Light diffuser with colored variable diffusion

Abstract

The invention provides a light diffuser comprising a macro diffusion efficiency variation wherein at least part of the diffuser is colored. The invention also provides light diffuser comprising a macro diffusion efficiency variation visible to the naked eye wherein at least part of the diffuser is colored for rear projection displays, back-lighted imaging media, and a liquid crystal display component and device. The invention further provides a process for preparing such a diffuser.

1 . A light diffuser polymeric film comprising a macro diffusion efficiency variation visible to the naked eye having a total light transmission of at least 80% wherein at least part of the diffuser is selectively colored.  
   
   
       2 . The light diffuser of  claim 1  wherein said color has a density of greater than 0.2.  
   
   
       3 . The light diffuser of  claim 1  wherein specular areas of said macro diffusion efficiency variation are colored.  
   
   
       4 . The light diffuser of  claim 1  wherein diffuse areas of said macro diffusion efficiency variation are colored.  
   
   
       5 . The light diffuser of  claim 1  wherein gradient areas of said macro diffusion efficiency variation are colored.  
   
   
       6 . The light diffuser of  claim 1  wherein said colored part of the diffuser comprises dye based colorants.  
   
   
       7 . The light diffuser of  claim 1  wherein said colored part of the diffuser comprises pigment based colorants.  
   
   
       8 . The light diffuser of  claim 1  wherein said colored part of the diffuser comprises fluorescent materials.  
   
   
       9 . The light diffuser of  claim 1  wherein said part of the diffuser corresponds to color wavelength band of from 10 to 70 nm.  
   
   
       10 . The light diffuser of  claim 1  wherein said colored part of the diffuser comprises text.  
   
   
       11 . The light diffuser of  claim 1  wherein said colored part of the diffuser comprises graphics.  
   
   
       12 . The light diffuser of  claim 1  wherein said colored part of the diffuser comprise an image.  
   
   
       13 . The light diffuser of  claim 1  wherein said part of the diffuser comprises chromatic transmission.  
   
   
       14 . The light diffuser of  claim 13  wherein the chromatic transmission comprises yellow light at 570 to 620 nm.  
   
   
       15 . The light diffuser of  claim 13  wherein the chromatic transmission comprises magenta light at 630 to 690 and 425 to 480 nm.  
   
   
       16 . The light diffuser of  claim 13  wherein the chromatic transmission comprises cyan light at 480 to 520 nm.  
   
   
       17 . The light diffuser of  claim 13  wherein the chromatic transmission comprises red light at 630 to 690 nm.  
   
   
       18 . The light diffuser of  claim 13  wherein the chromatic transmission comprises green light at 525 to 590 nm.  
   
   
       19 . The light diffuser of  claim 13  wherein the chromatic transmission comprises blue light at 425 to 480 nm.  
   
   
       20 . The light diffuser of  claim 1  wherein the diffusion efficiency varies more than 5 percent in two different locations of the diffuser.  
   
   
       21 . The light diffuser of  claim 1  wherein the diffusion efficiency varies more than 50 percent in two different locations of the diffuser.  
   
   
       22 . The light diffuser of  claim 1  wherein the diffusion efficiency variation comprises a gradient.  
   
   
       23 . The light diffuser of  claim 1  that is rectangular in shape wherein there is diffusion efficiency variation along a diagonal of the rectangle.  
   
   
       24 . The light diffuser of  claim 1  that is rectangular in shape wherein there is diffusion efficiency variation along the width or height.  
   
   
       25 . The light diffuser of  claim 1  wherein there is diffusion efficiency variation from the center to the perimeter.  
   
   
       26 . The light diffuser of  claim 1  wherein there is diffusion efficiency variation along the perimeter.  
   
   
       27 . The light diffuser of  claim 1  wherein the diffusion efficiency variation is such that iso-efficiency exhibits an elliptical pattern.  
   
   
       28 . The light diffuser of  claim 1  wherein the diffusion efficiency variation comprises a repeating pattern.  
   
   
       29 . The light diffuser of  claim 1  wherein the diffusion efficiency variation comprises a specular component.  
   
   
       30 . The light diffuser of  claim 1  wherein the diffusion efficiency variation provides values at least 10% less on the edges than in the center of said light diffuser.  
   
   
       31 . The light diffuser of  claim 1  further comprising a base and a plurality of convex or concave complex lenses of the surface of said base.  
   
   
       32 . The plurality of complex lenses of  claim 31  wherein the said convex or concave complex lenses are randomly distributed on the surface of the base.  
   
   
       33 . The plurality of complex lenses of  claim 31  wherein said concave or convex complex lenses have an average width in the x and y direction of 3 to 60 microns.  
   
   
       34 . The plurality of complex lenses of  claim 31  wherein said concave or convex complex lenses have a height/diameter ratio of 0.03 to 1.0.  
   
   
       35 . The light diffuser of  claim 1  further comprising a microvoided polymer sheet.  
   
   
       36 . The light diffuser of  claim 35  wherein the microvoided polymer sheet comprises substantially circular voids.  
   
   
       37 . The light diffuser of  claim 1  wherein said light diffuser comprises a surface diffuser.  
   
   
       38 . The light diffuser of  claim 1  wherein said light diffuser comprises a bulk diffuser.  
   
   
       39 . The light diffuser of  claim 1  wherein said light diffuser comprises a base comprising a surface microstructure.  
   
   
       40 . The light diffuser of  claim 1  wherein h the macro diffusion efficiency varies by greater than 5% at two locations of the film surface at least 2 cm apart using a 25.4 mm port.  
   
   
       41 . The method of applying color to macro diffusion efficiency variation comprising color transfer.  
   
   
       42 . The method of  claim 41  wherein said application of color transfer comprises ink-jet.  
   
   
       43 . The method of  claim 41  wherein said application of color transfer comprises electrophotography.  
   
   
       44 . The method of  claim 41  wherein said application of color transfer comprises flexo, gravure, or screen ink printing.  
   
   
       45 . The method of  claim 41  wherein said application of color transfer comprises thermal dye transfer.  
   
   
       46 . A media comprising a colored part of the diffuser that forms graphics, text, or images.  
   
   
       47 . A back lighted imaging media comprising a light source and a light diffuser comprising a colored part of the diffuser.  
   
   
       48 . A liquid crystal device comprising a light source and a light diffuser comprising a colored part of the diffuser, wherein the light diffuser is located between the light source and a polarizing film.