Abstract: A component has a substrate (1) made of a transparent material, for example glass. On this layer (1), there is a linear polarizer (2) on which there is a layer (3) of a photo-oriented polymer network (PPN)(-LPP) which is oriented in locally varying fashion via its surface which covers the substrate. The layer (3) is adjoined by an anisotropic layer (4) of cross-linked liquid-crystal monomers. This layer (4) then has a molecular arrangement whose orientation is defined by the underlying orientation layer (3). The layer (4) will have been photocross-linked by exposure to a suitable wavelength of light, with the result that the molecular orientation defined by the PPN layer (3) is fixed. The element, denoted as a whole by 7, can then be used as an optical component which is protected against forgery, it being possible for the orientation pattern of the liquid-crystal layer or the optical information stored therein to be made visible by means of an external polarizer (5), for example.

Abstract: A liquid crystal display has a plurality of image elements, all the image elements are subdivided identically into at least two zones, the zones being formed so that they have different liquid crystal structures, each of the zones of a respective one of the image elements being electrically controllable.

Abstract: An optical component having a hybrid layer structure includes an orienting layer, a further layer in contact with the orienting layer and incorporating a cross-linked liquid crystalline monomer and at least one additional orienting layer on top of the liquid crystalline layer, and preferably includes one additional cross-linked liquid crystalline monomer. The layers have different functions, such as orienting or retarding. At least one of the orienting layers should be a photo-orientating polymer network layer, or have locally varying orienting pattern. These optical components are useful in transmittance and reflective liquid crystal displays, such as rotation cells, STN cells, ferroelectric cells, and cells having an addressable active matrix. Such cells are useful in optical and integrated optical devices, and may be used for safeguarding against counterfeiting and copying in transmission.

Abstract: In one embodiment, the invention relates to compounds of the formula (I) wherein G1 and G2 independently represent a polymerizable mesogenic residue, and X, Sp, and Q are as defined herein. The compounds of the invention may, for example, be useful as curable liquid crystals and for preparing liquid crystal films.

Abstract: A liquid crystal display cell comprising a chiral ferroelectric smectic liquid crystal layer whose helix structure is influenced by the action of an electric field such that its optical anisotropy alters; a pair of transparent plates between which the liquid crystal is disposed and which have a surface structure for aligning the molecule of the liquid crystal and are provided with electrodes to produce an electric field therein; and one polarizer each before and after the liquid crystal, such that a ratio d/p of the thickness d of the liquid crystal layer to the pitch height p of the helical twisting is greater than 5, the smectic tilt angle &thgr;o between 0.39 radians and 0.87 radians and the product d·&thgr;2·&Dgr;n·1/&lgr; (phase factor) of the thickness d, the square of the tilt angle &thgr;°, the value of the birefringence &Dgr;n and the reciprocal of the wavelength &lgr; of light bending is greater than 0.45 radians2.

Abstract: A photoactive polymer of the general formula I: in which: P is a photoactive group which can photoisomerise and/or photodimerise; B represents an aromatic or alicyclic group, or B further represents a nitrogen atom or —CR2—; A, C, D each independently of the other represents an aromatic or alicyclic group; M represents a repeating monomer unit in a homo- or copolymer; S1, S2, S3, S4, S5 represent a single covalent bond or a spacer unit; n1, n2 are each independently a positive integer up to 2 with the proviso that n1+n2≦2; R1 is a hydrogen atom, or a straight-chain or branched alkyl residue wherein R2 represents a hydrogen atom or lower alkyl. The photoactive polymers may be used as orientation layers for liquid crystals and in the construction of unstructured and structured optical elements and multi-layer systems.

Abstract: A method of imparting a property to a material, the property being that cross-linkable monomeric or pre-polymeric liquid crystal molecules which may be placed on the layer would adopt preferred alignment. The method comprises exposing the material to unpolarised or circularly polarised radiation from an oblique direction, wherein the material is, for example, cross-linked by the irradiation, allowing monomeric or pre-polymeric liquid crystal molecules applied to or mixed with the exposed material to adopt the preferred alignment and while aligned cross-linking them. The invention also relates to LCD elements incorporating a preferred alignment.

Abstract: The present invention relates to polymers of the general formula I: in which M1, M1′, M2 denote a recurring monomer unit from the group: acrylate, methacrylate, 2-chloroacrylate, 2-phenylacrylate; w, w1, w2 are molar fractions of the comonomers with 0<w≦1, 0≦w1<1 and 0≦w2≦0.

Abstract: A compound of formula (I): wherein MG1 and MG3 each independently represent an optionally-substituted aliphatic group with 1 to 80 C-atoms, in which one or more C-atoms may be replaced by a heteroatom, in such a way that oxygen atoms are not linked to one another; or an optionally-substituted aromatic or non-aromatic carbocyclic or heterocyclic ring system, with 1 to 80 C-atoms; and MG2 represents a group comprising at least two and up to four optionally-substituted aromatic or non-aromatic carbocyclic or heterocyclic ring systems, with 1 to 80 C-atoms, wherein, when MG2 represents a group comprising four optionally-substituted ring systems, at least three of the ring systems are aligned in between B1 and B2. The groups MG1, MG2 and MG3 in these new “staircase molecules” may be selected so that each one has one or more of the properties which are required in an LCP material prepared by polymerizing the compound.

Abstract: Compounds of formula (I) wherein A, C and D represent (1) or (2), B represents (3) or (4) wherein at least one of the substituents is other than hydrogen and also at least one of the phenylene rings may be replaced by a 1,4-phenylene ring in which one or two non-adjacent CH groups have been replaced by nitrogen; k, l, m are 0 or 1, wherein k+l+m must be equal to 1 or 2; Z1, Z2, Z3 each independently of the others represents a single bond, —CH2CH2—, —CH2O—, —OCH2—, —COO—, —OOC—, —CH═CH—COO—, —OOC—CH═CH—, —(CH2)4—, —O(CH2)3—, —(CH2)3O— or —C≡C—; R1, R2 represent crosslinkable groups, and S1, S2 represent spacer units.

Abstract: A method is provided to align liquid crystals in liquid crystal displays by using photo-crosslinkable low molecular weight materials. The material contains a polymerizable group and a photosensitive group. The material is dissolved in a solvent and is disposed onto a substrate and the solvent is removed. The resulting film is then cured with UV light to cross-link and induce anisotropy in the material. Also, a liquid crystal display that contains an alignment layer that is the is the photo-reaction product of a photo-crosslinkable material that contains at least one polymerizable group and at least one photosensitive group.

Abstract: Orientation layers of monomeric or polymeric liquid crystal layers having any desired azimuthal orientation direction and a tilt angle are produced by irradiating at an angle differing from the normal to the surface photopolymers orienting parallel to linearly polarized light.

Abstract: Optically active butane-1,2,3,4-tetraol derivatives of formula (I). The compounds may be used as doping agents for liquid crystals for a wide range of applications, such as solid state cholesteric filters for projection displays, circular polarizers, and optical filters.

Abstract: A major disadvantage of known reflective displays consists in the fact that they ideally have a switching angle of ±45° in the so-called symmetric mode. With the liquid crystal mixtures known to date, this is not possible without hysteresis effects occurring even at small switching angles and resulting in the switching time being increased to an impermissible extent. The invention relates to a novel reflective, ferroelectric display which can be actuated without DC voltage and has a maximum switching angle &agr; which is ±22.5°. The liquid crystal display according to the invention is distinguished in particular by the fact that a further birefringent element is arranged between the two plates bounding the birefringent liquid crystal layer.

Abstract: A liquid crystal device comprising ferroelectric liquid crystal material aligned by a liquid crystal polymer (LCP) network layer (18) under 20 nm thick, which itself was aligned by a photo-oriented linearly photopolymerized (LPP) layer (16) under 20 nm thick, exhibits low voltage drop over the aligning layer and has a remarkable contrast ratio.

Abstract: Chiral prolinol derivatives of formula (1). The compounds may be used as doping agents for liquid crystals for a wide range of applications, including solid state cholesteric filters for projection displays, circular polarizers and optical filters.

Abstract: Photocrosslinkable, mesogenic mixtures, especially for optical or electro-optical devices, exhibit improved properties when, in addition to containing two or more liquid-crystalline monomers each having at least two terminal polymerizable groups, they contain at least one non-liquid-crystalline monomer having no or, at most, one alicyclic or aromatic structural unit and having at least one terminal polymerizable group.

Abstract: A polarization mask for producing light of locally different polarization from unpolarized or uniformly polarized light. On the light output side, discrete areas with different polarization directions are present, which are either static or switchable. The mask is useful for, among other things, the transfer of polarization pattern onto a PPN layer.

Abstract: An optical component in the form of an identification element (such as for counterfeit protection or copy protection) includes an optically anisotropic layer comprising regions of different optical axes that is arranged over a reflector. The anisotropic layer may be implemented with a liquid crystal polymer in which the orientation of the liquid crystals is different in different areas. Such an orientation pattern is initially hidden from a viewer, but becomes visible by means of an additional polariser. To improve the visual appearance of the identification element, a white light hologram may be used for the reflector.

Abstract: An optical component having a hybrid layer structure includes an orienting layer, a further layer in contact with the orienting layer and incorporating a cross-linked liquid crystalline monomer and at least one additional orienting layer on top of the liquid crystalline layer, and preferably includes one additional cross-linked liquid crystalline monomer. The layers have different functions, such as orienting or retarding. At least one of the orienting layers should be a photo-orientating polymer network layer, or have locally varying orienting pattern. These optical components are useful in transmittance and reflective liquid crystal displays, such as rotation cells, STN cells, ferroelectric cells, and cells having an addressable active matrix. Such cells are useful in optical and integrated optical devices, and may be used for safeguarding against counterfeiting and copying in transmission.