Patents by Inventor Yoshinobu Nagamine

Yoshinobu Nagamine 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).

  • Quartz glass crucible for pulling a semiconductor single crystal
    Patent number: 5306388
    Abstract: A quartz glass crucible for pulling a single crystal, which comprises a cylindrical straight wall portion, a bottom wall portion and a curved intermediate wall portion connecting the straight portion and the bottom portion. The straight portion has an opaque area positioned within about 75% or less of the total height of the crucible, measured from the upper open end of the crucible. The opaque area in the straight portion has a total bubble volume which ranges from about 7.times.10.sup.-3 cm.sup.3 /cm.sup.3 to 30.times.10.sup.-3 cm.sup.3 /cm.sup.3. The remaining straight portion, the curved intermediate portion and the bottom portion consist of transparent material having a total volume of bubbles of about 4.times.10.sup.-3 cm.sup.3 /cm.sup.3 or less.
    Type: Grant
    Filed: January 31, 1992
    Date of Patent: April 26, 1994
    Assignee: Toshiba Ceramics Co., Ltd.
    Inventors: Toshio Nakajima, Tohru Ito, Yoshinobu Nagamine