Article of manufacture with micro-features of differing surface roughness

Abstract

An article of manufacture includes first and second micro-features of well-defined shape. In some embodiments, the article of manufacture is a light guide or redirecting film and the second micro-features are micro-optical elements configured to disrupt a specular optical path that includes the second micro-optical element. In other embodiments, the article of manufacture is a patterning tool for use in making an optical substrate. Embodiments of the optical substrate are formed by injection molding or embossing using the patterning tool.

1 . (canceled) 
     
     
         2 . A light guide, comprising:
 opposed major surfaces configured to propagate light input to the light guide therebetween by total internal reflection;   a light input edge extending between the major surfaces; and   micro-optical elements of well-defined shape at at least one of the major surfaces, the micro-optical elements embodied as three-dimensional features recessed into or protruding from the major surface and configured to extract incident light from the light guide with a defined light ray angle distribution, the micro-optical elements comprising at least one distinct surface having a surface roughness configured to impart a diffuse component to light incident thereon and disrupt a specular optical path of the propagating light between the light input edge and the micro-optical element of the propagating light.   
     
     
         3 . The light guide of  claim 2 , wherein the surface roughness of the at least one distinct surface is an average surface roughness ranging from about 1 μm to about 5 μm. 
     
     
         4 . The light guide of  claim 2 , wherein the surface roughness of the at least one distinct surface is an average surface roughness ranging from about 3 μm to about 5 μm. 
     
     
         5 . The light guide of  claim 2 , wherein the at least one distinct surface has a surface roughness greater than a surface roughness of the opposed major surfaces. 
     
     
         6 . The light guide of  claim 5 , wherein the opposed major surfaces have a surface roughness of less than about 0.10 μm. 
     
     
         7 . The light guide of  claim 2 , wherein the micro-optical elements are frustoconical in shape and comprise a side surface and an end surface, and the side surface or the end surface is the at least one distinct surface. 
     
     
         8 . The light guide of  claim 7 , wherein the side surface and the end surface each have a surface roughness configured to impart a diffuse component to light incident thereon. 
     
     
         9 . The light guide of  claim 2 , wherein the micro-optical elements each comprise a first surface and a second surface that comes together with the first surface to form a ridge having ends that intersect the major surface, and the first surface or the second surface is the at least one distinct surface. 
     
     
         10 . The light guide of  claim 9 , wherein the first surface and the second surface each have a surface roughness configured to impart a diffuse component to light incident thereon. 
     
     
         11 . The light guide of  claim 2 , wherein the surface roughness of the respective micro-optical elements decreases with increasing distance from the light input edge. 
     
     
         12 . The light guide of  claim 2 , further comprising additional micro-optical elements of well-defined shape at at least one of the major surfaces embodied as three-dimensional features recessed into or protruding from the major surface and configured to extract incident light from the light guide with a defined light ray angle distribution, the additional micro-optical elements having a surface roughness lower than the roughness of the at least one distinct surface. 
     
     
         13 . The light guide of  claim 12 , wherein the additional micro-optical elements have a surface roughness of less than about 0.10 μm. 
     
     
         14 . The light guide of  claim 12 , wherein the micro-optical elements and the additional micro-optical elements have nominally the same shape. 
     
     
         15 . The light guide of  claim 12 , wherein the additional micro-optical elements are frustoconical in shape. 
     
     
         16 . The light guide of  claim 12 , wherein the additional micro-optical elements each comprise a first surface and a second surface that comes together with the first surface to form a ridge having ends that intersect the major surface. 
     
     
         17 . A lighting assembly, comprising:
 the light guide of  claim 1 ; and   a light source adjacent the light input edge comprising solid-state light emitters to edge light the light guide.   
     
     
         18 . A light redirecting film, comprising:
 opposed major surfaces; and   micro-optical elements of well-defined shape at at least one of the major surfaces, the micro-optical elements embodied as three-dimensional features recessed into or protruding from the major surface and configured to refract incident light from the light guide with a defined light ray angle distribution, the micro-optical elements comprising at least one distinct surface, wherein the at least one distinct surface has a surface roughness ranging from about 1 μm to about 5 μm and is configured to impart a diffuse component to light incident thereon, and the surface roughness of the at least one distinct surface is greater than a surface roughness of the opposed major surfaces.   
     
     
         19 . The light redirecting film of  claim 18 , wherein the micro-optical elements are nominally frustoconical in shape and each comprise a side surface and an end surface, and the side surface or the end surface is the at least one distinct surface. 
     
     
         20 . The light redirecting film of  claim 18 , wherein the micro-optical elements each comprise a first surface and a second surface that comes together with the first surface to form a ridge having ends that intersect the major surface, and the first surface or the second surface is the at least one distinct surface. 
     
     
         21 . The light redirecting film of  claim 18 , further comprising additional micro-optical elements of well-defined shape at at least one of the major surfaces embodied as three-dimensional features recessed into or protruding from the major surface and configured to refract incident light from the light guide with a defined light ray angle distribution, the additional micro-optical elements having a surface roughness lower than the roughness of the at least one distinct surface. 
     
     
         22 . A light guide, comprising:
 opposed major surfaces configured to propagate light input to the light guide therebetween by total internal reflection;   a light input edge extending between the major surfaces; and   light extracting means at at least one of the major surfaces for extracting light from the light guide with a defined light ray angle distribution and for imparting a diffuse component to light incident thereon to disrupt a specular optical path of the propagating light.