Patents by Inventor Frieder Kropfgans

Frieder Kropfgans 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: 9194663
    Abstract: A transparent device for protection from an action of shock, projectiles, fragments or shock waves is provided. The device is a laminate having brittle-fracture, transparent materials that are joined together by way of transparent intermediate layers of organic polymers. The laminate is closed on the protective side facing away from the side of action by a fragment-protective layer that is formed as a transparent polymer layer in a thickness of 0.5 mm to 12 mm. The laminate has facing the side of action a chemically prestressed, brittle-fracture panel that is at a distance of 3 mm to 20 mm from the side of action.
    Type: Grant
    Filed: March 30, 2011
    Date of Patent: November 24, 2015
    Assignee: SCHOTT AG
    Inventors: Kurt Schaupert, Thilo Hinrich Zachau, Frieder Kropfgans
  • Patent number: 8815392
    Abstract: A process is disclosed for producing a doped gallium arsenide single crystal by melting a gallium arsenide starting material and subsequently solidifying the gallium arsenide melt, wherein the gallium arsenide melt contains an excess of gallium relative to the stoichiometric composition, and wherein it is provided for a boron concentration of at least 5×1017 cm?3 in the melt or in the obtained crystal. The thus obtained crystal is characterized by a unique combination of low dislocation density, high conductivity and yet excellent, very low optic absorption, particularly in the range of the near infrared.
    Type: Grant
    Filed: November 8, 2012
    Date of Patent: August 26, 2014
    Assignee: Freiberger Compound Materials GmbH
    Inventors: Ulrich Kretzer, Frank Börner, Stefan Eichler, Frieder Kropfgans
  • Publication number: 20130199360
    Abstract: A transparent device for protection from an action of shock, projectiles, fragments or shock waves is provided. The device is a laminate having brittle-fracture, transparent materials that are joined together by way of transparent intermediate layers of organic polymers. The laminate is closed on the protective side facing away from the side of action by a fragment-protective layer that is formed as a transparent polymer layer in a thickness of 0.5 mm to 12 mm. The laminate has facing the side of action a chemically prestressed, brittle-fracture panel that is at a distance of 3 mm to 20 mm from the side of action.
    Type: Application
    Filed: March 30, 2011
    Publication date: August 8, 2013
    Applicant: SCHOTT AG
    Inventors: Kurt Schaupert, Thilo Hinrich Zachau, Frieder Kropfgans
  • Patent number: 8329295
    Abstract: A process is disclosed for producing a doped gallium arsenide single crystal by melting a gallium arsenide starting material and subsequently solidifying the gallium arsenide melt, wherein the gallium arsenide melt contains an excess of gallium relative to the stoichiometric composition, and wherein it is provided for a boron concentration of at least 5×1017 cm?3 in the melt or in the obtained crystal. The thus obtained crystal is characterized by a unique combination of low dislocation density, high conductivity and yet excellent, very low optic absorption, particularly in the range of the near infrared.
    Type: Grant
    Filed: July 9, 2009
    Date of Patent: December 11, 2012
    Assignee: Freiberger Compound Materials GmbH
    Inventors: Ulrich Kretzer, Frank Börner, Stefan Eichler, Frieder Kropfgans
  • Publication number: 20110084210
    Abstract: A large-volume scintillation crystal affording a high scintillation yield and having high mechanical strength is obtained by growing a crystal from a melt containing strontium iodide, barium iodide or a mixture thereof and by doping with an activator. To this end, the melt is enclosed in a closed volume. Before and/or during the growing, the melt is in diffusion-permitting connection, via the enclosed volume, with an oxygen getter which sets a constant oxygen potential in the closed volume and the melt. Such a scintillation crystal is suitable for detecting UV-, gamma-, beta-, alpha- and/or positron radiation.
    Type: Application
    Filed: October 7, 2010
    Publication date: April 14, 2011
    Inventors: Johann-Christoph Von Saldern, Christoph Seitz, Frieder Kropfgans, Jochen Alkemper, Gunther Wehrhan, Lutz Parthier
  • Publication number: 20100006777
    Abstract: A process is disclosed for producing a doped gallium arsenide single crystal by melting a gallium arsenide starting material and subsequently solidifying the gallium arsenide melt, wherein the gallium arsenide melt contains an excess of gallium relative to the stoichiometric composition, and wherein it is provided for a boron concentration of at least 5×1017 cm?3 in the melt or in the obtained crystal. The thus obtained crystal is characterized by a unique combination of low dislocation density, high conductivity and yet excellent, very low optic absorption, particularly in the range of the near infrared.
    Type: Application
    Filed: July 9, 2009
    Publication date: January 14, 2010
    Inventors: Ulrich KRETZER, Frank Borner, Stefan Eichler, Frieder Kropfgans