Patent Publication Number: US-2007115692-A1

Title: Liquid crystal display having liquid crystal panel secured using micro-adhesive units

Description:
FIELD OF THE INVENTION  
      The present invention relates to liquid crystal displays, and more particularly to a liquid crystal display configured to provide strong bonding between a liquid crystal panel and a frame thereof.  
     BACKGROUND  
      A common kind of liquid crystal display includes a liquid crystal panel, and a backlight module providing a planar light source for the liquid crystal panel. The liquid crystal panel is received and fixed within a frame of the backlight module by way of double-sided adhesive tape or similar means. Thereby, the liquid crystal panel is protected from external impact, and shifting of the liquid crystal panel relative to the backlight module is avoided.  
      Referring to  FIG. 8 , this shows a conventional liquid crystal display. The liquid crystal display  1  includes a liquid crystal panel  10 , and a backlight module  20  providing a uniform planar light source for the liquid crystal panel  10 .  
      The backlight module  20  includes a frame  22  having a receiving space, an optical film  21  having a plurality of protrusions formed on side edges thereof, a light guide plate  24  having a top emitting surface  241  and an opposite back surface  242 , a reflective sheet  25 , and a flexible printed circuit board  27  having a plurality of light sources  26  attached thereon. The receiving space of the frame  22  is cooperatively formed by first, second, third and fourth side walls  221 ,  222 ,  223 , and  224  connected end-to-end. The side walls  221 ,  222 ,  223 , and  224  include depressed supporting parts  2220  at inner sides thereof respectively. The supporting part  2220  of the second side wall  222  has a plurality of cutouts  2222 . The supporting parts  2220  at the first, third, and fourth side walls  221 ,  223 , and  224  include a plurality of coplanar bonding parts  227 . The receiving space of the frame  22  is divided by the supporting parts  2220  into upper and lower receiving spaces  228 ,  229 . Three gaps  2271 ,  2274  and  2275  are defined in the supporting members  227  at the first, third, and fourth side walls  221 ,  223 , and  224  respectively.  
      A process of assembling the liquid crystal display  1  is as follows. Firstly, the light guide plate  24  is fittingly received in the lower receiving space  229  of the frame  22 . The reflective sheet  25  is received in the lower receiving space  229  below the back surface  242  of the light guide plate  24 . Secondly, the optical film  21  is received in the upper receiving space  228  of the frame  22  adjacent to the emitting surface  241  of the light guide plate  24 , with the protrusions of the optical film  21  wedging in the gaps  2271 ,  2274 , and  2275 . Then, the flexible printed circuit board  27  is disposed on the supporting part  2220  of the second side wall  222 , with the light sources  226  wedging in the cutouts  2222 . Thirdly, the liquid crystal panel  10  is received in the upper receiving space  228  and fixed to the bonding parts  227  via a plurality of double-sided adhesive tapes  30 .  
      The surfaces of the liquid crystal panel  10  to which the double-sided adhesive tapes  30  are attached are flat. Similarly, the surfaces of the supporting members  227  to which the double-sided adhesive tapes  30  are attached are also flat. The bonding strength between the respective surfaces is proportional to the contact areas of the surfaces. If the contact areas are too small, or if the liquid crystal display  1  is used in a rugged application or environment, the bonding strength may not be enough to securely and reliably fix the liquid crystal panel  10  to the supporting members  227 . For example, if the liquid crystal display  1  is subjected to external impact or vibration, the liquid crystal panel  10  is liable to slide in the frame  22  or become dislodged from the frame  22 . When this happens, the functioning of the liquid crystal display  1  may be impaired, and the liquid crystal panel  10  may sustain damage.  
      Accordingly, what is needed is a liquid crystal display configured to have a liquid crystal panel securely fixed relative to a backlight module thereof.  
     SUMMARY  
      An exemplary liquid crystal display includes a backlight module and a light crystal panel. The backlight module includes a frame having a bonding part with a plurality of micro adhesive units, and the liquid crystal panel is adhered to the bonding part via the micro adhesive units.  
      A detailed description of embodiments of the present invention is given below with reference to the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      In the drawings, all the views are schematic.  
       FIG. 1  is an exploded, isometric view of a liquid crystal display in accordance with a first embodiment of the present invention.  
       FIG. 2  is a view of a frame of the liquid crystal display of  FIG. 1  shown in isolation.  
       FIG. 3  is an inverted, isometric view of the frame of  FIG. 2 .  
       FIG. 4  is an enlarged cross-sectional view of part of the frame of  FIG. 2 , taken along line IV-IV thereof.  
       FIG. 5  is a cross-sectional view of part of a frame of a liquid crystal display according to a second embodiment of the present invention.  
       FIG. 6  is a cross-sectional view of part of a frame of a liquid crystal display according to a third embodiment of the present invention.  
       FIG. 7  is a cross-sectional view of part of a frame of a liquid crystal display according to a fourth embodiment of the present invention.  
       FIG. 8  is an exploded, isometric view of a conventional liquid crystal display. 
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS  
      Referring to FIGS.  1  to  3 , these show a liquid crystal display  5  in accordance with a first embodiment of the present invention. The liquid crystal display  5  includes a liquid crystal panel  50  having a display area  51  and a non-display area  52 , and a backlight module  60  providing a uniform planar light source for the liquid crystal panel  50 .  
      The backlight module  60  includes a frame  62  having a receiving space, an optical film  61  having a plurality of protrusions on side edge portions thereof, a light guide plate  64  having a top emitting surface  641  and an opposite back surface  642 , a reflective sheet  65  having a reflective side (not labeled) and a back side (not labeled), and a flexible printed circuit board  67  having a plurality of light sources  66  attached thereon. The receiving space of the frame  62  is formed by first, second, third, and fourth side walls  621 ,  622 ,  623 , and  624  connected end-to-end. The side walls  621 ,  622 ,  623 , and  624  include depressed supporting parts  6220  at inner sides thereof respectively. The supporting part  6220  of the second side wall  622  has a plurality of concave parts  6222 , and the supporting parts  6220  of the first, third, and fourth side walls  621 ,  623 , and  624  include a plurality of bonding parts  627 . The bonding parts  627  and back sides of the supporting parts  6220  have a plurality of micro adhesive units. The micro adhesive units can for example be concave pits such as hemispherical pits  6275 ,  6276 , as shown in  FIG. 4 . The receiving space of the frame  62  is divided by the supporting parts  6220  into upper and lower receiving spaces  628 ,  629 . Three gaps  6271 ,  6273 , and  6274  are defined in the supporting members  627  at the first, third, and fourth side walls  621 ,  623 , and  624  respectively.  
      A process of assembly of the liquid crystal display  5  is as follows. Firstly, the light guide plate  64  is received in the lower receiving space  629  of the frame  62 . Secondly, the optical film  61  is disposed in the upper receiving space  628  of the frame  62  adjacent to the emitting surface  641  of the light guide plate  64 , with the protrusions of the optical film  61  wedging in the gaps  6271 ,  6273 , and  6274 . Then the flexible printed circuit board  67  is disposed on the supporting part  6220  of the second side wall  622 , with the light sources  626  wedging in the concave parts  6222 . Thirdly, glue is coated on the bonding parts  627 , with the glue also filling the hemispherical pits  6275  thereof. Similarly, glue is coated on the back sides of the supporting parts  6220 , with the glue also filling the hemispherical pits  6276  thereof. Then the liquid crystal panel  50  is attached to the frame  62  adjacent to the optical film  61 , by pressing the non-display area  52  of the liquid crystal panel  50  onto the bonding parts  627  adjacent to the optical film  61 . Then the reflective sheet  65  is attached to the frame  62  such that the reflective side of the reflective sheet  65  is adjacent the back surface  642  of the light guide plate  61 , by pressing the reflective sheet  65  onto the back sides of the supporting parts  6220 . The glue is preferably pressure sensitive adhesive or double adhesive tape with liquid or semi-liquid adhesive.  
      Interface areas between the non-display area  52  of the liquid crystal panel  51  and the bonding parts  627  are increased by the hemispherical pits  6275 , and interface areas between the reflective sheet  65  and the back sides of the supporting parts  6220  are increased by the hemispherical pits  6276 . Therefore the bonding strength between the liquid crystal panel  51  and the frame  62  is increased, and the bonding strength between the reflective sheet  65  and the frame  62  is increased. Thus sliding of the liquid crystal panel  50  relative to the frame  62  can be avoided, and sliding of the reflective sheet  65  relative to the frame  62  can also be avoided.  
      Referring to  FIG. 5 , this is a cross-sectional view of part of a frame of a liquid crystal display according to a second embodiment of the present invention. The liquid crystal display of the second embodiment is similar to the above-described first embodiment. The liquid crystal display includes a plurality of supporting parts (not labeled) and a plurality of bonding portions (not labeled), each having a plurality of micro adhesive units. The micro adhesive units are rectangular pits  7275 . That is, a side cross-section of each of the rectangular pits  7275  is rectangular. Interface areas where glue is applied are increased by the rectangular pits  7275 .  
      Referring to  FIG. 6 , this is a cross-sectional view of part of a frame of a liquid crystal display according to a third embodiment of the present invention. The liquid crystal display of the third embodiment is similar to the above-described first embodiment. The liquid crystal display includes a plurality of supporting parts (not labeled) and a plurality of bonding portions (not labeled), each having a plurality of micro adhesive units. The micro adhesive units are trapezoid-shaped pits  8275 . That is, a side cross-section of each of the trapezoid-shaped pits  8275  is trapezoidal. Interface areas where glue is applied are increased by the trapezoid-shaped pits  8275 .  
      Referring to  FIG. 7 , this is a cross-sectional view of part of a frame of a liquid crystal display according to a fourth embodiment of the present invention. The liquid crystal display of the fourth embodiment is similar to the above-described first embodiment. The liquid crystal display includes a plurality of supporting parts (not labeled) and a plurality of bonding portions (not labeled), each having a plurality of micro adhesive units. The micro adhesive units are triangular protruding parts  9275 . That is, a side cross-section of each of the protruding parts  9275  is triangular. Interface areas where glue is applied are increased by the triangular protruding parts  9275 .  
      In alternative embodiments, any combination of the hemispherical pits  6275 ,  6276 , rectangular pits  7275 , trapezoid-shaped pits  8275 , and the protruding parts  9275  can be employed in the one same liquid crystal display. The micro adhesive units are not limited to the above-described hemispherical pits  6275 ,  6276 , rectangular pits  7275 , trapezoid-shaped pits  8275 , and the protruding parts  9275 . The micro adhesive units can have any of various regular or irregular curved and/or rectilinear shapes and configurations, such as concavities or domes. The hemispherical pits  6275 ,  6276 , rectangular pits  7275 , trapezoid-shaped pits  8275 , and the protruding parts  9275  can further or alternatively be formed on the non-display area  52  of the liquid crystal panel  50 , and/or further or alternatively formed on a periphery of the reflective side of the reflective sheet  65 . The hemispherical pits  6275 ,  6276 , rectangular pits  7275 , trapezoid-shaped pits  8275 , and the protruding parts  9275  can be arranged linearly, or according to a predetermined pattern, or randomly.  
      While examples and preferred and exemplary embodiments have been described, it is to be understood that the invention is not limited thereto. To the contrary, the above description is intended to cover various modifications and similar arrangements as would be apparent to those skilled in the art. Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements.