Window and display device comprising a window

Abstract

A window and a display device including the same are disclosed. The window includes a base layer including a first non-folded area, a second non-folded area, a folded area disposed between the first non-folded area and the second non-folded area in a first direction, and at least one first recessed portion overlapping the folded area and extending in a second direction intersecting the first direction; a first nano-pattern layer disposed in the at least one first recessed portion and including a first protrusion pattern; and a first soft portion disposed on the first nano-pattern layer.

Description

[0001] Cross-reference to related applications

[0002] This application claims priority and benefit to Korean Patent Application No. 10-2021-0034283, filed with the Korean Intellectual Property Office on March 16, 2021, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates to windows and display devices including windows, and to windows having improved optical properties while ensuring folding and impact resistance properties, and display devices including such windows. Background Technology

[0004] Electronic devices that provide images to users, such as smartphones, digital cameras, laptops, navigation systems, and smart TVs, include display devices for displaying images. The display device generates images and provides them to the user via a display screen.

[0005] Recently, with the development of display device technology, various types of display devices are being developed. For example, various flexible display devices that can be deformed, folded, or rolled into curved shapes are being developed. Flexible display devices with various shape changes are easy to carry and improve user convenience.

[0006] A foldable display device in a flexible display apparatus can be folded relative to a folding axis extending in one direction. The foldable display device may include a flexible display panel and a flexible window disposed on the display panel.

[0007] It should be understood that this background section is intended in part to provide useful background for understanding the art. However, this background section may also include ideas, concepts, or knowledge that were known or understood by a person skilled in the art prior to the corresponding valid application date of the subject matter disclosed herein. Summary of the Invention

[0008] This disclosure provides windows and display devices that have improved optical properties while ensuring folding and shock resistance.

[0009] The embodiment provides a window that may include: a base layer including a first non-folded region, a second non-folded region, a folded region disposed in a first direction between the first non-folded region and the second non-folded region, and at least one first recessed portion overlapping the folded region and extending in a second direction intersecting the first direction; a first nanopattern layer disposed in at least one first recessed portion and including a first protruding pattern; and a first soft portion disposed on the first nanopattern layer.

[0010] In one embodiment, the window may further include a second soft portion disposed on the upper surface of the base layer, wherein the first soft portion and the second soft portion comprise the same material.

[0011] In an embodiment, the window may further include a second nanopattern layer disposed on the upper surface of the substrate layer on a portion overlapping the first non-folded region and the second non-folded region, and includes a second protrusion pattern.

[0012] In an implementation, the first protrusion pattern may include at least one of a substantially conical shape, a substantially parabolic shape, and a substantially hemispherical shape.

[0013] In an implementation, the linewidth of each first protrusion pattern can be in the range of about 100 nm to about 350 nm, and the height of each first protrusion pattern can be in the range of about 200 nm to about 3000 nm.

[0014] In an embodiment, at least one first recessed portion may include a plurality of first recessed portions, and the plurality of first recessed portions may be spaced apart in a first direction.

[0015] In one embodiment, at least one first recessed portion may be recessed from the upper surface of the substrate layer, and the depth of the recessed portion from the upper surface may be less than the thickness of the substrate layer.

[0016] In an embodiment, at least one first recessed portion may include: a first inner surface on a base layer and extending upward on a third party intersecting the first and second directions; a second inner surface extending upward on the third party and facing the first inner surface; and a first bottom surface perpendicular to the first and second inner surfaces.

[0017] In one embodiment, the first nanopattern layer may be disposed on the first bottom surface.

[0018] In one embodiment, the first nanopattern layer may be disposed on the first inner surface and the second inner surface.

[0019] In one embodiment, at least one second recessed portion may be formed in the substrate layer, recessed from the lower surface of the substrate layer and extending in a second direction, and the window may further include a third nanopattern layer disposed on at least one second recessed portion and including a third protruding pattern.

[0020] In an embodiment, at least one first recessed portion may include a plurality of first recessed portions, and at least one second recessed portion may include a plurality of second recessed portions, and the plurality of first recessed portions and the plurality of second recessed portions may be alternately arranged in a first direction.

[0021] In an embodiment, the window may further include a third soft portion disposed in at least one second recessed portion.

[0022] In an embodiment, at least one first recessed portion may penetrate the base layer, and at least one first recessed portion may be comprised of a third inner surface and a fourth inner surface, wherein the third inner surface is on the base layer and extends upward on a third party intersecting the first and second directions, and the fourth inner surface extends upward on the third party and faces the third inner surface.

[0023] In one embodiment, the first nanopattern layer may contact at least a portion of the third or fourth inner surface.

[0024] In an implementation, at least one first recessed portion may have a substantially curved surface shape extending in a first direction.

[0025] In one embodiment, the display device may include: a display module including a folded region folded about a folding axis extending in one direction; and a window disposed on the display module and folded together with the display module, wherein the window may include: a base layer including a first recessed portion overlapping the folded region and extending in the folding direction; a first nanopattern layer disposed in the first recessed portion and including a first protruding pattern; and a first soft portion disposed on the first nanopattern layer; the first recessed portion may be recessed from the upper surface of the base layer.

[0026] In an embodiment, the display device may further include a second soft portion disposed on the upper surface of the substrate layer, wherein the first soft portion and the second soft portion may comprise the same material.

[0027] In an implementation, the first protrusion pattern may each include at least one of a substantially conical shape, a substantially parabolic shape, and a substantially hemispherical shape.

[0028] In an implementation, the linewidth of each first protrusion pattern can be in the range of about 100 nm to about 350 nm, and the height of each first protrusion pattern can be in the range of about 200 nm to about 3000 nm. Attached Figure Description

[0029] The accompanying drawings are included to provide a further understanding of this disclosure and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments and, together with the description, serve to explain the principles of this disclosure. In the drawings:

[0030] Figure 1 This is a schematic perspective view of the display device according to the embodiment;

[0031] Figure 2 It is shown Figure 1A diagram showing the folded state of the display device;

[0032] Figure 3 This is an exploded perspective view showing a display device according to an embodiment;

[0033] Figure 4 This is a schematic cross-sectional view of the display module according to the implementation method;

[0034] Figure 5 This is a schematic cross-sectional view of a portion of a window according to an embodiment;

[0035] Figure 6 This is a schematic perspective view showing a portion of the nanopatterned layer according to an embodiment;

[0036] Figure 7A and Figure 7B This is a schematic cross-sectional view showing a portion of the nanopatterned layer according to an embodiment; and

[0037] Figures 8 to 11 This is a schematic cross-sectional view showing a portion of a window according to an embodiment. Detailed Implementation

[0038] In the following description, embodiments will be described with reference to the accompanying drawings.

[0039] In this specification, when a component (or area, layer, part, etc.) is referred to as being on, connected to, or coupled to another component, it means that it is directly connected to or directly coupled to another component, or that a third component, or other component, or other multiple components may be arranged or disposed between them.

[0040] It should be understood that the terms “connected to” or “linked to” can include physical connection or physical linkage, or electrical connection or electrical linkage.

[0041] The same reference numerals denote the same elements. In the accompanying drawings, the thickness, scale, and dimensions of parts may be exaggerated in order to effectively depict the technical content.

[0042] In the specification and claims, the term "and / or" is intended, for the purposes of its meaning and interpretation, to include any combination of the terms "and" and "or". For example, "A and / or B" can be understood to mean "A, B, or A and B". The terms "and" and "or" can be used in a combined or separate sense and can be understood as equivalent to "and / or".

[0043] In the specification and claims, the phrase "at least one" is intended, for the purposes of its meaning and interpretation, to include the meaning of "at least one selected from the group of...". For example, "at least one of A and B" can be understood to mean "A, B, or A and B".

[0044] Terms such as "first" and "second" may be used to describe various components, but these components should not be limited by these terms. These terms are used only to distinguish one component from others. For example, without departing from the scope of this disclosure, a first component may be referred to as a second component, and similarly, a second component may be referred to as a first component. Unless the context clearly indicates otherwise, singular expressions include plural expressions. For example, unless the context clearly indicates otherwise, the singular forms "an," "a," and "the" are intended to also include the plural forms as used herein.

[0045] Terms such as “below,” “down,” “above,” and “up” are used to describe the relationships between the components shown in the accompanying drawings. These terms are relative concepts and are described based on, but not limited to, the directions indicated in the drawings.

[0046] For example, the spatial relative terms “below,” “under,” “down,” “above,” “up,” etc., may be used herein to describe the relationship between one element or component and another, as shown in the accompanying drawings. It should be understood that, in addition to the orientations depicted in the drawings, the spatial relative terms are intended to cover different orientations of the device in use or operation. For example, in the case where the device shown in the figures is flipped, a device located “below” or “under” another device may be placed “above” another device. Accordingly, the descriptive term “below” can include both “down” and “up” orientations. The device may also be oriented in other directions, and therefore the spatial relative terms may be interpreted differently depending on the orientation.

[0047] The term “overlapping” or “overlapping” means that the first object may be above or below the second object, or to one side of the second object, or vice versa. Additionally, the term “overlapping” may include layering, stacking, facing or confronting, extending over, covering or partially covering, or any other suitable term that will be understood and appreciated by one of ordinary skill in the art.

[0048] When an element is described as not overlapping with or not overlapping with another element, this may include elements spaced apart from each other, offset from each other, or arranged side by side, or any other suitable terms that will be understood and appreciated by one of ordinary skill in the art.

[0049] The terms "facing" and "oriented" mean that the first element can be directly or indirectly opposite the second element. In the case where a third element is inserted between the first and second elements, although the first and second elements still face each other, they can be understood as being indirectly opposite each other.

[0050] The terms “comprises,” “comprising,” “includes,” and / or “including,” “has,” “have,” and / or “having,” and variations thereof, when used in this specification, specify the presence of the stated features, integrals, steps, operations, elements, components, and / or groups thereof, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or groups thereof.

[0051] In this specification, "direct contact" may mean that no layer, film, region, or plate is added between one part and another. For example, "direct contact" may mean placing two layers or two components without using additional components such as adhesive components between them.

[0052] The phrase “in a plan view” means viewing an object from top, and the phrase “in a schematic sectional view” means viewing an object from the side, where the object is vertically cut across a section.

[0053] As used herein, “about” or “approximately” includes the value and the average of the value within an acceptable range of deviations from the particular value, as determined by a person skilled in the art in view of the measurement in question and the error (i.e., limitations of the measurement system) associated with the measurement of the particular quantity. For example, “about” may mean within one or more standard deviations of the value, or within ±30%, ±20%, ±10%, ±5% of the value.

[0054] Unless otherwise defined, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. Terms defined in common dictionaries shall be interpreted as having a meaning consistent with their meaning in the context of the relevant art and shall not be interpreted as having an ideal or overly formal meaning unless so defined herein.

[0055] In the following description, embodiments will be described with reference to the accompanying drawings.

[0056] Figure 1 This is a schematic perspective view of a display device DD according to an embodiment. Figure 2 It is shown Figure 1 The diagram shows the folded state of the display device DD.

[0057] Reference Figure 1 and Figure 2The display device DD can be a foldable display device. The display device DD according to this disclosure can be used not only in large electronic devices such as televisions and monitors, but also in small and medium-sized electronic devices such as mobile phones, tablets, car navigation systems, game consoles, and smartwatches.

[0058] The upper surface of the display device DD can be defined as the display surface DS, and when the display device DD is unfolded, the display surface DS can have a plane defined by a first direction DR1 and a second direction DR2. A third direction DR3 that intersects or intersects with the first direction DR1 and the second direction DR2 can be defined as the thickness direction of the display device DD. The front (or upper) surface and rear (or lower) surface of the components constituting the display device DD can be defined relative to the third direction DR3.

[0059] The display surface DS may include a display area DA and a non-display area NDA surrounding or adjacent to the display area DA. The display area DA is the area on which the image IM is displayed, and the non-display area NDA is the area on which the image IM is not displayed. Figure 1 The image shows an example of an application icon and a user TC who touches at least one icon.

[0060] The display area DA can be substantially rectangular in shape. The non-display area NDA can surround the display area DA or can be adjacent to the display area DA. However, the implementation is not limited to this, and the shapes of the display area DA and the non-display area NDA can be designed relatively differently. It should be understood that the shapes described herein do not have to be precise shapes, and can include shapes that substantially correspond to or are within the given shape or the shape described herein.

[0061] The first non-folding region NFA1, the folding region FA, and the second non-folding region NFA2 can be sequentially defined on the display device DD along the first direction DR1. For example, the folding region FA can be defined between the first non-folding region NFA1 and the second non-folding region NFA2. Figure 1 and Figure 2 A folded region FA and a first non-folded region NFA1 and a second non-folded region NFA2 are shown, but the number of folded regions FA and the number of first non-folded regions NFA1 and second non-folded regions NFA2 are not limited thereto. For example, the display device DD may include three or more non-folded regions and folded regions disposed between the non-folded regions.

[0062] The display device DD can be folded relative to the folding axis FX. For example, the folding area FA can be bent relative to the folding axis FX. The folding axis FX can extend along a second direction DR2. The folding axis FX can be defined as an axis parallel to the short side of the display device DD.

[0063] When the display device DD is folded, the display surfaces of the first non-folded region NFA1 and the second non-folded region NFA2 can face each other. Therefore, the display surface DS can be concealed from the outside in the folded state. In an embodiment, a rear surface display area (not shown) can be provided on the rear surface of the display device DD. When the display device DD is folded, the rear surface display area can be exposed to the outside, and this can be referred to as "inward folding". However, this is an example, and the operation of the display device DD is not limited to this.

[0064] For example, in one embodiment, when the display device DD is folded, the first non-folded region NFA1 and the second non-folded region NFA2 can face away from each other. Therefore, the display region DA can be exposed to the outside in the folded state, and this can be referred to as "outward folding".

[0065] The display device DD can perform only one of the inward folding and outward folding operations. As an example, the display device DD can perform both inward folding and outward folding operations. The same area of ​​the display device DD, such as the folding area FA, can be folded inward and outward. As an example, a portion of the display device DD can be folded inward, and other areas of the display device DD can be folded outward.

[0066] Figure 3 This is an exploded perspective view of a display device DD according to an embodiment.

[0067] Reference Figure 3 The display device DD may include display modules DM and windows WL that can be stacked sequentially on top of each other along a third direction DR3. Each of the display modules DM and windows WL can be stacked relative to the folding axis FX (see [link to folding axis]). Figure 1 and Figure 2 )fold.

[0068] The display module DM can generate an image IM in response to an electrical signal. The display module DM may include a display panel DP. The display panel DP can generate the image IM. The display panel DP may be a liquid crystal display panel or a light-emitting display panel, and is not particularly limited thereto. For example, the light-emitting display panel may be an organic light-emitting display panel or a quantum dot light-emitting display panel. The light-emitting layer of the organic light-emitting display panel may include organic light-emitting materials. Within the spirit and scope of this disclosure, the light-emitting layer of the quantum dot light-emitting display panel may include quantum dots, quantum rods, etc.

[0069] Although not shown separately, the display device DD may also include a support member supporting the display module DM. The support member may be disposed below or beneath the display module DM to support the display module DM and prevent deformation of the display module DM. The support member may have an integral plate shape corresponding to the shape of the display module DM. A support member with an integral plate shape may include a structure that overlaps with the folding region FA and increases its flexibility. However, the shape of the support member is not limited to this, and the support member may have the shape of at least two plates with a folding region FA between them, and the at least two plates are spaced apart from each other.

[0070] A window (WL) can be installed on the display module (DM) and protect it. The window WL prevents damage or malfunction to the display module (DM) due to external impacts. The window WL may include an optically transparent insulating material. Therefore, the user can identify the image (IM) generated in the display module (DM) through the window WL. For example, the display surface (DS) of the display device (DD) can be defined by the window WL.

[0071] The window WL may include a substrate layer BS, a first soft portion SP1, and a second soft portion SP2. A first recessed portion RE1 may be defined in the substrate layer BS. The first recessed portion RE1 may overlap with the folded region FA and may be recessed from the upper surface of the substrate layer BS. A first nanopatterned layer NPL1 may be disposed on the first recessed portion RE1.

[0072] The first soft portion SP1 can be disposed on the first recessed portion RE1. For example, the first soft portion SP1 can be disposed on the first nanopattern layer NPL1 disposed on the first recessed portion RE1, and can completely fill the first recessed portion RE1. Therefore, the first soft portion SP1 can be parallel to the upper surface UF of the substrate layer BS.

[0073] The second soft portion SP2 can be disposed on the upper surface UF of the substrate layer BS. The second soft portion SP2 can be disposed to completely cover the upper surface UF of the substrate layer BS or to completely overlap with the upper surface UF of the substrate layer BS. Therefore, at least a portion of the second soft portion SP2 can contact the first soft portion SP1 disposed on the first recessed portion RE1.

[0074] Figure 4 This is a schematic cross-sectional view of the display module DM according to an embodiment. In the following text, reference will be made to... Figure 4 The stacking structure of the display module DM according to the embodiment is described. The above description can be similarly applied to the description of each component, and redundant descriptions will be omitted.

[0075] Reference Figure 4 The display module DM may include a display panel DP, an input sensing component ISP, and an anti-reflective layer POL.

[0076] The display module DM can display image IM and can sense user input. The display module DM can be a flexible display module. For example, the display module DM can be folded relative to the folding axis FX (see...). Figure 2 ).

[0077] The display panel DP may include a base substrate SUB, a circuit layer CL, a display element layer OL, and a thin film sealing layer TFE. In an embodiment, the base substrate SUB, the circuit layer CL, the display element layer OL, and the thin film sealing layer TFE may be stacked on top of each other sequentially along the third direction DR3.

[0078] The base substrate SUB may include a flexible material, and may be, for example, a plastic substrate. The plastic substrate may include at least one of acrylic resin, methacrylic resin, polyisoprene resin, vinyl resin, epoxy resin, urethane resin, cellulose resin, siloxane resin, polyimide resin, polyamide resin, and dinaphthalene-based phenyl resin. For example, the base substrate SUB may include a single layer of polyimide resin. However, embodiments are not limited thereto, and the base substrate SUB may be a stacked structure including an insulating layer.

[0079] Within the spirit and scope of this disclosure, the circuit layer CL may include an insulating layer, a semiconductor pattern, a conductive pattern, a signal line, etc.

[0080] Insulating, semiconductor, and conductive layers can be formed on a base substrate (SUB) through coating and deposition, and can be selectively patterned using multiple photolithography processes. Semiconductor patterns, conductive patterns, and signal lines for the circuit layer (CL) can be formed.

[0081] The display element layer OL can be disposed on the circuit layer CL. The display element layer OL may include light-emitting elements. For example, the display element layer OL may include organic light-emitting materials, quantum dots, quantum rods, or micro LEDs.

[0082] A thin-film sealing layer (TFE) can be disposed on the display element layer OL to cover or overlap the display element layer OL. The TFE can include inorganic layers, organic layers, and inorganic layers that can be sequentially stacked on top of each other. The inorganic layers can include inorganic materials and can protect the pixels from moisture or oxygen. The organic layers can include organic materials and can protect the pixels from foreign substances such as dust particles.

[0083] In the above description, it has been assumed that the display panel DP is an organic light-emitting display panel, but the implementation is not limited to this. For example, the display panel DP can be a liquid crystal display panel.

[0084] The input sensing section (ISP) may include sensors for sensing external inputs. These sensors may sense external inputs capacitively. External inputs can include various types of inputs, such as a part of the user's body, light, heat, a pen, or pressure.

[0085] The input sensing component (ISP) can be disposed on the thin-film sealing layer (TFE) or directly on the TFE. For example, the input sensing component (ISP) can be formed on the TFE through a continuous process. However, the implementation is not limited to this, and the input sensing component (ISP) can be formed by a separate process and then bonded to the display panel (DP) via an adhesive.

[0086] An anti-reflective layer (POL) can be disposed on the input sensing section (ISP). The anti-reflective layer (POL) can be a film used to prevent the effects of reflection of external light. The anti-reflective layer (POL) can reduce the reflectivity of external light incident on the display panel (DP) from outside the display device (DD). For example, the anti-reflective layer (POL) may include a phase retarder and / or a polarizer.

[0087] The display module DM may include adhesive components. For example, the layers of the display module DM can be connected to each other by adhesive components disposed between adjacent layers.

[0088] Figure 5 This is a schematic cross-sectional view showing a portion of the window WL according to an embodiment. For ease of description, Figure 5 It is shown that the base layer BS and the second soft part SP2 are separate. Figure 6 This is a schematic perspective view showing a portion of the first nanopatterned layer NPL1 according to an embodiment. Figure 7A and Figure 7B This is a schematic cross-sectional view showing a portion of the first nanopatterned layer NPL1 according to an embodiment. Figure 7A and Figure 7B It shows along Figure 6 The portion intercepted by the line a-a'.

[0089] Reference Figure 3 and Figure 5 The window (WL) is installed on the display module (DM) to protect it from external scratches and to facilitate folding and unfolding operations. Therefore, the window (WL) used in flexible display devices must possess high impact resistance to protect the display module (DM) and high flexibility to facilitate folding operations.

[0090] The window WL according to this disclosure has a pattern on the folded portion of the substrate BS, thereby exhibiting both excellent impact resistance and high flexibility. The window WL according to an embodiment will be described in more detail below.

[0091] The window WL may include a substrate layer BS, a first soft portion SP1, and a second soft portion SP2. The substrate layer BS may be disposed on the display module DM. The substrate layer BS may be made of an optically transparent and physically robust and rigid material. For example, the substrate layer BS may include materials such as transparent glass, colorless polyimide (CPI), polyethylene terephthalate (PET), and cyclic olefin polymers (COP). However, the material of the substrate layer BS is not limited to these.

[0092] The base layer BS may include a first non-folded region NFA1, a folded region FA, and a second non-folded region NFA2 arranged or disposed sequentially along a first direction DR1.

[0093] The substrate layer BS may include an upper surface UF and a lower surface LF. The upper surface UF and the lower surface LF may be defined by a plane defined by a first direction DR1 and a second direction DR2. In an embodiment, the upper surface UF and the lower surface LF of the substrate layer BS may each have a flat surface.

[0094] The first recessed portion RE1 may be defined within the substrate layer BS. For example, the first recessed portion RE1 may overlap with the folded region FA and may be recessed from the upper surface UF of the substrate layer BS in a third direction DR3. The first recessed portion RE1 may not be defined within the first non-folded region NFA1 and the second non-folded region NFA2. In this disclosure, the first recessed portion RE1 may be referred to as a pattern, and the region defining the first recessed portion RE1 and the region overlapping the first recessed portion RE1 may be referred to as a patterned region. For example, the folded region FA of the substrate layer BS may be referred to as a patterned region.

[0095] The first recessed portion RE1 may be defined by a first inner surface ISF1, a second inner surface ISF2, and a first bottom surface BF1 defined in the base layer BS. The first inner surface ISF1 and the second inner surface ISF2 may each extend in a third direction DR3 and may be parallel to the plane defined by the second direction DR2 and the third direction DR3. The first inner surface ISF1 and the second inner surface ISF2 may be disposed facing each other.

[0096] The first bottom surface BF1 may be disposed between one end of the first inner surface ISF1 and one end of the second inner surface ISF2. The first bottom surface BF1 may be parallel to the upper surface UF of the substrate layer BS. In an embodiment, the first bottom surface BF1 may be perpendicular to the first inner surface ISF1 and the second inner surface ISF2.

[0097] In this embodiment, multiple first recessed portions RE1 can be provided. Each first recessed portion RE1 can extend in the second direction DR2. For example, each first recessed portion RE1 can be parallel to... Figure 2 The folded axis FX is shown. The first recessed portions RE1 can be spaced apart from each other along the first direction DR1. The depth of each first recessed portion RE1 relative to the third direction DR3 can be less than the thickness of the substrate layer BS relative to the third direction DR3.

[0098] Figure 5 The illustration shows ten first recessed portions RE1 defined in the upper surface UF of the substrate layer BS, but this is merely an example. Therefore, the implementation is not limited thereto. Within the spirit and scope of this disclosure, the number of first recessed portions RE1 defined in the upper surface UF of the substrate layer BS can vary depending on the display device DD in the folded state (see [link to relevant documentation]). Figure 1 The curvature of the folded region FA is changed.

[0099] Reference Figure 5 and Figure 6 The first nanopattern layer NPL1, including the first protruding pattern PR1, can be disposed on the first recessed portion RE1. For example, the first nanopattern layer NPL1 can be disposed on the first bottom surface BF1 of the first recessed portion RE1, or on the first inner surface ISF1 and the second inner surface ISF2 of the first recessed portion RE1. However, the embodiments are not limited thereto, and as... Figure 5 As shown, the first nanopatterned layer NPL1 can be disposed on all of the first bottom surface BF1, the first inner surface ISF1, and the second inner surface ISF2. A detailed description of the first nanopatterned layer NPL1 will be described later.

[0100] In this embodiment, the first soft portion SP1 may be disposed in the first recessed portion RE1. For example, the first soft portion SP1 may be disposed on the first nanopatterned layer NPL1 disposed on the first recessed portion RE1. The first soft portion SP1 may be disposed on the first nanopatterned layer NPL1 and may be configured to fill the first recessed portion RE1 such that the upper surface of the first soft portion SP1 is parallel to the upper surface UF of the substrate layer BS.

[0101] The first soft portion SP1 may comprise an optically transparent and flexible material. For example, the first soft portion SP1 may comprise a material whose hardness and strength are physically lower than those of the substrate layer BS. For example, the first soft portion SP1 may comprise a transparent polymer resin, but is not limited thereto. Since the first soft portion SP1 may comprise a flexible material, the folding characteristics in the folding region FA can be further improved when the first soft portion SP1 is disposed in the first recessed portion RE1.

[0102] The second soft portion SP2 can be disposed on the upper surface UF of the substrate layer BS. For example, the second soft portion SP2 can be disposed to completely cover the upper surface UF of the substrate layer BS or to completely overlap the upper surface UF of the substrate layer BS. Accordingly, at least a portion of the second soft portion SP2 can contact the first soft portion SP1. The upper and lower surfaces of the second soft portion SP2 can each be parallel to the plane defined by the first direction DR1 and the second direction DR2. In an embodiment, the thickness of the second soft portion SP2 relative to the third direction DR3 can be less than the thickness of the substrate layer BS relative to the third direction DR3. For example, the thickness of the second soft portion SP2 can be in the range of about 0.2 μm to about 10.0 μm, but is not limited thereto.

[0103] In this embodiment, the second soft portion SP2 can protect the window WL. For example, the second soft portion SP2 can protect the base layer BS included in the window WL from external impacts. The second soft portion SP2 can improve the durability of the window WL. When the first soft portion SP1 is disposed in the first recessed portion RE1, a height difference may occur between the first soft portion SP1 and the upper surface UF of the base layer BS, resulting in fine irregularities. In this disclosure, when the second soft portion SP2 is disposed on the upper surface UF of the base layer BS, the second soft portion SP2 can bond to both the first soft portion SP1 and the upper surface UF of the base layer BS, and can flatten the irregularities, thereby further improving the durability of the window WL.

[0104] The second soft portion SP2 may comprise an optically transparent and flexible material. For example, the second soft portion SP2 may comprise a material whose hardness and strength are physically lower than those of the substrate layer BS. For example, the second soft portion SP2 may comprise a transparent polymer resin, but is not limited thereto.

[0105] In this embodiment, the first soft portion SP1 and the second soft portion SP2 may comprise the same or similar materials. The first soft portion SP1 and the second soft portion SP2 can be formed using the same process and thus can have an integral shape on the substrate layer BS. When forming the window WL, the first recessed portion RE1 of the substrate layer BS and the entire upper surface UF of the substrate layer BS can be coated with resin, and the first soft portion SP1 and the second soft portion SP2 can be formed using a heat- or light-cured resin. However, the method of forming the first soft portion SP1 and the second soft portion SP2 is not limited to this.

[0106] The display device according to an embodiment may include a window, which may include a base layer defining a recessed portion therein and a soft portion disposed in the recessed portion. The recessed portion may be configured to overlap with a folded area and a pattern may be formed on the window. Therefore, the display device according to an embodiment can ensure both high flexibility in the folded area and impact resistance in the non-folded area, thereby further improving the reliability of the display device.

[0107] In a window where a pattern is formed in a folded area, Fresnel reflection caused by external light may occur at the interface between the pattern area and the window due to the difference in refractive index, and the pattern area may be visually recognizable to the outside due to this reflection.

[0108] To prevent this light reflection, methods have been used to match the refractive index of the patterned region material to that of the window material, or to induce destructive interference by applying multilayer films with different refractive indices. However, these methods may focus on refractive index matching and therefore may have limitations in terms of physical properties such as stability, thermomechanical properties, and the adhesion of the stacked films. With multilayer films, it may be advantageous to achieve antireflective effects over a wide range, but the selection of materials that can be used as stacking materials may be limited due to the limited number of materials with a specific or given refractive index.

[0109] The display device according to an embodiment is provided with a window in which a pattern is formed in a folded area, and the window may include a nanopattern layer on the pattern, the nanopattern layer having a three-dimensionally shaped nanostructure with protruding patterns. Accordingly, the amount of light reflected at the interface between the window and the pattern can be effectively reduced, and thus the optical characteristics of the display device can be improved. Various materials that meet physical properties (e.g., glass transition temperature, modulus, and elongation) can be applied to the pattern area, and ultra-low reflection can be achieved even with refractive index changes, such as those caused by thermomechanical deformation or temperature variations, thereby providing a display device with guaranteed reliability.

[0110] Reference Figure 5 and Figure 6 According to the embodiment, the first nanopattern layer NPL1 can be disposed in the first recessed portion RE1 of the substrate layer BS. Figure 6 The illustration shows a first nanopatterned layer NPL1 disposed on a first bottom surface BF1, but the implementation is not limited thereto. For example, the first nanopatterned layer NPL1 may be disposed on a first inner surface ISF1 and a second inner surface ISF2 of the first recessed portion RE1.

[0111] The first nanopatterned layer NPL1 may include a base portion BP and a first protrusion pattern PR1. The base portion BP may be a component providing a base surface on which the first protrusion pattern PR1 is disposed. In embodiments, the first protrusion pattern PR1 and the base portion BP may have an integral shape. However, embodiments are not limited thereto.

[0112] The base portion BP can be disposed on or directly disposed on the first bottom surface BF1 of the first recessed portion RE1, but the implementation is not limited thereto. Therefore, depending on the processing method or processing conditions, the base portion BP of the first nanopattern layer NPL1 can be omitted, and the first protruding pattern PR1 can be disposed on or directly disposed on the first bottom surface BF1 of the first recessed portion RE1.

[0113] Reference Figure 6 and Figure 7A The first protrusion pattern PR1 can represent a nanoscale structure. For example, the first protrusion pattern PR1 can be a moth eye pattern. A moth eye pattern is a pattern in which nanoscale structures are arranged or set in a period or at intervals, and can refer to a biomimetic pattern that simulates the compound eye structure of a moth.

[0114] In one embodiment, the first protrusion patterns PR1 can be uniformly disposed on the base portion BP, and each has a height h1 and a linewidth d1. In another embodiment, the height h1 of each first protrusion pattern PR1 can be in the range of about 200 nm to about 3000 nm, and the linewidth d1 of each first protrusion pattern PR1 can be in the range of about 100 nm to about 350 nm. When the height h1 and linewidth d1 of each of the first protrusion patterns PR1 satisfy the above ranges, an anti-reflection effect can be exhibited throughout the visible light band, and the diffraction of light by the pattern can be minimized, thereby reducing reflectivity. In this disclosure, the linewidth d1 can represent the spacing between the centers of adjacent first protrusion patterns PR1.

[0115] In an implementation, the ratio of the linewidth d1 to the height h1 of each first protrusion pattern PR1 can be in the range of about 0.03 to about 1.75, for example, in the range of about 0.04 to about 1.5. When the ratio of the linewidth d1 to the height h1 of each first protrusion pattern PR1 satisfies the above range, the wavelength dependence of the reflection characteristics can be reduced, which may be more advantageous in terms of anti-reflection. Within the above range of height h1 and linewidth d1, a smaller ratio of the linewidth d1 to the height h1 of each first protrusion pattern PR1 may be desirable.

[0116] In an implementation, the first protrusion pattern PR1 can be arranged or set in various forms within the aforementioned range of line width d1. Figure 6The corresponding first protrusion pattern PR1 is shown to be uniformly arranged in a matrix or set on the base portion BP, but the implementation is not limited to this.

[0117] Reference Figure 7B The heights of the first protruding patterns PR1-1 can be different from each other. For example, the line width d1 of each first protruding pattern PR1-1 can be constant, and the heights of the first protruding patterns PR1-1 can be different from each other within the range mentioned above.

[0118] Each of the first protrusion patterns PR1 may include a conical shape. For example, each of the first protrusion patterns PR1 may have a conical shape defined by a sidewall SW with a positive slope. Figure 7A The bottom surfaces of the first raised patterns PR1 are shown to be in contact with each other, but the implementation is not limited to this. The bottom surfaces of the first raised patterns PR1 may not be in contact with each other, and the first raised patterns PR1 may be arranged spaced apart from each other.

[0119] The shape of each of the first protrusion patterns PR1 can be varied to effectively prevent reflection. In embodiments, the first protrusion pattern PR1 may include any one of a conical shape, a parabolic shape, and a hemispherical shape. However, the shape of each of the first protrusion patterns PR1 is not limited to these. For example, the first protrusion pattern PR1 can have various shapes as long as the refractive index can change continuously in the height direction. For example, the first protrusion pattern PR1 may be shaped such that its cross-sectional area increases from top to bottom. Assuming the first soft portion SP1 (see...) Figure 5 ) set in Figure 7A On the first protruding pattern PR1, the first protruding pattern PR1 and the first soft part SP1 are... Figure 7A The cross-sectional area ratios at points a, b, c, and d can gradually increase. Correspondingly, the refractive index varies linearly with the height of the first protrusion pattern PR1, thus preventing reflection of incident light due to differences in refractive index. Here, the effective refractive index (n) of the first protrusion pattern PR1... RI This is represented by Equation 1.

[0120] [Equation 1]

[0121] n RI =n RS ×A+n PR ×B

[0122] In equation 1, n RS It is the refractive index of the first soft part SP1, n PRLet n be the refractive index of the first protruding pattern PR1, A be the cross-sectional area ratio of the first soft portion SP1 to the first protruding pattern PR1, and B be the cross-sectional area ratio of the first protruding pattern PR1 to the first soft portion SP1. For example, A is the ratio of the cross-sectional area of ​​the first soft portion SP1 to the sum of the cross-sectional areas of the first protruding pattern PR1 and the first soft portion SP1. B is the ratio of the cross-sectional area of ​​the first protruding pattern PR1 to the sum of the cross-sectional areas of the first protruding pattern PR1 and the first soft portion SP1. Here, n... PR It can be greater than n RS The first protruding pattern PR1 is used as an example in the description of Equation 1, but the implementation is not limited thereto. Equation 1 can be similarly applied to the second and third protruding patterns.

[0123] The first nanopatterned layer NPL1 can be made of various materials. For example, within the spirit and scope of this disclosure, the first nanopatterned layer NPL1 may include at least one material selected from the group consisting of curable resins, metals, metal oxides, carbides (such as silicon carbide), hollow inorganic oxides (such as hollow silicon dioxide), silicon wafer materials, etc.

[0124] However, the implementation methods are not limited to this.

[0125] The curable resin is not particularly limited, as long as the resin can form a pattern through a UV curing reaction, but at least one selected from the group consisting of acrylic resins, epoxy resins, and urea resins can be used. However, the embodiments are not limited to this, and photocurable resins or thermosetting resins that can be cured by, for example, visible light can also be used.

[0126] Examples of metals may include metals such as Au, Zn, Sn, Ti, Si, Al, Ag, Zr, Ni, Mn, Cu, Cr, Fe, Co, Pt, Pd, Wu, and Ba, as well as metal alloys to which at least one metallic element or at least one non-metallic element is added.

[0127] Within the spirit and scope of this disclosure, examples of metal oxides may include nanoparticles of metal oxides that individually comprise metals such as Au, Zn, Sn, Ti, Si, Al, Ag, Zr, Ni, Mn, Cu, Cr, Fe, Co, Pt, Pd, Wu, and Ba, or combinations comprising at least two of them, and, for example, metal oxides may include SiO2, Al2O3, CeO2, etc. x ZnO, TiO2, SnO2, etc.

[0128] In cases where the first nanopatterned layer NPL1 may comprise nanoparticles of metal oxides, the nanoparticles may be coated with a resin. For example, at least one of siloxanes, polysilazanes, and polymethyl methacrylate (PMMA) may be used as the resin, and polysilazane may be used, for example.

[0129] In the embodiments, within the spirit and scope of this disclosure, the first nanopattern layer NPL1 can be formed by using various methods, such as dry etching (e.g., plasma etching, ion beam etching, and laser etching), wet etching using an etching solution, dip coating, calcination, thermal embossing, nanoimprint lithography, anodizing, nanosphere lithography, laser holographic lithography, etc.

[0130] However, the implementation methods are not limited to this.

[0131] Figures 8 to 11 This is a window showing the implementation method. W Schematic sectional views of a portion of L-1, WL-2, WL-3, and WL-4. In the following text, for reference... Figures 8 to 11 Windows WL-1, WL-2, WL-3, and WL-4, which are described according to embodiments, use the same reference numerals as those used for the parts described above, and detailed descriptions thereof will be omitted herein.

[0132] Reference Figure 8 According to the embodiments, window WL-1 may also include a second nanopattern layer NPL2.

[0133] The second nanopatterned layer NPL2 can be disposed on the upper surface UF-1 of the substrate layer BS-1 on the portion overlapping the first non-folded region NFA1 and the second non-folded region NFA2. The substrate layer BS-1 may also include a lower surface LF-1. A portion of the second nanopatterned layer NPL2 can be disposed on the upper surface UF-1 of the substrate layer BS-1 on the portion overlapping the folded region FA. For example, the second nanopatterned layer NPL2 can be disposed on the upper surface UF-1 of the substrate layer BS-1 on the portion thereon where the first recessed portion RE1-1 is not defined.

[0134] The first nanopattern layer NPL1-1 may be disposed on the first recessed portion RE1-1. For example, the first nanopattern layer NPL1-1 may be disposed on all of the first inner surface ISF1-1, the second inner surface ISF2-1, and the first bottom surface BF1-1 of the first recessed portion RE1-1. However, the implementation is not limited to this. For example, the first nanopattern layer NPL1-1 may be disposed on the first bottom surface BF1-1 of the first recessed portion RE1-1, and may not be disposed on the first inner surface ISF1-1 and the second inner surface ISF2-1.

[0135] Since the first nanopattern layer NPL1-1 is disposed on the first recessed portion RE1-1, and the second nanopattern layer NPL2 is disposed on the portion of it that does not define the first recessed portion RE1-1, an anti-reflective effect against external light can be exhibited across the entire substrate layer BS-1. For example, an anti-reflective effect against external light can be exhibited across the entire first non-folded region NFA1, the folded region FA, and the second non-folded region NFA2, thereby further improving the optical characteristics and visibility of the display device DD.

[0136] In this embodiment, the first nanopatterned layer NPL1-1 and the second nanopatterned layer NPL2 can be formed using the same process. Therefore, the first nanopatterned layer NPL1-1 and the second nanopatterned layer NPL2 can comprise the same or similar materials. However, the embodiment is not limited thereto.

[0137] The second nanopatterned layer NPL2 can interact with Figure 6 The first nanopatterned layer NPL1 shown is identical. For example, the second nanopatterned layer NPL2 may include a base portion BP and a second protrusion pattern disposed on the base portion BP, and the second protrusion pattern may be identical to... Figure 6 The first protrusion pattern PR1 shown is the same. However, the implementation is not limited to this.

[0138] The first soft portion SP1-1 can be disposed on the first recessed portion RE1-1. For example, the first soft portion SP1-1 can be disposed on the first nanopattern layer NPL1-1 disposed in the first recessed portion RE1-1.

[0139] The second soft portion SP2-1 can be disposed on the second nanopattern layer NPL2. The second soft portion SP2-1 can completely cover or completely overlap the second nanopattern layer NPL2, and may not contact the upper surface UF-1 of the substrate layer BS-1. In an embodiment, at least a portion of the second soft portion SP2-1 can contact the first soft portion SP1-1. Since the window WL-1 of the embodiment may also include the second nanopattern layer NPL2, damage to the nanoscale second protrusion pattern due to scratch resistance is possible. Such damage may reduce the anti-reflective effect of the second nanopattern layer NPL2, thereby degrading the visibility of the display device. In the window WL-1 of this disclosure, since the second soft portion SP2-1 is disposed on the second nanopattern layer NPL2, the second nanopattern layer NPL2 can be protected from external impacts, thereby preventing degradation of the visibility of the display device DD.

[0140] Reference Figure 9 ,and Figure 5Compared to the window WL shown, the first recessed portion RE1-2 of the window WL-2 according to the embodiment may be different in shape.

[0141] In the window WL-2 according to the embodiment, the first recessed portion RE1-2 may have the shape of a hole penetrating the substrate layer BS-2 in the third direction DR3. Therefore, the depth of the first recessed portion RE1-2 may be the same as the thickness of the substrate layer BS-2.

[0142] In one embodiment, the first recessed portion RE1-2 may be defined by a third inner surface ISF3 and a fourth inner surface ISF4 of the base layer BS-2. The third inner surface ISF3 and the fourth inner surface ISF4 may each penetrate the base layer BS-2 in a third direction DR3 and may be parallel to the plane defined by the second direction DR2 and the third direction DR3. The third inner surface ISF3 and the fourth inner surface ISF4 may be disposed facing each other.

[0143] like Figure 9 As shown, multiple first recessed portions RE1-2 can be provided. Each first recessed portion RE1-2 can extend in the second direction DR2. For example, the first recessed portion RE1-2 can be parallel to... Figure 2 The folded shaft FX is shown as an extension. The first recessed portions RE1-2 can be arranged or positioned at intervals from each other in the first direction DR1.

[0144] Reference Figure 9 and Figure 6 The first nanopatterned layer NPL1-2 can be disposed on the first recessed portion RE1-2. Since the first recessed portion RE1-2 penetrates the substrate layer BS-2, the first nanopatterned layer NPL1-2 can contact at least a portion of the third inner surface ISF3 or the fourth inner surface ISF4. However, the embodiment is not limited thereto, and the first nanopatterned layer NPL1-2 can be disposed entirely on the third inner surface ISF3 and the fourth inner surface ISF4.

[0145] The first soft portion SP1-2 can be disposed on the first recessed portion RE1-2. For example, the first soft portion SP1-2 can be disposed on the first nanopattern layer NPL1-2 and completely fill the first recessed portion RE1-2. Accordingly, the upper and lower surfaces of the first soft portion SP1-2 can be disposed parallel to the upper surface UF-2 and lower surface LF-2 of the substrate layer BS-2, respectively.

[0146] The second soft portion SP2-2 can be disposed on the upper surface UF-2 of the substrate layer BS-2. For example, the second soft portion SP2-2 can be disposed on the entire upper surface UF-2 of the substrate layer BS-2, such that at least a portion of the second soft portion SP2-2 can contact the first soft portion SP1-2. The substrate layer BS-2 may also include a lower surface LF-2.

[0147] Reference Figure 10 ,and Figure 5 Compared to the window WL shown, the window WL-3 according to the embodiment may also include a second recessed portion RE2.

[0148] The first recessed portion RE1-3 and the second recessed portion RE2, overlapping the folded region FA, may be defined within the base layer BS-3. The first recessed portion RE1-3 and the second recessed portion RE2 may not be defined within each of the first unfolded region NFA1 and the second unfolded region NFA2 of the base layer BS-3. The first recessed portion RE1-3 may be recessed from the upper surface UF-3 of the base layer BS-3 in a downward direction (e.g., opposite to the third direction DR3). The second recessed portion RE2 may be recessed from the lower surface LF-3 of the base layer BS-3 in an upward direction (e.g., in the third direction DR3). The depth of each of the first recessed portion RE1-3 and the second recessed portion RE2 relative to the third direction DR3 may be smaller than or less than the thickness of the base layer BS-3 relative to the third direction DR3.

[0149] The first recessed portion RE1-3 and the second recessed portion RE2 can each extend in the second direction DR2. For example, the first recessed portion RE1-3 and the second recessed portion RE2 can extend parallel to the second direction DR2. Figure 2 The folded axis FX extends in the direction shown.

[0150] The second recessed portion RE2 may be defined by a fifth inner surface ISF5, a sixth inner surface ISF6, and a second bottom surface BF2 defined in the base layer BS-3. The fifth inner surface ISF5 and the sixth inner surface ISF6 may extend in the third direction DR3 and may be parallel to the plane defined by the second direction DR2 and the third direction DR3. The fifth inner surface ISF5 and the sixth inner surface ISF6 may be disposed facing each other.

[0151] The second bottom surface BF2 can be disposed between one end of the fifth inner surface ISF5 and one end of the sixth inner surface ISF6. The second bottom surface BF2 can be parallel to the upper surface UF-3 of the base layer BS-3. In an embodiment, the second bottom surface BF2 can be perpendicular to the fifth inner surface ISF5 and the sixth inner surface ISF6.

[0152] Multiple first recessed portions RE1-3 and multiple second recessed portions RE2 can be provided. The first recessed portions RE1-3 and the second recessed portions RE2 can be arranged alternately or provided along the first direction DR1. In the first direction DR1, the second recessed portions RE2 can be provided between adjacent first recessed portions RE1-3. The corresponding first recessed portions RE1-3 and the corresponding second recessed portions RE2 can be provided spaced apart from each other along the first direction DR1.

[0153] Reference Figure 10 and Figure 6 The first nanopatterned layer NPL1-3 can be disposed on the first recessed portion RE1-3. For example, the first nanopatterned layer NPL1-3 can be disposed on the first bottom surface BF1-2, or it can be disposed on the first inner surface ISF1-2 and the second inner surface ISF2-2. The first soft portion SP1-3 can be disposed on the first recessed portion RE1-3. For example, the first soft portion SP1-3 can be disposed on the first nanopatterned layer NPL1-3 and completely fill the first recessed portion RE1-3. Accordingly, the first soft portion SP1-3 can be parallel to the upper surface UF-3 of the substrate layer BS-3. The second soft portion SP2-3 can be disposed on the upper surface UF-3 of the substrate layer BS-3.

[0154] A third nanopattern layer NPL3, including a third protruding pattern, can be disposed on the second recessed portion RE2. For example, the third nanopattern layer NPL3 can be disposed on the second bottom surface BF2 of the second recessed portion RE2. The third nanopattern layer NPL3 can also be disposed on the fifth inner surface ISF5 and the sixth inner surface ISF6 of the second recessed portion RE2. The third nanopattern layer NPL3 can be combined with... Figure 6 The first nanopatterned layer NPL1 shown is the same. For example, the third nanopatterned layer NPL3 may include a base portion BP and a third protrusion pattern disposed on the base portion BP, and the third protrusion pattern may be similar to... Figure 6 The first protrusion pattern PR1 shown is identical. However, the implementation is not limited to this. For example, within the spirit and scope of this disclosure, the first protrusion pattern PR1 and the third protrusion pattern may differ from each other in shape, height, and line width.

[0155] The third soft portion SP3 can be disposed on the second recessed portion RE2. For example, the third soft portion SP3 can be disposed on the third nanopattern layer NPL3 and completely fill the second recessed portion RE2. Therefore, the third soft portion SP3 can be parallel to the lower surface LF-3 of the substrate layer BS-3.

[0156] The third soft portion SP3 may comprise an optically transparent and flexible material. For example, the third soft portion SP3 may comprise a material whose hardness and strength are physically lower than those of the material of the base layer BS-3. For example, the third soft portion SP3 may comprise a transparent polymer resin, but the embodiments are not limited thereto. Since the third soft portion SP3 may comprise a material with flexible properties, the folding characteristics of the window WL-3 can be further improved when the third soft portion SP3 is disposed on the second recessed portion RE2. The first soft portions SP1-3 and the third soft portion SP3 may comprise the same or similar materials, but the embodiments are not limited thereto.

[0157] In the window WL-3 of the embodiment, the first recessed portion RE1-3 and the second recessed portion RE2 are respectively defined on the upper surface UF-3 and the lower surface LF-3 to overlap with the folded area FA of the base layer BS-3. The first soft portion SP1-3 and the third soft portion SP3, which have flexible properties, are respectively disposed on the first recessed portion RE1-3 and the second recessed portion RE2, thereby further improving the folding characteristics of the window WL-3.

[0158] Due to the difference in refractive index between the first soft portion SP1-3 and the base layer BS-3, light reflection may occur at the interface between the first soft portion SP1-3 and the base layer BS-3. For example, light reflection may occur at the first inner surface ISF1-2, the second inner surface ISF2-2, and the first bottom surface BF1-2 of the first recessed portion RE1-3. In this disclosure, since at least one of the first inner surface ISF1-2, the second inner surface ISF2-2, and the first bottom surface BF1-2 of the first recessed portion RE1-3 is provided with a first nanopattern layer NPL1-3, light reflection that may occur at the interface can be suppressed. Therefore, the phenomenon that the patterned area in which the first recessed portion RE1-3 is formed can be visually identified externally can be prevented.

[0159] Due to the difference in refractive index between the third soft portion SP3 and the base layer BS-3, light reflection may occur at the interface between the third soft portion SP3 and the base layer BS-3. For example, light reflection may occur at the fifth inner surface ISF5, the sixth inner surface ISF6, and the second bottom surface BF2 of the second recessed portion RE2. In this disclosure, since at least one of the fifth inner surface ISF5, the sixth inner surface ISF6, and the second bottom surface BF2 of the second recessed portion RE2 is provided with a third nanopattern layer NPL3, light reflection that may occur at the interface can be suppressed. Therefore, the phenomenon that the patterned area in which the second recessed portion RE2 is formed can be visually identified externally can be prevented.

[0160] Reference Figure 11 ,and Figure 5Compared to the window shown, the first recessed portion RE1-4 of the window WL-4 in the embodiment may be different.

[0161] The depth of the first recessed portion RE1-4 defined in the substrate layer BS-4 may not be constant. For example, the first recessed portion RE1-4 may have a substantially curved surface shape extending along the first direction DR1. For example, the depth of the first recessed portion RE1-4 may be maximum at its center and may gradually increase away from each of the first non-folded region NFA1 and the second non-folded region NFA2. The substrate layer BS-4 may also include an upper surface UF-4 and a lower surface LF-4. A first soft portion SP1-4 may be disposed on the first recessed portion RE1-4. For example, the first soft portion SP1-4 may be disposed on a first nanopatterned layer NPL1-4 disposed in the first recessed portion RE1-4. The window WL-4 may also include a second soft portion SP2-4.

[0162] Reference Figure 11 and Figure 6 Since the first recessed portion RE1-4 has a curved surface shape, the first nanopattern layer NPL1-4 can be disposed on the curved surface of the first recessed portion RE1-4. The first nanopattern layer NPL1-4 can be disposed on the entire curved surface of the first recessed portion RE1-4. However, the embodiment is not limited to this, and the first nanopattern layer NPL1-4 can be disposed on a portion of the curved surface of the first recessed portion RE1-4.

[0163] In display devices that include windows with patterns formed in folded areas, light incident from the outside onto the patterned area may be reflected at the interface between the patterned area and the window due to differences in refractive index, causing the patterned area to be visually recognized from the outside. In this disclosure, by employing a nanopattern layer with nanoscale protrusions at the interface between the patterned area and the window, the phenomenon of the patterned area being visually recognized from the outside can be prevented through an ultra-low reflection effect. Therefore, when a window with a nanopattern layer is applied to a display device, the optical characteristics of the display device can be improved.

[0164] Unlike methods that match the refractive index values ​​of the material filling the pattern area and the window refractive index value in the same or similar way, the permissible refractive index range is widened, thereby increasing the selectivity for the material type of the pattern area. Therefore, materials that meet physical properties such as glass transition temperature, modulus, and elongation can be appropriately selected. Since low reflectivity can be exhibited even when the refractive index changes due to thermomechanical deformation or temperature variations, the reliability of the display device can be further improved.

[0165] According to an embodiment, the folding characteristics and optical characteristics of the display device can be improved by a recessed portion disposed on the window and a nanopattern layer disposed on the recessed portion. A nanopattern layer comprising a protruding pattern having a moth-eye structure can be provided, such that the pattern defining the recessed portion is not visually recognizable from the outside.

[0166] The embodiments have been described above with reference to them. However, those skilled in the art or those of ordinary skill in the art will understand that various modifications and changes can be made to this disclosure without departing from the spirit and scope thereof. Therefore, the scope of this disclosure is not limited to what is described in the specific embodiments of the specification, but is intended to include its equivalents and may be determined by the claims.

Claims

1. Windows, including: The base layer includes: First non-folded area; The second non-folded area; A folded region is disposed in a first direction between the first non-folded region and the second non-folded region; and At least one first recessed portion overlaps with the folded region and extends in a second direction intersecting the first direction; A first nanopatterned layer is disposed in the at least one first recessed portion and includes a first protruding pattern; and The first soft portion is disposed on the first nanopattern layer.

2. The window according to claim 1, further comprising: The second soft portion is disposed on the upper surface of the substrate layer. The first soft portion and the second soft portion are made of the same material.

3. The window according to claim 1, further comprising: A second nanopattern layer is disposed on the upper surface of the substrate layer on the portion overlapping the first non-folded region and the second non-folded region, and includes a second protrusion pattern.

4. The window according to claim 1, wherein, The first protrusion pattern includes at least one of a conical shape, a parabolic shape, and a hemispherical shape.

5. The window according to claim 1, wherein, The linewidth of each of the first protrusion patterns is in the range of 100 nm to 350 nm, and The height of each of the first protrusion patterns is in the range of 200 nm to 3000 nm.

6. The window according to claim 1, wherein, The at least one first recessed portion includes a plurality of first recessed portions, and The plurality of first recessed portions are spaced apart in the first direction.

7. The window according to claim 1, wherein, The at least one first recessed portion is recessed from the upper surface of the substrate layer, and The depth of the first recessed portion recessed from the upper surface is less than the thickness of the base layer.

8. The window according to claim 7, wherein, The at least one first recessed portion includes: A first inner surface, on the base layer, and extending upward at a third direction intersecting the first and second directions; The second inner surface extends upward from the third party and faces the first inner surface; and The first bottom surface is perpendicular to the first inner surface and the second inner surface.

9. The window according to claim 8, wherein, The first nanopattern layer is disposed on the first bottom surface.

10. The window according to claim 8, wherein, The first nanopattern layer is disposed on the first inner surface and the second inner surface.

11. The window according to claim 1, wherein, At least one second recessed portion is formed in the base layer, recessed from the lower surface of the base layer and extending in the second direction; and The window also includes a third nanopattern layer disposed on the at least one second recessed portion and including a third protruding pattern.

12. The window according to claim 11, wherein, The at least one first recessed portion includes a plurality of first recessed portions. The at least one second recessed portion includes a plurality of second recessed portions, and The plurality of first recessed portions and the plurality of second recessed portions are alternately arranged in the first direction.

13. The window according to claim 11, further comprising: The third soft portion is disposed in the second recessed portion.

14. The window according to claim 1, wherein, The at least one first recessed portion penetrates the base layer, and The at least one first recessed portion includes a third inner surface and a fourth inner surface, wherein, The third inner surface is on the base layer and extends upward on a third surface intersecting the first and second directions. The fourth inner surface extends upward from the third inner surface and faces the third inner surface.

15. The window according to claim 14, wherein, The first nanopatterned layer contacts at least a portion of the third inner surface or the fourth inner surface.

16. The window according to claim 1, wherein, The at least one first recessed portion has a curved surface shape extending in the first direction.

17. A display device, comprising: The display module includes a folded area folded around a folding axis extending in one direction; as well as A window is provided on the display module and folds together with the display module, wherein... The window includes: The base layer includes a first recessed portion that overlaps with the folded region and extends in the direction; A first nanopattern layer is disposed in the first recessed portion and includes a first protruding pattern; and The first soft portion is disposed on the first nanopattern layer, and The first recessed portion is recessed from the upper surface of the substrate layer.

18. The display device according to claim 17, further comprising: The second soft portion is disposed on the upper surface of the base layer. The first soft portion and the second soft portion are made of the same material.

19. The display device according to claim 17, wherein, Each of the first protrusion patterns includes at least one of a conical shape, a parabolic shape, and a hemispherical shape.

20. The display device according to claim 17, wherein The linewidth of each of the first protrusion patterns is in the range of 100 nm to 350 nm, and The height of each of the first protrusion patterns is in the range of 200 nm to 3000 nm.

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