Patents by Inventor Keisuke Kojima

Keisuke Kojima 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: 11079550
    Abstract: A grating coupler having first and second ends for coupling a light beam to a waveguide of a chip includes a substrate configured to receive the light beam from the first end and transmit the light beam through the second end, the substrate having a first refractive index n1, a grating structure having curved grating lines arranged on the substrate, the grating structure having a second refractive index n1, wherein the curved grating lines have line width w and height d and are arranged by a pitch ?, wherein the second refractive index n2 is less than first refractive index n1, and a cladding layer configured to cover the grating structure, wherein the cladding layer has a third refractive index n3. The curves of the grating lines are constructed such that the emitting beam is shaped for efficient coupling to another optical component. The curves can also be tilted to reduce coupling back into the waveguide.
    Type: Grant
    Filed: January 28, 2020
    Date of Patent: August 3, 2021
    Assignee: Mitsubishi Electric Research Laboratories, Inc.
    Inventors: Keisuke Kojima, Satoshi Nishikawa, Shusaku Hayashi, Yosuke Suzuki, Jonathan Klamkin, Yingheng Tang
  • Publication number: 20210181427
    Abstract: A grating coupler having first and second ends for coupling a light beam to a waveguide of a chip includes a substrate configured to receive the light beam from the first end and transmit the light beam through the second end, the substrate having a first refractive index n1, a grating structure having curved grating lines arranged on the substrate, the grating structure having a second refractive index n1, wherein the curved grating lines have line width w and height d and are arranged by a pitch ?, wherein the second refractive index n2 is less than first refractive index n1, and a cladding layer configured to cover the grating structure, wherein the cladding layer has a third refractive index n3. The curves of the grating lines are constructed such that the emitting beam is shaped for efficient coupling to another optical component. The curves can also be tilted to reduce coupling back into the waveguide.
    Type: Application
    Filed: February 23, 2021
    Publication date: June 17, 2021
    Applicants: Mitsubishi Electric Research Laboratories, Inc., Mitsubishi Electric Corporation
    Inventors: Keisuke Kojima, Satoshi Nishikawa, Shusaku Hayashi, Yosuke Suzuki, Jonathan Klamkin, Yingheng Tang
  • Publication number: 20210176866
    Abstract: A printed wiring board includes a resin insulating layer, via conductors formed in the resin insulating layer, metal posts formed on the via conductors, respectively, and a solder resist layer formed on the resin insulating layer such that the metal posts have lower portions embedded in the solder resist layer and upper portions exposed from the solder resist layer, respectively. The metal posts are formed such that each of the metal posts has a top portion having a diameter in a range of 0.8 to 0.9 times a diameter of a respective one of the lower portions of the metal posts.
    Type: Application
    Filed: November 27, 2020
    Publication date: June 10, 2021
    Applicant: IBIDEN CO., LTD.
    Inventors: Masashi AWAZU, Keisuke KOJIMA
  • Patent number: 10996400
    Abstract: An optical waveguide interferometer that includes a first optical section, a second optical section, and a set of optical waveguides configured to connect the first and second optical sections, such that light propagating between the first optical section and the second optical section passes through each optical waveguide in the set, wherein the set of optical waveguides includes a first optical waveguide having a first length and a first width and a second optical waveguide having a second length and a second width, wherein the second length is greater than the first length, and the second width is greater than the first width.
    Type: Grant
    Filed: August 4, 2016
    Date of Patent: May 4, 2021
    Assignees: Mitsubishi Electric Research Laboratories, Inc.
    Inventors: Keisuke Kojima, Bingnan Wang, Toshiaki Koike-Akino, Koichi Akiyama, Eiji Yagyu, Satoshi Nishikawa, Kosuke Shinohara
  • Publication number: 20210116645
    Abstract: A grating coupler having first and second ends for coupling a light beam to a waveguide of a chip includes a substrate configured to receive the light beam from the first end and transmit the light beam through the second end, the substrate having a first refractive index n1, a grating structure having curved grating lines arranged on the substrate, the grating structure having a second refractive index n1, wherein the curved grating lines have line width w and height d and are arranged by a pitch ?, wherein the second refractive index n2 is less than first refractive index n1, and a cladding layer configured to cover the grating structure, wherein the cladding layer has a third refractive index n3. The curves of the grating lines are constructed such that the emitting beam is shaped for efficient coupling to another optical component. The curves can also be tilted to reduce coupling back into the waveguide.
    Type: Application
    Filed: January 28, 2020
    Publication date: April 22, 2021
    Applicants: Mitsubishi Electric Research Laboratories, Inc., Mitsubishi Electric Corporation
    Inventors: Keisuke Kojima, Satoshi Nishikawa, Shusaku Hayashi, Yosuke Suzuki, Jonathan Klamkin, Yingheng Tang
  • Publication number: 20210108681
    Abstract: A rolling bearing includes an inner ring, an outer ring, a plurality of balls, and a cage that holds the balls. The cage includes an annular portion and a plurality of cage bars. Each of the balls is received a pocket between each pair of cage bars that is adjacent in the circumferential direction. A portion of the pocket in a second axial direction opens with a dimension that is smaller than a diameter of the balls. The cage bar includes a flat surface that is continuous with an inner peripheral surface of the annular portion, and an inclined surface that extends away from the inner ring toward the second axial direction from the flat surface.
    Type: Application
    Filed: October 7, 2020
    Publication date: April 15, 2021
    Applicant: JTEKT CORPORATION
    Inventors: Keisuke KOJIMA, Katsuyuki HARADA, Naoki MASUDA, Hironori HIRAOKA
  • Publication number: 20210095721
    Abstract: A rolling bearing includes: an inner ring; an outer ring; a plurality of rolling elements provided between an inner ring raceway and an outer ring raceway; and a cage that holds the rolling elements at intervals in a circumferential direction. The cage includes an annular portion provided in a first axial direction with respect to the rolling elements, and a plurality of cage bars provided to extend in a second axial direction from the annular portion. The annular portion includes a contact surface that makes sliding contact with a shoulder portion. The cage bars each include a first projecting portion and a second projecting portion. The second projecting portion covers a part of the inner ring raceway on a side of the shoulder portion.
    Type: Application
    Filed: September 30, 2020
    Publication date: April 1, 2021
    Applicant: JTEKT CORPORATION
    Inventors: Keisuke KOJIMA, Katsuyuki HARADA, Naoki MASUDA, Hironori HIRAOKA
  • Patent number: 10962717
    Abstract: A grating coupler having first and second ends for coupling a light beam to a waveguide of a chip includes a substrate configured to receive the light beam from the first end and transmit the light beam through the second end, the substrate having a first refractive index n1, a grating structure having curved grating lines arranged on the substrate, the grating structure having a second refractive index n1, wherein the curved grating lines have line width w and height d and are arranged by a pitch ?, wherein the second refractive index n2 is less than first refractive index n1, and a cladding layer configured to cover the grating structure, wherein the cladding layer has a third refractive index n3.
    Type: Grant
    Filed: February 28, 2020
    Date of Patent: March 30, 2021
    Assignees: Mitsubishi Electric Research Laboratories, Inc., Mitsubishi Electric Corporation
    Inventors: Keisuke Kojima, Mitsunobu Gotoda, Toshiaki Koike-Akino, Muhammad Tahersima
  • Patent number: 10921525
    Abstract: A grating coupler having first and second ends for coupling a light beam to a waveguide of a chip includes a substrate configured to receive the light beam from the first end and transmit the light beam through the second end, the substrate having a first refractive index n1, a grating structure having curved grating lines arranged on the substrate, the grating structure having a second refractive index n1, wherein the curved grating lines have line width w and height d and are arranged by a pitch ?, wherein the second refractive index n2 is less than first refractive index n1, and a cladding layer configured to cover the grating structure, wherein the cladding layer has a third refractive index n3.
    Type: Grant
    Filed: January 29, 2019
    Date of Patent: February 16, 2021
    Assignees: Mitsubishi Electric Research Laboratories, Inc., Mitsubishi Electric Corporation
    Inventors: Keisuke Kojima, Mitsunobu Gotoda, Toshiaki Koike-Akino, Mohammad Tahersima
  • Patent number: 10859769
    Abstract: A photonic device for splitting optical beams includes an input port configured to receive an input beam having an input power, a power splitter including perturbation segments arranged in a first region and a second region of a guide material having a first refractive index, each segment having a second refractive index, wherein the first region is configured to split the input beam into a first beam and a second beam, wherein and the second region is configured to separately guide the first and second beams, wherein the first refractive index is greater than the second refractive index, and output ports including first and second output ports connected the power splitter to respectively receive and transmit the first and second beams.
    Type: Grant
    Filed: December 10, 2018
    Date of Patent: December 8, 2020
    Assignee: Mitsubishi Electric Research Laboratories, Inc.
    Inventors: Keisuke Kojima, Mohammad hossein Taher sima, Toshiaki Koike-Akino
  • Patent number: 10838282
    Abstract: An optical ring circuit for modulating light from a light source into an optical signal includes a ring modulator located near a waveguide to couple a light propagating the waveguide, the ring modulator including a pair of electrodes, a signal generator to transmit an electrical signal corresponding to the optical signal, a filter circuit to generate an output signal, wherein the filter circuit includes an adder unit and at least one tap unit having a delay unit and a coefficient unit, wherein the adder unit adds the electrical signal from the signal generator and a signal passed from the tap unit for pre-compensating signal components of the electrical signal by at least twice delay time of the delay unit, and a driver circuit to apply a voltage to the electrodes based on the output signal.
    Type: Grant
    Filed: September 7, 2018
    Date of Patent: November 17, 2020
    Assignees: Mitsubishi Electric Research Laboratories, Inc., Mitsubishi Electric Corporation
    Inventors: Keisuke Kojima, Min Teng, Toshiaki Koike-Akino, Chungwei Lin, Kieran Parsons, Mitsunobu Gotoda, Koichi Akiyama
  • Patent number: 10749554
    Abstract: A communication system transmits an input block of bits over a communication channel using a prefix tree that maps a dyadic distribution of compositions of output symbols to prefixes of variable lengths. A path to each leaf of the prefix tree is defined by a prefix formed by a unique sequence of binary values of a length equal to a depth of the leaf. Each leaf is associated with a composition that has at least a number of unique permutations equals to two in a power of a length of a suffix of the block of input bits. The system selects a composition identified in the prefix tree by a prefix, permutes the selected composition according to a suffix, and transmits the permuted composition over a communication channel. The compositions are selected to reduce one or combination of energy and kurtosis of transmission.
    Type: Grant
    Filed: October 2, 2019
    Date of Patent: August 18, 2020
    Assignee: Mitsubishi Electric Research Laboratories, Inc.
    Inventors: David Millar, Toshiaki Koike-Akino, Kieran Parsons, Keisuke Kojima
  • Publication number: 20200241204
    Abstract: A grating coupler having first and second ends for coupling a light beam to a waveguide of a chip includes a substrate configured to receive the light beam from the first end and transmit the light beam through the second end, the substrate having a first refractive index n1, a grating structure having curved grating lines arranged on the substrate, the grating structure having a second refractive index n1, wherein the curved grating lines have line width w and height d and are arranged by a pitch ?, wherein the second refractive index n2 is less than first refractive index n1, and a cladding layer configured to cover the grating structure, wherein the cladding layer has a third refractive index n3.
    Type: Application
    Filed: February 28, 2020
    Publication date: July 30, 2020
    Applicants: Mitsubishi Electric Research Laboratories, Inc., Mitsubishi Electric Corporation
    Inventors: Keisuke Kojima, Mitsunobu Gotoda, Toshiaki Koike-Akino, Mohammad Tahersima
  • Publication number: 20200241205
    Abstract: A grating coupler having first and second ends for coupling a light beam to a waveguide of a chip includes a substrate configured to receive the light beam from the first end and transmit the light beam through the second end, the substrate having a first refractive index n1, a grating structure having curved grating lines arranged on the substrate, the grating structure having a second refractive index n1, wherein the curved grating lines have line width w and height d and are arranged by a pitch ?, wherein the second refractive index n2 is less than first refractive index n1, and a cladding layer configured to cover the grating structure, wherein the cladding layer has a third refractive index n3.
    Type: Application
    Filed: February 28, 2020
    Publication date: July 30, 2020
    Applicants: Mitsubishi Electric Research Laboratories, Inc., Mitsubishi Electric Corporation
    Inventors: Keisuke Kojima, Mitsunobu Gotoda, Toshiaki Koike-Akino, Muhammad Tahersima
  • Publication number: 20200239612
    Abstract: An acrylic rubber has a residual calcium content of 60 wt ppm or less and a polymer pH of 7.0 or less, and preferably has a carboxyl group.
    Type: Application
    Filed: January 31, 2018
    Publication date: July 30, 2020
    Applicant: ZEON CORPORATION
    Inventors: Keisuke KOJIMA, Kazuhiro EJIRI, Hirofumi MASUDA
  • Publication number: 20200174194
    Abstract: A grating coupler having first and second ends for coupling a light beam to a waveguide of a chip includes a substrate configured to receive the light beam from the first end and transmit the light beam through the second end, the substrate having a first refractive index n1, a grating structure having curved grating lines arranged on the substrate, the grating structure having a second refractive index n1, wherein the curved grating lines have line width w and height d and are arranged by a pitch ?, wherein the second refractive index n2 is less than first refractive index n1, and a cladding layer configured to cover the grating structure, wherein the cladding layer has a third refractive index n3.
    Type: Application
    Filed: January 29, 2019
    Publication date: June 4, 2020
    Inventors: Keisuke Kojima, Mitsunobu Gotoda, Toshiaki Koike-Akino, Mohammad Tahersima
  • Patent number: 10597491
    Abstract: A complex that includes a metal fine particle dispersant including a branched polymer compound having an ammonium group and having a weight average molecular weight of 500 to 5,000,000; and a metal fine particle, wherein the metal fine particle includes platinum (Pt) or palladium (Pd), the metal fine particle dispersant includes a branched polymer compound of Formula (1):
    Type: Grant
    Filed: August 6, 2019
    Date of Patent: March 24, 2020
    Assignees: NISSAN CHEMICAL CORPORATION, KYUSHU UNIVERSITY
    Inventors: Keisuke Kojima, Akihiro Tanaka, Keisuke Odoi, Hideo Nagashima, Takashi Sue
  • Publication number: 20200081188
    Abstract: A photonic device for splitting optical beams includes an input port configured to receive an input beam having an input power, a power splitter including perturbation segments arranged in a first region and a second region of a guide material having a first refractive index, each segment having a second refractive index, wherein the first region is configured to split the input beam into a first beam and a second beam, wherein and the second region is configured to separately guide the first and second beams, wherein the first refractive index is greater than the second refractive index, and output ports including first and second output ports connected the power splitter to respectively receive and transmit the first and second beams.
    Type: Application
    Filed: December 10, 2018
    Publication date: March 12, 2020
    Applicant: Mitsubishi Electric Research Laboratories, Inc.
    Inventors: Keisuke Kojima, Mohammad hossein Taher sima, Toshiaki Koike-Akino
  • Patent number: 10583460
    Abstract: Provided is a method for forming a multilayer coating film giving excellent low temperature impact resistance to a substrate that comprises a metal material and a plastic material. The method for forming a multilayer coating film comprises sequential steps of forming an uncured primer coating film, an uncured first colored coating film, an uncured second colored coating film and an uncured clear coating film on a substrate; and heating the same so as to simultaneously cure these 4 coating films, wherein the aqueous first colored paint and aqueous second colored paint are each a 1-package type paint composition containing a specific hydroxyl group-containing resin and a specific blocked polyisocyanate compound.
    Type: Grant
    Filed: September 26, 2017
    Date of Patent: March 10, 2020
    Assignee: KANSAI PAINT CO., LTD.
    Inventors: Takashi Nakayabu, Kazushi Konishi, Kohei Onishi, Masuo Kondo, Keisuke Kojima
  • Patent number: 10554309
    Abstract: A method decodes an optical signal transmitted over an optical channel from a transmitter to a receiver. The method produces, from the transmitted optical signal, a digital signal including received data symbols and received pilot symbols and determines phase noise on the pilot symbols using a statistical probability distribution of phase noise on the optical channel and errors between phases of the received pilot symbols and the transmitted pilot signals. The method estimates phase noise on the data symbols using an interpolation of the phase noise on the pilot symbols and compensates the digital signal with the phase noise on the data symbols to produce a filtered signal with an equalized phase. The method demodulates and decodes the filtered signal to produce an estimate of the transmitted optical signal.
    Type: Grant
    Filed: January 18, 2018
    Date of Patent: February 4, 2020
    Assignee: Mitsubishi Electric Research Laboratories, Inc.
    Inventors: David Millar, Milutin Pajovic, Toshiaki Koike-Akino, Keisuke Kojima, Kieran Parsons