Patents by Inventor Masatada Hirota

Masatada Hirota 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: 20240118634
    Abstract: The electrophotographic photosensitive member includes a support and a photosensitive layer on the support, in which a surface layer of the electrophotographic photosensitive member contains a particle, the surface layer has a particle partially exposed from the surface layer among the particle contained in the surface layer, the particle has a volume average particle diameter of 50.0 nm or more and 350.0 nm or less; in a cross-section of the surface layer, the number of the particle partially exposed from the surface layer is 80% by number or more based on a total number of the particle contained in the surface layer; and a total volume of an exposed portion of the particle partially exposed from the surface layer is 30% by volume or more and 80% by volume or less based on an entire volume of the particle contained in the surface layer.
    Type: Application
    Filed: November 30, 2023
    Publication date: April 11, 2024
    Inventors: SHUNTARO WATANABE, TOMOHITO ISHIDA, NOBUHIRO NAKAMURA, HIROYUKI WATANABE, TATSUYA YAMAAI, MASATADA HIROTA
  • Publication number: 20240118635
    Abstract: Provided is an electrophotographic photosensitive member that achieves satisfactory transferability. An electrophotographic photosensitive member including a charge generating layer, a charge transporting layer, and a protection layer laminated on a support in the stated order, wherein the protection layer contains a binder resin and particles, and wherein when an average thickness of the protection layer in a site free of the particles is represented by T and a volume-average particle diameter of the particles is represented by Dm in a cross-section of the protection layer, the following formula (a) is satisfied.
    Type: Application
    Filed: November 30, 2023
    Publication date: April 11, 2024
    Inventors: TOMOHITO ISHIDA, SHUNTARO WATANABE, NOBUHIRO NAKAMURA, TATSUYA YAMAAI, HIROYUKI WATANABE, MASATADA HIROTA
  • Publication number: 20240004322
    Abstract: The electrophotographic photosensitive member includes a surface layer containing a binder resin, electroconductive particles, and insulating particles, wherein when a volume resistivity of the insulating particles is represented by R1 [?·cm], a volume resistivity of the electroconductive particles is represented by R2 [?·cm], a ratio of an area of the insulating particles that are exposed to a total area of the surface layer is represented by S1 [%], a ratio of an area of the electroconductive particles that are exposed to the total area of the surface layer is represented by S2 [%], an average exposed height of the insulating particles exposed to a surface of the electrophotographic photosensitive member is represented by L1 [nm], and an average exposed height of the electroconductive particles exposed to the surface of the electrophotographic photosensitive member is represented by L2 [nm], those parameters satisfy specific relational formulae.
    Type: Application
    Filed: June 23, 2023
    Publication date: January 4, 2024
    Inventors: KOHEI MAKISUMI, SHUNTARO WATANABE, TAICHI SATO, TOMOHITO ISHIDA, MASATADA HIROTA, TSUTOMU NISHIDA
  • Publication number: 20230408937
    Abstract: An electrophotographic photosensitive member including a surface layer containing a binder resin and metal oxide particles. An average primary particle diameter of the metal oxide particles measured from a cross-section of the surface layer is 20 to 70 nm. A content ratio of the metal oxide particles in the surface layer measured from the cross-section of the surface layer is 30 to 75 vol % with respect to a total volume of the surface layer.
    Type: Application
    Filed: June 16, 2023
    Publication date: December 21, 2023
    Inventors: TAICHI SATO, SHUNTARO WATANABE, MASATADA HIROTA, KOHEI MAKISUMI, TOMOHITO ISHIDA, TSUTOMU NISHIDA
  • Publication number: 20230115474
    Abstract: Provided is an electrophotographic photosensitive member including an electroconductive support, a photosensitive layer, and a protection layer, wherein the protection layer comprises an electroconductive particle, the electroconductive particle has a surface comprising a metal oxide containing a titanium atom and a niobium atom, an atomic concentration ratio of the niobium atom to the titanium atom in the metal oxide is 0.01 to 0.20, the electroconductive particle is surface-treated with a compound having a silicon atom, a content ratio of the electroconductive particle in the protection layer is 5 vol % or more and less than 40 vol % with respect to a total volume of the protection layer, and relative concentrations of a plurality of atoms at a surface of the protection layer, which are determined by X-ray photoelectron spectroscopy, satisfy specific conditions.
    Type: Application
    Filed: September 28, 2022
    Publication date: April 13, 2023
    Inventors: Shuntaro Watanabe, Taichi Sato, Kohei Makisumi, Masatada Hirota, Kunihiko Sekido