Patents by Inventor Ryoichi Tokimitsu

Ryoichi Tokimitsu 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).

  • Publication number: 20230259047
    Abstract: Provided is an electrophotographic photosensitive member including a surface layer, wherein the surface layer contains a fluorine atom-containing resin particle, a binder material, and a polymer having specific structural units.
    Type: Application
    Filed: January 30, 2023
    Publication date: August 17, 2023
    Inventors: TOSHIYASU SHIRASUNA, JUN OHIRA, EILEEN TAKEUCHI, IKUYO KUROIWA, TSUYOSHI SHIMADA, TAKANORI UENO, KENICHI IKARI, HARUHIKO MITSUDA, RYOICHI TOKIMITSU
  • Publication number: 20230259045
    Abstract: Provided is an electrophotographic photosensitive member including a surface layer, which is excellent in dispersibility of fluorine atom-containing resin particles and is suppressed from causing a ghost image. Specifically, provided is an electrophotographic photosensitive member including a surface layer, wherein the surface layer contains a fluorine atom-containing resin particle, a binder material, and a polymer A having specific structural units.
    Type: Application
    Filed: January 19, 2023
    Publication date: August 17, 2023
    Inventors: Ryoichi Tokimitsu, Haruhiko Mitsuda, Jun Ohira, Toshiyasu Shirasuna, Ikuyo Kuroiwa, Tsuyoshi Shimada, Takanori Ueno, Kenichi Ikari, Eileen Takeuchi
  • Publication number: 20230259044
    Abstract: The present disclosure provides an electrophotographic photosensitive member having excellent dispersibility of fluorine atom-containing resin particles, and excellent durability, with an occurrence of a ghost suppressed. In the electrophotographic photosensitive member having a surface layer, the surface layer includes a fluorine atom-containing resin particle, a binder material, a charge transport substance, and a polymer A having a specific structural unit, wherein the binder material is a thermoplastic resin, and a film thickness of the surface layer is 35 ?m or larger and 50 ?m or smaller.
    Type: Application
    Filed: January 30, 2023
    Publication date: August 17, 2023
    Inventors: HARUHIKO MITSUDA, RYOICHI TOKIMITSU, EILEEN TAKEUCHI, JUN OHIRA, Toshiyasu Shirasuna, IKUYO KUROIWA, TSUYOSHI SHIMADA, TAKANORI UENO, KENICHI IKARI
  • Publication number: 20230259048
    Abstract: The present disclosure provides an electrophotographic photosensitive member having a surface layer that is excellent in dispersibility of a fluorine atom-containing resin particle and suppresses a potential fluctuation at the time of repeated use. The electrophotographic photosensitive member having the surface layer, wherein the surface layer includes the fluorine atom-containing resin particle, a binder material, and a polymer A having a specific structural unit.
    Type: Application
    Filed: January 30, 2023
    Publication date: August 17, 2023
    Inventors: JUN OHIRA, TOSHIYASU SHIRASUNA, IKUYO KUROIWA, TSUYOSHI SHIMADA, TAKANORI UENO, KENICHI IKARI, HARUHIKO MITSUDA, RYOICHI TOKIMITSU, EILEEN TAKEUCHI
  • Patent number: 11599034
    Abstract: An electrophotographic photosensitive member that has an electroconductive support and a photosensitive layer on the electroconductive support, and reduces image failures. The surface layer of the electrophotographic photosensitive member includes a cured product of a composition of: a charge transporting compound having a specific polymerizable functional group; a polytetrafluoroethylene particle having a specific primary particle diameter; and a polymer having specific structural units and having weight average molecular weight.
    Type: Grant
    Filed: January 15, 2021
    Date of Patent: March 7, 2023
    Assignee: Canon Kabushiki Kaisha
    Inventors: Ryoichi Tokimitsu, Naoto Kameyama, Eileen Takeuchi
  • Publication number: 20220404725
    Abstract: An image forming method includes a charging step, an image exposure step, a developing step, a transferring step, a cleaning step, and a fixing step. A toner contains toner particles, the toner particles contain a resin A including a unit A1 including an alkyl group having 18 to 36 carbon atoms in the side chain, and the electrophotographic photoreceptor includes a surface layer containing (i) fluorine-containing resin particles and (ii) a fluorine-based polymer B.
    Type: Application
    Filed: June 7, 2022
    Publication date: December 22, 2022
    Inventors: Haruhiko Mitsuda, Ryoichi Tokimitsu, Takeshi Hashimoto
  • Patent number: 11204560
    Abstract: Provided is an electrophotographic photosensitive member including a support and a surface layer, wherein the surface layer contains a copolymer of a composition containing a specific hole transporting compound and a specific compound.
    Type: Grant
    Filed: April 22, 2020
    Date of Patent: December 21, 2021
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Ryoichi Tokimitsu, Koichi Nakata, Haruki Mori, Shubun Kujirai
  • Publication number: 20210240092
    Abstract: An electrophotographic photosensitive member that has an electroconductive support and a photosensitive layer on the electroconductive support, and reduces image failures. The surface layer of the electrophotographic photosensitive member includes a cured product of a composition of: a charge transporting compound having a specific polymerizable functional group; a polytetrafluoroethylene particle having a specific primary particle diameter; and a polymer having specific structural units and having weight average molecular weight.
    Type: Application
    Filed: January 15, 2021
    Publication date: August 5, 2021
    Inventors: Ryoichi Tokimitsu, Naoto Kameyama, Eileen Takeuchi
  • Patent number: 10976677
    Abstract: The present disclosure provides an electrophotographic photosensitive member that has mechanical durability, and can achieve both of suppression of an image flow and adequate electrical characteristics.
    Type: Grant
    Filed: December 12, 2019
    Date of Patent: April 13, 2021
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Ryoichi Tokimitsu, Koichi Nakata, Haruki Mori, Shubun Kujirai
  • Publication number: 20200341391
    Abstract: Provided is an electrophotographic photosensitive member including a support and a surface layer, wherein the surface layer contains a copolymer of a composition containing a specific hole transporting compound and a specific compound.
    Type: Application
    Filed: April 22, 2020
    Publication date: October 29, 2020
    Inventors: Ryoichi Tokimitsu, Koichi Nakata, Haruki Mori, Shubun Kujirai
  • Publication number: 20200201200
    Abstract: The present disclosure provides an electrophotographic photosensitive member that has mechanical durability, and can achieve both of suppression of an image flow and adequate electrical characteristics.
    Type: Application
    Filed: December 12, 2019
    Publication date: June 25, 2020
    Inventors: Ryoichi Tokimitsu, Koichi Nakata, Haruki Mori, Shubun Kujirai
  • Patent number: 10365569
    Abstract: The present invention provides: an electrophotographic photosensitive member which can achieve both of abrasion resistance and electrical characteristics; a production method of the electrophotographic photosensitive member; and a process cartridge and an electrophotographic apparatus having the electrophotographic photosensitive member. A surface layer of the electrophotographic photosensitive member includes a cured product and a specific amount of an alcohol or carboxylic acid having a specific structure, wherein the cured product is a polymerized product of a hole transporting compound having an acryloyloxy group or a methacryloyloxy group.
    Type: Grant
    Filed: August 3, 2018
    Date of Patent: July 30, 2019
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Ryoichi Tokimitsu, Masaki Nonaka, Haruki Mori, Takahiro Mitsui
  • Patent number: 10310395
    Abstract: Provided are an electrophotographic photosensitive member capable of satisfying abrasion resistance and electrical properties and suppressing image deletion, and an electrophotographic apparatus and a process cartridge having the electrophotographic photosensitive member. A surface layer of the electrophotographic photosensitive member contains a polymer of a hole transport material having a polymerizable functional group, wherein the hole transport material has a specific structure.
    Type: Grant
    Filed: June 7, 2018
    Date of Patent: June 4, 2019
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Koichi Nakata, Haruki Mori, Shinji Takagi, Masaki Nonaka, Ryoichi Tokimitsu
  • Publication number: 20190049867
    Abstract: The present invention provides: an electrophotographic photosensitive member which can achieve both of abrasion resistance and electrical characteristics; a production method of the electrophotographic photosensitive member; and a process cartridge and an electrophotographic apparatus having the electrophotographic photosensitive member. A surface layer of the electrophotographic photosensitive member includes a cured product and a specific amount of an alcohol or carboxylic acid having a specific structure, wherein the cured product is a polymerized product of a hole transporting compound having an acryloyloxy group or a methacryloyloxy group.
    Type: Application
    Filed: August 3, 2018
    Publication date: February 14, 2019
    Inventors: RYOICHI TOKIMITSU, Masaki Nonaka, Haruki Mori, Takahiro Mitsui
  • Publication number: 20180284629
    Abstract: Provided are an electrophotographic photosensitive member capable of satisfying abrasion resistance and electrical properties and suppressing image deletion, and an electrophotographic apparatus and a process cartridge having the electrophotographic photosensitive member. A surface layer of the electrophotographic photosensitive member contains a polymer of a hole transport material having a polymerizable functional group, wherein the hole transport material has a specific structure.
    Type: Application
    Filed: June 7, 2018
    Publication date: October 4, 2018
    Inventors: Koichi Nakata, Haruki Mori, Shinji Takagi, Masaki Nonaka, Ryoichi Tokimitsu
  • Patent number: 10067431
    Abstract: An electrophotographic photosensitive member, in which occurrences of image defects are suppressed, and a method for manufacturing the electrophotographic photosensitive member are provided. In addition, a process cartridge and an electrophotographic apparatus, which include the electrophotographic photosensitive member, are provided. The surface layer of the electrophotographic photosensitive member contains a cured material, and the cured material is a copolymer of a hole transport compound having a chain-polymerizable functional group and a vinyl ester compound containing a long-chain alkyl group.
    Type: Grant
    Filed: April 24, 2017
    Date of Patent: September 4, 2018
    Assignee: Canon Kabushiki Kaisha
    Inventors: Shinji Takagi, Masaki Nonaka, Haruki Mori, Ryoichi Tokimitsu, Koichi Nakata
  • Patent number: 9983490
    Abstract: The present invention provides an electrophotographic apparatus in which the deterioration of electrical properties in repetitive use is suppressed even in the case where an electrophotographic photosensitive member absorbs moisture under a high-temperature and high-humidity environment. An undercoat layer of the electrophotographic photosensitive member provided in the electrophotographic apparatus contains (?) a metal oxide particle, (?) a particular benzophenone compound and (?) a compound represented by the following formula (2). wherein R11 to R15 each independently represent a hydrogen atom, a hydroxy group, a halogen atom, an alkyl group, an alkoxy group or an amino group and A1 represents an alkenyl group having 2 or more and 4 or less carbon atoms.
    Type: Grant
    Filed: March 27, 2017
    Date of Patent: May 29, 2018
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Tsuyoshi Shimada, Ryoichi Tokimitsu, Mai Murakami, Kan Tanabe, Wataru Kitamura, Haruhiko Mitsuda
  • Patent number: 9946175
    Abstract: To provide an electrophotographic photosensitive member which satisfies abrasion resistance and electrical properties and which is difficult to cause image deletion. A surface layer of the electrophotographic photosensitive member of this invention contains a polymerized product of a hole transporting compound having a polymerizable functional group, in which the hole transporting compound is at least one compound selected from the group consisting of: a compound consisting of one or more carbon atoms, one or more hydrogen atoms, and one or more halogen atoms; and a compound consisting of one or more carbon atoms, one or more hydrogen atoms, one or more oxygen atoms, and one or more halogen atoms.
    Type: Grant
    Filed: March 23, 2015
    Date of Patent: April 17, 2018
    Assignee: Canon Kabushiki Kaisha
    Inventors: Koichi Nakata, Shinji Takagi, Yuzo Tokunaga, Masaki Nonaka, Ryoichi Tokimitsu
  • Patent number: 9829810
    Abstract: In an electrophotographic photosensitive member including a support and a photosensitive layer formed on the support, a surface layer of the electrophotographic photosensitive member contains a cured product obtained by copolymerizing at least one compound (i) selected from the group consisting of a triphenylamine compound having a hydroxymethyl group and a benzidine compound having a hydroxymethyl group, and at least one compound (ii) selected from the group consisting of a compound represented by the following formula (1), a compound represented by the following formula (2), a compound represented by the following formula (3), and a compound represented by the following formula (4):
    Type: Grant
    Filed: November 3, 2016
    Date of Patent: November 28, 2017
    Assignee: Canon Kabushiki Kaisha
    Inventors: Masaki Nonaka, Ryoichi Tokimitsu, Shinji Takagi, Koichi Nakata, Haruki Mori
  • Patent number: 9811012
    Abstract: The present invention provides an electrophotographic photosensitive member in which an undercoat layer contains a metal oxide particle, a particular benzophenone compound and a particular ketone compound, a process cartridge and an electrophotographic apparatus each including the electrophotographic photosensitive member and a process for producing the electrophotographic photosensitive member.
    Type: Grant
    Filed: September 15, 2016
    Date of Patent: November 7, 2017
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Mai Murakami, Ryoichi Tokimitsu, Wataru Kitamura