Patents by Inventor Rokuo Ichiyasu

Rokuo Ichiyasu 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: 5098649
    Abstract: A rare earth metal-iron group metal target for a magneto-optical disk is produced by mixing power (a) produced by the rapid quenching treatment of an alloy composed of at least one rare earth metal and at least one iron group metal in a composition range which permits the formation of an eutectic structure, with powder (b) from at least one iron group metal in an amount necessary for meeting the composition requirements of the target; and subjecting the resulting mixture to pressure sintering in vacuum or in an inert gas atmosphere at a temperature lower than a liquid phase-appearing temperature of the mixture to produce a rare earth metal-iron group metal intermetallic bonding layer betwen the particles.
    Type: Grant
    Filed: June 26, 1990
    Date of Patent: March 24, 1992
    Assignee: Hitachi Metals, Ltd.
    Inventors: Shunichiro Matsumoto, Tsutomu Inui, Rokuo Ichiyasu, Yoshitaka Chiba
  • Patent number: 5062885
    Abstract: A rare earth metal-iron group metal target for a magneto-optical disk is produced by mixing powder (a) produced by the rapid quenching treatment of an alloy composed of at least one rare earth metal and at least one iron group metal in a composition range which permits the formation of an eutectic structure, with powder (b) from at least one iron group metal in an amount necessary for meeting the composition requirements of the target; and subjecting the resulting mixture to pressure sintering in vacuum or in an inert gas atmosphere at a temperature lower than a liquid phase-appearing temperature of the mixture to produce a rare earth metal-iron group metal intermetallic bonding layer between the particles.
    Type: Grant
    Filed: June 26, 1990
    Date of Patent: November 5, 1991
    Assignee: Hitachi Metals, Ltd.
    Inventors: Shunichiro Matsumoto, Tsutomu Inui, Rokuo Ichiyasu, Yoshitaka Chiba
  • Patent number: 4957549
    Abstract: A rare earth metal-iron group metal target for a magneto-optical disk is produced by mixing powder (a) produced by the rapid quenching treatment of an alloy composed of at least one rare earth metal and at least one iron group metal in a composition range which permits the formation of an eutectic structure, with powder (b) from at least one iron group metal in an amount necessary for meeting the composition requirements of the target; and subjecting the resulting mixture to pressure sintering in vacuum or in an inert gas atmosphere at a temperature lower than a liquid phase-appearing temperature of the mixture to produce a rare earth metal-iron group metal intermetallic bonding layer between the particles.
    Type: Grant
    Filed: April 20, 1988
    Date of Patent: September 18, 1990
    Assignee: Hitachi Metals, Ltd.
    Inventors: Shunichiro Matsumoto, Tsutomu Inui, Rokuo Ichiyasu, Yoshitaka Chiba
  • Patent number: 4941920
    Abstract: A sintered target member consisting essentially of 50-75 weight % of Co, 3-12 weight % of Cr and balance substantially Ni, which has a structure comprising dispersion phases consisting essentially of one or more elements constituting the target member and having a maximum permeability of 50 or less. This target member is produced by mixing metal or alloy powders corresponding to low-permeability dispersion phases, charging the resulting mixture into a metal container; sealing the metal container under reduced pressure; sintering it at a temperature of 900.degree.-1300.degree. C. and pressure of 500 atm or more; and removing the metal container from the resulting sintered body.
    Type: Grant
    Filed: November 23, 1988
    Date of Patent: July 17, 1990
    Assignee: Hitachi Metals, Ltd.
    Inventors: Tsutomu Inui, Shun-ichiro Matsumoto, Rokuo Ichiyasu, Takeo Mizuguchi