Patents by Inventor Kazunari Hagiwara

Kazunari Hagiwara 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: 10452021
    Abstract: A process cartridge configured to be detachably attachable to a main body of an electrophotographic image forming apparatus, in which an occurrence of an image failure is suppressed, wherein the process cartridge includes an electrophotographic photosensitive member and a cleaning member arranged in contact with the electrophotographic photosensitive member, wherein an elastic deformation modulus of a surface layer of the electrophotographic photosensitive member is 35% or larger, and the cleaning member is formed of a urethane foam, wherein a density of the urethane foam is 200 to 500 kg/cm3, and a 25% compressive load of the urethane foam is 0.3 MPa or smaller.
    Type: Grant
    Filed: November 21, 2018
    Date of Patent: October 22, 2019
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Daisuke Miura, Shuhei Iwasaki, Akira Sakakibara, Tatsuya Yamaai, Kazunori Noguchi, Harunobu Ogaki, Kazunari Hagiwara, Yuji Kawaguchi
  • Patent number: 10444660
    Abstract: A developing apparatus includes a developer carrying member, a developer container, and a regulating member to regulate the thickness of the developer. The regulating member includes a support member having one end fixed to the developer container and the other end free, with the support member extending in a direction opposite to the rotating direction of the developer carrying member, and a contact member to be fixed to the other end of the support member and to contact the developer carrying member. The contact member includes a contact curved surface along a peripheral surface of the developer carrying member, and an opposite surface to face the developer carrying member. The contact pressure of the contact curved surface applied to the developer carrying member decreases as a location on the developer carrying member approaches a downstream side in the rotating direction.
    Type: Grant
    Filed: October 10, 2018
    Date of Patent: October 15, 2019
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Kazunari Hagiwara, Takaaki Shinkawa, Koji An, Takashi Mukai, Takuya Kitamura
  • Patent number: 10437171
    Abstract: A regulating portion includes a first contact portion, a second contact portion, opposed surface portion, and a second opposed surface portion. When, in a plane orthogonal to the rotation axis direction of a developer bearing member, the fixed end and the free end of a supporting member are connected by an imaginary straight line, a contact position where the first contact portion contacts the developer bearing member is located on the downstream side, in the rotation direction of the developer bearing member, of a point of contact of a tangent line parallel to the imaginary straight line with the outer periphery of the developer bearing member.
    Type: Grant
    Filed: September 25, 2018
    Date of Patent: October 8, 2019
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Koji An, Kazunari Hagiwara, Takaaki Shinkawa, Takashi Mukai, Takuya Kitamura
  • Publication number: 20190278198
    Abstract: When a new development device is mounted, a control unit of an image forming apparatus identifies a development device type. When an identification result corresponds to a first development device containing a first amount of developer, an agitation member operates in a first mode. When the identification result corresponds to a second development device containing a second amount of developer higher than the first amount, the agitation member operates in a second mode. A second operation amount of the agitation member in the second mode is higher than a first operation amount of the agitation member in the first mode. A developer containing chamber of the development device is provided with a discharge opening from which the developer is discharged. The operations in the first and second modes are performed after a sealing member sealing the discharge opening is removed and also before a normal image forming process is executed.
    Type: Application
    Filed: March 7, 2019
    Publication date: September 12, 2019
    Inventors: Jun Miura, Takuya Kitamura, Kazunari Hagiwara, Takashi Hiramatsu, Koji An
  • Patent number: 10394162
    Abstract: A relation between a first thickness of a resin layer in an upstream portion of a contact nip in which the resin layer that covers a supporting member of a regulating blade makes contact with a developing roller and a second thickness of the resin layer in a downstream portion of the contact nip is set such that the second thickness is smaller than the first thickness. A potential difference having the same polarity as a toner charging polarity toward the supporting member is created between the supporting member and the developing roller.
    Type: Grant
    Filed: October 5, 2018
    Date of Patent: August 27, 2019
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Takashi Mukai, Kazunari Hagiwara, Koji An, Takaaki Shinkawa, Takuya Kitamura
  • Publication number: 20190163120
    Abstract: A process cartridge configured to be detachably attachable to a main body of an electrophotographic image forming apparatus, in which an occurrence of an image failure is suppressed, wherein the process cartridge includes an electrophotographic photosensitive member and a cleaning member arranged in contact with the electrophotographic photosensitive member, wherein an elastic deformation modulus of a surface layer of the electrophotographic photosensitive member is 35% or larger, and the cleaning member is formed of a urethane foam, wherein a density of the urethane foam is 200 to 500 kg/cm3, and a 25% compressive load of the urethane foam is 0.3 MPa or smaller.
    Type: Application
    Filed: November 21, 2018
    Publication date: May 30, 2019
    Inventors: Daisuke Miura, Shuhei Iwasaki, Akira Sakakibara, Tatsuya Yamaai, Kazunori Noguchi, Harunobu Ogaki, Kazunari Hagiwara, Yuji Kawaguchi
  • Publication number: 20190113861
    Abstract: A relation between a first thickness of a resin layer in an upstream portion of a contact nip in which the resin layer that covers a supporting member of a regulating blade makes contact with a developing roller and a second thickness of the resin layer in a downstream portion of the contact nip is set such that the second thickness is smaller than the first thickness. A potential difference having the same polarity as a toner charging polarity toward the supporting member is created between the supporting member and the developing roller.
    Type: Application
    Filed: October 5, 2018
    Publication date: April 18, 2019
    Inventors: Takashi Mukai, Kazunari Hagiwara, Koji An, Takaaki Shinkawa, Takuya Kitamura
  • Publication number: 20190113862
    Abstract: Provided is a developing apparatus including a developer carrying member, a developer container, and a regulating member to regulate the thickness of the developer. The regulating member includes a support member such that one end is fixed to the developer container, the other end is a free end, and the support member extends in a direction opposite to the rotating direction of the developer carrying member, and a contact member to be fixed to the other end of the support member and to contact the developer carrying member. The contact member includes a contact curved surface along a peripheral surface of the developer carrying member, and an opposite surface to face the developer carrying member. The contact pressure of the contact curved surface applied to the developer carrying member decreases as a location on the developer carrying member approaches downstream side in the rotating direction.
    Type: Application
    Filed: October 10, 2018
    Publication date: April 18, 2019
    Inventors: Kazunari Hagiwara, Takaaki Shinkawa, Koji An, Takashi Mukai, Takuya Kitamura
  • Publication number: 20190101847
    Abstract: A regulating portion includes a first contact portion, a second contact portion, opposed surface portion, and a second opposed surface portion. When, in a plane orthogonal to the rotation axis direction of a developer bearing member, the fixed end and the free end of a supporting member are connected by an imaginary straight line, a contact position where the first contact portion contacts the developer bearing member is located on the downstream side, in the rotation direction of the developer bearing member, of a point of contact of a tangent line parallel to the imaginary straight line with the outer periphery of the developer bearing member.
    Type: Application
    Filed: September 25, 2018
    Publication date: April 4, 2019
    Inventors: Koji An, Kazunari Hagiwara, Takaaki Shinkawa, Takashi Mukai, Takuya Kitamura
  • Patent number: 9594320
    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: Grant
    Filed: June 12, 2015
    Date of Patent: March 14, 2017
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Makoto Fukatsu, Manami Haraguchi, Atsushi Nakamoto, Kazunari Hagiwara, Tatsuaki Orihara, Shuhei Tokiwa
  • Patent number: 9501000
    Abstract: The present invention relates to an image forming apparatus that forms an image by consecutively superposing toner images that have been formed on a plurality of photosensitive drums, on an intermediate transfer member or a transfer medium. The image forming apparatus is made compact and operates at a low cost. Since a current supply member supplies a current in a rotational direction of an intermediate transfer belt, multiple first transfer portions do not need corresponding voltage sources. Even in the case where a charging member supplies a current, the potential of the intermediate transfer belt is maintained at a predetermined potential by a constant-voltage element connected to support rollers.
    Type: Grant
    Filed: November 13, 2015
    Date of Patent: November 22, 2016
    Assignee: Canon Kabushiki Kaisha
    Inventors: Kenji Karashima, Satoshi Tsuruya, Yoshikuni Ito, Yasuhiro Horiguchi, Takeshi Fujino, Takahiro Kawamoto, Takayuki Tanaka, Osamu Iwasaki, Kazunari Hagiwara
  • Patent number: 9442418
    Abstract: A developing device includes: a developing container for accommodating developer, a developer carrying member, and a plate-like elastic member. In a state in which the elastic member contacts the developer carrying member without being deformed, an angle formed between a flat reference surface passing through a surface of the elastic member which is continuous to a contact portion of the elastic member with the developer carrying member and which is downstream of the contact portion with respect to the movement direction and a tangent plane of the developer carrying member and a contact position between the elastic member and the developer carrying member is 10° or more and 45° or less, and the elastic member includes a first region including the contact portion and a second region which is provided continuously from the first region toward the supporting portion and which is lower in rigidity than the first region.
    Type: Grant
    Filed: October 14, 2015
    Date of Patent: September 13, 2016
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Takahiro Kawamoto, Kazuhisa Kemmochi, Masayoshi Kato, Makoto Fukatsu, Atsushi Nakamoto, Kazunari Hagiwara, Yasunori Chigono, Shuhei Tokiwa, Takeshi Yamamoto
  • 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
  • Publication number: 20160070194
    Abstract: The present invention relates to an image forming apparatus that forms an image by consecutively superposing toner images that have been formed on a plurality of photosensitive drums, on an intermediate transfer member or a transfer medium. The image forming apparatus is made compact and operates at a low cost. Since a current supply member supplies a current in a rotational direction of an intermediate transfer belt, multiple first transfer portions do not need corresponding voltage sources. Even in the case where a charging member supplies a current, the potential of the intermediate transfer belt is maintained at a predetermined potential by a constant-voltage element connected to support rollers.
    Type: Application
    Filed: November 13, 2015
    Publication date: March 10, 2016
    Inventors: Kenji Karashima, Satoshi Tsuruya, Yoshikuni Ito, Yasuhiro Horiguchi, Takeshi Fujino, Takahiro Kawamoto, Takayuki Tanaka, Osamu Iwasaki, Kazunari Hagiwara
  • 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
  • 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
  • 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