KR20230054654A - Foldable display device - Google Patents

Abstract

The present invention includes: a display panel including a folding area and at least one non-folding area adjacent to the folding area; a touch screen panel embedded in the display panel; a plurality of frames disposed below the display panel to support the display panel; an adhesive layer for attaching the display panel to the plurality of frames; a plurality of housings to receive the display panel and the plurality of frames; a plurality of covers disposed on a front surface of the display panel; and a hinge unit disposed below the folding area to guide folding of the display panel, wherein the adhesive layer includes at least one open area in an area overlapping the hinge unit to reduce bending of the folding area. According to the present invention, it is possible to prevent unintended waviness to the folding area of the display panel.

Description

Foldable display device {FOLDABLE DISPLAY DEVICE}

The present invention relates to a foldable display device including a hinge unit, and more particularly, to a foldable display device including an adhesive pattern for attaching the hinge unit to a display panel.

Display devices used for computer monitors, TVs, mobile phones, etc. include an electroluminescence display device that emits light by itself and a liquid crystal display (LCD) that requires a separate light source.

The range of applications of display devices is diversifying from computer monitors and TVs to personal portable devices, and research into display devices having a reduced volume and weight while having a large display area is being conducted.

Recently, a foldable display device that can be freely folded and unfolded by forming a display unit and wires on a flexible substrate has attracted attention as a next-generation display device.

The foldable display device may include a display panel having flexibility to enable folding, a hinge unit for folding the display panel, and an adhesive film for bonding the display panel and the hinge unit. When the foldable display device is folded, a curvature occurs in one region of the display panel to be folded, and an adhesive film attached to one region of the display panel to be folded also has a curvature. Due to the aforementioned curvature, one region of the foldable display panel and the length of the adhesive film attached thereto change, resulting in unintended waviness in the folding region of the foldable display device.

Accordingly, the inventors of the present invention recognized that there is a need for a structure and method for improving unintended waviness in a folding region.

Accordingly, the inventors of the present invention invented a foldable display device in which the curvature of the folding area is reduced by patterning the adhesive film attached to the folding area.

An object to be solved by the present invention is to provide a foldable display device in which curvature of a folding area is minimized.

Another problem to be solved by the present invention is to provide a foldable display device in which adhesive strength between a display panel and a hinge unit is enhanced.

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

A foldable display device according to an exemplary embodiment of the present invention includes a display panel including a folding area and at least one non-folding area adjacent to the folding area, a touch screen panel embedded in the display panel, and A plurality of frames disposed below and supporting the display panel, an adhesive layer attaching the display panel and the plurality of frames, a plurality of housings accommodating the display panel and the plurality of frames, and a plurality of housings disposed on the front surface of the display panel. A plurality of covers and a hinge unit disposed below the folding area and guiding folding of the display panel, wherein the adhesive layer has at least one open area in an area overlapping the hinge unit.

Other embodiment specifics are included in the detailed description and drawings.

In the present invention, by attaching adhesive patterns spaced apart from each other to the folding area of the display panel, force is not applied to the outer surface of the folding area in a folded state, thereby preventing unintended waviness in the folding area FA of the display panel. can prevent

The present invention prevents separation between the folding area of the display panel and the hinge unit even in a folded state, so that separation of the display panel and the adhesive pattern does not occur even in the folded state.

In the present invention, by applying an adhesive pattern to the adhesive layer, folding reliability can be improved despite multiple times of folding.

Effects according to the present invention are not limited by the contents exemplified above, and more various effects are included in the present invention.

1A is a diagram illustrating a non-folding state of a foldable display device according to an exemplary embodiment of the present invention.
1B is a diagram illustrating a folded state of a foldable display device according to an exemplary embodiment of the present invention.
2 is an exploded perspective view of a foldable display device according to an exemplary embodiment.
3A is a diagram for explaining a hinge unit of a foldable display device according to an exemplary embodiment.
3B is a diagram for explaining a coupling relationship between hinge units of a foldable display device according to an exemplary embodiment.
4A is a side view illustrating a hinge unit in a non-folding state of a foldable display device according to an exemplary embodiment of the present invention.
4B is a side view illustrating a hinge unit of a foldable display according to an exemplary embodiment in a folded state.
5A is a cross-sectional view taken along line I-I' of FIG. 3B.
5B is a cross-sectional view of a foldable display device according to an exemplary embodiment in a folded state.
6A is a cross-sectional view of a foldable display device according to another exemplary embodiment in a non-folding state.
6B is a cross-sectional view of a foldable display device according to another exemplary embodiment in a folded state.
7A is a cross-sectional view of a foldable display device according to another exemplary embodiment in a non-folding state.
7B is a cross-sectional view of a foldable display device according to another exemplary embodiment in a folded state.

Advantages and features of the present invention, and methods of achieving them, will become clear with reference to the detailed description of the following embodiments taken in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in a variety of different shapes, only these embodiments make the disclosure of the present invention complete, and common knowledge in the art to which the present invention pertains. It is provided to completely inform the person who has the scope of the invention, and the present invention is only defined by the scope of the claims.

The shapes, areas, ratios, angles, numbers, etc. disclosed in the drawings for explaining the embodiments of the present invention are illustrative, and the present invention is not limited thereto. Like reference numbers designate like elements throughout the specification. In addition, in describing the present invention, if it is determined that a detailed description of related known technologies may unnecessarily obscure the subject matter of the present invention, the detailed description will be omitted. When 'includes', 'has', 'consists', etc. mentioned in the present invention is used, other parts may be added unless 'only' is used. In the case where a component is expressed in the singular, the case including the plural is included unless otherwise explicitly stated.

In interpreting the components, even if there is no separate explicit description, it is interpreted as including the error range.

In the case of a description of a positional relationship, for example, 'on top of', 'on top of', 'at the bottom of', 'next to', etc. Or, unless 'directly' is used, one or more other parts may be located between the two parts.

When an element or layer is referred to as “on” another element or layer, it includes all cases where another element or layer is directly on top of another element or another layer or other element intervenes therebetween.

In addition, although first, second, etc. are used to describe various components, these components are not limited by these terms. These terms are only used to distinguish one component from another. Therefore, the first component mentioned below may also be the second component within the technical spirit of the present invention.

Like reference numbers designate like elements throughout the specification.

The area and thickness of each component shown in the drawings is shown for convenience of description, and the present invention is not necessarily limited to the area and thickness of the illustrated component.

Each feature of the various embodiments of the present invention can be partially or entirely combined or combined with each other, technically various interlocking and driving are possible, and each embodiment can be implemented independently of each other or can be implemented together in a related relationship. may be

Hereinafter, the present invention will be described with reference to the drawings.

1A is a diagram illustrating a non-folding state of a foldable display device according to an exemplary embodiment of the present invention. 1B is a diagram illustrating a folded state of a foldable display device according to an exemplary embodiment of the present invention. 2 is an exploded perspective view of a foldable display device according to an exemplary embodiment.

1A and 2 , the foldable display device 100 according to an exemplary embodiment of the present invention includes a display panel 110, an adhesive layer 120 attaching other components to the display panel 110, and a display panel. A plurality of frames 131 and 132 supporting the display panel 110, a hinge unit 140 folding the display panel 110, a plurality of housings 151 and 152 housing the display panel 110, and the display panel 110 ) It includes a plurality of covers 161 and 162 protecting the.

The display panel 110 is a panel on which images are displayed, and display elements for displaying images and circuits, wires, and components for driving the display elements may be disposed.

The display panel 110 is divided into a folding area FA and non-folding areas NFA1 and NFA2 according to whether it is folded. Also, the display panel 110 is divided into a display area and a non-display area according to whether or not an image is displayed.

The display area is an area for displaying an image, and a display element for displaying an image and a circuit unit for driving the display element may be disposed. For example, when the foldable display 100 is an electroluminescent display, the display element may include an electroluminescent element, and when the foldable display 100 is a liquid crystal display, the display element may include a liquid crystal element. can include Hereinafter, for convenience of description, it is assumed that the foldable display 100 according to various embodiments of the present invention is the foldable display 100 including the electroluminescent device, but is not limited thereto.

The circuit unit may include various thin film transistors, capacitors, wires, and the like for driving the EL device. For example, the circuit unit may include various components such as a driving thin film transistor, a switching thin film transistor, a storage capacitor, a gate wire and a data wire, but is not limited thereto.

The non-display area is an area in which an image is not displayed, and is an area in which circuits, wires, and components for driving display elements of the display area are disposed. Driving circuits such as gate drivers and data drivers may be disposed in the non-display area. For example, the driving circuit is mounted on the non-display area of the display panel 110 as a gate in panel (GIP), or is connected to the display panel 110 using a tape carrier package (TCP) or a chip on film (COF) method. can be connected

The non-display area may be defined as an area surrounding the display area. However, the non-display area may also be defined as an area extending from the display area or may be defined as an area in which display elements are not disposed, but is not limited thereto.

Meanwhile, the display panel may also be defined as a display area and a non-display area, but as described above, it may also be defined as a folding area FA and non-folding areas NFA1 and NFA2.

The folding area FA is an area where the display panel 110 is folded, and is an area that is folded with a specific radius of curvature when the display panel 110 is folded. 1A and 2 illustrate that the folding area FA is disposed in the center of the display panel 110, the arrangement of the folding area FA may be variously changed, but is not limited thereto.

The non-folding areas NFA1 and NFA2 are areas where the display panel 110 maintains a flat state. The non-folding areas NFA1 and NFA2 are areas extending to both sides of the folding area FA. That is, the non-folding areas NFA1 and NFA2 may be defined with the folding area FA interposed therebetween.

Specifically, the non-folding areas NFA1 and NFA2 include a first non-folding area NFA1 disposed on one side of the folding area FA and a second non-folding area NFA2 disposed on the other side of the folding area FA. ) can be distinguished. In FIGS. 1A and 2 , the first non-folding area NFA1 and the second non-folding area NFA2 are illustrated as having the same size, but the first non-folding area NFA1 and the second non-folding area NFA2 are not limited thereto. (NFA2) can have different sizes.

Also, as shown in FIG. 1B , when the foldable display device 100 is folded, the non-folding areas NFA1 and NFA2 on both sides of the folding area FA may face each other. Further, when the first non-folding area NFA1 and the second non-folding area NFA2 have different sizes, when the foldable display 100 is in a folded state, the non-folding area having a relatively wide size ( A portion of NFA1 and NFA2) is exposed to the outside, and a portion of the non-folding area (NFA1 and NFA2) exposed to the outside continues to display the date, time, battery level, notification, etc. even when the foldable display device 100 is off. It can be.

The adhesive layer 120 is attached to the lower portion of the display panel 110 and serves to attach the display panel 110 and other components.

That is, the adhesive layer 120 serves to adhere the display panel 110 to the plurality of frames 131 and 132 and to adhere the display panel 110 to the hinge unit 140 .

In detail, the adhesive layer 120 attaches the first non-folding area NFA1 of the display panel 110 and the first frame 131 and attaches the second non-folding area NFA2 of the display panel 110 to the second frame. 132 is attached, and the folding area FA of the display panel 110 and the hinge unit 140 are attached.

As will be described later, the adhesive layer 120 attaching the folding area FA of the display panel 110 and the hinge unit 140 may include a plurality of adhesive patterns 121 spaced apart from each other.

In addition, the adhesive layer 120 is made of acrylic resin, poly(meth)acrylate-based resin, vinyl resin, styrene resin, ester-based resin, rubber-based resin, epoxy-based resin, polyimide resin, polyimide resin, etc. It may be made of an optical clear adhesive (OCA) composed of an amide resin, a phenoxy resin, a polyurethane resin, or the like, but is not limited thereto and may be made of a pressure sensitive adhesive (PSA).

Additionally, the foldable display device 100 according to an embodiment of the present invention may further include a touch screen for a user interface using a user's touch, and the touch screen panel may be attached to the display panel 110 or , may be embedded inside the display panel 110 .

The plurality of frames 131 and 132 support the first non-folding area NFA1 and the second non-folding area NFA2 of the display panel 110 and improve the internal rigidity and impact resistance of the foldable display device 100 . play a role in

The plurality of frames 131 and 132 overlap the first non-folding area NFA1, and the first frame 131 and the second non-folding area 131 accommodating the display panel 110 corresponding to the first non-folding area NFA1. It may include a second frame 132 overlapping the folding area NFA2 and accommodating the display panel 110 corresponding to the second non-folding area NFA2.

Specifically, the first frame 131 corresponds to the bonding surface of the first frame 131 and the first non-folding area NFA1 through the medium of the adhesive layer 120 overlapping the first non-folding area NFA1. By attaching the display panel 110 corresponding to the first non-folding area NFA1, the display panel 110 corresponding to the first non-folding area NFA1 is supported. Similarly, the second frame 132 is also connected to the bonding surface of the second frame 132 and the second non-folding area NFA2 through the medium of the adhesive layer 120 overlapping the second non-folding area NFA2. By attaching the corresponding display panel 110, the display panel 110 corresponding to the second non-folding area NFA2 is supported.

In addition, each of the plurality of frames 131 and 132 may be made of a high-rigidity plastic material, such as polycarbonate (PC) or polyimide (PI), to improve rigidity and impact resistance. It may be made of one of rigid materials such as glass and metal, but is not limited thereto.

In addition, each of the plurality of frames 131 and 132 may include a plurality of housing coupling protrusions 131a and 132a for fastening with the plurality of housings 151 and 152 .

Specifically, as shown in FIG. 2 , the first frame 131 includes a plurality of first housing coupling protrusions 131a on the rear side of the first frame 131 for coupling with the first housing 151. The second frame 132 may also include a plurality of second housing coupling protrusions 132a on the rear side of the second frame 132 for coupling with the second housing 152 .

The plurality of housings 151 and 152 serve to accommodate the plurality of frames 131 and 132 and protect the foldable display 100 from external impact and external contaminants.

Specifically, the first housing 151 surrounds the sidewall of the first frame 131 and is fastened via the first housing coupling protrusion 131a attached to the first frame 131, so that the first frame 131 ) and the display panel 110 corresponding to the first non-folding area NFA1 attached to the first frame 131 is not exposed to the outside. In addition, the second housing 152 is also fastened via the second housing coupling protrusion 132a attached to the second frame 132 while surrounding the sidewall of the second frame 132, so that the second frame 132 And, the display panel 110 corresponding to the second non-folding area NFA2 attached to the second frame 132 is not exposed to the outside.

As described above, the plurality of housings 151 and 152 are formed to surround internal components of the foldable display device 100, thereby protecting the foldable display device 100 from external shocks and contaminants. there is.

Additionally, a system driving unit for driving the display panel 110 may be accommodated in each of the plurality of housings 151 and 152 .

Next, the plurality of covers 161 and 162 are disposed on the entire surface of the display panel 110, expose the display area of the display panel 110, and close the outer portion of the display panel 110.

The plurality of covers 161 are composed of a first cover 161 and a second cover 162 formed in a 'c' shape to correspond to the non-display area of the display panel 110, and the first cover 161 and The second cover 162 is symmetrically disposed on the front surface of the display panel 110 .

In addition, the first cover 161 is formed on the front side of the first non-folding area NFA1 with the display panel 110 corresponding to the first non-folding area NFA1 and the first frame 131 interposed therebetween, and the first housing ( 151), and the second cover 162 also interposes the display panel 110 corresponding to the second non-folding area NFA2 and the second frame 132 in front of the second non-folding area NFA2. It is coupled with the second housing 152.

3A is a diagram for explaining a hinge unit of a foldable display device according to an exemplary embodiment. 3B is a diagram for explaining a coupling relationship between hinge units of a foldable display device according to an exemplary embodiment.

Specifically, FIG. 3A is an enlarged perspective view of one side of the hinge unit 140, and FIG. 3B shows the hinge unit 140, the first frame 131, the second frame 132, the adhesive layer 120, and the display panel ( 110) is a diagram for explaining the arrangement relationship.

For convenience of explanation, in FIG. 3B , the display panel 110 is illustrated as not covering one side of the adhesive layer 120, but this is only for explaining the arrangement relationship between the adhesive layer 120 and the hinge unit 140, The display panel 110 of the foldable display 100 according to an exemplary embodiment of the present invention and the adhesive layer 120 completely overlap each other.

The hinge unit 140 is disposed on the rear surface of the folding area FA of the display panel 110 and serves to guide folding of the folding area FA of the display panel 110 .

More specifically, the hinge unit 140 is coupled between the first frame 131 and the second frame 131, and the display panel 110 is bonded by the adhesive pattern 121 disposed on the front surface of the hinge unit 140. attached to the folding area FA of the display panel 110 to guide the folding of the folding area FA.

That is, in the foldable display device 100 according to an embodiment of the present invention, the hinge unit 140 is simply bound between the first frame 131 and the second frame 132 attached to the display panel 110. Instead of being indirectly disposed on the rear surface of the folding area FA of the display panel 110, the hinge unit 140 is directly disposed on the rear surface of the folding area FA of the display panel 110 by the adhesive pattern 121. attached

As shown in FIG. 3A , the hinge unit 140 includes a plurality of hinge segments 141 to 147 and a plurality of hinge connectors 149 connecting the plurality of hinge segments 141 to 147 . Also, the plurality of hinge segments 141 to 147 and the plurality of hinge connectors 149 are coupled by a hinge axis extending in the X direction.

The plurality of hinge segments 141 to 147 are attached to both sides of the curvature implementation parts 141b to 147b and the curvature implementation parts 141b to 147b, each formed in a bar shape extending in the X direction, so that the hinge It may include curvature setting units 141a to 147a that set the radius of curvature of the folding unit 140 . The aforementioned curvature implementing units 141b to 147b and the curvature setting units 141a to 147a may be molded products formed of one material, but are not limited thereto, and the curvature implementing units 141b to 147b and the curvature setting units 141a to 147a are not limited thereto. 147a) may be formed separately and combined.

The curvature setting units 141a to 147a are connected to the plurality of hinge connectors 149 and rotate in the YZ plane to realize the folding curvature of the hinge unit 140 .

That is, as described above, since the curvature setting units 141a to 147a and the hinge connector 149 are coupled by a hinge shaft extending in the X direction, the curvature setting units 141a to 147a are fixed in the X direction and cannot be moved. Although impossible, rotation is possible within the rotation radius of the hinge connector 149 in the YZ plane.

Specifically, each of the curvature setting units 141a to 147a may be formed in a shape in which the width gradually decreases in the Z direction. Due to the shape of the curvature setting units 141a to 147a described above, the hinge unit 140 can be folded with a constant folding radius of curvature in the Z direction by the curvature setting units 141a to 147a connected to the hinge connector 149. there is.

In the folded state, the folding radius of curvature of the hinge unit 140 is determined by the width of the curvature setting units 141a to 147a in the Z direction.

Specifically, when the width of the curvature setting units 141a to 147a in the Z direction is narrow, the folding radius of curvature of the hinge unit 140 is relatively small, and on the contrary, when the width of the curvature setting units 141a to 147a in the Z direction is wide. In this case, the folding radius of curvature of the hinge unit 140 is relatively large.

Also, the curvature implementers 141b to 147b are completely coupled to the curvature setters 141a to 147a, and the display panel 110 extends as much as the folding radius of curvature of the hinge unit 140 determined by the curvature setters 141a to 147a. ) serves to fold the folding area FA.

Specifically, each of the bar-shaped curvature implementing portions 141b to 147b extending in the X-axis direction is attached to the folding area FA of the display panel 110 by the adhesive pattern 121 extending in the X-direction. , The curvature implementation units 141b to 147b moved according to the folding radius of curvature implemented in the curvature setting units 141a to 147a fold the folding area FA of the display panel 110, thereby folding the display panel 110. Implements folding by the radius of curvature.

As described above, by the hinge unit 140 attached to the lower portion of the display panel 110 via the adhesive pattern 121 , the display panel 110 may have a constant folding radius of curvature.

4A is a side view illustrating a hinge unit in a non-folding state of a foldable display device according to an exemplary embodiment. 4B is a side view illustrating a hinge unit of a foldable display according to an exemplary embodiment in a folded state.

Specifically, in FIGS. 4A and 4B , a hinge connector is provided to describe the arrangement of the curvature setting units 141a to 147a of the plurality of hinge segments 141 to 147 in a folded state and a non-folded state of the foldable display 100 . A side view is shown except for (149).

In addition, since FIGS. 4A and 4B are side views of the foldable display device 100, the curvature implementing parts 141b to 147b of the plurality of hinge segments 141 to 147 are not shown, and the plurality of hinge segments 141 to 147 Since only the curvature setting units 141a to 147a are shown, the plurality of hinge segments 141 to 147 in FIGS. 4A and 4B refer to the curvature setting units of the plurality of hinge segments 141 to 147 shown in FIG. 3A ( 141a to 147a).

Referring to FIG. 4A , the plurality of hinge segments 141 to 147 of the foldable display 100 according to an exemplary embodiment may be divided into first to seventh hinge segments 141 to 147 .

Specifically, the first hinge segment 141 is coupled to the first frame 131, the first to seventh hinge segments 141 to 147 are connected to each other by the hinge connector 149 described above, and the seventh hinge segment (147) may be combined with the second frame (132).

Here, the coupling between the first hinge segment 141 and the first frame 131 and the coupling between the seventh hinge segment 147 and the second frame 132 are preferably screw coupling, but are not limited thereto, and various methods such as hook coupling are used. Combination methods may be applied.

And, as described above, each of the first to seventh hinge segments 141 to 147 may have a reduced width in the Z direction and be folded.

In this regard, referring to FIG. 4B , each of the first to seventh segments 141 to 147 are folded until they come into contact with each other.

That is, when the first to seventh hinge segments 141 to 147 come into contact with each other, the first to seventh hinge segments 141 to 147 are no longer folded and are fixed to determine the bending radius of curvature.

Accordingly, the folding area FA of the display panel 110 attached to the first to seventh hinge segments 141 to 147 by the adhesive pattern 121 is folded, resulting in a foldable display according to an embodiment of the present invention. Device 100 is folded.

5A is a cross-sectional view taken along line I-I' of FIG. 3B. 5B is a cross-sectional view of a foldable display device according to an exemplary embodiment in a folded state.

5A and 5B are also cross-sectional views of the foldable display 100, so the curvature setting units 141a to 147a of the hinge segments 141 to 147 are not shown, and the curvature implementation units of the hinge segments 141 to 147 ( 141b to 147b), the hinge segments 141 to 147 in FIGS. 5A and 5B mean the curvature implementation parts 141b to 147b of the hinge segments 141 to 147 shown in FIG. 3A.

As shown in FIG. 5A , a plurality of adhesive patterns 121 may be disposed to overlap the folding area FA of the display panel 110 .

The plurality of adhesive patterns 121 are some components of the above-described adhesive layer 120 and, for example, are attached to the first adhesive pattern 121a adjacent to the first non-folding area NFA1 and the first adhesive pattern 121a. It may be composed of an adjacent second adhesive pattern 121b, a third adhesive pattern 121c, and a fourth adhesive pattern 121d adjacent to the second non-folding area NFA2.

Also, the first to fourth adhesive patterns 121a to 121d may be spaced apart from each other by a predetermined distance, and the distance between the plurality of adhesive patterns 121a to 121d is equal to the width of the first to fourth adhesive patterns 121a to 121d. can be equal to

Also, a plurality of hinge segments 141 to 147 may be attached to the lower portion of the adhesive pattern 121 .

Specifically, the plurality of hinge segments 141 to 147 include a first group of hinge segments 141, 143, 145, and 147 and a second group of hinge segments 142, 144, and 146 that are alternately disposed with each other. And, only the hinge segments 141 , 143 , 145 , and 147 of the first group may be adhered to the plurality of adhesive patterns 121 .

Here, the hinge segments 141, 143, 145, and 147 of the first group mean the first hinge segment 141, the third hinge segment 143, the fifth hinge segment 145, and the seventh hinge segment 147. The second group of hinge segments 142 , 144 , and 146 may mean the second hinge segment 142 , the fourth hinge segment 144 , and the sixth hinge segment 146 .

Specifically, the first hinge segment 141 is attached to the first adhesive pattern 121a, the third hinge segment 143 is attached to the second adhesive pattern 121b, and the fifth hinge segment 145 is attached to the first adhesive pattern 121a. It is attached to the third adhesive pattern 121c, and the seventh hinge segment 147 is attached to the fourth adhesive pattern 121d.

And the second hinge segment 142, the fourth hinge segment 144, and the sixth hinge segment 146 that are not attached to the adhesive pattern 121 are connected to the first hinge segment 141 through the hinge connector 149, It is only connected to the third hinge segment 143, the fifth hinge segment 145, and the seventh hinge segment 147, and is not attached to the plurality of adhesive patterns 121, and the folding area of the display panel 110 ( FA) does not touch.

That is, the second hinge segment 142 is disposed to overlap the spaced apart space between the first adhesive pattern 121a and the second adhesive pattern 121b, and the fourth hinge segment 144 is disposed to overlap the second adhesive pattern 121b. and the third adhesive pattern 121c, and the sixth hinge segment 146 is disposed to overlap the spaced apart space between the third adhesive pattern 121c and the fourth adhesive pattern 121d. .

As shown in FIG. 5B , when the foldable display device 100 according to an embodiment of the present invention is in a folded state, as described above, the hinge unit 140 in a folded state, that is, a plurality of hinge units arranged in a folded state. Only some of the hinge segments 141 to 147 of are attached to the folding area FA of the display panel 110 via the plurality of adhesive members 121, thereby folding the folding area FA of the display panel 110. .

When the foldable display device 100 is folded, the outer surface of the folding area FA of the display panel 110 adjacent to the hinge unit 140 is longer than in the non-folding state.

If the adhesive layer is tightly attached between the folding area of the display panel and the hinge unit, as in the conventional foldable display device, the outer surface of the folding area of the display panel is stretched when the foldable display device is folded. The inner surface of the contacting adhesive layer is contracted. When the inner surface of the contracted adhesive layer presses on the outer surface of the extended folding area of the display panel, unintended waviness occurs in the folding area of the display panel or delamination of the folding area of the display panel and the adhesive layer 120 occurs. ) had a problem.

Also, in the conventional foldable display device, the adhesive layer may be removed between the folding area of the display panel and the hinge unit. In this case, since it occurs in the spaced space between the folding area of the display panel and the hinge unit, when the foldable display device is folded, the outer surface of the extended folding area of the display panel is pushed into the spaced space between the hinge unit, resulting in display There is also a problem that unintended waviness occurs in the folding area of the panel.

However, when the display device 100 according to an exemplary embodiment of the present invention is in a folded state, the outer surface of the folding area FA of the display panel 110 may be stretched, but the folding area FA of the display panel 110 By attaching the adhesive patterns 121 spaced apart from each other, the adhesive patterns 121 themselves do not stretch or contract. Accordingly, since no force is applied to the outer surface of the folding area FA where the adhesive pattern 121 is stretched, unintended waviness does not occur in the folding area FA of the display panel 110, and folding Even in this state, separation between the display panel 110 and the adhesive pattern 121 does not occur.

Further, in the foldable display device 100 according to an exemplary embodiment of the present invention, a plurality of adhesive patterns 121 spaced apart from each other are disposed between the folding area FA of the display panel 110 and the hinge unit 140. . The plurality of adhesive patterns 121 spaced apart from each other prevent separation between the folding area FA of the display panel 110 and the hinge unit 140 even in the folded state, so that the foldable display device 100 is stretched when folded. The outer surface of the folding area FA of the display panel 110 is fixed so as not to be pushed outward. Due to this, unintended waviness does not occur in the folding area FA of the display panel 110 .

As described above, the foldable display device 100 according to an exemplary embodiment of the present invention can prevent waviness of the folding area FA of the display panel 110 despite being folded a plurality of times. Reliability can be improved.

Hereinafter, a foldable display device according to another exemplary embodiment of the present invention will be described. Since the foldable display device according to one embodiment of the present invention and the foldable display device according to another embodiment of the present invention differ only in the shape of some of the hinge segments among the plurality of hinge segments, this will be intensively described and duplicated Omit the content.

6A is a cross-sectional view of a foldable display device according to another exemplary embodiment in a non-folding state. 6B is a cross-sectional view of a foldable display device according to another exemplary embodiment in a folded state.

6A and 6B are also cross-sectional views of the foldable display 200, so the curvature setting parts of the hinge segments 241 to 247 are not shown, and only the curvature implementation parts of the hinge segments 241 to 247 are shown. The hinge segments 241 to 247 in FIG. 6B mean curvature implementation parts of the hinge segments 241 to 247 .

In the foldable display 200 according to another exemplary embodiment of the present invention, the heights of the hinge segments 241 to 247 constituting the hinge unit 240, that is, the lengths in the Z direction, may be different from each other. Specifically, the lengths of the curvature implementation parts of the plurality of hinge segments 241 to 247 may be different.

That is, as shown in FIG. 6A , the hinge unit 240 may include first to seventh hinge segments 241 to 247, and the first hinge segment 241 is attached to the first adhesive pattern 121a. The third hinge segment 243 is attached to the second adhesive pattern 121b, the fifth hinge segment 245 is attached to the third adhesive pattern 121c, and the seventh hinge segment 247 is attached to the fourth It is attached with the adhesive pattern 121d.

In addition, the second hinge segment 242, the fourth hinge segment 244, and the sixth hinge segment 246 that are not attached to the adhesive pattern 121 are connected to the first hinge segment 241 and the third hinge through a hinge connector. It is only connected to the segments 243, the fifth hinge segment 245, and the seventh hinge segment 247, and is not attached to the plurality of adhesive patterns 121, but extends to the folding area FA of the display panel 110. come into contact

Specifically, the second hinge segment 242 extends to fill the separation space between the first adhesive pattern 121a and the second adhesive pattern 121b, and the fourth hinge segment 244 extends to the second adhesive pattern 121b. ) and the third adhesive pattern 121c, and the sixth hinge segment 246 extends to fill the space between the third adhesive pattern 121c and the fourth adhesive pattern 121d. do.

Thus, the second hinge segment 242 and the fourth hinge segment are longer than the Z-direction lengths of the first hinge segment 241, the third hinge segment 243, the fifth hinge segment 245, and the seventh hinge segment 247 244 and the length of the sixth hinge segment 246 in the Z direction may be long.

As shown in FIG. 6B , when the foldable display device 200 according to another embodiment of the present invention is also folded, the outer surface of the folding area FA of the display panel 110 adjacent to the hinge unit 240 is increased than when it is in the non-folding state.

In the case of another embodiment of the present invention, the second hinge segment 242 fills the separation space between the first adhesive pattern 121a and the second adhesive pattern 121b, and the fourth hinge segment 244 is the second adhesive The space between the pattern 121b and the third adhesive pattern 121c is filled, and the sixth hinge segment 246 fills the space between the third adhesive pattern 121c and the fourth adhesive pattern 121d. .

Accordingly, when the foldable display device 200 according to another embodiment of the present invention is folded, the second hinge segment 242 extending the outer surface of the folding area FA of the stretched display panel 110 and the fourth hinge The segment 244 and the sixth hinge segment 246 cannot push it into the space between the plurality of adhesive patterns 121 . Accordingly, unintended waviness does not occur in the folding area FA of the display panel 110 .

Hereinafter, a foldable display device according to another exemplary embodiment of the present invention will be described. The foldable display device according to one embodiment of the present invention and the foldable display device according to another embodiment of the present invention differ only in the adhesive layer 120 overlapping the folding area FA of the display panel. Focus on the description and omit duplicate content.

7A is a cross-sectional view of a foldable display device according to another exemplary embodiment in a non-folding state. 7B is a cross-sectional view of a foldable display device according to another exemplary embodiment in a folded state.

7A and 7B are also cross-sectional views of the foldable display 300, so the curvature setting units 141a to 147a of the hinge segments 141 to 147 are not shown, and the curvature implementation units of the hinge segments 141 to 147 ( 141b to 147b), the hinge segments 141 to 147 in FIGS. 7A and 7B mean the curvature implementation parts 141b to 147b of the hinge segments 141 to 147 shown in FIG. 3A.

In the foldable display device 300 according to another embodiment of the present invention, the adhesive layer 320 includes a plurality of adhesive patterns 321 spaced apart from each other in a portion overlapping the folding area FA of the display panel 110 . In addition, a plurality of non-adhesive patterns 322 disposed between the plurality of adhesive patterns 321 may be further included.

Here, the adhesive strength of the plurality of non-adhesive patterns 322 is lower than the adhesive strength of the plurality of adhesive patterns 321 .

Specifically, the plurality of adhesive patterns 321 are some components of the above-described adhesive layer 320, and as an example, the first adhesive pattern 321a adjacent to the first non-folding area NFA1, the first adhesive pattern ( The second adhesive pattern 321b adjacent to 321a), the third adhesive pattern 321c, and the fourth adhesive pattern 321d adjacent to the second non-folding area NFA2 may be configured.

And the plurality of non-adhesive patterns 322 are also some components of the above-described adhesive layer 320, the first non-adhesive pattern 322a disposed between the first adhesive pattern 321a and the second adhesive pattern 321b, A second non-adhesive pattern 322b disposed between the second adhesive pattern 321b and the third adhesive pattern 321c, and a third non-adhesive pattern disposed between the third adhesive pattern 321c and the fourth adhesive pattern 321d. An adhesive pattern 322c may be included.

The first hinge segment 141 is attached to the first adhesive pattern 321a, the third hinge segment 143 is attached to the second adhesive pattern 321b, and the fifth hinge segment 145 is attached to the third adhesive pattern 321b. It is attached to the adhesive pattern 321c, and the seventh hinge segment 147 is attached to the fourth adhesive pattern 121.

The second hinge segment 242 contacts the first non-adhesive pattern 322a, but is not adhered to the first non-adhesive pattern 322a because the first non-adhesive pattern 322a is not adhesive, and the fourth hinge The segment 242 also contacts the second non-adhesive pattern 322b, but since the second non-adhesive pattern 322b is not adhesive, it is not adhered to the second non-adhesive pattern 322b, and the sixth hinge segment 246 Also, although it contacts the third non-adhesive pattern 322c, it cannot adhere to the third non-adhesive pattern 322c because the third non-adhesive pattern 322c is not adhesive.

However, the second hinge segment 142, the fourth hinge segment 144, and the sixth hinge segment 146 are the first hinge segment 141, the third hinge segment 143, It is only connected to the fifth hinge segment 145 and the seventh hinge segment 147 .

In this regard, an additional configuration or process may be further provided to the plurality of non-adhesive patterns 322 in order to relatively weaken the adhesive strength of the plurality of non-adhesive patterns 322 compared to the plurality of adhesive patterns 321 . For example, when the plurality of non-adhesive patterns 322 are made of OCA like the plurality of adhesive patterns 321, the adhesive force can be controlled by adding additives to the OCA.

For example, additives that cause heat, UV, light, or chemical reactions may be mixed in the adhesive layer 320 . Therefore, it is possible to control physical properties of the plurality of non-adhesive patterns 322 by performing an additional process only on the plurality of non-adhesive patterns 322 . Therefore, even if the plurality of adhesive patterns 321 and the plurality of non-adhesive patterns 322 are made of the same material, the adhesive strength of the plurality of adhesive patterns 321 and the plurality of non-adhesive patterns 322 may be different due to additives. can That is, portions of the adhesive layer 320 corresponding to the plurality of non-adhesive patterns 322 may include additives that cause heat, UV, light, or chemical reactions. However, it is not limited thereto.

For example, as described above, the adhesive layer 320 may include an acrylic resin, a poly(meth)acrylate resin, a vinyl resin, a styrene resin, an ester resin, a rubber resin, an epoxy resin, a polyimide resin, and a polyamide resin. , phenoxy resin, polyurethane resin, and the like, but is not limited thereto.

In addition, an additive such as a photoinitiator that reacts to UV may be further included only in a portion corresponding to the non-adhesive pattern 322 . For example, the photoinitiator reacting to UV is BASF's Iracure or 2,4,6-trimethylbenzoyl-diphenyl-phosphineoxide (2,4,6-Trimethylbenzoyldiphenyl-phosphineoxide, TPO) series It may include at least one selected from the group consisting of compounds, acryl phosphine-based compounds, and combinations thereof, but is not limited thereto.

In addition, when UV is irradiated on the non-adhesive pattern 322 including the photoinitiator, the photoinitiator can generate radicals to initiate a polymerization reaction of materials constituting the non-adhesive pattern 322, and cross-linking of the non-adhesive pattern 322 Density can be improved. Accordingly, by additionally irradiating UV only to the plurality of non-adhesive patterns 322, the crosslinking density of the plurality of non-adhesive patterns 322 may be improved, and the adhesive strength of the plurality of non-adhesive patterns 322 may be increased to the plurality of adhesive patterns. (321) can be weakened.

Meanwhile, an additive such as a heat curing agent that reacts to heat may be further included in the non-adhesive pattern 322 . For example, the thermal curing agent that reacts to heat is at least one selected from the group consisting of NCO-based curing agents such as Asahi Kasei's MFA-75x and MHG-80B, epoxy-based curing agents, aziridine-based curing agents, Zn chelates as chelate curing agents, and combinations thereof It may include, but is not limited thereto.

In addition, when heat is applied to the plurality of non-adhesive patterns 322 containing a thermosetting agent, the material constituting the non-adhesive patterns 322 is cured, so that the crosslinking density can be improved. Accordingly, by additionally applying heat to the plurality of non-adhesive patterns 322, the crosslinking density of the plurality of non-adhesive patterns 322 may be improved, and the adhesive strength of the plurality of non-adhesive patterns 322 may be increased by increasing the adhesive strength of the plurality of non-adhesive patterns 322 ( 321) can be weakened.

As shown in FIG. 7B , when the foldable display device 300 according to another embodiment of the present invention is also folded, the outside of the folding area FA of the display panel 110 adjacent to the hinge unit 140 The side is stretched more than when it is in a non-folding state.

In another embodiment of the present invention, the first non-adhesive pattern 322a fills the separation space between the first adhesive pattern 321a and the second adhesive pattern 321b, and the second non-adhesive pattern 322b The space between the second adhesive pattern 321b and the third adhesive pattern 321c is filled, and the third non-adhesive pattern 322c is the space between the third adhesive pattern 321c and the fourth adhesive pattern 321d. fill the space

Accordingly, when the foldable display device 300 according to another embodiment of the present invention is folded, the folding area FA of the display panel 110 that is extended is formed by the plurality of non-adhesive patterns 322 to form the plurality of adhesive patterns 321 . ) cannot be pushed into the space between them. Accordingly, unintended waviness does not occur in the folding area FA of the display panel 110 .

A backlight unit including a light source package and a display device using the same according to various embodiments of the present disclosure can be described as follows.

A foldable display device according to an exemplary embodiment of the present invention includes a display panel including a folding area and at least one non-folding area adjacent to the folding area, disposed below the at least one non-folding area, and supporting the display panel. At least one frame disposed under the folding area, a hinge unit that guides the folding of the display panel, and a plurality of adhesive patterns disposed between the folding area and the hinge unit and spaced apart from each other to reduce the bending of the folding area. can reduce

According to another feature of the present invention, the hinge unit may include a plurality of hinge segments and a hinge connector connecting the plurality of hinge segments.

According to another feature of the present invention, each of the plurality of hinge segments,

The hinge unit may include a curvature setting unit configured to set a bending radius of curvature of the hinge unit and a curvature implementation unit coupled to the curvature setting unit and configured to fold the folding region by the folding radius of curvature.

According to another feature of the present invention, only some of the plurality of hinge segments may be adhered to the plurality of adhesive patterns.

According to another feature of the present invention, the plurality of segments include a first group of hinge segments and a second group of hinge segments that are alternately disposed, and only the first group of hinge segments are adhered to the plurality of adhesive patterns. It can be.

According to another feature of the present invention, the hinge segments of the second group may be overlapped in the spaced apart space between the plurality of adhesive patterns.

According to another feature of the present invention, the hinge segments of the second group may be in contact with the lower surface of the folding area.

According to another feature of the present invention, a plurality of non-adhesive patterns disposed between a plurality of adhesive patterns spaced apart from each other may be further included.

According to another feature of the present invention, the plurality of non-adhesive patterns may include a photoinitiator or a thermal curing agent that reacts to UV.

According to another feature of the present invention, the plurality of segments include a first group of hinge segments and a second group of hinge segments that are alternately disposed with each other, the first group of hinge segments being adhered to a plurality of adhesive patterns, , the second group of hinge segments may be in contact with a plurality of non-adhesive patterns.

A foldable display device according to an embodiment of the present invention includes a display panel including at least one folding area, a hinge unit folding the folding area by a folding radius of curvature, and an adhesive layer bonding the display panel and the hinge unit, One side of the folding area is deformed in a folded state, the adhesive layer overlaps the folding area, and includes a plurality of adhesive patterns maintaining a shape in a folded state in a non-folded state, thereby strengthening the adhesive force between the display panel and the hinge unit. can

According to another feature of the present invention, the plurality of adhesive patterns may be spaced apart from each other, the interval between the plurality of adhesive patterns may be closer in a non-folding state, and the interval between the plurality of adhesive patterns may be farther apart in a folded state.

According to another feature of the present invention, a hinge unit may be disposed between the plurality of adhesive patterns.

According to another feature of the present invention, the adhesive layer may further include a plurality of non-adhesive patterns having lower adhesive strength than the plurality of adhesive patterns between the plurality of adhesive patterns.

Although the embodiments of the present invention have been described in more detail with reference to the accompanying drawings, the present invention is not necessarily limited to these embodiments, and may be variously modified without departing from the technical spirit of the present invention. . Therefore, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention, but to explain, and the scope of the technical idea of the present invention is not limited by these embodiments. Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive. The protection scope of the present invention should be construed according to the claims below, and all technical ideas within the equivalent range should be construed as being included in the scope of the present invention.

100, 200, 300: foldable display device
110: display panel
120, 320: adhesive layer
121, 321: adhesive pattern
322: non-adhesive pattern
131: first frame
132: second frame
140: hinge unit
141 to 147: hinge segment
149: hinge connector
151: first housing
152: second housing
161: first cover
162: second cover
FA: folding area
NFA1: first non-folding area
NFA2: second non-folding area

Claims (10)

a display panel including a folding area and at least one non-folding area adjacent to the folding area;
a touch screen panel embedded inside the display panel;
a plurality of frames disposed under the display panel to support the display panel;
an adhesive layer attaching the display panel and the plurality of frames;
a plurality of housings accommodating the display panel and the plurality of frames;
a plurality of covers disposed on the front surface of the display panel; and
a hinge unit disposed below the folding area and guiding folding of the display panel;
The foldable display device of claim 1 , wherein the adhesive layer has at least one open area in an area overlapping the hinge unit. According to claim 1,
The foldable display device further includes a plurality of adhesive patterns disposed in the open area and spaced apart from each other. According to claim 2,
The hinge unit,
a plurality of hinge segments; and
Including a hinge connector connecting the plurality of hinge segments,
The foldable display device of claim 1 , wherein only some of the plurality of hinge segments are adhered to the plurality of adhesive patterns. According to claim 1,
The plurality of frames,
a first frame accommodating a display panel corresponding to a first non-folding area; and
A foldable display device comprising a second frame accommodating a display panel corresponding to a second non-folding area. According to claim 4,
The plurality of frames,
A foldable display device made of any one of polycarbonate (PC), polyimide (PI), glass, and metal. According to claim 4,
The plurality of frames,
A foldable display device comprising a plurality of housing coupling protrusions engaged with the plurality of housings, respectively. According to claim 4,
The plurality of housings,
a first housing surrounding a sidewall of the first frame; and
A foldable display device comprising a second housing surrounding a sidewall of the second frame. According to claim 1,
The adhesive layer is
Acrylic resin, poly(meth)acrylate resin, vinyl resin, styrene resin, ester resin, rubber resin, epoxy resin, polyimide resin, polyamide resin, phenoxy resin, polyurethane resin, PSA (Pressure Sensitive Adhesive) ), a foldable display device made of any one of. According to claim 1,
The plurality of covers,
A foldable display device comprising a first cover and a second cover formed in a 'c' shape to correspond to the non-display area of the display panel and symmetrically disposed on the front surface of the display panel. According to claim 2,
The foldable display device further includes a plurality of non-adhesive patterns disposed between the plurality of adhesive patterns spaced apart from each other.

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