摘要:
A photopolymer mixture is capable of use for a liquid crystal alignment layer. An alignment layer is formed from such a photopolymer mixture. The mixture comprises at least two polymerisable materials which are blended together in proportion so as to give a predetermined, preferably low, surface energy. A low surface energy, e.g., less than 4×10−2 N/m, can result in an alignment layer which imparts a particular orientation to liquid crystal molecules with out requiring any post-cure treatments. The polymerisable materials may be monomers, oligomers, or diluents that form long chain molecules when cured, and the mixture may contain additives to lower the overall surface energy.
摘要:
A method of aligning liquid crystal material by bringing into contact with a thin layer of polymer which contains the anthracenyl group, the polymer having previously been treated with plane polarised ultraviolet light. A liquid crystal cell is described wherein each of the substrates defining two opposing cell walls are coated on their inner surface with a suitable polymer for carrying out the invention. A typical embodiment of the invention would have repeat unit (II). ##STR1##
摘要:
A nematic liquid crystal device with two bistable switched states, having two cell walls treated which provide a bigrating on one or both cell walls. The bigrating enables the liquid crystal molecules at a surface to lie in two different angular directions, 45 or 90 degrees apart. The bigrating may be symmetric or asymmetric, with the surface energy of each of the gratings of the bigratings being nearly equal.
摘要:
This invention relates to a photopolymer mixture capable of use for a liquid crystal alignment layer and to an alignment layer formed from such a photopolymer mixture. The mixture comprises at least two polymerisable materials which are blended together in proportion so as to give a predetermined, preferably low, surface energy. A low surface energy, e.g. less than 4×10−2 N/m can result in an alignment layer which imparts a particular orientation to liquid crystal molecules with out requiring any post cure treatments. The polymerisable materials may be monomers, oligomers or diluents that form long chain molecules when cured and the mixture may contain additives to lower the overall surface energy.
摘要翻译:本发明涉及能够用于液晶取向层的光聚合物混合物和由这种光聚合物混合物形成的取向层。 该混合物包含至少两种可聚合的材料,它们按比例混合在一起,以产生预定的,优选低的表面能。 低表面能,例如 小于4×10 -2 N / m可导致定向层,其对液晶分子施加特定取向,不需要任何后固化处理。 可聚合材料可以是固化时形成长链分子的单体,低聚物或稀释剂,并且混合物可以含有添加剂以降低整个表面能。
摘要:
Liquid crystal devices are described that exhibit bistable, tri-stable or other multistable operation. The stable liquid crystal configurations are attained using a surface alignment grating (144) on the internal surface of at least one cell wall (142). The surface profile of the surface alignment grating comprises three or more defect sites per grating period and permit the liquid crystal molecules to adopt any one of two or more stable pretilt angles in the same azimuthal plane. Application of a suitable voltage causes the liquid crystal material to switch between the stable configurations.
摘要:
A bistable nematic liquid crystal device is addressed by application of a row waveform to successive row electrodes of an x, y matrix of pixels whilst one of two data waveforms are applied to each column electrode. The row waveform has a period of two or more time slots (ts), with two dc pulses of opposite amplitude for causing a switching to a dark state, and two dc pulses of opposite amplitude for causing a switching to a light state. The data waveforms have the same period as the strobe with dc pulses of opposite amplitude and combine with the strobe pulses to switch the device. The device can be addressed in two field periods, one field switching to a dark state, the other field switching to a light state. Alternatively, the device can be blanked to the dark state then selectively switched to the light state. When blanking is used, the row waveform has blanking de pulses placed a short time before selective switching to reduce overall addressing time. Zero voltage pulses may be used within the two or more time slot period of the strobe and data waveforms; these reduce rms. voltages appearing at the pixels and enhance contrast ratio.
摘要:
A liquid crystal device comprises a layer of nematic or long pitch cholesteric liquid crystal material contained between two cell walls. One wall (A) carries a surface treatment giving a first azimuthal alignment direction with or without a surface pretilt to liquid crystal molecules. The other wall (B) carries a surface treatment (17) capable of separately providing both a preferred, substantially homeotropic alignment of the adjacent liquid crystal, and a defined azimuthal second alignment direction to the adjacent liquid crystal dependent upon liquid crystal molecular arrangement. The first and second alignment directions are approximately orthogonal. Polarisers may be arranged on either side of the cell walls with their polarisation axes parallel or perpendicular to the two azimuthal directions. Alternatively an amount of dichroic dye may be incorporated in the liquid crystal material, and the device operated with one or two polarisers. The device operates between two different voltage levels, one level providing a non twisted liquid crystal molecular arrangement, the other and higher voltage providing a twisted molecular arrangement.
摘要:
An optical sensing device that incorporates either a surface plasmon-polariton or guided mode apparatus for converting radiation between s and p modes together with a sensor for detecting a maximum in conversion between the s and p modes.
摘要:
A photopolymer mixture is capable of use for a liquid crystal alignment layer. An alignment layer is formed from such a photopolymer mixture. The mixture comprises at least two polymerisable materials which are blended together in proportion so as to give a predetermined, preferably low, surface energy. A low surface energy, e.g., less than 4×10−2 N/m, can result in an alignment layer which imparts a particular orientation to liquid crystal molecules with out requiring any post-cure treatments. The polymerisable materials may be monomers, oligomers, or diluents that form long chain molecules when cured, and the mixture may contain additives to lower the overall surface energy.
摘要:
A method and apparatus for forming a patterned layer having a surface profile that provides relief structures within an electronic device. The method comprises the steps of taking a carrier film (50) having an inverse of the required surface profile formed on one side thereof, taking a layer of fixable material (54) located on a substrate (52), laminating the carrier film (50) and substrate (52) such the carrier film causes the required surface profile to be formed in the layer of fixable material with a predetermined offset, and then fixing the fixable material. Lamination may be performed using rollers (56,58) or a vacuum process. The process is designed to ensure that the offset can be kept as low as possible, preferably to within 150 nm.