Abstract: The display in a diffusion type electrochromic display device is turned off with high response by applying an A.C. input voltage having a frequency of one to ten times as high as the cut-off frequency. The diffusion type electrochromic display device is an EC display device which uses an EC composition consisting of an EC compound coloring in a reduced state and a solvent in which the solubility of the compound to the solvent is 10.sup.-2 mol/(100 g solvent) or more in a reduced state and 10.sup.-1 mol/(100 g solvent) or more in an oxidized state. The cut-off frequency is a critical frequency at a freqency higher than which the oxidization or reduction of the EC compound cannot follow the change in the input voltage, which is normally 20 to 50 Hz.

Abstract: A liquid crystal electro-optical element which comprises a nematic liquid crystal composition having a positive dielectric anisotropy which is composed of p-n-alkylbenzylidene-p'-cyanoaniline and an improver selected from the group consisting of p-n-alkyl cyanobenzene, p-alkylbenzylidene-p'-alkoxyaniline, and p-alkoxybenzylidene-p'-n-alkylaniline.

Abstract: By incorporating at least one of p-n-alkylcyanobenzene, p-cyanobenzylideneaniline and p-cyanophenyl p'-n-octyloxybenzoate into a Schiff base type nematic liquid crystal composition having negative dielectric anisotropy, a nematic liquid crystal composition having positive dielectric anisotropy is obtained. The nematic liquid crystal composition of the latter exhibits a liquid crystal state in a broad temperature range including room temperature and is useful for a torsion effect type electrooptical display device which can operate at low voltages.

Abstract: In a structure comprising a pair of facing electrode plates and a layer of a nematic liquid crystal having a positive dielectric anisotropy, which is supported between said facing electrode plates, when each of the electrode surfaces coming into contact with the nematic liquid crystal layer is provided with a coating of poly-p-xylylene and/or its substituted product and the surface of said coating is furnished with a predetermined orientation, a liquid crystal device of the torsion effect type having good electro-optical characteristics is provided. When a layer of an epoxy resin or silane coupling agent is formed between the coating of the poly-p-xylylene type resin and the electrode surface, the adhesion of the poly-p-xylylene type resin coating is improved.

Abstract: In a liquid crystal display device comprising a pair of opposed electrode-mounted plates and a nematic liquid crystal layer, the electrode terminals are mounted on one plate by transferring the connection of one electrode to the opposite plate without directly contacting the liquid crystal material by interposing an electrically conductive material between the corresponding electrode terminal and the one electrode. In accordance with changes of environment, distinct patterns are obtained by making the front electrode of the liquid crystal display element transparent and the back electrode thereof a partial light-transmissive, mirror-like plane. The life of the liquid crystal element under application of D.C. field is increased by using titanium, zirconium and palladium as an essential component of the negative electrode of said element.

Abstract: In a liquid crystal display device comprising a pair of opposed electrode-mounted plates and a nematic liquid crystal layer, the electrode terminals are mounted on one plate by transferring the connection of one electrode to the opposite plate without directly contacting the liquid crystal material by interposing an electrically conductive material between the corresponding electrode terminal and the one electrode. In accordance with changes of environment, distinct patterns are obtained by making the front electrode of the liquid crystal display element transparent and the back electrode thereof a partial light-transmissive, mirror-like plane. The life of the liquid crystal element under application of D.C. field is increased by using titanium, zirconium and palladium as an essential component of the negative electrode of said element.