Patents by Inventor Toshihisa Yokoyama

Toshihisa Yokoyama 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).

  • Process and apparatus for producing a planar body of an oxide single crystal
    Patent number: 6565654
    Abstract: In a process for producing a planar body of an oxide single crystal with a &mgr; pulling-down method, a shoulder portion having a larger width is grown without any polycrystal regions, cracks or crystal deteriorations in a central portion of the planar body. A raw material of the oxide single crystal is melted in a crucible. A seed crystal is contacted to a melt of the raw material near an opening of a nozzle 13 of the crucible. Then, the melt 18 is drawn from the opening by pulling down the seed crystal to form a planar body 14A. A temperature distribution of the nozzle 13 in a direction perpendicular to the drawing direction B is controlled by supplying heat to the nozzle 13 and/or by removing heat from the nozzle 13.
    Type: Grant
    Filed: July 2, 2001
    Date of Patent: May 20, 2003
    Assignee: NGK Insulators, Ltd.
    Inventors: Toshihisa Yokoyama, Masahiro Murasato, Katsuhiro Imai, Minoru Imaeda
  • Process and apparatus for producing a planar body of an oxide single crystal
    Publication number: 20020029736
    Abstract: In a process for producing a planar body of an oxide single crystal with a &mgr; pulling-down method, a shoulder portion having a larger width is grown without any polycrystal regions, cracks or crystal deteriorations in a central portion of the planar body. A raw material of the oxide single crystal is melted in a crucible. A seed crystal is contacted to a melt of the raw material near an opening of a nozzle 13 of the crucible. Then, the melt 18 is drawn from the opening by pulling down the seed crystal to form a planar body 14A. A temperature distribution of the nozzle 13 in a direction perpendicular to the drawing direction B is controlled by supplying heat to the nozzle 13 and/or by removing heat from the nozzle 13.
    Type: Application
    Filed: July 2, 2001
    Publication date: March 14, 2002
    Inventors: Toshihisa Yokoyama, Masahiro Murasato, Katsuhiro Imai, Minoru Imaeda
  • Process and apparatus for producing an oxide single crystal
    Publication number: 20020007780
    Abstract: A planar body of an oxide single crystal having a good crystallinity is grown stably to prevent cracks in the crystal when the planar body of the oxide single crystal is grown with a &mgr; pulling-down method. A raw material of the oxide single crystal is melted in a crucible 7. A seed crystal 15 is contacted to a melt 8. An oxide single crystal 31 is grown by pulling down the seed crystal 15 to draw the melt from an opening 13c of the crucible 7. A cooler is provided under the opening 13c of the crucible 7, which cool the oxide single crystal drawn from the opening of the crucible.
    Type: Application
    Filed: May 14, 2001
    Publication date: January 24, 2002
    Applicant: NGK Insulators, Ltd.
    Inventors: Toshihisa Yokoyama, Ken-Ichi Noda, Katsuhiro Imai, Minoru Imaeda