Backlight unit and liquid crystal display including the same

Abstract

A backlight unit and a liquid crystal display including the same are provided. The backlight includes a light guiding plate, a reflector, and at least one LED assembly including an LED light source, a substrate, and a support plate. A plurality of protrusions formed on a cover of the liquid crystal display are configured to mate to a plurality of concave portions formed on the light guiding plate, the reflector, and the LED assembly to mount the various components of the liquid crystal display onto the cover.

What is claimed is: 
     
       1. A display device comprising:
 a display panel having a plurality of electrodes and pixels; and   an edge type backlight provided adjacent to the display panel, the backlight having
 a plurality of optical sheets adjacent to the display panel; 
 a light guide panel having at least one light incident area to receive light from a first direction and a light emitting area to emit light received through the light incident area in a second direction towards the plurality of optical sheets, the first and second directions being different directions; 
 at least one light source, at least one incident area of the light guide panel being adjacent to at least one light source to receive light output; 
 a reflector adjacent to the light guide panel to reflect light towards the second direction; and 
 a bottom cover including a plate, the plate provided adjacent to the reflector and having a prescribed length in the first direction and a prescribed width in a third direction, 
 the plate further including at least one post having a first prescribed height, and 
 the reflector and the light guide panel having at least one opening having a second prescribed height to receive the at least one post, 
   wherein the plate further includes at least one peg, the at least one peg having a height less than the at least one post, the at least one post being positioned closer to the at least one light source than the at least on peg, and the at least one post and the peg being separate from each other.   
     
     
       2. The display device of  claim 1 , wherein the second prescribed height being greater than the first prescribed height. 
     
     
       3. The display device of  claim 1 , wherein the at least one light source comprises a first LED assembly having a plurality of light emitting diodes provided on a first substrate and arranged in the third direction, the LED assembly further including a first support plate extending in the first direction and provided adjacent to the first substrate, the first support plate including a first opening and a second opening, which are fitted over the at least one post and the at least one peg. 
     
     
       4. A display device of comprising:
 a display panel having a plurality of electrodes and pixels; and   an edge type backlight provided adjacent to the display panel, the backlight having
 a plurality of optical sheets adjacent to the display panel; 
 a light guide panel having at least one light incident area to receive light from a first direction and a light emitting area to emit light received through the light incident area in a second direction towards the plurality of optical sheets, the first and second directions being different directions; 
   at least one light source, at least one incident area of the light guide panel being adjacent to at least one light source to receive light output;   a reflector adjacent to the light guide panel to reflect light towards the second direction; and
 a bottom cover including a plate, the plate provided adjacent to the reflector and having a prescribed length in the first direction and a prescribed width in a third direction, 
 the plate further including at least one post having a first prescribed height and 
 the reflector and the light guide panel having at least one opening having a second prescribed height to receive the at least one post, 
   wherein the at least one light source comprises a first LED assembly having a plurality of first light emitting diodes provided on a first substrate and arranged in the third direction,   the first LED assembly further including a first support plate extending in the first direction and provided adjacent to the first substrate, the first support plate including a first opening and a second opening,   the at least one post including a first post and at least one of a second post, a third post or a fourth post, the first post located closest in the first direction to the plurality of first light emitting diodes,   the at least one peg including a first peg,   the first and second openings fitted over the first post and the first peg, and   the at least one opening of the reflector and the light guide panel includes a first slot and at least one of a second slot, a third slot or a fourth slot.   
     
     
       5. The display device of  claim 4 , wherein the at least one light source further comprises a second LED assembly having a plurality of second light emitting diodes provided on a second substrate and arranged in the third direction, the second LED assembly being provided on a side of the plate opposite from the first LED assembly, the second LED assembly further including a second support plate extending in the first direction and provided adjacent to the second substrate, the second support plate including a third opening and a fourth opening,
 the second post located closest in the first direction to the plurality of second light emitting diodes,   the at least one peg further including a second peg, and   the third and fourth openings fitted over the second post and the second peg.   
     
     
       6. The display device of  claim 5 , wherein
 the at least one light source further comprises a third LED assembly having a plurality of third light emitting diodes provided on a third substrate and arranged in the first direction, the third LED assembly being provided on a side of the plate between the first LED assembly and the second LED assembly, the third LED assembly further including a third support plate extending in the third direction and provided adjacent to the third substrate, the third support plate including a fifth opening and a sixth opening, the third post located closest in the third direction to the plurality of third light emitting diodes, the at least one peg further including a third peg, and the fifth and sixth openings fitted over the third post and the third peg; and   the at least one light source further comprises a fourth LED assembly having a plurality of fourth light emitting diodes provided on a fourth substrate and arranged in the first direction, the fourth LED assembly being provided on a side of the plate between the first LED assembly and the second LED assembly and opposite of the third LED assembly, the fourth LED assembly further including a fourth support plate extending in the third direction and provided adjacent to the fourth substrate, the fourth support plate including a seventh opening and a eighth opening, the fourth post located closest in the third direction to the plurality of fourth light emitting diodes, the at least one peg further including a fourth peg, and the seventh and eighth openings fitted over the fourth post and the fourth peg.   
     
     
       7. The display device of  claim 4 , wherein the first and second slots are provided at diagonally opposite corners of the light guide panel and the reflector, and the first and second slots fit over the first and second posts of the plate. 
     
     
       8. The display device of  claim 7 , wherein the first, second, third and fourth slots are provided at the corners of the light guide panel and the reflector, and the first, second, third and fourth slots fit over the first, second, third and fourth posts of the plate. 
     
     
       9. The display device of  claim 3 , wherein the at least one first post is provided between two adjacent first light emitting diodes separated by a first prescribed distance while remaining first light emitting diodes are separated by a second prescribed distance, the first prescribed distance being greater than the second prescribed distance. 
     
     
       10. The display device of  claim 3 , wherein each of the plurality of first light emitting diodes includes a lens, and the lens includes both a concave portion and a convex portion. 
     
     
       11. A display device comprising:
 a display panel having a plurality of electrodes and pixels; and   a backlight provided adjacent to the display panel, the backlight having
 a plurality of optical sheets adjacent to the display panel; 
 a light guide panel having at least one light incident area to receive light from a first direction and a light emitting area to emit light received through the light incident area in a second direction towards the plurality of optical sheets, the first and second directions being different directions; 
 at least one light source, at least one incident area of the light guide panel being adjacent to at least one light source to receive light output; 
 a reflector adjacent to the light guide panel to reflect light towards the second direction; and 
 a bottom cover including a plate, the plate provided adjacent to the reflector and having a prescribed length in the first direction and a prescribed width in a third direction, 
 the plate further including at least one post extending in the second direction, 
 the at least one light source comprising a first LED assembly having a plurality of first light emitting diodes provided on a substrate, which is supported by a first support plate, the first support plate having a first opening to receive the at least one post, the first LED assembly further comprising at least one peg extending in the first direction, 
 the light guide panel having at least one slot to receive the at least one peg. 
   
     
     
       12. The display device of  claim 11 , wherein the at least one peg is provided between adjacent first light emitting diodes. 
     
     
       13. The display device of  claim 12 , wherein the at least one peg and the at least one slot prevent the at least one light guide panel from contacting the plurality of first light emitting diodes. 
     
     
       14. The display device of  claim 12 , wherein at least one of the first light emitting diodes includes lens from which light is output toward the at least one light incident area of the light guide panel, and a gap is provided between the lens and the at least one light incident area by the at least one peg and the at least one slot. 
     
     
       15. The display device of  claim 11 , wherein the at least one peg is provided between two adjacent first light emitting diodes separated by a first prescribed distance while remaining first light emitting diodes are separated by a second prescribed distance, the first prescribed distance being greater than the second prescribed distance. 
     
     
       16. The display device of  claim 11 , wherein the at least one peg has a first prescribed height in the second direction, and the at least one light guide panel has a second prescribed height in the second direction, the second prescribed height being greater than the first prescribed height. 
     
     
       17. The display device of  claim 11 , wherein the bottom cover includes a first peg on a first side and a second peg on a second side, the at least one peg provided between the first and second pegs, and the light guide panel further includes first and second slots to receive the first and second pegs. 
     
     
       18. The display device of  claim 17 , wherein when the display device is oriented in a vertical direction such that the second direction is perpendicular to the direction of gravity, the at least one peg and the first and second pegs support the weight of the light guide panel. 
     
     
       19. The display device of  claim 18 , wherein the at least one peg comprises a plurality of pegs, and the at least one slot comprises a plurality of slots to receive the plurality of pegs. 
     
     
       20. A backlight unit, comprising:
 a light guiding plate;   a light source assembly including at least one light source facing a side surface of the light guiding plate;   a reflector disposed below the light guiding plate to reflect light towards the light guiding plate;   a bottom cover, comprising:   a plate disposed below the reflector;   a first protrusion protruding at a predetermined length from an upper surface of the plate, the first protrusion configured to be in close contact with the side surface of the light guiding plate; and   a second protrusion protruding at a predetermined length from the upper surface of the plate, the second protrusion configured to be coupled to the light source assembly by being inserted in a portion of the light source assembly,   wherein the length of the first protrusion is configured to be different from the length of the second protrusion, and   wherein the first protrusion and the second protrusion are positioned on the bottom cover such that a first distance from the first protrusion to a nearest light source is shorter than a second distance from the second protrusion to a nearest light source.   
     
     
       21. The backlight unit of claim 20, wherein the length of the first protrusion is greater than the length of the second protrusion. 
     
     
       22. The backlight unit of claim 20, wherein the first protrusion is configured to be a predetermined distance away from the second protrusion. 
     
     
       23. The backlight unit of claim 20, wherein the light guiding plate includes at least one opening or recess defined at a predetermined position of the side surface thereof,
 and wherein the first protrusion is inserted in the at least one opening or recess of the light guiding plate, thereby supporting the light guiding plate.   
     
     
       24. The backlight unit of claim 20, wherein the reflector includes at least one opening or recess defined at a predetermined position of a side surface thereof,
 and wherein the first protrusion inserted in the at least one opening or recess of the reflector, thereby supporting the reflector.   
     
     
       25. The backlight unit of claim 20, further comprising a plurality of optical sheets placed above the light guiding plate. 
     
     
       26. The backlight unit of claim 20, wherein the light source assembly comprises:
 a substrate on which the at least one light source is mounted; and   a support on which the substrate is mounted, the support including:   a vertical part on which the substrate is mounted; and   a horizontal part perpendicularly bent at a lower end of the vertical part to be placed on the plate,   wherein the at least one light source includes an LED.   
     
     
       27. The backlight unit of claim 26, wherein the reflector is placed on the horizontal part of the support. 
     
     
       28. The backlight unit of claim 27, wherein the second protrusion is configured to pass through the horizontal part of the support,
 wherein the length of the second protrusion is configured to be identical to or less than a thickness of the horizontal part of the support.   
     
     
       29. The backlight unit of claim 27, wherein the first protrusion is configured to pass through the horizontal part of the support. 
     
     
       30. The backlight unit of claim 20, wherein the second protrusion is disposed below the light guiding plate and the reflector. 
     
     
       31. The backlight unit of claim 20, wherein when the reflector and the light guiding plate are assembled, a height of an upper end of the first protrusion is identical to or less than a height of an upper surface of the light guiding plate. 
     
     
       32. The backlight unit of claim 20, wherein the light source assembly includes:
 a first light source; and   a second light source adjacent to the first light source,   wherein the first protrusion is positioned between the first and second light sources.   
     
     
       33. The backlight unit of claim 32, wherein the light source assembly further includes a third light source adjacent to the second light source,
 wherein a gap between the first and second light sources is greater than a gap between the second and third light sources.   
     
     
       34. The backlight unit of claim 33, wherein the light source assembly further includes a fourth light source adjacent to the first light source,
 wherein the gap between the second and third light sources is the same as a gap between the first and fourth light source.   
     
     
       35. A display device, including:
 a display panel;   a backlight unit disposed below the display panel, the backlight unit including:   a plurality of optical sheets disposed below the display panel;   a light guiding plate disposed below the plurality of optical sheets;   a light source assembly including at least one light source facing a side surface of the light guiding plate;   a reflector disposed below the light guiding plate to reflect light towards the light guiding plate;   a bottom cover, comprising:   a plate disposed below the reflector;   a first protrusion protruding at a predetermined length from an upper surface of the plate, the first protrusion configured to be in close contact with the side surface of the light guiding plate; and   a second protrusion protruding at a predetermined length from the upper surface of the plate, the second protrusion configured to be coupled to the light source assembly by being inserted in a portion of the light source assembly,   wherein the length of the first protrusion is configured to be different from the length of the second protrusion,   wherein the first protrusion and the second protrusion are positioned on the bottom cover such that a first distance from the first protrusion to the nearest light source is shorter than a second distance from the second protrusion to the nearest light source.