Abstract: The commercial production of DHF (Deformed Helix Ferroelectric) cells, in particular DHF color display cells, has scarcely become established to date. This is in particular because the DHF cells required for this purpose and based on the known prior art have short switching times and a good angular range of view but relatively high voltages and currents are required for their operation. Moreover, for the production of a DHF cell, the liquid crystal mixture must additionally be oriented or formatted by means of an electric field. The present invention relates to a ferroelectric display cell which does not have these disadvantages and in particular is distinguished by the fact thatthe display is dark at U=0 and bright at .vertline.U.vertline.>0,the current-voltage hysteresis characteristic has two maxima of equal size,the birefringence .DELTA.n in the field-free state is greater than that in the saturated state andthe saturation voltage is relatively low even with very small spontaneous polarization P.sub.

Abstract: This invention provides a liquid crystal achromatic polarization rotator switch, and an achromatic shutter using the rotator switch. The rotator switch requires input light of a fixed orientation and switches between rotating the polarization by zero degrees and by a fixed angle, .beta.. The achromatic shutter uses an achromatic 90-degree rotator switch positioned between a pair of polarizers. A first embodiment of the rotator switch comprises one planar-aligned rotatable smectic liquid crystal half-wave retarder in series with one passive half-wave retarder. The smectic liquid crystal cell has fixed retardance and is driven between two orientations for off- and on-states. A second embodiment of the rotator switch utilizes two variable birefringence liquid crystal cells. The variable birefringence cells having fixed orientation and variable retardance. In the off-state both retarders have zero retardance and in the on-state they have half-wave retardance.

Abstract: A thin film of ferroelectric layered superlattice material in a flat panel display device is energized to selectively influence the display image. In one embodiment, a voltage pulse causes the layered superlattice material to emit electrons that impinge upon a phosphor, causing the phosphor to emit light. In another embodiment, an electric potential creates a remanent polarization in the layered superlattice material, which exerts an electric field in liquid crystal layer, thereby influencing the transmissivity of light through the liquid crystal. The layered superlattice material is a metal oxide formed using a special liquid precursor containing an alkoxycarboxylate. The thin film of layered superlattice material is formed using a spin-on technique and low-temperature heat treating. The thin film thickness is preferably in the range 500-1400 .ANG. so that polarizability and transparency of the thin film is enhanced.

Abstract: A liquid crystal device is constituted by a pair of substrates each having thereon an electrode, and a smectic liquid crystal having a plurality of smectic liquid crystal layers disposed between the substrates. The smectic liquid crystal is disposed to form a first region wherein the smectic liquid crystal layers are aligned to have a layer inclination angle smaller than a calculated layer inclination angle based on a temperature-dependent layer spacing-changing characteristic or are aligned in a direction perpendicular to the substrates to form a bookshelf structure, and a second region wherein the smectic liquid crystal layers are aligned to form a chevron structure having a substantial layer inclination angle or having a layer inclination angle substantially equal to a calculated layer inclination angle based on a temperature-dependent layer spacing-changing characteristic.

Abstract: A manufacturing method includes a process of once heating a liquid crystal material to a temperature at which an isotropic phase appears therein and then cooling the liquid crystal material, the liquid crystal material being a ferroelectric liquid crystal or antiferroelectric liquid crystal, to be performed under an applied AC electric field which generates an electroclinic effect in a temperature range of from a temperature 20.degree. C. above a phase transition temperature at which a transition in phase occurs from a smectic A phase to a chiral smectic C phase to a temperature 20.degree. C. below the phase transition temperature.

Abstract: Disclosed is a liquid crystal device comprising a liquid crystal cell filled with a liquid crystal material capable of exhibiting a smectic phase, said cell including upper and lower substrates each having in order an electrode and an orientation film in contact with the liquid crystal material, a cross angle e formed by the orientation treatment directions of the orientation films is 180.degree.-.delta. or 360.degree.-.delta. (0.degree.<.delta..ltoreq.90.degree.). Also disclosed is a process for preparing the above-mentioned liquid crystal device comprising treating the orientation films and preparing the liquid crystal cell so as to have the orientation treatment directions of the orientation films form the cross angle .THETA. within the above range in the cell.

Abstract: A polymer having spontaneous polarization with the same codes as liquid crystal is introduced into a liquid crystal layer of the smectic liquid crystal cell so that the responding speed is improved (second liquid crystal cell). In another way, a polymer having spontaneous polarization with opposite codes to the liquid crystal is introduced into liquid crystal showing .tau.-V.sub.min characteristic so that a driving voltage is lowered (first liquid crystal cell). These polymers are previously added to a liquid crystal composite before injecting into the liquid crystal cell. In another way, after a photochemically polymeric monomer is added to the liquid crystal composite and the obtained product is injected into the liquid crystal cell, the monomer is polymerized by the projection of a light. Furthermore, the liquid crystal cell into which the polymer is introduced is heated again so as to show I phase and is cooled so that the tone display is realized.

Abstract: Disclosed and claimed is a liquid crystal mixture, a liquid crystal device and a display device using the liquid crystal mixture. The liquid crystal display device according to the present invention has improved contrast due to the specific temperature of the liquid crystal mixture. More specifically, the liquid crystal mixture has a temperature range generating a chiral smectic C phase and a temperature range generating a smectic A phase, and having a difference between the cone angle at (T.sub.C/A -10).degree. C. and the cone angle at (T.sub.C/A -40).degree. C. in the temperature range generating the chiral smectic C phase of from zero (0) degree to ten (10) degrees.

Abstract: A liquid crystal display according to this invention has a pair of transparent electrodes, a non-chiral smectic liquid crystal therebetween, a polarizer and an analyzer which are attached to the electrodes. The smectic layers are perpendicular to the electrodes and the liquid crystal has a twisted structure where the twist angle is twice the molecular tilt angle. In this configuration, the molecular director is forced to continuously rotate along the cone surface formed by the requirement that the molecules are tilted with respect to the layer normal and pinned at the surfaces. The basic principles of the optical modulation in the present invention are similar to those in twist nematic liquid crystal structures.

Abstract: A liquid crystal device is constituted by (a) a pair of base plates each having an orientation control film thereon, and (b) a liquid crystal composition interposed between the base plates. The liquid crystal composition comprises a mixture including at least one liquid crystal compound which has a temperature range in which it shows chiral smectic phase and at least one optically active substance which does not have a temperature range in which it shows chiral smectic phase. The liquid crystal composition has a temperature range in which it shows cholesteric phase and is placed in chiral smectic phase which has been formed through cholesteric phase on temperature decrease. The liquid crystal composition comprises liquid crystal molecules having long axes forming a pre-tilt in the chiral smectic phase.

Abstract: Disclosed is a liquid crystal device comprising a liquid crystal cell filled with a liquid crystal material capable of exhibiting a smectic phase, said cell including upper and lower substrates each having in order an electrode and an orientation film in contact with the liquid crystal material, a cross angle .THETA. formed by the orientation treatment directions of the orientation films is 180.degree.-.delta. or 360.degree.-.delta. (0.degree.<.delta..ltoreq.90.degree.). Also disclosed is a process for preparing the above-mentioned liquid crystal device comprising treating the orientation films and preparing the liquid crystal cell so as to have the orientation treatment directions of the orientation films form the cross angle .THETA. within the above range in the cell.

Abstract: A liquid crystal panel has a memory function that is reliable for a long time. The panel employs a ferroelectric or antiferroelectric liquid crystal material involving at least two kinds of layer structures of minimum energy. The layer structures are defined at least by (1) a c-director parameter that is in parallel with substrates of the panel and has at least one minimal value, or (2) an a-director parameter that is orthogonal to the substrates and has at least one maximal value. Due to these layer structures, the panel is stable, resistant to mechanical and electrical stress, reliable in operation, and excellent in memory function.

Abstract: A ferroelectric liquid crystal display device according to the present invention includes: a pair of substrates disposed so as to oppose each other, at least one of the pair of substrates being transparent; electrodes formed on an inside face of each of the pair of substrates; and a display medium for displaying an image, the display medium being divided into at least one liquid crystal region composed essentially of ferroelectric liquid crystal and a polymer region composed essentially of liquid crystalline polymer, and the display medium being controlled by applying a voltage to the electrodes.

Abstract: The present invention relates to obtain an electrooptical device having a high response speed by using a spontaneously polarized ferroelectric liquid crystal. Spontaneously polarized ferroelectric liquid crystal in the smectic-A state is sealed into a proper transparent case. An electric field is applied perpendicularly to a light path direction so as to change the orientation directions of liquid crystal molecules, thereby changing the refractive index distribution. A liquid crystal electrooptical device having both deflection and focusing functions is provided by adjusting the shape of the electrodes while maintaining the polarization state of an input light beam.

Abstract: This invention provides a phase modulator comprising an electro-optically rotatable smectic liquid crystal half-wave retarder in combination with a cholesteric liquid crystal circular polarizer. Rotation of the half-wave retarder varies the phase delay of the modulator. A polarizing interferometer is provided utilizing the phase modulator of this invention in combination with a second cholesteric circular polarizer and a linear polarizer. A tunable Fabry-Perot resonator which does not require ordinary mirrors is provided utilizing the phase modulator of this invention in combination with a second cholesteric circular polarizer.

Abstract: Multiplex addressed ferroelectric liquid crystal devices containing liquid crystal mixtures composed of components A, B and C. Component A consists of one or more optically active compounds capable of imparting a spontaneous polarization to the material. Component B is a compound or compounds of the formula: ##STR1## where R.sub.1 and R.sub.2 independently represent straight or branched chain C.sub.3 -C.sub.12 alkyl or alkoxy groups, a, b and c are independently 0, 1 or 2 and the total of a+b+c is not greater than 4. Component C is selected from a range of liquid crystal components.

Abstract: Ferroelectric liquid-crystal systems having high spontaneous polarization, in particular >35 nC cm.sup.-2, and good orientation properties in the ferroelectric phase, in particular the S.sub.C * phase, contain at least three different optically active compounds, preferably as dopes in a base mixture which is not itself optically active and has a nematic phase above the smectic phase. The optically active compounds are selected so that they do not all induce a helix of the same rotation sense in the nematic phase. Their relative concentrations are selected so that the total resultant pitch of the helix throughout the cholesteric phase is not less than 10 .mu.m.

Abstract: An optically inactive mesomorphic compound represented by the following formula (I): ##STR1## wherein R denotes a linear or branched alkyl group having 1-18 carbon atoms or a linear or branched alkoxy group having 1-18 carbon atoms; and m is an integer of 2-18, is suitable as a component for a liquid crystal composition providing improved response characteristics and a high contrast. A liquid crystal device is constituted by disposing the liquid crystal composition between a pair of substrates. The liquid crystal device may preferably be used as a display panel constituting a liquid crystal apparatus providing good display characteristics.