Angular selective light control sheeting and method of making the same

Abstract

An angular selective light control sheeting and a method of making the same are disclosed. The light control sheeting includes a layer of an optically clear elastic material which has a series of parallel slits formed by means of surface slitting with a sharp object such as a razor or blade. Each slit is filled with an opaque material which prevents light transmission through the slit walls. The method includes a step of slitting of an elastic, optically transmissive plastic sheet with a blade and forming at least one array of substantially parallel linear slits in a surface of the sheet, a step of stretching the sheet in a direction perpendicular to the linear slits, and a step of introducing an opaque material into the interior of the slits.

What is claimed is: 
     
         1 . An angular selective light control sheet material, comprising:
 a layer of an optically transmissive elastic material; and   a plurality of deep and narrow slits formed in a surface of said layer;   wherein at least one of said slits comprises a layer of an opaque material.   
     
     
         2 . An angular selective light control sheet material as recited in  claim 1 , wherein said optically transmissive elastic material is configurable for its slitting using a sharp object such as a blade or a razor. 
     
     
         3 . An angular selective light control sheet material as recited in  claim 1 , wherein the material of said optically transmissive layer comprises plasticized polyvinyl chloride. 
     
     
         4 . An angular selective light control sheet material as recited in  claim 1 , wherein an elongation at yield of said optically transmissive elastic material is at least 10%. 
     
     
         5 . An angular selective light control sheet material as recited in  claim 1 , wherein an elongation at yield of said optically transmissive elastic material is at least 30%. 
     
     
         6 . An angular selective light control sheet material as recited in  claim 1 , wherein an elastic modulus of said optically transmissive elastic material is less than 70 MPa. 
     
     
         7 . An angular selective light control sheet material as recited in  claim 1 , wherein said optically transmissive elastic material has a durometer hardness between 70 Shore A and 95 Shore A, as measured in accordance with ASTM D2240 type A scale. 
     
     
         8 . An angular selective light control sheet material as recited in  claim 1 , wherein said optically transmissive elastic material comprises thermoplastic polyurethane. 
     
     
         9 . An angular selective light control sheet material as recited in  claim 1 , wherein said optically transmissive elastic material is selected from the group of polymeric materials consisting of optically clear or translucent thermoplastic elastomers, polyurethanes, and silicones. 
     
     
         10 . An angular selective light control sheet material as recited in  claim 1 , further comprising a protective optically transmissive layer attached to said surface. 
     
     
         11 . An angular selective light control sheet material as recited in  claim 1 , further comprising a light diffusing layer or surface. 
     
     
         12 . An angular selective light control sheet material as recited in  claim 1 , wherein said layer of an opaque material comprises an electrochromic material. 
     
     
         13 . An angular selective light control sheet material as recited in  claim 1 , wherein said opaque material comprises a dark or colored pigment, dye or ink. 
     
     
         14 . An angular selective light control sheet material as recited in  claim 1 , wherein said opaque material comprises high refractive index particles. 
     
     
         15 . An angular selective light control sheet material as recited in  claim 1 , wherein said opaque material comprises carbon black. 
     
     
         16 . An angular selective light control sheet material as recited in  claim 1 , wherein said opaque material comprises an adhesive component. 
     
     
         17 . An angular selective light control sheet material as recited in  claim 1 , wherein said opaque material comprises a light absorbing pigment matrix selected from the group consisting of titanium black, acetylene black, aniline black, perylene black, strontium titanium oxide, chromium oxide, and ceria. 
     
     
         18 . An angular selective light control sheet material as recited in  claim 1 , wherein the layer of optically transmissive elastic material is laminated to at least one light permeable substrate. 
     
     
         19 . An angular selective light control sheet material as recited in  claim 1 , wherein said slits are regularly formed along two or more directions. 
     
     
         20 . An angular selective light control sheet material as recited in  claim 1 , wherein said slits are formed an angle with respect to a normal to said surface.