Patents by Inventor Ivan Dozov

Ivan Dozov has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20130076610
    Abstract: The present invention relates to a method of addressing a bistable matrix screen, in which the following two steps are reiterated: A. a disturbance signal is applied to each pixel of a marking area for a time t1, said disturbance signal being higher than a threshold signal such that each pixel of the area leaves its initial stable state, said disturbance signal being lower than a switching signal such that each pixel of the area having one of the stable states as its initial state does not switch into the other stable state, each pixel of the area then being in an intermediate disturbed state that is intermediate between the two stable states, and then B. no signal is applied to each pixel of the area for a time t2 to allow each pixel of the area to return to its initial stable state.
    Type: Application
    Filed: October 8, 2009
    Publication date: March 28, 2013
    Applicant: NEMOPTIC S.A.
    Inventors: Ivan Dozov, Francois Leblanc, Jean-Denis Laffitte, Stephane Joly, Philippe Martinot-Lagarde, Jacques Angele
  • Patent number: 8361343
    Abstract: The present invention provides a nematic liquid crystal composition suitable for a bistable nematic liquid crystal display. A bistable nematic liquid crystal display having a wide nematic phase temperature range and operating temperature range can be obtained by using a nematic liquid crystal composition comprising at least 20% by weight of a specific liquid crystal compound (A) having a polar group and 5 to 50% by weight of a specific liquid crystal compound (B) not having a polar group, along with comprising, in the compound (B), at least 3% by weight of a specific liquid crystal compound having a alkenyl group.
    Type: Grant
    Filed: May 16, 2008
    Date of Patent: January 29, 2013
    Assignees: DIC Corporation, Nemoptic
    Inventors: Hidetoshi Nakata, Takeshi Kuriyama, Kiyofumi Takeuchi, Haruyoshi Takatsu, Daniel Stoenescu, Jean-Claude Dubois, Ivan Dozov
  • Patent number: 8252202
    Abstract: A nematic liquid crystal composition of the present invention includes at least 20% by weight of one, or two or more compounds selected from compound group A; and 5 to 50% by weight of one, or two or more compounds selected from compound group B, wherein the relative proportions of the above-mentioned compounds used in the nematic liquid crystal composition is determined to simultaneously obtain the specific physical characteristics for the composition, and an anchoring breaking voltage U?/4 is less than or equal to 25 V when the product (?n·d) of the refractive index anisotropy (?n) at 20° C. and the thickness (d) is 140 nm and the liquid crystal composition is confined between two substrates for a bistable nematic liquid crystal display in which at least one of the substrates have a weak zenithal anchoring force.
    Type: Grant
    Filed: May 16, 2008
    Date of Patent: August 28, 2012
    Assignees: DIC Corporation, Nemoptic
    Inventors: Hidetoshi Nakata, Kiyofumi Takeuchi, Haruyoshi Takatsu, Daniel Stoenescu, Ivan Dozov, Jean-Claude Dubois
  • Publication number: 20110211148
    Abstract: A nematic liquid crystal composition of the present invention includes at least 20% by weight of one, or two or more compounds selected from compound group A; and 5 to 50% by weight of one, or two or more compounds selected from compound group B, wherein the relative proportions of the above-mentioned compounds used in the nematic liquid crystal composition is determined to simultaneously obtain the specific physical characteristics for the composition, and an anchoring breaking voltage U?/4 is less than or equal to 25 V when the product (?n·d) of the refractive index anisotropy (?n) at 20° C. and the thickness (d) is 140 nm and the liquid crystal composition is confined between two substrates for a bistable nematic liquid crystal display in which at least one of the substrates have a weak zenithal anchoring force.
    Type: Application
    Filed: May 16, 2008
    Publication date: September 1, 2011
    Applicants: DIC CORPORATION, NEMOPTIC
    Inventors: Hidetoshi Nakata, Kiyofumi Takeuchi, Haruyoshi Takatsu, Daniel Stoenescu, Ivan Dozov, Jean-Claude Dubois
  • Patent number: 7812903
    Abstract: The invention concerns a liquid crystal display device comprising two substrates (10, 20) provided with respective electrodes (12, 22) and located on either side of a layer of liquid crystal molecules (30) and means defining two stable states for the liquid crystal molecules, in the absence of an electric field.
    Type: Grant
    Filed: August 11, 2005
    Date of Patent: October 12, 2010
    Assignee: Nemoptic
    Inventors: Cécile Barron, Sébastien Perny, Lorenzo Bajic, Ivan Dozov
  • Publication number: 20100201930
    Abstract: The present invention provides a nematic liquid crystal composition suitable for a bistable nematic liquid crystal display. A bistable nematic liquid crystal display having a wide nematic phase temperature range and operating temperature range can be obtained by using a nematic liquid crystal composition comprising at least 20% by weight of a specific liquid crystal compound (A) having a polar group and 5 to 50% by weight of a specific liquid crystal compound (B) not having a polar group, along with comprising, in the compound (B), at least 3% by weight of a specific liquid crystal compound having a alkenyl group.
    Type: Application
    Filed: May 16, 2008
    Publication date: August 12, 2010
    Applicants: DIC CORPORATION, NEMOPTIC
    Inventors: Hidetoshi Nakata, Takeshi Kuriyama, Kiyofumi Takeuchi, Haruyoshi Takatsu, Daniel Stoenescu, Jean-Claude Dubois, Ivan Dozov
  • Publication number: 20080303992
    Abstract: The invention concerns a liquid crystal display device comprising two substrates (10, 20) provided with respective electrodes (12, 22) and located on either side of a layer of liquid crystal molecules (30) and means defining two stable states for the liquid crystal molecules, in the absence of an electric field.
    Type: Application
    Filed: August 11, 2005
    Publication date: December 11, 2008
    Inventors: Cecile Barron, Sebastien Perny, Lorenzo Bajic, Ivan Dozov
  • Patent number: 7224417
    Abstract: The present invention relates to a nematic bistable display device, characterized in that it comprises control means (40) for producing, after the anchoring is broken, hybrid textures in which two bistable textures coexist in a controlled proportion within the same pixel, these being separated by 180° volume disclination lines or by 180° reorientation walls on one of the surfaces, and means (40) for the long-term stabilization of the hybrid textures by transformation of the volume lines into surface walls and the immobilization of these walls on the surface.
    Type: Grant
    Filed: May 2, 2002
    Date of Patent: May 29, 2007
    Assignee: Nemoptic
    Inventors: Jacques Angele, Philippe Martinot-Lagarde, Ivan Dozov, Daniel Stoenescu, Romain Vercelletto
  • Publication number: 20060249708
    Abstract: A method of using a liquid crystal composition in a bistable liquid crystal device having a weak zenithal anchoring comprising at least 40% by weight of compounds with strong molecular polarisability and strong dipole moment.
    Type: Application
    Filed: April 3, 2006
    Publication date: November 9, 2006
    Inventors: Jean-Claude Dubois, Didier Gallaire, Stephane Joly, Ivan Dozov, Philippe Martinot-Lagarde, Daniel Stoenescu
  • Patent number: 7067180
    Abstract: Method of producing nematic liquid-crystal devices, wherein a low zenithal anchoring energy of the liquid crystal is obtained on at least one of its confinement plates by the steps consisting in: depositing, on a substrate, a polymer or a copolymer or a terpolymer chosen from the polymers or copolymers derived from those of the poly(vinyl chloride-co-vinyl alkyl ether) type or from those of the poly(vinyl chloride-co-vinyl aryl ether) type; stabilizing this polymer coating; and defining an azimuthal orientation of the coating for inducing a controlled azimuthal anchoring of the liquid crystal.
    Type: Grant
    Filed: June 4, 2003
    Date of Patent: June 27, 2006
    Assignee: Nemoptic
    Inventors: Sandrine Lamarque-Forget, Sebastien Jacquier, Ivan Dozov, Luc Faget
  • Publication number: 20040125294
    Abstract: The present invention relates to a nematic bistable display device, characterized in that it comprises control means (40) for producing, after the anchoring is broken, hybrid textures in which two bistable textures coexist in a controlled proportion within the same pixel, these being separated by 180° volume disclination lines or by 180° reorientation walls on one of the surfaces, and means (40) for the long-term stabilization of the hybrid textures by transformation of the volume lines into surface walls and the immobilization of these walls on the surface.
    Type: Application
    Filed: November 3, 2003
    Publication date: July 1, 2004
    Inventors: Jacques Angele, Philippe Martinot-Lagarde, Ivan Dozov, Daniel Stoenescu, Romain Vercelletto
  • Publication number: 20030232154
    Abstract: Method of producing nematic liquid-crystal devices, wherein a low zenithal anchoring energy of the liquid crystal is obtained on at least one of its confinement plates by the steps consisting in:
    Type: Application
    Filed: June 4, 2003
    Publication date: December 18, 2003
    Inventors: Sandrine Lamarque-Forget, Sebastien Jacquier, Ivan Dozov, Luc Faget
  • Patent number: 6452573
    Abstract: The present invention relates to a liquid crystal display device comprising a liquid crystal material sandwiched between two confinement plates (1, 2), the device being characterized by the fact that at least one of the plates (2) is provided with treatment which defines degenerate or nearly degenerate azimuth anchoring without azimuth orientation memory.
    Type: Grant
    Filed: April 16, 1999
    Date of Patent: September 17, 2002
    Assignee: Nemoptic, S.A.
    Inventors: Philippe Martinot-Lagarde, Ivan Dozov, Eric Polossat, Eric Raspaud, Philippe Auroy, Olivier Ou Ramdane, Georges Durand, Sandrine Forget
  • Patent number: 6327017
    Abstract: A display device including two parallel transparent plates (10, 12) having transparent electrodes on the inner surfaces thereof and containing a liquid crystal material (20). The device includes means defining a monostable anchoring for each plate (10, 12), means (40) controllable to break at least one of the anchorings, and means for thereafter inducing volume bistability.
    Type: Grant
    Filed: September 14, 1998
    Date of Patent: December 4, 2001
    Assignee: Nemoptic S.A.
    Inventors: Ricardo Barberi, Ivan Dozov, Georges Durand, Philippe Martinot-Lagarde, Maurizio Nobili, Eric Polossat, Ioannis Lelidis, Michele Giocondo
  • Publication number: 20010012080
    Abstract: A display device including two parallel transparent plates (10, 12) having transparent electrodes on the inner surfaces thereof and containing a liquid crystal material (20). The device includes means defining a monostable anchoring for each plate (10, 12), means (40) controllable to break at least one of the anchorings, and means for thereafter inducing volume bistability.
    Type: Application
    Filed: September 14, 1998
    Publication date: August 9, 2001
    Inventors: RICARDO BARBERI, IVAN DOZOV, GEORGES DURAND, PHILIPPE MARTINOT-LAGARDE, MAURIZIO NOBILI, ERIC POLOSSAT, IOANNIS LELIDIS, MICHELE GIOCONDO
  • Patent number: 5995173
    Abstract: 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.
    Type: Grant
    Filed: November 8, 1996
    Date of Patent: November 30, 1999
    Assignee: Instituto Nationale per La Fisica Della Materia
    Inventors: Riccardo Barberi, Roberto Bartolino, Ivan Dozov, Georges Durand, Michele Giocondo, Jun Li
  • Patent number: 4564266
    Abstract: 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.
    Type: Grant
    Filed: April 21, 1983
    Date of Patent: January 14, 1986
    Assignee: Centre National de la Recherche Scientifique (CNRS)
    Inventors: Georges E. A. Durand, Philippe Martinot-Lagarde, Ivan Dozov