Foldable display device

Abstract

The present disclosure provides a foldable display, an apparatus of which includes a first support plate and a second support plate, a display panel disposed on the first support plate and the second support plate, and a hinge assembly disposed between the first support plate and the second support plate, the hinge assembly including a hinge arm, a gear arm coupled to the hinge arm, an inner frame disposed below the hinge arm and the gear arm and fixing the hinge arm and the gear arm, a hinge housing accommodating the inner frame, the hinge arm, and the gear arm below the inner frame, and a foreign matter prevention element inserted between the hinge housing and the inner frame and connected to the hinge arm to operate with folding of the hinge arm when the hinge arm is folded.

Description

[0001] Cross-reference to related applications

[0002] This application claims the benefit of priority to Korean Patent Application No. 10-2021-0187582, filed in Korea on December 24, 2021, the entire contents of which are expressly incorporated herein by reference. Technical Field

[0003] This disclosure relates to foldable display devices, and more particularly, to foldable display devices having a hinge structure that allows for inward folding (e.g., folding the foldable display device inward to reduce the size of the foldable display device in the longitudinal direction). Background Technology

[0004] Recently, portable terminals such as wireless terminals, personal digital assistants (PDAs), portable multimedia players (PMPs), and electronic storage devices are shrinking in size for portability. However, because users want to access various information such as text messages, videos, still images, MP3s, and games through the portable terminal's screen (e.g., display unit or monitor), there is a need to enlarge the display unit's screen and make it larger. However, since the reduction in the size of portable terminals leads to a reduction in the size of the display screen, there are limitations in both increasing the screen size (e.g., the display screen) and meeting the requirement of a reduced overall terminal size.

[0005] As a way to overcome this limitation, flexible display devices, such as bendable display devices, foldable display devices, or rollable sliding display devices, have recently been developed.

[0006] Flexible display devices can be realized by forming a substrate of plastic material. However, any alternative material can be used as the substrate for a flexible display device. Because flexible display devices can be easily carried when folded and can achieve (e.g., have) a large screen when unfolded, they can be applied to a variety of applications, such as televisions and monitors, as well as mobile devices such as mobile phones, e-books, and e-newspapers. Summary of the Invention

[0007] The inventors of this disclosure have invented a structure in which a hinge mechanism is used in the area where the display panel is folded to realize a foldable display device in a flexible display device. However, the inventors of this disclosure have recognized that when using only four-axis gears (e.g., four general-purpose gears) to realize a folding hinge, it is not feasible to manufacture a kit with a small thickness, or to achieve a small thickness, the gear size becomes smaller, which reduces the durability of the gears and increases the variation in gear defects.

[0008] Accordingly, the inventors of the present disclosure invented a foldable display apparatus having a new hinge structure that forms a folding trajectory based on a dual-axis rotation structure. Also, the inventors of the present disclosure invented a new hinge structure of a foldable display apparatus that includes two bevel gears and a link slider structure for moving in synchronization between the axes of the two bevel gears during dual-axis rotation. In particular, in the foldable display apparatus of the present disclosure, the thickness of the foldable display apparatus can be minimized by using two bevel gears instead of four ordinary gears.

[0009] Accordingly, an aspect of the present disclosure is to provide a foldable display apparatus having a hinge structure that allows internal folding (e.g., folding a foldable display apparatus in half, or folding a foldable display apparatus around itself) and is capable of securing durability (e.g., having enhanced durability) without increasing the thickness of the foldable display apparatus.

[0010] Also, the inventors of the present disclosure have implemented a holding force using friction between components constituting a hinge to hold a certain folding angle of a foldable display apparatus during a folding operation and an unfolding operation of the foldable display apparatus. However, the inventors of the present disclosure have recognized that the holding force required to hold a certain folding angle of a foldable display apparatus decreases due to continuous folding operations and unfolding operations of the foldable display apparatus. Also, the inventors of the present disclosure have recognized that, unlike a folding phone (e.g., a flip phone of a folding phone), a foldable display apparatus is heavy and thus requires a high holding force.

[0011] Accordingly, the inventors of the present disclosure developed a new structure of a foldable display apparatus that is capable of implementing a holding torque and a free stop function to hold a certain folding angle of a foldable display apparatus by applying a cam structure, in which the cam structure includes a compression spring.

[0012] Accordingly, another aspect of the present disclosure is to provide a foldable display apparatus having a new structure in which a holding force can be permanently implemented without being reduced even when a foldable display apparatus is continuously used, and a high holding force can be implemented even when a foldable display apparatus is heavy.

[0013] Also, the inventors of the present disclosure have recognized that, when a hinge is folded, an avoidance structure is required to implement (e.g., support) the curvature of a display panel (e.g., a curved portion of a display panel), and the impact resistance performance is reduced due to the avoidance structure.

[0014] Accordingly, still another aspect of the present disclosure is to provide a foldable display apparatus having improved impact resistance while securing a relief space for achieving a curvature of a display panel when folded (e.g., a support space for a bending / folding portion of the display panel).

[0015] In addition, the inventors of the present disclosure have recognized that, in a state in which the hinge assembly is folded, foreign matter (e.g., contaminants such as dust and dirt) enters a gap between the hinge housing and the inner frame, thereby causing damage to the hinge assembly.

[0016] Accordingly, another object of the present disclosure is to provide a foldable display apparatus in which damage to the hinge assembly is prevented by preventing entry of foreign matter.

[0017] The objects of the present disclosure are not limited to the above-mentioned objects, and other objects not mentioned above will be clearly understood by those skilled in the art from the following description.

[0018] A foldable display apparatus according to an embodiment of the present disclosure includes a first support plate and a second support plate, a display panel disposed on the first support plate and the second support plate, and a hinge assembly disposed between the first support plate and the second support plate, the hinge assembly including a hinge arm, a gear arm coupled to the hinge arm, an inner frame disposed below the hinge arm and the gear arm and fixing the hinge arm and the gear arm, a hinge housing accommodating the inner frame, the hinge arm, and the gear arm below the inner frame, and a foreign matter entry prevention element inserted between the hinge housing and the inner frame and connected to the hinge arm to operate with folding of the hinge arm when the hinge arm is folded.

[0019] Further details of the embodiments are included in the detailed description and the accompanying drawings.

[0020] According to the present disclosure, impact resistance and durability can be improved without increasing the thickness of the foldable display apparatus.

[0021] According to the present disclosure, a holding force for holding a certain folding angle of the foldable display apparatus can be implemented.

[0022] According to the present disclosure, by improving components of the hinge assembly, durability of the foldable display apparatus can be improved without increasing costs, and folding reliability can be secured.

[0023] According to the present disclosure, damage to the hinge assembly can be prevented by preventing entry of foreign matter.

[0024] Effects according to the present disclosure are not limited to the above-illustrated content, and more various effects are included in the present specification. BRIEF DESCRIPTION OF DRAWINGS

[0025] The present disclosure will become more fully understood from the detailed description given herein below and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present disclosure.

[0026] Figure 1 is a perspective view of a foldable display device according to an embodiment of the present disclosure.

[0027] Figure 2 is an exploded perspective view of a foldable display device according to an embodiment of the present disclosure.

[0028] Figure 3 is a perspective view showing a part of a configuration of a foldable display device according to an embodiment of the present disclosure.

[0029] Figure 4 is an exploded perspective view of a hinge assembly according to an embodiment of the present disclosure.

[0030] Figure 5A is a perspective view of a hinge assembly according to an embodiment of the present disclosure.

[0031] Figure 5B is a magnified view of a part of Figure 5A .

[0032] Figure 6 is a cross-sectional view taken along line B-B' of Figure 5B .

[0033] Figure 7A is a perspective view showing an unfolded state of a hinge assembly.

[0034] Figure 7B is a perspective view showing a folded state of a hinge assembly.

[0035] Figure 8A is another perspective view showing an unfolded state of a hinge assembly.

[0036] Figure 8B is a magnified view of a part of Figure 8A .

[0037] Figure 9 is a cutaway perspective view showing a folded state of a foldable display device according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0038] Hereinafter, various embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0039] Figure 1 is a perspective view of a foldable display device according to an embodiment of the present disclosure.

[0040] Figure 2 is an exploded perspective view of a foldable display apparatus according to an embodiment of the disclosure.

[0041] Figure 3 is a perspective view showing a part of a configuration of a foldable display apparatus according to an embodiment of the disclosure.

[0042] Figure 3 shows a foldable display apparatus 100 according to an embodiment of the disclosure. Figure 1

[0043] Referring to Figures 1 to 3 , the foldable display apparatus 100 according to an embodiment of the disclosure can be configured to include a set of housings 110 and 120, a set of frames 150, 151, 160, and 161, a hinge assembly 200, a display panel 180, and bezel covers 130 and 140. Alternatively, the bezel covers 130 and 140 can constitute a single integral member attached (e.g., fixedly attached or detachably attached) to the display panel 180.

[0044] The foldable display apparatus 100 according to an embodiment of the disclosure can further include hinge supports 250 disposed in the hinge assembly 200 and support covers 171 and 172.

[0045] In addition, the hinge assembly 200 according to an embodiment of the disclosure can further include foreign matter prevention elements 236a and 236b interposed between the hinge housing 210 and the inner frame 220.

[0046] In Figures 1 to 3 , components of the foldable display apparatus 100 are shown for ease of explanation, but substantially various components for driving the foldable display apparatus 100 can also be included.

[0047] The set of housings 110 and 120 can be disposed under the display panel 180, the hinge assembly 200, and the set of frames 150, 151, 160, and 161.

[0048] The set of housings 110 and 120 is a set of external covers, and can include a first cover 110 on the left side and a second cover 120 on the right side, but the disclosure is not limited thereto.

[0049] ​The first cover 110 and the second cover 120 can be disposed in one region and another region of the foldable display apparatus 100 according to an embodiment of the disclosure, which is folded and unfolded (e.g., a first region). In the foldable display apparatus 100 according to an embodiment of the disclosure, folding and unfolding operations are performed based on a boundary region between the first cover 110 and the second cover 120 by an external force applied by a user.

[0050] The first cover 110 and the second cover 120 can be disposed to have the same shape.

[0051] The set of frames 150, 151, 160, and 161 is a set of built-in frames on which various hardware components of the foldable display apparatus 100 can be mounted, and on which the display panel 180 can be seated.

[0052] To this end, the set of frames 150, 151, 160, and 161 can include a first support plate 150 located at a left side (e.g., a first lateral side) and a second support plate 160 located at a right side (e.g., a second lateral side), and a first frame 151 located at the left side and a second frame 161 located at the right side, but the disclosure is not limited thereto. However, the first support plate 150 and the second support plate 160 can be disposed as a single integral member. In addition, the single integral support plate can include an insertion groove for receiving the hinge assembly 200, and the hinge assembly 200 can be flush with a top surface of the support plate.

[0053] The first support plate 150 and the second support plate 160 can be individually disposed to be folded independently of each other, and the hinge assembly 200 can be disposed therebetween.

[0054] The support covers 171 and 172 are arranged at an upper portion of the hinge assembly 200 disposed between the first support plate 150 and the second support plate 160 to cover a central portion (e.g., a central lateral portion) of the hinge assembly 200, but the disclosure is not limited thereto.

[0055] In this case, the support covers 171 and 172 can include a first support cover 171 located at a left side (e.g., a first lateral side) and a second support cover 172 located at a right side (e.g., a second lateral side), but the disclosure is not limited thereto.

[0056] The first frame 151 and the second frame 161 can be individually disposed to be folded independently of each other. For example, the first frame 151 and the second frame 161 can be rotated independently of each other (e.g., about a central hinge axis).

[0057] In addition, the first support cover 171 and the second support cover 172 are individually disposed to be folded independently of each other.

[0058] The first and second frames 151 and 161 can surround and fix (e.g., be attached to) edges of the first and second bezel covers 130 and 140 and the first and second support plates 150 and 160, respectively.

[0059] In this case, the first and second support plates 150 and 160 can include first and second fastening units coupled to the hinge assembly 200, respectively.

[0060] The first and second support plates 150 and 160 can be disposed to have the same shape, and the first and second fastening units can be disposed to face each other and be symmetrical. However, the first and second support plates 150 and 160 can have different shapes from each other.

[0061] A plurality of fastening grooves are formed in the first and second fastening units, and a plurality of fastening grooves are formed in one surface of the hinge assembly 200 facing the hinge arms 230, so that the hinge assembly 200 can be fixed thereto by a predetermined fastening element.

[0062] An insertion groove can be formed in a folding portion (e.g., a transverse central portion) between the first and second support plates 150 and 160, and the hinge housing 210 of the hinge assembly 200 can be inserted into the insertion groove.

[0063] The foldable display device 100 according to an embodiment of the disclosure is characterized in that it is implemented in an inner folding manner in which a screen unit is arranged internally when folded.

[0064] Meanwhile, the first and second support plates 150 and 160 can be base members (e.g., support members) for supporting the display panel 180 and various components of the foldable display device 100. In addition, the first and second support plates 150 and 160 can accommodate various components for driving the foldable display device 100.

[0065] The first and second support plates 150 and 160 according to an embodiment of the disclosure can be disposed in one area (e.g., a first area) and another area (e.g., a second area) of folding and unfolding the foldable display device 100. For example, the foldable display device 100 can be folded and unfolded (e.g., onto itself) based on a boundary area between the first and second support plates 150 and 160 by an external force applied by a user.

[0066] The hinge arms 230 can connect the first and second fastening units of the first and second support plates 150 and 160. In this case, in some cases, one or more hinge arms 230 of the hinge assembly 200 can be provided. In Figure 2In particular, the pair of hinge arms 230 can connect one side and the other side (e.g., opposite sides) of the first and second fastening units, respectively.

[0067] In particular, the pair of hinge arms 230 can connect one side and the other side (e.g., opposite sides) of the first and second fastening units, respectively.

[0068] As described above, the hinge assembly 200 can be disposed at a portion where the foldable display apparatus 100 is folded and unfolded, so that the folding operation and the unfolding operation of the foldable display apparatus 100 can be facilitated. In addition, the hinge assembly 200 can provide a predetermined holding force to hold the foldable display apparatus 100 in a folded state at a certain angle or any desired angle. For example, a user can move (e.g., fold) the foldable display apparatus 100 to any position, and the hinge assembly 200 will help to hold the position. In this case, the holding force of the hinge assembly 200 can be provided by a cam structure including a compression spring, that is, the cam structure can exert the holding force by a frictional force. The detailed structure and functions of the hinge assembly 200 will be described later with reference to FIGS. 6 to 9. Figures 4 to 9

[0069] The display panel 180 can be disposed on one surface (e.g., a top surface) of both the first support plate 150 and the second support plate 160. As the display panel 180, one of various display panels such as an organic light emitting display panel or a liquid crystal display panel can be used, but any type of display can be used.

[0070] The display panel 180 is a component that displays an image to a user, and can include a plurality of sub-pixels. In the display panel 180, a plurality of scan lines and a plurality of data lines cross each other, and each of the plurality of sub-pixels can be connected to the scan lines and the data lines. In addition, each of the plurality of sub-pixels can be connected to a high potential power line, a low potential power line, an initialization signal line, an emission control signal line, etc.

[0071] The sub-pixel is the smallest unit constituting a screen, and each of the plurality of sub-pixels can include a light emitting element and a pixel circuit for driving the light emitting element. Depending on the type of the display panel 180, the plurality of light emitting elements can be defined differently. For example, when the display panel 180 is an organic light emitting display panel, the light emitting element can be an organic light emitting element including an anode, a light emitting unit, and a cathode. Hereinafter, a description is made based on the assumption that the light emitting element is an organic light emitting element, but the type of the light emitting element is not limited thereto.

[0072] The pixel circuit is a circuit for controlling the driving of the light emitting element. For example, the pixel circuit can include a plurality of transistors and a capacitor, but is not limited thereto. ​

[0073] In addition, the display panel 180 can have flexibility such that it can be folded and unfolded as the foldable display device 100 is folded and unfolded.

[0074] The foldable display device 100 can be folded such that the first support plate 150 and the second support plate 160 form a certain folding angle. For example, in Figure 1 and Figure 2 In the drawings, the first support plate 150 and the second support plate 160 are shown to be completely unfolded to have an angle of, for example, 180°, but the foldable display device 100 can be folded at any certain angle. In this case, the display panel 180 disposed on the first support plate 150 and the second support plate 160 can also be folded at a certain angle as the first support plate 150 and the second support plate 160 are folded.

[0075] In addition, the foldable display device 100 can maintain a certain folding angle by a holding force provided by the hinge assembly 200. For example, the first support plate 150 and the second support plate 160 can be fixed by the hinge assembly 200 while maintaining a certain folding angle, and a user can manipulate the foldable display device 100 to move to a certain folding angle. Accordingly, the foldable display device 100 can be folded at a certain angle according to the user's intention, and can be maintained in a folded state at a certain angle by the holding force of the hinge assembly 200.

[0076] The bezel covers 130 and 140 can cover the upper bezel of the display panel 180 on the upper surface of the display panel 180.

[0077] The bezel covers 130 and 140 can include a first bezel cover 130 located at the left side (e.g., the first lateral side) and a second bezel cover 140 located at the right side (e.g., the second lateral side), but the present disclosure is not limited thereto.

[0078] Meanwhile, the embodiment of the present disclosure is characterized in that the "T"-shaped hinge support 250 is disposed between the pair of gear arms 240 of the hinge assembly 200. By the up / down method (e.g., vertical movement) of the hinge support 250, an avoidance structure for achieving (e.g., supporting) the curvature of the display panel 180 at the time of folding is fixed, and at the same time, the gear arms 240 can be supported, thereby improving the impact resistance performance of the foldable display device 100.

[0079] In addition, the embodiment of the present disclosure is characterized in that the foreign matter entry prevention elements 236a and 236b are inserted between the hinge housing 210 and the inner frame 220 of the hinge assembly 200. The foreign matter entry prevention elements 236a and 236b are connected to the pair of hinge arms 230 and operate together with the folding of the hinge arms 230 when the hinge arms 230 are folded, thereby blocking the entry of foreign matter inward (e.g., into the hinge housing 210) after folding.

[0080] Hereinafter, a detailed description will be given of the hinge assembly 200 according to an embodiment of the present disclosure with reference to the accompanying drawings. Figures 4 to 9 The detailed description includes the specific structure and functions of the hinge support 250 and the foreign matter entry prevention elements 236a and 236b of the hinge assembly 200.

[0081] Figure 4 is an exploded perspective view of a hinge assembly according to an embodiment of the present disclosure.

[0082] Figure 5A is a perspective view of a hinge assembly according to an embodiment of the present disclosure.

[0083] Figure 5B is a partial A of Figure 5A is an enlarged view of a portion A.

[0084] Figure 6 is a cross-sectional view taken along line B-B' of Figure 5B

[0085] Referring to Figures 4 to 6 , the hinge assembly 200 according to an embodiment of the present disclosure can be configured to include the hinge housing 210, the inner frame 220, the pair of hinge arms 230, and the pair of gear arms 240.

[0086] In addition, the hinge assembly 200 according to an embodiment of the present disclosure can further include an upper hinge arm cover and a lower hinge arm cover fastened at upper and lower portions of the hinge arms 230, but the present disclosure is not limited thereto.

[0087] In addition, the support covers 171 and 172 are provided on an upper portion of the hinge assembly 200 to cover a central portion of the hinge assembly 200, but the present disclosure is not limited thereto. Each of the support covers 171 and 172 can include a plurality of holes to allow connection to the first frame 151 and the second frame 161. That is, a plurality of fasteners correspond to the plurality of holes of the support covers 171 and 172, and thus the hinge assembly 200 is fixed to the first support plate 150 and the second support plate 160.

[0088] The support covers 171 and 172 can include a first support cover 171 located on the left side (e.g., the first lateral side) and a second support cover 172 located on the right side (e.g., the second lateral side), but the present disclosure is not limited thereto. ​

[0089] The first and second frames 151 and 161 can be separately provided to be folded independently of each other.

[0090] The hinge assembly 200 includes a pair of hinge arms 230 at one side thereof, and the pair of hinge arms 230 are rotatably connected to each other. For example, the hinge arms 230 can include a first hinge arm 230a and a second hinge arm 230b having a symmetrical structure (e.g., symmetrically arranged with respect to the first and second frames 151 and 161 or the insertion groove formed between the first and second frames 151 and 161), but the present disclosure is not limited thereto. In addition, the hinge assembly 200 can include a pair of hinge arms 230 at the other side thereof.

[0091] The first and second hinge arms 230a and 230b can have a structure in which they are symmetrical to each other (e.g., symmetrically arranged).

[0092] The hinge arm 230 according to an embodiment of the present disclosure is characterized in that it has a dual-axis folding (rotating) structure. For example, when a 4-axis gear is used to implement a folding hinge, it is not feasible to manufacture a gear set having a small thickness, or in order to achieve a small thickness, the gear size becomes small and durability can be affected, which can cause defects in the gear set. Accordingly, the present disclosure is characterized in that the foldable display device 100 has a new hinge structure that forms a folding trajectory based on a dual-axis rotating structure. For example, the present disclosure is characterized in that the foldable display device 100 has a dual-axis (e.g., or multi-axis) folding hinge structure that can be folded in an internal direction of the foldable product. In addition, the present disclosure is characterized in that the foldable display device 100 has a new hinge structure having two bevel gears 241 (241a, 241b) and a link slider structure for synchronization between axes during dual-axis rotation. The hinge arm 230 is a dual-axis folding lever and can be referred to as a lever wing.

[0093] The bevel gear 241 can be a gear for synchronization of the hinge arm 230 for dual-axis folding. Accordingly, the bevel gear 241 can be referred to as a synchronization gear.

[0094] The bevel gear 241 can 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.

[0095] The first and second bevel gears 241a and 241b can have a virtual axis different from a rotation axis C that is an actual axis. For example, the first and second bevel gears 241a and 241b can have a virtual axis substantially perpendicular to the rotation axis C.

[0096] Each of the first and second tooth portions formed in the first and second bevel gears 241a and 241b can be formed only in a portion of a circumference, but the present disclosure is not limited thereto.

[0097] The first and second bevel gears 241a and 241b can be disposed to be engaged with each other. However, the present disclosure is not limited thereto, and the first and second bevel gears 241a and 241b can be engaged with first and second rotary gears, respectively, and the first and second rotary gears can be configured to be engaged with each other.

[0098] The left and right synchronization can be maintained by the two synchronization gears 241 of the present disclosure, i.e., the first and second bevel gears 241a and 241b.

[0099] The first and second bevel gears 241a and 241b can include second idler gears engaged with first idler gears of the respective first and second hinge arms 230a and 230b, so as to convert and transmit the rotation of each of the first and second hinge arms 230a and 230b in a vertical direction. The rotation direction of the second idler gears of the first and second bevel gears is perpendicular to the rotation direction of the first idler gears of the first and second hinge arms.

[0100] At the end portions (e.g., lateral end portions) of the first and second gear arms 240a and 240b, sliding pins 242 protruding toward the first and second hinge arms 230a and 230b, respectively, are disposed, and the protrusions 238 of the first and second hinge arms 230a and 230b facing the first and second gear arms 240a and 240b can include sliding spaces 239 through which the sliding pins 242 are movable. For example, each of the first and second hinge arms 230a and 230b includes a protrusion 238, and each protrusion 238 includes a sliding space 239. The first gear arm 240a includes a sliding pin 242 that extends into and slides within the sliding space 239 of the first hinge arm 230a during the folding and unfolding operations, and the second gear arm 240b includes a sliding pin 242 that extends into and slides within the sliding space 239 of the second hinge arm 230b during the folding and unfolding operations. Accordingly, during the folding or unfolding operation of the foldable display apparatus 100, the sliding pins 242 move within the sliding spaces 239, and the first and second gear arms 240a and 240b can rotate in coordination with the rotation of the first and second hinge arms 230a and 230b, which will be described later with reference to Figure 7A and Figure 7B and Figure 8A and Figure 8B in detail.

[0101] The gear arm 240 can be rotatably fastened to the shaft.

[0102] The gear arm 240 can be referred to as a dual axis folding stopper, and can also be referred to as a joystick stopper.

[0103] For example, the gear arm 240 can be 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 can be fastened to be interlocked with the first gear arm 240a and the second gear arm 240b, respectively.

[0104] The gear arm 240 can be a link configuration connected to the dual axis hinge arm 230. For example, the first gear arm 240a and the second gear arm 240b can be connected to the first hinge arm 230a and the second hinge arm 230b, respectively. Accordingly, during a folding operation or an unfolding operation of the foldable display device 100, the first hinge arm 230a and the second hinge arm 230b can rotate together with the rotation of the first gear arm 240a and the second gear arm 240b, and can be kept in left-right synchronization 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.

[0105] Accordingly, 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.

[0106] The shaft can constitute a frame for the installation and assembly of the cam 245.

[0107] A compression spring 260 for implementing the friction of the cam 245 can be provided on the outer surface of the shaft between the gear arm 240 and the cam 245.

[0108] On the gear arm 240 fastened to the outer surface of the shaft, a second stopper 246 for maintaining the folding and unfolding angles of the hinge arm 230 and the gear arm 240 together with the plurality of cams 245 can be provided. Accordingly, the cam 245 can be a component for the torque of the folding and unfolding of the hinge arm 230. The cam 245 can also be referred to as a slide cam.

[0109] Meanwhile, a predetermined hinge housing 210 accommodating the inner frame 220, the hinge arm 230, and the gear arm 240 can be provided in the lower portion of the hinge assembly 200.

[0110] The hinge housing 210 is an external cover of the hinge assembly 200, has a predetermined length, and can have a space therein to accommodate the inner frame 220, the hinge arm 230, and the gear arm 240 in the space. The hinge housing 210 can also be referred to as a hinge cover.

[0111] The inner frame 220 can be a frame for fixing the inside of the hinge assembly 200. The inner frame 220 can include a plurality of fastening grooves (not shown) and a through groove (not shown). The inner frame 220 is an outer cover that accommodates a pair of first and second bevel gears 241a and 241b, and can also be referred to as a housing cover.

[0112] In addition, a fixing member 211 facing the fastening grooves of the inner frame 220 is formed in the hinge housing 210, and a fixing groove (or fixing hole) 212 is formed in the fixing member 211, so that the fixing member 211 can be fastened and fixed to the fixing groove by a fastening member such as a screw.

[0113] The hinge housing 210 can have a predetermined size, and thus the inner frame 220, the hinge arms 230, and the gear arms 240 can be accommodated in the space of the hinge housing 210.

[0114] Meanwhile, a distance between the centers of rotation of the pair of shafts can be formed to be greater than a distance D between the rotation axes C, which are the centers of rotation of the pair of hinge arms 230. In this case, a pair of virtual axes passing through the centers of the pair of shafts can serve as a center axis to which the components constituting the hinge housing 210 are coupled. The pair of virtual axes can be disposed to correspond to the first and second covers, respectively.

[0115] In this case, there can be an axial height H between the folded portions of the first and second hinge arms 230a and 230b, which are in contact with the display panel, and the rotation axes C, but the present disclosure is not limited thereto.

[0116] Meanwhile, as described above, the embodiment of the present disclosure is characterized in that the "T"-shaped hinge support 250 is disposed between the first and second gear arms 240a and 240b of the hinge assembly 200. However, the hinge support 250 can have any shape and can completely cover the area between the first and second gear arms 240a and 240b. By the up / down method (e.g., vertical movement) of the hinge support 250, a relief structure for achieving the curvature of the display panel when folded is fixed, and at the same time, the first and second gear arms 240a and 240b can be supported, thereby improving the impact resistance performance.

[0117] The hinge support 250 can be disposed in the inner frame 220 between the first and second gear arms 240a and 240b in the longitudinal direction of the inner frame 220.

[0118] The hinge support 250 can have a "T" shape in which an upper end protrudes to both sides thereof. For example, the hinge support 250 can have a "T" shape in a cross section cut in a direction perpendicular to the longitudinal direction.

[0119] The hinge support 250 can have an empty inner space for accommodating the display panel 180, but is not limited thereto.

[0120] The hinge support 250 can support a folding portion (e.g., a folded portion) of the display panel 180.

[0121] The current foldable display device requires an avoidance structure to achieve the curvature of the display panel when the hinge is folded, and due to the avoidance structure, the impact resistance performance can be deteriorated (e.g., reduced). For example, conventionally, there is a gap between the folding portion of the display panel and the hinge assembly in order to achieve the R shape (e.g., "U" shape or curved shape) of the display panel when folded, such that the impact resistance performance (e.g., puncture resistance and drop ball resistance) is weakened, so that the foldable display device is vulnerable to impact and penetration.

[0122] Accordingly, the embodiment of the disclosure is characterized in that the "T" shaped hinge support 250 is disposed between the first gear arm 240a and the second gear arm 240b of the hinge assembly 200, such that an avoidance space for achieving the curvature of the display panel is formed by lowering the hinge support 250 during folding, and the folding portion of the display panel is supported by raising the hinge support 250 during unfolding.

[0123] In addition, the embodiment of the disclosure is characterized in that the foreign matter entry prevention elements 236a and 236b are inserted between the hinge housing 210 and the inner frame 220 of the hinge assembly 200.

[0124] The foreign matter entry prevention elements 236a and 236b can include a first foreign matter entry prevention element 236a located on the left side (e.g., the first lateral side) and a second foreign matter entry prevention element 236b located on the right side (e.g., the second lateral side), but the disclosure is not limited thereto.

[0125] The first foreign matter entry prevention element 236a and the second foreign matter entry prevention element 236b can be separately provided to be folded independently of each other.

[0126] The first foreign matter entry prevention element 236a and the second foreign matter entry prevention element 236b are connected to the first hinge arm 230a and the second hinge arm 230b, respectively, and operate together with the folding of the first hinge arm 230a and the second hinge arm 230b when the first hinge arm 230a and the second hinge arm 230b are folded, thereby preventing the inward entry of foreign matter after folding.

[0127] The first foreign matter prevention element 236a and the second foreign matter prevention element 236b can be formed such that one portion thereof in which the first gear arm 240a and the second gear arm 240b are disposed has a larger area than one portion thereof in which the first hinge arm 230a and the second hinge arm 230b are disposed, but the present disclosure is not limited thereto.

[0128] The first foreign matter prevention element 236a and the second foreign matter prevention element 236b have a central portion having a curvature along a curvature of the outer side of the inner frame 220 (e.g., overlapping and directly contacting), such that the inner frame 220 is accommodated therein, and both sides of the first foreign matter prevention element 236a and the second foreign matter prevention element 236b on which the first gear arm 240a and the second gear arm 240b are disposed can have flat surfaces such that the first gear arm 240a and the second gear arm 240b are seated thereon. In addition, the curved inner portion (e.g., central portion) of the first foreign matter prevention element 236a and the second foreign matter prevention element 236b can be installed in the curved portion (e.g., curved side) of the hinge housing 210.

[0129] Meanwhile, as described above, the present disclosure is characterized by having a link slider structure and two bevel gears 241a and 241b for synchronization between the shafts during biaxial rotation, which will be described in detail with reference to Figure 7A and Figures 7B to 8A and Figure 8B .

[0130] Figure 7A is a perspective view showing an unfolded state of the hinge assembly.

[0131] Figure 7B is a perspective view showing a folded state of the hinge assembly.

[0132] Figure 8A is another perspective view showing an unfolded state of the hinge assembly.

[0133] Figure 8B is an enlarged view of a portion of Figure 8A .

[0134] Figure 8A and Figure 8B cut perspective view of the hinge assembly taken along line B-B' of Figure 5B .

[0135] Figure 7B and Figure 8A and Figure 8B show a portion of the configuration of the hinge assembly, in which the hinge housing 210 and the inner frame 220 are omitted for ease of description. In addition, in Figure 8AIn the drawings, the illustration of the first hinge arm 230a and the second hinge arm 230b is omitted for convenience of description.

[0136] Referring to Figure 7A and Figure 7B and Figure 8A and 8B , the hinge assembly can be configured to include the hinge housing 210, the inner frame 220, the first and second hinge arms 230a and 230b, and the first and second gear arms 240.

[0137] The hinge assembly according to the embodiments of the disclosure can further include an upper hinge arm cover and a lower hinge arm cover fastened at upper and lower portions of the first and second hinge arms 230a and 230b.

[0138] The hinge assembly can include a pair of hinge arms 230a and 230b, and the hinge arms 230a and 230b can include the first and second hinge arms 230a and 230b symmetrical to each other.

[0139] The first and second hinge arms 230a and 230b according to the embodiments of the disclosure are characterized by having a dual-axis folding (rotating) structure.

[0140] In this case, the first and second hinge arms 230a and 230b can be folded (e.g., rotated) along a folding trajectory of the housing cover rail 235 (see Figure 7B the arrow of which indicates the path of the hinge arms 230a, 230b.

[0141] For example, a pair of guide pins 234 (e.g., the guide pins 234 can be provided inside the first and second hinge arms 230a and 230b) protruding toward the inside of the first and second hinge arms 230a and 230b can be provided at the upper end of the inner frame 220, and a pair of housing cover rails 235 into which the pair of guide pins 234 are fitted can be provided on the first and second hinge arms 230a and 230b facing the pair of guide pins 234, but the disclosure is not limited thereto. Accordingly, the first and second hinge arms 230a and 230b can be folded (e.g., rotated) along the folding trajectory of the housing cover rail 235 while being guided by the pair of guide pins 234.

[0142] In addition, the embodiments of the disclosure are characterized by having two bevel gears 241a and 241b and a link slider structure for synchronization between the shafts during dual-axis rotation.

[0143] In particular, in the foldable display apparatus of the disclosure, by using two bevel gears 241a and 242a instead of four ordinary gears, the thickness of the foldable display apparatus can be minimized.

[0144] For example, when adjusting the left-right synchronization with four ordinary gears, the thickness of the hinge assembly is increased by the thickness of the four gears arranged vertically. Accordingly, in an embodiment of the disclosure, the thickness and weight of the hinge assembly can be reduced by adjusting the left-right synchronization using two bevel gears 241a and 241b. In addition, a folding of an R value (e.g., a radius) smaller than the existing case can be achieved.

[0145] Specifically, the bevel gears 241 can 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.

[0146] The first bevel gear 241a and the second bevel gear 241b can have a virtual axis different from a rotation axis C that is an actual rotation axis. For example, the first bevel gear 241a and the second bevel gear 241b can have a virtual axis substantially perpendicular to the rotation axis C.

[0147] Each of the first tooth portion and the second tooth portion formed in the first bevel gear 241a and the second bevel gear 241b, respectively, can be formed only in a portion of a circumference, but the disclosure is not limited thereto.

[0148] The first bevel gear 241a and the second bevel gear 241b can be arranged to be meshed with each other. However, the disclosure is not limited thereto, and the first bevel gear 241a and the second bevel gear 241b can be meshed with first and second rotation gears, respectively, and the first and second rotation gears can be configured to be meshed with each other.

[0149] The first bevel gear 241a and the second bevel gear 241b can include a second idler gear 232b meshed with a first idler gear 232a of the respective first and second hinge arms 230a and 230b, so as to convert and transmit the rotation of each of the first and second hinge arms 230a and 230b in the vertical direction (see Figure 8A and Figure 8B ). The first idler gear 232a can have an orientation perpendicular to an orientation of the second idler gear 232b.

[0150] In this case, the first idler gear 232a and the second idler gear 232b can be disposed in a substantially perpendicular direction to convert rotation in the perpendicular direction. For example, 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, respectively, through the second idler gear 232b, and the first hinge arm 230a and the second hinge arm 230b are slidably fastened (e.g., fastened via a gear connection between the first idler gear 212a and the second idler gear 232b) to the first gear arm 240a and the second gear arm 240b, respectively, so that the folding operation and the unfolding operation of the foldable display apparatus 100 can be performed while maintaining left-right synchronization.

[0151] For example, when the first hinge arm 230a and the second hinge arm 230b are folded / unfolded in the perpendicular direction, the first bevel gear 241a and the second bevel gear 241b (e.g., due to their physical connection with the hinge arms 230a, 230b) rotate in the horizontal direction, thereby adjusting (e.g., maintaining) synchronization.

[0152] Meanwhile, the rotation axes C of the first hinge arm 230a and the second hinge arm 230b and a pair of virtual axes B passing through the center of the pair of axes can be different from each other. For example, the rotation axes C around which the first hinge arm 230a and the second hinge arm 230b fold / unfold and the virtual axes B around which the first gear arm 240a and the second gear arm 240b fold / unfold do not coincide with each other, and they can be connected with the linkage slider structure and thus interlocked with each other.

[0153] In addition, the virtual axes B around which the first gear arm 240a and the second gear arm 240b fold / unfold are central axes of the axes, and the rotation axes C around which the first hinge arm 230a and the second hinge arm 230b fold / unfold are central axes of the housing cover guide rails 235. The two different folding / unfolding axes can be connected with the linkage slider structure so that they are interlocked with each other.

[0154] For example, the embodiment of the disclosure is characterized in that two first bevel gears 241a and second bevel gears 241b are provided for synchronization between the axes during bi-axial rotation, and 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.

[0155] For example, at the end portions (e.g., lateral end portions) of the first gear arm 240a and the second gear arm 240b, sliding pins 242 protruding toward the first hinge arm 230a and the second hinge arm 230b are respectively provided. A sliding space 239 in which the sliding pins 242 can move can be 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. Accordingly, during a folding operation or an unfolding operation of the foldable display apparatus, the sliding pins 242 move within the sliding spaces 239 of the first hinge arm 230a and the second hinge arm 230b, and the first gear arm 240a and the second gear arm 240b can rotate (e.g., fold / unfold) together with the rotation (e.g., folding / unfolding) of the first hinge arm 230a and the second hinge arm 230b. As described above, the dual-axis hinge operation can be synchronized by the two first bevel gears 241a and second bevel gears 241b and the link slider structure.

[0156] In this case, the sliding space 239 can be provided in the protrusion 238 of the first hinge arm 230a and the second hinge arm 230b, but the present disclosure is not limited thereto.

[0157] Meanwhile, the present disclosure is characterized in that a holding force is implemented using friction between components constituting a hinge, in order to hold a certain folding angle of a foldable display apparatus during a folding operation and an unfolding operation of the foldable display apparatus.

[0158] For example, the hinge assembly according to the present disclosure can be provided at a portion where the foldable display apparatus is folded and unfolded, thereby facilitating a folding operation and an unfolding operation of the foldable display apparatus. In addition, the hinge assembly according to the present disclosure can provide a holding force to hold the foldable display apparatus in a folded state at a certain angle.

[0159] As described above, a display panel can be provided on one surface of the first support plate and the second support plate. 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 can have flexibility so that it can be folded and unfolded together with folding and unfolding of the foldable display apparatus.

[0160] The foldable display apparatus can be folded so that the first support plate and the second support plate form a certain folding angle. For example, although the first hinge arm 230a and the second hinge arm 230b are fully unfolded to have an angle of, for example, 180° in Figure 7A and Figure 8A are shown, the foldable display apparatus can be folded at a certain angle. For example, in Figure 7BIn the middle, the first hinge arm 230a and the second hinge arm 230b are shown in a folded state having an angle of, for example, 90°, but the present disclosure is not limited thereto. In this case, the display panel arranged at the upper portions of the first hinge arm 230a and the second hinge arm 230b and the first support plate and the second support plate can also be folded together with the folding of the first hinge arm 230a and the second hinge arm 230b.

[0161] The foldable display device 100 can be folded at a certain angle according to the user's intention. Also, the foldable display device can be completely folded or unfolded according to the user's intention (for example, by the user's operation of the foldable display device 100). The foldable display device can be folded inward (for example, or inwardly folded) as well as folded or unfolded such that the display panel is disposed inside thereof, and can be folded outward as well as folded or unfolded such that the display panel 180 is disposed outside thereof.

[0162] The foldable display device 100 can maintain a certain folding angle by the holding force provided from the hinge assembly. In other words, the first hinge arm 230a and the second hinge arm 230b and the first support plate 150 and the second support plate 160 can be fixed in a state in which they maintain a certain folding angle by the hinge assembly. Accordingly, the foldable display device 100 can be folded at a certain angle according to the user's intention (for example, by the user's operation of the foldable display device 100), and can be maintained in a folded state at a certain angle by the holding force of the hinge assembly 200 (for example, the frictional force due to the cam 245). Also, any number of cams 245 can be provided.

[0163] In particular, the present disclosure is characterized in that the holding torque and the free stop function can be implemented to maintain a certain folding angle of the foldable display device by the structure of the cam 245 including the compression spring 260.

[0164] For example, the holding torque and the free stop function can be implemented by applying the compression spring 260 and the cam structure 245 during opening or closing rotation.

[0165] In particular, the hinge assembly 200 of the present disclosure can include a pair of cam structures 245 serving as a free stop hinge, for example, which can be formed of a first cam structure of the cam 245 and a second cam structure of the first gear arm 240a and the second gear arm 240b.

[0166] In this case, the free stop hinge means that the hinge device does not provide a stop force at 180 degrees during the opening and closing operation of the foldable display device, and means that the foldable display device does not receive a stop force from the hinge device except at 0 degrees and 360 degrees.

[0167] The first and second cam structures 245 can be configured as rotating cams. However, the present disclosure is not limited thereto, and one of the first and second cam structures can be configured as a rotating cam, and the other cam structure can be configured as a sliding cam. When a cam operation is performed with cam surfaces facing each other, the first and second cam structures can support a stop state of the foldable display apparatus. The cam operation provides a force in close contact with each other to the compression spring 260, and can operate rotation and / or sliding of the first and second cam structures by the cam operation.

[0168] The first cam structure employed in the hinge assembly according to the embodiment of the present disclosure is configured as a cam 245 including a main body and first stoppers 245b provided on one surface of the main body, and the second cam structure can include second stoppers 246 provided on one surface of the first and second gear arms 240a and 240b. Each first stopper 245b can engage a corresponding second stopper 246 and can have a shape corresponding to the second stopper 246. Further, each first stopper 245b can have a concave shape at least substantially matching a convex shape of the corresponding second stopper 246.

[0169] At the center of the main body of the cam 245, a first hinge hole for insertion of a shaft can be formed in the axial direction (e.g., the longitudinal direction) of the shaft.

[0170] In addition, at the center of the first and second gear arms 240a and 240b, a second hinge hole for insertion of a shaft can be formed in the axial direction (e.g., the longitudinal direction) of the shaft.

[0171] In addition, the first stoppers 245b can have a mountain-shaped protruding shape (e.g., an inverted "U" shape) and can protrude from the main body in the direction of the first and second gear arms 240a and 240b. The second stoppers 246 can have a mountain-shaped protruding shape (e.g., a "U" shape) and can protrude from the first and second gear arms 240a and 240b toward the cam 245. However, the present disclosure is not limited thereto.

[0172] A plurality of first stoppers 245b can be provided at predetermined intervals with respect to the first hinge hole. A plurality of second stoppers 246 can be provided at predetermined intervals with respect to the second hinge hole. The plurality of first stoppers 245b and the plurality of second stoppers 246 can be provided at positions facing each other.

[0173] Meanwhile, the cam structure of the present disclosure can allow an increase in the number of the first and second cam structures in order to increase the torque applied by the cam structure, and thus increase the holding force of the hinge assembly 200.

[0174] For example, the present disclosure is characterized in that the first cam structure and the second cam structure are provided in a number of 2x3 (see Figure 5A and Figure 5B ). Thus, even in the case of a small part where the thickness of the hinge assembly is thin, sufficient friction torque can be ensured.

[0175] As described above, by applying a cam structure of 2x3, a leaf spring for assisting free stop is not required, thereby preventing dust from being generated due to the leaf spring and preventing a part from being broken. For example, when a leaf spring is used in a foldable display device as in the related art, a gap allowing dust and other contaminants to intrude is provided. Thus, folding reliability can be ensured.

[0176] In addition, as described above, the embodiment of the present disclosure is characterized in that the first foreign matter prevention element 236a and the second foreign matter prevention element 236b are inserted between the hinge housing 210 and the inner frame 220 of the hinge assembly 200 and operate together with folding of the first hinge arm 230a and the second hinge arm 230b when the first hinge arm 230a and the second hinge arm 230b are folded, thereby preventing foreign matter from intruding inward after folding. For example, the first foreign matter prevention element 236a and the second foreign matter prevention element 236b provide a seal (e.g., a dust seal) to block dust and other contaminants, thereby enhancing the reliability of the hinge assembly 200 of the present disclosure. This will be described in detail with reference to Figure 9 .

[0177] Figure 9 is a cutaway perspective view showing a folded state of a foldable display device according to an embodiment of the present disclosure.

[0178] Referring to Figure 9 , the group housing 110 can be disposed under the hinge assembly and the group frames 150 and 160.

[0179] As described above, the group frames 150 and 160 can include a first support plate 150 located at the left side and a second support plate 160 located at the right side and a first frame located at the left side and a second frame located at the right side, but the present disclosure is not limited thereto.

[0180] The first support plate 150 and the second support plate 160 can be separately disposed to be folded independently of each other, and the hinge assembly can be disposed therebetween.

[0181] The foldable display device according to an embodiment of the disclosure can be implemented in an inner folding manner (e.g., folding onto itself), in which the screen unit is disposed inside (e.g., not exposed to the outside) when folded. Accordingly, the screen unit (e.g., the display device 180) can be protected from damage caused by external force, for example, by dropping of the foldable display device 100.

[0182] In addition, the first support plate 150 and the second support plate 160 according to an embodiment of the disclosure can be disposed in one area and the other area in which the foldable display device is folded and unfolded.

[0183] The hinge assembly can include a hinge housing 210, first and second hinge arms 230a and 230b, and an inner frame 220.

[0184] The hinge assembly can include a pair of hinge arms 230a and 230b, and the hinge arms 230a and 230b can include first and second hinge arms 230a and 230b having structures symmetrical to each other.

[0185] The first and second hinge arms 230a and 230b according to an embodiment of the disclosure are characterized by having a dual-axis folding (e.g., rotating) structure.

[0186] In addition, an embodiment of the disclosure is characterized by having two bevel gears 241a and 241b and a link slider structure for synchronization between the shafts during dual-axis rotation.

[0187] In this case, the first and second bevel gears 241a and 241b can include second idler gears 232b engaged with first idler gears 232a of the respective first and second hinge arms 230a and 230b, so as to translate and transfer rotation of each of the first and second hinge arms 230a and 230b in a perpendicular direction (e.g., a rotating direction). The first and second bevel gears 241a and 241b are rotatably fastened (e.g., or engaged or rotatably engaged) to the first idler gears 232a of the first and second hinge arms 230a and 230b, respectively, by the second idler gears 232b of the first and second bevel gears 241a and 241b. The first and second hinge arms 230a and 230b are slidably fastened to the first and second gear arms, respectively, so that folding and unfolding operations of the foldable display device 100 can be performed while maintaining left-right synchronization (e.g., synchronization of the hinge assembly 200 and thus of the display device 180 attached to the hinge assembly 200).

[0188] Further, embodiments of the disclosure are characterized in that a 'T'-shaped hinge support 250 is disposed between the first gear arm and the second gear arm of the hinge assembly. By the up / down method (e.g., vertical movement) of the hinge support 250, it is ensured that a relief structure for realizing (e.g., supporting) the bending of the display panel 180 at the time of folding, while the gear arms can be supported, thereby improving the impact resistance performance of the foldable display device 200.

[0189] Further, embodiments of the disclosure are characterized in that the foreign matter entry prevention elements 236a and 236b are inserted between the hinge housing 210 and the inner frame 220 of the hinge assembly.

[0190] The foreign matter entry prevention elements 236a and 236b can include a first foreign matter entry prevention element 236a located at the left side (e.g., the first lateral side) and a second foreign matter entry prevention element 236b located at the right side (e.g., the second lateral side), but the disclosure is not limited thereto.

[0191] For example, in the case of an inner folding method in which a screen unit is disposed inside when the foldable display device is folded, a foreign matter can enter a gap between the hinge housing and the inner frame when the hinge assembly is folded. The entered foreign matter can interfere with the operation of the bevel gears or cams of the hinge assembly, or can cause damage in a serious case.

[0192] In the case of the foregoing structure, it is difficult to control the gap size due to assembly tolerances between the hinge housing and the inner frame, and thus it is vulnerable to foreign matter entry.

[0193] Therefore, embodiments of the disclosure are characterized in that the first foreign matter entry prevention element 236a and the second foreign matter entry prevention element 236b are inserted between the hinge housing 210 and the inner frame 220 of the hinge assembly 200 and operate together with the folding of the first hinge arm 230a and the second hinge arm 230b when the first hinge arm 230a and the second hinge arm 230b are folded, thereby preventing the inward entry of foreign matter after folding.

[0194] The first foreign matter entry prevention element 236a and the second foreign matter entry prevention element 236b are connected to the first hinge arm 230a and the second hinge arm 230b, respectively, and operate together with the folding of the first hinge arm 230a and the second hinge arm 230b when the first hinge arm 230a and the second hinge arm 230b are folded, thereby preventing the inward entry of foreign matter after folding.

[0195] The first foreign matter prevention element 236a and the second foreign matter prevention element 236b can be fastened to the first hinge arm 230a and the second hinge arm 230b, respectively, by a method such as welding, soldering, adhesive bonding, or any other type of bonding, such that the first foreign matter prevention element 236a and the second foreign matter prevention element 236b operate simultaneously with the movement / operation of the first hinge arm 230a and the second hinge arm 230b.

[0196] The first foreign matter prevention element 236a and the second foreign matter prevention element 236b can rotate while sliding along the curvature of the inner side of the hinge housing 210 and the outer side of the inner frame 220. To this end, the first foreign matter prevention element 236a and the second foreign matter prevention element 236b can be formed to have a curvature along the curvature of the outer side of the inner frame 220. For example, the first foreign matter prevention element 236a and the second foreign matter prevention element 236b can have a curvature that matches the curvature of the inner frame 220 to reduce a gap in the foldable display device 100, thereby preventing foreign matter (e.g., dust or other contaminants) from entering the hinge assembly 200 or any other components of the foldable display device 100.

[0197] The centers of rotation of the first foreign matter prevention element 236a and the second foreign matter prevention element 236b coincide with the centers of rotation of the first hinge arm 230a and the second hinge arm 230b, such that they can be folded together (see the dotted line in FIG. 13). Figure 6

[0198] In an embodiment of the disclosure, the inward entry of foreign matter can be prevented by minimizing the gap between the components of the hinge assembly 200 with size management (e.g., size matching, shape matching, etc.).

[0199] Embodiments of the disclosure can also be described as follows:

[0200] According to an aspect of the disclosure, a foldable display device is provided. The foldable display device includes a first support plate and a second support plate, a display panel disposed on the first support plate and the second support plate, and a hinge assembly disposed between the first support plate and the second support plate, the hinge assembly including a hinge arm, a gear arm coupled to the hinge arm, an inner frame arranged below the hinge arm and the gear arm and fixing the hinge arm and the gear arm, a hinge housing accommodating the inner frame, the hinge arm, and the gear arm below the inner frame, and a foreign matter prevention element inserted between the hinge housing and the inner frame and connected to the hinge arm to operate with folding of the hinge arm when the hinge arm is folded.

[0201] The hinge arm can include first and second hinge arms rotatably connected to each other. ​

[0202] The gear arms can include first and second gear arms fastened to interlock with the first and second hinge arms.

[0203] The hinge assembly can include first and second bevel gears coupled to the first and second hinge arms in a vertical direction, respectively.

[0204] The display panel can perform a folding operation and an unfolding operation about a rotation axis different from central axes of the first and second bevel gears.

[0205] The first and second bevel gears can be arranged to mesh with each other, and the first and second bevel gears can include second idler gears meshing with first idler gears of the first and second hinge arms, respectively.

[0206] The first and second idler gears can be disposed in directions perpendicular to each other.

[0207] The first and second hinge arms can rotate with rotation of the first and second gear arms, and can maintain left-right synchronization through the first and second bevel gears connected to the first and second hinge arms, respectively.

[0208] The foldable display apparatus can further include sliding pins protruding toward the first and second hinge arms at end portions of the first and second gear arms, respectively.

[0209] The sliding pins can be slidably moved along sliding spaces provided in the first and second hinge arms facing the first and second gear arms during the folding operation and the unfolding operation.

[0210] The foldable display apparatus can further include a pair of guide pins provided at upper ends of the inner frame and protruding toward the first and second hinge arms, and a pair of housing cover guide rails provided on the first and second hinge arms facing the pair of guide pins, the pair of guide pins being fitted in the pair of housing cover guide rails, wherein the first and second hinge arms are foldable (rotatable) along folding trajectories of the housing cover guide rails while being guided by the pair of guide pins.

[0211] The foreign matter entry prevention elements can include first and second foreign matter entry prevention elements on left and right sides, and the first and second foreign matter entry prevention elements can be separately disposed to be folded independently of each other.

[0212] The first and second foreign matter entry prevention elements can rotate while sliding along curvatures of inner sides of the hinge housing and outer sides of the inner frame.

[0213] The rotation centers of the first foreign matter entry prevention element and the second foreign matter entry prevention element can coincide with the rotation centers of the first hinge arm and the second hinge arm, so that they rotate together.

[0214] The first foreign matter entry prevention element and the second foreign matter entry prevention element can be formed such that the area of the portion in which the first gear arm and the second gear arm are disposed is greater than the area of the portion in which the first hinge arm and the second hinge arm are disposed.

[0215] The first foreign matter entry prevention element and the second foreign matter entry prevention element can have a central portion having a curvature along the curvature of the outer side of the inner frame, so that the inner frame is accommodated therein, and both sides of the first foreign matter entry prevention element and the second foreign matter entry prevention element on which the first gear arm and the second gear arm are disposed can have flat surfaces, so that the first gear arm and the second gear arm are located thereon.

[0216] For example, the various embodiments described herein can be implemented in a computer readable medium using software, hardware, or some combination thereof. For example, embodiments described herein can be implemented within one or more of application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), processors, controllers, micro-controllers, microprocessors, other electronic units designed to perform the functions described herein, or a selective combination thereof. In some cases, such embodiments are implemented by a controller. For example, the controller is a hardware-embedded processor that executes appropriate algorithms (e.g., flowcharts) for performing the described functions, and thus has sufficient structure. Furthermore, embodiments such as processes and functions can be implemented together with separate software modules, each of which performs at least one of the functions and operations. The software code can be implemented with software applications written in any suitable programming language. Furthermore, the software code can be stored in a memory and executed by the controller, thereby making the controller a special-purpose controller that is specially configured to perform the described functions and algorithms. Thus, the components shown in the drawings have sufficient structure to implement appropriate algorithms for performing the described functions.

[0217] Although the embodiments of the present disclosure have been described in detail with reference to the accompanying drawings, the present disclosure is not limited thereto and can be implemented in various forms without departing from the technical concept of the present disclosure. Therefore, the embodiments of the present disclosure are provided only for the purpose of illustration, and are not intended to limit the technical concept of the present disclosure. The scope of the technical concept of the present disclosure is not limited thereto. Therefore, it should be understood that the above-described embodiments are illustrative in all aspects and do not limit the present disclosure. The scope of protection of the present disclosure should be interpreted based on the appended claims and all technical concepts within the equivalent scope thereof should be interpreted as falling within the scope of the present disclosure.

Claims

1. A foldable display apparatus, comprising: a first support plate; a second support plate; a display panel disposed on the first support plate and the second support plate; and a hinge assembly disposed between the first support plate and the second support plate, the hinge assembly comprising: a hinge arm; a gear arm coupled to the hinge arm; an inner frame disposed under the hinge arm and the gear arm and fixed to at least one of the hinge arm and the gear arm; a hinge housing accommodating the inner frame, the hinge arm, and the gear arm; and a foreign matter prevention element inserted between the hinge housing and the inner frame and connected to the hinge arm to operate with movement of the hinge arm, wherein the hinge arm comprises a first hinge arm and a second hinge arm rotatably connected to the first hinge arm, wherein the foreign matter prevention element comprises a first foreign matter prevention element on a first lateral side and a second foreign matter prevention element on a second lateral side, wherein a center of rotation of the first foreign matter prevention element coincides with a center of rotation of the first hinge arm, wherein a center of rotation of the second foreign matter prevention element coincides with a center of rotation of the second hinge arm, and wherein the first foreign matter prevention element and the second foreign matter prevention element rotate while sliding along a curved inner surface of the hinge housing and a curved outer surface of the inner frame. the gear arm comprises: 2.The foldable display apparatus of claim 1, wherein, a first gear arm fastened to the first hinge arm; and a second gear arm fastened to the second hinge arm. the hinge assembly further comprises: 3.The foldable display apparatus of claim 2, wherein, a first bevel gear coupled to the first hinge arm; and a second bevel gear coupled to the second hinge arm. the display panel performs a folding operation and an unfolding operation about a rotation axis different from rotation axes of the first bevel gear and the second bevel gear. 4.The foldable display apparatus of claim 3, wherein, the first bevel gear and the second bevel gear are engaged to synchronize movement of the first hinge arm and the second hinge arm. 5.The foldable display apparatus of claim 3, wherein, 6.The foldable display apparatus of claim 5, each of the first hinge arm and the second hinge arm comprises a first idler gear, wherein, wherein each of the first bevel gear and the second bevel gear comprises a second idler gear, wherein the second idler gear of the first bevel gear is engaged with the first idler gear of the first hinge arm, and wherein the second idler gear of the second bevel gear is engaged with the first idler gear of the second hinge arm. a rotation direction of the second idler gear of the first bevel gear is perpendicular to a rotation direction of the first idler gear of the first hinge arm, and a rotation direction of the second idler gear of the second bevel gear is perpendicular to a rotation direction of the first idler gear of the second hinge arm. 7.The foldable display apparatus of claim 6, wherein, each of the first hinge arm and the second hinge arm comprises a protrusion, and 8.The foldable display apparatus of claim 2, wherein, wherein each protrusion comprises a sliding space. ​ 9.The foldable display apparatus of claim 8, wherein, The first gear arm includes a sliding pin that extends into and slides within a sliding space of the first hinge arm during a folding operation and an unfolding operation of the display panel, and wherein the second gear arm includes a sliding pin that extends into and slides within a sliding space of the second hinge arm during a folding operation and an unfolding operation of the display panel. 10.The foldable display apparatus of claim 2, further comprising: a pair of guide pins disposed at upper ends of the inner frame and protruding toward the first and second hinge arms; and a pair of housing cover guide rails receiving the pair of guide pins and disposed on the first and second hinge arms, wherein the first and second hinge arms rotate along folding trajectories of the respective housing cover guide rails while being guided by the pair of guide pins. The first foreign matter prevention element moves independently of the second foreign matter prevention element. 11.The foldable display apparatus of claim 2, wherein, The first and second foreign matter prevention elements each include a first portion and a second portion, 12.The foldable display apparatus of claim 2, wherein, wherein the first and second gear arms are disposed on the first portions of the respective one of the first and second foreign matter prevention elements, wherein the first and second hinge arms are disposed on the second portions of the respective one of the first and second foreign matter prevention elements, and wherein the first portion is larger than the second portion for each of the first and second foreign matter prevention elements. The first and second foreign matter prevention elements each have a central portion having a curvature accommodating a curved outer surface of the inner frame, and 13.The foldable display apparatus of claim 2, wherein, wherein the first and second foreign matter prevention elements each include a flat surface on which the respective one of the first and second gear arms is seated. 14.A foldable display apparatus comprising: a support plate including a groove formed along a longitudinal axis of the support plate; a display panel disposed in the groove of the support plate; a hinge assembly disposed between the support plate and the display panel and at a lateral center of the support plate, and including: a hinge arm; a gear arm coupled to the hinge arm; an inner frame fixed to the hinge arm and the gear arm; a hinge housing accommodating the inner frame, the hinge arm, and the gear arm; and a foreign matter prevention element disposed between the hinge housing and the inner frame, wherein the hinge arm includes a first hinge arm and a second hinge arm rotatably connected to the first hinge arm, ​ wherein the foreign object prevention element comprises a first foreign object prevention element on a first lateral side and a second foreign object prevention element on a second lateral side, wherein a center of rotation of the first foreign object prevention element coincides with a center of rotation of the first hinge arm, wherein a center of rotation of the second foreign object prevention element coincides with a center of rotation of the second hinge arm; and wherein the first and second foreign object prevention elements rotate while sliding along a curved inner surface of the hinge housing and a curved outer surface of the inner frame.

15. The foldable display device of claim 14, wherein, the hinge assembly further comprising: a first bevel gear coupled to the first hinge arm; and a second bevel gear coupled to the second hinge arm and meshed with the first bevel gear to synchronize movement of the first and second hinge arms. 16.The foldable display apparatus of claim 15, wherein, each of the first and second hinge arms comprises a first idler gear, wherein each of the first and second bevel gears comprises a second idler gear, wherein the second idler gear of the first bevel gear is meshed with the first idler gear of the first hinge arm, and wherein the second idler gear of the second bevel gear is meshed with the first idler gear of the second hinge arm. 17.The foldable display apparatus of claim 14, wherein, each of the first and second foreign object prevention elements has a central portion having a curvature that accommodates a curvature of the curved outer surface of the inner frame.

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