Patents by Inventor Yu Yonezawa

Yu Yonezawa 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: 11682510
    Abstract: A composite magnetic material includes a powder and a resin. The powder has a main component containing Fe or Fe and Co. An average minor axis length in primary particles of the powder is 100 nm or less. A point satisfying (X, Y)=(?/Av (%), (Av-?)) on an XY coordinate plane is present within a region (including a boundary) surrounded by three points ?(24.5, 6.7), ?(72.0, 1.2), and ?(24.5, 1.2), in which an average of aspect ratios in the primary particles of the powder is set to Av, and a standard deviation of the aspect ratios in the primary particles of the powder is set to ?.
    Type: Grant
    Filed: February 18, 2020
    Date of Patent: June 20, 2023
    Assignee: TDK CORPORATION
    Inventors: Isao Kanada, Yu Yonezawa
  • Publication number: 20230034570
    Abstract: A water electrolysis system includes a plurality of conversion circuits configured to convert a first power generated by a solar power generation apparatus into a plurality of second powers, respectively, a control circuit configured to control at least a number of driven conversion circuits among the plurality of conversion circuits, and a plurality of water electrolysis cells configured to receive the plurality of second powers from the plurality of conversion circuits, respectively, wherein the control circuit includes a detector configured to detect an occurrence of a change in the first power, the change exceeding a predetermined amount per predetermined time, and the control circuit increases the number of driven conversion circuits in response to the detector detecting the occurrence of the change.
    Type: Application
    Filed: October 12, 2022
    Publication date: February 2, 2023
    Applicant: FUJITSU LIMITED
    Inventors: Yu Yonezawa, YOSHIYASU NAKASHIMA
  • Patent number: 11264892
    Abstract: A power-supply apparatus includes a power-supply circuit to which an input voltage and an input current are input, to include a switching element to be controlled by a control signal so as to generate an output voltage and an output current, a memory, and a processor coupled to the memory and the processor to calculate a first duty ratio of the control signal so that the output voltage approaches a target voltage, calculate a second duty ratio of the control signal for the switching element, based on the input voltage, the input current, the output voltage, and the output current, detect deterioration of the power-supply circuit, based on the first duty ratio and the second duty ratio, generate the control signal of the first duty ratio when the power-supply circuit has not deteriorated, and generate the control signal for stopping the power-supply circuit when the power-supply circuit has deteriorated.
    Type: Grant
    Filed: September 21, 2018
    Date of Patent: March 1, 2022
    Assignee: FUJITSU LIMITED
    Inventors: Hiroshi Nakao, Yu Yonezawa, Yoshiyasu Nakashima
  • Patent number: 11189408
    Abstract: Provided is a soft magnetic alloy including Fe as a main component, in which a slope of an approximate straight line, plotted between cumulative frequencies of 20 to 80% on Fe content in each grid of 80000 grids or more, each of which has 1 nm×1 nm×1 nm, is ?0.1 to ?0.4, provided that Fe content (atom %) of each grid is Y axis, and the cumulative frequencies (%) obtained in descending order of Fe content in each grid is X axis, and an amorphization ratio X is 85% or more.
    Type: Grant
    Filed: February 26, 2018
    Date of Patent: November 30, 2021
    Assignee: TDK CORPORATION
    Inventors: Kazuhiro Yoshidome, Hiroyuki Matsumoto, Kenji Horino, Akito Hasegawa, Yu Yonezawa, Syota Goto, Seigo Tokoro
  • Patent number: 11028492
    Abstract: An electrolytic system includes, a power generator that outputs a first DC power, a plurality of converters each of which converts the first DC power into a second DC power according to a target duty ratio, and outputs voltage information and current information of the second DC power, a plurality of electrolyzers each of which receives the second DC power output from each of the plurality of converters and generates a gas, a control circuit that outputs control information by which the first DC power approaches a maximum power, based on a voltage value and a current value of the first DC power, and a selection circuit that outputs the target duty ratio, and a selection signal as to whether to select each of the plurality of electrolyzers and each of the plurality of converters, based on the control information and the voltage information and the current information.
    Type: Grant
    Filed: October 5, 2018
    Date of Patent: June 8, 2021
    Assignee: FUJITSU LIMITED
    Inventors: Yu Yonezawa, Hiroshi Nakao, Yoshiyasu Nakashima, Daiji Yamashita
  • Patent number: 10943718
    Abstract: Provided is a soft magnetic alloy including Fe, as a main component, and including C. the soft magnetic alloy includes an Fe composite network phase having Fe-rich grids connected in a continuous measurement range including 80000 grids, each of which size is 1 nm×1 nm×1 nm. An average of C content ratio of the Fe-poor grids having cumulative frequency of 90% or more from lower C content is 5.0 times or more to an average of C content ratio of the whole soft magnetic alloy.
    Type: Grant
    Filed: February 26, 2018
    Date of Patent: March 9, 2021
    Assignee: TDK CORPORATION
    Inventors: Kazuhiro Yoshidome, Hiroyuki Matsumoto, Kenji Horino, Akito Hasegawa, Yu Yonezawa, Syota Goto, Hajime Amano
  • Publication number: 20210050791
    Abstract: A power supply device includes: a control circuit; a first switching element controlled by a first control signal having a duty ratio decided based on a difference between an output voltage of a power supply device and a target value, an integrated value of the difference, and a predetermined gain value; and a second switching element controlled by a second control signal having a phase opposite to a phase of the first control signal, the control circuit being configured to measure an input voltage of the power supply device, calculate a set duty ratio based on the input voltage and the target value, the set duty ratio being obtained by dividing a target duty ratio by the gain value, set the set duty ratio as an initial value of the integrated value, and control the first and second switching elements by generating the first and second control signals.
    Type: Application
    Filed: July 28, 2020
    Publication date: February 18, 2021
    Applicant: FUJITSU LIMITED
    Inventors: Yu Yonezawa, YOSHIYASU NAKASHIMA
  • Patent number: 10923258
    Abstract: A dust core excellent in DC superimposition characteristics and low in eddy current loss at a high frequency band of several MHz, and an inductor element using the dust core. A dust core contains large and small particles of insulated soft magnetic material powder, wherein the large and small particles have a saturation magnetic flux density of 1.4 T or more, and wherein in the soft magnetic material powder observed in a cross section of the dust core, a ratio of an area occupied by large particles to an area occupied by small particles in the cross section is 9:1 to 5:5, when a group of particles having particle size of 3 ?m or more and 15 ?m or less is defined as the large particles, and group of particles having a particle size of 300 nm or more and 900 nm or less is defined as the small particles.
    Type: Grant
    Filed: November 21, 2018
    Date of Patent: February 16, 2021
    Assignee: TDK CORPORATION
    Inventors: Hideharu Moro, Akihiro Harada, Yu Yonezawa
  • Patent number: 10872717
    Abstract: A composite magnetic material includes a needle-like powder and a spherical powder. The needle-like powder includes a soft magnetic material and has an average minor-axis length of 100 nm or less and an average aspect ratio of 3.0 or more and 10.0 or less. The spherical powder includes a soft magnetic material and has an average major-axis length of 100 nm or less and an average aspect ratio of less than 3.0.
    Type: Grant
    Filed: June 13, 2018
    Date of Patent: December 22, 2020
    Assignee: TDK CORPORATION
    Inventors: Yu Yonezawa, Yoshihiro Shinkai
  • Patent number: 10854365
    Abstract: Provided is a soft magnetic alloy including Fe, as a main component, and including B. Among 80000 pieces of a grid having 1 nm×1 nm×1 nm in a continuous measurement range of the soft magnetic alloy, 4000 pieces of the grid from lower Fe content shows B content variation (?B) of 2.8 or more, and an amorphization ratio X of the soft magnetic alloy of 85% or more.
    Type: Grant
    Filed: February 26, 2018
    Date of Patent: December 1, 2020
    Assignee: TDK CORPORATION
    Inventors: Kazuhiro Yoshidome, Hiroyuki Matsumoto, Kenji Horino, Akito Hasegawa, Yu Yonezawa, Syota Goto, Seigo Tokoro
  • Patent number: 10797595
    Abstract: A current detection circuit included in a power supply detects a current flowing to an inductance element from a detection tap of an inductance element connected between an output terminal and an output of a first switching element. A control circuit included in the power supply controls a first control terminal of the first switching element and a second control terminal of a second switching element and calculates an output current flowing to a load based on the current detected by the current detection circuit.
    Type: Grant
    Filed: July 22, 2019
    Date of Patent: October 6, 2020
    Assignee: FDK CORPORATION
    Inventors: Yu Yonezawa, Jun Oikawa, Eiji Nagashima, Yoshiyasu Nakashima
  • Publication number: 20200273610
    Abstract: A composite magnetic material includes a powder and a resin. The powder has a main component containing Fe or Fe and Co. An average minor axis length in primary particles of the powder is 100 nm or less. A point satisfying (X, Y)=(?/Av (%), (Av-?)) on an XY coordinate plane is present within a region (including a boundary) surrounded by three points ?(24.5, 6.7), ?(72.0, 1.2), and ?(24.5, 1.2), in which an average of aspect ratios in the primary particles of the powder is set to Av, and a standard deviation of the aspect ratios in the primary particles of the powder is set to ?.
    Type: Application
    Filed: February 18, 2020
    Publication date: August 27, 2020
    Applicant: TDK Corporation
    Inventors: Isao KANADA, Yu YONEZAWA
  • Publication number: 20200184033
    Abstract: A simulation apparatus of a power supply circuit includes an input processing circuit configured to process a pulse signal output from a control device that controls the power supply circuit, a memory, a processor coupled to the memory and configured to derive a response signal with respect to the pulse signal processed by the input processing circuit, by a calculation using a plurality of transfer functions that represents characteristics of the power supply circuit, and process the response signal to transmit to a device that displays the response signal, and an output processing circuit configured to process the response signal to transmit to the control device.
    Type: Application
    Filed: November 5, 2019
    Publication date: June 11, 2020
    Applicant: FUJITSU LIMITED
    Inventors: Yu Yonezawa, YOSHIYASU NAKASHIMA
  • Patent number: 10627455
    Abstract: A capacitor life diagnosis apparatus includes ringing detection circuitry that detects ringing of an output voltage of a power source including a capacitor at an output end, and signal generation circuitry that generates a signal indicating a life of the capacitor based on the ringing detected by the ringing detection circuitry.
    Type: Grant
    Filed: March 10, 2017
    Date of Patent: April 21, 2020
    Assignee: FUJITSU LIMITED
    Inventors: Hiroshi Nakao, Yu Yonezawa, Takahiko Sugawara, Yoshiyasu Nakashima
  • Publication number: 20200082964
    Abstract: A composite magnetic body with high permeability and low magnetic loss in a high-frequency region of a gigahertz band; and a high-frequency electronic component using the same, the electronic component being compact and having low-insertion loss. This composite magnetic body has a high permeability and a low magnetic loss especially in a high-frequency region of a gigahertz band, and is provided with: a plurality of magnetic nanowires 361-363 aligned so as not to cross each other; and insulators 365-367 that electrically insulate the plurality of magnetic nanowires 361-363.
    Type: Application
    Filed: March 30, 2018
    Publication date: March 12, 2020
    Applicant: TDK CORPORATION
    Inventors: Takeshi SAKAMOTO, Yoshihiro SHINKAI, Yu YONEZAWA, Hideharu MORO, Kensuke ARA, Tohru OIKAWA, Isao KANADA, Kenji HORINO, Kyung-Ku CHOI
  • Patent number: 10541072
    Abstract: A soft magnetic alloy includes a main component of Fe. The soft magnetic alloy includes a Fe composition network phase where regions whose Fe content is larger than an average composition of the soft magnetic alloy are linked. The Fe composition network phase contains Fe content maximum points that are locally higher than their surroundings. A virtual-line total distance per 1 ?m3 of the soft magnetic alloy is 10 mm to 25 mm provided that the virtual-line total distance is a sum of virtual lines linking the maximum points adjacent each other. A virtual-line average distance that is an average distance of the virtual lines is 6 nm or more and 12 nm or less.
    Type: Grant
    Filed: September 28, 2017
    Date of Patent: January 21, 2020
    Assignee: TDK CORPORATION
    Inventors: Kazuhiro Yoshidome, Hiroyuki Matsumoto, Yu Yonezawa, Syota Goto, Hideaki Yokota, Akito Hasegawa, Masahito Koeda, Seigo Tokoro
  • Publication number: 20190341848
    Abstract: A current detection circuit included in a power supply detects a current flowing to an inductance element from a detection tap of an inductance element connected between an output terminal and an output of a first switching element. A control circuit included in the power supply controls a first control terminal of the first switching element and a second control terminal of a second switching element and calculates an output current flowing to a load based on the current detected by the current detection circuit.
    Type: Application
    Filed: July 22, 2019
    Publication date: November 7, 2019
    Applicant: FDK CORPORATION
    Inventors: Yu YONEZAWA, Jun OIKAWA, Eiji NAGASHIMA, Yoshiyasu NAKASHIMA
  • Patent number: 10345360
    Abstract: A capacitor life diagnosis device includes: a first fluctuation detecting unit configured to detect a maximum value of fluctuation in output voltage of a first capacitor every fixed time; and an output unit configured to predict a residual life of the first capacitor on the basis of temporal transition of the maximum value of fluctuation in the output voltage detected by the first fluctuation detecting unit, and output a signal indicating the residual life of the first capacitor.
    Type: Grant
    Filed: May 24, 2016
    Date of Patent: July 9, 2019
    Assignee: FUJITSU LIMITED
    Inventors: Hiroshi Nakao, Yu Yonezawa, Takahiko Sugawara, Yoshiyasu Nakashima
  • Publication number: 20190189319
    Abstract: To provide a dust core excellent in DC superimposition characteristics and low in eddy current loss at a high frequency band of several MHz, and an inductor element using the dust core. A dust core contains large particles and small particles of insulated soft magnetic material powder, wherein the large particles and the small particles have a saturation magnetic flux density of 1.4 T or more, and wherein in the soft magnetic material powder observed in a cross section of the dust core, a ratio of an area occupied by the large particles to an area occupied by the small particles in the cross section is 9:1 to 5:5, when a group of particles having a particle size of 3 ?m or more and 15 ?m or less is defined as the large particles, and a group of particles having a particle size of 300 nm or more and 900 nm or less is defined as the small particles.
    Type: Application
    Filed: November 21, 2018
    Publication date: June 20, 2019
    Applicant: TDK CORPORATION
    Inventors: Hideharu MORO, Akihiro HARADA, Yu YONEZAWA
  • Publication number: 20190127867
    Abstract: An electrolytic system includes, a power generator that outputs a first DC power, a plurality of converters each of which converts the first DC power into a second DC power according to a target duty ratio, and outputs voltage information and current information of the second DC power, a plurality of electrolyzers each of which receives the second DC power output from each of the plurality of converters and generates a gas, a control circuit that outputs control information by which the first DC power approaches a maximum power, based on a voltage value and a current value of the first DC power, and a selection circuit that outputs the target duty ratio, and a selection signal as to whether to select each of the plurality of electrolyzers and each of the plurality of converters, based on the control information and the voltage information and the current information.
    Type: Application
    Filed: October 5, 2018
    Publication date: May 2, 2019
    Applicant: FUJITSU LIMITED
    Inventors: Yu Yonezawa, Hiroshi Nakao, YOSHIYASU NAKASHIMA, Daiji Yamashita