Abstract: First display electrodes are formed on a first electrode substrate. Second display electrodes are formed on a second electrode substrate in such a direction as to intersect at right angles with the first display electrodes. In order to obtain a liquid crystal display device provided with a screen having a large contrast ratio, masking films for intermittently masking regions between the display electrodes, formed on at least one of the first electrode substrate, and the second electrode substrate are formed on the display electrodes on the other electrode substrate.

Abstract: An improved supertwisted nematic liquid crystal display device which comprises a pair of glass substrates each having an electrode and an orientation film formed on the surface of the electrode, and a liquid crystal composition comprising a specific base liquid crystal and optically active substance added thereto and interposed between the glass substrates so that the liquid crystal molecules have a twist angle .phi. of 210.degree. to 270.degree..

Abstract: A colored liquid-crystal display device comprising a positive dielectric anisotropy nematic liquid-crystal layer with the dielectric constant anisotropy, the liquid-crystal layer having an optically active substance; a pair of electrode substrates facing each other and sandwiching therebetween the positive dielectric anisotropy nematic liquid-crystal layer in such a manner that the positive dielectric anisotropy nematic liquid-crystal is formed into a twisted structure with a fixed angle of twist of the liquid-crystal molecules, .phi., of the positive dielectric anisotropy nematic liquid-crystal layer in the direction of a thickness d of the positive dielectric anisotropy nematic liquid-crystal layer; and a polarizer and a analyzer positioned outside of the pair of electrode substrates, respectively, wherein the twist angle .phi. is set to be in the range of 180.degree. to 300.degree. and the product of the refractivity anisotropy .DELTA.

Abstract: There is provided a liquid crystal display device which includes: a double-layered-type liquid crystal cell. The cell is composed of a first cell layer and a second cell layer. The liquid crystal cell contains liquid crystal molecules with a twisted nematic orientation therein. Further, a voltage applying device is in the first cell layer. The dependency of the birefringence on the wavelength of light of the first cell layer is larger than that of the second cell layer. Accordingly, the liquid crystal display device produces a distinct and clear color image, and is useful for full-color display and multicolor display.

Abstract: A liquid crystal display comprising two substrates and a nematic liquid crystal present between said two substrates, wherein each of said substrates comprises a glass plate, an electrode thereon and an aligning layer subjected to a molecular aligning treatment for a pretilt angle of 1.degree. to 30.degree. on the electrode, wherein an optically active material is added to the nematic crystal which has a positive dielectric anisotropy, wherein the average alignment direction in the longer direction of said liquid crystal molecule is twisted at an angle .phi. of 210.degree. to 300.degree. to impart a spiral structure to the liquid crystal and a ratio d/p of the spiral pitch p of the liquid crystal molecule and the liquid crystal thickness d are(.phi./360-1/4)<d/p<.phi./360;an improvement being present in that the nematic liquid crystal contains one or more compounds represented by the following formula (I) in an amount of not less than 10% by weight: ##STR1## wherein n.sub.1 and n.sub.

Abstract: A liquid-crystal display device of the twisted nematic type which comprises (1) a pair of electrode substrates facing each other, each being provided with an orientation membrane, the surface of which is treated by rubbing, and (2) a specific nematic liquid-crystal composition having a positive dielectric anisotropy containing a pyrimidine derivative of formula (I), ##STR1## wherein R.sub.1 and R.sub.2 are each a straight-chain alkyl group of 1 to 12 carbon atoms and containing an optically active substance, sandwiched between the two electrode substrates and arranged so that the axes of the liquid-crystal molecules will be twisted by an angle .phi. in the range of 210.degree..ltoreq..phi..ltoreq.300.degree., which shows excellent multiplex driving characteristics and suitable for use in display units of heavy-duty multiplex driving type.

Abstract: The twisted nematic liquid crystal display device of this invention relates to a liquid crystal cell having a twisted spiral structure by disposing a pair of substrates opposedly to each other with the rubbed orientation films formed on the electrodes, placing a nematic liquid crystal having a positive dielectric anisotrophy containing an optically active substance between this pair of substrates, and shifting the orientation direction of the liquid crystal molecules by a specified angle of .phi. on both substrates, in which the angle .phi. is set in a range of 210.degree..ltoreq..phi..ltoreq.300.degree., and the ratio d/p of the spiral pitch p of the liquid crystal molecules to layer thickness d of the liquid crystal cell is set in a range of (.phi./360-1/4)<d/p<.phi./360.