Display device

Abstract

The utility model relates to a display device. The display device may include a display module, a functional layer, and an adhesive layer. The display module may define a folding area and first and second non-folding areas, and may display an image. The functional layer may be disposed on the display module. The bonding layer can be clamped between the display module and the lower surface of the functional layer and bonded to the functional layer. The lower surface of the functional layer may be provided with a recess overlapping the folding region. The functional layer may be provided with a nanopattern protruding from a bottom surface of the recessed portion. The adhesive layer may be sandwiched in the recessed portion and adhered to the nanopattern. The interval between adjacent nanopatterns among the nanopatterns may be 50 nm or more and 190 nm or less.

Description

Technical Field

[0001] This utility model relates to a display device, and more specifically, to a flexible display device that improves the phenomenon of wrinkles in the folded area caused by repeated folding and unfolding operations. Background Technology

[0002] Electronic devices such as smartphones, digital cameras, laptops, navigators, and smart TVs that provide images to users include display devices for displaying images. The display device generates images and provides the generated images to the user through a display screen.

[0003] Recently, with the development of display device technology, various forms of display devices are being developed.

[0004] For example, various flexible display devices are being developed that can deform into curved shapes and can be folded or rolled up.

[0005] While flexible display devices offer portability and improved user convenience, repeated folding and unfolding can cause wrinkles in the folded areas. As mentioned above, wrinkles can lead to image distortion and reduce user confidence in the product; therefore, various technologies are being developed to suppress wrinkle formation. Utility Model Content

[0006] An embodiment of this utility model provides a flexible display device that improves the phenomenon of wrinkles in the folded area.

[0007] According to one aspect of the present invention, the display device may include a display module, a first functional layer, and a first adhesive layer.

[0008] The display module can display images and can define a folded area, a first non-folded area, and a second non-folded area. The folded area is folded around a folding axis defined along a first direction. The first non-folded area and the second non-folded area are arranged along a second direction that intersects the first direction, separated by the folded area.

[0009] The first functional layer can be arranged on the display module and can include an upper surface and a lower surface facing each other.

[0010] The first adhesive layer can be sandwiched between the display module and the lower surface of the first functional layer and bonded to the first functional layer.

[0011] A first recess that overlaps with the folded area may be provided on the lower surface of the first functional layer.

[0012] The first functional layer may be equipped with a first nanopattern protruding from the bottom surface of the first recess.

[0013] The first adhesive layer can be sandwiched within the first recess and adhered to the first nanopattern.

[0014] The spacing between adjacent nanopatterns in the first nanopattern can be greater than 50 nm and less than 190 nm.

[0015] According to one embodiment of the present invention, the first recessed portion can be symmetrically arranged with respect to the folding axis.

[0016] According to one embodiment of the present invention, the distance between the bottom surface of the first recess and the upper surface of the first functional layer can be less than the thickness of the first functional layer at other parts that overlap with the first non-folded region and the second non-folded region.

[0017] According to one embodiment of the present invention, the distance between the end of each of the first nanopatterns and the upper surface of the first functional layer can be the same as the thickness of the first functional layer at other portions that overlap with the first non-folded region and the second non-folded region.

[0018] According to one embodiment of the present invention, the bottom surface of the first recess may be a shape that protrudes toward the upper surface of the first functional layer.

[0019] According to one embodiment of the present invention, a first-1 recessed pattern corresponding to the first nanopattern can be provided on the upper surface of the first adhesive layer, so that the first nanopattern can be arranged in the first-1 recessed pattern.

[0020] According to one embodiment of the present invention, each of the first nanopatterns may have a conical shape or a cylindrical shape.

[0021] The diameter of the bottom surface of each of the first nanopatterns can be greater than 10 nm and less than 190 nm.

[0022] According to one embodiment of the present invention, each of the first nanopatterns may have a quadrangular prism shape.

[0023] Each of the bottom surfaces of the first nanopatterns can have a side length of more than 10 nm and less than 190 nm.

[0024] The height of each of the first nanopatterns can be greater than 10 nm and less than 190 nm.

[0025] According to one embodiment of the present invention, the first functional layer may include a window that exposes the image displayed by the display module to the outside.

[0026] The display device according to one embodiment of the present invention may further include a second functional layer.

[0027] The second functional layer can be arranged between the display module and the first functional layer.

[0028] A second-1 recessed portion overlapping the folded area may be provided on the upper surface of the second functional layer.

[0029] The second functional layer may be equipped with a second nanopattern protruding from the bottom surface of the second-first recess.

[0030] The first adhesive layer can be sandwiched within the second-1 recess and bonded to the second-1 nanopattern.

[0031] The spacing between adjacent nanopatterns in the second-first nanopattern can be greater than 50 nm and less than 190 nm.

[0032] According to one embodiment of the present invention, the second-first recess can be symmetrically arranged with respect to the folding axis.

[0033] According to one embodiment of the present invention, a first-second recessed pattern corresponding to the second-first nanopattern can be provided on the lower surface of the first adhesive layer, so that the second-first nanopattern can be arranged in the first-second recessed pattern.

[0034] The display device according to one embodiment of the present invention may further include a second adhesive layer.

[0035] The second adhesive layer can be sandwiched between the display module and the second functional layer.

[0036] According to one embodiment of the present invention, the second functional layer may include a polarizing film.

[0037] According to one embodiment of the present invention, a second-2 recessed portion overlapping the folded area may be provided on the lower surface of the second functional layer.

[0038] The second functional layer may be equipped with a second nanopattern protruding from the bottom surface of the second-second recess.

[0039] The second adhesive layer can be sandwiched within the second-2 recess and bonded to the second-2 nanopattern.

[0040] The spacing between adjacent nanopatterns in the second-second nanopattern can be greater than 50 nm and less than 190 nm.

[0041] The display device according to an embodiment of the present invention may further include a third functional layer and a third adhesive layer.

[0042] The third functional layer can be arranged on the opposite side of the first functional layer, separated from the display module.

[0043] The third adhesive layer can be sandwiched between the display module and the third functional layer.

[0044] A third recess that overlaps with the folded area may be provided on the upper surface of the third functional layer.

[0045] The third functional layer may be equipped with a third nanopattern protruding from the bottom surface of the third recess.

[0046] The third adhesive layer can be sandwiched within the third recess and adhered to the third nanopattern.

[0047] The spacing between adjacent nanopatterns in the third nanopattern can be greater than 50 nm and less than 190 nm.

[0048] According to one embodiment of the present invention, the display module may include a display panel.

[0049] In a display panel, a first base substrate, a circuit layer, a display element layer, and a packaging layer can be stacked sequentially.

[0050] A fourth recess that overlaps with the folded area may be provided on the lower surface of the first base substrate.

[0051] The first base substrate may be equipped with a fourth nanopattern protruding from the bottom surface of the fourth recess.

[0052] The third adhesive layer can be sandwiched within the fourth recess and adhered to the fourth nanopattern.

[0053] The spacing between adjacent nanopatterns in the fourth nanopattern can be greater than 50 nm and less than 190 nm.

[0054] According to one embodiment of the present invention, the third functional layer may include a protective film.

[0055] According to one embodiment of the present invention, the display module may include a display panel, a color filter layer, and a second base substrate.

[0056] The display panel may contain a first base substrate, a circuit layer, a display element layer, and an encapsulation layer stacked sequentially.

[0057] The color filter layer can be arranged on the encapsulation layer.

[0058] The second base substrate can be disposed on the color filter layer and provide the base surface of the color filter.

[0059] A fifth recess that overlaps with the folded area may be provided on the upper surface of the second base substrate.

[0060] The second base substrate may be equipped with a fifth nanopattern protruding from the bottom surface of the fifth recess.

[0061] The first adhesive layer can be sandwiched within the fifth recess and bonded to the fifth nanopattern.

[0062] The spacing between adjacent nanopatterns in the fifth nanopattern can be greater than 50 nm and less than 190 nm.

[0063] According to another aspect of this utility model, the display device may include a display module, a functional layer, and an adhesive layer.

[0064] The display module can display images and can define a folded area, a first non-folded area, and a second non-folded area. The folded area is folded around a folding axis defined along a first direction. The first non-folded area and the second non-folded area are arranged along a second direction that intersects the first direction, separated by the folded area.

[0065] The functional layer can be arranged on the display module and can include an upper surface and a lower surface facing each other.

[0066] The adhesive layer can be sandwiched between the display module and the lower surface of the first functional layer and bonded to the first functional layer.

[0067] The functional layer may be equipped with nanopatterns of protruding morphology that overlap with the folded region.

[0068] The adhesive layer can be sandwiched between the nanopatterns and adhered to the nanopatterns.

[0069] Each of the nanopatterns can have one of the following shapes: conical, cylindrical, or prism.

[0070] The diameter of the bottom surface or the length of each side of each of the nanopatterns can be greater than 10 nm and less than 190 nm, and the height of each of the nanopatterns can be greater than 10 nm and less than 190 nm.

[0071] According to an embodiment of the present invention, due to the nanopattern, the bonding area between the functional layer and the adhesive layer in the folded area can be increased. As a result, even under repeated folding and unfolding operations, the generation of wrinkles caused by the separation between the functional layer and the adhesive layer in the folded area can be suppressed.

[0072] Furthermore, when the spacing between adjacent nanopatterns is designed to be greater than 50 nm, the adhesive can smoothly penetrate between the nanopatterns.

[0073] Furthermore, by designing the spacing between adjacent nanopatterns to be less than 190 nm, diffraction and reduced visibility in the visible light region caused by the addition of patterns can be prevented. Attached Figure Description

[0074] Figure 1 This is a perspective view showing a flexible display device according to an embodiment of the present invention.

[0075] Figure 2 It is Figure 1 The diagram shows the display device in a folded state.

[0076] Figure 3 It is shown that... Figure 1 The bottom view of a portion of the overlapping folded area of ​​the first functional layer.

[0077] Figure 4 It is shown Figure 3 A partial 3D image.

[0078] Figure 5 It is along Figure 3 The AA cutoff shown Figure 1 A cross-sectional view shown for a display device.

[0079] Figure 6 yes Figure 5 A variation of the display device.

[0080] Figure 7 yes Figure 6 A variation of the display device.

[0081] Figure 8 It is shown in Figure 5 The figure shows an embodiment of a display device with an additional second functional layer.

[0082] Figure 9 It is shown in Figure 5 A diagram of an embodiment of a display device with an additional third functional layer.

[0083] Figure 10 It is shown in Figure 8 A diagram of an embodiment of a display device with an additional third functional layer.

[0084] Figure 11 It is used for explanation Figure 9 and Figure 10 The diagram shows the structure of the display panel.

[0085] Figure 12 yes Figure 5 A variation of the display device.

[0086] Figure 13 yes Figure 9 A variation of the display device.

[0087] Figure 14 It is used for explanation Figure 12 and Figure 13 The diagram shows the structure of the display module.

[0088] Figure 15 This is a graph showing the results of measuring adhesive forces while varying the height of each nanopattern and the distance between adjacent nanopatterns.

[0089] Explanation of reference numerals in the attached figures:

[0090] Detailed Implementation

[0091] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0092] To aid in understanding this invention, the accompanying drawings are not shown to actual scale, but rather the dimensions of some of the constituent elements are exaggerated.

[0093] The terms used in the specification and claims of this utility model should not be limited to their ordinary or dictionary meanings, but should be based on the principle that the inventor can appropriately define the concepts of the terms in order to best describe his own utility model, and should only be interpreted as meanings and concepts that conform to the technical idea of ​​this utility model.

[0094] In this specification, unless otherwise stated, the singular form may include the plural form.

[0095] Furthermore, when it is recorded that a certain part "includes" a certain constituent element, it means that the corresponding part may also include other constituent elements.

[0096] Furthermore, when it is recorded as "above" a certain constituent element, it means above or below the corresponding constituent element, and does not necessarily mean that it is located on the upper side based on the direction of gravity.

[0097] Furthermore, when a constituent element is described as being "connected to" or "integrated with" another constituent element, it may include not only cases where the corresponding constituent element is directly connected to or integrated with the other constituent element, but also cases where the corresponding constituent element is indirectly connected to or integrated through the other constituent element.

[0098] Furthermore, when describing a constituent element, terms such as "first" and "second" may be used, but these terms are only used to distinguish the corresponding constituent element from another constituent element, and the nature, order, or sequence of the corresponding constituent elements are not limited by these terms.

[0099] Figure 1 This is a perspective view showing a flexible display device according to an embodiment of the present invention.

[0100] Reference Figure 1 According to an embodiment of the present invention, the flexible display device DD is an image display device, and a display area DA and a peripheral area NA can be defined in the display device DD.

[0101] The display area DA is the area where the image is displayed, and the surrounding area NA is the area surrounding the display area DA that does not display the image. In some embodiments, the surrounding area NA may be omitted.

[0102] In this embodiment, the display area DA is shown as a rectangle and the surrounding area NA is a shape that surrounds the display area DA. However, it is not limited to this and the shapes of the display area DA and the surrounding area NA can be designed in various ways.

[0103] Figure 2 It is Figure 1 The diagram shows the display device in a folded state.

[0104] Reference Figure 1 and Figure 2 According to an embodiment of the present invention, the flexible display device DD can be a foldable display device that is folded around a folding axis FX defined along a first direction DR1.

[0105] The display device DD may include a display module DM, a first functional layer FL1, and a first adhesive layer AL1.

[0106] The display module DM can define a folded region FA, a first non-folded region NFA1, and a second non-folded region NFA2.

[0107] The folding area FA is the area folded around the folding axis FX when the display device DD is folded.

[0108] The first non-folding area NFA1 and the second non-folding area NFA2 are areas that remain flat and are not folded during the folding operation of the display device DD.

[0109] The first non-folded region NFA1 and the second non-folded region NFA2 can be arranged facing each other along the second direction DR2, which intersects the first direction DR1, separated by the folded region FA.

[0110] That is, the first non-folded region NFA1, the folded region FA, and the second non-folded region NFA2 can be arranged sequentially along the second direction DR2. In other words, the folded region FA can be arranged between the first non-folded region NFA1 and the second non-folded region NFA2 along the second direction DR2.

[0111] In this embodiment, only one folded region FA and two non-folded regions NFA1 and NFA2 are shown. However, the number of folded regions FA and the number of non-folded regions NFA1 and NFA2 are not necessarily limited to this. For example, more than three non-folded regions and multiple folded regions arranged between the non-folded regions can also be defined in the display module DM.

[0112] The display module DM can display images, and the structure of the display module DM will be described later.

[0113] The first functional layer FL1 can be arranged on the display module DM and bonded to the display module DM through the first adhesive layer AL1.

[0114] The first functional layer FL1 can be a window that exposes the image displayed by the display module DM to the outside.

[0115] Here, the window can protect the display module DM from external impacts and can include an optically transparent insulating material.

[0116] For example, the window may include glass or plastic. The window may have a single-layer or multi-layer structure. For example, the window may include multiple plastic films bonded together by adhesive, or it may include a glass substrate and plastic films bonded together by adhesive.

[0117] However, in this embodiment, the first functional layer FL1 is not limited to the window, but can also be other types of film or resin layers bonded to the encapsulation layer of the display module DM or the base substrate by means of an adhesive layer.

[0118] The first adhesive layer AL1 can be sandwiched between the display module DM and the first functional layer FL1 and directly bonded to the first functional layer FL1.

[0119] The first adhesive layer AL1 can be arranged to overlap with the folded area FA and the pair of non-folded areas NFA1 and NFA2 of the display module DM. For example, the first adhesive layer AL1 can completely overlap with the folded area FA and the pair of non-folded areas NFA1 and NFA2 of the display module DM.

[0120] The first adhesive layer AL1 may include, but is not limited to, optically clear adhesive (OCA).

[0121] Figure 3 It is shown that... Figure 1 The bottom view of the overlapping portion of the folded area of ​​the first functional layer. Figure 4 It is shown Figure 3 A portion of the 3D image, Figure 5 It is along Figure 3 The AA cutoff shown Figure 1 A cross-sectional view shown for a display device.

[0122] Reference Figures 3 to 5 The first functional layer FL1 may include an upper surface 111 and a lower surface 112 facing each other along a third direction DR3 intersecting the first direction DR1 and the second direction DR2. The third direction DR3 may be the thickness direction of the display device DD. Each of the upper surface 111 and the lower surface 112 may extend along the first direction DR1 and the second direction DR2. The upper surface 111 may be the opposite side of the lower surface 112, which may be arranged facing the display module DM. That is, the first adhesive layer AL1 may be sandwiched between the display module DM and the lower surface 112 of the first functional layer FL1. A first recess 113 overlapping the folded area FA may be provided on the lower surface 112 of the first functional layer FL1.

[0123] The first recess 113 may be a recessed space formed by cutting away the first functional layer FL1 to form the first nanopattern NP1 described later, but it is not necessarily limited to this.

[0124] In this specification, nanopatterns can be formed using ion beam (e.g., ion beam milling) processes. Using an ion beam allows for control of shapes at dimensions of tens of nanometers.

[0125] The first recess 113 can be symmetrically arranged with respect to the folding axis FX. That is, the distance from the folding axis FX to one end of the first recess 113 in the second direction DR2 can be the same as the distance from the folding axis FX to the other end of the first recess 113 in the second direction DR2. For example, the two ends of the first recess 113 in the second direction DR2 can overlap with the two ends of the folding region FA in the second direction DR2.

[0126] The two ends of the first recess 113 in the first direction DR1 can overlap with the two ends of the folded region FA in the first direction DR1.

[0127] Because of the first recess 113, the thickness of the first functional layer FL1 at the part that overlaps with the folded region FA can be less than the thickness of the first functional layer FL1 at the part that overlaps with the non-folded regions NFA1 and NFA2.

[0128] As a result, the bending characteristics of the first functional layer FL1 can be improved when the display device DD is folded.

[0129] That is, the distance H1 from the bottom surface 113a of the first recess 113 along the third direction DR3 to the upper surface 111 of the first functional layer FL1 can be less than the thickness H2 of the first functional layer FL1 at other parts that overlap with the first non-folded region NFA1 and the second non-folded region NFA2.

[0130] The first nanopattern NP1 can protrude from the bottom surface 113a of the first recess 113.

[0131] In this embodiment, the bottom surface 113a of the first recess 113 can be defined as a virtual surface, and the first functional layer FL1, which is provided with the first recess 113 and equipped with the first nanopattern NP1, can have an integral shape.

[0132] The first adhesive layer AL1 can be sandwiched in the first recess 113 and bonded to the first nanopattern NP1.

[0133] As a result, for each unit area of ​​the plane extending along the first direction DR1 and the second direction DR2, the bonding area between the first functional layer FL1 and the first adhesive layer AL1 can be larger at the portion overlapping the folded region FA than at the portion overlapping the unfolded regions NFA1 and NFA2.

[0134] Each of the first nanopatterns NP1 can be a quadrangular prism shape. In this case, the side length D (hereinafter, according to the embodiment, may also be referred to as the diameter D of the bottom surface) of each of the first nanopatterns NP1 can be 10 nm or more and 190 nm or less, and the height H3 of each of the first nanopatterns NP1 can be 10 nm or more and 190 nm or less. When it is 10 nm or more, patterning using an ion beam is possible, and when it is 190 nm, which is half of the minimum wavelength of visible light 380 nm, the possibility of diffraction in the visible light region can be completely eliminated.

[0135] As another example, each of the first nanopatterns NP1 may have a conical or cylindrical shape. In this case, the diameter D of the bottom surface of each of the first nanopatterns NP1 may be greater than 10 nm and less than 190 nm, and the height H3 of each of the first nanopatterns NP1 may be greater than 10 nm and less than 190 nm.

[0136] For the bonding area between the first functional layer FL1 and the first adhesive layer AL1, the case where the first nanopattern NP1 is a quadrangular prism shape can be larger than the case where the first nanopattern NP1 is a conical or cylindrical shape. As a result, the adhesive force in the folded region FA can be improved.

[0137] Furthermore, the aspect ratio (i.e., H3 / D) of each of the first nanopatterns NP1 can be between 0.5 and 1.

[0138] In this specification, as described above, nanopatterns, as nanoscale structures, should be shown in a relatively very small size compared to other parts. However, those skilled in the art will understand that showing them in a larger size than the actual size is simply for ease of illustration.

[0139] The first nanopattern NP1 can be arranged in a matrix along the first direction DR1 and the second direction DR2, but it is not necessarily limited to this.

[0140] The spacing G1 between adjacent first nanopatterns NP1 can be 50 nm or more and 190 nm or less. Here, the spacing G1 between adjacent first nanopatterns NP1 can refer to the length of the portion of the line segment connecting the centers of the bottom surfaces of each of the adjacent first nanopatterns NP1 that does not overlap with each of the adjacent first nanopatterns NP1. When the spacing G1 between the first nanopatterns NP1 is 50 nm or more, as explained below with reference to experimental data, the permeability of the first adhesive layer AL1 to the first nanopatterns NP1 can be ensured when stacking the first functional layer FL1. When the spacing G1 between the first nanopatterns NP1 is 190 nm or less, as described above, the possibility of diffraction in the visible light region can be completely eliminated.

[0141] When the spacing G1 between the first nanopatterns NP1 is 50 nm or more, as described above, when the first functional layer FL1 is stacked, the permeability of the first adhesive layer AL1 to the first nanopatterns NP1 can be ensured. As a result, a first-1 recessed pattern 211 corresponding to the first nanopattern NP1 can be provided on the upper surface of the first adhesive layer AL1, and the first nanopattern NP1 can be arranged in the first-1 recessed pattern 211.

[0142] For example, if each of the first nanopatterns NP1 is a quadrangular prism, then each of the first-1 recessed patterns 211 can be the same quadrangular prism shape. As another example, if each of the first nanopatterns NP1 is a conical shape, then each of the first-1 recessed patterns 211 can be the same conical shape. As yet another example, if each of the first nanopatterns NP1 is a cylindrical shape, then each of the first-1 recessed patterns 211 can be the same cylindrical shape.

[0143] Furthermore, as described above, the first recess 113 can be a recessed space formed by cutting away the first functional layer FL1 to form the first nanopattern NP1. In this case, to minimize the ion beam trimming operation, the first functional layer FL1 can be cut so that the depth of the first recess 113 is formed to be the same as the height H3 of each of the first nanopatterns NP1. As a result, the distance H4 from the end of each of the first nanopatterns NP1 along the third direction DR3 to the upper surface 111 of the first functional layer FL1 can be the same as the thickness H2 of the first functional layer FL1 at the other portions overlapping with the first non-folded region NFA1 and the second non-folded region NFA2.

[0144] Figure 6 yes Figure 5 A variation of the display device.

[0145] Reference Figure 6 The bottom surface 113a of the first recess 113 can also be a shape that protrudes toward the upper surface 111 of the first functional layer FL1.

[0146] For example, the distance H1 from the bottom surface 113a of the first recess 113 along the third direction DR3 to the upper surface 111 of the first functional layer FL1 can be minimized at the center of the folded region FA in the second direction DR2.

[0147] As a result, during the folding operation of the display device DD, and Figure 5 Compared to the situation shown, the bending characteristics of the first functional layer FL1 can be further improved.

[0148] Furthermore, in this modified example, each of the first nanopatterns NP1 can protrude in a direction perpendicular to the bottom surface 113a of the first recess 113.

[0149] Figure 7 yes Figure 6 A variation of the display device.

[0150] Reference Figure 7The closer the first nanopattern is to the center of the folding region FA in the second direction DR2, the larger the height H3 of each of the first nanopatterns NP1. As a result, since the radius of curvature is relatively small during the folding operation of the display device DD, a relatively large adhesive force can be expected at the center of the folding region FA in the second direction DR2 where the bending stress is relatively large.

[0151] Figure 8 It is shown in Figure 5 The figure shows an embodiment of a display device with an additional second functional layer.

[0152] Reference Figure 8 The display device DD may further include a second functional layer FL2 disposed between the display module DM and the first functional layer FL1, and may also include a second adhesive layer AL2 sandwiched between the display module DM and the second functional layer FL2.

[0153] The second functional layer FL2 may include an upper surface 121 and a lower surface 122 facing each other along a third direction DR3. Each of the upper surface 121 and the lower surface 122 may extend along a first direction DR1 and a second direction DR2. The upper surface 121 may be disposed toward the first functional layer FL1, and the lower surface 122 may be disposed toward the display module DM. That is, the first adhesive layer AL1 may be sandwiched between the lower surface 112 of the first functional layer FL1 and the upper surface 121 of the second functional layer FL2. A second-first recess 123 overlapping the folded area FA may be provided on the upper surface 121 of the second functional layer FL2.

[0154] The second-1 recess 123 may be a recessed space formed by cutting off the second functional layer FL2 in order to form the second-1 nanopattern NP2-1 described later, but it is not necessarily limited to this.

[0155] The second-first recess 123 can be symmetrically arranged with respect to the folding axis FX. That is, the distance from the folding axis FX to one end of the second-first recess 123 in the second direction DR2 can be the same as the distance from the folding axis FX to the other end of the second-first recess 123 in the second direction DR2. For example, the two ends of the second-first recess 123 in the second direction DR2 can overlap with the two ends of the folding region FA in the second direction DR2.

[0156] The two ends of the recess 123 in the first direction DR1 can overlap with the two ends of the folded region FA in the first direction DR1.

[0157] Because of the second-1 recess 123, the thickness of the second functional layer FL2 at the part that overlaps with the folded region FA can be less than the thickness of the second functional layer FL2 at the part that overlaps with the non-folded regions NFA1 and NFA2.

[0158] As a result, the bending characteristics of the second functional layer FL2 can be improved when the display device DD is folded.

[0159] The second-1 nanopattern NP2-1 can protrude from the bottom surface 123a of the second-1 recess 123.

[0160] In this embodiment, the bottom surface 123a of the second-1 recess 123 can be defined as a virtual surface, and the second functional layer FL2, which is provided with the second-1 recess 123 and equipped with the second-1 nanopattern NP2-1, can have an integral shape.

[0161] The first adhesive layer AL1 can be sandwiched within the second-1 recess 123 and bonded to the second-1 nanopattern NP2-1.

[0162] As a result, for each unit area of ​​the second functional layer FL2 and the first adhesive layer AL1 in the plane extending along the first direction DR1 and the second direction DR2, the portion overlapping the folded region FA can be larger than the portion overlapping the non-folded regions NFA1 and NFA2.

[0163] The above description of the first nanopattern NP1 can also be applied to the second-first nanopattern NP2-1.

[0164] For example, each of the second-1 nanopatterns NP2-1 can be a prism, a cone, or a cylinder. Furthermore, the side length or diameter of the bottom surface of each of the second-1 nanopatterns NP2-1 can be 10 nm or more and 190 nm or less, and the height of each of the second-1 nanopatterns NP2-1 can be 10 nm or more and 190 nm or less. The aspect ratio of each of the second-1 nanopatterns NP2-1 can be between 0.5 and 1. The second-1 nanopatterns NP2-1 can be arranged in a matrix along the first direction DR1 and the second direction DR2, but are not necessarily limited to this arrangement. The spacing G2-1 between adjacent second-1 nanopatterns NP2-1 can be 50 nm or more and 190 nm or less.

[0165] When the spacing G2-1 between the 2-1 nanopatterns NP2-1 is 50 nm or more, the permeability of the first adhesive layer AL1 to the 2-1 nanopatterns NP2-1 can be ensured. As a result, a first-2 recessed pattern 212 corresponding to the 2-1 nanopattern NP2-1 can be provided on the lower surface of the first adhesive layer AL1, and the 2-1 nanopattern NP2-1 can be arranged in the first-2 recessed pattern 212.

[0166] For example, if each of the second-first nanopatterns NP2-1 is a prism, then each of the first-second recessed patterns 212 can be a prism. As another example, if each of the second-first nanopatterns NP2-1 is a cone, then each of the first-second recessed patterns 212 can be a cone. As yet another example, if each of the second-first nanopatterns NP2-1 is a cylinder, then each of the first-second recessed patterns 212 can be a cylinder.

[0167] Furthermore, the height of each of the second-1 nanopatterns NP2-1 can be the same as the depth of the second-1 recess 123, which will be obvious to those skilled in the art. Figure 6 and Figure 7 The description of the modified examples can also be applied to the 2-1 recess 123 and the 2-1 nanopattern NP2-1.

[0168] The second adhesive layer AL2 can be sandwiched between the display module DM and the second functional layer FL2 and directly bonded to the second functional layer FL2.

[0169] The second adhesive layer AL2 can be arranged to overlap with the folded area FA and the pair of non-folded areas NFA1 and NFA2 of the display module DM. For example, the second adhesive layer AL2 can completely overlap with the folded area FA and the pair of non-folded areas NFA1 and NFA2 of the display module DM.

[0170] The second adhesive layer AL2 may include, but is not limited to, optically clear adhesive (OCA).

[0171] A second-second recess 124 overlapping the folded region FA may be provided on the lower surface 122 of the second functional layer FL2.

[0172] The second-2 recess 124 may be a recessed space formed by cutting off the second functional layer FL2 in order to form the second-2 nanopattern NP2-2 described later, but it is not necessarily limited to this.

[0173] The second-2 recess 124 can be symmetrically arranged with respect to the folding axis FX. That is, the distance from the folding axis FX to one end of the second-2 recess 124 in the second direction DR2 can be the same as the distance from the folding axis FX to the other end of the second-2 recess 124 in the second direction DR2. For example, the two ends of the second-2 recess 124 in the second direction DR2 can overlap with the two ends of the folding region FA in the second direction DR2.

[0174] The two ends of the second-2 recess 124 in the first direction DR1 can overlap with the two ends of the folded region FA in the first direction DR1.

[0175] Because of the second-2 recess 124, the thickness of the second functional layer FL2 at the part that overlaps with the folded region FA can be less than the thickness of the second functional layer FL2 at the part that overlaps with the unfolded regions NFA1 and NFA2.

[0176] As a result, the bending characteristics of the second functional layer FL2 can be improved when the display device DD is folded.

[0177] The second-2 nanopattern NP2-2 can protrude from the bottom surface 124a of the second-2 recess 124.

[0178] In this embodiment, the bottom surface 124a of the second-2 recess 124 can be defined as a virtual surface, and the second functional layer FL2, which is provided with the second-2 recess 124 and equipped with the second-2 nanopattern NP2-2, can have an integral shape.

[0179] The second adhesive layer AL2 can be sandwiched within the second-2 recess 124 and bonded to the second-2 nanopattern NP2-2.

[0180] As a result, for each unit area of ​​the second functional layer FL2 and the second adhesive layer AL2 extending along the first direction DR1 and the second direction DR2, the portion overlapping the folded region FA can be larger than the portion overlapping the non-folded regions NFA1 and NFA2.

[0181] The above description of the first nanopattern NP1 can also be applied to the second nanopattern NP2-2.

[0182] For example, each of the second-2 nanopatterns NP2-2 can be a prism, a cone, or a cylinder. Furthermore, the side length or diameter of the bottom surface of each of the second-2 nanopatterns NP2-2 can be 10 nm or more and 190 nm or less, and the height of each of the second-2 nanopatterns NP2-2 can be 10 nm or more and 190 nm or less. The aspect ratio of the second-2 nanopatterns NP2-2 can be from 0.5 to 1. The second-2 nanopatterns NP2-2 can be arranged in a matrix along the first direction DR1 and the second direction DR2, but are not necessarily limited to this arrangement. The spacing G2-2 between adjacent second-2 nanopatterns NP2-2 can be 50 nm or more and 190 nm or less.

[0183] When the spacing G2-2 between the 2-2 nanopatterns NP2-2 is 50 nm or more, the permeability of the second adhesive layer AL2 to the 2-2 nanopatterns NP2-2 can be ensured. As a result, a second recessed pattern 221 corresponding to the 2-2 nanopatterns NP2-2 can be provided on the upper surface of the second adhesive layer AL2, and the 2-2 nanopatterns NP2-2 can be arranged in the second recessed pattern 221.

[0184] For example, if each of the second-2 nanopatterns NP2-2 is a prism, then each of the second recessed patterns 221 can be a prism shape. As another example, if each of the second-2 nanopatterns NP2-2 is a cone shape, then each of the second recessed patterns 221 can be a cone shape. As yet another example, if each of the second-2 nanopatterns NP2-2 is a cylinder shape, then each of the second recessed patterns 221 can be a cylinder shape.

[0185] Furthermore, the height of each of the second-2 nanopatterns NP2-2 can be the same as the depth of the second-2 recess 124, which will be obvious to those skilled in the art. Figure 6 and Figure 7 The description of the modified example can also be applied to the 2-2 recess 124 and the 2-2 nanopattern NP2-2.

[0186] The second functional layer FL2 can be a polarizing film that blocks external light incident through the upper surface of the window from being reflected by the elements constituting the display module DM and thus visible from the outside.

[0187] However, it is not necessary to limit it to this. The second functional layer FL2 can also be other types of film or resin layers sandwiched between the window and the display module DM and bonded to the window and the display module DM through the first adhesive layer AL1 sandwiched between the window and the second functional layer FL2 and the second adhesive layer AL2 sandwiched between the second functional layer FL2 and the display module DM.

[0188] Figure 9 It is shown in Figure 5 A diagram of an embodiment of a display device with an additional third functional layer. Figure 10 It is shown in Figure 8 A diagram of an embodiment of a display device with an additional third functional layer.

[0189] Reference Figure 9 and Figure 10 The display device DD may also include a third functional layer FL3 and a third adhesive layer AL3.

[0190] The third functional layer FL3 can be arranged on the opposite side of the first functional layer FL1, separated by the display module DM.

[0191] The third functional layer FL3 may include an upper surface 131 and a lower surface 132 facing each other along a third direction DR3. Each of the upper surface 131 and the lower surface 132 may extend along a first direction DR1 and a second direction DR2. The upper surface 131 may be arranged facing the display module DM, and the lower surface 132 may be the opposite side of the upper surface 131. The third adhesive layer AL3 may be sandwiched between the display module DM and the upper surface 131 of the third functional layer FL3. A third recess 133 overlapping the folded area FA may be provided on the upper surface 131 of the third functional layer FL3.

[0192] The third recess 133 may be a recessed space formed by cutting away the third functional layer FL3 in order to form the third nanopattern NP3 described later, but it is not necessarily limited to this.

[0193] The third recess 133 can be symmetrically arranged with respect to the folding axis FX. That is, the distance from the folding axis FX to one end of the third recess 133 in the second direction DR2 can be the same as the distance from the folding axis FX to the other end of the third recess 133 in the second direction DR2. For example, the two ends of the third recess 133 in the second direction DR2 can overlap with the two ends of the folding region FA in the second direction DR2.

[0194] The two ends of the third recess 133 in the first direction DR1 can overlap with the two ends of the folded region FA in the first direction DR1.

[0195] Because of the third recess 133, the thickness of the third functional layer FL3 at the part that overlaps with the folded region FA can be less than the thickness of the third functional layer FL3 at the part that overlaps with the non-folded regions NFA1 and NFA2.

[0196] As a result, the bending characteristics of the third functional layer FL3 can be improved when performing the folding operation of the display device DD.

[0197] The third nanopattern NP3 can protrude from the bottom surface 133a of the third recess 133.

[0198] In this embodiment, the bottom surface 133a of the third recess 133 can be defined as a virtual surface, and the third functional layer FL3, which is provided with the third recess 133 and equipped with the third nanopattern NP3, can have an integral shape.

[0199] The third adhesive layer AL3 can be sandwiched within the third recess 133 and bonded to the third nanopattern NP3.

[0200] As a result, for each unit area of ​​the plane extending along the first direction DR1 and the second direction DR2, the bonding area between the third functional layer FL3 and the third adhesive layer AL3 can be larger at the portion overlapping the folded region FA than at the portion overlapping the unfolded regions NFA1 and NFA2.

[0201] The above description of the first nanopattern NP1 can also be applied to the third nanopattern NP3.

[0202] For example, each of the third nanopatterns NP3 can be a prism, a cone, or a cylinder. Furthermore, the side length or diameter of the base surface of each of the third nanopatterns NP3 can be 10 nm or more and 190 nm or less, and the height of each of the third nanopatterns NP3 can be 10 nm or more and 190 nm or less. The aspect ratio of each of the third nanopatterns NP3 can be between 0.5 and 1. The third nanopatterns NP3 can be arranged in a matrix along the first direction DR1 and the second direction DR2, but are not necessarily limited to this arrangement. The spacing G3 between adjacent third nanopatterns NP3 can be 50 nm or more and 190 nm or less.

[0203] When the spacing G3 between the third nanopatterns NP3 is 50 nm or more, the permeability of the third adhesive layer AL3 to the third nanopatterns NP3 can be ensured. As a result, a third-first recessed pattern 231 corresponding to the third nanopattern NP3 can be provided on the lower surface of the third adhesive layer AL3, and the third nanopattern NP3 can be arranged in the third-first recessed pattern 231.

[0204] For example, if each of the third nanopatterns NP3 is a quadrangular prism, then each of the third-1 recessed patterns 231 can be a quadrangular prism. As another example, if each of the third nanopatterns NP3 is a conical shape, then each of the third-1 recessed patterns 231 can be a conical. As yet another example, if each of the third nanopatterns NP3 is a cylindrical shape, then each of the third-1 recessed patterns 231 can be a cylindrical.

[0205] Furthermore, the height of each of the third nanopatterns NP3 can be the same as the depth of the third recess 133, which will be obvious to those skilled in the art. Figure 6 and Figure 7 The description of the modified examples can also be applied to the third recess 133 and the third nanopattern NP3.

[0206] The third adhesive layer AL3 can be sandwiched between the display module DM and the third functional layer FL3 and directly bonded to the display module DM and the third functional layer FL3.

[0207] The third adhesive layer AL3 can be arranged to overlap with the folded area FA and the pair of non-folded areas NFA1 and NFA2 of the display module DM. For example, the third adhesive layer AL3 can completely overlap with the folded area FA and the pair of non-folded areas NFA1 and NFA2 of the display module DM.

[0208] The third adhesive layer AL3 may include optically clear adhesive (OCA), but is not necessarily limited to this.

[0209] The display module DM may include a display panel DP on which a first base substrate BS1, a circuit layer CL, a display element layer EDL, and a packaging layer TFE are stacked sequentially. A fourth recess 102 overlapping the folded area FA may be provided on the lower surface 101 of the first base substrate BS1. The structure of the display panel DP will be described in detail below with reference to other accompanying drawings.

[0210] The fourth recess 102 may be a recessed space formed by cutting away the first base substrate BS1 to form the fourth nanopattern NP4 described later, but it is not necessarily limited to this.

[0211] The fourth recess 102 can be symmetrically arranged with respect to the folding axis FX. That is, the distance from the folding axis FX to one end of the fourth recess 102 in the second direction DR2 can be the same as the distance from the folding axis FX to the other end of the fourth recess 102 in the second direction DR2. For example, the two ends of the fourth recess 102 in the second direction DR2 can overlap with the two ends of the folding region FA in the second direction DR2.

[0212] The two ends of the fourth recess 102 in the first direction DR1 can overlap with the two ends of the folded region FA in the first direction DR1.

[0213] Due to the fourth recess 102, the thickness of the display module DM in the folded region FA can be less than the thickness of the display module DM in the non-folded regions NFA1 and NFA2.

[0214] As a result, the bending characteristics of the display module DM can be improved when performing the folding operation of the display device DD.

[0215] The fourth nanopattern NP4 can protrude from the bottom surface 102a of the fourth recess 102.

[0216] In this embodiment, the bottom surface 102a of the fourth recess 102 can be defined as a virtual surface, and the first base substrate BS1, which is provided with the fourth recess 102 and equipped with the fourth nanopattern NP4, can have an integral shape.

[0217] The third adhesive layer AL3 can be sandwiched within the fourth recess 102 and bonded to the fourth nanopattern NP4.

[0218] As a result, for each unit area of ​​the first base substrate BS1 and the third adhesive layer AL3 extending along the first direction DR1 and the second direction DR2, the folded region FA can be larger than the non-folded regions NFA1 and NFA2.

[0219] The above description of the first nanopattern NP1 can also be applied to the fourth nanopattern NP4.

[0220] For example, each of the fourth nanopatterns NP4 can be a prism, a cone, or a cylinder. Furthermore, the side length or diameter of the base surface of each of the fourth nanopatterns NP4 can be 10 nm or more and 190 nm or less, and the height of each of the fourth nanopatterns NP4 can be 10 nm or more and 190 nm or less. The aspect ratio of each of the fourth nanopatterns NP4 can be between 0.5 and 1. The fourth nanopatterns NP4 can be arranged in a matrix along the first direction DR1 and the second direction DR2, but are not necessarily limited to this arrangement. The spacing G4 between adjacent fourth nanopatterns NP4 can be 50 nm or more and 190 nm or less.

[0221] When the spacing G4 between the fourth nanopatterns NP4 is 50 nm or more, the permeability of the third adhesive layer AL3 to the fourth nanopatterns NP4 can be ensured. As a result, a third-second recessed pattern 232 corresponding to the fourth nanopattern NP4 can be provided on the upper surface of the third adhesive layer AL3, and the fourth nanopattern NP4 can be arranged in the third-second recessed pattern 232.

[0222] For example, if each of the fourth nanopatterns NP4 is a quadrangular prism, then each of the third-second recessed patterns 232 can be a quadrangular prism. As another example, if each of the fourth nanopatterns NP4 is a conical shape, then each of the third-second recessed patterns 232 can be a conical shape. As yet another example, if each of the fourth nanopatterns NP4 is a cylindrical shape, then each of the third-second recessed patterns 232 can be a cylindrical shape.

[0223] Furthermore, the height of each of the fourth nanopatterns NP4 can be the same as the depth of the fourth recess 102, which will be obvious to those skilled in the art. Figure 6 and Figure 7 The description of the modified examples can also be applied to the fourth recess 102 and the fourth nanopattern NP4.

[0224] The third functional layer FL3 can be a protective film arranged on the opposite side of the window with the display module DM as the reference, protecting the lower part of the display module DM from external impacts. However, it is not limited to this. The third functional layer FL3 can also be a film or resin layer arranged on the opposite side of the window with the display module DM as the reference and bonded to the display module DM with the third adhesive layer AL3 as the medium, and can perform other functions (e.g., shielding, neutral plane position adjustment, etc.) in addition to performing the function of protecting against external impacts.

[0225] Figure 11 It is used for explanation Figure 9 and Figure 10 The diagram shows the structure of the display panel.

[0226] Reference Figure 11 The display panel DP may include a first base substrate BS1, a circuit layer CL, a display element layer EDL, and a packaging layer TFE.

[0227] The first base substrate BS1 may be a structure that provides a base surface for arranging circuit layers CL.

[0228] The first base substrate BS1 may include a polymer resin such as glass, ceramic, metal, or polyimide. However, it is not limited to this; the first base substrate BS1 may be an inorganic layer, an organic layer, or a composite material layer, and may be formed as a single layer or multiple layers.

[0229] The circuit layer CL can be disposed on the first base substrate BS1 and can include multiple wirings and multiple transistors. The circuit layer CL can include pixel transistors for driving the light-emitting elements ED1, ED2, and ED3 of the display element layer EDL. The circuit layer CL can include peripheral transistors disposed in the peripheral region NA and outputting signals for controlling the pixel transistors.

[0230] The display element layer (EDL) may include the pixel definition film (PDL) and light-emitting elements (ED1, ED2, ED3).

[0231] Each of the light-emitting elements ED1, ED2, and ED3 may include a first electrode EL1, a hole functional layer HFL, light-emitting layers EML1, EML2, and EML3, an electron functional layer EFL, and a second electrode EL2.

[0232] The pixel definition film (PDL) can be disposed on the circuit layer CL and can be arranged to cover the area between the first electrodes EL1 on the plane. The PDL can be disposed corresponding to the non-light-emitting area NPA. The light-emitting areas PA1, PA2, and PA3 can be defined by the PDL. The PDL can be used to distinguish the light-emitting elements ED1, ED2, and ED3.

[0233] The pixel definition film (PDL) may include one or more organic insulating materials selected from the group consisting of polyimide, polyamide, acrylic resin, benzocyclobutene, and phenolic resin.

[0234] The first electrode EL1 can be disposed on the circuit layer CL. The first electrode EL1 can be conductive and can be electrically connected to a transistor to receive electrical signals.

[0235] The hole functional layer (HFL) facilitates the movement of holes from the first electrode EL1 to the light-emitting layers EML1, EML2, and EML3, while the electron functional layer (EFL) facilitates the movement of electrons from the second electrode EL2 to the light-emitting layers EML1, EML2, and EML3.

[0236] exist Figure 11 The example illustrates a case where the hole functional layer (HFL) is arranged between the first electrode EL1 and the light-emitting layers EML1, EML2, and EML3, and the electron functional layer (EFL) is arranged between the second electrode EL2 and the light-emitting layers EML1, EML2, and EML3.

[0237] However, this is not the only limitation. The positions of the hole functional layer (HFL) and the electron functional layer (EFL) can be changed depending on whether the first electrode EL1 and the second electrode EL2 are anodes or cathodes.

[0238] exist Figure 11 The example illustrates a case in which light-emitting layers EML1, EML2, and EML3 of light-emitting elements ED1, ED2, and ED3 are arranged within an opening OH defined by a pixel definition film PDL, and the hole functional layer HFL, electron functional layer EFL, and second electrode EL2 are provided as common layers throughout the light-emitting elements ED1, ED2, and ED3.

[0239] However, it is not limited to this; at least one of the hole functional layer HFL and the electron functional layer EFL can also be patterned and set within the opening OH defined by the pixel definition film PDL.

[0240] The second electrode EL2 can be disposed on the light-emitting layers EML1, EML2, and EML3. The second electrode EL2 can be opposite to the first electrode EL1. The second electrode EL2 can have an integral shape extending from the light-emitting regions PA1, PA2, and PA3 to the non-light-emitting region NPA. The second electrode EL2 can be a common electrode.

[0241] At least some of the light-emitting elements ED1, ED2, and ED3 can emit light in different wavelength ranges from each other.

[0242] For example, the first light-emitting element ED1 can emit red light, the second light-emitting element ED2 can emit green light, and the third light-emitting element ED3 can emit blue light.

[0243] However, it is not limited to this. The first light-emitting element ED1, the second light-emitting element ED2, and the third light-emitting element ED3 shown in the figure can all emit light in the same wavelength range. For example, they can also emit blue light.

[0244] Figure 12 yes Figure 5Modifications of the display device, Figure 13 yes Figure 9 A variation of the display device.

[0245] Reference Figure 12 and Figure 13 The display module DM may include: a display panel DP, on which a first base substrate BS1, a circuit layer CL, a display element layer EDL, and a packaging layer TFE are stacked in sequence; a color filter layer CFL, disposed on the packaging layer TFE; and a second base substrate BS2, disposed on the color filter layer CFL and providing a base surface for the color filter, wherein a fifth recess 104 overlapping the folded area FA may be provided on the upper surface 103 of the second base substrate BS2. The structure of the display module DM will be described in detail below with reference to other accompanying drawings.

[0246] The fifth recess 104 may be a recessed space formed by cutting away the second base substrate BS2 in order to form the fifth nanopattern NP5 described later, but it is not necessarily limited to this.

[0247] The fifth recess 104 can be symmetrically arranged with respect to the folding axis FX. That is, the distance from the folding axis FX to one end of the fifth recess 104 in the second direction DR2 can be the same as the distance from the folding axis FX to the other end of the fifth recess 104 in the second direction DR2. For example, the two ends of the fifth recess 104 in the second direction DR2 can overlap with the two ends of the folded region FA in the second direction DR2.

[0248] The two ends of the fifth recess 104 in the first direction DR1 can overlap with the two ends of the folded region FA in the first direction DR1.

[0249] Because of the fifth recess 104, the thickness of the folded area FA of the display module DM can be less than the thickness of the non-folded areas NFA1 and NFA2 of the display module DM.

[0250] As a result, the bending characteristics of the display module DM can be improved when performing the folding operation of the display device DD.

[0251] The fifth nanopattern NP5 can protrude from the bottom surface 104a of the fifth recess 104.

[0252] In this embodiment, the bottom surface 104a of the fifth recess 104 can be defined as a virtual surface, and the second base substrate BS2, which is provided with the fifth recess 104 and equipped with the fifth nanopattern NP5, can have an integral shape.

[0253] The first adhesive layer AL1 can be sandwiched within the fifth recess 104 and bonded to the fifth nanopattern NP5.

[0254] As a result, for each unit area of ​​the second base substrate BS2 and the first adhesive layer AL1 extending along the first direction DR1 and the second direction DR2, the folded region FA can have a larger bonding area than the non-folded regions NFA1 and NFA2.

[0255] The above description of the first nanopattern NP1 can also be applied to the fifth nanopattern NP5.

[0256] For example, each of the fifth nanopatterns NP5 can be a prism, a cone, or a cylinder. Furthermore, the side length or diameter of the base surface of each of the fifth nanopatterns NP5 can be 10 nm or more and 190 nm or less, and the height of each of the fifth nanopatterns NP5 can be 10 nm or more and 190 nm or less. The aspect ratio of each of the fifth nanopatterns NP5 can be between 0.5 and 1. The fifth nanopatterns NP5 can be arranged in a matrix along the first direction DR1 and the second direction DR2, but are not necessarily limited to this arrangement. The spacing G5 between adjacent fifth nanopatterns NP5 can be 50 nm or more and 190 nm or less.

[0257] When the spacing G5 between the fifth nanopatterns NP5 is 50 nm or more, the permeability of the first adhesive layer AL1 to the fifth nanopatterns NP5 can be ensured. As a result, the lower surface of the first adhesive layer AL1 can be provided with the first-third recessed pattern 213 corresponding to the fifth nanopattern NP5, and the fifth nanopattern NP5 can be arranged in the first-third recessed pattern 213.

[0258] For example, if each of the fifth nanopatterns NP5 is a prism, then each of the first-third recessed patterns 213 can be a prism. As another example, if each of the fifth nanopatterns NP5 is a cone, then each of the first-third recessed patterns 213 can be a cone. As yet another example, if each of the fifth nanopatterns NP5 is a cylinder, then each of the first-third recessed patterns 213 can be a cylinder.

[0259] Furthermore, the height of each of the fifth nanopatterns NP5 can be the same as the depth of the fifth recess 104, which will be obvious to those skilled in the art. Figure 6 and Figure 7 The description of the modified examples can also be applied to the fifth recess 104 and the fifth nanopattern NP5.

[0260] Figure 14 It is used for explanation Figure 12 and Figure 13 The diagram shows the structure of the display module.

[0261] Reference Figure 14 As described above, the display module DM may include a display panel DP, a color filter layer CFL disposed on the encapsulation layer TFE of the display panel DP, and a second base substrate BS2 disposed on the color filter layer CFL and providing a base surface for color filters CF1, CF2, and CF3.

[0262] Display panel DP and reference Figure 11 The content described is the same, so detailed descriptions will be omitted.

[0263] The color filter layer CFL may include color filters CF1, CF2, CF3 and a light-shielding part BM.

[0264] The first color filter CF1 allows red light to pass through, the second color filter CF2 allows green light to pass through, and the third color filter CF3 allows blue light to pass through. For example, the first color filter CF1 can be a red color filter, the second color filter CF2 can be a green color filter, and the third color filter CF3 can be a blue color filter.

[0265] Each of the color filters CF1, CF2, and CF3 may include a polymeric photosensitive resin and a pigment or dye.

[0266] The light-blocking section BM can be a black matrix. The light-blocking section BM can include organic or inorganic light-blocking materials containing black pigments or dyes. The light-blocking section BM can be used to prevent light leakage and can distinguish the boundaries between adjacent color filters CF1, CF2, and CF3.

[0267] Color filters CF1, CF2, and CF3 can be arranged corresponding to the light-emitting areas PA1, PA2, and PA3, respectively, and the light-shielding part BM can be arranged corresponding to the non-light-emitting area NPA.

[0268] A barrier layer (BFL) may also be disposed below the color filter layer (CFL). The barrier layer (BFL) can function to prevent the permeation of moisture and / or oxygen. In some embodiments, the barrier layer (BFL) may be omitted.

[0269] The second base substrate BS2 may be a composition of the base surface that provides color filters CF1, CF2, and CF3.

[0270] The second base substrate BS2 may include glass, ceramic, metal, or a polymer resin such as polyimide. However, it is not limited to this; the second base substrate BS2 may be an inorganic layer, an organic layer, or a composite material layer, and may be formed as a single layer or multiple layers.

[0271] Figure 15 This is a graph showing the results of measuring adhesive forces while varying the height of each nanopattern and the distance between adjacent nanopatterns.

[0272] Reference Figure 15 For nanopatterns NP1, NP2-1, NP2-2, NP3, NP4, and NP5 with pattern heights of 10 nm, 50 nm, 100 nm, 200 nm, 300 nm, and 400 nm, the results of pull-off adhesion tests based on measurement standards ASTM D4541 and ISO 4624, while changing the distance between adjacent nanopatterns NP1, NP2-1, NP2-2, NP3, NP4, and NP5, confirmed that the increase in adhesion can vary when the pattern height is increased with a boundary of 50 nm between adjacent nanopatterns NP1, NP2-1, NP2-2, NP3, NP4, and NP5.

[0273] Specifically, when the distance between adjacent nanopatterns NP1, NP2-1, NP2-2, NP3, NP4, and NP5 is greater than 50 nm, it can be confirmed that the adhesive force increases with the increase of pattern height. This is likely due to the increase in adhesive area. However, when the distance between adjacent nanopatterns NP1, NP2-1, NP2-2, NP3, NP4, and NP5 is less than 50 nm, it can be confirmed that the adhesive force does not increase with the increase of pattern height, but rather decreases. This is likely due to the adhesive not penetrating smoothly between the patterns.

[0274] As a result, when the distance between adjacent nanopatterns NP1, NP2-1, NP2-2, NP3, NP4, and NP5 is greater than 50 nm, the bonding area can be increased by increasing the pattern height, thereby achieving the desired increase in adhesive force. However, when the distance is less than 50 nm, even if the pattern height is increased to improve adhesive force, the desired increase in adhesive force cannot be achieved, and the adhesive force may even decrease.

[0275] Therefore, as mentioned above, when designing nanopatterns, it is necessary to consider not only the diffraction possibility in the visible light region, but also the permeability of the adhesive into the nanopatterns.

[0276] As mentioned above, when considering both the diffraction probability in the visible light region and the adhesive permeability, the distance between adjacent nanopatterns can be limited to more than 50 nm and less than 190 nm.

[0277] In addition, Figure 15In this context, adhesive force is represented by a normalized value, so the unit is omitted.

[0278] The above description focuses on preferred embodiments of the present invention, but these are merely examples and do not limit the scope of the present invention. Anyone skilled in the art to which this invention pertains can modify and alter the embodiments in various ways by adding, altering, deleting, or supplementing constituent elements without departing from the technical concept of the present invention as described in the claims, and these modifications and alterations are also included within the scope of the claims of this invention.

Claims

1. A display device, characterized by comprising: including: a display module that displays an image and is defined with a folding area and first and second non-folding areas, the folding area being folded with a folding axis defined along a first direction, the first and second non-folding areas being arranged across the folding area along a second direction intersecting the first direction; a first functional layer arranged on the display module and including upper and lower surfaces facing each other; a first adhesive layer interposed between the display module and the lower surface of the first functional layer and adhered to the first functional layer, wherein a first recessed portion overlapping the folding area is provided at the lower surface of the first functional layer, the first functional layer is provided with first nano-patterns protruding from a bottom surface of the first recessed portion, the first adhesive layer is interposed in the first recessed portion and adhered to the first nano-patterns, a distance between nano-patterns adjacent to each other in the first nano-patterns is 50 nm or more and 190 nm or less. 2.The display device according to claim 1, wherein a distance between the bottom surface of the first recessed portion and an upper surface of the first functional layer is smaller than a thickness at other portions of the first functional layer overlapping the first and second non-folding areas. 3.The display device according to claim 2, wherein a distance between an end portion of each of the first nano-patterns and the upper surface of the first functional layer is the same as the thickness at the other portions of the first functional layer overlapping the first and second non-folding areas. 4.The display device according to claim 1, wherein each of the first nano-patterns has a conical shape or a cylindrical shape, a diameter of a bottom surface of each of the first nano-patterns is 10 nm or more and 190 nm or less, and a height of each of the first nano-patterns is 10 nm or more and 190 nm or less. 5.The display device according to claim 1, wherein each of the first nano-patterns has a quadrangular prism shape, each of the side lengths of a bottom surface of each of the first nano-patterns is 10 nm or more and 190 nm or less, and a height of each of the first nano-patterns is 10 nm or more and 190 nm or less. further including: a second functional layer arranged between the display module and the first functional layer, a 2-1 recessed portion overlapping the folding area is provided at an upper surface of the second functional layer, the second functional layer is provided with 2-1 nano-patterns protruding from a bottom surface of the 2-1 recessed portion, the first adhesive layer is interposed in the 2-1 recessed portion and adhered to the 2-1 nano-patterns, a distance between nano-patterns adjacent to each other in the 2-1 nano-patterns is 50 nm or more and 190 nm or less. further including: a second adhesive layer interposed between the display module and the second functional layer, a 2-2 recessed portion overlapping the folding area is provided at a lower surface of the second functional layer, 6. The display device of claim 1, wherein ​ ​ ​ ​ ​ ​ 7. The display device of claim 6, wherein ​ ​ ​ The second functional layer is provided with second-2 nanometer patterns protruding from a bottom surface of the second-2 recessed portion, The second adhesive layer is sandwiched in the second-2 recessed portion and adheres to the second-2 nanometer patterns, The interval between the nanometer patterns adjacent to each other in the second-2 nanometer patterns is 50 nm or more and 190 nm or less.

8. The display device of claim 1, wherein, Further comprising: A third functional layer arranged on the opposite side of the first functional layer across the display module; And A third adhesive layer sandwiched between the display module and the third functional layer, wherein a third recessed portion overlapping the folding area is provided on an upper surface of the third functional layer, The third functional layer is provided with third nanometer patterns protruding from a bottom surface of the third recessed portion, The third adhesive layer is sandwiched in the third recessed portion and adheres to the third nanometer patterns, The interval between the nanometer patterns adjacent to each other in the third nanometer patterns is 50 nm or more and 190 nm or less.

9. The display device according to claim 8, wherein The display module includes: A display panel having a first base substrate, a circuit layer, a display element layer, and an encapsulation layer stacked in this order, wherein a fourth recessed portion overlapping the folding area is provided on a lower surface of the first base substrate, The first base substrate is provided with fourth nanometer patterns protruding from a bottom surface of the fourth recessed portion, The third adhesive layer is sandwiched in the fourth recessed portion and adheres to the fourth nanometer patterns, The interval between the nanometer patterns adjacent to each other in the fourth nanometer patterns is 50 nm or more and 190 nm or less.

10. The display device according to claim 1, wherein The display module includes: A display panel having a first base substrate, a circuit layer, a display element layer, and an encapsulation layer stacked in this order; A color filter layer arranged on the encapsulation layer; and A second base substrate arranged on the color filter layer and providing a base surface of the color filter, wherein a fifth recessed portion overlapping the folding area is provided on an upper surface of the second base substrate, The second base substrate is provided with fifth nanometer patterns protruding from a bottom surface of the fifth recessed portion, The first adhesive layer is sandwiched in the fifth recessed portion and adheres to the fifth nanometer patterns, The interval between the nanometer patterns adjacent to each other in the fifth nanometer patterns is 50 nm or more and 190 nm or less.

Images