Patents by Inventor Bertrand Caillaud

Bertrand Caillaud 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).

  • Patent number: 11531212
    Abstract: Stereoscopic 3D systems include a conversion system having a polarization beam-splitting element to separate a randomly polarized incident image-beam into one transmitted image-beam and at least one reflected image-beam, first and second polarization modulators arranged to modulate states of the transmitted and reflected image-beams between first and second output linear polarization states, the modulators including first and second pi-cell liquid crystal elements aligned in mutually crossed orientation and switched between first and second optical-states, one of the optical-states having in-plane optical retardation corresponding to a quarter-wave plate (QWP), an additional QWP proximate to one of the pi-cell liquid crystal elements and perpendicularly aligned to the optical axis for the in-plane optical retardation for one of the pi-cell liquid crystal elements.
    Type: Grant
    Filed: November 20, 2020
    Date of Patent: December 20, 2022
    Inventors: Stephen Palmer, Bertrand Caillaud, YanLong Li
  • Publication number: 20210157163
    Abstract: Stereoscopic 3D systems include a conversion system having a polarization beam-splitting element to separate a randomly polarized incident image-beam into one transmitted image-beam and at least one reflected image-beam, first and second polarization modulators arranged to modulate states of the transmitted and reflected image-beams between first and second output linear polarization states, the modulators including first and second pi-cell liquid crystal elements aligned in mutually crossed orientation and switched between first and second optical-states, one of the optical-states having in-plane optical retardation corresponding to a quarter-wave plate (QWP), an additional QWP proximate to one of the pi-cell liquid crystal elements and perpendicularly aligned to the optical axis for the in-plane optical retardation for one of the pi-cell liquid crystal elements.
    Type: Application
    Filed: November 20, 2020
    Publication date: May 27, 2021
    Inventors: Stephen Palmer, Bertrand Caillaud, YanLong Li
  • Patent number: 9740017
    Abstract: An optical polarization device for a stereoscopic image projector, including: a polarizer optical element including two beam splitter-polarizer plates, joined to one another; first and second optical reflectors configured to modify, respectively, a trajectory of first and second light beams reflected such that the reflected and transmitted light beams are projected to form one and same stereoscopic image; first, second, and third polarization modulators configured to selectively switch the optical polarization, respectively, of a transmitted light beam, of the first and of the second reflected light beams, between the first and second states of optical polarization; and a control circuit for the polarization modulators.
    Type: Grant
    Filed: May 27, 2014
    Date of Patent: August 22, 2017
    Assignee: VOLFONI R&D
    Inventors: Minh Hoang, Christophe Brossier, Bertrand Caillaud, Simon-Pierre Delord
  • Publication number: 20160124238
    Abstract: An optical polarization device for a stereoscopic image projector, including: a polarizer optical element including two beam splitter-polarizer plates, joined to one another; first and second optical reflectors configured to modify, respectively, a trajectory of first and second light beams reflected such that the reflected and transmitted light beams are projected to form one and same stereoscopic image; first, second, and third polarization modulators configured to selectively switch the optical polarization, respectively, of a transmitted light beam, of the first and of the second reflected light beams, between the first and second states of optical polarization; and a control circuit for the polarization modulators.
    Type: Application
    Filed: May 27, 2014
    Publication date: May 5, 2016
    Applicant: VOLFONI R&D
    Inventors: Minh HOANG, Christophe BROSSIER, Bertrand CAILLAUD, Simon-Pierre DELORD
  • Patent number: 8817196
    Abstract: An optical shuttering device is provided, which includes an optical cell with a liquid crystal material between first and second transparent substrates and controlled by an electronic switching circuit. The switching circuit includes a power supply module, providing a control voltage, and a switching element mounted in series between the power supply module and the cell, making it possible to switch the cell between an on state and an off state. The electronic switching circuit furthermore includes a current source mounted in series between the power supply module and the switching element. The substrates preferably have different thickness and material.
    Type: Grant
    Filed: November 16, 2009
    Date of Patent: August 26, 2014
    Assignee: Institut Telecom/Telecom Bretagne
    Inventors: Jean-Louis De Bougrenet De La Tocnaye, Bertrand Caillaud, Emmanuel Daniel, Robert Bellini, Olivier Castany
  • Patent number: 8648899
    Abstract: The invention relates to liquid crystal lenses having dynamically switchable light transmission, including: a shutter (2) including two transparent substrates (21, 22) and a nematic liquid crystal layer (20) arranged between the substrates (21, 22); and a control circuit capable of alternately applying a bias voltage or a relaxation voltage across the liquid crystal to render the shutter (2)clear or opaque, the falling edges between the bias voltage and the relaxation voltage having a duration of 80 to 900 ?s.
    Type: Grant
    Filed: October 7, 2010
    Date of Patent: February 11, 2014
    Assignee: Volfoni R&D
    Inventors: Thierry Henkinet, Bertrand Caillaud
  • Patent number: 8368848
    Abstract: A method is provided for manufacturing an electrooptic cell, which includes two plates of optically transparent material and at least one thickness of a composite gel based on a smectic liquid crystal and on a polymer provided between the plates, wherein the gel is in a smectic phase at ambient temperature. The method includes injecting a mixture of a ferroelectric and/or anti-ferroelectric smectic liquid and a monomer between the plates, wherein the monomer content of the mixture is between 5 and 25% by weight. The mixture is heated to above its smectic phase/nematic phase transmission temperature so that the mixture is in the nematic phase. The mixture is irradiated, by ultraviolet radiation, so as to polymerize the monomer and thus obtain the gel. During the irradiation step, an electric or magnetic field is applied to the mixture.
    Type: Grant
    Filed: April 2, 2008
    Date of Patent: February 5, 2013
    Assignees: Institut Telecom/Telecom Bretagne, Lixys
    Inventors: Bertrand Caillaud, Pascal Gautier, Jean-Louis De Bougrenet De La Tocnaye, Laurent Dupont, Aline Guenot
  • Publication number: 20120200790
    Abstract: The invention relates to liquid crystal lenses having dynamically switchable light transmission, including: a shutter (2) including two transparent substrates (21, 22) and a nematic liquid crystal layer (20) arranged between the substrates (21, 22); and a control circuit capable of alternately applying a bias voltage or a relaxation voltage across the liquid crystal to render the shutter (2) clear or opaque, the falling edges between the bias voltage and the relaxation voltage having a duration of 80 to 900 ?s.
    Type: Application
    Filed: October 7, 2010
    Publication date: August 9, 2012
    Applicant: Volfoni R&D
    Inventors: Thierry Henkinet, Bertrand Caillaud
  • Publication number: 20120038840
    Abstract: An optical shuttering device is provided, which includes an optical cell with a liquid crystal material between first and second transparent substrates and controlled by an electronic switching circuit. The switching circuit includes a power supply module, providing a control voltage, and a switching element mounted in series between the power supply module and the cell, making it possible to switch the cell between an on state and an off state. The electronic switching circuit furthermore includes a current source mounted in series between the power supply module and the switching element. The substrates preferably have different thickness and material.
    Type: Application
    Filed: November 16, 2009
    Publication date: February 16, 2012
    Applicant: INSTITUT TELECOM / TELECOM BRETAGNE
    Inventors: Jean-Louis De Bougrenet De La Tocnaye, Bertrand Caillaud, Emmanuel Daniel, Robert Bellini, Olivier Castany
  • Publication number: 20100039588
    Abstract: A method is provided for manufacturing an electrooptic cell, which includes two plates of optically transparent material and at least one thickness of a composite gel based on a smectic liquid crystal and on a polymer provided between the plates, wherein the gel is in a smectic phase at ambient temperature. The method includes injecting a mixture of a ferroelectric and/or anti-ferroelectric smectic liquid and a monomer between the plates, wherein the monomer content of the mixture is between 5 and 25% by weight. The mixture is heated to above its smectic phase/nematic phase transmission temperature so that the mixture is in the nematic phase. The mixture is irradiated, by ultraviolet radiation, so as to polymerize the monomer and thus obtain the gel. During the irradiation step, an electric or magnetic field is applied to the mixture.
    Type: Application
    Filed: April 2, 2008
    Publication date: February 18, 2010
    Applicant: INSTITUT TELECOM/TELECOM BRETAGNE
    Inventors: Bertrand Caillaud, Pascal Gautier, Jean-Louis De Bougrenet De La Tocnaye, Laurent Dupont, Aline Guenot