Abstract:
A backplate having a folding region and an unfolding region adjacent to the folding region includes: first and second material layers corresponding to the folding and unfolding regions; and a third material layer between the first and second material layers, the third material layer is more rigid than the first and second materials layers, wherein the first and second material layers extend from the folding region to the unfolding regions such that a thickness of the first and second material layers is gradually reduced from the folding region to the unfolding region.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present application claims the benefit of Republic of Korea Patent Application No. 10-2016-0053393 filed in the Republic of Korea on Apr. 29, 2016, which is hereby incorporated by reference in its entirety for all purposes as if fully set forth herein. 
       BACKGROUND 
     Field of the Disclosure 
       [0002]    The present disclosure relates to a display device, and more particularly to a liquid crystal display device having a narrow bezel. 
       Discussion of the Background 
       [0003]    Recently, as the information technology and the mobile communication technology progress, display devices that process and display a large amount of information have rapidly advanced. The display devices are classified into an emissive type display device having a self-emissive property and a non-emissive type display device including an additional light source. 
         [0004]    For example, the non-emissive type display device may include a liquid crystal display (LCD) device. Since the LCD device does not include a self-emissive element, an additional light source is required. As a result, a backlight unit having a light source is disposed on a rear surface of a liquid crystal panel and supplies a light to the liquid crystal panel to display an image. 
         [0005]    The backlight unit includes one of a cold cathode fluorescent lamp (CCFL), an external cathode fluorescent lamp (EEFL) and a light emitting diode (LED) as the light source. Specifically, the LED has been widely used because of its advantages such as small size, low power consumption, and high reliability. 
         [0006]    The backlight unit is classified into a side light type and a direct light type according to an arrangement structure of lamps. In the side light type backlight unit, one lamp or a pair of lamps are disposed at one side portion of a light guide plate, or two lamps or two pairs of lamps are disposed at both side portions of a light guide plate. In a direct light type backlight unit, a plurality of lamps are disposed under an optical sheet. 
         [0007]    Under a circumstance where a large-sized LCD device has been the subject of a recent research according to user&#39;s demand, the direct light type backlight unit has superiority for the large-sized LCD device to the side light type backlight unit. 
         [0008]      FIG. 1  is a cross-sectional view showing a liquid crystal display device including a direct light type backlight unit having a light emitting diode as a light source according to the related art. 
         [0009]    In  FIG. 1 , a liquid crystal display (LCD) device  1  includes a liquid crystal panel  10  having first and second substrates  12  and  14  and a backlight unit  20  disposed on a rear surface of the liquid crystal panel  10 . 
         [0010]    The backlight unit  20  includes a reflecting plate  22 , a plurality of light emitting diodes (LEDs)  28 , a diffusing plate  26  on the plurality of LEDs  28  and a plurality of optical sheets  27  on the diffusing plate  26 . 
         [0011]    Light emitted from adjacent two or three LEDs  28  are superposed and mixed and enters the liquid crystal panel  10  to provide a surface light source. 
         [0012]    The backlight unit  20  having the plurality of LEDs  28  and the liquid crystal panel  10  are modularized by a top frame  40 , a main frame  30  and a bottom frame  50 . The main frame  30  having a rectangular ring shape surrounds edge portions of the liquid crystal panel  10  and the backlight unit  20 , the top frame  40  surrounds front edge portions of the liquid crystal panel  10 , and the bottom frame  50  covers a rear surface of the backlight unit  20 . The main frame  30 , the top frame  40  and the bottom frame  50  are combined with each other such that the backlight unit  20  and the liquid crystal panel  10  are integrated. 
         [0013]    Since the usage of the LCD device  1  is enlarged from a portable computer to a monitor of a desktop computer and a wall-mountable television, a LCD device having a large-sized display area, a reduced weight and a reduced volume has been widely researched. 
         [0014]    In addition, a LCD device having a narrow bezel, where a display region is enlarged and a non-display region of the bezel is reduced, as well as a light weight and a thin profile has been required. 
         [0015]    However, the LCD device  1  has problems in obtaining a narrow bezel. For example, since the light from the plurality of LEDs  28  of the light source of the backlight unit  20  may not enter the edge portions of the liquid crystal panel  10 , it may become difficult to obtain a narrow bezel. 
         [0016]    The light emitted from the plurality of LEDs  28  of a point light source enters the liquid crystal panel  10  with a luminous view angle, and there exists a blind angle at the edge portions of the liquid crystal panel  10  where the light from the plurality of LEDs  28  does not enter the liquid crystal panel  10 . Since the blind angle at the edge portions of the liquid crystal panel  10  is blocked, it is difficult to obtain the narrow bezel. 
         [0017]    To display a single image with a large-sized panel (e.g. about 100 inches), a multi-panel display device such as a video wall where a plurality of LCD devices  1  are combined with each other in a tile shape has been widely researched. In the multi-panel display device, the bezel of each of the plurality of LCD devices  1  functions as an obstructive factor for continuity of an image. As a result, the LCD device  1  having a narrow bezel is required for the multi-panel display device. 
       SUMMARY 
       [0018]    Accordingly, the present disclosure is directed to a liquid crystal display device having a narrow bezel and a multi-panel display device including the same that substantially obviates one or more of problems due to limitations and disadvantages of the prior art. 
         [0019]    In accordance with the present disclosure, as embodied and broadly described herein, the present disclosure provides a display device including: a first liquid crystal liquid crystal display (LCD) device including: a liquid crystal panel; a backlight unit under the liquid crystal panel, the backlight unit including a first light emitting diode (LED) assembly having a plurality of first LEDs, a second LED assembly having a plurality of second LEDs, a diffusing plate, a reflecting plate and an optical sheet; a main frame having a rectangular ring shape and surrounding the liquid crystal panel and the backlight unit, the main frame including a vertical part and a light guide bar protruding from an inner surface of the vertical part, the second LED assembly disposed under the light guide bar; and a bottom frame combined with the main frame, the liquid crystal panel and the backlight unit are disposed on the bottom frame. 
         [0020]    It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the embodiments as claimed. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0021]    The accompanying drawings, which are included to provide a further understanding of the disclosure and are incorporated in and constitute a part of this specification, illustrate embodiments and together with the description serve to explain the principles of the disclosure. In the drawings: 
           [0022]      FIG. 1  is a cross-sectional view showing a liquid crystal display device including a direct light type backlight unit having a light emitting diode as a light source according to the related art. 
           [0023]      FIG. 2  is an exploded perspective view showing a liquid crystal display device according to a first embodiment of the present disclosure. 
           [0024]      FIG. 3A  is a perspective view showing a main frame of a liquid crystal display device according a first embodiment of the present disclosure. 
           [0025]      FIG. 3B  is a cross-sectional view showing a main frame of a liquid crystal display device according a first embodiment of the present disclosure. 
           [0026]      FIGS. 4A and 4B  are cross-sectional views showing a liquid crystal display device according to first and second embodiments, respectively, of the present disclosure. 
           [0027]      FIGS. 5A to 5C  are perspective views showing a main frame of a liquid crystal display device according to third to fifth embodiments, respectively, of the present disclosure. 
           [0028]      FIG. 6  is a cross-sectional view showing a multi-panel display device according to a sixth embodiment of the present disclosure. 
           [0029]      FIG. 7  is a cross-sectional view showing a compensation structure for an image severance phenomenon according to a sixth embodiment of the present disclosure. 
           [0030]      FIG. 8A  is a view showing a multi-panel display device according to the related art. 
           [0031]      FIG. 8B  is a view showing a multi-panel display device according to a sixth embodiment of the present disclosure. 
       
    
    
     DETAILED DESCRIPTION 
       [0032]    Reference will now be made in detail to the present disclosure, examples of which are illustrated in the accompanying drawings. 
         [0033]      FIG. 2  is an exploded perspective view showing a liquid crystal display device according to a first embodiment of the present disclosure. 
         [0034]    In  FIG. 2 , a liquid crystal display (LCD) device  100  includes a liquid crystal panel  110 , a backlight unit  120 , a top frame (case top)  140 , a main frame (guide panel)  200  and a bottom frame (cover bottom)  150 . 
         [0035]    The backlight unit  120  is disposed on a rear surface of the liquid crystal panel  110 . The main frame  200  having a rectangular ring shape surrounds edge portions of the liquid crystal panel  110  and the backlight unit  120 . The top frame  140  is disposed on a front surface of the liquid crystal panel  110 , and the bottom frame  150  is disposed on a rear surface of the backlight unit  120 . The top frame  140 , the main frame  200  and the bottom frame  150  are combined with each other to modularize the liquid crystal panel  110  and the backlight unit  120 . 
         [0036]    The liquid crystal panel  110  includes first and second substrates  112  and  114  facing and spaced apart from each other and a liquid crystal layer (not shown) between the first and second substrates  112  and  114 . Although not shown, a plurality of gate lines and a plurality of data lines are formed on an inner surface of the first substrate (lower substrate, array substrate)  112 . The gate line and the data line cross each other to define a pixel, and a thin film transistor (TFT) is connected to the gate line and the data line. A transparent pixel electrode in each pixel is connected to the TFT. In addition, a black matrix covering the gate line, the data line and the TFT is formed on an inner surface of the second substrate (upper substrate, color filter substrate)  114 , and a color filter layer including red, green and blue color filters is formed on the black matrix. A transparent common electrode is formed on the color filter layer. 
         [0037]    A printed circuit board (PCB)  117  is connected to at least one side of the liquid crystal panel  110  through a connector  116  such as a flexible printed circuit (FPC). The PCB  117  is bent and contacts a rear surface of the bottom frame  150  through a modularization process. 
         [0038]    Although not shown, a first alignment layer is formed between the first substrate  112  and the liquid crystal layer, and a second alignment layer is formed between the second substrate  114  and the liquid crystal layer. In addition, a seal pattern is formed in edge portions between the first and second substrates  112  and  114  to prevent a leakage of the liquid crystal layer. First and second polarizing plates  119   a  and  119   b  (of  FIG. 4A ) are formed on outer surfaces of the first and second substrates  112  and  114 , respectively. 
         [0039]    The backlight unit  120  supplies a light to the liquid crystal panel  110  so that a transmittance difference of the liquid crystal panel  110  can be realized. The backlight unit  120  includes a first LED assembly  128 , a reflecting plate  125 , a diffusing plate  123  spaced apart from the first LED assembly  128  through a guide support  127 , and an optical sheet  121  over the diffusing plate  123 . 
         [0040]    The first LED assembly  128  is a main light source of the backlight unit  120  and includes a first LED PCB  128   b  and a plurality of first LEDs  128   a  on the first LED PCB  128   b . The first LED PCB  128   b  has a plate shape disposed on an inner surface of a lower surface  151  of the bottom frame  150 . The plurality of first LEDs  128   a  are disposed to be spaced apart from each other. 
         [0041]    Although not shown, for an excellent emitting efficiency and an excellent brightness, the plurality of first LEDs  128   a  may include a blue LED having a blue LED chip and a yellow fluorescent material such as cerium-doped yttrium aluminum garnet (YAG:Ce). A blue light emitted from the blue LED chip passes through the fluorescent material to be mixed with a yellow light emitted from the fluorescent material such that the first LED  128   a  emits a white light to the diffusing plate  123 . 
         [0042]    The reflecting plate  125  includes a plurality of through holes  125   a . The plurality of first LEDs  128   a  penetrate through the plurality of through holes  125   a  such that the reflecting plate  125  covers the first LED PCB  128   b  and the lower surface  151  of the bottom frame  150  except the plurality of first LEDs  128   a . As a result, the light toward a lower portion of the plurality of first LEDs  128   a  is reflected to the diffusing plate  123  and a brightness of light is improved. 
         [0043]    The diffusing plate  123  and the optical sheet  121  are disposed over the plurality of first LEDs  128   a  exposed through the plurality of through holes  125   a  of the reflecting plate  125  for improving a uniformity of brightness. The diffusing plate  123  and the optical sheet  121  are supported by the guide support  127  to prevent a deflection of the diffusing plate  123  and the optical sheet  121 . The optical sheet  121  may include a diffusing sheet and at least one collimating sheet to diffuse or collimate a light passed through the diffusing plate  123  and to provide a more uniform surface light source to the liquid crystal panel  110 . 
         [0044]    Accordingly, after the light emitted from the plurality of first LEDs  128   a  of the first LED assembly  128  is processed to become a uniform light of high quality while passing through the diffusing plate  123  and the optical sheet  121  and enters the liquid crystal panel  110 , the liquid crystal panel  110  displays an image of high brightness using the light. 
         [0045]    The liquid crystal panel  110  and the backlight unit  120  are modularized through the top frame  140 , the main frame  200  and the bottom frame  150 . The top frame  140  has a bent rectangular ring shape of a cross-section of “L” shape to cover edge portions of front and side surfaces of the liquid crystal panel  110 . The top frame  140  includes a first edge part  141  covering the side surface of the liquid crystal panel  110  and a second edge part  143  covering the edge portion of the front surface of the liquid crystal panel  110 . The top frame  140  has an opening so that an image of the liquid crystal panel  110  can be displayed through the opening. 
         [0046]    The main frame  200  has a rectangular ring shape to support edge portions of rear surfaces of the liquid crystal panel  110 , the diffusing plate  123  and the optical sheet  121  and to divide positions of the liquid crystal panel  110  and the backlight unit  120 . 
         [0047]    In addition, the main frame  200  maintains an optical gap or an air gap between the first LED assembly  128  and the diffusing plate  123 . In the direct light type backlight unit  120  according to a first embodiment of the present disclosure, the optical gap or the air gap is formed between the first LED assembly  128  and the diffusing plate  123 . The optical gap is a space where the lights emitted from the plurality of first LEDs  128   a  of the first LED assembly  128  are mixed. For example, the light from the plurality of first LEDs  128   a  may be uniformly mixed in the optical gap to enter the diffusing plate  123 , or the optical gap may prevent a heat expansion of the diffusing plate  123  due to a heat of a high temperature generated from the plurality of first LEDs  128   a.    
         [0048]    The main frame  200  includes a vertical part  210  for maintaining the optical gap between the first LED assembly  128  and the diffusing plate  123  and a light guide bar  220  protruding an inner surface of the vertical part  210  to support the edge portions of the rear surface of the diffusing plate  123  and the optical sheet  121 . The light guide bar  220  has a horizontal surface  221  (of  FIG. 3A ) perpendicularly extending from the vertical part  210 . The edge portions of the rear surface of the liquid crystal panel  110  is attached and fixed to a front surface  210   a  (of  FIG. 3A ) of the vertical part  210  through an adhesive pad (not shown) such as a double-sided tape, and the edge portions of the rear surface of the diffusing plate  123  and the optical sheet  121  are disposed on and supported by the horizontal surface  221  of the light guide bar  220 . As a result, the optical gap between the first LED assembly  128  and diffusing plate  123  is maintained. 
         [0049]    Specifically, a second LED assembly  129  is disposed under the light guide bar  220 . The second LED assembly  129  as an auxiliary light source of the backlight unit  120  includes a second LED PCB  129   b  having a bar shape and a plurality of second LEDs  129   a  spaced apart from each other on the second LED PCB  129   b.    
         [0050]    Although not shown, for excellent emitting efficiency and excellent brightness, the plurality of first LEDs  129   a  may include a blue LED having a blue LED chip and a yellow fluorescent material such as cerium-doped yttrium aluminum garnet (YAG:Ce). A blue light emitted from the blue LED chip passes through the fluorescent material to be mixed with a yellow light emitted from the fluorescent material such that the second LED  129   a  emits a white light to the light guide bar  220 . 
         [0051]    The light emitted from the plurality of second LEDs  129   a  enters the light guide bar  220  and passes through the light guide bar  220  by several total reflections to be provided to the edge portions of the liquid crystal panel  110 . 
         [0052]    As a result, in the LCD device  100  according to a first embodiment of the present disclosure, the light is uniformly supplied to a whole region of the liquid crystal panel  110  and an image is displayed through the whole of the liquid crystal panel  110 . Since a display region of the liquid crystal panel  110  is enlarged and a non-display region of a bezel of the liquid crystal panel  110  is reduced, the LCD device  100  of a narrow bezel is obtained. 
         [0053]    The bottom frame  150  is a base of modularization of the LCD device  100  where the liquid crystal panel  110  and the backlight unit  120  are disposed. The bottom frame  150  includes a lower surface  151  of a plate shape and a side surface  153  perpendicularly bent from edge portions of the lower surface  151 . 
         [0054]    The main frame  200  surrounding the edge portions of the liquid crystal panel  110  and the backlight unit  120  is combined with the top frame  140  surrounding the front edge portions of the liquid crystal panel  110  and the bottom frame  150  covering the rear surface of the backlight unit  120  so that the liquid crystal panel  110  and the backlight unit  120  can be modularized. 
         [0055]    The top frame  140  may be referred to as a case top, a top cover or a top case, the main frame  200  may be referred to as a guide panel, a support main or a main support, and the bottom frame  150  may be referred to as a cover bottom, a bottom cover or a lower cover. 
         [0056]    To obtain the LCD device  100  having a light weight and a thin profile, a top frame  140  may be omitted. The LCD device  100  may have a light weight and a thin profile and a fabrication process of the LCD device  100  may be simplified by omission of the top frame  140 . In addition, a fabrication cost of the LCD device  100  may be reduced by omission of the top frame  140  of a metallic material. 
         [0057]    In the LCD device  100  according to the first embodiment of the present disclosure, light is uniformly supplied to the edge portions of the liquid crystal panel  110  by forming the light guide bar  220  of the main frame  200  and disposing the second LED assembly  129  as an auxiliary light source under the light guide bar  220 . Since the light is uniformly supplied to the whole region of the liquid crystal panel  110 , a display region of the liquid crystal panel  110  is enlarged and a non-display region of a bezel of the liquid crystal panel  110  is reduced. As a result, the LCD device  100  of a narrow bezel is obtained. 
         [0058]      FIG. 3A  is a perspective view showing a main frame of a liquid crystal display device according a first embodiment of the present disclosure, and  FIG. 3B  is a cross-sectional view showing a main frame of a liquid crystal display device according a first embodiment of the present disclosure. 
         [0059]    In  FIGS. 3A and 3B , the main frame  200  having a rectangular ring shape includes the vertical part  210  having front and rear surfaces  210   a  and  210   b  and the light guide bar  220  protruding from an inner surface of the vertical part  210 . 
         [0060]    The vertical part  210  of the main frame  200  may include a synthetic resin such as polycarbonate and may be formed through a molding process. The light guide bar  220  of the main frame  200  may include a transparent resin such as an acrylic resin. For example, the light guide bar  220  may include a plastic material such as polymethylmethacrylate (PMMA) and polycarbonate (PC). The light guide bar  220  may be formed of PMMA having advantages in transparency, weatherability and coloring property and inducing diffusion of a light. 
         [0061]    The light guide bar  220  includes first and second horizontal surfaces  221  and  225  and first and second slanting surfaces  223  and  227  opposite to each other. The first horizontal surface  221  perpendicularly extends from an inner surface of the vertical part  210 . The first slanting surface  223  obliquely extends from an edge portion of the first horizontal surface  221  with an obtuse angle toward the rear surface  210   b  of the vertical part  210 . The second slanting surface  227  obliquely extends from an opposite surface of the first horizontal surface  221 . The first and second slanting surfaces  223  and  227  may be disposed closer from the first horizontal surface  221  to the second horizontal surface  225 . 
         [0062]    The first and second slanting surfaces  223  and  227  are connected to both edge portions of the second horizontal surface  225 . As a result, the inner surface of the vertical part  210  and the second slanting surface  227  of the light guide bar  220  define an inner space A of the main frame  200 , and the second LED assembly  129  (of  FIG. 2 ) of the auxiliary light source is disposed in the inner space A. 
         [0063]    The light guide bar  220  includes a chamfer part  229  having a shape where the second slanting surface  227  and the second horizontal surface  225  are removed. The chamfer part  229  includes a light incident surface  229   a  parallel to the first and second horizontal surfaces  221  and  225 , and the plurality of second LEDs  129   a  (of  FIG. 2 ) of the second LED assembly  129  in the inner surface A between the inner surface of the vertical part  210  and the second slanting surface  227  are disposed to face into the light incident surface  229   a.    
         [0064]    The light guide bar  220  includes a hook  228  protruding from the first slanting surface  223  and the second horizontal surface  225 . 
         [0065]    A pattern (not shown) may be formed on the second slanting surface  227  of the light guide bar  220  for supplying a uniform surface light source. To guide a light incident into the light guide bar  220 , the pattern may include an elliptical pattern, a polygonal pattern or a hologram pattern. The pattern may be formed through a printing method or an injection molding method. 
         [0066]    In the main frame  200  according to the first embodiment of the present disclosure, since the light guide bar  220  guides the light to the vertical part  210  and the second LED assembly  129  of the auxiliary light source is disposed under the light guide bar  220 , the light is uniformly supplied to the edge portions of the liquid crystal panel  110 . 
         [0067]      FIGS. 4A and 4B  are cross-sectional views showing a liquid crystal display device according to first and second embodiments, respectively, of the present disclosure. 
         [0068]    In  FIG. 4A , the backlight unit  120  (of  FIG. 2 ) includes the first LED assembly  128 , the reflecting plate  125 , the diffusing plate  123  and the optical sheet  121 . The first LED assembly  128  includes the first LED PCB  128   b  of a plate shape and the plurality of first LEDs  128   a  on the first LED PCB  128   b , and the plurality of through holes  125   a  of the reflecting plate  125  expose the plurality of first LEDs  128   a  of the first LED assembly  128 . The diffusing plate  123  and the optical sheet  121  are disposed over the first LED assembly  128 . 
         [0069]    The liquid crystal panel  110  including the first and second substrates  112  and  114  and the liquid crystal layer between the first and second substrates  112  and  114  is disposed over the backlight unit  120 , and the first and second polarizing plates  119   a  and  119   b  selectively transmitting a light are formed on the outer surfaces of the first and second substrates  112  and  114 , respectively. 
         [0070]    The backlight unit  120  and the liquid crystal panel  110  are modularized and integrated as one body by the main frame  200 , the top frame  140  and the bottom frame  150 . The first LED assembly  128  is disposed over the lower surface  151  of the bottom frame  150 , and the reflecting plate  125  is disposed over the first LED assembly  128  such that the plurality of through holes  125   a  selectively expose the plurality of first LEDs  128   a.    
         [0071]    The diffusing plate  123  is disposed over the first LED assembly  128  with the optical gap and is supported by the guide support  127 . The optical sheet  121  is disposed over the diffusing plate  123 . 
         [0072]    The main frame  200  surrounds the edge portions of the backlight unit  120  including the first LED assembly  128 , the diffusing plate  123  and the optical sheet  121 , and the edge portions of the rear surface of the diffusing plate  123  and the optical sheet  121  are disposed on and are supported by the first horizontal surface  221  of the light guide bar  220  of the main frame  200 . The edge portions of the rear surface of the liquid crystal panel  110  over the optical sheet  121  are disposed on and are supported by the front surface  210   a  of the vertical part  210  of the main frame  200 . 
         [0073]    Since the edge portions of the rear surface of the diffusing plate  123  and the optical sheet  121  are disposed on and are supported by the first horizontal surface  221  of the main frame  200 , the diffusing plate  123  is spaced apart from the plurality of first LEDs  128   a  of the first LED assembly  128  by the main frame  200  and the guide support  127  to maintain the optical gap. 
         [0074]    The top frame  140  surrounds the edge portions of the front and side surfaces of the liquid crystal panel  110  such that an inner surface of the first edge part  141  of the top frame  140  contacts an outer surface of the vertical part  210  of the main frame  200 , and the top frame  140  and the main frame  200  are assembled and combined. In addition, the inner surface of the vertical part  210  of the main frame  200  contacts an outer surface of the side surface  153  of the bottom surface  150 , and the main frame  200  and the bottom frame  150  are assembled and combined. As a result, the top frame  140 , the main frame  200  and the bottom frame  150  are assembled and combined, and the backlight unit  120  and the liquid crystal panel  110  are modularized as one body by the main frame  200 , the top frame  140  and the bottom frame  150 . 
         [0075]    The LCD device  100  (of  FIG. 2 ) further includes the second LED assembly  129  as the auxiliary light source. The second LED assembly  129  is disposed under the light guide bar  220  of the main frame  200  in the inner space A between the inner surface of the vertical part  210  and the second slanting surface  227  of the light guide bar  220 . 
         [0076]    The second LED assembly  129  is disposed in the inner space A such that the plurality of second LEDs  129   a  face into the light incident surface  229   a  of the chamfer part  229  of the light guide bar  220 . As a result, light enters the light guide bar  220 . 
         [0077]    The light emitted from the plurality of second LEDs  129   a  and incident into the light guide bar  220  passes through the light guide bar  220  by several total reflections to be emitted from the light guide bar  220  as a surface light source. In addition, the pattern (not shown) is formed on the second slanting surface  227  of the light guide bar  220  for guiding a light, and the light incident into the light guide bar  220  is emitted through the first horizontal surface  221  and the first slanting surface  223  as a surface light source. 
         [0078]    The light emitted through the first slanting surface  223  is mixed with the light emitted from the plurality of first LEDs  128   a  of the first LED assembly  128  and is uniformly processed through the diffusing plate  123  and the optical sheet  121  to be supplied to the liquid crystal panel  110 . The light emitted through the first horizontal surface  221  is uniformly processed through the diffusing plate  123  and the optical sheet  121  to be supplied to the edge portions of the liquid crystal panel  110 . 
         [0079]    In the LCD device  100  according to the first embodiment of the present disclosure, since the relatively large amount of light is supplied to the liquid crystal panel  110 , the brightness of the LCD device  100  increases. In addition, since light is supplied to the edge portions of the liquid crystal panel  110 , the image is displayed through the whole of the liquid crystal panel  110 . Accordingly, the bezel of the non-display region of the liquid crystal panel  110  is reduced, and the LCD device  100  having a narrow bezel is obtained. 
         [0080]    Since a temperature of the plurality of first LEDs  128   a  of the first LED assembly  128  and the plurality of second LEDs  129   a  of the second LED assembly  129  as an emitting element increases according to a time of usage, a lifetime and a brightness of the plurality of first LEDs  128   a  may be changed according to the time of usage. 
         [0081]    Since the first LED assembly  128  is disposed on the lower surface  151  of the bottom frame  150 , heat of a relatively high temperature generated from the plurality of first LEDs  128   a  of the first LED assembly  128  is rapidly and effectively radiated through the lower surface  151  of the bottom frame  150  of a metallic material. 
         [0082]    However, since the second LED assembly  129  is disposed over a smaller portion of the lower surface  151  as compared with the first LED assembly  128 , an LED housing  230  may be disposed between the second LED assembly  129  and the lower surface  151  for radiating heat of a relatively high temperature generated from the plurality of second LEDs  129   a  of the second LED assembly  129 . 
         [0083]    The LED housing  230  may have a bar shape where the second LED assembly  129  is disposed and may include a metallic material having a relatively high heat conductivity. The LED housing  230  may have a heat sink type. For example, one edge portion of the LED housing  230  having the second LED assembly  129  thereon may be disposed such that the second LED assembly  230  faces into the light incident surface  229   a  of the light guide bar  220 , and the other edge portion of the LED housing  230  may have a plurality of radiation fins  235  thereon. As a result, heat of a relatively high temperature generated from the plurality of second LEDs  129   a  of the second LED assembly  129  is rapidly and effectively radiated through the LED housing  230  having the plurality of radiation fins  235 . 
         [0084]    The LED housing may have a hole  231  and a step part  233  may be formed in the hole  231 . When the hook  228  is inserted into the hole  231 , the hook  228  of the light guide bar  220  may be assembled with the step part  233  such that the light guide bar  220  and the LED housing  230  are strongly combined. The hook  228  of the light guide bar  220  may protrude from the first slanting surface  223  and the second horizontal surface  225  toward a central portion of the main frame  200  opposite to the vertical part  210 . 
         [0085]    In  FIG. 4B , a step part  233  may be formed on an end portion of the LED housing  230 , and the hook  228  of the light guide bar  220  of the main frame  200  may be assembled with the step part  233  such that the light guide bar  220  and the LED housing  230  are strongly combined. The hook  228  of the light guide bar  220  may protrude from the first slanting surface  223  and the second horizontal surface  225  toward the inner space A and the vertical part  210 . The LED housing  230  may be disposed only in the inner space A in the second embodiment. 
         [0086]    In the main frame  200  according to the first and second embodiments of  FIGS. 4A and 4B , since the hook  228  of the light guide bar  220  is combined with the step part  233  of the LED housing  230 , the optical gap between the light incident surface  229   a  of the light guide bar  220  and the plurality of second LEDs  129   a  of the second LED assembly  129  is maintained. In addition, since the heat of a relatively high temperature of the plurality of second LEDs  129   a  is rapidly and effectively radiated through the LED housing  230 , a thermal deformation of the light guide bar  220  of the main frame  200  of a transparent resin such as PMMA and PC is minimized. 
         [0087]      FIGS. 5A to 5C  are perspective views showing a main frame of a liquid crystal display device according to third to fifth embodiments, respectively, of the present disclosure. 
         [0088]    In the main frame  200  of  FIG. 5A , the light guide bar  220  of a transparent resin such as PMMA and PC protrudes from the inner surface of the vertical part  210  of a synthetic resin for a molding process. The light guide bar  220  includes first and second horizontal surfaces  221  and  225  and first, second and third slanting surfaces  223 ,  227  and  226 . The first and second horizontal surfaces  221  and  225  are parallel to each other. The hook  228  protrudes from the first slanting surface  223  and the second horizontal surface  225  at both end portions of the light guide bar  220 . 
         [0089]    The inner space A is defined between the inner surface of the vertical part  210  and the second slanting surface  227 , and the chamfer part  229  including the light incident surface  229   a  is formed on the second slanting surface  227  and the second horizontal surface  225 . The third slanting surface  226  is disposed between the first horizontal surface  221  and the first slanting surface  223  with obtuse angles. 
         [0090]    In the main frame  200  of  FIG. 5B , a first connecting portion B between the first horizontal surface  221  and the third slanting surface  226  and a second connecting portion C between the third slanting surface  226  and the first slanting surface  223  are formed to be rounded. 
         [0091]    In the light guide bar  220  of the main frame  200  according to the third and fourth embodiments of the present disclosure, the third slanting surface  226  may be disposed between the first horizontal surface  221  and the first slanting surface  223 , or the first connecting portion B between the first horizontal surface  221  and the third slanting surface  226  and the second connecting portion C between the third slanting surface  226  and the first slanting surface  223  are rounded. As a result, deterioration such as a bright line of a step shape due to a light bounce phenomenon at a corner region of the light guide bar  220  is minimized. 
         [0092]    While the light emitted from the plurality of second LEDs  129   a  (of  FIG. 4A ) of the second LED assembly  129  (of  FIG. 4A ) is totally reflected in the light guide bar  220 , a portion of the light may not be totally reflected at the corner region of the light guide bar  220  and the light bounce phenomenon where the light is scattered may occur. The light bounce phenomenon may cause deterioration such as the bright line of the step shape where the corner region of the light guide bar  220  is relatively brighter than the other region. Since the bright line of the step shape reduces the brightness uniformity, a product reliability of the LCD device  100  (of  FIG. 2 ) is reduced. 
         [0093]    In the main frame  200  according to the third embodiment of the present disclosure of  FIG. 5A , since the third slanting surface  226  is further formed in the light guide bar  220 , a region corresponding the corner region increases to alleviate the bright line of the step shape by a light spread. In the main frame  200  according to the fourth embodiment of the present disclosure, since the first and second connecting portions B and C are rounded, the light bounce phenomenon at the corner region is minimized to prevent the bright line of the step shape. Accordingly, the reduction of the brightness uniformity of the LCD device  100  is prevented and the product reliability of the LCD device  100  is improved. 
         [0094]    In  FIG. 5C , a portion of the vertical part  210  and the first horizontal surface  221  of the light guide bar  220  is removed at a corner region of the main frame  200 , and a reflecting sheet  240  instead of the removed portion is disposed at the corner region of the main frame  200 . The light brightness at the corner region of the main frame  200  is further improved. 
         [0095]    While the light emitted from the plurality of second LEDs  129   a  (of  FIG. 4A ) of the second LED assembly  129  (of  FIG. 4A ) in the inner space A between the vertical part  210  and the second slanting surface  227  enters the light guide bar  220 , a portion of the light may not enter the light guide bar  220  and light leakage where a light is emitted toward the central portion of the main frame  200  opposite to the vertical part  210  may occur. 
         [0096]    In the main frame  200  according to the fifth embodiment of the present disclosure of  FIG. 5C , since the reflecting sheet  240  is disposed at the corner region of the main frame  200  and the portion of the main frame  200  at the corner region is removed, the light that does not enter the light guide bar  220  among the light emitted from the plurality of second LEDs  129   a  is reflected on the reflecting sheet  240  and enters the light guide bar  220  through the removed portion of the main frame  200 . As a result, the light brightness at the corner region of the main frame  200  is improved. 
         [0097]      FIG. 6  is a cross-sectional view showing a multi-panel display device according to a sixth embodiment of the present disclosure, and  FIG. 7  is a cross-sectional view showing a compensation structure for an image severance phenomenon according to a sixth embodiment of the present disclosure. 
         [0098]    In  FIG. 6 , a multi-panel display device  300  includes a plurality of liquid crystal display (LCD) devices  100   a  and  100   b  and a plurality of optical members  310   a  and  310   b  over the plurality of LCD devices  100   a  and  100   b , respectively. Each of the plurality of LCD devices  100   a  and  100   b  may have the same structure as the LCD device  100  (of  FIG. 2 ) of the first embodiment. The plurality of LCD devices  100   a  and  100   b  are connected to each other in a tile shape. Each of the plurality of optical members  310   a  and  310   b  includes a plurality of optical fibers  311   a  and  311   b  for overcoming an image severance phenomenon. 
         [0099]    To display a single image with a large-sized panel (e.g. about 100 inches) such as a video wall, the plurality of LCD devices  100   a  and  100   b  are disposed in a tile shape. Since each of the plurality of LCD devices  100   a  and  100   b  includes a bezel D, an image severance phenomenon where an image is not displayed in a connecting region of the plurality of LCD devices  100   a  and  100   b  may occur. However, since the plurality of optical members  310   a  and  310   b  for expanding and displaying the connecting region are disposed over the plurality of LCD devices  100   a  and  100   b , the image of each of the plurality of LCD devices  100   a  and  100   b  expands and is displayed in the bezel D through the plurality of optical members  310   a  and  310   b . As a result, the image severance phenomenon due to the bezel D may be prevented. 
         [0100]    In  FIG. 7 , each of the plurality of LCD devices  100   a  and  100   b  includes the liquid crystal panel  110  where a plurality of pixels P are defined. The liquid crystal panel  110  includes a display region AA and a non-display region NA. The display region AA displays an image and is disposed at a central portion of the liquid crystal panel  110 , and the non-display region NA surrounds the display region AA and does not display an image. 
         [0101]    The non-display region NA may be formed by a non-display area of the liquid crystal panel  110  itself, a portion blocked by the backlight unit  120  (of  FIG. 2 ) and the top frame  140  for modularizing the liquid crystal panel  110  and the backlight unit  120 . Since each of the plurality of LCD devices  100   a  and  100   b  includes the non-display region NA, the image severance phenomenon where an image is not displayed due to the non-display region NA may occur in the bezel D of the connecting region of the plurality of LCD devices  100   a  and  100   b.    
         [0102]    However, since the plurality of optical members  310   a  and  310   b  over the plurality of LCD devices  100   a  and  100   b  refract or expand a light path of an image displayed by the plurality of LCD devices  100   a  and  100   b  in the non-display region NA, the image is displayed in the non-display region NA of the bezel D of the connecting region of the plurality of LCD devices  100   a  and  100   b , and the image severance phenomenon is prevented. 
         [0103]    Each of the plurality of optical members  310   a  and  310   b  includes a plurality of optical fibers  311   a  and  311   b  and a resin support  313 . Each of the plurality of optical fibers  311   a  and  311   b  has a lower input surface and an upper output surface. The resin support  313  is disposed among the plurality of optical fibers  311   a  and  311   b  and supports the plurality of optical fibers  311   a  and  311   b  so that the plurality of optical fibers  311   a  and  311   b  can be combined with each other. Each of the plurality of optical members  310   a  and  310   b  has a light transparency. 
         [0104]    A lower surface of each of the plurality of optical members  310   a  and  310   b  corresponds to and is disposed over each of the plurality of LCD devices  100   a  and  100   b . The input surface of each of the plurality of optical fibers  311   a  and  311   b  may correspond to each of the plurality of pixels P of the liquid crystal panel  110 . Light emitted from each of the plurality of pixels P and incident to the input surface of each of the plurality of optical fibers  311   a  and  311   b  is totally reflected in each of the plurality of optical fibers  311   a  and  311   b  and is emitted from the output surface of each of the plurality of optical fibers  311   a  and  311   b . As a result, the image of the plurality of pixels P of the liquid crystal panel  110  is displayed by an upper surface of each of the plurality of optical members  310   a  and  310   b.    
         [0105]    Each of the plurality of optical fibers  311   a  and  311   b  in the plurality of optical members  310   a  and  310   b  includes at least one core in a central portion thereof and a cladding wrapping the core. Since a refractive index of the core is greater than a refractive index of the cladding, the light incident to the input surface is transmitted to the output surface through a total reflection. 
         [0106]    Each of the plurality of optical members  310   a  and  310   b  includes a non-expansion region E in a central portion thereof and an expansion region F in an edge portion thereof. The expansion region F surrounds the non-expansion region E. The plurality of optical fibers  311   a  and  311   b  are classified into a plurality of first optical fibers  311   a  in the non-expansion region E and a plurality of second optical fibers  311   b  in the expansion region F. The non-expansion region E corresponds to a first portion of the display region AA, and the expansion region F corresponds to the non-display region NA and a second portion of the display region AA surrounding the first portion of the display region AA. 
         [0107]    The plurality of first optical fibers  311   a  in the non-expansion region E may have a straight type where the light incident to the input surface is intactly emitted from the output surface. The input surface and the output surface may have the same area as each other in the straight type optical fiber. The plurality of first optical fibers  311   a  may transmit the image of the plurality of pixels P from the lower surface of the plurality of optical members  310   a  and  310   b  without expansion. 
         [0108]    The plurality of second optical fibers  311   b  in the expansion region F may have a bent type where the light incident to the input surface is emitted from the output surface by refraction and expansion. The plurality of second optical fibers  311   b  may transmit the image of the plurality of pixels P from the lower surface of the plurality of optical members  310   a  and  310   b  with expansion. 
         [0109]    In the plurality of second optical fibers  311   b  of the expansion region F, the input surface and the output surface are not aligned along a straight line such that the input surface corresponds to the plurality of pixels P in the edge portions of the plurality of LCD devices  100   a  and  100   b  and the output surface corresponds to the non-display region NA of the plurality of LCD devices  100   a  and  100   b . As a result, the plurality of second optical fibers  311   b  have a slanted and bent structure toward the non-display region NA of the plurality of LCD devices  100   a  and  100   b.    
         [0110]    An expansion ratio of the image by each of the plurality of optical fibers  311   a  and  311   b  is determined according to a size ratio between areas of the output surface and the input surface of each of the plurality of optical fibers  311   a  and  311   b . In each of the plurality of second optical fiber  311   b  of the expansion region F, an area of the output surface may be greater than an area of the input surface. Since the light incident to the input surface of each of the plurality of second optical fibers  311   b  is totally reflected and is emitted from the output surface having an area greater than the input surface, the image of the corresponding pixels P is expanded by the size ratio between the output surface and the input surface to be recognized. 
         [0111]    Since the image is displayed even through the non-display region NA of the plurality of LCD devices  100   a  and  100   b , the image severance phenomenon in the bezel D of the connecting region of the plurality of LCD devices  100   a  and  100   b  is prevented while the single image is displayed through the plurality of LCD devices  100   a  and  100   b.    
         [0112]    The resin support  313  may include a heat curable resin or a light curable resin. After the plurality of optical fibers  311   a  and  311   b  are arranged and a space among the plurality of optical fibers  311   a  and  311   b  is filled with a resin, the resin is cured with a heat or a light such as ultraviolet (UV). As a result, the plurality of optical members  310   a  and  310   b  including the plurality of optical fibers  311   a  and  311   b  are formed. 
         [0113]    Although the resin support  313  may include a transparent resin, a material for the resin support  313  is not limited to the transparent resin. A refractive index of the resin for the resin support  313  may be smaller than a refractive index of the plurality of optical fibers  311   a  and  311   b.    
         [0114]    In the multi-panel display device  300  according to the sixth embodiment where the plurality of optical members  310   a  and  310   b  are disposed over the plurality of LCD devices  100   a  and  100   b , since each of the plurality of LCD devices  100   a  and  100   b  has a relatively small non-display region NA, the image severance phenomenon due to the bezel D is effectively prevented. 
         [0115]    In each of the plurality of LCD devices  100   a  and  100   b , since the light guide bar  220  is formed in the main frame  200  and the second LED assembly  129  of the auxiliary light source is disposed under the light guide bar  220 , the light is uniformly supplied to the edge portions of the liquid crystal panel  110 . Since the light is uniformly supplied to the whole region of the liquid crystal panel  110 , the display region AA of the liquid crystal panel  110  is enlarged and the non-display region NA of the bezel D is reduced. Accordingly, the plurality of LCD devices  100   a  and  100   b  having a narrow bezel are obtained. 
         [0116]    Each of the plurality of LCD devices  100   a  and  100   b  includes the backlight unit  120  (of  FIG. 2 ), and the backlight unit  120  includes the first LED assembly  128 , the reflecting plate  125 , the diffusing plate  123  spaced apart from the first LED assembly  128  through the guide support  127 , and the optical sheet  121  over the diffusing plate  123 . The first LED assembly  128  includes the first LED PCB  128   b  of a plate shape and a plurality of first LEDs  128   a  on the first LED PCB  128   b , and the plurality of first LEDs  128   a  penetrate through the plurality of through holes  125   a  of the reflecting plate  125  such that the reflecting plate  125  covers the first LED PCB  128   b  except the plurality of first LEDs  128   a.    
         [0117]    The liquid crystal panel  110  including the first and second substrates  112  and  114  and the liquid crystal layer (not shown) between the first and second substrates  112  and  114  is disposed over the backlight unit  120 , and the first and second polarizing plates  119   a  and  119   b  selectively transmitting a light are formed on the outer surfaces of the first and second substrates  112  and  114 , respectively. 
         [0118]    The backlight unit  120  and the liquid crystal panel  110  are modularized and integrated as one body by the main frame  200 , the top frame  140  and the bottom frame  150 . The edge portions of the rear surface of the diffusing plate  123  and the optical sheet  121  are disposed on and are supported by the first horizontal surface  221  of the main frame  200 , and the edge portions of the rear surface of the liquid crystal panel  110  over the optical sheet  121  are disposed on and are supported by the front surface  210   a  of the vertical part  210  of the main frame  200 . 
         [0119]    The backlight unit  120  further includes the second LED assembly  129  as the auxiliary light source. The second LED assembly  129  is disposed under the light guide bar  220  of the main frame  200  in the inner space A between the inner surface of the vertical part  210  and the second slanting surface  227  of the light guide bar  220 . The plurality of second LEDs  129   a  face into the light incident surface  229   a  of the chamfer part  229  of the light guide bar  220  and the light of the plurality of second LEDs  129   a  enters the light guide bar  220 . 
         [0120]    The light emitted from the plurality of second LEDs  129   a  and incident into the light guide bar  220  passes through the light guide bar  220  by several total reflections to be emitted from the light guide bar  220  as a surface light source. In addition, the pattern (not shown) is formed on the second slanting surface  227  of the light guide bar  220  for guiding a light, and the light incident into the light guide bar  220  is emitted through the first horizontal surface  221  and the first slanting surface  223  as a surface light source. 
         [0121]    The light emitted through the first slanting surface  223  is mixed with the light emitted from the plurality of first LEDs  128   a  of the first LED assembly  128  and is uniformly processed through the diffusing plate  123  and the optical sheet  121  to be supplied to the liquid crystal panel  110 . The light emitted through the first horizontal surface  221  is uniformly processed through the diffusing plate  123  and the optical sheet  121  to be supplied to the edge portions of the liquid crystal panel  110 . 
         [0122]    In each of the plurality of LCD devices  100   a  and  100   b  of the multi-panel display device  300  according to the sixth embodiment of the present disclosure, since the relatively large amount of light is supplied to the liquid crystal panel  110 , the brightness of each of the plurality of LCD devices  100   a  and  100   b  increases. In addition, since the display region AA is enlarged and the non-display region NA of the bezel D is reduced, each of the plurality of LCD devices  100   a  and  100   b  has a narrow bezel. Accordingly, the image severance phenomenon due to the bezel D is effectively prevented. Further, since the brightness of the image in the edge portions of each of the plurality of LCD devices  100   a  and  100   b  increases, the image severance phenomenon is minimized even when the multi-panel display device  300  according to the sixth embodiment of the present disclosure has the bezel D corresponding to the related art bezel. 
         [0123]      FIG. 8A  is a view showing a multi-panel display device according to the related art, and  FIG. 8B  is a view showing a multi-panel display device according to a sixth embodiment of the present disclosure. 
         [0124]    The bezel of the multi-panel display device of  FIG. 8A  has the same width as the bezel of the multi-panel display device of  FIG. 8B . In addition, each of the plurality of LCD devices of the multi-panel display device of  FIG. 8A  does not include the second LED assembly, and each of the plurality of LCD devices of the multi-panel display device  300  of  FIG. 8A  includes the second LED assembly  129 . 
         [0125]    In  FIG. 8A , when the plurality of LCD devices are disposed in a tile shape, an image severance phenomenon may occur due to the bezel of each of the plurality of LCD devices. 
         [0126]    In  FIG. 8B , each of the plurality of LCD devices  100   a  and  100   b  of the multi-panel display device  300  includes the light guide bar  220  of the main frame  200  and the second LED assembly  129  of the auxiliary light source under the light guide bar  220 . Since the light is uniformly supplied to the edge portions of the liquid crystal panel  110 , the brightness of the edge portions of each of the plurality of LCD devices  100   a  and  100   b  increases. 
         [0127]    Accordingly, the bezel D of each of the plurality of LCD devices  100   a  and  100   b  may be recognized to be reduced, and the image severance phenomenon for the image displayed by the plurality of LCD devices  100   a  and  100   b  may be recognized to be minimized. Since a contrast ratio in the edge portions of the bezel D of the plurality of LCD devices  100   a  and  100   b  increases according to increase of the brightness in the edge portions of the plurality of LCD devices  100   a  and  100   b , a user may recognize the width of the bezel D to be reduced. 
         [0128]    Although the plurality of optical members  310   a  and  310   b  are disposed over the plurality of LCD devices  100   a  and  100   b  in the sixth embodiment, the plurality of optical members  310   a  and  310   b  each having a rectangular ring shape may be disposed only over the edge portions of each of the plurality of LCD devices  100   a  and  100   b  in another embodiment. 
         [0129]    Consequently, in the LCD device  100  according to the first to fifth embodiments of the present disclosure and the multi-panel display device  300  according to the sixth embodiment of the present disclosure, since the light guide bar  220  is disposed on the main frame  200  surrounding the edge portions of the liquid crystal panel  110  and the backlight unit  120  and the second LED assembly  129  of the auxiliary light source of the backlight unit  120  is disposed under the light guide bar  220 , the light is uniformly supplied to the edge portions of the liquid crystal panel  110 . Since the light is uniformly supplied to the whole region of the liquid crystal panel  110 , the display region AA of the liquid crystal panel  110  is enlarged and the non-display region NA except the display region AA is reduced, the LCD device  100 ,  100   a  and  100   b  having a narrow bezel D is obtained. 
         [0130]    In the multi-panel display device  300  according to the sixth embodiment, the image severance phenomenon is prevented due to each of the plurality of LCD devices  100   a  and  100   b  having a narrow bezel D. In addition, since the brightness in the edge portions of each of the plurality of LCD devices  100   a  and  100   b  increases, the bezel D of each of the plurality of LCD devices  100   a  and  100   b  is recognized to be reduced even when the bezel has the width corresponding to the related art bezel. As a result, the image severance phenomenon is minimized. 
         [0131]    It will be apparent to those skilled in the art that various modifications and variations can be made in a backplate and a foldable display device including the same of the present disclosure without departing from the sprit or scope of the disclosure. Thus, it is intended that the present disclosure covers the modifications and variations of these aspects provided they come within the scope of the appended claims and their equivalents.