Patents by Inventor Keiichi Matsumoto

Keiichi Matsumoto 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: 11990727
    Abstract: It is difficult to flatten the gain profile of an optical amplifier without increasing the power consumption, the cost, and the size of the optical amplifier; therefore, a monitoring apparatus for optical amplifier according to an exemplary aspect of the invention includes an optical filtering means for receiving a monitor light beam of the optical amplifier and transmitting a filtered monitor light beam with a set range of wavelength band; a photoelectric conversion means for converting the filtered monitor light beam into a monitoring signal; and a spectrum information generating means for generating spectrum information based on the monitoring signal, the spectrum information including information on a spectrum profile of output of the optical amplifier.
    Type: Grant
    Filed: March 7, 2018
    Date of Patent: May 21, 2024
    Assignee: NEC CORPORATION
    Inventors: Emmanuel Le Taillandier De Gabory, Keiichi Matsumoto
  • Publication number: 20240136640
    Abstract: A capacitor 1 which is provided so as to be installable in a first loading part C of a first electrical power device and a second loading part S103 of a second electrical power device S is configured to have an external shape such that a first abutment part which, upon loading of the capacitor into the first loading part, comes into abutment with the first loading part C differs from a second abutment part 26 which, upon loading of the capacitor into the second loading part S103, comes into abutment with the second loading part S103.
    Type: Application
    Filed: February 25, 2022
    Publication date: April 25, 2024
    Inventors: Daisuke MISU, Keiichi ITO, Yuya TABUCHI, Takashi MATSUMOTO, Kosuke YONETA
  • Publication number: 20240114780
    Abstract: An emitting layer of an organic EL device contains a fluorescent first compound, a delayed fluorescent second compound, and a third compound that satisfy numerical formulae (Numerical Formula 1) to (Numerical Formula 4). (Numerical Formula 1): |Af(M1)?Af(M2)|?0.40 eV, (Numerical Formula 2): Ip(M2)?5.75 eV, (Numerical Formula 3): |Ip(M2)?Ip(M3)|?0.25 eV, (Numerical Formula 4): S1(M3)?S1(M2). Af(M1) is an affinity of the first compound, Af(M2) is an affinity of the second compound, Ip(M2) is an ionization potential of the second compound, S1(M2) is a lowest singlet energy of the second compound, Ip(M3) is an ionization potential of the third compound, and S1(M3) is a lowest singlet energy of the third compound.
    Type: Application
    Filed: June 1, 2023
    Publication date: April 4, 2024
    Applicant: IDEMITSU KOSAN CO.,LTD.
    Inventors: Yukitoshi JINDE, Hisato MATSUMOTO, Keiichi YASUKAWA
  • Publication number: 20240107725
    Abstract: An imaging device according to the present disclosure includes a front case, a rear case, and a shield member. The front case supports an imaging optical unit. The rear case includes an electrically conductive output mechanism configured to output a signal output from the imaging optical unit. The shield member electrically connects the front case and the output mechanism.
    Type: Application
    Filed: December 1, 2023
    Publication date: March 28, 2024
    Inventors: Yasutaka MATSUMOTO, Makoto SAITO, Yoshihisa SHIMAZU, Keiichi UJITA
  • Publication number: 20240097397
    Abstract: It is difficult to construct an optical fiber transmission system enabling relay optical amplification using a coupled multi-core optical fiber as an optical transmission path; therefore, an optical amplification device includes first optical spatial layout converting means for converting a spatial layout of a plurality of optical signal beams propagating through each of a plurality of cores, from a coupled state in which optical signal beams interfere between a plurality of cores to a non-coupled state in which optical signal beam interference is reduced between a plurality of cores; optical amplifying means for amplifying, in the non-coupled state, the plurality of optical signal beams with the non-coupled state and generating a plurality of amplified optical signal beams; and second optical spatial layout converting means for converting a spatial layout of the plurality of amplified optical signal beams from the non-coupled state to the coupled state.
    Type: Application
    Filed: November 28, 2023
    Publication date: March 21, 2024
    Applicant: NEC Corporation
    Inventors: Hitoshi TAKESHITA, Keiichi MATSUMOTO, Shigeyuki YANAGIMACHI
  • Patent number: 11881675
    Abstract: It is difficult to construct an optical fiber transmission system enabling relay optical amplification using a coupled multi-core optical fiber as an optical transmission path; therefore, an optical amplification device includes first optical spatial layout converting means for converting a spatial layout of a plurality of optical signal beams propagating through each of a plurality of cores, from a coupled state in which optical signal beams interfere between a plurality of cores to a non-coupled state in which optical signal beam interference is reduced between a plurality of cores; optical amplifying means for amplifying, in the non-coupled state, the plurality of optical signal beams with the non-coupled state and generating a plurality of amplified optical signal beams; and second optical spatial layout converting means for converting a spatial layout of the plurality of amplified optical signal beams from the non-coupled state to the coupled state.
    Type: Grant
    Filed: April 2, 2020
    Date of Patent: January 23, 2024
    Assignee: NEC CORPORATION
    Inventors: Hitoshi Takeshita, Keiichi Matsumoto, Shigeyuki Yanagimachi
  • Patent number: 11876339
    Abstract: A pumping light source outputs pumping lights. A pumping light source outputs a pumping light. Optical multiplexers couple the pumping lights to a plurality of cores. The optical multiplexer couples the pumping light to the clad. A pumping light source drive unit drives a pumping light source. A pumping light source drive unit drives a pumping light source. A monitoring unit outputs a monitoring signal indicating a monitoring result of the number of wavelengths used in each of optical signals amplified by the plurality of the cores. The control unit controls the power of the pumping lights based on the monitoring signal. The control unit controls the power of each of the pumping lights in accordance with the number of wavelengths used in each of the optical signals and controls the power of the pumping light so that signal qualities of the optical signals fall within a prescribed range.
    Type: Grant
    Filed: March 30, 2018
    Date of Patent: January 16, 2024
    Assignee: NEC CORPORATION
    Inventors: Keiichi Matsumoto, Emmanuel Le Taillandier De Gabory
  • Patent number: 11870208
    Abstract: Provided are a low-cost and low power-consumption optical fiber amplifier, an optical fiber amplifier control method, and a transmission system. The optical fiber amplifier comprises: an optical fiber to which pumping light is supplied and which amplifies an optical signal, the optical fiber including a plurality of cores in a cladding; a light source which outputs the pumping light; a combining means which supplies the pumping light from the light source to the cladding of the optical fiber and causes the pumping light to be combined with the optical signal; a collect means which collects, without collecting the signal light, pumping light among the supplied pumping light that has not been absorbed by the optical fiber; a monitor means which monitors residual pumping light that has passed through the optical fiber and collected by the collect means; and a control means which controls the state of the pumping light.
    Type: Grant
    Filed: March 6, 2019
    Date of Patent: January 9, 2024
    Assignee: NEC CORPORATION
    Inventors: Keiichi Matsumoto, Emmanuel Le Taillandier De Gabory, Shigeyuki Yanagimachi
  • Publication number: 20230412297
    Abstract: An optical amplifier that amplifies an incident WDM signal and includes cores having an amplification medium, the optical amplifier includes: a wavelength demultiplexer configured to demultiplex the incident WDM signal into wavelength bands and introducing the demultiplexed WDM signals into the cores separately; a wavelength multiplexer configured to multiplex amplified optical signals propagated through the cores and outputting the multiplexed signal; and an wavelength demultiplexing controller configured to monitor an amplification rate of a specific wavelength band of an amplified WDM signal or a scale associated with an amplification rate of a specific wavelength band, demultiplexing, from the incident WDM signal, an optical signal of a wavelength band having relatively-small optical amplification efficiency according to a monitoring result, and controlling demultiplexing performed by the wavelength demultiplexer in such a way as to amplify, with a relatively-large amplification rate, the optical signal o
    Type: Application
    Filed: October 26, 2020
    Publication date: December 21, 2023
    Applicant: NEC Corporation
    Inventors: Keiichi MATSUMOTO, Hitoshi Takeshita, Hidemi Noguchi, Emmanuel Le Taillandier de Gabory
  • Publication number: 20230327767
    Abstract: The optical transmission system of the present invention includes a multi-core transmission path which includes a plurality of cores, and in which optical signals propagate through the plurality of cores, a first optical repeating means for amplifying the optical signals by individually exciting first multi-core optical amplification mediums, and a second optical repeating means for amplifying the optical signals by collectively exciting second multi-core optical amplification mediums, wherein the first optical repeating means is positioned spaced apart from the second optical repeating means by a distance determined on the basis of either a first transmissible distance due to the first optical repeating means and a second transmissible distance due to the second optical repeating means.
    Type: Application
    Filed: September 11, 2020
    Publication date: October 12, 2023
    Applicant: NEC Corporation
    Inventors: Hitoshi Takeshita, Keiichi Matsumoto, Hidemi Noguchi, Kohei Hosokawa
  • Patent number: 11683116
    Abstract: A light amplification device according to an example aspect of the invention includes a wavelength demultiplexing unit configured to demultiplex the wavelength division multiplexed signal light into a plurality of wavelength bands; a plurality of light amplification media configured to amplify the plurality of pieces of demultiplexed multiplex signal light; a wavelength multiplexing unit configured to multiplex the amplified demultiplexed multiplex signal light; a plurality of excitation energy supply units configured to supply excitation energy to each of the plurality of light amplification media; and a control unit, wherein the control unit includes a wavelength multiplexing/demultiplexing control unit configured to control the wavelength demultiplexing unit and the wavelength multiplexing unit in such a way that a starting wavelength and a wavelength number become an optimum starting wavelength and an optimum wavelength number when a sum of power consumption of the plurality of excitation energy supply un
    Type: Grant
    Filed: May 13, 2022
    Date of Patent: June 20, 2023
    Assignee: NEC CORPORATION
    Inventors: Keiichi Matsumoto, Kohei Hosokawa
  • Publication number: 20230047836
    Abstract: Provided are a monitoring device, a monitoring method, an optical amplifier, and an optical transmission system that are adapted for an increase in the number of cores in a multi-core optical fiber transmission path, and that are suitable for crosstalk monitoring. The monitoring device monitors a multi-core optical fiber transmission path comprising a plurality of use core and at least one or more non-use cores. The monitoring device comprises: an applying means for applying dithering to signal light propagating in the use cores; a monitoring means for monitoring the power of the non-use cores; and a separating means for separating a monitoring result from the monitoring means into power components from the plurality of use cores.
    Type: Application
    Filed: February 15, 2021
    Publication date: February 16, 2023
    Applicant: NEC Corporation
    Inventors: Keiichi Matsumoto, Hidemi Noguchi
  • Publication number: 20230026901
    Abstract: Provided are a monitoring device, a monitoring method, and an optical transmission system which are adapted for an increase in the number of cores of a multi-core optical fiber transmission path and suitable for crosstalk monitoring. The monitoring device monitors a multi-core optical fiber transmission path having a plurality of use cores and at least one or more non-use cores, and comprises: an applying means for applying, at a start point of the multi-core optical fiber transmission path, dithering to signal light propagating in the use cores; a monitoring means for monitoring the power of the non-use cores at an input side of a relay in the multi-core optical fiber transmission path; and a separating means for separating a monitoring result from the monitoring means into power components from the plurality of use cores.
    Type: Application
    Filed: February 15, 2021
    Publication date: January 26, 2023
    Applicant: NEC Corporation
    Inventors: Keiichi MATSUMOTO, Hidemi NOGUCHI, Emmanuel LE TAILLANDIER DE GABORY
  • Publication number: 20220385026
    Abstract: Light amplification devices using coupled multi-core optical fibers have a figure of merit that temporally varies, which makes it difficult to perform performance evaluation and to build a light transmission system using the same. Accordingly, a light amplification device of the present invention comprises: a band control means that controls the wavelength band of a light carrier to generate a band control light; and a band control light amplification means that has a plurality of light amplification media through which the band control light propagates, wherein the band control light amplification means amplifies the band control light in a coupled state in which the light propagating through the plurality of light amplification media induces a crosstalk and wherein the band control means controls the wavelength band such that the band control light having propagated through the plurality of light amplification media has a reduced coherence.
    Type: Application
    Filed: October 7, 2019
    Publication date: December 1, 2022
    Applicant: NEC Corporation
    Inventors: Hitoshi TAKESHITA, Keiichi MATSUMOTO, Hidemi NOGUCHI
  • Publication number: 20220376811
    Abstract: A light amplification device according to an example aspect of the invention includes a wavelength demultiplexing unit configured to demultiplex the wavelength division multiplexed signal light into a plurality of wavelength bands; a plurality of light amplification media configured to amplify the plurality of pieces of demultiplexed multiplex signal light; a wavelength multiplexing unit configured to multiplex the amplified demultiplexed multiplex signal light; a plurality of excitation energy supply units configured to supply excitation energy to each of the plurality of light amplification media; and a control unit, wherein the control unit includes a wavelength multiplexing/demultiplexing control unit configured to control the wavelength demultiplexing unit and the wavelength multiplexing unit in such a way that a starting wavelength and a wavelength number become an optimum starting wavelength and an optimum wavelength number when a sum of power consumption of the plurality of excitation energy supply un
    Type: Application
    Filed: May 13, 2022
    Publication date: November 24, 2022
    Applicant: NEC Corporation
    Inventors: Keiichi MATSUMOTO, Kohei HOSOKAWA
  • Patent number: 11374377
    Abstract: It is necessary to reduce the power consumption of a plurality of optical amplifiers when there is a difference in the required pumping power between the plurality of optical amplifiers; therefore, an optical amplifying apparatus according to an exemplary aspect of the invention includes a plurality of optical amplifying means for amplifying a plurality of optical signals, each of the plurality of optical amplifying means including a gain medium; a plurality of laser light generating means for generating a plurality of laser beams; at least one optical coupling means for coupling the plurality of laser beams variably in accordance with a coupling factor and outputting a plurality of excitation light beams, each of the plurality of excitation light beams exciting the gain medium; and controlling means for controlling the coupling factor and an output power of each of the plurality of laser light generating means.
    Type: Grant
    Filed: April 20, 2017
    Date of Patent: June 28, 2022
    Assignee: NEC CORPORATION
    Inventors: Emmanuel Le Taillandier De Gabory, Shigeyuki Yanagimachi, Shigeru Nakamura, Keiichi Matsumoto
  • Publication number: 20220166179
    Abstract: It is difficult to construct an optical fiber transmission system enabling relay optical amplification using a coupled multi-core optical fiber as an optical transmission path; therefore, an optical amplification device includes first optical spatial layout converting means for converting a spatial layout of a plurality of optical signal beams propagating through each of a plurality of cores, from a coupled state in which optical signal beams interfere between a plurality of cores to a non-coupled state in which optical signal beam interference is reduced between a plurality of cores; optical amplifying means for amplifying, in the non-coupled state, the plurality of optical signal beams with the non-coupled state and generating a plurality of amplified optical signal beams; and second optical spatial layout converting means for converting a spatial layout of the plurality of amplified optical signal beams from the non-coupled state to the coupled state.
    Type: Application
    Filed: April 2, 2020
    Publication date: May 26, 2022
    Applicant: NEC Corporation
    Inventors: Hitoshi TAKESHITA, Keiichi MATSUMOTO, Shigeyuki YANAGIMACHI
  • Patent number: 11329444
    Abstract: To solve the problem that the power consumption of optical amplifiers is not optimized over the life time of an amplifier, the optical amplifier includes a gain medium for amplifying a plurality of optical channels, the gain medium including a plurality of cores through which the plurality of optical channels to propagate respectively and a cladding area surrounding the plurality of cores, a monitor that monitors the temperature of the optical amplifier and producing a monitoring result, a first light source that emits a first light beam to excite the cladding area, a second light source that emits a plurality of second light beams to excite each of the plurality of cores individually, and a controller that controls the first light source and the second light source based on the produced monitoring result.
    Type: Grant
    Filed: September 20, 2016
    Date of Patent: May 10, 2022
    Assignee: NEC CORPORATION
    Inventors: Emmanuel Le Taillandier de Gabory, Shigeru Nakamura, Shigeyuki Yanagimachi, Keiichi Matsumoto
  • Publication number: 20220045473
    Abstract: The optical amplifier, which amplifies wavelength multiplexed signal light, comprises: a multi-core optical fiber which includes cladding and a first core and a second core disposed in the cladding, and which is doped with rare-earth ions; an excitation light source for supplying excitation light to the cladding of the multi-core optical fiber; and a wavelength demultiplexing means for separating the wavelength bands of the wavelength multiplexed signal light that has propagated through the first core. The signal light of a relatively long wavelength band among a plurality of wavelength bands separated by the wavelength demultiplexing means is caused to propagate through the second core, and is then multiplexed with the signal light of a relatively short wavelength band among the plurality of wavelength bands separated by the wavelength demultiplexing means, and the resultant multiplexed signal light is output.
    Type: Application
    Filed: December 19, 2019
    Publication date: February 10, 2022
    Applicant: NEC Corporation
    Inventors: Keiichi MATSUMOTO, Emmanuel LE TAILLANDIER DE GABORY, Shigeyuki YANAGIMACHI
  • Publication number: 20210399514
    Abstract: An optical amplification apparatus includes an optical amplification medium, having a gain in a wavelength band of signal light, configured to receive the signal light; excitation light introduction means for introducing, into the optical amplification medium, excitation light to excite the optical amplification medium; and residual excitation light introduction means for introducing, into the optical amplification medium, residual excitation light output from the optical amplification medium, the residual excitation light having a wavelength component of the excitation light, wherein the residual excitation light introduction means includes, on a side of one end of the optical amplification medium, residual excitation light multiplexing means for multiplexing the signal light and the residual excitation light, and on a side of another end of the optical amplification medium, space propagation type wavelength demultiplexing means for wavelength-demultiplexing the signal light and the residual excitation light
    Type: Application
    Filed: September 27, 2019
    Publication date: December 23, 2021
    Applicant: NEC Corporation
    Inventors: Hitoshi TAKESHITA, Keiichi MATSUMOTO, Emmanuel LE TAILLANDIER DE GABORY