Abstract:
A display apparatus comprises a first substrate comprising a first external surface and a first internal surface; a second substrate having a second external surface and a second internal surface facing the first internal surface of the first substrate; and a display unit disposed between the first and second substrates and comprising an array of pixels. The first substrate comprises a first side connecting the first external surface and the first internal surface. In a cross section perpendicular to the first external surface, the first side comprises a first straight region and a first curved region located between the straight region and the first internal surface. The second substrate comprises a second side connecting the first external surface and the first internal surface. The second side comprises a second straight region and a second curved region located between the straight region and the second internal surface.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims the benefit of Korean Patent Application No. 10-2015-0053138, filed on Apr. 15, 2015, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference. 
       BACKGROUND 
       [0002]    1. Field 
         [0003]    One or more embodiments relate to a display apparatus and a method of manufacturing the same, and more particularly, to a display apparatus that is easily manufactured and has increased impact resistance, and a method of manufacturing the display apparatus. 
         [0004]    2. Discussion of the Related Technology 
         [0005]    Studies are actively being conducted on a display apparatus, such as an organic light-emitting display apparatus or a liquid crystal display apparatus, since the display apparatus is thin and flexible. The display apparatus may have a structure in which a first substrate, on which a display unit is formed, is combined to a second substrate by using an encapsulation member, with the display unit interposed between the first and second substrates. 
         [0006]    However, an external impact may easily damage the first substrate and/or the second substrate of the display apparatus having such a structure. 
       SUMMARY 
       [0007]    One or more embodiments include a display apparatus that is easily manufactured and has increased impact resistance, and a method of manufacturing the display apparatus. 
         [0008]    One aspect of the invention provides a display apparatus, which may comprise: a first substrate comprising a first external surface and a first internal surface; a second substrate having a second external surface and a second internal surface facing the first internal surface of the first substrate; and a display unit disposed between the first and second substrates and comprising an array of pixels, wherein the first substrate comprises a first side connecting the first external surface and the first internal surface, wherein, in a cross section perpendicular to the first external surface, the first side comprises a first straight region and a first curved region located between the first straight region and the first internal surface, wherein the second substrate comprises a second side connecting the first external surface and the first internal surface, wherein, in the cross section, the second side comprises a second straight region and a second curved region located between the second straight region and the second internal surface. 
         [0009]    In the foregoing apparatus, the apparatus may further comprise an adhesive member disposed between the first internal surface and the second internal surface and combining the first and second substrates together. The adhesive member may comprise an outer side surface and an inner side surface which are curved, wherein a radius of curvature of the inner side surface is less than a radius of curvature of the outer surface. The adhesive member may comprise an outer side surface which is curved, wherein the first curved region of the first substrate, the outer side surface of the adhesive member, and the second curved region of the second substrate may form a convex surface. In the cross section, the convex surface may have a continuously curved feature. 
         [0010]    Still in the foregoing apparatus, the first straight region of the first substrate may be substantially perpendicular to the first external surface of the first substrate. The second straight region of the second substrate may be substantially perpendicular to the second external surface of the second substrate. The apparatus may further comprise a film covering the first external surface while not covering the first side of the first substrate. 
         [0011]    Another aspect of the invention provides a method of manufacturing a display apparatus, which may comprise: providing an intermediate product comprising: a first substrate comprising a first external surface and a first internal surface; a second substrate comprising a second external surface and a second internal surface; a display unit comprising an array of pixels disposed between the first substrate and the second substrate; and an adhesive member located between the first internal surface of the first substrate and the second internal surface of the second substrate to surround the display unit and combining the first and second substrates together; and cutting the intermediate product to make a final product, wherein, in the final product, the first substrate comprises a first side connecting the first external surface and the first internal surface, wherein, in a cross section perpendicular to the first external surface, the first side comprises a first straight region and a first curved region located between the first straight region and the first internal surface, and further such that the second substrate comprises a second side connecting the first external surface and the first internal surface, wherein, in the cross section, the second side comprises a second straight region and a second curved region located between the second straight region and the second internal surface. 
         [0012]    In the foregoing method, the method may further comprise irradiating light beams to a part of the adhesive member such that after curing the adhesive member, the adhesive member comprises a cured portion and an uncured portion, the cured portion being disposed between the display unit and the uncured portion. Cutting may comprise moving a first cutter to contact the first substrate at a first cutting point on the first external surface, the first cutting point being located between an outermost end of the cured portion and the display unit when viewed in a viewing direction perpendicular to the first external surface. When a center of the cured portion is defined between the outermost end and an innermost end of the cured portion, the first cutting point may be located between the outermost end and the center of the cured portion. Cutting may further comprise advancing the first cutter in a thickness direction of the first substrate toward the first internal surface only by a first distance which is smaller than a thickness of the first substrate, wherein a remaining portion of the first substrate is cut without further advancing the first cutter in the thickness direction of the first substrate toward the first internal surface. 
         [0013]    Still in the foregoing method, cutting may further comprise moving a second cutter to contact the second substrate at a second cutting point on the second external surface, the second cutting point being located between the outermost end of the cured portion and the display unit when viewed in a viewing direction perpendicular to the first external surface. Cutting may further comprise advancing the first cutter in a thickness direction of the first substrate toward the first internal surface only a first distance which is smaller than a thickness of the first substrate, and advancing the second cutter in a thickness direction of the second substrate toward the second internal surface only a second distance which is smaller than a thickness of the second substrate, wherein remaining portions of the first and second substrates are cut without further advancing the first and second cutters toward the first and second interior surfaces, respectively. The remaining portions of the first and second substrates may be spontaneously cut or the remaining portions of the first and second substrates are cut by applying a force to the first or second substrate. Cutting may further comprise transferring the first cutter along a first predetermined line along the first external surface and transferring the second cutter along a second predetermined line along the second external surface after advancing the first and second cutters, wherein the first and second predetermined lines overlap the cured portion of the adhesive member. 
         [0014]    Yet in the foregoing method, the method may further comprise forming a conductive pattern for a touch screen and a blocking pattern over the second external surface of the second substrate, wherein the blocking pattern blocks the light beams not to reach the other part of the adhesive member while irradiating the light beams to form the uncured portion of the adhesive member. The uncured portion of the adhesive member and the blocking pattern may be removed while cutting the intermediate product such that the final product does not comprise the blocking pattern and the uncured portion of the adhesive member. The method may further comprise adhering a film covering at least one of the first external surface of the first substrate and the second external surface of the second substrate while not covering side surfaces of the first substrate and the second substrate. 
         [0015]    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. 
         [0016]    According to one or more embodiments, a display apparatus includes: a first substrate having a first external surface and a first internal surface; a second substrate having a second external surface and a second internal surface facing the first internal surface of the first substrate; and a display unit disposed between the first and second substrates and including a display device, wherein the first substrate has a first constant region having a uniform width and a first increasing region having an increasing width, in a direction from the first external surface to the first internal surface, and the second substrate has a second constant region having a uniform width and a second increasing region having an increasing width, in a direction from the second external surface to the second internal surface. 
         [0017]    The display apparatus may further include a combining member disposed between an edge of the first internal surface and an edge of the second internal surface to combine the first and second substrates together. 
         [0018]    A radius of curvature of an inner surface of the combining member in a direction of the display unit may be less than a radius of curvature of an outer surface of the combining member in a direction opposite to the display unit. 
         [0019]    A side surface of the first increasing region of the first substrate, an outer surface of the combining member in a direction opposite to the display unit, and a side surface of the second increasing region of the second substrate may form a convex surface. The convex surface may be a continuous surface. 
         [0020]    A side surface of the first constant region of the first substrate may be perpendicular to the first external surface of the first substrate. 
         [0021]    A side surface of the second constant region of the second substrate may be perpendicular to the second external surface of the second substrate. 
         [0022]    The display apparatus may further include a film covering at least one of the first external surface of the first substrate and the second external surface of the second substrate while not covering side surfaces of the first substrate and the second substrate. 
         [0023]    According to one or more embodiments, a method of manufacturing a display apparatus, the method includes: preparing a first substrate having a first external surface and a second internal surface; preparing a second substrate having a second external surface and a second internal surface; forming a display unit having a display device, on the first internal surface of the first substrate; locating a combining member between the first internal surface of the first substrate and the second internal surface of the second substrate to surround the display unit and combining the first and second substrates together; and cutting the first and second substrates such that a region of the first substrate, which corresponds to the display unit, has a first constant region having a uniform width and a first increasing region having an increasing width in a direction from the first external surface to the first internal surface, and a region of the second substrate, which corresponds to the display unit, has a second constant region having a uniform width and a second increasing region having an increasing width in a direction from the second external surface to the second internal surface. 
         [0024]    The method may further include exposing a part of the combining member in a direction of the display unit or exposing a part of the combining member excluding an edge of the combining member. 
         [0025]    The cutting may include start cutting at a cutting point in regions of the first external surface of the first substrate and the second external surface of the second substrate which correspond to the combining member, the cutting point being closer to the display unit than a location between an exposed region of the combining member and an unexposed region of the combining member which is far from the display unit. 
         [0026]    When a center of the exposed region of the combining member is a first point, the boundary between the exposed region of the combining member and the unexposed region of the combining member which is far from the display unit, is a second point, and a center between the first and second points is a third point, the cutting point may correspond to the third point, or correspond to a position between the second and third points. 
         [0027]    The cutting may include cutting the first and second substrates only up to the first constant region of the first substrate and the second constant region of the second substrate by using a cutting wheel. 
         [0028]    The cutting may include simultaneously cutting the first and second substrates inward by making the cutting wheel contact the first external surface of the first substrate and the second external surface of the second substrate. 
         [0029]    The cutting may include letting the first increasing region of the first substrate and the second increasing region of the second substrate be self-cut by internal stress. 
         [0030]    The method may further include forming a conductive pattern and a blocking pattern for a touch screen, on the second external surface of the second substrate, wherein the exposing may include exposing only a region of the combining member in a direction of the display unit by using the blocking pattern, or exposing a region of the combining member excluding an edge of the combining member. 
         [0031]    The cutting may include cutting the first and second substrates such that the blocking pattern is removed. 
         [0032]    The method may further include adhering a film covering at least one of the first external surface of the first substrate and the second external surface of the second substrate while not covering side surfaces of the first substrate and the second substrate. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0033]    These and/or other aspects will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings in which: 
           [0034]      FIGS. 1 through 7  are cross-sectional views for describing processes of a method of manufacturing a display apparatus, according to an embodiment; 
           [0035]      FIG. 8  is an enlarged cross-sectional view of a region B of  FIG. 7 ; 
           [0036]      FIG. 9  is a cross-sectional view for describing a process of a method of manufacturing a display apparatus, according to another embodiment; 
           [0037]      FIG. 10  is a cross-sectional view for describing a process of a method of manufacturing a display apparatus, according to another embodiment; 
           [0038]      FIGS. 11 and 12  are respectively a plan view and a cross-sectional view for describing a process of method of manufacturing a display apparatus, according to another embodiment; and 
           [0039]      FIG. 13  is a cross-sectional view for describing a process of a method of manufacturing a display apparatus, according to another embodiment. 
       
    
    
     DETAILED DESCRIPTION 
       [0040]    Reference will now be made in detail to embodiments, examples of which are illustrated in the accompanying drawings. In this regard, the present 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 present description. 
         [0041]    In drawings, like reference numerals refer to like elements throughout and overlapping descriptions shall not be repeated. 
         [0042]    It will be understood that when a layer, region, or component is referred to as being “formed on,” another layer, region, or component, it can be directly or indirectly formed on the other layer, region, or component. That is, for example, intervening layers, regions, or components may be present. Sizes of elements 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. 
         [0043]    In the following examples, 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. 
         [0044]    As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. Expressions such as “at least one of,” when preceding a list of elements, modify the entire list of elements and do not modify the individual elements of the list. 
         [0045]      FIGS. 1 through 7  are cross-sectional views for describing processes of a method of manufacturing a display apparatus, according to an embodiment. 
         [0046]    According to the method of the current embodiment, a first substrate  110  is prepared. The first substrate  110  that may be formed of glass has a first internal surface  111  and a first external surface  112 , as shown in  FIG. 1 , and the first external surface  112  may be understood to be an external surface after the first substrate  110  is combined to a second substrate  120  later. Here, a side surface of the first substrate  110  may be understood to be a region connecting the first internal surface  111  to the first external surface  112 . 
         [0047]    After preparing the first substrate  110  as such, a display unit  130  having a display device is formed on or over the first internal surface  111  of the first substrate  110 . The display device may be an organic light-emitting device, a liquid crystal device, or another display device. Of course, a structure of the display unit  130  is not limited thereto, and the display unit  130  may further include an electronic device, such as a thin-film transistor and/or a capacitor. 
         [0048]    Meanwhile, the second substrate  120  (refer to  FIG. 2 ) that may be formed of glass is prepared. The second substrate  120  has a second internal surface  121  and a second external surface  122 . An order of preparing the first and second substrates  110  and  120  is not limited, for example, the first and second substrates  110  and  120  may be simultaneously prepared or one of the first and second substrates  110  and  120  may be prepared first. 
         [0049]    Then, as shown in  FIG. 2 , a combining or adhesive member  140  is located between the first internal surface  111  of the first substrate  110  and the second internal surface  121  of the second substrate  120  to surround the display unit  130 , thereby combining or bonding the first and second substrates  110  and  120 . The combining member  140  may have a width of 200 to 800 um and a thickness of 2 to 10 um. The combining or adhesive member  140  may be formed of, for example, frit. Frit is a subsidiary material of a glass raw material, and may be cured after being exposed to a laser beam. Frit may be a composition including 15 to 40 wt % of V 2 O 5 , 10 to 30 wt % of TeO 2 , 1 to 15 wt % of P 2 O 5 , 1 to 15 wt % of BaO, 1 to 20 wt % of ZnO, 5 to 30 wt % of ZrO 2 , 5 to 20 wt % of WO 3 , and 1 to 15 wt % of BaO as main ingredients, and at least one of Fe 2 O 3 , CuO, MnO, Al 2 O 3 , Na 2 O, and Nb 2 O 5  as an additive. Frit having such a composition may have a thermal expansion coefficient of 40 to 100×10 −7 /° C. and a glass transition temperature of 250 to 400° C. By using such frit, a region cured later enables the first and second substrate  110  and  120  to have internal stress having a distribution described below such that side surfaces of the first and second substrates  110  and  120  are convex when the first and second substrates  110  and  120  are cut, as described in detail later. In embodiments, the adhesive member  140  may function as a seal member for sealing between the first and second substrates and protecting the display unit from outside materials or substances, for example, moisture. 
         [0050]    The combining member  140  may combine the first and second substrates  110  and  120  together via any one of various methods. For example, the combining member  140  may be located along an edge of the second internal surface  121  of the second substrate  120  and then bond the first and second substrates  110  and  120 . Alternatively, the combining member  140  may be located along an edge of the first internal surface of the first substrate  110  around the display unit  130  and then bond the first and second substrates  110  and  120 . In any cases, a side surface of the combining member  140  becomes convex as shown in  FIG. 2  when the first and second substrates  110  and  120  are bonded, as shown in  FIG. 2 . In  FIG. 2 , a side surface of the combining member  140  is convex towards the display unit  130 , and the other side surface of the combining member  140  is also convex externally. 
         [0051]    The, the first and second substrates  110  and  120  are cut to manufacture a display apparatus shown in  FIG. 7 . Cut shapes of the first and second substrates  110  and  120  will be described in detail with reference to  FIG. 7  and  FIG. 8  that is an enlarged cross-sectional view of a region B of  FIG. 7 . When cutting the first and second substrates  110  and  120 , the first and second substrates  110  and  120  are cut such that the side surfaces have pre-set shapes. 
         [0052]    In the first substrate  110 , a region of the first substrate  110 , which corresponds to the display unit  130 , has a first constant region CR 1  having a uniform width and a first increasing region IR 1  having an increasing width, in a direction (a +y direction) from the first external surface  112  to the first internal surface  111 . Here, a width may be understood to be a length in an x-axis direction in  FIGS. 7 and 8 . As shown in  FIG. 7 , a width measured along the x-axis direction between the first constant region CR 1  of the right side and the corresponding constant region of the left side is substantially uniform, whereas a width measured along the x-axis direction between the increasing region IR 1  of the right side and the increasing region of the left side is changing. Also, the region corresponding to the display unit  130  may not only includes a region on which the display unit  130  is disposed, but may also include a region corresponding to the combining member  140  (a region  141  of  FIGS. 7 and 8 ). When the first substrate  110  is cut, the side surface of the first substrate  110  may have a first constant side surface  110   b  that is adjacent to the first external surface  112  and approximately perpendicular to the first external surface  112 , and a first increasing side surface  110   a  that is convex externally in a direction (the +y direction) from the first constant side surface  110   b  to the first internal surface  111  of the first substrate  110 . Here, the first constant side surface  110   b  is a side surface of the first constant region CR 1  of the first substrate  110 . 
         [0053]    As shown in  FIG. 7 , in a cross section taken perpendicular to the external surface of the first substrate, the constant region CR 1  may be illustrated as a straight portion extending along a thickness direction of the first substrate. Further, in the same cross section, the increasing region IR 1  may be illustrated as a convexly curved portion. 
         [0054]    In the second substrate  120 , a region of the second substrate  120 , which corresponds to the display unit  130 , has a second constant region CR 2  having a uniform width and a second increasing region IR 2  having an increasing width, in a direction (a −y direction) from the second external surface  122  to the second internal surface  121 . Here, a width may be understood to be a length in an x-axis direction in  FIGS. 7 and 8 . Also, the region corresponding to the display unit  130  may not only includes a region on which the display unit  130  is disposed, but may also include a region corresponding to the combining member  140  (the region  141  of  FIGS. 7 and 8 ). When the second substrate  120  is cut, the side surface of the second substrate  120  may have a second constant side surface  120   b  that is adjacent to the second external surface  122  and approximately perpendicular to the second external surface  122 , and a second increasing side surface  120   a  that is convex externally in a direction (the −y direction) from the second constant side surface  120   b  to the second internal surface  121  of the second substrate  120 . Here, the second constant side surface  120   b  is a side surface of the second constant region CR 2  of the second substrate  120 . 
         [0055]    As shown in  FIG. 7 , in a cross section taken perpendicular to the external surface of the second substrate, the constant region CR 2  may be illustrated as a straight portion extending along a thickness direction of the second substrate. Further, in the same cross section, the increasing region IR 2  may be illustrated as a convexly curved portion. 
         [0056]    In the display apparatus manufactured according to the method of the current embodiment, a side surface of the display apparatus is convex in overall, as shown in  FIGS. 7 and 8 . When the side surface of the display apparatus is convex as such, a probability of the side surface of the display apparatus being damaged by an external impact is remarkably low compared to when the side surface of the display apparatus is flat and perpendicular to the first external surface  112  of the first substrate  110  or the second external surface  122  of the second substrate  120 , because, when the side surface of the display apparatus is convex, an effect as if the display apparatus has an arch structure is displayed, and thus impact resistance, in detail, strength with respect to a side impact, is increased. Accordingly, the display apparatus having excellent impact resistance is realized. 
         [0057]    In embodiments, with respect to a thickness of the first substrate  110  in the +y direction, a region occupied by the first constant region CR 1  may be larger than a region occupied by the first increasing region IR 1 . For example, with respect to the thickness of the first substrate  110  in the +y direction, the region occupied by the first constant region CR 1  may be smaller than or equal to ½ of the region occupied by the first increasing region IR 1 . Similarly, with respect to a thickness of the second substrate  120  in the +y direction, a region occupied by the second constant region CR 2  may be smaller than or equal to ½ of the region occupied by the second increasing region IR 2 . 
         [0058]    Meanwhile, in the display apparatus manufactured according to the method of the current embodiment, the first substrate  110  has the first constant region CR 1  in which the region of the first substrate  110 , which corresponds to the display unit  130 , has the uniform width in the direction (the +y direction) from the first external surface  112  to the first internal surface  111 , as shown in  FIGS. 7 and 8 . Accordingly, in the first constant region CR 1 , the first external surface  112  and the first constant side surface  110   b  of the first substrate  110  are approximately perpendicular to each other, and as a result, a boundary is clear between the first external surface  112  and the first constant side surface  110   b  of the first substrate  110 . Accordingly, a region of the first external surface  112  of the first substrate  110  is clear, and thus when a functional film, such as a reflection prevention film, a temporary protection film, or a polarization film, is attached on the first external surface  112  of the first substrate  110 , the functional film may cover all of the first external surface  112  while not covering the side surface, i.e., the first constant side surface  110   b  of the first substrate  110 . 
         [0059]    If the first substrate  110  does not have the first constant region CR 1 , the side surface of the first substrate  110  may only include the first increasing side surface  110   a  that is convex, and not include the first constant side surface  110   b . In this case, an angle formed by the first increasing side surface  110   a  and the first external surface  112  at a region where the first increasing side surface  110   a  and the first external surface  112  contact each other is obtuse, and thus a boundary in the region where the first increasing side surface  110   a  and the first external surface  112  contact each other may not be clear. Accordingly, when a film is attached to the first external surface  112 , it is difficult to specify an edge of the first external surface  112  where the film is to be attached, and thus the film may not be attached to an accurate location 
         [0060]    The same is applied to the second substrate  120 . In the display apparatus manufactured according to the method of the current embodiment, the second substrate  120  has the second constant region CR 2  in which the region of the second substrate  120 , which corresponds to the display unit  130 , has the uniform width in the direction (the −y direction) from the second external surface  122  to the second internal surface  121 , as shown in  FIGS. 7 and 8 . Accordingly, in the second constant region CR 2 , the second external surface  122  and the second constant side surface  120   b  of the second substrate  120  are approximately perpendicular to each other, and as a result, a boundary is clear between the second external surface  122  and the second constant side surface  120   b  of the second substrate  120 . Accordingly, a region of the second external surface  122  of the second substrate  120  is clear, and thus when a functional film, such as a reflection prevention film, a temporary protection film, or a polarization film, is attached on the second external surface  122  of the second substrate  120 , the functional film may cover all of the second external surface  122  while not covering the side surface, i.e., the second constant side surface  120   b  of the second substrate  120 . 
         [0061]    If the second substrate  120  does not have the second constant region CR 2 , the side surface of the second substrate  120  may only include the second increasing side surface  120   a  that is convex, and not include the second constant side surface  120   b . In this case, an angle formed by the second increasing side surface  120   a  and the second external surface  122  at a region where the second increasing side surface  120   a  and the second external surface  122  contact each other is obtuse, and thus a boundary in the region where the second increasing side surface  120   a  and the second external surface  122  contact each other may not be clear. Accordingly, when a film is attached to the second external surface  122 , it is difficult to specify an edge of the second external surface  122  where the film is to be attached, and thus the film may not be attached to an accurate location 
         [0062]    A method of easily cutting the first and second substrates  110  and  120  will now be described in detail with reference to  FIGS. 3 through 6 . After bonding the first and second substrates  110  and  120  as described above with reference to  FIG. 2 , a region of the combining or adhesive member  140  is exposed to light beams (for example, laser beams) as shown in  FIG. 3 . In detail, only the region  141  of the combining member  140  is exposed. The region  141  may be exposed via any one of various methods, and for example, using a photo mask  200 . The photo mask has a blocking unit  220  formed on a partial region thereof and a light transmission or penetration plate portion  210  as shown in  FIG. 3 . The photo mask  200  is located such that the blocking unit  220  corresponds to the region  142  and the light transmission portion  210  corresponds to the region  141  of the combining member  140 , and then a laser beam may be irradiated to the combining member  140 . The laser beam may have 50 to 60 watts and uniformity of 90 to 95%. Irradiating the laser beams to the portion  141  of the adhesive member  140 , for example, formed of glass frit, cause the portion  141  to melt and then be cured. Thus, the adhesive member  140  may include a cured portion  141  and an uncured portion  142 . 
         [0063]    Subsequently, the first and second substrates  110  and  120  are cut at a cutting point in regions of the first external surface  112  and the second external surface  122  which correspond to the combining member  140 . The cutting point is closer to the display unit than a location (a second point P 2  of  FIG. 4 ) between the exposed region  141  of the combining member  140  and an unexposed region  142  of the combining member  140 . Referring to  FIG. 4 , for example, the first and second substrates  110  and  120  may be cut from locations on the first and second external surfaces  112  and  122 , which correspond to the second point P 2  or a third point P 3  of the combining member  140 . 
         [0064]    Such a point where the cutting starts will now be described in detail. A center of the region  141  of the combining member  140  may be defined as a first point P 1 , the boundary between the exposed region  141  of the combining member  140  and the unexposed region  142  of the combining member  140 , may be defined as the second point P 2 , and a center between the first and second points P 1  and P 2  may be defined as the third point P 3 . In this case, the cutting point where the cutting starts may be locations on the first and second substrates  110  and  120 , which correspond to the third point P 3 , or locations on the first and second substrates  110  and  120 , which are between the second and third points P 2  and P 3 . In  FIG. 5 , the first and second substrates  110  and  120  are cut from locations corresponding to the third point P 3  by using cutting wheels  310  and  320 . 
         [0065]      FIG. 6  is an enlarged cross-sectional view of a region A of  FIG. 5 , and illustrates internal stress generated by the combining member  140  in the first and second substrates  110  and  120 . In  FIG. 6 , thin dashed lines indicate the internal stress and thick dashed lines indicate a cutting line CL. As described above with reference to  FIG. 3 , when only the region  141  of the combining member  140  is exposed to light beams and cured, the region  141  applies stress to the first and second substrates  110  and  120 , but the region  142  that is not exposed only contacts the first and second substrates  110  and  120  and does not apply stress to the first and second substrates  110  and  120  because, when the region  141  is cured after being exposed, the volume of the region  141  is reduced and thus stress is applied to the first and second substrates  110  and  120 , but the region  142  does not go through such processes. Accordingly, the internal stress is distributed in the first and second substrates  110  and  120  as shown in the thin dashed lines in  FIG. 6 . 
         [0066]    Under such circumstances, when the cutting starts from, for example, locations on the first and second substrates  110  and  120 , which correspond to the third point P 3  of the combining member  140 , by using the cutting wheels  310  and  320 , as shown in  FIG. 5 , the vicinities of the first external surface  112  of the first substrate  110  and the second external surface  122  of the second substrate  120  are cut first. Accordingly, the first constant side surface  110   b  (refer to  FIG. 8 ) of the first substrate  110  and the second constant side surface  120   b  (refer to  FIG. 8 ) of the second substrate  120  are formed. 
         [0067]    At this time, the first and second substrates  110  and  120  are naturally or spontaneously cut along the cutting line CL of  FIG. 6  such that the side surfaces of the first and second substrates  110  and  120  are convex according to the internal stress of the first and second substrates  110  and  120  formed by the stress applied by the region  141  to the first and second substrates  110  and  120 , and thus the side surfaces of the first and second substrates  110  and  120  are convex as shown in  FIGS. 7 and 8 . The cutting line CL may pass through a boundary between the region  141  and the region  142  of the combining member  140  as shown in  FIG. 6  because the region  141  is located on a side near to the display unit  130  with respect to the cutting line CL since the region  141  combines the first and second substrate  110  and  120 , and the region  142  is located on a side distant from the display unit  130  with respect to the cutting line CL since the region  142  only contacts the first and second substrates  110  and  120  and does not combine the first and second substrate  110  and  120 . 
         [0068]    If the first and second substrates  110  and  120  are not naturally or spontaneously cut despite the first constant side surface  110   b  (refer to  FIG. 8 ) and the second constant side surface  120   b  (refer to  FIG. 8 ) are formed, slight force or a slight impact may be applied to the first substrate  110  and/or the second substrate  120  such that the side surfaces of the first and second substrates  110  and  120  are naturally cut along the cutting line CL of  FIG. 6  to be convex. For reference, with respect to the cutting line CL of  FIG. 6 , regions excluding those approximately perpendicular to the first external surface  112  of the first substrate  110  and the second external surface  122  of the second substrate  120  may be understood to be approximately perpendicular to the internal stress (the thin dashed lines in  FIG. 6 ) formed in the first and second substrates  110  and  120 . In the illustrated embodiments, the first and second substrates may be cut without further advancing the cutting wheels beyond the constant regions CR 1  and CR 2  toward the adhesive member  140 . 
         [0069]    When the first constant side surface  110   b  (refer to  FIG. 8 ) and the second constant side surface  120   b  (refer to  FIG. 8 ) are respectively formed in the first and second substrates  110  and  120 , the first external surface  112  of the first substrate  110  and the second external surface  122  of the second substrate  120  may be simultaneously cut inward by respectively using the cutting wheels  320  and  310 . 
         [0070]    As described above, with respect to the cutting line CL of  FIG. 6 , the first and second substrates  110  and  120  are naturally or spontaneously cut according to the internal stress of the first and second substrates  110  and  120  along the regions excluding those approximately perpendicular to the first external surface  112  of the first substrate  110  and the second external surface  122  of the second substrate  120 . If the first constant side surface  110   b  (refer to  FIG. 8 ) of the first substrate  110  is formed first and the second constant side surface  120   b  (refer to  FIG. 8 ) of the second substrate  120  is formed later, the first and second substrates  110  and  120  may start to be cut by the internal stress at the moment when the first constant side surface  110   b  (refer to  FIG. 8 ) of the first substrate  110  is formed. In this case, the second constant side surface  120   b  (refer to  FIG. 8 ) of the second substrate  120 , which is approximately perpendicular to the second external surface  122  of the second substrate  120 , may not be properly formed. Accordingly, the first external surface  112  of the first substrate  110  and the second external surface  122  of the second substrate  120  may be simultaneously cut inward by respectively using the cutting wheels  320  and  310 , so as to form the first constant side surface  110   b  (refer to  FIG. 8 ) and the second constant side surface  120   b  (refer to  FIG. 8 ). 
         [0071]    Meanwhile, in the display apparatus manufactured as such, a radius of curvature of an inner surface  141   b  of the region  141  and a radius of curvature of an outer surface  141   a  of the region  141  may be different, as shown in  FIG. 8 . In detail, the radius of curvature of the inner surface  141   b  may be smaller than the radius of curvature of the outer surface  141   a.    
         [0072]    As described above, while locating the combining member  140  and combining the first and second substrates  110  and  120 , the side surface of the combining member  140  becomes convex as shown in  FIG. 2 . Accordingly, in the region  141  of the combining member  140  of  FIG. 8 , the inner surface  141   b  maintains to be convex. 
         [0073]    Meanwhile, as shown in  FIGS. 5 and 6 , when the combining member  140  is exposed and then the first and second substrates  110  and  120  are cut, the combining member  140  is cut near the boundary between the regions  141  and  142  while being cut along the cutting line CL. At this time, as shown in  FIG. 8 , the first increasing side surface  110   a  of the first substrate  110 , which is the side surface of the first increasing region IR 1 , the outer surface  141   a  of the region  141 , and the second increasing side surface  120   a  of the second substrate  120 , which is the side surface of the second increasing region IR 2 , form a convex surface, and in detail, such a convex surface is continuous. Here, the outer surface  141   a  of the region  141  is near a vertex of the convex surface, and thus a radius of curvature of the outer surface  141   a  is larger than a radius of curvature of the inner surface  141   b.    
         [0074]      FIG. 9  is a cross-sectional view for describing a process of a method of manufacturing a display apparatus, according to another embodiment. According to the method described above, when a region of the combining member  140  is exposed to light beams, the photo mask  200  in which the blocking unit  220  is formed on a partial region as shown in  FIG. 3  is used. However, according to the method of the current embodiment, a blocking pattern  222  formed on the second external surface  122  of the second substrate  120  as shown in  FIG. 9  is used instead of the photo mask  200 . As shown in  FIG. 9 , the blocking pattern  222  may correspond to the region  142  of the combining member  140  instead of the region  141 . The blocking pattern  222  may prevent a laser beam from irradiating on the region  141  of the combining member  140 . 
         [0075]    While manufacturing the display apparatus, the display apparatus having a touch screen function may be manufactured. In order to realize the touch screen function, a touch screen conductive pattern is formed on the second external surface  122  of the second substrate  120 , and by simultaneously forming the blocking pattern  222  and the touch screen conductive pattern, the blocking pattern  222  may be naturally formed without having to perform an additional operation. Of course, when the first and second substrates  110  and  120  are cut later, the blocking pattern  222  may be removed from the display apparatus. 
         [0076]    The touch screen conductive pattern or the blocking pattern  222  may be formed on the second external surface  122  of the second substrate  120  before bonding the second substrate  120  to the first substrate  110 . 
         [0077]      FIG. 10  is a cross-sectional view for describing a process of a method of manufacturing a display apparatus, according to another embodiment. 
         [0078]    According to the methods described above with reference to  FIGS. 3 and 9 , when a region of the combining member  140  is exposed, only the region  141  of the combining member  140  is exposed. However, an embodiment is not limited thereto. For example, as shown in  FIG. 10 , when a touch screen conductive pattern  224  exists on the second external surface  122  of the second substrate  120 , as well as the blocking pattern  222 , the touch screen conductive pattern  224  may block a laser beam like the blocking pattern  222 . Accordingly, only the region  141  excluding two regions  142  and  143  at edges of the combining member  140  may be exposed to a laser beam. For reference,  FIG. 10  illustrates only a part of the touch screen conductive pattern  224 . 
         [0079]    In this case, the first and second substrates  110  and  120  are cut from locations corresponding to the third point P 3  adjacent to the display unit  130  than a boundary between the exposed region  141  of the combining member  140  and the unexposed region  142  of the combining member  142  which is far from the display unit from among the regions  142  and  143 , in regions of the first and second external surfaces  112  and  122 , which correspond to the combining member  140 . 
         [0080]      FIGS. 11 and 12  are respectively a plan view and a cross-sectional view for describing a process of method of manufacturing a display apparatus, according to another embodiment. Hereinabove, one display apparatus is manufactured, but an embodiment is not limited thereto. For example, as shown in  FIG. 11 , a plurality of display cells C may be simultaneously manufactured to manufacture a plurality of display apparatuses. 
         [0081]    For example, a mother panel MP shown in  FIG. 11  may be formed by forming a plurality of display units spaced apart on the first substrate  110 , and combining the first and second substrates  110  and  120  by using the combining member  140 . Here, the combining member  140  may surround each of the plurality of display units. In  FIG. 11 , dashed lines around the display cells C show regions where the combining member  140  is located. Next, as shown in  FIG. 12 , a region of the combining member  140  may be exposed.  FIG. 12  is a cross-sectional view of a region of two adjacent display cells of  FIG. 11 . Then, when parts of the first and second substrates  110  and  120  are cut, by using a cutting wheel, from regions of the first and second substrates  110  and  120 , which correspond to the region  141  of the combining member  140 , for example, from the third point P 3  of  FIG. 12 , the plurality of display apparatuses having convex side surfaces may be manufactured. 
         [0082]    According to a general method of manufacturing a display apparatus, the combining member  140  is entirely exposed, and then the first and second substrates  110  and  120  are cut from a center region between the adjacent display cells C, i.e., from a center region between the combining members  140  of the adjacent display cells C. Accordingly, a gap G between the adjacent display cells C needs to be sufficiently maintained to obtain a cut location, and thus the number of display cells C simultaneously formed on the mother panel MP is limited. 
         [0083]    However, according to the method of the current embodiment, while cutting the first and second substrates  110  and  120 , the first and second substrates  110  and  120  are cut on the combining member  140  along the dashed lines instead of between the display cells C. Accordingly, the gap G between the display cells C may be reduced, and thus the number of display cells C simultaneously formed on the mother panel MP may be increased, thereby remarkably reducing expenses and time for manufacturing the display apparatuses. 
         [0084]    Meanwhile, in  FIGS. 11 and 12 , the adjacent display cells C individually include the combining member  140 , but an embodiment is not limited thereto. For example, FIG.  13  is a cross-sectional view for describing a process of a method of manufacturing a display apparatus, according to another embodiment. As shown in  FIG. 13 , the adjacent display cells C may share the combining member  140 . In this case, when the combining member  140  is exposed to light beams by using the photo mask  200  in which the blocking unit  220  is formed on the partial region, only the region  141  of the combining member  140  may be exposed. In this case, the photo mask  200  may be located so that the blocking unit  220  may correspond to a center region of the combining member  140 . Then, a plurality of display apparatuses having convex side surfaces may be manufactured by cutting parts of the first and second substrates  110  and  120  by using a cutting wheel, from regions of the first and second substrates  110  and  120 , which correspond to the region  141  of the combining member  140 , for example, from the third point P 3  of  FIG. 13 . 
         [0085]    Of course, as modified examples of the methods described above with reference to  FIGS. 12 and 13 , the plurality of display apparatuses may be manufactured by forming a blocking pattern corresponding to the blocking unit  220  of the photo mask  200  on the second external surface  122  of the second substrate  120 , instead of using the photo mask  200 . 
         [0086]    The methods of manufacturing a display apparatus have been described above, but embodiments are not limited thereto, and a display apparatus may also be within the scope of the present invention. 
         [0087]    A display apparatus according to an embodiment may have a structure shown in  FIG. 7  and  FIG. 8  that is the enlarged cross-sectional view of the region B of  FIG. 7 . In embodiments, the display apparatus may include the first substrate  110 , the second substrate  120 , and the display unit  130  disposed between the first and second substrates  110  and  120 . Here, the first substrate  110  may have the first constant region CR 1  having a uniform width and the first increasing region IR 1  having an increasing width, in the direction (the +y direction) from the first external surface  112  to the first internal surface  111 . Also, the second substrate  120  may have the second constant region CR 2  having a uniform width and the second increasing region IR 2  having an increasing width, in the direction (the −y direction) from the second external surface  122  to the second internal surface  121 . 
         [0088]    The display apparatus according to the current embodiment has a side surface that is convex overall as shown in  FIGS. 7 and 8 . When the side surface is convex as such, a probability of the display apparatus being damaged by an external impact is low compared to when the side surface is flat and perpendicular to the first or second external surface  112  or  122 . When the side surface of the display apparatus is convex overall, an effect as if the display apparatus has an arch structure is displayed, and thus impact resistance, in detail, strength with respect to a side impact, is increased. Accordingly, the display apparatus having excellent impact resistance is realized. 
         [0089]    At this time, with respect to a thickness of the first substrate  110  in the +y direction, a region occupied by the first constant region CR 1  may be larger than a region occupied by the first increasing region IR 1 . For example, with respect to the thickness of the first substrate  110  in the +y direction, the region occupied by the first constant region CR 1  may be smaller than or equal to ½ of the region occupied by the first increasing region IR 1 . Similarly, with respect to a thickness of the second substrate  120  in the +y direction, a region occupied by the second constant region CR 2  may be smaller than or equal to ½ of the region occupied by the second increasing region IR 2 . 
         [0090]    Meanwhile, as shown in  FIGS. 7 and 8 , in the display apparatus according to the current embodiment, the first substrate  110  has the first constant region CR 1  in which the region of the first substrate  110 , which corresponds to the display unit  130 , has the uniform width in the direction (the +y direction) from the first external surface  112  to the first internal surface  111 . Accordingly, in the first constant region CR 1 , the first external surface  112  and the first constant side surface  110   b  of the first substrate  110  are approximately perpendicular to each other, and as a result, a boundary is clear between the first external surface  112  and the first constant side surface  110   b  of the first substrate  110 . Accordingly, a region of the first external surface  112  of the first substrate  110  is clear, and thus when a functional film, such as a reflection prevention film, a temporary protection film, or a polarization film, is attached on the first external surface  112  of the first substrate  110 , the functional film may cover all of the first external surface  112  while not covering the side surface, i.e., the first constant side surface  110   b  of the first substrate  110 . 
         [0091]    If the first substrate  110  does not have the first constant region CR 1 , the side surface of the first substrate  110  may only include the first increasing side surface  110   a  that is convex, and not include the first constant side surface  110   b . In this case, an angle formed by the first increasing side surface  110   a  and the first external surface  112  at a region where the first increasing side surface  110   a  and the first external surface  112  contact each other is obtuse, and thus a boundary in the region where the first increasing side surface  110   a  and the first external surface  112  contact each other may not be clear. Accordingly, when a film is attached to the first external surface  112 , it is difficult to specify an edge of the first external surface  112  where the film is to be attached, and thus the film may not be attached to an accurate location. The same is applied to the second substrate  120 . 
         [0092]    Meanwhile, as shown in  FIGS. 7 and 8 , the display apparatus according to the current embodiment may further include the combining member  140  that combines the first and second substrates  110  and  120  by being located between the edge of the first internal surface  111  and the edge of the second internal surface  121 . At this time, a radius of curvature of the inner surface  141   b  of the region  141  and a radius of curvature of the outer surface  141   a  of the region  141  may be different from each other. In detail, the radius of curvature of the inner surface  141   b  may be smaller than the radius of curvature of the outer surface  141   a , and details thereof have been described above with reference to the method of manufacturing the display apparatus. 
         [0093]    Regarding the side surface of the display apparatus, the first increasing side surface  110   a  of the first substrate  110 , which is the side surface of the first increasing region IR 1 , the outer surface  141   a  of the region  141 , and the second increasing side surface  120   a  of the second substrate  120 , which is the side surface of the second increasing region IR 2 , form a convex surface, and in detail, such a convex surface is continuous. Here, the outer surface  141   a  of the region  141  is near a vertex of the convex surface. 
         [0094]    The display apparatus according to an embodiment may further include a film that covers at least one of the first external surface  112  of the first substrate  110  and the second external surface  122  of the second substrate  120 , while not covering a side surface. Accordingly, the film may be accurately located as described above. 
         [0095]    According to the one or more embodiments described above, a display apparatus that is easily manufactured and has increased impact resistance, and a method of manufacturing the display apparatus may be realized. 
         [0096]    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.