Patents by Inventor Atsushi Takedoi

Atsushi Takedoi 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).

  • Magnetic iron oxide particles and method of producing the same
    Patent number: 5582914
    Abstract: Disclosed herein are magnetic iron oxide particles which have a spindle shape and a substantially uniform particle size and shape, and are substantially free of dendrites and have a large axial ratio (major axial diameter/minor axial diameter) and an excellent print-through characteristic, and a method of producing the same.
    Type: Grant
    Filed: February 16, 1994
    Date of Patent: December 10, 1996
    Assignee: Toda Kogyo Corp.
    Inventors: Atsushi Takedoi, Mamoru Tanihara, Tosiharu Harada, Masaru Isoai, Kazuhiro Fujita
  • Magnetic iron oxide particles and method of producing same
    Patent number: 5314750
    Abstract: Disclosed herein are magnetic iron oxide particles which have a spindle shape and a substantially uniform particle size and shape, and are substantially free of dendrites and have a large axial ratio (major axial diameter/minor axial diameter) and an excellent print-through characteristic, and a method of producing the same.
    Type: Grant
    Filed: October 27, 1992
    Date of Patent: May 24, 1994
    Assignee: Toda Kogyo Corp.
    Inventors: Atsushi Takedoi, Mamoru Tanihara, Tosiharu Harada, Masaru Isoai, Kazuhiro Fujita
  • Plate-like magnetite particles, plate-like maghemite particles and processes of producing the same
    Patent number: 5093100
    Abstract: Disclosed herein are poreless, non-sintered plate-like magnetite particles having an average particle diameter of more than 0.5 .mu.m and not more than 2.0 .mu.m, and a BET specific surface area of not more than 6.0 m.sup.2 /g, and poreless, non-sintered plate-like maghemite particles having an average particle diameter of more than 0.5 .mu.m and not more than 2.0 .mu.m, and a BET specific surface area of not more than 6.0 m.sup.2 /g.
    Type: Grant
    Filed: March 15, 1990
    Date of Patent: March 3, 1992
    Assignee: Toda Kogyo Corp.
    Inventors: Hideaki Sadamura, Atsushi Takedoi
  • Spindle-like magnetic iron oxide particles and process for producing the same
    Patent number: 4873010
    Abstract: Disclosed herein are magnetic iron oxide particles comprising spindle-like magnetite or maghemite particles having an aspect ratio(major:minor) of less than 4:1 and containing 0.1 to 20 atomic % of Si to Fe, and a process for producing the same.
    Type: Grant
    Filed: April 15, 1987
    Date of Patent: October 10, 1989
    Assignee: Toda Kogyo Corp.
    Inventors: Atsushi Takedoi, Hiroyuki Kondo, Masaru Isoai, Yoshitaka Yoshinaga, Tosiharu Harada, Yosiro Okuda, Hiroshi Sumita, Hirofumi Kawasaki, Kohji Mori