Abstract:
A display device using a window includes: a display panel; a window protecting the display panel from an external environment; and an adhesive layer adhering a top surface of the display panel to a bottom surface of the window. In the display device, the window has at least one irregularity on a bottom surface thereof. Accordingly, it is possible to provide a display device using a window having improved strength.

Description:
CLAIM OF PRIORITY 
       [0001]    This application makes reference to, incorporates into this specification the entire contents of, and claims all benefits accruing under 35 U.S.C. §119 from an application earlier filed in the Korean Intellectual Property Office filed on Nov. 2, 2012 and there duly assigned Serial No. 10-2012-0123684. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to a display device, and more particularly, to a display device using a window having improved strength. 
         [0004]    2. Description of the Related Art 
         [0005]    In general, a window substrate applied to a touch screen, such as a cellular phone, a portable terminal, or the like, is used to protect a display device, and performs the functions of preventing a scratch from being generated on the display device and protecting the display device from an external impact. Such a related art window substrate has high hardness so that its surface is protected from a scratch. However, when the window substrate falls due to a user&#39;s mistake or when an external strong impact is applied to the window substrate, the window substrate is easily broken. 
       SUMMARY OF THE INVENTION 
       [0006]    The present invention provides a display device using a window having improved strength. 
         [0007]    According to an aspect of the present invention, there is provided a display device, including: a display panel; a window protecting the display panel from an external environment; and an adhesive layer adhering a top surface of the display panel to a bottom surface of the window, the window having at least one irregularity on the bottom surface thereof. 
         [0008]    As described above, according to the present invention, it is possible to provide a display device using a window having improved strength by dispersing stress transferred to the window when an impact is applied to the display device. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]    A more complete appreciation of the invention, and many of the attendant advantages thereof, will be readily apparent as the same becomes better understood by reference to the following detailed description when considered in conjunction with the accompanying drawings, in which like reference symbols indicate the same or similar components, wherein: 
           [0010]      FIG. 1A  shows a section in which a window is attached to a display panel in a display device according to an embodiment of the present invention. 
           [0011]      FIG. 1B  shows a top surface of the display device shown in  FIG. 1A . 
           [0012]      FIG. 2A  shows a section in which a window is attached to a display panel in a display device according to another embodiment of the present invention. 
           [0013]      FIG. 2B  shows a top surface of the display device shown in  FIG. 2A . 
           [0014]      FIG. 3A  shows a section in which a window is attached to a display panel in a display device according to still another embodiment of the present invention. 
           [0015]      FIG. 3B  shows a top surface of the display device shown in  FIG. 3A . 
           [0016]      FIG. 4A  shows a section in which a window is attached to a display panel in a display device according to still another embodiment of the present invention. 
           [0017]      FIG. 4B  shows a top surface of the display device shown in  FIG. 4A . 
           [0018]      FIG. 5A  shows a section in which a window is attached to a display panel in a display device according to still another embodiment of the present invention. 
           [0019]      FIG. 5B  shows a top surface of the display device shown in  FIG. 5A . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0020]    In the following detailed description, only certain exemplary embodiments of the present invention have been shown and described, simply by way of illustration. As those skilled in the art will realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. Accordingly, the drawings and description are to be regarded as illustrative in nature and not restrictive. In addition, when an element is referred to as being “on” another element, it can be directly on the element or be indirectly on the element with one or more intervening elements interposed therebetween. Also, when an element is referred to as being “connected to” another element, it can be directly connected to the element or be indirectly connected to the element with one or more intervening elements interposed therebetween. Hereinafter, like reference numerals refer to like elements. 
         [0021]    Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. 
         [0022]      FIG. 1A  shows a section in which a window is attached to a display panel in a display device according to an embodiment of the present invention.  FIG. 1B  shows a top surface of the display device shown in  FIG. 1A . 
         [0023]    First, referring to  FIG. 1A , the display device includes a display panel  120 , an adhesive layer  140  and a window  160 . 
         [0024]    The display panel  120  displays images. The display panel  120  may be a display panel such as a liquid crystal display (LCD) or organic light emitting diode (OLED) display. 
         [0025]    The adhesive layer  140  is positioned between the display panel  120  and the window  160  so as to adhere the top surface of the display panel  120  to the bottom surface of the window  160 . The adhesive layer  140  may be made of a photocurable resin or thermosetting resin having high transmittance and adhesion performance. For example, the adhesive layer  140  may be formed by coating resin such as acrylic resin, and then curing the coated resin through ultraviolet (UV) irradiation. The adhesive layer  140  has relatively excellent elasticity, so as to protect the display panel  120  from an external impact, thereby improving the mechanical stability and reliability of the display device. 
         [0026]    The window  160  is positioned on the display panel  120  so as to protect the display panel  120  from an external environment. That is, the window  160  functions to prevent a scratch from being generated on the display panel  120  or to protect the display panel  120  from an external impact. The window  160  may be made of a transparent material. Specifically, the window  160  may be made of a plastic material, such as an acrylic material, or a glass material, which has impact resistance and optical transparency. 
         [0027]    The window  160  has at least one irregularity on the bottom surface thereof. Specifically, the window  160  may have one concave pattern  162  formed at a central portion of the bottom surface thereof. The concave pattern  162  is a pattern in which the window  160  is recessed away from the display panel  120 . 
         [0028]    Referring to  FIG. 1B , the window  160  has one concave pattern  162  formed at the central portion of the bottom surface thereof. Since the window  160  has a vertically long shape, the concave pattern  162  may have a vertically long elliptical shape. It will be apparent that the concave pattern  162  may have other shapes. If stress is generated by applying an impact to a right lower corner portion of the window  160 , the stress is transferred to the opposite side, i.e., a left upper corner portion of the window  160 . In a case where the bottom surface of the window  160  is a flat surface having no irregularity, the left upper corner portion of the window  160  is cracked or broken due to the impact applied to the right lower corner portion of the window  160 . However, the display device according to this embodiment of the invention has the irregularity formed on the bottom surface of the window  160 . The irregularity performs a buffering function with respect to the transferred stress. Specifically, referring to  FIG. 1B , the concave pattern  162  formed on the stress transfer path disperses the transferred stress. The concave pattern  162  has an elliptical shape. Thus, if the stress is transferred to the concave pattern  162 , the advancing direction of the stress is dispersed in all directions, so that the strength of the stress transferred to the left upper corner portion of the window  160  is decreased. As a result, the possibility that the left upper corner portion of the window  160  will be cracked or broken is remarkably reduced. It will be apparent that the shape and size of the concave pattern  162  may be appropriately defined. The resin constituting the adhesive layer  140  may be filled in the concave pattern  162 . 
         [0029]    Accordingly, the display device according to this embodiment of the invention has the concave pattern  162  formed at the central portion of the bottom surface of the window  160 , and the concave pattern  162  of the window  160  performs a buffering function when an impact is applied to the window  160 , so that the stress transferred to the opposite side of the impact point is decreased, thereby preventing the window  160  from being broken. 
         [0030]    The display panel  120  may include a touch panel (not shown) sensing an external input so as to implement a touch screen. In this case, the touch panel (not shown) may be positioned on the display panel  120  or may be implemented inside the display panel  120 . In a case where the touch panel (not shown) is positioned on the display panel  120 , a first adhesive layer (not shown) is positioned on the display panel  120 , the touch panel (not shown) is positioned on the first adhesive layer (not shown), a second adhesive layer (not shown) is positioned on the touch panel (not shown), and the window  160  is positioned on the second adhesive layer (not shown). The first and second adhesive layers (not shown) are similar to the adhesive layer  140  described above. 
         [0031]      FIG. 2A  shows a section in which a window is attached to a display panel in a display device according to another embodiment of the present invention.  FIG. 2B  shows a top surface of the display device shown in  FIG. 2A . 
         [0032]    First, referring to  FIG. 2A , the display device according to this embodiment includes a display panel  220 , an adhesive layer  240  and a window  260 . This embodiment is similar to the embodiment of  FIG. 1 , except for the window  260 . Hereinafter, the window  260  will be described in detail. 
         [0033]    The window  260  has at least one irregularity on the bottom surface thereof. Specifically, the window  260  may have one convex pattern  262  formed at a central portion of the bottom surface thereof. The convex pattern  262  is a pattern in which the window  260  convexly protrudes toward the display panel  220 . 
         [0034]    Referring to  FIG. 2B , the window  260  has one convex pattern  262  formed at the central portion of the bottom surface thereof. Since the window  260  has a vertically long shape, the convex pattern  262  may have a vertically long elliptical shape. It will be apparent that the convex pattern  262  may have other shapes. If stress is generated by applying an impact to a right lower corner portion of the window  260 , the stress is transferred to the opposite side, i.e., a left upper corner portion of the window  260 . The convex pattern  262  formed on the stress transfer path disperses the transferred stress. The convex pattern  262  has an elliptical shape. Thus, if the stress is transferred to the convex pattern  262 , the advancing direction of the stress is dispersed in all directions, so that the strength of the stress transferred to the left upper corner portion of the window  260  is decreased. As a result, the possibility that the left upper corner portion of the window  260  will be cracked or broken is remarkably reduced. It will be apparent that the shape and size of the convex pattern  262  may be appropriately defined. 
         [0035]    Accordingly, the display device according to this embodiment of the invention has the convex pattern  262  formed at the central portion of the bottom surface of the window  260 , and the convex pattern  262  of the window  260  performs a buffering function when an impact is applied to the window  260  so that the stress transferred to the opposite side of the impact point is decreased, thereby preventing the window  260  from being broken. 
         [0036]      FIG. 3A  shows a section in which a window is attached to a display panel in a display device according to still another embodiment of the present invention.  FIG. 3B  shows a top surface of the display device shown in  FIG. 3A . 
         [0037]    First, referring to  FIG. 3A , the display device according to this embodiment includes a display panel  320 , an adhesive layer  340  and a window  360 . This embodiment is similar to the embodiments of  FIGS. 1 and 2 , except for the window  360 . Hereinafter, the window  360  will be described in detail. 
         [0038]    The window  360  has at least one irregularity on the bottom surface thereof. Specifically, the window  360  may have a plurality of concave patterns  362  formed on the bottom surface thereof. The concave pattern  362  is a pattern in which the window  360  is recessed away from the display panel  320 . 
         [0039]    Referring to  FIG. 3B , the window  360  has nine concave patterns  362  formed on the bottom surface thereof. Each concave pattern  362  may have a circular shape. It will be apparent that the concave pattern  362  may have other shapes. If stress is generated by applying an impact to a right lower corner portion of the window  360 , the stress is transferred to the opposite side, i.e., a left upper corner portion of the window  360 . The concave patterns  362  formed on the stress transfer path disperse the transferred stress. Each concave pattern  362  has a circular shape. Thus, if the stress is transferred to each concave pattern  362 , the advancing direction of the stress is dispersed in all directions, so that the strength of the stress transferred to the left upper corner portion of the window  360  is decreased. Specifically, in a case where the stress is generated at the right lower corner portion of the window  360 , the stress transferred to a second concave pattern b is smaller than that transferred to a first concave pattern a, and the stress transferred to a third concave pattern c is smaller than that transferred to the second concave pattern b. The stress finally transferred to the left upper corner portion of the window  360  is smaller than that transferred to the third concave pattern c. 
         [0040]    As a result, the possibility that the left upper corner portion of the window  360  will be cracked or broken is remarkably reduced. This is because the stress is dispersed as it passes through the concave patterns  362  one by one, and therefore, the stress advancing in a specific direction is decreased. It will be apparent that the shape and size of the concave pattern  362  may be appropriately defined. The resin constituting the adhesive layer  340  may be filled in the concave pattern  362 . 
         [0041]    Accordingly, the display device according to this embodiment of the invention has the plurality of the concave patterns  362  formed on the bottom surface of the window  360 , and the concave patterns  362  of the window  360  perform a buffering function when an impact is applied to the window  360  so that the stress transferred to the opposite side of the impact point is decreased, thereby preventing the window  360  from being broken. 
         [0042]      FIG. 4A  shows a section in which a window is attached to a display panel in a display device according to still another embodiment of the present invention.  FIG. 4B  shows a top surface of the display device shown in  FIG. 4A . 
         [0043]    First, referring to  FIG. 4A , the display device according to this embodiment includes a display panel  420 , an adhesive layer  440  and a window  460 . This embodiment is similar to the embodiments of  FIG. 3 , except for the window  460 . Hereinafter, the window  460  will be described in detail. 
         [0044]    The window  460  has at least one irregularity on the bottom surface thereof. Specifically, the window  260  may have a plurality of convex patterns  462  formed on the bottom surface thereof. The convex pattern  462  is a pattern in which the window  460  protrudes convexly toward the display panel  420 . 
         [0045]    Referring to  FIG. 4B , the window  460  has nine convex patterns  462  formed on the bottom surface thereof. Each convex pattern  462  may have a circular shape. It will be apparent that the convex pattern  462  may have other shapes. If stress is generated by applying an impact to a right lower corner portion of the window  460 , the stress is transferred to the opposite side, i.e., a left upper corner portion of the window  460 . The convex patterns  462  formed on the stress transfer path disperse the transferred stress. Each convex pattern  462  has a circular shape. Thus, if the stress is transferred to each convex pattern  462 , the advancing direction of the stress is dispersed in all directions so that the strength of the stress transferred to the left upper corner portion of the window  460  is decreased. Specifically, in a case where the stress is generated at the right lower corner portion of the window  460 , the stress transferred to a second convex pattern b is smaller than that transferred to a first convex pattern a, and the stress transferred to a third convex pattern c is smaller than that transferred to the second convex pattern b. The stress finally transferred to the left upper corner portion of the window  460  is smaller than that transferred to the third convex pattern c. 
         [0046]    As a result, the possibility that the left upper corner portion of the window  460  will be cracked or broken is remarkably reduced. This is because the stress is dispersed as it passes through the convex patterns  462  one by one, and therefore, the stress advancing in a specific direction is decreased. It will be apparent that the shape and size of the convex pattern  462  may be appropriately defined. 
         [0047]    Accordingly, the display device according to this embodiment has the plurality of the convex patterns  462  formed on the bottom surface of the window  460 , and the convex patterns  462  of the window  460  perform a buffering function when an impact is applied to the window  460  so that the stress transferred to the opposite side of the impact point is decreased, thereby preventing the window  460  from being broken. 
         [0048]      FIG. 5A  shows a section in which a window is attached to a display panel in a display device according to still another embodiment of the present invention.  FIG. 5B  shows a top surface of the display device shown in  FIG. 5A . 
         [0049]    First, referring to  FIG. 5A , the display device according to this embodiment includes a display panel  520 , an adhesive layer  540  and a window  560 . This embodiment is similar to the embodiments of  FIGS. 3 and 4 , except for the window  560 . Hereinafter, the window  560  will be described in detail. 
         [0050]    The window  560  has at least one irregularity on the bottom surface thereof. Specifically, the window  560  may have at least one concave pattern  562  and at least one convex pattern  564  on the bottom surface thereof. The concave pattern  562  is a pattern in which the window  560  is recessed away from the display panel  520 . The convex pattern  564  is a pattern in which the window  560  is protrudes convexly toward the display panel  520 . The concave pattern(s)  562  and the convex pattern(s)  564  may be alternately arranged. 
         [0051]    Referring to  FIG. 5B , the window  560  has five concave patterns  562  and four convex patterns  564  on the bottom surface thereof, and the concave patterns  562  and the convex patterns  564  are alternately arranged. Each concave pattern  562  and each convex pattern  564  may have a circular shape. It will be apparent that each concave pattern  562  and each convex pattern  564  may have other shapes. If stress is generated by applying an impact to a right lower corner portion of the window  560 , the stress is transferred to the opposite side, i.e., a left upper corner portion of the window  560 . The concave and convex patterns  562  and  564 , respectively, formed on the stress transfer path disperse the transferred stress. Each of the concave and convex patterns  562  and  564 , respectively, has a circular shape. Thus, if the stress is transferred to each of the concave and convex patterns  562  and  564 , respectively, the advancing direction of the stress is dispersed in all directions so that the strength of the stress transferred to the left upper corner portion of the window  560  is decreased. Specifically, in a case where the stress is generated at the right lower corner portion of the window  560 , the stress transferred to a convex pattern b is smaller than that transferred to a first concave pattern a, and the stress transferred to a second concave pattern c is smaller than that transferred to the convex pattern b. The stress finally transferred to the left upper corner portion of the window  560  is smaller than that transferred to the second concave pattern c. 
         [0052]    As a result, the possibility that the left upper corner portion of the window  560  will be cracked or broken is remarkably reduced. This is because the stress is dispersed as it passes through the concave or convex patterns  562  or  564 , respectively, one by one, and therefore, the stress advancing in a specific direction is decreased. It will be apparent that the shape and size of each of the convex and concave patterns  562  and  564 , respectively, may be appropriately defined. The resin constituting the adhesive layer  540  may be filled in the concave pattern  562 . 
         [0053]    Accordingly, the display device according to this embodiment has at least one concave pattern  562  and at least one convex pattern  564  on the bottom surface of the window  560 , and the concave and convex patterns  562  and  564 , respectively, of the window  560  perform a buffering function when an impact is applied to the window  560  so that the stress transferred to the opposite side of the impact point is decreased, thereby preventing the window  560  from being broken. 
         [0054]    While the present invention has been described in connection with certain 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, and equivalents thereof.