Light unit and a LCD liquid crystal display comprising the light unit

Abstract

Provided is a light unit including a plurality of LED light sources formed on a PCB, a resin layer stacked on the PCB to diffuse and guide emitted light forwards, and a diffusion plate having an optical pattern printed thereon to shield light emitted from the LED light sources. The optical pattern is composed of a diffusion pattern implemented as at least one layer, or a combination of the diffusion pattern layer and a light shielding pattern. The light unit forms an optical pattern for shielding or diffusing light on a surface of a light diffusion plate of the back-light unit, and combines a diffusion pattern and a metal pattern to attain uniformity of light and realize a yellow-light shielding effect, thus leading to a reliable light quality.

The invention claimed is: 
     
       1. A light unit, comprising:
 a printed circuit board (PCB) which extends in a horizontal direction; 
 a plurality of LED light sources formed on the PCB; 
 a resin layer on the PCB and surrounding the LED light sources, the resin layer being configured to diffuse and guide light emitted from the LED light sources; 
 a diffusion plate on the resin layer; and  
 an optical pattern disposed between the diffusion plate and the resin layer, 
 wherein the optical pattern is disposed on a lower surface of the diffusion plate and comprises a first pattern on a lower surface of the diffusion plate, a second pattern on a lower surface of the first pattern, and a third pattern on a lower surface of the second pattern, 
 wherein the first pattern is a diffusion pattern, 
 wherein the second pattern is a shielding pattern, 
 wherein the shielding pattern at least one of the first pattern, the second pattern, and the third pattern is configured to shield light emitted from the LED light sources, and 
 wherein the optical pattern is implemented by overlapping printing the shielding pattern onto the diffusion pattern in a vertical direction 
 wherein a vertical direction is perpendicular to the lower surface of the diffusion plate, 
 wherein an imaginary plane, taken in the vertical direction and including an outer lateral surface of the second pattern, also includes a portion of the first pattern and a portion of the third pattern, 
 wherein an area of the first pattern is larger than an area of the second pattern, 
 wherein the optical pattern includes a first region, a second region, and a third region from the imaginary plane toward a light emitting direction of each of the LED light sources, 
 wherein the first region is closest to the imaginary plane, the third region is farthest from the imaginary plane, and the second region is disposed between the first region and the third region, and 
 wherein the first region is formed of three layers, the second region is formed of two layers, and the third region is formed of one layer in the optical pattern. 
 
     
     
       2. The light unit of  claim 1 , wherein the optical pattern is disposed on a in direct physical contact with the lower surface of the diffusion plate. 
     
     
       3. The light unit of  claim 1 , wherein the diffusion pattern comprises at least one substance selected from the group consisting of TiO 2 , CaCO 3 , BaSO 4 , Al 2 O 3 , and silicon. 
     
     
       4. The light unit of  claim 1 , wherein the second pattern is disposed on a portion of in direct physical contact with the first pattern, and
 wherein the first pattern is disposed on in direct physical contact with the lower surface of the diffusion plate. 
 
     
     
       5. The light unit of  claim 1 , wherein the a second pattern is formed by overlapping printing on an upper or lower portion of in direct physical contact with the first pattern, thereby shielding or reflecting the emitted light; and
 wherein the optical pattern further comprises a third pattern comprising a diffusion is in direct physical contact with the second pattern, and 
 wherein the third first pattern is disposed between the first pattern and the second pattern in direct physical contact with the lower surface of the diffusion plate. 
 
     
     
       6. The light unit of  claim 1 , wherein the diffusion pattern comprises a substance containing TiO 2  or a substance containing TiO 2  and CaCO 3 . 
     
     
       7. The light unit of  claim 1 , wherein the first pattern has a thickness in a range of from 4μm to 100 μm. 
     
     
       8. The light unit of  claim 1 , wherein the shielding optical pattern comprises light shielding ink containing Al or a mixture of Al and TiO 2 . 
     
     
       9. The light unit of  claim 1 , wherein at least one of the first or  pattern and the second pattern further comprises beads. 
     
     
       10. The light unit of  claim 1 , wherein the second pattern has a thickness in a range of from 4 μm to 100 μm. 
     
     
       11. The light unit of  claim 5 , wherein the third pattern comprises a substance containing TiO 2  or a substance containing TiO 2  and CaCO 3 . 
     
     
       12. The light unit of  claim 5  claim 1, wherein the third pattern has a thickness in a range of from 4 μm to 100 μm. 
     
     
       13. The light unit of  claim 1 , further comprising a surface treatment layer formed disposed between the resin layer and the diffusion plate and configured to receive the optical pattern, wherein a thickness of the surface treatment layer is equal to or greater than a thickness of the optical pattern. 
     
     
       14. The light unit of  claim 13 , wherein the surface treatment layer comprises the same material as the resin layer. 
     
     
       15. The light unit of  claim 1 , further comprising:
 a reflection film on the PCB and having at least one reflection pattern formed thereon. 
 
     
     
       16. The light unit of  claim 15 , wherein the reflection pattern comprises reflective ink containing TiO 2  or Al 2 O 3 . 
     
     
       17. The light unit of  claim 1 , wherein the resin layer further comprises beads. 
     
     
       18. A liquid crystal display comprising a light unit according to  claim 1 . 
     
     
       19. The light unit of  claim 13 , wherein the optical pattern is buried in the surface treatment layer. 
     
     
       20. The light unit of claim 1, wherein the optical pattern is spaced apart from the resin layer.  
     
     
       21. The light unit of claim 20, comprising a surface treatment layer disposed between the resin layer and the diffusion plate and configured to receive the optical pattern,
 wherein a thickness of the surface treatment layer is equal to or greater than a thickness of the optical pattern, and   wherein the optical pattern is buried in the surface treatment layer.    
     
     
       22. The light unit of claim 1, wherein each of the LED light sources comprises a front surface from which light is emitted and a rear surface opposite to the front surface.  
     
     
       23. The light unit of claim 22, wherein at least one of the first pattern, the second pattern, and the third pattern is disposed so as not to overlap in the vertical direction with the rear surface of each of the LED light sources.  
     
     
       24. The light unit of claim 22, wherein the area of the first pattern, the area of the second pattern, and an area of the third pattern are all different from each other, and
 wherein the second pattern is disposed so as not to overlap in the vertical direction with the rear surface of each of the LED light sources.    
     
     
       25. The light unit of claim 1, wherein an area of the lower surface of the first pattern is larger than an area of the lower surface of the second pattern,
 wherein an entire upper surface of the second pattern is disposed within a region of the lower surface of the first pattern,   wherein an entire lower surface of the second pattern is positioned lower than the entire lower surface of the first pattern, and   wherein an entire lower surface of the third pattern is positioned lower than the entire lower surface of the second pattern.    
     
     
       26. The light unit of claim 25, wherein the first pattern, the second pattern, and the third pattern of the optical pattern are formed of a material that is non-metallic, inorganic, or both.