Patents by Inventor Nobuya Uchida
Nobuya Uchida 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: 7794859Abstract: A rare-earth magnet having a protective film for enhancing a corrosion resistance is provided. The protective film is a three-layer film including a first protective layer with a crystalline structure ? (for example, a polycrystalline structure), a second protective layer with a crystalline structure ? (for example, a columnar-crystalline structure), and a third protective layer with the crystalline structure ? from the side near a magnet body. Since the adjoining first and second protective layers have different crystalline structures from each other, and the adjoining second and third protective layers have also different crystalline structures from each other, compactness among the three layers in the protective film may be improved. Therefore, development of a pinhole is restrained, and corrosion of the protective film can be restrained.Type: GrantFiled: October 2, 2006Date of Patent: September 14, 2010Assignee: TDK CorporationInventors: Takeshi Sakamoto, Nobuya Uchida, Yoshitomo Tanaka, Yasuyuki Nakayama
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Patent number: 7553561Abstract: A rare earth magnet having excellent corrosion resistance is provided. It has a magnet body (10) containing a rare earth element, and a protective film (20) formed on the magnet body (10). In the protective film (20), a first protective film (21), a second protective film (22) and a third protective film (23) are laminated in this order from the side of the magnet body (10). These are in a polycrystalline state and composed of a metal plated film, for example. The first protective film (21) and the third protective film (23) have a smaller mean crystal grain size than that of the second protective film (22). Microcrystallization of the first protective film (21) can improve the density of the interface between the protective film (20) and the magnet body (10), and decrease the number of pinholes.Type: GrantFiled: July 19, 2005Date of Patent: June 30, 2009Assignee: TDK CorporationInventors: Takeshi Sakamoto, Nobuya Uchida, Yoshitomo Tanaka, Yasuyuki Nakayama
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Publication number: 20080053573Abstract: A rare earth magnet having excellent corrosion resistance is provided. It has a magnet body (10) containing a rare earth element, and a protective film (20) formed on the magnet body (10). In the protective film (20), a first protective film (21), a second protective film (22) and a third protective film (23) are laminated in this order from the side of the magnet body (10). These are in a polycrystalline state and composed of a metal plated film, for example. The first protective film (21) and the third protective film (23) have a smaller mean crystal grain size than that of the second protective film (22). Microcrystallization of the first protective film (21) can improve the density of the interface between the protective film (20) and the magnet body (10), and decrease the number of pinholes.Type: ApplicationFiled: July 19, 2005Publication date: March 6, 2008Applicant: TDK CORPORATIONInventors: Takeshi Sakamoto, Nobuya Uchida, Yoshitomo Tanaka, Yasuyuki Nakayama
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Patent number: 7255752Abstract: A method for manufacturing an R-T-B system rare earth permanent magnet that is a sintered body comprising a main phase consisting of an R2T14B phase (wherein R represents one or more rare earth elements (providing that the rare earth elements include Y), and T represents one or more transition metal elements essentially containing Fe, or Fe and Co), and a grain boundary phase containing a higher amount of R than the above main phase, wherein a product that is rich in Zr exists in the above R2T14B phase, the above manufacturing method comprising the steps of: preparing an R-T-B alloy containing as a main component the R2T14B phase and also containing Zr, and an R-T alloy containing R and T as main components, wherein the amount of R is higher than that of the above R-T-B alloy; obtaining a mixture of the R-T-B alloy powder and the R-T alloy powder; preparing a compacted body with a certain form from the above mixture; and sintering the above compacted body, wherein, in the above sintering step, the above produType: GrantFiled: March 11, 2004Date of Patent: August 14, 2007Assignee: TDK CorporationInventors: Chikara Ishizaka, Gouichi Nishizawa, Tetsuya Hidaka, Akira Fukuno, Nobuya Uchida
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Publication number: 20070077454Abstract: The present invention provides a rare-earth magnet capable of enhancing a corrosion resistance. A protective film is a three-layer film including a first protective layer with a crystalline structure ? (for example, a polycrystalline structure), a second protective layer with a crystalline structure ? (for example, a columnar-crystalline structure), and a third protective layer with the crystalline structure ? from the side near a magnet body. Since the adjoining first and second protective layers have different crystalline structures from each other, and the adjoining second and third protective layers have also different crystalline structures from each other, compactness among the three layers in the protective film may be improved. Therefore, development of a pinhole is restrained, and corrosion of the protective film can be restrained.Type: ApplicationFiled: October 2, 2006Publication date: April 5, 2007Applicant: TDK CORPORATIONInventors: Takeshi Sakamoto, Nobuya Uchida, Yoshitomo Tanaka, Yasuyuki Nakayama
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Patent number: 6811620Abstract: An R—T—B system rare earth permanent magnet, which is a sintered body comprising: a main phase consisting of an R2T14B phase (wherein R represents one or more rare earth elements (providing that the rare earth elements include Y), and T represents one or more transition metal elements essentially containing Fe, or Fe and Co); and a grain boundary phase containing a higher amount of R than the above main phase, wherein a product that is rich in Zr exists in the above R2T14B phase. The product that is rich in Zr has a platy or acicular form. The R—T—B system rare earth permanent magnet containing the product enables to inhibit the grain growth, while keeping a decrease in magnetic properties to a minimum, and to obtain a wide suitable sintering temperature range.Type: GrantFiled: March 11, 2004Date of Patent: November 2, 2004Assignee: TDK CorporationInventors: Chikara Ishizaka, Gouichi Nishizawa, Tetsuya Hidaka, Akira Fukuno, Nobuya Uchida
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Publication number: 20040187970Abstract: An R-T-B system rare earth permanent magnet, which is a sintered body comprising: a main phase consisting of an R2T14B phase (wherein R represents one or more rare earth elements (providing that the rare earth elements include Y), and T represents one or more transition metal elements essentially containing Fe, or Fe and Co); and a grain boundary phase containing a higher amount of R than the above main phase, wherein a product that is rich in Zr exists in the above R2T14B phase. The product that is rich in Zr has a platy or acicular form. The R-T-B system rare earth permanent magnet containing the product enables to inhibit the grain growth, while keeping a decrease in magnetic properties to a minimum, and to obtain a wide suitable sintering temperature range.Type: ApplicationFiled: March 11, 2004Publication date: September 30, 2004Applicant: TDK CORPORATIONInventors: Chikara Ishizaka, Gouichi Nishizawa, Tetsuya Hidaka, Akira Fukuno, Nobuya Uchida
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Publication number: 20040187962Abstract: A method for manufacturing an R—T—B system rare earth permanent magnet that is a sintered body comprising a main phase consisting of an R2T14B phase (wherein R represents one or more rare earth elements (providing that the rare earth elements include Y), and T represents one or more transition metal elements essentially containing Fe, or Fe and Co), and a grain boundary phase containing a higher amount of R than the above main phase, wherein a product that is rich in Zr exists in the above R2T14B phase, the above manufacturing method comprising the steps of: preparing an R—T—B alloy containing as a main component the R2T14B phase and also containing Zr, and an R-T alloy containing R and T as main components, wherein the amount of R is higher than that of the above R—T—B alloy; obtaining a mixture of the R—T—B alloy powder and the R-T alloy powder; preparing a compacted body with a certain form from the above mixture; and sintering the above compacted body, whereType: ApplicationFiled: March 11, 2004Publication date: September 30, 2004Applicant: TDK CORPORATIONInventors: Chikara Ishizaka, Gouichi Nishizawa, Tetsuya Hidaka, Akira Fukuno, Nobuya Uchida
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Patent number: 5662740Abstract: In the manufacture of a single crystal film by epitaxial growth method, defects such as cracking are avoided by increasing the deviation of the lattice constant of the resulting film in the direction of growth from the substrate. Preferably, the deviation is increased at the rate of (0.4.about.9).times.10.sup.-4 %/.mu.m.Type: GrantFiled: October 17, 1994Date of Patent: September 2, 1997Assignee: TDK CorporationInventors: Kazuhito Yamasawa, Atsushi Oido, Akio Nakata, Nobuya Uchida
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Patent number: 5434101Abstract: In the manufacture of a single crystal film by epitaxial growth method, defects such as cracking are avoided by increasing the deviation of the lattice constant of the resulting film in the direction of growth from the substrate. Preferably, the deviation is increased at the rate of (0.4.about.9).times.10.sup.-4 %/.mu.m.Type: GrantFiled: March 2, 1993Date of Patent: July 18, 1995Assignee: TDK CorporationInventors: Kazuhito Yamasawa, Atsushi Oido, Akio Nakata, Nobuya Uchida