Foldable display device

Abstract

A foldable display device according to an exemplary embodiment of the present invention 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, wherein the 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 respectively coupled to the first hinge arm and the second hinge arm in a vertical direction; and a first gear arm and a second gear arm fastened in a manner interlocking with the first hinge arm and the second hinge arm, wherein the display panel performs folding and unfolding operations about a rotation axis different from the central axis of the first bevel gear and the second bevel gear.

Description

[0001] Cross-reference to related applications

[0002] This application claims the benefit and priority of Korean Patent Application No. 10-2021-0187510, filed in Korea on December 24, 2021, the entire contents of which are expressly incorporated herein by reference. Technical Field

[0003] The present invention relates to a foldable display device, and more specifically, to a foldable display device having a hinge structure that allows inner folding. Background Technology

[0004] Recently, to facilitate portability, the size of portable terminals such as wireless devices, personal digital assistants (PDAs), portable multimedia players (PMPs), and electronic notebooks has been decreasing. However, because users want to receive various information such as text messages, videos, still images, MP3s, and games on the screen of portable terminals, the display unit's screen needs to be larger and of greater size. However, the reduction in the size of portable terminals leads to a reduction in the size of the display screen, thus creating limitations in satisfying both requirements.

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

[0006] Flexible display devices can be realized by forming a substrate of plastic material. Because flexible display devices are easy to carry when folded and can achieve a large screen when unfolded, they can be used in 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 invention have developed a structure in which a mechanism including a hinge 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 invention recognize that when only a 4-axis gear is used to realize the folding hinge, it is not feasible to manufacture a set with a small thickness, or to achieve a small thickness, the gear size becomes smaller, and durability may be compromised.

[0008] Therefore, the inventors of this invention have invented a foldable display device having a novel hinge structure that forms a folding trajectory based on a dual-axis rotation structure. Furthermore, the inventors of this invention have invented a novel hinge structure for a foldable display device having a link slider for achieving synchronization between the axes during dual-axis rotation and two bevel gears. In particular, in the foldable display device of this invention, the thickness of the foldable display device can be minimized by using two bevel gears instead of four conventionally sized ones.

[0009] Therefore, one aspect of the present invention is to provide a foldable display device having a hinge structure that allows for internal folding and ensures durability without increasing the thickness of the foldable display device.

[0010] Furthermore, the inventors of this invention recognized that friction between the components constituting the hinge can generate a holding force for maintaining a specific folding angle of the foldable display device during folding and unfolding operations. However, the inventors of this invention also recognized that the holding force for maintaining a specific folding angle of the foldable display device decreases due to continuous folding and unfolding operations. Furthermore, the inventors of this invention recognized that, unlike foldable telephones, foldable display devices are heavier and therefore require a higher holding force.

[0011] Therefore, the inventors of this invention have developed a novel structure for a foldable display device that achieves holding torque and free stop functions by employing a cam structure including a compression spring, thereby enabling the foldable display device to maintain a specific folding angle.

[0012] Therefore, another aspect of the present invention is to provide a foldable display device with a novel structure, wherein the holding force can be permanently achieved even when the foldable display device is used continuously without reducing the holding force, and a high holding force can be achieved even when the foldable display device is heavy.

[0013] Furthermore, the inventors of this invention recognized that an escape structure is needed to achieve the curvature of the display panel when the hinge is folded, and that the escape structure would degrade the impact resistance.

[0014] Therefore, another aspect of the present invention is to provide a foldable display device that has improved impact resistance while ensuring escape space for the curvature of the display panel when folded.

[0015] Another aspect of the present invention is to provide a foldable display device that has improved usability by using magnetic force to remove the space between the display panel and the hinge support.

[0016] The purpose of this invention is not limited to the above-described purpose, and other purposes not mentioned above will be clearly understood by those skilled in the art based on the following description.

[0017] A foldable display device according to an exemplary embodiment of the present invention 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, wherein the 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 respectively coupled to the first hinge arm and the second hinge arm in the vertical direction; and a first gear arm and a second gear arm fastened in a manner interlocked with the first hinge arm and the second hinge arm, wherein the display panel is capable of performing folding and unfolding operations about a rotation axis different from the central axis of the first bevel gear and the second bevel gear.

[0018] Further details of the exemplary embodiments are included in the detailed description and accompanying drawings.

[0019] According to the present invention, the impact resistance and durability of the foldable display device can be improved without increasing the thickness of the foldable display device.

[0020] According to the present invention, a holding force can be achieved to maintain a specific folding angle of the foldable display device.

[0021] According to the present invention, by improving the components of the hinge assembly, the durability of the foldable display device can be improved without increasing the cost, and folding reliability can be ensured.

[0022] According to the present invention, by fixing the display panel during folding, reverse folding can be prevented, usability can be improved and the occurrence of wrinkles can be minimized.

[0023] The effects of the present invention are not limited to those illustrated above; many more effects are included in this application. Attached Figure Description

[0024] Figure 1 This is a perspective view of a foldable display device according to a first exemplary embodiment of the present invention.

[0025] Figure 2 This is a schematic exploded perspective view of a foldable display device according to a first exemplary embodiment of the present invention.

[0026] Figure 3 This is a perspective view illustrating a portion of the structure of a foldable display device according to a first exemplary embodiment of the present invention.

[0027] Figure 4This is an exploded perspective view of a hinge assembly according to a first exemplary embodiment of the present invention.

[0028] Figure 5A This is a perspective view of a hinge assembly according to a first exemplary embodiment of the present invention.

[0029] Figure 5B yes Figure 5A A magnified view of part A.

[0030] Figure 6A This is a plan view of a hinge assembly according to a first exemplary embodiment of the present invention.

[0031] Figure 6B It is along Figure 6A The sectional view taken by line B-B'.

[0032] Figure 7A It is a perspective view illustrating the unfolded state of the hinged assembly.

[0033] Figure 7B It is a perspective view illustrating the folded state of the hinged assembly.

[0034] Figure 8A This is another perspective view illustrating the unfolded state of the hinged assembly.

[0035] Figure 8B yes Figure 8A A magnified view of a portion of it.

[0036] Figure 9A This is a cut-away perspective view illustrating the unfolded state of a foldable display device according to a first exemplary embodiment of the present invention.

[0037] Figure 9B This is a cross-sectional perspective view illustrating the folded state of a foldable display device according to a first exemplary embodiment of the present invention.

[0038] Figure 10 This is a perspective view illustrating a portion of the construction of a hinge assembly according to a first exemplary embodiment of the present invention.

[0039] Figure 11A and 11B It is along Figure 3 A sectional view taken by line A-A'.

[0040] Figure 12 This is a plan view of a hinge assembly according to a second exemplary embodiment of the present invention.

[0041] Figure 13 It is along Figure 12 A sectional view taken by line C-C'. Detailed Implementation

[0042] The advantages and features of the present invention, and the methods for achieving these advantages and features, are described below with reference to the appendix. Figure 1 The exemplary embodiments described in detail will become clear. However, the invention is not limited to the exemplary embodiments disclosed herein, but will be implemented in various forms. Exemplary embodiments are provided by way of example only to enable those skilled in the art to fully understand the disclosure and scope of the invention. Therefore, the invention will be limited only by the scope of the appended claims.

[0043] The shapes, dimensions, proportions, angles, quantities, etc., shown in the accompanying drawings for the purpose of describing exemplary embodiments of the invention are merely examples, and the invention is not limited thereto. Similar reference numerals denote similar elements throughout the application. Furthermore, in the following description of the invention, detailed explanations of known related technologies may be omitted to avoid unnecessarily obscuring the subject matter of the invention. Terms such as “comprising,” “having,” and “including” as used herein are generally intended to allow for the addition of additional components, unless these terms are used in conjunction with the term “only.”

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

[0045] When using terms such as “on top of,” “above,” “below,” and “after” to describe the positional relationship between two parts, one or more parts may be placed between the two parts, unless these terms are used with the terms “immediately following” or “directly.”

[0046] When an element or layer is disposed "on" another element or layer, the element or layer may be disposed directly on the other element or layer or other layers or elements may be inserted between them.

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

[0048] The same reference numerals generally denote the same elements throughout the application.

[0049] For ease of illustration, the dimensions and thickness of each component shown in the accompanying drawings are illustrated. However, the invention is not limited to the dimensions and thickness of the illustrated components.

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

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

[0052] Figure 1 This is a perspective view of a foldable display device according to a first exemplary embodiment of the present invention.

[0053] Figure 2 This is a schematic exploded perspective view of a foldable display device according to a first exemplary embodiment of the present invention.

[0054] Figure 3 This is a perspective view illustrating a portion of the structure of a foldable display device according to a first exemplary embodiment of the present invention.

[0055] Figure 3 It shows Figure 1 The components in the foldable display device 100 according to the first exemplary embodiment of the present invention, excluding the display panel 180 and the bezel covers 130 and 140.

[0056] Reference Figures 1 to 3 According to a first exemplary embodiment of the present invention, the foldable display device 100 may be configured to include: set housings 110 and 120; set frames 150, 151, 160 and 161; hinge assembly 200; display panel 180; and bezel covers 130 and 140.

[0057] The foldable display device 100 according to a first exemplary embodiment of the present invention may further include a hinge support portion 250 and support covers 171 and 172 disposed in the hinge assembly 200.

[0058] exist Figure 1 For ease of explanation, the components of the foldable display device 100 are briefly illustrated, but in reality, it may further include various components for driving the foldable display device 100.

[0059] The housings 110 and 120 can be positioned below the display panel 180, the hinge assembly 200, and the frame assembly (150, 151, 160, and 161).

[0060] The housing 110 and 120 is a set of outer covers and may include a first cover 110 located on the left and a second cover 120 located on the right, but the invention is not limited thereto.

[0061] The first cover 110 and the second cover 120 may be disposed in one region and another region of the foldable display device 100 according to a first exemplary embodiment of the present invention. In the foldable display device 100 according to the first exemplary embodiment of the present invention, the folding operation and the unfolding operation are performed by an external force applied by the user based on the boundary region between the first cover 110 and the second cover 120.

[0062] The first cover 110 and the second cover 120 can be configured to have the same shape.

[0063] The sets of frames 150, 151, 160 and 161 are a set of built-in frames on which various hardware components of the foldable display device 100 can be installed and the display panel 180 can be placed.

[0064] Therefore, the complete frame set 150, 151, 160 and 161 may include a first support plate 150 located on the left side, a second support plate 160 located on the right side, a first frame 151 located on the left side and a second frame 161 located on the right side, but the present invention is not limited thereto.

[0065] The first support plate 150 and the second support plate 160 can be detachably configured to fold independently of each other, and the hinge assembly 200 can be disposed between the first support plate 150 and the second support plate 160.

[0066] Support covers 171 and 172 are disposed on the upper part of the hinge assembly 200 located between the first support plate 150 and the second support plate 160 to cover the center of the hinge assembly 200, but the invention is not limited thereto.

[0067] Support covers 171 and 172 may include a first support cover 171 located on the left and a second support cover 172 located on the right, but the invention is not limited thereto.

[0068] The first frame 151 and the second frame 161 can be detachably configured to fold independently of each other.

[0069] Furthermore, the first support cover 171 and the second support cover 172 are detachably configured to fold independently of each other.

[0070] The first frame 151 and the second frame 161 can respectively surround and fix the edges of the first side cover 130 and the first support plate 150, as well as the edges of the second side cover 140 and the second support plate 160.

[0071] In this case, the first support plate 150 and the second support plate 160 may include a first fastening unit and a second fastening unit respectively coupled to the hinge assembly 200.

[0072] The first support plate 150 and the second support plate 160 may be configured to have the same shape, and the first fastening unit and the second fastening unit may be configured to face each other and be symmetrical.

[0073] Although not shown in detail, multiple fastening grooves are formed in the first fastening unit and the second fastening unit, and multiple fastening grooves are formed in a corresponding surface of the hinge assembly 200 facing the hinge arm 230, so that the hinge assembly 200 can be secured by predetermined fastening elements.

[0074] The slot may be formed in the fold between the first support plate 150 and the second support plate 160, and the hinge housing of the hinge assembly 200 may be inserted into the slot.

[0075] A feature of the foldable display device 100 according to a first exemplary embodiment of the present invention is that it is implemented in an internal folding manner when folded, with the screen unit disposed inside.

[0076] Meanwhile, the first support plate 150 and the second support plate 160 can serve as basic components for supporting the display panel 180 and various parts of the foldable display device 100. Furthermore, the first support plate 150 and the second support plate 160 can accommodate various components for driving the foldable display device 100.

[0077] According to a first exemplary embodiment of the present invention, a first support plate 150 and a second support plate 160 may be disposed in one region and another region for folding and unfolding the foldable display device 100. That is, the foldable display device 100 may be folded and unfolded by an external force applied by a user based on the boundary region between the first support plate 150 and the second support plate 160.

[0078] The hinge arm 230 can connect to a first fastening unit of the first support plate 150 and a second fastening unit of the second support plate 160. In this case, one or more hinge arms 230 of the hinge assembly 200 can be provided as needed. Figure 2 The image shows a pair of hinge arms 230 disposed on one side and the other side of the hinge assembly 200, but the invention is not limited thereto.

[0079] Specifically, a pair of hinged arms 230 can connect one side and the other side of the first fastening unit and the second fastening unit, respectively.

[0080] As described above, the hinge assembly 200 can be disposed at the portion of the foldable display device in which it is folded and unfolded, thereby facilitating the folding and unfolding operations of the foldable display device 100. Furthermore, the hinge assembly 200 can provide a predetermined holding force to hold the foldable display device 100 in a folded state at a specific angle. In this case, the holding force of the hinge assembly 200 can be provided from a cam structure including a compression spring. (See below for further details.) Figures 4 to 11A Sections 11B and 11B describe the specific structure and function of the hinge assembly 200.

[0081] The display panel 180 can be disposed on one surface of the first support plate 150 and the second support plate 160. The display panel 180 can be one of various display panels, such as an organic light-emitting display panel or a liquid crystal display panel.

[0082] Although not shown in the figures, the display panel 180 is a component for displaying images to a user and may include multiple sub-pixels. In the display panel 180, multiple scan lines and multiple data lines intersect each other, and each of the multiple sub-pixels can be connected to the scan lines and data lines. Furthermore, each of the multiple sub-pixels can be connected to a high-potential power line, a low-potential power line, an initialization signal line, a light emission control signal line, etc.

[0083] A subpixel is the smallest unit constituting a screen, and each of a plurality of subpixels may include a light-emitting element and pixel circuitry for driving the light-emitting element. The plurality of light-emitting elements may be defined differently depending on the type of display panel 180. For example, when display panel 180 is an organic light-emitting display panel, the light-emitting element may be an organic light-emitting element comprising an anode, a light-emitting unit, and a cathode. In the following description, it is assumed that the light-emitting element is an organic light-emitting element, but the type of light-emitting element is not limited thereto.

[0084] A pixel circuit is a circuit used to control the driving of a light-emitting element. A single pixel circuit may include, for example, multiple transistors and capacitors, but is not limited to these.

[0085] In addition, the display panel 180 may be flexible, so that it can be folded and unfolded as the foldable display device 100 is folded and unfolded.

[0086] The foldable display device 100 can be folded, thereby forming a specific folding angle between the first support plate 150 and the second support plate 160. That is, in... Figure 1 and Figure 2The diagram shows the first support plate 150 and the second support plate 160 fully extended to an angle of, for example, 180°, but the foldable display device 100 can be folded at a specific 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 specific angle as the first support plate 150 and the second support plate 160 are folded.

[0087] Furthermore, the foldable display device 100 can maintain a specific folding angle through the holding force provided by the hinge assembly 200. That is, the first support plate 150 and the second support plate 160 can be fixed by the hinge assembly 200 while maintaining a specific folding angle. Therefore, the foldable display device 100 can be folded at a specific angle according to the user's intention, and can be maintained at a specific angle by the holding force of the hinge assembly 200.

[0088] Bezel covers 130 and 140 can cover the upper bezel of the display panel 180 on the upper surface of the display panel 180.

[0089] The frame covers 130 and 140 may include a first frame cover 130 located on the left and a second frame cover 140 located on the right, but the invention is not limited thereto.

[0090] Meanwhile, a feature of the first exemplary embodiment of the present invention is that a T-shaped hinge support 250 is disposed between a pair of gear arms of the hinge assembly 200. In particular, by means of up / down movement of the hinge support 250 when the display panel 180 is unfolded / folded, an escape structure for realizing the curvature of the display panel 180 when folded is ensured, and at the same time, the gear arms can be supported, thereby improving impact resistance.

[0091] In the following text, reference will be made to Figures 4 to 11A and Figure 11B The specific structure and function of the hinge assembly 200, including the hinge support 250, are described in detail.

[0092] Figure 4 This is an exploded perspective view of a hinge assembly according to a first exemplary embodiment of the present invention.

[0093] Figure 5A This is a perspective view of a hinge assembly according to a first exemplary embodiment of the present invention.

[0094] Figure 5B yes Figure 5A A magnified view of part A.

[0095] Figure 6A This is a plan view of a hinge assembly according to a first exemplary embodiment of the present invention.

[0096] Figure 6B It is along Figure 6A The sectional view taken by line B-B'.

[0097] exist Figure 4 In the diagram, the gear arm 240 is omitted from the upper left and the hinge arm 230 is omitted from the upper right to show the internal structure.

[0098] In addition, Figure 5B The second hinge arm 230b is omitted from the illustration to show a pair of bevel gears 241a and 241b.

[0099] Reference Figures 4 to 6A and Figure 6B According to a first exemplary embodiment of the present invention, the hinge assembly 200 may be configured to include a hinge housing 210, a pair of hinge arms 230 and an inner frame 220.

[0100] Furthermore, although not shown, the hinge assembly 200 according to the first exemplary embodiment of the present invention may further include an upper hinge arm cover and a lower hinge arm cover fastened to the upper and lower parts of the hinge arm 230, but the present invention is not limited thereto.

[0101] The hinge assembly 200 includes a pair of hinge arms 230 located on one side thereof, the pair of hinge arms 230 being rotatably connected to each other. That is, the hinge arms 230 may include a first hinge arm 230a and a second hinge arm 230b having a symmetrical structure, but the invention is not limited thereto.

[0102] The first hinge arm 230a and the second hinge arm 230b may have a structure that is symmetrical to each other.

[0103] A feature of the hinge arm 230 according to a first exemplary embodiment of the present invention is that it has a dual-axis folding (rotation) structure. That is, when using a 4-axis gear to implement the folding hinge, it is not feasible to manufacture a configuration with a small thickness, or to achieve a smaller thickness, the gear size becomes smaller, which may compromise durability. Therefore, a feature of the present invention is that the foldable display device 100 has a folding trajectory (or folding path, folding trace) formed based on a dual-axis rotation structure (by... Figure 6A The invention features a novel hinge structure (represented by the dashed line). Specifically, a characteristic of the invention is that the foldable display device 100 has a dual-axis folding hinge structure that allows folding in the inner direction within the foldable product. Furthermore, a characteristic of the invention is that the novel hinge structure of the foldable display device 100 includes a link slider structure for synchronizing between the axes during dual-axis rotation and two bevel gears 241. The hinge arm 230 is a dual-axis folding rod and may be referred to as a lever wing.

[0104] The bevel gear 241 can be a gear used to synchronize the articulated arm 230 for dual-axis folding. Therefore, the bevel gear 241 can be referred to as a synchronizing gear.

[0105] The bevel gear 241 may include a first bevel gear 241a coupled to the first hinge arm 230a in the vertical direction and a second bevel gear 241b coupled to the second hinge arm 230b.

[0106] The first bevel gear 241a and the second bevel gear 241b may have virtual axes different from the rotation axis A, which is the actual axis. That is, the first bevel gear 241a and the second bevel gear 241b may have virtual axes that are substantially perpendicular to the rotation axis A. The display panel 180 may perform folding and unfolding operations about rotation axes different from the central axes of the first bevel gear 241a and the second bevel gear 241b.

[0107] Each of the first tooth portion and the second tooth portion formed in the first bevel gear 241a and the second bevel gear 241b may be formed only in a portion of the periphery, but the invention is not limited thereto.

[0108] The first bevel gear 241a and the second bevel gear 241b may be configured to mesh with each other. However, the present invention is not limited thereto; the first bevel gear 241a and the second bevel gear 241b may mesh with the first rotating gear and the second rotating gear respectively, and the first rotating gear and the second rotating gear may be configured to mesh with each other.

[0109] The left and right synchronization can be maintained by the two synchronizing gears 241 of the present invention, namely the first bevel gear 241a and the second bevel gear 241b.

[0110] The first bevel gear 241a and the second bevel gear 241b may include a second idle gear that meshes with the first idle gear of the corresponding first hinge arm 230a and the second hinge arm 230b, so as to convert and transmit rotation of each of the first hinge arm 230a and the second hinge arm 230b in the vertical direction.

[0111] In this configuration, the first and second idler gears can be positioned in a substantially vertical direction to allow for rotational switching in the vertical direction. Specifically, each of the first bevel gear 241a and the second bevel gear 241b is rotatably fastened to the first idler gear of each of the first hinge arm 230a and the second hinge arm 230b via the second idler gear. Simultaneously, 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, thereby enabling the folding and unfolding operations of the foldable display device 100 to be performed while maintaining left-right synchronization.

[0112] Sliding pins 242 protruding toward the first hinge arm 230a and the second hinge arm 230b are respectively provided at the ends of the first gear arm 240a and the second gear arm 240b (see...). Figure 8A Furthermore, a sliding space 239 may 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. For example, the protrusion 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 may include the sliding space 239, wherein the sliding pin 242 is slidably moved via the sliding space 239. Therefore, during the folding or unfolding operation of the foldable display device 100, the sliding pin 242 moves within the sliding space 239, and the first gear arm 240a and the second gear arm 240b can rotate in coordination with the rotation of the first hinge arm 230a and the second hinge arm 230b. (See below for further details.) Figure 8A and 8B as well as Figure 9A and 9B Provide a detailed description.

[0113] Meanwhile, the gear arm 240 is rotatably fastened to the shaft 233.

[0114] The gear arm 240 can be referred to as a dual-axis folding brake (detents) and also as a lever brake (leverdetents).

[0115] In other words, 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 in a manner that interlocks with the first gear arm 240a and the second gear arm 240b respectively, or in other words, the first gear arm 240a and the second gear arm 240b can be fastened in a manner that interlocks with the first hinge arm 230a and the second hinge arm 230b respectively.

[0116] The gear arm 240 can be a connection structure to the dual-axis hinge arm 230. That is, 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. Therefore, during the folding or 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.

[0117] Therefore, 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.

[0118] The shaft portion 233 can form a frame for mounting and assembling the cam 245.

[0119] A compression spring 260 for generating the frictional force of the cam 245 may be disposed on the outer surface of the shaft portion 233 located between the gear arm 240 (first gear arm 240a and second gear arm 240b) and the cam 245.

[0120] On the gear arm 240, which is fastened to the outer surface of the shaft portion 233, a second brake 246 may be provided for maintaining the folding and unfolding angles of the articulated arm 230 and the gear arm 240 together with a plurality of cams 245. Therefore, the cams 245 may be components for achieving the folding and unfolding torque of the articulated arm 230. The cams 245 may also be referred to as sliding cams.

[0121] Meanwhile, a predetermined hinge housing 210 for accommodating the inner frame 220, hinge arm 230 and gear arm 240 may be provided in the lower part of the hinge assembly 200.

[0122] The hinge housing 210 is the outer cover of the hinge assembly 200, having a predetermined length and having space therein to accommodate the inner frame 220, the hinge arm 230, and the gear arm 240. The hinge housing 210 may also be referred to as the hinge cover.

[0123] The inner frame 220 may be a frame for securing the interior of the hinge assembly 200. The inner frame 220 may include a plurality of fastening grooves (not shown) and through grooves (not shown). The inner frame 230 is an outer cover for accommodating a pair of first bevel gears 241a and second bevel gears 241b, and may also be referred to as a housing cover.

[0124] Furthermore, a fixing member 211 facing the fastening groove of the inner frame 220 is formed in the hinged 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 fixed and fastened to the fastening groove by a fastening member such as a screw.

[0125] The hinged housing 210 may have a predetermined size so that the internal frame 220, the hinge arm 230 and the gear arm 240 can be accommodated in the space of the hinged housing 210.

[0126] Meanwhile, the distance between the rotation centers of the pair of shaft portions 233 can be made greater than the distance D between the rotation axes A, which serve as the rotation centers of the pair of hinged arms 230. The first gear arm 240a and the second gear arm 240b are rotatably coupled to the pair of shaft portions 233.

[0127] In this configuration, a pair of virtual axes passing through the center of a pair of shaft portions 233 can serve as a central axis, wherein the components constituting the hinged housing 210 are coupled to the central axis. The pair of virtual axes can be configured to correspond to the first cover 110 and the second cover 120, respectively.

[0128] The axial height H may exist between the folded portion (where the first hinge arm 230a and the second hinge arm 230b are in contact with the display panel 180) and the rotation axis A, but the present invention is not limited thereto.

[0129] Meanwhile, as described above, a feature of the first exemplary embodiment of the present invention is that a T-shaped hinge support portion 250 is disposed between the first gear arm 240a and the second gear arm 240b of the hinge assembly 200. By means of up / down movement of the hinge support portion 250 during the unfolding / folding of the display panel 180, an escape structure for realizing the curvature of the display panel 180 during folding is ensured, and simultaneously, the first gear arm 240a and the second gear arm 240b are supported, thereby improving impact resistance.

[0130] The hinged support 250 can be disposed in the inner frame 220 in the longitudinal direction (length direction) of the inner frame 220 located between the first gear arm 240a and the second gear arm 240b.

[0131] The hinged support 250 may be T-shaped, with its upper end protruding in a direction perpendicular to the longitudinal direction.

[0132] The hinged support 250 may have an empty internal space, but is not limited thereto.

[0133] Furthermore, as described above, a feature of the present invention is that it has two bevel gears 241a and 241b for achieving synchronization between the shafts during dual-axis rotation, and a linking slider structure, which will be referred to... Figure 7A and 7B to Figure 9A and Figure 9B Provide a detailed description.

[0134] Figure 7A It is a perspective view illustrating the unfolded state of the hinged assembly.

[0135] Figure 7B It is a perspective view illustrating the folded state of the hinged assembly.

[0136] Figure 8A This is another perspective view illustrating the unfolded state of the hinged assembly.

[0137] Figure 8B yes Figure 8A A magnified view of a portion of it.

[0138] Figure 9AThis is a cross-sectional perspective view illustrating the unfolded state of a foldable display device according to a first exemplary embodiment of the present invention.

[0139] Figure 9B This is a cross-sectional perspective view illustrating the folded state of a foldable display device according to a first exemplary embodiment of the present invention.

[0140] Figure 8A and 8B As an example, along Figure 6A A cross-sectional perspective view of the hinge assembly taken by line B-B'.

[0141] For ease of explanation, Figure 7A and 7B as well as Figure 8A and 8B This shows a portion of the hinge assembly with the hinge housing removed.

[0142] For ease of explanation, Figure 9A and 9B The specific unfolded and folded states of the foldable display device with the display panel and bezel cover omitted are shown respectively.

[0143] Reference Figure 7A and 7B to Figure 9A and 9B The housings 110 and 120 may be located below the hinge assembly and the housing frames 150 and 160.

[0144] As described above, the complete frame may include a first support plate 150 located on the left side, a second support plate 160 located on the right side, a first frame located on the left side, and a second frame located on the right side, but the present invention is not limited thereto.

[0145] The first support plate 150 and the second support plate 160 can be detachably configured to fold independently of each other, and a hinge assembly can be disposed between the first support plate 150 and the second support plate 160.

[0146] The foldable display device according to the first exemplary embodiment of the present invention can be implemented in an internal folding manner in which the screen unit is disposed inside when folded.

[0147] Furthermore, according to the first exemplary embodiment of the present invention, the first support plate 150 and the second support plate 160 may be disposed in one region and another region for folding and unfolding of the foldable display device.

[0148] The hinge assembly may include a hinge housing 210, a first hinge arm 230a and a second hinge arm 230b, and an inner frame 220.

[0149] Furthermore, the hinge assembly according to the first exemplary embodiment of the present invention may further include an upper hinge arm cover and a lower hinge arm cover fastened to the upper and lower portions of the first hinge arm 230a and the second hinge arm 230b.

[0150] The hinge assembly may include a pair of hinge arms 230a and 230b, which may include a first hinge arm 230a and a second hinge arm 230b that are symmetrical to each other.

[0151] A feature of the first hinge arm 230a and the second hinge arm 230b according to a first exemplary embodiment of the present invention is that they have a dual-axis folding (rotation) structure.

[0152] In this configuration, the first hinge arm 230a and the second hinge arm 230b can follow the folding trajectory of the housing cover rail 235 (see...). Figure 7B The arrow) folds (rotates).

[0153] That is, a pair of guide pins 234 protruding toward the first hinge arm 230a and the second hinge arm 230b located on the inner side may be provided at the upper end of the inner frame 220, and a pair of outer cover tracks 235, in which the pair of guide pins 234 are mounted, may be provided on the first hinge arm 230a and the second hinge arm 230b facing the pair of guide pins 234, but the present invention is not limited thereto. Therefore, the first hinge arm 230a and the second hinge arm 230b can be folded or rotated along the folding trajectory of the outer cover track 235 while being guided by the pair of guide pins 234.

[0154] Furthermore, a feature of the first exemplary embodiment of the present invention is that it has a link slider structure for achieving synchronization between the axes during dual-axis rotation, and two bevel gears 241a and 241b.

[0155] In particular, in the foldable display device of the present invention, the thickness of the foldable display device can be minimized by using two bevel gears instead of four ordinary gears.

[0156] In other words, when adjusting left and right synchronization using four ordinary gears, the thickness of the hinge assembly can be increased compared to the thickness of the four vertically arranged gears. In contrast, in the first exemplary embodiment of the present invention, by adjusting the left and right synchronization with the two bevel gears 241a and 241b, the thickness and weight of the hinge assembly can be reduced. Furthermore, folding with a smaller R value (R representing any curvature) than existing housings can be achieved.

[0157] 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.

[0158] The first bevel gear 241a and the second bevel gear 241b may have virtual axes that are different from the rotation axis A, which is the actual axis. That is, the first bevel gear 241a and the second bevel gear 241b may have virtual axes that are substantially perpendicular to the rotation axis A.

[0159] Each of the first tooth portion and the second tooth portion formed in the first bevel gear 241a and the second bevel gear 241b may be formed only in a portion of the periphery, but the invention is not limited thereto.

[0160] The first bevel gear 241a and the second bevel gear 241b may be configured to mesh with each other. However, the present invention is not limited thereto; the first bevel gear 241a and the second bevel gear 241b may mesh with the first rotating gear and the second rotating gear respectively, and the first rotating gear and the second rotating gear may be configured to mesh with each other.

[0161] The first bevel gear 241a and the second bevel gear 241b may include a second idler gear 232b that meshes with a first idler gear 232a of the corresponding first hinge arm 230a and second hinge arm 230b, so as to convert and transmit rotation of each of the first hinge arm 230a and the second hinge arm 230b in the vertical direction (see reference). Figure 8A and 8B ).

[0162] In this configuration, the first idler gear 232a and the second idler gear 232b can be positioned substantially perpendicular to each other to allow for rotational switching in the vertical direction. Specifically, 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, via the second idler gear. 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, thereby enabling the folding and unfolding operations of the foldable display device 100 to be performed while maintaining left-right synchronization.

[0163] In other words, 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 rotate in the horizontal direction, thereby adjusting synchronization.

[0164] Meanwhile, the rotation axis A of the first hinge arm 230a and the second hinge arm 230b may be different from the pair of virtual axes passing through the pair of shaft portions 233. That is, the rotation axis A around which the first hinge arm 230a and the second hinge arm 230b are folded / unfolded does not coincide with the virtual axis around which the first gear arm 240a and the second gear arm 240b are folded / unfolded, and they can be connected to the link slider structure, thereby interlocking with each other.

[0165] Therefore, the virtual axis around which the first gear arm 240a and the second gear arm 240b fold / unfold is the central axis of the shaft portion 233, and the rotation axis A around which the first hinge arm 230 and the second hinge arm 230b fold / unfold is the central axis of the outer cover track 235. The two different folding / unfolding axes can be connected to the link slider structure, thereby interlocking with each other.

[0166] In other words, a feature of the first exemplary embodiment of the present invention is that two first bevel gears 241a and second bevel gears 241b are provided to achieve synchronization between the shafts during dual-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.

[0167] In other words, at the ends 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, respectively. A sliding space 239 in which the sliding pin 242 is movable 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. Therefore, during the folding or unfolding operation of the foldable display device, the sliding pin 242 moves in the sliding space 239, and the first gear arm 240a and the second gear arm 240b can rotate (fold / unfold) in coordination with the rotation (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 the second bevel gear 241b and the connecting slider structure.

[0168] In this case, the sliding space 239 may be provided in the protrusions 238 of the first hinge arm 230a and the second hinge arm 230b, but the present invention is not limited thereto.

[0169] Meanwhile, a feature of the present invention is that the retaining force is achieved by utilizing the frictional force between the components constituting the hinge, so as to maintain a specific retaining angle of the foldable display device during folding and unfolding operations.

[0170] In other words, the hinge assembly according to the invention can be disposed at the folding and unfolding portions of the foldable display device to facilitate the folding and unfolding operations of the foldable display device. Furthermore, the hinge assembly according to the invention provides a holding force for maintaining the foldable display device in a folded state at a specific angle.

[0171] As described above, the display panel can be disposed 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. Furthermore, the display panel can be flexible so that it can be folded and unfolded in conjunction with the folding and unfolding of the foldable display device.

[0172] The foldable display device can be folded such that the first support plate 150 and the second support plate 160 form a specific folding angle. That is, although the illustration shows the first support plate 150 and the second support plate 160 fully unfolded to have an angle of, for example, 180° (e.g., ...). Figure 9A (as shown), but the foldable display device can be folded at a specific angle. That is to say, in... Figure 9B The illustration shows the first support plate 150 and the second support plate 160 in a folded state with an angle of, for example, 90°, but the invention is not limited thereto. In this case, the display panel disposed on the first support plate 150 and the second support plate 160 can also be folded together with the folding of the first support plate 150 and the second support plate 160.

[0173] The foldable display device can be folded at a specific angle according to the user's intention. Furthermore, the foldable display device can be completely folded or unfolded according to the user's intention. The foldable display device can be folded inwards (or folded to the inside), folded or unfolded so that the display panel is positioned on its inner side; and it can be folded outwards, folded or unfolded so that the display panel is positioned on its outer side.

[0174] The foldable display device can maintain a specific folding angle through a holding force provided by the hinge assembly. In other words, the first support plate 150 and the second support plate 160 can be fixed to a state in which they are maintained at a specific folding angle by the hinge assembly. Therefore, the foldable 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 through the holding force of the hinge assembly.

[0175] In particular, a feature of the present invention is that a holding torque and free stop function are achieved by employing a structure of a cam 245 including a compression spring 260, thereby maintaining a specific folding angle of the foldable display device, as referred to Figure 10 This will be explained in detail.

[0176] Figure 10 This is a perspective view illustrating a portion of the structure of the hinge assembly according to a first exemplary embodiment of the present invention.

[0177] Figure 10 As an example, a partial construction of the hinge assembly, including a compression spring 260 and a cam 245, is shown.

[0178] Reference Figure 10In this invention, torque can be achieved through the cam structure of the first gear arm 240a, the second gear arm 240b and the cam 245, as well as the compression force of the compression spring 260.

[0179] In other words, the torque holding and free stop functions can be achieved during opening or closing rotation by using a compression spring 260 and a cam structure.

[0180] Specifically, the hinge assembly of the present invention may include a pair of cam structures serving as a free-stop hinge portion, for example, formed by a first cam structure of cam 245 and a second cam structure of a first gear arm 240a and a second gear arm 240b.

[0181] In this context, a free-stop hinge refers to a hinge that does not provide a stopping force at 180 degrees during the opening and closing operation of the foldable display device, and also refers to a foldable display device that does not receive a stopping force from the hinge except at 0 degrees and 360 degrees.

[0182] The first and second cam structures can be configured as rotating cams. However, the invention is not limited thereto; one of the cam structures in 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. The first and second cam structures can support the stopped state of the foldable display device while performing cam operations using cam surfaces facing each other. The cam operation provides a force to the compression spring 260 for close contact with each other, and can be achieved through the rotational and / or sliding cam operations of the first and second cam structures.

[0183] The first cam structure used in the articulated assembly according to the first exemplary embodiment of the present invention is configured to include a cam 245 comprising a body 245a and a first brake 245b disposed on a surface of the body 245a, and the second cam structure may include a second brake 246 disposed on a surface of the first gear arm 240a and the second gear arm 240b.

[0184] At the center of the body 245a of the cam 245, a first hinge hole for inserting the shaft portion 233 can be formed in the axial direction of the shaft portion 233.

[0185] Furthermore, at the center of the first gear arm 240a and the second gear arm 240b, a second hinge hole for inserting the shaft portion 233 can be formed in the axial direction of the shaft portion 233.

[0186] The first brake 245b may have a mountain-shaped protrusion and may protrude from the body 245a in a direction toward the first gear arm 240a and the second gear arm 240b. The second brake 246 may have a mountain-shaped protrusion and may protrude from the first gear arm 240a and the second gear arm 240b toward the cam 245. The mountain shape indicates a sliding surface with an ascending slope, a descending slope, and a flat sliding surface. However, the invention is not limited thereto.

[0187] A plurality of first brakes 245b may be arranged at predetermined intervals relative to the first hinge hole. A plurality of second brakes 246 may be arranged at predetermined intervals relative to the second hinge hole. The plurality of first brakes 245b and the plurality of second brakes 246 may be arranged in positions facing each other.

[0188] Meanwhile, the cam structure of the present invention allows for an increase in the number of first cam structures and second cam structures in order to increase torque.

[0189] In other words, a feature of the present invention is that the first cam structure and the second cam structure are configured to have a quantity of 2×3. Therefore, sufficient frictional torque can be ensured even through a small portion of the hinge assembly with a relatively thin thickness.

[0190] As described above, by employing a 2×3 cam structure, the leaf spring used for assisting in free stopping is eliminated, thereby preventing dust accumulation on the leaf spring and preventing multiple parts from breaking. Therefore, folding reliability is ensured.

[0191] Meanwhile, as described above, a feature of the first exemplary embodiment of the present invention is that a T-shaped hinge support portion 250 is disposed between the first hinge arm 230a and the second hinge arm 230b. By adjusting the up / down movement of the hinge support portion 250 during the unfolding / folding of the display panel 180, an escape structure for realizing the curvature of the display panel during folding is ensured, and simultaneously, the first gear arm 240a and the second gear arm 240b can be supported, thereby improving impact resistance.

[0192] Figure 11A and 11B It is along Figure 3 A sectional view taken by line A-A'.

[0193] Figure 11A This is a cross-sectional view illustrating the folded state of a foldable display device. Figure 11B It is a cross-sectional view illustrating the unfolded state of a foldable display device.

[0194] Reference Figure 11A and 11BThe hinged support 250 can be disposed in the inner frame 220 in the longitudinal direction of the inner frame 220 located between the first gear arm 240a and the second gear arm 240b.

[0195] The hinged support portion 250 may have a T-shape, with its upper end protruding to both sides. That is, for example, the hinged support portion 250 may have a T-shape in a cross-section cut along a direction perpendicular to the longitudinal direction.

[0196] The hinged support 250 may have an empty internal space, but is not limited thereto.

[0197] The hinge support 250 can support the folding portion 180a of the display panel 180.

[0198] Current foldable display devices require escape structures to achieve the curvature of the display panel when the hinge is folded, and these escape structures can degrade shock resistance. That is, traditionally, a gap exists between the fold of the display panel and the hinge assembly to achieve the R-shape of the display panel when folded, making it vulnerable to shocks such as punctures and ball drops.

[0199] Therefore, a feature of the first exemplary embodiment of the present invention is that a T-shaped hinge support 250 is disposed between the first gear arm 240a and the second gear arm 240b of the hinge assembly 200, thereby lowering the hinge support 250 (see reference) during folding. Figure 11A An escape space D is formed to realize the curvature of the display panel 180, and the hinge support 250 is raised during unfolding (see reference). Figure 11B The folding part 180a supports the display panel 180.

[0200] Specifically, refer to Figure 11B When the foldable display device is unfolded, the lift bumps 244 can raise the hinge support portion 250, thereby supporting the folded portion 180a of the display panel 180. That is, the lift bumps 244 are configured to protrude from the inner ends of the first gear arm 240a and the second gear arm 240b, respectively. Furthermore, when the foldable display device is unfolded, the lift bumps 244 move from the lower part to the upper part simultaneously with the unfolding of the first gear arm 240a and the second gear arm 240b, and raise the two protruding upper ends of the hinge support portion 250, thereby raising the hinge support portion 250.

[0201] On the other hand, refer to Figure 11AWhen the foldable display device is folded, since the lifting protrusion 244 moves downward and no longer restricts the hinge support 250, the hinge support 250 descends again by the restoring force of the compression spring 256 provided on the outside of the hinge support 250 or on the hinge support 250, thereby forming an escape space D for realizing the curvature of the display panel 180.

[0202] At this point, a compression spring 256 with a very thin thickness can be used, and compared to ordinary springs, the compression spring 256 can be compressed even when it is thin.

[0203] Furthermore, the compression spring 256 may be disposed on the outside of the hinge support portion 250 having a T-shape and having a triangular pyramid shape, so that the spring lines do not overlap, taking into account the thickness of the hinge assembly, but is not limited thereto.

[0204] Furthermore, a feature of the present invention is that by utilizing magnetic force during folding to remove the space between the display panel and the hinge support, a foldable display device with improved usability is provided, referring to... Figure 12 and 13 This will be explained in detail.

[0205] Figure 12 This is a plan view of a hinge assembly according to a second exemplary embodiment of the present invention.

[0206] Figure 13 It is along Figure 12 A sectional view taken by line C-C'.

[0207] Figure 13 The display panel 1180 is installed Figure 12 A partial cross-sectional view of a foldable display device on a hinge assembly.

[0208] Figure 12 and 13 The second exemplary embodiment of the present invention shown differs from the first exemplary embodiment described above only in that: magnetic material is disposed on the lower part of the display panel 1180 and magnet 1270 is disposed in the hinge support portion 1250 facing it; the other structures are substantially the same, and therefore repeated descriptions will be omitted. The same reference numerals are used for the same components.

[0209] Reference Figure 12 and 13 According to a second exemplary embodiment of the present invention, the hinge assembly may include a hinge housing, a pair of hinge arms 1230a and 1230b, and an inner frame 1220.

[0210] The hinge assembly may include a first hinge arm 1230a and a second hinge arm 1230b having structures that are symmetrical to each other on one side.

[0211] The articulated arms 1230a and 1230b according to a second exemplary embodiment of the present invention have a dual-axis folding (rotation) structure.

[0212] Furthermore, a feature of the second exemplary embodiment of the present invention is that it has two bevel gears for achieving synchronization between the shafts during dual-axis rotation, as well as a linking slider structure.

[0213] The first hinge arm 1230a and the second hinge arm 1230b are slidably fastened to the first gear arm 1240a and the second gear arm 1240b, respectively, so that the folding and unfolding operations of the foldable display device can be performed while maintaining left and right synchronization.

[0214] Gear arms 1240a and 1240b are rotatably fastened to shaft 1233.

[0215] A compression spring 1260 for generating the frictional force of the cam 1245 may be disposed on the outer surface of the shaft portion 1233 located between the gear arms 1240a and 1240b and the cam 1245.

[0216] Furthermore, a second brake 1246 may be provided on the gear arms 1240a and 1240b, which are fastened to the outer surface of the shaft portion 1233, for maintaining the folding and unfolding angles of the hinge arms 1230a and 1230b and the gear arms 1240a and 1240b together with the plurality of cams 1245.

[0217] Meanwhile, as described above, a feature of the second exemplary embodiment of the present invention is that a T-shaped hinge support portion 1250 is disposed between the first gear arm 1240a and the second gear arm 1240b of the hinge assembly. By adjusting the up / down movement of the hinge support portion 1250 during the unfolding / folding of the display panel 1180, an escape structure for realizing the curvature of the display panel 1180 during folding is ensured, and simultaneously, the first gear arm 1240a and the second gear arm 1240b are supported, thereby improving impact resistance.

[0218] Furthermore, when the foldable display device is unfolded, the lifting protrusion 1244 can lift the hinge support 1250, thereby supporting the folding portion 1180a of the display panel 1180.

[0219] When the foldable display device is folded, there is a space between the display panel 1180 and the hinge support 1250, touch defects such as vibration or double pressing may occur when touched with a pen. In addition, since the folding part 1180a of the display panel 1180 does not have an external fixing part, reverse folding may occur during folding, which may damage the display panel 1180.

[0220] Therefore, a feature of the second exemplary embodiment of the present invention is that a predetermined magnetic sheet 1185 is attached to the rear surface of the display panel 1180, and a magnet 1270 is disposed in the internal space of the hinge support 1250 facing the magnetic sheet 1185 along the longitudinal direction of the hinge support 1250.

[0221] For example, magnetic sheet 1185 can be formed by mixing ferromagnetic powder with polymer resin. Compared to existing hard metal sheets, magnetic sheet 1185 is flexible and facilitates its processing, and the magnetic force can be adjusted according to the content of ferromagnetic powder.

[0222] In this context, ferromagnetic materials are materials that can be magnetized even without an external magnetic field. Furthermore, monatomic ferromagnetic materials include iron, nickel, cobalt, etc. Metal oxides such as iron oxides, chromium oxides, and ferrites can also exhibit ferromagnetic properties.

[0223] In addition, the magnetic sheet 1185 can be attached to the rear surface of the display panel 1180 via the adhesive film 1181.

[0224] The adhesive film 1181 may be formed from an optically transparent adhesive film (OCA film), but is not limited thereto.

[0225] The magnetic sheet 1185 can be attached to the entire rear surface of the display panel 1180, but is not limited to this; it can also be attached only to the rear surface of the folded portion 1180a of the display panel 1180. Furthermore, a compression spring 1256 with a very thin thickness can be used.

[0226] As described above, in the second exemplary embodiment of the present invention, the magnetic sheet 1185 is attached to the rear surface of the display panel 1180 and the magnet 1270 is configured to face the magnetic sheet 1185 within the internal space of the hinge support portion 1250, thereby eliminating the space between the display panel 1180 and the hinge assembly and maximizing airtightness. Therefore, touch defects such as vibration or double pressure during touch can be prevented, and the phenomenon of the fold portion 1180a of the display panel 1180 being folded backwards during folding operation can also be prevented.

[0227] For reference, as a result of the punch test, a similar degree is obtained in the glass cover in the case of the second exemplary embodiment of the present invention, but the strain inside the display panel 1180 is reduced.

[0228] For example, it can be seen that, in the case of the glass cover, the tension before and after applying the magnet 1270 is 131.9 MPa and 130.9 MPa, respectively; in the case of the insulating layer inside the display panel 1180, the tension before and after applying the magnet 1270 is 0.221% and 0.198%, respectively; and in the case of the thin-film transistor, the tension before and after applying the magnet 1270 is 0.326% and 0.396%, respectively.

[0229] Exemplary embodiments of the present invention may also be described below.

[0230] According to one aspect of the present invention, 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, wherein the 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 respectively coupled to the first hinge arm and the second hinge arm in a vertical direction; and a first gear arm and a second gear arm fastened in a manner interlocking with the first hinge arm and the second hinge arm, wherein the display panel performs folding and unfolding operations about a rotation axis different from the central axis of the first bevel gear and the second bevel gear.

[0231] The first bevel gear and the second bevel gear may be configured to mesh with each other, wherein the first bevel gear and the second bevel gear may include a second idler gear that meshes with a first idler gear of the first hinge arm and the second hinge arm, respectively.

[0232] The first idler gear and the second idler gear can be arranged in a direction perpendicular to each other.

[0233] The foldable display device may further include a pair of shafts, wherein the first gear arm and the second gear arm are rotatably coupled to the pair of shafts.

[0234] The first articulated arm and the second articulated arm can rotate together with the rotation of the first gear arm and the second gear arm, wherein left and right synchronization can be maintained by the first bevel gear and the second bevel gear respectively connected to the first articulated arm and the second articulated arm.

[0235] The foldable display device may further include a compression spring disposed on the outer surface of a shaft located between the first gear arm and the second gear arm and the cam.

[0236] The cam may include a body and a first brake disposed on one surface of the body, wherein the first gear arm and the second gear arm may include a second brake disposed on one surface thereon.

[0237] The first brake may protrude from the body in a direction toward the first gear arm and the second gear arm, wherein the second brake may protrude from the first gear arm and the second gear arm in a direction toward the cam.

[0238] The foldable display device may further include a hinge support portion disposed in the inner frame in the longitudinal direction of the inner frame located between the first gear arm and the second gear arm.

[0239] The hinged support may have a T-shape in a cross-section cut along a direction perpendicular to the longitudinal direction.

[0240] When the display panel is folded, the hinge support can descend to form an escape space for realizing the curvature of the display panel, and when the display panel is unfolded, the hinge support can rise to support the folded portion of the display panel.

[0241] The foldable display device may further include a lifting protrusion, which is configured to protrude from the inner ends of the first gear arm and the second gear arm, respectively. When the display panel is unfolded, the lifting protrusion can move from the lower part to the upper part simultaneously with the unfolding of the first gear arm and the second gear arm, and can lift the two protruding upper ends of the hinge support to lift the hinge support.

[0242] When the display panel is folded, the lifting protrusion can move downward, and the hinge support can be lowered again by the restoring force of the compression spring provided on the hinge support, thereby forming the escape space.

[0243] The compression spring may be disposed on the outside of the hinged support having a T-shape and may have a triangular pyramid shape.

[0244] The foldable display device may further include a sliding pin that protrudes at the ends of the first gear arm and the second gear arm toward the first hinge arm and the second hinge arm, respectively.

[0245] During the folding and unfolding operations, the sliding pin can be slidably moved along a sliding space provided in the first and second hinge arms facing the first and second gear arms.

[0246] The foldable display device may further include: a pair of guide pins disposed on the upper end of the inner frame and protruding toward the first hinge arm and the second hinge arm; and a pair of housing cover tracks disposed on the first hinge arm and the second hinge arm facing the pair of guide pins, and the pair of guide pins being fitted into the pair of housing cover tracks, wherein the first hinge arm and the second hinge arm can be folded or rotated along the folding trajectory of the housing cover tracks while being guided by the pair of guide pins.

[0247] The foldable display device may further include: a magnetic sheet attached to the rear surface of the display panel; and a magnet disposed in the internal space of the hinge support facing the magnetic sheet.

[0248] The magnetic sheet can be attached to the rear surface of the display panel via an adhesive film, wherein the magnet can be arranged along the longitudinal direction of the hinge support.

[0249] The magnetic sheet may be attached only to the rear surface of the folded portion of the display panel.

[0250] Although exemplary embodiments of the present invention have been described in detail with reference to the accompanying drawings, the present invention is not limited thereto, and can be implemented in many different forms without departing from the technical concept of the present invention. Therefore, the exemplary embodiments of the present invention are provided for illustrative purposes only and are not intended to limit the technical concept of the present invention. The scope of the technical concept of the present invention is not limited thereto. Therefore, it should be understood that the above exemplary embodiments are illustrative in all respects and do not limit the present invention. The scope of protection of the present invention should be interpreted based on the appended claims, and all technical concepts within the equivalent scope should be interpreted as falling within the scope of the present invention.

Claims

1. A foldable display device, comprising: First support plate and second support plate; A display panel is disposed on the first support plate and the second support plate; as well as A hinge assembly disposed between the first support plate and the second support plate. The hinge assembly includes: A first hinge arm and a second hinge arm that are rotatably connected to each other; A first bevel gear and a second bevel gear are respectively coupled to the first hinge arm and the second hinge arm in the vertical direction; and The first gear arm and the second gear arm are fastened in a manner that interlocks with the first hinge arm and the second hinge arm. The display panel performs folding and unfolding operations around a rotation axis different from the central axis of the first and second bevel gears. The first bevel gear and the second bevel gear are configured to mesh with each other, and The first bevel gear and the second bevel gear include a second idler gear that meshes with a first idler gear of the first hinge arm and the second hinge arm, respectively.

2. The foldable display device according to claim 1, wherein the first idler gear and the second idler gear are arranged in a direction perpendicular to each other.

3. The foldable display device according to claim 1, further comprising: A pair of shafts, wherein the first gear arm and the second gear arm are rotatably coupled to the pair of shafts.

4. The foldable display device according to claim 1, wherein the first hinge arm and the second hinge arm rotate together with the rotation of the first gear arm and the second gear arm. The first bevel gear and the second bevel gear, which are respectively connected to the first hinge arm and the second hinge arm, maintain left-right synchronization.

5. The foldable display device according to claim 3, further comprising: A compression spring is disposed on the outer surface of a shaft located between the first gear arm and the second gear arm and the cam.

6. The foldable display device according to claim 5, wherein the cam includes a body and a first brake disposed on one surface of the body. The first gear arm and the second gear arm each include a second brake disposed on one of their surfaces.

7. The foldable display device according to claim 6, wherein the first brake protrudes from the body in a direction toward the first gear arm and the second gear arm. The second brake protrudes from the first gear arm and the second gear arm in the direction toward the cam.

8. The foldable display device according to claim 1, further comprising: A hinged support portion is disposed in the inner frame in the longitudinal direction of the inner frame located between the first gear arm and the second gear arm.

9. The foldable display device according to claim 8, wherein the hinge support has a T-shape in a cross-section cut along a direction perpendicular to the longitudinal direction.

10. The foldable display device according to claim 9, wherein when the display panel is folded, the hinge support descends to form an escape space for realizing the curvature of the display panel, and when the display panel is unfolded, the hinge support rises to support the folded portion of the display panel.

11. The foldable display device according to claim 10, further comprising: A lifting protrusion, wherein the lifting protrusion is configured to protrude from the inner ends of the first gear arm and the second gear arm respectively. When the display panel is unfolded, the lifting protrusion moves from the lower part to the upper part simultaneously with the unfolding of the first gear arm and the second gear arm, and lifts the two protruding upper ends of the hinge support to raise the hinge support.

12. The foldable display device according to claim 11, wherein when the display panel is folded, the lifting protrusion moves downward, and the hinge support descends again by the restoring force of the compression spring disposed on the hinge support to form the escape space.

13. The foldable display device according to claim 12, wherein the compression spring is disposed on the outside of the hinge support having a T-shape and has a triangular pyramid shape.

14. The foldable display device according to claim 1, further comprising: Sliding pins protrude toward the first hinge arm and the second hinge arm at the ends of the first gear arm and the second gear arm, respectively.

15. The foldable display device of claim 14, wherein during the folding operation and the unfolding operation, the sliding pin is slidably movable along a sliding space provided in the first hinge arm and the second hinge arm facing the first gear arm and the second gear arm.

16. The foldable display device according to claim 8, further comprising: A pair of guide pins, the pair of guide pins being disposed on the upper end of the inner frame and protruding toward the first hinge arm and the second hinge arm; as well as A pair of housing cover tracks are disposed on a first hinge arm and a second hinge arm facing a pair of guide pins, and the pair of guide pins are fitted into the pair of housing cover tracks. The first and second hinge arms fold or rotate along the folding trajectory of the outer casing track while being guided by the pair of guide pins.

17. The foldable display device according to claim 1, further comprising: A magnetic sheet, the magnetic sheet being attached to the rear surface of the display panel; as well as A magnet is disposed in the internal space of the hinged support facing the magnetic sheet.

18. The foldable display device of claim 17, wherein the magnetic sheet is attached to the rear surface of the display panel via an adhesive film. The magnet is arranged along the longitudinal direction of the hinged support.

19. The foldable display device of claim 17, wherein the magnet is attached only to the rear surface of the folded portion of the display panel.

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