Patents by Inventor Hiroshi Mayuzumi

Hiroshi Mayuzumi 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: 10078286
    Abstract: A charging member which has high charging ability and prevents generation of abnormal discharge is provided. The charging member includes a support and a surface layer. The surface layer contains a polymetalloxane having a specific structure.
    Type: Grant
    Filed: April 5, 2016
    Date of Patent: September 18, 2018
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Kineo Takeno, Hiroshi Mayuzumi, Masataka Kodama, Noriyuki Doi, Kenichi Yamauchi, Noriko Suzumura, Hiroki Masu
  • Patent number: 10036971
    Abstract: Provided is a charging member that suppresses the occurrence of abnormal discharge under low temperature and low humidity. The charging member includes a support and a surface layer on the support, and the surface layer contains a compound represented by the following formula (a), (b), (c), or (d).
    Type: Grant
    Filed: May 26, 2015
    Date of Patent: July 31, 2018
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Noriyuki Doi, Kineo Takeno, Noriko Suzumura, Hiroshi Mayuzumi, Masataka Kodama, Kenichi Yamauchi, Hiroki Masu
  • Publication number: 20160299450
    Abstract: A charging member which has high charging ability and prevents generation of abnormal discharge is provided. The charging member includes a support and a surface layer. The surface layer contains a polymetalloxane having a specific structure.
    Type: Application
    Filed: April 5, 2016
    Publication date: October 13, 2016
    Inventors: Kineo Takeno, Hiroshi Mayuzumi, Masataka Kodama, Noriyuki Doi, Kenichi Yamauchi, Noriko Suzumura, Hiroki Masu
  • Publication number: 20150331348
    Abstract: Provided is a charging member that suppresses the occurrence of abnormal discharge under low temperature and low humidity. The charging member includes a support and a surface layer on the support, and the surface layer contains a compound represented by the following formula (a), (b), (c), or (d).
    Type: Application
    Filed: May 26, 2015
    Publication date: November 19, 2015
    Inventors: Noriyuki Doi, Kineo Takeno, Noriko Suzumura, Hiroshi Mayuzumi, Masataka Kodama, Kenichi Yamauchi, Hiroki Masu
  • Patent number: 8971766
    Abstract: The present invention provides an electrophotographic member capable of more definitely suppressing occurrence of a C set image. The electrophotographic member has a surface layer including a modified polysiloxane having a structure represented by the following formula (1). In the formula (1), G represents a bivalent group having an ethylene oxide chain represented by (—O—C2H4—) and L represents polysiloxane having at least a SiO4/2(Q) unit or a SiO3/2(T) unit.
    Type: Grant
    Filed: June 4, 2013
    Date of Patent: March 3, 2015
    Assignee: Canon Kabushiki Kaisha
    Inventors: Tomohito Taniguchi, Hiroshi Mayuzumi, Yusuke Yagisawa
  • Publication number: 20130266338
    Abstract: The present invention provides an electrophotographic member capable of more definitely suppressing occurrence of a C set image. The electrophotographic member has a surface layer including a modified polysiloxane having a structure represented by the following formula (1). In the formula (1), G represents a bivalent group having an ethylene oxide chain represented by (—O—C2H4—) and L represents polysiloxane having at least a SiO4/2(Q) unit or a SiO3/2(T) unit.
    Type: Application
    Filed: June 4, 2013
    Publication date: October 10, 2013
    Inventors: Tomohito Taniguchi, Hiroshi Mayuzumi, Yusuke Yagisawa
  • Patent number: 8383234
    Abstract: Provided is the following charging member of an electrophotographic apparatus. The charging member suppresses the occurrence of each of a streak-like image, a spot-like image, and a rough image that occur when image formation is performed over a long time period. Also provided are a process cartridge and an electrophotographic apparatus each having the charging member. A compound having a siloxane dendrimer structure at a vinyl group or a side chain of a vinyl polymer is incorporated into the surface layer of the charging member comprising a conductive substrate and the surface layer.
    Type: Grant
    Filed: February 13, 2012
    Date of Patent: February 26, 2013
    Assignee: Canon Kabushiki Kaisha
    Inventors: Hiroshi Mayuzumi, Tomohito Taniguchi, Hidekazu Matsuda, Nozomu Takahata, Yusuke Yagisawa, Satoshi Koide, Masataka Kodama
  • Patent number: 8277947
    Abstract: A charging member is provided having a support, a conductive elastic layer formed on the support and a surface layer formed on the conductive elastic layer. The surface layer contains a polysiloxane having at least one of structures represented by the following formulas (1a1), (1a2), (1b1) and (1b2): Toners and external additives used in the toners clinging to the charging member surface can be minimized even through repeated use over a long period of time, thus the charging member can perform stable charging and image reproduction even when used in the DC contact charging method.
    Type: Grant
    Filed: February 23, 2007
    Date of Patent: October 2, 2012
    Assignee: Canon Kabushiki Kaisha
    Inventors: Hiroshi Mayuzumi, Noriaki Kuroda
  • Patent number: 8227087
    Abstract: A charging member is provided having a support, a conductive elastic layer formed on the support and a surface layer formed on the conductive elastic layer. The surface layer contains a polysiloxane having at least one of structures represented by the following formulas (1a1), (1a2), (1b1) and (1b2): Toners and external additives used in the toners clinging to the charging member surface can be minimized even through repeated use over a long period of time, thus the charging member can perform stable charging and image reproduction even when used in the DC contact charging method.
    Type: Grant
    Filed: December 1, 2011
    Date of Patent: July 24, 2012
    Assignee: Canon Kabushiki Kaisha
    Inventors: Hiroshi Mayuzumi, Noriaki Kuroda
  • Publication number: 20120141162
    Abstract: Provided is the following charging member of an electrophotographic apparatus. The charging member suppresses the occurrence of each of a streak-like image, a spot-like image, and a rough image that occur when image formation is performed over a long time period. Also provided are a process cartridge and an electrophotographic apparatus each having the charging member. A compound having a siloxane dendrimer structure at a vinyl group or a side chain of a vinyl polymer is incorporated into the surface layer of the charging member comprising a conductive substrate and the surface layer.
    Type: Application
    Filed: February 13, 2012
    Publication date: June 7, 2012
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Hiroshi Mayuzumi, Tomohito Taniguchi, Hidekazu Matsuda, Nozomu Takahata, Yusuke Yagisawa, Satoshi Koide, Masataka Kodama
  • Publication number: 20120076924
    Abstract: A charging member is provided having a support, a conductive elastic layer formed on the support and a surface layer formed on the conductive elastic layer. The surface layer contains a polysiloxane having at least one of structures represented by the following formulas (1a1), (1a2), (1b1) and (1b2): Toners and external additives used in the toners clinging to the charging member surface can be minimized even through repeated use over a long period of time, thus the charging member can perform stable charging and image reproduction even when used in the DC contact charging method.
    Type: Application
    Filed: December 1, 2011
    Publication date: March 29, 2012
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Hiroshi Mayuzumi, Noriaki Kuroda
  • Publication number: 20110044725
    Abstract: A charging member is provided which can inhibit defective images due to poor charging and adhering substances from occurring even after being repeatedly used for a long time, and can inhibit deformation and defective images due to the C set, caused by a change in rotational speed accompanying such deformation even after being left standing in a stopping state for a long time. The charging member includes a conductive support and a surface layer. The surface layer includes a binder and resin particles dispersed in the binder, each resin particle having a depressed portion on its surface. Protrusions resulting from the resin particles are formed on the surface of the surface layer. The protrusions each have a depressed portion resulting from the depressed portion of the resin particle, and the surface of the resin particle is covered with the binder.
    Type: Application
    Filed: November 3, 2010
    Publication date: February 24, 2011
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Hiroshi Mayuzumi, Tomohito Taniguchi
  • Patent number: 7869741
    Abstract: A charging member is provided which can inhibit defective images due to poor charging and adhering substances from occurring even after being repeatedly used for a long time, and can inhibit deformation and defective images due to the C set, caused by a change in rotational speed accompanying such deformation even after being left standing in a stopping state for a long time. The charging member includes a conductive support and a surface layer. The surface layer includes a binder and resin particles dispersed in the binder, each resin particle having a depressed portion on its surface. Protrusions resulting from the resin particles are formed on the surface of the surface layer. The protrusions each have a depressed portion resulting from the depressed portion of the resin particle, and the surface of the resin particle is covered with the binder.
    Type: Grant
    Filed: February 3, 2010
    Date of Patent: January 11, 2011
    Assignee: Canon Kabushiki Kaisha
    Inventors: Hiroshi Mayuzumi, Tomohito Taniguchi
  • Publication number: 20100226684
    Abstract: A charging member is provided having a support, a conductive elastic layer formed on the support and a surface layer formed on the conductive elastic layer. The surface layer contains a polysiloxane having at least one of structures represented by the following formulas (1a1), (1a2), (1b1) and (1b2): Toners and external additives used in the toners clinging to the charging member surface can be minimized even through repeated use over a long period of time, thus the charging member can perform stable charging and image reproduction even when used in the DC contact charging method.
    Type: Application
    Filed: February 23, 2007
    Publication date: September 9, 2010
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Hiroshi Mayuzumi, Noriaki Kuroda
  • Publication number: 20100135695
    Abstract: A charging member is provided which can inhibit defective images due to poor charging and adhering substances from occurring even after being repeatedly used for a long time, and can inhibit deformation and defective images due to the C set, caused by a change in rotational speed accompanying such deformation even after being left standing in a stopping state for a long time. The charging member includes a conductive support and a surface layer. The surface layer includes a binder and resin particles dispersed in the binder, each resin particle having a depressed portion on its surface. Protrusions resulting from the resin particles are formed on the surface of the surface layer. The protrusions each have a depressed portion resulting from the depressed portion of the resin particle, and the surface of the resin particle is covered with the binder.
    Type: Application
    Filed: February 3, 2010
    Publication date: June 3, 2010
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Hiroshi Mayuzumi, Tomohito Taniguchi
  • Patent number: 6023597
    Abstract: A cellular conductive roller has closed cells and open cells with conductive powder filling the open cells of the cellular conductive roller. A method for making a cellular conductive roller includes filling the open cells in the cellular conductive roller with conductive powder, adhering a tacky sheet to the surface of said cellular conductive roller; then peeling said tacky sheet off the surface of said cellular conductive roller. Also disclosed is an electrophotographic device using the cellular conductive roller and a process cartridge into which the cellular conductive roller is integrated.
    Type: Grant
    Filed: May 29, 1996
    Date of Patent: February 8, 2000
    Assignee: Canon Kabushiki Kaisha
    Inventors: Hiroshi Mayuzumi, Yoshiaki Nishimura, Jun Murata, Nobutoshi Hayashi, Akiya Kume, Yukinori Nagata
  • Patent number: 6001454
    Abstract: A charging member supplied with a voltage to charge a charge-receiving member such as an electrophotographic photosensitive member has an elastic layer of an ethylene-propylene copolymer containing a diene component. The ethylene-propylene copolymer has an iodine value of 23-32. The charging member is improved in resistance to permanent deformation while providing excellent images for a long period.
    Type: Grant
    Filed: August 1, 1997
    Date of Patent: December 14, 1999
    Assignee: Canon Kabushiki Kaisha
    Inventors: Jun Murata, Yoshiaki Nishimura, Hiroshi Mayuzumi
  • Patent number: 5824408
    Abstract: A white electroconductive coating composition includes a white pigment having a whiteness of at least 60, a white conductive material having a whiteness of at least 50 and a volume resistivity of at most 1.times.10.sup.10 ohm.cm. The coating composition is suitable to provide a a coating film showing a whiteness of at least 60 and a surface resistivity of at most 1.times.10.sup.11 ohm/cm.sup.2. Such a white conductive layer may be formed on a back side of a surface insulating film of a transfer material carrying member of an electrophotographic image forming apparatus to provide a reference white pattern for detecting a density of a toner image formed on the carrying member, thereby allowing controlled image formation based on the detected density data.
    Type: Grant
    Filed: April 26, 1996
    Date of Patent: October 20, 1998
    Assignee: Canon Kabushiki Kaisha
    Inventors: Akiya Kume, Yoshiaki Nishimura, Jun Murata, Nobutoshi Hayashi, Yukinori Nagata, Hiroshi Mayuzumi
  • Patent number: 5819142
    Abstract: The present invention pertains to a charging member which is energized to charge a chargeable member by contact-electrification and which comprises a conductive elastic layer having a surface layer containing a polymer having a main chain containing a structural unit of the following formula:--O--(CH.sub.2).sub.n --O--CO--wherein n is an integer of from 4 to 10.With stable charging properties, the charging member of the present invention has relatively uniform surface resistance, little dependency on the environmental conditions, and decreased contamination of photosensitive bodies and the like.
    Type: Grant
    Filed: May 13, 1997
    Date of Patent: October 6, 1998
    Assignee: Canon Kaubshiki Kaisha
    Inventors: Jun Murata, Yoshiaki Nishimura, Akiya Kume, Hiroshi Mayuzumi