Patents by Inventor Taku Murase

Taku Murase 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).

  • Publication number: 20070246681
    Abstract: W-type ferrite has improved magnetic properties, in particular, coercive force. A high coercive force (HcJ) and a high residual magnetic flux density (Br) can be simultaneously attained by a ferrite magnetic material comprising an oxide having a composition wherein metal elements Sr, Ba and Fe in total have a composition ratio represented by the formula Sr(1?x)BaxFe2+aFe3+b in which 0.03?x?0.80, 1.1?a?2.4, and 12.3?b?16.1. The ferrite magnetic material can form any of a ferrite sintered magnet, a ferrite magnet powder, a bonded magnet as a ferrite magnet powder dispersed in a resin, and a magnetic recording medium as a film-type magnetic phase. As for the ferrite sintered magnet, there can be attained a fine sintered structure that has a mean grain size of 0.6 ?m or less.
    Type: Application
    Filed: March 3, 2005
    Publication date: October 25, 2007
    Applicant: TDK CORPORATION
    Inventors: Yoshihiko Minachi, Noboru Ito, Junichi Nagaoka, Shunsuke Kurasawa, Taku Murase
  • Publication number: 20070202359
    Abstract: A multilayer film (1) is formed by alternately layering a Co-based amorphous alloy layer (2) and a natural-oxidation layer (3) of the Co-based amorphous alloy (2) on a substrate (4). A magnetic thin film for high frequencies and a magnetic device which can be used in high frequency regions of the GHz band are obtained by making a volume ratio of the natural-oxidation layer (3) to the whole multilayer film (1) fall within a range of 5 to 50%.
    Type: Application
    Filed: September 30, 2004
    Publication date: August 30, 2007
    Applicant: TDK CORPORATION
    Inventors: Kyung-Ku Choi, Taku Murase
  • Publication number: 20070183923
    Abstract: A high frequency magnetic thin film characterized by comprising a first layer made of a T-L composition (here, T is Fe or FeCo, and L is one or more of C, B, and N) and a second layer comprising a Co-based amorphous alloy arranged on either of the surfaces of the first layer. The high frequency magnetic thin film is a multilayer film of a plurality of the first layers and a plurality of the second layers or desirably is a multilayer film of alternately laminated first and second layers. The high frequency magnetic thin film of the present invention exhibits the properties such that the real part (??) of the complex permeability is 400 or more at 1 GHz, a quality factor Q (Q=??/??) is 4 or more, and a saturation magnetization is 14 kG (1.4 T) or more.
    Type: Application
    Filed: April 4, 2007
    Publication date: August 9, 2007
    Applicant: TDK CORPORATION
    Inventors: Kyung-Ku CHOI, Taku MURASE, Yohtaro YAMAZAKI
  • Patent number: 7238298
    Abstract: An Ni—Cu—Zn-based ferrite material contains TiO2 alone as an additive in an amount of 0.1 wt %<x?4.0 wt % in which x denotes a content of the TiO2 and unavoidable impurities. The principal components thereof are 43.0 to 49.8 mol % of Fe2O3, 4.0 to 13.0 mol % of CuO, 5 to 35 mol % of ZnO and the balance of NiO.
    Type: Grant
    Filed: October 6, 2004
    Date of Patent: July 3, 2007
    Assignee: TDK Corporation
    Inventors: Takuya Aoki, Taku Murase
  • Patent number: 7224254
    Abstract: A high frequency magnetic thin film characterized by comprising a first layer made of a T-L composition (here, T is Fe or FeCo, and L is one or more of C, B, and N) and a second layer comprising a Co-based amorphous alloy arranged on either of the surfaces of the first layer. The high frequency magnetic thin film is a multilayer film of a plurality of the first layers and a plurality of the second layers or desirably is a multilayer film of alternately laminated first and second layers. The high frequency magnetic thin film of the present invention exhibits the properties such that the real part (??) of the complex permeability is 400 or more at 1 GHz, a quality factor Q (Q=??/??) is 4 or more, and a saturation magnetization is 14 kG (1.4T) or more.
    Type: Grant
    Filed: January 10, 2003
    Date of Patent: May 29, 2007
    Assignee: TDK Corporation
    Inventors: Kyung-Ku Choi, Taku Murase, Yohtaro Yamazaki
  • Publication number: 20070099033
    Abstract: A ferrite magnetic material comprising a main phase of W-type is provided which has magnetic properties improved through the optimization of additives. The ferrite magnetic material comprises a main constituent having a compound represented by composition formula AFe2+aFe3+bO27 (wherein A comprises at least one element selected from Sr, Ba and Pb; 1.5?a?2.1; and 12.9?b?16.3), a first additive containing a Ca constituent (0.3 to 3.0 wt % in terms of CaCO3) and/or a Si constituent (0.2 to 1.4 wt % in terms of SiO2), and a second additive containing at least one of an Al constituent (0.01 to 1.5 wt % in terms of Al2O3), a W constituent (0.01 to 0.6 wt % in terms of WO3), a Ce constituent (0.001 to 0.6 wt % in terms of CeO2), a Mo constituent (0.001 to 0.16 wt % in terms of MoO3), and a Ga constituent (0.001 to 15 wt % in terms of Ga2O3).
    Type: Application
    Filed: December 8, 2004
    Publication date: May 3, 2007
    Inventors: Yoshihiko Minachi, Junichi Nagaoka, Shunsuke Kurasawa, Noboru Ito, Taku Murase, Takeshi Masuda, Kenya Takagawa, Hidenobu Umeda
  • Publication number: 20070072005
    Abstract: By using a DM (discontinuous multilayer) structure formed of ferromagnetic metal in amorphous state and amorphous metal different from the ferromagnetic metal, a magnetic thin film for high frequencies is realized that has a high magnetic permeability in a high-frequency region of a GHz band and that has a high saturated magnetization. This magnetic thin film for high frequencies is preferably provided so that: (i) the ferromagnetic metal is predominantly composed of Fe or FeCo and contains one or more elements selected from the group of C, B, and N and the amorphous metal is a Co-base amorphous alloy; and (ii) the amorphous metal is CoZrNb.
    Type: Application
    Filed: September 10, 2004
    Publication date: March 29, 2007
    Applicant: TDK CORPORATION
    Inventors: Kyung-Ku Choi, Yohtaro Yamakazi, Taku Murase
  • Publication number: 20070009767
    Abstract: The present invention provides a ferrite magnetic material comprising as a main constituent a compound represented by a composition formula, AFe2+aFe3+bO27 (wherein 1.1?a?2.4, 12.3?b?16.1; and A comprises at least one element selected from Sr, Ba and Pb), and also comprising as additives a Ca constituent in terms of CaCO3 and a Si constituent in terms of SiO2 so as to satisfy the relation CaCO3/SiO2=0.5 to 1.38 (molar ratio). By making the relation CaCO3/SiO2=0.5 to 1.38 (molar ratio) be satisfied, the coercive force (HcJ) and the residual magnetic flux density (Br) can be made to simultaneously attain high levels.
    Type: Application
    Filed: July 20, 2004
    Publication date: January 11, 2007
    Inventors: Yoshihiko Minachi, Junichi Nagaoka, Noboru Ito, Shunsuke Kurasawa, Taku Murase, Kenya Takagawa, Hidenobu Umeda
  • Publication number: 20060257677
    Abstract: There can be obtained a magnetic thin film for high frequency 1 which has both a high permeability and a high saturation magnetization by combining a T-L composition layer 5 comprising a T-L composition, wherein T is Fe or FeCo, and L is at least one element selected from the group consisting of C, B and N, with a Co based amorphous alloy layer 3 disposed on either of the surfaces of the T-L composition layer 5. Further, there can be obtained a magnetic thin film for high frequency 1 which has both a high permeability and a high saturation magnetization, and at the same time has a high resistivity by further providing the magnetic thin film with, in addition to the T-L composition layer 5 and the Co based amorphous alloy layer 3, a high resistance layer 7 having an electric resistance higher than the T-L composition layer 5 and the Co based amorphous alloy layer 3.
    Type: Application
    Filed: December 16, 2003
    Publication date: November 16, 2006
    Inventors: Kyung-Ku Choi, Taku Murase
  • Publication number: 20060228589
    Abstract: A granular substance (1) having soft magnetic properties is provided which contains a matrix (3) composed of a nonmagnetic insulating organic material and ferromagnetic metal particles (2) dispersed in the matrix (3) and having a mean particle size of 50 nm or less, wherein the volume ratio of the matrix (3) is in the range of 5 to 50%. When the granular substance (1) is in the form of a film, it has a complex permeability the real part (??) of which is 40 or more at 1 GHz, a quality factor Q (Q=??/?? where ?? is the imaginary part of the complex permeability) of 1 or more, and a saturation magnetization of 5 kG or more.
    Type: Application
    Filed: December 16, 2003
    Publication date: October 12, 2006
    Inventors: Kyung-Ku Choi, Taku Murase, Nobuyuki Hiratsuka, Kouichi Kakizaki
  • Publication number: 20060118756
    Abstract: A Mn—Zn based ferrite sintered body containing 62 to 68 mol % of Fe2O3 and 12 to 20 mol % of ZnO is made to contain, as main constituents, NiO and/or LiO0.5. Additionally, a Mn—Zn based ferrite sintered body containing 62 to 68 mol % of Fe2O3 and 12 to 23 mol % of ZnO is made to contain, as additives, Si and Ca. This sintered body can achieve such properties that the saturation magnetic flux density at 100° C. is 450 mT or more (magnetic field for measurement: 1194 A/m), the minimum core loss value is 1200 kW/m3 or less (measurement conditions: 100 kHz, 200 mT), the bottom temperature at which the minimum core loss value is exhibited is from 60 to 130° C., and the initial permeability at room temperature is 700 or more.
    Type: Application
    Filed: July 21, 2003
    Publication date: June 8, 2006
    Inventors: Kenya Takagawa, Eiichiro Fukuchi, Taku Murase
  • Patent number: 7034649
    Abstract: A ferrite material having a high Q value and also having a small absolute value of ??ir in a wide temperature range between ?40° C. and 160° C. A ferrite material, which comprises, as main constituents, 45.5 to 48 mol % of Fe2O3, 5 to 10.5 mol % of CuO, 26 to 30 mol % of ZnO, and the balance substantially being NiO, and further comprises, as an additive, cobalt oxide within a range between 0.005 and 0.045 wt % in terms of CoO. The ferrite material of the present invention has properties such as each of the absolute value of ??ir?40˜20 and the absolute value of ??ir20˜160 of 3 ppm/° C. or less, and a Q value at 125 kHz of 170 or more.
    Type: Grant
    Filed: August 31, 2004
    Date of Patent: April 25, 2006
    Assignee: TDK Corporation
    Inventors: Kensaku Asakura, Takuya Aoki, Taku Murase
  • Publication number: 20060046921
    Abstract: A dielectric ceramic composition having a main ingredient including a dielectric oxide expressed by the formula {(Me1-xCax)O}m.(Zr1-yTiy)O2, where the symbol Me indicating the name of the element in said formula is at least one of Sr, Mg, and Ba and where the symbols m, x, and y indicating the molar ratios of the formulation in the formula are in relationships of 0.995?m<1.020, 0<x?0.15, and 0?y?1.00, a first sub ingredient including an oxide of R (where R is a rare earth element), a second sub ingredient including an oxide of Mg, and a third sub ingredient including an oxide of Mn, wherein the ratios of the sub ingredients with respect to 100 moles of the main ingredient are first sub ingredient: 0.1 to 6 moles (value converted to oxide of R), second sub ingredient: 0.1 to 5 moles (value converted to oxide of Mg), and third sub ingredient: 0.1 to 2.
    Type: Application
    Filed: August 29, 2005
    Publication date: March 2, 2006
    Applicant: TDK Corporation
    Inventors: Kazushige Ito, Akira Sato, Taku Murase
  • Publication number: 20060045839
    Abstract: The present invention provides a production method of a ferrite material comprising as main constituents Fe2O3: 62 to 68 mol %, ZnO: 12 to 20 mol %, and MnO substantially constituting the balance, wherein the method comprises a compacting step for obtaining a compacted body by using a powder containing the main constituents, the powder having a specific surface area falling within a range between 2.5 and 5.0 m2/g and a 90% particle size of 10 ?m or less, and a sintering step for sintering the compacted body obtained in the compacting step. Accordingly, the saturation magnetic flux density of the Mn—Zn based ferrite can be improved.
    Type: Application
    Filed: December 26, 2003
    Publication date: March 2, 2006
    Inventors: Kenya Takagawa, Eiichiro Fukuchi, Taku Murase
  • Publication number: 20050238904
    Abstract: There is provided a Mn—Zn based ferrite member excellent in mass productivity, high in withstand voltage, low in loss and excellent in direct current superposition property. The Mn—Zn based ferrite member is provided with a surface layer portion having the properties that ?5 defined in the specification satisfies the relation that ?5?103 ?m and ?50 defined in the specification satisfies the relation that ?50?102 ?m.
    Type: Application
    Filed: April 21, 2005
    Publication date: October 27, 2005
    Inventors: Takashi Kajino, Kenya Takagawa, Taku Murase, Takuya Aoki
  • Publication number: 20050199851
    Abstract: An Ni—Cu—Zn-based ferrite material contains TiO2 alone as an additive in an amount of 0.1 wt %<x?4.0 wt % in which x denotes a content of the TiO2 and unavoidable impurities. The principal components thereof are 43.0 to 49.8 mol % of Fe2O3, 4.0 to 13.0 mol % of CuO, 5 to 35 mol % of ZnO and the balance of NiO.
    Type: Application
    Filed: October 6, 2004
    Publication date: September 15, 2005
    Applicant: TDK CORPORATION
    Inventors: Takuya Aoki, Taku Murase
  • Publication number: 20050167632
    Abstract: The present invention provides a Mn—Zn ferrite which is low in the loss in the frequency range between a few 10 kHz and a few 100 kHz and high in the saturation magnetic flux density in the vicinity of 100° C. The present invention comprising the steps of compacting a powder having a specific surface area (based on the BET method) of 2.0 to 5.0 m2/g and a 50% particle size of 0.7 to 2.0 ?m into a compacted body having a predetermined shape and obtaining a sintered body by sintering the compacted body. It is preferable that a Mn—Zn ferrite comprises, as main constituents, 54 to 57 mol % of Fe2O3, 5 to 10 mol % of ZnO, 4 mol % or less (not inclusive of 0%) of NiO, and the balance substantially being MnO.
    Type: Application
    Filed: January 10, 2005
    Publication date: August 4, 2005
    Inventors: Eiichiro Fukuchi, Akira Kakinuma, Kenya Takagawa, Fumitaka Baba, Taku Murase
  • Publication number: 20050116803
    Abstract: A high frequency magnetic thin film characterized by comprising a first layer made of a T-L composition (here, T is Fe or FeCo, and L is one or more of C, B, and N) and a second layer comprising a Co-based amorphous alloy arranged on either of the surfaces of the first layer. The high frequency magnetic thin film is a multilayer film of a plurality of the first layers and a plurality of the second layers or desirably is a multilayer film of alternately laminated first and second layers. The high frequency magnetic thin film of the present invention exhibits the properties such that the real part (??) of the complex permeability is 400 or more at 1 GHz, a quality factor Q (Q=??/??) is 4 or more, and a saturation magnetization is 14 kG (1.4 T) or more.
    Type: Application
    Filed: January 10, 2003
    Publication date: June 2, 2005
    Inventors: Kyung-Ku Choi, Taku Murase, Yohtaro Yamazaki
  • Publication number: 20050062576
    Abstract: A ferrite material having a high Q value and also having a small absolute value of ??ir in a wide temperature range between ?40° C. and 160° C. A ferrite material, which comprises, as main constituents, 45.5 to 48 mol % of Fe2O3, 5 to 10.5 mol % of CuO, 26 to 30 mol % of ZnO, and the balance substantially being NiO, and further comprises, as an additive, cobalt oxide within a range between 0.005 and 0.045 wt % in terms of CoO. The ferrite material of the present invention has properties such as each of the absolute value of ??ir?40˜20 and the absolute value of ??ir20˜160 of 3 ppm/° C. or less, and a Q value at 125 kHz of 170 or more.
    Type: Application
    Filed: August 31, 2004
    Publication date: March 24, 2005
    Inventors: Kensaku Asakura, Takuya Aoki, Taku Murase
  • Publication number: 20040046152
    Abstract: The present invention provides a method for manufacturing a permanent magnet based on oxide magnetic material, comprising a binder addition step for adding a binder to raw material powder containing oxide magnetic materials for mixing; a water content adjustment step for adjusting the water content of a molding mixture containing the raw material powder and the binder; an in-magnetic-field dry molding step for loading the molding mixture with adjusted water content into a mold and pressing it in a magnetic field applied while aligning the directions of easy magnetization of oxide magnetic material powder particles; and a sintering step for sintering the molded body; wherein the binder in the binder addition step is a wax based on fatty acid ester, and wherein the molding mixture charged into the mold in the in-magnetic-field dry molding step contains aggregates, in which the percentage of existence of aggregates in size of 500 &mgr;m or more is 0.01 to 0.
    Type: Application
    Filed: June 23, 2003
    Publication date: March 11, 2004
    Inventors: Taeko Tsubokura, Tsuneo Suzuki, Takahiro Mori, Taku Murase