Diffuser-integrated prism sheet for backlight units and method of manufacturing the same

Abstract

A diffuser-integrated prism sheet is provided, in which diffuser layers are provided on the upper and lower surfaces of the prism sheet and prism-shaped protrusions are formed in the prism sheet. The prism sheet for backlight units includes a lower diffuser layer having a light diffusion structure, a lower layer formed on the lower diffuser layer, a first intermediate layer formed on the lower layer and having prism-shaped protrusions formed parallel to each other, a second intermediate layer formed on the first intermediate layer, an upper layer formed on the second intermediate layer, and an upper diffuser layer formed on the upper layer and having a light diffusion structure, wherein an air layer is formed between the lower surface of the second intermediate layer and the valleys of the prism-shaped protrusions of the first intermediate layer.

What is claimed is: 
     
         1 . A diffuser-integrated prism sheet for backlight units, comprising:
 a lower layer, having a light diffusion structure formed on a lower surface thereof and a plurality of prism-shaped protrusions formed parallel to each other on an upper surface thereof;   an upper layer, formed on an upper surface of the lower layer; and   an upper diffuser layer, formed on an upper surface of the upper layer and having a light diffusion structure formed on an upper surface of the upper diffuser layer, and wherein an air layer is formed between a lower surface of the upper layer and valleys of the prism-shaped protrusions of the lower layer, and ridges of the prism-shaped protrusions of the lower layer and the lower surface of the upper layer are integrated with each other using an adhesive.   
     
     
         2 . The prism sheet according to  claim 1 , wherein the upper layer is formed of polyethylene terephthalate (PET), and the lower layer is formed of polycarbonate (PC). 
     
     
         3 . The prism sheet according to  claim 1 , wherein the light diffusion structure formed on the lower surface of the lower diffuser layer comprises a plurality of hemispherical protrusions for diffusing light. 
     
     
         4 . The prism sheet according to  claim 1 , wherein the light diffusion structure formed on the upper surface of the upper diffuser layer comprises a plurality of hemispherical protrusions for diffusing light. 
     
     
         5 . The prism sheet according to  claim 1 , wherein the light diffusion structure formed on the lower surface of the lower diffuser layer comprises a plurality of hemispherical recesses for diffusing light. 
     
     
         6 . The prism sheet according to  claim 1 , wherein the light diffusion structure formed on the upper surface of the upper diffuser layer comprises a plurality of hemispherical recesses for diffusing light. 
     
     
         7 . The prism sheet according to  claim 1 , wherein a cross-section of each of the prism-shaped protrusions has a triangular shape, a pentagonal shape, or a heptagonal shape.