Patents by Inventor Teruhiko Fujiwara
Teruhiko Fujiwara 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).
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Publication number: 20060170524Abstract: A high-frequency core is a molded body obtained by molding a mixture of a soft magnetic metallic glass powder and a binder in an amount of 10% or less in mass ratio. The powder has an alloy composition represented by a general formula (Fe1-a-bNiaCob)100-x-y-z(M1-pM?p)xTyBz (where 0?a?0.30, 0?b?0.50,0?a+b?0.50,0?p?0.5, 1 atomic %?x?5 atomic %, 1 atomic %?y?12 atomic %, 12 atomic %?z?25 atomic %, 22?(x+y+z)?32, M being at least one selected from Zr, Nb, Ta, Hf, Mo, Ti, V, Cr, and W, M? being at least one selected from Zn, Sn, R (R being at least one element selected from rare earth metals including Y), T being at least one selected from Al, Si, C, and P). An inductance component includes the high-frequency core and at least one turn of winding wound around the core.Type: ApplicationFiled: August 20, 2004Publication date: August 3, 2006Inventors: Teruhiko Fujiwara, Akiri Urata, Akihira Inoue
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Patent number: 6995643Abstract: In order to provide an inductance part having excellent DC superposition characteristic and core-loss, a magnetically biasing magnet, which is disposed in a magnetic gap of a magnetic core, is a bond magnet comprising magnetic powder and plastic resin with the content of the resin being 20% or more on the base of volumetric ratio and which has a specific resistance of 0.1?·cm or more. The magnetic powder used is rare-earth magnetic powder having an intrinsic coercive force of 5 kOe or more, Curie point of 300° C. or more, and an average particle size of 2.0–50 ?m. A magnetically biasing magnet used in an inductance part that is treated by the reflow soldering method has a resin content of 30% or more and the magnetic powder used therein is Sm—Co magnetic powder having an intrinsic coercive force of 10 kOe or more, Curie point of 500° C. or more, and an average particle size of 2.5–50 ?m. A thin magnet having a thickness of 500 ?m or less can be realized for a small-sized inductance part.Type: GrantFiled: January 6, 2005Date of Patent: February 7, 2006Assignee: NEC Tokin CorporationInventors: Teruhiko Fujiwara, Masayoshi Ishii, Haruki Hoshi, Keita Isogai, Hatsuo Matsumoto, Toru Ito, Tamiko Ambo
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Publication number: 20050254989Abstract: A high-frequency core is a molded body obtained by molding a mixture of a soft magnetic metallic glass powder and a binder in an amount of 10% or less in mass ratio. The powder has an alloy composition represented by (Fe1-aCoa)100-x-y-z-q-r(M1-pM?p)xTyBzCqAlr(0<a<0.50, 0<p<0.5, 2 atomic %<x<5 atomic %, 8 atomic %<y<12 atomic %, 12 atomic %<z<17 atomic %, 0.1 atomic %<q<1.0 atomic %, 0.2 atomic %<r<2.0 atomic % and 25<(x+y+z+q+r)<30, M being at least one selected from Zr, Nb, Ta, Hf, Mo, Ti, V, Cr, and W, M? being at least one selected from Zn, Sn, and R (R being at least one element selected from rare earth metals including Y), T being at least one selected from Si and P). An inductance component is formed by the core and a winding.Type: ApplicationFiled: May 9, 2005Publication date: November 17, 2005Applicants: NEC TOKIN CORPORATION, TOHOKU UNIVERSITYInventors: Teruhiko Fujiwara, Akiri Urata, Akihisa Inoue
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Patent number: 6906608Abstract: An inductor component according to the present invention includes a magnetic core including at least one magnetic gap having a gap length of about 50 to 10,000 ?m in a magnetic path, a magnet for magnetic bias arranged in the neighborhood of the magnetic gap in order to supply magnetic bias from both sides of the magnetic gap, and a coil having at least one turn applied to the magnetic core. The aforementioned magnet for magnetic bias is a bonded magnet containing a resin and a magnet powder dispersed in the resin and having a resistivity of 1 ?·cm or more. The magnet powder includes a rare-earth magnet powder having an intrinsic coercive force of 5 KOe or more, a Curie point of 300° C. or more, the maximum particle diameter of 150 ?m or less, and an average particle diameter of 2.0 to 50 ?m m and coated with inorganic glass, and the rare-earth magnet powder is selected from the group consisting of a Sm—Co magnet powder, Nd—Fe—B magnet powder, and Sm—Fe—N magnet powder.Type: GrantFiled: May 11, 2004Date of Patent: June 14, 2005Assignee: NEC TOKIN CorporationInventors: Teruhiko Fujiwara, Masayoshi Ishii, Haruki Hoshi, Keita Isogai, Toru Ito, Tamiko Ambo
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Publication number: 20050116804Abstract: In order to provide an inductance part having excellent DC superposition characteristic and core-loss, a magnetically biasing magnet, which is disposed in a magnetic gap of a magnetic core, is a bond magnet comprising magnetic powder and plastic resin with the content of the resin being 20% or more on the base of volumetric ratio and which has a specific resistance of 0.1 ?·cm or more. The magnetic powder used is rare-earth magnetic powder having an intrinsic coercive force of 5 kOe or more, Curie point of 300° C. or more, and an average particle size of 2.0-50 ?m. A magnetically biasing magnet used in an inductance part that is treated by the reflow soldering method has a resin content of 30% or more and the magnetic powder used therein is Sm—Co magnetic powder having an intrinsic coercive force of 10 kOe or more, Curie point of 500° C. or more, and an average particle size of 2.5-50 ?m. A thin magnet having a thickness of 500 ?m or less can be realized for a small-sized inductance part.Type: ApplicationFiled: January 6, 2005Publication date: June 2, 2005Applicant: NEC Tokin CorporationInventors: Teruhiko Fujiwara, Masayoshi Ishii, Haruki Hoshi, Keita Isogai, Hatsuo Matsumoto, Toru Ito, Tamiko Ambo
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Patent number: 6856231Abstract: In order to provide an inductance part having excellent DC superposition characteristic and core-loss, a magnetically biasing magnet, which is disposed in a magnetic gap of a magnetic core, is a bond magnet comprising magnetic powder and plastic resin with the content of the resin being 20% or more on the base of volumetric ratio and which has a specific resistance of 0.1?•cm or more. The magnetic powder used is rare-earth magnetic powder having an intrinsic coercive force of 5 kOe or more, Curie point of 300° C. or more, and an average particle size of 2.0-50 ?m. A magnetically biasing magnet used in an inductance part that is treated by the reflow soldering method has a resin content of 30% or more and the magnetic powder used therein is Sm—Co magnetic powder having an intrinsic coercive force of 10 kOe or more, Curie point of 500° C. or more, and an average particle size of 2.5-50 ?m. A thin magnet having a thickness of 500 ?m or less can be realized for a small-sized inductance part.Type: GrantFiled: September 10, 2001Date of Patent: February 15, 2005Assignee: NEC Tokin CorporatonInventors: Teruhiko Fujiwara, Masayoshi Ishii, Haruki Hoshi, Keita Isogai, Hatsuo Matsumoto, Toru Ito, Tamiko Ambo
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Publication number: 20040207500Abstract: An inductor component according to the present invention includes a magnetic core including at least one magnetic gap having a gap length of about 50 to 10,000 &mgr;m in a magnetic path, a magnet for magnetic bias arranged in the neighborhood of the magnetic gap in order to supply magnetic bias from both sides of the magnetic gap, and a coil having at least one turn applied to the magnetic core. The aforementioned magnet for magnetic bias is a bonded magnet containing a resin and a magnet powder dispersed in the resin and having a resistivity of 1 &OHgr;·cm or more. The magnet powder includes a rare-earth magnet powder having an intrinsic coercive force of 5 KOe or more, a Curie point of 300° C. or more, the maximum particle diameter of 150 &mgr;m or less, and an average particle diameter of 2.Type: ApplicationFiled: May 11, 2004Publication date: October 21, 2004Applicant: NEC TOKIN CORPORATIONInventors: Teruhiko Fujiwara, Masayoshi Ishii, Haruki Hoshi, Keita Isogai, Toru Ito, Tamiko Ambo
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Patent number: 6788185Abstract: A powder core is obtained by compaction-forming magnetic powder. The magnetic powder is an alloy comprising 1-10 wt % Si, 0.1-1.0 wt % O, and balance Fe. An insulator comprising SiO2 and MgO as main components is interposed between powder particles having a particle size of 150 &mgr;m or less.Type: GrantFiled: July 29, 2003Date of Patent: September 7, 2004Assignee: NEC Tokin CorporationInventors: Teruhiko Fujiwara, Masayoshi Ishii, Yoshitaka Saito
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Publication number: 20040168303Abstract: An inductor component contains a drum magnetic core made of a magnetic material having a structure including integrated flanges at both ends of a columnar material, a coil wound around the columnar material in the drum magnetic core and placed between the flanges, and a permanent magnet placed in the neighborhood of the drum magnetic core with the coil wound around. This inductor component contains a sleeve core fitted to the outside of the drum magnetic core. The permanent magnet is placed in at least one gap in a closed magnetic circuit formed with the drum magnetic core and the sleeve core in order to apply a direct-current magnetic field in the direction opposite to the direction of a magnetic field generated by a magnetomotive force due to the coil.Type: ApplicationFiled: March 1, 2004Publication date: September 2, 2004Applicant: NEC TOKIN CORPORATIONInventors: Hatsuo Matsumoto, Toru Ito, Masahiro Kondo, Ryutaro Isoda, Toshiya Sato, Tadakuni Sato, Teruhiko Fujiwara, Masayoshi Ishii, Haruki Hoshi
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Patent number: 6778056Abstract: An inductance component comprises a magnetic core having at least one magnetic gap, means for generating a direct-current biased magnetic field produced by mounting a permanent magnet in the vicinity of a generally closed magnetic circuit which passes through the magnetic gap in the magnetic core or on the outside thereof, and a coil wound around the magnetic core, wherein the permanent magnet is mounted near the magnetic gap at one or more legs of the magnetic core which sandwich the magnetic gap.Type: GrantFiled: August 1, 2001Date of Patent: August 17, 2004Assignee: NEC Tokin CorporationInventors: Toru Ito, Hatsuo Matsumoto, Teruhiko Fujiwara, Kazuyuki Okita, Toshiya Sato
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Patent number: 6753751Abstract: An inductor component according to the present invention includes a magnetic core including at least one magnetic gap having a gap length of about 50 to 10,000 &mgr;m in a magnetic path, a magnet for magnetic bias arranged in the neighborhood of the magnetic gap in order to supply magnetic bias from both sides of the magnetic gap, and a coil having at least one turn applied to the magnetic core. The aforementioned magnet for magnetic bias is a bonded magnet containing a resin and a magnet powder dispersed in the resin and having a resistivity of 1 &OHgr;·cm or more. The magnet powder includes a rare-earth magnet powder having an intrinsic coercive force of 5 KOe or more, a Curie point of 300° C. or more, the maximum particle diameter of 150 &mgr;m or less, and an average particle diameter of 2.Type: GrantFiled: November 29, 2001Date of Patent: June 22, 2004Assignee: NEC Tokin CorporationInventors: Teruhiko Fujiwara, Masayoshi Ishii, Haruki Hoshi, Keita Isogai, Toru Ito, Tamiko Ambo
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Patent number: 6734771Abstract: An inductor component is provided which includes a magnetic core having at least one gap, an excitation coil disposed on the magnetic core so as to form a magnetic path on the magnetic core, at least one permanent magnet disposed near the at least one gap, and at least one first soft magnetic material piece disposed between the at least one permanent magnet and the magnetic core, wherein the first soft magnetic material piece is formed of a soft magnetic material which has a smaller permeability and less eddy current loss than the magnetic core.Type: GrantFiled: November 16, 2001Date of Patent: May 11, 2004Assignee: NEC Tokin CorporationInventors: Kazuyuki Okita, Toru Ito, Toshiya Sato, Teruhiko Fujiwara
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Patent number: 6717504Abstract: A low-profile magnetic core capable of reducing the thickness of an inductor component is provided. The magnetic core includes at least one gap in a magnetic path, and a permanent magnet is inserted in the gap. The magnetic core has an alternating current magnetic permeability at 20 kHz of 45 or more in a magnetic field of 120 Oe under application of direct current, and has a core loss characteristic of 100 kW/m3 or less under the conditions of 20 kHz and the maximum magnetic flux density of 0.1 T. An inductor component is produced by applying at least one turn of coil to the aforementioned magnetic core.Type: GrantFiled: October 24, 2001Date of Patent: April 6, 2004Assignee: NEC Tokin CorporationInventors: Teruhiko Fujiwara, Masayoshi Ishii, Haruki Hoshi, Keita Isogai, Toru Ito, Tamiko Ambo
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Patent number: 6710693Abstract: An inductor component contains a drum magnetic core made of a magnetic material having a structure including integrated flanges at both ends of a columnar material, a coil wound around the columnar material in the drum magnetic core and placed between the flanges, and a permanent magnet placed in the neighborhood of the drum magnetic core with the coil wound around. This inductor component contains a sleeve core fitted to the outside of the drum magnetic core. The permanent magnet is placed in at least one gap in a closed magnetic circuit formed with the drum magnetic core and the sleeve core in order to apply a direct-current magnetic field in the direction opposite to the direction of a magnetic field generated by a magnetomotive force due to the coil.Type: GrantFiled: March 22, 2002Date of Patent: March 23, 2004Assignee: NEC Tokin CorporationInventors: Hatsuo Matsumoto, Toru Ito, Masahiro Kondo, Ryutaro Isoda, Toshiya Sato, Tadakuni Sato, Teruhiko Fujiwara, Masayoshi Ishii, Haruki Hoshi
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Publication number: 20040021542Abstract: A powder core is obtained by compaction-forming magnetic powder. The magnetic powder is an alloy comprising 1-10 wt % Si, 0.1-1.0 wt % O, and balance Fe. An insulator comprising SiO2 and MgO as main components is interposed between powder particles having a particle size of 150 &mgr;m or less.Type: ApplicationFiled: July 29, 2003Publication date: February 5, 2004Applicant: NEC TOKIN CORPORATIONInventors: Teruhiko Fujiwara, Masayoshi Ishii, Yoshitaka Saito
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Patent number: 6646532Abstract: Preparation is made of alloy powder comprising 3.0-8.0 wt % Si, 0.1-1.0 wt % O, 0-2.0 wt % (0 being exclusive) of at least one element selected from Mn, Al, V, Cr, and Ti, and balance Fe and having a particle size substantially equal to 150 &mgr;m or less. A binder is mixed with the alloy powder to form a mixture. The mixture is compaction-formed by the use of a die. Thus, a powder core is obtained which has a 20 kHz a.c. permeability equal to 20 or more under an applied d.c. magnetic field of 12000 A/m, a core loss characteristic of 1000 kW/m3 under the conditions of 20 kHz and 0.1 T, saturation magnetization of 10000 G or more, and coercive force of 3.0 Oe or less.Type: GrantFiled: February 26, 2002Date of Patent: November 11, 2003Assignee: NEC Tokin CorporationInventors: Teruhiko Fujiwara, Masayoshi Ishii, Yoshitaka Saito
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Patent number: 6639499Abstract: In an inductance component in which a cylindrical excitation coil (26) is fitted around a predetermined portion of a magnetic core (21) forming a magnetic path, a permanent magnet (25) is inserted into the magnetic path to apply a magnetic bias to the magnetic core. The permanent magnet is arranged outside the cylindrical excitation coil. It is preferable that the permanent magnet is spaced from the predetermined portion of the magnetic core along the magnetic path at least by a distance which corresponds to ½ of an average of inner diameters of the cylindrical excitation coil.Type: GrantFiled: August 31, 2001Date of Patent: October 28, 2003Assignee: NEC Tokin CorporationInventors: Kazuyuki Okita, Teruhiko Fujiwara
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Patent number: 6621399Abstract: A powder core is obtained by compaction-forming magnetic powder. The magnetic powder is an alloy comprising 1-10 wt % Si, 0.1-1.0 wt % O, and balance Fe. An insulator comprising SiO2 and MgO as main components is interposed between powder particles having a particle size of 150 &mgr;m or less.Type: GrantFiled: January 17, 2002Date of Patent: September 16, 2003Assignee: NEC Tokin CorporationInventors: Teruhiko Fujiwara, Masayoshi Ishii, Yoshitaka Saito
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Patent number: 6621398Abstract: Disposed in a magnetic gap of a magnetic core, a magnetically biasing permanent magnet is a bond magnet comprising rare-earth magnetic powder and a binder resin. The rare-earth magnetic powder has an intrinsic coercive force of 5 kOe or more, a Curie temperature of 300° C. or more, and an average particle size of 2.0-50 &mgr;m. The rare-earth magnetic power has a surface coated with a metallic layer containing an oxidation-resistant metal. In order to enable a surface-mount to reflow, the rare-earth magnetic powder may have the intrinsic coercive force of 10 kOe or more, the Curie temperature of 500° C. and the average particle size of 2.5-50 &mgr;m. In addition, to prevent specific resistance from degrading, the metallic layer desirably may be coated with a glass layer consisting of low-melting glass having a softening point less than a melting point of the oxidation-resistant metal.Type: GrantFiled: November 28, 2001Date of Patent: September 16, 2003Assignee: NEC Tokin CorporationInventors: Teruhiko Fujiwara, Masayoshi Ishii, Haruki Hoshi, Keita Isogai, Hatsuo Matsumoto, Toru Ito, Tamiko Ambo
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Publication number: 20030160677Abstract: Preparation is made of alloy powder comprising 3.0-8.0 wt % Si, 0.1-1.0 wt % O, 0-2.0 wt % (0 being exclusive) of at least one element selected from Mn, Al, V, Cr, and Ti, and balance Fe and having a particle size substantially equal to 150 &mgr;m or less. A binder is mixed with the alloy powder to form a mixture. The mixture is compaction-formed by the use of a die. Thus, a powder core is obtained which has a 20 kHz a.c. permeability equal to 20 or more under an applied d.c. magnetic field of 12000 A/m, a core loss characteristic of 1000 kW/m3 under the conditions of 20 kHz and 0.1 T. saturation magnetization of 10000 G or more, and coercive force of 3.0 Oe or less.Type: ApplicationFiled: February 26, 2002Publication date: August 28, 2003Applicant: NEC TOKIN CORPORATIONInventors: Teruhiko Fujiwara, Masayoshi Ishii, Yoshitaka Saito