Patents by Inventor Yasunobu Ogata
Yasunobu Ogata 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: 20140001398Abstract: The present invention relates to ferromagnetic particles capable of exhibiting a high purity and excellent magnetic properties from the industrial viewpoints and a process for producing the ferromagnetic particles, and also provides an anisotropic magnet, a bonded magnet and a compacted magnet which are obtained by using the ferromagnetic particles.Type: ApplicationFiled: January 19, 2012Publication date: January 2, 2014Applicant: TOHOKU UNIVERSITYInventors: Migaku Takahashi, Tomoyuki Ogawa, Yasunobu Ogata, Naoya Kobayashi, Chammika Ruwan Polwatta Gallage, Kaori Kohara
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Publication number: 20130257573Abstract: The present invention relates to ferromagnetic particles comprising an Fe16N2 compound phase in an amount of not less than 70% as measured by Mössbauer spectrum, and at least one metal element X selected from the group consisting of Mn, Ni, Ti, Ga, Al, Ge, Zn, Pt and Si in such an amount that a molar ratio of the metal element X to Fe is 0.04 to 25%, the ferromagnetic particles having a BHmax value of not less than 5 MGOe, and a process for producing the ferromagnetic particles, and further relates to an anisotropic magnet or a bonded magnet which is obtained by magnetically orienting the ferromagnetic particles. The ferromagnetic particles according to the present invention can be produced in an industrial scale and are in the form of Fe16N2 particles comprising different kinds of metal elements having a large BHmax value.Type: ApplicationFiled: September 22, 2011Publication date: October 3, 2013Applicants: TOHOKU UNIVERSITY, TODA KOGYO CORPORATIONInventors: Migaku Takahashi, Tomoyuki Ogawa, Yasunobu Ogata, Akimasa Sakuma, Naoya Kobayashi, Chammika Ruwan Polwatta Gallage, Kaori Kohara
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Publication number: 20120244356Abstract: The present invention relates to Fe16N2 particles in the form of a single phase which are obtained by subjecting iron oxide or iron oxyhydroxide whose surface may be coated with at least alumina or silica, if required, as a starting material, to reducing treatment and nitridation treatment, a process for producing the Fe16N2 particles in the form of a single phase for a heat treatment time of not more than 36 hr, and further relates to an anisotropic magnet or a bonded magnet which is obtained by magnetically orienting the Fe16N2 particles in the form of a single phase. The Fe16N2 particles according to the present invention can be produced in an industrial scale and have a large BHmax value.Type: ApplicationFiled: October 19, 2010Publication date: September 27, 2012Inventors: Migaku Takahashi, Tomoyuki Ogawa, Yasunobu Ogata, Naoya Kobayashi
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Patent number: 8206606Abstract: An oxide magnetic material includes a ferrite with a hexagonal structure as its main phase. Metallic elements included in the oxide magnetic material are represented by the formula: Ca1-x-x?LaxSrx?Fe2n-yCoy, where atomic ratios x, x? and y and a molar ratio n satisfy 0.4?x?0.6, 0.01?x??0.3, 0.2?y?0.45 and 5.2?n?5.8, respectively.Type: GrantFiled: June 25, 2008Date of Patent: June 26, 2012Assignee: Hitachi Metals, Ltd.Inventors: Seiichi Hosokawa, Yoshinori Kobayashi, Yasunobu Ogata, Etsushi Oda
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Patent number: 7970312Abstract: An image forming apparatus includes a main body, an openable/closable cover panel, a unitary assembly, a holder, and a fastener. The openable/closable cover panel covers an opening in the main body. The unitary assembly is detachably attached to an inner side of the cover panel. The fastener fastens the assembly in place on the cover panel. The holder includes a positioning surface and first and second guide surfaces to hold the assembly on the cover panel. The positioning surface receives a positioning pin projecting from the assembly. The first and second guide surfaces are disposed on opposite sides of the positioning surface, and each guide surface slidably guides the positioning pin onto the positioning surface. The second guide surface is elastically displaceable to cause the positioning pin to slide off onto the positioning surface as the positioning pin presses against the second guide surface.Type: GrantFiled: October 28, 2009Date of Patent: June 28, 2011Assignee: Ricoh Company LimitedInventor: Yasunobu Ogata
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Patent number: 7962079Abstract: A disclosed fixing device includes a fixing member configured to heat and melt a toner image to fix it onto a recording medium; a pressure member abutting the fixing member to form a nip into which the recording medium is fed; a separating member disposed on the downstream side in the moving direction of the fixing member in relation to the nip in a manner to oppose the fixing member, and configured to perform a separating operation to prevent the recording medium from winding around the fixing member; an electrically grounded frame supporting the fixing member, the pressure member and the separating member; and a conductive member inserted between a supporting portion of the frame and a supported portion of the separating member and having a higher electric resistance than the frame. The separating member and the frame are rendered electrically conductive to each other only via the conductive member.Type: GrantFiled: October 7, 2008Date of Patent: June 14, 2011Assignee: Ricoh Company, Ltd.Inventor: Yasunobu Ogata
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Patent number: 7906036Abstract: A sintered ferrite magnet having a basic composition represented by the general formula: A1?x?y+aCax+bRy+cFe2n?zCoz+dO19 (atomic ratio), wherein a, b, c and d represent the amounts of an A element, Ca, an R element and Co added in the pulverization step of an oxide magnet material, which are numerals meeting the conditions of 0.03?x?0.4, 0.1?y?0.6, 0?z?0.4, 4?n?10, x+y<1, 0.03?x+b?0.4, 0.1?y+c?0.6, 0.1?z+d?0.4, 0.50?[(1?x?y+a)/(1?y+a+b)]?0.97, 1.1?(y+c)/(z+d)?1.8, 1.0?(y+c)/x?20, and 0.1?x/(z+d)?1.2.Type: GrantFiled: September 13, 2004Date of Patent: March 15, 2011Assignee: Neomax Co., Ltd.Inventors: Takashi Takami, Yasunobu Ogata
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Patent number: 7881635Abstract: An intermediate transfer unit can be detached from a device main body through an opening that is covered by an openable and closable front cover. A sheet path is provided between the intermediate transfer unit and the front cover. A portion of a convey-guiding unit of the sheet path falls in the way when detaching the detachable intermediate transfer unit. The portion of the convey-guiding unit, which falls in the way when detaching the detachable intermediate transfer unit, is formed as a detachable convey-guiding member that is detachably attached to the device main body.Type: GrantFiled: February 14, 2008Date of Patent: February 1, 2011Assignee: Ricoh Company, LimitedInventors: Yoshikazu Yamazoe, Yutaka Naito, Yasunobu Ogata, Shin Yamamoto
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Publication number: 20100124028Abstract: An image forming apparatus includes a main body, an openable/closable cover panel, a unitary assembly, a holder, and a fastener. The openable/closable cover panel covers an opening in the main body. The unitary assembly is detachably attached to an inner side of the cover panel. The fastener fastens the assembly in place on the cover panel. The holder includes a positioning surface and first and second guide surfaces to hold the assembly on the cover panel. The positioning surface receives a positioning pin projecting from the assembly. The first and second guide surfaces are disposed on opposite sides of the positioning surface, and each guide surface slidably guides the positioning pin onto the positioning surface. The second guide surface is elastically displaceable to cause the positioning pin to slide off onto the positioning surface as the positioning pin presses against the second guide surface.Type: ApplicationFiled: October 28, 2009Publication date: May 20, 2010Inventor: Yasunobu OGATA
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Publication number: 20090261288Abstract: An oxide magnetic material includes a ferrite with a hexagonal structure as its main phase. Metallic elements included in the oxide magnetic material are represented by the formula: Ca1-x-x?LaxSrx?Fe2n-yCoy, where atomic ratios x, x? and y and a molar ratio n satisfy 0.4?x?0.6, 0.01?x??0.3, 0.2?y?0.45 and 5.2?n?5.8, respectively.Type: ApplicationFiled: June 25, 2008Publication date: October 22, 2009Applicant: HITACHI METALS, LTD.Inventors: Seiichi Hosokawa, Yoshinori Kobayashi, Yasunobu Ogata, Etsushi Oda
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Publication number: 20090110452Abstract: A disclosed fixing device includes a fixing member configured to heat and melt a toner image to fix it onto a recording medium; a pressure member abutting the fixing member to form a nip into which the recording medium is fed; a separating member disposed on the downstream side in the moving direction of the fixing member in relation to the nip in a manner to oppose the fixing member, and configured to perform a separating operation to prevent the recording medium from winding around the fixing member; an electrically grounded frame supporting the fixing member, the pressure member and the separating member; and a conductive member inserted between a supporting portion of the frame and a supported portion of the separating member and having a higher electric resistance than the frame. The separating member and the frame are rendered electrically conductive to each other only via the conductive member.Type: ApplicationFiled: October 7, 2008Publication date: April 30, 2009Inventor: Yasunobu OGATA
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Publication number: 20080193162Abstract: An intermediate transfer unit can be detached from a device main body through an opening that is covered by an openable and closable front cover. A sheet path is provided between the intermediate transfer unit and the front cover. A portion of a convey-guiding unit of the sheet path falls in the way when detaching the detachable intermediate transfer unit. The portion of the convey-guiding unit, which falls in the way when detaching the detachable intermediate transfer unit, is formed as a detachable convey-guiding member that is detachably attached to the device main body.Type: ApplicationFiled: February 14, 2008Publication date: August 14, 2008Inventors: Yoshikazu Yamazoe, Yutaka Naito, Yasunobu Ogata, Shin Yamamoto
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Patent number: 7169319Abstract: A ferrite magnet having a basic composition represented by the following general formula: (A1?xRx)O.n[(Fe1?yMy)2O3] by atomic ratio, wherein A is Sr and/or Ba, R is at least one of rare earth elements including Y, M is at least one element selected from the group consisting of Co, Mn, Ni and Zn, and x, y and n are numbers meeting the conditions of 0.01?x?0.4, [x/(2.6n)]?y?[x/(1.6n)], and 5?n?6, and substantially having a magnetoplumbite-type crystal structure, is obtained by uniformly mixing a compound of Sr and/or Ba with an iron compound; calcining the resultant uniform mixture; adding a compound of the R element and/or the M element to the resultant calcined powder at a pulverization step thereof; and sintering the resultant mixture. The compound of the R element and/or the M element may be added at a percentage of more than 0 atomic % and 80 atomic % or less, on an element basis, at a mixing step before calcination.Type: GrantFiled: October 14, 2004Date of Patent: January 30, 2007Assignee: Neomax Co., Ltd.Inventors: Takashi Takami, Yutaka Kubota, Yasunobu Ogata
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Publication number: 20060284136Abstract: A sintered ferrite magnet having a basic composition represented by the general formula: A1?x?y+aCax+bRy+cFe2n?zCoz+dO19 (atomic ratio), wherein a, b, c and d represent the amounts of an A element, Ca, an R element and Co added in the pulverization step of an oxide magnet material, which are numerals meeting the conditions of 0.03?x?0.4, 0.1?y?0.6, 0?z?0.4, 4?n?10, x+y?1, 0.03?x+b?0.4, 0.1?y+c?0.6, 0.1?z+d?0.4, 0.50?[(1?x?y+a)/(1?y+a+b)]?0.97, 1.1?(y+c)/(z+d)?1.8, 1.0?(y+c)/x?20, and 0.1?x/(z+d)?1.2.Type: ApplicationFiled: September 14, 2004Publication date: December 21, 2006Inventors: Takashi Takami, Yasunobu Ogata
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Publication number: 20050098761Abstract: A ferrite magnet having a basic composition represented by the following general formula: (A1-xRx)O.n[(Fe1-yMy)2O3] by atomic ratio, wherein A is Sr and/or Ba, R is at least one of rare earth elements including Y, M is at least one element selected from the group consisting of Co, Mn, Ni and Zn, and x, y and n are numbers meeting the conditions of 0.01?x?0.4, [x/(2.6n)]?y?[x/(1.6n)], and 5?n?6, and substantially having a magnetoplumbite-type crystal structure, is obtained by uniformly mixing a compound of Sr and/or Ba with an iron compound; calcining the resultant uniform mixture; adding a compound of the R element and/or the M element to the resultant calcined powder at a pulverization step thereof; and sintering the resultant mixture. The compound of the R element and/or the M element may be added at a percentage of more than 0 atomic % and 80 atomic % or less, on an element basis, at a mixing step before calcination.Type: ApplicationFiled: October 14, 2004Publication date: May 12, 2005Inventors: Takashi Takami, Yutaka Kubota, Yasunobu Ogata
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Patent number: 6858156Abstract: A ferrite magnet having a basic composition represented by the following general formula: (A1?xRx)O.n[(Fe1?yMy)2O3] by atomic ratio, wherein A is Sr and/or Ba, R is at least one of rare earth elements including Y, M is at least one element selected from the group consisting of Co, Mn, Ni and Zn, and x, y and n are numbers meeting the conditions of 0.01?x?0.4, [x/(2.6n)]?y?[x/(1.6n)], and 5?n?6, and substantially having a magnetoplumbite crystal structure, is obtained by uniformly mixing a compound of Sr and/or Ba with an iron compound; calcining the resultant uniform mixture; adding a compound of the R element and/or the M element to the resultant calcined powder at a pulverization step thereof; and sintering the resultant mixture. The compound of the R element and/or the M element may be added at a percentage of more than 0 atomic % and 80 atomic % or less, on an element basis, at a mixing step before calcination.Type: GrantFiled: January 16, 2003Date of Patent: February 22, 2005Assignee: Hitachi Metals, Ltd.Inventors: Takashi Takami, Yutaka Kubota, Yasunobu Ogata
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Patent number: 6737011Abstract: A ferrite magnet having a basic composition represented by the following general formula: (A1−xRx)O.n[(Fe1−yMy)2O3] by atomic ratio, wherein A is Sr and/or Ba, R is at least one of rare earth elements including Y, M is at least one element selected from the group consisting of Co, Mn, Ni and Zn, and x, y and n are numbers meeting the conditions of 0.01≦x≦0.4, [x/(2.6n)]≦y≦[x/(1.6n)], and 5≦n≦6, and substantially having a magnetoplumbite crystal structure, is obtained by uniformly mixing a compound of Sr and/or Ba with an iron compound; calcining the resultant uniform mixture; adding a compound of the R element and/or the M element to the resultant calcined powder at a pulverization step thereof; and sintering the resultant mixture. The compound of the R element and/or the M element may be added at a percentage of more than 0 atomic % and 80 atomic % or less, on an element basis, at a mixing step before calcination.Type: GrantFiled: November 9, 1999Date of Patent: May 18, 2004Assignee: Hitachi Metals, Ltd.Inventors: Takashi Takami, Yutaka Kubota, Yasunobu Ogata
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Publication number: 20030168785Abstract: A ferrite magnet having a basic composition represented by the following general formula: (A1-xRx)O.n[(Fe1-yMy)2O3] by atomic ratio, wherein A is Sr and/or Ba, R is at least one of rare earth elements including Y, M is at least one element selected from the group consisting of Co, Mn, Ni and Zn, and x, y and n are numbers meeting the conditions of 0.01≦x≦0.4, [x/(2.6n)]≦y≦[x/(1.6n)], and 5≦n≦6, and substantially having a magnetoplumbite-type crystal structure, is obtained by uniformly mixing a compound of Sr and/or Ba with an iron compound; calcining the resultant uniform mixture; adding a compound of the R element and/or the M element to the resultant calcined powder at a pulverization step thereof; and sintering the resultant mixture. The compound of the R element and/or the M element may be added at a percentage of more than 0 atomic % and 80 atomic % or less, on an element basis, at a mixing step before calcination.Type: ApplicationFiled: January 16, 2003Publication date: September 11, 2003Applicant: HITACHI METALS, LTD.Inventors: Takashi Takami, Yutaka Kubota, Yasunobu Ogata
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Patent number: 6537463Abstract: A resin-bonded magnet composed substantially of (a) an R—T—N-based magnetic powder having a basic composition of R&agr;T100−&agr;−&bgr;N&bgr;, wherein R is at least one selected form the group consisting of rare earth elements including Y, T is Fe or Fe and Co, 5≦&agr;≦20, and 5≦&bgr;≦30, (b) a ferrite magnetic powder having a substantially magnetoplumbite-type crystal structure and a basic composition represented by (A1−xR′x) O[(Fe1−yMy)2O3] by atomic ratio, wherein A is Sr and/or Ba, R′ is at least one selected from the group consisting of rare earth elements including Y, La being indispensable, M is Co or Co and Zn, 0.01≦x<0.4, 0.005≦y≦0.04, and 5.0≦n≦6.4, and (c) a binder. The ferrite magnet powder is preferably an anisotropic, granulated powder or an anisotropic, sintered ferrite magnet powder.Type: GrantFiled: December 11, 2000Date of Patent: March 25, 2003Assignee: Hitachi Metals, Ltd.Inventors: Katsunori Iwasaki, Masahiro Tobise, Yasunobu Ogata, Mikio Shindo, Hiroshi Okajima
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Patent number: 6528159Abstract: A diamond sintered body tool (20) having superior adhesion resistance, chipping resistance and high strength includes a tool base material (22) including a diamond sintered body, and a surface layer (21) formed on a surface of the tool base material (22). The surface layer (21) includes at least one of silicon, a silicon oxide, a silicon carbide, a silicon nitride and a solid solution thereof. The tool base material (22) has an inner portion (22b) including a first content of an iron group metal, and a surface portion (22a) surrounding the inner portion (22b ) and including a second content of the iron group metal lower than the first content.Type: GrantFiled: September 1, 2000Date of Patent: March 4, 2003Assignee: Sumitomo Electric Industries, Ltd.Inventors: Yasuyuki Kanada, Yoshihiro Kuroda, Noboru Yamazaki, Yasunobu Ogata, Kunihiro Tomita, Tetsuo Nakai, Makoto Abe