摘要:
A liquid crystal is used as the phase modulating medium in a microwave phase modulating cell (20). Applied electric and/or magnetic fields transverse to the direction of wave propagation create a birefringence that changes the velocity of wave propagation and the index of refraction of the medium. The phase modulating cell (20) is used singly or in arrays to direct microwave beams.
摘要:
A composite material (20) has electrically conducting, elongated particles (22) dispersed in a liquid crystal (24). The index of refraction to microwaves is controllable by the application of a transverse electric field that aligns the liquid crystal material (24) and the particles (22). A phase modulating cell (31) is formed by placing the composite material (20) inside a microwave wave guide (32), with transverse electrodes (36) built into the sides of the wave guide (32). Another set of transverse electrodes or magnet pole pieces (30) can be provided to align the liquid crystal material (24) and the particles (22) in another direction, thereby switching the index of refraction of the cell (31). The particles (22) may be made of a ferromagnetic material, to permit magentic as well as electrical switching.
摘要:
Liquid crystals are induced to assume a uniform tilted alignment in the absence of an applied field by treating the surface of a substrate to provide a desired tilted surface microstructure and free hydroxyl groups. A long chain alcohol having the formula ROH, where R is a carbon chain having at least about 6 carbon atoms therein, is chemically reacted with the tilted surface microstructure and the alkoxy groups derived therefrom are chemically bonded to the microstructure. Subsequently introduced liquid crystals assume a tilted-perpendicular alignment at a tilt angle of about 0.5.degree. to about 6.degree.. The liquid crystals exhibit a significantly greater photostability than has previously been achieved. The microstructure is preferably obtained by depositing sequential layers of SiO.sub.x at medium and shallow grazing angles, where x is from 1 to 2, with the substrate rotated 90.degree. between depositions.
摘要:
Liquid crystals are induced to assume substantially perpendicular alignment on the surfaces of substrates used to fabricate electro-optical device by causing long chain alcohols to react in the vapor phases with surface OH.sup.- inherently found on oxide coatings provided on the substrates. The process facilitates liquid crystal alignment in prefabricated electro-optical cells.
摘要:
A number of alkyl and alkoxy-substituted ortho-cyanophenyl biphenylcarboxylate esters have been prepared for use as components for nematic liquid crystal mixtures which can be used in homeotropically aligned, field effect display devices or in dynamic scattering displays.These materials have large negative dielectric anisotropies and high birefringence.
摘要:
New nematic liquid crystal (LC) ester mixtures with relatively short average molecular lengths are made by including one or more binary sets of components which have identical, or nearly identical, molecular lengths. Undesirable solids solution phase effects are avoided by either utilizing appreciable asymmetry in the alkyl end groups or by combining LC esters of different classes.
摘要:
Apparatus for positioning a golf ball on a tee and for retrieving golf balls and tees. A hand-operated apparatus for setting golf balls on tees without requiring the golfer to bend is described. The device may also be used for retrieving golf balls and tees, and may itself be retrieved if dropped by using the handle of a golf club. The apparatus comprises a hollow outer shaft having a fixed handle at one end and a base for pivotably holding two golf ball encircling jaws at the other. An inner shaft, slidably disposed within the outer shaft and connected to a movable handle at one end, and jaw-actuating wires at the other permits a user to operate the jaws with one hand. A coil spring located between the fixed and movable handles provides a force therebetween, keeping the jaws closed in their normal position. A golf ball and tee placed within the jaws may be set in the ground by pushing on the fixed handle, and released from the apparatus, such that the golf ball remains on the tee, by pulling the movable handle against the operation of the spring.
摘要:
A composite material having droplets of a liquid crystal material in a matrix of a coploymer of a multifunctional acrylate, or a mixture of different multifunctional acrylates, and a multifunctional mercaptan is prepared by photopolymerization. The liquid crystal material is initially mixed with a multifunctional acrylate monomer, a multifunctional mercaptan, and a photoinitiator to form a solution. The solution is exposed to ultraviolet light, whereupon the multifunctional acrylate monomer and multifunctional mercaptan copolymerize in a step reaction, and the liquid crystal separates from the copolymer as droplets dispersed throughout the copolymer matrix. The resulting material is placed between transparent, electrically conducting plates to form an electro-optic display device.
摘要:
We have disclosed a new class of thermosetting copolymers derived from terephthalonitrile N,N'-dioxide and polyimide oligomer that cure through addition reactions to form essentially void-free cured resins that exhibit outstanding high temperature stability. These copolymers may be formed from either acetylene terminated polyimide oligomers or nitrile terminated polyimide oligomers. Copolymers prepared in accordance with our invention exhibit little or no outgassing during cure and are extremely useful in the preparation of laminates where high temperature stability and high strength is required.
摘要:
There is disclosed a circularly polarized light source including a circular light polarizer using cholesteric liquid crystal material in an arrangement such that substantially 100% of the unpolarized light input may be utilized in a circularly polarized output in either a narrow band or wide band configuration. The circular polarizer itself comprises one or a plurality of liquid crystal cells having liquid crystal material of a predetermined ratio by weight of cholesteric to nematic liquid crystal type in each cell. The ratio of the types of materials determines a central wavelength to which each cell is tuned in its polarizing action. If a single cell is used, light of a predetermined bandwidth around its central wavelength is polarized. If a plurality of cells are stacked in a sandwich arrangement wherein each cell is tuned to a different wavelength selected in such a sequentially stepped fashion that the bandwidths for the cells form a continuous spectrum, then there is formed a wideband polarizer which can readily encompass the entire visible wavelength region of the spectrum.