Patents by Inventor Masayuki Ohsawa

Masayuki Ohsawa 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: 8958729
    Abstract: A magnet roller includes a roller-shaped body constructed of a magnetic field generating material, a first support rod provided to a first axial end of the body; and a second support rod provided to a second axial end of the body. At least one of the first and second support rods is constructed of a nonmagnetic material and includes a projecting part projecting outside the body from an end face of the body and a buried part united to the projecting part and positioned inside the body. The buried part includes a reduced-area portion smaller than a base end of the projecting part adjacent to the buried part in cross-sectional area perpendicular to an axial direction of the first and second support rods.
    Type: Grant
    Filed: February 7, 2013
    Date of Patent: February 17, 2015
    Assignee: Ricoh Company, Ltd.
    Inventors: Takashi Innami, Noriyuki Kamiya, Masayuki Ohsawa, Yoshiyuki Takano, Hiroya Abe
  • Patent number: 8824932
    Abstract: A development device includes a developer container, a developer carrier, exposed partly from a casing, facing a latent image carrier in a development area, a magnetic field generator inside the developer carrier, having multiple magnetic poles including a conveyance pole to convey the developer downstream from the development area to a developer release portion, a developer agitator, and a developer regulator. A predetermined gap is kept between an outer surface of the developer carrier and an inner wall of the casing downstream from an opening of the casing, upstream from a developer release portion, in a direction in which the developer carrier rotates. Multiple recesses are formed in the outer surface of the developer carrier at a pitch in a circumferential direction shorter than half a width of a magnetic flux density of the developer conveyance pole in a direction perpendicular to an axial direction of the developer carrier.
    Type: Grant
    Filed: February 2, 2011
    Date of Patent: September 2, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Katsumi Masuda, Takamasa Ozeki, Nobuyuki Taguchi, Yuuki Satoh, Toshiki Hayashi, Kyohta Koetsuka, Toshio Kojima, Masayuki Ohsawa, Noriyuki Kamiya, Takumi Terasaka
  • Patent number: 8731444
    Abstract: A develop roller includes a magnet roller, and a develop sleeve containing the magnet roller and comprising a plurality of depressions in an elliptic shape regularly arranged with an interval in a longitudinal direction on a surface onto which developer is attracted by a magnetic force of the magnet roller, wherein the depressions are arranged such that a longitudinal direction of the depressions is intersected with the longitudinal direction of the develop sleeve, and a downstream side of the depressions are formed to be deeper than an upstream side in a rotary direction of the develop sleeve.
    Type: Grant
    Filed: April 21, 2011
    Date of Patent: May 20, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Masayuki Ohsawa, Toshio Kojima, Kyohta Koetsuka, Yoshiyuki Takano, Noriyuki Kamiya, Takashi Innami, Takumi Terasaka
  • Patent number: 8682230
    Abstract: A development device including a developer container, a developer bearer, a magnetic field generator, a developer agitator to supply the developer to the developer bearer, and a developer regulator to adjust a layer thickness of the developer carried on the developer bearer. Multiple oval recesses oblique to the axial direction of the developer bearer are formed in the outer circumferential surface of the developer bearer and arranged in a circumferential direction and the axial direction thereof. An upstream inner wall of the recess in the rotational direction of the developer bearer applies a force to the developer as the developer bearer rotates, and an angle between a long axis of the recess and the axial direction is set so that the force applied by the upstream inner wall of the recess has a component in a direction substantially identical to the developer conveyance direction of the developer agitator.
    Type: Grant
    Filed: August 31, 2011
    Date of Patent: March 25, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Nobuyuki Taguchi, Katsumi Masuda, Takamasa Ozeki, Yuuki Satoh, Toshiki Hayashi, Kyohta Koetsuka, Toshio Kojima, Masayuki Ohsawa, Noriyuki Kamiya, Takumi Terasaka
  • Patent number: 8600271
    Abstract: A magnet roller includes a magnetic field generator being columnar, a support element being columnar, coaxially provided at both ends of the magnetic field generator, and whose diameter is smaller than that of the magnetic field generator, a level element extending along an axis of the magnetic field generator with a distance from the axis, the distance larger than the diameter of the support element, and a high magnetic power element being a main magnetic pole provided on the level element, extending long along the axis of the magnetic field generator.
    Type: Grant
    Filed: April 13, 2011
    Date of Patent: December 3, 2013
    Assignee: Ricoh Company, Ltd.
    Inventors: Takashi Innami, Kyohta Koetsuka, Yoshiyuki Takano, Noriyuki Kamiya, Masayuki Ohsawa, Takumi Terasaka
  • Patent number: 8565652
    Abstract: A development roller includes a magnet roller and a rotatably supported development sleeve including inside thereof the magnet roller, the development sleeve is formed in a cylindrical shape and configured such that a shaft center of the cylindrical shape is inconsistent with a rotation axis of the development sleeve, the development sleeve includes an outer surface provided with many circular or elliptical depressions in a planar view, the depressions being regularly arranged at intervals, and a depth of the depression provided in a portion of the outer surface close to the rotation axis is larger than a depth of the depression provided in a portion of the outer surface far from the rotation axis.
    Type: Grant
    Filed: May 17, 2012
    Date of Patent: October 22, 2013
    Assignee: Ricoh Company, Ltd.
    Inventors: Takumi Terasaka, Toshio Kojima, Kyohta Koetsuka, Noriyuki Kamiya, Masayuki Ohsawa, Hiroya Abe
  • Patent number: 8535116
    Abstract: A magnetic particle carrying device includes a magnetic field generator and a hollow cylindrical structure. The magnetic field generator generates a magnetic field. The hollow cylindrical structure encases the magnetic field generator and attracts magnetic particles on an external surface of the hollow structure using the magnetic field. The external surface of the hollow cylindrical structure is provided with a plurality of elliptical depressions. The depressions include first type depressions and second type depressions. A long axis of a first type of elliptical depression is substantially extending in an axial direction of the hollow cylindrical structure, and a long axis of a second type of elliptical depression is substantially extending in a circumferential direction of the hollow cylindrical structure. The external surface of the hollow cylindrical structure has more elliptical depressions of the second type than elliptical depressions of the first type.
    Type: Grant
    Filed: January 21, 2011
    Date of Patent: September 17, 2013
    Assignee: Ricoh Company, Ltd.
    Inventors: Hiroya Abe, Tsuyoshi Imamura, Kyohta Koetsuka, Tadaaki Hattori, Yoshiyuki Takano, Noriyuki Kamiya, Masayuki Ohsawa, Mieko Terashima, Takashi Innami
  • Publication number: 20130236216
    Abstract: A magnet roller includes a roller-shaped body constructed of a magnetic field generating material, a first support rod provided to a first axial end of the body; and a second support rod provided to a second axial end of the body. At least one of the first and second support rods is constructed of a nonmagnetic material and includes a projecting part projecting outside the body from an end face of the body and a buried part united to the projecting part and positioned inside the body. The buried part includes a reduced-area portion smaller than a base end of the projecting part adjacent to the buried part in cross-sectional area perpendicular to an axial direction of the first and second support rods.
    Type: Application
    Filed: February 7, 2013
    Publication date: September 12, 2013
    Inventors: Takashi Innami, Noriyuki Kamiya, Masayuki Ohsawa, Yoshiyuki Takano, Hiroya Abe
  • Patent number: 8500615
    Abstract: A magnetic roller includes a solid-core roller having magnetic anisotropy in a direction orthogonal to a central axis thereof. The solid-core roller includes a body part, and shaft parts disposed on both ends of the body part, a concave groove provided in an outer circumference face of the body part to extend in an axial direction, and a magnetic block disposed in the concave groove, the magnetic block having a direction of magnetic anisotropy substantially orthogonal to a direction of the magnetic anisotropy of the magnetic roller.
    Type: Grant
    Filed: January 3, 2008
    Date of Patent: August 6, 2013
    Assignee: Ricoh Company, Ltd.
    Inventors: Tsuyoshi Imamura, Yoshiyuki Takano, Kyohta Koetsuka, Tadaaki Hattori, Noriyuki Kamiya, Hiroya Abe, Mieko Terashima, Masayuki Ohsawa, Takashi Innami
  • Patent number: 8331834
    Abstract: A developing unit includable in a process cartridge and in an image forming apparatus includes a developer bearing member including a magnetic field generator and a nonmagnetic hollow member, a developer container, an agitation/conveyance member, and a developer regulating member. The magnetic field generator has first and second magnetic poles to generate respective magnetic forces for removing the developer from the developer bearing member after the developer passes the development region. A developer-releasing region releases the developer from the developer bearing member using a release force. The developer is disposed higher than a surface of the developer in the developer storing chamber. A component of a magnetic flux density of the magnetic field generated by the magnetic field generator in a direction normal to the developer-releasing region is directed to a same direction as the first and second magnetic poles across the developer-releasing region without forming a local maximum point.
    Type: Grant
    Filed: March 26, 2009
    Date of Patent: December 11, 2012
    Assignee: Ricoh Company, Ltd.
    Inventors: Kyohta Koetsuka, Masayuki Ohsawa, Yoshiyuki Takano, Katsumi Masuda, Yoshio Hattori, Yuji Suzuki, Takamasa Ozeki, Hiroyuki Uenishi
  • Publication number: 20120294655
    Abstract: A development roller includes a magnet roller and a rotatably supported development sleeve including inside thereof the magnet roller, the development sleeve is formed in a cylindrical shape and configured such that a shaft center of the cylindrical shape is inconsistent with a rotation axis of the development sleeve, the development sleeve includes an outer surface provided with many circular or elliptical depressions in a planar view, the depressions being regularly arranged at intervals, and a depth of the depression provided in a portion of the outer surface close to the rotation axis is larger than a depth of the depression provided in a portion of the outer surface far from the rotation axis.
    Type: Application
    Filed: May 17, 2012
    Publication date: November 22, 2012
    Applicant: RICOH COMPANY, LTD.
    Inventors: Takumi TERASAKA, Toshio Kojima, Kyohta Koetsuka, Noriyuki Kamiya, Masayuki Ohsawa, Hiroya Abe
  • Patent number: 8135316
    Abstract: An image forming device comprises a process cartridge. The process cartridge comprises a development roller. The development roller comprises a magnet roller and a developing sleeve 132. The magnet roller is fixed. The depressions 139 each having an oval shape are formed on the external surface of the developing sleeve 132. Both ends of the depressions 139 which are adjacent with each other along the longitudinal direction of the developing sleeve 132 are overlapped with each other and both ends of the depressions 139 which are adjacent with each other along the circumferential direction of the developing sleeve 132 are spaced with each other.
    Type: Grant
    Filed: December 21, 2009
    Date of Patent: March 13, 2012
    Assignee: Ricoh Company, Ltd.
    Inventors: Toshio Kojima, Kyohta Koetsuka, Noriyuki Kamiya, Rei Suzuki, Tadaaki Hattori, Yoshiyuki Takano, Masayuki Ohsawa, Hiroya Abe, Takashi Innami
  • Patent number: 8135315
    Abstract: A developing unit includable in a process cartridge and in an image forming apparatus includes a developer bearing member including a magnetic field generator and a nonmagnetic hollow member, a developer container, an agitation/conveyance member, a developer regulating member to regulate the thickness of a layer of the two-component developer. The magnetic field generator has first and second magnetic poles to generate respective magnetic forces for removing the developer from the developer bearing member after the developer passes the development region. The second magnetic pole generates a magnetic force to attract the developer to form a magnetic brush on the developer bearing member. The developer regulating member includes a magnetic member outwardly disposed on an exterior perimeter surface of the developer bearing member upstream from the developer regulating member, and one planar surface of the magnetic member faces the second magnetic pole across an effective development region.
    Type: Grant
    Filed: March 27, 2009
    Date of Patent: March 13, 2012
    Assignee: Ricoh Company, Ltd.
    Inventors: Takamasa Ozeki, Katsumi Masuda, Yoshio Hattori, Hiroyuki Uenishi, Yuji Suzuki, Kyohta Koetsuka, Masayuki Ohsawa, Yoshiyuki Takano, Takeroh Kurenuma, Akira Azami, Nobuyuki Taguchi
  • Publication number: 20120057907
    Abstract: A development device including a developer container, a developer bearer, a magnetic field generator, a developer agitator to supply the developer to the developer bearer, and a developer regulator to adjust a layer thickness of the developer carried on the developer bearer. Multiple oval recesses oblique to the axial direction of the developer bearer are formed in the outer circumferential surface of the developer bearer and arranged in a circumferential direction and the axial direction thereof. An upstream inner wall of the recess in the rotational direction of the developer bearer applies a force to the developer as the developer bearer rotates, and an angle between a long axis of the recess and the axial direction is set so that the force applied by the upstream inner wall of the recess has a component in a direction substantially identical to the developer conveyance direction of the developer agitator.
    Type: Application
    Filed: August 31, 2011
    Publication date: March 8, 2012
    Inventors: Nobuyuki TAGUCHI, Katsumi Masuda, Takamasa Ozeki, Yuuki Satoh, Toshiki Hayashi, Kyohta Koetsuka, Toshio Kojima, Masayuki Ohsawa, Noriyuki Kamiya, Takumi Terasaka
  • Publication number: 20110274471
    Abstract: A develop roller includes a magnet roller, and a develop sleeve containing the magnet roller and comprising a plurality of depressions in an elliptic shape regularly arranged with an interval in a longitudinal direction on a surface onto which developer is attracted by a magnetic force of the magnet roller, wherein the depressions are arranged such that a longitudinal direction of the depressions is intersected with the longitudinal direction of the develop sleeve, and a downstream side of the depressions are formed to be deeper than an upstream side in a rotary direction of the develop sleeve.
    Type: Application
    Filed: April 21, 2011
    Publication date: November 10, 2011
    Applicant: RICOH COMPANY, LTD.
    Inventors: Masayuki OHSAWA, Toshio Kojima, Kyohta Koetsuka, Yoshiyuki Takano, Noriyuki Kamiya, Takashi Innami, Takumi Terasaka
  • Publication number: 20110262190
    Abstract: A magnet roller includes a magnetic field generator being columnar, a support element being columnar, coaxially provided at both ends of the magnetic field generator, and whose diameter is smaller than that of the magnetic field generator, a level element extending along an axis of the magnetic field generator with a distance from the axis, the distance larger than the diameter of the support element, and a high magnetic power element being a main magnetic pole provided on the level element, extending long along the axis of the magnetic field generator.
    Type: Application
    Filed: April 13, 2011
    Publication date: October 27, 2011
    Applicant: RICOH COMPANY, LTD.
    Inventors: Takashi INNAMI, Kyohta Koetsuka, Yoshiyuki Takano, Noriyuki Kamiya, Masayuki Ohsawa, Takumi Terasaka
  • Patent number: 8023867
    Abstract: A magnet roller includes a cylindrical roller body including a side surface in which a groove is formed, a magnet body which is disposed in the groove, and a magnetic metal member which is attached to a surface of the magnet body, which is remote from an opening of the groove.
    Type: Grant
    Filed: February 29, 2008
    Date of Patent: September 20, 2011
    Assignee: Ricoh Company, Ltd.
    Inventors: Yoshiyuki Takano, Tsuyoshi Imamura, Kyohta Koetsuka, Noriyuki Kamiya, Masayuki Ohsawa, Hiroya Abe, Takashi Innami, Tadaaki Hattori, Mieko Terashima
  • Publication number: 20110194874
    Abstract: A development device includes a developer container, a developer carrier, exposed partly from a casing, facing a latent image carrier in a development area, a magnetic field generator inside the developer carrier, having multiple magnetic poles including a conveyance pole to convey the developer downstream from the development area to a developer release portion, a developer agitator, and a developer regulator. A predetermined gap is kept between an outer surface of the developer carrier and an inner wall of the casing downstream from an opening of the casing, upstream from a developer release portion, in a direction in which the developer carrier rotates. Multiple recesses are formed in the outer surface of the developer carrier at a pitch in a circumferential direction shorter than half a width of a magnetic flux density of the developer conveyance pole in a direction perpendicular to an axial direction of the developer carrier.
    Type: Application
    Filed: February 2, 2011
    Publication date: August 11, 2011
    Inventors: Katsumi Masuda, Takamasa Ozeki, Nobuyuki Taguchi, Yuuki Satoh, Toshiki Hayashi, Kyohta Koetsuka, Toshio Kojima, Masayuki Ohsawa, Noriyuki Kamiya, Takumi Terasaka
  • Publication number: 20110130074
    Abstract: A magnetic particle carrying device includes a magnetic field generator and a hollow cylindrical structure. The magnetic field generator generates a magnetic field. The hollow cylindrical structure encases the magnetic field generator and attracts magnetic particles on an external surface of the hollow structure using the magnetic field. The external surface of the hollow cylindrical structure is provided with a plurality of elliptical depressions. The depressions include first type depressions and second type depressions. A long axis of a first type of elliptical depression is substantially extending in an axial direction of the hollow cylindrical structure, and a long axis of a second type of elliptical depression is substantially extending in a circumferential direction of the hollow cylindrical structure. The external surface of the hollow cylindrical structure has more elliptical depressions of the second type than elliptical depressions of the first type.
    Type: Application
    Filed: January 21, 2011
    Publication date: June 2, 2011
    Inventors: Hiroya ABE, Tsuyoshi IMAMURA, Kyohta KOETSUKA, Tadaaki HATTORI, Yoshiyuki TAKANO, Noriyuki KAMIYA, Masayuki OHSAWA, Mieko TERASHIMA, Takashi INNAMI
  • Patent number: 7917067
    Abstract: A magnetic field generating member with high stiffness and small size, an image development device, a process cartridge and an image forming apparatus including the magnetic field generating member as well as a manufacturing method of the magnetic field generating member are provided where the magnetic field generating member includes a main body, a groove provided in the main body, an interposition member configured to be fitted in the groove of the main body and including a concave portion and a magnetic member as a long magnetic compact fixed into the concave portion of the interposition member.
    Type: Grant
    Filed: December 30, 2008
    Date of Patent: March 29, 2011
    Assignee: Ricoh Company, Ltd.
    Inventors: Yoshiyuki Takano, Kyohta Koetsuka, Noriyuki Kamiya, Masayuki Ohsawa, Mieko Terashima, Rei Suzuki, Hiroya Abe, Takashi Innami, Tadaaki Hattori