Patents by Inventor Takumi Furukawa

Takumi Furukawa 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: 11169454
    Abstract: Provided an electrophotographic electro-conductive member that can stably suppress an occurrence of fogging in an electrophotographic image. The member comprises a support having an electro-conductive outer surface, and an electro-conductive layer on the outer surface of the support, the electro-conductive layer having a matrix including a cross-linked product of a first rubber, and domains dispersed in the matrix, the domains each includes a cross-linked product of a second rubber and an electro-conductive particle, at least some of the domains is exposed to the outer surface of the electro-conductive member to constitute protrusions on an outer surface of the member, the outer surface of the electro-conductive member is constituted by the matrix and the domains exposed to the outer surface of the electrophotographic electro-conductive member, the electrophotographic electro-conductive member has an impedance of 1.0×103? or more and 1.0×108? or less, and some of the domains satisfy two specific requirements.
    Type: Grant
    Filed: March 24, 2020
    Date of Patent: November 9, 2021
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Satoru Nishioka, Kazuhiro Yamauchi, Hiroaki Watanabe, Takumi Furukawa, Yasuhiro Fushimoto, Masahiro Kurachi, Kenji Takashima, Yuichi Kikuchi, Kana Sato
  • Patent number: 11112748
    Abstract: An electrophotographic developing member includes an electro-conductive support and an electro-conductive layer provided on the support, wherein the electro-conductive layer has a matrix containing a first rubber and a plurality of domains dispersed in the matrix, and the domain contains a second rubber and an electronic conductive agent and when a frequency is log-log-plotted on a horizontal axis and an impedance is log-log-plotted on a vertical axis with respect to an impedance measured by applying an alternating current voltage having an amplitude of 1 V on the electro-conductive layer while changing a frequency between 1.0×10?2 Hz to 1.0×107 Hz under a specific environment, an inclination of an impedance on a high frequency side is ?0.8 or more and ?0.3 or less and an impedance on a low frequency side is 1.0×104? to 1.0×1011?.
    Type: Grant
    Filed: October 14, 2020
    Date of Patent: September 7, 2021
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Masaki Yamada, Yuichi Kikuchi, Tetsuo Hino, Kazuhiro Yamauchi, Takumi Furukawa, Hiroaki Watanabe, Kenya Terada, Yuya Tomomizu, Toshimitsu Nakazawa
  • Publication number: 20210116856
    Abstract: A process cartridge is provided, which is configured to recover, with a developing member, developer remaining on an image bearing member after transfer of a developer image to a transfer receiving member, wherein a charging member has a shaft that is conductive and an elastic layer supported on the shaft and being in contact with the image bearing member; the elastic layer has a matrix containing a first rubber, and a plurality of domains containing a second rubber and an electron-conductive agent and interspersed within the matrix. The electric resistance of the domains is lower than the electric resistance of the matrix. The matrix is exposed on an outer surface of the elastic layer and forms multiple depressed portions, and the domains include a domains exposed at a bottom section of the depressed portion.
    Type: Application
    Filed: October 13, 2020
    Publication date: April 22, 2021
    Inventors: Takashi Mukai, Takashi Hiramatsu, Shuhei Tokiwa, Takayuki Namiki, Takumi Furukawa, Yuichi Kikuchi, Kazuhiro Yamauchi
  • Publication number: 20210048759
    Abstract: An electro-conductive layer of an electrophotographic electro-conductive member has a matrix-domain structure. The matrix contains a first rubber. The domain contains a second rubber and electro-conductive particles. Where ? represents an average of ratios of the cross-sectional area of the electro-conductive particles contained in each of the domains to the cross-sectional area of each of the domains appearing on a cross-section of the electro-conductive layer in a thickness direction, and ? represents a standard deviation of the ratios, ?/? is 0 or more and 0.4 or less, and ? is 20% or more and 40% or less. At least eight of samples with a first cubic shape 9 ?m on a side, which are sampled at arbitrary nine positions on the electro-conductive layer, satisfy the specified condition.
    Type: Application
    Filed: October 15, 2020
    Publication date: February 18, 2021
    Inventors: Tetsuo Hino, Yasuhiro Fushimoto, Norifumi Muranaka, Masafumi Kyogaku, Masaki Yamada, Hiroshi Inoue, Takumi Furukawa, Hiroaki Watanabe, Kenya Terada, Yuya Tomomizu, Toshimitsu Nakazawa
  • Publication number: 20210041796
    Abstract: An electroconductive member for electrophotography has an electroconductive support and an electroconductive layer in the order mentioned. The electroconductive layer has a matrix including a crosslinked product of a first rubber, and a domain including a crosslinked product of a second rubber and an electroconductive particle. The impedance of the outer surface of the electroconductive member is 1.0×103 to 1.0×108 ?. 80% by number or more of domains observed at each of a total of nine 15-?m square observation regions, which are disposed at any three points in a thickness region from the outer surface to a specific depth on each of cross sections in the thickness direction at three points: the center of the electroconductive layer in the longitudinal direction and points at a specific distance from the both edges of the electroconductive layer toward the center, satisfy specific requirements.
    Type: Application
    Filed: October 16, 2020
    Publication date: February 11, 2021
    Inventors: Satoru Nishioka, Masahiro Kurachi, Kenji Takashima, Yuichi Kikuchi, Kazuhiro Yamauchi, Kana Sato, Takumi Furukawa, Hiroaki Watanabe, Kenya Terada, Yuya Tomomizu, Toshimitsu Nakazawa
  • Publication number: 20210033996
    Abstract: Provided is an electrophotographic electroconductive member including an electroconductive support and an electroconductive layer on the support, an electroconductive member is used, in which an electroconductive layer has a matrix comprising a first rubber, and domains dispersed in the matrix, the domains each comprising a second rubber and an electronic electroconductive agent, and for impedance measured by applying an AC voltage with an amplitude of 1 V to the electroconductive layer while varying frequencies between 1.0×10?2 Hz to 1.0×107 Hz under a specific environment, when a double logarithmic plot with a frequency on an abscissa and an impedance on an ordinate is obtained, a slope on a high frequency side is ?0.8 or more and ?0.3 or less, and the impedance a low frequency side is from 1.0×103 to 1.0×107?.
    Type: Application
    Filed: October 16, 2020
    Publication date: February 4, 2021
    Inventors: Yuichi Kikuchi, Satoru Nishioka, Kenji Takashima, Kazuhiro Yamauchi, Masahiro Kurachi, Takumi Furukawa, Hiroaki Watanabe, Kenya Terada, Yuya Tomomizu, Toshimitsu Nakazawa
  • Publication number: 20210026295
    Abstract: An electrophotographic developing member includes an electro-conductive support and an electro-conductive layer provided on the support, wherein the electro-conductive layer has a matrix containing a first rubber and a plurality of domains dispersed in the matrix, and the domain contains a second rubber and an electronic conductive agent and when a frequency is log-log-plotted on a horizontal axis and an impedance is log-log-plotted on a vertical axis with respect to an impedance measured by applying an alternating current voltage having an amplitude of 1 V on the electro-conductive layer while changing a frequency between 1.0×10?2 Hz to 1.0×107 Hz under a specific environment, an inclination of an impedance on a high frequency side is ?0.8 or more and ?0.3 or less and an impedance on a low frequency side is 1.0×104? to 1.0×1011?.
    Type: Application
    Filed: October 14, 2020
    Publication date: January 28, 2021
    Inventors: Masaki Yamada, Yuichi Kikuchi, Tetsuo Hino, Kazuhiro Yamauchi, Takumi Furukawa, Hiroaki Watanabe, Kenya Terada, Yuya Tomomizu, Toshimitsu Nakazawa
  • Patent number: 10845724
    Abstract: Provided an electro-conductive member that can be used as a charging member capable of preventing the emergence of a ghost image. The member comprises an electro-conductive support and an electro-conductive layer, the electro-conductive layer has a matrix including a first cross-linked rubber, and domains, the domains each includes a second cross-linked rubber and an electronically conductive agent, at least some of the domains are exposed to an outer surface of the member to constitute protrusions, the outer surface is constituted by the matrix and the exposed domains, and in a double logarithmic plot with a frequency on the abscissa and an impedance on the ordinate, a slope at a frequency of 1.0×105 Hz to 1.0×106 Hz is ?0.8 to ?0.3, and an impedance at a frequency of 1.0×10?2 Hz to 1.0×101 Hz is 1.0×103 to 1.0×107?.
    Type: Grant
    Filed: March 25, 2020
    Date of Patent: November 24, 2020
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Yuichi Kikuchi, Satoru Nishioka, Kenji Takashima, Kazuhiro Yamauchi, Masahiro Kurachi, Takumi Furukawa
  • Publication number: 20200310266
    Abstract: Provided an electro-conductive member that can be used as a charging member capable of preventing the emergence of a ghost image. The member comprises an electro-conductive support and an electro-conductive layer, the electro-conductive layer has a matrix including a first cross-linked rubber, and domains, the domains each includes a second cross-linked rubber and an electronically conductive agent, at least some of the domains are exposed to an outer surface of the member to constitute protrusions, the outer surface is constituted by the matrix and the exposed domains, and in a double logarithmic plot with a frequency on the abscissa and an impedance on the ordinate, a slope at a frequency of 1.0×105 Hz to 1.0×106 Hz is ?0.8 to ?0.3, and an impedance at a frequency of 1.0×10?2 Hz to 1.0×101 Hz is 1.0×103 to 1.0×107?.
    Type: Application
    Filed: March 25, 2020
    Publication date: October 1, 2020
    Inventors: Yuichi Kikuchi, Satoru Nishioka, Kenji Takashima, Kazuhiro Yamauchi, Masahiro Kurachi, Takumi Furukawa
  • Publication number: 20200310265
    Abstract: Provided an electrophotographic electro-conductive member that can stably suppress an occurrence of fogging in an electrophotographic image. The member comprises a support having an electro-conductive outer surface, and an electro-conductive layer on the outer surface of the support, the electro-conductive layer having a matrix including a cross-linked product of a first rubber, and domains dispersed in the matrix, the domains each includes a cross-linked product of a second rubber and an electro-conductive particle, at least some of the domains is exposed to the outer surface of the electro-conductive member to constitute protrusions on an outer surface of the member, the outer surface of the electro-conductive member is constituted by the matrix and the domains exposed to the outer surface of the electrophotographic electro-conductive member, the electrophotographic electro-conductive member has an impedance of 1.0×103? or more and 1.0×108? or less, and some of the domains satisfy two specific requirements.
    Type: Application
    Filed: March 24, 2020
    Publication date: October 1, 2020
    Inventors: Satoru Nishioka, Kazuhiro Yamauchi, Hiroaki Watanabe, Takumi Furukawa, Yasuhiro Fushimoto, Masahiro Kurachi, Kenji Takashima, Yuichi Kikuchi, Kana Sato
  • Patent number: 10663913
    Abstract: Provided is a process cartridge having a charging member and an electrophotographic photosensitive member to be charged by being in contact with the charging member, wherein the electrophotographic photosensitive member has a support and a photosensitive layer in this order, and a surface layer of the electrophotographic photosensitive member has a Martens hardness of 230 N/mm2 or less.
    Type: Grant
    Filed: November 21, 2018
    Date of Patent: May 26, 2020
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Tatsuya Yamaai, Kazunori Noguchi, Shuhei Iwasaki, Akira Sakakibara, Daisuke Miura, Harunobu Ogaki, Takumi Furukawa, Yuya Tomomizu
  • Patent number: 10558136
    Abstract: A charging member including an electro-conductive support; and an elastic layer, the elastic layer is a surface layer thereof and is constituted by a mono layer, the elastic layer includes domains and a matrix, an outer surface of the charging member is constituted by a surface of the matrix and surfaces of the domains, and the charging member has concave portions on the outer surface, the domains exist at bottom portions of the respective concave portions and are exposed to the outer surface of the charging member only at the bottom portions of the respective concave portions, the elastic layer has a volume resistivity of 1×105 ?cm or more and 1×108 ?cm or less, and A2 is 20 times or more of A1, wherein A1 and A2 are current values obtained by a prescribed method.
    Type: Grant
    Filed: April 2, 2019
    Date of Patent: February 11, 2020
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Takumi Furukawa, Hiroaki Watanabe, Kenya Terada, Yuya Tomomizu, Toshimitsu Nakazawa
  • Patent number: 10545453
    Abstract: Provided are a process cartridge and an electrophotographic apparatus each suppressed in fluctuation in charging potential at the time of its long-term use. The process cartridge includes: an electrophotographic photosensitive member having a surface layer containing a resin and a charge-transporting substance; and a charging member configured to charge the electrophotographic photosensitive member, wherein an average of Martens hardnesses of the surface layer of the electrophotographic photosensitive member measured at a pushing force of 7 mN is 245 N/mm2 or more, and wherein in a core defined by three-dimensional surface texture standards (ISO 25178-2:2012) of the surface of the charging member, an average of Martens hardnesses measured at a pushing force of 0.04 mN is 2 N/mm2 or more and 20 N/mm2 or less, and an average of adhesivenesses measured with a scanning probe microscope in a field of view of 2-micrometer square is 70 mV or less.
    Type: Grant
    Filed: November 20, 2018
    Date of Patent: January 28, 2020
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Shuhei Iwasaki, Kazunori Noguchi, Harunobu Ogaki, Tatsuya Yamaai, Daisuke Miura, Akira Sakakibara, Takumi Furukawa, Yuya Tomomizu
  • Publication number: 20190324379
    Abstract: Disclosed is a charging member comprising an electro-conductive support; and an elastic layer, the elastic layer is a surface layer thereof and is constituted by a mono layer, the elastic layer includes domains and a matrix, an outer surface of the charging member is constituted by a surface of the matrix and surfaces of the domains, and the charging member has concave portions on the outer surface, the domains exist at bottom portions of the respective concave portions and are exposed to the outer surface of the charging member only at the bottom portions of the respective concave portions, the elastic layer has a volume resistivity of 1×105 ?cm or more and 1×108 ?cm or less, and A2 is 20 times or more of A1, wherein A1 and A2 are current values obtained by a prescribed method.
    Type: Application
    Filed: April 2, 2019
    Publication date: October 24, 2019
    Inventors: Takumi Furukawa, Hiroaki Watanabe, Kenya Terada, Yuya Tomomizu, Toshimitsu Nakazawa
  • Patent number: 10416588
    Abstract: A charging member includes an electro-conductive substrate, an elastic layer, and a surface layer provided in this order. The elastic layer has, on an outer surface thereof, concave portions that are independent of each other, and hold insulating particles. The insulating particle is exposed to the surface of the elastic layer. A site in which an outer edge of the projection image derived from each of the insulating particles and an outer edge of a projection image derived from each of the concave portions are separated, exists. The charging member has convex portions derived from the insulating particles exposed to the surface of the elastic layer, and concave portions derived from the concave portions of the elastic layer. The surface layer has a volume resistivity of 1.0×1015 ?cm or more.
    Type: Grant
    Filed: October 20, 2017
    Date of Patent: September 17, 2019
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Hiroki Masu, Kazuhiro Yamauchi, Yuichi Kikuchi, Masaki Tsunoda, Takumi Furukawa
  • Patent number: 10401779
    Abstract: A charge roller includes, in a surface thereof, recesses that have sizes that are equivalent to or larger than a volume average particle diameter of a toner accommodated in a developing unit and that are capable of collecting the toner retransferred to a photosensitive drum.
    Type: Grant
    Filed: August 3, 2018
    Date of Patent: September 3, 2019
    Assignee: Canon Kabushiki Kaisha
    Inventors: Shinji Katagiri, Tsuguhiro Yoshida, Shuichi Tetsuno, Takayuki Tanaka, Takahiro Ikeda, Satoru Motohashi, Takumi Furukawa
  • Patent number: 10317811
    Abstract: It is intended to provide a charging member capable of maintaining high charging performance even when used over a long period. The charging member has an electroconductive support and an electroconductive elastic layer as a surface layer, wherein the electroconductive elastic layer has a roughened surface, and the electroconductive elastic layer has an average Martens' hardness Mc of 2 N/mm2 or larger and 20 N/mm2 or smaller measured with an indentation strength of 0.04 mN at a core surface defined according to a three dimensional surface texture standard (ISO 25178-2:2012), and has an average viscosity Vc of 70×10?3 V or smaller measured in a square of 2 ?m long×2 ?m wide field of view under a scanning probe microscope.
    Type: Grant
    Filed: September 13, 2017
    Date of Patent: June 11, 2019
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Yuya Tomomizu, Takumi Furukawa, Hiroaki Watanabe, Kenya Terada, Kazuhiro Gesho
  • Publication number: 20190163119
    Abstract: Provided is a process cartridge having a charging member and an electrophotographic photosensitive member to be charged by being in contact with the charging member, wherein the electrophotographic photosensitive member has a support and a photosensitive layer in this order, and a surface layer of the electrophotographic photosensitive member has a Martens hardness of 230 N/mm2 or less.
    Type: Application
    Filed: November 21, 2018
    Publication date: May 30, 2019
    Inventors: Tatsuya Yamaai, Kazunori Noguchi, Shuhei Iwasaki, Akira Sakakibara, Daisuke Miura, Harunobu Ogaki, Takumi Furukawa, Yuya Tomomizu
  • Publication number: 20190163118
    Abstract: Provided are a process cartridge and an electrophotographic apparatus each suppressed in fluctuation in charging potential at the time of its long-term use. The process cartridge includes: an electrophotographic photosensitive member having a surface layer containing a resin and a charge-transporting substance; and a charging member configured to charge the electrophotographic photosensitive member, wherein an average of Martens hardnesses of the surface layer of the electrophotographic photosensitive member measured at a pushing force of 7 mN is 245 N/mm2 or more, and wherein in a core defined by three-dimensional surface texture standards (ISO 25178-2:2012) of the surface of the charging member, an average of Martens hardnesses measured at a pushing force of 0.04 mN is 2 N/mm2 or more and 20 N/mm2 or less, and an average of adhesivenesses measured with a scanning probe microscope in a field of view of 2-micrometer square is 70 mV or less.
    Type: Application
    Filed: November 20, 2018
    Publication date: May 30, 2019
    Inventors: Shuhei Iwasaki, Kazunori Noguchi, Harunobu Ogaki, Tatsuya Yamaai, Daisuke Miura, Akira Sakakibara, Takumi Furukawa, Yuya Tomomizu
  • Publication number: 20190064726
    Abstract: A charge roller includes, in a surface thereof, recesses that have sizes that are equivalent to or larger than a volume average particle diameter of a toner accommodated in a developing unit and that are capable of collecting the toner retransferred to a photosensitive drum.
    Type: Application
    Filed: August 3, 2018
    Publication date: February 28, 2019
    Inventors: Shinji Katagiri, Tsuguhiro Yoshida, Shuichi Tetsuno, Takayuki Tanaka, Takahiro Ikeda, Satoru Motohashi, Takumi Furukawa