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).
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Publication number: 20130076610Abstract: 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: ApplicationFiled: October 8, 2009Publication date: March 28, 2013Applicant: NEMOPTIC S.A.Inventors: Ivan Dozov, Francois Leblanc, Jean-Denis Laffitte, Stephane Joly, Philippe Martinot-Lagarde, Jacques Angele
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Patent number: 8361343Abstract: 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: GrantFiled: May 16, 2008Date of Patent: January 29, 2013Assignees: DIC Corporation, NemopticInventors: Hidetoshi Nakata, Takeshi Kuriyama, Kiyofumi Takeuchi, Haruyoshi Takatsu, Daniel Stoenescu, Jean-Claude Dubois, Ivan Dozov
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Patent number: 8252202Abstract: 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: GrantFiled: May 16, 2008Date of Patent: August 28, 2012Assignees: DIC Corporation, NemopticInventors: Hidetoshi Nakata, Kiyofumi Takeuchi, Haruyoshi Takatsu, Daniel Stoenescu, Ivan Dozov, Jean-Claude Dubois
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Publication number: 20110211148Abstract: 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: ApplicationFiled: May 16, 2008Publication date: September 1, 2011Applicants: DIC CORPORATION, NEMOPTICInventors: Hidetoshi Nakata, Kiyofumi Takeuchi, Haruyoshi Takatsu, Daniel Stoenescu, Ivan Dozov, Jean-Claude Dubois
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Patent number: 7812903Abstract: 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: GrantFiled: August 11, 2005Date of Patent: October 12, 2010Assignee: NemopticInventors: Cécile Barron, Sébastien Perny, Lorenzo Bajic, Ivan Dozov
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Publication number: 20100201930Abstract: 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: ApplicationFiled: May 16, 2008Publication date: August 12, 2010Applicants: DIC CORPORATION, NEMOPTICInventors: Hidetoshi Nakata, Takeshi Kuriyama, Kiyofumi Takeuchi, Haruyoshi Takatsu, Daniel Stoenescu, Jean-Claude Dubois, Ivan Dozov
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Publication number: 20080303992Abstract: 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: ApplicationFiled: August 11, 2005Publication date: December 11, 2008Inventors: Cecile Barron, Sebastien Perny, Lorenzo Bajic, Ivan Dozov
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Patent number: 7224417Abstract: 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: GrantFiled: May 2, 2002Date of Patent: May 29, 2007Assignee: NemopticInventors: Jacques Angele, Philippe Martinot-Lagarde, Ivan Dozov, Daniel Stoenescu, Romain Vercelletto
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Publication number: 20060249708Abstract: 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: ApplicationFiled: April 3, 2006Publication date: November 9, 2006Inventors: Jean-Claude Dubois, Didier Gallaire, Stephane Joly, Ivan Dozov, Philippe Martinot-Lagarde, Daniel Stoenescu
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Patent number: 7067180Abstract: 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: GrantFiled: June 4, 2003Date of Patent: June 27, 2006Assignee: NemopticInventors: Sandrine Lamarque-Forget, Sebastien Jacquier, Ivan Dozov, Luc Faget
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Publication number: 20040125294Abstract: 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: ApplicationFiled: November 3, 2003Publication date: July 1, 2004Inventors: Jacques Angele, Philippe Martinot-Lagarde, Ivan Dozov, Daniel Stoenescu, Romain Vercelletto
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Publication number: 20030232154Abstract: 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: ApplicationFiled: June 4, 2003Publication date: December 18, 2003Inventors: Sandrine Lamarque-Forget, Sebastien Jacquier, Ivan Dozov, Luc Faget
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Patent number: 6452573Abstract: 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: GrantFiled: April 16, 1999Date of Patent: September 17, 2002Assignee: Nemoptic, S.A.Inventors: Philippe Martinot-Lagarde, Ivan Dozov, Eric Polossat, Eric Raspaud, Philippe Auroy, Olivier Ou Ramdane, Georges Durand, Sandrine Forget
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Patent number: 6327017Abstract: 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: GrantFiled: September 14, 1998Date of Patent: December 4, 2001Assignee: Nemoptic S.A.Inventors: Ricardo Barberi, Ivan Dozov, Georges Durand, Philippe Martinot-Lagarde, Maurizio Nobili, Eric Polossat, Ioannis Lelidis, Michele Giocondo
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Publication number: 20010012080Abstract: 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: ApplicationFiled: September 14, 1998Publication date: August 9, 2001Inventors: RICARDO BARBERI, IVAN DOZOV, GEORGES DURAND, PHILIPPE MARTINOT-LAGARDE, MAURIZIO NOBILI, ERIC POLOSSAT, IOANNIS LELIDIS, MICHELE GIOCONDO
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Patent number: 5995173Abstract: 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: GrantFiled: November 8, 1996Date of Patent: November 30, 1999Assignee: Instituto Nationale per La Fisica Della MateriaInventors: Riccardo Barberi, Roberto Bartolino, Ivan Dozov, Georges Durand, Michele Giocondo, Jun Li
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Patent number: 4564266Abstract: 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: GrantFiled: April 21, 1983Date of Patent: January 14, 1986Assignee: Centre National de la Recherche Scientifique (CNRS)Inventors: Georges E. A. Durand, Philippe Martinot-Lagarde, Ivan Dozov