Reflecting cholesteric LCD having viewer side layer which either scatters or transmits light depending on angle
AssigneeMinolta Co., Ltd.
InventorsKiyofumi Hashimoto, Takuji Hatano, Masakazu Okada
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Abstract
A reflecting liquid crystal display unit that reflects light entering from an observer side to display an image. The reflecting liquid crystal display has a composite layer of cholesteric liquid crystal material and polymer resin, and an an isotropic scattering layer. The an isotoropic scattering layer scatters light entering this layer at a relative large incident angle passes light entering this layer at a relative small incident angle. The an isotoropic scattering layer is provided on an observer side of the composite layer.
Claims18
A reflecting liquid crystal display unit formed of a plurality of layers, wherein, arranged from an observer side of said display unit, said display unit comprises:
- a first layer that (i) passes light that is incident on an observer side surface of said first layer and within an angular range with respect to a direction normal to the observer side surface of said first layer and (ii) scatters light outside said angular range;
- and
- a second layer which includes liquid crystal material and reflects light received through said first layer to display an image, said second layer having a selective reflection wavelength which varies with viewing angle;
- wherein said first layer is adapted to reduce a level of color discrepancy of said liquid crystal display unit across a predetermined range of viewing angles.
A reflective cholesteric liquid crystal display unit which is capable of color display comprising, in order from an observer side:
- an anisotropic light scattering layer, said anisotropic light scattering layer having a scattering characteristic such that light incident thereon for a first range of incident angles, relative to a normal thereto, is substantially scattered and light incident thereon for a second range of incident angles, relative to a normal thereto, is substantially transmitted;
- a second layer, which is arranged contiguous with said anisotropic light scattering layer, either directly or through another layer, and which includes a mixture of a liquid crystal material and a chiral ingredient, said second layer having a selective reflection wavelength when liquid crystal molecules therein are arranged in a planar alignment, said selective reflection wavelength varying with viewing angle;
- a light absorbing layer, which is arranged contiguous with said second layer, either directly or through another layer;
- wherein said anisotropic light scattering layer is adapted to reduce a color discrepancy of said liquid crystal display unit across a predetermined range of viewing angles to a level which is less than a level of color discrepancy which would be achieved with said liquid crystal display unit without said anisotropic light scattering layer.
Dependencies are inferred from the claim text.