Abstract: A heat resistant polymer composition, an alignment layer formed using the same, and an LCD having the alignment layer are provided. The heat resistant polymer composition includes 10-25% by weight of a polyimide resin or polyamic acid, 0.1-1% by weight of an adhesive agent, and balance of a solvent. The adhesive agent improves thermal stability. Thus, the LCD having the alignment layer formed using the same can accomplish a desirable pre-tilt angle of liquid crystals and desirable alignment properties of liquid crystal molecules.

Abstract: A treating agent for liquid crystal alignment useful for formation of a liquid crystal alignment film obtained by coating a film on a substrate equipped with transparent electrodes, baking the film, and subjecting the film surface to a rubbing treatment, wherein the treating agent for liquid crystal alignment contains a polyimide precursor containing a repeating unit of the formula (I) and a solvent-soluble polyimide resin containing a repeating unit of the formula (II), and at least 1 mol % of R.sub.4 of the solvent-soluble polyimide resin of the formula (II) being a bivalent organic group constituting a diamine which has a long-chain alkyl group or fluorine-containing alkyl group with a carbon number of at least 6, and the solvent-soluble polyimide resin of the formula (II) being from 1 to 80% by weight based on the total polymer weight: ##STR1## (wherein each of R.sub.1 and R.sub.2 is a tetravalent organic group which constitutes tetracarboxylic acid or its derivative, each of R.sub.2 and R.sub.

Abstract: A process for inducing pre-tilt in alignment of a liquid crystal medium comprising exposing at least one optical alignment layer, comprising anisotropically absorbing molecules and hydrophobic moieties, to polarized light; the polarized light having a wavelength within the absorption band of said anisotropically absorbing molecules; wherein the exposed anisotropically absorbing molecules induce alignment of the liquid crystal medium at an angle + and -.theta. with respect to the direction of the polarization of the incident light beam and along the surface of the optical alignment layer, and induce a pre-tilt at an angle .PHI. with respect to the surface of the optical alignment layer and applying a liquid crystal medium to said optical alignment layer, is described. The invention also is directed to liquid crystal display elements made by the process of the invention and to novel polyimide compositions that are useful as optical alignment layers in the invention.

Abstract: A polyimide alignment film based on pyromellitic dianhydride and a bis(4-aminophenoxy) aromatic compound, such as 1,3-bis(4-aminophenoxy)benzene or 1,4-bis(4-aminophenoxy)benzene, providing low tilt angles of from 1 to 2 degrees when used in liquid crystal displays.

Abstract: A liquid crystal display (LCD) includes first and second LCD panels in an opposed relationship defining a space therebetween. A respective one of the first and second LCD panels includes a substrate and two alignment layers on the substrate. A plurality of alignment regions are formed on the alignment layers which define a plurality of pixel areas, a respective one of the pixel areas having a first alignment surface on a first alignment region, the first alignment surface being operative to align molecules of a liquid crystal material in contact therewith toward a first direction, and a second alignment surface on an exposed portion of the second alignment layer disposed laterally adjacent the first alignment region, the second alignment region being operative to align molecules of the liquid crystal material in contact therewith toward a second direction opposite the first direction.

Abstract: A crosslinking type liquid crystal polymer, an oriented crosslinking film thereof, and a method of producing the oriented crosslinking film are disclosed. The crosslinking type liquid crystal polymer comprises a liquid crystal polymer containing a polyfunctional azide compound represented by the following formula (A);R.sup.1 --(N.sub.3).sub.n (A)wherein R.sup.1 represents an organic group and n represents an integer of from 1 to 5.

Abstract: Photosensitive orientation material providing unidirectional LC alignment to generate a high pretilt angle for various LC compounds, and superior thermal stability, and being suitable for mass production, especially for active matrix LC displays, including polysiloxane, and a derivative of a cinnamoyl group.

Abstract: A chiral smectic liquid crystal device with good planar homogeneity in a layer normal direction can be constituted by disposing a chiral smectic liquid crystal having no cholesteric phase between a pair of substrates having mutually different characters, particularly in terms of Iso-SmA phase transition temperature. The liquid crystal may preferably have a layer spacing-changing characteristic such that it provides a layer spacing d.sub.A at a first transition point where the layer spacing of the liquid crystal begins to decrease on temperature decrease in the vicinity of a transition temperature from SmA phase to SmC* phase and a layer spacing d.sub.min at a second transition point where the layer spacing of the liquid crystal begins to increase on further temperature decrease from the first transition point, satisfying 0.96.ltoreq.d.sub.min /d.sub.A.

Abstract: A liquid crystal device is constituted by a pair of oppositely disposed substrates having opposing inner surfaces and opposing electrodes thereon, and a chiral smectic liquid crystal assuming two stable states disposed between the opposing electrodes. The opposing inner surfaces of the pair of substrates have been subjected to an aligning treatment such that the liquid crystal placed in one of the two stable states moves under application of an electric field in a direction identical to one in which the liquid crystal placed in the other of the two stable states moves under the application of the electric field. The liquid crystal device has an effective optical modulation region and a peripheral region outside the effective optical modulation region, wherein the effective optical modulation region and the photosensitive member have been subjected to different aligning treatments.

Abstract: The invention provides optical modulation devices and displays of the DHFLCtype having a high contrast. Said modulation devices comprise a first substrate and a second substrate which are positioned substantially parallel to each other and which are provided, on their facing surfaces, with, in succession, an electrode layer and an orientation layer. This advantageous effect is achieved by using different orientation layers, the surfaced energy of the orientation layer of the first substrate being different from the surface energy of the orientation layer of the second substrate, said difference in surface energy being at least 5 mN/m. The orientation layer having the high surface energy is preferably made from rubbed polyimide, and the orientation layer having the low surface energy is preferably made from unrubbed polyorganosilsesquioxane. The optically active layer of the modulation devices in accordance with the invention exhibits a "tilted-bookshelf" structure.

Abstract: A liquid crystal display device permitting low voltage driving which presents good display quality for a long time and excellent characteristics in low power consumption when voltage is supplied at a high temperature of about 50.degree. C. under a driving condition of a low frequency of 200 or less in terms of the number of polarity inversion per second. The display device includes a liquid crystal composition in which the voltage corresponding to 50% threshold value is 1.5 V or less is selected, and a fluorine-containing polymer material such as a fluorine-containing polyimide is used.

Abstract: A method for the formation of orientation film of a liquid crystal display. The method comprises the steps of forming polyvinyl-4-fluorocinnamate (hereinafter "PVCN-F") film on the surfaces of two opposite substrates and irradiating the two PVCN-F films formed with linearly polarized UV lights having different energy. The method in accordance with the present invention is capable of not only providing the pretilt angle to a fabricated LCD but also adjusting it by illuminating two substrates with linearly polarized UV beams having different energies from each other, respectively. In addition, the LCD fabricated by the method according to the present invention requires a much lower driving voltage, as compared with the conventional LCD having an orientation film of planar structure. Furthermore, phase distortion and light scattering phenomena do not occur in the LCD, so that display characteristics such as contrast and the like can be improved.

Abstract: A liquid crystal device is constituted by a pair of substrates at least one of which is provided with an alignment control film, and a liquid crystal composition disposed between the substrates and contacting the alignment control film. The alignment control film comprises an amide polymer and a pyridine-based polymer. The liquid crystal device using a mixture alignment control film described above is effective in improving a switching characteristic by minimizing a depolarization field while keeping a uniform alignment characteristic.

Abstract: Aligning films formed on electrode plates of a liquid crystal cell containing an antiferroelectric liquid crystal are each made of a polyimide film represented by the following chemical formula: ##STR1## wherein x.sub.1 and Y.sub.

Abstract: In a ferroelectric liquid crystal display comprising a pair of transparent substrates each provided with a transparent electrode and an aligning film and a liquid crystal layer sandwiched between said substrates, the aligning film is subjected to a deionization treatment with, for example, an ion-exchange resin to reduce the total content of impurity ions in the aligning film of a polyimide resin or the like to 300 ppm or less, to reduce the total content of impurity cations to 200 ppm or less, to reduce the total content of Cl.sup.-, (COO.sub.2).sup.2- and CH.sub.3 COO.sup.- to 100 ppm or less and the content of each of these ions to 50 ppm or less, or to reduce the total content of PO.sub.4.sup.3-, NO.sub.3.sup.- and SO.sub.4.sup.2- to 100 ppm or less and the content of each of these ions to 50 ppm or less.

Abstract: A single substrate polymeric cholesteric liquid crystal (CLC) device useful in display applications such as for high efficiency polarizers and color filters is created by a process that coats a first substrate with a polyimide layer and a second substrate with an amorphous fluoropolymer layer. Both layers are buffed and liquid CLC material is placed between the grooved layers. After annealing, the amorphous fluoropolymer coated substrate is removed, leaving the CLC material bonded to a single substrate.

Abstract: A liquid crystal device is constituted by disposing a liquid crystal between a pair of substrates; at least one of which has thereon an alignment film comprising a polyimide formed by reaction between at least two acid components including an acid component of formula (1) below and at least one component of formula (2) or (3) below and a diamine component of formula (4) below: ##STR1## wherein R.sub.1 and R.sub.2 independently denote an alkyl group.

Abstract: A liquid crystal display device having a matrix of pixels in driven for gradational display with better temperature compensation and better flicker suppression by a driving method, wherein (a) a first voltage signal is applied to a pixel on a selected scanning line, the first voltage signal including a clear pulse, a writing pulse of a polarity opposite to that of the clear pulse and a correction pulse of a polarity opposite to that of the writing pulse, (b) a second voltage signal is applied to an associated pixel on a subsequent scanning line, the second voltage signal including a clear pulse, a writing pulse and a correction pulse of which polarities are respectively opposite to corresponding pulses of the first voltage signal, and (c) the correction pulse applied to the pixel on the selected scanning line is determined based on gradation data for the associated pixel on the subsequent scanning line, and the writing pulse applied to the pixel on the selected scanning line is determined based on gradation d

Abstract: A liquid crystal device is constituted by a first substrate and a second substrate disposed opposite to each other, and a liquid crystal lacking cholesteric phase disposed between the first and second substrates. The first substrate has a surface contacting the liquid crystal showing a surface energy .gamma..sub.1 (dyne/cm) and the second substrate has a surface contacting the liquid crystal showing a surface energy .gamma..sub.2 (dyne/cm) satisfying .gamma..sub.1 >.gamma..sub.2. The surface of the first substrate is provided with a film of a polyimide or an aromatic polyamide, and the surface of the first substrate having been selectively subjected to a uniaxial aligning treatment. As a result, the liquid crystal can assume a stable alignment state of a bookshelf structure or one close thereto having a small layer inclination angle. The resultant device can show a high contrast and a good responsiveness.

Abstract: The object of the present invention is to provide an alignment layer material for forming a liquid crystal alignment layer having an excellent adhesion to a glass substrate, having less dependency of display characteristics on the viewing angle with a high contrast.(Constitution)A composition used for an alignment layer material comprising a mixture of a polymer (A) which is a block copolymer containing a siloxane compound as a constituting component, and a homopolymer or copolymer (B) having the following repeating unit (1): ##STR1## is disclosed.

Abstract: A liquid crystal device having a first substrate on which a first group of belt-shaped electrodes are formed, a second substrate on which a second group of belt-shaped electrodes are formed so as to cross the first group of belt-shaped electrodes, and a chiral smectic liquid crystal arranged between the first and second substrates, wherein a first orientation film formed on the first group of belt-shaped electrodes and second orientation films formed in spaces among the belt-shaped electrodes are different.

Abstract: A liquid crystal device is formed by disposing a chiral smectic liquid crystal between a pair of substrates, each having thereon a group of electrodes for driving the chiral smectic liquid crystal and an alignment control film comprising a fluorine-containing polyimide provided with a uniaxial rubbing axis such that the uniaxial alignment axes provided to the pair of substrates intersect each other at a prescribed intersection angle. In the device, the liquid crystal molecules are aligned to provide a director forming a pre-tilt angle with the polyimide film surfaces of the substrates, whereby formation of splay alignment state in the chiral smectic liquid crystal molecules is suppressed. The liquid crystal device provides an improved contrast and also a broad drive margin.