Patents by Inventor Keiko Kikuchi

Keiko Kikuchi 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: 8723508
    Abstract: A method for analyzing the DC superposition characteristics of an inductance device using an electromagnetic field simulator, comprising a first step of determining an initial magnetization curve from initial magnetization to saturation magnetization, and pluralities of minor loops at different operating points, on a toroidal core made of the same magnetic material as that of the inductance device, and obtaining point-list data showing the relation between magnetic flux density or magnetic field strength and incremental permeability from the incremental permeability at each operating point; a second step of determining an operating point at a predetermined direct current on each element obtained by mesh-dividing an analysis model of the inductance device by an electromagnetic field simulator based on the initial magnetization curve of the core, allocating the incremental permeability to the operating point from the point-list data, and integrating the inductance of each element obtained from the incremental p
    Type: Grant
    Filed: September 30, 2009
    Date of Patent: May 13, 2014
    Assignee: Hitachi Metals, Ltd.
    Inventors: Takeshi Tachibana, Satoru Tanaka, Keiko Kikuchi
  • Publication number: 20110181274
    Abstract: A method for analyzing the DC superposition characteristics of an inductance device using a magnetic field analysis simulator, comprising a first step of determining an initial magnetization curve from initial magnetization to saturation magnetization, and pluralities of minor loops at different operating points, on a toroidal core made of the same magnetic material as that of the inductance device, and obtaining point-list data showing the relation between magnetic flux density or magnetic field strength and incremental permeability from the incremental permeability at each operating point; a second step of determining an operating point at a predetermined direct current on each element obtained by mesh-dividing an analysis model of the inductance device by a magnetic field analysis simulator based on the initial magnetization curve of the core, allocating the incremental permeability to the operating point from the point-list data, and integrating the inductance of each element obtained from the incremental
    Type: Application
    Filed: September 30, 2009
    Publication date: July 28, 2011
    Applicant: HITACHI METALS, LTD.
    Inventors: Takeshi Tachibana, Satoru Tanaka, Keiko Kikuchi
  • Patent number: 7981359
    Abstract: A rotor comprising bonded magnet portions mainly composed of magnet powder and a binder, which are embedded in a soft magnetic portion mainly composed of soft magnetic powder and a binder, the rotor being produced by a compression-molding method, and the magnetic pole surfaces of the bonded magnet portions being embedded in the soft magnetic portion.
    Type: Grant
    Filed: December 7, 2004
    Date of Patent: July 19, 2011
    Assignee: Hitachi Metals, Ltd.
    Inventors: Masahiro Masuzawa, Shigeho Tanigawa, Masahiro Mita, Keiko Kikuchi
  • Patent number: 7965163
    Abstract: Provided is an annular reactor core formed of a U-shaped core and core legs. Core joints including end portions and two protrusions form the U-shaped core. Between the protrusions of these core joints, a plurality of (two) core legs 6 formed of core blocks are arranged so as to have gaps and the protrusions. The ratio A/B, which is a ratio of the length A of the protrusions of the core joint to the average length B of the core blocks constituting the core legs in a magnetic path direction, is optimized so as to be not less than 0.3 but not more than 8.0, whereby an increase in copper loss due to leak magnetic fluxes of the gap portions is suppressed.
    Type: Grant
    Filed: January 10, 2008
    Date of Patent: June 21, 2011
    Assignee: Hitachi Metals, Ltd.
    Inventors: Toru Abe, Hiroki Hamakake, Keiko Kikuchi
  • Publication number: 20100171580
    Abstract: Provided is an annular reactor core formed of a U-shaped core and core legs. Core joints including end portions and two protrusions form the U-shaped core. Between the protrusions of these core joints, a plurality of (two) core legs 6 formed of core blocks are arranged so as to have gaps and the protrusions. The ratio A/B, which is a ratio of the length A of the protrusions of the core joint to the average length B of the core blocks constituting the core legs in a magnetic path direction, is optimized so as to be not less than 0.3 but not more than 8.0, whereby an increase in copper loss due to leak magnetic fluxes of the gap portions is suppressed.
    Type: Application
    Filed: January 10, 2008
    Publication date: July 8, 2010
    Inventors: Toru Abe, Hiroki Hamakake, Keiko Kikuchi
  • Publication number: 20060170301
    Abstract: A rotor comprising bonded magnet portions mainly composed of magnet powder and a binder, which are embedded in a soft magnetic portion mainly composed of soft magnetic powder and a binder, the rotor being produced by a compression-molding method, and the magnetic pole surfaces of the bonded magnet portions being embedded in the soft magnetic portion.
    Type: Application
    Filed: December 7, 2004
    Publication date: August 3, 2006
    Inventors: Masahiro Masuzawa, Shigeho Tanigawa, Masahiro Mita, Keiko Kikuchi
  • Patent number: 6992553
    Abstract: A polar-anisotropic ring magnet having magnetization directions in alignment with its normal line at each magnetic pole position and in alignment with its tangential line at each middle position between adjacent magnetic poles, and having a substantially constant angle difference in a magnetization direction between adjacent elements, the elements being obtained by division at an equal angle pitch between the magnetic pole position and the middle position adjacent to the magnetic pole position.
    Type: Grant
    Filed: June 18, 2003
    Date of Patent: January 31, 2006
    Assignee: Hitachi Metals, Ltd.
    Inventors: Masahiro Masuzawa, Keiko Kikuchi
  • Patent number: 6885267
    Abstract: An magnetic-field-generating apparatus comprising permanent magnet segments arranged to form a ring-shaped magnetic circuit having a center hole; adjacent permanent magnet segments having such different magnetization directions that their magnetization directions successively change along a circumferential direction of the magnetic circuit; a basic magnetization phase angle ? between the magnetization directions of the adjacent permanent magnet segments being 720/N (°); and a magnetization direction of at least one permanent magnet segment in an essential unit obtained by circumferentially dividing the ring to ¼ being deviated from the basic magnetization phase angle ? by such a deviating angle that a uniform magnetic flux flows in one direction along a diameter of the center hole.
    Type: Grant
    Filed: March 17, 2004
    Date of Patent: April 26, 2005
    Assignee: Hitachi Metals Ltd.
    Inventors: Yoshihiko Kuriyama, Keiko Kikuchi
  • Publication number: 20050076973
    Abstract: A polar-anisotropic ring magnet having magnetization directions in alignment with its normal line at each magnetic pole position and in alignment with its tangential line at each middle position between adjacent magnetic poles, and having a substantially constant angle difference in a magnetization direction between adjacent elements, the elements being obtained by division at an equal angle pitch between the magnetic pole position and the middle position adjacent to the magnetic pole position.
    Type: Application
    Filed: June 18, 2003
    Publication date: April 14, 2005
    Inventors: Masahiro Masuzawa, Keiko Kikuchi
  • Patent number: 6873291
    Abstract: A surface-mounted antenna comprising a substrate made of a high-dielectric constant material having a dielectric constant ?r of 6 or more, a ribbon-shaped radiation electrode having one end which is grounded and the other end which is open, a grounding electrode connected or capacitance-coupled to one end of the radiation electrode, and a current-feeding electrode in a portal shape formed on a side surface separate from the radiation electrode with a gap; the current-feeding electrode having a current-feeding portion at one end, a grounding portion at the other end, and a portion substantially in alignment with the radiation electrode between them; and the length of the aligning portion, a gap width or a portal shape being able to be properly set such that capacitance owned by the current-feeding electrode and inductance can be adjusted for easily achieving impedance matching.
    Type: Grant
    Filed: June 14, 2002
    Date of Patent: March 29, 2005
    Assignee: Hitachi Metals, Ltd.
    Inventors: Hiroyuki Aoyama, Keiko Kikuchi, Yasunori Takaki, Hidetoshi Hagiwara
  • Publication number: 20040263303
    Abstract: An magnetic-field-generating apparatus comprising permanent magnet segments arranged to form a ring-shaped magnetic circuit having a center hole; adjacent permanent magnet segments having such different magnetization directions that their magnetization directions successively change along a circumferential direction of the magnetic circuit; a basic magnetization phase angle &thgr; between the magnetization directions of the adjacent permanent magnet segments being 720/N (°); and a magnetization direction of at least one permanent magnet segment in an essential unit obtained by circumferentially dividing the ring to ¼ being deviated from the basic magnetization phase angle &thgr; by such a deviating angle that a uniform magnetic flux flows in one direction along a diameter of the center hole.
    Type: Application
    Filed: March 17, 2004
    Publication date: December 30, 2004
    Applicant: HITACHI METALS, LTD.
    Inventors: Yoshihiko Kuriyama, Keiko Kikuchi
  • Patent number: 6639559
    Abstract: To provide an antenna element having a radiation electrode formed mainly on one surface of a dielectric substrate. The radiation electrode is substantially symmetric in form with respect to the center thereof, and has a first half and a second half with the same direction of main polarization of radiation emitted therefrom. Each of the halves of the radiation electrode may be a quarter-wave antenna for a wavelength of the emitted radiation. A power supply conductor to be connected to a high frequency signal source is connected to the first half of the radiation electrode, and a ground conductor to be connected to a ground is connected to the second half. A total impedance of the first half of the radiation electrode and the power supply conductor and a total impedance of the second half of the radiation electrode and the ground conductor can substantially match to one another, so that resonance between the halves of the radiation electrode can be enhanced and a wider bandwidth can be realized.
    Type: Grant
    Filed: February 26, 2002
    Date of Patent: October 28, 2003
    Assignees: Hitachi Ltd., Hitachi Metals Ltd.
    Inventors: Hiroshi Okabe, Eriko Takeda, Hiroyuki Aoyama, Keiko Kikuchi
  • Publication number: 20030006936
    Abstract: A surface-mounted antenna comprising a substrate made of a high-dielectric constant material having a dielectric constant ∈r of 6 or more, a ribbon-shaped radiation electrode having one end which is grounded and the other end which is open, a grounding electrode connected or capacitance-coupled to one end of the radiation electrode, and a current-feeding electrode in a portal shape formed on a side surface separate from the radiation electrode with a gap; the current-feeding electrode having a current-feeding portion at one end, a grounding portion at the other end, and a portion substantially in alignment with the radiation electrode between them; and the length of the aligning portion, a gap width or a portal shape being able to be properly set such that capacitance owned by the current-feeding electrode and inductance can be adjusted for easily achieving impedance matching.
    Type: Application
    Filed: June 14, 2002
    Publication date: January 9, 2003
    Applicant: HITACHI METALS, LTD.
    Inventors: Hiroyuki Aoyama, Keiko Kikuchi, Yasunori Takaki, Hidetoshi Hagiwara
  • Patent number: 6476767
    Abstract: A chip antenna element comprises (a) a radiation electrode formed on at least one surface of an insulating substrate, such that the radiation electrode extends from a first end of the substrate or its vicinity to a second end of the substrate or its vicinity, with a width decreasing substantially continuously and/or stepwise, thereby having a wide rear end on the side of the first end of the substrate and a narrow tip end on the side of the second end of the substrate, (b) a first grounding electrode connecting directly or via a gap to the rear end of the radiation electrode, (c) a second grounding electrode opposing the tip end of the radiation electrode via a gap, and (d) a feeding electrode formed on at least one surface of the substrate at a position facing an intermediate point of the radiation electrode, with or without contact with the radiation electrode.
    Type: Grant
    Filed: April 13, 2001
    Date of Patent: November 5, 2002
    Assignee: Hitachi Metals, Ltd.
    Inventors: Hiroyuki Aoyama, Kenichi Tonomura, Keiko Kikuchi, Yuta Sugiyama
  • Publication number: 20020126049
    Abstract: To provide an antenna element having a radiation electrode formed mainly on one surface of a dielectric substrate. The radiation electrode is substantially symmetric in form with respect to the center thereof, and has a first half and a second half with the same direction of main polarization of radiation emitted therefrom. Each of the halves of the radiation electrode may be a quarter-wave antenna for a wavelength of the emitted radiation. A power supply conductor to be connected to a high frequency signal source is connected to the first half of the radiation electrode, and a ground conductor to be connected to a ground is connected to the second half. A total impedance of the first half of the radiation electrode and the power supply conductor and a total impedance of the second half of the radiation electrode and the ground conductor can substantially match to one another, so that resonance between the halves of the radiation electrode can be enhanced and a wider bandwidth can be realized.
    Type: Application
    Filed: February 26, 2002
    Publication date: September 12, 2002
    Applicant: HITACHI LTD., HITACHI METALS, LTD.
    Inventors: Hiroshi Okabe, Eriko Takeda, Hiroyuki Aoyama, Keiko Kikuchi
  • Publication number: 20010050637
    Abstract: A chip antenna element comprises (a) a radiation electrode formed on at least one surface of an insulating substrate, such that the radiation electrode extends from a first end of the substrate or its vicinity to a second end of the substrate or its vicinity, with a width decreasing substantially continuously and/or stepwise, thereby having a wide rear end on the side of the first end of the substrate and a narrow tip end on the side of the second end of the substrate, (b) a first grounding electrode connecting directly or via a gap to the rear end of the radiation electrode, (c) a second grounding electrode opposing the tip end of the radiation electrode via a gap, and (d) a feeding electrode formed on at least one surface of the substrate at a position facing an intermediate point of the radiation electrode, with or without contact with the radiation electrode.
    Type: Application
    Filed: April 13, 2001
    Publication date: December 13, 2001
    Inventors: Hiroyuki Aoyama, Kenichi Tonomura, Keiko Kikuchi, Yuta Sugiyama