Foldable display device

Abstract

The foldable display device includes: a first body and a second body; and a hinge part connected to the first body and the second body. The hinge part includes: a first joint having at least one first recessed part; a second joint facing the first joint; a third joint located at one side of the first joint; a first leaf spring located in the first recessed part; and a first fastening connection component fixed to the third joint through the first leaf spring and the first joint.

Description

Technical Field

[0001] The present invention relates to a foldable display device. Background Art

[0002] Display devices such as organic light-emitting display devices and liquid crystal display devices include display panels manufactured by forming multiple layers and elements on a substrate. Glass is used as a substrate for the display panel. However, glass substrates have the disadvantages of being heavy and easily broken. In addition, glass substrates are generally rigid, so it is difficult to deform the display panel. In recent years, flexible display panels using flexible substrates that are light, impact-resistant, and easily deformable, as well as flexible display devices including such display panels have been developed.

[0003] Flexible display devices can be classified into bendable display devices, foldable display devices, rollable display devices, stretchable display devices, etc. according to their uses or shapes. Among them, the foldable display device can be opened or closed like a book.

[0004] The foldable display device can be carried compactly after being folded, and can be unfolded to enjoy a wide screen when in use. In order to fold the foldable display device, a mechanical structure such as a hinge is required. However, it is preferred that such a mechanical structure is small in size, strong, and does not damage the display panel. Summary of the invention

[0005] The embodiments provide a foldable display device having a hinge portion with a simple and strong structure. The embodiments also provide a foldable display device that can prevent damage to a display panel and improve the flatness of the display panel.

[0006] A foldable display device according to an embodiment includes: a first body and a second body; and a hinge portion connected to the first body and the second body. The hinge portion includes: a first joint having at least one first recessed portion; a second joint facing the first joint; a third joint located on one side of the first joint; a first leaf spring located in the first recessed portion; and a first fastening component fixed to the third joint through the first leaf spring and the first joint.

[0007] It may be that the outer surface of the first joint faces the inner surface of the third joint, and the outer surface of the first joint and the inner surface of the third joint are curved surfaces.

[0008] The first joint may have a first opening in the first recessed portion, the first fastening component may include a portion located in the first opening, and a length of the first opening may be greater than a diameter of a portion of the first fastening component located in the first opening.

[0009] The third joint may be slidably coupled to the first joint.

[0010] The first joint, the second joint and the third joint may be arranged in a first direction when the foldable display device is unfolded. The first joint, the second joint and the third joint may extend in a second direction intersecting the first direction.

[0011] It may be that the third joint has at least one third recessed portion, and the first recessed portion and the third recessed portion do not overlap in the first direction.

[0012] The hinge portion may include: a fourth joint located on one side of the second joint; a fifth joint located on one side of the third joint; a third leaf spring located in the third recessed portion; and a third fastening component fixed to the fifth joint via the third leaf spring and the third joint.

[0013] It may be that the outer surface of the third joint faces the inner surface of the fifth joint, and the outer surface of the third joint and the inner surface of the fifth joint are curved surfaces.

[0014] It may be that the first leaf spring and the third leaf spring do not overlap in the first direction.

[0015] The hinge portion may include: a first connection portion located at one side of the fifth joint; a fifth leaf spring located in a fifth recessed portion of the fifth joint; and a fifth fastening component fixed to the first connection portion via the fifth leaf spring and the fifth joint.

[0016] It may be that the third leaf spring and the fifth leaf spring do not overlap in the first direction.

[0017] The hinge part may include: a first rotation control part including a first gear and a first arm part; and a second rotation control part including a second gear and a second arm part. The teeth of the first gear and the teeth of the second gear may be meshed with each other, and the first arm part passes through the holes of the first joint, the third joint, and the fifth joint and is inserted into the hole of the first connection part.

[0018] The first gear and the second gear may overlap with the first joint and the second joint respectively in the second direction.

[0019] The first joint and the second joint may include a shaft and a head having holes on both sides of the shaft, respectively. The hinge may also include a connecting component having at least two protrusions. The corresponding protrusions of the connecting component may be inserted into the holes of the head of the first joint and the holes of the head of the second joint, so that the first joint and the second joint are combined.

[0020] The foldable display device may further include: a display panel located on the first body, the second body, and the hinge portion, and the hinge portion supports the display panel in a manner that the display panel can be bent.

[0021] The foldable display device may further include: a height difference compensation layer located between the first body, the second body, the hinge part and the display panel. The height difference compensation layer may include a cut pattern or be segmented in a region overlapping with the hinge part.

[0022] A foldable display device according to an embodiment includes: a display panel; and a hinge portion, which supports the display panel in a manner that the display panel can be bent. The hinge portion includes: a joint portion, including a first joint and a second joint adjacent to each other; and a third joint and a fourth joint adjacent to the first joint and the second joint, respectively. The hinge portion also includes: a first rotation control portion, including a first gear and a first arm portion; and a second rotation control portion, including a second gear and a second arm portion. The teeth of the first gear and the teeth of the second gear are meshed with each other, the first arm portion passes through the first joint and the third joint, and the second arm portion passes through the second joint and the fourth joint.

[0023] The first arm portion and the second arm portion may each include a bent portion.

[0024] The hinge portion may further include: a first leaf spring located on an inner surface of the first joint; and a fastening component penetrating the first leaf spring and the first joint and fixed to the third joint.

[0025] It may be that, in the first joint, the length of the opening through which the fastening component passes may be greater than the diameter of a portion of the fastening component passing through the opening.

[0026] (Effects of the Invention)

[0027] According to each embodiment, a foldable display device having a simple and strong structure can be provided. In addition, in the foldable display device, the flatness of the display panel can be improved, and damage to the display panel can be prevented. In addition, the effects that can be recognized throughout the specification can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is a plan view of a foldable display device according to an embodiment.

[0029] Figure 2 is Figure 1 A side view of the hinge portion of the foldable display device in the unfolded state is shown.

[0030] Figure 3 is Figure 1 A side view of the hinge portion of the foldable display device in a folded state is shown.

[0031] Figure 4 It is a perspective view showing a hinge portion according to an embodiment in an unfolded state.

[0032] Figure 5 Yes means Figure 4 A perspective view of the hinge portion in a folded state is shown.

[0033] Figure 6 yes Figure 4 An exploded perspective view of the hinge portion is shown.

[0034] Figure 7 It is an exploded perspective view of a hinge portion according to an embodiment.

[0035] Figure 8 is Figure 7 The cross-sectional view of the region corresponding to the line AA' in the state where the hinge portion is unfolded is shown.

[0036] Fig. 9 is Figure 7 The cross-sectional view of the region corresponding to the line AA' in a state where part of the hinge portion is folded is shown.

[0037] Fig.10 It is a perspective view of a hinge part involved in one embodiment.

[0038] Fig.11 is Fig.10 A cross-sectional view of the area where the rotation control portion is located when the hinge portion is unfolded is shown.

[0039] Fig.12 is Fig.10 A cross-sectional view of the region where the rotation control portion is located in a state where the hinge portion is folded.

[0040] Fig.13 is a three-dimensional diagram of a foldable display device according to an embodiment.

[0041] Fig.14 is Fig.13A partial stereoscopic view of the foldable display device in an unfolded state.

[0042] Fig.15 is Fig.13 A partial perspective view of the foldable display device in a folded state.

[0043] Fig.16 It is a partial stereoscopic diagram of a height difference compensation layer involved in one embodiment.

[0044] Fig.17 is a cross-sectional view of a display panel according to an embodiment. DETAILED DESCRIPTION

[0045] With reference to the accompanying drawings, the embodiments are described in detail so that those skilled in the art can easily implement the embodiments. The invention can be implemented in various different ways and is not limited to the embodiments described herein.

[0046] In order to clearly describe the invention, parts not related to the invention are omitted, and the same or similar components are denoted by the same reference numerals throughout the specification.

[0047] The dimensions and thickness of each structure shown in the figure are arbitrarily shown for the convenience of explanation, and the present invention is not necessarily limited to the figure. In the figure, in order to clearly indicate each layer and region, the thickness is enlarged. In the figure, for the convenience of explanation, the thickness of some layers and regions is exaggerated.

[0048] When a layer, film, region, plate or other part is located "on" or "over" another part, this includes not only the case where it is directly on the other part, but also the case where there are other parts in between. Conversely, when a part is directly on another part, it means that there is no other part in between.

[0049] Throughout the specification, when a part “includes” a certain constituent element, unless there is any contrary description, it does not exclude other constituent elements but means that other constituent elements may be included.

[0050] Throughout the specification, “on a plane” means that a target portion is observed from above, and “on a cross section” means that a cross section cut vertically with respect to the target portion is observed from the side.

[0051] In the drawings, a symbol x used to indicate a direction is a first direction, y is a second direction perpendicular to the first direction, and z is a third direction perpendicular to the first direction and the second direction.

[0052] Figure 1 is a plan view of a foldable display device according to an embodiment, Figure 2 is Figure 1The side view of the hinge part HU of the foldable display device in the unfolded state is shown. Figure 3 is Figure 1 FIG. 4 is a side view of the hinge portion HU of the foldable display device in a folded state.

[0053] Reference Figure 1 The foldable display device (hereinafter referred to as the display device) may include a bendable area BA and a first flat area FA1 and a second flat area FA2 located on both sides of the bendable area BA. The bendable area BA is an area that is bent when the display device is folded, and the first flat area FA1 and the second flat area FA2 are areas that are substantially not bent. Figure 1 As shown, the display device can be unfolded flatly as a whole.

[0054] Although one bendable area BA is illustrated, the display device may include a plurality of bendable areas BA that are separated from each other or bent at different curvature radii. For example, the display device may include two or more bendable areas and three or more flat areas.

[0055] Reference Figure 1 , Figure 2 as well as Figure 3 The display device includes a first body BD1, a second body BD2, and a hinge unit HU located between the first body BD1 and the second body BD2. The hinge unit HU is connected to the first body BD1 and the second body BD2. The hinge unit HU is foldably connected to the first body BD1 and the second body BD2. The hinge unit HU includes a joint unit JU having a plurality of joints. Through the sliding rotation of the joint unit JU, the display device can be folded so that the first body BD1 and the second body BD2 face each other.

[0056] The display device includes a display panel DP located on the main body (BD1, BD2) and the hinge part HU. The display panel DP can be attached to the main body (BD1, BD2). Various components constituting the display device, such as a drive device, a processor, a memory, a printed circuit board, a battery, a communication module, a speaker, various sensors, etc., can be arranged inside the main body (BD1, BD2). Figure 1 In order to clearly show the main body (BD1, BD2) and the hinge part HU located below the display panel DP, the display panel DP is not shown. Figure 2 as well as Figure 3As shown, the display panel DP may not be visible when the display device is observed from the side, but the display panel DP is schematically shown to indicate the position of the display panel DP in the display device. The display panel DP may be roughly located in a display area DA spanning the first flat area FA1, the second flat area FA2, and the entire bendable area BA. The display area DA is an area corresponding to the screen where the image is displayed.

[0057] The display panel DP is a panel on which pixels capable of displaying images are formed on a substrate. The display panel DP may include light emitting diodes corresponding to the pixels. The display panel DP is a flexible panel at least a portion of which can be bent. The display panel DP may be flexible and bendable in at least a region corresponding to the bendable region BA of the display device, or may be flexible as a whole.

[0058] like Figure 1 as well as Figure 2 As shown, the first body BD1 and the second body BD2 may flatly support the display panel DP on the first flat area FA1 and the second flat area FA2. Figure 2 as well as Figure 3 As shown, the hinge portion HU can support the display panel DP in a bendable manner in the bendable area BA. Figure 3 As shown, the display device can be folded so that the display panel DP is exposed to the outside (thus the screen is exposed to the outside), or can be folded in the opposite way.

[0059] An elastic layer made of a material such as thermoplastic polyurethane (TPU) may be provided between the body (BD1, BD2) and the hinge part HU and the display panel DP. The elastic layer may flatten the display panel DP and may mitigate and disperse impact applied to the display panel DP.

[0060] Reference Figure 4 , Figure 5 as well as Figure 6 , describing a hinge portion HU according to an embodiment.

[0061] Figure 4 1 is a perspective view showing an unfolded state of a hinge portion HU according to an embodiment. Figure 5 Yes means Figure 4 The three-dimensional view of the hinge part HU in the folded state is shown. Figure 6 yes Figure 4 An exploded perspective view of the hinge part HU is shown. Figure 4 , Figure 5 as well as Figure 6 The hinge unit HU is separated from the display device and is shown in the figure.

[0062] Reference Figure 4 as well as Figure 5The hinge part HU includes a first connector CP1, a second connector CP2, and a joint part JU located between the first connector CP1 and the second connector CP2. The joint part JU is connected to the first connector CP1 and the second connector CP. The first connector CP1 is connected to the first body BD1, and the second connector CP2 is connected to the second body BD2. When the display device is unfolded, Figure 4 As shown, the main planes of the first connection portion CP1 and the second connection portion CP2 are flush with each other. Figure 5 As shown, the first connection portion CP1 and the second connection portion CP2 face each other.

[0063] Reference Figure 6 The joint part JU includes a plurality of joints (J1, J2, J3, J4, J5, J6) and a plurality of leaf springs LS. The joint part JU may further include a connecting member (Ca, Cb) connecting the first joint J1 and the second joint J2, and may further include a plurality of rotation controllers (Ra1, Rb1, Ra2, Rb2) for controlling the rotation angle of the joint part JU.

[0064] Each joint (J1, J2, J3, J4, J5, J6) may be elongated in the second direction y. Each joint (J1, J2, J3, J4, J5, J6) may include a spindle SP and a head HD located on both sides of the spindle SP. One or more recessed portions RC are formed on the inner surface of the spindle SP of each joint (J1, J2, J3, J4, J5, J6) along the second direction y (see Figure 7 ), the leaf spring LS is located in the recessed portion RC. Here, the inner surface of the joint portion (J1, J2, J3, J4, J5, J6) refers to the surface facing the center of the joint portion JU when the display device is unfolded. Hereinafter, unless otherwise specified, the description of the joint (J1, J2, J3, J4, J5, J6) is mainly based on the characteristics of the shaft portion SP.

[0065] Among the multiple joints (J1, J2, J3, J4, J5, J6), the first joint J1 and the second joint J2 are located in the center and face each other. The opposing surfaces (outer surfaces) of the first joint J1 and the second joint J2 can be curved surfaces. The first joint J1 and the second joint J2 can be roughly cylindrical in shape when combined with each other. The facing inner surfaces of the first joint J1 and the second joint J2 can be tightly connected to each other. The first joint J1 and the second joint J2 can respectively include holes in the head HD, and at both ends of the first joint J1 and the second joint J2, corresponding protrusions of the connecting parts (Ca, Cb) are inserted into the holes of the head HD, so that the first joint J1 and the second joint J2 can be combined so as not to be separated from each other.

[0066] The third joint J3 is adjacent to the first joint J1, and the fourth joint J4 is adjacent to the second joint J2. The facing surfaces (inner surfaces) of the third joint J3 and the fourth joint J4 may be curved surfaces, and the opposite surfaces (outer surfaces) may be curved surfaces. At least a portion of the inner surfaces of the third joint J3 and the fourth joint J4 may be substantially consistent with and tightly connected to the outer surfaces of the first joint J1 and the second joint J2, respectively. By combining with the leaf spring LS in the recessed portion RC of the first joint J1 and the second joint J2, the third joint J3 and the fourth joint J4 may be slidably combined with the first joint J1 and the second joint J2, respectively.

[0067] The fifth joint J5 is adjacent to the third joint J3, and the sixth joint J6 is adjacent to the fourth joint J4. The facing surfaces (inner surfaces) of the fifth joint J5 and the sixth joint J6 may be curved surfaces, and the opposite surfaces (outer surfaces) may be curved surfaces. At least a portion of the inner surfaces of the fifth joint J5 and the sixth joint J6 may be substantially consistent with and tightly connected to the outer surfaces of the third joint J3 and the fourth joint J4, respectively. Through the combination of the leaf spring LS in the recessed portion RC of the third joint J3 and the fourth joint J4, the fifth joint J5 and the sixth joint J6 may be slidably combined with the third joint J3 and the fourth joint J4, respectively.

[0068] The fifth joint J5 is combined with the first connection part CP1, and the sixth joint J6 is combined with the second connection part CP2. The facing surfaces (inner surfaces) of the first connection part CP1 and the second connection part CP2 can be curved surfaces. At least a portion of the inner surfaces of the first connection part CP1 and the second connection part CP2 can be roughly consistent with and tightly connected to the outer surfaces of the fifth joint J5 and the sixth joint J6, respectively. Through the combination of the leaf spring LS in the recessed portion RC based on the fifth joint J5 and the sixth joint J6, the first connection part CP1 and the second connection part CP2 can be slidably combined with the fifth joint J5 and the sixth joint J6, respectively.

[0069] Reference Figure 7 , Figure 8 as well as Fig. 9 , illustrating the slidable connection of the joints (J1, J2, J3, J4, J5, J6) and the connecting parts (CP1, CP2) of the joint part JU and the rotation of the hinge part HU.

[0070] Figure 7 is an exploded perspective view of a hinge portion according to an embodiment. Figure 8 is Figure 7 A cross-sectional view of the region corresponding to the line AA' in the unfolded state of the hinge portion shown, Fig. 9 is Figure 7 This is a cross-sectional view of a region corresponding to line AA' in a state where a part of the hinge portion is folded. Figure 7 , Figure 8 as well as Fig. 9 The first joint J1, the third joint J3, the fifth joint J5 and the first connection part CP1 located on one side relative to the center of the hinge part HU and their connection relationship. The second joint J2, the fourth joint J4, the sixth joint J6 and the second connection part CP2 located on the other side relative to the center of the hinge part HU and their connection relationship can be relative to the center of the hinge part HU. Figure 7 , Figure 8 as well as Fig. 9 The situation shown is relatively symmetrical.

[0071] Reference Figure 7 , Figure 8 as well as Fig. 9 , the fifth joint J5 includes three recessed portions RC on the inner surface, and the leaf spring LS is located in each recessed portion RC. The fifth joint J5 has an opening OP in the recessed portion RC. A fastening component (fastener) FM such as a screw is fixed to the first connection portion CP1 through the hole of the leaf spring LS and the opening OP of the fifth joint J5. The body (shank) of the fastening component FM can pass through the leaf spring LS and the fifth joint J5 and be fixed to the first connection portion CP1, and the head (head) of the fastening component FM can tightly connect the leaf spring LS to the fifth joint J5 and the first connection portion CP1. The opening OP can be roughly rectangular, and its length l can be formed to be larger than the diameter d of the portion (body) of the fastening component located in the opening OP. Thus, if Figure 8 as well as Fig. 9 As shown, the first connection portion CP1 can rotate together with the leaf spring LS and the fastening connection member FM combined therewith within a range defined by the opening OP, with the rotation axis parallel to the second direction y as the center.

[0072] Since the inner surface of the first connection part CP1 and the outer surface of the fifth joint J5 are substantially consistent, the first connection part CP1 can make the fifth joint J5 rotate like sliding without deviation in a tightly connected state. In addition, since the leaf spring LS is tightly connected to the fifth joint J5 and thus is tightly connected, a torque between the first connection part CP1 and the fifth joint J5 can be generated during sliding rotation. Therefore, no additional structure for realizing torque is required, and sliding rotation between the first connection part CP1 and the fifth joint J5 can occur when an external force greater than a predetermined value is applied.

[0073] The third joint J3 includes two recessed portions RC on the inner surface, and a leaf spring LS is located in each recessed portion RC. The recessed portion RC of the third joint J3 can be configured to be staggered with the recessed portion RC of the fifth joint J5. That is, in the second direction y, the recessed portion RC of the third joint J3 can be located between the three recessed portions RC of the fifth joint J5. The recessed portion RC of the third joint J3 and the leaf spring LS in the recessed portion RC may not overlap with the recessed portion RC of the fifth joint J5 and the leaf spring LS in the recessed portion RC in the first direction x. Thus, the leaf spring LS in the recessed portion RC of the fifth joint J5 and the leaf spring LS in the recessed portion RC of the third joint J3 can be arranged not to interfere with each other, thereby ensuring the joining area of ​​the fastening connection component FM.

[0074] The connection relationship between the third joint J3 and the fifth joint J5 can directly use the connection relationship between the fifth joint J5 and the first connection part CP1 mentioned above. That is, the fastening connection component FM is fixed to the fifth joint J5 through the hole of the leaf spring LS and the opening OP of the third joint J3, and the fifth joint J5 can rotate with the leaf spring LS and the fastening connection component FM connected thereto, with the rotation axis parallel to the second direction y as the center, within the range defined by the opening OP. Since the inner surface of the fifth joint J5 and the outer surface of the third joint J3 are substantially consistent, the fifth joint J5 can rotate like sliding in a state of being tightly connected to the third joint J3. In addition, since the leaf spring LS is tightly connected to the third joint J3 and is thus tightly connected, a torque between the fifth joint J5 and the third joint J3 can be generated during sliding rotation.

[0075] The first joint J1 includes three recessed portions RC on the inner surface, and a leaf spring LS is located in each recessed portion RC. The recessed portion RC of the first joint J1 can be configured to be staggered with the recessed portion RC of the third joint J3. That is, in the second direction y, the recessed portion RC of the first joint J1 can be located between and on both sides of the two recessed portions RC of the third joint J3. The recessed portion RC of the first joint J1 and the leaf spring LS in the recessed portion RC may not overlap with the recessed portion RC of the third joint J3 and the leaf spring LS in the recessed portion RC in the first direction x. Thus, the leaf spring LS in the recessed portion RC of the third joint J3 and the leaf spring LS in the recessed portion RC of the first joint J1 can be arranged not to interfere with each other, thereby ensuring the joining area of ​​the fastening connection component FM.

[0076] The connection relationship between the first joint J1 and the third joint J3 can directly apply the connection relationship between the third joint J3 and the fifth joint J5 mentioned above. That is, the fastening component FM is fixed to the third joint J3 through the hole of the leaf spring LS and the opening OP of the first joint J1, and the third joint J3 can rotate with the leaf spring LS and the fastening component FM connected thereto, with the rotation axis parallel to the second direction y as the center, within the range defined by the opening OP. Since the inner surface of the third joint J3 and the outer surface of the first joint J1 are substantially consistent, the third joint J3 can rotate like sliding in a state of being tightly connected to the first joint J1. In addition, since the leaf spring LS is tightly connected to the first joint J1 and is thus tightly connected, a torque can be generated between the third joint J3 and the first joint J1 during sliding rotation.

[0077] In this way, the joints (J1, J3, J5) of the hinge part HU and the first connection part CP1 are connected, so that the hinge part HU can rotate around at least one rotation axis parallel to the second direction y. The rotation angles of the third joint J3, the fifth joint J5 and the first connection part CP1 can be adjusted by adjusting the length l of the opening OP of each joint (J1, J3, J5). Since the hinge part HU is composed of a small number of parts, the hinge part HU can be formed simply and firmly, and the reliability against impact and folding can be improved. In addition, since the inner surface and the outer surface of each joint (J1, J3, J5) are closely connected with a curved surface, they can be bent with a small radius. In addition, when the display device is folded, the portion of the joint (J1, J2, J3, J4, J5, J6) connected to the display panel DP is a curved surface without corners, so that the stress concentration on a specific part of the display panel DP can be reduced, and the damage to the display panel DP can be reduced.

[0078] Although the example in which the first joint J1 and the fifth joint J5 include three recessed portions and the third joint J3 includes two recessed portions has been described, the number of recessed portions included in each joint ( J1 , J3 , J5 ) may be changed in various forms.

[0079] Reference Fig.10 , Fig.11 as well as Fig.12 , illustrating the folding of the hinge part HU.

[0080] Fig.10 is a perspective view of a hinge portion HU according to an embodiment. Fig.11 is Fig.10 The cross-sectional view of the area where the rotation control parts (Ra1, Ra2) are located when the hinge part HU is unfolded is shown. Fig.12 is Fig.10 The cross-sectional view of the region where the rotation control parts (Ra1, Ra2) are located in the state where the hinge part HU is folded is shown. Fig.10 , Fig.11 as well as Fig.12 The figure shows the connection relationship between the joints (J1, J2, J3, J4, J5, J6) located on one side relative to the center of the hinge part HU in the second direction y and the connection relationship between the connection parts (CP1, CP2) and the rotation control parts (Ra1, Ra2). The figure shows the connection relationship between the joints (J1, J2, J3, J4, J5, J6) located on the other side relative to the center of the hinge part HU in the second direction y and the connection relationship between the connection parts (CP1, CP2) and the rotation control parts (Rb1, Rb2). Fig.10 , Fig.11 as well as Fig.12 The situation shown is symmetrical.

[0081] Reference Fig.10 , Fig.11 as well as Fig.12 The hinge part HU includes a pair of rotation control parts (Ra1, Ra2) on one side. Figure 6 As shown, the hinge part HU may also include a pair of rotation control parts (Rb1, Rb2) on the other side.

[0082] The first rotation control unit Ra1 includes a first gear GR1 and a first arm AM1 , and the second rotation control unit Ra2 includes a second gear GR2 and a second arm AM2 .

[0083] The first gear GR1 and the second gear GR2 can be arranged to overlap with the first joint J1 and the second joint J2 in the second direction y, respectively. The teeth of the first gear GR1 and the teeth of the second gear GR2 are meshed with each other. The first gear GR1 and the second gear GR2 each have a hole at the approximate center, and the protrusion or tip of the connecting component Ca is inserted into the hole of the first gear GR1 and the second gear GR2, so that the first gear GR1 and the second gear GR2 can rotate around the rotation axis (the center of each gear (GR1, GR2)). Since the first gear GR1 and the second gear GR2 are meshed, when the first gear GR1 rotates, the second gear GR2 can also rotate, and conversely, when the second gear GR2 rotates, the first gear GR1 can also rotate.

[0084] The first arm portion AM1 extending from the first gear GR1 passes through the holes formed at the first joint J1, the third joint J3 and the fifth joint J5, respectively, and is inserted into the hole of the first connection portion CP1. Similarly, the second arm portion AM2 extending from the second gear GR2 can pass through the holes formed at the second joint J2, the fourth joint J4 and the sixth joint J6, respectively, and be inserted into the hole of the second connection portion CP2. Therefore, when the first arm portion AM1 rotates, the first joint J1, the third joint J3, the fifth joint J5 and the first connection portion CP1 can rotate together as a whole. In addition, when the second arm portion AM2 rotates, the second joint J2, the fourth joint J4, the sixth joint J6 and the second connection portion CP2 can rotate together as a whole. In addition, the hinge portion HU can be folded at an angle corresponding to the rotation angle of the first gear GR1 and the second gear GR2.

[0085] On the other hand, when the display device is folded or unfolded, the first arm AM1 can slide in the holes of the first joint J1, the third joint J3, the fifth joint J5 and the first connection part CP1, and the second arm AM2 can slide in the holes of the second joint J2, the fourth joint J4, the sixth joint J6 and the second connection part CP2. The first arm AM1 and the second arm AM2 may include a bent portion so that such action can be achieved without damage to the joints (J1, J2, J3, J4, J5, J6) and the connection parts (CP1, CP2).

[0086] Fig.13 is a three-dimensional diagram of a foldable display device according to an embodiment, Fig.14 is Fig.13 A partial stereoscopic view of the foldable display device in an unfolded state, Fig.15 is Fig.13 A partial stereoscopic view of the foldable display device in a folded state, Fig.16 FIG. 1 is a partial three-dimensional diagram of a height difference compensation layer SC according to an embodiment. Fig.14 as well as Fig.15 In order to clearly show the height difference compensation layer SC located below the display panel DP, a part of the display device is cut out for illustration, and the display panel DP is not shown.

[0087] Reference Fig.13 , Fig.14 as well as Fig.15 The display device includes a step compensation layer SC located between the main body (BD1, BD2) and the hinge part HU and the display panel DP. The step compensation layer SC may be attached to the main body (BD1, BD2) and the hinge part HU.

[0088] When the display device is folded, in order to reduce the stress of the display panel DP, the connection part (CP1, CP2) of the hinge part HU may be configured to slide and insert into the gaps SL1, SL2 of the main body (BD1, BD2). For this sliding insertion, the connection part (CP1, CP2) may include insertion parts IS1, IS2. When the display device is folded, the insertion parts IS1, IS2 are completely inserted into the gaps SL1, SL2 of the main body (BD1, BD2), so that there may be no or almost no height difference between the hinge part HU and the main body (BD1, BD2). When the display device is unfolded, a height difference may occur between the hinge part HU and the main body (BD1, BD2). The height difference compensation layer SC can cover this height difference, provide an overall flat surface, and can support the display panel DP flatly. The height difference compensation layer SC can also compensate for the height difference that may occur between the joints (J1, J2, J3, J4, J5, J6) of the joint part JU.

[0089] The height difference compensation layer SC may be a metal sheet formed of a metal or a metal alloy such as stainless steel (also called SUS) or Invar. The height difference compensation layer SC may be formed with a cut pattern having a plurality of openings in a portion corresponding to the bendable area BA, so that the bending stress in the bendable area BA can be reduced and the bend can be easily made. Each opening of the cut pattern may be formed longer in a direction parallel to the bending axis. The height difference compensation layer SC may be formed with a plurality of openings in a portion corresponding to the bendable area BA, such as Fig.16 As shown in FIG. 1 , the height difference compensation layer SC can be formed of a polymer such as polyimide (PI) or polyethylene terephthalate (PET).

[0090] The display panel DP may be directly attached to the height difference compensation layer SC, or a functional layer such as an elastic layer may be provided between the display panel DP and the height difference compensation layer SC.

[0091] Reference Fig.17, illustrating the structure of a display panel DP that the display device may include.

[0092] Fig.17 is a cross-sectional view of a display panel DP according to an embodiment. Fig.17 The cross section shown corresponds approximately to one pixel area.

[0093] The display panel DP basically includes a substrate SB, a transistor TR formed on the substrate SB, and a light emitting diode LED connected to the transistor TR.

[0094] The substrate SB may be a flexible substrate formed of a polymer such as polyimide (PI), polyamide (PA), polyethylene terephthalate (PET), etc. The substrate SB may include a barrier layer to prevent moisture, oxygen, etc. from penetrating from the outside. The substrate SB may include one or more polymer layers and one or more barrier layers, and the polymer layers and the barrier layers may be alternately stacked.

[0095] A first insulating layer IN1 is provided on the substrate SB. The first insulating layer IN1 may be referred to as a buffer layer, which may block impurities that may diffuse from the substrate SB to the semiconductor layer A and reduce the pressure on the substrate SB during the formation of the semiconductor layer A. The barrier layer and the first insulating layer IN1 may include inorganic insulating materials such as silicon oxide and silicon nitride.

[0096] A semiconductor layer A of the transistor TR is provided on the first insulating layer IN1, and a second insulating layer IN2 is provided on the semiconductor layer A. The semiconductor layer A includes a source region, a drain region, and a channel region between these regions. The semiconductor layer A may include semiconductor materials such as polycrystalline silicon, oxide semiconductor, and amorphous silicon. The second insulating layer IN2 may be referred to as a gate insulating layer, and may include an inorganic insulating material.

[0097] A gate conductor including a gate electrode G of the transistor TR is disposed on the second insulating layer IN2. The gate conductor may include a metal or a metal alloy such as molybdenum (Mo), copper (Cu), aluminum (Al), silver (Ag), chromium (Cr), tantalum (Ta), titanium (Ti).

[0098] A third insulating layer IN3 is disposed on the gate conductor. The third insulating layer IN3 may be referred to as an interlayer insulating layer, and may include an inorganic insulating material.

[0099] A data conductor including a source electrode S and a drain electrode D of the transistor TR is provided on the third insulating layer IN3. The source electrode S and the drain electrode D are respectively connected to the source region and the drain region of the semiconductor layer A through the openings of the third insulating layer IN3 and the second insulating layer IN2. The data conductor may include metals or metal alloys such as aluminum (Al), copper (Cu), silver (Ag), molybdenum (Mo), chromium (Cr), gold (Au), platinum (Pt), palladium (Pd), tantalum (Ta), tungsten (W), titanium (Ti), and nickel (Ni).

[0100] A fourth insulating layer IN4 is disposed on the data conductor. The fourth insulating layer IN4 may be referred to as a planarization layer, and may include an organic insulating material.

[0101] A first electrode E1 is disposed on the fourth insulating layer IN4. The first electrode E1 may be referred to as a pixel electrode. The first electrode E1 is connected to the drain electrode D through an opening of the fourth insulating layer IN4, so as to receive a data voltage for controlling the brightness of the light emitting diode LED.

[0102] A fifth insulating layer IN5 is provided on the fourth insulating layer IN4. The fifth insulating layer IN5 may be referred to as a pixel definition layer, and has an opening overlapping the first electrode E1. In the opening of the fifth insulating layer IN5, a light emitting layer EL is provided on the first electrode E1, and a second electrode E2 is provided on the light emitting layer EL. The second electrode E2 may be referred to as a common electrode.

[0103] The first electrode E1, the light emitting layer EL and the second electrode E2 together constitute a light emitting diode LED. The light emitting diode LED may be an organic light emitting diode. The first electrode E1 and the second electrode E2 may be the anode and cathode of the light emitting diode LED, respectively.

[0104] An encapsulation layer EC is provided on the second electrode E2. The encapsulation layer EC encapsulates the light emitting diode LED, thereby preventing moisture or oxygen from penetrating from the outside. The encapsulation layer EC may include one or more inorganic material layers and one or more organic material layers, and the inorganic material layers and the organic material layers may be alternately stacked.

[0105] A touch sensing layer TS may be provided on the encapsulation layer EC. The touch sensing layer TS may include touch electrodes formed of transparent conductive materials such as ITO and IZO, metal mesh, etc. The touch electrodes may be formed of a single layer or multiple layers. The touch sensing layer TS may be directly located on the encapsulation layer EC, or may be formed separately and attached to the encapsulation layer EC.

[0106] An anti-reflection layer 200 for reducing external light reflection may be provided on the touch sensing layer TS. The anti-reflection layer 200 may include a polarizing layer. Alternatively, the anti-reflection layer 200 may not be formed separately, but the encapsulation layer EC or the touch sensing layer TS may be formed with a refractive index matching structure to obtain an anti-reflection effect.

[0107] A cover window 300 for protecting the entire upper surface of the display panel DP may be provided on the anti-reflection layer 200. The cover window 300 is a flexible window that is optically transparent and at least a portion of which can be bent. In the cover window 300, at least the area corresponding to the bendable area BA of the display device is flexible and can be bent, and the entirety may be flexible. The cover window 300 may be a polymer film formed of polymers such as polyimide (PI), polyethylene terephthalate (PET), and polyurethane (PU) for flexibility. The cover window 300 may be a glass film in which the area corresponding to the bendable area BA of the display device is locally formed to be thin (for example, a thickness of less than 100 μm). The cover window 300 may be attached to the anti-reflection layer 200 by an adhesive such as OCA or PSA.

[0108] A protective layer PF for protecting the display panel DP may be disposed under the substrate SB, and a functional layer 400 may be disposed under the protective layer PF. The functional layer 400 may include functional plates such as a cushion layer, a heat dissipation plate, a shading plate, and a waterproof tape.

[0109] The case where the display panel DP is a light-emitting display panel is described as an example, but the display panel DP may be various display panels such as a display panel including a liquid crystal layer.

[0110] Although the embodiments of the present invention have been described in detail above, the scope of rights of the present invention is not limited thereto, and various modifications and improvements made by those skilled in the art using the basic concept of the present invention defined by the claims also fall within the scope of rights of the present invention.

Claims

1. A foldable display device, comprising: a first subject and a second subject; as well as A hinge part connected to the first body and the second body, The hinge portion comprises: A first joint having at least one first recessed portion; a second joint, facing the first joint; a third joint, located on one side of the first joint; A first leaf spring located in the first recessed portion; and A first fastening member is fixed to the third joint via the first leaf spring and the first joint, The third joint is slidably coupled to the first joint.

2. The foldable display device according to claim 1, wherein: The outer surface of the first joint faces the inner surface of the third joint, The outer surface of the first joint and the inner surface of the third joint are curved surfaces.

3. The foldable display device according to claim 1, wherein: The first joint has a first opening in the first recessed portion, The first fastening member includes a portion located in the first opening, The length of the first opening is greater than the diameter of a portion of the first fastening component within the first opening.

4. The foldable display device according to claim 1, wherein: In a state where the foldable display device is unfolded, the first joint, the second joint, and the third joint are arranged in a first direction, The first joint, the second joint, and the third joint extend in a second direction intersecting the first direction, respectively.

5. The foldable display device according to claim 4, wherein: The third joint has at least one third recessed portion, The first recessed portion and the third recessed portion do not overlap in the first direction.

6. The foldable display device according to claim 5, wherein: The hinge portion comprises: a fourth joint, located on one side of the second joint; a fifth joint, located on one side of the third joint; A third leaf spring located in the third recessed portion; and The third fastening member is fixed to the fifth joint via the third leaf spring and the third joint.

7. The foldable display device according to claim 6, wherein: The outer surface of the third joint faces the inner surface of the fifth joint, The outer surface of the third joint and the inner surface of the fifth joint are curved surfaces.

8. The foldable display device according to claim 6, wherein: The first leaf spring and the third leaf spring do not overlap in the first direction.

9. The foldable display device according to claim 6, wherein: The hinge portion comprises: A first connecting portion, located at one side of the fifth joint; a fifth leaf spring located in a fifth recessed portion of the fifth joint; and The fifth fastening member is fixed to the first connection portion via the fifth leaf spring and the fifth joint.

10. The foldable display device according to claim 9, wherein: The third leaf spring and the fifth leaf spring do not overlap in the first direction.

11. The foldable display device according to claim 9, wherein: The hinge portion comprises: A first rotation control unit includes a first gear and a first arm; and The second rotation control unit includes a second gear and a second arm. The teeth of the first gear mesh with the teeth of the second gear. The first arm portion passes through the holes of the first joint, the third joint, and the fifth joint, and is inserted into the hole of the first connection portion.

12. The foldable display device according to claim 11, wherein: The first gear and the second gear overlap with the first joint and the second joint in the second direction, respectively.

13. The foldable display device according to claim 1, wherein: The first joint and the second joint each include a shaft portion and a head portion having holes located on both sides of the shaft portion, The hinge portion further comprises a connecting member having at least two protrusions, The corresponding protrusions of the connection member are inserted into the hole of the head of the first joint and the hole of the head of the second joint, so that the first joint and the second joint are combined.

14. The foldable display device according to claim 1, further comprising: a display panel, located on the first body, the second body and the hinge portion, The hinge portion supports the display panel so that the display panel can be bent.

15. The foldable display device according to claim 14, further comprising: A height difference compensation layer is located between the first body, the second body, the hinge part and the display panel. The height difference compensation layer includes a cut pattern or is segmented in a region overlapping the hinge portion.

16. A foldable display device, comprising: Display panel; as well as a hinge portion that supports the display panel in a bendable manner, The hinge portion comprises: A joint portion, comprising a first joint and a second joint adjacent to each other, and a third joint and a fourth joint adjacent to the first joint and the second joint respectively; A first rotation control unit includes a first gear and a first arm; and The second rotation control unit includes a second gear and a second arm. The teeth of the first gear mesh with the teeth of the second gear. The first arm portion passes through the first joint and the third joint, The second arm portion passes through the second joint and the fourth joint, The hinge portion further comprises: a first leaf spring located on an inner surface of the first joint; and a fastening connection member that penetrates the first leaf spring and the first joint and is fixed to the third joint, The third joint is slidably coupled to the first joint.

17. The foldable display device according to claim 16, wherein: The first arm portion and the second arm portion each include a bent portion.

18. The foldable display device according to claim 16, wherein: In the first joint, a length of the opening through which the fastening member passes is greater than a diameter of a portion of the fastening member passing through the opening.

Images