The inner surfaces of a pair of substrates of a liquid crystal display are treated with a solution of a surfactant to provide a uniform stable alignment of the liquid crystal material confined between the inner surfaces. The inner surfaces are first wetted by the soluton of the surfactant, a silane derivative, and the solution is then heated, while the inner surfaces are in contact with the solution, to a temperature between about 75.degree.C and a temperature just below the boiling point of the solution.
A guest-host liquid crystal display device has tilted homeotropic orientation using a nematic liquid crystal having negative dielectric anisotropy as a host and a dichroic dye as a guest which is prepared by overcoating an inorganic insulating layer; treating said layer to provide orientation; and treating the layer with a silane surfactant.
A liquid crystal display device comprising two substrates being provided in parallel to each other at a given distance and each having a Nesa film on the counterposed surface, at least one of the substrates being transparent, and a liquid crystal being filled between the substrates, the counterposed surfaces of the substrates each being coated with polymer of organosilicone compound having groups reacting with the substrates to a thickness of 300-1,500 .ANG. as an alignment film. The device has thick alignment films and good electrooptical characteristics.
An orientation layer for liquid crystal display devices is formed from an organic tin compound of the type: wherein R is an organic radical; X is a reactive residual radical and n is an integer ranging from 1 to 3, by applying such organic tin compound onto a free surface of a carrier plate of a liquid crystal display device and generating the desired layer. In a preferred embodiment, the organic radical is an alkyl and the reactive residual radical is chlorine. In a preferred embodiment, the orientation layer is applied via an immersion technique wherein a select organic tin compound is dissolved in a suitable organic solvent, applied to a carrier plate surface and thereafter dried at somewhat elevated temperatures. The so-obtained orientation layer is stable, strongly adherent to its substrate and gives adjacent liquid crystal molecules a specific angle of incidence, whose size depends on the selected tin compound as well as on the liquid crystal material utilized and can range between about 20.degree. and 90.degree.. Smaller angles of incidence can be obtained by rubbing the orientation layer. These orientation layers can also be made electrically conductive by doping and subsequent pyrolysis. In this manner, transparent electrodes and orientation layers for liquid crystal display devices can be produced from substantially identical starting materials and with very similar production conditions.
A holding plate for a liquid crystal having an electrode on the side contacting with the liquid crystal, characterized in that the plate is coated with a film comprising a certain specific silane compound, which is to be incorporated into a liquid crystal indication apparatus and assures a good homogeneous orientation of the molecules of the liquid crystal at the initial stage (i.e. in a non-excited state).
Homeotropic surface alignment is provided in liquid crystal display cells, utilizing high temperature peripheral sealing material, by fabricating the empty cell prior to introducing a solution of a homeotropic-aligning surfactant dissolved in a volatile solvent. The solvent is evaporated to provide a surfactant film on the cell cavity interior surfaces. The cell is then filled with the liquid crystal material and the cell is sealed.
