Other

Kent State University

S.t. Lagerwall S.a.r.l.

Ecsibeo Ab

Japan Science and Technology Agency

Ecsibeo Ppf2 Ab

Ecsibeo Ppfi Ab

Lachezar Komitov

Uvis Light Ab

Komitov, Lachezar

Liang-Chy Chien

Sven T Lagerwall

Sang Hwa Kim

Bertil Helgee

Gunnar Andersson

Bengt Stebler

Kent Skarp

Ingolf Dahl

Jun Yamamoto

Dietrich Demus

Hiroshi Yokoyama

Qiu-Hong Hu

Nils Olsson

Andriy Kozachenko

Kurt Flatischler

Gurumurthy Hegde

Seung Hee Lee

Torbj&ouml;rn Lagerwall

A liquid crystal device comprising a first substrate; a second substrate; and a liquid crystal layer sandwiched between the first substrate and the second substrate, the liquid crystal layer comprising a nematic liquid crystal material and a polymer network. The polymer network is anchored to said first substrate and is configured to alternatingly induce splay deformation and bend deformation of the nematic liquid crystal material along a line parallel with the first substrate. Hereby, the relaxation time &#x3c4;of the liquid crystal device is reduced.

Polymer network stabilized flexoelectric polarization

In a preparation method, a chiral or cholesteric liquid crystal, a photoreactive monomer, and a photoinitiator are disposed in a liquid crystal cell. A principal surface of the liquid crystal cell is illuminated with ultraviolet light selected to have a non-uniform ultraviolet light intensity profile in the liquid crystal cell. The illuminating cooperates with the photoinitiator to polymerize at least a portion of the photoreactive monomer near the principal surface to generate a polymer network having a density corresponding to the non-uniform ultraviolet light intensity profile. The polymer network biases the liquid crystal toward a selected helical alignment direction. In some embodiments, the illuminating includes illuminating with first and second ultraviolet light intensity profiles to produce surface and volume polymer network components.

Method of fabricating electro-optical devices with polymer-stabilized liquid crystal molecules

A liquid crystal device is provided, having one or several display segments, a first display substrate, a second display substrate, a layer of liquid crystal material disposed between the first and second substrate; and layer of conductive material disposed on the substrates. The conductive layers form electrodes for applying an electric field across the liquid crystal for switching the liquid crystal material between a first optical state and a second optical state different from the first optical state. Image features of the display are further defined by the inclusion of a layer of patterned non-conductive or passive dielectric material on at least one of the substrates, the patterned material forming a mask defining image elements of the display segments.

Cholesteric liquid crystal display (LCD) device, and method for its production

An electro-optic device including a liquid crystal material is disclosed, comprising antiferroelectric liquid crystals with large molecular tilt &#x3b8; of about 45&#xb0; degrees, disposed between two flat glass or polymer substrates. The liquid crystal molecules are preferably oriented parallel to the substrates (so-called HAF texture). The device is e.g. placed between two crossed polarizers so that in field-off conditions the impinging light is not passing through the device due to the isotropic optical properties of the antiferreoelectric liquid crystal aligned in HAF texture. An applied electric field induces a continuous transition of the optically isotropic antiferreoelectric (AF) state to ferroelectric (F) one which is birefringent enabling the transmission of light. The field-induced continuous switching between the optically isotropic antiferreoelectric state and the birefringent ferroelectric state enables the generation and fast switching of high contrast as well as generation of grey scale levels.

Liquid crystal device for generation and fast switching of high contrast images

The present invention relates to a liquid crystal device driven by a linear coupling, such as ferroelectric and/or flexoelectric coupling, between an inhomogenous in-plane electric field generated by an electrode pattern over a first sub-volume of the bulk layer adjacent to said electrode pattern and liquid crystals in a polarized state comprised in said first sub-volume and/or in an optional alignment layer applied on said electrode pattern said polarization being stronger than any possible similar liquid crystal polarization of the bulk layer outside said first sub-volume, said alignment layer, and/or a second sub-volume of the bulk layer adjacent the inner surface of the other substrate, or an optional second alignment layer or an optional electrode pattern applied thereon.

Liquid crystal device

The invention relates to a polymer for use as a surface-director alignment layer in a liquid crystal device, the polymer comprising a polymeric backbone and side-chains attached thereto, wherein the polymeric backbone lacks directly coupled ring structures, and each side-chain of at least some of the side-chains comprises at least two unsubstituted and/or substituted phenyls coupled via a coupling selected from the group consisting of a carbon-carbon single bond (&#x2014;), a carbon-carbon double bond containing unit (&#x2014;CH&#x2550;CH&#x2014;), a carbon-carbon triple bond containing unit (&#x2014;C&#x2261;C&#x2014;), a methylene ether unit (&#x2014;CHO&#x2014;), an ethylene ether unit (&#x2014;CHCHO&#x2014;), an ester unit (&#x2014;COO&#x2014;) and an azo unit (&#x2014;N&#x2550;N&#x2014;), exhibits a permanent and/or induced dipole moment that in ordered phase provides dielectric anisotropy, and is attached to the polymeric backbone via at least two spacing atoms.

Polymers for use as alignment layers in liquid crystal devices

The invention relates to a liquid crystal device comprising a liquid crystal bulk layer and a dynamic surface-director alignment layer, wherein the liquid crystal bulk layer comprises a liquid crystalline material possessing a phase sequence consisting of isotropic phase, nematic phase and optionally crystalline phase(s), and the surface-director alignment layer comprises a chiral smectic liquid crystalline polysiloxane. The invention also relates to a method for its manufacturing.

Liquid crystal device and a method for manufacturing thereof

A fast and highly practical photoinduced switching liquid crystal device is provided. In the photoinduced switching liquid crystal device, in-plane switching of an optical anisotropic axis of dichroic nematic liquid crystal is performed at a high speed by light.

Photoinduced switching liquid crystal device utilizing photoisomerization

An electro-optic device includes a liquid crystal cell (') and at least one electrode (&#x2032;) arranged to selectively electrically bias the liquid crystal cell (&#x2032;). A chiral or cholesteric liquid crystal (&#x2032;) is disposed in the liquid crystal cell (&#x2032;). The liquid crystal (&#x2032;) has an optic axis substantially along a selected optic axis direction in the absence of an electrical bias. A polymeric network () is disposed at an inside surface of the liquid crystal cell (&#x2032;). The polymeric network () extends partway into the liquid crystal cell (&#x2032;) leaving at least a portion of the liquid crystal cell (&#x2032;) substantially free of the polymeric network ().

Electro-optical devices from polymer-stabilized liquid crystal molecules

An electrooptic device ( ), and the methods for manufacturing, including a liquid crystal material ( ) disposed between electroded flat glass or polymer substrates ( ) which have been precoated with a e.g. a chiral smectic surface layer ( ) in such way that the surface layer is able to mediate switching of the liquid crystal ( ) between different optical states. The chiral smectic surface layer can be a polymer, oligomer or monomer liquid crystal with paraelectric, ferroelectric, ferrielectric or antiferroelectric response, which is insoluble in the liquid crystal used for the bulk ( ) between the electroded substrates ( ). the switchable surface director enforces a certain orientation of the optic axis in the bulk liquid crystal ( ), which can be a conventional non-chiral or chiral nematic or smectic in a twisted or non-twisted configuration.

Liquid crystal device and a method for producing it having directly controllable dynamic surface-director alignment layer

A device for influencing light has a polarizer, a ferroelectric or electroclinic response type liquid crystal halfwave plate whose liquid crystals are in the smectic phase with bookshelf geometry and have molecular axes which are rotatable around a first direction corresponding to the direction of incoming light in response to an electric field applied across the electrodes on either side of the halfwave plate, a quarter wave retarder plate, and a mirror. The polarizer, plates and mirror are arranged such that incoming light is passed from the polarizer through the liquid crystal plate and the retarder plate, and is reflected by the mirror in a second direction opposite to the first direction back through the retarder and the liquid crystal plate so as to provide a reflected polarized light plane to the polarizer. The polarizer has a first polarization direction set parallel to one electrically selectable molecular axis direction of the liquid crystal molecules, which is selected in response to a first electric field level. The retarder plate has its slow axis inclined either 45.degree. or 135.degree. relative to the optic axis of the liquid crystal. The liquid crystal, furthermore, is of a material which produces an angular difference 2.theta. in optic axis direction in response to a second electric field level whose polarity is opposite that of the first electric field level. This allows the device to rotate the reflected polarized light plane by an angle of 8.theta. in response to the second electric field level.

Growing community of inventors

Göteborg, Sweden

Lachezar Komitov