Abstract:
A device for controlling the polarization state of transmitted light comprises first and second cell walls enclosing a layer of a chiral liquid crystal material. The material has a uniformly orientated helical axis in the absence of an applied field, and electrodes for applying an electric field substantially normal to the helical axis. An applied electric field flexoelectrically couples to the molecules, causing distortion of the helical structure and hence changes the bulk birefringence of the cell.
Abstract:
The invention relates to a method of manufacturing a liquid crystal display device comprising an orienting layer (5), the method comprising the steps of forming the orienting layer (5) on the substrate (1), adding a monomer to a liquid crystalline material (7) and forming an anchoring network (10) in a layer of the liquid crystalline material near the orienting layer from mixture of a photo-initiator and the monomer, the monomer being cured in the anchoring network. The anchoring network improves the anchoring of the liquid crystalline material to the orienting layers, so that the anchoring network keeps the liquid crystalline molecules in place in case the surface of the orienting layers is damaged
Abstract:
An electro-optically active polymer gel material comprising a high molecular weight alignment polymer adapted to be homogeneously dispersed throughout a liquid crystal to control the alignment of the liquid crystal molecules and/or confer mechanical stability is provided. The electro-optically active polymer gel comprises a homogenous gel in which the polymer strands of the gel are provided in low concentration and are well solvated by the small molecule liquid crystal without producing unacceptable slowing of its electrooptic response. During formation of the gel, a desired orientation is locked into the gel by physical or chemical cross-linking of the polymer chains. The electro-optically active polymer is then utilized to direct the orientation in the liquid crystal gel in the "field off" state of a liquid crystal display. The electro-optically active polymer also provides a memory of the mesostructural arrangement of the liquid crystal and acts to suppress the formation of large scale deviations, such as, for example, fan-type defects in an FLC when subjected to a mechanical shock. A method of making an electro-optically active polymer gel material and an electrooptic device utilizing the electro-optically active polymer gel of the present invention is also provided.
Abstract:
A new liquid crystalline light modulating cell and material are characterized by phase-separated polydomains of polymer networks dispersed in chiral nematic liquid crystal having positive dielectric anisotropy, the polymer being present in an amount less than 10 % by weight of the total weight of the material and, preferably, being cross-linked. The liquid crystal in the vicinity of the polydomains is less responsive to an applied field than surrounding regions of liquid crystal, whereby the new material exhibits different optical states in response to different field conditions. In one embodiment, the material is light scattering in a field-OFF condition and optically clear in a field-ON condition, while in another embodiment, the new material is optically clear in a field-OFF condition and light scattering in a filed-ON condition. In still another embodiment, the new material exhibits stability at zero field in both a colored, light reflecting state and a light scattering state, as well as being optically clear in the presence of a field.
Abstract:
A new liquid crystalline light modulating cell and material are characterized by phase-separated polydomains of polymer networks dispersed in chiral nematic liquid crystal having positive dielectric anisotropy, the polymer being present in an amount less than 10 % by weight of the total weight of the material and, preferably, being cross-linked. The liquid crystal in the vicinity of the polydomains is less responsive to an applied field than surrounding regions of liquid crystal, whereby the new material exhibits different optical states in response to different field conditions. In one embodiment, the material is light scattering in a field-OFF condition and optically clear in a field-ON condition, while in another embodiment, the new material is optically clear in a field-OFF condition and light scattering in a filed-ON condition. In still another embodiment, the new material exhibits stability at zero field in both a colored, light reflecting state and a light scattering state, as well as being optically clear in the presence of a field.
Abstract:
A fast flexoelectro-optic switching device containing bimesogen-doped and polymer-stabilized vertical standing helix (PSVSH) in a cholesteric liquid crystal. The PSVSH device exhibits a response time of less than 0.7 millisecond, high contrast and negligible hysteresis which is suitable for applications including blur-free displays, field-sequential color displays and active optical elements.
Abstract:
A backlight assembly for a display device is provided. The backlight assembly includes a transparent waveguide layer, a plurality of light sources, and a tunable grating layer. The light sources are arranged along an edge of the waveguide layer. Each light source transmits light into the waveguide layer through the edge. The grating layer is coupled to the waveguide layer, and has multiple rows. Each row of the grating layer is segmented into a series of cells so the grating layer is sectioned into an array of cells. Each cell is independently controllable to either not extract incident light received from within the waveguide layer, or to extract the incident light for emission from the backlight assembly. In another configuration, the waveguide layer is not present, and the light sources transmit light directly into an edge of the grating layer.