Patents by Inventor Hiroko Tokoro

Hiroko Tokoro 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).

  • Patent number: 11574652
    Abstract: Provided is a recording device. The recording device includes: an external magnetic field application unit that is configured to apply an external magnetic field to a magnetic recording medium; a light irradiation unit that is configured to irradiate light; and a light focusing unit that is configured to focus the light from the light irradiation unit by resonating the light to generate an enhanced magnetic field in which a magnetic field of the light is enhanced, in which magnetization of the magnetic recording medium is inverted by applying the external magnetic field and the enhanced magnetic field to the magnetic recording medium.
    Type: Grant
    Filed: August 13, 2021
    Date of Patent: February 7, 2023
    Assignees: THE UNIVERSITY OF TOKYO, OSAKA UNIVERSITY, FUJIFILM Corporation
    Inventors: Shin-ichi Ohkoshi, Marie Yoshikiyo, Kenta Imoto, Kosuke Nakagawa, Asuka Namai, Hiroko Tokoro, Makoto Nakajima, Masashi Shirata, Kenji Naoi
  • Publication number: 20220375663
    Abstract: A raw material solution containing trivalent iron ions, or trivalent iron ions and ions of a metal element that partially substitutes Fe sites, and an alkaline aqueous solution for neutralizing the raw material solution are added to a reaction system to adjust the pH of the reaction system from 1.0 to 3.0 or lower. Hydroxycarboxylic acid is added to the obtained reaction solution and the pH of the reaction system is then neutralized from 7.0 to 10.0 or lower. The obtained precipitate of a substituent metal element-containing iron oxyhydroxide is coated with silicon oxide, followed by heating so as to form particles of ?-iron oxide in which Fe sites are partially substituted by other metal elements, and then, a slurry containing the particles is classified. The iron-based oxide magnetic powder has a particle shape close to a perfect sphere and is suitable for use in a magnetic recording medium.
    Type: Application
    Filed: September 29, 2020
    Publication date: November 24, 2022
    Inventors: Shin-ichi OHKOSHI, Asuka NAMAl, Hiroko TOKORO, Marie YOSHIKIYO, Kazuhiro YAMAGA, Yasuto MIYAMOTO, Yuki MINEYAMA, Kenji SAKANE, Tetsuya KAWAHITO
  • Publication number: 20210375314
    Abstract: Provided is a recording device. The recording device includes: an external magnetic field application unit that is configured to apply an external magnetic field to a magnetic recording medium; a light irradiation unit that is configured to irradiate light; and a light focusing unit that is configured to focus the light from the light irradiation unit by resonating the light to generate an enhanced magnetic field in which a magnetic field of the light is enhanced, in which magnetization of the magnetic recording medium is inverted by applying the external magnetic field and the enhanced magnetic field to the magnetic recording medium.
    Type: Application
    Filed: August 13, 2021
    Publication date: December 2, 2021
    Applicants: The University of Tokyo, OSAKA UNIVERSITY, FUJIFILM Corporation
    Inventors: Shin-ichi OHKOSHI, Marie YOSHIKIYO, Kenta IMOTO, Kosuke NAKAGAWA, Asuka NAMAI, Hiroko TOKORO, Makoto NAKAJIMA, Masashi SHIRATA, Kenji NAOI
  • Patent number: 10669161
    Abstract: There are provided an oriented body such as a magnetic sheet in which a value of degree of orientation of magnetic particles is beyond 3.5, and a method for producing the same, and a device for producing the same, wherein the oriented body such as a magnetic sheet is produced through the steps of: mixing a mixed solution containing a solvent and a vehicle and ?-iron oxide particles by shaking stirring, and dispersing the ?-iron oxide particles in the mixed solution; providing a mixed solution in which the ?-iron oxide particles are dispersed, on a predetermined substrate; and removing the solvent while applying a magnetic field to the substrate provided with the mixed solution, to obtain an oriented body.
    Type: Grant
    Filed: January 18, 2016
    Date of Patent: June 2, 2020
    Assignees: THE UNIVERSITY OF TOKYO, DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Shin-ichi Ohkoshi, Hiroko Tokoro, Koji Nakabayashi, Asuka Namai, Kenta Imoto, Kenji Masada
  • Publication number: 20190048243
    Abstract: A heat storage/dissipation material has a constitution in which heat storage/dissipation titanium oxide made of Ti3O5 is dispersed in heat transfer oil in a liquid form, the heat storage/dissipation titanium oxide not undergoing phase transition into a ?-phase that has properties of a non-magnetic semiconductor and maintaining a state of a paramagnetic metal as long as the heat storage/dissipation titanium oxide is not subjected to pressure or light for heat dissipation. The heat storage/dissipation material is capable of maintaining a state of storing heat as long as the heat storage/dissipation material is not subjected to the pressure or the light for heat dissipation and is capable of releasing heat when subjected to the pressure or the light for heat dissipation, and therefore is capable of releasing the stored heat at a desired timing.
    Type: Application
    Filed: October 16, 2018
    Publication date: February 14, 2019
    Inventors: Shin-Ichi Ohkoshi, Hiroko Tokoro, Marie Yoshikiyo, Asuka Namai
  • Publication number: 20190035521
    Abstract: There is provided a magnetic substance containing substituted ?-iron oxide particles applicable as a magnetic toner of one-component development system, and a technique related thereto, which is the magnetic substance containing substituted ?-iron oxide particles in which a part of ?-iron oxide is substituted with a metal element other than iron, and satisfying at least one of the following conditions: (Condition 1) A molar extinction coefficient of a magnetic substance dispersion liquid at a wavelength of 450 nm is less than 770 dm3 mol?1 cm?1. (Condition 2) A molar extinction coefficient of the magnetic substance dispersion liquid at a wavelength of 500 nm is less than 430 dm3 mol?1 cm?1.
    Type: Application
    Filed: January 19, 2017
    Publication date: January 31, 2019
    Applicants: THE UNIVERSITY OF TOKYO, DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Shin-ichi OHKOSHI, Hiroko TOKORO, Kenji MASADA, Toshihiko UEYAMA
  • Patent number: 10099941
    Abstract: A magnetic ?-form iron oxide nanopowder is a novel magnetic iron oxide nanopowder having magnetic polarization and spontaneous electric polarization and having physical properties similar to those of half-metals; and a process produces the magnetic nanopowder. The magnetic powder has a composition represented by Fe2O3 and has a crystal structure belonging to the monoclinic system.
    Type: Grant
    Filed: June 18, 2015
    Date of Patent: October 16, 2018
    Assignees: THE UNIVERSITY OF TOKYO, DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Shin-ichi Ohkoshi, Marie Yoshikiyo, Asuka Namai, Hiroko Tokoro, Waka Tarora, Tomomichi Nasu, Takayuki Yoshida, Manabu Tanaka
  • Patent number: 9916922
    Abstract: There is provided an iron oxide magnetic nanoparticle powder having a ferromagnetic property even if the particles have an average particle size of 15 nm or less, preferably 10 nm or less, and a method of producing the same, an iron oxide magnetic nanoparticle thin film containing the iron oxide magnetic nanoparticle powder and a method of producing the same, wherein the iron oxide magnetic nanoparticles having an ?-Fe2O3 single phase, having the average particle size of 15 nm or less, and further 10 nm or less, are generated by using ?-FeO(OH) (iron oxide hydroxide) nanoparticles as a starting material, and coating the (iron oxide hydroxide) nanoparticles with silicon oxide, and applying heat treatment thereto under an atmospheric air, and further the iron oxide magnetic nanoparticle thin film is obtained by using the iron oxide magnetic nanoparticles.
    Type: Grant
    Filed: April 24, 2014
    Date of Patent: March 13, 2018
    Assignees: The University of Tokyo, Dowa Electronics Materials Co., Ltd.
    Inventors: Shin-ichi Ohkoshi, Marie Yoshikiyo, Asuka Namai, Hiroko Tokoro, Waka Tarora, Takayuki Yoshida, Manabu Tanaka
  • Publication number: 20170349448
    Abstract: There are provided an oriented body such as a magnetic sheet in which a value of degree of orientation of magnetic particles is beyond 3.5, and a method for producing the same, and a device for producing the same, wherein the oriented body such as a magnetic sheet is produced through the steps of: mixing a mixed solution containing a solvent and a vehicle and ?-iron oxide particles by shaking stirring, and dispersing the ?-iron oxide particles in the mixed solution; providing a mixed solution in which the ?-iron oxide particles are dispersed, on a predetermined substrate; and removing the solvent while applying a magnetic field to the substrate provided with the mixed solution, to obtain an oriented body.
    Type: Application
    Filed: January 18, 2016
    Publication date: December 7, 2017
    Applicants: THE UNIVERSITY OF TOKYO, DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Shin-ichi OHKOSHI, Hiroko TOKORO, Koji NAKABAYASHI, Asuka NAMAI, Kenta IMOTO, Kenji MASADA
  • Publication number: 20170137302
    Abstract: A magnetic ?-form iron oxide nanopowder is a novel magnetic iron oxide nanopowder having magnetic polarization and spontaneous electric polarization and having physical properties similar to those of half-metals; and a process produces the magnetic nanopowder. The magnetic powder has a composition represented by Fe2O3 and has a crystal structure belonging to the monoclinic system.
    Type: Application
    Filed: June 18, 2015
    Publication date: May 18, 2017
    Applicants: THE UNIVERSITY OF TOKYO, DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Shin-ichi OHKOSHI, Marie YOSHIKIYO, Asuka NAMAI, Hiroko TOKORO, Waka TARORA, Tomomichi NASU, Takayuki YOSHIDA, Manabu TANAKA
  • Publication number: 20160237331
    Abstract: A heat storage/dissipation material has a constitution in which heat storage/dissipation titanium oxide made of Ti3O5 is dispersed in heat transfer oil in a liquid form, the heat storage/dissipation titanium oxide not undergoing phase transition into a ?-phase that has properties of a non-magnetic semiconductor and maintaining a state of a paramagnetic metal as long as the heat storage/dissipation titanium oxide is not subjected to pressure or light for heat dissipation. The heat storage/dissipation material is capable of maintaining a state of storing heat as long as the heat storage/dissipation material is not subjected to the pressure or the light for heat dissipation and is capable of releasing heat when subjected to the pressure or the light for heat dissipation, and therefore is capable of releasing the stored heat at a desired timing.
    Type: Application
    Filed: October 6, 2014
    Publication date: August 18, 2016
    Inventors: Shin-ichi OHKOSHI, Hiroko TOKORO, Marie YOSHIKIYO, Asuka NAMAI
  • Publication number: 20160104560
    Abstract: There is provided an iron oxide magnetic nanoparticle powder having a ferromagnetic property even if the particles have an average particle size of 15 nm or less, preferably 10 nm or less, and a method of producing the same, an iron oxide magnetic nanoparticle thin film containing the iron oxide magnetic nanoparticle powder and a method of producing the same, wherein the iron oxide magnetic nanoparticles having an ?-Fe2O3 single phase, having the average particle size of 15 nm or less, and further 10 nm or less, are generated by using ?-FeO(OH) (iron oxide hydroxide) nanoparticles as a starting material, and coating the (iron oxide hydroxide) nanoparticles with silicon oxide, and applying heat treatment thereto under an atmospheric air, and further the iron oxide magnetic nanoparticle thin film is obtained by using the iron oxide magnetic nanoparticles.
    Type: Application
    Filed: April 24, 2014
    Publication date: April 14, 2016
    Inventors: Shin-ichi OHKOSHI, Marie YOSHIKIYO, Asuka NAMAI, Hiroko TOKORO, Waka TARORA, Takayuki YOSHIDA, Manabu TANAKA
  • Patent number: 9079782
    Abstract: A titanium oxide particle that can develop non-conventional and novel physical properties, a method for manufacturing the same, and a magnetic memory, an optical information recording medium, and a charge accumulation type memory using the same are provided. A silica-coated titanium hydroxide compound particle is directly produced through a sol-gel technique and not through a reverse micelle technique, and the silica-coated titanium hydroxide compound particle is subjected to a calcination process. Hence, a titanium oxide particle 1 can be provided which can develop non-conventional and novel physical properties such that it does not perform phase transition at a room temperature and a Ti3O5 particle body can always maintain the characteristic as a paramagnetic metal in all temperature ranges unlike conventional bulk bodies that perform phase transition between a non-magnetic semiconductor and a paramagnetic metal at a temperature near about 460 K.
    Type: Grant
    Filed: April 15, 2011
    Date of Patent: July 14, 2015
    Assignee: The University of Tokyo
    Inventors: Shin-ichi Ohkoshi, Hiroko Tokoro, Fumiyoshi Hakoe, Yoshihide Tsunobuchi, Kazuhito Hashimoto
  • Patent number: 9005569
    Abstract: A microstructure that can develop non-conventional and novel physical properties and a method for producing the same are provided. Ethanol is added to a mixture solution produced by adding a surfactant solution to a peroxotitanic acid aqueous solution to produce precipitates, and the precipitates collected from the mixture solution are let dried to produce precursor powders 5. The precursor powders 5 are calcined at a predetermined temperature. Accordingly, a microstructure 2 can be produced which is formed of monophasic Ti4O7 in nano size. The microstructure 2 of monophasic Ti4O7 produced in this fashion can be fine-grained in nano size unlike prior-art crystals.
    Type: Grant
    Filed: November 19, 2010
    Date of Patent: April 14, 2015
    Assignee: The University of Tokyo
    Inventors: Shin-ichi Ohkoshi, Deepa Dey, Yoshihide Tsunobuchi, Kazuhito Hashimoto, Hiroko Tokoro, Fumiyoshi Hakoe
  • Patent number: 8609261
    Abstract: There are provided titanium oxide particles capable of manifesting an unprecedented property, a manufacturing method thereof and a magnetic memory as well as a charge storage type memory employing the titanium oxide particles. Unlike-conventional bulk bodies phase-transited between nonmagnetic semiconductors and paramagnetic metals around about 460K, provided are titanium oxide particles 3 capable of manifesting an unprecedented property that Ti3O5 particles do not undergo phase transitions at room temperature and allow a paramagnetic metal property thereof to be consistently maintained in any temperature range.
    Type: Grant
    Filed: November 26, 2009
    Date of Patent: December 17, 2013
    Assignee: The University of Tokyo
    Inventors: Shin-ichi Ohkoshi, Tomoyuki Matsuda, Yoshihide Tsunobuchi, Kazuhito Hashimoto, Hiroko Tokoro
  • Patent number: 8535816
    Abstract: There are provided a fine structural body capable of manifesting an unprecedented property; a manufacturing method thereof; and a magnetic memory, a charge storage memory and an optical information recording medium employing such fine structural body. Unlike conventional bulk bodies phase-transited between nonmagnetic semiconductors and paramagnetic metals around about 460K, there can be provided a fine structural body 1 comprised of Ti3O5, but capable of manifesting an unprecedented property in which a paramagnetic metal property thereof is consistently maintained in all temperature ranges without undergoing phase transition to a nonmagnetic semiconductor.
    Type: Grant
    Filed: July 13, 2009
    Date of Patent: September 17, 2013
    Assignee: The University of Tokyo
    Inventors: Shin-ichi Ohkoshi, Yoshihide Tsunobuchi, Hiroko Tokoro, Fumiyoshi Hakoe, Kazuhito Hashimoto
  • Publication number: 20130105723
    Abstract: A titanium oxide particle that can develop non-conventional and novel physical properties, a method for manufacturing the same, and a magnetic memory, an optical information recording medium, and a charge accumulation type memory using the same are provided. A silica-coated titanium hydroxide compound particle is directly produced through a sol-gel technique and not through a reverse micelle technique, and the silica-coated titanium hydroxide compound particle is subjected to a calcination process. Hence, a titanium oxide particle 1 can be provided which can develop non-conventional and novel physical properties such that it does not perform phase transition at a room temperature and a Ti3O5 particle body can always maintain the characteristic as a paramagnetic metal in all temperature ranges unlike conventional bulk bodies that perform phase transition between a non-magnetic semiconductor and a paramagnetic metal at a temperature near about 460 K.
    Type: Application
    Filed: April 15, 2011
    Publication date: May 2, 2013
    Applicant: THE UNIVERSITY OF TOKYO
    Inventors: Shin-ichi Ohkoshi, Hiroko Tokoro, Fumiyoshi Hakoe, Yoshihide Tsunobuchi, Kazuhito Hashimoto
  • Publication number: 20120275990
    Abstract: A microstructure that can develop non-conventional and novel physical properties and a method for producing the same are provided. Ethanol is added to a mixture solution produced by adding a surfactant solution to a peroxotitanic acid aqueous solution to produce precipitates, and the precipitates collected from the mixture solution are let dried to produce precursor powders 5. The precursor powders 5 are calcined at a predetermined temperature. Accordingly, a microstructure 2 can be produced which is formed of monophasic Ti4O7 in nano size. The microstructure 2 of monophasic Ti4O7 produced in this fashion can be fine-grained in nano size unlike prior-art crystals.
    Type: Application
    Filed: November 19, 2010
    Publication date: November 1, 2012
    Applicant: The University of Tokyo
    Inventors: Shin-ichi Ohkoshi, Deepa Dey, Yoshihide Tsunobuchi, Kazuhito Hashimoto, Hiroko Tokoro, Fumiyoshi Hakoe
  • Publication number: 20110287282
    Abstract: There are provided a fine structural body capable of manifesting an unprecedented property; a manufacturing method thereof; and a magnetic memory, a charge storage memory and an optical information recording medium employing such fine structural body. Unlike conventional bulk bodies phase-transited between nonmagnetic semiconductors and paramagnetic metals around about 460K, there can be provided a fine structural body 1 comprised of Ti3O5, but capable of manifesting an unprecedented property in which a paramagnetic metal property thereof is consistently maintained in all temperature ranges without undergoing phase transition to a nonmagnetic semiconductor.
    Type: Application
    Filed: July 13, 2009
    Publication date: November 24, 2011
    Inventors: Shin-ichi Ohkoshi, Yoshihide Tsunobuchi, Hiroko Tokoro, Fumiyoshi Hakoe, Kazuhito Hashimoto
  • Publication number: 20110204278
    Abstract: There are provided titanium oxide particles capable of manifesting an unprecedented property, a manufacturing method thereof and a magnetic memory as well as a charge storage type memory employing the titanium oxide particles. Unlike-conventional bulk bodies phase-transited between nonmagnetic semiconductors and paramagnetic metals around about 460K, provided are titanium oxide particles 3 capable of manifesting an unprecedented property that Ti3O5 particles do not undergo phase transitions at room temperature and allow a paramagnetic metal property thereof to be consistently maintained in any temperature range.
    Type: Application
    Filed: November 26, 2009
    Publication date: August 25, 2011
    Applicant: THE UNIVERSITY OF TOKYO
    Inventors: Shin-ichi Ohkoshi, Tomoyuki Matsuda, Yoshihide Tsunobuchi, Kazuhito Hashimoto, Hiroko Tokoro