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).

  • 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
  • Publication number: 20170315458
    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: Application
    Filed: April 24, 2017
    Publication date: November 2, 2017
    Inventors: Shinji Takagi, Masaki Nonaka, Haruki Mori, Ryoichi Tokimitsu, Koichi Nakata
  • Patent number: 9804512
    Abstract: An electrophotographic photosensitive member includes a support, an undercoat layer which contains a metal oxide particle and is formed on the support, a charge generating layer formed on the undercoat layer, and a charge transporting layer formed on the charge generating layer. Either or both of the undercoat layer and the charge generating layer contain a compound represented by formula (1).
    Type: Grant
    Filed: March 6, 2014
    Date of Patent: October 31, 2017
    Assignee: Canon Kabushiki Kaisha
    Inventors: Ryoichi Tokimitsu, Yuka Ishiduka, Wataru Kitamura, Mai Murakami, Kan Tanabe
  • Publication number: 20170285499
    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: Application
    Filed: March 27, 2017
    Publication date: October 5, 2017
    Inventors: Tsuyoshi Shimada, Ryoichi Tokimitsu, Mai Murakami, Kan Tanabe, Wataru Kitamura, Haruhiko Mitsuda
  • Patent number: 9778582
    Abstract: An electrophotographic photosensitive member includes an undercoat layer that includes metal oxide particles and a compound having at least three hydroxyl groups and a carbonyl or dicarbonyl group.
    Type: Grant
    Filed: November 29, 2012
    Date of Patent: October 3, 2017
    Assignee: Canon Kabushiki Kaisha
    Inventors: Wataru Kitamura, Ryoichi Tokimitsu, Yuka Ishiduka, Mai Murakami, Kenichi Kaku
  • Publication number: 20170131646
    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: Application
    Filed: November 3, 2016
    Publication date: May 11, 2017
    Inventors: Masaki Nonaka, Ryoichi Tokimitsu, Shinji Takagi, Koichi Nakata, Haruki Mori
  • Publication number: 20170108789
    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: Application
    Filed: March 23, 2015
    Publication date: April 20, 2017
    Inventors: Koichi Nakata, Shinji Takagi, Yuzo Tokunaga, Masaki Nonaka, Ryoichi Tokimitsu
  • Publication number: 20170090309
    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: Application
    Filed: September 15, 2016
    Publication date: March 30, 2017
    Inventors: Mai Murakami, Ryoichi Tokimitsu, Wataru Kitamura
  • Patent number: 9594318
    Abstract: Provided is an electrophotographic photosensitive member, including: a support; and a photosensitive layer formed on the support, in which a surface layer of the electrophotographic photosensitive member contains a polymerized product of a compound represented by the following structural formula (1).
    Type: Grant
    Filed: August 21, 2015
    Date of Patent: March 14, 2017
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Koichi Nakata, Shinji Takagi, Masaki Nonaka, Ryoichi Tokimitsu, Haruki Mori
  • Patent number: 9557664
    Abstract: The present invention provides an electrophotographic photosensitive member which includes an undercoat layer, and the undercoat layer contains metal oxide particles and a compound represented by the formula (1).
    Type: Grant
    Filed: March 27, 2014
    Date of Patent: January 31, 2017
    Assignee: Canon Kabushiki Kaisha
    Inventors: Yuka Ishiduka, Ryoichi Tokimitsu, Wataru Kitamura, Mai Murakami, Kan Tanabe
  • Patent number: 9411252
    Abstract: An electrophotographic photosensitive member includes an undercoat layer containing a silane coupling agent having a divalent group represented by —NH— and an urethane resin. The modulus of elastic deformation (we/wt) of a surface of the undercoat layer satisfies formula (X), where the modulus of elastic deformation is measured by a universal hardness test.
    Type: Grant
    Filed: November 28, 2012
    Date of Patent: August 9, 2016
    Assignee: Canon Kabushiki Kaisha
    Inventors: Mai Murakami, Kenichi Kaku, Wataru Kitamura, Yuka Ishiduka, Ryoichi Tokimitsu, Hideaki Nagasaka, Takeshi Murakami
  • Patent number: 9335646
    Abstract: Provided are an electrophotographic photosensitive member in which a variation in the light-area potential is suppressed even when the electrophotographic photosensitive member is repeatedly used for a long time in a high-temperature, high-humidity environment, a method of producing the electrophotographic photosensitive member, and a process cartridge and an electrophotographic apparatus that include the electrophotographic photosensitive member. The electrophotographic photosensitive member includes a support, an undercoat layer, and a photosensitive layer, wherein the undercoat layer contains a urethane resin and zinc oxide particles whose surfaces have been treated with a particular amount of an aminosilane compound.
    Type: Grant
    Filed: November 28, 2012
    Date of Patent: May 10, 2016
    Assignee: Canon Kabushiki Kaisha
    Inventors: Kenichi Kaku, Wataru Kitamura, Yuka Ishiduka, Mai Murakami, Ryoichi Tokimitsu, Hideaki Nagasaka, Takeshi Murakami