Patent Publication Number: US-2006017863-A1

Title: Liquid crystal display apparatus

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
      This application claims the benefit of Korean Patent Application No. 2004-0057040, filed on Jul. 22, 2004, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.  
     BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      Apparatuses consistent with the present invention relate to a liquid crystal display (LCD) apparatus, and more particularly, to an LCD apparatus having an improved structure in which a supporter is provided between a surface light source and an optical sheet.  
      2. Description of the Related Art  
      Generally, an LCD apparatus comprises an LCD panel displaying a picture thereon, an optical sheet provided in a rear of the LCD panel, and a backlight unit illuminating the optical sheet and the LCD panel.  
      The backlight unit is classified into a direct type and an edge type according to its dispositions. In the case of the direct type, a light source is disposed under the optical sheet and directly emits light to the optical sheet and the LCD panel. In the case of the edge type, the light source is disposed at the edges of a light guide plate and emits light to the optical sheet and the LCD panel via the light guide plate.  
      Hereinbelow, the direct type LCD apparatus comprising a surface light source disposed under the optical sheet and emitting light toward the LCD panel will be described.  
       FIG. 1  is a schematic section view of a conventional LCD apparatus comprising the surface light source.  
      As shown therein, a conventional LCD apparatus  101  comprises an LCD panel  105 ; a plurality of optical sheets  110  provided in a rear of the LCD panel  105  and enhancing concentration efficiency of incident light on the LCD panel  105 ; a surface light source  120  disposed under and spaced from the optical sheets and emitting light to the LCD panel  105 ; and a mold frame  107  supporting the LCD panel  105 , the surface light source  120 , etc. The surface light source  120  comprises a plurality of lamps  121  disposed at the same intervals in a rear of the optical sheets  110 , and a substrate  125  provided in a rear of the lamps  121 .  
      The surface light source  120  is disposed in the rear of the optical sheets  110  and directly emits light to the optical sheets  110 , so that the light concentration efficiency of the surface light source  120  is enhanced as compared with that of the edge type LCD apparatus, thereby realizing high brightness. Thus, because the size of LCD apparatuses is on the rise, the surface light source  120  is widely used in the larger sized LCD apparatuses.  
      The plurality of lamps  121  are disposed on the substrate  125  and spaced not only from each other but also from the optical sheets  110 . However, in the conventional LCD apparatus, the surface light source and the optical sheet are spaced from each other, and thus it is difficult to keep a distance between the surface light source and the optical sheet uniformly when they are assembled into the LCD apparatus. Further, the larger the size of the LCD apparatus, the weaker the relative strength of the surface light source and the optical sheet. In this case, the surface light source and the optical sheet need to be stably supported.  
     SUMMARY OF THE INVENTION  
      Accordingly, it is an exemplary aspect of the present invention to provide an LCD apparatus having an improved structure which stably supports a surface light source and an optical sheet.  
      The foregoing and/or other aspects of the present invention are also achieved in an exemplary embodiment by providing an LCD apparatus comprising: an LCD panel displaying a picture thereon; an optical sheet provided in a rear of the LCD panel; a surface light source spacedly provided in a rear of the optical sheet and emitting light to the optical sheet; and a supporter provided between the optical sheet and the surface light source and supporting the optical sheet and the surface light source.  
      According to an exemplary aspect of the invention, the surface light source comprises an upper plate formed with a plurality of protruding portions protruding toward the rear of the optical sheets, and a lower plate coupled to the upper plate and forming a discharging space between the protruding portion and the lower plate.  
      According to an exemplary aspect of the invention, the supporter comprises a plurality of accommodating portions to accommodate the respective protruding portions, and a plurality of surface light source supporting portions formed between the respective accommodating portions and contacting the upper plate between the respective protruding portions.  
      According to an exemplary aspect of the invention, the surface light source is attached to the upper plate between the respective protruding portions.  
      According to an exemplary aspect of the invention, the surface light source comprises a plurality of lamps spaced from each other, and a plate provided in a rear of the respective lamps, and the supporter comprises a plurality of accommodating portions to accommodate the respective lamps, and a plurality of surface light source supporting portions formed between the respective accommodating portions and contacting the plate between the respective lamps.  
      According to an exemplary aspect of the invention, the surface light source supporting portion is attached to the plate between the respective protruding portions.  
      According to an exemplary aspect of the invention, the supporter uniformizes the light emitted from the surface light source to the optical sheet.  
      According to an exemplary aspect of the invention, the supporter includes PMMA material. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      The above and/or other aspects and advantages of the present invention will become apparent and more readily appreciated from the following description of the illustrative embodiments, taken in conjunction with the accompany drawings of which:  
       FIG. 1  is a schematic section view of a conventional LCD apparatus;  
       FIG. 2  is a schematic section view of an LCD apparatus according to a first exemplary embodiment of the present invention;  
       FIG. 3  is a partially enlarged perspective view of the LCD apparatus of  FIG. 2 ;  
       FIG. 4  is a schematic section view of an LCD apparatus according to a second exemplary embodiment of the present invention; and  
       FIG. 5  is a partially enlarged perspective view of the LCD apparatus of  FIG. 4 . 
    
    
     DETAILED DESCRIPTION OF EXEMPLARY, NON-LIMITING EMBODIMENTS  
      Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout. The embodiments are described below in order to explain the present invention by referring to the figures.  
     First Exemplary Embodiment  
      As shown in  FIGS. 2 and 3 , an LCD apparatus  1  according to an embodiment of the present invention comprises an LCD panel  5  displaying a picture thereon; an optical sheet  10  disposed at a rear of the LCD panel  5 ; a surface light source  20  spacedly disposed from a rear of the optical sheet  10  and emitting light to the LCD panel  5 ; a frame  7  provided outside of both the LCD panel  5  and the surface light source  20  and supporting the LCD panel  5  and the surface light source  20 ; and a supporter  30  provided between the optical sheet  10  and the surface light source  20  and supporting the optical sheet  10  and the surface light source  20 .  
      The LCD panel  5  comprises a pair of substrates (not shown) and a liquid crystal (not shown) sandwiched between the substrates. When voltage is applied between the pair of substrates filled with the liquid crystal, the molecular arrangement of the liquid crystal is changed and thus the transmissivity of the light emitting from the surface light source  20  is adjusted, thereby displaying a picture.  
      The optical sheet  10  comprises a plurality of sheets to enhance concentration efficiency of the light emitted from the surface light source  20  to the LCD panel  5 . That is, the optical sheets  10  comprise a plurality of diffusion sheets  11  to diffuse and uniformize the light emitted from the surface light source  20 ; a prism sheet  13  to change a traveling path of the light diffused by the diffusion sheet  11  at a predetermined angle; etc.  
      The frame  7  is provided outside of the LCD panel  5 , the optical sheets  10 , and the surface light source  20 , and supports the LCD panel  5 , the optical sheets  10 , the surface light source  20 , etc.  
      The surface light source  20  is spaced from the rear of the optical sheet  10 , and comprises an upper plate  21  formed with a plurality of protruding portions  22  spaced from each other, and a lower plate  25  coupled to the upper plate  21  to form a discharging space  29  between the protruding portion  22  and the lower plate  25 . Further, the surface light source  20  comprises a fluorescent layer  27  coated on an inner wall of the protruding portion  22  forming the discharging space  29 , and electrodes  26  to make a discharge in the discharging space  29 .  
      The discharging space  29  is filled with inert gas such as mercury (Hg) gas, argon (Ar) gas, or the like. The inert gas filled in the discharging space  29  is discharged when voltage is applied between the electrodes  26 , thereby generating ultraviolet rays.  
      The fluorescent layer  27  is preferably coated on the inner wall of the protruding portion  22 , but may be coated on the lower plate  25 . The fluorescent layer  27  absorbs the ultraviolet rays generated by the voltage applied between the electrodes  26  and then transforms the ultraviolet rays into visible rays.  
      The electrodes  26  are preferably provided in the lower plate  25 , but may be provided in the upper plate  21 . The electrodes  26  make plasma discharge in the discharging space  29  when voltage is applied therebetween, and thus the ultraviolet rays due to the plasma discharge excites the fluorescent layer  27  to generate the visible rays, thereby emitting light.  
      The upper plate  21  is made of glass material, so that the light can travel from the discharging space  29  toward the optical sheet  10  through the upper plate  21 . Alternatively, the upper plate  21  may be made of various materials such as plastics as long as the light can travel from the discharging space  29  toward the optical sheet  10  through the upper plate  21 . Further, the upper plate  21  is formed with a contact-supporting portion  23  formed between the protruding portions  22  in order to contact a surface light source supporting portion  33  of the supporter  30  (to be described later).  
      The protruding portions  22  are spaced from each other, and each of them is longitudinally formed in the upper plate  21  and has a semi-elliptical section. Alternatively, the protruding portion  22  may have a semicircular section, a rectangular section, a triangular section, or the like.  
      The contact-supporting portion  23  is formed between the protruding portions  22 , and has a bottom surface contact-coupled to an upper surface of the lower plate  25  and a top surface contact-coupled to the surface light source supporting portion  33  of the supporter  30 . Here, the bottom and top surfaces of the contact-supporting portion  23  are coupled to the lower plate  25  and the surface light source supporting portion  33  by an adhesive, respectively, but may be coupled by a double sided tape, a screw, a bolt or the like.  
      The lower plate  25  is coupled to the upper plate  21  so as to form the discharging space  29 . The lower plate  25  is preferably, but not necessarily, made of a flat glass plate. Alternatively, the lower plate  25  may be made of various materials such as a flat plastic plate. Further, the lower plate  25  can be provided with a reflecting sheet (not shown) to reflect the light generated in the discharging space  29  toward the optical sheet  10 .  
      The supporter  30  comprises a plurality of accommodating portions  31  to accommodate the plurality of protruding portion  22 , and the surface light source supporting portions  33  formed between the respective accommodating portions  31  and contacting the upper plate  21  between the respective accommodating portions  31 . The supporter  30  uniformizes the light emitted from the surface light source  20  to the optical sheet  10 . The supporter  30  is made of PMMA (polymethylmethacrylate) material or the like, which is excellent in diffusion and transmissivity of the light, so that the supporter  30  can function as a light guide plate. A top surface of the supporter  30  is flat in correspondence to the shape of the optical sheet  10 . Further, the top surface of the supporter  30  can contact and support the optical sheet  10  so as to prevent the optical sheet  10  from bending toward the surface light source  10 .  
      The accommodating portion  31  is shaped corresponding to the shape of the protruding portion  22  and accommodates the protruding portion  22 . Here, the accommodating portion  31  can be spaced from the protruding portion  22  or contact the protruding portion  22  when it accommodates the protruding portion  22 . The accommodating portion  31  can have a semi-elliptical section corresponding to the shape of the protruding portion  22 . Alternatively, the accommodating portion  31  may have various sections such as a semicircular section, a rectangular section, or the like as long as it can accommodate the protruding portion  22 .  
      The surface light source supporting portion  33  is attached to the upper plated  21  between the respective protruding portions  22 . That is, the surface light source supporting portion  33  is formed between the respective accommodating portions  31  and attached to the contact-supporting portion  23  of the upper plate  21 , thereby allowing the supporter  30  to support the surface light source  20 . At this time, the surface light source supporting portion  33  is attached to the contact-supporting portion  23  by an adhesive or the like.  
      With this configuration, a process of assembling the LCD apparatus  1  according to the first embodiment of the present invention is as follows.  
      First, there are provided the surface light source  20  formed with the plurality of protruding portions  22 , and the supporter  30  formed with the plurality of accommodating portions  31  to accommodate the respective protruding portion  22 . Then, the supporter  30  is put on the surface light source  20 . That is, the protruding portion  22  of the surface light source  20  is accommodated in the accommodating portion  31  of the supporter  30 , and the surface light source supporting portion  33  of the supporter  30  is in contact with the contact-supporting portion  23  of the surface light source  20 . At this time, the adhesive is applied between the surface light source supporting portion  33  and the contact-supporting portion  23 , so that the surface light source supporting portion  33  and the contact-supporting portion  23  are attached, thereby coupling the supporter  30  with the surface light source  20 . Thereafter, the plurality of optical sheets  10  and the LCD panel  5  are put on the supporter  30 , and then the frame  7  is coupled to them.  
      With this configuration, the LCD apparatus  1  according to the first embodiment of the present invention comprises the supporter  30  provided between the optical sheet  10  and the surface light source  20  and supporting the optical sheet  10  and the surface light source  20 , thereby keeping a distance between the surface light source  20  and the optical sheet  10  uniformly when they are assembled into the LCD apparatus  1 . Particularly, in the case where the area of the surface light source  20  and the optical sheet  10  is large relatively to the thickness thereof, due to the size of LCD apparatuses being on the rise, the supporter stably supports the surface light source  20  and the optical sheet  10  to prevent the strength of the surface light source  20  and the optical sheet  10  from becoming weaker. Further, the supporter  30  uniformizes the light emitted from the surface light source  20  to the optical sheet  10 , thereby functioning as a light guide plate.  
     Second Embodiment  
       FIGS. 4 and 5  are respectively a schematic section view and an exploded perspective view of an LCD apparatus according to a second embodiment of the present invention. Contrary to the first embodiment, an LCD apparatus  1   a  according to the second embodiment of the present invention comprises a surface light source  40  provided with a plurality of lamps  41 , and a supporter  30   a  formed with a plurality of accommodating portions  31   a  to accommodate the plurality of lamps  41 .  
      The surface light source  40  comprises the plurality of lamps  41  arranged to be spaced from each other, and a plate  45  provided at a rear of the plurality of lamps  41 . The lamp  41  has a circular section and is longitudinally shaped like a bar. The plate  45  is flat, and may function as a reflecting sheet to reflect the light emitted from the lamp  41  toward the optical sheet  10 .  
      The supporter  30   a  comprises the plurality of accommodating portions  31   a  to accommodate the respective lamps  41 , and a surface light source supporting portion  33   a  formed between the accommodating portions  31   a  to contact the plate  45  between the lamps  41 . The supporter  30   a  uniformizes the light emitted from the surface light source  40  to the optical sheet  10 . That is, the supporter  30   a  is made of PMMA (polymethylmethacrylate) material or the like, for example, thereby functioning as a light guide plate.  
      The accommodating portion  31   a  is recessed on the bottom surface of the supporter  30   a  in order to accommodate each of the lamps  41 . Alternatively, the accommodating portion  31   a  may accommodate each pair of lamps  41  and may accommodate three or more lamps  41 .  
      The surface light source supporting portion  33  is attached to the plate  45  between the respective lamps  41 . The surface light source supporting portion  33  is preferably attached to the plate  45  by an adhesive, but may be attached by a double sided tape, a screw, or the like.  
      With this configuration, the LCD apparatus according to the second embodiment of the present invention comprises the supporter provided between the optical sheet and the surface light source and supporting the optical sheet and the surface light source, thereby keeping a distance between the surface light source and the optical sheet constant when they are assembled into the LCD apparatus. Particularly, in the case where the area of the surface light source and the optical sheet is large relative to the thickness thereof, due to the size of LCD apparatuses being on the rise, the supporter stably supports the surface light source and the optical sheet to prevent the strength of the surface light source and the optical sheet from becoming weaker. Further, the supporter uniformizes the light emitted from the surface light source to the optical sheet, thereby functioning as a light guide plate.  
      As described above, the present invention provides an LCD apparatus which can be easily assembled and stably support a surface light source and an optical sheet even though the size thereof is increased.  
      Further, the present invention provides an LCD apparatus in which a supporter uniformizes light emitted from a surface light source to an optical sheet, thereby functioning as a light guide plate.  
      Although a few exemplary embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.