Abstract:
Provided is a display device including, a substrate, a display pan&amp; disposed on the substrate, a sealing substrate disposed over the display panel, a sealing part disposed between the substrate and the sealing substrate to at least partially surround the display panel, and a buffer part proximate to a corner region of the sealing part to at least partially surround the corner region of the sealing part, the buffer part extending from the substrate to the sealing substrate.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims priority to, and the benefit of, Korean Patent Application No. 10-2013-0057245 filed in the Korean Intellectual Property Office on May 21, 2013, the entire contents of which are incorporated herein by reference. 
       BACKGROUND OF THE INVENTION 
       [0002]    (a) Field of the Invention 
         [0003]    The present disclosure relates generally to display devices. More specifically, the present disclosure relates to impact-resistant display devices. 
         [0004]    (b) Description of the Related Art 
         [0005]    Current display devices come in many different forms, utilizing many different technologies. Examples of such display devices are a liquid crystal display (LCD), a plasma display panel (PDP), an organic light emitting diode device (OLED device), field effect display (FED), electrophoretic display device, and the like. 
         [0006]    The OLED device includes two electrodes and an organic emission layer disposed therebetween. Here, electrons from one electrode and holes from the other electrode combine in the organic emission layer to thereby form excitons, which release energy to emit light. 
         [0007]    The OLED device has a self-luminance characteristic and, unlike the LCD, does not need a separate light source, thereby decreasing thickness and weight thereof. Further, the OLED device exhibits desirable characteristics such as low power consumption, high luminance, and fast response speed, and thus receives attention as a potential next generation display device. 
         [0008]    The foregoing organic emission layer may be degraded due to external factors such as external moisture or oxygen or ultraviolet rays, and thus packaging technology for sealing the organic emission layer is of interest. 
         [0009]    Referring to  FIG. 1 , in the case of a portable terminal including an OLED device, a sealing substrate  10  and a sealing member  20  are used to seal an organic emission layer. However, the sealing substrate  10  and the sealing member  20  are vulnerable to external impact. That is, the sealing substrate  10  and the sealing member  20  may be damaged by external impact, causing moisture or oxygen to infiltrate into the organic emission layer. 
         [0010]    The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art. 
       SUMMARY 
       [0011]    The present invention provides a display device having advantages of preventing damage to a sealing member sealing the display panel due to external impact, and thus preventing resultant infiltration of oxygen or moisture into the display panel. 
         [0012]    An exemplary embodiment provides a display device including a substrate, a display panel, a sealing substrate, a sealing part, and a buffer part. The display panel is disposed on the substrate. The sealing substrate is disposed over the display panel. The sealing part is disposed between the substrate and the sealing substrate to at least partially surround the display panel. The buffer part is proximate to a corner region of the sealing part to at least partially surround the corner region of the sealing part, the buffer part extending from the substrate to the sealing substrate. 
         [0013]    The buffer part may be contact both the substrate and the sealing substrate. 
         [0014]    Here, at least a section of the buffer part may have two portions oriented so as to have an included angle therebetween, where this included angle can be a predetermined angle. 
         [0015]    Here, a sectional shape of the buffer part may correspond to a sectional shape of the corner region of the sealing part. 
         [0016]    Here, a thickness of the buffer part in a direction parallel to the substrate may be equal to or larger than a thickness of the sealing part in the same direction. 
         [0017]    Here, the buffer part may have a hole therein. 
         [0018]    Here, a section of the buffer part may have an at least approximate arrow shape. 
         [0019]    The buffer part may be plural in number and multiple corner regions may also be present. Each buffer part may be disposed adjacent to a respective one of the corner regions. 
         [0020]    The buffer part and the sealing part may be formed of the same material. 
         [0021]    The buffer part may be formed of any one or more of acryl-based resin, frit, metal, and silicon-based resin. 
         [0022]    According to an exemplary embodiment of the present invention, the display device can prevent the sealing member sealing the display panel from being damaged by external impact, and thus prevent the display panel from being degraded by infiltration of oxygen or moisture. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0023]      FIG. 1  is a portable terminal of the prior art, including a sealing substrate and a sealing member. 
           [0024]      FIG. 2  is a partial perspective view of a display device according to an exemplary embodiment. 
           [0025]      FIG. 3  is a plan view of a display device according to an exemplary embodiment. 
           [0026]      FIG. 4A  to  FIG. 4D  are partial cross-sectional views showing several shapes of buffer parts, respectively. 
           [0027]      FIG. 5  is a cross-sectional view taken along line A-A of  FIG. 3 . 
           [0028]      FIG. 6  is an enlarged view of area P of  FIG. 5 . 
       
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
       [0029]    The present invention will be described more fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments of the invention are shown. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. The drawings and description are to be regarded as illustrative in nature and not restrictive. Like reference numerals designate like elements throughout the specification. 
         [0030]    Furthermore, as the size and thickness of the respective structural components shown in the drawings are arbitrarily illustrated for explanatory convenience, the present invention is not necessarily limited to the illustrated sizes and thicknesses. 
         [0031]    In the drawings, the thickness of layers, films, panels, regions, etc., are exaggerated for clarity. In the drawings, for understanding and ease of description, the thicknesses of some layers and areas are exaggerated. It will be understood that when an element such as a layer, film, region, or substrate is referred to as being “on” another element, it can be directly on the other element or intervening elements may also be present. 
         [0032]    In addition, unless explicitly described to the contrary, the word “comprise” and variations such as “comprises” or “comprising”, will be understood to imply the inclusion of stated elements but not the exclusion of any other elements. Further, in the specification, the word “˜on” means positioning on or above or below the object portion, but does not essentially mean positioning on the upper side of the object portion based on a gravity direction. 
         [0033]    Referring to  FIG. 2  to  FIG. 6 , in order to prevent a sealing member sealing a display panel from being damaged by external impact in a display device, a buffer part may be formed outside a corner region of the sealing member. 
         [0034]    The display device according to an exemplary embodiment may include a substrate  400 , a display panel  500 , a sealing substrate  100 , a sealing part  200 , and a buffer part  300 . 
         [0035]    An organic light emitting diode (OLED) device including an organic emission layer is employed in display panel  500  in the display device of this exemplary embodiment. However, the display device is not limited to utilizing an OLED device, but may instead be, for example, a liquid display device, a field effect display device, or an electrophoretic display device. 
         [0036]    The substrate  400  may be formed of an insulating substrate made of glass, quartz, ceramic, plastic, or the like. However, the substrate  400  is not limited thereto, and may instead be formed of a metal substrate made of stainless steel or the like. 
         [0037]    In addition, referring to  FIG. 5 , the display panel  500  may be formed on the substrate  400  to display an image. Here, the display panel  500  includes an organic emission layer, and detailed descriptions thereof will be later described. 
         [0038]    The sealing substrate  100  sealing the display panel  500  is disposed above the display panel  500 . The sealing substrate  100  protects the display panel  500  from external moisture, oxygen, or impacts. Particularly, the sealing substrate  100  may prevent the organic emission layer of the display panel  500  from being degraded by moisture or oxygen. 
         [0039]    Here, the sealing substrate  100  may be formed of various materials, and specifically, may be formed of a glass material or a plastic material. 
         [0040]    Meanwhile, the sealing part  200  is disposed between the sealing substrate  100  and the substrate  400 . In addition, the sealing part  200  is disposed around the display panel  500  to surround the display panel  500 . 
         [0041]    Here, the sealing substrate  100  and the substrate  400  are coupled to each other by the sealing part  200 . The sealing part  200  may be formed of a material containing frit. However, the sealing part is not limited thereto, and may be formed of any of various known materials by which the sealing substrate  100  and the substrate  400  are coupled with each other. 
         [0042]    Referring to  FIG. 2  and  FIG. 3 , the display device according to an exemplary embodiment may include a buffer part  300  formed adjacent or proximate to a corner region of the sealing part  200 . 
         [0043]    The buffer part  300  may absorb external impact to prevent the sealing part  200  and the sealing substrate  100  from being damaged by external impact. That is, in the case where external impact is generated, the buffer part  300  may absorb at least some of the impact transferred to the corner regions of the sealing part  200 . 
         [0044]    The buffer part  300  is disposed to at least partially surround the corner region of the sealing part  200 . More specifically, the buffer part  300  is spaced apart from the corner region at a predetermined distance. In addition, the buffer part  300  is disposed between the substrate  400  and the sealing substrate  100 . 
         [0045]    Here, the buffer part  300  may contact, or extend between, both the substrate  400  and the sealing substrate  100 . That is, like the sealing part  200 , the buffer part  300  contacts both the sealing substrate  100  and the substrate  400  to thereby couple the sealing substrate and the substrate  400  to each other. 
         [0046]    Meanwhile, referring to  FIG. 3 , multiple buffer parts  300  may be used. Here, the plural buffer parts  300  are, respectively, disposed adjacently to corner regions for the respective corner regions. That is, one buffer part  300  is present at or near each corner of the sealing part  200  and/or substrate  400 . The buffer part  300  is disposed at each of the respective corner regions, to thereby prevent impact forces from transferring to the sealing part  200 , or reduce the amount of force transferred thereto. 
         [0047]    According to an exemplary embodiment, the buffer part  300  may be formed in a shape corresponding to a sectional shape of the corner region of the sealing part  200 . That is, the buffer part  300  may be formed in a sectional shape the same as or similar to the sectional shape of the sealing part  200 , i.e. the buffer part  300  may have a shape the same as or similar to the shape of the corner of sealing part  200  that it covers or corresponds to. 
         [0048]    Referring to  FIG. 2  and  FIG. 3 , the buffer part  30  may have a curved or arcuate shape, or a shape bent at a predetermined angle. In other words, it may have two extensions or portions with a predetermined included angle therebetween. Here, the bending or included angle of the buffer part  300  may be equal to a bending or included angle of the sealing part  200 . However, the bending or included angle of the buffer part  300  is not limited thereto, but may be different from the bending or included angle of the sealing part  200 . 
         [0049]    Here, the thickness of the buffer part  300  is equal to or larger than the thickness of the sealing part  200 . Here, the thickness T of the buffer part  300  is measured in a direction perpendicular to an edge of the substrate  400  shown in  FIG. 3 . 
         [0050]    Since the buffer  300  has the foregoing thickness, the buffer part  300  itself can scatter or dissipate the impact transferred from the external part. 
         [0051]    Meanwhile, referring to  FIG. 4A  to  FIG. 4D , the buffer part  300  may take on various shapes and configurations. 
         [0052]    For example, as shown in  FIG. 4A , the buffer part  300  may have an at least approximately arrow shaped configuration, i.e. a shape having three extensions protruding from a central body. In this case, the extensions extend toward a center of the arc of the adjacent corner of sealing part  200 , as well as ±45° thereto, although any directions are contemplated. In addition, as shown in  FIG. 4B , a hole may be formed in the buffer part  300 . Here, the outer edge and the hole of buffer part  300  may have any shape. Meanwhile, as shown in  FIG. 4C , the section of the buffer part  300  may have a polygonal shape of which an inside is filled. In addition, as shown in  FIG. 4D , the section of the buffer part  300  may have a configuration with plural polygons of any shape, number, and spacing. 
         [0053]    The buffer part  300  may have any shape or configuration, so long as it reduces or absorbs impact forces and thus reduces or eliminates the amount of force transferred to, for example, the corner region of the sealing part  200 . That is, the buffer part  300  may be formed in various shapes so long as the impact transferred from the external part is at least partially dissipated inside the buffer part  300 . 
         [0054]    According to an exemplary embodiment, the buffer part  300  and the sealing part  200  may be formed of the same material. For example, in the case where the sealing part  200  is formed of a material containing frit, the buffer part  300  may also be formed of the same material containing frit. 
         [0055]    Alternatively, the buffer part  300  may be formed of a different material from the sealing part  200 . For example, the buffer part  300  may be formed of any one of acryl-based resin, frit, metal, and silicon-based resin. 
         [0056]      FIG. 6  is an enlarged cross-sectional view of the display device, showing area P of  FIG. 5  in further detail. 
         [0057]    With reference to  FIG. 6 , a display device, particularly an organic light emitting diode (OLED) device, according to an exemplary embodiment, will be described in more detail. 
         [0058]    Referring to  FIG. 6 , a driving transistor (Qd) may be formed above a display substrate  123  which may be formed of transparent glass, plastic, or the like. Here, the display substrate  123  corresponds to the substrate  400  of  FIG. 5 , although this need not necessarily be the case. 
         [0059]    Here, a protective layer  122   b  is formed on the driving transistor Qd. The protective layer  122   b  may be formed of an inorganic material or an organic material. In the case where the protective layer  122   b  is formed of the organic material, a surface thereof may be flat. 
         [0060]    The protective layer  122   b  may be formed with a via hole  122   a  exposing a portion of the driving transistor Qd. 
         [0061]    In addition, a first electrode  122   d  is formed on the protective layer  122   b.  The first electrode  122   d  may include a reflective electrode and a transparent electrode formed thereon. The reflective electrode may be formed of metal having high reflectivity, such as, silver (Ag) or aluminum (Al), or an alloy thereof. The transparent electrode may be formed of a transparent conductive oxide, such as indium tin oxide (ITO) or indium zinc oxide (IZO). 
         [0062]    Here, a pixel defining layer  122   c  is formed on the protective layer  122   b  while covering the periphery of the edge of the first electrode  122   d.    
         [0063]    Referring to  FIG. 6 , an organic emission layer  122   e  is formed on the first electrode  122   d    
         [0064]    In addition, a second electrode  122   f  is formed on the organic emission layer  122   e  and the pixel defining layer  122   c.    
         [0065]    The organic emission layer  122   e  may include a light emission layer (not shown) in which light emission actually occurs, and further include organic layers (not shown) for effectively transferring carriers, such as holes or electrodes, to the light emission layer. The organic layers may include a hole injection layer and a hole transfer layer which are disposed between the first electrode  122   d  and the light emission layer, as well as an electron injection layer and an electron transfer layer which are disposed between the second electrode  122   f  and the light emission layer. 
         [0066]    In addition, a capping layer  125  may be formed on the second electrode  122   f  to cover and protect the second electrode  122   f,  and the capping layer  125  may be formed of an organic layer. 
         [0067]    In addition, according to an exemplary embodiment, a sealing substrate  100  may be spaced apart from the capping layer  125 . 
         [0068]    Meanwhile, several layers disposed between the display substrate  123  and the sealing substrate  100  may be included within a display panel  500  (see  FIG. 5 ) 
         [0069]    The display device according to an exemplary embodiment can prevent the sealing part sealing the display panel from being damaged due to external impact, via inclusion of added buffer parts surrounding, at least partially surrounding, or placed proximate to the corresponding corner regions of the sealing part. 
         [0070]    While this invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. 
         [0000]    
       
         
               
             
               
               
               
             
           
               
                   
               
               
                 &lt;Description of symbols&gt; 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 100: sealing substrate 
                 200: sealing part 
               
               
                   
                 300: buffer part 
                 400: substrate 
               
               
                   
                 500: display panel