ARTICLE OF MANUFACTURE WITH MICRO-FEATURES OF DIFFERING SURFACE ROUGHNESS
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.