Patents by Inventor Haruhiko Mitsuda

Haruhiko Mitsuda 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: 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
  • 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: 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: 10935898
    Abstract: An electrophotographic photosensitive member includes a support, an undercoat layer, a photosensitive layer, and a surface layer, the undercoat layer containing a binder resin and strontium titanate particles, the surface layer being a cured film of a composition containing at least one compound selected from a guanamine compound and a melamine compound, and a charge transport material having at least one substituent selected from —OH, —OCH3, —NH2, —SH, and —COOH.
    Type: Grant
    Filed: October 17, 2019
    Date of Patent: March 2, 2021
    Assignee: Canon Kabushiki Kaisha
    Inventors: Ikuyo Kuroiwa, Kumiko Takizawa, Tsuyoshi Shimada, Kan Tanabe, Haruhiko Mitsuda, Takanori Ueno, Tatsuya Ikezue, Wataru Kitamura
  • Patent number: 10921723
    Abstract: Provided is an electrophotographic photosensitive member that can achieve both of abrasion resistance and the suppression of a ghost. The electrophotographic photosensitive member includes: a support; an undercoat layer; a charge-generating layer; and a charge-transporting layer, the undercoat layer, the charge-generating layer, and the charge-transporting layer being arranged in the stated order on the support, wherein the charge-transporting layer includes a charge-transporting substance, and a polymer containing a structure represented by the following general formula (1) and a structure represented by the following general formula (2), wherein the charge-generating layer includes a phthalocyanine crystal and a binder resin, and wherein the undercoat layer includes strontium titanate particles and a binder resin.
    Type: Grant
    Filed: October 9, 2019
    Date of Patent: February 16, 2021
    Assignee: Canon Kabushiki Kaisha
    Inventors: Kumiko Takizawa, Tsuyoshi Shimada, Takanori Ueno, Ikuyo Kuroiwa, Haruhiko Mitsuda, Kan Tanabe, Tatsuya Ikezue
  • Patent number: 10908521
    Abstract: An electrophotographic photoconductor includes, in sequence, a support member; an undercoating layer containing a binder resin and an inorganic particle; and a photosensitive layer, wherein the binder resin of the undercoating layer is an alkyd-melamine resin, and the inorganic particle of the undercoating layer contains a strontium titanate particle.
    Type: Grant
    Filed: October 22, 2019
    Date of Patent: February 2, 2021
    Assignee: Canon Kabushiki Kaisha
    Inventors: Haruhiko Mitsuda, Tatsuya Ikezue, Kumiko Takizawa, Kan Tanabe, Ikuyo Kuroiwa, Takanori Ueno, Tsuyoshi Shimada
  • Patent number: 10838314
    Abstract: The electrophotographic photosensitive member includes an undercoat layer and a surface layer on or above a support in this order, in which the undercoat layer contains metal oxide particles and a specific binder resin, the surface layer contains a charge transporting substance, fluororesin particles, and a specific binder resin, an arithmetic average roughness Ra of a surface of the undercoat layer is 0.15 ?m or less, a refractive index (a) of the metal oxide particles and a refractive index (b) of the binder resin contained in the undercoat layer satisfy a specific relationship, and a refractive index (c) of the binder resin contained in the surface layer and a refractive index (d) of the fluororesin particles satisfy a specific relationship.
    Type: Grant
    Filed: October 16, 2019
    Date of Patent: November 17, 2020
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Tatsuya Ikezue, Kumiko Takizawa, Ikuyo Kuroiwa, Kan Tanabe, Tsuyoshi Shimada, Haruhiko Mitsuda, Takanori Ueno
  • Patent number: 10732525
    Abstract: An electrophotographic apparatus includes an electrophotographic photosensitive member, a charging roller disposed so as to come into contact with the electrophotographic photosensitive member, and a charging device operable to apply only a DC voltage to charge the electrophotographic photosensitive member. The electrophotographic photosensitive member includes a support member, an undercoat layer over the support member, and a photosensitive layer over the undercoat layer and having a plurality of discrete recesses in the surface thereof. The undercoat layer contains zinc oxide particles and a binder resin. The undercoat layer has cavities therein, and the cavities account for 5.00% or less of the volume of the undercoat layer.
    Type: Grant
    Filed: April 17, 2019
    Date of Patent: August 4, 2020
    Assignee: Canon Kabushiki Kaisha
    Inventors: Tsuyoshi Shimada, Kan Tanabe, Haruhiko Mitsuda
  • Publication number: 20200133148
    Abstract: The electrophotographic photosensitive member includes an undercoat layer and a surface layer on or above a support in this order, in which the undercoat layer contains metal oxide particles and a specific binder resin, the surface layer contains a charge transporting substance, fluororesin particles, and a specific binder resin, an arithmetic average roughness Ra of a surface of the undercoat layer is 0.15 ?m or less, a refractive index (a) of the metal oxide particles and a refractive index (b) of the binder resin contained in the undercoat layer satisfy a specific relationship, and a refractive index (c) of the binder resin contained in the surface layer and a refractive index (d) of the fluororesin particles satisfy a specific relationship.
    Type: Application
    Filed: October 16, 2019
    Publication date: April 30, 2020
    Inventors: Tatsuya Ikezue, Kumiko Takizawa, Ikuyo Kuroiwa, Kan Tanabe, Tsuyoshi Shimada, Haruhiko Mitsuda, Takanori Ueno
  • Publication number: 20200133146
    Abstract: Provided are an electrophotographic photosensitive member excellent in suppression of the occurrence of a photomemory, and a process cartridge and an electrophotographic apparatus each including the electrophotographic photosensitive member. The electrophotographic photosensitive member includes in this order: an electroconductive support; an undercoat layer; and a photosensitive layer, wherein the undercoat layer contains strontium titanate particles and a binder resin, and the photosensitive layer contains a butanediol adduct of titanyl phthalocyanine.
    Type: Application
    Filed: October 15, 2019
    Publication date: April 30, 2020
    Inventors: Tsuyoshi Shimada, Kumiko Takizawa, Ikuyo Kuroiwa, Kan Tanabe, Haruhiko Mitsuda, Tatsuya Ikezue, Takanori Ueno
  • Publication number: 20200133147
    Abstract: Provided is an electrophotographic photosensitive member that can achieve both of abrasion resistance and the suppression of a ghost. The electrophotographic photosensitive member includes: a support; an undercoat layer; a charge-generating layer; and a charge-transporting layer, the undercoat layer, the charge-generating layer, and the charge-transporting layer being arranged in the stated order on the support, wherein the charge-transporting layer includes a charge-transporting substance, and a polymer containing a structure represented by the following general formula (1) and a structure represented by the following general formula (2), wherein the charge-generating layer includes a phthalocyanine crystal and a binder resin, and wherein the undercoat layer includes strontium titanate particles and a binder resin.
    Type: Application
    Filed: October 9, 2019
    Publication date: April 30, 2020
    Inventors: Kumiko Takizawa, Tsuyoshi Shimada, Takanori Ueno, Ikuyo Kuroiwa, Haruhiko Mitsuda, Kan Tanabe, Tatsuya Ikezue
  • Publication number: 20200133150
    Abstract: An electrophotographic photoconductor includes, in sequence, a support member; an undercoating layer containing a binder resin and an inorganic particle; and a photosensitive layer, wherein the binder resin of the undercoating layer is an alkyd-melamine resin, and the inorganic particle of the undercoating layer contains a strontium titanate particle.
    Type: Application
    Filed: October 22, 2019
    Publication date: April 30, 2020
    Inventors: Haruhiko Mitsuda, Tatsuya Ikezue, Kumiko Takizawa, Kan Tanabe, Ikuyo Kuroiwa, Takanori Ueno, Tsuyoshi Shimada
  • Publication number: 20200133145
    Abstract: An electrophotographic photoconductor includes, in sequence, a support, an undercoat layer, a charge generation layer containing a charge generation material and a first binder resin, and a charge transport layer containing a charge transport material and a second binder resin. The charge generation material in the charge generation layer is chlorogallium phthalocyanine having diffraction peaks at Bragg angles (2?±0.2°) of 7.4°, 16.6°, 25.5°, and 28.3° in an X-ray diffraction pattern obtained by using Cu K-? radiation. The undercoat layer contains strontium titanate particles and a third binder resin.
    Type: Application
    Filed: October 18, 2019
    Publication date: April 30, 2020
    Inventors: Kan Tanabe, Tatsuya Ikezue, Kumiko Takizawa, Haruhiko Mitsuda, Ikuyo Kuroiwa, Takanori Ueno, Tsuyoshi Shimada
  • Publication number: 20200133149
    Abstract: The present disclosure provides an electrophotographic photosensitive member that can suppress a black spot and an exposure memory. The electrophotographic photosensitive member has a support, an undercoat layer and a photosensitive layer having a mono-layer structure in this order, wherein the undercoat layer contains a binder resin and strontium titanate particles; and the photosensitive layer having a mono-layer structure contains a binder resin, a charge generation material, a hole transport material and an electron transport material.
    Type: Application
    Filed: October 21, 2019
    Publication date: April 30, 2020
    Inventors: Takanori Ueno, Kumiko Takizawa, Kan Tanabe, Haruhiko Mitsuda, Ikuyo Kuroiwa, Tsuyoshi Shimada, Wataru Kitamura, Shinji Takagi, Tatsuya Ikezue
  • Publication number: 20200124996
    Abstract: An electrophotographic photosensitive member includes a support, an undercoat layer, a photosensitive layer, and a surface layer, the undercoat layer containing a binder resin and strontium titanate particles, the surface layer being a cured film of a composition containing at least one compound selected from a guanamine compound and a melamine compound, and a charge transport material having at least one substituent selected from —OH, —OCH3, —NH2, —SH, and —COOH.
    Type: Application
    Filed: October 17, 2019
    Publication date: April 23, 2020
    Inventors: Ikuyo Kuroiwa, Kumiko Takizawa, Tsuyoshi Shimada, Kan Tanabe, Haruhiko Mitsuda, Takanori Ueno, Tatsuya Ikezue, Wataru Kitamura
  • Publication number: 20190332022
    Abstract: An electrophotographic apparatus includes an electrophotographic photosensitive member, a charging roller disposed so as to come into contact with the electrophotographic photosensitive member, and a charging device operable to apply only a DC voltage to charge the electrophotographic photosensitive member. The electrophotographic photosensitive member includes a support member, an undercoat layer over the support member, and a photosensitive layer over the undercoat layer and having a plurality of discrete recesses in the surface thereof. The undercoat layer contains zinc oxide particles and a binder resin. The undercoat layer has cavities therein, and the cavities account for 5.00% or less of the volume of the undercoat layer.
    Type: Application
    Filed: April 17, 2019
    Publication date: October 31, 2019
    Inventors: Tsuyoshi Shimada, Kan Tanabe, Haruhiko Mitsuda
  • Patent number: 10241429
    Abstract: There is provided an electrophotographic photosensitive member, a process cartridge and an electrophotographic apparatus that are excellent in charging properties and can suppress residual potential in the case where a strontium titanate particle is used as a metal oxide particle in an undercoat layer of the electrophotographic photosensitive member. An electrophotographic photosensitive member in which an undercoat layer contains a strontium titanate particle having a maximum peak at a position of 2?=32.20±0.20 (? represents a Bragg angle) in a CuK? characteristic X-ray diffraction pattern, the maximum peak having a half-value width of 0.10 deg or more and 0.50 deg or less, and a process cartridge and an electrophotographic apparatus each provided with the electrophotographic photosensitive member.
    Type: Grant
    Filed: April 24, 2018
    Date of Patent: March 26, 2019
    Assignee: Canon Kabushiki Kaisha
    Inventors: Tsuyoshi Shimada, Kumiko Takizawa, Eileen Takeuchi, Ikuyo Kuroiwa, Wataru Kitamura, Kan Tanabe, Haruhiko Mitsuda
  • Publication number: 20180314173
    Abstract: There is provided an electrophotographic photosensitive member, a process cartridge and an electrophotographic apparatus that are excellent in charging properties and can suppress residual potential in the case where a strontium titanate particle is used as a metal oxide particle in an undercoat layer of the electrophotographic photosensitive member. An electrophotographic photosensitive member in which an undercoat layer contains a strontium titanate particle having a maximum peak at a position of 2?=32.20±0.20 (? represents a Bragg angle) in a CuK? characteristic X-ray diffraction pattern, the maximum peak having a half-value width of 0.10 deg or more and 0.50 deg or less, and a process cartridge and an electrophotographic apparatus each provided with the electrophotographic photosensitive member.
    Type: Application
    Filed: April 24, 2018
    Publication date: November 1, 2018
    Inventors: Tsuyoshi Shimada, Kumiko Takizawa, Eileen Takeuchi, Ikuyo Kuroiwa, Wataru Kitamura, Kan Tanabe, Haruhiko Mitsuda