Patents by Inventor Yumiko Kitahata

Yumiko Kitahata 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 powder, method for producing the same and magnetic recording medium comprising the same
    Patent number: 7510790
    Abstract: A magnetic powder consisting of substantially spherical or ellipsoidal particles comprising a transition metal which comprises iron and a rear earth element which is mainly present in the outer layer of the magnetic powder particles, and having a particle size of 5 to 200 nm, a coercive force of 80 to 400 kA/m and a saturation magnetization of 10 to 25 ?Wb/g.
    Type: Grant
    Filed: September 12, 2005
    Date of Patent: March 31, 2009
    Assignee: Hitachi Maxell, Ltd.
    Inventors: Mikio Kishimoto, Yuji Sasaki, Yumiko Kitahata, legal representative, Hideaki Watanabe, Shinichi Kitahata
  • Magnetic powder, method for producing the same and magnetic recording medium comprising the same
    Publication number: 20060008645
    Abstract: A magnetic powder consisting of substantially spherical or ellipsoidal particles comprising a transition metal which comprises iron and a rear earth element which is mainly present in the outer layer of the magnetic powder particles, and having a particle size of 5 to 200 nm, a coercive force of 80 to 400 kA/m and a saturation magnetization of 10 to 25 ?Wb/g.
    Type: Application
    Filed: September 12, 2005
    Publication date: January 12, 2006
    Inventors: Nikio Kishimoto, Yuji Sasaki, Shinichi Kitahata, Yumiko Kitahata, Hideaki Watanabe
  • Magnetic powder, method for producing the same and magnetic recording medium comprising the same
    Patent number: 6964811
    Abstract: A magnetic powder consisting of substantially spherical or ellipsoidal particles comprising a transition metal which comprises iron and a rear earth element which is mainly present in the outer layer of the magnetic powder particles, and having a particle size of 5 to 200 nm, a coercive force of 80 to 400 kA/m and a saturation magnetization of 10 to 25 uWb/g.
    Type: Grant
    Filed: February 21, 2003
    Date of Patent: November 15, 2005
    Assignee: Hitachi Maxell, Ltd.
    Inventors: Mikio Kishimoto, Yuji Sasaki, Yumiko Kitahata, Hideaki Watanabe, Shinichi Kitahata
  • Magnetic powder, method for producing the same and magnetic recording medium comprising the same
    Publication number: 20040072025
    Abstract: A magnetic powder consisting of substantially spherical or ellipsoidal particles comprising a transition metal which comprises iron and a rear earth element which is mainly present in the outer layer of the magnetic powder particles, and having a particle size of 5 to 200 nm, a coercive force of 80 to 400 kA/m and a saturation magnetization of 10 to 25 &mgr;Wb/g.
    Type: Application
    Filed: February 21, 2003
    Publication date: April 15, 2004
    Inventors: Mikio Kishimoto, Yuji Sasaki, Shinichi Kitahata, Yumiko Kitahata, Hideaki Watanabe