Flexible cover window and foldable display device

Abstract

Disclosed are a flexible cover window and a foldable display device having the flexible cover window. The flexible cover window includes: a lower glass substrate including a first lower glass substrate and a second lower glass substrate, the first lower glass substrate and the second lower glass substrate being spaced apart from each other; an upper glass substrate disposed above the lower glass substrate and thinner than the lower glass substrate; and an adhesive member disposed between the lower glass substrate and the upper glass substrate and extending between the first lower glass substrate and the second lower glass substrate.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to and the benefit of Korean Patent Application No. 10-2020-0060897 filed on May 21, 2020, in the Korean Intellectual Property Office, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present invention relates to a flexible cover window and a foldable display device. Background Art

[0004] Mobile electronic devices are widely used. In recent years, in addition to small electronic devices such as mobile phones, tablet PCs have also been widely used as mobile electronic devices.

[0005] Such mobile electronic devices include display devices to provide users with various functions, for example, visual information such as images or pictures. Recently, as other components for driving the display devices have been miniaturized, the proportion of display devices in electronic devices has gradually increased, and development of display devices that can be variously transformed (for example, can be bent or folded) is underway.

[0006] A foldable display device among the display devices may include a display panel and a flexible cover window for protecting the display panel, and the display panel and the flexible cover window may be foldable. Summary of the invention

[0007] One or more embodiments include a flexible cover window and a foldable display device having improved durability.

[0008] Additional aspects will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the presented embodiments of the disclosure.

[0009] According to an embodiment, the flexible cover window may include: a lower glass substrate including a first lower glass substrate and a second lower glass substrate, the first lower glass substrate and the second lower glass substrate being spaced apart from each other; an upper glass substrate disposed above the lower glass substrate and thinner than the lower glass substrate; and an adhesive member disposed between the lower glass substrate and the upper glass substrate and extending between the first lower glass substrate and the second lower glass substrate.

[0010] In an implementation, an adhesive member may connect the first lower glass substrate, the second lower glass substrate, and the upper glass substrate to each other.

[0011] In an embodiment, the flexible cover window may include a bending area, a first extension area, and a second extension area, the first extension area and the second extension area are respectively connected to corresponding sides of the bending area. The first lower glass substrate may be positioned in the first extension area, and the second lower glass substrate may be positioned in the second extension area.

[0012] In an implementation, the upper glass substrate may include a lower surface facing the lower glass substrate and a side surface intersecting the lower surface, and the adhesive member may extend from the lower surface of the upper glass substrate to cover the side surface of the upper glass substrate.

[0013] In an implementation, an end portion of the first lower glass substrate and an end portion of the second lower glass substrate may each include at least two step shapes, wherein the end portion of the first lower glass substrate and the end portion of the second lower glass substrate face each other.

[0014] In an implementation, the first lower glass substrate may include a plurality of first protrusion portions protruding toward the second lower glass substrate, and the second lower glass substrate may include a plurality of second protrusion portions protruding toward the first lower glass substrate.

[0015] In an embodiment, each of the plurality of first protruding portions may face a corresponding one of the plurality of second protruding portions.

[0016] In an implementation, the first lower glass substrate may include a plurality of recesses, each of the plurality of recesses being disposed between two adjacent first protrusions of the plurality of first protrusions, and each of the plurality of second protrusions may face a corresponding one of the plurality of recesses.

[0017] In an implementation, the bonding member may have a refractive index that is the same as a refractive index of at least one of the lower glass substrate and the upper glass substrate.

[0018] In an implementation, at least one of the lower glass substrate and the upper glass substrate may be an ultra-thin tempered glass.

[0019] According to another embodiment, a foldable display device may include: a display panel including a display area; and a flexible cover window covering the display panel. The flexible cover window may include: a lower glass substrate including a first lower glass substrate and a second lower glass substrate, the first lower glass substrate and the second lower glass substrate being spaced apart from each other; an upper glass substrate disposed above the lower glass substrate and thinner than the lower glass substrate; and an adhesive member disposed between the lower glass substrate and the upper glass substrate and extending between the first lower glass substrate of the lower glass substrate and the second lower glass substrate of the lower glass substrate, and the foldable display device can be folded relative to a folding axis intersecting the display area.

[0020] In an implementation, an adhesive member may connect the first lower glass substrate, the second lower glass substrate, and the upper glass substrate to each other.

[0021] In an embodiment, the flexible cover window may include a first extension area, a second extension area, and a bending area corresponding to the folding axis, the first extension area and the second extension area are respectively connected to corresponding sides of the bending area, the first lower glass substrate can be positioned in the first extension area, and the second lower glass substrate can be positioned in the second extension area.

[0022] In an implementation, the upper glass substrate may include a lower surface facing the lower glass substrate and a side surface intersecting the lower surface. The adhesive member may extend from the lower surface of the upper glass substrate to cover the side surface of the upper glass substrate.

[0023] In an implementation, an end portion of the first lower glass substrate and an end portion of the second lower glass substrate may each include at least two step shapes, wherein the end portion of the first lower glass substrate and the end portion of the second lower glass substrate face each other.

[0024] In an implementation, the first lower glass substrate may include a plurality of first protrusion portions protruding toward the second lower glass substrate, and the second lower glass substrate may include a plurality of second protrusion portions protruding toward the first lower glass substrate.

[0025] In an implementation, the bonding member may have a refractive index that is the same as a refractive index of at least one of the lower glass substrate and the upper glass substrate.

[0026] In an implementation, at least one of the lower glass substrate and the upper glass substrate may be an ultra-thin tempered glass.

[0027] In an embodiment, the display panel may include a first surface facing the flexible cover window and a second surface opposite to the first surface. The foldable display device may be folded such that the first surface of the display panel faces itself with respect to a folding axis.

[0028] In an embodiment, the display panel may include a first surface facing the flexible cover window and a second surface opposite to the first surface. The foldable display device may be folded such that the second surface faces itself with respect to the folding axis. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The above and other aspects, features and advantages of certain embodiments of the present disclosure will become more apparent from the following description in conjunction with the accompanying drawings, in which:

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

[0031] Figure 2is a schematic cross-sectional view of a display panel and a flexible cover window according to an embodiment;

[0032] Figure 3 is a schematic cross-sectional view of a display panel and a flexible cover window according to another embodiment;

[0033] Figure 4A and Figure 4B are schematic cross-sectional views each of a display panel and a flexible cover window according to another embodiment;

[0034] FIG. 5A to FIG. 5E are each a top view of a portion of a flexible cover window according to various embodiments;

[0035] Figure 6 is a schematic cross-sectional view of a display panel according to an embodiment; and

[0036] Figure 7 and Figure 8 Each is a cross-sectional view of a state in which a foldable display device according to an embodiment is folded about a folding axis. DETAILED DESCRIPTION

[0037] Reference will now be made in detail to embodiments, examples of which are shown in the accompanying drawings, in which the same reference numerals represent the same elements throughout. Embodiments may have different forms and should not be construed as being limited to the descriptions set forth herein. Therefore, embodiments are described below solely by reference to the accompanying drawings to explain aspects of the specification. As used herein, the terms "and" or "or" include any and all combinations of one or more of the associated listed items. Throughout this disclosure, the expression "at least one of a, b, and c" or "selected from at least one of a, b, and c" means: only a; only b; only c; both a and b; both a and c; both b and c; all of a, b, and c; or variations thereof.

[0038] Since the present disclosure allows for various variations and multiple embodiments, specific embodiments will be shown in the drawings and described in detail in the written description. Hereinafter, the effects and features of the present disclosure and methods for implementing them will be more fully described with reference to the drawings, in which embodiments of the present disclosure are shown. However, the present disclosure can be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein.

[0039] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. When describing with reference to the accompanying drawings, the same or corresponding elements will be given the same reference numerals, and redundant descriptions of these elements will be omitted.

[0040] It should be understood that although the terms "first", "second", etc. may be used herein to describe various components, these components should not be limited by these terms. These terms are only used to distinguish one component from another.

[0041] As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise.

[0042] It will also be understood that the terms “comprises” and / or “comprising” as used herein specify the presence of stated features or components, but do not preclude the presence or addition of one or more other features or components.

[0043] It should be understood that when a layer, region, or component is referred to as being "on another layer, region, or component," "formed on another layer, region, or component," "positioned on another layer, region, or component," or "disposed on another layer, region, or component," it may be directly or indirectly on the other layer, region, or component, directly or indirectly formed on the other layer, region, or component, directly or indirectly positioned on the other layer, region, or component, or directly or indirectly disposed on the other layer, region, or component. For example, there may be intervening layers, regions, or components.

[0044] For convenience of explanation, the sizes of elements in the drawings may be exaggerated. For example, since the sizes and thicknesses of components are arbitrarily shown in the drawings for convenience of explanation, the following embodiments are not limited thereto.

[0045] When a certain embodiment can be implemented differently, a specific process order can be performed differently from the described order. For example, two processes described in succession can be performed substantially simultaneously, or in the reverse order of the described order.

[0046] It should be understood that when a layer, region, or element is referred to as being "connected to" another layer, region, or element, it may be directly or indirectly connected to the other layer, region, or element. For example, there may be intervening layers, regions, or elements. For example, it should be understood that when a layer, region, or element is referred to as being "electrically connected to" another layer, region, or element, it may be directly or indirectly electrically connected to the other layer, region, or element. For example, there may be intervening layers, regions, or elements.

[0047] The display device is a device configured to display a video or a still image, and can be used as a display screen of various products such as a television, a laptop computer, a monitor, a billboard, or the Internet of Things (IOT), and mobile electronic devices such as mobile phones, smart phones, tablet personal computers (PCs), mobile communication terminals, electronic notebooks, electronic books, portable multimedia players (PMPs), navigators, or ultra-mobile PCs (UMPCs). The display device according to the embodiment can be used in wearable devices such as smart watches, watch phones, glass-type displays, or head-mounted displays (HMDs). The display device according to the embodiment can be used as a dashboard of a vehicle, a central information display (CID) positioned at the center instrument panel or dashboard of the vehicle, an interior mirror display instead of a vehicle side mirror, or positioned at the back of the front seat as a display for entertainment of passengers in the rear seats of the vehicle.

[0048] Figure 1 is a schematic perspective view of a foldable display device 1 according to an embodiment. Figure 2 is a schematic cross-sectional view of a display panel DP and a flexible cover window CW according to an embodiment.

[0049] Reference Figure 1 The foldable display device 1 may include a display panel DP, a flexible cover window CW (see, for example Figure 2 ) and a lower cover LC. The lower cover LC may include a first portion P1 and a second portion P2 supporting the display panel DP. The lower cover LC may be folded relative to a folding axis FAX located between the first portion P1 and the second portion P2. In an embodiment, the lower cover LC may include a hinge portion HP located between the first portion P1 and the second portion P2.

[0050] The display panel DP may include a display area DA. Pixels (not shown) are arranged in the display area DA of the display panel DP to display an image. The pixels may each emit red light, green light, or blue light. As another example, in another embodiment, the pixels may each emit red light, green light, blue light, or white light. Hereinafter, for ease of description, portions arranged at the left and right sides relative to the folding axis FAX in the display area DA are referred to as a first display area DA1 and a second display area DA2, respectively.

[0051] The display panel DP may be folded with respect to a folding axis FAX intersecting the display area DA. For example, the display panel DP may be folded together with the lower cover LC and the flexible cover window CW, and portions of the display panel DP folded with respect to the folding axis FAX intersecting the display area DA may face each other. As another example, the foldable display device 1 may be folded such that the first portion P1 and the second portion P2 face each other.

[0052] In some embodiments, the display panel DP may be folded with respect to a plurality of folding axes FAX intersecting the display area DA. Hereinafter, a case where the display panel DP is folded with respect to one folding axis FAX will be described in detail.

[0053] Figure 1 The folding axis FAX is shown to extend in the y direction, but in another embodiment, the folding axis FAX may extend in the x direction. As another example, the folding axis FAX on the xy plane may also extend in a direction intersecting the x direction and the y direction.

[0054] The flexible cover window CW can be easily folded in response to an external force without generating cracks, etc., and can protect the display panel DP. The flexible cover window CW can be disposed on the display panel DP. The flexible cover window CW can be attached to the display panel DP. In an embodiment, the flexible cover window CW can be attached to the display panel DP by a pressure sensitive adhesive (PSA).

[0055] Reference Figure 1 and Figure 2 , the flexible cover window CW may include a lower glass substrate 100, an upper glass substrate 200, and an adhesive member 300. The lower glass substrate 100 and the upper glass substrate 200 may include glass, sapphire, or plastic. In some embodiments, the lower glass substrate 100 and the upper glass substrate 200 may include the same material.

[0056] In an embodiment, at least one of the lower glass substrate 100 and the upper glass substrate 200 may be ultra-thin tempered glass (UTG). For example, the lower glass substrate 100 may be UTG, and the upper glass substrate 200 may be glass. As another example, the lower glass substrate 100 may be glass, and the upper glass substrate 200 may be UTG. As another example, both the lower glass substrate 100 and the upper glass substrate 200 may be UTG. In some embodiments, at least one of the lower glass substrate 100 and the upper glass substrate 200 may be a glass substrate treated by a physical strengthening method or a chemical strengthening method using an ion exchange method. For example, the upper glass substrate 200 may be a glass substrate treated by a physical strengthening method or a chemical strengthening method using an ion exchange method. As another example, both the lower glass substrate 100 and the upper glass substrate 200 may be glass substrates treated by a physical strengthening method or a chemical strengthening method using an ion exchange method.

[0057] The lower glass substrate 100 may include a first lower glass substrate 100A and a second lower glass substrate 100B. The first lower glass substrate 100A and the second lower glass substrate 100B may be spaced apart from each other. In this case, the first lower glass substrate 100A may be positioned to correspond to the first display area DA1 and / or the first portion P1, and the second lower glass substrate 100B may be positioned to correspond to the second display area DA2 and / or the second portion P2.

[0058] In an embodiment, the thickness of the first lower glass substrate 100A may be the same as the thickness of the second lower glass substrate 100B. The thickness of the first lower glass substrate 100A may be defined as the shortest distance between the upper surface of the first lower glass substrate 100A and the lower surface of the first lower glass substrate 100A, and Figure 2 In the embodiment of the present invention, the thickness of the first lower glass substrate 100A may be the distance between the upper surface of the first lower glass substrate 100A and the lower surface of the first lower glass substrate 100A in the z direction. The thickness of the second lower glass substrate 100B may be defined as the shortest distance between the upper surface of the second lower glass substrate 100B and the lower surface of the second lower glass substrate 100B, and Figure 2 In the embodiment, the thickness of the second lower glass substrate 100B may be a distance in the z direction between the upper surface of the second lower glass substrate 100B and the lower surface of the second lower glass substrate 100B. In another embodiment, the thickness of the first lower glass substrate 100A may be different from the thickness of the second lower glass substrate 100B. Hereinafter, a case where the first lower glass substrate 100A and the second lower glass substrate 100B have the same thickness will be described in detail.

[0059] The upper glass substrate 200 may be disposed above the lower glass substrate 100. The upper glass substrate 200 may be disposed above the first lower glass substrate 100A and the second lower glass substrate 100B. The upper glass substrate 200 may extend from above the first lower glass substrate 100A to above the second lower glass substrate 100B. In another example, the upper glass substrate 200 may extend from above the second lower glass substrate 100B to above the first lower glass substrate 100A. For example, the upper glass substrate 200 may also be disposed above the space between the first lower glass substrate 100A and the second lower glass substrate 100B.

[0060] In an embodiment, the upper glass substrate 200 may be easily bent in response to an external force without generating cracks, etc. For example, the upper glass substrate 200 may be folded in response to an external force. In this case, the flexible cover window CW may include a first extension area EXA1, a second extension area EXA2, and a bending area BA, and the upper glass substrate 200 may be folded by bending the bending area BA of the upper glass substrate 200. Figure 2The upper glass substrate 200 is shown to include one bending area BA, but in another embodiment, the upper glass substrate 200 may include a plurality of bending areas. The first extension area EXA1 and the second extension area EXA2 may be connected to corresponding sides of the bending area BA, respectively. Figure 2 In the embodiment, the first extension area EXA1 may extend from the bending area BA in the negative x-direction, and the second extension area EXA2 may extend from the bending area BA in the x-direction.

[0061] In an embodiment, the first lower glass substrate 100A and the second lower glass substrate 100B may be spaced apart from each other relative to the bending area BA. For example, the first lower glass substrate 100A may be disposed in the first extension area EXA1, and the second lower glass substrate 100B may be disposed in the second extension area EXA2. In some embodiments, a portion of the first lower glass substrate 100A and / or a portion of the second lower glass substrate 100B may extend to the bending area BA.

[0062] For example, the first lower glass substrate 100A may overlap only the first extension area EXA1. As another example, a portion of the first lower glass substrate 100A may overlap only the first extension area EXA1. Figure 2 The second lower glass substrate 100B may extend in the x direction to overlap with the bending area BA. The second lower glass substrate 100B may overlap only with the second extension area EXA2. As another example, a portion of the second lower glass substrate 100B may overlap with the second extension area EXA2. Figure 2 The negative x-direction extends to overlap with the bending area BA.

[0063] In an embodiment, the upper glass substrate 200 may be thinner than the lower glass substrate 100. For example, the second thickness d2 of the upper glass substrate 200 may be less than the first thickness d1 of the lower glass substrate 100. The first thickness d1 of the lower glass substrate 100 may be a distance between a lower surface of the lower glass substrate 100 facing the display panel DP and an upper surface 100US of the lower glass substrate 100 opposite to the lower surface of the lower glass substrate 100. The second thickness d2 of the upper glass substrate 200 may be a distance between a lower surface 200LS of the upper glass substrate 200 facing the lower glass substrate 100 and an upper surface of the upper glass substrate 200 opposite to the lower surface 200LS of the upper glass substrate 200.

[0064] In an embodiment, the flexible cover window CW can be easily bent in response to an external force. In this case, the bending area BA of the upper glass substrate 200 can be bent. Because the second thickness d2 of the upper glass substrate 200 is relatively smaller than the first thickness d1 of the lower glass substrate 100, the upper glass substrate 200 has a smaller rigidity than the lower glass substrate 100, and thus can be easily bent. For example, the repulsive force against bending can be reduced. The first lower glass substrate 100A and the second lower glass substrate 100B can be positioned in the first extension area EXA1 and the second extension area EXA2, respectively, and the display panel DP can be protected. In this case, because the lower glass substrate 100 can be thicker than the upper glass substrate 200, the lower glass substrate 100 can protect the display panel DP from external impacts. For example, the flexible cover window CW according to an embodiment of the present disclosure can reduce the repulsive force against bending and can easily protect the display panel DP from external impacts.

[0065] In an experimental example, the strength of the flexible cover window CW can be measured as the height of the pen when the flexible cover window CW is damaged due to the pen being dropped from a certain height onto the flexible cover window CW. For example, in the case where the pen is dropped from a first height, the flexible cover window CW including an upper glass substrate may be damaged. In the case where the pen is dropped from a second height, the flexible cover window CW including an upper glass substrate and a lower glass substrate having the same thickness may be damaged. The second height may be about 1.5 to 5 times higher than the first height. In the case where the flexible cover window CW includes an upper glass substrate and a lower glass substrate that is 5 times thicker than the upper glass substrate, the third height of the pen when the flexible cover window CW is damaged is about 2 to 3 times higher than the second height.

[0066] The adhesive member 300 may be disposed between the lower glass substrate 100 and the upper glass substrate 200. The adhesive member 300 may be continuously positioned in the first extension area EXA1, the second extension area EXA2, and the bending area BA of the upper glass substrate 200. For example, the adhesive member 300 may extend from the bending area BA of the upper glass substrate 200 to between the upper surface 100US of the lower glass substrate 100 and the lower surface 200LS of the upper glass substrate 200. Therefore, the adhesive member 300 may connect the lower glass substrate 100 and the upper glass substrate 200.

[0067] The adhesive member 300 may extend between the first lower glass substrate 100A and the second lower glass substrate 100B. For example, the adhesive member 300 may extend between the side surface 100SSA of the first lower glass substrate 100A and the side surface 100SSB of the second lower glass substrate 100B, and the side surface 100SSA of the first lower glass substrate 100A and the side surface 100SSB of the second lower glass substrate 100B face each other. Therefore, the adhesive member 300 may fill the space between the first lower glass substrate 100A and the second lower glass substrate 100B, and the durability of the flexible cover window CW may be increased.

[0068] The adhesive member 300 may connect the first lower glass substrate 100A to the second lower glass substrate 100B, and the adhesive member 300 may connect the first lower glass substrate 100A, the second lower glass substrate 100B, and the upper glass substrate 200 to each other. In some embodiments, the adhesive member 300 may also be connected to the display panel DP.

[0069] In an embodiment, the adhesive member 300 may include a resin. For example, the adhesive member 300 may be an optically clear resin (OCR), and may include at least one of acrylic resin, epoxy resin, silicone resin, and polyurethane resin. In an embodiment, the adhesive member 300 may be a PSA.

[0070] In an embodiment, the bonding member 300 is transparent to transmit light. For example, the refractive index of the bonding member 300 may be the same as at least one of the refractive index of the lower glass substrate 100 and the refractive index of the upper glass substrate 200. For example, the refractive index of the bonding member 300 may be the same as the refractive index of the lower glass substrate 100 and the refractive index of the upper glass substrate 200. The refractive index of the bonding member 300 may be substantially the same as the refractive index of glass. Therefore, at the boundary between the lower glass substrate 100 and the bonding member 300 or the boundary between the bonding member 300 and the upper glass substrate 200, the refraction of light transmitted through the flexible cover window CW may be reduced.

[0071] In some embodiments, the upper portion of the upper glass substrate 200 may further include a protective layer (not shown) that protects the upper surface of the flexible cover window CW. The protective layer may include at least one of an anti-fingerprint layer and a hard coating layer for enhancing strength. In some embodiments, an anti-scattering layer (not shown) may be located between the flexible cover window CW and the display panel DP. In the event that the lower glass substrate 100 is damaged, the anti-scattering layer may fix the damaged lower glass substrate 100. For example, the anti-scattering layer may include a polyurethane resin.

[0072] Figure 3 is a schematic cross-sectional view of a display panel DP and a flexible cover window CW according to another embodiment.

[0073] Reference Figure 3 , the foldable display device may include a display panel DP and a flexible cover window CW. The flexible cover window CW may include a lower glass substrate 100, an upper glass substrate 200 disposed above the lower glass substrate 100 and thinner than the lower glass substrate 100, and an adhesive member 300 located between the lower glass substrate 100 and the upper glass substrate 200. The lower glass substrate 100 may include a first lower glass substrate 100A and a second lower glass substrate 100B spaced apart from each other, and the adhesive member 300 may extend between the first lower glass substrate 100A and the second lower glass substrate 100B.

[0074] In an embodiment, the upper glass substrate 200 may include a lower surface 200LS of the upper glass substrate 200 and a side surface 200SS of the upper glass substrate 200, the lower surface 200LS facing the lower glass substrate 100 and the side surface 200SS intersecting the lower surface 200LS of the upper glass substrate 200. The side surface 200SS of the upper glass substrate 200 may be an end of the upper glass substrate 200. In this case, the adhesive member 300 may extend from the lower surface 200LS of the upper glass substrate 200 to the side surface 200SS of the upper glass substrate 200. Therefore, the adhesive member 300 may cover the side surface 200SS of the upper glass substrate 200. Because the adhesive member 300 covers the side surface 200SS of the upper glass substrate 200, the edge of the upper glass substrate 200 may be prevented from being damaged. In some embodiments, the end of the upper glass substrate 200 may be surrounded by the cover member and the adhesive member 300. Therefore, the end of the upper glass substrate 200 may be prevented from being damaged.

[0075] Figure 4A and Figure 4B Each is a schematic cross-sectional view of a display panel DP and a flexible cover window CW according to another embodiment.

[0076] Reference Figure 4A and Figure 4B , the foldable display device may include a display panel DP and a flexible cover window CW. The flexible cover window CW may include a lower glass substrate 100, an upper glass substrate 200 disposed above the lower glass substrate 100 and thinner than the lower glass substrate 100, and an adhesive member 300 located between the lower glass substrate 100 and the upper glass substrate 200. The lower glass substrate 100 may include a first lower glass substrate 100A and a second lower glass substrate 100B spaced apart from each other, and the adhesive member 300 may extend between the first lower glass substrate 100A and the second lower glass substrate 100B.

[0077] In an embodiment, the end EPA of the first lower glass substrate 100A and the end EPB of the second lower glass substrate 100B may include at least two step shapes, respectively, and the end EPA of the first lower glass substrate 100A and the end EPB of the second lower glass substrate 100B face each other. For example, the end EPA of the first lower glass substrate 100A and the end EPB of the second lower glass substrate 100B may include steps. The end EPA of the first lower glass substrate 100A may overlap with at least one of the first extension area EXA1 and the bending area BA. The end EPB of the second lower glass substrate 100B may overlap with at least one of the second extension area EXA2 and the bending area BA.

[0078] The at least two step shapes described above can minimize the visibility of the boundary between the lower glass substrate 100 and the bonding member 300. For example, even in the case where the refractive index of the lower glass substrate 100 is slightly different from the refractive index of the bonding member 300, the at least two step shapes described above can minimize or reduce the visibility of the boundary between the lower glass substrate 100 and the bonding member 300 due to the difference between the refractive indices.

[0079] By having at least two step shapes at the end EPA of the first lower glass substrate 100A and the end EPB of the second lower glass substrate 100B, the restoring force of the bonding member 300 can be improved. For example, in the case where the bonding member 300 is repeatedly stretched or contracted, fatigue failure of the bonding member 300 can be prevented.

[0080] An area in which the lower glass substrate 100 contacts the adhesive member 300 may increase, and thus a degree of adhesion between the lower glass substrate 100 and the adhesive member 300 may increase.

[0081] Reference Figure 4A , the distance between the end EPA of the first lower glass substrate 100A and the end EPB of the second lower glass substrate 100B (the end EPA of the first lower glass substrate 100A and the end EPB of the second lower glass substrate 100B face each other) may be reduced in the direction from the lower glass substrate 100 toward the upper glass substrate 200. In this case, the bonding member 300 may be located between the first lower glass substrate 100A and the second lower glass substrate 100B. Therefore, the width of the bonding member 300 may be reduced in the direction from the lower glass substrate 100 toward the upper glass substrate 200. For example, the second width dis2 of the bonding member 300 located between the upper surface 100US of the lower glass substrate 100 may be smaller than the first width dis1 of the bonding member 300 facing the display panel DP. As another example, in some embodiments, the first width dis1 may be defined as the width of the bonding member 300 exposed between the first lower glass substrate 100A and the second lower glass substrate 100B.

[0082] Reference Figure 4B , the distance between the end EPA of the first lower glass substrate 100A and the end EPB of the second lower glass substrate 100B (the end EPA of the first lower glass substrate 100A and the end EPB of the second lower glass substrate 100B face each other) may increase in the direction from the lower glass substrate 100 toward the upper glass substrate 200. In this case, the width of the adhesive member 300 may increase in the direction from the lower glass substrate 100 toward the upper glass substrate 200. For example, the second width dis2 of the adhesive member 300 located between the upper surface 100US of the lower glass substrate 100 may be greater than the first width dis1 of the adhesive member 300 facing the display panel DP.

[0083] FIG. 5A to FIG. 5E Each is a plan view of a portion of a flexible cover window according to various embodiments. FIG. 5A to FIG. 5E Each is a plan view of a portion of the first lower glass substrate 100A, the second lower glass substrate 100B, and the adhesive member 300 .

[0084] Reference FIG. 5A to FIG. 5E , the lower glass substrate may include a first lower glass substrate 100A and a second lower glass substrate 100B spaced apart from each other, and the adhesive member 300 may be located between the first lower glass substrate 100A and the second lower glass substrate 100B. The first lower glass substrate 100A may overlap with the first extension area EXA1 of the upper glass substrate, and the second lower glass substrate 100B may overlap with the second extension area EXA2 of the upper glass substrate.

[0085] In an embodiment, the first lower glass substrate 100A may include a first protruding portion PPA protruding toward the second lower glass substrate 100B. The first protruding portion PPA may protrude in a direction from the first extension area EXA1 toward the bending area BA. In an embodiment, the first protruding portion PPA may overlap the bending area BA. In another embodiment, the first protruding portion PPA may overlap both the bending area BA and the first extension area EXA1. In another embodiment, the first protruding portion PPA may overlap the first extension area EXA1. A plurality of first protruding portions PPA may be provided, and a first recess RA may be provided between two first protruding portions PPA adjacent to each other. In some embodiments, the first lower glass substrate 100A may not include the first protruding portion PPA.

[0086] The second lower glass substrate 100B may include a second protruding portion PPB protruding toward the first lower glass substrate 100A. The second protruding portion PPB may protrude in a direction from the second extension area EXA2 toward the bending area BA. In an embodiment, the second protruding portion PPB may overlap the bending area BA. In another embodiment, the second protruding portion PPB may overlap both the bending area BA and the second extension area EXA2. In another embodiment, the second protruding portion PPB may overlap the second extension area EXA2. A plurality of second protruding portions PPB may be provided, and a second recess RB may be provided between two second protruding portions PPB adjacent to each other. In some embodiments, the second lower glass substrate 100B may not include the second protruding portion PPB.

[0087] By means of the first protruding portion PPA, the contact area between the first lower glass substrate 100A and the adhesive member 300 increases, and thus the degree of adhesion between the first lower glass substrate 100A and the adhesive member 300 increases. By means of the second protruding portion PPB, the contact area between the second lower glass substrate 100B and the adhesive member 300 increases, and thus the degree of adhesion between the second lower glass substrate 100B and the adhesive member 300 may increase.

[0088] The restoring force of the bonding member 300 may be improved by at least one of the first protrusion part PPA and the second protrusion part PPB. For example, the first protrusion part PPA and the second protrusion part PPB may prevent fatigue failure of the bonding member 300 when the bonding member 300 is repeatedly stretched or contracted.

[0089] Reference Figure 5A , each of the first protruding portions PPA may face a corresponding one of the second protruding portions PPB. In this case, a planar shape of the first lower glass substrate 100A and a planar shape of the second lower glass substrate 100B may be symmetrical to each other with respect to the adhesive member 300 .

[0090] The width t1 of the first protruding portion PPA may be smaller than the width u1 of the first recess RA. The width t1 of the first protruding portion PPA may be defined as Figure 5A The width u1 of the first recess RA may be defined as the distance in the y direction between two adjacent first protruding portions PPA. Similarly, the width of the second protruding portion PPB may be smaller than the width of the second recess RB.

[0091] Reference Figure 5B At least one of the first protrusion portion PPA and the second protrusion portion PPB may include a curved portion. For example, at least one of the first protrusion portion PPA and the second protrusion portion PPB may have a semi-elliptical shape or a semi-circular shape.

[0092] Reference Figure 5C , each of the first protruding portions PPA may face a corresponding one of the second recesses RB. Each of the second protruding portions PPB may face a corresponding one of the first recesses RA. Therefore, the first protruding portions PPA and the second protruding portions PPB may be alternately arranged.

[0093] The width of the first protrusion portion PPA may be smaller than the width of the first recess RA. Similarly, the width of the second protrusion portion PPB may be smaller than the width of the second recess RB.

[0094] Reference Figure 5D , each of the first protruding portions PPA may face a corresponding one of the second recesses RB. Each of the second protruding portions PPB may face a corresponding one of the first recesses RA.

[0095] The width t1 of the first protrusion portion PPA may be greater than the width u1 of the first recess RA. Similarly, the width of the second protrusion portion PPB may be greater than the width of the second recess RB.

[0096] Reference Figure 5E , the first protruding portion PPA may overlap the first extension area EXA1, and the second protruding portion PPB may overlap the second extension area EXA2. In this case, a portion of the adhesive member 300 may overlap the first extension area EXA1, and another portion of the adhesive member 300 may overlap the second extension area EXA2.

[0097] Figure 6 is a schematic cross-sectional view of a display panel DP according to an embodiment.

[0098] The display panel DP may be a light-emitting display panel including a light-emitting element. For example, the display panel DP may be an organic light-emitting display panel using an organic light-emitting diode including an organic light-emitting layer, a micro light-emitting diode display panel using a micro light-emitting diode (micro LED), a quantum dot light-emitting display panel using a quantum dot light-emitting diode including a quantum dot light-emitting layer, or an inorganic light-emitting display panel using an inorganic light-emitting diode including an inorganic semiconductor. Hereinafter, a case where the display panel DP is an organic light-emitting display panel will be described in detail.

[0099] Reference Figure 6 , in the display panel DP, the display layer DL and the thin film encapsulation layer TFE may be disposed on the substrate 10. The display layer DL may include a pixel circuit layer PCL and a display element layer DEL.

[0100] The substrate 10 may include glass, or may include a polymer resin such as polyethersulfone, polyarylate, polyetherimide, polyethylene naphthalate, polyethylene terephthalate, polyphenylene sulfide, polyimide, polycarbonate, cellulose triacetate, or cellulose acetate propionate.

[0101] There may be a barrier layer (not shown) between the display layer DL and the substrate 10. The barrier layer prevents penetration of foreign substances and may include a single layer or multiple layers including silicon nitride (SiN x ) or silicon oxide (SiO x ) of organic materials.

[0102] The pixel circuit layer PCL is disposed on the substrate 10 . Figure 6 The pixel circuit layer PCL including the thin film transistor TFT and the buffer layer 11 , the first gate insulating layer 13 a , the second gate insulating layer 13 b , the insulating interlayer 15 and the planarizing insulating layer 17 disposed below or / and above the elements of the thin film transistor TFT is shown.

[0103] The buffer layer 11 may include an inorganic insulating material such as silicon nitride, silicon oxynitride, and silicon oxide, and may include a single layer or a multilayer including the inorganic insulating material.

[0104] The thin film transistor TFT may include a semiconductor layer 12, and the semiconductor layer 12 may include polycrystalline silicon. As another example, the semiconductor layer 12 may include amorphous silicon, an oxide semiconductor, or an organic semiconductor. The semiconductor layer 12 may include a channel region 12c and a drain region 12a and a source region 12b respectively located at respective sides of the channel region 12c. The gate electrode 14 may overlap the channel region 12c.

[0105] The gate electrode 14 may include a low resistance metal material. The gate electrode 14 may include a conductive material including molybdenum (Mo), aluminum (Al), copper (Cu), titanium (Ti), etc., and the gate electrode 14 may include a multilayer or a single layer including the conductive material.

[0106] The first gate insulating layer 13a between the semiconductor layer 12 and the gate electrode 14 may include an inorganic insulating material such as silicon oxide (SiO 2 ), silicon nitride (SiN x ), silicon oxynitride (SiON), aluminum oxide (Al 2 O 3 ), titanium oxide (TiO 2 ), Tantalum Oxide (Ta 2 O 5 ), hafnium oxide (HfO 2 ), zinc oxide (ZnO), etc.

[0107] The second gate insulating layer 13b may cover the gate electrode 14. Similar to the first gate insulating layer 13a, the second gate insulating layer 13b may include an inorganic insulating material such as silicon oxide (SiO 2 ), silicon nitride (SiN x ), silicon oxynitride (SiON), aluminum oxide (Al 2 O 3 ), titanium oxide (TiO 2 ), Tantalum Oxide (Ta 2 O 5 ), hafnium oxide (HfO 2 ), zinc oxide (ZnO), etc.

[0108] The second gate insulating layer 13b may be provided with an upper electrode Cst2 of the storage capacitor Cst. The upper electrode Cst2 may overlap the gate electrode 14 thereunder. The gate electrode 14 and the upper electrode Cst2 overlapping each other and the second gate insulating layer 13b therebetween may form a storage capacitor Cst. For example, the gate electrode 14 may serve as a lower electrode Cst1 of the storage capacitor Cst.

[0109] Therefore, the storage capacitor Cst and the thin film transistor TFT may be formed to overlap each other. In some embodiments, the storage capacitor Cst may be formed not to overlap the thin film transistor TFT.

[0110] The upper electrode Cst2 may include aluminum (Al), platinum (Pt), palladium (Pd), silver (Ag), magnesium (Mg), gold (Au), nickel (Ni), neodymium (Nd), iridium (Ir), chromium (Cr), calcium (Ca), molybdenum (Mo), titanium (Ti), tungsten (W) and / or copper (Cu), and may include a single layer or multiple layers of the above materials.

[0111] The insulating interlayer 15 may cover the upper electrode Cst2. The insulating interlayer 15 may include silicon oxide (SiO 2 ), silicon nitride (SiN x ), silicon oxynitride (SiON), aluminum oxide (Al 2 O 3 ), titanium oxide (TiO 2 ), Tantalum Oxide (Ta 2 O 5 ), hafnium oxide (HfO 2 ), zinc oxide (ZnO), etc. The insulating intermediate layer 15 may include a single layer or multiple layers, and the single layer or multiple layers include the above-mentioned inorganic insulating material.

[0112] Each of the drain electrode 16a and the source electrode 16b may be disposed on the insulating interlayer 15. The drain electrode 16a and the source electrode 16b may be electrically connected to the drain region 12a and the source region 12b via the contact holes in the first gate insulating layer 13a, the second gate insulating layer 13b, and the insulating interlayer 15, respectively. The drain electrode 16a and the source electrode 16b may include a material having conductivity. The drain electrode 16a and the source electrode 16b may include a conductive material, the conductive material including molybdenum (Mo), aluminum (Al), copper (Cu), titanium (Ti), etc., and the drain electrode 16a and the source electrode 16b may include a multilayer or a single layer, the multilayer or the single layer including the material. In an embodiment, the drain electrode 16a and the source electrode 16b may have a multilayer structure of Ti / Al / Ti.

[0113] The planarization insulating layer 17 may include an organic insulating layer. The planarization insulating layer 17 may include an organic insulating material such as a general polymer such as polymethyl methacrylate (PMMA) or polystyrene (PS), a polymer derivative having a phenol-based group, an acryl-based polymer, an imide-based polymer, an aryl ether-based polymer, an amide-based polymer, a fluorine-based polymer, a p-xylene-based polymer, a vinyl alcohol-based polymer, and a blend thereof.

[0114] The display element layer DEL is disposed on the pixel circuit layer PCL having the above structure. The display element layer DEL includes an organic light emitting diode OLED, and a pixel electrode 21 of the organic light emitting diode OLED may be electrically connected to the thin film transistor TFT via a contact hole of the planarization insulating layer 17 .

[0115] The pixel PX may include an organic light emitting diode OLED and a thin film transistor TFT. Each pixel PX may emit, for example, red, green, or blue light from the organic light emitting diode OLED, or may emit, for example, red, green, blue, or white light from the organic light emitting diode OLED.

[0116] The pixel electrode 21 may include a conductive oxide material such as indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), indium oxide (In 2 O 3 ), indium gallium oxide (IGO) or aluminum zinc oxide (AZO). In another embodiment, the pixel electrode 21 may include a reflective film, which includes silver (Ag), magnesium (Mg), aluminum (Al), platinum (Pt), palladium (Pd), gold (Au), nickel (Ni), neodymium (Nd), iridium (Ir), chromium (Cr) or a compound thereof. In another embodiment, the pixel electrode 21 may also include a reflective film made of ITO, IZO, ZnO or In on / under the reflective film. 2 O 3The film formed.

[0117] A pixel defining film 19 may be disposed on the pixel electrode 21, and the pixel defining film 19 has an opening 19OP exposing a central portion of the pixel electrode 21. The pixel defining film 19 may include an organic insulating material and / or an inorganic insulating material. The opening 19OP may define a light emitting area EA of light emitted from the organic light emitting diode OLED. For example, the width of the opening 19OP may correspond to the width of the light emitting area EA.

[0118] The light emitting layer 22 may be disposed in the opening 19OP of the pixel defining film 19. The light emitting layer 22 may include a polymer or a low molecular weight organic material that emits light of a predetermined color.

[0119] Although not shown, a first functional layer and a second functional layer may be provided under the light emitting layer 22 and on the light emitting layer 22, respectively. The first functional layer may include, for example, a hole transport layer, or may include, for example, a hole transport layer and a hole injection layer. The second functional layer is an element provided on the light emitting layer 22, and is optional. The second functional layer may include an electron transport layer and / or an electron injection layer. The first functional layer and / or the second functional layer may be a common layer formed to completely cover the substrate 10 like the common electrode 23 described below.

[0120] The common electrode 23 may include a conductive material having a low work function. For example, the common electrode 23 may include a transparent or semi-transparent layer including silver (Ag), magnesium (Mg), aluminum (Al), platinum (Pt), palladium (Pd), gold (Au), nickel (Ni), neodymium (Nd), iridium (Ir), chromium (Cr), lithium (Li), calcium (Ca) or an alloy thereof. As another example, on the transparent or semi-transparent layer including the above materials, the common electrode 23 may also include a conductive material such as ITO, IZO, ZnO or In 2 O 3 layer.

[0121] In an embodiment, the thin film encapsulation layer TFE includes at least one inorganic encapsulation layer and at least one organic encapsulation layer. In an embodiment, the thin film encapsulation layer TFE includes a first inorganic encapsulation layer 31, an organic encapsulation layer 32, and a second inorganic encapsulation layer 33, which are stacked in the order stated, for example, Figure 6 as shown in .

[0122] The first inorganic encapsulation layer 31 and the second inorganic encapsulation layer 33 may include at least one inorganic material among aluminum oxide, titanium oxide, tantalum oxide, hafnium oxide, zinc oxide, silicon oxide, silicon nitride and silicon oxynitride. The organic encapsulation layer 32 may include a polymer-based material. The polymer-based material may include an acryl-based resin, an epoxy-based resin, polyimide, polyethylene, etc. In an embodiment, the organic encapsulation layer 32 may include acrylate.

[0123] In another embodiment, the thin film encapsulation layer TFE may have a structure in which the substrate 10 and the upper substrate as a transparent member are connected by a sealing member to seal the internal space between the substrate 10 and the upper substrate. A hygroscopic agent, a filling material, etc. may be disposed in the internal space. The sealing member may be a sealant, and in another embodiment, the sealing member may be made of a material cured by laser. For example, the sealing member may be a glass frit. The sealing member may include an organic sealant (such as a carbamate-based resin, an epoxy-based resin, or an acryl-based resin) or an inorganic sealant (such as silica gel). Carbamate-based resins may include, for example, carbamate acrylates. Acryl-based resins may include, for example, butyl acrylate or ethylhexyl acrylate. The sealing member may be made of a material cured by heat.

[0124] A touch electrode layer (not shown) including a touch electrode may be provided on the thin film encapsulation layer TFE, and an optical functional layer (not shown) may be provided on the touch electrode layer. The touch electrode layer may obtain coordinate information in response to an external input (e.g., a touch event). The optical functional layer may reduce the reflectance of light (external light) incident on the display panel DP, and / or may improve the color purity of light emitted from the display panel DP. In an embodiment, the optical functional layer may include a retarder and a polarizer. The retarder may be a film type or a liquid crystal coating type, and may include a λ / 2 retarder and / or a λ / 4 retarder. The polarizer may also be a film type or a liquid crystal coating type. The film type may include a stretched synthetic resin film, and the liquid crystal coating type may include a liquid crystal arranged in a predetermined orientation. The retarder and the polarizer may also include a protective film.

[0125] In another embodiment, the optical functional layer may include a black matrix and a color filter. The color filter may be set in consideration of the color of light emitted from each of the pixels PX of the display panel DP. Each of the color filters may include a red pigment, a green pigment, or a blue pigment, or a red dye, a green dye, or a blue dye. As another example, each of the color filters may include quantum dots in addition to the pigment or dye. As another example, some of the color filters may not include the pigment or dye, and may include scattering particles such as titanium oxide.

[0126] In another embodiment, the optical function layer may include a destructive interference structure. The destructive interference structure may include a first reflective layer and a second reflective layer disposed on different layers. The first reflected light and the second reflected light respectively reflected by the first reflective layer and the second reflective layer may destructively interfere with each other, and thus the external light reflectance may be reduced.

[0127] There may be an adhesive member between the touch electrode layer and the optical function layer. The adhesive member may be any adhesive member commonly known in the prior art. The adhesive member may be PSA.

[0128] In an embodiment, a flexible cover window may be disposed on the optical function layer, and the optical function layer and the flexible cover window may be connected to each other by an adhesive member.

[0129] Figure 7 and Figure 8 is a schematic cross-sectional view of a state in which the foldable display device 1 according to the embodiment is folded about a folding axis FAX.

[0130] Reference Figure 7 and Figure 8 , the foldable display device 1 may include a display panel DP and a flexible cover window CW covering the display panel DP, the display panel DP including a display area. The flexible cover window CW may include a lower glass substrate 100, an upper glass substrate 200 disposed above the lower glass substrate 100 and thinner than the lower glass substrate 100, and an adhesive member 300 located between the lower glass substrate 100 and the upper glass substrate 200. The lower glass substrate 100 may include a first lower glass substrate 100A and a second lower glass substrate 100B spaced apart from each other, and the adhesive member 300 may extend between the first lower glass substrate 100A and the second lower glass substrate 100B. The foldable display device 1 may be folded relative to a folding axis FAX.

[0131] The flexible cover window CW may include a bending area BA corresponding to the folding axis FAX and a first extension area EXA1 and a second extension area EXA2 respectively connected to the corresponding sides of the bending area BA. The first lower glass substrate 100A may be positioned in the first extension area EXA1. For example, the first lower glass substrate 100A may overlap with the first extension area EXA1. The second lower glass substrate 100B may be positioned in the second extension area EXA2. For example, the second lower glass substrate 100B may overlap with the second extension area EXA2.

[0132] In an embodiment, a first lower glass substrate 100A and a second lower glass substrate 100B that are thicker than the upper glass substrate 200 may be positioned in the first extension area EXA1 and the second extension area EXA2, respectively. Therefore, in the bending area BA, the flexibility of the flexible cover window CW may be increased. The first lower glass substrate 100A may overlap with the upper glass substrate 200 in the first extension area EXA1, and the second lower glass substrate 100B may overlap with the upper glass substrate 200 in the second extension area EXA2. Therefore, the lower glass substrate 100 and the upper glass substrate 200 may protect the display panel DP from external impact in the first extension area EXA1 and the second extension area EXA2. For example, the flexible cover window CW may maintain high strength in the first extension area EXA1 and the second extension area EXA2.

[0133] Reference Figure 7 , the display panel DP may include a first surface S1 facing the flexible cover window CW and a second surface S2 opposite to the first surface S1. In this case, the foldable display device 1 may be folded so that the first surface S1 of the display panel DP faces itself relative to the folding axis FAX. For example, the foldable display device 1 may be an inner foldable foldable display device.

[0134] In this case, the foldable display device 1 can be folded so that the upper surfaces 100US of the lower glass substrates 100 face each other relative to the folding axis FAX. The foldable display device 1 can be folded so that the upper surfaces of the first lower glass substrate 100A and the second lower glass substrate 100B face each other relative to the folding axis FAX.

[0135] The foldable display device 1 can be folded so that the upper surface 200US of the upper glass substrate 200 faces itself relative to the folding axis FAX. The upper surface 100US of the lower glass substrate 100 can face the lower surface 200LS of the upper glass substrate 200, and the upper surface 200US of the upper glass substrate 200 can be opposite to the lower surface 200LS of the upper glass substrate 200.

[0136] Reference Figure 8 , the display panel DP may include a first surface S1 facing the flexible cover window CW and a second surface S2 opposite to the first surface S1. In this case, the foldable display device 1 may be folded so that the second surface S2 of the display panel DP faces itself relative to the folding axis FAX. For example, the foldable display device 1 may be an external foldable display device.

[0137] In this case, the foldable display device 1 can be folded so that the lower surfaces 100LS of the lower glass substrate 100 face each other with respect to the folding axis FAX. The foldable display device 1 can be folded so that the lower surface of the first lower glass substrate 100A and the lower surface of the second lower glass substrate 100B face each other with respect to the folding axis FAX. The foldable display device 1 can be folded so that the lower surface 200LS of the upper glass substrate 200 faces itself with respect to the folding axis FAX.

[0138] The flexible cover window according to the above-described embodiment may have both flexibility and high strength.

[0139] The foldable display device including the flexible cover window can have flexibility in the bending area corresponding to the folding axis, and since the lower glass substrate thicker than the upper glass substrate is positioned to correspond to the first extension area and the second extension area extending from the bending area, the foldable display device can maintain high strength.

[0140] It should be understood that the embodiments described herein should be understood in a descriptive sense only and not for limiting purposes. The description of features or aspects in each embodiment should generally be considered applicable to other similar features or aspects in other embodiments. Although one or more embodiments have been described with reference to the accompanying drawings, it will be understood by those of ordinary skill in the art that various changes in form and detail may be made therein without departing from the spirit and scope defined by the appended claims.

Claims

1. Flexible cover window, including: A lower glass substrate, comprising a first lower glass substrate and a second lower glass substrate, wherein the first lower glass substrate and the second lower glass substrate are spaced apart from each other relative to a bending area of ​​the flexible cover window; an upper glass substrate, disposed above the lower glass substrate and thinner than the lower glass substrate; as well as An adhesive member is disposed between the lower glass substrate and the upper glass substrate and extends between the first lower glass substrate and the second lower glass substrate.

2. The flexible cover window according to claim 1, wherein: The adhesive member connects the first lower glass substrate, the second lower glass substrate, and the upper glass substrate to each other.

3. The flexible cover window according to claim 1, wherein: The flexible cover window comprises the bending area, a first extension area and a second extension area, wherein the first extension area and the second extension area are respectively connected to corresponding sides of the bending area; The first lower glass substrate is positioned in the first extension region, and The second lower glass substrate is positioned in the second extension region.

4. The flexible cover window according to claim 1, wherein: The upper glass substrate includes a lower surface facing the lower glass substrate and a side surface intersecting the lower surface, and The adhesive member extends from the lower surface of the upper glass substrate to cover the side surface of the upper glass substrate.

5. The flexible cover window according to claim 1, wherein: An end portion of the first lower glass substrate and an end portion of the second lower glass substrate face each other and each include at least two step shapes.

6. The flexible cover window according to claim 1, wherein: The first lower glass substrate includes a plurality of first protrusions protruding toward the second lower glass substrate, and The second lower glass substrate includes a plurality of second protrusions protruding toward the first lower glass substrate.

7. The flexible cover window according to claim 6, wherein: Each of the plurality of first protruding portions faces a corresponding one of the plurality of second protruding portions.

8. The flexible cover window according to claim 6, wherein: The first lower glass substrate includes a plurality of recesses, each of the plurality of recesses being disposed between two adjacent first protruding portions of the plurality of first protruding portions, and Each of the plurality of second protrusions faces a corresponding one of the plurality of recesses.

9. The flexible cover window according to claim 1, wherein: The bonding member has a refractive index that is the same as a refractive index of at least one of the lower glass substrate and the upper glass substrate.

10. The flexible cover window according to claim 1, wherein: At least one of the lower glass substrate and the upper glass substrate includes ultra-thin tempered glass.

11. A foldable display device comprising: A display panel including a display area; as well as A flexible cover window covers the display panel. Wherein, the flexible cover window comprises: A lower glass substrate, comprising a first lower glass substrate and a second lower glass substrate, wherein the first lower glass substrate and the second lower glass substrate are spaced apart from each other relative to a bending area of ​​the flexible cover window; an upper glass substrate disposed above the lower glass substrate and thinner than the lower glass substrate; and an adhesive member disposed between the lower glass substrate and the upper glass substrate and extending between the first lower glass substrate of the lower glass substrates and the second lower glass substrate of the lower glass substrates, and The foldable display device is foldable about a folding axis intersecting the display area, and the bending area corresponds to the folding axis.

12. The foldable display device according to claim 11, wherein: The adhesive member connects the first lower glass substrate, the second lower glass substrate, and the upper glass substrate to each other.

13. The foldable display device according to claim 11, wherein: The flexible cover window comprises a first extension area, a second extension area and the bending area, wherein the first extension area and the second extension area are respectively connected to corresponding sides of the bending area. The first lower glass substrate is positioned in the first extension region, and The second lower glass substrate is positioned in the second extension region.

14. The foldable display device according to claim 11, wherein: The upper glass substrate includes a lower surface facing the lower glass substrate and a side surface intersecting the lower surface, and The adhesive member extends from the lower surface of the upper glass substrate to cover the side surface of the upper glass substrate.

15. The foldable display device according to claim 11, wherein: An end portion of the first lower glass substrate and an end portion of the second lower glass substrate face each other and each include at least two step shapes.

16. The foldable display device according to claim 11, wherein: The first lower glass substrate includes a plurality of first protrusions protruding toward the second lower glass substrate, and The second lower glass substrate includes a plurality of second protrusions protruding toward the first lower glass substrate.

17. The foldable display device according to claim 11, wherein: The bonding member has a refractive index that is the same as a refractive index of at least one of the lower glass substrate and the upper glass substrate.

18. The foldable display device according to claim 11, wherein: At least one of the lower glass substrate and the upper glass substrate includes ultra-thin tempered glass.

19. The foldable display device according to claim 11, wherein: The display panel includes a first surface facing the flexible cover window and a second surface opposite to the first surface, and The foldable display device is foldable such that the first surface of the display panel faces itself relative to the folding axis.

20. The foldable display device according to claim 11, wherein: The display panel includes a first surface facing the flexible cover window and a second surface opposite to the first surface, and The foldable display device is foldable such that the second surface faces itself relative to the folding axis.

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