Optical sheet and method for fabricating the same

Abstract

An optical sheet and a method for fabricating the optical sheet, wherein a diffusion pattern is formed to diffuse and condense light. The optical sheet includes a prism pattern having a plurality of mountains and ravines to condense light generated from a light source and a plurality of diffusion patterns irregularly formed on the prism pattern to diffuse the light.

1 . An optical sheet for a display device, the optical sheet being disposed between a light guide plate and a display panel, the optical sheet comprising:
 a prism pattern including a plurality of inclined surfaces defining a plurality of mountains and ravines to condense light from the light guide plate; and   a plurality of diffusion patterns irregularly formed on the prism pattern to diffuse the light from the light guide plate,   wherein the optical sheet transmits the diffused and condensed light to the display panel.   
     
     
         2 . The optical sheet of  claim 1 , wherein the plurality of diffusion patterns have a concave or convex shape. 
     
     
         3 . The optical sheet of  claim 2 , wherein the plurality of diffusion patterns have a curved surface or a polyhedral surface. 
     
     
         4 . The optical sheet of  claim 3 , wherein a diffusion pattern has a different cross-sectional area size than an adjacent diffusion pattern. 
     
     
         5 . The optical sheet of  claim 1 , wherein the plurality of mountains and ravines are extended in a first direction and arranged in a second direction crossing the first direction. 
     
     
         6 . The optical sheet of  claim 5 , wherein the plurality of mountains of the prism pattern have a pitch of about 20 μm to 200 μm. 
     
     
         7 . The optical sheet of  claim 6 , wherein the plurality of diffusion patterns have a diameter of about 10 μm to 20 μm. 
     
     
         8 . The optical sheet of  claim 5 , wherein the plurality of mountains are arranged in a straight line or a curved line. 
     
     
         9 . The optical sheet of  claim 5 , wherein the plurality of mountains of the prism pattern are arranged at irregular intervals. 
     
     
         10 . The optical sheet of  claim 5 , wherein the plurality of inclined surfaces include a first inclined surface and a second inclined surface defining a ravine of the plurality of ravines, and a ravine line is defined along an intersection of the first inclined surface and the second inclined surface. 
     
     
         11 . The optical sheet of  claim 10 , wherein a part of the plurality of diffusion patterns is irregularly arranged along the ravine line. 
     
     
         12 . The optical sheet of  claim 11 , wherein the part of the plurality of diffusion patterns is disposed between the first inclined surface and the second inclined surface. 
     
     
         13 . The optical sheet of  claim 12 , wherein the part of the plurality of diffusion patterns has a peak less than a peak of the plurality of mountains in cross sectional view. 
     
     
         14 . The optical sheet of  claim 5 , wherein each of the plurality of mountains has a scalene triangular cross section in which two sides are different in length. 
     
     
         15 . The optical sheet of  claim 5 , wherein a peak of each of the plurality of mountains is round.