Patents by Inventor Yuka Ishiduka

Yuka Ishiduka 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: 11782353
    Abstract: A method for producing an electrophotographic photosensitive member including: forming a photosensitive layer; and forming a protective layer, wherein the step of forming the photosensitive layer forms a photosensitive layer having an amount of residual solvent of a first solvent in the photosensitive layer of 0.05% to 2.50% and an amount of residual solvent of a second solvent in the photosensitive layer of 0.50% to 2.50%, and the step of forming the protective layer includes step (A) of forming a cured film and step (B) of forming the protective layer having wrinkle shapes, wherein, in step (A), the irradiated coating film is heated at a heating temperature lower than a boiling point of the first solvent and in step (B), the cured film is heated at a heating temperature higher than a boiling point of the first solvent.
    Type: Grant
    Filed: April 13, 2021
    Date of Patent: October 10, 2023
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Nobuhiro Nakamura, Tomohito Ishida, Shuhei Iwasaki, Hiroyuki Watanabe, Tatsuya Yamaai, Yuka Ishiduka, Yota Ito, Takeshi Murakami
  • Patent number: 11703773
    Abstract: An electrophotographic photosensitive member that is excellent in image smearing resistance and low torque while maintaining its electrophotographic characteristic. The electrophotographic photosensitive member is an electrophotographic photosensitive member including, in this order: a support; a photosensitive layer; and a protection layer as a surface layer, wherein the protection layer has a surface having a developed area ratio Sdr of 1.0% to 40.0%, and wherein an A value represented by the following formula (1) is 0.10 to 0.27: A=S1/S2 . . . formula (1), where, in the formula (1), S1 represents a peak area based on C?C stretching vibration of an aromatic ring by attenuated total reflection Fourier transform infrared spectroscopy, and S2 represents a peak area based on C?O stretching vibration of an ester group by the same method.
    Type: Grant
    Filed: February 24, 2022
    Date of Patent: July 18, 2023
    Assignee: Canon Kabushiki Kaisha
    Inventors: Tsutomu Nishida, Yuka Ishiduka, Tatsuya Ohsawa
  • Patent number: 11619888
    Abstract: An electrophotographic image forming apparatus in which streak-like banding to be formed in an electrophotographic photosensitive member is suppressed. The electrophotographic image forming apparatus includes an electrophotographic photosensitive member, which has a protective layer, and a developer carrying member for supplying a developer. The protective layer contains a cured product containing an aromatic ring and an ester group, by attenuated total reflection Fourier transform infrared spectroscopy, when a peak area based on C?C stretching vibration of the aromatic ring is represented by S1, and a peak area based on C?O stretching vibration of the ester group is represented by S2, an area ratio S1/S2 is 0.10 to 0.27, and a rotation speed ratio D1/D2 of a rotation speed D1 of the developer carrying member to a rotation speed D2 of the electrophotographic photosensitive member is 0.80 to 1.20.
    Type: Grant
    Filed: February 25, 2022
    Date of Patent: April 4, 2023
    Assignee: Canon Kabushiki Kaisha
    Inventors: Yuka Ishiduka, Tsutomu Nishida, Tatsuya Ohsawa
  • Publication number: 20220276580
    Abstract: An electrophotographic image forming apparatus in which streak-like banding to be formed in an electrophotographic photosensitive member is suppressed. The electrophotographic image forming apparatus comprises an electrophotographic photosensitive member, which has a protective layer, and a developer carrying member for supplying a developer. The protective layer contains a cured product containing an aromatic ring and an ester group, by attenuated total reflection Fourier transform infrared spectroscopy, when a peak area based on C?C stretching vibration of the aromatic ring is represented by S1, and a peak area based on C?O stretching vibration of the ester group is represented by S2, an area ratio S1/S2 is 0.10 to 0.27, and a rotation speed ratio D1/D2 of a rotation speed D1 of the developer carrying member to a rotation speed D2 of the electrophotographic photosensitive member is 0.80 to 1.20.
    Type: Application
    Filed: February 25, 2022
    Publication date: September 1, 2022
    Inventors: Yuka Ishiduka, Tsutomu Nishida, Tatsuya Ohsawa
  • Publication number: 20220276576
    Abstract: An electrophotographic photosensitive member that is excellent in image smearing resistance and low torque while maintaining its electrophotographic characteristic. The electrophotographic photosensitive member is an electrophotographic photosensitive member comprising, in this order: a support; a photosensitive layer; and a protection layer as a surface layer, wherein the protection layer has a surface having a developed area ratio Sdr of 1.0% to 40.0%, and wherein an A value represented by the following formula (1) is 0.10 to 0.27: A=S1/S2 . . . formula (1), where, in the formula (1), S1 represents a peak area based on C?C stretching vibration of an aromatic ring by attenuated total reflection Fourier transform infrared spectroscopy, and S2 represents a peak area based on C?O stretching vibration of an ester group by the same method.
    Type: Application
    Filed: February 24, 2022
    Publication date: September 1, 2022
    Inventors: Tsutomu Nishida, Yuka Ishiduka, Tatsuya Ohsawa
  • Patent number: 11392074
    Abstract: Provided is an electrophotographic photosensitive drum that achieves both of a reduction in torque of the electrophotographic photosensitive drum at the time of its cleaning and an improvement in image transferability. The electrophotographic photosensitive drum includes: a support; and a photosensitive layer arranged on the support, the electrophotographic photosensitive drum having arranged on an outer surface thereof at least two structure groups having different appearance periods, wherein when, out of the two structure groups, a group including structures having a smaller appearance period is defined as a first structure group, and a group including structures having a larger appearance period is defined as a second structure group, a height of the first structure group is lower than a height of the second structure group.
    Type: Grant
    Filed: April 13, 2021
    Date of Patent: July 19, 2022
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Tomohito Ishida, Nobuhiro Nakamura, Shuhei Iwasaki, Hiroyuki Watanabe, Tatsuya Yamaai, Yuka Ishiduka, Yota Ito, Takeshi Murakami
  • Patent number: 11392050
    Abstract: A process cartridge which allows any spot and stripe as image defects to be suppressed is provided. A process cartridge, in which an electroconductive layer of a charging member has a matrix including a first rubber, and domains dispersed in the matrix, the domains include a second rubber and an electron electroconductive agent, at least some of the domains are exposed on a surface of the charging member, when a volume resistivity of the matrix is 105 times or more a volume resistivity of the domains, a protective layer of an electrophotographic photosensitive member includes a metal oxide particle, and when a number average primary particle size of the metal oxide particle is defined as Sm and an average value of equivalent circle diameters of the domains is defined as Sd, the Sd/Sm satisfies the following expression (1): 0.5<Sd/Sm<100 . . . expression (1).
    Type: Grant
    Filed: October 14, 2020
    Date of Patent: July 19, 2022
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Tsutomu Nishida, Yuka Ishiduka, Kenichi Kaku, Nobuhiro Nakamura, Hiroyuki Watanabe, Hideharu Shimozawa, Atsushi Okuda, Yuichi Kikuchi, Kazuhiro Yamauchi
  • Patent number: 11366402
    Abstract: There is provided a process cartridge detachably attachable to a main body of an electrophotographic apparatus, the process cartridge including an electrophotographic photosensitive member and a charging member, wherein an outer surface of the charging member is composed of at least a matrix and at least a part of domains, a volume resistivity of the matrix is 1.0×105 times or more of a volume resistivity of the domain, an average value Sd of circle equivalent diameters of the domains observed on the outer surface of the charging member is in a predetermined range, the electrophotographic photosensitive member contains a support, a photosensitive layer, and a protective layer in this order and when a surface roughness of the protective layer is measured, each of a protruding valley portion Rvk, a load length ratio Mr2, and Sd/Rvk is in a predetermined range.
    Type: Grant
    Filed: October 14, 2020
    Date of Patent: June 21, 2022
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Yuka Ishiduka, Tsutomu Nishida, Hideharu Shimozawa, Nobuhiro Nakamura, Hiroyuki Watanabe, Kenichi Kaku, Kazuhiro Yamauchi, Yuichi Kikuchi, Kazuhisa Shida, Atsushi Okuda
  • Patent number: 11256186
    Abstract: The present disclosure provides an electrophotographic photosensitive member that suppresses electric potential fluctuations in repeated use. The electrophotographic photosensitive member includes a support, a photosensitive layer and a protective layer, in this order, wherein the photosensitive layer includes a compound having a structure represented by formula (1), and the protective layer includes a resin having a structure represented by formula (2) and a structure represented by formula (3).
    Type: Grant
    Filed: February 10, 2020
    Date of Patent: February 22, 2022
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Hideharu Shimozawa, Tsutomu Nishida, Atsushi Okuda, Yuka Ishiduka, Kenichi Kaku, Nobuhiro Nakamura, Hiroyuki Watanabe
  • Publication number: 20210325794
    Abstract: There is provided an electrophotographic photosensitive member having drum shape, the electrophotographic photosensitive member including a support and a photosensitive layer, wherein an outer surface of the electrophotographic photosensitive member has wrinkles, and when an observation region having square form with one side of 100 ?m is placed at an arbitrary position on the outer surface, a line that passes through a central point of the observation region and is parallel to a circumferential direction of the electrophotographic photosensitive member is defined as a first reference line L1, and 3,599 reference lines obtained by rotating the first reference line L1 at every 0.1° around the central point are defined as L2 to L3,600, respectively, each of L1 to L3,600 intersects with convex portions of the wrinkles at a plurality of locations and has at least two different intersection angles selected from the plurality of locations.
    Type: Application
    Filed: April 14, 2021
    Publication date: October 21, 2021
    Inventors: Shuhei Iwasaki, Tomohito Ishida, Nobuhiro Nakamura, Hiroyuki Watanabe, Tatsuya Yamaai, Yuka Ishiduka, Yota Ito, Takeshi Murakami
  • Patent number: 11003102
    Abstract: Provided are an electrophotographic apparatus and a process cartridge each capable of suppressing the occurrence of a black spot (white background contamination) in an output image under a low-temperature and low-humidity environment. The electrophotographic apparatus includes: an electrophotographic photosensitive member including a support, a photosensitive layer, and a protective layer in the stated order; an exposing device; a developing device; and a cleaning device, wherein the protective layer has a triarylamine structure and a specific structure at a ratio in a specific range, and a toner contains toner particles each containing at least a resin, and an external additive. The toner has a volume-average particle diameter of 7 ?m or more. The external additive contains a compound containing a titanium atom. The ratio of the mass of the compound containing a titanium atom to the total mass of the toner is 0.6 mass % or more.
    Type: Grant
    Filed: March 11, 2020
    Date of Patent: May 11, 2021
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Yuka Ishiduka, Tsutomu Nishida, Hideharu Shimozawa, Nobuhiro Nakamura, Hiroyuki Watanabe
  • Publication number: 20210116833
    Abstract: There is provided a process cartridge detachably attachable to a main body of an electrophotographic apparatus, the process cartridge including an electrophotographic photosensitive member and a charging member, wherein an outer surface of the charging member is composed of at least a matrix and at least a part of domains, a volume resistivity of the matrix is 1.0×105 times or more of a volume resistivity of the domain, an average value Sd of circle equivalent diameters of the domains observed on the outer surface of the charging member is in a predetermined range, the electrophotographic photosensitive member contains a support, a photosensitive layer, and a protective layer in this order and when a surface roughness of the protective layer is measured, each of a protruding valley portion Rvk, a load length ratio Mr2, and Sd/Rvk is in a predetermined range.
    Type: Application
    Filed: October 14, 2020
    Publication date: April 22, 2021
    Inventors: Yuka Ishiduka, Tsutomu Nishida, Hideharu Shimozawa, Nobuhiro Nakamura, Hiroyuki Watanabe, Kenichi Kaku, Kazuhiro Yamauchi, Yuichi Kikuchi, Kazuhisa Shida, Atsushi Okuda
  • Publication number: 20210116826
    Abstract: A process cartridge which allows any spot and stripe as image defects to be suppressed is provided. A process cartridge, in which an electroconductive layer of a charging member has a matrix including a first rubber, and domains dispersed in the matrix, the domains include a second rubber and an electron electroconductive agent, at least some of the domains are exposed on a surface of the charging member, when a volume resistivity of the matrix is 105 times or more a volume resistivity of the domains, a protective layer of an electrophotographic photosensitive member includes a metal oxide particle, and when a number average primary particle size of the metal oxide particle is defined as Sm and an average value of equivalent circle diameters of the domains is defined as Sd, the Sd/Sm satisfies the following expression (1): 0.5<Sd/Sm<100 . . . expression (1).
    Type: Application
    Filed: October 14, 2020
    Publication date: April 22, 2021
    Inventors: Tsutomu Nishida, Yuka Ishiduka, Kenichi Kaku, Nobuhiro Nakamura, Hiroyuki Watanabe, Hideharu Shimozawa, Atsushi Okuda, Yuichi Kikuchi, Kazuhiro Yamauchi
  • Patent number: 10838315
    Abstract: An electrophotographic photosensitive member having a protective layer wherein the density unevenness among output images is reduced with abrasion resistance maintained is provided. The present invention is an electrophotographic photosensitive member having a support, a photosensitive layer and a protective layer in this order, wherein the protective layer has a triarylamine structure and a cyclic structure represented by the formula (1) or (2): and an A value expressed by expression (4), A=S1/S2, wherein, in expression (4), S1 is a peak area based on in-plane deformation vibration of terminal olefin (CH2?), and S2 is a peak area based on stretching vibration of C?O among peak areas of a spectrum obtained by measuring a surface of the protective layer by total reflection Fourier transform infrared spectroscopy using Ge as an internal reflection element and using a measurement condition of 45° as an incidence angle is from 0.065 to 0.100.
    Type: Grant
    Filed: February 11, 2019
    Date of Patent: November 17, 2020
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Hideharu Shimozawa, Tsutomu Nishida, Atsushi Okuda, Yuka Ishiduka, Nobuhiro Nakamura, Hiroyuki Watanabe
  • Patent number: 10831118
    Abstract: A method for producing an electrophotographic photosensitive member having a photosensitive layer and a protective layer above a support in this order includes: forming a coating film for a protective layer by coating a coating liquid for the protective layer for forming the protective layer on the photosensitive layer and curing the coating film for the protective layer, in which the coating liquid for the protective layer contains a solvent, a compound represented by a general formula (1), a compound represented by a general formula (2), and a compound represented by a general formula (3) at a specific ratio. In addition, in an electrophotographic photosensitive member having a photosensitive layer and a protective layer above a support in this order, the protective layer is obtained by curing a coating liquid for the protective layer.
    Type: Grant
    Filed: May 28, 2019
    Date of Patent: November 10, 2020
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Hiroyuki Watanabe, Tsutomu Nishida, Yuka Ishiduka, Atsushi Okuda, Hideharu Shimozawa, Nobuhiro Nakamura, Koichi Nakata, Haruki Mori, Kenichi Kaku
  • Publication number: 20200292949
    Abstract: Provided are an electrophotographic apparatus and a process cartridge each capable of suppressing the occurrence of a black spot (white background contamination) in an output image under a low-temperature and low-humidity environment. The electrophotographic apparatus includes: an electrophotographic photosensitive member including a support, a photosensitive layer, and a protective layer in the stated order; an exposing device; a developing device; and a cleaning device, wherein the protective layer has a triarylamine structure and a specific structure at a ratio in a specific range, and a toner contains toner particles each containing at least a resin, and an external additive. The toner has a volume-average particle diameter of 7 ?m or more. The external additive contains a compound containing a titanium atom. The ratio of the mass of the compound containing a titanium atom to the total mass of the toner is 0.6 mass % or more.
    Type: Application
    Filed: March 11, 2020
    Publication date: September 17, 2020
    Inventors: Yuka Ishiduka, Tsutomu Nishida, Hideharu Shimozawa, Nobuhiro Nakamura, Hiroyuki Watanabe
  • Publication number: 20200264526
    Abstract: The present disclosure provides an electrophotographic photosensitive member that suppresses electric potential fluctuations in repeated use. The electrophotographic photosensitive member includes a support, a photosensitive layer and a protective layer, in this order, wherein the photosensitive layer includes a compound having a structure represented by formula (1), and the protective layer includes a resin having a structure represented by formula (2) and a structure represented by formula (3).
    Type: Application
    Filed: February 10, 2020
    Publication date: August 20, 2020
    Inventors: Hideharu Shimozawa, Tsutomu Nishida, Atsushi Okuda, Yuka Ishiduka, Kenichi Kaku, Nobuhiro Nakamura, Hiroyuki Watanabe
  • Patent number: 10747131
    Abstract: To provide an electrophotographic photosensitive member which does not cause film exfoliation in long-term use. An electrophotographic photosensitive member, having: a support; a layered photosensitive layer; and a protective layer in this order, wherein the protective layer is a single layer, the protective layer includes: at least two specific structures, the two specific structures are included in the protective layer at a mass ratio of 20% or more and 240% or less, and a peak area based on in-plane deformation vibration of terminal olefin (CH2?) of the protective layer and a peak area based on stretching vibration of C?O of acryloyloxy groups, the peak areas being determined by total reflection Fourier transform infrared spectroscopy under conditions where an internal reflection element is Ge, and an incidence angle is 45°, have a fixed relationship.
    Type: Grant
    Filed: May 28, 2019
    Date of Patent: August 18, 2020
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Hiroyuki Watanabe, Tsutomu Nishida, Yuka Ishiduka, Atsushi Okuda, Hideharu Shimozawa, Nobuhiro Nakamura, Daisuke Miura
  • Patent number: 10747130
    Abstract: Provided is a process cartridge including: an electrophotographic photoreceptor; a charging unit configured to charge the electrophotographic photoreceptor through abutment against the electrophotographic photoreceptor; a developing unit configured to develop an electrostatic latent image formed on the electrophotographic photoreceptor with a toner to form a toner image; and a cleaning unit configured to remove the toner on the electrophotographic photoreceptor by bringing a blade into abutment against the electrophotographic photoreceptor, wherein the toner includes a toner base containing a coloring agent and a binder resin, and has a surface layer containing an organosilicon polymer having a specific sticking ratio to a toner base, and wherein the electrophotographic photoreceptor includes a supporting member and a surface layer, and the surface layer has a specific universal hardness value and a specific elastic deformation ratio (We).
    Type: Grant
    Filed: May 28, 2019
    Date of Patent: August 18, 2020
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Atsushi Okuda, Tsutomu Nishida, Yuka Ishiduka, Nobuhiro Nakamura, Hiroyuki Watanabe, Hideharu Shimozawa, Satoshi Otsuji, Kentaro Yamawaki, Daisuke Miura
  • Patent number: 10691033
    Abstract: The present invention provides an electrophotographic photosensitive member sequentially including: a support; a photosensitive layer; and a protection layer formed on the support, wherein the protection layer has a triarylamine structure and a specific cyclic structure, and a specific A-value obtained by measurement using total reflection Fourier transform infrared spectroscopy is 0.010 or more and 0.050 or less.
    Type: Grant
    Filed: February 27, 2019
    Date of Patent: June 23, 2020
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Tsutomu Nishida, Atsushi Okuda, Yuka Ishiduka, Nobuhiro Nakamura, Hiroyuki Watanabe, Hideharu Shimozawa