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US 8,913,215 B2Granted
Bistable switchable liquid crystal window
AssigneeKent State University
InventorsDeng-Ke Yang, Lei Shi, Rui Bao
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Abstract
A bistable switchable liquid crystal device is provided in which the device can be switched between a transparent and an opaque state by a predetermined voltage pulse. The device is based on polymer stabilized cholesteric materials. No additional amount of voltage has to be applied to the device in order to sustain the optical states. Therefore, the device is energy-saving.
Claims41
A bistable switchable liquid crystal device comprising:
- a first transparent substrate having an interior and exterior surface;
- a second transparent substrate having an interior and exterior surface, wherein the first and second substrates are separated by a predetermined distance;
- an electrically conductive layer located on the interior surface of at least one of the first and second substrates;
- a cholesteric liquid crystal material comprising at least one nematic liquid crystal material;
- and
- a polymer matrix comprising at least one chiral material and at least one polymerizable material, wherein the cholesteric liquid crystal material is provided adjacent the at least one electrically conductive layer, and wherein the cholesteric liquid crystal material is switched from a transparent homeotropic state to a light scattering focal conic state upon application of a high frequency voltage pulse and from a light scattering focal conic state to a transparent homeotropic state upon application of a low frequency voltage pulse.
3 more elements
A bistable switchable liquid crystal device comprising:
- a first transparent substrate having an interior and exterior surface;
- a second transparent substrate having an interior and exterior surface, wherein the first and second substrates are separated by a predetermined distance;
- an electrically conductive layer located on the interior surface of each of the first and second substrates;
- a liquid crystal material comprising at least one nematic liquid crystal material;
- and
- a polymer matrix comprising at least one chiral material and at least one polymerizable material, wherein the liquid crystal material is provided adjacent the at least one electrically conductive layer, and wherein the liquid crystal material is switchable to an optically transparent homeotropic state upon application of an electric field or an elevated temperature.
3 more elements
A bistable switchable liquid crystal device comprising:
- a first transparent substrate having an interior and exterior surface;
- a second transparent substrate having an interior and exterior surface, wherein the first and second substrates are separated by a predetermined distance;
- an electrically conductive layer located on the interior surface of at least one of the first and second substrates;
- a liquid crystal material comprising at least one nematic liquid crystal material;
- and
- a polymer matrix comprising at least one chiral material and at least one polymerizable material, wherein the liquid crystal material is contained adjacent the at least one electrically conductive layer, and wherein the liquid crystal material is switchable between a transparent homeotropic state to a light scattering focal conic state upon application of a first predetermined frequency voltage pulse and from a light scattering focal conic state to a transparent homeotropic state upon application of a second predetermined frequency voltage pulse, where the first predetermined frequency is lower than the second predetermined frequency.
3 more elements
An electro-optical device comprising:
- at least one transparent substrate, at least one electrically conductive layer located on the at least one transparent substrate, a liquid crystal material comprising at least one nematic liquid crystal material disposed on the at least one substrate in association with a polymer matrix, wherein the liquid crystal material of the polymer matrix is switchable between a transparent state to a light scattering state by exposing the liquid crystal material to a predetermined temperature, and wherein the liquid crystal material is selected to allow switching to occur automatically upon being exposed to a predetermined temperature.
Dependencies are inferred from the claim text.