Display device

Abstract

To provide a display device capable of eliminating bubbles generated in a bonding process of a display module.SOLUTION: A foldable display device comprises: a system middle frame capable of folding relative to a folding axis; and a foldable display module having a folding area that is bonded with the system middle frame and capable of folding relative to the folding axis, and a plurality of flat areas connected through the folding area. The foldable display module includes: a display panel including the plurality of flat areas and the folding area; and a bottom plate that is bonded between the display panel and the system middle frame, and includes a plurality of folding patterns arranged in the folding area and a plurality of aperture patterns arranged in the plurality of flat areas.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present specification relates to a display device. [Background technology]

[0002] 2. Description of the Related Art Electroluminescence displays (ELDs) have advantages of using light-emitting elements to achieve high brightness, low driving voltage, and the ability to be made ultra-thin, as well as being able to be implemented in any shape.

[0003] The electroluminescent display device can be applied to a display device whose display area can be folded or unfolded depending on the application. In the display device, air bubbles generated during the bonding process can cause screen defects, so a method for removing the air bubbles is required.

[0004] Display devices require a heat dissipation method because image retention can occur due to heat generated by circuit components. Summary of the Invention [Problem to be solved by the invention]

[0005] The present disclosure provides a display device capable of eliminating air bubbles generated during a display module bonding process, thereby improving screen defects.

[0006] The present specification provides a display device capable of improving the heat dissipation characteristics of a display module.

[0007] The problems to be solved in the various embodiments of this specification are not limited to those described above, and other problems not mentioned will be clearly understood by those having ordinary skill in the art to which the technical ideas of this specification belong from the following description. [Means for solving the problem]

[0008] A foldable display device according to an embodiment includes a system middle frame foldable about a folding axis, and a foldable display module attached to the system middle frame and having a folding region foldable about the folding axis and a plurality of flat regions connected via the folding region, wherein the foldable display module includes a display panel including a plurality of flat regions and folding regions, and a bottom plate attached between the display panel and the system middle frame and including a plurality of folding patterns arranged in the folding region and a plurality of opening patterns arranged in the plurality of flat regions, wherein each of the plurality of bubble discharge patterns may include an outer hole pattern and an inner hole pattern connected to the outer hole pattern.

[0009] A foldable display device according to an embodiment may include a display panel including a plurality of flat regions and a folding region disposed between the plurality of flat regions and foldable based on a folding axis; a bottom plate attached to a rear surface of the display panel and including a plurality of folding patterns disposed corresponding to the folding regions and a plurality of opening patterns having external hole patterns and internal hole patterns of different sizes disposed corresponding to the plurality of flat regions; and a system middle frame attached to the bottom plate via a plurality of adhesives separately disposed on the rear surface of the bottom plate corresponding to the plurality of flat regions and foldable based on the folding axis.

[0010] Specific details of various embodiments other than the above-described means for solving the problems are included in the following description and drawings. [Effects of the Invention]

[0011] In the foldable display device according to one embodiment, even if air bubbles are generated during the bonding process of the foldable display module and the system middle frame, the air bubbles can be removed through an opening pattern (air bubble exhaust pattern) provided in the flat area of ​​the bottom plate of the foldable display module, thereby preventing screen defects caused by the air bubbles and improving product yield, thereby achieving the effects of reducing production energy and greenhouse gas emissions.

[0012] In an embodiment of the foldable display device, the opening pattern (air bubble discharge pattern) of the bottom plate has an outer width smaller than the inner width, thereby minimizing the reduction in the bonding area of ​​the adhesive disposed between the foldable display module and the system middle frame and preventing a reduction in adhesive strength. This prevents the foldable display module from moving due to vibration or impact, and prevents wrinkles on the screen.

[0013] A foldable display device according to an embodiment may improve the heat dissipation characteristics of a foldable display module by using a bottom plate having an opening pattern (air bubble discharge pattern). Furthermore, the foldable display device according to an embodiment may further improve the heat dissipation characteristics for heat generated by circuit components by making the internal width of the opening pattern (air bubble discharge pattern) in an area overlapping with the printed circuit board larger than the internal width of other parts. Therefore, the foldable display device according to an embodiment may improve the heat dissipation characteristics, thereby reducing deterioration of the display panel and extending its lifespan, thereby achieving low power consumption.

[0014] The effects obtained in this specification are not limited to those mentioned above, and other effects not mentioned will be clearly understood by those having ordinary skill in the art to which this specification pertains from the following description. [Brief explanation of the drawings]

[0015] [Figure 1] 1A and 1B are perspective views schematically illustrating configurations of a foldable display device before and after coupling according to an embodiment; [Figure 2] 1A and 1B are perspective views schematically illustrating configurations of a foldable display device before and after coupling according to an embodiment; [Figure 3] 1A to 1C are cross-sectional views schematically illustrating configurations of a foldable display device before and after coupling according to an embodiment. [Figure 4] 1A to 1C are cross-sectional views schematically illustrating configurations of a foldable display device before and after coupling according to an embodiment. [Figure 5] 1A and 1B are diagrams illustrating a cross-sectional structure of a foldable display device and a rear structure of a bottom plate according to an embodiment; [Figure 6] FIG. 10 is a plan view illustrating the rear structure of a bottom plate according to one embodiment. [Figure 7A] 1A and 1B are perspective views illustrating the structure of a bottom plate according to an embodiment as viewed from above and from behind, respectively. [Figure 7B] 1A and 1B are perspective views illustrating the structure of a bottom plate according to an embodiment as viewed from above and from behind, respectively. [Figure 8] FIG. 2 is a cross-sectional view illustrating a portion of a bottom plate according to one embodiment. [Figure 9] 10A and 10B are plan views illustrating rear structures of bottom plates according to various embodiments. [Figure 10] 10A and 10B are plan views illustrating rear structures of bottom plates according to various embodiments. [Figure 11] 10A and 10B are plan views illustrating rear structures of bottom plates according to various embodiments. [Figure 12] 10A and 10B are plan views illustrating rear structures of bottom plates according to various embodiments. [Figure 13] 10A and 10B are schematic diagrams illustrating a bubble discharging process in a bottom plate bonding process according to an embodiment; [Figure 14] 1 is a cross-sectional view illustrating an example of an overlapping region between a bottom plate and a driving circuit unit in a foldable display device according to an embodiment; [Figure 15A]1A and 1B are plan and rear views illustrating the structure of a foldable display device before and after assembly according to an embodiment; [Figure 15B] 1A and 1B are plan and rear views illustrating the structure of a foldable display device before and after assembly according to an embodiment; [Figure 16A] 1A and 1B are plan and rear views illustrating the structure of a foldable display device before and after assembly according to an embodiment; [Figure 16B] 1A and 1B are plan and rear views illustrating the structure of a foldable display device before and after assembly according to an embodiment; [Figure 17A] 1A and 1B are plan and rear views illustrating a foldable display device according to an embodiment; [Figure 17B] 1A and 1B are plan and rear views illustrating a foldable display device according to an embodiment; [Figure 18] 1 is a cross-sectional view illustrating an example of an area where a printed circuit board is arranged in a foldable display device according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0016] The advantages and features of the present specification, as well as methods for achieving them, will become apparent from the following detailed description of the embodiments in conjunction with the accompanying drawings. However, the present specification is not limited to the embodiments disclosed below, and may be embodied in various different forms. These embodiments are provided solely to ensure that the disclosure of the present specification is complete and to fully convey the scope of the invention to those skilled in the art. The present specification is defined only by the scope of the claims.

[0017] The shapes, sizes, ratios, angles, numbers, etc. disclosed in the drawings for illustrating the embodiments of this specification are illustrative only and do not limit the present specification to the details shown in the drawings. The same reference numerals refer to the same elements throughout this specification. In addition, if a detailed description of related prior art is deemed to unnecessarily obscure the gist of this specification, the detailed description will be omitted. When terms such as "comprise," "have," and "consist of" are used in this specification, other parts may be added unless "only" is used. When a component is expressed in the singular, it also includes the plural unless otherwise explicitly stated.

[0018] When interpreting elements, the error range is interpreted as being included even if there is no separate explicit description of the error range.

[0019] In the case of a description of a positional relationship, for example, when the positional relationship of two parts is described using "above," "on top," "below," or "beside," one or more other parts may be located between the two parts, unless the words "immediately" or "directly" are used.

[0020] When describing a temporal relationship, for example, when the temporal precedence relationship is described using "after," "following," "next to," or "before," it can also include cases where the relationship is not consecutive, unless the words "immediately" or "directly" are used.

[0021] Although terms such as "first" and "second" are used to describe various components, these components are not limited by these terms. These terms are used merely to distinguish one component from another. Therefore, a first component referred to below may also be a second component within the technical concept of this specification.

[0022] In describing components in this specification, terms such as first, second, A, B, a, b, etc. may be used. These terms are used merely to distinguish the component from other components, and do not limit the nature, order, sequence, or number of the components. When a component is described as being "connected," "coupled," or "connected" to another component, it should be understood that the component can be directly connected or connected to the other component, but that other components may be "intervening" between each component that can be indirectly connected or connected unless otherwise explicitly stated.

[0023] The term "at least one" should be understood to include all combinations of one or more of the associated components. For example, the meaning of "at least one of the first, second, and third components" can include not only the first, second, or third component, but also all combinations of two or more of the first, second, and third components.

[0024] The features of each of the embodiments of this specification can be partially or wholly combined or combined with each other, and various technical interlocking and driving mechanisms are possible, and each embodiment can be implemented independently of each other or can be implemented together in a linked relationship.

[0025] The present invention will be described in detail with reference to the accompanying drawings and examples below. The scales of the components shown in the drawings are different from the actual scales for the convenience of explanation, and are not limited to the scales shown in the drawings.

[0026] 1 and 2 are perspective views illustrating the configuration of a foldable display device according to an embodiment before and after coupling, FIGS. 3 and 4 are cross-sectional views illustrating the configuration of a foldable display device according to an embodiment before and after coupling, FIG. 5 is a view illustrating the cross-sectional structure of a foldable display device according to an embodiment and the rear structure of a bottom plate, FIG. 6 is a plan view illustrating the rear structure of a bottom plate according to an embodiment, FIGS. 7A and 7B are perspective views illustrating the structures of a bottom plate according to an embodiment as seen from the top and rear, respectively, and FIG. 8 is a cross-sectional view illustrating a portion of a bottom plate according to an embodiment.

[0027] 1 to 8, a foldable display device 1000 according to an embodiment may include a foldable display module 500 including a display panel 100, and a system middle frame 700 that is attached to the foldable display module 500 via an adhesive 600 and is foldable based on a folding core (FCL).

[0028] In Figures 1 to 8, the first direction (X) and the second direction (Y) may be the lateral direction (horizontal direction) and the longitudinal direction (vertical direction) on the plane of the display device 1000, and the third direction (Z) may be the thickness direction of the display device 1000.

[0029] The foldable display module 500 according to one embodiment may include a display panel 100, a bottom plate (300) disposed on the rear surface of the display panel 100, and a driving circuit unit 200 connected to a bezel region (BZ) of the display panel 100 to drive the display panel 100.

[0030] The foldable display module 500 can be assembled by attaching it to the system middle frame 700 via an adhesive 600 arranged on the upper surface of the system middle frame 700, bending the circuit film 210 of the driving circuit unit 200, and placing a printed circuit board (hereinafter referred to as PCB) 230 on the back surface of the system middle frame 700.

[0031] The foldable display device 1000 according to an embodiment may include a plurality of flat areas (FA) and a folding area (FPA) disposed between the plurality of flat areas (FA) and connected to the flat areas (FA). The folding area (FPA) of the foldable display device 1000 may be disposed along a folding axis (FCL) of the system middle frame 700. The foldable display device 1000 according to an embodiment may include, but is not limited to, one folding area (FPA) disposed between two flat areas (FA). The foldable display device 1000 according to an embodiment may include three or more flat areas (FA) and two or more folding areas (FPAs), including a folding area (FPA) disposed between adjacent flat areas (FA).

[0032] The foldable display apparatus 1000 can maintain a folded state in which the folding area (FPA) is folded and an unfolded state in which the folding area (FPA) is unfolded based on the folding line (FCL) of the system middle frame 700. The foldable display apparatus 1000 according to an embodiment can be folded in an in-folding manner in which the display areas (DA) of the display panels 100 face each other on the inside. The foldable display apparatus 1000 according to an embodiment can be folded in an out-folding manner in which the rear surfaces face each other on the inside.

[0033] The foldable display apparatus 1000 according to one embodiment may be folded in a second direction (Y) based on a folding line (FCL) in a first direction (X), but is not limited thereto. When the folding line (FCL) direction is the second direction (Y), the foldable display apparatus 1000 may be folded in the first direction (X).

[0034] The display panel 100 according to an embodiment may be a flexible display panel. The flexible display panel may be an electroluminescent display panel, a micro light emitting diode (LMD) display panel, or a liquid crystal display panel. The LMD display panel may be an organic light emitting diode (OLED) display panel, a quantum dot light emitting diode (QD) display panel, or an inorganic light emitting diode (ILD) display panel.

[0035] The display panel 100 according to an embodiment may include a display area (DA) for displaying an image and a bezel area (BZ) located around the periphery of the display area (DA). The display panel 100 according to an embodiment may further include a touch sensor array superimposed on the display area (DA). The display panel 100 according to an embodiment may provide a touch sensing function for sensing whether or not a user touches something and the touch coordinates, in addition to a display function for displaying an image.

[0036] The display panel 100 according to an embodiment may include a display unit 110 disposed on a back plate 140, a polarizer 120 disposed on the display unit 110, and a cover film 130 disposed on the polarizer 120. The display panel 100 according to an embodiment may further include another upper substrate layer disposed on the display unit 110 and having an optical property improving function or a protection function. The display panel 100 according to an embodiment may further include a support plate 150 disposed on the rear surface of the back plate 140, and may further include another lower substrate layer having a reinforcing function or a protection function. The support plate 150 may be referred to as a top plate.

[0037] The display unit 110 of the display panel 100 according to one embodiment may include a pixel array including a plurality of subpixels disposed on a backplate 140, an encapsulation layer for sealing the pixel array, and a touch sensor array including sensor electrodes disposed on the encapsulation layer. The pixel array may include a circuit element layer including a plurality of thin film transistors and a plurality of signal lines, and a light emitting element layer disposed on the circuit element layer and including a plurality of light emitting elements each realizing a plurality of subpixels. The circuit element layer may include a gate driving circuit for driving gate lines among the plurality of signal lines. The gate driving circuit may be disposed in the bezel region (BZ) or may be distributed throughout the display region (DA) and the bezel region (BZ).

[0038] The plurality of thin film transistors arranged in the display unit 110 of the display panel 100 may include at least one of low temperature polysilicon (LTPS) transistors using LTPS semiconductors and oxide transistors using metal oxide semiconductors. The display panel 100 according to an embodiment may be configured so that both LTPS transistors and oxide transistors are present to reduce power consumption.

[0039] The bottom plate 300 according to an embodiment is attached to the rear surface of the display panel 100 via an adhesive 610 and may provide a folding characteristic to the display panel 100. The bottom plate 300 may reinforce the rigidity of the foldable display module 500 and provide a heat dissipation function. For example, the bottom plate 300 may be expressed as a metal plate or a metal sheet. The bottom plate 300 may have a laminated structure of a plurality of metal layers 310, 320, and 330.

[0040] The bottom plate 300 according to one embodiment may include a folding area (FPA) in which a folding pattern 340 is arranged, and flat areas (FA) located on both sides of the folding area (FPA) and in which a bubble discharge pattern 350 is arranged. The bubble discharge pattern 350 may be represented as an opening pattern or an inner pattern.

[0041] The rear surface of the bottom plate 300, which corresponds to the rear surface of the foldable display module 500, may be bonded to the upper surface of the system middle frame 700 via adhesives 600 corresponding to each of the plurality of flat areas (FA).

[0042] The adhesive 600 can be separated so as to overlap with each of the flat areas (FA) of the foldable display module 500, and can be placed on the upper surface of the system middle frame 700, and can not overlap with the folding area (FPA).

[0043] The foldable display module 500 has a plurality of flat areas (FA) which are bonded to the upper surface of the system middle frame 700 via a plurality of adhesives 600, thereby increasing the adhesion between the foldable display module 500 and the system middle frame 700.

[0044] The system middle frame 700 may support the foldable display module 500 to enhance its rigidity, and may have a foldable structure based on a folding core (FCL). The system middle frame 700 according to an embodiment may include a plurality of plates, and the plurality of plates may be coupled to each other via hinge units disposed in a folding area (FPA), thereby having a foldable structure based on the folding core (FCL).

[0045] The driving circuit unit 200 is connected to a bezel region (BZ) of the display panel 100 and may include a plurality of circuit films 210 on which a plurality of driving ICs 220 are mounted, and a PCB 230 connected to the plurality of circuit films 210 and on which a plurality of driving ICs 240 and 250 are mounted. The circuit film 210 may be a flexible circuit such as a chip-on-film (CHP) or a flexible printed circuit (FPC). The driving ICs 220 mounted on the circuit film 210 may be a data driving circuit that drives data lines of the display panel 100. The plurality of driving ICs 240 and 250 mounted on the PCB 230 may include a timing controller, a power management circuit, a touch driving circuit, a touch controller, etc.

[0046] The PCB 230 superimposed on the rear surface of the system middle frame 700 can be attached and fixed to the rear surface of the system middle frame 700 via an adhesive 620 .

[0047] According to an embodiment, the adhesives 600, 610, and 620 may include at least one of an optical clear adhesive (OCA), a pressure sensitive adhesive (PSA), a heat-reactive adhesive, a general adhesive, and a double-sided tape.

[0048] According to an embodiment, the bottom plate 300 may have a laminated structure of multiple metal layers 310, 320, and 300. According to an embodiment, the bottom plate 300 may have a clad metal structure in which first to third metal layers 310, 320, and 300 are laminated, but is not limited thereto. The bottom plate 300 may include first and third metal layers 310 and 330 made of a metal or non-ferrous metal that provides rigidity and a second metal layer 320 disposed between the first and third metal layers 310 and 330 and made of a non-ferrous metal that has excellent heat dissipation properties. For example, the first and third metal layers 310 and 330 may include at least one of metal materials such as stainless steel (SUS), magnesium (Mg), and titanium (Ti). The second metal layer 320 may include at least one of metal materials such as aluminum (Al), copper (Cu), and the like. The embodiments of the present specification are not limited thereto.

[0049] According to an embodiment, the plurality of folding patterns 340 arranged in the folding area (FPA) of the bottom plate 300 may have the form of a plurality of slits penetrating the plurality of metal layers 310, 320, and 330. The size, spacing, and number of the plurality of folding patterns 340 may be changed depending on the position, taking into consideration the folding characteristics and elastic restoring force of the foldable display apparatus 1000.

[0050] In one embodiment of the bottom plate 300, the plurality of folding patterns 340 may include a plurality of slit patterns extending along a first direction (X), which is the direction of the folding axis (FCL) of the folding area (FPA), and arranged parallel to a second direction (Y) perpendicular to the folding axis (FCL). The spacing between the plurality of folding patterns 340 decreases toward the center of the folding axis (FCL) along the second direction (Y) in the folding area (FPA), thereby improving folding characteristics.

[0051] The plurality of opening patterns (hereinafter, referred to as bubble discharge patterns) 350 arranged in the flat area (FA) of the bottom plate 300 may have a double hole shape formed in some of the metal layers 310, 320, and 330. The plurality of bubble discharge patterns 350 may be connected in a matrix shape in the flat area (FA) to serve as a passage for discharging bubbles and to perform a heat dissipation function for dissipating heat.

[0052] In the bottom plate 300 according to one embodiment, each of the plurality of bubble discharge patterns 350 may include an outer hole pattern 352 formed in the outer first metal layer 310 located on the rear surface of the bottom plate 300, and an inner hole pattern 354 formed in the inner second metal layer 320 and connected to the outer hole pattern 352. For example, the outer hole pattern 352 may be different from the inner hole pattern 354. The outer hole pattern 352 may have a narrower width than the inner hole pattern 354. After the bottom plate 300 is bonded to the system middle frame 700 via the adhesive 600, the flat area (FA) of the bottom plate 300 may include an adhesive section to which the adhesive 600 is attached and an unattached section to which the adhesive 600 is not attached due to the outer hole pattern 352. The adhesive area of ​​the adhesive 600 in the flat area (FA) of the bottom plate 300 is larger than the area of ​​the non-adhesive area due to the external hole pattern 352, and the width of the external hole pattern 352 is smaller than the width of the internal hole pattern 354, thereby minimizing the area of ​​the non-adhesive area of ​​the adhesive 600.

[0053] In one embodiment, a material having a higher etching rate for the second metal layer 320 than for the first metal layer 310 of the bottom plate 300 can be used, and by over-etching the second metal layer 320 more than the first metal layer 310, the inner hole pattern 354 can be formed to have a width greater than that of the outer hole pattern 352.

[0054] Therefore, the bottom plate 300 according to the embodiment can further improve the bubble discharge function and heat dissipation function by the inner hole pattern 354 having a width wider than that of the outer hole pattern 352 .

[0055] Furthermore, the bottom plate 300 according to an embodiment has outer hole patterns 352 having a width smaller than that of the inner hole patterns 354, thereby minimizing an increase in the area of ​​the unbonded section of the adhesive 600 and the bottom plate 300 due to the outer hole patterns 352 of the bubble discharge pattern 350. Therefore, the bottom plate 300 according to an embodiment can minimize a decrease in the bonding area of ​​the adhesive 600 disposed between the foldable display module 500 and the system middle frame 700, thereby preventing a decrease in adhesive strength, thereby preventing the foldable display module 500 from moving due to vibration or impact, and preventing wrinkles on the screen.

[0056] In one embodiment, the folding pattern 340 disposed in the folding area (FPA) of the bottom plate 300 can be formed in the same process by using a double-sided etching method, and the bubble discharge pattern 350 disposed in the flat area (FA) can be formed by using a single-sided etching method.

[0057] 9 to 12 are plan views illustrating rear structures of bottom plates according to various embodiments.

[0058] Referring to FIG. 9, a bottom plate 300A according to an embodiment may include a plurality of bubble discharge patterns 350A arranged in diagonal stripes on a plurality of flat areas (FA).

[0059] Referring to FIG. 10, a bottom plate 300B according to an embodiment may include a plurality of bubble discharge patterns 350B arranged in stripes in a first direction (X) on a plurality of flat areas (FA).

[0060] Referring to FIG. 11, a bottom plate 300C according to an embodiment may include a plurality of bubble discharge patterns 350C arranged in a matrix form diagonally intersecting a plurality of flat areas (FA).

[0061] Referring to FIG. 12, a bottom plate 300D according to an embodiment may include a plurality of bubble discharge patterns 350D arranged in stripes in a second direction (Y) on a plurality of flat areas (FA).

[0062] FIG. 13 is a schematic diagram illustrating a bubble discharging process in a bottom plate bonding process according to an embodiment.

[0063] Referring to FIG. 13, even if air bubbles (B) are generated during the process of bonding the rear surface of the flat area (FA) of the bottom plate 300 of one embodiment to the system middle frame 700 (FIG. 4) via the adhesive 600, the air bubbles (B) can be removed through the air bubble discharge pattern 350 of the bottom plate 300 by the bonding pressure, thereby preventing screen defects due to air bubbles and improving product yield.

[0064] FIG. 14 is a cross-sectional view illustrating an example of an overlapping area between a bottom plate and a driving circuit unit in a foldable display device according to an embodiment.

[0065] 14, the flat area (FA) of the bottom plate 300E according to one embodiment may overlap the PCB 230 with the adhesive 600 and the system middle frame 700 sandwiched therebetween. The bottom plate 300E according to one embodiment may include a first air bubble discharge pattern (first opening pattern) 350A arranged in an overlapping area 360 with the PCB 230 of the flat area (FA), and a second air bubble discharge pattern (second opening pattern) 350B arranged in the remaining area of ​​the flat area (FA) that does not overlap with the PCB 230.

[0066] The outer hole pattern 352A of the first air bubble discharge pattern 350A may have the same or similar width as the outer hole pattern 352B of the second air bubble discharge pattern 350B. The inner hole pattern 354A of the first air bubble discharge pattern 350A may have a larger width than the inner hole pattern 354B of the second air bubble discharge pattern 350B.

[0067] As a result, the first bubble discharge pattern 350A of the bottom plate 300B according to one embodiment can further improve the heat dissipation characteristics of the circuit components 240 on the PCB 230, thereby reducing deterioration of the display panel and extending its lifespan, thereby achieving a low power consumption effect.

[0068] 15A to 17B are plan views and rear views illustrating structures of foldable display devices according to various embodiments before and after assembly.

[0069] The foldable display modules 500A, 500B, and 500C of the foldable display devices 1000A, 1000B, and 1000C according to various embodiments shown in FIGS. 15A to 17B may include a bottom plate 300E having first and second bubble discharge patterns 350A and 350B as shown in FIG. 14.

[0070] 15A and 15B, a foldable display module 500A of a foldable display device 1000A according to an embodiment may include a plurality of driving circuits 200A coupled to both bezel regions of a display panel 100A facing in a second direction (Y). The first driving circuit coupled to the first bezel region of the display panel 100A may include a plurality of FPCs 210A and a PCB 230A, and the second driving circuit coupled to the second bezel region of the display panel 100A may include a plurality of FPCs (212A, 214A, 216A) and a plurality of PCBs (232A, 234A).

[0071] After the bottom plate 300E (FIG. 14) of the foldable display module 500A is attached to and assembled with the system middle frame 700A, the FPC 210A and PCB 230A of the first driving circuit unit and the FPC (212A, 214A, 216A) and PCB (232A, 234A) of the second driving circuit unit are arranged on the back of the system middle frame 700A and can be overlapped with the display panel 100A.

[0072] The bottom plate 300E (FIG. 14) of the foldable display module 500A according to one embodiment may include a first bubble vent pattern 350A (FIG. 14) arranged in areas 360A and 362A (corresponding to 360 in FIG. 14) of the flat area (FA) that overlap with the first and second driving circuits 200A, respectively, of the driving circuit unit 200A, and a second bubble vent pattern 350B (FIG. 14) arranged in the remaining area of ​​the flat area (FA). For example, the inner hole pattern 354A of the first bubble vent pattern 350A has a larger width than the inner hole pattern 354B of the second bubble vent pattern 350B, thereby further improving the heat dissipation characteristics of the driving circuit unit.

[0073] 16A and 16B, a foldable display module 500B of a foldable display device 1000B according to an embodiment may include a driving circuit unit connected to one bezel region of a display panel 100B. The driving circuit unit 200B connected to one bezel region of the display panel 100B may include a plurality of FPCs (212B, 214B, 216B) and a plurality of PCBs (230B, 232B).

[0074] After the bottom plate 300E (FIG. 14) of the foldable display module 500B is attached and assembled to the system middle frame 700B, the driving circuit unit 200B has a plurality of FPCs (212B, 214B, 216B) and a plurality of PCBs (230B, 232B) arranged on the back surface of the system middle frame 700B, and can be overlapped with the display panel 100B.

[0075] The bottom plate 300E (FIG. 14) of the foldable display module 500B according to one embodiment includes a first air bubble vent pattern 350A (FIG. 14) arranged in an area 360B (corresponding to 360 in FIG. 14) of the flat area (FA) that overlaps with the driving circuit unit, and a second air bubble vent pattern 350B (FIG. 14) arranged in the remaining area of ​​the flat area (FA). The internal hole pattern 354A of the first air bubble vent pattern 350A has a larger width than the internal hole pattern 354B of the second air bubble vent pattern 350B, thereby further improving the heat dissipation characteristics of the driving circuit unit.

[0076] 17A and 17B, a foldable display module 500C of a foldable display device 1000C according to an embodiment may include a plurality of driving circuits 200C coupled to both bezel regions of a display panel 100C facing in the second direction (Y). The first driving circuit coupled to the first bezel region of the display panel 100C may include a plurality of FPCs 210C and PCBs 230C, and the second driving circuit coupled to the second bezel region of the display panel 100C may include a plurality of FPCs 212C and PCBs 232C.

[0077] After the bottom plate 300E (FIG. 14) of the foldable display module 500C is attached and assembled to the system middle frame 700C, the first driving circuit unit FPC210C and PCB230C and the second driving circuit unit FPC212C and PCB232C are arranged on the back of the system middle frame 700C and can be overlapped with the display panel 100C.

[0078] The bottom plate 300E (FIG. 14) of the foldable display module 500C according to one embodiment includes a first air bubble vent pattern 350A (FIG. 14) arranged in areas 360C and 362C (corresponding to 360 in FIG. 14) of the flat area (FA) that overlap the first and second driving circuit units 200C of the driving circuit unit 200C, respectively, and a second air bubble vent pattern 350B (FIG. 14) arranged in the remaining area of ​​the flat area (FA). The inner hole pattern 354A of the first air bubble vent pattern 350A has a width greater than the inner hole pattern 354B of the second air bubble vent pattern 350B, thereby further improving the heat dissipation characteristics of the driving circuit unit.

[0079] FIG. 18 is a cross-sectional view illustrating an area where a printed circuit board is arranged in a foldable display device according to an embodiment.

[0080] 18, in a foldable display device according to an embodiment, a foldable display module including a display panel 100 and a bottom plate 300E is attached to a system middle frame 700. The circuit film 210 connected to the bezel region of the display panel 100 can be bent toward the rear surface of the system middle frame 700 and overlap the rear surface of the system middle frame 700 with a reinforcing pad 630 sandwiched therebetween.

[0081] The PCB 230 , which is connected to the display panel 100 via the circuit film 210 and on which a plurality of driving ICs 240 and 250 are mounted, can be attached and fixed to the rear surface of the system middle frame 700 via an adhesive 620 .

[0082] As shown in FIG. 14, in one embodiment of the bottom plate 300E, the internal hole pattern 354A of the first air bubble discharge pattern 350A arranged in the overlapping area 360 of the flat area (FA) with the PCB 230 has a larger width than the internal hole pattern 354B of the second air bubble discharge pattern 350B arranged in the remaining area of ​​the flat area (FA) that does not overlap with the PCB 230. This further improves the heat dissipation characteristics of the circuit components 240 and 250 on the PCB 230, thereby reducing deterioration of the display panel and extending its lifespan, thereby achieving a low power consumption effect.

[0083] As described above, in the foldable display device according to an embodiment, even if air bubbles are generated during the bonding process of the foldable display module and the system middle frame, the air bubbles can be removed through the opening pattern (air bubble exhaust pattern) provided in the flat area of ​​the bottom plate of the foldable display module, thereby preventing screen defects caused by the air bubbles and improving product yield, thereby achieving the effects of reducing production energy and greenhouse gas emissions.

[0084] In an embodiment of the foldable display device, the opening pattern (air bubble discharge pattern) of the bottom plate has an outer width smaller than the inner width, thereby minimizing the reduction in the bonding area of ​​the adhesive disposed between the foldable display module and the system middle frame and preventing a reduction in adhesive strength. This prevents the foldable display module from moving due to vibration or impact, and prevents wrinkles on the screen.

[0085] A foldable display device according to an embodiment may improve the heat dissipation characteristics of a foldable display module by using a bottom plate having an opening pattern (air bubble discharge pattern). Furthermore, the foldable display device according to an embodiment may further improve the heat dissipation characteristics for heat generated by circuit components by making the internal width of the opening pattern (air bubble discharge pattern) in an area overlapping with the printed circuit board larger than the internal width of other parts. Therefore, the foldable display device according to an embodiment may improve the heat dissipation characteristics, reduce deterioration of the display panel, and extend its lifespan, thereby achieving low power consumption.

[0086] A foldable display device according to an embodiment includes a system middle frame foldable about a folding axis, and a foldable display module coupled to the system middle frame and having a folding region foldable about the folding axis and a plurality of flat regions connected via the folding region, the foldable display module including a display panel including a plurality of flat regions and a folding region, and a bottom plate coupled between the display panel and the system middle frame and including a plurality of folding patterns disposed in the folding region and a plurality of opening patterns disposed in the plurality of flat regions, each of the opening patterns including an outer hole pattern and an inner hole pattern connected to the outer hole pattern, the inner hole pattern may have a width greater than that of the outer hole pattern.

[0087] In one embodiment of a foldable display device, the bottom plate includes a plurality of stacked metal layers, and among the plurality of metal layers, an outer metal layer closest to the system middle frame may have an outer hole pattern, and an inner metal layer located inside the outer metal layer may have an inner hole pattern.

[0088] In one embodiment of the foldable display device, the bottom plate includes stacked first to third metal layers, and an outer hole pattern may be formed in the first metal layer closest to the system middle frame, and an inner hole pattern may be formed in the second metal layer located inside the first metal layer.

[0089] In a foldable display device according to an embodiment, the bottom plate may be attached to the upper surface of the system middle frame via a plurality of adhesives that overlap the plurality of flat regions and do not overlap the folding region.

[0090] In one embodiment of a foldable display device, the flat areas of the bottom plate include adhesive sections where adhesive is adhered and unadhesive sections where adhesive is not adhered due to an external hole pattern, and the area of ​​the adhesive sections may be larger than the area of ​​the unadhesive sections.

[0091] In a foldable display device according to an embodiment, the plurality of opening patterns may be arranged in a stripe shape extending in at least one direction selected from a first direction parallel to the folding axis, a second direction perpendicular to the first direction, and a diagonal direction of a plane of the first and second directions, or may be connected and arranged in a matrix shape.

[0092] In a foldable display device according to an embodiment, the plurality of folding patterns of the bottom plate have a plurality of slit shapes extending through the plurality of metal layers in the same direction as the folding axis, and the closer to the folding axis of the folding region from the flat region, the shorter the interval between the plurality of folding patterns can be.

[0093] In the foldable display device according to an embodiment, the foldable display module may further include a driving circuit unit connected to the display panel and disposed on a rear surface of the system middle frame.

[0094] In one embodiment of a foldable display device, the plurality of opening patterns of the bottom plate may include a plurality of first opening patterns arranged in a first region of the flat region that overlaps with the driving circuit unit, and a plurality of second opening patterns arranged in a second region of the flat region that does not overlap with the driving circuit unit and that are different in size from the plurality of first opening patterns.

[0095] In the foldable display device according to an embodiment, the first inner hole patterns of the plurality of first opening patterns may have a width greater than the second inner hole patterns of the plurality of second opening patterns.

[0096] In the foldable display device according to an embodiment, the first outer hole patterns of the plurality of first opening patterns may have the same or similar width as the second outer hole patterns of the plurality of second opening patterns.

[0097] In one embodiment of a foldable display device, the driving circuit unit is connected to the display panel via a circuit film and includes a printed circuit board on which a plurality of driving circuits are mounted, and the plurality of first opening patterns can be arranged in an area overlapping the printed circuit board.

[0098] A foldable display device according to an embodiment may include a display panel including a plurality of flat regions and a folding region disposed between the plurality of flat regions and foldable based on a folding axis; a bottom plate attached to a rear surface of the display panel and including a plurality of folding patterns disposed corresponding to the folding regions and a plurality of opening patterns having external hole patterns and internal hole patterns of different sizes disposed corresponding to the plurality of flat regions; and a system middle frame attached to the bottom plate via a plurality of adhesives separately disposed on the rear surface of the bottom plate corresponding to the plurality of flat regions and foldable based on the folding axis.

[0099] In a foldable display device according to an embodiment, the inner hole pattern may have a width greater than that of the outer hole pattern.

[0100] In one embodiment of the foldable display device, the bottom plate includes stacked first to third metal layers, and an outer hole pattern is provided in the first metal layer attached to the system middle frame via an adhesive, and an inner hole pattern may be provided in the second metal layer located inside the first metal layer.

[0101] In one embodiment of a foldable display device, the plurality of opening patterns of the bottom plate may include a plurality of first opening patterns arranged in a first region of the flat region that overlaps with the driving circuit unit, and a plurality of second opening patterns arranged in a second region of the flat region that does not overlap with the driving circuit unit and that are different in size from the plurality of first opening patterns.

[0102] In the foldable display device according to an embodiment, the first inner hole patterns of the plurality of first opening patterns may have a width greater than the second inner hole patterns of the plurality of second opening patterns.

[0103] In one embodiment of a foldable display device, the driving circuit unit is connected to the display panel via a circuit film and includes a printed circuit board on which a plurality of driving circuits are mounted, and the plurality of first opening patterns can be arranged in an area overlapping the printed circuit board.

[0104] The features, structures, effects, etc. described in the various examples of this specification are included in at least one example of this specification and are not necessarily limited to one example. Furthermore, the features, structures, effects, etc. exemplified in at least one example of this specification can be combined or modified in other examples by a person skilled in the art to which the technical ideas of this specification belong. Therefore, content related to such combinations and modifications should be interpreted as being included in the technical scope or scope of rights of this specification.

[0105] The present specification described above is not limited by the above-mentioned examples and the attached drawings, and various substitutions, modifications, and alterations are possible within the scope of the technical subject matter of the present specification, which will be apparent to those skilled in the art to which the present specification pertains. Therefore, the scope of the present specification is defined by the claims below, and all modifications and alterations derived from the meaning, scope, and equivalent concepts of the claims should be construed as being included in the scope of the present specification. [Explanation of symbols]

[0106] 1000: Foldable display device 500: Foldable display module 100: Display panel 200: Drive circuit section 210: Circuit Film 220, 240, 250: Driver IC 230: PCB 600, 610, 620: Adhesive 700: System middle frame FPA: Folding Area FA: flat area FCL: Folding shaft 110: Display unit 120: Polarizing plate 130: Protective film 140: Backplate 150: Support plate 300: Bottom plate 310, 320, 330: 1st, 2nd, 3rd metal layer 340: Folding pattern 350: Opening pattern (bubble discharge pattern) 352: External hole pattern 354: Internal hole pattern

Claims

1. A system middle frame that can be folded based on a folding axis, and a foldable display module coupled to the system middle frame, the foldable display module having a folding region foldable around the folding axis and a plurality of flat regions connected via the folding region; The foldable display module is a display panel including the plurality of flat regions and the folding region; and a bottom plate bonded between the display panel and the system middle frame, the bottom plate including a plurality of folding patterns disposed in the folding region and a plurality of opening patterns disposed in the plurality of flat regions; the bottom plate includes a plurality of stacked metal layers; each of the plurality of opening patterns includes an outer hole pattern and an inner hole pattern connected to the outer hole pattern; the external hole pattern is provided in an external metal layer among the plurality of metal layers that is closest to the system middle frame, the internal hole pattern is provided in an internal metal layer, among the plurality of metal layers, that is located closer to the display panel than the external metal layer, The foldable display module is a driving circuit unit connected to the display panel and disposed on a rear surface of the system middle frame; The plurality of opening patterns of the bottom plate are a plurality of first opening patterns arranged in a first region of the plurality of flat regions that overlaps with the drive circuit unit; and a plurality of second opening patterns disposed in a second region of the plurality of flat regions that does not overlap with the driving circuit unit, the second opening patterns having sizes different from the plurality of first opening patterns;

2. In the plurality of opening patterns, 10. The display device of claim 1, wherein the inner hole pattern has a width greater than that of the outer hole pattern.

3. the plurality of metal layers include first to third metal layers stacked one on top of the other; 2. The display device of claim 1, wherein the external hole pattern is provided on the first metal layer closest to the system middle frame, and the internal hole pattern is provided on the second metal layer located closer to the display panel than the first metal layer.

4. The bottom plate is The display device according to claim 1 , wherein the display device is attached to the upper surface of the system middle frame via a plurality of adhesives that overlap the plurality of flat regions and do not overlap the folding region.

5. The plurality of flat areas of the bottom plate are The adhesive section has an adhesive layer and an unadhesive section where the adhesive layer is not attached due to the outer hole pattern. The display device according to claim 4 , wherein the adhesive section has an area larger than the non-adhesive section.

6. The plurality of opening patterns are 2. The display device of claim 1, wherein the display elements are arranged in a stripe pattern extending in at least one of a first direction parallel to the folding axis, a second direction perpendicular to the first direction, and a diagonal direction between the first direction and the second direction, or are arranged connected in a matrix pattern.

7. The plurality of folding patterns of the bottom plate are: a plurality of slits extending through the plurality of metal layers and in the same direction as the folding axis; The display device of claim 1 , wherein the spacing between the plurality of folding patterns decreases from the plurality of flat regions toward the folding axis of the folding region.

8. 2. The display device of claim 1, wherein a first interior hole pattern of the plurality of first opening patterns has a width greater than a second interior hole pattern of the plurality of second opening patterns.

9. 10. The display device of claim 1, wherein a first outer hole pattern of the plurality of first opening patterns has the same or similar width as a second outer hole pattern of the plurality of second opening patterns.

10. The drive circuit unit a printed circuit board connected to the display panel via a circuit film and having a plurality of driving circuits mounted thereon; The display device according to claim 1 , wherein the plurality of first opening patterns are arranged in an area overlapping the printed circuit board.

11. a display panel including a plurality of flat regions and a folding region disposed between the plurality of flat regions and foldable about a folding axis; a bottom plate attached to a rear surface of the display panel, the bottom plate including a plurality of folding patterns arranged corresponding to the folding regions, and a plurality of opening patterns arranged corresponding to the plurality of flat regions and having outer hole patterns and inner hole patterns of different sizes; a system middle frame that is attached to the bottom plate via a plurality of adhesives separately disposed on the rear surface of the bottom plate corresponding to the plurality of flat areas and is foldable about the folding axis; and a driving circuit unit connected to the display panel and disposed on a rear surface of the system middle frame; the bottom plate includes a plurality of stacked metal layers; the external hole pattern is provided in an external metal layer among the plurality of metal layers that is closest to the system middle frame, the internal hole pattern is provided in an internal metal layer, among the plurality of metal layers, that is located closer to the display panel than the external metal layer, The plurality of opening patterns of the bottom plate are a plurality of first opening patterns arranged in a first region of the plurality of flat regions that overlaps with the drive circuit unit; and a plurality of second opening patterns disposed in a second region of the plurality of flat regions that does not overlap with the driving circuit unit, the second opening patterns having sizes different from the plurality of first opening patterns;

12. 12. The display device of claim 11, wherein the inner hole pattern has a width greater than the outer hole pattern.

13. the plurality of metal layers include first to third metal layers stacked one on top of the other; 13. The display device of claim 12, wherein the external hole pattern is provided on the first metal layer that is attached to the system middle frame via the plurality of adhesives, and the internal hole pattern is provided on the second metal layer that is located closer to the display panel than the first metal layer.

14. The plurality of opening patterns are 12. The display device of claim 11, wherein the display elements are arranged in a stripe pattern extending in at least one of a first direction parallel to the folding axis, a second direction perpendicular to the first direction, and a diagonal direction between the first direction and the second direction, or are arranged connected in a matrix pattern.

15. The plurality of folding patterns of the bottom plate are: a plurality of slits extending through the bottom plate in the first direction; 15. The display device of claim 14, wherein the spacing between the plurality of folding patterns decreases from the plurality of flat regions toward the folding axis of the folding region.

16. 12. The display device of claim 11, wherein a first interior hole pattern of the plurality of first opening patterns has a width greater than a second interior hole pattern of the plurality of second opening patterns.

17. 12. The display device of claim 11, wherein a first outer hole pattern of the plurality of first opening patterns has the same or similar width as a second outer hole pattern of the plurality of second opening patterns.

18. The drive circuit unit a printed circuit board connected to the display panel via a circuit film and having a plurality of driving circuits mounted thereon; The display device of claim 16 , wherein the plurality of first opening patterns are arranged in an area overlapping the printed circuit board.

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