Abstract:
A liquid crystal display having a display panel including first and second display regions that are different from each other, a light source supplying light to the display panel, and a light guide plate having an area which is divided into a first region corresponding to the first display region and a second region corresponding to the second display region, the light guide plate allowing light incident from the light source to progress toward, wherein each of the first and second regions includes a light incident surface through which the light is incident, a light emitting surface through which the light successively incident from the light incident surface emits, and a rear surface opposed to the light emitting surface. The light emitting surface of the first region includes a plurality of first optical patterns refracting the light emitted by the light source to prevent light leakage from the first region onto the second display region.

Description:
CLAIM OF PRIORITY 
       [0001]    this application makes reference to, incorporates the same herein, and claims all benefits accruing under 35 U.S.C. §119 from an application earlier filed in the Korean Intellectual Property Office on the 24 th  of Feb. 2015 and there duly assigned Serial No. 10-2015-0025958. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present disclosure herein relates to a display apparatus including a backlight unit that includes a light guide plate having optical patterns. 
         [0004]    2. Description of the Related Art 
         [0005]    Generally, a liquid crystal display is a device for displaying a desired image by adjusting light transmittance of liquid crystal cells arranged in a matrix configuration according to image signal information. The liquid crystal display forms an image on a liquid crystal panel using light supplied from a backlight unit. 
         [0006]    Since the liquid crystal display using the aforementioned principle has characteristics such as light weight, slimness, and low power consumption, its application has extended. The liquid crystal display is used in office automation devices or audio/video devices according to such a tendency. In the liquid crystal display, transmittance of light is adjusted according to signals applied to a plurality of control switches arranged in a matrix configuration to display a desired image on a screen. 
         [0007]    Recently, the liquid crystal display is widely applied to a monitor for a computer, a display apparatus for a television as well as for a vehicle navigation system, and portable display apparatuses for a notebook, a handheld terminal, and the like. Since most of the liquid crystal displays are non-emissive type displays which adjust an amount of light incident from the outside to display an image, these liquid crystal displays require backlight units including a separates light source for irradiating light on a liquid crystal display panel. 
         [0008]    The backlight unit includes an light emitting diode that is a light source, a light guide plate coupled to a light-emitting surface of the light emitting diode, and a plurality of sheets on the light guide plate. 
         [0009]    Light incident to the light guide plate from the light emitting diode is totally reflected on an interface due to a refractive index difference from air, is emitted through a light-emitting surface, and is supplied to a liquid crystal panel. 
       SUMMARY OF THE INVENTION 
       [0010]    The present disclosure prevents a light leakage phenomenon between a plurality of display regions independently driven in a display apparatus including the plurality of display regions. 
         [0011]    Embodiments of the invention provide display apparatuses including: a display panel including first and second display regions that are different from each other; a light source supplying light to the display panel; and a light guide plate having an area which is divided into a first region corresponding to the first display region and a second region corresponding to the second display region, the light guide plate allowing light incident from the light source to progress toward, wherein each of the first and second regions includes a light incident surface through which the light is incident, a light emitting surface through which the light successively incident from the light incident surface emits, and a rear surface opposed to the light emitting surface. The light emitting surface of the first region may include a plurality of first optical patterns. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]    A more complete appreciation of the present invention, and many of the attendant advantages thereof, will become 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: 
           [0013]      FIG. 1A  is a view illustrating a display apparatus according to an embodiment of the invention; 
           [0014]      FIG. 1B  is a plan view of a backlight unit included in a display apparatus illustrated in  FIG. 1A ; 
           [0015]      FIG. 2  is an exploded perspective view of a display device including a backlight unit provided with a light guide plate according to an embodiment of the invention; 
           [0016]      FIG. 3A  is an exploded perspective view of a backlight unit according to an embodiment of the invention; 
           [0017]      FIGS. 3B and 3C  are cross-sectional views taken along line I-I′ of a light guide plate according to an embodiment of the invention; 
           [0018]      FIG. 4A  is an exploded perspective view of a backlight unit according to an embodiment of the invention; 
           [0019]      FIG. 4B  is a cross-sectional view taken along line J-J′ of a light guide plate illustrated in  FIG. 4A ; 
           [0020]      FIG. 5A  is an exploded perspective view of a backlight unit according to an embodiment of the invention; and 
           [0021]      FIG. 5B  is a cross-sectional view taken along line K-K′ of a light guide plate illustrated in  FIG. 5A . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0022]    Terms used in this specification are selected as general terms that are widely used today while considering the functions of the present specification, but may vary depending on intention of engineers engaged in the art, practices or the advent of new technologies. Also, in certain cases, the terms are randomly selected by an applicant, and in this case, the meaning will be described in the description of the corresponding embodiment. Accordingly, a term used herein shall be interpreted based on practical meanings and the contents throughout the specification instead of a simple name of the term. 
         [0023]    Moreover, although exemplary embodiments are described in detail with reference to the accompanying drawings and contents described therein, it should be understood that the disclosure is not limited to or restricted by the embodiments. 
         [0024]    Hereinafter, exemplary embodiments of the invention will be described in more detail with reference to the accompanying drawings. 
         [0025]      FIG. 1A  is a view illustrating a display apparatus according to an embodiment of the invention.  FIG. 1B  is a plan view of a backlight unit included in a display apparatus illustrated in  FIG. 1A ; 
         [0026]    Referring to  FIG. 1A , a display apparatus  100  may include a display panel  110  displaying an image. The display panel  110  may include first and second display regions R 1  and R 2  which are independently driven according to a driving method, displayed content, function, or the like. 
         [0027]    In an embodiment, the display panel  110  may include the first display region R 1  that is a sub region displaying simple information and a second display region R 2  that is a main display region displaying detailed information. 
         [0028]    The first region R 1  may display real-time information. For example, the first display region R 1  may display simple information related to an event generated in real time in the display apparatus  100  or in a mobile device pairing with the display apparatus  100 . The first display region R 1  may display information on the number of messages, the number of calls, a caller, or the like received in the mobile device in real time. Also, the first display region R 1  may display real-time information related to environmental conditions with respect to current time, current weather, current temperature, or the like. 
         [0029]    The second display region R 2  may display various contents played in the display apparatus  100 . For example, the second display region R 2  may display detailed information related to an event generated in the display apparatus  100  or in the mobile device pairing with the display apparatus  100 . The second display region R 2  may display a received message text, detailed information on a received call, information on a caller list, or the like. Also, the second display region R 2  may display various contents executed in the display apparatus  100 , such as a movie, drama, game, or TV application. 
         [0030]    Since the first display region R 1  displays simple information such as real time state information, the first display region R 1  may have a size relatively smaller than that of the second display region R 2 . 
         [0031]    Also, since the first display region R 1  provides state information in real time, the first display region R 1  may be continuously driven. On the contrary, the second display region R 2  may be intermittently driven according to user input. For example, the first display region R 1  is maintained to be turned on even if a user turns off the second display region R 2 , so that the first display region R 1  may continuously provide state information on current information, current weather, current temperature, or the like to the user. Therefore, the first display region R 1  is continuously driven in regardless of input for deactivating the second display region R 2 , and thus may provide real-time information with respect to the display apparatus  100  to the user. 
         [0032]    Since the first and second display regions R 1  and R 2  perform different functions, the first and second display regions R 1  and R 2  may be independently driven. However, in this case, a light leakage phenomenon may be generated between the first and second display regions R 1  and R 2 . 
         [0033]    In more detail, referring to the  FIG. 1B , a backlight unit providing light to the display panel  110  may include a light source unit  40  and a light guide plate  140 . In addition, the light source unit  40  may include a plurality of light sources LED 1  and LED 2 , and a panel P mounted with the plurality of light sources LED 1  and LED 2 . The plurality of light sources LED 1  and LED 2  provided to the light source unit  40  allow light to be incident on the light guide plate  140 . Also, the light incident on the light guide plate  140  may be reflected inside the light guide plate  140  and be emitted through a light emitting surface of the light guide plate  140 . The emitted light may be provided to the display panel  110  opposed to the light guide plate  140 . 
         [0034]    At least one first light source LED 1  providing light to the first display region R 1  may irradiate light on a first region R 1 ′ of the light guide plate  140  corresponding to the first display region R 1 . In more detail, the first light source LED 1  may irradiate light on a light-incident surface of the first region R 1 ′. 
         [0035]    At least one second light source LED 2  providing light to the second display region R 2  may irradiate light on a second region R 2 ′ of the light guide plate  140  corresponding to the second display region R 2 . In more detail, the second light source LED 2  may irradiate light on a light-incident surface of the second region R 2 ′. 
         [0036]    When only the first display region R 1  is selectively driven, the first light source LED 1  may irradiate light having a specific incident angle range on the light-incident surface of the first region R 1 ′. Since the first light source LED 1  irradiates light at a specific incident angle θ, light L 1  incident on the second region R 2 ′ may exist. Alternatively, light L 2 , which is incident on the incident-surface of the first region R 1 ′ and then is incident on the second region R 2 ′, may exist. Alternatively, although light is incident on the light-incident surface of the first region R 1 ′ and emitted to the light emitting surface of the first region R 1 , the light, which is incident not on the first display region R 1  but on the second display region R 2 , may exist due to low straightness of the light. As a result, a light leakage phenomenon, in which light provided from the first light source LED 1  in order to drive the first display region R 1  is emitted to the second display region R 2 , is generated. When only the first display region R 1  is driven, such a light leakage phenomenon is easily visible to the user, so that the quality of the display apparatus  100  is lowered. 
         [0037]    In order to prevent the light leakage phenomenon, the display apparatus  100  according to an embodiment of the invention may include a light guide plate on which optical patterns for preventing the light leakage are formed. 
         [0038]      FIG. 2  is an exploded perspective view of a display device including a backlight unit provided with a light guide plate according to an embodiment of the invention. 
         [0039]    Referring to  FIG. 2 , a display apparatus  100  may include a display panel  110 , a backlight unit providing light to the display panel  110 , a panel guide  130  covering and supporting the display panel  110  and the backlight unit, a bottom cover  170  coupled to the panel guide  130  and receiving the backlight unit, and a top case  180  covering a front edge of the display panel  110 . 
         [0040]    The display panel  110  may include a color filter array substrate  110   a , a TFT array substrate  110   b , and a liquid crystal layer (not shown) therebetween. In the display panel  110 , liquid crystal cells each constituting a pixel unit may be arranged in a matrix configuration, and the liquid crystal cells adjust light transmittance according to a signal transmitted from a pixel driving circuit  113  to display an image. 
         [0041]    Although not shown in  FIG. 2 , a plurality of gate lines and a plurality of data lines are disposed in a matrix configuration on the TFT array substrate  110   b  so as to intersect with each other. Also, a thin film transistor (TFT) may be provided on the intersecting region of each gate line and each data line. Signal voltage transferred from the pixel driving circuit  113  is applied between a pixel electrode and a common electrode (not shown) of the color filter array substrate  110   a  described later through the thin film transistor. Liquid crystal molecules between the pixel electrode and the common electrode may be arranged according to the signal voltage to determine light transmittance. Although not shown, the color filter array substrate  110   a  may include a color filter and a common electrode with a black matrix in-between. The common electrode is made of a transparent conductive material such as indium tin oxide (ITO) or indium zinc oxide (IZO). 
         [0042]    The flexible printed circuit board  115  may be disposed such that one end thereof is connected to one side of the display panel  110 . The pixel driving circuit  113  for driving pixels of the display panel  110  may be provided on the flexible printed circuit board  115 . 
         [0043]    The backlight unit may include a light source unit  40  generating light and a light guide plate  140  propagating light generated in the light source unit  40  toward the display panel  110 . The light source unit  40  may be disposed on one side surface of the light guide plate  140 . Also, the backlight unit may include a reflective sheet  160  attached to a rear surface of the light guide plate  140  to reflect light incident on the rear surface toward the display panel  110  and to thereby improve light efficiency, and a plurality of optical sheets  120  stacked on a light emitting surface of the light guide plate  140  to scatter light emitted from the light guide plate  140 . 
         [0044]    The light source unit  40  may include light sources LED 1  and LED 2  generating light, and a panel P mounted with the first and second light sources LED 1  and LED 2 . Each of the first and second light sources LED 1  and LED 2  may be a cold cathode fluorescent lamp (CCFL), an external electrode fluorescent lamp (EEFL), or a light-emitting diode (LED) element. Hereinafter, for convenience in description, an embodiment in which the first and second light sources LED 1  and LED 2  are light-emitting diodes (LEDs) will be described. 
         [0045]    The panel P mounted with the light sources LED 1  and LED 2  is a flexible printed circuit board, and may provided therein with an inner circuit providing external power to the light sources LED 1  and LED 2 . 
         [0046]    The light guide plate  140  functions to guide light incident from the light sources LED 1  and LED 2  so as to be incident on the display panel  110 . The light guide plate  140  may have a structure in which one surface thereof is inclined, an opposite surface thereof opposed to the one surface has a wedge shape, or the one surface and the opposite surface all have a flat pate type. 
         [0047]    Various optical patterns  141  for controlling light may be formed on a surface of the light guide plate  140 . In particular, various optical patterns  141  for preventing light leakage may be formed on the light guide plate  140  according to an embodiment of the invention. Details thereof will be described below with reference to  FIGS. 3A to 5B . 
         [0048]    The plurality of optical sheets  120  is provided to diffuse and collect light incident from the light guide plate  140 , and may include a diffusion sheet  121 , a prism sheet  123 , and a protection sheet  125 . The number of the diffusion sheet  121 , and the prism sheet  123 , and the protection sheet may be variously determined according to embodiments. 
         [0049]    The diffusion sheet  121  may function to diffuse light provided from the light source unit  40  and to provide the diffused light to the display panel  110 . Triangular prisms may be formed in a predetermined arrangement on one surface of the prism sheet  123 . The prism sheet  123  may function to collect light diffused in the diffusion sheet  121  in a direction orthogonal to a surface of the display panel  110 . The protection sheet  125  may function to protect the prism sheet  123  vulnerable to scratch. 
         [0050]    The panel guide  130  may have a square frame shape surrounding side surfaces of the light guide plate  140 , and be formed of a plastic material such as a PC material or metal material. The panel guide  130  functions to support and fix the display panel  110 , the light guide panel  140 , and the optical sheets  120 . 
         [0051]    The reflective sheet  160  may be disposed on a rear surface of the light guide plate  140  to reflect a portion of light emitted to the rear surface of the light guide plate  140  toward the light emitting surface, thereby improving light efficiency, and to adjust a total reflected amount of incident light to allow the entire light emitting surface to have uniform luminance distribution. 
         [0052]    The bottom cover  170  has a rectangular box shape of which one side is open, and receives constituent elements of the backlight covered by the panel guide  130 . 
         [0053]    The bottom cover  170  is coupled to the top case  180  surrounding outer edges of an upper surface of the display panel  110  and a side surface of the panel guide  130  to constitute a display apparatus  100 . 
         [0054]      FIG. 3A  is an exploded perspective view of a backlight unit according to an embodiment of the invention.  FIGS. 3B and 3C  are cross-sectional views taken along line I-I′ of a light guide plate according to an embodiment of the invention. In particular,  FIG. 3B  is a cross-sectional view of the light guide plate illustrated in  FIG. 3A . Optical sheets and reflective sheets are excluded in the present drawings in order to efficiently describe characteristics of the invention. Also, descriptions will be made on the basis of the backlight unit of the display apparatus in which only the first display region R 1  of display panel  110  is driven. Further, the position of LED 1  is represented as from the side of the light guide plate, not from beneath the light guide plate. 
         [0055]    Referring to  FIG. 3A , a light guide plate  140  may include a light-incident surface  140   a  on which light from light sources LED 1  and LED 2  is incident, a light emitting surface  140   b  through which light continuously incident from the light-incident surface  140   a  is emitted, and a rear surface  140   c  opposite to the light emitting surface  140   b.    
         [0056]    At least one first light source LED 1  supplying light to the first display region R 1  may be disposed so as to correspond to the light-incident surface  140   a  of a first region R 1 ′ of the light guide plate  140  which corresponds to the first display region R 1  of display panel  110 . Also, at least one second light source LED 2  supplying light to the second display region R 2  may be disposed so as to correspond to the light-incident surface  140   a  of a first region R 2 ′ of the light guide plate  140  which corresponds to the second display region R 2  of display panel  110 . The first light source LED 1  and the second light source LED 2  may independently irradiate light on the light-incident surface  140   a  of the first region R 1 ′ and the light-incident surface  140   a  of the second region R 2 ′, respectively. 
         [0057]    First optical patterns  141  may be formed on a portion of the light emitting surface  140   b  which corresponds to the first region R 1 ′. The first optical patterns  141  may have a lenticular lens shape or semi-cylindrical lens shape. In this case, each of the first optical patterns  141  may have a concave shape with respect to a light emitting direction. Alternatively, each of the first optical patterns  141  may have a cross-section protruding away from the light guide plate  140 . The first optical patterns  141  may function to prevent a light leakage phenomenon into the second display region R 2 . 
         [0058]    Referring to  FIG. 3B , light  13  incident on the first region R 1 ′ of the guide plate  140  from the first light source LED 1  may be refracted by the first optical patterns  141  formed on the light emitting surface  140   b  of the first region R 1 ′ to be emitted. In particular, light passing through the first optical patterns  141  may be refracted in a direction directed away from the second region R 2 ′ to the first display region R 1  to be emitted. As a result, the light  13  passing through the first optical patterns  141  may be improved in terms of straightness of light traveling from the light guide plate  140  to the display panel  110 . Accordingly, when the first display region R 1  is solely driven, an amount of light incident on the second display region R 2  is reduced, so that a light leakage phenomenon into the second display region R 2  may be prevented. 
         [0059]    Alternatively, a portion  14  of light incident on the first region R 1 ′ of the light guide plate  140  from the first light source LED 1  may be re-incident on the rear surface  140   c  of the first region R 1 ′ by the first optical patterns  141  formed on the light emitting surface  140   b  of the first region R 1 ′, and then be emitted through the light emitting surface  140   b  of the first region R 1 ′ by the reflective sheet  160  ( FIG. 2 ) provided on the rear surface  140   c . In particular, the portion  14  of light re-incident on the rear surface  140   c  may travel in a direction away from the second display region R 2  to the first display region R 1 . As a result, the portion  14  of light reflected by the first optical patterns  141  travels in an inner direction of the first region R 1 ′, so that an amount of light incident on the second display region R 2  is reduced, and accordingly, a light leakage phenomenon may be prevented. 
         [0060]    This is because the first optical patterns  141  have a concave shape or a lenticular shape to improve straightness of light passing through the first optical patterns  141 , and to allow light capable of traveling toward the second display region R 2  to be re-incident inside the first region R 1 ′ and emitted on the the first display region R 1 . 
         [0061]    The first optical patterns  141  may be formed by attaching a lenticular-shaped film or tape to the light emitting surface  140   b  of the first region R 1 ′ of the light guide plate  140  or partially patterning the light emitting surface  140   b  of the first region R 1 ′ of the light guide plate  140 . In the present specification, for convenience in description, descriptions have been made on the basis of the light guide plate  140  in which the lenticular-shaped film is partially attached to the light emitting surface  140   b  of the first region R 1 ′ of the light guide plate  140 . 
         [0062]    In order to further improve the light leakage preventing effect, as described in  FIG. 3C , the light guide plate  140  may be provided with a light leakage preventing groove “H” in the light emitting surface  140   b  between the first and second regions R 1 ′ and R 2 ′. In other words, the light guide plate  140  may provided with the light leakage preventing groove “H” in a portion of the light emitting surface  140   b  corresponding to a boundary of the first and second display regions R 1  and R 2 . The light leakage preventing groove “H” has a shape that is dented toward an inside of the light emitting guide  140  and has a triangular cross-section. 
         [0063]    A light leakage preventing film  10  for preventing a light leakage may be attached to a surface of the light leakage preventing groove “H”. The light leakage preventing film  10  may absorb light  15  incident on a surface thereof, or allow light  16  to be re-incident on a rear surface  140   c  of the first region R 1 , thereby reducing an amount of light incident on the second region R 2 ′. 
         [0064]      FIG. 4A  is an exploded perspective view of a backlight unit according to an embodiment.  FIG. 4B  is a cross-sectional view taken along line J-J′ of a light guide plate illustrated in  FIG. 4A . The same elements as the elements relating to  FIGS. 1 to 3C  described as above will be described by using the like reference numerals in the present drawings and detailed descriptions relating to  FIGS. 1 to 3C  may be applied in the present drawings in the same or similar manner. Also, the present drawings will be described on the basis of a backlight unit of a display apparatus in which only the first display region R 1  is driven. Further, the position of LED 1  is represented as from the side of the light guide plate, not from beneath the light guide plate. 
         [0065]    Referring to  FIGS. 4A and 4B , a light guide plate  143  may be provided with a light emitting surface  143   b  as well as a plurality of second optical patterns  142  for preventing a light leakage even on a rear surface  143   c  of a first region R 1 ′ corresponding to the first display region R 1 . The second optical patterns  142  may be formed on the rear surface  143   c  of the first region R 1 ′ so as to respectively one-to-one correspond to the first optical patterns  141 . The first optical patterns  141  and the second optical patterns  142  may be opposed to each other. 
         [0066]    The second optical patterns  142  has a reflective surface that may also have a lenticular lens shape or semi-cylindrical lens shape like the first optical patterns  141 . In this case, each of the second optical patterns  142  may have a concave shape with respect to an opposite direction to a light emitting direction of light. Also, each of the second optical patterns  142  may have a cross-section protruding toward the outside of the light guide plate  143 . The second optical patterns  142  may be formed by attaching a lenticular-shaped film or tape to the rear surface  143   c  of the first region R 1 ′ of the light guide plate  143  or partially patterning the rear surface  143   c  of the first region R 1 ′ of the light guide plate  143 . Also, the second optical patterns  142  may function to prevent a light leakage phenomenon into the second display region R 2  like the first optical patterns  141 . 
         [0067]    In more detail, light  17  incident on a light-incident surface  143   a  of the first region R 1 ′ from a first light source LED 1  may travel to the rear surface  143   c  on which the second optical patterns  142  are formed. The light  17  traveling to the rear surface  143   c  may be reflected toward the light emitting surface  143   b  of the first region R 1 ′ by the second optical patterns  142 . In particular, the light  17  may travel in a direction directed from the second display region R 2  to the first display region R 1 , that is, toward an inside of the first display region R 1  and the light emitting surface  143   b . Thus, the light  17  incident on the light emitting surface  143   b  may be improved in terms of straightness of light to be emitted to the first display region R 1 . As a result, when the first display region R 1  is solely driven, an amount of light incident on the second display region R 2  is reduced, so that a light leakage phenomenon into the second display region R 2  may be prevented. 
         [0068]    Also, a portion  18  of light re-incident on the second optical patterns  142  by the first optical patterns  141  may be also reflected toward an inside of the first region R 1 ′ and the light emitting surface  143   b  by the second optical pattern  142 . The portion  18  of the light incident on the light emitting surface  143   b  may be improved in terms of straightness of light by the first optical patterns  141  to be emitted to the first display region R 1 . As a result, an amount of light, which is incident on the second display region R 2  that is not driven, is reduced, so that the light leakage phenomenon is prevented. 
         [0069]    Although not shown in the present drawings, optical patterns having the same lenticular lens shape or semi-cylindrical lens shape as that of the first or second optical patterns ( 141  and  142 ) may be additionally formed even on the light emitting surface  143   b  of the second region R 2 ′. The optical patterns formed on the light emitting surface  143   b  of the second region R 2 ′ may function to prevent light of the second display region R 2  from leaking into the first display region R 1  in the similar manner as the first and second optical patterns  141  and  142 . 
         [0070]      FIG. 5A  is an exploded perspective view of a backlight unit according to an embodiment.  FIG. 5B  is a cross-sectional view taken along line K-K′ of a light guide plate illustrated in  FIG. 5A . The same elements as the elements relating to  FIGS. 1 to 3C  described as above will be described by using the like reference numerals in the present drawings and detailed descriptions relating to  FIGS. 1 to 3C  may be applied in the present drawings in the same or similar manner. Also, the present drawings will be described on the basis of a backlight unit of a display apparatus  100  in which only the first display region R 1  is driven. 
         [0071]    Referring to  FIGS. 5A and 5B , a light source LED 3  may include a narrow beam angle LED element. The narrow beam angle LED element means a light-emitting diode element having a relatively narrow beam angle ranging from about 5° to about 50°. Since the light source LED 3  includes the narrow beam angle LED element, the amount of light incident on a light-incident surface  145   a  of a second region R 2 ′ from the light source LED 3  may be reduced. As a result, the light leakage phenomenon of the second display region R 2 , which is generated by light incident on the second region R 2 ′, may be prevented. The light source LED 2  may also include a narrow beam angle LED element, or a wide beam angle LED element. 
         [0072]    Narrow beam angle light incident on the light-incident surface  145   a  of the first region R 1 ′ from the light source LED 3  may be reflected toward a light emitting surface  145   b  of the first region R 1 ′ by third optical patterns  144 . The third optical patterns  144  may function to reflect the narrow beam angle light incident from the light source LED 3  toward the light emitting surface  145   b . The third optical patterns  144  may be formed on a rear surface  145   c  of the first region R 1 ′ so as to be opposed to the first optical patterns  141 , and have a shape dented toward an inside of a light guide plate  145 . Also, the third optical patterns  144  may have a triangular cross-section. For example, the third optical patterns  144  may have a concave pattern. The straightness of the narrow beam angle light  19  is improved by the third optical patterns  144 , so that luminance of the first display region R 1  may be improved. 
         [0073]    Since a display apparatus according to an embodiment of the invention includes a light guide plate on which optical patterns for preventing a light leakage are formed, a light leakage phenomenon between display regions independently driven may be prevented. 
         [0074]    Although respective drawings have been described individually for convenience in description, a foldable display apparatus may be designed such that the embodiments illustrated in the respective drawings may be merged to realize a new embodiment. Also, the display apparatus  100  is not limited to the configurations and methods of the above-described embodiments, but all or some of the respective embodiments may be selectively combined and executed so that various modifications can be made within the scope of the disclosure as claimed. 
         [0075]    Although preferred embodiments of the invention have been illustrated and described, the invention is not limited to the above-mentioned embodiments and various modified embodiments may be available by those skilled in the art without the scope of the appended claims of the invention. In addition, these modified embodiments should not be appreciated separately from technical spirits or prospects.