Patents by Inventor Masahiro Onizuka
Masahiro Onizuka 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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Patent number: 6346673Abstract: A split ferrite core including first and second split ferrite cores. The first split ferrite core body includes first and second leg portions, and the first leg portion is vertical with respect to the second leg portion. The second split ferrite core body includes third and forth leg portions, and the third leg portion is vertical with respect to the forth leg portion. The first leg portion of the first split ferrite core body abuts against the forth leg portion of second split ferrite core body, and the second leg portion of the first split ferrite core body abuts against the third leg portion of second split ferrite core body.Type: GrantFiled: December 6, 1999Date of Patent: February 12, 2002Assignee: TDK CorporationInventor: Masahiro Onizuka
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Patent number: 6268787Abstract: A ferrite-core housing case 20 has a first split case half 21, and a second split case half 22 that is openable with respect to the first split case half 22, and houses a ferrite core 1 for a flat cable. A pair of spring portions 27 which press the ferrite core 1 are formed in at least one of the first and second split case halves 21 and 22, and a fulcrum of each of the spring portions 27 is located on a side face 22b of the split case half while an acting point is located on a center side.Type: GrantFiled: December 3, 1999Date of Patent: July 31, 2001Assignee: TDK CorporationInventor: Masahiro Onizuka
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Patent number: 6217790Abstract: A BALUN transformer core material contains a Z-type hexagonal system ferrite having an in-plane anisotropy and a high magnetic permeability and such a high resonance frequency as to be in excess of a Snake's limiting line, and therefore, in the BALUN transformer core material, the frequency properties of the magnetic permeability are extremely good. A BALUN transformer core obtained by pressing and sintering this BALUN transformer core material has a high initial magnetic permeability and specific resistance. Moreover, a BALUN transformer obtained by applying a winding to the BALUN transformer core is provided with superior properties which are not poorer as compared with a BALUN transformer constituted of a conventional spinel ferrite, and it is a BALUN transformer having high properties which can be used in a high-frequency band of 300 MHz or more.Type: GrantFiled: January 10, 2000Date of Patent: April 17, 2001Assignee: TDK CorporationInventors: Masahiro Onizuka, Kouki Sato
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Patent number: 6147928Abstract: An anti-noise component for a flat cable including a flat O-like ferrite core having a slit-like hole through which a flat cable is passed, and an openable and closeable case which covers the ferrite core while the slit-like hole is exposed through the case. Further, the case integrally has a coupling portion including a pawl for fixation to an apparatus on which the component is to be mounted.Type: GrantFiled: March 3, 1999Date of Patent: November 14, 2000Assignee: TDK CorporationInventors: Masahiro Onizuka, Yutaka Saito, Yoshikazu Suto
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Patent number: 6114940Abstract: There is disclosed a BALUN transformer core material which has no magnetic permeability, contains a non-magnetic material and is not influenced by the frequency property of the magnetic permeability even in a high-frequency band. A BALUN transformer core which is obtained by pressing and sintering the BALUN transformer core material has no magnetic permeability and has a high specific resistance. A BALUN transformer which is obtained by applying a winding to the BALUN transformer core is a high-property BALUN transformer which can be operated in a high-frequency band of 600 MHz or more.Type: GrantFiled: June 10, 1998Date of Patent: September 5, 2000Assignee: TDK CorporationInventors: Sei Kakinuma, Kouki Sato, Masahiro Onizuka, Ko Ito
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Patent number: 6033593Abstract: A BALUN transformer core material contains a Z-type hexagonal system ferrite having an in-plane anisotropy and a high magnetic permeability and such a high resonance frequency as to be in excess of a Snake's limiting line, and therefore, in the BALUN transformer core material, the frequency properties of the magnetic permeability are extremely good. A BALUN transformer core obtained by pressing and sintering this BALUN transformer core material has a high initial magnetic permeability and specific resistance. Moreover, a BALUN transformer obtained by applying a winding to the BALUN transformer core is provided with superior properties which are not poorer as compared with a BALUN transformer constituted of a conventional spinel ferrite, and it is a BALUN transformer having high properties which can be used in a high-frequency band of 300 MHz or more.Type: GrantFiled: June 10, 1998Date of Patent: March 7, 2000Assignee: TDK CorporationInventors: Masahiro Onizuka, Kouki Sato
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Patent number: 5966065Abstract: A core for inductance elements is formed of a sintered body of .alpha.-ferric oxide. The core has a flexural strength of at least 6 kgf/mm.sup.2 as measured by a three-point bending method, a specific resistance of at least 10.sup.6 .OMEGA..multidot.cm, a Vickers hardness of 800 to 1,500, and an iron content of 75 to 99.9 wt %, calculated as Fe.sub.2 O.sub.3. The core is produced by granulating, and forming a ferric iron powder, and holding a formed body for sintering at 950 to 1,500.degree. C. for 5 min. to 5 hours in an atmospheric environment.Type: GrantFiled: June 20, 1997Date of Patent: October 12, 1999Assignee: TDK CorporationInventors: Masahiro Onizuka, Koh Itoh, Sei Kakinuma
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Patent number: 5954992Abstract: The invention provides a hexagonal Z type magnetic oxide sintered material having a high resistivity and high density, and an impedance device using the same. The hexagonal Z type magnetic oxide sintered material contains a main oxide component containing M wherein M is at least one of Ba and Sr, Co, and Fe and an auxiliary oxide component containing Si, having a resistivity of at least 10.sup.6 .OMEGA.-cm, a sintered density of at least 4.6 g/cm.sup.3, and an initial magnetic permeability of 5 to 25. Pb may be contained in the auxiliary oxide component. Co may be partially replaced by Me wherein Me is at least one of Ni, Zn, and Cu.Type: GrantFiled: July 28, 1997Date of Patent: September 21, 1999Assignee: TDK CorporationInventors: Masahiro Onizuka, Yutaka Saito
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Patent number: 5750045Abstract: Ferrite materials including spinel and magnetoplumbite ferrite materials are prepared by using a mixture containing at least one metal chloride and at least one metal oxide as a starting raw material and roasting the mixture in a steam-containing atmosphere to carry out pyrolysis reaction and solid phase reaction at the same time.Type: GrantFiled: July 6, 1995Date of Patent: May 12, 1998Assignee: TDK CorporationInventors: Yoshito Nihira, Takeshi Nomura, Masahiro Onizuka
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Patent number: 4623773Abstract: A nonflammable electrospark machining solution which provides a high machining rate composed primarily of a saccharide such as cane sugar, fruit sugar or malt sugar with the density of saccharide being 5 to 55% by weight. A preservative may be added such as benzoic acid, salicylic acid, dehydroacetic acid or ethyl para-hydroxybenzoate with the latter being preferred in an amount of 0.01 to 0.1% by weight of the machining solution. Also, an anticorrosive such as sodium nitride, sodium polyphosphate, sodium dichromate, sodium silicate and triethanol amine is preferably added in an amount of 0.05 to 0.1% by weight of the machining solution.Type: GrantFiled: March 19, 1984Date of Patent: November 18, 1986Assignee: Mitsubishi Denki Kabushiki KaishaInventor: Masahiro Onizuka
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Patent number: 4536633Abstract: A dielectric fluid for electrical discharge machining which contains an ester solution. The dielectric fluid presents no fire hazard during use due to a high flash point, low combustibility and the fact that it is not easily ionizable. In addition, the dielectric is not malodorous and not toxic. The invention also encompasses a method for EDM machining using this dielectric fluid.Type: GrantFiled: December 7, 1983Date of Patent: August 20, 1985Assignee: Mitsubishi Denki Kabushiki KaishaInventor: Masahiro Onizuka