Wire Grid Polarizers in Window Shading Applications and Varying Thickness Wave Retarders
A light transmissive panel is provided comprising a first sheet and a second sheet, wherein each sheet is made up of a nonbirefringant substrate and a wire grid polarizer pattern of continuously varying absorption axis orientation formed on the nonbirefringant substrate. The wire grid polarizer patterns on each of the first and second sheet are mechanically translatable relative to each other, wherein the mechanical translation controls transmission of light through the light transmissive panel. Also taught is an example wherein each sheet of the panel is made of a wire grid polarizer that is laminated with a continuous variable thickness wave plate retarder, wherein the continuous variable thickness wave plate retarder rotates input light by an amount determined by the thickness of the wave plate retarder. Also taught is an example wherein each sheet of the panel is made up of a traditional polarizer and continuously varying thickness wave retarder.
1 . A light transmissive panel comprising:
a first sheet comprising a first non-birefringent substrate, a first reflective polarizer layer over the first substrate, and a first wave retarder layer over the first polarizer layer wherein the first wave retarder rotates light by a first predetermined amount; and
a second sheet comprising a second non-birefringent substrate, a second reflective polarizer layer over the second substrate, and a second wave retarder layer over the second polarizer layer wherein the second wave retarder rotates light by a second predetermined amount;
said first and second sheets being mechanically translatable relative to each other, said mechanical translation controlling transmission of light through said light transmissive panel.
2 . The light transmissive panel of claim 1 , wherein said first and second wave retarders are each wave retarders of continuously varying thickness.
3 . The light transmissive panel of claim 1 , wherein said first and second wave retarders have a discretely varying thickness in order to approach a continuously varying pattern.
4 . The light transmissive panel of claim 1 , wherein said translation controls transmission of light on a gray scale from near 50% to near 100% opacity.
5 . The light transmissive panel of claim 1 , wherein said panel is a window, skylight, or aftermarket augmentation to either.
6 . The light transmissive panel of claim 1 , wherein said first and second wave retarders are each variable wave retarders.
7 . The light transmissive panel of claim 1 , wherein said first and second reflective polarizers are each wire grid polarizers.