Patents by Inventor Takafumi Okamoto
Takafumi Okamoto 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: 20160071649Abstract: A ceramic capacitor having dielectric ceramic layers that include Ba, Re (Re is at least one of La, Ce, Pr, Nd, and Sm), Ti, Zr, M (M is at least one of Mg, Al, Mn, and V), Si, and optionally Sr, where at least some of the Ba, Re, Ti, and Zr and optionally Sr are in the form of a perovskite compound. Respective amounts, expressed as parts by mol, of the elements of the dielectric ceramic layers satisfy, with respect to a total of 100 of the Ti amount and the Zr amount, 0?a?20.0 where a is the Sr amount; 0.5?b?10.0 where b is the Re amount; 46?c?90 where c is the Zr amount; 0.5?d?10.0 where d is the M amount; 0.5?e?5.0 where e is the Si amount; and 0.990?m?1.050 where m is a ratio of a total of the Ba amount, the Sr amount, and the Re amount, to the total of the Ti amount and the Zr amount.Type: ApplicationFiled: November 19, 2015Publication date: March 10, 2016Inventors: Takafumi Okamoto, Shoichiro Suzuki
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Patent number: 9153382Abstract: A multilayer ceramic capacitor exhibits superior life characteristics in a high temperature load test despite the use of very thin dielectric layers. As a dielectric ceramic constituting a dielectric layer of the multilayer ceramic capacitor, a perovskite-type compound is used and contains Ba and Ti (a portion of Ba can be replaced with at least one of Ca and Sr, and a portion of Ti can be replaced with Zr) as a main component, and including La within the range of 2-6 parts by mole, Mg within the range of 3-5 parts by mole, and Mn within the range of 1.5-3 parts by mole in a case where a total content of Ti and Zr is 100 parts by mole.Type: GrantFiled: July 8, 2013Date of Patent: October 6, 2015Assignee: Murata Manufacturing Co., Ltd.Inventors: Takafumi Okamoto, Noriyuki Inoue
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Publication number: 20150109717Abstract: A multilayer ceramic capacitor includes a multilayer body including a plurality of stacked dielectric layers including a dielectric ceramic that includes a plurality of crystal grains and a plurality of internal electrodes disposed at a plurality of interfaces between the dielectric layers, and external electrodes. The multilayer body includes a Ba and Ti containing perovskite compound, La, Mg and Mn, and satisfies conditions such that in a case in which a content of Ti is set to 100 molar parts, a fraction of each content of La, Mg and Mn relative to the content of Ti is such that La is about 1.2 to about 6.0 molar parts, Mg is about 0.5 to about 5.0 molar parts and Mn is about 1.0 to about 3.0 molar parts, and an average number of crystal grains included in each of the dielectric layers in the stacking direction is one or more to three or less.Type: ApplicationFiled: December 29, 2014Publication date: April 23, 2015Inventor: Takafumi OKAMOTO
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Publication number: 20150103467Abstract: A multilayer ceramic capacitor includes a multilayer body including a plurality of stacked dielectric layers including a dielectric ceramic that includes a plurality of crystal grains and a plurality of internal electrodes disposed at a plurality of interfaces between the dielectric layers, and external electrodes. The multilayer body includes a Ba and Ti containing perovskite compound, La, Mg, Mn and Al, and satisfies conditions such that in a case in which a content of Ti is set to 100 molar parts, a fraction of each content of La, Mg, Mn and Al relative to the content of Ti is such that La is about 0.2 to about 1.2 molar parts, Mg is about 0.1 molar part or less, Mn is about 1.0 to about 3.0 molar parts and Al is about 0.5 to about 2.5 molar parts, and an average number of crystal grains included in each of the dielectric layers in the stacking direction is one or more to three or less.Type: ApplicationFiled: December 18, 2014Publication date: April 16, 2015Inventor: Takafumi OKAMOTO
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Patent number: 8592335Abstract: A dielectric ceramic composition contains a barium titanate based composite oxide as its main constituent, and contains a first accessory constituent including at least Al and a second accessory constituent including one or more elements selected from among Fe, Co, Ni, Cu, and Zn, wherein the content of the Al is 0.02 to 6 parts by mol with respect to 100 parts by mol of the main constituent, and the content ratio of the second accessory constituent to the Al is 0.01 to 0.4 in terms of mols. Dielectric layers are formed from a sintered body of the dielectric ceramic composition. The addition of various types of accessory elements such as rare-earth elements is possible, if necessary. This invention achieves a dielectric ceramic composition which is capable of ensuring favorable DC bias characteristics while ensuring high reliability, and a laminated ceramic capacitor using the dielectric ceramic composition.Type: GrantFiled: February 21, 2012Date of Patent: November 26, 2013Assignee: Murata Manufacturing Co., Ltd.Inventors: Takafumi Okamoto, Noriyuki Inoue, Hitoshi Nishimura
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Publication number: 20130294007Abstract: A multilayer ceramic capacitor exhibits superior life characteristics in a high temperature load test despite the use of very thin dielectric layers. As a dielectric ceramic constituting a dielectric layer of the multilayer ceramic capacitor, a perovskite-type compound is used and contains Ba and Ti (a portion of Ba can be replaced with at least one of Ca and Sr, and a portion of Ti can be replaced with Zr) as a main component, and including La within the range of 2-6 parts by mole, Mg within the range of 3-5 parts by mole, and Mn within the range of 1.5-3 parts by mole in a case where a total content of Ti and Zr is 100 parts by mole.Type: ApplicationFiled: July 8, 2013Publication date: November 7, 2013Inventors: Takafumi OKAMOTO, Noriyuki INOUE
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Patent number: 8385049Abstract: Provided is a dielectric ceramic which exhibits desired high temperature load resistance characteristics even under a high electric field strength on the order of 15 kV/mm. The dielectric ceramic contains, as its main constituent, a perovskite compound represented by the general formula (Ba1-h-i-mCahSriGdm)k(Ti1-y-j-n-o-pZryHfjMgnZnoMnp)O3, 0?h?0.03, 0?i?0.03; 0.042?m?0.074; 0.94?k?1.075; 0?(y+j)?0.05; 0.015?n?0.07; 0?o?0.04; 0?p?0.05; and 1.0<m/(n+o)<4.3. The dielectric ceramic can be used advantageously as a material for a dielectric ceramic layer provided in a laminated ceramic capacitor.Type: GrantFiled: April 20, 2011Date of Patent: February 26, 2013Assignee: Murata Manufacturing Co., Ltd.Inventors: Noriyuki Inoue, Hitoshi Nishimura, Toshihiro Okamatsu, Takafumi Okamoto
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Patent number: 8358494Abstract: A laminated ceramic capacitor is provided which is excellent in reliability even when its dielectric ceramic layers thinned. For a dielectric ceramic in a laminated ceramic capacitor, a ceramic is used which includes a main component containing a barium titanate based composite oxide represented by the general formula: (Ba1-h-m-xCahSrmRex)k(Ti1-n-yZrnMy)O3, where Re is La or the like, M is Mg or the like, and the respective relationships of 0.05?x?0.50, 0.02?y?0.3, 0.85?k?1.05, 0?h?0.25, 0?m?0.50, and 0?n?0.40 are satisfied; and an accessory component as a sintering aid, wherein the average grain diameter of crystal grains in a sintered body is 0.6 ?m or less.Type: GrantFiled: June 2, 2010Date of Patent: January 22, 2013Assignee: Murata Manufacturing Co., Ltd.Inventors: Hitoshi Nishimura, Noriyuki Inoue, Takafumi Okamoto
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Publication number: 20120147524Abstract: A dielectric ceramic composition contains a barium titanate based composite oxide as its main constituent, and contains a first accessory constituent including at least Al and a second accessory constituent including one or more elements selected from among Fe, Co, Ni, Cu, and Zn, wherein the content of the Al is 0.02 to 6 parts by mol with respect to 100 parts by mol of the main constituent, and the content ratio of the second accessory constituent to the Al is 0.01 to 0.4 in terms of mols. Dielectric layers are formed from a sintered body of the dielectric ceramic composition. The addition of various types of accessory elements such as rare-earth elements is possible, if necessary. This invention achieves a dielectric ceramic composition which is capable of ensuring favorable DC bias characteristics while ensuring high reliability, and a laminated ceramic capacitor using the dielectric ceramic composition.Type: ApplicationFiled: February 21, 2012Publication date: June 14, 2012Applicant: MURATA MANUFACTURING CO., LTD.Inventors: Takafumi Okamoto, Noriyuki Inoue, Hitoshi Nishimura
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Publication number: 20110205687Abstract: Provided is a dielectric ceramic which exhibits desired high temperature load resistance characteristics even under a high electric field strength on the order of 15 kV/mm. The dielectric ceramic contains, as its main constituent, a perovskite compound represented by the general formula (Ba1-h-i-mCahSriGdm)k(Ti1-y-j-n-o-pZryHfjMgnZnoMnp)O3, 0?h?0.03, 0?i?0.03; 0.042?m?0.074; 0.94?k?1.075; 0?(y+j)?0.05; 0.015?n?0.07; 0?o?0.04; 0?p?0.05; and 1.0<m/(n+o)<4.3. The dielectric ceramic can be used advantageously as a material for a dielectric ceramic layer provided in a laminated ceramic capacitor.Type: ApplicationFiled: April 20, 2011Publication date: August 25, 2011Applicant: MURATA MANUFACTURING CO., LTD.Inventors: Noriyuki Inoue, Hitoshi Nishimura, Toshihiro Okamatsu, Takafumi Okamoto
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Patent number: 7976990Abstract: A technique includes operating a fuel cell, which produces an effluent flow. The technique includes routing the effluent flow through an electrochemical pump to extract fuel from the effluent flow to produce a first feedback flow. The technique includes using the effluent flow to produce a second feedback flow separate from the first feedback flow and routing the second feedback flow through a venturi to the fuel cell.Type: GrantFiled: December 6, 2005Date of Patent: July 12, 2011Assignee: Honda Motor Co., Ltd.Inventors: Arne W. Ballantine, Michael D. Gasda, James F. McElroy, Robert A. Dross, Takafumi Okamoto
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Publication number: 20100328844Abstract: A laminated ceramic capacitor is provided which is excellent in reliability even when its dielectric ceramic layers thinned. For a dielectric ceramic in a laminated ceramic capacitor, a ceramic is used which includes a main component containing a barium titanate based composite oxide represented by the general formula: (Ba1-h-m-xCahSrmRex)k(Ti1-n-yZrnMy)O3, where Re is La or the like, M is Mg or the like, and the respective relationships of 0.05?x?0.50, 0.02?y?0.3, 0.85?k?1.05, 0?h?0.25, 0?m?0.50, and 0?n?0.40 are satisfied; and an accessory component as a sintering aid, wherein the average grain diameter of crystal grains in a sintered body is 0.6 ?m or less.Type: ApplicationFiled: June 2, 2010Publication date: December 30, 2010Applicant: MURATA MANUFACTURING CO., LTD.Inventors: Hitoshi NISHIMURA, Noriyuki Inoue, Takafumi Okamoto
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Publication number: 20070128479Abstract: A technique includes operating a fuel cell, which produces an effluent flow. The technique includes routing the effluent flow through an electrochemical pump to extract fuel from the effluent flow to produce a first feedback flow. The technique includes using the effluent flow to produce a second feedback flow separate from the first feedback flow and routing the second feedback flow through a venturi to the fuel cell.Type: ApplicationFiled: December 6, 2005Publication date: June 7, 2007Inventors: Arne Ballantine, Michael Gasda, James McElroy, Robert Dross, Takafumi Okamoto
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Publication number: 20070030561Abstract: A relay amplifier provided at a branching point of an electric power line in an electric power line communication for amplifying communication signals, comprising a plurality of signal couplers provided at the respective electric power lines on both sides of the branching point for transmitting/receiving the communication signals to/from the electric power lines; and an amplifier for amplifying the communication signals inputted from the plurality of signal couplers.Type: ApplicationFiled: August 19, 2004Publication date: February 8, 2007Applicants: Mitsubishi Materials Corporation, Mitsubishi Denki Kabushiki KaishaInventors: Kenzo Nakamura, Nobuyuki Yamashita, Masahiko Nakamura, Takafumi Okamoto, Sawako Ojima, Yasuaki Hori, Masafumi Narikawa, Naoki Ishikawa
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Patent number: 7105202Abstract: A process for coating the inner wall surface of a thin tube having an inside diameter of 0.2 to 5 mm with a resin. The tube is first filled with a resin particulate dispersion. The dispersion filling the tube is held therein by its surface tension and does not flow out. A heater is positioned about the upper end of the tube and is moved down toward its lower end to heat the tube and thereby cause minute resin particles to adhere to its inner wall surface. Then, the tube is heated in a furnace and is cooled to have its inner wall surface coated with the resin.Type: GrantFiled: May 12, 2005Date of Patent: September 12, 2006Assignee: Honda Motor Co., Ltd.Inventors: Takafumi Okamoto, Eri Ishikawa
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Publication number: 20050255240Abstract: A process for coating the inner wall surface of a thin tube having an inside diameter of 0.2 to 5 mm with a resin. The tube is first filled with a resin particulate dispersion. The dispersion filling the tube is held therein by its surface tension and does not flow out. A heater is positioned about the upper end of the tube and is moved down toward its lower end to heat the tube and thereby cause minute resin particles to adhere to its inner wall surface. Then, the tube is heated in a furnace and is cooled to have its inner wall surface coated with the resin.Type: ApplicationFiled: May 12, 2005Publication date: November 17, 2005Applicant: Honda Motor Co., Ltd.Inventors: Takafumi Okamoto, Eri Ishikawa
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Patent number: 6833204Abstract: A method of operating a phosphoric acid fuel cell is provided, in which the phosphoric acid fuel cell effects power generation at a high output. A power-generating cell is provided with an electrolyte layer comprising a matrix composed of basic polymer impregnated with acidic liquid electrolyte such as phosphoric acid. The phosphoric acid fuel cell has a fuel cell stack comprising a single unit of the power-generating cell or a predetermined number of the power-generating cells electrically connected in series to one another. When the phosphoric acid fuel cell is operated, the supply pressures of the oxygen-containing gas and the hydrogen-containing gas are set so that the pressure on a cathode electrode of the power-generating cell is higher than that of an anode electrode.Type: GrantFiled: June 29, 2001Date of Patent: December 21, 2004Assignee: Honda Giken Kogyo Kabushiki KaishaInventors: Hiroyuki Oyanagi, Shuji Sato, Masahiro Ise, Takafumi Okamoto
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Patent number: 6815109Abstract: A fuel cell system comprises a fuel cell stack including stacked power-generating cells, a cooling medium-circulating passage for supplying a cooling medium to the fuel cell stack in a circulating manner to cool the power-generating cells, and a heat exchange means arranged for the cooling medium-circulating passage, for performing a heat exchange treatment for the cooling medium used to cool the power-generating cells, wherein the operation temperature of the fuel cell stack is set to be within a range of 100° C. to 210° C. Accordingly, it is possible to improve durability of the fuel cell system in the high output operation and to easily miniaturize the fuel cell system.Type: GrantFiled: June 5, 2001Date of Patent: November 9, 2004Assignee: Honda Giken Kogyo Kabushiki KaishaInventors: Takafumi Okamoto, Koji Okazaki, Shuji Sato
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Patent number: 6767661Abstract: A fuel cell system comprises a medium-circulating passage for supplying, in a circulating manner, a temperature-adjusting medium to a fuel cell stack, and first and second temperature sensors for detecting medium temperatures at a temperature-adjusting medium inlet and a temperature-adjusting medium outlet. The medium-circulating passage is provided with a pump for circulating the medium, a heater for heating the medium, a radiator for cooling the medium, a bypass passage for bypassing the radiator, and first through third opening/closing valves for selectively supplying the temperature-adjusting medium to the radiator and the bypass passage.Type: GrantFiled: September 6, 2001Date of Patent: July 27, 2004Assignee: Honda Giken Kogyo Kabushiki KaishaInventors: Takafumi Okamoto, Masahiro Ise, Shuji Sato
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Patent number: 6696185Abstract: The present invention provides a fuel cell having a simple structure which is suitable for miniaturization, and which makes it possible to reduce ion conductive resistance of a solid polymer oxide itself and ion conductive resistance and contact resistance between the solid polymer oxide and electrode plates, and a fastening method therefor.Type: GrantFiled: December 24, 1997Date of Patent: February 24, 2004Assignee: Honda Giken Kogyo Kabushiki KaishaInventor: Takafumi Okamoto