Patent Publication Number: US-2013250498-A1

Title: Display panel and display apparatus having the same

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority from Korean Patent Application No. 10-2012-0028501, filed on Mar. 20, 2012 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety. 
     BACKGROUND 
     1. Field 
     Methods and apparatuses consistent with exemplary embodiments relate to a display panel and a display apparatus having the same, and more particularly, to a display panel which includes a protective film having improved strength, and a display apparatus having the same. 
     2. Description of the Related Art 
     A flat panel display (FPD), which is a slim and light image display apparatus, has recently become the most common type of display apparatus. The representative FPD includes a plasma display panel (PDP), a liquid crystal display (LCD), a light emitting diode (LED), and an organic light emitting diode (OLED). The FPD is being used in various products such as a television, a monitor, a camera, a navigation system, and a game machine. 
     The FPD is vulnerable to external impact due to its thin thickness. To solve this problem, a protective film for enhancing impact resistance may be attached to a display panel of the FPD. A polyethylene terephthalate (PET) film may be used as the protective film. 
     However, if external impact is applied to the protective film of the related-art FPD, impact strength is concentrated in a direction in which the impact is applied and therefore most of the amount of the impact is transmitted to the display panel, and thus there is a problem in that the display panel is easily damaged. 
     Various attempts to solve this problem have been made. For example, the related-art FPD employs a plurality of protective films or adds an extra impact resistance layer to the protective film. 
     However, these protective films or additional impact resistance layers may increase the film manufacturing cost and may complicate the film manufacturing process. 
     SUMMARY 
     One or more exemplary embodiments may overcome the above disadvantages and other disadvantages not described above. However, it is understood that one or more exemplary embodiment are not required to overcome the disadvantages described above, and may not overcome any of the problems described above. 
     One or more exemplary embodiments provide a display panel which includes a protective film having improved strength, and a display apparatus having the same. 
     According to an aspect of an exemplary embodiment, there is provided a display panel including: a panel body, and a protective film which is adhered to a front surface of the panel body by an adhesive, wherein a rear surface of the protective film adhered to the panel body includes a convex portion and a concave portion which are formed alternately. 
     The adhesive may be maintained in a gel state. 
     The protective film may be made of an elastic material. 
     The protective film may be made of polyethylene terephthalate (PET). 
     A cross section of the convex portion of the rear surface of the protective film and the concave portion of the rear surface of the protective film may have one of round, triangular, quadrangular, and trapezoidal shapes. 
     Each of the convex portion and the concave portion of the rear surface of the protective film may be extended in a lengthwise direction of the display panel. 
     Each of the convex portion and the concave portion of the rear surface of the protective film may be extended in a width direction of the display panel. 
     Each of the convex portion and the concave portion of the rear surface of the protective film may be extended in a diagonal direction of the display panel. 
     The adhesive may be a pressure sensitive adhesive (PSA). 
     The PSA may be a color PSA. 
     The display panel may further include a hard coating layer which is formed on a front surface of the protective film. 
     The display panel may be one of a PDP panel, an LCD panel, an LED panel, and an OLED panel. 
     According to an aspect of an exemplary embodiment, there is provided a display apparatus including the above-described display panel. 
     According to the various exemplary embodiments described above, when external impact is applied to the display panel, the impact strength is dispersed by the elastic deformation of the convex portions and the concave portions formed on the protective film so that damage of the display panel can be prevented. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING FIGURES 
       The above and/or other aspects will be more apparent by describing in detail exemplary embodiments, with reference to the accompanying drawings, in which: 
         FIG. 1  is an exploded perspective view schematically illustrating a display apparatus according to an exemplary embodiment; 
         FIG. 2  is a schematic cross section view of a display panel included in the display apparatus of  FIG. 1 ; 
         FIG. 3  is a perspective view schematically illustrating a protective film included in the display panel of  FIG. 2 ; 
         FIG. 4  is an enlarged cross section view of portion ‘A’ of  FIG. 2 ; 
         FIGS. 5 and 6  are views schematically illustrating the display panel of  FIG. 2  when external impact is applied to the display panel; 
         FIG. 7  is a schematic cross section view of a display panel according to a second exemplary embodiment; 
         FIG. 8  is an enlarged cross section view of portion ‘A’ of  FIG. 7 ; 
         FIG. 9  is a cross section view schematically illustrating a display panel according to a third exemplary embodiment; 
         FIG. 10  is a cross section view schematically illustrating a display panel according to a fourth exemplary embodiment; 
         FIG. 11  is a cross section view schematically illustrating a display panel according to a fifth exemplary embodiment; and 
         FIG. 12  is a perspective view schematically illustrating a protective film according to an alternative exemplary embodiment. 
     
    
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     Hereinafter, exemplary embodiments will be described in greater detail with reference to the accompanying drawings. 
     In the following description, same reference numerals are used for the same elements when they are depicted in different drawings. The matters defined in the description, such as detailed construction and elements, are provided to assist in a comprehensive understanding of exemplary embodiments. Thus, it is apparent that exemplary embodiments can be carried out without those specifically defined matters. Also, functions or elements known in the related art are not described in detail since they would obscure the exemplary embodiments with unnecessary detail. 
       FIG. 1  is an exploded perspective view schematically illustrating a display apparatus according to an exemplary embodiment. 
     Referring to  FIG. 1 , a display apparatus  1  includes a housing  10  and a display panel  100 . 
     The display apparatus  1  is a PDP television which is one of the flat panel displays. In an alternative embodiment, the display apparatus  1  may be other flat panel displays such as an LCD television, an LED television, and an OLED television. The display apparatus  1  may be a computer monitor to which such a flat panel display is applied. 
     The housing  10  contains the display panel  100  and various parts of the display apparatus  1  such as a control board (not shown) to control an operation of the display panel  100  and a power board (not shown) to supply power to the display panel  100 . 
     The housing  10  includes a front housing  12  and a rear housing  14  which are removably connected to each other. The front housing  12  forms a front edge of the display apparatus  1  and has a rectangular opening  12   a  to allow an image to be exposed to the outside. The rear housing  14  has a receiving space formed therein to receive the aforementioned various parts. 
     The display panel  100  is a PDP. The PDP is a panel that creates or forms an image by emitting a fluorescent substance using a gas discharge phenomenon and is a representative one of the flat panel display panel. In an alternative embodiment, if the display apparatus  1  is a flat panel display other than the PDP, the display apparatus  1  may include a corresponding display panel. For example, an LCD panel, an LED panel, or an OLED panel may be provided in the display apparatus  1 . 
       FIG. 2  is a schematic cross section view of the display panel provided in the display apparatus of  FIG. 1 ,  FIG. 3  is a perspective view schematically illustrating a protective film provided in the display panel of  FIG. 2 , and  FIG. 4  is an enlarged cross section view of portion ‘A’ of  FIG. 2 . 
     Referring to  FIGS. 2 to 4 , the display panel  100  includes a panel body  120  and a protective film  150 . 
     Although the panel body  120  is illustrated as a single substrate in  FIG. 2 , the panel body  120  may include a pair of substrates (not shown) as in a general PDP. A plurality of discharge cells (not shown) corresponding to pixels are formed between the pair of substrates (not shown), and each discharge cell emits a fluorescent substance due to ultraviolet rays generated by gas discharge, so that visually identifiable visible rays are generated. The principle of realizing an image of the PDP is well known and thus a detailed description is omitted. 
     The protective film  150  is adhered to a front surface  122  of the panel body  120  by an adhesive  190 . The protective film  150  protects the panel body  120  from external impact. If the panel body  120  is damaged, the protective film  150  prevents broken pieces from being scattered to the front of the display apparatus  1 . 
     A front surface  160  of the protective film  150  is exposed to the front of the display apparatus  1  and has a flat surface. A rear surface  180  of the protective film  150  is adhered to the front surface  122  of the panel body  120  using the adhesive  190 , and includes a plurality of convex portions  182  and a plurality of concave portions  186  unlike the front surface  160 . 
     The convex portions  182  and the concave portions  186  are formed alternately. That is, concave portions  186  are formed at opposite sides of one convex portion  182  and convex portions  182  are formed at opposite sides of one concave portion  186 . As shown in  FIG. 3 , the convex portions  182  and the concave portions  186  are extended in a lengthwise direction (Y) of the protective film  150 . That is, the convex portions  182  and the concave portions  186  are extended in a lengthwise direction of the display panel  100 , and the convex portions  182  are parallel to one another and the concave portions  186  are also parallel to one another. In an alternative embodiment, the convex portions and the concave portions may be extended in a width direction of the display panel (in an X direction of  FIG. 3 ). 
     A cross section of each of the convex portion  182  and the concave portion  186  has a round shape having a substantially semi-circular shape. In an alternative exemplary embodiment, the cross section of the convex portion  182  and the concave portion  186  may have a semi-oval shape. 
     The protective film  150  is made of polyethylene terephthalate (PET). The polyethylene terephthalate is a thermo-plastic resin and is an elastic material that is heat-resistant and has good elasticity. Thus, the protective film  150  is elastically deformable. In an alternative embodiment, the protective film  150  may be made of other elastic materials which are elastically deformable. 
     If the display panel  100  receives an external impact, the protective film  150  is elastically deformed to absorb the external impact in part or in whole and to mitigate the impact on the panel body  120 . 
     The adhesive  190  may be a pressure sensitive adhesive (PSA). The PSA refers to an adhesive that makes two objects adhere to each other with light pressure. In an alternative embodiment, the adhesive  190  may be a color PSA to which an optical function is added. The color PSA has an optical function in addition to its original adhering function, and, if the color PSA is applied to the PDP, it is possible to shield neon emission and absorb near-infrared ray. An adhesive other than the PSA may be used. 
     The adhesive  190  is maintained in a gel state after adhering. The gel is a solidified colloid liquid like a jelly and refers to a liquid lump having viscosity. The adhesive  190  being maintained in the gel state enables the convex portions  182  and the concave portions  186  to be elastically deformed. Also, the adhesive  190  being maintained in the gel state may absorb the external impact applied to the display panel  100 . 
       FIGS. 5 and 6  are views schematically illustrating the display panel of  FIG. 2  when the display panel receives an external impact. 
     Referring to  FIG. 5 , if the front of the display panel  100  receives an external impact (a ball B shown in  FIG. 5 ), the strength of the impact is dispersed in the arrow directions due to the presence of the convex portions  182  and the concave portions  186 . The protective film  150  also suffers elastic deformation. The elastic deformation occurs not only in the convex portion  182  in which the impact is directly received, but also in the concave portions  186  formed at opposite sides of the convex portion  182  due to the dispersion of forces. That is, the external impact is absorbed by not only the elastic deformation of the convex portion  182  to which the impact is directly applied, but also the elastic deformation of the concave portions  186  formed at the opposite sides of the convex portion  182 . 
     Referring to  FIG. 6 , if the display panel  100  receives an external impact (a ball (B) shown in  FIG. 6 ), the strength of the impact is dispersed in the arrow directions similarly as shown in  FIG. 5  due to the presence of the convex portions  182  and the concave portions  186 . The protective film  150  is also elastically deformed. In  FIG. 6 , since the external impact is applied in a direction toward the concave portions  186 , larger elastic deformation occurs in the concave portions  186 . Meanwhile, the convex portions  182  formed at opposite sides of the concave portion  186  contract. That is, even if the external impact is applied in the direction toward the concave portion  186 , the external impact is absorbed by not only the elastic deformation of the concave portions  186 , to which the impact is directly applied, but also by the elastic deformation of the convex portions  182  formed at the opposite sides of the concave portion  186 . 
     As shown in  FIGS. 5 and 6 , if the display panel  100  receives an external impact, the protective film  150  disperses and absorbs the impact using the elastic deformation of the convex portions  182  and the concave portions  186 . The elastic deformation is possible because the adhesive  190  is maintained in the gel state as described above. 
     The adhesive  190  also absorbs the external impact as described above. Due to the presence of the convex portions  182 , the concave portions  186 , and the adhesive  190 , the panel body  120  of the display panel  100  may not be subjected to the external impact or the effect of the impact may be reduced. 
     As described above, without adding a separate member to improve impact resistance to the protective film  150 , the display panel  100  can improve the strength of the protective film  150 . Therefore, there is no need to increase the thickness of the display panel  100  since the thickness of the protective film  100  is not increased, and thus, the display panel  100  can still be made slim, a manufacturing cost of the protective film  100  can be reduced, and a manufacturing process of the protective film  100  can be simplified. 
       FIG. 7  is a schematic cross section view of a display panel according to a second exemplary embodiment, and  FIG. 8  is an enlarged view of portion ‘A’ of  FIG. 7 . 
     A display panel  200  according to a second exemplary embodiment is similar to the display panel  100  of the aforementioned embodiment. For instance, a panel body  220 , a front surface  222  of the panel body  220 , a rear surface  280  of a protective film  250 , a convex portion  282  of the protective film  250 , and a concave portion  286  of the protective film  250  are the same as those of the above-described display panel  100 . An adhesive  290  is also the same as the aforementioned adhesive  190 . Therefore, these elements are not explained repeatedly. 
     Referring to  FIGS. 7 and 8 , the display panel  200  includes a hard coating layer  295 . 
     The hard coating layer  295  is formed on a front surface  260  of the protective film  250  and thus is exposed to the front of the display apparatus. The hard coating layer  295  performs an optical function of preventing specular reflection or diffuse reflection of light. Accordingly, the display panel  200  according to the present exemplary embodiment can provide a clearer and high quality image for a user by using the hard coating layer  295 . 
     Also, since the hard coating layer  295  is further exposed to the front side of the display apparatus than the protective film  250 , the hard coating layer  295  can protect the protective film  250  from scratch caused by external impact. 
       FIG. 9  is a cross section view schematically illustrating a display panel according to a third exemplary embodiment,  FIG. 10  is a cross section view schematically illustrating a display panel according to a fourth exemplary embodiment, and  FIG. 11  is a cross section view schematically illustrating a display panel according to a fifth exemplary embodiment. 
     Display panels  300 ,  400 , and  500  according to the third to the fifth exemplary embodiments are similar to the display panel  100  of the aforementioned exemplary embodiment. For instance, panel bodies  320 ,  420 , and  520 , front surfaces  322 ,  422 , and  522  of the panel bodies  320 ,  420 , and  520 , and front surfaces  360 ,  460 , and  560  of the protective films  350 ,  450 , and  550  are the same as those corresponding elements of the display panel  100  described above. Adhesives  390 ,  490 , and  590  are also the same as the adhesive  190  described above. Therefore, these elements are not explained repeatedly. 
     Rear surfaces  380 ,  480 , and  580  of the protective films  350 ,  450 , and  550  are generally similar to the rear surface  180  of the protective film  150  described above. Hereinafter, a difference between the rear surfaces  380 ,  480 ,  580  and the rear surface  180  of the protective film  150  will be mainly explained. 
     Referring to  FIGS. 9 to 11 , a cross section of a convex portion  382  and a concave portion  386  of the protective film  350  according to the third exemplary embodiment has a substantially triangular shape. The triangular shape may be an equilateral triangle or an isosceles triangle. A cross section of a convex portion  482  and a concave portion  486  of the protective film  450  according to the fourth exemplary embodiment has a substantially quadrangular shape. The quadrangular shape may be a square or a rectangle. A cross section of a convex portion  582  and a concave portion  586  of the protective film  550  according to the fifth exemplary embodiment has a substantially trapezoidal shape. In an alternative embodiment, the cross section of the convex portion and the concave portion may have other polygonal shapes or saw-toothed shape. 
     However, it is noted that the cross section shapes of the convex and concave portions of the protective film are not limited to those described above. 
     In the third to the fifth exemplary embodiments, if the display panels  300 ,  400 , and  500  receive an external impact or an external impact is applied thereto, the convex portions  382 ,  482 , and  582  and the concave portions  386 ,  486 , and  586  absorb the external impact through elastic deformation and mitigate the impact on the panel bodies  320 ,  420 , and  520 . 
       FIG. 12  is a perspective view schematically illustrating a protective film according to an alternative embodiment. 
     A protective film  650  is similar to the protective film  150  described above. 
     A rear surface  680  of the protective film  650  includes a plurality of convex portions  682  and a plurality of concave portions  686 . As in the above exemplary embodiments, the convex portions  682  and the concave portions  686  are formed alternately. Each of the convex portions  682  and the concave portions  686  is extended in a diagonal direction (Y) of the protective film  650 . That is, the convex portions  682  and the concave portions  686  are extended in the diagonal direction of a display panel (not shown). The convex portions  682  are parallel to one another and the concave portions  686  are also parallel to one another. In an alternative embodiment, the convex portions and the concave portions may be extended in the other diagonal direction (an X direction in  FIG. 12 ). 
     The protective film  650  is different from the protective film  150  of the aforementioned embodiment in the extending direction of the convex portions  682  and the convex portions  686 , but has the same function as that of the protective film  150 . That is, if the protective film  650  is provided in the display panel, the impact on the panel body can be mitigated. 
     The foregoing exemplary embodiments and advantages are merely exemplary and are not to be construed as limiting the present inventive concept. The exemplary embodiments can be readily applied to other types of apparatuses. Also, the description of the exemplary embodiments is intended to be illustrative, and not to limit the scope of the claims, and many alternatives, modifications, and variations will be apparent to those skilled in the art.