Abstract:
A backlight module is disclosed. The backlight module includes a back plate, a diffuser and a supporter. The diffuser is disposed over the back plate. The supporter is disposed between the back plate and the diffuser and includes a seat and a fixing member. The fixing member has one or more protrusions formed thereon and the seat and fixing member are adapted to fix a light source.

Description:
The application claims the benefit of Taiwan application Ser. No. 94101522, filed Jan. 19, 2005, the subject matter of which is incorporated herein by reference. 
   BACKGROUND 
   The present invention relates to a backlight module, and more particularly, relates to a backlight module with supporters, maintaining spacing between the light source and the diffuser. 
   In a liquid crystal display (LCD) unit of a liquid crystal display, a backlight module is generally utilized as a light source. According to the structure, the backlight module can be an edge type or direct type module. Since the disclosure seeks to improve the direct type backlight module, a description of edge type backlight modules is omitted. 
     FIG. 1  is a cross-section of a conventional direct type backlight module. In  FIG. 1 , a direct type backlight module  10  includes a reflector  11 , a diffuser  12 , a plurality of supporters  13  and cold cathode fluorescent lamps  14 . The reflector  11  is at the bottom of the direct type backlight module  10 . The diffuser  12  is disposed on the reflector  11 , and the fluorescent lamps  14  are disposed therebetween. The reflector  11  reflects the light provided by the fluorescent lamps  14 , passing through the diffuser  12  as a light source for flat displays. The supporters  13  are disposed on the reflector  11  and abut the diffuser  12 , protecting the diffuser  12  from deformation which may deteriorate optical characteristics of the backlight module  10 . 
   Furthermore, the fluorescent lamps  14  in large backlight modules are long and thin, subject to damage during assembly or transport. Thus, the conventional backlight module  10  further comprises transparent O-rings  15  disposed manually on the fluorescent lamps  14  to provide support for the fluorescent lamps  14  and prevent excessive deformation. This assembly step, however, is inefficient, and the fluorescent lamps  14  easily crack during assembly, increasing costs of the finished modules. 
   SUMMARY 
   In order to address the disadvantages of the aforementioned backlight module, an embodiment of the present invention provides an easily assembled supporter for a direct type backlight module, securing the fluorescent lamps and maintaining spacing between the diffuser and the fluorescent lamps, protecting both from deformation. 
   An embodiment of the present invention provides a backlight module utilizing the abovementioned supporters. 
   Accordingly, an embodiment of the present invention provides a backlight module comprising a reflector, a diffuser, a plurality of supporters and fluorescent lamps disposed therebetween. The diffuser is disposed on the reflector. The supporter comprises a seat and a fixing member. The seat is disposed on the reflector. The fixing member is secured on the seat and comprises a protrusion abutting the diffuser, preventing deformation and maintaining spacing between the reflector and diffuser. The fluorescent lamps are fixed by the seat and fixing member, providing light required by the backlight module. 
   In the embodiment, the supporter is made of transparent material or white material. The seat has a first hook, and the first hook secures the seat to the reflector. The fixing member comprises a second hook, and the second hook secures the fixing member to the seat. The seat further has a plurality of holding portions, and the fixing member has a plurality of corresponding curved portions to fix the fluorescent lamps. The holding portions and the corresponding curved portions surround and fix the fluorescent lamps when the fixing member is secured on the seat. The protrusion is located between two adjacent curved portions of the fixing member, point contacting and supporting the diffuser. 
   Furthermore, between the fluorescent lamps and the curved portion of the fixing member is a gap. The reflector has multiple pieces, by which can minimize deformation of the reflector. 

   
     DESCRIPTION OF THE DRAWINGS 
     The invention can be more fully understood by reading the subsequent detailed description in conjunction with the examples and references made to the accompanying drawings, wherein: 
       FIG. 1  is a cross-section of a conventional direct type backlight module; 
       FIG. 2  is a cross-section of a direct type backlight module in an embodiment of the present invention; 
       FIG. 3  is a partial exploded perspective view of the direct type backlight module in  FIG. 2 ; 
       FIG. 4  is a schematic view of the enlarged area a in  FIG. 2 ; 
       FIG. 5  is a schematic view of a direct type backlight module in another embodiment of the present invention; and 
       FIG. 6  is a schematic view of a reflector in an embodiment of the present invention. 
   

   DETAILED DESCRIPTION 
     FIG. 2  is a cross-section of a direct type backlight module in an embodiment of the present invention. In order to simplify the drawing, only five light sources  24  are shown although the disclosure is not limited thereto. 
   The backlight module  20  in an embodiment of the present invention comprises a back plate  21 , a reflector  22 , a diffuser  23 , a plurality of light sources  24  (such as fluorescent lamp or the similarities) and supporters  30 . The reflector  22  is disposed on the back plate  21  to reflect light. The diffuser  23  is disposed above the reflector  22 , defining an inner space by the reflector  22  and the diffuser  23 . The supporters  30  are disposed between the reflector  22  and the diffuser  23  and comprise a seat  31  and a fixing member  32 . The light sources  24  are separately fixed with the same spacing by the seat  31  and fixing member  32 , providing light required by backlight module  20 . The seat  31  is disposed on the reflector  22 . The fixing member  32  is secured on the seat  31  and comprises a protrusion  321  abutting the diffuser  23 , maintaining the inner space between the reflector  22  and diffuser  23 . 
   In  FIG. 2 , the supporter  30  is made of transparent material or white material. The seat  31  of the supporter  30  comprises a plurality of holding portions  311 . The fixing member  32  comprises a plurality of curved portions  322  corresponding to the holding portions  311 . The seat  31  or fixing member  32  are integral and formed by plastic molding injection. The seat  31  is fixed on the reflector  22  and the back plate  21  by a first hook  312 . The light sources  24  are separately arranged on the holding portions  311  of the seat  31 . The fixing member  32  is then fixed on the seat  31  by second hooks  323  and  323 ′. Thus, the holding portions  311  of the seat  31  and the curved portions  322  of the fixing member  32  surround and secure the light sources  24  of the backlight module  20 . It is noted that a gap between parallel sections of the seat  31  and the fixing member  32  is substantially in a range of about 0 mm to about 1 mm after the seat  31  and the fixing member  32  are assembled. 
     FIG. 3  is a partial exploded perspective view of the direct type backlight module in  FIG. 2 . In order to simplify the drawing,  FIG. 3  shows only a supporter  30  and part of the reflector  22  and diffuser  23 . Referring to  FIGS. 2 and 3 , during assembly of the backlight module  20  of this embodiment of the present invention, the seat  31  is first disposed on the reflector  22  with the first hook  312  passing through a hole  221 . The light sources  24  are separately disposed on the holding portions  311  and perpendicular to the seat  31 , providing proper support for the middle of the light sources  24 . After the arrangement of the light sources  24 , the second hook  323  of the fixing member  32  is inserted into the hole  222 , engaging the left side of the fixing member  32  with the back plate  21  and the reflector  22 . The second hook  323 ′ at the other side of the fixing member  32  then passes a hole  313  on the back plate  21  and a hole on the reflector  22 , such that the fixing member  32  is secured on the seat  31 . The holding portions  311  of the seat  31  and the curved portions  322  of the fixing member  32  surround and secure the light sources  24  of the backlight module  20 , protecting the light sources  24  from damages. Finally, the diffuser  23  is disposed above the reflector  22 , thus finishing assembly of the direct type backlight module  20  of this embodiment. 
   The protrusion  321  is located between two adjacent curved portions of the fixing member  32 , point contacting and supporting the diffuser  23 . Thus, the predetermined inner space is maintained between the reflector  22  and the diffuser  23 . 
   Furthermore, to fix the supporter  30  on the reflector  22 , adhesive is applied on the bottom of the seat  31 , or the seat  31  and fixing member  32  is fixed on the reflector  22  by a screw  25  as shown in  FIG. 3 . 
     FIG. 4  shows the enlarged area a in  FIG. 2 . In  FIG. 4 , there is a gap g between the fluorescent tube and the curved portion of the fixing member  32 , which provides buffer space for heat expansion of the light sources  24 . 
     FIG. 5  is another schematic view of a direct type backlight module  20  in another embodiment of the present invention. In  FIG. 5 , the supporters are separately utilized. The seat  31  and the fixing member  32  are separately disposed on the reflector  22 . For example, the seat  31  is disposed depart from the fixing member  32  a distance or the seat  31  is near the fixing member  32 . The light sources  24  are arranged on the holding portions  331  of the seat and the diffuser  23  are supported by the protrusion  321  of the fixing member. 
   Furthermore, the reflector  22  can be divided into multiple pieces to minimize deformation thereof and reduce cost. 
   Accordingly, the supporters utilized by the direct type backlight module of the invention are divided into two parts, such that the assembly steps can be simplified. Furthermore, the protrusions of the supporters provide proper support for the diffuser, preventing downward deformation by gravity which deteriorates lamination uniformity of the backlight module. 
   While the present invention has been described by way of example and in terms of preferred embodiment, it is to be understood that the invention is not limited thereto. On the contrary, it 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.