Display device

Abstract

To provide a display device with improved flatness of a folding area even after folding / unfolding operation for a long time in the display device.SOLUTION: A display device comprises: a panel assembly including a display panel including a first unfolding area, a second unfolding area, and a folding area between the first unfolding area and the second unfolding area, and a plate arranged under the display panel and including a slit pattern on the folding area; and a middle plate arranged under the plate. The middle plate includes a first middle plate portion on the first unfolding area, a second middle plate portion on the second unfolding area, and a vertical middle plate portion on the folding area.SELECTED DRAWING: Figure 19

Description

Technical Field

[0001] This specification relates to a display device, and more specifically, to a display device that can be folded or unfolded.

Background Art

[0002] Display devices are becoming increasingly smaller in order to meet consumers' purchasing needs. The miniaturization of display devices enhances design and portability, and enables the display of high technological capabilities, so many manufacturers are working on it.

[0003] In particular, recently, display devices that can fold or, conversely, unfold a folded display device have been developed. The display device can be folded or unfolded based on a hinge device. The display device is applicable to small display devices such as smartphones, and is also applicable to medium-sized display devices such as tablet PCs and laptops.

Summary of the Invention

Problems to be Solved by the Invention

[0004] The problem to be solved by this specification is to provide a display device in which the flatness of the folding area is improved even after a long period of folding / unfolding operations in the display device.

[0005] Another problem to be solved by this specification is to provide a display device in which the middle plate protruding toward the display panel does not physically contact the display panel, so that no additional stress is applied.

[0006] Another problem to be solved by this specification is to provide a display device in which wrinkles in the display panel are improved.

[0007] Another problem to be solved by this specification is to provide a display device that can prevent the application of additional stress that may occur when the display panel bends because the middle plate protruding toward the display panel supports the upper structure.

[0008] The problems of this specification are not limited to those described above, and other technical problems can be inferred from the following embodiments.

Means for Solving the Problems

[0009] A display device according to an embodiment for solving the above problems includes a display panel including a first unfolding region, a second unfolding region, and a folding region between the first unfolding region and the second unfolding region, and a panel assembly including a plate disposed below the display panel and including a slit pattern on the folding region, and a middle plate disposed below the plate, and the middle plate includes a first middle plate portion on the first unfolding region, a second middle plate portion on the second unfolding region, and a vertical middle plate portion on the folding region.

[0010] A display device according to another embodiment for solving the above problems includes a display panel including a first unfolding region, a second unfolding region, and a folding region between the first unfolding region and the second unfolding region, and a panel assembly including a plate disposed below the display panel, and a middle plate disposed below the plate, and a distance between the middle plate and the plate in the folding region is shorter than a distance between the middle plate and the plate in the first unfolding region.

[0011] Specific matters of other embodiments are included in the detailed description and the drawings.

Effects of the Invention

[0012] The display device according to the embodiment can improve the flatness of the folding area even when the folding / unfolding operation is repeated over a long period of time.

[0013] Since the middle plate protruding toward the display panel of the display device according to the embodiment does not physically contact the display panel, the durability and lifespan can be improved without further stress being applied.

[0014] The display device according to the embodiment can improve the wrinkles of the display panel.

[0015] The bonding layer of the display device according to the embodiment may slip during the folding operation. However, since the middle plate can support the upper structure in the unfolded state, it becomes easier for the bonding layer to recover after slipping.

[0016] However, the effects obtained in this specification are not limited to the effects described above, and other effects not mentioned will be clearly understood by those of ordinary skill in the technical field to which this specification belongs from the following description.

Brief Description of the Drawings

[0017]

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MODE FOR CARRYING OUT THE INVENTION

[0018] Hereinafter, embodiments will be described with reference to the drawings.

[0019] The same reference numerals refer to the same components. Also, in the drawings, the thickness, ratio, and dimensions of the components may be exaggerated for an effective explanation of the technical content. Since the scale of the components shown in the drawings has a scale different from the actual one for convenience of explanation, it is not limited to the scale shown in the drawings.

[0020] In this specification, when a certain component (or region, layer, part, etc.) is referred to as being "on", "connected to", or "coupled to" another component, it means that it may be directly connected / coupled to the other component or a third component may be disposed between them.

[0021] "And / or" includes all combinations of one or more of the associated configurations that can be defined.

[0022] Terms such as first, second, etc. can be used to describe various components, but the above components are not limited by the above terms. The above terms are only used for the purpose of distinguishing one component from another. For example, without departing from the scope of the rights of this embodiment, the first component may be called the second component, and similarly the second component may also be called the first component. Singular expressions include plural expressions unless otherwise clearly indicated in the context.

[0023] Terms such as "below", "lower side", "above", "upper side" are used to describe the interrelationship of the configurations shown in the drawings. The above terms are relative concepts and are described based on the directions shown in the drawings. For example, unless "immediately" or "directly" is used, one or more other parts may be located between two parts. Spatially relative terms such as "below", "beneath", "lower", "above", "upper" can be used to easily describe the correlation between a certain element or component and other elements or components as shown in the illustration. Spatially relative terms should be understood as terms including different directions of elements during use or operation in addition to the directions shown in the illustration. For example, when the illustrated element is inverted, the element described as "below" or "beneath" another element may be placed "above" the other element. Therefore, the exemplary term "below" can include both the directions of below and above.

[0024] Terms such as "comprising" or "having" are intended to specify that there are features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, and should be understood not to preclude the possibility of the existence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0025] The features of each of the various embodiments in this specification can be partially or wholly combined or combined with each other, various linkages and drives are technically possible, and each embodiment may be implemented independently of each other or may be implemented in relation to each other together.

[0026] Hereinafter, the display device of this specification will be examined through the attached drawings and embodiments as follows.

[0027] FIG. 1 is a diagram showing the unfolding state of the display device according to the first embodiment. FIG. 2 is a diagram showing the folding state of the display device according to the first embodiment.

[0028] Referring to FIG. 1, the front, upper, lower, right, left, and back surfaces of the display device 10 in the unfolding state are shown. Referring to FIG. 2, the front, upper, lower, right, left, and back surfaces of the display device 10 in the folding state are shown.

[0029] Referring to FIG. 1, the display device 10 may include a display panel PNL including a display area DA including a plurality of pixels. A non-display area may be arranged around the display area DA. The non-display area may not include pixels and may be a bezel area. The display panel PNL may include a folding area FA, a first unfolding area NFA1 located on one side of the folding area FA, and a second unfolding area NFA2 located on the other side of the folding area FA. The portions of the first unfolding area NFA1, the folding area FA, and the second unfolding area NFA2 of the display panel PNL corresponding to the display area DA can display images.

[0030] The display device 10 includes a hinge assembly 200 that can rotate about a folding axis A1. The hinge assembly 200 may not be substantially observable on the front and rear surfaces of the display device 10 in the unfolded state. This is because the hinge assembly 200 is arranged on the rear portion of the display device 10 and covered by a cover frame CF.

[0031] The hinge assembly 200 may have a shape that is formed long along the folding axis A1. The hinge assembly 200 may be disposed within the folding region FA. The folding region FA is a region where the display panel PNL is folded by the hinge assembly 200. The first unfolding region NFA1 and the second unfolding region NFA2 are regions that are symmetric to each other with respect to the folding region FA. The first unfolding region NFA1 is a region located on one side with respect to the folding axis A1, and the second unfolding region NFA2 is a region located on the other side with respect to the folding axis A1.

[0032] A top frame TF may be disposed on the front surface of the display device 10. The top frame TF may be disposed so as to cover the edge of the display panel PNL. The front surface of the display device 10 refers to the surface on which an image is displayed by the display panel PNL. Since the display device 10 is folded with respect to the folding axis A1, the top frame TF may include two top frames TF1 and TF2 that are physically separated from each other. The top frame TF includes a first top frame TF1 disposed on one side with respect to the folding axis A1 and a second top frame TF2 disposed on the other side. The height from the lower surface of the display device 10 to the top frame TF may be higher than or substantially the same as the height to the display panel PNL. Therefore, the display panel PNL may not be visible when observed from the side. The first top frame TF1 and the second top frame TF2 are as shown in FIG. 3.

[0033] The side and the back of the display device 10 may be covered by a cover frame CF. The back of the display device 10 is the opposite side of the front, and the side refers to the surface between the front and the back. Since the display device 10 is folded with respect to the folding axis A1, the cover frame CF may include two cover frames CF1 and CF2 that are physically separated from each other. The cover frame CF includes a first cover frame CF1 disposed on one side with respect to the folding axis A1 and a second cover frame CF2 disposed on the other side. The first cover frame CF1 and the second cover frame CF2 are as shown in FIG. 3.

[0034] The hinge assembly 200 is disposed near the back of the display device 10 and is disposed along the folding axis A1. The hinge assembly 200 may be disposed so as to be covered by the cover frames CF1 and CF2 in the unfolded state. In the unfolded state, the hinge assembly 200 of the display device 10 may be disposed so as not to be visible from the outside. Alternatively, in the unfolded state, the hinge assembly 200 of the display device 10 may be disposed so that only a minimum portion is visible from the outside.

[0035] Although not shown, a camera module capable of taking images may be disposed on the front, back, and / or side of the display device 10. Further, buttons capable of controlling the functions of the display device and configurations capable of performing functions may be disposed on the front, back, and / or side of the display device. For example, a volume button, a power button, a mode switch button, a speaker, a microphone, an antenna, a flash, etc. may be disposed.

[0036] Although not shown, the display device 10 may include sensors for sensing an operating state or an external environment. For example, the display device 10 may include a gesture sensor, a grip sensor, a color sensor, an infrared sensor, an illuminance sensor, a ultrasonic sensor, an iris recognition sensor, a distance detection sensor, a LiDAR sensor, etc.

[0037] Although not shown in the drawings, the display device 10 may include a connector for supplying a signal from the outside. For example, it may include a charging connector, a USB connector, an earphone jack connector, etc.

[0038] Referring to FIG. 2, when the display device 10 is folded, the display panel PNL is folded such that the first unfolding region NFA1 and the second unfolding region NFA2 face each other with respect to the folding axis A1. The hinge assembly 200 can be exposed to the outside when the cover frames CF1 and CF2 rotate and are folded.

[0039] In the folded state, the display panel PNL is not visible from the outside. Only the cover frames CF1 and CF2 of the display device 10 and the hinge assembly 200 are visible from the outside.

[0040] According to various embodiments, the cover frames CF1 and CF2 are not limited to the forms and combinations shown in FIGS. 1 and 2, and can also be implemented by other shapes and combinations of components. According to one embodiment, the first cover frame CF1 and the second cover frame CF2 may be arranged on both sides with respect to the folding axis A1 and may have a shape that is overall symmetric with respect to the folding axis A1. According to one embodiment, the first cover frame CF1 and the second cover frame CF2 may be arranged asymmetrically with respect to the folding axis A1 and may have an asymmetric shape. According to one embodiment, depending on the folded state, unfolded state, and intermediate state of the display device 10, the angle and distance formed between the first cover frame CF1 and the second cover frame CF2 may change. According to one embodiment, each of the first cover frame CF1 and the second cover frame CF2 may be physically separated into a frame that covers only the back surface of the display device 10 and a frame that covers only the side surface.

[0041] According to various embodiments, the first cover frame CF1 and the second cover frame CF2 can form an internal accommodation space through a structural connection. The hinge assembly 200 and the display panel PNL may be accommodated in the internal accommodation space.

[0042] According to various embodiments, components for driving the display device 10 may be arranged in the internal accommodation space. For example, a battery, a control printed circuit board, a flat cable, a flexible printed circuit board, etc. may be arranged in the internal accommodation space.

[0043] According to various embodiments, depending on the folding angle of the display device 10, the size of the portion of the hinge assembly 200 that is exposed to the outside may vary. For example, when the display device 10 is in a folded state, many portions of the hinge assembly 200 may be exposed between the first cover frame CF1 and the second cover frame CF2. When the display device 10 is in an unfolded state, the hinge assembly 200 may be substantially covered by the first cover frame CF1 and the second cover frame CF2. When the display device 10 is in an intermediate state between the folded state and the unfolded state, relatively few portions of the hinge assembly 200 may be exposed between the first cover frame CF1 and the second cover frame CF2.

[0044] According to various embodiments, when the display device 10 is in an unfolded state, the angle formed between the first cover frame CF1 and the second cover frame CF2 may be 180 degrees. As a result, the angle formed between the first unfolded region NFA1 and the second unfolded region NFA2 may be 180 degrees. Therefore, the display panel PNL can be in a completely flat state.

[0045] According to various embodiments, when the display device 10 is in an intermediate state between the folding state and the unfolding state, the folding may be stopped at the folding angle. This can be referred to as a so-called free stop.

[0046] According to various embodiments, the cover frame CF and the top frame TF may be formed of glass or a polymer. The cover frame CF and the top frame TF may be transparent or opaque. For example, the cover frame CF and the top frame TF may be formed of coated or colored glass, ceramic, polymer, aluminum, stainless steel, magnesium, or a combination thereof.

[0047] FIG. 3 is an exploded perspective view of a display device according to a first embodiment. FIG. 4 is a cross-sectional view of the display device according to the first embodiment. FIG. 5 is a schematic diagram showing that the middle plate, the plate, the display panel, and the cover member of the display device according to FIG. 4 are fastened to the hinge assembly.

[0048] Referring to FIGS. 3 to 5, a direction along the folding axis A1 along which the display device 10 in this specification is folded is defined as the axial direction AD. A direction from the first unfolding region NFA1 of the display device 10 through the folding region FA to the second unfolding region NFA2 is defined as the side direction SD. A direction in which the display panel PNL of the display device 10 faces is defined as the upper direction UD. A direction opposite to the upper direction UD is defined as the lower direction BD.

[0049] The top frame TF is disposed at the uppermost part in the upper direction UD of the display device 10. The top frame TF includes a first top frame TF1 disposed on one side with respect to the folding axis A1 and a second top frame TF2 disposed on the other side. The top frame TF is disposed so as to cover the edge of the display panel PNL. The top frame TF can protect the display panel PNL from external impacts. The top frame TF can form the bezel of the display device 10.

[0050] A cover member CG may be disposed below the top frame TF. The cover member CG may be disposed on the upper part of the display panel PNL. The cover member CG may be formed of a glass material including glass or quartz, etc. However, it is not limited thereto, and the cover member CG may be formed of a plastic material.

[0051] By being disposed on the upper part of the display panel 100, the cover member CG can serve to protect the members disposed below the cover member CG from the outside. On the other hand, since the display device 10 functions as a display device, the cover member CG needs to have flexibility. For this reason, the modulus of the cover member CG is preferably 70 GPa or less, and the thickness is also preferably about 100 μm or less. However, if the thickness of the cover member CG is too thin, it cannot serve to protect the members below the cover member CG described above. Therefore, the cover member CG preferably has a thickness of at least about 20 μm or more. The cover member CG may be a cover layer formed by chemical strengthening.

[0052] On the other hand, although the cover member CG serves to protect the members disposed below the cover member CG from the outside, since it is formed of a glass material as described above, the cover member CG may be broken by an external force to generate glass fragments, and the glass fragments may scatter outside the display device 10. In order to prevent the scattering of glass fragments due to the breakage of the cover member CG in advance, a film layer, a hard coat layer, etc. can be further disposed on the upper part of the cover member CG.

[0053] A panel assembly PNLA is disposed on the lower part of the cover member CG. The panel assembly PNLA includes a display panel PNL and a plate PLT. The display panel PNL may include a flexible substrate, a circuit element layer disposed on the flexible substrate and including transistors, a light-emitting layer disposed on the circuit element layer and including light-emitting elements, a sealing layer disposed on the light-emitting layer, a touch layer disposed on or inside the sealing layer, a polarizing plate for reducing the specular reflectance from the front, a cover glass disposed on the upper part of the touch layer, and the like. The display panel PNL may include a first unfolding region NFA1, a folding region FA, and a second unfolding region NFA2.

[0054] The plate PLT may include various plates disposed under the display panel PNL to support the display panel PNL. For example, one or more plates may include a back plate for supporting the display panel PNL, a top plate disposed under the back plate and formed of a SUS material, a bottom plate disposed under the top plate, having a pattern formed in the folding portion and formed of a SUS material, a heat dissipation sheet having a heat dissipation function, a middle plate for covering a plane not flattened by various configurations of the hinge assembly, and the like.

[0055] As shown in FIGS. 3 to 5, a slit pattern PTN may be formed in the plate PLT. The slit pattern PTN may be formed at a position corresponding to the folding region FA of the display panel PNL. The slit pattern PTN may be a slit-shaped etching portion formed in the plate PLT. The plate PLT is formed of a metal such as a SUS material, for example, but due to the strong properties of the metal, problems may occur when the plate PLT is folded or unfolded. The slit pattern PTN can complement the flexibility of the plate PLT. The plate PLT shown in FIG. 3 may typically be a bottom plate.

[0056] A middle plate MST is disposed below the panel assembly PNLA. The middle plate MST supports a configuration disposed in a further upper direction UD than it. Also, a hinge assembly 200 and a cover frame CF are disposed in a lower direction BD of the middle plate MST, and their upper surfaces may not be flat. The middle plate MST can flatten a non-flattened lower surface. The middle plate MST may be formed of a material such as plastic, polyimide, or metal in order to increase the rigidity of the display device 10. For example, the middle plate MST may include aluminum or SUS, but is not limited thereto. The middle plate MST may be a pair of middle plates MST.

[0057] The middle plate MST may include a first middle plate portion MSTH1 disposed in the first unfolding region NFA1 and a second middle plate portion MSTH2 disposed in the second unfolding region NFA2.

[0058] A hinge assembly 200 is disposed below the panel assembly PNLA. The hinge assembly 200 is disposed below the folding region FA. The hinge assembly 200 may have a long shape along the axial direction AD. The hinge assembly 200 can perform a folding motion in which one side and the other side rotate with respect to the folding axis A1. A detailed description of the hinge assembly 200 will be described later with reference to FIG. 5 and the like.

[0059] A cover frame CF is disposed below the hinge assembly 200. A receiving groove in which a part of the hinge assembly 200 can be seated may be formed on the upper surface of the cover frame CF. The cover frame CF includes a first cover frame CF1 disposed on one side with respect to the folding axis A1 and a second cover frame CF2 disposed on the other side. The cover frame CF may be a housing that defines the side surface and the back surface of the display device 10. The cover frame CF can protect the display device 10 from external impacts. The cover frame CF can be coupled to the hinge assembly 200. By rotating the cover frames CF1 and CF2, the folding and unfolding of the display device 10 can be realized.

[0060] Coupling members BM1, BM2, and BM3 for coupling them may be further disposed between the adjacent members MST, PLT, PNL, and CG. The first coupling member BM1 can couple the middle plate portions MSTH1 and MSTH2 and the upper plate PLT in each unfolding region NFA1 and NFA2. The second coupling member BM2 can couple the plate PLT, PTN, and the upper display panel PNL. The third coupling member BM3 can couple the display panel PNL and the cover member CG.

[0061] As shown in FIG. 5, the plate PLT, the middle plate portions MSTH1, and the middle plate portion MSTH2 coupled to each other can be installed (fixed) on the cover frames CF1 and CF2. The display device 10 can perform folding and unfolding operations by means of the hinge assembly 200 disposed on the cover frames CF1 and CF2.

[0062] Hereinafter, with reference to FIGS. 6 to 16, the specific structure and function of the hinge assembly 200 including the hinge support 250 will be described in detail.

[0063] FIG. 6 is an exploded perspective view of the hinge assembly according to the first embodiment. FIG. 7 is a perspective view of the hinge assembly according to the first embodiment. FIG. 8 is an enlarged view showing a portion A of FIG. 7. FIG. 9 is a plan view of the hinge assembly according to the first embodiment. FIG. 10 is a cross-sectional view taken along line A-A' of FIG. 9. In FIG. 6, in order to show the internal configuration, the illustration of the gear arm 240 is omitted in the upper left part, and the illustration of the hinge arm 230 is omitted in the upper right part. In FIG. 8, the illustration of the second hinge arm 230b is omitted in order to show the pair of bevel gears 241a and 241b.

[0064] Referring to FIGS. 6 to 10, the hinge assembly 200 according to the first embodiment can be composed of a hinge housing 210, a pair of hinge arms 230, and an inner frame 220.

[0065] Although not shown, the hinge assembly 200 of the first embodiment may further include a hinge arm upper cover and a hinge arm lower cover that are respectively fastened at the upper and lower parts of the hinge arm 230, but is not limited thereto. The hinge assembly 200 includes a pair of hinge arms 230 on one side, and the pair of hinge arms 230 may be rotatably connected to each other. That is, the hinge arm 230 can be composed of a first hinge arm 230a and a second hinge arm 230b having a symmetric structure with respect to each other, but is not limited thereto. The first hinge arm 230a and the second hinge arm 230b may have a symmetric structure with respect to each other.

[0066] The hinge arm 230 according to the first embodiment is characterized by having a two-axis folding (rotation) structure. That is, when implementing a folding hinge using a four-axis gear, there may be a problem with durability in order to produce a thin set or to miniaturize the gear for thinning. Therefore, the present invention is a display device (refer to 10 in FIG. 1) having a new hinge structure that forms a folding locus (displayed by a dotted line in FIG. 10) based on a two-axis rotation structure. That is, it is a display device (refer to 10 in FIG. 1) having a two-axis folding hinge structure that can be folded in the inner direction in the display device according to the first embodiment. Further, the first embodiment is characterized in that the display device 10 having a new hinge structure having two bevel gears 241 and a link slider structure for inter-axis synchronization (sync, sink) during two-axis rotation. The hinge arm 230 is a two-axis folding lever and is also called a lever wing.

[0067] The bevel gear 241 may be a gear for synchronizing (syncing) the two-axis folding hinge arm 230. Therefore, the bevel gear 241 is also called a sync gear.

[0068] The bevel gear 241 may include a first bevel gear 241a coupled to the first hinge arm 230a and a second bevel gear 241b coupled to the second hinge arm 230b.

[0069] The first bevel gear 241a and the second bevel gear 241b may have a virtual axis different from the rotation axis R_AXIS which is an actual axis. That is, the first bevel gear 241a and the second bevel gear 241b may have a virtual axis substantially perpendicular to the rotation axis R_AXIS.

[0070] Each of the first tooth form portion and the second tooth form portion formed on the first bevel gear 241a and the second bevel gear 241b may be formed only on a part of the circumference, but is not limited thereto.

[0071] The first bevel gear 241a and the second bevel gear 241b may be arranged to mesh with each other. However, it is not limited thereto, and each of the first bevel gear 241a and the second bevel gear 241b may mesh with a first rotating gear and a second rotating gear, and the first rotating gear and the second rotating gear may be configured to mesh with each other.

[0072] The left and right sinks can be maintained through the two bevel gears 241, that is, the first bevel gear 241a and the second bevel gear 241b.

[0073] The first bevel gear 241a and the second bevel gear 241b may include a second idle gear that meshes with a first idle gear of each of the first hinge arm 230a and the second hinge arm 230b in order to convert and transmit the rotation of each of the first hinge arm 230a and the second hinge arm 230b in a vertical direction.

[0074] At this time, the first idle gear and the second idle gear are arranged in a substantially vertical direction and can convert the rotation in the vertical direction. That is, the first bevel gear 241a and the second bevel gear 241b are each rotatably fastened to the first idle gear of each of the first hinge arm 230a and the second hinge arm 230b through the second idle gear, while the first hinge arm 230a and the second hinge arm 230b are each slidably fastened to the first gear arm 240a and the second gear arm 240b, and the folding and unfolding operations of the display device 10 can be performed while maintaining the left and right sinks.

[0075] At the ends of the first gear arm 240a and the second gear arm 240b, there are provided slide pins 242 protruding toward the first hinge arm 230a and the second hinge arm 230b respectively. The protruding portions 238 of the first hinge arm 230a and the second hinge arm 230b facing the first gear arm 240a and the second gear arm 240b can be provided with slide spaces 239 in which the slide pins 242 can move. Therefore, during the folding or unfolding operation of the display device 10, the slide pins 242 move within the slide spaces 239, and the first gear arm 240a and the second gear arm 240b can rotate in conjunction with the rotation of the first hinge arm 230a and the second hinge arm 230b. A detailed description of this will be given later with reference to FIGS. 13 to 16.

[0076] On the other hand, the gear arm 240 can be rotatably fastened to a shaft 233.

[0077] The gear arm 240 is a two-axis folding detent and is also called a lever detent.

[0078] That is, the gear arm 240 is configured to include a first gear arm 240a and a second gear arm 240b, and the first hinge arm 230a and the second hinge arm 230b may be fastened to the first gear arm 240a and the second gear arm 240b respectively so as to be interlocked.

[0079] The gear arm 240 may have a link configuration that is connected to the two-axis hinge arm 230. That is, the first gear arm 240a and the second gear arm 240b may be connected to the first hinge arm 230a and the second hinge arm 230b, respectively. Therefore, during the folding or unfolding operation of the display device 10, the first hinge arm 230a and the second hinge arm 230b can rotate together due to the rotation of the first gear arm 240a and the second gear arm 240b, and the left and right sinks can be maintained by the first bevel gear 241a and the second bevel gear 241b connected to the first hinge arm 230a and the second hinge arm 230b, respectively.

[0080] In this way, the first hinge arm 230a and the second hinge arm 230b can be interlocked with the first gear arm 240a and the second gear arm 240b, respectively.

[0081] The shaft 233 can form a frame for the seating and assembly of the cam 245.

[0082] A compression spring 260 for generating the frictional force of the cam 245 may be provided on the outer surface of the shaft 233 between the gear arm 240 and the cam 245.

[0083] On the gear arm 240 fastened to the outer surface of the shaft 233, together with a plurality of cams 245, a second detent 246 for maintaining the folding and unfolding angles of the hinge arm 230 and the gear arm 240 may be provided. Therefore, the cam 245 may be a configuration for the folding and unfolding torque of the hinge arm 230. The cam 245 is also called a slide cam.

[0084] On the other hand, a predetermined hinge housing 210 for housing the inner frame 220, the hinge arm 230, and the gear arm 240 may be provided at the lower part of the hinge assembly 200.

[0085] The hinge housing 210 is an exterior cover of the hinge assembly 200, has a predetermined length, and has a space inside, so that the inner frame 220, the hinge arm 230, and the gear arm 240 can be accommodated in the space. The hinge housing 210 is also called a hinge cover.

[0086] The inner frame 220 may be a frame that fixes the inside of the hinge assembly 200. The inner frame 220 may be provided with a plurality of fastening grooves (not shown) and through grooves (not shown). The inner frame 220 is an exterior cover that houses a pair of first and second bevel gears 241a, 241b, and is also called a housing cover.

[0087] In addition, a fixing member 211 facing the fastening groove of the inner frame 220 is formed on the hinge housing 210, a fixing groove (or fixing hole) 212 is formed in the fixing member 211, and it can be fixed by fastening with a fastening member such as a screw to the fastening groove.

[0088] The hinge housing 210 has a predetermined size, and the inner frame 220, the hinge arm 230, and the gear arm 240 can be accommodated in the space of the hinge housing 210.

[0089] On the other hand, the distance between the rotation centers of the pair of shafts 233 may be formed larger than the distance D between the rotation axes R_AXIS that are the rotation centers of the pair of hinge arms 230.

[0090] At this time, a pair of virtual axes passing through the centers of the pair of shafts 233 can serve as the central axis to which the components constituting the hinge housing 210 are coupled. A pair of virtual axes are provided, and each can correspond to the first cover 110 and the second cover 120.

[0091] There may or may not be an axial height H between the folding part where the first hinge arm 230a and the second hinge arm 230b are in contact with the display panel 180 and the rotation axis R_AXIS.

[0092] On the other hand, as described above, the first embodiment is characterized in that a "T"-shaped hinge support 250 is arranged between the first gear arm 240a and the second gear arm 240b of the hinge assembly 200. By means of the hinge support 250 up / down method, a relief structure for embodying the curvature of the display panel 180 during folding is ensured, and the impact resistance characteristics can be improved by supporting the first gear arm 240a and the second gear arm 240b.

[0093] The hinge support 250 may be arranged along the length direction of the inner frame 220 within the inner frame 220 between the first gear arm 240a and the second gear arm 240b.

[0094] The hinge support 250 may have a "T" shape with its upper end protruding in a direction perpendicular to the length direction.

[0095] The hinge support 250 may have an empty space inside, but is not limited thereto.

[0096] On the other hand, as described above, the present invention is characterized by having not only two bevel gears 241a, 241b but also a link slider structure for axial synchronization during two-axis rotation, which will be described in detail with reference to FIGS. 10 to 16.

[0097] FIG. 11 is a perspective view showing the unfolded state of the hinge assembly. FIG. 12 is a perspective view showing the folded state of the hinge assembly. FIG. 13 is another perspective view showing the unfolded state of the hinge assembly. FIG. 14 is an enlarged view showing a part of FIG. 13. FIG. 15 is a cutaway perspective view showing the unfolded state of the display device according to the first embodiment. FIG. 16 is a cutaway perspective view showing the folded state of the display device according to the first embodiment.

[0098] FIGS. 11, 12, 13, and 14 show a part of the configuration of the hinge assembly with the hinge housing removed for convenience of explanation.

[0099] FIGS. 15 and 16 show specific unfolded and folded states of the display device with the display panel and bezel cover omitted for convenience of explanation, respectively.

[0100] Referring to FIGS. 11, 12, 15, and 16, the set housing 110 may be disposed at the lower portions of the hinge assembly and the set frames 150, 160.

[0101] The set frames 150, 160 may include a first support plate 150 on the left side and a second support plate 160 on the right side, and a first frame on the left side and a second frame on the right side, but are not limited thereto.

[0102] The first support plate 150 and the second support plate 160 may be separately provided so as to be folded independently of each other, and a hinge assembly may be provided therebetween.

[0103] The display device according to the first embodiment can be implemented by an infolding method in which the screen portion is disposed inside when folded.

[0104] Also, the first support plate 150 and the second support plate 160 of the first embodiment may be disposed in one side region and the other side region where the folding and unfolding of the display device are performed.

[0105] The hinge assembly can be composed of a hinge housing 210, first and second hinge arms 230a, 230b, and an inner frame 220.

[0106] Also, the hinge assembly of the first embodiment may further include, but is not limited to, a hinge arm upper cover and a hinge arm lower cover that are fastened at the upper and lower portions of the first and second hinge arms 230a, 230b.

[0107] The hinge assembly includes a pair of hinge arms 230a, 230b, and the hinge arms 230a, 230b may include a first hinge arm 230a and a second hinge arm 230b having a symmetrical structure with respect to each other.

[0108] The first hinge arm 230a and the second hinge arm 230b according to the first embodiment are characterized by having a biaxial folding (rotation) structure.

[0109] At this time, the first hinge arm 230a and the second hinge arm 230b can be folded (rotated) along the folding trajectory of the housing cover rail 235 (see the arrow in FIG. 12).

[0110] That is, at the upper end of the inner frame 220, a pair of guide pins 234 protruding toward the inner first hinge arm 230a and second hinge arm 230b are provided, and the first hinge arm 230a and the second hinge arm 230b facing the pair of guide pins 234 may be provided with a pair of housing cover rails 235 that sandwich the pair of guide pins 234, but are not limited thereto. Therefore, with the first hinge arm 230a and the second hinge arm 230b guided by the pair of guide pins 234, they can be folded (rotated) along the folding trajectory of the housing cover rail 235.

[0111] Further, the first embodiment is characterized by having two bevel gears 241a, 241b and a link slider structure for axis synchronization (sync) during two-axis rotation. By using two bevel gears instead of four general gears, the thickness of the display device can be minimized. That is, when adjusting the left and right sync with four general gears, the thickness of the hinge assembly may increase due to the thickness of the four vertically arranged gears. Therefore, the first embodiment can reduce the thickness and weight of the hinge assembly by adjusting the left and right sync with two bevel gears 241a, 241b. Also, folding with a smaller R value than before becomes possible.

[0112] Specifically, the bevel gear 241 may include a first bevel gear 241a coupled to the first hinge arm 230a and a second bevel gear 241b coupled to the second hinge arm 230b.

[0113] The first bevel gear 241a and the second bevel gear 241b may have a virtual axis different from the rotation axis R_AXIS which is the actual axis. That is, the first bevel gear 241a and the second bevel gear 241b may have a virtual axis substantially perpendicular to the rotation axis R_AXIS.

[0114] Each of the first tooth form portion and the second tooth form portion formed on the first bevel gear 241a and the second bevel gear 241b may be formed only on a part of the circumference, but is not limited thereto.

[0115] The first bevel gear 241a and the second bevel gear 241b may be arranged to mesh with each other. However, it is not limited thereto, and each of the first bevel gear 241a and the second bevel gear 241b may mesh with a first rotating gear and a second rotating gear, and the first rotating gear and the second rotating gear may be configured to mesh with each other.

[0116] The first bevel gear 241a and the second bevel gear 241b may include a second idler gear 232b that meshes with the first idler gear 232a of each of the first hinge arm 230a and the second hinge arm 230b to convert and transmit the rotation of each of the first hinge arm 230a and the second hinge arm 230b in a vertical direction (see FIGS. 13 and 14).

[0117] At this time, the first idler gear 232a and the second idler gear 232b are arranged in directions substantially perpendicular to each other and can convert the rotation in the vertical direction. That is, the first bevel gear 241a and the second bevel gear 241b are rotatably fastened to the first idler gear 232a of the first hinge arm 230a and the second hinge arm 230b through the second idler gear 232b, respectively. The first hinge arm 230a and the second hinge arm 230b are slidably fastened to the first gear arm 240a and the second gear arm 240b, respectively, and can perform the folding and unfolding operations of the display device while maintaining the left and right sinks.

[0118] That is, when the first hinge arm 230a and the second hinge arm 230b are folded / unfolded in the vertical direction, the first bevel gear 241a and the second bevel gear 241b will rotate in the horizontal direction to adjust the sink.

[0119] On the other hand, the rotation axis R_AXIS of the first hinge arm 230a and the second hinge arm 230b and the pair of virtual axes B passing through the centers of the pair of shafts 233 may be different from each other. That is, the rotation axis R_AXIS around which the first hinge arm 230a and the second hinge arm 230b are folded / unfolded does not coincide with the virtual axis B around which the first gear arm 240a and the second gear arm 240b are folded / unfolded, and they can be connected by a link slide structure to interlock with each other.

[0120] Therefore, the virtual axis B about which the first gear arm 240a and the second gear arm 240b fold / unfold is the central axis of the shaft 233, and the rotation axis R_AXIS about which the first hinge arm 230a and the second hinge arm 230b fold / unfold is the central axis of the housing cover rail 235. A link slide structure can be used to connect the two different folding / unfolding axes in an interlocking manner.

[0121] That is, in the first embodiment, two first bevel gears 241a and two second bevel gears 241b are provided for shaft synchronization during two-axis rotation, while the first gear arm 240a and the second gear arm 240b are slidably fastened to the first hinge arm 230a and the second hinge arm 230b, respectively.

[0122] That is, at the ends of the first gear arm 240a and the second gear arm 240b, slide pins 242 protruding toward the first hinge arm 230a and the second hinge arm 230b are provided, respectively, and slide spaces 239 in which the slide pins 242 can move are provided in the first hinge arm 230a and the second hinge arm 230b facing the first gear arm 240a and the second gear arm 240b. Therefore, during the folding or unfolding operation of the display device, the slide pins 242 move within the slide spaces 239, and the first gear arm 240a and the second gear arm 240b can rotate (or fold / unfold) in conjunction with the rotation (or folding / unfolding) of the first hinge arm 230a and the second hinge arm 230b. In this way, the two-axis hinge operation can be synchronized through the two first bevel gears 241a and the second bevel gears 241b, and the link slider structure.

[0123] At this time, the slide space 239 may be provided within the side protrusions 238 of the first hinge arm 230a and the second hinge arm 230b, but is not limited thereto. On the one hand, when the folding and unfolding operations of the display device (refer to 10 in FIG. 1) are performed, in order to maintain a specific folding angle of the display device, a holding force is embodied by using the frictional force between the components constituting the hinge.

[0124] That is, the hinge assembly is arranged at a portion where the folding and unfolding of the display device are performed, and can facilitate the folding and unfolding operations of the display device. In addition, the hinge assembly can provide a holding force so as to maintain the state in which the display device is folded at a specific angle.

[0125] As described above, the display panel may be arranged on one surface of the first support plate 150 and the second support plate 160. As the display panel, one of various display panels such as an organic light-emitting display panel and a liquid crystal display panel can be used. In addition, the display panel may have flexibility so as to be foldable and unfoldable along with the folding and unfolding of the display device.

[0126] The display device may be folded so that the first support plate 150 and the second support plate 160 form a specific folding angle. That is, in FIG. 15, the first support plate 150 and the second support plate 160 are shown to be fully unfolded so as to have an angle of, for example, 180°, but the display device may be folded at a specific angle. That is, in FIG. 16, the first support plate 150 and the second support plate 160 are shown to be folded so as to have an angle of, for example, 90°, but it is not limited thereto. In such a case, the display panel arranged on the upper portions of the first support plate 150 and the second support plate 160 may also be folded along with the folding of the first support plate 150 and the second support plate 160.

[0127] The display device may be folded at a specific angle according to the user's intention. Also, the display device may be completely folded or unfolded according to the user's intention. The display device may be inner-folded (or in-folded), and may be folded or unfolded so that the display panel is disposed inside, or may be out-folded, and may be folded or unfolded so that the display panel is disposed outside.

[0128] The display device can maintain a specific folding angle by the holding force provided from the hinge assembly. In other words, the first support plate 150 and the second support plate 160 can be fixed in a state of maintaining a specific folding angle by the hinge assembly. Therefore, the display device can be folded at a specific angle according to the user's intention and can maintain the folded state at a specific angle by the holding force of the hinge assembly.

[0129] In particular, the present invention is characterized in that it can maintain a specific folding angle of the display device by applying a cam 245 structure including a compression spring 260 to implement a holding torque and a free stop function.

[0130] FIG. 17 is a cross-sectional view showing a folding state of the display device according to the first embodiment of FIG. 4. FIG. 18 is a cross-sectional view showing a modification of the display device according to the first embodiment.

[0131] Referring to FIG. 17, the display panel PNL, the cover member CG, the plate PLT, and the middle plate MST may each be folded with reference to the folding region FA. The first middle plate portion MSTH1 and the second middle plate portion MSTH2 may overlap in the thickness direction. The slit pattern PTN may be disposed in the folding region FA.

[0132] In the unfolded state of the display device 10, the folding region FA has a flat shape as shown in FIG. 4, but in the folded state, the folding region FA may be folded and bent as shown in FIG. 17. When the display device 10 repeatedly performs the folding / unfolding operation over a long period of time, deformation may occur in the folding region FA with a large amount of deformation. When the unfolding operation is repeated, the folding region FA may bend downward as shown in FIG. 18. More specifically, when the folding / unfolding operation is repeated, since the deformation of the folding region FA is large, the cover member CG, the display panel PNL, and the slit pattern PTN disposed in the folding region FA may each bend downward and may not return to the original state. Even if the cover member CG, the display panel PNL, and the slit pattern PTN disposed in the folding region FA are restored, the restoration time may be longer than a predetermined time. In this case, the bent shape (or wrinkled shape) may be visually recognized from the outside, which may cause display defects. Since there is no other support member at the lower part of the cover member CG, the display panel PNL, and the slit pattern PTN disposed in the folding region FA, the sagging of the bent shape (or wrinkled shape) may become more severe over time.

[0133] The display device according to the following second embodiment is introduced to solve the problem that the folding region FA of the display device according to the first embodiment bends.

[0134] FIG. 19 is a cross-sectional view of the display device according to the second embodiment. FIG. 20 is a cross-sectional view showing the folded state of the display device according to the second embodiment. FIG. 21 is a cross-sectional view showing a modified example of the display device according to the second embodiment.

[0135] Referring to FIGS. 19 to 21, the middle plate MST_1 of the display device 11 according to the second embodiment is different from the display device 10 according to FIG. 4 in that it can also be arranged in the folding region FA.

[0136] More specifically, the middle plate MST_1 can project upward toward the upper members PNL and PTN in the folding region FA. The middle plate MST_1 may further include a vertical middle plate that projects upward toward the upper members PNL and PTN in the folding region FA. The middle plate MST_1 may be formed by etching. However, the middle plate MST_1 may be formed by various methods.

[0137] The separation distance between the middle plate MST_1 and the plate PLT (or the separation distance from the slit pattern PTN) in the folding region FA may be smaller than the separation distance between the middle plate MST_1 and the plate PLT in the unfolding regions NFA1 and NFA2. For this purpose, the vertical middle plate of the middle plate MST_1 may further include a third middle plate portion MSTH3 connected to the first middle plate portion MSTH1_1 and a fourth middle plate portion MSTH4 connected to the second middle plate portion MSTH2_1. The third and fourth middle plate portions MSTH3 and MSTH4 can each project further upward from the surfaces of the first and second middle plate portions MSTH1 and MSTH2 toward the upper members PNL and PTN. The thicknesses of the third and fourth middle plate portions MSTH3 and MSTH4 may be larger than the thicknesses of the first and second middle plate portions MSTH1 and MSTH2, respectively.

[0138] The surface heights of the third and fourth middle plate portions MSTH3 and MSTH4 may be higher than the surface heights of the first and second middle plate portions MSTH1 and MSTH2, respectively.

[0139] The third and fourth middle plate parts MSTH3 and MSTH4 can serve to prevent the cover member CG, the display panel PNL, and the slit pattern PTN in the folding area FA from sagging downward. As described above with reference to FIG. 18, when there is no other support member at the lower part, the cover member CG, the display panel PNL, and the slit pattern PTN arranged in the folding area FA may become more severely sagged in a sagging shape (or a wrinkled shape) over time. However, in the case of the display device 11 according to the second embodiment, by arranging the third and fourth middle plate parts MSTH3 and MSTH4, which have a higher surface height than the first and second middle plate parts MSTH1 and MSTH2, in the folding area FA, it is possible to prevent in advance the cover member CG, the display panel PNL, and the slit pattern PTN arranged in the folding area FA from becoming more severely sagged in a sagging shape (or a wrinkled shape) over time.

[0140] The height H2 by which the third and fourth middle plate parts MSTH3 and MSTH4 protrude with reference to the surface height of the first middle plate part MSTH1_1 may be smaller than the height H1 by which the first coupling member BM1 protrudes with reference to the surface height of the first middle plate part MSTH1_1. The surface of the first coupling member BM1 may be located on the same line as the lower surface of the slit pattern PTN. When the surfaces of the third and fourth middle plate parts MSTH3 and MSTH4 are located on the same line as the lower surface of the slit pattern PTN and the third and fourth middle plate parts MSTH3 and MSTH4 are in direct contact with the slit pattern PTN, physical interference may occur between the slit pattern PTN and the middle plate MST_1 during the folding operation, and the folding operation may not be performed smoothly.

[0141] Further, in order for the third and fourth middle plate portions MSTH3 and MSTH4 to prevent the cover member CG, the display panel PNL, and the slit pattern PTN in the folding region FA from deflecting, the surfaces of the third and fourth middle plate portions MSTH3 and MSTH4 are preferably positioned between the lower surface and the upper surface of the first coupling member BM1. However, it is not limited thereto, and the surface heights of the third and fourth middle plate portions MSTH3 and MSTH4 may be located on the same line as the surface height (or upper surface height) of the first coupling member BM1.

[0142] Furthermore, the third and fourth middle plate portions MSTH3 and MSTH4 are preferably positioned at the central portion of the folding region FA in order to easily prevent the cover member CG, the display panel PNL, and the slit pattern PTN in the folding region FA from deflecting. Therefore, the first and second middle plate portions MSTH1_1 and MSTH2_1 can each extend to the folding region FA. The first and second middle plate portions MSTH1_1 and MSTH2_1 each extend to the folding region FA, and since each middle plate portion MSTH3 and MSTH4 is connected to the adjacent first and second middle plate portions MSTH1_1 and MSTH2_1, the third and fourth middle plate portions MSTH3 and MSTH4 can be separated from the inner surfaces of the first coupling member BM1 located in the respective unfolding regions NFA1 and NFA2.

[0143] The third and fourth middle plate portions MSTH3 and MSTH4 of the display device 11 according to the second embodiment can be separated from each other with reference to the bisector of the folding region FA. The fact that the third and fourth middle plate portions MSTH3 and MSTH4 are separated from each other with reference to the bisector of the folding region FA is for smoothly performing the folding operation by the hinge assembly 200 of the display device 10 described above. As described above with reference to FIG. 3, since the middle plate MST_1 is formed of a material such as plastic, polyimide, or metal in order to increase the rigidity of the display device 11, when the middle plate MST_1 is integrally formed over the unfolding regions NFA1 and NFA2 and the folding region FA, the stress on the display device 11 may increase during the folding operation. Therefore, as in the case of the middle plate MST of the display device 10 according to FIG. 4, the first and third middle plate portions MSTH1_1 and MSTH3 can be physically separated from the second and fourth middle plate portions MSTH2_1 and MSTH4.

[0144] As shown in FIG. 21, when the folding state and the unfolding state of the display device 11 are repeated, the folding region FA may bend downward as shown in FIG. 18.

[0145] More specifically, when the folding area FA repeats the folding / unfolding operation, since the deformation is large, the cover member CG, the display panel PNL, and the slit pattern PTN arranged in the folding area FA may each bend downward and may not return to their original state. Even if the cover member CG, the display panel PNL, and the slit pattern PTN arranged in the folding area FA are restored, the restoration time may be longer than a predetermined time. In this case, the bent shape (or wrinkled shape) may be visually recognized from the outside, which may cause display defects. In addition, since there is no other support member below the cover member CG, the display panel PNL, and the slit pattern PTN arranged in the folding area FA, the sagging of the bent shape (or wrinkled shape) may become more severe over time.

[0146] However, according to the display device 11 according to the second embodiment, the third and fourth middle plate portions MSTH3 and MSTH4 of the folding area FA are formed so as to further protrude upward from the surfaces of the first and second middle plate portions MSTH1 and MSTH2 toward the upper members PNL and PTN. Thus, even if the cover member CG, the display panel PNL, and the slit pattern PTN arranged in the folding area FA bend downward due to repeated folding / unfolding states, they bend only up to the surfaces of the third and fourth middle plate portions MSTH3 and MSTH4 (the third and fourth middle plate portions MSTH3 and MSTH4 come into contact with the slit pattern PTN). Therefore, the restoration time of the cover member CG, the display panel PNL, and the slit pattern PTN arranged in the folding area FA can be shortened.

[0147] Furthermore, it is possible to prevent in advance the bent shape (or wrinkled shape) of the folding area FA from being visually recognized from the outside and causing display defects. In addition, since the slit pattern PTN bends only up to the surfaces of the third and fourth middle plate portions MSTH3 and MSTH4, the bending phenomenon (or wrinkle generation phenomenon) of the folding area FA can be improved.

[0148] In addition, since the middle plate MST_1 is separated from the display panel PNL with the plates PLT and PTN interposed therebetween, it is possible to prevent in advance the phenomenon of applying further stress to the display panel PNL by additionally forming the third and fourth middle plate portions MSTH3 and MSTH4.

[0149] Since other explanations have been described above with reference to FIGS. 1 to 18, detailed explanations are omitted.

[0150] The above description and the attached drawings merely exemplarily show the technical idea of this specification. Those with ordinary knowledge in the technical field to which this specification pertains can make various modifications or deformations such as combinations, separations, substitutions, and changes of configurations without departing from the essential characteristics of this specification. Therefore, the embodiments disclosed in this specification are for the purpose of explanation rather than for limiting the technical idea of this specification, and the scope of the technical idea of this specification is not limited by such embodiments. The protection scope of this specification should be interpreted by the following claims, and all technical ideas within the equivalent scope should be construed as being included in the scope of rights of this specification.

Explanation of Reference Numerals

[0151] 10: Display device PLT: Plate PTN: Slit pattern MST: Middle plate MSTH1 to MSTH4: First to fourth middle plates PNL: Display panel CG: Cover member

Claims

1. A panel assembly including a display panel including a first unfolding region, a second unfolding region, and a folding region between the first unfolding region and the second unfolding region, and a plate disposed below the display panel and including a slit pattern on the folding region, and a middle plate disposed below the plate, wherein the middle plate includes a first middle plate portion on the first unfolding region, a second middle plate portion on the second unfolding region, and a vertical middle plate portion on the folding region, a display device.

2. The display device according to claim 1, wherein the vertical middle plate portion protrudes toward the plate.

3. The display device according to claim 2, wherein the vertical middle plate portion includes a third middle plate portion connected to the first middle plate portion and a fourth middle plate portion connected to the second middle plate portion.

4. The display device according to claim 3, wherein the third middle plate portion and the fourth middle plate portion are spaced apart from each other.

5. The display device according to claim 3, wherein a distance between the third middle plate portion and the plate is shorter than a distance between the first middle plate portion and the plate.

6. The display device according to claim 3, wherein a distance between the fourth middle plate portion and the plate is shorter than a distance between the second middle plate portion and the plate.

7. The display device according to claim 1, wherein the first unfolding region and the second unfolding region are folded with respect to the folding region and overlap each other in a folded state.

8. The display device according to claim 7, wherein the slit pattern on the folding region is spaced apart from the vertical middle plate portion in an unfolded state.

9. The display device according to claim 8, wherein the folding region of the display panel bends downward in the unfolded state.

10. The display device according to claim 8, wherein the slit pattern on the folding region is in direct contact with the vertical middle plate portion.

11. The display device according to claim 1, further comprising an in-folding hinge assembly disposed in the folding region below the panel assembly and including a hinge cover.

12. The display device according to claim 11, further comprising a first frame cover and a second frame cover coupled to the in-folding hinge assembly.

13. The in-folding hinge assembly includes a first hinge arm and a second hinge arm rotatably connected to each other, a first bevel gear and a second bevel gear coupled in a direction perpendicular to the first hinge arm and the second hinge arm respectively, and a first gear arm and a second gear arm fastened to be interlocked with the first hinge arm and the second hinge arm. The display panel performs folding and unfolding operations about a rotation axis different from the central axes of the first bevel gear and the second bevel gear, according to the display device of claim 11.

14. The first bevel gear and the second bevel gear are arranged to mesh with each other. The display device according to claim 13, wherein the first bevel gear and the second bevel gear each include a second idle gear meshing with a first idle gear of the first hinge arm and the second hinge arm respectively.

15. The display device according to claim 14, wherein the first idle gear and the second idle gear are arranged in a direction perpendicular to each other.

16. A panel assembly including a display panel including a first unfolding region, a second unfolding region, and a folding region between the first unfolding region and the second unfolding region, and a plate disposed below the display panel, and a middle plate disposed below the plate. In the display device, the distance between the middle plate and the plate in the folding region is shorter than the distance between the middle plate and the plate in the first unfolding region.

17. The middle plate includes a first middle plate portion on the first unfolding region, a second middle plate portion on the second unfolding region, and a vertical middle plate portion on the folding region. The vertical middle plate portion protrudes toward the plate, and the display device according to claim 16.

18. The vertical middle plate portion includes a third middle plate portion connected to the first middle plate portion and a fourth middle plate portion connected to the second middle plate portion, The third middle plate portion and the fourth middle plate portion are separated from each other, and the display device according to claim 17.

19. The first unfolding region and the second unfolding region are folded with reference to the folding region, and in the folded state, they overlap each other. In the unfolded state, the slit pattern on the folding region is separated from the vertical middle plate portion, and the display device according to claim 18.

20. In the unfolded state, the folding region of the display panel bends downward, and the slit pattern on the folding region is in direct contact with the vertical middle plate portion, and the display device according to claim 19.

Images