Light reflector with variable diffuse light reflection

Abstract

Disclosed is a diffuse reflector polymeric film comprising a macro reflection efficiency variation. The invention provides improved light reflection for a back lit display while simultaneously diffusely reflecting specular light sources.

1 . A diffuse reflector polymeric film comprising a macro reflection efficiency variation visible to the naked eye, including a reflective layer that has a reflectivity at 500 nanometers of greater than 50%.  
   
   
       2 . The film of  claim 1  in which the macro reflection efficiency varies by greater than 5% at two locations of the film surface at least 2 cm apart using a 25.4 mm port.  
   
   
       3 . The diffuse reflector of  claim 2  wherein the reflection efficiency varies by more than 50 percent at two different locations of the diffuse reflector.  
   
   
       4 . The diffuse reflector of  claim 1  wherein the reflection efficiency variation comprises a gradient.  
   
   
       5 . The diffuse reflector of  claim 1  that is rectangular in shape wherein there is reflection efficiency variation along a diagonal of the rectangle.  
   
   
       6 . The diffuse reflector of  claim 1  that is rectangular in shape wherein there is reflection efficiency variation along the width or height of the rectangle.  
   
   
       7 . The diffuse reflector of  claim 1  wherein there is reflection efficiency variation from the center to the perimeter.  
   
   
       8 . The diffuse reflector of  claim 1  wherein there is a reflection efficiency variation along the perimeter.  
   
   
       9 . The diffuse reflector of  claim 1  wherein the reflection efficiency variation is such that iso-efficiency exhibits an elliptical pattern.  
   
   
       10 . The diffuse reflector of  claim 1  wherein the reflection efficiency variation comprises a repeating pattern.  
   
   
       11 . The diffuse reflector of  claim 1  wherein the reflection efficiency variation comprises a specular reflection component.  
   
   
       12 . The diffuse reflector of  claim 1  wherein the reflection efficiency variation provides values at least 10% less on the edges than in the center of said diffuse reflector.  
   
   
       13 . The diffuse reflector of  claim 1  wherein the diffuse reflector comprises at least one reflective layer and at least one film.  
   
   
       14 . The diffuse reflector of  claim 13  wherein the reflective layer is adhesively bonded to the film.  
   
   
       15 . The diffuse reflector of  claim 13  wherein the reflective layer is integral to the bottom surface of the film.  
   
   
       16 . The diffuse reflector of  claim 13  wherein the reflective layer is integral to the top surface of the film.  
   
   
       17 . The diffuse reflector of  claim 13  wherein the film is reflective.  
   
   
       18 . The diffuse reflector of  claim 13  wherein the reflective layer comprises a metal.  
   
   
       19 . The diffuse reflector of  claim 13  wherein the reflective layer comprises an alloy.  
   
   
       20 . The diffuse reflector of  claim 13  wherein the reflective layer comprises an oxide.  
   
   
       21 . The diffuse reflector of  claim 13  wherein the reflective layer comprises layers of polymer with differing indexes of refraction.  
   
   
       22 . The diffuse reflector of  claim 13  wherein the reflective layer comprises greater than 30 layers of polymer with differing indexes of refraction between at least two adjacent layers of 0.03 to 0.15.  
   
   
       23 . The diffuse reflector of  claim 13  wherein the reflective layer thickness is 0.5 nanometers to 50 micrometers.  
   
   
       24 . The diffuse reflector of  claim 13  wherein the reflective layer thickness is 0.25 to 50 nanometers.  
   
   
       25 . The diffuse reflector of  claim 13  wherein the reflective layer thickness is from 0.50 to 50.0 nanometers.  
   
   
       26 . The diffuse reflector of  claim 13  wherein the reflective layer has a reflectivity at 500 nanometers of greater than 50%.  
   
   
       27 . The diffuse reflector of  claim 13  wherein the reflective layer has a reflectivity at 500 nanometers of greater than 94%.  
   
   
       28 . The diffuse reflector of  claim 13  wherein the reflective layer has a resistivity of 0.03 to 1800 ohms per square.  
   
   
       29 . The diffuse reflector of  claim 1  further comprising a base and a plurality of convex or concave complex lenses on the surface of said base.  
   
   
       30 . The diffuse reflector of  claim 29  wherein the complex lenses are reflective.  
   
   
       31 . The diffuse reflector of  claim 29  wherein the said convex or concave complex lenses are randomly distributed on the surface.  
   
   
       32 . The diffuse reflector of  claim 29  wherein said concave or convex complex lenses have an average width in the x and y direction of 3 to 60 microns.  
   
   
       33 . The diffuse reflector of  claim 29  wherein said concave or convex complex lenses have a height/diameter ratio of 0.03 to 1.0.  
   
   
       34 . The diffuse reflector of  claim 29  wherein said concave or convex complex lenses comprise a multiple of minor lenses wherein the minor lenses have a width in the x and y direction of 2 to 20 microns.  
   
   
       35 . The diffuse reflector of  claim 1  further comprising a microvoided polymer sheet.  
   
   
       36 . The diffuse reflector of  claim 35  wherein the microvoided polymer sheet comprises substantially circular voids.  
   
   
       37 . The diffuse reflector of  claim 1  wherein said diffuse reflector comprises a surface diffuser.  
   
   
       38 . The diffuse reflector of  claim 1  wherein said diffuse reflector comprises a bulk diffuser.  
   
   
       39 . The diffuse reflector of  claim 1  wherein said diffuse reflector comprises a base comprising a surface microstructure.  
   
   
       40 . The diffuse reflector of  claim 1  wherein said diffuse reflector comprises a colored element.  
   
   
       41 . The diffuse reflector of  claim 1  wherein said macro reflection efficiency variation comprises chromatic reflection.  
   
   
       42 . A process comprising providing a diffuse reflector wherein the light reflection efficiency is selectively modified.  
   
   
       43 . The process of  claim 42  wherein a heat gradient or pattern is applied to the diffuse reflector.  
   
   
       44 . The process of  claim 42  wherein a pressure gradient or pattern is applied to the diffuse reflector.  
   
   
       45 . A back lighted imaging media comprising a light source and a diffuse reflector comprising a macro reflection efficiency variation according to  claim 1 .  
   
   
       46 . A liquid crystal device comprising a light source and a diffuse reflector comprising a macro reflection efficiency variation according to  claim 1 , wherein the diffuse reflector is located between the light source and a polarizing film.  
   
   
       47 . The diffuse reflector of  claim 1  wherein the polymeric film comprises a polyolefin.  
   
   
       48 . The diffuse reflector of  claim 1  wherein the polymeric film comprises a polyester.