Patents by Inventor Shuhei Tokiwa

Shuhei Tokiwa 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: 9405217
    Abstract: Provided is a developer carrying member which depends on a sheet-passing speed to a small extent while maintaining satisfactory developability, and can stably suppress a fogging amount with time. The developer carrying member includes: an electro-conductive mandrel; and an electro-conductive elastic layer, in which: the elastic layer contains a resin j, an electro-semiconductive particle p, and an electro-conductive particle c; and when an electroconductivity of the resin j is defined as ?j, a dielectric constant of the resin j is defined as ?j, an electroconductivity of the electro-semiconductive particle p is defined as ?p and a dielectric constant of the electro-semiconductive particle p is defined as ?p, ?j, ?j, ?p, and ?p satisfy relationships represented by the following formulae (1) and (2), ?j, ?j, ?p and ?p being calculated by an AC impedance method. ?j<?p<0.
    Type: Grant
    Filed: October 13, 2015
    Date of Patent: August 2, 2016
    Assignee: Canon Kabushiki Kaisha
    Inventors: Shuhei Tokiwa, Kazunari Hagiwara, Tatsuaki Orihara, Makoto Fukatsu, Atsushi Nakamoto
  • Publication number: 20160109824
    Abstract: A developing device includes: a developing container, a developer carrying member, and a plate-like elastic member. An angle formed between a reference surface passing through a surface of the elastic member continuous to a contact portion of the elastic member with the developer carrying member and downstream of the contact portion with respect to the movement direction of the developer carrying member and a tangent plane of the developer carrying member under no load at a contact position between the elastic member and the developer carrying member is 10° or more and 45° or less. The elastic member includes a first region including the contact portion and a second region provided continuously from the first region toward the supporting portion of the elastic member and lower in rigidity than the first region. The second region is provided downstream of the reference surface with respect to the movement direction.
    Type: Application
    Filed: October 14, 2015
    Publication date: April 21, 2016
    Inventors: Takahiro Kawamoto, Kazuhisa Kemmochi, Masayoshi Kato, Makoto Fukatsu, Atsushi Nakamoto, Kazunari Hagiwara, Yasunori Chigono, Shuhei Tokiwa, Takeshi Yamamoto
  • Patent number: 9298128
    Abstract: In an image forming apparatus having a photosensitive drum that carries a toner image, a developing roller is provided to be capable of rotating while carrying toner and supplies the toner to the photosensitive drum in order to develop a latent image, and a voltage applying device applies a voltage to the developing roller. The developing roller includes a conductive base layer and a surface layer covering the base layer, and a surface charge density of the developing roller is equal to or smaller than a surface charge density of the toner.
    Type: Grant
    Filed: November 5, 2014
    Date of Patent: March 29, 2016
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Tatsuaki Orihara, Shuhei Tokiwa, Kazunari Hagiwara, Manami Haraguchi, Makoto Fukatsu, Atsushi Nakamoto
  • Patent number: 9261814
    Abstract: A developing roller that is capable of carrying toner on a surface thereof, and that supplies the toner carried on the surface to a surface of a photosensitive drum when a voltage is applied thereto, includes: an elastic layer; and a surface layer that covers the elastic layer and contains aluminum oxide, wherein the aluminum oxide of the surface layer contains tetracoordinated aluminum atoms and hexacoordinated aluminum atoms existing in a higher proportion than the tetracoordinated aluminum atoms.
    Type: Grant
    Filed: November 4, 2014
    Date of Patent: February 16, 2016
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Kazunari Hagiwara, Tatsuaki Orihara, Shuhei Tokiwa, Yasuyuki Matsumoto, Manami Haraguchi, Atsushi Nakamoto, Yasuhiro Horiguchi
  • Patent number: 9261811
    Abstract: A developing roller that is capable of carrying toner on a surface thereof, and that supplies the toner carried on the surface to a surface of a photosensitive drum when a voltage is applied thereto, includes: a rubber layer; and a surface layer that covers the rubber layer, contains alumina, and has a higher volume resistivity than the rubber layer.
    Type: Grant
    Filed: November 4, 2014
    Date of Patent: February 16, 2016
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Kazunari Hagiwara, Tatsuaki Orihara, Shuhei Tokiwa, Yasuyuki Matsumoto, Naoki Fuei, Makoto Fukatsu, Yoshikuni Ito
  • Publication number: 20160033894
    Abstract: Provided is a developer carrying member which depends on a sheet-passing speed to a small extent while maintaining satisfactory developability, and can stably suppress a fogging amount with time. The developer carrying member includes: an electro-conductive mandrel; and an electro-conductive elastic layer, in which: the elastic layer contains a resin j, an electro-semiconductive particle p, and an electro-conductive particle c; and when an electroconductivity of the resin j is defined as ?j, a dielectric constant of the resin j is defined as ?j, an electroconductivity of the electro-semiconductive particle p is defined as ?p and a dielectric constant of the electro-semiconductive particle p is defined as ?p, ?j, ?j, ?p, and ?p satisfy relationships represented by the following formulae (1) and (2), ?j, ?j, ?p and ?p being calculated by an AC impedance method. ?j<?p<0.
    Type: Application
    Filed: October 13, 2015
    Publication date: February 4, 2016
    Inventors: Shuhei Tokiwa, Kazunari Hagiwara, Tatsuaki Orihara, Makoto Fukatsu, Atsushi Nakamoto
  • Publication number: 20150378271
    Abstract: Provided is a toner, including a toner particle having a core particle containing a binder resin and a colorant. The toner particle has a protrusion on a surface thereof, and the protrusion contains an olefin-based polymer having a cyclic olefin structure. When an average radius of curvature of the protrusion, an average particle diameter of the core particle, a projected area of the toner particle, and a projected area of the protrusion that are calculated from a planar projected image of an image of the toner particle photographed with a scanning electron microscope are represented by Rs (?m), Rc (?m), S, and S1, respectively, the average radius of curvature Rs of the protrusion is 0.004Rc ?m or more and 0.100Rc ?m or less, and an average of a surface coverage “100×S1/S” % is 5% or more and 90% or less.
    Type: Application
    Filed: June 12, 2015
    Publication date: December 31, 2015
    Inventors: Makoto Fukatsu, Manami Haraguchi, Atsushi Nakamoto, Kazunari Hagiwara, Tatsuaki Orihara, Shuhei Tokiwa
  • Patent number: 9134649
    Abstract: In an image forming apparatus having a photosensitive drum capable of carrying a toner image, a developing roller that is provided to be capable of rotating while carrying toner, and that supplies the toner to the photosensitive drum by contacting the photosensitive drum, a regulating blade that regulates a layer thickness of the toner carried on the developing roller, and a voltage applying device for applying a voltage to the developing roller and the regulating blade. The developing roller includes a conductive base layer and a surface layer covering the base layer, and a surface charge density of the developing roller is equal to or smaller than a surface charge density of the toner.
    Type: Grant
    Filed: November 5, 2014
    Date of Patent: September 15, 2015
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Tatsuaki Orihara, Shuhei Tokiwa, Kazunari Hagiwara, Manami Haraguchi, Makoto Fukatsu, Atsushi Nakamoto
  • Publication number: 20150132030
    Abstract: In an image forming apparatus having a photosensitive drum that carries a toner image, a developing roller that is provided to be capable of rotating while carrying toner, and that supplies the toner to the photosensitive drum in order to develop a latent image, and voltage applying device for applying a voltage to the developing roller, the developing roller includes a conductive base layer and a surface layer covering the base layer, and a surface charge density of the developing roller is equal to or smaller than a surface charge density of the toner.
    Type: Application
    Filed: November 5, 2014
    Publication date: May 14, 2015
    Inventors: Tatsuaki Orihara, Shuhei Tokiwa, Kazunari Hagiwara, Manami Haraguchi, Makoto Fukatsu, Atsushi Nakamoto
  • Publication number: 20150132032
    Abstract: A developing roller that is capable of carrying toner on a surface thereof, and that supplies the toner carried on the surface to a surface of a photosensitive drum when a voltage is applied thereto, includes: an elastic layer; and a surface layer that covers the elastic layer and contains aluminum oxide, wherein the aluminum oxide of the surface layer contains tetracoordinated aluminum atoms and hexacoordinated aluminum atoms existing in a higher proportion than the tetracoordinated aluminum atoms.
    Type: Application
    Filed: November 4, 2014
    Publication date: May 14, 2015
    Inventors: Kazunari Hagiwara, Tatsuaki Orihara, Shuhei Tokiwa, Yasuyuki Matsumoto, Manami Haraguchi, Atsushi Nakamoto, Yasuhiro Horiguchi
  • Publication number: 20150132028
    Abstract: In an image forming apparatus having a photosensitive drum capable of carrying a toner image, a developing roller that is provided to be capable of rotating while carrying toner, and that supplies the toner to the photosensitive drum by contacting the photosensitive drum, a regulating blade that regulates a layer thickness of the toner carried on the developing roller, and voltage applying device for applying a voltage to the developing roller and the regulating blade, the developing roller includes a conductive base layer and a surface layer covering the base layer, and a surface charge density of the developing roller is equal to or smaller than a surface charge density of the toner.
    Type: Application
    Filed: November 5, 2014
    Publication date: May 14, 2015
    Inventors: Tatsuaki Orihara, Shuhei Tokiwa, Kazunari Hagiwara, Manami Haraguchi, Makoto Fukatsu, Atsushi Nakamoto
  • Publication number: 20150132031
    Abstract: A developing roller that is capable of carrying toner on a surface thereof, and that supplies the toner carried on the surface to a surface of a photosensitive drum when a voltage is applied thereto, includes: a rubber layer; and a surface layer that covers the rubber layer, contains alumina, and has a higher volume resistivity than the rubber layer.
    Type: Application
    Filed: November 4, 2014
    Publication date: May 14, 2015
    Inventors: Kazunari Hagiwara, Tatsuaki Orihara, Shuhei Tokiwa, Yasuyuki Matsumoto, Naoki Fuei, Makoto Fukatsu, Yoshikuni Ito