Patents by Inventor Jean-Michel Roquais

Jean-Michel Roquais 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).

  • Cathode for cathode ray tube with improved lifetime
    Patent number: 7372192
    Abstract: Impregnated cathode for a vacuum tube comprising an emissive part in the form of a porous pellet impregnated with a compound of alkaline earth metals; the pellet is placed in a dish made of a refractory material and covered with a porous metal foil forming the emissive surface of the cathode. Moreover, the pellet has a separation surface between a heavily impregnated zone and a zone which is not impregnated or weakly impregnated so that the said separation surface comprises at least a hollow part facing the emissive surface. By virtue of the shape of this separation surface, the lifetime of the cathode is improved.
    Type: Grant
    Filed: November 29, 2002
    Date of Patent: May 13, 2008
    Assignee: Thomson Licensing
    Inventors: Jean-Luc Ricaud, Jean-Michel Roquais
  • Oxide cathode for electron gun with a differentially doped metallic substrate
    Patent number: 7208864
    Abstract: The metallic substrate of this cathode has a thickness ?100 ?m and contains a plurality of reducing agents as Si or Al and on the top face 111, 0.005%<Mg?0.1%, Si or Al?0.025%, and W?3%, on the bottom face 122, Mg weight concentration is inferior to the Mg weight concentration on the top face, and Si or Al weight concentration is superior to Si or Al weight concentration on the top face and superior to 0.02%. Lifetime is maximized and turn-on-time is minimized.
    Type: Grant
    Filed: July 21, 2003
    Date of Patent: April 24, 2007
    Assignee: Thomson Licensing
    Inventors: Jean-Michel Roquais, Donald John Wierschke
  • Oxide cathode for electron gun with a differentially doped metallic substrate
    Publication number: 20060158086
    Abstract: The metallic substrate of this cathode has a thickness ?100 ?m and contains a plurality of reducing agents as Si or Al and on the top face 111, 0.005%<Mg?0.1%, Si or Al?0.025%, and W?3%, on the bottom face 122, Mg weight concentration is inferior to the Mg weight concentration on the top face, and Si or Al weight concentration is superior to Si or Al weight concentration on the top face and superior to 0.02%. Lifetime is maximized and turn-on-time is minimized.
    Type: Application
    Filed: July 21, 2003
    Publication date: July 20, 2006
    Inventors: Jean-Michel Roquais, Donald Wierschke
  • Cathode for cathode ray tube with improved lifetime
    Publication number: 20050140262
    Abstract: Impregnated cathode for a vacuum tube comprising an emissive part in the form of a porous pellet impregnated with a compound of alkaline earth metals; the pellet is placed in a dish made of a refractory material and covered with a porous metal foil forming the emissive surface of the cathode. Moreover, the pellet has a separation surface between a heavily impregnated zone and a zone which is not impregnated or weakly impregnated so that the said separation surface comprises at least a hollow part facing the emissive surface. By virtue of the shape of this separation surface, the lifetime of the cathode is improved.
    Type: Application
    Filed: November 29, 2002
    Publication date: June 30, 2005
    Inventors: Jean-Luc Ricaud, Jean-Michel Roquais
  • Cathode-ray tube cathode and alloy therefor
    Patent number: 6798128
    Abstract: A nickel alloy for the manufacture of cathodes for cathode-ray tubes, comprises magnesium and aluminium in proportions chosen so as to allow good adhesion of an emissive oxide layer to the basis metal cap consisting of the alloy.
    Type: Grant
    Filed: April 25, 2001
    Date of Patent: September 28, 2004
    Assignee: Thomson Licensing S.A.
    Inventors: Jean-Michel Roquais, Fabian Poret, Régine Le Doze, Marie Paul
  • Cathode-ray tube cathode and alloy therefor
    Publication number: 20030164668
    Abstract: A nickel alloy for the manufacture of cathodes for cathode-ray tubes, comprises magnesium and aluminium in proportions chosen so as to allow good adhesion of an emissive oxide layer to the basis metal cap consisting of the alloy.
    Type: Application
    Filed: April 25, 2001
    Publication date: September 4, 2003
    Inventors: Jean-Michel Roquais, Fabian Poret, Regine Le Doze, Marie Paul