Backlight assembly for liquid crystal display apparatus

Abstract

A backlight assembly includes a light guide plate for emitting a light in two direction and a brightness control member for controlling the brightness ratio of the light emitting in the two directions. An LCD apparatus including first and second LCD panels, displays images in the two directions with individual brightnesses which are similar to one another or different from one another depending on the brightness control member.

1 . A backlight assembly for emitting a light in two directions, comprising: 
 a light guide plate having a light incident surface for changing a first light provided into a space between a first display area and a second display area into a second light, a first light emitting surface for emitting a portion of the second light to the first display area as a third light and a second light emitting surface for emitting a remained portion of the second light to the second display area as a fourth light, the light guide plate being disposed between the first and second display areas; and    a brightness control part for reflecting a portion of the fourth light to the first display area and transmitting a remained portion of the fourth light to the second display area, so that a first brightness at the first display area and a second brightness at the second display area have a predetermined brightness ratio, respectively.    
   
   
       2 . The backlight assembly of  claim 1 , wherein the second light emitting surface comprises at least one light reflecting pad having a dot shape, for reflecting the second light to the first display area and the light reflecting pad becomes larger according as the light reflecting pad is spaced more apart from the light incident surface.  
   
   
       3 . The backlight assembly of  claim 1 , wherein the first and second light emitting surfaces are parallel to each other.  
   
   
       4 . The backlight assembly of  claim 1 , wherein the light guide plate has a wedge shape in which a thickness thereof becomes thinner as it is far from the light incident surface.  
   
   
       5 . The backlight assembly of  claim 1 , wherein the brightness control part comprises a sheet for reflecting and transmitting a light.  
   
   
       6 . The backlight assembly of  claim 1 , wherein the first brightness is greater than the second brightness.  
   
   
       7 . The backlight assembly of  claim 1 , wherein the first light is emitted from a point light source such as a light emitting diode or a linear light source such as a CCFL.  
   
   
       8 . The backlight assembly of  claim 1 , further comprising an optical sheet for increasing optical properties of the third light, the optical sheet being disposed adjacent to the first light emitting surface.  
   
   
       9 . A backlight assembly for emitting a light in two directions, comprising: 
 a lamp assembly disposed between a first display area and a second display area, for providing a first light and a fifth lights into a space between the first and second display areas, the first and fifth lights having a path different to each other;    a first light guide plate having a first light incident surface for changing the first light into a second light, a first surface for reflecting a portion of the second light to the first display area as a third light and a second surface for emitting the third light, the second surface being faced to the first surface;    a second light guide plate having a second light incident surface for changing the fifth light into a sixth light, a third surface for reflecting a portion of the sixth light to the second display area as a seventh light and a fourth surface for emitting the seventh light, the fourth surface being faced to the third surface; and    a reflecting plate disposed between the first and third surfaces, for reflecting a remained portion of the second light leaked from the first surface to the first display area as a fourth light and reflecting a remained portion of the fifth light leaked from the third surface to the second display area as an eighth light.    
   
   
       10 . The backlight assembly of  claim 9 , wherein the first and second surfaces are parallel to each other and the third and fourth surfaces are parallel to each other.  
   
   
       11 . The backlight assembly of  claim 10 , wherein the first and third surfaces comprise a first light reflecting pad and a second light reflecting pad having a dot shape, respectively, the first and second light reflecting pads become larger according as the first and second light reflecting pads are spaced more apart from the first and second light incident surface.  
   
   
       12 . The backlight assembly of  claim 10 , further comprising a first optical sheet disposed at a place facing the first surface, for increasing optical properties of the third light and a second optical sheet disposed at a place facing the fourth surface, for increasing optical properties of the seventh light.  
   
   
       13 . The backlight assembly of  claim 10 , wherein the first optical sheet comprises a first body portion having a plate shape and a first brightness enhancing protrusion portion protruded from the first body portion facing to the second surface to have a triangle shape in section, and the second optical sheet comprises a second body portion having a plate shape and a second brightness protrusion portion protruded from the second body portion facing to the fourth surface to have a triangle shape in section.  
   
   
       14 . The backlight assembly of  claim 10 , wherein the first light guide plate has a plane size greater than that of the second light guide plate.  
   
   
       15 . The backlight assembly of  claim 14 , wherein the first and third surfaces comprise a first light reflecting pad and a second light reflecting pad having a dot shape, respectively, the first and second light reflecting pads become larger according as the first and second light reflecting pads are spaced more apart from the first and second light incident surface, and a change rate of size of the second light reflecting pad is greater than that of the first light reflecting pad.  
   
   
       16 - 21 . (canceled)  
   
   
       22 . The backlight assembly of  claim 9 , wherein the lamp assembly comprises: 
 a lamp for generating light in a radial shape; and    a lamp reflector for changing the light from the lamp into the first and fifth lights, the lamp reflector being fixed to the second and fourth surfaces while receiving the lamp therein.    
   
   
       23 - 42 . (canceled)