Abstract:
A display includes a panel and a backlight module. The backlight module includes a reflective board, a shell, at least two lenses and a light source. The lenses are installed on the reflective board. The reflective board is installed on the shell. The light source is installed in the shell and the light from the light source passes through the lenses. Each lens includes a bottom portion on the reflective board and an extending portion protruding slantwise from the bottom portion. The extending portion includes a reflective surface opposite to the reflective board approximately. A light from the light source is reflected onto the reflective board via the reflective surface, and then reflected onto the panel via the reflective board.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to a lens and a backlight module of a display utilizing the same. 
     2. Description of the Related Art 
     A conventional lens  10  is shown in  FIG. 1 . A light source  20  emits light to enter the lens  10 . The lens  10  comprises an incident surface  11 , a refracting surface  12 , a reflective surface  13  and an exiting surface  14 . The light emitted from the light source  20  enters the lens  10  via the incident surface  11 . After the light enters the lens  10 , the light is divided into two optical paths A and B. The optical path A shows light transmitted to the refracting surface  12  from the incident surface  11 , passes through the refracting surface  12  to leave the lens  10 . The optical path B shows light transmitted to the reflective surface  13  from the incident surface  11 , passes through the exiting surface  14  to leave the lens  10 . Referring to  FIG. 1 , regardless of whether the light is transmitted in the optical path A or the optical path B, the light finally leaves the lens  10  horizontally. When the conventional lens  10  is applied to the backlight module, the light passes through the lens  10  and proceeds toward two sides of the backlight module. The conventional lens  10  increases the distance of adjacent lenses  10 , however, the conventional lens  10  do not control light distribution. Thus, the thickness of the backlight module must be increased (about 50 mm) for averaging the lights. 
     SUMMARY OF INVENTION 
     The present invention provides a lens and a backlight module of display utilizing the same. The lens is installed on a reflective board. A light is emitted by a light source. The lens comprises a bottom portion on the reflective board and an extending portion. The extending portion comprises a reflective surface. The reflective surface is located opposite to the reflective board. The light strikes the reflective surface and is reflected onto the reflective board. 
     The lens further comprises a refracting portion, wherein the light passes through the refracting portion to strike the reflective surface. 
     A backlight module comprises a reflective board, a shell, at least two lenses and a light source. The reflective board is installed in the shell. The light source is installed under the lens. The reflective surface is located opposite to the reflective board. The structure of the lenses are left-right reversed. A light emitted from the light source strikes the reflective surface and is reflected onto the reflective board. 
     A display comprises a panel and the backlight module. The reflective surface is located opposite to the reflective board. A light emitted from the light source strikes the reflective surface, is reflected onto the reflective board and is then reflected onto the panel. 
     A detailed description is given in the following embodiments with reference to the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       The present invention can be more fully understood by reading the subsequent detailed description and examples with references made to the accompanying drawings, wherein: 
         FIG. 1  is a schematic view showing a conventional lens; 
         FIG. 2  is a schematic view showing an embodiment of a backlight module of the invention; 
         FIG. 3  is a schematic view showing a lens in  FIG. 2 ; 
         FIG. 4  is a schematic view showing another embodiment of a backlight module of the invention; and 
         FIG. 5  is a schematic view showing a lens in  FIG. 4 . 
     
    
    
     DETAILED DESCRIPTION OF INVENTION 
     The following description is of the best-contemplated mode of carrying out the invention. This description is made for the purpose of illustrating the general principles of the invention and should not be taken in a limiting sense. The scope of the invention is best determined by the appended claims. 
     Referring to  FIG. 2 , a display  40  comprises a panel  41  and a backlight module  30 . The backlight module  30  comprises a reflective board  31 , a plurality of lenses  32   a ,  32   b ,  32   c , and  32   d , a shell  34  and a light source  33 . The reflective board  31  is installed in the shell  34 . Each lens  32   a ,  32   b ,  32   c , and  32   d  comprises a bottom portion  321  and an extending portion  322 . The bottom portion  321  is parallel to and installed on the reflective board  31 . The extending portion  322  comprises reflective surface  323  located opposite to the reflective board  31 . The panel  41  is located opposite to the reflective board  31 . The backlight module  30  is installed between the panel  41  and the reflective board  31 . In this embodiment, the lens  32   a  connects to the lens  32   b , and the lens  32   c  connects to the lens  32   d . Note that the structure of the lenses  32   a  and  32   c  and the structure of the lenses  32   b  and  32   d  are left-right reversed. The lenses  32   a ,  32   b ,  32   c , and  32   d  respectively comprise first surfaces  324   a ,  324   b ,  324   c  and  324   d . The first surface  324   a  connects to the first surface  324   b , and the first surface  324   c  connects to the first surface  324   d . The lenses  32   b  and  32   c  further comprise connecting surfaces  325   b  and  325   c . The lens  32   b  connects to the lens  32   c  via connection of the connecting surfaces  325   b  and  325   c.    
     The lenses  32   a ,  32   b ,  32   c , and  32   d  further respectively comprise a second surface  326  and an incident surface  327 . The light emitted from the light source  33  enters the lenses  32   a ,  32   b ,  32   c , and  32   d  via the incident surface  327  and reaches the reflective surface  323 . The light is then reflected to strike the bottom portion  321  via the reflective surface  323 , and then passes through the bottom portion  321  to strike the reflective board  31 . Finally, the light is reflected to the panel  41  of the display  40  via the reflective board  31 . 
       FIG. 3  shows the structure of the lens  32   b . The bottom portion  321  and the extending portion  322  extend in the same direction (as indicated by arrow C of  FIG. 3 ). The second surface  326  is located between the reflective surface  323  and the bottom portion  321 . The incident surface  327  is located between the bottom portion  321  and the first surface  324   b . The first surface  324   b  further connects to the reflective surface  323 . Note that the second surface  326  and the reflective surface  323  form an included angle θ. The incident surface  327  is concave. When the lens  32   b  is assembled in the backlight module  30 , the light source  33  is installed under the lens  32   b  and fixed in the shell  34  (shown in  FIG. 2 ). The first surface  324   b  is substantially perpendicular to the bottom portion  321 . 
       FIG. 4  is a schematic view showing another embodiment of a backlight module  50 . Referring to  FIG. 4 , a display  40  comprises a panel  41  and a backlight module  50 . The backlight module  50  comprises a reflective board  51 , a plurality of lenses  52   a ,  52   b ,  52   c , and  52   d , a shell  54  and a light source  53 . Each lens  52   a ,  52   b ,  52   c , and  52   d  comprises a bottom portion  521 , an extending portion  522  and a refracting portion  528 . The bottom portion  521  is parallel to and installed on the reflective board  51 . The extending portion  522  comprises reflective surface  523  located opposite to the reflective board  51 . The refracting portion  528  is located between the bottom portion  521  and the extending portion  522 . In this embodiment, the refracting portion  528  is curved. The panel  41  is located opposite to the reflective board  51 . The backlight module  50  is installed between the panel  41  and the reflective board  51 . In this embodiment, the lens  52   a  connects to the lens  52   b , and the lens  52   c  connects to the lens  52   d . Note that the structure of the lenses  52   a  and  52   c  and the structure of the lenses  52   b  and  52   d  are left-right reversed. The lenses  52   a ,  52   b ,  52   c , and  52   d  respectively comprise first surfaces  524   a ,  524   b ,  524   c  and  524   d . The first surface  524   a  connects to the first surface  524   b , and the first surface  524   c  connects to the first surface  524   d . The lenses  52   b  and  52   c  further comprise connecting surfaces  525   b  and  525   c . The lens  52   b  connects to the lens  52   c  via connection of the connecting surfaces  525   b  and  525   c.    
     The lenses  52   a ,  52   b ,  52   c , and  52   d  further respectively comprise a second surface  526  and an incident surface  527 . The light emitted from the light source  53  enters the lenses  52   a ,  52   b ,  52   c , and  52   d  via the incident surface  527  and reaches the reflective surface  523 . The light then passes through the refracting portion  528  and strikes the reflective surface  523 . The light is reflected to the bottom portion  521  via the reflective surface  523 , and then passes through the bottom portion  521  to strike the reflective board  51 . Finally, the light is reflected to the panel  41  of the display  40  via the reflective board  51 . 
       FIG. 5  shows the structure of the lens  52   b . The bottom portion  521  and the extending portion  522  extend in the same direction (shown as arrow D of  FIG. 5 ). The second surface  526  is located between the reflective surface  523  and the refracting portion  528 . The refracting portion  528  is adjacent to the bottom portion  521 . The incident surface  527  is located between the bottom portion  521  and the first surface  524   b . The first surface  524   b  further connects to the reflective surface  523 . Note that the incident surface  527  is concave. When the lens  52   b  is assembled in the backlight module  50 , the light source  53  is installed under the lens  52   b  and fixed in the shell  54  (shown in  FIG. 4 ). The first surface  524   b  is substantially perpendicular to the bottom portion  521 . 
     The lenses  32   a ,  32   b ,  32   c ,  32   d ,  52   a ,  52   b ,  52   c , and  52   d  and the backlight modules  30  and  50  of the display utilizing the lens can increase the distance of adjacent lenses. Moreover, the lenses  32   a ,  32   b ,  32   c ,  32   d ,  52   a ,  52   b ,  52   c , and  52   d  and the backlight modules  30  and  50  can prevent increased backlight module thickness for averaging the lights. After the light strikes the reflective surfaces  323  and  523  and the reflective boards  31  and  51 , the light is directly reflected to the panel  41 . Thus, the backlight modules  30  and  50  utilizing the lenses  32   a ,  32   b ,  32   c ,  32   d ,  52   a ,  52   b ,  52   c , and  52   d  not only increase the distance of adjacent lenses but also directly guides the light to the panel  41 . 
     While the invention has been described by way of example and in terms of the preferred embodiments, it is to be understood that the invention is not limited to the disclosed embodiments. To 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.