Patents by Inventor Hans-Joerg Axmann

Hans-Joerg Axmann 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: 20060201412
    Abstract: The method produces highly uniform, low-stress single crystals, especially of calcium fluoride. A single crystal drawn from a melt apparatus with a suitable process is cooled and subsequently subjected to a tempering step. The method is characterized by rapid cooling in a temperature range between less than or equal to 1300° C. and greater than or equal to 1050° C. with a cooling rate of greater than or equal to 10 K/h and preferably less than or equal to 60 K/h.
    Type: Application
    Filed: March 2, 2006
    Publication date: September 14, 2006
    Inventors: Christian Poetisch, Gunther Wehrhahn, Lutz Parthier, Hans-Joerg Axmann, Joerg Staeblein
  • Patent number: 6969502
    Abstract: In the method for growing large-volume monocrystals crystal raw material is heated in a melting vessel with heating elements to a temperature above its melting point until a melt is formed. A monocrystal is then formed on the bottom of the melting vessel by lowering the temperature at least to the crystallization point. A solid/liquid phase boundary is formed between the monocrystal and the melt. The monocrystal grows towards the melt surface in a direction that is perpendicular to the phase boundary. A vertical axial temperature gradient is produced and maintained between the bottom of the melting vessel and its upper opening and heat inflow and/or heat outflow through side walls of the melting vessel is prevented, so that the solid/liquid phase boundary has a curvature radius of at least one meter. A crystal-growing device for performing this process is also described.
    Type: Grant
    Filed: March 2, 2001
    Date of Patent: November 29, 2005
    Assignee: Schott Glas
    Inventors: Gunther Wehrhan, Peter Elzner, Ewald Moersen, Richard Schatter, Hans-Joerg Axmann, Thorsten Reichardt
  • Patent number: 6932864
    Abstract: In the method and apparatus for measuring the position of the phase interface during growth of a crystal from a melt in a crystal growth container according to the VGF method an incident optical signal is propagated to the phase interface between the melt and the crystal through a window (16) in the container (10) and a received optical signal reflected from the phase interface (14) is measured to determine the position of the phase interface. The position of the phase interface is established from the reflected signal by triangulation with a confocal optic system, by interferometric balancing or by transit time of the optical signal. The window (16) is preferably mounted in a preferably tilted orientation at the end of a tube (15), which is immersed in the melt (12).
    Type: Grant
    Filed: April 23, 2002
    Date of Patent: August 23, 2005
    Assignee: Schott Glas
    Inventors: Lutz Parthier, Frank-Thomas Lentes, Gunther Wehrhan, Burkhard Speit, Hans-Joerg Axmann
  • Publication number: 20030089307
    Abstract: The invention relates to a method for growing large-volume monocrystals with a uniform orientation and consisting of a melt of crystal raw material, in a device comprising a sealable housing (10) in which a melting vessel (20) with side walls (22), a bottom (24), a top opening (26) facing said bottom (24) and optionally a lid (28) are located; and at least one heating element (50, 50′). According to said method, a crystal raw material in the melting vessel (20) is heated with heating elements (50, 50′) to a temperature above the melting point until a melt with a surface is formed. A monocrystal is then formed on the bottom of the melting vessel by lowering the temperature to at least the crystallisation point. Said monocrystal forms a solid/liquid interphase with the melt and grows towards the melt surface on said interphase, in a direction that is perpendicular to the interphase.
    Type: Application
    Filed: October 23, 2002
    Publication date: May 15, 2003
    Inventors: Gunther Wehrhan, Peter Elzner, Ewald Moersen, Richard Schatter, Hans-Joerg Axmann, Thorsten Reichardt
  • Publication number: 20020157599
    Abstract: In the method and apparatus for measuring the position of the phase interface during growth of a crystal from a melt in a crystal growth container according to the VGF method an incident optical signal is propagated to the phase interface between the melt and the crystal through a window (16) in the container (10) and a received optical signal reflected from the phase interface (14) is measured to determine the position of the phase interface. The position of the phase interface is established from the reflected signal by triangulation with a confocal optic system, by interferometric balancing or by transit time of the optical signal. The window (16) is preferably mounted in a preferably tilted orientation at the end of a tube (15), which is immersed in the melt (12).
    Type: Application
    Filed: April 23, 2002
    Publication date: October 31, 2002
    Inventors: Lutz Parthier, Frank-Thomas Lentes, Gunther Wehrhan, Burkhard Speit, Hans-Joerg Axmann