Centre National De La Recherche Scientifique

Nemoptic, S.a.

Instituto Nationale Per La Fisica Della Materia

Georges E Durand

Philippe Martinot-Lagarde

Ivan N Dozov

Riccardo Barberi

Michele Giocondo

Eric Polossat

Marguerite Boix

Ioannis Lelidis

Mohamed Monkade

Maurizio Nobili

Philippe Auroy

Ricardo Barberi

Jun Li

Philippe R Martinot Lagarde

Claude Germain

Olivier Ou Ramdane

Eric Raspaud

Michelle Giocondo

Sandrine Forget

Roberto Bartolino

The present invention relates to a liquid crystal display device comprising a liquid crystal material sandwiched between two confinement plates ( ), the device being characterized by the fact that at least one of the plates ( ) is provided with treatment which defines degenerate or nearly degenerate azimuth anchoring without azimuth orientation memory.

Liquid crystal device comprising anchoring means on at least one confinement plate providing a degenerated orientation

A display device including two parallel transparent plates (,) having transparent electrodes on the inner surfaces thereof and containing a liquid crystal material (,). The device includes means defining a monostable anchoring for each plate (,), means (,) controllable to break at least one of the anchorings, and means for thereafter inducing volume bistability.

Bistable liquid crystal display device in which nematic liquid crystal has monostable anchorings

The present invention relates to a display device based on liquid crystals, comprising a nematic liquid-crystal material (10) with positive dielectric anisotropy sandwiched between two transparent confinement plates (20, 30) each provided with transparent electrodes (22, 32), characterized in that at least one of the plates, (30), defines a quasi-bistable anchoring and in that it is provided with main electrical supply means (40) suitable for applying a temporary electric field to the liquid-crystal material (10) capable of breaking the anchoring on the aforementioned plate (30) and subsequently allowing, due to the effect of hydrodynamic instabilities, various localized orientations of the liquid-crystal molecules (10) corresponding to the preferred orientations of the quasi-bistable anchoring.

Bistable display device based on nematic liquid crystals allowing grey

Nematic liquid crystal display with surface bistability and control by

A method applicable to a liquid crystal cell comprising two parallel transparent plates (11, 12) coated on their facing inert faces with electrode-forming conductive coatings (14,15), and with a shim (13) interposed between the plates, the space in said cells between said plates containing a substance (17) including molecules which are endowed with nematic properties, wherein: controlled variations in surface impedance are defined on at least one of the electrode coatings in selected zones (16) thereof; and a variable frequency excitation electrical voltage is applied between the electrodes (14, 15) provided on respective ones of said plates (11, 12), and voltage being selected to be suitable for producing alternately an electric field extending normally to the electrodes and an electric field which slopes relative to the normal to said electrodes at said zones (16) having a controlled impedance variation.

Liquid crystal optical devices enabling high frequency ac excitation to

An electro-optical method and apparatus uses liquid crystals. The method includes the step of filling a space between two parallel transparent plates with a material which comprises molecules having nematic properties, the structure of the molecules initially defining a substantially rectilinear nematic director perpendicular to the plates. A structure is then conferred on the material defining a second nematic director curved at least once in a plane perpendicular to the plate by application of a high frequency electrical field to the material, such that the second nematic director arrives substantially perpendicularly at at least one of the two plates. A twist is imparted to the second nematic director along a component at right angles to said plane perpendicular to the plates to impart a twist in the second nematic director. Light is caused to arrive with an incidence substantially at right angles to one of the plates to pass through the material, a rotation of polarization of the light, at an outlet from the plates, depending on the twist imparted to the second nematic director.

Electro-optical devices using liquid crystals having a twist in a plane

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Orsay, France

Georges E Durand