Patents by Inventor Yasutake Hirota

Yasutake Hirota 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 member and electronic component
    Patent number: 9627111
    Abstract: A magnetic member includes a plurality of superparamagnetic particles held by the magnetic member. Each of the plurality of superparamagnetic particles is formed with a particle size which is set at least such that a Neel relaxation time ?n in the each of the superparamagnetic particles becomes shorter than a cycle P of an alternating current magnetic field applied to the magnetic member (?n<P) when the magnetic member is used as an electronic component.
    Type: Grant
    Filed: November 9, 2010
    Date of Patent: April 18, 2017
    Assignee: Ferrotec Corporation
    Inventors: Yasutake Hirota, Kenichi Katsuma, Masatake Hirooka, Takayuki Hachida
  • Current sensor having at least one cancel coil
    Patent number: 9448262
    Abstract: A current sensor according to the present invention includes a sensor element and a detector. The sensor element includes a core member, an exciting coil and a detection coil. The sensor element is configured such that, while the exciting coil is fed with an excitation signal, comprising a fundamental component, and when the signal to be detected flows, a signal, including a harmonic component, corresponding to the permeability ? of the core member at that point, being superposed on the fundamental component, is outputted from the detection coil. The detector includes a component extraction unit, a level specification unit, and an information output unit.
    Type: Grant
    Filed: March 12, 2013
    Date of Patent: September 20, 2016
    Assignee: Ferrotec Corporation
    Inventors: Takayuki Hachida, Yasutake Hirota
  • Magnetic Member and Electronic Component
    Publication number: 20120229238
    Abstract: A magnetic member includes a plurality of superparamagnetic particles held by the magnetic member. Each of the plurality of superparamagnetic particles is formed with a particle size which is set at least such that a Neel relaxation time ?n in the each of the superparamagnetic particles becomes shorter than a cycle P of an alternating current magnetic field applied to the magnetic member (?n<P) when the magnetic member is used as an electronic component.
    Type: Application
    Filed: November 9, 2010
    Publication date: September 13, 2012
    Applicant: FERROTEC CORPORATION
    Inventors: Yasutake Hirota, Kenichi Katsuma, Masakake Hirooka, Takayuki Hachida
  • Ferrofluid composition and process
    Patent number: 6277298
    Abstract: The invention relates to a composition and process for producing a chemically stable magnetic fluid comprising a plurality of magnetic particles covered first with a small molecular weight surface modifier, which is a nondispersant and acts as a surfactant-accepting layer, and then with at least one surfactant. The surface modifier/surfactant coated magnetic particles are then suspended in a silicone oil-based, hydrocarbon oil-based or an ester oil-based carrier liquid.
    Type: Grant
    Filed: October 28, 1999
    Date of Patent: August 21, 2001
    Inventors: Lucian Borduz, Shiro Tsuda, Yasutake Hirota
  • Composition and method of making a ferrofluid having an improved chemical stability
    Patent number: 6261471
    Abstract: The invention relates to a composition and a process for producing a magnetic fluid comprising finely divided magnetic particles covered with at least one surfactant. A fluorocarbon-silane surface modifier is employed which is added to cover the free oxidizable exterior surface of the outer layer of the particles to increase the acid resistance of the colloid.
    Type: Grant
    Filed: October 15, 1999
    Date of Patent: July 17, 2001
    Inventors: Shiro Tsuda, Yasutake Hirota, Hisao Suzuki
  • Process for producing a magnetic fluid and composition therefor
    Patent number: 6056889
    Abstract: The invention relates to a composition and a process for producing a chemically stable magnetic fluid comprising finely divided magnetic particles covered with surfactants. A surface modifier is also employed which is added to cover thoroughly the free oxidizable exterior surface of the outer layer of the particles to assure better chemical stability of the colloid under different environmental conditions.
    Type: Grant
    Filed: October 10, 1997
    Date of Patent: May 2, 2000
    Assignee: Ferrotec Corporation
    Inventors: Shiro Tsuda, Kacey Wiley Heckman, Yasutake Hirota, Stefan Borduz, Lucian Borduz