Patents by Inventor Takahide Kurahashi

Takahide Kurahashi 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: 9154004
    Abstract: In the rare earth sintered magnet, the ratio of R2 to the sum of R1 and R2 that are contained in crystal grain boundaries surrounding the crystal grains in the rare earth sintered magnet body is higher than the ratio of R2 to the sum of R1 and R2 in the crystal grains, and the concentration of R2 increases from the central portion of the rare earth sintered magnet body toward the surface of the rare earth sintered magnet body. In addition, the degree of unevenness in residual magnetic flux density on the surface of the rare earth sintered magnet body is smaller than 3.0%.
    Type: Grant
    Filed: March 4, 2011
    Date of Patent: October 6, 2015
    Assignee: TDK CORPORATION
    Inventors: Makoto Iwasaki, Fumitaka Baba, Satoshi Tanaka, Hideki Sasaki, Takahide Kurahashi, Hitoshi Maro, Keiichi Morimoto, Seiichi Endo
  • Publication number: 20120139388
    Abstract: In the rare earth sintered magnet, the ratio of R2 to the sum of R1 and R2 that are contained in crystal grain boundaries surrounding the crystal grains in the rare earth sintered magnet body is higher than the ratio of R2 to the sum of R1 and R2 in the crystal grains, and the concentration of R2 increases from the central portion of the rare earth sintered magnet body toward the surface of the rare earth sintered magnet body. In addition, the degree of unevenness in residual magnetic flux density on the surface of the rare earth sintered magnet body is smaller than 3.0%.
    Type: Application
    Filed: March 4, 2011
    Publication date: June 7, 2012
    Applicant: TDK CORPORATION
    Inventors: Makoto Iwasaki, Fumitaka Baba, Satoshi Tanaka, Hideki Sasaki, Takahide Kurahashi, Hitoshi Maro, Keiichi Morimoto, Seiichi Endo
  • Patent number: 7286025
    Abstract: A technique for improving a circulator element for its temperature characteristic is provided. A circulator element including a garnet type ferrite material, and a permanent magnet for applying a direct-current magnetic field to the garnet type ferrite material, wherein S11 represents the saturation magnetization of said garnet type ferrite material at a temperature T1, S12 represents one at a temperature T2, and S13 represents one at a temperature T3; and S21 represents the saturation magnetization of said permanent magnet at a temperature T1, S22 represents one at a temperature T2, and S23 represents one at a temperature T3, where T1<T2<T3, and the saturation magnetizations S11, S12, S13, S21, S22 and S23 are relative values providing that the saturation magnetizations at the temperature T2 is 1, and wherein the relations |(S12?S11)/(T2?T1)|<|(S22?S21)/(T2?T1)| and |(S13?S12)/(T3?T2)|>|(S23?S22)/(T3?T2)| are satisfied.
    Type: Grant
    Filed: July 6, 2005
    Date of Patent: October 23, 2007
    Assignee: TDK Corporation
    Inventors: Kenji Endou, Takahide Kurahashi, Sakae Henmi, Hidenori Ohata
  • Publication number: 20060006956
    Abstract: A technique for improving a circulator element for its temperature characteristic is provided. A circulator element including a garnet type ferrite material, and a permanent magnet for applying a direct-current magnetic field to the garnet type ferrite material, wherein S11 represents the saturation magnetization of said garnet type ferrite material at a temperature T1, S12 represents one at a temperature T2, and S13 represents one at a temperature T3; and S21 represents the saturation magnetization of said permanent magnet at a temperature T1, S22 represents one at a temperature T2, and S23 represents one at a temperature T3, where T1?T2?T3, and the saturation magnetizations S11, S12, S13, S21, S22 and S23 are relative values providing that the saturation magnetizations at the temperature T2 is 1, and wherein the relations |(S12?S11)/(T2?T1)|<|(S22?S21)/(T2?T1)| and |(S13?S12)/(T3?T2)|>|(S23?S22)/(T3?T2)| are satisfied.
    Type: Application
    Filed: July 6, 2005
    Publication date: January 12, 2006
    Inventors: Kenji Endou, Takahide Kurahashi, Sakae Henmi, Hidenori Ohata
  • Patent number: 6462628
    Abstract: An isolator device with a built-in power amplifier includes a single dielectric multi-layered substrate, a high frequency power amplifier circuit, an isolator element, and circuit elements provided to the dielectric multi-layered substrate. The high frequency power amplifier circuit and the isolator element are connected with each other through the circuit elements and united with the single dielectric multi-layered substrate.
    Type: Grant
    Filed: March 26, 2001
    Date of Patent: October 8, 2002
    Assignee: TDK Corporation
    Inventors: Ryoichi Kondo, Takahide Kurahashi, Shinya Nakai, Hajime Kato
  • Patent number: 6433649
    Abstract: A non-reciprocal circuit element includes a microstrip TMn10 resonator (n is a positive integer) with a metal disk and branches projecting from the metal disk in a trigonally symmetric structure, and a ferrite magnetic body spontaneously magnetized and coaxially disposed on the microstrip TMn10 resonator. The metal disk and the branches are formed on a non-magnetic dielectric board having a ground conductor on its bottom face. The ferrite magnetic body is arranged so that a position of an electric field node matches to one of the branches.
    Type: Grant
    Filed: May 14, 2001
    Date of Patent: August 13, 2002
    Assignee: TDK Corporation
    Inventors: Taro Miura, Makoto Hasegawa, Takahide Kurahashi, Hidenori Ohata, Sakae Henmi, Kazuaki Suzuki
  • Publication number: 20010045872
    Abstract: A non-reciprocal circuit element includes a microstrip TMn10 resonator (n is a positive integer) with a metal disk and branches projecting from the metal disk in a trigonally symmetric structure, and a ferrite magnetic body spontaneously magnetized and coaxially disposed on the microstrip TMn10 resonator. The metal disk and the branches are formed on a non-magnetic dielectric board having a ground conductor on its bottom face. The ferrite magnetic body is arranged so that a position of an electric field node matches to one of the branches.
    Type: Application
    Filed: May 14, 2001
    Publication date: November 29, 2001
    Applicant: TDK CORPORATION
    Inventors: Taro Miura, Makoto Hasegawa, Takahide Kurahashi, Hidenori Ohata, Sakae Henmi, Kazuaki Suzuki
  • Publication number: 20010017576
    Abstract: An isolator device with a built-in power amplifier includes a single dielectric multi-layered substrate, a high frequency power amplifier circuit, an isolator element, and circuit elements provided to the dielectric multi-layered substrate. The high frequency power amplifier circuit and the isolator element are connected with each other through the circuit elements and united with the single dielectric multi-layered substrate.
    Type: Application
    Filed: March 26, 2001
    Publication date: August 30, 2001
    Applicant: TDK CORPORATION
    Inventors: Ryoichi Kondo, Takahide Kurahashi, Shinya Nakai, Hajime Kato
  • Patent number: 6235221
    Abstract: A multilayer ceramic part of the invention comprises an internal conductor layer and a ceramic layer which are formed by co-firing. The internal conductor layer is formed of an electrical conducting material containing silver as a main component, and the ceramic layer is formed of an yttrium-iron-garnet based oxide magnetic material with silver added thereto. Thus, the multilayer ceramic part can be fabricated in high yields, even when its size is much more smaller than that of a multilayer ceramic part fabricated until now.
    Type: Grant
    Filed: May 20, 1999
    Date of Patent: May 22, 2001
    Assignee: TDK Corporation
    Inventors: Kazuaki Suzuki, Takahide Kurahashi, Hidenori Ohata
  • Patent number: 6215371
    Abstract: A non-reciprocal circuit element includes a plurality of inner conductors intersecting with keeping insulation with each other, a shield conductor connected in common to one end of the inner conductors, and a capacitor connected between the shield conductor and a ground of the non-reciprocal circuit element, for adjusting only eigen values of in-phase excitation. Thus, smaller size, lighter weight and lower height can be attained and also temperature characteristics can be optionally adjusted without changing material used and without inviting increased insertion loss.
    Type: Grant
    Filed: July 16, 1999
    Date of Patent: April 10, 2001
    Assignee: TDK Corporation
    Inventors: Takahide Kurahashi, Hidenori Ohata, Akihito Watanabe, Yoshinori Matsumaru
  • Patent number: 6120884
    Abstract: An object is to provide a conductor paste of quality which uses a silver base internal conductor, suppresses the generation of voids and the concomitant occurrence of cracks even when co-fired with ceramic material by the conductor melting method, and has improved productivity, reduced cost, and improved electrical properties. The conductor paste is prepared by dispersing a silver base conductive material and a metal oxide in a vehicle. At least one of Ga oxide, La oxide, Pr oxide, Sm oxide, Eu oxide, Gd oxide, Dy oxide, Er oxide, Tm oxide, and Yb oxide is used as the metal oxide. The conductor paste is fired at a temperature between the melting point and lower than the boiling point of the conductive material.
    Type: Grant
    Filed: May 12, 1998
    Date of Patent: September 19, 2000
    Assignee: TDK Corporation
    Inventors: Katsuhiko Igarashi, Hidenori Ohata, Takahide Kurahashi, Kazuaki Suzuki
  • Patent number: 5847628
    Abstract: A ground conductor and a signal conductor are provided in an insulating magnetic body respectively. The insulating magnetic body is a compound member that combines ferromagnetic metal particles and an insulating resin. A signal transmission element, a connector or a circuit board with high frequency stopping and low pass characteristics which will ensure reliable absorption of high frequency components in the high frequency range, can be provided. The ground conductor and the signal conductor are provided on opposite sides of the insulating magnetic body.
    Type: Grant
    Filed: September 25, 1997
    Date of Patent: December 8, 1998
    Assignee: TDK Corporation
    Inventors: Fumio Uchikoba, Shigeyuki Nakajima, Takashi Ito, Taro Miura, Makoto Kobayashi, Takahide Kurahashi, Yasushi Iijima
  • Patent number: 5796323
    Abstract: A ground conductor and a signal conductor are provided in an insulating magnetic body respectively. The insulating magnetic body is a compound member that combines ferromagnetic metal particles and an insulating resin. A signal transmission element, a connector or a circuit board with high frequency stopping and low pass characteristics which will ensure reliable absorption of high frequency components in the high frequency range, can be provided.
    Type: Grant
    Filed: June 12, 1997
    Date of Patent: August 18, 1998
    Assignee: TDK Corporation
    Inventors: Fumio Uchikoba, Shigeyuki Nakajima, Takashi Ito, Taro Miura, Makoto Kobayashi, Takahide Kurahashi, Yasushi Iijima
  • Patent number: 5594397
    Abstract: A ground conductor and a signal conductor are provided in an insulating magnetic body respectively. The insulating magnetic body is a compound member that combines ferromagnetic metal particles and an insulating resin. A signal transmission element, a connector or a circuit board with high frequency stopping and low pass characteristics which will ensure reliable absorption of high frequency components in the high frequency range, can be provided.
    Type: Grant
    Filed: March 23, 1995
    Date of Patent: January 14, 1997
    Assignee: TDK Corporation
    Inventors: Fumio Uchikoba, Shigeyuki Nakajima, Takashi Ito, Taro Miura, Makoto Kobayashi, Takahide Kurahashi, Yasushi Iijima