Patent Publication Number: US-2011058355-A1

Title: Liquid crystal display device and method for assembling same

Description:
BACKGROUND 
     1. Technical Field 
     The present disclosure relates generally to liquid crystal display (LCD) devices and, more particularly, to an LCD device having a backlight module without a dedicated housing. 
     2. Description of Related Art 
     LCD devices have largely replaced conventional cathode ray tube (CRT) display devices due to their excellent display quality and thinner, lighter construction. 
     However, market and industry demands continually require further reduction of LCD device thickness for enhanced portability, necessitating ongoing structural modification. 
     Therefore, there is room for improvement within the art. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The components in the drawings are not necessarily drawn to scale, the emphasis instead placed upon clearly illustrating the principles of the present disclosure. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views. 
         FIG. 1  is an assembled, isometric view of a first embodiment of an LCD device, the LCD device including a back cover and a side frame (not visible). 
         FIG. 2  is a isometric view of part of the back cover and the side frame of the LCD device of  FIG. 1 . 
         FIG. 3  is a cross-section of part of the LCD device of  FIG. 1 , taken along line III-III thereof. 
         FIG. 4  is a cross-section of part of the LCD device of  FIG. 1 , taken along line IV-IV thereof. 
         FIG. 5  is an assembled, isometric view of a second embodiment of an LCD device, the LCD device including a back cover and a side frame (not visible). 
         FIG. 6  is an isometric view of the back cover and the side frame of the LCD device of  FIG. 5 . 
         FIG. 7  is a cross-section of part of the LCD device of  FIG. 5 , taken along line VII-VII thereof. 
         FIG. 8  is an assembled, isometric view of a third embodiment of an LCD device. 
         FIG. 9  is a cross-section of part of the LCD device of  FIG. 8 , taken along line IX-IX thereof. 
         FIG. 10  is a cross-section view of part of a fourth embodiment of an LCD device. 
         FIG. 11  is a perspective view of a light guide plate used in an LCD device that is a variation of the LCD device of  FIG. 10 . 
         FIG. 12  is a flowchart of an exemplary method for assembling an LCD device. 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIGS. 1 through 3 , a first embodiment of an LCD device  100  includes a back cover  110 , a bezel  120 , a side frame  130 , a panel assembly  140 , and a backlight module  150 . The bezel  120  is fixed on the back cover  110 , and the panel assembly  140  is positioned between the bezel  120  and the back cover  110 . 
     The back cover  110  can be metal, such as aluminum alloy or stainless alloy. The back cover  110  can instead be nonmetallic material, such as plastic. 
     The back cover  110  includes a main body  112  and a holding frame  114 . The holding frame  114  is formed on the main body  112  and surrounds the side frame  130 . In the illustrated embodiment, a plurality of portions along a perimeter of the holding frame  114  are in the form of generally U-shaped protrusions that jut out from a main portion of the holding frame  114  in a direction toward an outside of the LCD device  100 , parallel to the back cover  110 . Thereby, a plurality of positioning grooves  116  is defined inside the U-shaped protrusions, respectively. In the illustrated embodiment, the side frame  130  includes a main portion  132 , and a plurality of positioning protrusions  134  extending outward from an outer edge of the main portion  132 . The positioning protrusions  134  are received in the positioning grooves  116 , respectively. The positioning protrusions  134  are fixed to the back cover  110  via fasteners  136 , respectively. In the illustrated embodiment, the fasteners  136  are screws. Thus, the side frame  130  is firmly fixed on the back cover  110 . In an alternative embodiment, there may be only one U-shaped protrusion, one positioning groove  116 , one positioning protrusion  134 , and one fastener  136 . 
     The backlight module  150  is directly positioned on the back cover  110 , below the panel assembly  140 . In the illustrated embodiment, there is a small gap between the backlight module  150  and the panel assembly  140 . Nevertheless, the backlight module  150  can be held in position between the back cover  110  and the panel assembly  140 . Thus, there is no need for a dedicated housing in the LCD device  100  to support the backlight module  150 . Accordingly, a thickness of the LCD device  100  can be reduced. 
     As described above, the side frame  130  is fixed on the back cover  110 ; and the side frame  130  surrounds the backlight module  150  and supports the panel assembly  140 . In addition, an adhesive member  122  is positioned between the panel assembly  140  and the bezel  120 . In the illustrated embodiment, the adhesive member  122  is simultaneously further positioned between at least one of the fasteners  136  and the bezel  120 . Thus, the side frame  130  and the panel assembly  140  are firmly held in position, in cooperation with the back cover  110  and the bezel  120 . 
     The backlight module  150  includes a reflective plate  151  and a light guide plate  152 . The reflective plate  151  has a first surface attached to the back cover  110 . The light guide plate  152  is positioned on a second surface of the reflective plate  151  which is at an opposite side of the light guide plate  152  from the first surface. 
     Referring also to  FIG. 4 , the backlight module  150  further includes a multifunction film  159  positioned on the light guide plate  152 . The multifunction film  159  can diffuse light as with a conventional light diffusion sheet, and also converge light as with a conventional prism sheet. That is, the multifunction film  159  can replace what is ordinarily a plurality of optical sheets, thereby further reducing the thickness of the LCD device  100 . 
     The backlight module  150  further includes a plurality of light sources  157  positioned adjacent to a light incident surface  153  of the light guide plate  152 . A light output surface  154  of the light guide plate  152  faces toward the panel assembly  140 . The multifunction film  159  is attached to the light output surface  154 . Each light source  157  can be a light-emitting diode (LED). Alternatively, the light sources  157  can be replaced by a single linear light source such as a cold cathode fluorescent lamp (CCFL). 
     Referring to  FIGS. 5 through 7 , a second embodiment of an LCD device  200  is similar to the LCD device  100  of the first embodiment. In the LCD device  200 , a side frame  130   a  defines a plurality of assembly holes  138 . The LCD device  200  further includes a plurality of elastic members  139 . In the illustrated embodiment, each elastic member  139  is generally in the form of a U-shaped clip. Each elastic member  139  includes a first leg  1391 , a second leg  1392 , and a connecting portion  1393  connecting the first leg  1391  to the second leg  1392 . The first leg  1391  is received in a corresponding assembly hole  138  of the side frame  130   a , and the second leg  1392  is attached to an outer surface of the holding frame  114 . In addition, the adhesive member  122  is positioned between the panel assembly  140  and the bezel  120 . In the illustrated embodiment, the adhesive member  122  is simultaneously further positioned between the connecting portion  1393  of at least one of the elastic members  139  and the bezel  120 . Thus, the side frame  130   a  and the panel assembly  140  are firmly held in position, in cooperation with the back cover  110  and the bezel  120 . 
     Referring to  FIGS. 8 and 9 , a third embodiment of an LCD device  300  differs from the LCD device  100  of the first embodiment only in that a side frame  130   b  is integrally formed with a back cover  110   b , and the adhesive member  122  is omitted. That is, the side frame  130   b  and the back cover  110   b  are portions of a single, one-piece, monolithic body without any internal seams. The side frame  130   b  surrounds the backlight module  150 , and supports the panel assembly  140 . Since the side frame  130   b  and the back cover  110   b  are integrally formed, the LCD device  300  is easily assembled. 
     Referring to  FIG. 10 , a fourth embodiment of an LCD device  400  differs from the LCD device  300  of the third embodiment only in that the reflective plate  151  of the LCD device  300  is replaced by a reflective layer  158 . The reflective layer  158  is coated on the side frame  130  and also the back cover  110 , and the reflective layer  158  on the side frame  130  surrounds three lateral sides of the light guide plate  152  other than the light incident surface  153 . 
     Referring to  FIG. 11 , in a variation of the fourth embodiment, the reflective layer  158  is omitted, and instead the light guide plate  152  is coated with reflective material. The light guide plate  152  includes the light incident surface  153  and the light output surface  154 , and three light reflective surfaces  155  connecting the light output surface  154 . The light reflective surfaces  155  are coated with the reflective material. 
       FIG. 12  shows an exemplary method for assembling an LCD device, such as, for example, the LCD device  100  of the first embodiment. The method includes the following steps. 
     In step  410 , the back cover  110  and the side frame  130  are provided, and the side frame  130  is positioned on the back cover  110 . In step  420 , the backlight module  150  is directly positioned on the back cover  110 , and surrounded by the side frame  130 . In step  430 , the panel assembly  140  is positioned on the side frame  130 , opposite to the backlight module  150 . In step  440 , the bezel  120  is fixed to the back cover  110 . 
     In particular, in step  420 , the reflective plate  151 , the light guide plate  152 , and the multifunction film  159  of the backlight module  150  are positioned on the back cover  110  in that order. 
     It should be pointed out that in the case of the method being adapted for assembling the LCD device  200 , in step  410 , the side frame  130  can be fixed to the back cover  110  by the elastic members  139 . In the case of the method being adapted for assembling the LCD device  300 , in step  410 , the side frame  130  integrally formed with the back cover  110  can be provided. 
     It is believed that the present embodiments and their advantages will be understood from the foregoing description, and it will be apparent that various changes may be made thereto without departing from the spirit and scope of the disclosure or sacrificing all of its material advantages.