Patent Publication Number: US-2022223820-A1

Title: Cover window, display device including the same, and apparatus for manufacturing the display device

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
     This application claims priority to and benefits of Korean Patent Application No. 10-2021-0003563 under 35 U.S.C. § 119, filed on Jan. 11, 2021, in the Korean Intellectual Property Office, the entire contents of which are incorporated herein by reference. 
     BACKGROUND 
     1. Technical Field 
     One or more embodiments relate to a cover window, a display device including the cover window, and an apparatus for manufacturing the display device. 
     2. Description of the Related Art 
     Recently, electronic devices based on mobility have been widely used. As portable electronic devices, tablet PCs, as well as small-sized electronic devices such as mobile phones, have been widely used recently. 
     Such a portable electronic device may include a display device that supports various functions and that provides a user with visual information such as images or videos. Recently, as sizes of components for driving a display device have been reduced, the relevance of the display device in an electronic device has gradually increased, and research for expanding a display area of the display device providing images or videos has been actively performed. 
     A display device may include a cover window for protecting a display panel of the display device. The cover window is at an outermost part of the display device and may be in direct contact with a user. 
     It is to be understood that this background of the technology section is, in part, intended to provide useful background for understanding the technology. However, this background of the technology section may also include ideas, concepts, or recognitions that were not part of what was known or appreciated by those skilled in the pertinent art prior to a corresponding effective filing date of the subject matter disclosed herein. 
     SUMMARY 
     One or more embodiments provide a cover window for providing a user with an excellent grip sense in case that the user contacts a display device, a display device including the cover window, and an apparatus for manufacturing the display device. 
     Also, in case that a display area of a display panel may include a curved surface that is curved in various directions and/or with various radii of curvature, one or more embodiments provide a cover window with which stress applied to the display panel is reduced in case that the cover window is attached to the display panel and damage to the display panel is reduced, a display device including the cover window, and an apparatus for manufacturing the display device. 
     However, the above technical features are examples, and the scope of the disclosure is not limited thereto. 
     Additional aspects will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of the presented embodiments of the disclosure. 
     According to an embodiment, a cover window may include a front portion including a flat surface; a first side portion extending from a first edge of the front portion, the first side portion being bent about a first axis that is parallel to the first edge of the front portion, a second side portion extending from a second edge crossing the first edge of the front portion, the second side portion being bent about a second axis that is parallel to the second edge of the front portion, and a corner portion between the first side portion to the second side portion, wherein the first side portion may include an outer surface and an inner surface opposite to the outer surface, and a curvature radius of the outer surface may be different from a curvature radius of the inner surface. 
     The curvature radius of the outer surface of the first side portion may be less than the curvature radius of the inner surface of the first side portion. 
     A thickness of the first side portion may vary in a direction away from the first edge of the front portion. 
     The thickness of the first side portion may be gradually increased and reduced in the direction away from the first edge of the front portion. 
     A maximum thickness of the first side portion may be greater than a thickness of the front portion. 
     An extending length of the first edge of the front portion and an extending length of the second edge of the front portion may be different from each other. 
     According to an embodiment, a display device may include a display panel including a display area including light-emitting devices, and a cover window disposed on the display panel, wherein the cover window may include a front portion including a flat surface; a first side portion extending from a first edge of the front portion, the first side portion being bent about a first axis that is parallel to the first edge of the front portion; a second side portion extending from a second edge crossing the first edge of the front portion, the second side portion being bent about a second axis that is parallel to the second edge of the front portion; and a corner portion between the first side portion to the second side portion, the first side portion and the second side portion of the cover window each may include an inner surface facing the display panel and an outer surface opposite to the inner surface, and a curvature radius of the outer surface of each of the first side portion and the second side portion may be different from a curvature radius of the inner surface of each of the first side portion and the second side portion. 
     The curvature radius of the outer surface of each of the first side portion and the second side portion may be less than the curvature radius of the inner surface of each of the first side portion and the second side portion. 
     The display panel may include a front display area corresponding to the front portion of the cover window; a first side display area and a second side display area respectively corresponding to the first side portion and the second side portion of the cover window; and a corner display area corresponding to the corner portion of the cover window. 
     The display panel may include a first portion bent along the inner surface of the first side portion of the cover window, and a second portion bent along the inner surface of the second side portion of the cover window. 
     A surface of the first portion in the display panel may have a curvature radius same as the curvature radius of the inner surface of the first side portion in the cover window, and a surface of the second portion in the display panel may have a curvature radius same as the curvature radius of the inner surface of the second side portion in the cover window. 
     A thickness of the first side portion may vary in a direction away from the first edge of the front portion. 
     The thickness of the first side portion may be gradually increased and reduced in the direction away from the first edge of the front portion. 
     A maximum thickness of the first side portion in the cover window may be greater than a thickness of the front portion. 
     According to an embodiment, a display device may include a display panel including a display area including light-emitting devices; and a cover window disposed on the display panel, wherein the cover window may include a front portion including a flat surface; a first side portion extending from a first edge of the front portion, the first side portion being bent about a first axis that is parallel to the first edge of the front portion; a second side portion extending from a second edge crossing the first edge of the front portion, the second side portion being bent about a second axis that is parallel to the second edge of the front portion; and a corner portion between the first side portion to the second side portion, a thickness of the first side portion of the cover window may vary in a direction away from the first edge of the front portion, and a thickness of the second side portion of the cover window may vary in a direction away from the second edge of the front portion. 
     The thickness of the first side portion of the cover window may be gradually increased and reduced in the direction away from the first edge of the front portion, and the thickness of the second side portion of the cover window may be gradually increased and reduced in the direction away from the second edge of the front portion. 
     A maximum thickness of each of the first side portion and the second side portion in the cover window may be greater than a thickness of the front portion. 
     According to an embodiment, an apparatus for manufacturing a display device may include a first mold including a support surface on which a cover window is disposed; and a second mold including a pressing surface that presses an upper surface of the cover window, the second mold facing the first mold, wherein the support surface of the first mold may include a flat support surface having a flat surface encompassed by a first direction and a second direction crossing the first direction; a first curved support surface extending from a first edge of the flat support surface and having a first curvature radius; a second curved support surface extending from a second edge crossing the first edge of the flat support surface, and having a second curvature radius; and a corner support surface between the first curved support surface and the second curved support surface to each other, the pressing surface of the second mold may include a flat pressing surface corresponding to the flat support surface and having a flat surface that is parallel to the flat support surface; a first curved pressing surface corresponding to the first curved support surface, and having a third curvature radius that is different from the first curvature radius of the first curved support surface; a second curved pressing surface corresponding to the second curved support surface, and having a fourth curvature radius that is different from the second curvature radius of the second curved support surface; and a corner pressing surface between the first curved pressing surface and the second curved pressing surface to each other. 
     The first curvature radius of the first curved support surface of the first mold may be greater than the third curvature radius of the first curved pressing surface of the second mold, and the second curvature radius of the second curved support surface of the first mold may be greater than the fourth curvature radius of the second curved pressing surface of the second mold. 
     A first distance between the first curved pressing surface of the second mold and the first curved support surface of the first mold may be greater than a second distance between the flat pressing surface of the second mold and the flat support surface of the first mold when the pressing surface of the second mold presses the cover window. 
     The first distance may vary in a direction away from the first edge of the flat support surface. 
     The first distance may be gradually increased and reduced in the direction away from the first edge of the flat support surface. 
     The apparatus may further include a moving portion that moves the second mold in a third direction crossing the first direction and the second direction. 
     Other aspects, features and advantages of the disclosure will become better understood through the accompanying drawings, the claims and the detailed description. 
     Such general aspects of the disclosure may be performed using systems, methods, computer-readable storage mediums, and/or combinations thereof. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other aspects, features, and advantages of embodiments of the disclosure will be more apparent from the following description taken in conjunction with the accompanying drawings, in which: 
         FIG. 1  is a schematic perspective view of a display device according to an embodiment; 
         FIG. 2  is a schematic cross-sectional view partially showing a display device according to an embodiment; 
         FIG. 3  is a schematic diagram of an equivalent circuit of a pixel in a display device according to an embodiment; 
         FIG. 4  is a schematic cross-sectional view showing a region of a cover window according to an embodiment; 
         FIG. 5  is a schematic perspective view partially showing a region of a cover window according to an embodiment; 
         FIG. 6  is an enlarged schematic cross-sectional view showing a region of a cover window according to an embodiment; 
         FIG. 7  is a schematic cross-sectional view of components in a display device according to an embodiment; 
         FIG. 8  is a schematic perspective view of an apparatus for manufacturing the display device of  FIG. 1 ; 
         FIG. 9  is a schematic perspective view of a first mold of an apparatus for manufacturing the display device, according to an embodiment; 
         FIG. 10  is a schematic perspective view of a second mold of an apparatus for manufacturing the display device, according to an embodiment; and 
         FIGS. 11A to 11C  are schematic cross-sectional views illustrating processes in a method of manufacturing a display device by using the apparatus for manufacturing a display device according to an embodiment. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     Reference will now be made in detail to embodiments, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout. In this regard, the embodiments may have different forms and should not be construed as being limited to the descriptions set forth herein. Accordingly, the embodiments are merely described below, by referring to the figures, to explain aspects of the description. 
     Throughout the disclosure, the phrase “at least one of” is intended to include the meaning of “at least one selected from the group of” for the purpose of its meaning and interpretation. For example, the expression “at least one of a, b or c” indicates 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. 
     In the specification and the claims, the term “and/or” is intended to include any combination of the terms “and” and “or” for the purpose of its meaning and interpretation. For example, “A and/or B” may be understood to mean “A, B, or A and B.” The terms “and” and “or” may be used in the conjunctive or disjunctive sense and may be understood to be equivalent to “and/or.” 
     As the disclosure allows for various changes and numerous embodiments, embodiments will be illustrated in the drawings and described in detail in the written description. The attached drawings for illustrating one or more embodiments are referred to in order to gain a sufficient understanding, the merits thereof, and the objectives accomplished by the implementation. However, the embodiments may have different forms and should not be construed as being limited to the descriptions set forth herein. 
     The embodiments will be described below in more detail with reference to the accompanying drawings. Those components that are the same or are in correspondence may be referred to by the same reference numeral regardless of the figure number, and redundant explanations may be omitted. 
     While such terms as “first,” “second,” etc., may be used to describe various components, such components are not be limited to the above terms. The above terms are used only to distinguish one component from another. For example, a first component may be referred to as a second component, and similarly, a second component may be referred to as a first component without departing from the scope of the disclosure. 
     An expression used in the singular encompasses the expression of the plural, unless it has a clearly different meaning in the context. 
     In the specification, it is to be understood that the terms “including,” “having,” and “comprising” and variations thereof are intended to indicate the existence of the features, numbers, steps, actions, components, parts, or combinations thereof disclosed in the specification, and are not intended to preclude the possibility that one or more other features, numbers, steps, actions, components, parts, or combinations thereof may exist or may be added. 
     The phrase “in a plan view” means viewing the object from the top, and the phrase “in a schematic cross-sectional view” means viewing a cross-section of which the object is vertically cut from the side. 
     It will be understood that when a layer, region, or component is referred to as being “formed on” another layer, region, or component, it may be directly or indirectly formed on the other layer, region, or component. For example, intervening layers, regions, or components may be present. 
     The spatially relative terms “below”, “beneath”, “lower”, “above”, “upper”, or the like, may be used herein for ease of description to describe the relations between one element or component and another element or component as illustrated in the drawings. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation, in addition to the orientation depicted in the drawings. For example, in the case where a device illustrated in the drawing is turned over, the device positioned “below” or “beneath” another device may be placed “above” another device. Accordingly, the illustrative term “below” may include both the lower and upper positions. The device may also be oriented in other directions and thus the spatially relative terms may be interpreted differently depending on the orientations. 
     The terms “overlap” or “overlapped” mean that a first object may be above or below or to a side of a second object, and vice versa. Additionally, the term “overlap” may include layer, stack, face or facing, extending over, covering, or partly covering or any other suitable term as would be appreciated and understood by those of ordinary skill in the art. 
     When an element is described as ‘not overlapping’ or ‘to not overlap’ another element, this may include that the elements are spaced apart from each other, offset from each other, or set aside from each other or any other suitable term as would be appreciated and understood by those of ordinary skill in the art. 
     The terms “face” and “facing” mean that a first element may directly or indirectly oppose a second element. In a case in which a third element intervenes between the first and second element, the first and second element may be understood as being indirectly opposed to one another, although still facing each other. 
     Sizes of components in the drawings may be exaggerated for convenience of explanation. In other words, since sizes and thicknesses of components in the drawings are arbitrarily illustrated for convenience of explanation, the following embodiments are not limited thereto. 
     When an embodiment may be implemented differently, a specific process order may be performed differently from the described order. For example, two consecutively described processes may be performed substantially at the same time or performed in an order opposite to the described order. 
     In the embodiments below, when layers, areas, or elements or the like are referred to as being “connected,” it will be understood that they may be directly connected or an intervening portion may be present between layers, areas or elements. For example, when layers, areas, or elements or the like are referred to as being “electrically connected,” they may be directly electrically connected, or layers, areas or elements may be indirectly electrically connected and an intervening portion may be present. 
     The x-axis, the y-axis and the z-axis are not limited to three axes of the rectangular coordinate system, and may be interpreted in a broader sense. For example, the x-axis, the y-axis, and the z-axis may be perpendicular to one another, or may represent different directions that are not perpendicular to one another. 
     “About” or “approximately” as used herein is inclusive of the stated value and means within an acceptable range of deviation for the particular value as determined by one of ordinary skill in the art, considering the measurement in question and the error associated with measurement of the particular quantity (i.e., the limitations of the measurement system). For example, “about” may mean within one or more standard deviations, or within ±30%, 20%, 10%, 5% of the stated value. 
     Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the disclosure pertains. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein. 
       FIG. 1  is a perspective view of a display device  1  according to an embodiment. 
     Referring to  FIG. 1 , the display device  1  may have a substantially rectangular shape in a plan view. In an embodiment, the display device  1  may have various shapes such as a substantially polygonal shape, for example, a substantially triangular shape, a substantially rectangular shape, etc., a substantially circular shape, a substantially elliptical shape, etc. within the spirit and the scope of the disclosure. In an embodiment, in case that the display device  1  has a substantially polygonal shape in a plan view, corners of the polygonal shape may be substantially round. Hereinafter, for convenience of description, an example in which the display device  1  has a substantially rectangular shape having substantially round corners in a plan view will be described below. 
     In an embodiment, the display device  1  may have short sides in a first direction (for example, ±x direction) and long sides in a second direction (for example, ±y direction). Here, the first direction and the second direction may cross or intersect each other. However, one or more embodiments are not limited thereto, and in an embodiment, the display device  1  may have short sides in the first direction and long sides in the second direction, or a side in the first direction and a side in the second direction may have the same lengths. 
     The display device  1  may include a display area DA and a peripheral area PA outside of the display area DA. Pixels PX may be disposed in the display area DA, and the display device  1  may provide images via the pixels PX in the display area DA. Each of the pixels PX may be defined as an emission area from which light is emitted by a light-emitting device in the display device  1 . Therefore, the display area DA may be defined by light-emitting devices. For example, each of the pixels PX may emit red light, green light, or blue light, and the display device  1  may provide images by using the light emitted from each of the pixels PX. 
     The display area DA may include a front display area FDA, side display areas SDA, and corner display areas CDA. For example, independent images may be provided by the pixels PX in each of the front display area FDA, the side display areas SDA, and the corner display areas CDA. In another example, one entire image may be provided by the pixels PX in each of the front display area FDA, the side display areas SDA, and the corner display areas CDA. For example, each of the front display area FDA, the side display areas SDA, and the corner display areas CDA may provide a part of one image. 
     The front display area FDA may be a flat display area, and may have, for example, a substantially rectangular shape in a plan view. For example, the front display area FDA may be at a center of the display device  1  and may be surrounded by the side display areas SDA. An image provided by the front display area FDA may occupy the largest ratio in the image provided by the display device  1 . 
     The side display areas SDA may be display areas adjacent to respective edges of the front display area FDA. For example, the front display area FDA having the substantially rectangular shape may include four edges FDA-E 1 , FDA-E 2 , FDA-E 3 , and FDA-E 4 , and the side display areas SDA may include first to fourth side display areas SDA 1 , SDA 2 , SDA 3 , and SDA 4  respectively adjacent to the four edges FDA-E 1 , FDA-E 2 , FDA-E 3 , and FDA-E 4 . However, one or more embodiments are not limited thereto, and there may be two or more side display areas SDA according to the shape of the front display area FDA in a plan view. 
     In an embodiment, each of the side display areas SDA may have a substantially curved surface extending and bending from each edge of the front display area FDA. For example, the first side display area SDA 1  may include a substantially curved surface that extends from the first edge FDA-E 1  of the front display area FDA in the −y direction and is bent about an axis extending in the ±x direction. The second side display area SDA 2  may include a substantially curved surface that extends from the second edge FDA-E 2  of the front display area FDA in the +x direction and is bent about an axis extending in the ±y direction. The third side display area SDA 3  may include a substantially curved surface that extends from the third edge FDA-E 3  of the front display area FDA in the +y direction and is bent about an axis extending in the ±x direction. The fourth side display area SDA 4  may include a substantially curved surface that extends from the fourth edge FDA-E 4  of the front display area FDA in the −x direction and is bent about an axis extending in the ±y direction. The curved surfaces of the first to fourth side display areas SDA 1 , SDA 2 , SDA 3 , and SDA 4  may have curvature radii that are the same as or different from one another. In case that the side display areas SDA include the curved surfaces as described above, the aesthetic feeling of the display device  1  may be improved. 
     As shown in  FIG. 1 , the first edge FDA-E 1  and the third edge FDA-E 3  of the front display area FDA may face each other, and the first side display area SDA 1  and the third side display area SDA 3  may be at opposite sides with the front display area FDA therebetween. The second edge FDA-E 2  and the fourth edge FDA-E 4  of the front display area FDA may face each other, and the second side display area SDA 2  and the fourth side display area SDA 4  may be at opposite sides with the front display area FDA therebetween. 
     In an embodiment, extending lengths of the first edge FDA-E 1  and the third edge FDA-E 3  of the front display area FDA in the first direction (for example, ±x direction) may be different from extending lengths of the second edge FDA-E 2  and the fourth edge FDA-E 4  in the second direction (for example, ±y direction). For example, the extending lengths of the first edge FDA-E 1  and the third edge FDA-E 3  of the front display area FDA in the first direction may be less than the extending lengths of the second edge FDA-E 2  and the fourth edge FDA-E 4  in the second direction. Accordingly, the extending lengths of the first side display area SDA 1  and the third side display area SDA 3  in the first direction may be less than the extending lengths of the second side display area SDA 2  and the fourth side display area SDA 4  in the second direction. However, one or more embodiments are not limited thereto, and the extending lengths of the first edge FDA-E 1  and the third edge FDA-E 3  of the front display area FDA in the first direction may be equal to the extending lengths of the second edge FDA-E 2  and the fourth edge FDA-E 4  in the second direction. 
     The first edge FDA-E 1  and the second edge FDA-E 2  of the front display area FDA cross or intersect each other to form a first corner FDA-CN 1  of the front display area FDA. Also, the second edge FDA-E 2  and the third edge FDA-E 3  of the front display area FDA cross or intersect each other to form a second corner FDA-CN 2  of the front display area FDA, the third edge FDA-E 3  and the fourth edge FDA-E 4  of the front display area FDA cross or intersect each other to form a third corner FDA-CN 3 , and the fourth edge FDA-E 4  and the first edge FDA-E 1  of the front display area FDA cross or intersect each other to form a fourth corner FDA-CN 4  of the front display area FDA. 
     The corner display areas CDA may be at corners of the front display area FDA and may each connect two adjacent side display areas SDA. For example, the first corner display area CDA 1  may be at the first corner FDA-CN 1  of the front display area FDA, and may connect the first side display area SDA 1  to the second side display area SDA 2 . The second corner display area CDA 2  may be at the second corner FDA-CN 2  of the front display area FDA and may connect the second side display area SDA 2  to the third side display area SDA 3 . The third corner display area CDA 3  may be at the third corner FDA-CN 3  of the front display area FDA and may connect the third side display area SDA 3  to the fourth side display area SDA 4 . The fourth corner display area CDA 4  may be at the fourth corner FDA-CN 4  of the front display area FDA and may connect the fourth side display area SDA 4  to the first side display area SDA 1 . 
     Because the corner display areas CDA each connect two side display areas SDA having the substantially curved surfaces bent in different directions, the corner display areas CDA may each have one curved surface or a curved surface, in which curved surfaces bent in various directions are continuously connected. Also, the corner display area CDA may have one curved surface or a curved surface, in which curved surfaces bent with various curvature radii are continuously connected, in case that two adjacent side display areas SDA are bent with different curvature radii. 
     The peripheral area PA may be an area that does not provide images, for example, a non-display area. The peripheral area PA may partially or entirely surround or may be adjacent to the display area DA. Drivers, etc. for providing electrical signals or electric power to each of the pixels PX may be disposed in the peripheral area PA. The peripheral area PA may include a pad that is a region to which an electronic device, a printed circuit board, etc. may be electrically connected. 
     The display device  1  may be used as a display screen in portable electronic devices such as a mobile phone, a smartphone, a tablet personal computer (PC), a mobile communication terminal, an electronic note, an electronic book, a portable multimedia player (PMP), a navigation device, an ultra-mobile PC (UMPC), and various products such as a television, a laptop computer, a monitor, a billboard, Internet of things (IoT), etc. within the spirit and the scope of the disclosure. Also, the display device  1  may be used in wearable devices such as a smartwatch, a watch phone, a glasses-type display, and a head-mounted display (HMD). Also, the display device  1  may be used in a dashboard of a vehicle, a center information display in a center fascia or dashboard of a vehicle, a rear-view mirror display that replaces a side-view mirror of a vehicle, a display screen in a rear side of a front seat as an entertainment for the back seat in a vehicle. 
       FIG. 2  is a schematic cross-sectional view partially showing the display device  1  according to an embodiment.  FIG. 2  may correspond to a cross-section of the electronic device  1 , taken along line II-II′ of  FIG. 1 . 
     Referring to  FIG. 2 , the display device  1  may include a display panel  10  and a cover window CW. The display panel  10  may have a stack structure including a substrate  100 , a pixel circuit layer PCL, a display layer DPL, a thin film encapsulation layer TFE, a touch electrode layer TEL, and an optical functional layer OFL. 
     The substrate  100  may have a multi-layered structure including a base layer including a polymer resin and an inorganic layer. For example, the substrate  100  may include the base layer including a polymer resin and a barrier layer including an inorganic insulating layer. For example, the substrate  100  may include a first base layer  101 , a first barrier layer  102 , a second base layer  103 , and a second barrier layer  104  that may be sequentially stacked each other in the stated order. The first and second base layers  101  and  103  may each include polyimide (PI), polyether sulfone (PES), polyarylate, polyetherimide (PEI), polyethylene naphthalate (PEN), polyethylene terephthalate (PET), polyphenylene sulfide (PPS), polycarbonate (PC), cellulose triacetate (TAC), and/or cellulose acetate propionate (CAP). The first barrier layer  102  and the second barrier layer  104  may each include an inorganic insulating material such as silicon oxide, silicon oxynitride, and/or silicon nitride. The substrate  100  may be flexible. 
     The pixel circuit layer PCL may be disposed on the substrate  100 . The pixel circuit layer PCL may include a pixel circuit PC including a thin film transistor TFT and a storage capacitor Cst. The pixel circuit layer PCL may include a buffer layer  111 , a first gate insulating layer  112 , a second gate insulating layer  113 , an interlayer insulating layer  114 , a first planarized insulating layer  115 , and a second planarized insulating layer  116  that may be under or below and/or on the elements of the pixel circuit PC. 
     The buffer layer  111  may reduce or prevent infiltration of impurities, moisture, or external air from below the substrate  100 , and may provide a planarized surface on the substrate  100 . The buffer layer  111  may include an inorganic insulating material such as silicon oxide, silicon oxynitride, and silicon nitride, and may have a single-layered or multi-layered structure including the stated materials. 
     The thin film transistor TFT on the buffer layer  111  may include a semiconductor layer Act, and the semiconductor layer Act may include polysilicon. As an example, the semiconductor layer Act may include amorphous silicon, an oxide semiconductor, an organic semiconductor, etc. within the spirit and the scope of the disclosure. The semiconductor layer Act may include a channel region C, and a drain region D and a source region S at opposite sides of the channel region C. A gate electrode GE may overlap the channel region C. 
     The gate electrode GE may include a low-resistive metal material. The gate electrode GE may include a conductive material including molybdenum (Mo), aluminum (Al), copper (Cu), titanium (Ti), etc., and may have a single-layered or multi-layered structure. 
     The first gate insulating layer  112  disposed between the semiconductor layer Act and the gate insulating layer GE may include an inorganic insulating material such as silicon oxide (SiO 2 ), silicon nitride (SiNx), silicon oxynitride (SiON), aluminum oxide (Al 2 O 3 ), titanium oxide (TiO 2 ), tantalum oxide (Ta 2 O 5 ), hafnium oxide (HfO 2 ), and zinc oxide (ZnO 2 ). 
     The second gate insulating layer  113  may cover or overlap the gate electrode GE. Similar to the first gate insulating layer  112 , the second gate insulating layer  113  may include an inorganic insulating material such as silicon oxide (SiO 2 ), silicon nitride (SiNx), silicon oxynitride (SiON), aluminum oxide (Al 2 O 3 ), titanium oxide (TiO 2 ), tantalum oxide (Ta 2 O 5 ), hafnium oxide (HfO 2 ), and zinc oxide (ZnO 2 ). 
     An upper electrode Cst 2  of the storage capacitor Cst may be disposed on the second gate insulating layer  113 . The upper electrode Cst 2  may overlap the gate electrode GE thereunder. Here, the gate electrode GE and the upper electrode Cst 2  overlapping each other with the second gate insulating layer  113  disposed therebetween may form the storage capacitor Cst. For example, the gate electrode GE may function as a lower electrode Cst 1  of the storage capacitor Cst. 
     As described above, the storage capacitor Cst and the thin film transistor TFT may overlap each other. In an embodiment, the storage capacitor Cst may not overlap the thin film transistor TFT. 
     The upper electrode Cst 2  may include aluminum (Al), platinum (Pt), palladium (Pd), silver (Ag), magnesium (Mg), gold (Au), nickel (Ni), neodymium (Nd), iridium (Ir), chrome (Cr), calcium (Ca), molybdenum (Mo), titanium (Ti), tungsten (W), and/or copper (Cu) in a single-layered or multi-layered structure. 
     The interlayer insulating layer  114  may cover or overlap the upper electrode Cst 2 . The interlayer insulating layer  114  may include an insulating material such as silicon oxide (SiO 2 ), silicon nitride (SiNx), silicon oxynitride (SiON), aluminum oxide (Al 2 O 3 ), titanium oxide (TiO 2 ), tantalum oxide (Ta 2 O 5 ), hafnium oxide (HfO 2 ), and zinc oxide (ZnO 2 ). The interlayer insulating layer  114  may have a single-layered or a multi-layered structure including the inorganic insulating material. 
     A drain electrode DE and a source electrode SE may be on the interlayer insulating layer  114 . The drain electrode DE and the source electrode SE may be respectively electrically connected to the drain region D and the source region S via contact holes in insulating layers thereunder. The drain electrode DE and the source electrode SE may include a highly conductive material. The drain electrode DE and the source electrode SE may include a conductive material including molybdenum (Mo), aluminum (Al), copper (Cu), titanium (Ti), etc., and may have a single-layered or multi-layered structure including the above materials. In an embodiment, the drain electrode DE and the source electrode SE may have a multi-layered structure including Ti/Al/Ti. 
     The first planarized insulating layer  115  may cover or overlap the drain electrode DE and the source electrode SE. The first planarized insulating layer  115  may include a general-purpose polymer (for example, polymethylmethacrylate (PMMA) or polystyrene (PS)), polymer derivatives having phenol groups, acryl-based polymer, imide-based polymer, aryl ether-based polymer, amide-based polymer, fluoride-based polymer, p-xylene-based polymer, vinyl alcohol-based polymer, and blends thereof. 
     The second planarized insulating layer  116  may be disposed on the first planarized insulating layer  115 . The second organic insulating layer  116  may include the same material or similar material as that of the first planarized insulating layer  115 , and an organic insulating material such as a general universal polymer (polymethylmethacrylate (PMMA) or polystyrene (PS)), polymer derivatives having phenol groups, acryl-based polymer, imide-based polymer, aryl ether-based polymer, amide-based polymer, fluoride-based polymer, p-xylene-based polymer, vinyl alcohol-based polymer, and blends thereof. 
     The display layer DPL may be disposed on the pixel circuit layer PCL having the above structure. The display layer DPL may include an organic light-emitting diode OLED as a light-emitting device  200 , and the organic light-emitting diode OLED may include a stack structure including a pixel electrode  210 , an intermediate layer  220 , and an opposite electrode  230 . The organic light-emitting diode OLED may emit, for example, red light, green light, or blue light. As an example, the organic light-emitting diode OLED may emit red light, green light, blue light, or white light. The organic light-emitting diode OLED emits light through an emission area, and the emission area may be defined as a pixel PX. 
     The pixel electrode  210  may be electrically connected to the thin film transistor TFT via contact holes in the second planarized insulating layer  116  and the first planarized insulating layer  115  and a contact metal CM disposed on the first planarized insulating layer  115 . 
     The pixel electrode  210  may include a conductive oxide such as indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), indium oxide (In 2 O 3 ), indium gallium oxide, or aluminum zinc oxide (AZO). In an embodiment, the pixel electrode  210  may include a reflective layer including argentum (Ag), magnesium (Mg), aluminum (Al), platinum (Pt), palladium (Pd), aurum (Au), nickel (Ni), neodymium (Nd), iridium (Ir), chromium (Cr), or a compound thereof. In an embodiment, the pixel electrode  210  may further include a layer including ITO, IZO, ZnO, or In 2 O 3  on and/or under or below the reflective layer. 
     A pixel defining layer  117  having an opening  117 OP exposing a center of the pixel electrode  210  may be disposed on the pixel electrode  210 . The pixel defining layer  117  may include an organic insulating material and/or an inorganic insulating material. The opening  117 OP of the pixel defining layer  117  may define an emission area of the light emitted from the organic light-emitting diode OLED. For example, a size or width of the opening  117 OP of the pixel defining layer  117  may correspond to a size or width of the emission area. Therefore, a size and/or a width of the pixel PX may be dependent upon the size and/or width of the corresponding opening  117 OP of the pixel defining layer  117 . 
     The intermediate layer  220  may include the emission layer  222  corresponding to the pixel electrode  210 . The emission layer  222  may include a polymer or low-molecular weight organic material emitting a color light. As an example, the emission layer  222  may include an inorganic light-emitting material or quantum dots. 
     A first functional layer  221  and a second functional layer  223  may be disposed on and under or below the emission layer  222 . The first functional layer  221  may include, for example, a hole transport layer (HTL), or an HTL and a hole injection layer (HIL). The second functional layer  223  may be disposed on the emission layer  222 , and may include an electron transport layer (ETL) and/or an electron injection layer (EIL). The first functional layer  221  and/or the second functional layer  223  may be common layers that may entirely cover or overlap the substrate  100 , like an opposite electrode  230  that will be described later. 
     The opposite electrode  230  may be disposed on the pixel electrode  210  and may overlap the pixel electrode  210 . The opposite electrode  230  may include a conductive material having a low work function. For example, the opposite electrode  230  may include a (semi-)transparent layer including argentum (Ag), magnesium (Mg), aluminum (Al), platinum (Pt), palladium (Pd), aurum (Au), nickel (Ni), neodymium (Nd), iridium (Ir), chromium (Cr), lithium (Li), calcium (Ca), or an alloy thereof. As an example, the opposite electrode  230  may further include a layer including ITO, IZO, ZnO, or In 2 O 3  on the (semi-)transparent layer including the above material. The opposite electrode  230  may be integrally formed to entirely cover or overlap the substrate  100 . 
     The display panel  10  may include light-emitting devices  200 , and the light-emitting devices  200  emit light via the pixels PX to provide images. For example, the display area DA (see  FIG. 1 ) may be defined by the light-emitting devices  200 . Therefore, the display panel  10  may include the display area DA defined by the light-emitting devices  200 , and the display area DA of the display panel  10  may correspond to the display area DA of the display device  1  described above with reference to  FIG. 1 . In other words, the front display area FDA, the side display areas SDA, and the corner display areas CDA of the display device  1  in  FIG. 1  may be the front display area FDA, the side display areas SDA, and the corner display areas CDA of the display panel  10 . 
     The thin film encapsulation layer TFE may be disposed on the display layer DPL and may cover or overlap the display layer DPL. The thin film encapsulation layer TFE may include at least one inorganic encapsulation layer and at least one organic encapsulation layer, and  FIG. 2  shows that the thin film encapsulation layer TFE may include a first inorganic encapsulation layer  310 , an organic encapsulation layer  320 , and a second inorganic encapsulation layer  330  that may be sequentially stacked each other. 
     The first inorganic encapsulation layer  310  and the second inorganic encapsulation layer  330  may each include one or more inorganic materials from aluminum oxide, titanium oxide, tantalum oxide, hafnium oxide, zinc oxide, silicon nitride, and silicon oxynitride. The organic encapsulation layer  320  may include a polymer-based material. The polymer-based material may include an acryl-based resin, an epoxy-based resin, polyimide, polyethylene, etc. within the spirit and the scope of the disclosure. In an embodiment, the organic encapsulation layer  320  may include acrylate. The organic encapsulation layer  320  may be obtained by curing a monomer or applying polymer. The organic encapsulation layer  320  may be transparent. 
     The touch electrode layer TEL including touch electrodes may be disposed on the thin film encapsulation layer TFE, and the optical functional layer OFL may be disposed on the touch electrode layer TEL. The touch electrode layer TFE may obtain coordinate information according to an external input, for example, a touch event. The optical functional layer OFL may reduce a reflectivity of light (external light) incident to the display device  1 , and/or may improve color purity of light emitted from the display device  1 . 
     An adhesive member may be disposed between the touch electrode layer TEL and the optical functional layer OFL. General adhesive members may be used without restriction within the spirit and the scope of the disclosure. The adhesive member may include a pressure sensitive adhesive (PSA) or an optically clear adhesive (OCA). 
     The cover window CW may be disposed on the display panel  10 . The cover window CW may be bonded to the display panel  10  via an adhesive member. The adhesive member may include, for example, a pressure sensitive adhesive (PSA) or an optically clear adhesive (OCA). 
     The cover window CW may have high transmittance in order to transmit light emitted from the display panel  10  and may have a reduced thickness in order to reduce a weight of the display device  1 . Also, the cover window CW may have an excellent strength and hardness in order to protect the display panel  10  against external shock. For example, the cover window CW may include a flexible window. The cover window CW may protect the display panel  10  while easily bending according to an external force without generating cracks. 
     The cover window CW may include, for example, glass or plastic. In an embodiment, the cover window CW may include ultra-thin glass (UTG) having a strength that is increased by a chemical strengthening or a thermal strengthening method. As an example, the cover window CW may include colorless polyimide (CPI). 
     In the above description, the display device  1  may include an organic light-emitting diode OLED as the light-emitting device  200 , but the display device  1  according to one or more embodiments is not limited thereto. In an embodiment, the display device  1  may include a light-emitting display device including an inorganic light-emitting diode (an inorganic light-emitting display or an inorganic EL display device). The inorganic light-emitting diode may include a PN junction diode including inorganic material semiconductor-based materials. In case that a voltage is applied to the PN junction diode in a forward direction, holes and electrons are injected, and energy generated by recombination of the holes and electrons is converted into light energy to emit light having a certain or selected color. The inorganic light-emitting diode may have a width of a few to hundreds of micrometers, and in an embodiment, the inorganic light-emitting diode may be referred to as a micro-LED. 
       FIG. 3  is a schematic diagram of an equivalent circuit of a pixel circuit PC in a display device according to an embodiment. 
     Referring to  FIG. 3 , the pixel circuit PC may include thin film transistors TFT (see  FIG. 2 ) and the storage capacitor Cst, and may be electrically connected to an organic light-emitting diode OLED. In an embodiment, the pixel circuit PC may include a driving thin film transistor T 1 , a switching thin film transistor T 2 , and the storage capacitor Cst. 
     The switching thin film transistor T 2  may be electrically connected to a scan line SL and a data line DL, and may transfer a data signal or a data voltage input from the data line DL to the driving thin film transistor T 1  based on a scan signal or a switching voltage input from the scan line SL. The storage capacitor Cst may be electrically connected to the switching thin film transistor T 2  and a driving voltage line PL and may store a voltage corresponding to a difference between a voltage transferred from the switching thin film transistor T 2  and a first power voltage ELVDD supplied to the driving voltage line PL. 
     The driving thin film transistor T 1  may be electrically connected to the driving voltage line PL and the storage capacitor Cst and may control a driving current flowing from the driving voltage line PL to the organic light-emitting diode OLED in response to the voltage value stored in the storage capacitor Cst. An opposite electrode (for example, a cathode) of the organic light-emitting diode OLED may receive supply of a second power voltage ELVSS. The organic light-emitting diode OLED may emit light having a certain or given luminance according to the driving current. 
       FIG. 3  shows an example in which the pixel circuit PC may include two thin film transistors and one storage capacitor, but one or more embodiments are not limited thereto. For example, the pixel circuit PC may include three or more thin film transistors and/or two or more storage capacitors. In an embodiment, the pixel circuit PC may include seven thin film transistors and one storage capacitor. The number of thin film transistors and the number of storage capacitors may vary depending on a design of the pixel circuit PC. Hereinafter, for convenience of description, an example in which the pixel circuit PC may include two thin film transistors and one storage capacitor will be described below. 
       FIG. 4  is a schematic cross-sectional view showing a region of the cover window CW according to an embodiment. 
     Referring to  FIG. 4 , the cover window CW may have a shape substantially corresponding to an entire shape of the display device  1  (see  FIG. 1 ). For example, in case that the display device  1  has a substantially rectangular shape in a plan view, the cover window CW may have a substantially rectangular shape in a plan view. In an embodiment, in case that the display device  1  has a substantially polygonal shape such as a substantially triangular shape, a substantially rectangular shape, etc. a substantially circular shape, a substantially elliptical shape, etc., the cover window CW may also have the above shapes. Hereinafter, for convenience of description, similar to the shape of the display device  1  shown in  FIG. 1 , an example in which the cover window CW has a substantially rectangular shape having substantially round corners will be described below. 
     The cover window CW may include a front portion FP, side portions SP, and corner portions CP. The front portion FP may have a flat surface, for example, may have a substantially rectangular shape in a plan view. In an embodiment, the front portion FP may be at a center of the cover window CW and may be surrounded by the side portions SP. The front portion FP of the cover window CW may correspond to the front display area FDA of the display device  1 . Here, the components “corresponding to” each other may denote that the components overlap each other when seen from a direction perpendicular to a surface of the cover window CW. 
     The side portions SP may be adjacent to respective edges of the front portion FP. For example, the front portion FP having the substantially rectangular shape has four edges FP-E 1 , FP-E 2 , FP-E 3 , and FP-E 4 , and, the side portions SP may include first to fourth side portions SP 1 , SP 2 , SP 3 , and SP 4  that are respectively adjacent to four edges FP-E 1 , FP-E 2 , FP-E 3 , and FP-E 4  of the front portion FP. However, one or more embodiments are not limited thereto, for example, two or more side portions may be provided. Each of the first to fourth side portions SP 1 , SP 2 , SP 3 , and SP 4  of the cover window CW may correspond to the first to fourth side display areas SDA 1 , SDA 2 , SDA 3 , and SDA 4  of the display device  1 . 
     In an embodiment, each of the side portions SP may extend and be bent from each of the edge of the front portion FP. For example, the first side portion SP 1  may extend from the first edge FP-E 1  of the front portion FP in a −y direction, and may be bent about an axis extending in a ±x direction. The second side portion SP 2  may extend from the second edge FP-E 2  in a +x direction, the second edge FP-E 2  of the front portion FP crossing or intersecting the first edge FP-E 1  of the front portion FP, and may be bent about an axis extending in a ±y direction. The third side portion SP 3  extends from the third edge FP-E 3  of the front portion FP in the +y direction, and may be bent about an axis extending in the ±x direction. The fourth side portion SP 4  extends from the fourth edge FP-E 4  of the front portion FP in the −x direction, and may be bent about an axis extending in the ±y direction. Each of the first to fourth side portions SP 1 , SP 2 , SP 3 , and SP 4  may be bent with the same curvature radius or different curvature radii from one another. 
     As shown in  FIG. 4 , the first edge FP-E 1  and the third edge FP-E 3  of the front portion FP face each other, and the second edge FP-E 2  and the fourth edge FP-E 4  may face each other. The first side portion SP 1  and the third side portion SP 3  are opposite to each other with the front portion FP therebetween, and the second side portion SP 2  and the fourth side portion SP 4  may be opposite to each other with the front portion FP therebetween. 
     In an embodiment, extending lengths of the first edge FP-E 1  and the third edge FP-E 3  of the front portion FP in the first direction (for example, ±x direction) may be different from extending lengths of the second edge FP-E 2  and the fourth edge FP-E 4  in the second direction (for example, ±y direction). For example, the extending lengths of the first edge FP-E 1  and the third edge FP-E 3  of the front portion FP in the first direction may be less than the extending lengths of the second edge FP-E 2  and the fourth edge FP-E 4  in the second direction. Accordingly, the extending lengths of the first side portion SP 1  and the third side portion SP 3  in the first direction may be less than the extending lengths of the second side portion SP 2  and the fourth side portion SP 4  in the second direction. However, one or more embodiments are not limited thereto, and the extending lengths of the first edge FP-E 1  and the third edge FP-E 3  of the front portion FP in the first direction may be equal to the extending lengths of the second edge FP-E 2  and the fourth edge FP-E 4  in the second direction. 
     The first edge FP-E 1  and the second edge FP-E 2  of the front portion FP cross or intersect each other to form a first corner FP-CN 1  of the front portion FP. Also, the second edge FP-E 2  and the third edge FP-E 3  of the front portion FP cross or intersect each other to form a second corner FP-CN 2  of the front portion FP, the third edge FP-E 3  and the fourth edge FP-E 4  of the front portion FP cross or intersect each other to form a third corner FP-CN 3  of the front portion FP, and the fourth edge FP-E 4  and the first edge FP-E 1  of the front portion FP cross or intersect each other to form a fourth corner FP-CN 4  of the front portion FP. 
     The corner portions CP may be at corner sides of the front portion FP and may connect two adjacent side portions SP. For example, the first corner portion CP 1  may be at the first corner FP-CN 1  side of the front portion FP, and may connect the first side portion SP 1  to the second side portion SP 2 . The second corner portion CP 2  may be at the second corner FP-CN 2  side of the front portion FP and may connect the second side portion SP 2  to the third side portion SP 3 . The third corner portion CP 3  may be at the third corner FP-CN 3  side of the front portion FP and may connect the third side portion SP 3  to the fourth side portion SP 4 . The fourth corner portion CP 4  may be at the fourth corner FP-CN 4  side of the front portion FP and may connect the fourth side portion SP 4  to the first side portion SP 1 . The first to fourth corner portions CP 1 , CP 2 , CP 3 , and CP 4  of the cover window CW may respectively correspond to the first to fourth corner display areas CDA 1 , CDA 2 , CDA 3 , and CDA 4  of the display device  1 . 
     Because the corner portion CP connects the side portions SP bent in different directions, the corner portion CP may have one curved surface or a curved surface in which curved surfaces bent in various directions are continuously connected. Also, the corner portions CP may each have one curved surface or a curved surface, in which curved surfaces bent with various curvature radii are continuously connected, in case that two adjacent side portions SP are bent with different curvature radii. 
     The cover window CW is at the outermost side of the display device  1  and may be a component that affects the outer appearance of the display device  1  and with which a user comes into contact or direct contact. The cover window CW may include the side portions SP and the corner portions CP that are bent, and thus, the aesthetic feeling of the outer appearance of the display device  1  may be improved and an excellent grip sense may be provided to the user who touches the display device  1 . 
     The cover window CW may further include a light-blocking portion BP. The light-blocking portion BP of the cover window CW may extend from edges of the side portions SP and the corner portions CP. The light-blocking portion BP may be opposite to the front portion FP with the side portions SP and the corner portions CP therebetween. In an example, the light-blocking portion BP may at least partially surround the side portions SP and the corner portions CP. The light-blocking portion BP may correspond to the peripheral area PA of the display device  1 . The light-blocking portion BP may include a light-blocking material and may block transmission of light. As such, various electronic devices in the peripheral area PA, for example, a non-display area, may be prevented from being visible to the user. 
       FIG. 5  is a schematic perspective view partially showing a region of the cover window CW according to an embodiment. 
       FIG. 5  shows the cover window CW based on the first side portion SP 1  and the second side portion SP 2  of the cover window CW, and for convenience of description, the first corner portion CP 1  (see  FIG. 4 ) may be omitted and cross-sections of the first side portion SP 1  and the second side portion SP 2  are shown. Like reference numerals denote the same components as those described above with reference to  FIG. 4 , and thus, detailed descriptions thereof are omitted. 
     Referring to  FIG. 5 , the first side portion SP 1  of the cover window CW extends from the first edge FP-E 1  of the front portion FP, and may be bent about a virtual first axis AX 1  that is parallel to the first edge FP-E 1 . For example, the first edge FP-E 1  of the front portion FP extends in the ±x direction, and the first axis AX 1  may also extend in the ±x direction. The first axis AX 1  is inside of the cover window CW, and the inside of the cover window CW denotes a side to which the display panel  10  is attached. 
     The second side portion SP 2  of the cover window CW extends from the second edge FP-E 2  of the front portion FP and may be bent about a virtual second axis AX 2  that is parallel to the second edge FP-E 2 . For example, the second edge FP-E 2  of the front portion FP extends in the ±y direction, and the second axis AX 2  may also extend in the ±y direction. For example, the first axis AX 1  and the second axis AX 2  may respectively extend in directions crossing or intersecting each other. The second axis AX 2  may be inside of the cover window CW. 
       FIG. 6  is an enlarged schematic cross-sectional view showing a region of the cover window CW according to an embodiment, and shows a schematic cross-sectional view of the first side portion SP 1  of the cover window CW. 
     Referring to  FIG. 6 , the first side portion SP 1  of the cover window CW may include an outer surface SP 1 -OS and an inner surface SP 1 -IS that are at opposite sides and have different curvature radii. For example, the first side portion SP 1  may include the inner surface SP 1 -IS located or disposed inside of the cover window CW and the outer surface SP 1 -OS that may be an opposite surface to the inner surface SP 1 -IS. As described above, ‘inside’ of the cover window CW may denote a side to which the display panel  10  is attached. The inner surface SP 1 -IS and the outer surface SP 1 -OS of the first side portion SP 1  may respectively include substantially curved surfaces. 
     Each of the inner surface SP 1 -IS and the outer surface SP 1 -OS of the first side portion SP 1  has a certain radius of curvature, for example, may have a curved line having a certain radius of curvature on a cross-section thereof. Here, ‘on the cross-section’ may denote ‘on a cross-section seen from a direction in which a virtual axis of the bending of each side portion SP extends’ or ‘on a virtual plane that is perpendicular to a virtual axis that is the axis of the bending of each side portion SP.’ For example,  FIG. 6  shows the cross-sectional shape of the first side portion SP 1 , and shows an aspect seen from an extending direction (for example, −x direction in  FIG. 6 ) of the first axis AX 1  (see  FIG. 5 ). 
     Also, the ‘curved line’ may include a part of a substantially elliptical shape or an atypical arc, as well as an arc. In case that the curved line is an arc, the radius of curvature may be determined as a radius of the arc. In case that the curved line may include a part of an ellipse or an atypical arc, the radius of curvature may be defined as a radius of an arc in case that at least a part of the curved line is approximately the arc. For convenience of description, a case in which the curved line may include the arc will be described below. 
     According to an embodiment, the inner surface SP 1 -IS and the outer surface SP 1 -OS of the first side portion SP 1  may have different curvature radii. A curvature radius R 1   IS  of the inner surface SP 1 -IS of the first side portion SP 1  may be different from a curvature radius R 1   OS  of the corresponding outer surface SP 1 -OS. In an embodiment, the curvature radius R 1   OS  of the outer surface SP 1 -OS of the first side portion SP 1  may be less than the curvature radius RI IS  of the inner surface SP 1 -IS. For example, the curvature radius R 1   OS  of the outer surface SP 1 -OS of the first side portion SP 1  may be about 3.9 mm or less and the curvature radius R 1   IS  of the inner surface SP 1 -IS may exceed about 3.9 mm. As an example, the curvature radius R 1   IS  of the outer surface SP 1 -OS of the first side portion SP 1  may be about 3.15 mm or less and the curvature radius R 1   IS  of the inner surface SP 1 -IS may exceed about 3.15 mm. 
     The outer surface SP 1 -OS of the first side portion SP 1  in the cover window CW may form an outermost surface of the display device  1 , and may be a surface that the user comes in contact or direct contact with. As the curvature radius R 1   OS  of the outer surface SP 1 -OS of the first side portion SP 1  decreases, a curvature of the first side portion SP 1  may increase. As the curvature of the first side portion SP 1  in the cover window CW increases, the user may be provided with excellent grip sense in case that contacting the first side portion SP 1  of the cover window CW. 
     According to an embodiment, a thickness t 1  of the first side portion SP 1  may change in a direction away from the first edge FP-E 1  of the front portion FP. Here, the ‘thickness’ of the first side portion SP 1  may be defined as a straight distance from an arbitrary point on the inner surface SP 1 -IS of the first side portion SP 1  to the outer surface SP 1 -OS corresponding to the inner surface SP 1 -IS in a normal direction to the point. However, a thickness t 0  of the front portion FP may be consistent. 
     In an embodiment, the thickness t 1  of the first side portion SP 1  may be gradually increased in a direction away from the first edge FP-E 1  of the front portion FP and may be reduced again. For example,  FIG. 6  shows thicknesses t 1   a,  t 1   b,  and t 1   c  at three arbitrary points of the first side portion SP 1 . The first thickness t 1   a  of the first side portion SP 1  may be less than the second thickness t 1   b  of the first side portion SP 1 , and the second thickness t 1   b  of the first side portion SP 1  may be greater than the third thickness t 1   c  of the first side portion SP 1 . 
     In an embodiment, the maximum thickness of the first side portion SP 1  may be greater than the thickness t 0  of the front portion FP. The second thickness t 1   b  of the first side portion SP 1  shown in  FIG. 6  may be the maximum thickness of the first side portion SP 1 , and, the second thickness t 1   b  of the first side portion SP 1  may be greater than the thickness t 0  of the front portion FP. 
     Due to the above characteristics of the thickness t 1  of the first side portion SP 1 , the curvature of the outer surface SP 1 -OS of the first side portion SP 1  may be greater than that of the corresponding inner surface SP 1 -IS. For example, the curvature radius R 1   OS  of the outer surface SP 1 -OS of the first side portion SP 1  may be less than the curvature radius R 1   IS  of the inner surface SP 1 -IS of the first side portion SP 1 . 
     In case that the display device  1  is dropped, the first side portion SP 1  of the cover window CW is highly likely to be damaged. According to an embodiment, in case that the first side portion SP 1  has a relatively greater thickness, the durability and impact resistance may be improved and the strength may be reinforced. 
     The characteristics of the first side portion SP 1  described above with reference to  FIG. 6  may be also applied to the other side portions, for example, the second to fourth side portions SP 2 , SP 3 , and SP 4 . For example, the second side portion SP 2  (see  FIG. 5 ) may include an inner surface located or disposed inside of the cover window CW and an outer surface opposite to the inner surface, and a curvature radius of the outer surface of the second side portion SP 2  may be different from a curvature radius of the corresponding inner surface. In an embodiment, the curvature radius of the outer surface of the second side portion SP 2  may be less than that of the corresponding inner surface. Also, a thickness of the second side portion SP 2  may vary in a direction away from the second edge FP-E 2  (see  FIG. 5 ) of the front portion FP. In an embodiment, the thickness of the second side portion SP 2  may be gradually increased in a direction away from the second edge FP-E 2 , and, may be reduced again. The maximum thickness of the second side portion SP 2  may be greater than the thickness t 0  of the front portion FP. Descriptions about the third side portion SP 3  and the fourth side portion SP 4  are omitted for simplicity of description. 
       FIG. 7  is a schematic cross-sectional view of components in the display device  1  according to an embodiment.  FIG. 7  may be a schematic cross-sectional view of the display device  1  taken along line VII-VII′ in  FIG. 1 . 
     Referring to  FIG. 7 , the display panel  10  of the display device  1  is inside of the cover window CW, and may be at least partially surrounded by the cover window CW to be protected against external shock. 
     The cover window CW may include an inner surface IS facing the display panel  10  and an outer surface OS opposite to the inner surface IS, and the display panel  10  may be attached to the inner surface IS of the cover window CW. Although not shown in  FIG. 7 , according to an embodiment, a pressure sensitive adhesive (PSA) or an optically clear adhesive (OCA) may be used to bond the display panel  10 . The inner surface IS may also include an inner surface front portion FP-IS, and the outer surface OS may include an outer surface front portion FP-OS. 
     The display area DA of the display panel  10  may correspond to a part of the cover window CW. For example, the front display area FDA of the display panel  10  corresponds to the front portion FP of the cover window CW, the first side display area SDA 1  of the display panel  10  corresponds to the first side portion SP 1  of the cover window CW, and the second side display area SDA 2  of the display panel  10  corresponds to the second side portion SP 2  of the cover window CW. Although not shown in  FIG. 7 , the third and fourth side display areas SDA 3  and SDA 4  (see  FIG. 1 ) of the display panel  10  may respectively correspond to the third and fourth side portions SP 3  and SP 4  (see  FIG. 4 ) of the cover window CW, and the first to fourth corner display areas CDA 1 , CDA 2 , CDA 3 , and CDA 4  of the display panel  10  may correspond to the first to fourth corner portions CP 1 , CP 2 , CP 3 , and CP 4  of the cover window CW. 
     According to an embodiment, the display panel  10  may include portions bent along the inner surfaces of the side portions SP of the cover window CW. For example, the display panel  10  may include a first portion  10   a  that is bent along the inner surface SP 1 -IS of the first side portion SP 1  of the cover window CW, and a second portion  10   b  that is bent along the inner surface SP 2 -IS of the second side portion SP 2  of the cover window CW. A surface of the first portion  10   a  in the display panel  10  may have a curvature radius that is the same as the curvature radius R 1   IS  of the inner surface SP 1 -IS of the first side portion SP 1  in the cover window CW, and the surface of the first portion  10   a  in the display panel  10  may be attached to the inner surface SP 1 -IS of the first side portion SP 1  of the cover window CW. Similarly, a surface of the second portion  10   b  in the display panel  10  may have the same curvature radius as a curvature radius R 2   IS  of the inner surface SP 2 -IS of the second side portion SP 2  in the cover window CW, and the surface of the second portion  10   b  of the display panel  10  may be attached to the inner surface SP 2 -IS of the second side portion SP 2  of the cover window CW. 
     In order for the display panel  10  to be attached to the inner surface IS of the cover window CW, a part of the display panel  10  may be bent. As the curvature radius of the bent part is reduced (for example, the curvature is increased), large stress may be applied to the bent part of the display panel  10 . In case that the large stress is applied to the display panel  10 , components such as a light-emitting device, an electronic device, etc. in the display panel  10  may be damaged, thereby causing the display device  1  to be defective. 
     According to an embodiment, the curvature radius R 1   IS  of the inner surface SP 1 -IS of the first side portion SP 1  in the cover window CW is greater than the curvature radius R 1   OS  of the corresponding outer surface SP 1 -OS, and the first portion  10   a  of the display panel  10  may be bent at the same curvature radius as the curvature radius R 1   IS  of the inner surface SP 1 -IS of the first side portion SP 1  in the cover window CW. As such, the stress applied to the first portion  10   a  of the display panel  10  may be reduced, and accordingly, damage and defects of the display device  1  may be reduced. The outer surface OS may also include an outer surface of the second side portion SP 2 -OS.  FIG. 7  also illustrates curvature radius R 2   OS  of the outer surface SP 2 -OS of the second side portion SP 2 . 
     The above effect may be further evident in the corner display areas CDA of the display panel  10 , in which the curved surfaces bent in various directions are continuously connected as one curved surface or a curved surface. The corner display areas CDA of the display panel  10  may be weakest points with respect to the stress due to the bending. Thus, in case that the inner surfaces of the corner portions CP in the cover window CW have relatively large curvature radii, the curvatures at the corner display areas CDA of the display panel  10  may be reduced and the damage and defects may be reduced. 
       FIG. 8  is a perspective view of an apparatus  1000  for manufacturing a display device of  FIG. 1 . 
     Referring to  FIG. 8 , the apparatus  1000  for manufacturing a display device may include a base  1100 , a heater  1200 , a first mold  1300 , a second mold  1400 , and a moving portion  1500 . 
     The base  1100  may have a flat upper surface on which the first mold  1300  may be arranged or disposed. The first mold  1300  is on the base  1100  and may have a support surface on which the cover window CW (see  FIG. 4 ) may be mounted or disposed. The support surface may have a flat surface defined by a first direction (for example, ±x direction) and a second direction (for example, ±y direction) that crosses or intersects the first direction. Also, the support surface of the first mold  1300  may have a shape substantially corresponding to that of an inner surface of the cover window CW after the cover window CW is completely molded. 
     The second mold  1400  may be on the first mold  1300 , facing the first mold  1300 . The second mold  1400  may have a pressing surface that presses the upper surface of the cover window CW mounted on the first mold  1300 . The pressing surface of the second mold  1400  may press the cover window CW to partially bend the cover window CW. The pressing surface of the second mold  1400  may have a shape substantially corresponding to that of an outer surface of the cover window CW after being molded. 
     The moving portion  1500  may move the second mold  1400  in a third direction (for example, ±z direction) that crosses or intersects the first and second directions. For example, the moving portion  1500  may move the second mold  1400  downward to and/or upward from the first mold  1300 . In an embodiment, the moving portion  1500  may be connected to the second mold  1400  and may include a linear driver (not shown). In an example, the linear driver of the moving portion  1500  may include a pneumatic cylinder, a hydraulic cylinder, or a linear motor. In another example, the linear driver of the moving portion  1500  may include a rack gear, a pinion gear, and a motor connected to the rack gear and the pinion gear. In another example, the linear driver of the moving portion  1500  may include a ball screw and a motor connected to the ball screw. One or more embodiments are not limited thereto, and the moving portion  1500  may include all kinds of devices and structures that may linearly move. 
     In an embodiment, the heater  1200  applies heat to the cover window CW to make the cover window CW be easily molded. The heater  1200  may include a first heater  1210  that is in contact with the first mold  1300  and a second heater  1220  spaced apart from the first mold  1300 . 
     The first heater  1210  may be disposed on the base  1100  and under or below the first mold  1300 . The first heater  1210  supplies or directly supplies conductive heat to the first mold  1300  and applies the heat to the cover window CW via the first mold  1300 . The first heater  1210  may be provided as a bar type or a plate type, for example, a ceramic heater. 
     The second heater  1220  may be formed, for example, as a coil that supplies radiant heat and convection heat to the cover window CW. In another example, the second heater  1220  may include a laser irradiation unit that irradiates laser to apply heat to the cover window CW. 
       FIG. 9  is a perspective view of the first mold  1300  of an apparatus for manufacturing a display device, according to an embodiment. 
     Referring to  FIG. 9 , the first mold  1300  may include a support surface  1310  on which the cover window CW (see  FIG. 4 ) is mounted. The support surface  1310  of the first mold  1300  may include a flat support surface  1320 , curved support surfaces  1330 , and corner support surfaces  1340 . 
     The flat support surface  1320  may have a flat surface defined by the first direction (for example, ±x direction) and the second direction (for example, ±y direction) that crosses or intersects the first direction. The flat support surface  1320  may correspond to an inner surface of the front portion FP (see  FIG. 4 ) of the cover window CW after the cover window CW is completely molded. 
     The curved support surfaces  1330  extend from respective edges of the flat support surface  1320  and may each have a certain radius of curvature. For example, the curved support surfaces  1330  may include a first curved support surface  1331  extending from a first edge  1320 -E 1  of the flat support surface  1320  and having a first curvature radius, a second curved support surface  1332  extending from a second edge  1320 -E 2  of the flat support surface  1320  and having a second curvature radius, a third curved support surface  1333  extending from a third edge  1320 -E 3  of the flat support surface  1320  and having a third curvature radius, and a fourth curved support surface  1334  extending from a fourth edge  1320 -E 4  of the flat support surface  1320  and having a fourth curvature radius. The first to fourth curved support surfaces  1331 ,  1332 ,  1333 , and  1334  may correspond to inner surfaces of the first to fourth side portions SP 1 , SP 2 , SP 3 , and SP 4  (see  FIG. 4 ) of the cover window CW, after the cover window CW is completely molded. 
     The corner support surfaces  1340  may be at corners of the flat support surface  1320 , and may connect two curved support surfaces adjacent to each other. In an example, the corner support surfaces  1340  may include first to fourth corner support surfaces  1341 ,  1342 ,  1343 , and  1344 . For example, the first corner support surface  1341  may be at a corner where the first edge  1320 -E 1  and the second edge  1320 -E 2  of the flat support surface  1320  cross or intersect each other, and may connect the first curved support surface  1331  and the second curved support surface  1332  to each other. Similarly, the second corner support surface  1342  may be at a corner where the second edge  1320 -E 2  and the third edge  1320 -E 3  of the flat support surface  1320  cross or intersect each other, and may connect the second curved support surface  1332  and the third curved support surface  1333  to each other. The third corner support surface  1343  may be at a corner where the third edge  1320 -E 3  and the fourth edge  1320 -E 4  of the flat support surface  1320  cross or intersect each other, and may connect the third curved support surface  1333  and the fourth curved support surface  1334  to each other. The fourth corner support surface  1344  may be at a corner where the fourth edge  1320 -E 4  and the first edge  1320 -E 1  of the flat support surface  1320  cross or intersect each other, and may connect the fourth curved support surface  1334  and the first curved support surface  1331  to each other. The first to fourth corner support surfaces  1341 ,  1342 ,  1343 , and  1344  may respectively correspond to the first to fourth corner portions CP 1 , CP 2 , CP 3 , and CP 4  (see  FIG. 4 ) of the cover window CW after the cover window CW is completely molded. 
     As such, the support surface  1310  of the first mold  1300  may have a shape substantially corresponding to that of an inner surface of the cover window CW after the cover window CW is completely molded. 
     Although  FIG. 9  shows that the first mold  1300  has a substantially rectangular shape with round corners in a plan view, one or more embodiments are not limited thereto. As described above, the substantially planar shape of the first mold  1300  may be changed according to the substantially planar shape of the display device  1  and the cover window CW. 
       FIG. 10  is a perspective view of the second mold  1400  of an apparatus for manufacturing the display device, according to an embodiment. 
     Referring to  FIG. 10 , the second mold  1400  may include a pressing surface  1410  facing the first mold  1300  (see  FIG. 9 ) and pressing the upper surface of the cover window CW (see  FIG. 4 ) that is mounted on the first mold  1300 . For example, the pressing surface  1410  of the second mold  1400  may be at a lower surface of the second mold  1400 . Therefore, in  FIG. 10 , the pressing surface  1410  of the second mold  1400  is depicted by dashed lines. The pressing surface  1410  of the second mold  1400  may include a flat pressing surface  1420 , curved pressing surfaces  1430 , and corner pressing surfaces  1440 . 
     The flat pressing surface  1420  corresponds to the flat support surface  1320  (see  FIG. 9 ) of the first mold  1300 , and may have a flat surface that is in parallel with the flat support surface  1320 . The flat pressing surface  1420  may correspond to an outer surface of the front portion FP (see  FIG. 4 ) of the cover window CW after the cover window CW is completely molded. 
     The curved pressing surfaces  1430  extend from respective edges of the flat pressing surface  1420  and may each have a certain radius of curvature. For example, the curved pressing surfaces  1430  may include a first curved pressing surface  1431  extending from a first edge  1420 -E 1  of the flat pressing surface  1420  and having a fifth curvature radius, a second curved pressing surface  1432  extending from a second edge  1420 -E 2  of the flat pressing surface  1420  and having a sixth curvature radius, a third curved pressing surface  1433  extending from a third edge  1420 -E 3  of the flat pressing surface  1420  and having a seventh curvature radius, and a fourth curved pressing surface  1434  extending from a fourth edge  1420 -E 4  of the flat pressing surface  1420  and having a eighth curvature radius. 
     The first to fourth curved pressing surfaces  1431 ,  1432 ,  1433 , and 1434  of the second mold  1400  may respectively correspond to the first to fourth curved support surfaces  1331 ,  1332 ,  1333 , and  1334  of the first mold  1300 . According to an embodiment, the fifth curvature radius of the first curved pressing surface  1431  may be different from the first curvature radius of the first curved support surface  1331 . The sixth curvature radius of the second curved pressing surface  1432  may be different from the second curvature radius of the second curved support surface  1332 . The seventh curvature radius of the third curved pressing surface  1433  may be different from the third curvature radius of the third curved support surface  1333 . The eighth curvature radius of the fourth curved pressing surface  1434  may be different from the fourth curvature radius of the fourth curved support surface  1334 . 
     The first to fourth curved pressing surfaces  1431 ,  1432 ,  1433 , and  1434  of the second mold  1400  may correspond to outer surfaces of the first to fourth side portions SP 1 , SP 2 , SP 3 , and SP 4  (see  FIG. 4 ) of the cover window CW, after the cover window CW is completely molded. 
     The corner pressing surfaces  1440  may be at corner sides of the flat pressing surface  1420  and may connect two adjacent curved pressing surfaces. In an example, the corner pressing surfaces  1440  may include first to fourth corner pressing surfaces  1441 ,  1442 ,  1443 , and  1444 . For example, the first corner pressing surface  1441  may be at a corner where the first edge  1420 -E 1  and the second edge  1420 -E 2  of the flat pressing surface  1420  cross or intersect each other, and may connect the first curved pressing surface  1431  and the second curved pressing surface  1432  to each other. Similarly, the second corner pressing surface  1442  may be at a corner where the second edge  1420 -E 2  and the third edge  1420 -E 3  of the flat pressing surface  1420  cross or intersect each other, and may connect the second curved pressing surface  1432  and the third curved pressing surface  1433  to each other. The third corner pressing surface  1443  may be at a corner where the third edge  1420 -E 3  and the fourth edge  1420 -E 4  of the flat pressing surface  1420  cross or intersect each other, and may connect the third curved pressing surface  1433  and the fourth curved pressing surface  1434  to each other. The fourth corner pressing surface  1444  may be at a corner where the fourth edge  1420 -E 4  and the first edge  1420 -E 1  of the flat pressing surface  1420  cross or intersect each other, and may connect the fourth curved pressing surface  1434  and the first curved pressing surface  1431  to each other. The first to fourth corner pressing surfaces  1441  to  1444  of the second mold  1400  may respectively correspond to the first to fourth corner support surfaces  1341  to  1344  of the first mold  1300 . 
     The first to fourth corner pressing surfaces  1441 ,  1442 ,  1443 , and  1444  may respectively correspond to outer surfaces of the first to fourth corner portions CP 1 , CP 2 , CP 3 , and CP 4  (see  FIG. 4 ) of the cover window CW after the cover window CW is completely molded. As such, the pressing surface  1410  of the second mold  1400  may have a shape substantially corresponding to that of an outer surface of the cover window CW after the cover window CW is completely molded. 
       FIGS. 11A to 11C  are schematic cross-sectional views illustrating processes in a method of manufacturing a display device by using the apparatus for manufacturing a display device according to an embodiment.  FIGS. 11A to 11C  are schematic cross-sectional views of the first mold  1300  and the second mold  1400  taken along line XI-XI′ in  FIGS. 9 and 10 . 
     Referring to  FIG. 11A , a cover window member CWm may be prepared on the flat support surface  1320  of the first mold  1300 . Here, the cover window member CWm may denote the cover window CW before being molded, and may include the same material or similar material as that of the cover window CW. 
     In an embodiment, a thickness tm of the cover window member CWm may be equal to or greater than the largest thickness of the side portions SP in the cover window CW after being molded. Therefore, the thickness tm of the cover window member CWm may be greater than that of the front portion FP of the cover window CW after being molded. For example, the thickness tm of the cover window member CWm may be equal to or greater than a maximum thickness t 1   b  of the first side portion SP 1  (see  FIG. 5 ) of the cover window CW (see  FIG. 6 ), and may be greater than that of the front portion FP of the cover window CW. In case that the thickness tm of the cover window member CWm before being molded is less than the maximum thickness t 1   b  of the first side portion SP 1  of the cover window CW after being molded, the first side portion SP 1  may not be formed constantly in a desired shape. 
     According to an embodiment, the curvature radius in each of the curved support surfaces  1320  (see  FIG. 9 ) of the first mold  1300  may be greater than that in each of the curved pressing surfaces  1420  (see  FIG. 10 ) of the second mold  1400 . For example, as shown in  FIG. 11A , a first curvature radius Ra of the first curved support surface  1331  of the first mold  1300  may be greater than a fifth curvature radius Re of the first curved pressing surface  1431  of the second mold  1400 , and a second curvature radius Rb of the second curved support surface  1332  of the first mold  1300  may be greater than a sixth curvature radius Rf of the second curved pressing surface  1432  of the second mold  1400 . Although not shown in  FIG. 11A , the third curvature radius of the third curved support surface  1333  of the first mold  1300  may be greater than the seventh curvature radius of the third curved pressing surface  1433  of the second mold  1400 , and the fourth curvature radius of the fourth curved support surface  1334  of the first mold  1300  may be greater than the eighth curvature radius of the fourth curved pressing surface  1434  of the second mold  1400 . As such, the curvature radii of the inner surfaces of the side portions SP in the cover window CW may be greater than those of corresponding outer surfaces, wherein the cover window CW is molded by using the first mold  1300  and the second mold  1400 . Also, the curvature radius of each of the curved support surfaces  1330  in the first mold  1300  is relatively large, and thus, the cover window CW may be easily extracted from the first mold  1300 . 
     Referring to  FIG. 11B , the second mold  1400  may be moved toward the first mold  1300  by the moving portion  1500  (see  FIG. 8 ) so as to press the cover window member CWm (see  FIG. 11A ) on the first mold  1300 . As the second mold  1400  presses the cover window member CWm, the cover window member CWm may be molded according to the shapes of the support surfaces  1310  of the first mold  1300  and the pressing surfaces  1410  of the second mold  1400 . The shape of the outer surface OS of the cover window CW substantially corresponds to the shape of the pressing surface  1410  of the second mold  1400 , and the shape of the inner surface IS of the cover window CW may substantially correspond to the shape of the support surface  1310  of the first mold  1300 . 
     The second mold  1400  is moved toward the first mold  1300 , but one or more embodiments are not limited thereto. The cover window CW may be molded according to relative movements of the first mold  1300  and the second mold  1400 , and thus, the first mold  1300  may be moved toward the second mold  1400 . 
     According to an embodiment, in case that the pressing surface  1410  of the second mold  1400  presses the cover window CW, gaps between the curved support surfaces  1320  (see  FIG. 9 ) of the first mold  1300  and corresponding curved pressing surfaces  1420  (see  FIG. 10 ) of the second mold  1400  may be greater than a gap between the flat support surface  1320  of the first mold  1300  and the flat pressing surface  1420  of the second mold  1400 . 
     For example, as shown in  FIG. 11B , a first distance dt 1  between the first curved pressing surface  1431  of the second mold  1400  and the first curved support surface  1331  of the first mold  1300  may be greater than a second distance dt 2  between the flat pressing surface  1420  of the second mold  1400  and the flat support surface  1320  of the first mold  1300 . A third distance dt 3  between the second curved pressing surface  1432  of the second mold  1400  and the second curved support surface  1332  of the first mold  1300  may be greater than the second distance dt 2 . Although not shown in  FIG. 11B , a distance between the third curved pressing surface  1433  of the second mold  1400  and the third curved support surface  1333  of the first mold  1300  and a distance between the fourth curved pressing surface  1434  of the second mold  1400  and the fourth curved support surface  1334  of the first mold  1300  may be greater than the second distance dt 2 . As such, the cover window CW may be formed such that the maximum thicknesses of the side portions SP in the cover window CW molded by using the first mold  1300  and the second mold  1400  may be greater than the thickness of the front portion FP of the cover window CW. 
     According to an embodiment, the distance between the curved support surfaces  1330  of the first mold  1300  and the curved pressing surfaces  1430  of the second mold  1400  may vary in a direction away from the respective edges of the flat support surface  1320  of the first mold  1300 . Here, ‘distance’ may be defined as a distance from an arbitrary point on the curved support surfaces  1330  to corresponding curved pressing surfaces  1430  in a normal direction with respect to the point. On the contrary, the second distance dt 2  between the flat support surface  1320  of the first mold  1300  and the flat pressing surface  1420  of the second mold  1400  may be consistent between any points on the surfaces. 
     For example, as shown in  FIG. 11B , the first distance dt 1  between the first curved pressing surface  1431  of the second mold  1400  and the first curved support surface  1331  of the first mold  1300  may be gradually increased in a direction away from the first edge  1320 -E 1  of the flat support surface  1320  of the first mold  1300 , and, is reduced again. The third distance dt 3  between the second curved pressing surface  1432  of the second mold  1400  and the second curved support surface  1332  of the first mold  1300  may be gradually increased in a direction away from the second edge  1320 -E 2  of the flat support surface  1320  and may be reduced again. Although not shown in  FIG. 11B , a distance between the third curved pressing surface  1433  (see  FIG. 10 ) of the second mold  1400  and the third curved support surface  1333  (see  FIG. 9 ) of the first mold  1300  may be also gradually increased and may be reduced again in a direction away from the third edge  1320 -E 3  (see  FIG. 9 ) of the flat support surface  1320 , and a distance between the fourth curved pressing surface  1434  (see  FIG. 10 ) of the second mold  1400  and the fourth curved support surface  1334  (see  FIG. 9 ) of the first mold  1300  may be gradually increased and reduced again in a direction away from the fourth edge  1320 -E 4  (see  FIG. 9 ) of the flat support surface  1320 . As such, the cover window CW molded by using the first mold  1300  and the second mold  1400  may be formed such that the thickness of each of the side portions SP in the cover window CW may vary in a direction away from each edge of the front portion FP. 
     According to an embodiment, in case that the cover window CW is molded, heat may be applied to the cover window CW in order to increase temperatures of the cover window CW and periphery of the cover window CW. As such, the deformation in the shape of the cover window CW may be easily performed. 
     According to an embodiment, a pressure applied to the cover window CW during the molding may be determined such that the thickness tm of the cover window member CWm is reduced to the thickness t 0  of the front portion FP of the cover window CW as the second mold  1400  presses the cover window CW. Here, the thickness t 0  of the front portion FP may be substantially equal to the second distance dt 2  between the flat support surface  1320  of the first mold  1300  and the flat pressing surface  1420  of the second mold  1400  in a state in which the first mold  1300  and the second mold  1400  press the cover window CW. As compared with a case, in which the thickness tm of the cover window member CWm is substantially equal to the thickness t 0  of the front portion FP of the cover window CW, the pressure applied to the cover window CW during molding may be relatively large because the thickness tm of the cover window member CWm is greater than the thickness t 0  of the cover window CW according to the embodiment. 
     The pressure applied to the cover window CW and the temperature during the molding increase, surface quality of the cover window CW may degrade. To complement this, according to an embodiment, in a polishing process performed after molding the cover window CW, a polishing time and a polishing pressure may be appropriately increased. 
     Referring to  FIG. 11C , the second mold  1400  may be moved away from the first mold  1300  by the moving portion  1500  (see  FIG. 8 ). 
     According to one or more embodiments as described above, in case that the display panel  10  is attached to the inner surface of the cover window CW, the stress applied to the display panel  10  may be reduced. Damage to the display panel  10  may be reduced and the yield may be improved. 
     The cover window, the display device including the cover window, and the apparatus for manufacturing a display device are described, but one or more embodiments are not limited thereto. For example, a method of manufacturing the cover window and a method of manufacturing the display device including the cover window may be also included in the scope of the disclosure. 
     According to the embodiment as described above, the cover window providing the user with excellent grip sense in case that the user contacts the display device, the display device including the cover window, and the apparatus for manufacturing a display device may be implemented. 
     Also, in case that a display area of a display panel may include a curved surface that is curved in various directions and with various radii of curvature, a cover window with which stress applied to the display panel is reduced in case that the display panel is attached to the cover window and damage to the display panel is reduced, a display device including the cover window, and an apparatus for manufacturing the display device may be implemented. However, the scope of one or more embodiments is not limited to the above effects. 
     It should be understood that embodiments described herein should be considered in a descriptive sense only and not for purposes of limitation. Descriptions of features or aspects within each embodiment should typically be considered as available for other similar features or aspects in other embodiments. While one or more embodiments have been described with reference to the figures, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope as defined by the following claims.