Optical substrates having light collimating and diffusion structures

Abstract

This invention discloses a method of forming an uneven structure on a substrate. Use a hard tool to penetrate into a mold to cut a first trench and a second trench in an order on a surface of a mold, wherein the hard tool has a smoothly-curved shape such that the transverse width of each of the first trench and the second trench increases as the penetrating depth of the hard tool increases, wherein when each of the first trench and the second trench marches along a first direction, the penetrating depth of the hard tool is controlled by repeating moving the hard tool up and down to cut the mold such that the transverse width of each of the first trench and the second trench varies according to the controlled penetrating depth of the hard tool, wherein the first trench and the second trench completely overlap with each other with no space therebetween. Then, use the surface of the mold to emboss a thin film on a substrate.

What is claimed is: 
     
         1 . A method of forming an uneven structure on a substrate, comprising:
 using a hard tool to penetrate into a mold to cut a first trench and a second trench in an order on a surface of a mold, wherein the hard tool has a smoothly-curved shape such that the transverse width of each of the first trench and the second trench increases as the penetrating depth of the hard tool increases, wherein when each of the first trench and the second trench marches along a first direction, the penetrating depth of the hard tool is controlled by repeating moving the hard tool up and down to cut the mold such that the transverse width of each of the first trench and the second trench varies according to the controlled penetrating depth of the hard tool, wherein the first trench and the second trench completely overlap with each other with no space therebetween; and   using the surface of the mold to emboss a thin film on a substrate.   
     
     
         2 . The method according to  claim 1 , wherein each of the first trench and the second trench is cut along the first direction by maintaining the position of the hard tool substantially along a straight line in the first direction. 
     
     
         3 . The method according to  claim 1 , wherein each of the first trench and the second trench has a longitudinal axis between the opposing edges thereof. 
     
     
         4 . The method according to  claim 1 , wherein the substrate is an optical substrate having a light input surface and a light output surface, and the uneven structure is formed on the light input surface of the substrate. 
     
     
         5 . The method according to  claim 4 , wherein the smoothly-curved shape is a lenticular shape such that the uneven structure is a lenticular structure. 
     
     
         6 . The method according to  claim 1 , wherein the substrate is an optical substrate having a light input surface and a light output surface, and the uneven structure is formed on the light output surface of the substrate. 
     
     
         7 . The method according to  claim 6 , wherein the smoothly-curved shape is a lenticular shape such that the uneven structure is a lenticular structure. 
     
     
         8 . The method according to  claim 1 , wherein the surface of the uneven structure has roughed or textured structure for diffusion. 
     
     
         9 . The method according to  claim 1 , wherein a portion of the uneven structure corresponding to one of the first trench and the second trench extends from a first edge of the substrate to a second edge of the substrate. 
     
     
         10 . The method according to  claim 1 , wherein a portion of the uneven structure corresponding to one of the first trench and the second trench extends from an edge of the substrate to a point inside the surface area of the substrate. 
     
     
         11 . The method according to  claim 1 , wherein a portion of the uneven structure corresponding to one of the first trench and the second trench extends from a first point inside the surface area of the substrate to a second point inside the surface area of the substrate. 
     
     
         12 . An uneven structure is formed by using a structured surface corresponding to the uneven structure of a mold to emboss a thin film on a substrate, wherein the structured surface corresponding to the uneven structure of the mold is formed by using a hard tool to penetrate into the mold to cut a first trench and a second trench in an order on the surface of the mold, wherein the hard tool has a smoothly-curved shape such that the transverse width of each of the first trench and the second trench increases as the penetrating depth of the hard tool increases, wherein when each of the first trench and the second trench marches along a first direction, the penetrating depth of the hard tool is controlled by repeating moving the hard tool up and down to cut the mold such that the transverse width of each of the first trench and the second trench varies according to the controlled penetrating depth of the hard tool, wherein the first trench and the second trench completely overlap with each other with no space therebetween. 
     
     
         13 . A method of mold making, comprising using a hard tool to penetrate into a mold to cut a first trench and a second trench in an order on a surface of a mold, wherein the hard tool has a smoothly-curved shape such that the transverse width of each of the first trench and the second trench increases as the penetrating depth of the hard tool increases, wherein when each of the first trench and the second trench marches along a first direction, the penetrating depth of the hard tool is controlled by repeating moving the hard tool up and down to cut the mold such that the transverse width of each of the first trench and the second trench varies according to the controlled penetrating depth of the hard tool, wherein the first trench and the second trench completely overlap with each other with no space therebetween. 
     
     
         14 . A method of forming an optical film, comprising:
 providing a substrate having a light input surface and a light output surface;   using the method recited in  claim 1  to form a uneven structure on the light input surface of the substrate for diffusing the light entering the optical film; and   forming a prismatic structure on a light output surface of the substrate.