Patents by Inventor Masashi Kawasaki

Masashi Kawasaki 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: 11974770
    Abstract: A medical device system that includes an ultrasound transducer and a processor. The ultrasound transducer includes a plurality of electrode plates to which a drive signal is supplied, and a plurality of piezoelectric elements that are alternately arranged with the electrode plates, and that generate ultrasound vibrations according to the drive signal. The ultrasound transducer also includes an electric wiring that electrically connects the electrode plates adjacent to each other, and a memory that stores reference information regarding specific initial characteristics. The processor analyzes the generated ultrasonic vibrations to determine a resonance point of the ultrasound transducer, and detects resonance point information regarding the resonance point. The processor then determines whether an abnormality has occurred in the ultrasound transducer by comparing the stored reference information and the detected resonance point information.
    Type: Grant
    Filed: October 7, 2020
    Date of Patent: May 7, 2024
    Assignee: OLYMPUS CORPORATION
    Inventors: Minoru Kawasaki, Masashi Yamada
  • Publication number: 20210383955
    Abstract: In order to obtain an inductor element advantageous for miniaturization, an inductor element 10 according to an embodiment of the present disclosure is provided with a metal medium 2 in which ordered spins are spatially arranged so as to have a non-collinear spin structure when traced in a certain direction. In the inductor element, an electric current I is applied through the metal medium so as to have a projective component of the direction. Preferable examples of the non-collinear spin structure for the metal medium include a spiral structure and a cycloidal structure.
    Type: Application
    Filed: August 1, 2019
    Publication date: December 9, 2021
    Inventors: Naoto NAGAOSA, Yoshinori TOKURA, Tomoyuki YOKOUCHI, Masashi KAWASAKI, Yoshichika OTANI, Maximilian Anton HIRSCHBERGER
  • Patent number: 11056597
    Abstract: A photoelectric conversion device includes a photoelectric conversion element formed of a polar material and including no p-n junction, and first and second electrodes provided on the photoelectric conversion element and arranged at an interval. Space-inversion symmetry of a structure of the photoelectric conversion element is broken. The first and second electrodes are each formed of a metal material that generates no substantial potential barrier preventing majority carriers for the photoelectric conversion element from moving from the electrode to the photoelectric conversion element. Light incidence on the photoelectric conversion element without voltage application between the first and second electrodes causes electromotive force to be generated between first and second electrodes, and enables electric current to be continuously taken out from the first and second electrodes.
    Type: Grant
    Filed: December 27, 2018
    Date of Patent: July 6, 2021
    Assignee: RIKEN
    Inventors: Masao Nakamura, Masashi Kawasaki, Yoshinori Tokura, Naoto Nagaosa, Takahiro Morimoto, Yoshio Kaneko
  • Patent number: 10468586
    Abstract: An electronic device is provided, including: a first drive electrode; a second drive electrode that is spaced apart from the first drive electrode; and a topological insulator that contacts both of the first drive electrode and the second drive electrode and has magnetism, wherein the topological insulator includes a first region having a first coercivity and a second region having a second coercivity that is different from the first coercivity. A fabrication method of a topological insulator is also provided, including: preparing a topological insulator having magnetism and a first coercivity; and forming a second region having a second coercivity that is different from the first coercivity by irradiating a partial region of the topological insulator with ions.
    Type: Grant
    Filed: February 12, 2018
    Date of Patent: November 5, 2019
    Assignee: RIKEN
    Inventors: Ryutaro Yoshimi, Masataka Mogi, Naoto Nagaosa, Masashi Kawasaki, Yoshinori Tokura, Wataru Koshibae
  • Publication number: 20190214513
    Abstract: A photoelectric conversion device includes a photoelectric conversion element formed of a polar material and including no p-n junction, and first and second electrodes provided on the photoelectric conversion element and arranged at an interval. Space-inversion symmetry of a structure of the photoelectric conversion element is broken. The first and second electrodes are each formed of a metal material that generates no substantial potential barrier preventing majority carriers for the photoelectric conversion element from moving from the electrode to the photoelectric conversion element.
    Type: Application
    Filed: December 27, 2018
    Publication date: July 11, 2019
    Applicant: RIKEN
    Inventors: Masao NAKAMURA, Masashi KAWASAKI, Yoshinori TOKURA, Naoto NAGAOSA, Takahiro MORIMOTO, Yoshio KANEKO
  • Patent number: 10217931
    Abstract: Provided is a magnetic element which can generate a skyrmion by a stacked film including a magnetic layer and a non-magnetic layer, and a skyrmion memory to which the magnetic element is applied and the like. Provided is a magnetic element for generating a skyrmion, the magnetic element comprising a two-dimensional stacked film, wherein the two-dimensional stacked film is at least one or more multiple layered films including a magnetic film and a non-magnetic film stacked on the magnetic film. Also, provided is a skyrmion memory including a plurality of the magnetic elements stacked in a thickness direction.
    Type: Grant
    Filed: March 6, 2017
    Date of Patent: February 26, 2019
    Assignee: RIKEN
    Inventors: Masao Nakamura, Jobu Matsuno, Masashi Kawasaki, Yoshinori Tokura, Yoshio Kaneko
  • Patent number: 10141068
    Abstract: A magnetic element capable of generating and erasing a skyrmion, including a magnet shaped as a thin layer and including a structure surrounded by a nonmagnetic material; a current path provided surrounding an end region including an end portion of the magnet, on one surface of the magnet; and a skyrmion sensor that detects the generation and erasing of the skyrmion. With Wm being width of the magnet and hm being height of the magnet, a size of the magnet, with the skyrmion of a diameter ? being generated, is such that 2?>Wm>?/2 and 2?>hm>?/2. With W being width of the end region in a direction parallel to the end portion of the magnet and h being height of the end region in a direction perpendicular to the end portion of the magnet, the end region is such that ??W>?/4 and 2?>h>?/2.
    Type: Grant
    Filed: March 1, 2017
    Date of Patent: November 27, 2018
    Assignee: RIKEN
    Inventors: Naoto Nagaosa, Wataru Koshibae, Junichi Iwasaki, Masashi Kawasaki, Yoshinori Tokura, Yoshio Kaneko
  • Publication number: 20180175285
    Abstract: An electronic device is provided, including: a first drive electrode; a second drive electrode that is spaced apart from the first drive electrode; and a topological insulator that contacts both of the first drive electrode and the second drive electrode and has magnetism, wherein the topological insulator includes a first region having a first coercivity and a second region having a second coercivity that is different from the first coercivity. A fabrication method of a topological insulator is also provided, including: preparing a topological insulator having magnetism and a first coercivity; and forming a second region having a second coercivity that is different from the first coercivity by irradiating a partial region of the topological insulator with ions.
    Type: Application
    Filed: February 12, 2018
    Publication date: June 21, 2018
    Inventors: Ryutaro YOSHIMI, Masataka MOGI, Naoto NAGAOSA, Masashi KAWASAKI, Yoshinori TOKURA, Wataru KOSHIBAE
  • Patent number: 10003010
    Abstract: Provided is a magnetic element capable of generating one skyrmion and erasing the one skyrmion. The magnetic element includes a magnet shaped like a substantially rectangular flat plate, an upstream electrode connected to the magnet in a width Wm direction of the magnet and made of a non-magnetic metal, a downstream electrode connected to the magnet in the width Wm direction to oppose the upstream electrode and made of a non-magnetic metal, and a skyrmion sensor configured to detect the skyrmion. Here, a width Wm of the substantially rectangular magnet is such that 3·?>Wm??, where ? denotes a diameter of the skyrmion, a length Hm of the substantially rectangular magnet is such that 2·?>Hm??, and the magnet has a notch structure at the edge between the upstream electrode and the downstream electrode.
    Type: Grant
    Filed: March 3, 2017
    Date of Patent: June 19, 2018
    Assignee: RIKEN
    Inventors: Naoto Nagaosa, Wataru Koshibae, Junichi Iwasaki, Masashi Kawasaki, Yoshinori Tokura, Yoshio Kaneko
  • Patent number: 9859017
    Abstract: To provide a magnetic element capable of performing skyrmion transfer, a skyrmion memory to which this magnetic element is applied, and a shift register, for example, a magnetic element capable of performing skyrmion transfer is provided, the magnetic element providing a transverse transfer arrangement in which the skyrmion is transferred substantially perpendicular to a current between an upstream electrode and a downstream electrode, and including a plurality of stable positions in which the skyrmion exists more stably than in other regions of a magnet, and a skyrmion sensor that detects a position of the skyrmion.
    Type: Grant
    Filed: March 5, 2017
    Date of Patent: January 2, 2018
    Assignee: RIKEN
    Inventors: Naoto Nagaosa, Wataru Koshibae, Junichi Iwasaki, Masashi Kawasaki, Yoshinori Tokura, Yoshio Kaneko
  • Patent number: 9824712
    Abstract: A magnetic storage media which has an endurance (durability) characteristics close to an infinite number of writing times of data and a data retention (holding) characteristics close to permanency, and is ultra-high-speed writable and erasable, and a data storage device and an image storage device which apply this magnetic storage media are provided. A magnetic storage media includes a thin layer magnet and a magnetic field generating unit arranged facing a surface of the magnet, and is capable of creating or eliminating a skyrmion by applying heat energy to another surface of the magnet positioned on the opposite side of the surface of the magnet, and a skyrmion memory includes the magnetic storage media.
    Type: Grant
    Filed: February 3, 2017
    Date of Patent: November 21, 2017
    Assignee: RIKEN
    Inventors: Naoto Nagaosa, Wataru Koshibae, Junichi Iwasaki, Masashi Kawasaki, Yoshinori Tokura, Yoshio Kaneko
  • Patent number: 9748000
    Abstract: Provided is a skyrmion memory circuit capable of circularly transferring a magnetic element skyrmion, comprising one or more current paths in a magnet having a closed-path pattern that are provided surrounding an end region including an end portion of the magnet in a plane of the magnet with the closed-path pattern, and applying current between an outer terminal connected to an outer circumferential portion of the closed-path pattern and an inner circumference electrode connected to an inner circumferential portion of the closed-path pattern, transferring the skyrmion in a direction substantially perpendicular to the direction of the applied current, and circulating the skyrmion in the magnet with the closed-path pattern.
    Type: Grant
    Filed: December 28, 2016
    Date of Patent: August 29, 2017
    Assignee: RIKEN
    Inventors: Naoto Nagaosa, Wataru Koshibae, Junichi Iwasaki, Masashi Kawasaki, Yoshinori Tokura, Yoshio Kaneko
  • Publication number: 20170206921
    Abstract: A magnetic storage media which has an endurance (durability) characteristics close to an infinite number of writing times of data and a data retention (holding) characteristics close to permanency, and is ultra-high-speed writable and erasable, and a data storage device and an image storage device which apply this magnetic storage media are provided. A magnetic storage media includes a thin layer magnet and a magnetic field generating unit arranged facing a surface of the magnet, and is capable of creating or eliminating a skyrmion by applying heat energy to another surface of the magnet positioned on the opposite side of the surface of the magnet, and a skyrmion memory includes the magnetic storage media.
    Type: Application
    Filed: February 3, 2017
    Publication date: July 20, 2017
    Inventors: Naoto NAGAOSA, Wataru KOSHIBAE, Junichi IWASAKI, Masashi KAWASAKI, Yoshinori TOKURA, Yoshio KANEKO
  • Publication number: 20170178746
    Abstract: To provide a magnetic element capable of performing skyrmion transfer, a skyrmion memory to which this magnetic element is applied, and a shift register, for example, a magnetic element capable of performing skyrmion transfer is provided, the magnetic element providing a transverse transfer arrangement in which the skyrmion is transferred substantially perpendicular to a current between an upstream electrode and a downstream electrode, and including a plurality of stable positions in which the skyrmion exists more stably than in other regions of a magnet, and a skyrmion sensor that detects a position of the skyrmion.
    Type: Application
    Filed: March 5, 2017
    Publication date: June 22, 2017
    Inventors: Naoto NAGAOSA, Wataru KOSHIBAE, Junichi IWASAKI, Masashi KAWASAKI, Yoshinori TOKURA, Yoshio KANEKO
  • Publication number: 20170179375
    Abstract: Provided is a magnetic element capable of generating one skyrmion and erasing the one skyrmion. The magnetic element includes a magnet shaped like a substantially rectangular flat plate, an upstream electrode connected to the magnet in a width Wm direction of the magnet and made of a non-magnetic metal, a downstream electrode connected to the magnet in the width Wm direction to oppose the upstream electrode and made of a non-magnetic metal, and a skyrmion sensor configured to detect the skyrmion. Here, a width Wm of the substantially rectangular magnet is such that 3·?>Wm??, where ? denotes a diameter of the skyrmion, a length Hm of the substantially rectangular magnet is such that 2·?>Hm??, and the magnet has a notch structure at the edge between the upstream electrode and the downstream electrode.
    Type: Application
    Filed: March 3, 2017
    Publication date: June 22, 2017
    Inventors: Naoto NAGAOSA, Wataru KOSHIBAE, Junichi IWASAKI, Masashi KAWASAKI, Yoshinori TOKURA, Yoshio KANEKO
  • Publication number: 20170179376
    Abstract: Provided is a magnetic element which can generate a skyrmion by a stacked film including a magnetic layer and a non-magnetic layer, and a skyrmion memory to which the magnetic element is applied and the like. Provided is a magnetic element for generating a skyrmion, the magnetic element comprising a two-dimensional stacked film, wherein the two-dimensional stacked film is at least one or more multiple layered films including a magnetic film and a non-magnetic film stacked on the magnetic film. Also, provided is a skyrmion memory including a plurality of the magnetic elements stacked in a thickness direction.
    Type: Application
    Filed: March 6, 2017
    Publication date: June 22, 2017
    Inventors: Masao NAKAMURA, Jobu MATSUNO, Masashi KAWASAKI, Yoshinori TOKURA, Yoshio KANEKO
  • Publication number: 20170178748
    Abstract: A magnetic element capable of generating and erasing a skyrmion, including a magnet shaped as a thin layer and including a structure surrounded by a nonmagnetic material; a current path provided surrounding an end region including an end portion of the magnet, on one surface of the magnet; and a skyrmion sensor that detects the generation and erasing of the skyrmion. With Wm being width of the magnet and hm being height of the magnet, a size of the magnet, with the skyrmion of a diameter ? being generated, is such that 2?>Wm>?/2 and 2?>hm>?/2. With W being width of the end region in a direction parallel to the end portion of the magnet and h being height of the end region in a direction perpendicular to the end portion of the magnet, the end region is such that ??W>?/4 and 2?>h>?/2.
    Type: Application
    Filed: March 1, 2017
    Publication date: June 22, 2017
    Inventors: Naoto NAGAOSA, Wataru KOSHIBAE, Junichi IWASAKI, Masashi KAWASAKI, Yoshinori TOKURA, Yoshio KANEKO
  • Publication number: 20170169898
    Abstract: Provided is a skyrmion memory circuit capable of circularly transferring a magnetic element skyrmion, comprising one or more current paths in a magnet having a closed-path pattern that are provided surrounding an end region including an end portion of the magnet in a plane of the magnet with the closed-path pattern, and applying current between an outer terminal connected to an outer circumferential portion of the closed-path pattern and an inner circumference electrode connected to an inner circumferential portion of the closed-path pattern, transferring the skyrmion in a direction substantially perpendicular to the direction of the applied current, and circulating the skyrmion in the magnet with the closed-path pattern.
    Type: Application
    Filed: December 28, 2016
    Publication date: June 15, 2017
    Inventors: Naoto NAGAOSA, Wataru KOSHIBAE, Junichi IWASAKI, Masashi KAWASAKI, Yoshinori TOKURA, Yoshio KANEKO
  • Publication number: 20160223413
    Abstract: The stress sensor includes: a magnetic material; a stress applied portion on the magnetic material; a magnet disposed so as to be adjacent to by a magnetic material; a magnetic sensor disposed via the magnetic material so as to be opposed to the stress applied portion, wherein the magnetic sensor detects a magnetic flux emitted from a magnetic domain generated in the magnetic material by a local stress applied to the stress applied portion. The local stress or stress distribution can be detected with a convenience structure, and can obtain a high spatial resolution by using a stress response phenomenon of a single magnetic domain.
    Type: Application
    Filed: December 30, 2015
    Publication date: August 4, 2016
    Inventors: Masashi KUBOTA, Masashi KAWASAKI, Yoshinori TOKURA
  • Patent number: 8759828
    Abstract: A ZnO-based semiconductor device includes an n type ZnO-based semiconductor layer, an aluminum oxide film formed on the n type ZnO-based semiconductor layer, and a palladium layer formed on the aluminum oxide film. With this configuration, the n type ZnO-based semiconductor layer and the palladium layer form a Schottky barrier structure.
    Type: Grant
    Filed: April 12, 2012
    Date of Patent: June 24, 2014
    Assignees: Rohm Co., Ltd., Tohoku University
    Inventors: Shunsuke Akasaka, Masashi Kawasaki, Atsushi Tsukazaki