their equivalent concepts should be construed as being included within the scope of this specification.

[0185] Note that although this specification and the drawings disclose preferred embodiments of this specification and specific terms are used, these are used merely in a general sense to easily explain the technical content of this specification and assist in understanding the invention, and are not intended to limit the scope of this specification. In addition to the embodiments disclosed herein, it is obvious to those of ordinary skill in the art to which this specification pertains that other variations can be implemented based on the technical idea of this specification.

[0186] According to a preferred embodiment, it is as follows.

[0187] The background and problems of this case are as follows (i) to (viii).

[0188] (i) In the case of a self-emitting display panel, due to heat generation inside the display panel, the temperature can rise more in the central region on the plane than in other regions, especially.

[0189] (ii) In particular, in the case of a display panel in which organic light-emitting elements (OLEDs) are arranged, the characteristics of the organic light-emitting elements (OLEDs) or the pixel circuits may be affected by heating. In particular, in the central region where the temperature rises, afterimages may occur instantaneously.

[0190] (iii) On the other hand, a display panel using organic light-emitting elements (OLEDs) etc. has a small thickness and is usually a flexible substrate that can be folded or wound. Therefore, it is desirable that the heat dissipation sheet attached to the back surface of the display panel is thin and flexible.

[0191] (iv) It has also been proposed to use a graphite sheet as the heat dissipation sheet (Patent Documents 1 to 3). The heat conductivity of the graphite sheet is much larger in the direction along the sheet surface than in the thickness direction. For example, when the heat conductivity in the thickness direction is about 10 W / m·k (5 to 20 W / m·k), the heat conductivity in the direction along the sheet surface can be about 2000 W / m·k (500 to 4000 W / m·k). The ratio of the heat conductivity in the direction along the sheet surface to that in the thickness direction can be, for example, 5 to 500 times or 10 to 300 times.

[0192] In this way, heat is first transmitted toward the periphery of the sheet, and heat dissipation can be performed over the entire sheet.

[0193] (v) Patent Document 1 discloses that a heat conduction sheet (50) obtained by bonding two graphite sheets having different heat conductivities in the thickness direction with an adhesive layer (specifically, "double-sided tape") is arranged in contact with a heat generating body (6) of an electronic device. According to Claims 2 to 3 of Patent Document 1, the heat conductivity in the thickness direction is 10 to 25 W / m·K for the first graphite sheet and 5 to 8 W / m·K for the second graphite sheet. Also, according to Claims 4 to 5 of Patent Document 1, the thickness is 50 to 100 μm for the first graphite sheet and 10 to 40 μm for the second graphite sheet.

[0194] (vi) Patent Document 2 discloses a composite graphite sheet in which a high-purity natural graphite sheet (100) having a low price and an appropriate thermal conductivity and a thinner artificial graphite sheet (200) are bonded together by an adhesive layer (200).

[0195] (vii) Patent Document 3 discloses a heat dissipation sheet (110) in which an "anisotropic heat conduction layer" (120) made of graphite is formed on one or both surfaces of a "heat dissipation metal layer" (110) by sputtering or the like.

[0196] (viii) However, such conventional technologies are not necessarily suitable for the display panel of an organic light-emitting element (OLED). In particular, the heat dissipation performance is not necessarily sufficient, and due to the need to use an adhesive layer or the like, it is not necessarily preferable in terms of process and structure.

[0197] Therefore, according to a particularly preferred embodiment, it is as follows in A1 to A7 or A1 to A10 below.

[0198] A1 The heat conduction sheet (heat dissipation member 60) of the sheet-like heat dissipation member (60) is composed of a thin artificial graphite sheet (second heat dissipation layer 652) located on the side of the display panel (10) and a thick natural graphite sheet (second heat dissipation layer 651).

[0199] A2 The artificial graphite sheet (second heat dissipation layer 652) has a thermal conductivity in the sheet surface direction at 25 °C of 1000 W / m·k in a specific example, more generally 500 to 2000 W / m·k or 700 to 1300 W / m·k, and the thickness can be 100 μm in a specific example, more generally 30 to 300 μm, 50 to 200 μm or 70 to 150 μm.

[0200] The A3 natural graphite sheet (the first heat dissipation layer 651) has a thermal conductivity in the sheet surface direction at 25°C of, in one specific example, 240 W / m·k, more generally 100 - 400 W / m·k or 150 - 300 W / m·k, and a thickness of, in one specific example, 820 μm, more generally 500 - 1100 μm, 600 - 1000 μm or 700 - 950 μm.

[0201] Note that the thermal conductivity in the sheet surface direction can be measured by the periodic heating method of ISO 22007-3. For example, "Advance Riko FTC-1" can be used. https: / / www.cerij.or.jp / service / 05_polymer / thermophysical_property_01.html

[0202] The ratio of the thermal conductivity in the sheet surface direction can be such that the ratio of the value of the artificial graphite sheet (the second heat dissipation layer 652) to the value of the natural graphite sheet (the first heat dissipation layer 651) is 2 - 8, 3 - 5 or 3.5 - 4.5.

[0203] The ratio of the thickness of the graphite sheets can be such that the ratio of the value of the natural graphite sheet (the first heat dissipation layer 651) to the value of the artificial graphite sheet (the second heat dissipation layer 652) is 10 - 30, 15 - 25, or 17 - 23.

[0204] The artificial graphite sheet (the second heat dissipation layer 652) and the natural graphite sheet (the first heat dissipation layer 651) that constitute the sheet-like heat dissipation member (60) are sandwiched and wrapped from above and below by plastic sheets (the housing plates 601, 602). The plastic sheets (the housing plates 601, 602) are fused at the peripheral part by ultrasonic sealing or the like to form a flange part (the flange 603) extending in the horizontal direction.

[0205] The sheet-like heat dissipation member (60) is housed so as to be sandwiched between the cover on the back side (rear cover 50) and the display panel (10). At this time, an adhesive layer (750) is disposed between the peripheral portion of the display panel (10) (black matrix BM) and the peripheral portion of the cover on the back side (rear cover 50). In this way, the two graphite sheets are fixed at predetermined positions.

[0206] The lower plastic sheet (housing plate 601) can be provided with exhaust holes (601c). Thereby, the air expanded during heating can be discharged. (Fig. 6 etc.)

[0207] A metal layer (heat dissipation layer 653) can be provided between the two graphite sheets. This metal layer is preferably a layer of aluminum or an alloy thereof (for example, an aluminum - magnesium alloy).

[0208] In one specific example, the thickness of the metal layer is 300μm, more generally 150 - 450μm, 200 - 400μm or 250 - 350μm. Also, the ratio of the thickness of the metal layer (heat dissipation layer 653) to the thickness of the artificial graphite sheet (second heat dissipation layer 652) can be 2 - 4 or 2.5 - 3.5.

Explanation of reference numerals

[0209] 50 Rear cover 750 Adhesive layer 10 Display panel BM Light - shielding layer 60 Heat dissipation member 600 Housing 650 Heat dissipation layer 601 First housing plate 602 Second housing plate 651 First heat dissipation layer 652 Second heat dissipation layer 601a First inner plate 601b First outer plate 602a Second inner plate 602b Second outer plate DR1 First direction DR2 Second direction DR3 Third direction Tp Thickness T1 Thickness T2 Thickness S1 First space S2 Second space

Claims

1. A display panel including an organic light emitting diode; and a heat dissipation member disposed opposite the display panel, The heat dissipation member is An organic light emitting diode display device including a plurality of heat dissipation layers having different thicknesses and different thermal conductivities.

2. The plurality of heat dissipation layers include A first heat dissipation layer; and 2. The organic light emitting diode display device according to claim 1, further comprising a second heat dissipation layer between the first heat dissipation layer and the display panel.

3. The second heat dissipation layer has a higher thermal conductivity than the first heat dissipation layer, The organic light emitting diode display device according to claim 2 , wherein the second heat dissipation layer has a smaller thickness than the first heat dissipation layer.

4. 4. The organic light emitting diode display device as claimed in claim 3, wherein a ratio between a thickness of the first heat dissipation layer and a thickness of the second heat dissipation layer is 19:

1.

5. The first heat dissipation layer has a thickness of 820 μm and a thermal conductivity in a layer direction of 240 W / m·k; 4. The organic light-emitting diode display device according to claim 3, wherein the second heat-dissipating layer has a thickness of 100 μm and a thermal conductivity in a layer direction of 1000 W / m·k.

6. the first heat dissipation layer comprises natural graphite; The organic light emitting diode display device according to claim 2 , wherein the second heat dissipation layer comprises artificial graphite.

7. The plurality of heat dissipation layers include A first heat dissipation layer; and a second heat dissipation layer between the first heat dissipation layer and the display panel; and The organic light emitting diode display device according to claim 1 , further comprising a third heat dissipation layer between the first heat dissipation layer and the second heat dissipation layer.

8. the third heat dissipation layer has a thickness greater than that of the second heat dissipation layer and less than that of the first heat dissipation layer; The organic light emitting diode display device according to claim 7 , wherein the first heat dissipation layer has a thermal conductivity greater than that of the third heat dissipation layer and less than that of the second heat dissipation layer.

9. 9. The organic light emitting diode display device of claim 8, wherein a ratio between a thickness of the first heat dissipation layer, a thickness of the third heat dissipation layer, and a thickness of the second heat dissipation layer is 16:3:

1.

10. The first heat dissipation layer has a thickness of 500 μm or 20 μm and a thermal conductivity of 240 W / m·k; the second heat dissipation layer has a thickness of 100 μm and a thermal conductivity of 1000 W / m·k; 9. The organic light emitting diode display device according to claim 8, wherein the third heat dissipation layer has a thickness of 300 μm and a thermal conductivity of 202 W / m·k.

11. the first heat dissipation layer comprises natural graphite; the third heat dissipation layer includes a metal; 8. The organic light emitting diode display device according to claim 7, wherein the second heat dissipation layer comprises artificial graphite.

12. The organic light emitting diode display device according to claim 11, wherein the third heat dissipation layer comprises aluminum.

13. The organic light emitting diode display device according to claim 1 , further comprising a housing surrounding the plurality of heat dissipation layers.

14. 14. The organic light emitting diode display device of claim 13, wherein the housing has an exhaust hole extending therethrough.

15. the housing has one surface and another surface opposed to each other, the other surface being disposed closer to the display panel than the one surface; The organic light emitting diode display device according to claim 14 , wherein the exhaust hole penetrates the other surface of the housing.

16. The organic light emitting diode display device according to claim 1 , further comprising a housing selectively surrounding at least one of the plurality of heat dissipation layers.

17. the plurality of heat dissipation layers include a first heat dissipation layer and a second heat dissipation layer between the first heat dissipation layer and the display panel; 17. The organic light emitting diode display device according to claim 16, wherein the housing surrounds the first heat dissipation layer.

18. the plurality of heat dissipation layers include a first heat dissipation layer, a second heat dissipation layer between the first heat dissipation layer and the display panel, and a third heat dissipation layer between the first heat dissipation layer and the second heat dissipation layer; 17. The organic light emitting diode display device according to claim 16, wherein the housing surrounds the first heat dissipation layer.

19. 2. The organic light emitting diode display device of claim 1, wherein a total thickness of the plurality of heat dissipation layers is 50% to 150% of a thickness of the display panel.

20. 20. The organic light emitting diode display device according to claim 19, wherein the total thickness of the plurality of heat dissipation layers is 0.5 mm to 1.5 mm.

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