Polymeric optical film

Abstract

An optical film includes a layer of simultaneously biaxially stretched polyolefin film that is substantially non-absorbing and non-scattering for at least one polarization state of visible light. The layer has x, y, and z orthogonal indices of refraction where at least two of the orthogonal indices of refraction are not equal. The layer has an in-plane retardance of 100 nm or less and an out-of-plane retardance of 50 nm or greater.

1 . An optical film comprising: 
 a layer of extruded simultaneously biaxially stretched polymer film being substantially non-absorbing and non-scattering for at least one polarization state of visible light; and having x, y, and z orthogonal indices of refraction wherein at least two of the orthogonal indices of refraction are not equal, an in-plane retardance of the layer being 100 nm or less and an out-of-plane retardance of the layer being 50 nm or greater.    
     
     
         2 . The optical film according to  claim 1 , wherein the layer of extruded simultaneously biaxially stretched polymer film is a polyolefin film.  
     
     
         3 . The optical film according to  claim 1 , wherein the polymer comprises at least one of: polypropylene, polyethylene, polyester, copolyester, polyacrylate, fluoropolymer, polybutylene, cyclic olefin polymer, poly(4-methyl-1-pentene), polymethacrylate and poly(vinylidene fluoride).  
     
     
         4 . An optical film comprising: 
 a layer of extruded simultaneously biaxially stretched polymer film being substantially non-absorbing and non-scattering for at least one polarization state of visible light; and having x, y, and z orthogonal indices of refraction wherein at least two of the orthogonal indices of refraction are not equal, an in-plane retardance of the layer being 100 nm or less and an out-of-plane retardance of the layer being 50 nm or greater and the layer has a length and a width of at least 0.65 meter and the in-plane and out-of-plane retardance are substantially uniform across the length and width.    
     
     
         5 . The optical film according to  claim 4 , wherein the width and length of the layer of extruded simultaneously biaxially stretched polymer film are each at least 1.3 meter.  
     
     
         6 . The optical film according to  claim 4 , wherein the width and length of the layer of extruded simultaneously biaxially stretched polymer film are each at least 1.5 meter.  
     
     
         7 . The optical film according to  claim 4 , wherein the in-plane retardance changes less than 4 nm/cm along the width and length of the layer of extruded simultaneously biaxially stretched polymer film.  
     
     
         8 . The optical film according to  claim 4 , wherein the in-plane retardance changes less than 2 nm/cm along the width and length of the layer of extruded simultaneously biaxially stretched polymer film.  
     
     
         9 . The optical film according to  claim 4 , wherein the in-plane retardance changes less than 1 nm/cm along the width and length of the layer of extruded simultaneously biaxially stretched polymer film.  
     
     
         10 . The optical film according to  claim 4 , wherein the layer of extruded simultaneously biaxially stretched polymer film has a thickness of 5 micrometers to 200 micrometers.  
     
     
         11 . An optical film comprising: 
 a layer of extruded simultaneously biaxially stretched polymer film being substantially non-absorbing and non-scattering for at least one polarization state of visible light; and having x, y, and z orthogonal indices of refraction wherein at least two of the orthogonal indices of refraction are not equal, an in-plane retardance of the layer being 100 nm or less and an out-of-plane retardance of the layer being 50 nm or greater and a thickness of 5 micrometers to 200 micrometers.    
     
     
         12 . The optical film according to  claim 1 ,  4  or  11  wherein the out-of-plane retardance of the layer of extruded simultaneously biaxially stretched polymer film is greater than 100 nm.  
     
     
         13 . The optical film according to  claim 1 ,  4  or  11 , wherein the out-of-plane retardance of the layer of extruded simultaneously biaxially stretched polymer film is greater than 150 nm.  
     
     
         14 . The optical film according to  claim 1 ,  4  or  11 , wherein the layer of extruded simultaneously biaxially stretched polymer film has a thickness of 5 micrometers to 25 micrometers.  
     
     
         15 . The optical film according to  claim 1 ,  4  or  11 , wherein the layer of extruded simultaneously biaxially stretched polymer film has a thickness of 7 micrometers to 75 micrometers.  
     
     
         16 . The optical film according to  claim 1 ,  4  or  11 , wherein the in-plane retardance of the layer of extruded simultaneously biaxially stretched polymer film is less than 20 nm.  
     
     
         17 . The optical film according to  claim 1 ,  4  or  11 , wherein the in-plane retardance of the layer of extruded simultaneously biaxially stretched polymer film is from 20 nm to 50 nm.  
     
     
         18 . The optical film according to  claim 1 , further comprising an LCP coating on the layer of extruded simultaneously biaxially stretched polymer film.  
     
     
         19 . The optical film according to  claim 18 , further comprising an oriented PVA film laminated to the LCP coating.  
     
     
         20 . The optical film according to  claim 18 , wherein the layer of extruded simultaneously biaxially stretched polymer film is laminated to glass.  
     
     
         21 . The optical film according to  claim 1 , further comprising an oriented PVA film laminated to the layer of extruded simultaneously biaxially stretched polymer film.  
     
     
         22 . The optical film according to  claim 21 , further comprising a TAC layer.  
     
     
         23 . The optical film according to  claim 21 , wherein the layer of extruded simultaneously biaxially stretched polymer film is laminated to glass.