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

Abstract

Disclosed is a diffuser-integrated prism sheet, 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. Also, a method of manufacturing the diffuser-integrated prism sheet is provided.

1 . A diffuser-integrated prism sheet for backlight units, comprising:
 a lower diffuser layer, having a light diffusion structure formed on a lower surface thereof;   a lower layer, formed on an upper surface of the lower diffuser layer;   a first intermediate layer, formed on an upper surface of the lower layer and having a plurality of prism-shaped protrusions formed parallel to each other;   a second intermediate layer, formed on an upper surface of the first intermediate layer;   an upper layer, formed on an upper surface of the second intermediate 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,   wherein an air layer is formed between a lower surface of the second intermediate layer and valleys of the prism-shaped protrusions of the first intermediate layer, and the first intermediate layer and the second intermediate layer are integrated with each other through fusion.   
     
     
         2 . The prism sheet according to  claim 1 , wherein the upper layer and the lower layer are formed of polyethyleneterephthalate (PET), and the lower diffuser layer, the first intermediate layer, the second intermediate layer, and the upper diffuser layer are formed of a UV light-curable acrylic resin or a heat-curable acrylic resin. 
     
     
         3 . A diffuser-integrated prism sheet for backlight units, comprising:
 a lower diffuser layer, having a light diffusion structure formed on a lower surface thereof;   a lower layer, formed on an upper surface of the lower diffuser layer;   an intermediate layer, formed on an upper surface of the lower layer and having a plurality of prism-shaped protrusions formed parallel to each other;   an upper layer, formed on an upper surface of the intermediate 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,   wherein an air layer is formed between a lower surface of the upper layer and valleys of the prism-shaped protrusions of the intermediate layer, and ridges of the prism-shaped protrusions of the intermediate layer and the lower surface of the upper layer are integrated with each other using an adhesive.   
     
     
         4 . The prism sheet according to  claim 3 , wherein the upper layer and the lower layer are formed of polyethyleneterephthalate (PET), and the intermediate layer is formed of a UV light-curable acrylic resin or a heat-curable acrylic resin. 
     
     
         5 . 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.   
     
     
         6 . The prism sheet according to  claim 5 , wherein the upper layer is formed of polyethyleneterephthalate (PET), and the lower layer is formed of polycarbonate (PC). 
     
     
         7 . 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. 
     
     
         8 . 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. 
     
     
         9 . 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. 
     
     
         10 . 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. 
     
     
         11 . 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. 
     
     
         12 . A method of manufacturing a diffuser-integrated prism sheet, comprising:
 applying a first uncured resin to a predetermined thickness on a lower surface of a first resin sheet;   passing the first resin sheet having the first uncured resin over a roll having a plurality of hemispherical recesses and in contact therewith to thus form a first uncured resin layer having a plurality of hemispherical protrusions, and then radiating UV light or applying heat to thus cure the first uncured resin layer, thereby forming a lower diffuser layer;   applying a second uncured resin to a predetermined thickness on an upper surface of the first resin sheet;   passing the first resin sheet having the second uncured resin over a roll having prism-shaped recesses and in contact therewith to thus form a second uncured resin layer having prism-shaped protrusions, and then radiating UV light or applying heat to thus cure the second uncured resin layer, thereby forming a first intermediate layer;   applying a third uncured resin to a predetermined thickness on an upper surface of a second resin sheet;   passing the second resin sheet having the third uncured resin over a roll having a plurality of hemispherical recesses and in contact therewith to thus form a third uncured resin layer having a plurality of hemispherical protrusions, and then radiating UV light or applying heat to thus cure the third uncured resin layer, thereby forming an upper diffuser layer;   applying a fourth uncured resin on a lower surface of the second resin sheet to thus form a fourth uncured resin layer, and then bringing the first resin sheet into close contact with the second resin sheet so that ridges of the prism-shaped protrusions of the first resin sheet come into contact with the fourth uncured resin layer of the second resin sheet and thus overlap therewith; and   radiating UV light or applying heat to thus cure the fourth uncured resin layer, thereby forming a second intermediate layer.   
     
     
         13 . A method of manufacturing a diffuser-integrated prism sheet, comprising:
 applying a first uncured resin to a predetermined thickness on a lower surface of a first resin sheet;   passing the first resin sheet having the first uncured resin over a roll having a plurality of hemispherical protrusions and in contact therewith to thus form a first uncured resin layer having a plurality of hemispherical recesses, and then radiating UV light or applying heat to thus cure the first uncured resin layer, thereby forming a lower diffuser layer;   applying a second uncured resin to a predetermined thickness on an upper surface of the first resin sheet;   passing the first resin sheet having the second uncured resin over a roll having prism-shaped recesses and in contact therewith to thus form a second uncured resin layer having prism-shaped protrusions, and then radiating UV light or applying heat to thus cure the second uncured resin layer, thereby forming a first intermediate layer;   applying a third uncured resin to a predetermined thickness on an upper surface of a second resin sheet;   passing the second resin sheet having the third uncured resin over a roll having a plurality of hemispherical protrusions and in contact therewith to thus form a third uncured resin layer having a plurality of hemispherical recesses, and then radiating UV light or applying heat to thus cure the third uncured resin layer, thereby forming an upper diffuser layer;   applying a fourth uncured resin on a lower surface of the second resin sheet to thus form a fourth uncured resin layer, and then bringing the first resin sheet into close contact with the second resin sheet so that ridges of the prism-shaped protrusions of the first resin sheet come into contact with the fourth uncured resin layer of the second resin sheet and thus overlap therewith; and   radiating UV light or applying heat to thus cure the fourth uncured resin layer, thereby forming a second intermediate layer.   
     
     
         14 . The method according to  claim 12 , wherein the first resin sheet and the second resin sheet are a polyethyleneterephthalate (PET) sheet, and the first uncured resin, the second uncured resin, the third uncured resin, and the fourth uncured resin are a UV light-curable acrylic resin or a heat-curable acrylic resin. 
     
     
         15 . A method of manufacturing a diffuser-integrated prism sheet, comprising:
 applying a first uncured resin to a predetermined thickness on a lower surface of a first resin sheet;   passing the first resin sheet having the first uncured resin over a roll having a plurality of hemispherical recesses and in contact therewith to thus form a first uncured resin layer having a plurality of hemispherical protrusions, and then radiating UV light or applying heat to thus cure the first uncured resin layer, thereby forming a lower diffuser layer;   applying a second uncured resin on an upper surface of the first resin sheet;   passing the first resin sheet having the second uncured resin over a roll having prism-shaped recesses and in contact therewith to thus form a second uncured resin layer having prism-shaped protrusions, and then radiating UV light or applying heat to thus cure the second uncured resin layer;   applying a third uncured resin to a predetermined thickness on an upper surface of a second resin sheet;   passing the second resin sheet having the third uncured resin over a roll having a plurality of hemispherical recesses and in contact therewith to thus form a third uncured resin layer having a plurality of hemispherical protrusions, and then radiating UV light or applying heat to thus cure the third uncured resin layer, thereby forming an upper diffuser layer;   applying an adhesive on ridges of the prism-shaped protrusions of the first resin sheet, and then bringing the first resin sheet into close contact with the second resin sheet so that the ridges of the prism-shaped protrusions of the first resin sheet come into contact with one surface of the second resin sheet; and   drying the adhesive.   
     
     
         16 . The method according to  claim 15 , wherein the first resin sheet and the second resin sheet are a polyethyleneterephthalate (PET) sheet, and the first uncured resin, the second uncured resin, and the third uncured resin are a UV light-curable acrylic resin or a heat-curable acrylic resin. 
     
     
         17 . A method of manufacturing a diffuser-integrated prism sheet, comprising:
 passing a first resin sheet between an upper roll having prism-shaped recesses and a lower roll having a plurality of hemispherical recesses to thus form the first resin sheet having prism-shaped protrusions on an upper surface thereof and a plurality of hemispherical protrusions on a lower surface thereof, and then cooling the first resin sheet to thus cure it;   applying an uncured resin to a predetermined thickness on an upper surface of a second resin sheet;   passing the second resin sheet having the uncured resin over a roll having a plurality of hemispherical recesses and in contact therewith to thus form an uncured resin layer having a plurality of hemispherical protrusions, and then radiating UV light or applying heat to thus cure the uncured resin layer, thereby forming an upper diffuser layer;   applying an adhesive on ridges of the prism-shaped protrusions of the first resin sheet, and then bringing the first resin sheet into close contact with the second resin sheet so that the ridges of the prism-shaped protrusions of the first resin sheet come into contact with one surface of the second resin sheet; and   drying the adhesive.   
     
     
         18 . A method of manufacturing a diffuser-integrated prism sheet, comprising:
 passing a first resin sheet between an upper roll having prism-shaped recesses and a lower roll having a plurality of hemispherical protrusions to thus form the first resin sheet having prism-shaped protrusions on an upper surface thereof and a plurality of hemispherical recesses in a lower surface thereof, and then cooling the first resin sheet to thus cure it;   applying an uncured resin to a predetermined thickness on an upper surface of a second resin sheet;   passing the second resin sheet having the uncured resin over a roll having a plurality of hemispherical recesses and in contact therewith to thus form an uncured resin layer having a plurality of hemispherical protrusions, and then radiating UV light or applying heat to thus cure the uncured resin layer, thereby forming an upper diffuser layer;   applying an adhesive on ridges of the prism-shaped protrusions of the first resin sheet, and then bringing the first resin sheet into close contact with the second resin sheet so that the ridges of the prism-shaped protrusions of the first resin sheet come into contact with one surface of the second resin sheet; and   drying the adhesive.   
     
     
         19 . The method according to  claim 17 , wherein the first resin sheet is a polycarbonate (PC) sheet, the second resin sheet is a polyethyleneterephthalate (PET) sheet, and the uncured resin is a UV light-curable acrylic resin or a heat-curable acrylic resin. 
     
     
         20 . The method according to  claim 15 , wherein the adhesive is any one selected from among highly transparent adhesives, induing silicone-urethane hybrid polymers, acrylic polymers, and polyester-based polymers. 
     
     
         21 . The method according to  claim 12 , wherein a cross-section of each of the prism-shaped protrusions has a triangular shape, a pentagonal shape, or a heptagonal shape. 
     
     
         22 . The prism sheet according to  claim 3 , wherein the light diffusion structure formed on the lower surface of the lower diffuser layer comprises a plurality of hemispherical protrusions for diffusing light. 
     
     
         23 . The prism sheet according to  claim 5 , wherein the light diffusion structure formed on the lower surface of the lower diffuser layer comprises a plurality of hemispherical protrusions for diffusing light. 
     
     
         24 . The prism sheet according to  claim 3 , wherein the light diffusion structure formed on the upper surface of the upper diffuser layer comprises a plurality of hemispherical protrusions for diffusing light. 
     
     
         25 . The prism sheet according to  claim 5 , wherein the light diffusion structure formed on the upper surface of the upper diffuser layer comprises a plurality of hemispherical protrusions for diffusing light. 
     
     
         26 . The prism sheet according to  claim 3 , wherein the light diffusion structure formed on the lower surface of the lower diffuser layer comprises a plurality of hemispherical recesses for diffusing light. 
     
     
         27 . The prism sheet according to  claim 5 , wherein the light diffusion structure formed on the lower surface of the lower diffuser layer comprises a plurality of hemispherical recesses for diffusing light. 
     
     
         28 . The prism sheet according to  claim 3 , wherein the light diffusion structure formed on the upper surface of the upper diffuser layer comprises a plurality of hemispherical recesses for diffusing light. 
     
     
         29 . The prism sheet according to  claim 5 , wherein the light diffusion structure formed on the upper surface of the upper diffuser layer comprises a plurality of hemispherical recesses for diffusing light. 
     
     
         30 . The prism sheet according to  claim 3 , wherein a cross-section of each of the prism-shaped protrusions has a triangular shape, a pentagonal shape, or a heptagonal shape. 
     
     
         31 . The prism sheet according to  claim 5 , wherein a cross-section of each of the prism-shaped protrusions has a triangular shape, a pentagonal shape, or a heptagonal shape. 
     
     
         32 . The method according to  claim 13 , wherein the first resin sheet and the second resin sheet are a polyethyleneterephthalate (PET) sheet, and the first uncured resin, the second uncured resin, the third uncured resin, and the fourth uncured resin are a UV light-curable acrylic resin or a heat-curable acrylic resin. 
     
     
         33 . The method according to  claim 18 , wherein the first resin sheet is a polycarbonate (PC) sheet, the second resin sheet is a polyethyleneterephthalate (PET) sheet, and the uncured resin is a UV light-curable acrylic resin or a heat-curable acrylic resin. 
     
     
         34 . The method according to  claim 17 , wherein the adhesive is any one selected from among highly transparent adhesives, induing silicone-urethane hybrid polymers, acrylic polymers, and polyester-based polymers. 
     
     
         35 . The method according to  claim 18 , wherein the adhesive is any one selected from among highly transparent adhesives, induing silicone-urethane hybrid polymers, acrylic polymers, and polyester-based polymers. 
     
     
         36 . The method according to  claim 13 , wherein a cross-section of each of the prism-shaped protrusions has a triangular shape, a pentagonal shape, or a heptagonal shape. 
     
     
         37 . The method according to  claim 15 , wherein a cross-section of each of the prism-shaped protrusions has a triangular shape, a pentagonal shape, or a heptagonal shape. 
     
     
         38 . The method according to  claim 17 , wherein a cross-section of each of the prism-shaped protrusions has a triangular shape, a pentagonal shape, or a heptagonal shape. 
     
     
         39 . The method according to  claim 18 , wherein a cross-section of each of the prism-shaped protrusions has a triangular shape, a pentagonal shape, or a heptagonal shape.