KR102480254B1 - Fordable display device - Google Patents

Abstract

The present invention relates to a foldable display device, and the foldable display device according to an exemplary embodiment includes a first system cover and a first system cover rotatably connected to each other so as to be switchable between a folded state and an unfolded state by a hinge. 2 a system cover, a first bottom frame disposed such that one side is supported by the first system cover and the other side supports the first area of the display panel; a second bottom frame having one side supported by the second system cover and the other side supporting the second area of the display panel; and a step compensating member disposed to be interposed between both the first system cover and the first bottom frame and between the second system cover and the second bottom frame in an unfolded state, wherein the step compensating member is fixed to the first bottom frame. a contact block, a moving block fixed to the contact block to be slidably movable, and a variable member interposed between the contact block and the moving block, and as the variable member expands, the moving block slides in a direction away from the contact block. and is supported by the first system cover, thereby compensating for a level difference on the display panel. Accordingly, damage to the display panel may be reduced by physically compensating for the level difference on the rear surface of the bottom frame.

Description

Foldable display device {FORDABLE DISPLAY DEVICE}

The present invention relates to a foldable display device, and more particularly, to a foldable display device in which the appearance quality of a display panel and user's viewing characteristics are improved by compensating for a step difference in a bottom frame.

Display devices used in computer monitors, TVs, mobile phones, etc. include Organic Light Emitting Displays (OLEDs), which emit light by themselves, and Liquid Crystal Displays (LCDs), which require a separate light source. there is.

Also, recently, a foldable display device capable of displaying an image even when bent like paper by forming a display unit and wires on a flexible substrate such as plastic, which is a flexible material, is attracting attention as a next-generation display device.

The foldable display device includes a display panel and a system cover supporting and protecting the display panel. The system cover is hinged to the hinge for folding and unfolding of the display panel. At this time, as the foldable display device is folded and unfolded, a step is generated in the bottom frame supporting the display panel, resulting in waviness in the display panel. Therefore, it is difficult to maintain the flatness of the display panel, and as the appearance quality of the display panel deteriorates, the user's luminous characteristics may deteriorate.

The inventors of the present invention recognized that when assembling the bottom frame supporting the display panel of the foldable display device, an initial level difference occurs between the display panel and the bottom frame due to an assembly tolerance between the bottom frames. In addition, the inventors of the present invention recognized that the hinge axis of the hinge of the system cover is worn or sagging due to repeated folding and unfolding of the foldable display device. Accordingly, the inventors of the present invention recognized that a step difference occurs in the bottom frame disposed on the lower surface of the system cover. Accordingly, the inventors of the present invention recognized that there is a need for a method for compensating for the step difference of the bottom frame on the rear surface of the bottom frame.

Accordingly, the inventors of the present invention invented a foldable display device capable of compensating for a level difference of the bottom frame only with physical force without using an additional current while supporting the bottom frame.

Accordingly, an object to be solved by the present invention is to provide a foldable display capable of physically compensating for a step difference on the rear surface of the bottom frame when a step difference occurs in the bottom frame.

Another object to be solved by the present invention is to provide a foldable display device in which interference of a step compensating member fixed to a lower surface of a bottom frame is minimized during folding and unfolding of the foldable display device.

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.

In order to solve the above problems, a foldable display device according to an embodiment of the present invention includes a first system cover and a second system rotatably connected to each other so as to be able to switch between a folded state and an unfolded state by a hinge. a first bottom frame disposed so that one side of the cover is supported by the first system cover and the other side supports the first area of the display panel; a second bottom frame having one side supported by the second system cover and the other side supporting the second area of the display panel; and a step compensating member disposed to be interposed between both the first system cover and the first bottom frame and between the second system cover and the second bottom frame in an unfolded state, wherein the step compensating member is fixed to the first bottom frame. a contact block, a moving block fixed to the contact block so as to be slidably movable, and a variable member interposed between the contact block and the moving block, and as the variable member expands, the moving block moves away from the contact block. and is supported by the first system cover, thereby compensating for a level difference on the display panel. Accordingly, by securing a space under the bottom frame and fixing the step compensating member, it is possible to compensate for the step difference between the deformed bottom frames only with physical force.

In order to solve the above problems, a foldable display according to another embodiment of the present invention includes a hinge, a system cover hinged to the hinge, at least partially supported by an inner surface of the system cover, a first bottom frame and A bottom frame including a second bottom frame, and any one of the first bottom frame and the second bottom frame to adjust the step difference between the first bottom frame and the second bottom frame between the bottom frame and the system cover when the system cover is unfolded. It includes a step compensating member fixed to one of the contact blocks fixed to one of the first bottom frame and the second bottom frame, a moving block fixed to the contact block so as to be slidably movable toward the system cover, and , and a variable member disposed between the contact block and the moving block. Accordingly, by securing a space under the bottom frame, interference between the step compensating member and the bottom frame may be minimized during folding and unfolding of the foldable display device.

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

According to the present invention, damage to a display panel can be reduced by physically compensating for a level difference on the rear surface of a bottom frame in a foldable display device.

In addition, the present invention secures a space under the bottom frame, thereby minimizing interference between the step compensating member and the bottom frame during folding and unfolding of the foldable display.

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

1 is a plan view 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.
3 is a rear view of a foldable display device according to an exemplary embodiment of the present invention.
4 is a cross-sectional view of the foldable display according to IV-IV′ of FIG. 3 .
5 is an enlarged perspective view illustrating a step compensating member of a foldable display device according to an exemplary embodiment.
6A to 6B are schematic cross-sectional views illustrating a process of changing a display device according to an exemplary embodiment from a folded state to an unfolded state.
7A to 7C are schematic cross-sectional views illustrating a process of compensating for a step difference in a display device according to an exemplary embodiment of the present invention.

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 forms, 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, sizes, ratios, angles, numbers, etc. disclosed in the drawings for explaining the embodiments of the present invention are illustrative, so the present invention is not limited to the illustrated details. 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 of', etc. mentioned in this specification 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 size and thickness of each component shown in the drawings are shown for convenience of description, and the present invention is not necessarily limited to the size and thickness of the illustrated components.

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 in detail with reference to the drawings.

1 is a plan view 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. 1 and 2 , the foldable display device 100 includes a display panel 110, a bottom frame 120, a hinge 140, a step compensating member 150, and a system cover 130. . In FIGS. 1 and 2 , components of the foldable display device 100 are briefly illustrated for convenience of explanation, but in reality, various components for driving the foldable display device 100 may be further included.

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. For example, the display panel 110 may be one of various display panels such as an organic light emitting display panel and a liquid crystal display panel. In addition, the display panel 160 may have flexibility so that it can be folded together when the foldable display device 100 is folded.

The display panel 110 includes a folding area FA and a non-folding area NFA.

The folding area FA is an area where the display panel 110 is folded, and is maintained flat when the foldable display device 100 is in an unfolded and unfolded state, and when the foldable display device 100 is in a folded state. , can be folded unevenly.

The non-folding area NFA is an area in which the display panel 110 maintains a flat state when the display panel 110 is in an unfolded state and a folded state. The non-folding area NFA may extend from both sides of the folding area FA and rotate according to the folding of the folding area FA. When in an unfolded state, the non-folding area (NFA) may form a plane with the folding area (FA), and when in a folding state, the non-folding area (NFA) may face each other.

The bottom frame 120 is disposed on the rear surface of the display panel 110 and supports the display panel 110 . The bottom frame 120 may protect the display panel 110 from the outside. Specifically, the bottom frame 120 includes the first bottom frame 120 - 1 disposed to support the first area of the display panel 110 based on the folding area FA and the second area of the display panel 110 . It may include a second bottom frame (120-2) for supporting. Here, the first area may be defined as an area located on one side of the display panel 110 with the folding area FA as the center, and the second area may be defined as an area located on the other side with the folding area FA as the center.

The first bottom frame 120 - 1 may support at least a portion of the folding area FA and the non-folding area NFA of the display panel 110 on the rear surface of the display panel 110 . An adhesive material or the like may be applied between the first bottom frame 120 - 1 and the non-folding area NFA of the display panel 110 to fix the display panel 110 to the first bottom frame 120 - 1 . there is.

Also, the second bottom frame 120 - 2 may support at least a portion of the folding area FA and the non-folding area NFA of the display panel 110 on the rear surface of the display panel 110 . An adhesive material or the like may be applied between the second bottom frame 120 - 2 and the non-folding area NFA of the display panel 110 to fix the display panel 110 to the second bottom frame 120 - 2 . there is. The first bottom frame 120-1 and the second bottom frame 120-2 are formed of a rigid material, but the bottom frame 120 has flexibility to be folded or non-folded together with the display panel 110. can have

The step compensating member 150 may be disposed under the bottom frame 120 to support the display panel 110 together with the system cover 130 . Specifically, the step compensation member 150 may support portions of the folding area FA and the non-folding area NFA of the display panel 110 . Since the step compensating member 150 is biased toward and fixed to the first bottom frame 120 - 1 of the bottom frame 120 , the folding area FA of the display panel 110 supported by the first bottom frame 120 - 1 and may be arranged to support a partial area of the non-folding area NFA. Accordingly, the step compensating member 150 may be disposed under the second bottom frame 120-2 to support only a partial area of the folding area FA supported by the second bottom frame 120-2. A detailed description of the step compensating member 150 will be described later with reference to FIGS. 3 and 4 .

The system cover 130 is a base member for supporting the display panel 110, the bottom frame 120, and various components of the foldable display 100, and has various components for driving the foldable display 100. elements can be accommodated. For example, the system cover 130 has a square frame structure and may be coupled to the bottom frame 120 at the bottom of the bottom frame 120 by a separate fixing member such as a screw SC.

The system cover 130 includes a first system cover 130-1 supporting the first bottom frame 120-1 and a second system cover 130-2 supporting the second bottom frame 120-2. can include The first system cover 130 - 1 and the second system cover 130 - 2 may be disposed on one side area and the other side area where the folded and unfolded states of the foldable display 100 are repeated. That is, the foldable display device 100 moves along the central axis of the system cover 130, that is, the boundary between the first system cover 130-1 and the second system cover 130-2, by an external force applied by a user. Folding and unfolding operations may be performed based on .

Hinges 140 are coupled to the first and second edges ED1 and ED2 of the first system cover 130-1 and the second system cover 130-2. Here, the first edge ED1 and the second edge ED2 may be defined as edge areas on the long side of the system cover 130, but are not limited thereto. The first system cover 130-1 and the second system cover 130-2 may be configured to have the same shape and are coupled to the first system cover 130-1 and the second system cover 130-2. The hinges 140 may be arranged to be symmetrical while facing each other.

The hinge 140 is a member that connects the first system cover 130-1 and the second system cover 130-2 to each other, and in some cases, one or more hinges may be provided. In FIGS. 1 and 2 , the hinge 140 is shown as being provided on one side and the other side of the first system cover 130-1 and the second system cover 130-2, but is not limited thereto.

Specifically, the hinge 140 may be disposed at a portion of the foldable display device 100 where folding and unfolding are performed, so that folding and unfolding operations of the foldable display device 100 can be easily performed. Referring to FIG. 1 , a hinge 140 includes a first hinge shaft 143 , a second hinge shaft 144 , a base plate 141 and a rotation plate 142 .

The hinge shafts 143 and 144 may serve as a central axis to which parts constituting the hinge 140 are coupled. Hinge shafts 143 and 144 are provided as a pair, and each may correspond to the first system cover 130-1 and the second system cover 130-2. The hinge shafts 143 and 144 extend from the base plate 141 coupled to the first system cover 130-1 and connect the second system cover 130-2 to the first hinge shaft 143 and the second It includes a second hinge shaft 144 extending from the rotating plate 142 coupled to the system cover 130-2 and connecting the first system cover 130-1.

The base plate 141 is coupled to one end of the hinge shafts 143 and 144. The base plate 141 may serve to fix components constituting the hinge 140 . That is, the base plate 141 is disposed at one end of the hinge shafts 143 and 144 to prevent components coupled to the hinge shafts 143 and 144 from being separated from the hinge shafts 143 and 144. Referring to FIG. 1 , the base plate 141 is fixed to the upper surface of the first system cover 130-1, and a component such as a screw SC may be additionally fastened. Accordingly, components such as screws allow the first system cover 130-1 and the base plate 141 to be more firmly coupled.

The rotating plate 142 is coupled to the other ends of the hinge shafts 143 and 144. The rotation plate 142 is fixed to the upper surface of the second system cover 130-2 and can freely rotate based on the hinge shafts 143 and 144. At this time, the rotation plate 142 and the second system cover 130-2 may be fixed by screws or the like, but is not limited thereto. In addition, the rotation plate 142 moves along with either the first system cover 130-1 or the second system cover 130-2 during the folding or unfolding operation of the foldable display device 100. can rotate

Hereinafter, the step compensating member 150 of the foldable display 100 according to an exemplary embodiment will be described in detail with reference to FIGS. 3 and 4 .

3 is a rear view of a foldable display device according to an exemplary embodiment of the present invention. 4 is a cross-sectional view of the foldable display according to IV-IV′ of FIG. 3 . 5 is an enlarged perspective view illustrating a step compensating member of a foldable display device according to an exemplary embodiment. In FIG. 3 , only the bottom frame 120 and the step compensating member 150 are illustrated for convenience of description. 5 is a view showing a state before the variable member 153 of the step compensating member 150 is thermally expanded.

Referring to FIG. 3 , when the foldable display 100 is in an unfolded state, a step compensating member 150 is disposed on the rear surface of the bottom frame 120 . The step compensating member 150 may be biased to one side based on the folding area FA of the bottom frame 120 and fixed. Specifically, the step compensating member 150 is fixed to overlap a portion of the folding area FA and the non-folding area NFA of the display panel 110 on the rear surface of the first bottom frame 120 - 1 , and It is arranged to overlap only at least a portion of the folding area FA of the display panel 110 on the rear surface of the second bottom frame 120 - 2 . 3 and 4, the step compensating member 150 is biased towards the first bottom frame 120-1 among the first bottom frame 120-1 and the second bottom frame 120-2 and is shown to be fixed. The step compensating member 150 may be biased toward the second bottom frame 120-2 of the first bottom frame 120-1 and the second bottom frame 120-2 and fixed thereto. In FIG. 3 , it is illustrated that three step compensating members 150 are disposed, but the present invention is not limited thereto, and the number of step compensating members 150 may change according to the size of the display panel 110 .

Referring to FIG. 4 , the recess portion is provided by the first bottom frame 120-1, the second bottom frame 120-2, the first system cover 130-1 and the second system cover 130-2. (recessed portion, 160) may be defined. The recessed portion 160 is an area recessed from the inner surface of the system cover 130 adjacent to the hinge 140 . Specifically, the inner surface of the system cover 130 adjacent to the hinge 140 is an empty space formed by retracting from the hinge 140 . The recess portion 160 is an empty space between the first bottom frame 120-1, the second bottom frame 120-2, the first system cover 130-1, and the second system, and the display panel 110 In the unfolded state of ), the step compensating member 150 is disposed within the recessed portion 160 .

Referring to FIG. 4 , the step compensating member 150 includes a contact block 151 fixed to the first bottom frame 120-1 and a moving block ( 152), a variable member 153 interposed between the contact block 151 and the moving block 152, and a stopper 154 fixed to the contact block 151.

The contact block 151 is a block that is fixed to one bottom frame under the bottom frame 120 and serves as a guide to compensate for a step difference, and has a flat plate shape. The contact block 151 may compensate for an initial step difference between the first bottom frame 120 - 1 and the second bottom frame 120 - 2 due to an assembly tolerance when the bottom frame 120 is assembled. In addition, as the folded and unfolded states of the display panel 110 are repeated, it can also serve as a guide for compensating for a level difference between the first bottom frame 120-1 and the second bottom frame 120-2. .

The stopper 154 is a structure that limits the height adjustment range of the moving block 152 . The stopper 154 may serve to limit the moving block 152 fixed to the stopper 154 by extending to both ends of the contact block 151 from lifting the bottom frame 120 above a certain height.

Specifically, the stopper 154 extends from both ends of the contact block 151 in the direction in which the first system cover 130-1 and the second system cover 130-2 are disposed, and connects these parts and may include a portion parallel to the contact block 151. That is, the stopper 154 extends from the contact block 151 and includes a hole in which the moving block 152 can be disposed between the contact block 151 and the stopper 154, and integrally with the contact block 151. It may be formed and have a downwardly convex 'concave' shape. However, it is not limited thereto, and the stopper 154 may have a structure separately attached to the lower surface of the contact block 151, and any structure capable of supporting the moving block 152 so as to be caught may be used.

The stopper 154 includes a first stopper 154-1 and a second stopper 154-2. The first stopper 154-1 and the second stopper 154-2 have a first surface 154a extending from the contact block 151 and a first surface 154a extending from the first surface 154a and parallel to the contact block 151. It is composed of a second surface 154b and a third surface 154-3 extending from the second surface 154b and connected to the contact block 151. That is, the stopper 154 may have a 'c' shape.

The moving block 152 serves to lift the bottom frame 120 as the deformable member 153 expands due to thermal expansion. Specifically, the moving block 152 is between the first part 152-1 having a protruding shape to span the first stopper 154-1 and the second stopper 154 and the first part 152-1. It includes a second part 152-2 protruding from.

That is, the moving block 154 has a shape in which the 'convex' shape is reversed, and is disposed between the first stopper 154-1 and the second stopper 154-2 so that the first part 152-1 It may be coupled so as to span the first stopper 154-1 and the second stopper 154-2, respectively. At this time, the moving block 152 may be configured to slide in an up and down direction while coming into contact with the stopper 154 fixed to the contact block 151, and the height adjustment range may be limited by the stopper 154.

The variable member 153 is a member that expands as the internal temperature of the foldable display 100 increases. Specifically, the variable member 153 is a member formed by bonding a plurality of layers having different coefficients of thermal expansion. The variable member 153 may be disposed between the moving block 152 and the contact block 151 .

The variable member 153 includes a first variable member 153-1 and a second variable member 153-2 having different thermal expansion coefficients. In detail, the variable member 153 consists of the first variable member 153-1 and the first variable member 153-1 configured such that both ends of the display panel 110 are bent and fixed to the contact block 151. Consisting of a second variable member 153-2 disposed between the bent ends and fixed to the first variable member 153-1 and disposed between the first variable member 153-1 and the contact block 151 do.

Both ends of the first variable member 153-1 are bent and fixed to the contact block 151. For example, the first variable member 153 - 1 may extend in the direction of the long axis of the display panel 110 . Both ends of the bent first deformable member 153-1 may be fixed to the contact block 151 using an adhesive material or the like.

The second variable member 153-2 is disposed between both ends of the first variable member 153-1 and the contact block 151, and -1) is disposed on the inner surface. As shown in FIG. 5 , the second variable member 153-2 may contact the first variable member 153-1 and the contact block 151 at the same time.

Here, the first deformable member 153-1 may be made of a metal material having a relatively higher coefficient of thermal expansion than the second deformable member 153-2. For example, the first variable member 153-1 may be made of a material such as copper or aluminum having a relatively high coefficient of thermal expansion, and the second variable member 153-2 may be made of SUS (Steel) having a relatively low coefficient of thermal expansion. 5, the central portion of the first deformable member 153-1 is a contact block by a first height Ha from the central portion of the first deformable member 153-1. (151) and may be spaced apart. In addition, the moving block 152 is spaced a predetermined distance from the center of the first variable member 153-1 to the lower surface of the first variable member 153-1 and is fixed to the stopper 154 fixed to the contact block 151. do.

As shown in FIG. 5 , before the variable member 153 of the foldable display 100 is thermally expanded, the first part of the moving block 152 having a protruding shape to be fixed to the stopper 154 ( A lower surface of the 152-1 may be spaced apart from the second surface 154b of the stopper 154 by a predetermined distance.

In a general foldable display device, when assembling a bottom frame supporting a display panel, an assembly tolerance between bottom frames may occur. That is, in the process of assembling the bottom frame, either one of the first bottom frame and the second bottom frame may move, and accordingly, a height difference between the first bottom frame and the second bottom frame occurs, and thus the first bottom frame and the second bottom frame Wrinkles may occur in the display panel disposed on the bottom frame near the boundary of the second bottom frame.

Accordingly, the foldable display device 100 according to an exemplary embodiment of the present invention arranges the contact block 151 under the bottom frame 120 supporting the display panel 110, so that when assembling the bottom frame 120, It is possible to prevent an assembly tolerance between the bottom frames 120 from occurring. Specifically, in the process of assembling the first bottom frame first bottom frame 120-1 and the second bottom frame 120-2, the first bottom frame 120-1 and the second bottom frame 120-2 When the contact block 151 is placed on the bottom of one of the contact blocks and then the other is assembled, the contact block 151 may serve as a guide. Accordingly, the first bottom frame 120-1 and the second bottom frame 120-2 are assembled in a state where the flatness between the first bottom frame 120-1 and the second bottom frame 120-2 is maintained. It can be. Therefore, in the foldable display device 100 according to an exemplary embodiment of the present invention, the step difference between the initial assembly of the display panel 110 and the bottom frame 120 is improved by the contact block 151, so that the display panel 110 It can compensate for curvature.

6A to 6B are schematic cross-sectional views illustrating a process of changing a display device according to an exemplary embodiment from a folded state to an unfolded state.

The foldable display device 100 may be in-folded so that the display panel 110 is disposed inside. That is, during in-folding, the foldable display 100 may be folded so that one side and the other side of the display panel 110 face each other.

Referring to FIG. 6A , the foldable display 100 may be in-folded so that the first bottom frame 120-1 and the second bottom frame 120-2 completely face each other by an external force. Hereinafter, for convenience of description, the foldable display 100 of FIG. 6A will be defined and described in an initial state in the case of in-folding. In this case, the first bottom frame 120 - 1 and the second bottom frame 120 - 2 may be disposed to completely face each other with the display panel 110 interposed therebetween.

In addition, the display panel 110 disposed on the first bottom frame 120-1 and the second bottom frame 120-2 also includes the first bottom frame 120-1 and the second bottom frame 120-2. By the movement of , one side and the other side of the display panel 110 may be in-folded to face each other. In addition, the display panel 110 may be in-folded with a central portion bent into a curved surface.

When the foldable display 100 is fully folded, the step compensating member 150 is fixed only to the first bottom frame 120-1, and when the second bottom frame 120-2 rotates, the step compensating member ( The second stopper 154-2 of 150 may be exposed to the outside. Accordingly, although not shown in FIG. 6A , the display panel ( 110) and a flexible folding cover configured to cover the step compensating member 150 may be further configured. Here, the flexible folding cover may be defined as a member that protects side ends of the system covers 130 from the outside when the foldable display device 100 is folded and the side ends of the system covers 130 are opened.

Referring to FIG. 6B , when the foldable display 100 is converted from a folded state to an unfolded state by an external force, the first bottom frame 120-1 and the second bottom frame 120-2 are outer shells. It can be in-folded to have. At this time, the display panel 110 disposed on the first bottom frame 120-1 and the second bottom frame 120-2 also includes the first bottom frame 120-1 and the second bottom frame 120-2. It can be in-folded by the movement of . In addition, the display panel 110 may be in-folded with a central portion corresponding to a boundary area between the first system cover 130-1 and the second system cover 130-2 where the hinge 140 is disposed and bent into a curved surface. there is.

When the foldable display 100 is in-folded, the second bottom frame 120-2 is connected to the contact block 151 of the step compensating member 150 fixed to the lower surface of the first bottom frame 120-1. You can press the top. Therefore, since the second bottom frame 120-2 presses the upper surface of the contact block 151, interference between the step compensating member 150 and the second bottom frame 120-2 or the display panel 110 does not occur. may not be

Hereinafter, a process of compensating for a step between bottom frames generated as the foldable display 100 is continuously folded and unfolded will be described with reference to FIGS. 7A to 7C .

7A to 7C are schematic cross-sectional views illustrating a process of compensating for a level difference in a display device according to an exemplary embodiment of the present invention.

Referring to FIG. 7A , while the foldable display 100 is repeatedly folded and unfolded, the hinge 140 is worn out or the seat 140 is sagging, and the step compensating member 150 is fixed. 1 A phenomenon in which the bottom frame 120-1 is struck downward may occur. Accordingly, as the first bottom frame 120-1 is hit, the step compensating member 150 fixed to the first bottom frame 120-1 is also hit downward together, and the first bottom frame 120-1 and A step may occur between the second bottom frames 120 - 2 , which may cause a bend in the display panel 110 .

However, in the foldable display device 100 according to an embodiment of the present invention, as the internal temperature of the foldable display device 100 increases, as shown in FIG. When the member 153 expands, the flexible first deformable member 153-1 can expand in the direction in which the moving block 152 is formed. Accordingly, when the foldable display 100 is in a thermally expanded state, the central portion of the first deformable member 153 - 1 may be spaced apart from the contact block 151 by the second height Hb. In addition, the second part 152-2 of the moving block 152 can slide downward until the bottom surface of the first part 152-1 comes into contact with the second surface 154b of the stopper 154. there is.

Specifically, when the internal temperature of the foldable display 100 rises due to heat generated from the battery or the like when the foldable display 100 is in use, the first variable member 153-1 of the step compensating member 150 ) and the temperature of the second variable member 153-2 may rise simultaneously. Further, as the second variable member 153-2 having a low coefficient of thermal expansion is disposed above the first variable member 153-1 and both ends of the first variable member 153-1 are bent, the variable member 153-1 is bent. The heat applied to 153 is concentrated in the center of the first variable member 153-1 and the second variable member 153-2. In this case, the foldable display device 100 according to an exemplary embodiment of the present invention combines the variable member 153 with a plurality of variable members having different thermal expansion coefficients, that is, the first variable member 153-1 having a high thermal expansion coefficient. By configuring the second variable member 153-2 with a low thermal expansion coefficient, the first variable member 153-1 and the second variable member 153-2 in which heat is intensively concentrated during thermal expansion of the variable member 153 ), the second variable member 153 - 2 having a low coefficient of thermal expansion may expand in only one direction, that is, in a direction away from the contact block 151 . In addition, the random expansion of the first deformable member 153-1 may be prevented by making the thermal expansion coefficients of the first deformable member 153-1 and the second deformable member 153-2 offset. Specifically, the first variable member 153 - 1 made of a metal having a high thermal expansion coefficient may expand in a random direction as the internal temperature of the foldable display 100 increases. Accordingly, by disposing the second variable member 153-2 made of a metal having a low thermal expansion coefficient on the first variable member 153-1, the second variable member 153-2 is formed by the first variable member 153-1. The first variable member 153-1 can expand in only one direction by offsetting the thermal expansion coefficient of 1).

In addition, the second variable member 153-2 made of a metal having a low thermal expansion coefficient is brought into contact with the contact block 151 before thermal expansion, that is, at or below a predetermined temperature, and after thermal expansion, as shown in FIG. 7B, It is preferable that the second deformable member 153-2 does not come into contact with the contact block 151 due to the movement of the first deformable member 153-1.

Accordingly, in the foldable display device 100 according to an exemplary embodiment of the present invention, the first variable member 153-1 having a high coefficient of thermal expansion may increase the internal temperature of the foldable display device 100 so that the moving block 152 ) direction, the moving block 152 can be slid and moved in a direction away from the contact block 151.

Therefore, in the foldable display device 100 according to an exemplary embodiment of the present invention, the temperature inside the foldable display device 100 is continuously increased by the stopper 154 fixed to the contact block 151, and the first variable It is possible to prevent the moving block 152 from rising above a predetermined height while preventing the member 153-1 from continuously expanding.

In a general foldable display device, a hinge axis of a hinge fixed to a system cover is worn due to continuous folding and unfolding, and as bottom frames supporting the display panel move excessively, a step between bottom frames is generated. Accordingly, as the display panel disposed on the bottom frame having the step is also curved, the user's luminous characteristics are deteriorated and the reliability of the display panel is deteriorated.

In addition, when an actuator such as a motor is used to compensate for a step difference between bottom frames of the foldable display device, the use time of the foldable display device may be reduced due to the use of current. In addition, when an elastic member such as a spring is used to compensate for a step difference, the thickness of the foldable display device can be increased because a space for fastening the elastic member must be secured.

Accordingly, the foldable display device 100 according to an exemplary embodiment of the present invention is capable of continuously folding and unfolding the foldable display device 100 by the variable member 153 included in the step compensating member 150. A step difference between the first bottom frame 120-1 and the second bottom frame 120-2 may be compensated for. Specifically, the first variable member 153-1 and the second variable member 153-2 constituting the variable member 153 are formed to have different coefficients of thermal expansion, so that the variable member 153 is variable by thermal expansion. The member 153 may slide the contact block 151 to compensate for the step difference.

Accordingly, the step compensation member 150 of the foldable display device 100 according to an exemplary embodiment of the present invention does not require additional current, and thus can compensate for the step difference between the deformed bottom frames 120 only with physical force. In addition, since a plurality of thin frames having different coefficients of thermal expansion are used, the thickness of the step compensating member 150 is formed thin, thereby improving the degree of freedom in design.

Accordingly, by simultaneously improving the curvature of the display panel 110, damage to the display panel 110 can be prevented, and the external quality of the foldable display device 100 can be improved. Reliability of the device 100 may be improved.

A foldable display device 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 first system cover and a second system cover rotatably connected to each other so as to be switchable between a folded state and an unfolded state by a hinge, and one side of the first system cover. A first bottom frame supported by and disposed to support the first area of the display panel on the other side, and a second bottom frame supported by the second system cover and disposed to support the second area of the display panel on the other side. A bottom frame and a step compensating member disposed to be interposed between both the first system cover and the first bottom frame and between the second system cover and the second bottom frame in an unfolded state, wherein the step compensating member comprises: It includes a contact block fixed to the frame, a moving block fixed to the contact block so as to be slidably movable, and a variable member interposed between the contact block and the moving block. As the variable member expands, the moving block becomes the contact block. It slides in a direction away from the first system cover and is supported by the first system cover, thereby compensating for a level difference on the display panel.

According to another feature of the present invention, the moving block may be configured to be slidably movable while contacting a stopper fixed to the contact block, so that a height adjustment range may be limited by the stopper.

According to another feature of the present invention, the stopper includes a first stopper and a second stopper extending from both ends of the contact block toward the system covers, and a moving block is disposed between the first stopper and the second stopper In the unfolded state, the first stopper may be positioned below the first bottom frame and the second stopper may be positioned below the second bottom frame.

According to another feature of the present invention, the deformable member may be formed by joining a plurality of frames having different coefficients of thermal expansion.

According to another feature of the present invention, the deformable member is disposed between a first deformable member configured such that both ends are bent and fixed to the contact block, and both ends of the first deformable member, and is fixed on the first deformable member. and a second deformable member, wherein the first deformable member may be made of a metal material having a higher coefficient of thermal expansion than the second deformable member.

According to another feature of the present invention, the second variable member may come into contact with the contact block at or below a predetermined temperature.

According to another feature of the present invention, in an unfolded state, a recessed porion is formed in the first system cover and the second system cover, and the step compensating member can be disposed in the recessed portion.

According to another feature of the present invention, at least one step compensating member may be disposed along the direction of the hinge axis of the hinge.

According to another feature of the present invention, it is configured to be fixed to one of the first system cover and the second system cover and slidably inserted into the other, and configured to cover the display panel and the step compensating member in a folded state. A flexible folding cover may be further included.

A foldable display device according to another embodiment of the present invention includes a hinge, a system cover hingedly connected to the hinge, a bottom frame at least partially supported by an inner surface of the system cover, and when the system cover is unfolded, the bottom frame and the system cover. A step compensating member fixed to any one of the bottom frames to adjust a step difference between bottom frames between the covers, wherein the step compensating member includes a contact block fixed to one of the bottom frames and a sliding movement of the contact block toward the system cover. It includes a moving block fixed as possible and a variable member interposed between the contact block and the moving block.

According to another feature of the present invention, the variable member may include a first variable member and a second variable member having different thermal expansion coefficients, and the first variable member may have a higher thermal expansion coefficient than the variable member.

According to another feature of the present invention, both ends of the first deformable member are bent and fixed to the contact block, and the second deformable member is between the first deformable member and the contact block, and at least one of the first deformable member and the contact block It can be placed in contact with .

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 following claims, and all technical ideas within the equivalent range should be construed as being included in the scope of the present invention.

100: foldable display device
110: display panel
120: bottom frame
120-1: 1st bottom frame
120-2: 2nd bottom frame
130: system cover
130-1: first system cover
130-2: Second system cover
140: hinge
141: base plate
142: rotating plate
143: first hinge axis
144: second hinge axis
150: absence of step compensation
151: contact block
152: moving block
152-1: first part
152-2: second part
153: variable member
153-1: first deformable member
153-2: first deformable member
154: stopper
154-1: first stopper
154-2: second stopper
154a: first side
154b: second side
154c: third side
160: recess part
ED1: 1st edge
ED2: 2nd edge
Ha: first height
Hb: second height
FA: folding area
NFA: non-folding area
SC: screw

Claims (12)

a first system cover and a second system cover rotatably connected to each other so as to be switchable between a folded state and an unfolded state by a hinge;
a first bottom frame having one side supported by the first system cover and the other side supporting the first area of the display panel;
a second bottom frame having one side supported by the second system cover and the other side supporting the second area of the display panel; and
A step compensating member disposed to be interposed between both the first system cover and the first bottom frame and between the second system cover and the second bottom frame in the unfolded state,
The step compensating member includes a contact block fixed to the first bottom frame, a moving block fixed to the contact block to be slidably movable, and a variable member interposed between the contact block and the moving block. do,
The foldable display device of claim 1 , wherein the moving block slides in a direction away from the contact block as the variable member expands, and is supported by the first system cover to compensate for a step difference on the display panel.
According to claim 1,
The moving block is configured to be slidably movable while contacting a stopper fixed to the contact block, so that a height adjustment range is limited by the stopper.
According to claim 2,
The stopper includes a first stopper and a second stopper extending from both ends of the contact block toward the system covers,
The moving block is disposed between the first stopper and the second stopper,
In the unfolded state, the first stopper is positioned below the first bottom frame, and the second stopper is positioned below the second bottom frame.
According to claim 1,
The variable member,
A foldable display device formed by bonding a plurality of layers having different coefficients of thermal expansion.
According to claim 4,
The variable member,
a first deformable member having both ends bent and fixed to the contact block; and
a second variable member disposed between both ends of the first variable member and fixed on the first variable member;
The foldable display device of claim 1 , wherein the first variable member is made of a metal material having a higher coefficient of thermal expansion than the second variable member.
According to claim 5,
The second variable member contacts the contact block at a temperature below a predetermined temperature.
According to claim 1,
In the unfolded state, a recessed portion is formed in the first system cover and the second system cover,
The step compensating member is disposed within the recess portion.
According to claim 1,
The foldable display device of claim 1 , wherein at least one step compensating member is disposed along a direction of a hinge axis of the hinge.
According to claim 1,
A flexible folding cover configured to be fixed to one of the first system cover and the second system cover and slidably inserted into the other, and configured to cover the display panel and the step compensating member in the folded state. Further comprising a foldable display device.
hinge;
a system cover rotatably connected by the hinge to be switchable between a folded state and an unfolded state;
a bottom frame at least partially supported by an inner surface of the system cover and including a first bottom frame and a second bottom frame; and
When the system cover is unfolded, a step fixed to either one of the first bottom frame and the second bottom frame is adjusted to adjust a step between the bottom frame and the system cover between the first bottom frame and the second bottom frame. including the absence of compensation;
The step compensating member includes a contact block fixed to one of the first bottom frame and the second bottom frame, a moving block fixed to the contact block to be slidably movable toward the system cover, the contact block and the A foldable display device including a variable member disposed between the moving blocks and expanding in volume as temperature increases.
According to claim 10,
The variable member,
a first variable member and a second variable member having different coefficients of thermal expansion;
The first variable member has a higher coefficient of thermal expansion than the second variable member.
According to claim 11,
Both ends of the first deformable member are bent and fixed to the contact block;
wherein the second variable member is disposed between the first variable member and the contact block to come into contact with at least one of the first variable member and the contact block.

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