Patent Document

BACKGROUND 
   1. Field of the Invention 
   The present invention relates to a direct-type backlight module including a fixing element and a plurality of elastic elements which cooperatively fix a plurality of light sources to a frame, and to a liquid crystal display using the backlight module. 
   2. General Background 
   Liquid crystal displays are commonly used as display devices for compact electronic apparatuses, not only because they provide good quality images but also because they are very thin. The liquid crystal in a liquid crystal display does not emit any light itself. The liquid crystal requires a light source so as to be able to clearly and sharply display text and images. Therefore, a typical liquid crystal display requires an accompanying backlight module. Generally, backlight modules include side-edge backlight modules and direct-type backlight modules. 
   Referring to  FIG. 6 , a typical liquid crystal display  1  includes a liquid crystal panel  19 , and a direct-type backlight module  10  below the liquid crystal panel  19 . 
   The backlight module  10  includes a frame  15 , a plurality of light sources  14 , a diffusing plate  12 , and a brightness enhancement film (BEF)  11 . Each light source  14  includes a supporting strip  141  and a plurality of light-emitting elements  142 . The supporting strip  141  includes a circuit (not shown) formed thereon. The light-emitting elements  142  are mounted on the supporting strip  141  in a line. An external power source provides power to the light-emitting elements  142  via wires (not shown) and the circuit. The frame  15  includes a substantially rectangular bottom plate  151 , and four side plates  150  upwardly extending from edges of the bottom plate  151 . The bottom plate  151  and the side plates  150  cooperatively define an accommodating space. The light sources  14 , the diffusing plate  12 , and the BEF  11  are accommodated in the accommodating space of the frame  15 , in that order from bottom to top. The light sources  14  are mounted on the bottom plate  151  of the frame  15  through screws or double-sided strips of adhesive tape. 
   In assembly of the backlight module  10 , the light sources  14  need to be fixed or stuck to the bottom plate  151  by hand. In the case of a large-sized liquid crystal display  1 , many light sources  14  are required. For such kinds of liquid crystal displays  1  in particular, the operation of attaching the light sources  14  is complicated and time consuming. 
   Therefore, a new direct-type backlight module that can overcome the above-described problems is desired. What is also desired is a liquid crystal display using such backlight module. 
   SUMMARY 
   In one preferred embodiment, a direct-type backlight module includes a plurality of light sources, a frame, and a fixing member. Each light source includes a supporting strip and at least one light-emitting member provided with the supporting strip. The frame includes a bottom plate. The bottom plate includes a plurality of elastic members. The fixing member is engaged with the elastic members thereby removably fixing the supporting strips of the light sources to the bottom plate of the frame. 
   Other novel features and advantages will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is an exploded, isometric view of a liquid crystal display according to a first embodiment of the present invention, the liquid crystal display including a direct-type backlight module, the backlight module including a plurality of light sources and a frame. 
       FIG. 2  is an enlarged view of a circled portion II of  FIG. 1 . 
       FIG. 3  is an isometric view showing the light sources attached in the frame of  FIG. 1 . 
       FIG. 4  is similar to  FIG. 2 , but showing a corresponding view in the case of a liquid crystal display according to a second embodiment of the present invention. 
       FIG. 5  is an exploded, isometric view of certain parts of a direct-type backlight module of a liquid crystal display according to a third embodiment of the present invention. 
       FIG. 6  is an exploded, isometric view of a conventional liquid crystal display. 
   

   DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
   Referring to  FIG. 1 , a liquid crystal display  2  according to a first embodiment of the present invention is shown. The liquid crystal display  2  includes a liquid crystal panel  29 , and a direct-type backlight module  20  below the liquid crystal panel  29 . The backlight module  20  is configured to provide planar light for the liquid crystal panel  29 . 
   The backlight module  20  includes a frame  25 , a plurality of light sources  24 , four fixing elements  26 , a diffusing plate  22 , and a BEF  21 . The light sources  24 , the diffusing plate  22 , and the BEF  21  are arranged in the frame  25 , in that order from bottom to top. 
   Each light source  24  includes a supporting strip  241  and a plurality of light-emitting elements  242 . The supporting strip  241  includes a circuit (not shown) formed thereon. The light-emitting elements  242  are mounted on the supporting strip  241  in a line. An external power source provides power to the light-emitting elements  242  via wires (not shown) and the circuit. Light emitted from the light-emitting elements  242  transmits through the diffusing plate  22  and the BEF  21  to illuminate the liquid crystal panel  29 . The light-emitting elements  242  can for example be light-emitting diodes (LEDs). 
   The frame  25  includes a rectangular bottom plate  251 , and four side plates  250  upwardly extending from edges of the bottom plate  251 . The bottom plate  251  and the side plates  250  cooperatively define an accommodating space, which space accommodates the light sources  24 , the diffusing plate  22 , and the BEF  21  therein. A plurality of elongated recesses  256  are formed in the bottom plate  251  of the frame  25 . The recesses  256  are arranged in a matrix pattern, which includes a plurality of rows and two columns. The light sources  24  are received in the recesses  256  respectively. The bottom plate  251  further includes a plurality of strip-shaped portions between the recesses  256 . A depth of the recesses  256  is less than a thickness of the supporting strips  241  of the light sources  24 . A pair of elastic elements  252  are formed at opposite ends of each strip-shaped portion, respectively. A pair of elastic elements  252  are also formed at the top of each column of the matrix, and at the bottom of each column of the matrix. That is, there are two elastic elements  252  between every two adjacent recesses  256 , two elastic elements  252  adjacent a top of the topmost strip-shaped portion of each column, and two elastic elements  252  adjacent a bottom of a bottommost strip-shaped portion of each column. Each two elastic elements  252  between every two adjacent recesses  256  are adjacent to two end portions of each of the two adjacent recesses  256 , respectively. 
   Referring also to  FIG. 2 , the elastic elements  252  are inseparably integrated with the bottom plate  251  of the frame  25 . That is, the frame  25  including the elastic elements  252  is of a single body of material. In the illustrated embodiment, the elastic elements  252  are stamped from the bottom plate  251 , with each elastic element  252  being generally L-shaped. In particular, each elastic element  252  includes a bending portion  253  and an extending portion  254 . The bending portion  253  extends substantially upwardly from the bottom plate  251 . The extending portion  254  extends approximately perpendicularly from the bending portion  253 . In particular, the extending portion  254  extends slightly down, such that an angle between the bending portion  253  and the extending portion  254  is approximately 90 degrees or less. 
   In the illustrated embodiment, the fixing elements  26  are four long cylindrical bars, each of which has a circular cross-section. Two of the fixing elements  26  are positioned at two sides of one of the columns of the matrix, respectively. The other two fixing elements  26  are positioned at two sides of the other column of the matrix, respectively. Each fixing element is elastically held in position below the extending portions  254  of the corresponding elastic elements  252 . Thus, the light sources  24  can be fixedly mounted in the recesses  256  of the bottom plate  251  of the frame  25  by means of the fixing elements  26 , which are elastically maintained in position by the elastic elements  252 . 
   Referring also to  FIG. 3 , in assembly of the backlight module  20 , the light sources  24  are mounted to the bottom plate  251  of the frame  25 . First, the light sources  24  are placed in the recesses  256  of the bottom plate  251 . Then, each of the fixing elements  26  is inserted between a corresponding column of elastic elements  252  and the bottom plate  251 . The elastic elements  252  resiliently exert downward force on the fixing elements  26  such that the fixing elements  26  downwardly press the supporting strips  241  of the light sources  24 . Thus, the light sources  24  are fixedly mounted to the bottom plate  251  of the frame  25 . 
   In summary, the backlight module  20  of the liquid crystal display  2  includes the elastic elements  252  and the fixing elements  26  which cooperatively fix the light sources  24  to the frame  25 . No matter how many light sources  24  are used, the assembly and disassembly of the backlight module  20  and the liquid crystal display  2  are simplified. 
   Referring to  FIG. 4 , a liquid crystal display according to a second embodiment of the present invention is similar to the liquid crystal display  2  of the first embodiment. However, in the second embodiment, a bottom plate  351  includes a plurality of strip-shaped portions between a plurality of recesses  356 . The bottom plate  351  further includes a plurality of pairs of first notches  357 , with each pair of first notches  357  located below a respective elastic element  352 . An extending portion  354  of each elastic element  352  includes a second notch  358  defined at a lower surface (not labeled) thereof. The first and second notches  357 ,  358  cooperatively accommodate the fixing elements  36 . That is, the fixing elements  36  are snappingly received between the extending portions  354  of the elastic elements  352  and the strip-shaped portions of the bottom plate  351 . In the illustrated embodiment, each of the first and second notches  357 ,  358  defines an arc-shaped profile. The arc-shaped profiles of each pair of first and second notches  357 ,  358  are located approximately along the periphery of a same imaginary circular cylinder. 
   Referring to  FIG. 5 , a direct-type backlight module  40  of a liquid crystal display according to a third embodiment of the present invention is similar to the backlight module  20  of the first embodiment. However, the direct-type backlight module  40  includes eight fixing elements  46 . Each column of light sources is fixed by four of the fixing elements  46 . 
   Further or alternative embodiments may include the following. In a first example, the recesses  26  can be arranged in other patterns. For example, a matrix pattern may include a plurality of rows and three columns. In a second example, the elastic elements  252  can be independent (discretely formed) elements, which are mounted to the bottom plate  251  of the frame  25 . In a third example, the fixing elements  26  can have other shapes, such as a bar shape with an elliptical cross-section. 
   It is to be further understood that even though numerous characteristics and advantages of the present embodiments have been set out in the foregoing description, together with details of the structures and functions of the embodiments, the disclosure is illustrative only; and that changes may be made in detail, especially in matters of shape, size and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.

Technology Category: 3