Liquid crystal display device
AssigneeNippon Electric Co., Ltd.
InventorsChizuka Tani, Fumihiro Ogawa
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Abstract
A liquid crystal cell includes a nematic liquid crystal of negative dielectric anisotropy is disposed between a pair of transparent electrode substrates. The electrode substrates have on their inner surfaces small grooves formed parallel to each other, the grooves on one surface being perpendicular to those on the other surface. In the absence of a voltage applied between the substrates, the long axes of the liquid crystal molecules are perpendicular to the inner surfaces of the electrode substrates. The addition of a small amount of a cholesteric liquid crystal material markedly improves the contrast of the display.
Claims13
A liquid crystal cell including a nematic liquid crystal of negative dielectric anisotropy disposed between a pair of transparent electrode substrates, said electrode substrates having small parallel grooves formed on their inner surfaces, said grooves on one substrate surface being perpendicular to those on the other substrate surface, an active surface agent disposed on the inner surface of at least one substrate for rendering the long axes of the liquid crystal molecules perpendicular to said inner surfaces of said substrates in the absence of a voltage applied between said substrates.
A liquid crystal device comprising:
- a polarizer for polarizing light entering said device;
- an analyzer for analyzing light after passage through said device;
- a first boundary substrate;
- a second boundary substrate, parallel to and spaced from said first substrate;
- said first and second substrates each having transparent electrodes on the interior surfaces thereof;
- a negative dielectric anisotropy, nematic liquid crystal material filling the volume defined by said first and second substrates;
- and said device being constructed such that said liquid crystal material is characterized by a quasihomeotropic boundary condition in the quiescent state, and a homogeneous twisted nematic bulk molecular arrangement in the active state.
Dependencies are inferred from the claim text.