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: 9217962
    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: December 9, 2011
    Date of Patent: December 22, 2015
    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: 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: 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: 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: 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
  • 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: 20140321891
    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: December 9, 2011
    Publication date: October 30, 2014
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Kenji Karashima, Satoshi Tsuruya, Yoshikuni Ito, Yasuhiro Horiguchi, Takeshi Fujino, Takahiro Kawamoto, Takayuki Tanaka, Osamu Iwasaki, Kazunari Hagiwara
  • Patent number: 8489011
    Abstract: An image forming apparatus includes a developer bearing member configured to bear a developer to develop a latent image, a developer regulating member configured to regulate an amount of the developer carried on the bearing member, a voltage application unit that can apply a plurality of direct current voltages of different values between the bearing member and the regulating member, and a current detection unit that can detect a plurality of direct currents of different values flowing in the regulating member when the voltage application unit applies the plurality of direct current voltages, wherein the image forming apparatus sets a direct current voltage value Vb applied by the voltage application unit when developing the latent image, so that the following expression is satisfied: |Vb|>|Vbmin|, where Vbmin indicates a direct current voltage value when the direct current detected by the current detection unit is a minimum value.
    Type: Grant
    Filed: December 12, 2012
    Date of Patent: July 16, 2013
    Assignee: Canon Kabushiki Kaisha
    Inventors: Kazunari Hagiwara, Norio Takahashi, Katsuhiro Sakaizawa, Rie Endo
  • Patent number: 8437678
    Abstract: An image forming apparatus includes a developer bearing member configured to bear a developer to develop a latent image, a developer regulating member configured to regulate an amount of the developer carried on the bearing member, a voltage application unit that can apply a plurality of direct current voltages of different values between the bearing member and the regulating member, and a current detection unit that can detect a plurality of direct currents of different values flowing in the regulating member when the voltage application unit applies the plurality of direct current voltages, wherein the image forming apparatus sets a direct current voltage value Vb applied by the voltage application unit when developing the latent image, so that the following expression is satisfied: |Vb|>|Vbmin|, where Vbmin indicates a direct current voltage value when the direct current detected by the current detection unit is a minimum value.
    Type: Grant
    Filed: September 2, 2009
    Date of Patent: May 7, 2013
    Assignee: Canon Kabushiki Kaisha
    Inventors: Kazunari Hagiwara, Norio Takahashi, Katsuhiro Sakaizawa, Rie Endo
  • Patent number: 8019258
    Abstract: An amount-of-developer regulating apparatus configured to restrict the amount of developer carried on a developer bearing member. The amount-of-developer regulating apparatus includes a flexible developer amount regulation member having a contact portion configured to contact with a developer bearing member, and first and second holding portions configured to hold the developer amount regulation member and to contact with the developer amount regulation member at further upstream and further downstream in a direction where the developer bearing member is rotationally moved than the contact portion. With a pressure distribution of the contact portion as to the developer bearing member, there are a plurality of local maximum values in the direction where the developer bearing member is rotationally moved. Thus, the apparatus can be reduced in size, and also image concentration unevenness after long-term use can be prevented.
    Type: Grant
    Filed: October 13, 2010
    Date of Patent: September 13, 2011
    Assignee: Canon Kabushiki Kaisha
    Inventors: Shinichi Nishida, Katsunori Yokoyama, Yasushi Shimizu, Kazunari Hagiwara, Katsuhiro Sakaizawa, Rie Endo, Naoto Kichijima
  • Publication number: 20110026978
    Abstract: An amount-of-developer regulating apparatus configured to restrict the amount of developer carried on a developer bearing member. The amount-of-developer regulating apparatus includes a flexible developer amount regulation member having a contact portion configured to contact with a developer bearing member, and first and second holding portions configured to hold the developer amount regulation member and to contact with the developer amount regulation member at further upstream and further downstream in a direction where the developer bearing member is rotationally moved than the contact portion. With a pressure distribution of the contact portion as to the developer bearing member, there are a plurality of local maximum values in the direction where the developer bearing member is rotationally moved. Thus, the apparatus can be reduced in size, and also image concentration unevenness after long-term use can be prevented.
    Type: Application
    Filed: October 13, 2010
    Publication date: February 3, 2011
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Shinichi Nishida, Katsunori Yokoyama, Yasushi Shimizu, Kazunari Hagiwara, Katsuhiro Sakaizawa, Rie Endo, Naoto Kichijima
  • Patent number: 7840168
    Abstract: An amount-of-developer regulating apparatus configured to restrict the amount of developer carried on a developer bearing member. The amount-of-developer regulating apparatus includes a flexible developer amount regulation member having a contact portion configured to contact with a developer bearing member, and first and second holding portions configured to hold the developer amount regulation member and to contact with the developer amount regulation member at further upstream and further downstream in a direction where the developer bearing member is rotationally moved than the contact portion. With a pressure distribution of the contact portion as to the developer bearing member, there are a plurality of local maximum values in the direction where the developer bearing member is rotationally moved. Thus, the apparatus can be reduced in size, and also image concentration unevenness after long-term use can be prevented.
    Type: Grant
    Filed: June 21, 2007
    Date of Patent: November 23, 2010
    Assignee: Canon Kabushiki Kaisha
    Inventors: Shinichi Nishida, Katsunori Yokoyama, Yasushi Shimizu, Kazunari Hagiwara, Katsuhiro Sakaizawa, Rie Endo, Naoto Kichijima
  • Patent number: 7773923
    Abstract: A developing apparatus in which a toner has a volume-average particle diameter R that is in a range of 4.0 ?m?R?6.2 ?m, a developing roller has an arithmetic mean roughness Ra (?m) that is not more than 0.10 times the volume-average particle diameter R of the toner, a voltage applied to a supply roller is of negative polarity, that is, a normal charging polarity of the toner, triboelectrification polarity of the supply roller with respect to the toner is negative, that is, of the normal charging polarity of the toner, and an abutment width S in which the developing roller and the supply roller abut each other is in a range of 2.5 mm?S?5.5 mm.
    Type: Grant
    Filed: May 9, 2008
    Date of Patent: August 10, 2010
    Assignee: Canon Kabushiki Kaisha
    Inventors: Kazunari Hagiwara, Katsuhiro Sakaizawa, Norio Takahashi, Rie Endo
  • Publication number: 20100061749
    Abstract: An image forming apparatus includes a developer bearing member configured to bear a developer to develop a latent image, a developer regulating member configured to regulate an amount of the developer carried on the bearing member, a voltage application unit that can apply a plurality of direct current voltages of different values between the bearing member and the regulating member, and a current detection unit that can detect a plurality of direct currents of different values flowing in the regulating member when the voltage application unit applies the plurality of direct current voltages, wherein the image forming apparatus sets a direct current voltage value Vb applied by the voltage application unit when developing the latent image, so that the following expression is satisfied: |Vb|>|Vbmin|, where Vbmin indicates a direct current voltage value when the direct current detected by the current detection unit is a minimum value.
    Type: Application
    Filed: September 2, 2009
    Publication date: March 11, 2010
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Kazunari Hagiwara, Norio Takahashi, Katsuhiro Sakaizawa, Rie Endo
  • Patent number: 7640150
    Abstract: An electrode material for a lithium secondary battery which includes particles each having a central portion and a surface portion covering the surface of the central portion. The central portion occupies 80 to 99% of a distance from a center to an outermost surface of the particle and the surface portion occupies 20 to 1% of the distance. The central portion includes LiM1-aDaO2 (M represents Co or Ni, D represents a transition metal element or Al replacing a part of Co or Ni as M, and M is not the same as D) having an ?-NaFeO2 structure. The surface portion includes LiM1-bEbO2 (M represents Co or Ni, E represents a metal element replacing a part of Co or Ni as M, and M is not the same as E) having an ?-NaFeO2 structure. The content of element E in the central portion satisfies the relation of E/(M+D+E)<0.05 in terms of an atomic ratio, and the content of element D in the surface portion satisfies the relation of D/(M+D+E)<0.05 in terms of an atomic ratio.
    Type: Grant
    Filed: November 26, 2008
    Date of Patent: December 29, 2009
    Assignee: Canon Kabushiki Kaisha
    Inventors: Kazunari Hagiwara, Soichiro Kawakami, Katsuhiko Inoue, Nobuyuki Suzuki
  • Patent number: 7615313
    Abstract: An electrode material for a lithium secondary battery which includes particles each having a central portion and a surface portion covering the surface of the central portion. A distance from a center to an outermost surface of the particle is occupied 80 to 99% by the central portion and 1 to 20% by the surface portion. The central portion includes LiM1-aDaO2 having an ?-NaFeO2 structure, and the surface portion includes LiM1-bEbO2 having an ?-NaFeO2 structure. (M is C or Ni; D is a transition metal element or Al replacing a part of Co or Ni as M; E is a metal element replacing a part of Co or Ni as M; and M is not the same as D or E.) The following relationships are satisfied in the central portion, in terms of atomic ratio: D/(M+D+E)<0.05 and E/(M+D+E)<0.05.
    Type: Grant
    Filed: June 21, 2004
    Date of Patent: November 10, 2009
    Assignee: Canon Kabushiki Kaisha
    Inventors: Kazunari Hagiwara, Soichiro Kawakami, Katsuhiko Inoue, Nobuyuki Suzuki
  • Publication number: 20090157339
    Abstract: An electrode material for a lithium secondary battery which includes particles each having a central portion and a surface portion covering the surface of the central portion. The central portion occupies 80 to 99% of a distance from a center to an outermost surface of the particle and the surface portion occupies 20 to 1% of the distance. The central portion includes LiM1-aDaO2 (M represents Co or Ni, D represents a transition metal element or Al replacing a part of Co or Ni as M, and M is not the same as D) having an ?-NaFeO2 structure. The surface portion includes LiM1-bEbO2 (M represents Co or Ni, E represents a metal element replacing a part of Co or Ni as M, and M is not the same as E) having an ?-NaFeO2 structure. The content of element E in the central portion satisfies the relation of E/(M+D+E)<0.05 in terms of an atomic ratio, and the content of element D in the surface portion satisfies the relation of D/(M+D+E)<0.05 in terms of an atomic ratio.
    Type: Application
    Filed: November 26, 2008
    Publication date: June 18, 2009
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Kazunari Hagiwara, Soichiro Kawakami, Katsuhiko Inoue, Nobuyuki Suzuki
  • Publication number: 20090003863
    Abstract: A developing apparatus in which a toner has a volume-average particle diameter R that is in a range of 4.0 ?m?R?6.2 ?m, a developing roller has an arithmetic mean roughness Ra (?m) that is not more than 0.10 times the volume-average particle diameter R of the toner, a voltage applied to a supply roller is of negative polarity, that is, a normal charging polarity of the toner, triboelectrification polarity of the supply roller with respect to the toner is negative, that is, of the normal charging polarity of the toner, and an abutment width S in which the developing roller and the supply roller abut each other is in a range of 2.5 mm?S?5.5 mm.
    Type: Application
    Filed: May 9, 2008
    Publication date: January 1, 2009
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Kazunari Hagiwara, Katsuhiro Sakaizawa, Norio Takahashi, Rie Endo
  • Publication number: 20080310886
    Abstract: A developer regulating apparatus including: a flexible sheet member, which regulates a thickness of a developer layer on a developing roller; and a holding member having wall surfaces for holding the sheet member in a curved state, wherein when the sheet member is not pressed by the developing roller, an angle of circumference of an arc of the sheet member is not larger than 180 degrees, a perpendicular bisector of a chord corresponding to the arc when the sheet member is pressed by the developing roller is provided downstream in a rotation direction of the developing roller with respect to a normal line of a surface of the developing roller which is parallel to the perpendicular bisector, and a sheet member holding line of the wall surface of the holding member upstream in the rotation direction is provided coplanar with the normal line or upstream of the normal line.
    Type: Application
    Filed: June 4, 2008
    Publication date: December 18, 2008
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Yasushi Shimizu, Kazunari Hagiwara, Shinichi Nishida, Hirokazu Usami, Hiraku Sasaki
  • Patent number: 7463854
    Abstract: A sheet-shaped regulation member is supported by a supporting unit with an elastic force occurring by bending a sheet-shaped regulation member in the longitudinal direction thereof, and a force received as a result of being pressed by a developing roller. Thus, direct contact can be securely made onto a developer bearing member, and a regulation member can be provided which enables easily attaching thereof to the supporting member, as well as enabling a developing apparatus, processing cartridge, and image forming apparatus, to be reduced in size.
    Type: Grant
    Filed: June 18, 2007
    Date of Patent: December 9, 2008
    Assignee: Canon Kabushiki Kaisha
    Inventors: Shinichi Nishida, Kazunari Hagiwara, Yasushi Shimizu, Katsunori Yokoyama, Naoto Kichijima, Hirokazu Usami