Patents by Inventor Masami Okamoto

Masami Okamoto 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: 10488774
    Abstract: An image forming apparatus including a developing device and a fixing device is provided. The fixing device includes a fixing rotator having a fixing surface, an opposing rotator opposing the fixing rotator to form a nip portion therebetween, and a fixing surface reformer having an abutting layer to abut the fixing surface. The abutting layer contains abrasive grains having an average grain size of 2.0-6.5 ?m on a surface which abuts the fixing surface. The toner comprises a crystalline polyester resin and exhibits G? (storage elastic modulus) of 1.0×107 Pa or lower at 70° C. in a temperature rising in a viscoelasticity measurement, G? of 1.0×107 Pa or higher at 70° C. in a temperature falling in the viscoelasticity measurement, and an endothermic peak indicating an amount of heat absorption of from 2.0 to 8.0 J/g, derived from the crystalline polyester resin, in a first temperature rising in DSC.
    Type: Grant
    Filed: March 1, 2019
    Date of Patent: November 26, 2019
    Assignee: Ricoh Company, Ltd.
    Inventors: Daisuke Inoue, Takahiro Honda, Masami Okamoto, Kenta Kashiwagi, Kaori Hemmi, Yoshihisa Hara
  • Patent number: 10481530
    Abstract: A separation member that is used to separate a conveyance object from two rotation members, the conveyance object having been sent out from a nip that is formed by the two rotation members that are in contact with one another, the separation member includes a wavy part directed toward the nip and inclined from a normal to a center line of the two rotation members at a predetermined angle. The wavy part covers a contact zone where the conveyance object can come into contact with the separation member along a conveyance direction and along a width direction of the conveyance object, and the wavy part has a plurality of depressions parallel to each other and extending in a direction inclined from the conveyance direction and inclined from the width direction, at least two of the depressions overlapping along the conveyance direction.
    Type: Grant
    Filed: June 18, 2018
    Date of Patent: November 19, 2019
    Assignee: RICOH COMPANY, LTD.
    Inventors: Seiji Saitoh, Keisuke Kubota, Masami Okamoto, Kenji Nozawa, Fumihiro Hirose, Kensuke Yamaji, Shuutaroh Yuasa, Yuuki Kikushima, Kaori Hemmi, Yuuta Kanda
  • Publication number: 20190271927
    Abstract: An image forming apparatus including a developing device and a fixing device is provided. The fixing device includes a fixing rotator having a fixing surface, an opposing rotator opposing the fixing rotator to form a nip portion therebetween, and a fixing surface reformer having an abutting layer to abut the fixing surface. The abutting layer contains abrasive grains having an average grain size of 2.0-6.5 ?m on a surface which abuts the fixing surface. The toner comprises a crystalline polyester resin and exhibits G? (storage elastic modulus) of 1.0×107 Pa or lower at 70° C. in a temperature rising in a viscoelasticity measurement, G? of 1.0×107 Pa or higher at 70° C. in a temperature falling in the viscoelasticity measurement, and an endothermic peak indicating an amount of heat absorption of from 2.0 to 8.0 J/g, derived from the crystalline polyester resin, in a first temperature rising in DSC.
    Type: Application
    Filed: March 1, 2019
    Publication date: September 5, 2019
    Inventors: Daisuke Inoue, Takahiro Honda, Masami Okamoto, Kenta Kashiwagi, Kaori Hemmi, Yoshihisa Hara
  • Patent number: 10394169
    Abstract: A fixing device includes a tubular rotator and a first heater disposed inside the tubular rotator and extended in a longitudinal direction of the first heater. The first heater heats the tubular rotator. A second heater is disposed inside the tubular rotator and extended in a longitudinal direction of the second heater. The second heater heats the tubular rotator. A heating adjuster is interposed between the first heater and the second heater. The heating adjuster adjusts heat conduction from the first heater to the second heater. A joint combines the heating adjuster with the second heater.
    Type: Grant
    Filed: August 14, 2017
    Date of Patent: August 27, 2019
    Assignee: RICOH COMPANY, LTD.
    Inventors: Fumihiro Hirose, Keisuke Kubota, Masami Okamoto, Jun Ogino, Kensuke Yamaji, Shuutaroh Yuasa, Yuuta Kanda
  • Publication number: 20180299809
    Abstract: A separation member that is used to separate a conveyance object from two rotation members, the conveyance object having been sent out from a nip that is formed by the two rotation members that are in contact with one another, the separation member includes a wavy part directed toward the nip and inclined from a normal to a center line of the two rotation members at a predetermined angle. The wavy part covers a contact zone where the conveyance object can come into contact with the separation member along a conveyance direction and along a width direction of the conveyance object, and the wavy part has a plurality of depressions parallel to each other and extending in a direction inclined from the conveyance direction and inclined from the width direction, at least two of the depressions overlapping along the conveyance direction.
    Type: Application
    Filed: June 18, 2018
    Publication date: October 18, 2018
    Inventors: Seiji Saitoh, Keisuke Kubota, Masami Okamoto, Kenji Nozawa, Fumihiro Hirose, Kensuke Yamaji, Shuutaroh Yuasa, Yuuki Kikushima, Kaori Hemmi, Yuuta Kanda
  • Patent number: 10095166
    Abstract: A fixing device includes a separator disposed downstream from a nip former in a recording medium conveyance direction and isolated from a pressure rotator via a fixing belt. The separator stretches the fixing belt. A presser is interposed between a fixing nip formed between the living belt and the pressure rotator and an upstream end of the separator in a rotation direction of the fixing belt. The presser comes into contact with an inner circumferential surface of the fixing belt to press the fixing belt against the pressure rotator. A pressure adjuster, contacting the pressure rotator, changes a pressing position of the pressure rotator relative to the fixing belt to adjust pressure exerted from the pressure rotator to the fixing belt. A presser position adjuster, contacting the presser, changes a presser position of the presser relative to the fixing belt according to the pressing position of the pressure rotator.
    Type: Grant
    Filed: May 23, 2017
    Date of Patent: October 9, 2018
    Assignee: Ricoh Company, Ltd.
    Inventors: Masami Okamoto, Keisuke Kubota, Seiji Saitoh, Shuutaroh Yuasa, Yuuta Kanda, Fumihiro Hirose, Kensuke Yamaji
  • Patent number: 10088786
    Abstract: A fixing device includes a fixing belt that is endless and rotatable in a rotation direction and a nip former stretching the fixing belt. A pressure rotator presses against the nip former via the fixing belt to form a fixing nip between the fixing belt and the pressure rotator, through which a recording medium is conveyed. A separator is disposed downstream from the nip former in a recording medium conveyance direction and stretches the fixing belt. The separator is spaced apart from the pressure rotator via the fixing belt. A presser is interposed between an exit of the fixing nip and an upstream end of the separator in the rotation direction of the fixing belt. The presser comes into contact with an inner circumferential surface of the fixing belt to press the fixing belt against the pressure rotator.
    Type: Grant
    Filed: February 28, 2017
    Date of Patent: October 2, 2018
    Assignee: RICOH COMPANY, LTD.
    Inventors: Keisuke Kubota, Seiji Saitoh, Masami Okamoto, Kensuke Yamaji, Fumihiro Hirose, Shuutaroh Yuasa, Yuuta Kanda
  • Patent number: 10012936
    Abstract: A fixing device includes a fixing belt that is endless and rotatable in a rotation direction and a nip former stretching the fixing belt and including an elastic layer as a surface layer. A pressure rotator presses against the nip former via the fixing belt to form a fixing nip between the fixing belt and the pressure rotator, through which a recording medium is conveyed. A presser is disposed downstream from an exit of the fixing nip in a recording medium conveyance direction. The presser brings the fixing belt into contact with the pressure rotator.
    Type: Grant
    Filed: March 2, 2017
    Date of Patent: July 3, 2018
    Assignee: Ricoh Company, Ltd.
    Inventors: Kensuke Yamaji, Keisuke Kubota, Seiji Saitoh, Masami Okamoto, Fumihiro Hirose, Shuutaroh Yuasa, Kenji Nozawa, Kaori Hemmi, Jun Ogino, Yuuta Kanda
  • Patent number: 10012937
    Abstract: A fixing device includes a fixing belt that is endless and rotatable in a rotation direction and a nip former stretching the fixing belt. A pressure rotator presses against the nip former via the fixing belt to form a fixing nip between the fixing belt and the pressure rotator, through which a recording medium is conveyed. A presser is disposed downstream from an exit of the fixing nip in a recording medium conveyance direction. The presser brings the fixing belt into contact with the pressure rotator. A gap retainer contacts the nip former and is coupled to the presser to retain isolation of the presser from the nip former.
    Type: Grant
    Filed: March 8, 2017
    Date of Patent: July 3, 2018
    Assignee: Ricoh Company, Ltd.
    Inventors: Shuutaroh Yuasa, Keisuke Kubota, Masami Okamoto, Seiji Saitoh, Fumihiro Hirose, Kensuke Yamaji, Jun Ogino, Yuuta Kanda
  • Patent number: 9996035
    Abstract: A fixing device includes a fixing belt that is endless and rotatable in a rotation direction and a nip former stretching the fixing belt. A pressure rotator presses against the nip former via the fixing belt to form a fixing nip between the fixing belt and the pressure rotator, through which a recording medium is conveyed. A presser is disposed downstream from an exit of the fixing nip in the rotation direction of the fixing belt. The presser brings the fixing belt into contact with the pressure rotator. A mover is coupled to the presser to move the presser between a contact position where the presser brings the fixing belt into contact with the pressure rotator and an isolation position where the presser isolates the fixing belt from the pressure rotator.
    Type: Grant
    Filed: March 2, 2017
    Date of Patent: June 12, 2018
    Assignee: Ricoh Company, Ltd.
    Inventors: Masami Okamoto, Seiji Saitoh, Keisuke Kubota, Shuutaroh Yuasa, Kensuke Yamaji, Fumihiro Hirose, Yuuta Kanda
  • Patent number: 9939761
    Abstract: A fixing device includes an endless fixing belt stretched taut across a first roller and a second roller and rotatable in a predetermined direction of rotation. A pressure rotator is pressed against the first roller via the fixing belt to form a fixing nip between the pressure rotator and the fixing belt, through which a recording medium is conveyed. A separation aid, disposed downstream from the fixing nip in the direction of rotation of the fixing belt to separate the recording medium from the fixing belt, includes a contact face contacting an inner circumferential surface of the fixing belt and a bulge disposed at a center of the contact face in a longitudinal direction of the separation aid. The bulge projects toward the inner circumferential surface of the fixing belt relative to each lateral end of the contact face in the longitudinal direction of the separation aid.
    Type: Grant
    Filed: October 27, 2015
    Date of Patent: April 10, 2018
    Assignee: Ricoh Company, Ltd.
    Inventors: Kenji Nozawa, Masahiko Satoh, Masami Okamoto, Keisuke Kubota, Yuuki Kikushima, Shuutaroh Yuasa, Fumihiro Hirose, Kensuke Yamaji, Kaori Hemmi
  • Publication number: 20180081309
    Abstract: A fixing device includes a tubular rotator and a first heater disposed inside the tubular rotator and extended in a longitudinal direction of the first heater. The first heater heats the tubular rotator. A second heater is disposed inside the tubular rotator and extended in a longitudinal direction of the second heater. The second heater heats the tubular rotator. A heating adjuster is interposed between the first heater and the second heater. The heating adjuster adjusts heat conduction from the first heater to the second heater. A joint combines the heating adjuster with the second heater.
    Type: Application
    Filed: August 14, 2017
    Publication date: March 22, 2018
    Inventors: Fumihiro HIROSE, Keisuke KUBOTA, Masami OKAMOTO, Jun OGINO, Kensuke YAMAJI, Shuutaroh YUASA, Yuuta KANDA
  • Publication number: 20170357197
    Abstract: A fixing device includes a separator disposed downstream from a nip former in a recording medium conveyance direction and isolated from a pressure rotator via a fixing belt. The separator stretches the fixing belt. A presser is interposed between a fixing nip formed between the living belt and the pressure rotator and an upstream end of the separator in a rotation direction of the fixing belt. The presser comes into contact with an inner circumferential surface of the fixing belt to press the fixing belt against the pressure rotator. A pressure adjuster, contacting the pressure rotator, changes a pressing position of the pressure rotator relative to the fixing belt to adjust pressure exerted from the pressure rotator to the fixing belt. A presser position adjuster, contacting the presser, changes a presser position of the presser relative to the fixing belt according to the pressing position of the pressure rotator.
    Type: Application
    Filed: May 23, 2017
    Publication date: December 14, 2017
    Inventors: Masami OKAMOTO, Keisuke Kubota, Seiji Saitoh, Shuutaroh Yuasa, Yuuta Kanda, Fumihiro Hirose, Kensuke Yamaji
  • Publication number: 20170269526
    Abstract: A fixing device includes a fixing belt that is endless and rotatable in a rotation direction and a nip former stretching the fixing belt. A pressure rotator presses against the nip former via the fixing belt to form a fixing nip between the fixing belt and the pressure rotator, through which a recording medium is conveyed. A presser is disposed downstream from an exit of the fixing nip in a recording medium conveyance direction. The presser brings the fixing belt into contact with the pressure rotator. A gap retainer contacts the nip former and is coupled to the presser to retain isolation of the presser from the nip former.
    Type: Application
    Filed: March 8, 2017
    Publication date: September 21, 2017
    Inventors: Shuutaroh YUASA, Keisuke Kubota, Masami Okamoto, Seiji Saitoh, Fumihiro Hirose, Kensuke Yamaji, Jun Ogino, Yuuta Kanda
  • Publication number: 20170269522
    Abstract: A fixing device includes a fixing belt that is endless and rotatable in a rotation direction and a nip former stretching the fixing belt. A pressure rotator presses against the nip former via the fixing belt to form a fixing nip between the fixing belt and the pressure rotator, through which a recording medium is conveyed. A separator is disposed downstream from the nip former in a recording medium conveyance direction and stretches the fixing belt. The separator is spaced apart from the pressure rotator via the fixing belt. A presser is interposed between an exit of the fixing nip and an upstream end of the separator in the rotation direction of the fixing belt. The presser comes into contact with an inner circumferential surface of the fixing belt to press the fixing belt against the pressure rotator.
    Type: Application
    Filed: February 28, 2017
    Publication date: September 21, 2017
    Applicant: Ricoh Company, Ltd.
    Inventors: Keisuke KUBOTA, Seiji SAITOH, Masami OKAMOTO, Kensuke YAMAJI, Fumihiro HIROSE, Shuutaroh YUASA, Yuuta KANDA
  • Publication number: 20170269525
    Abstract: A fixing device includes a fixing belt that is endless and rotatable in a rotation direction and a nip former stretching the fixing belt. A pressure rotator presses against the nip former via the fixing belt to form a fixing nip between the fixing belt and the pressure rotator, through which a recording medium is conveyed. A presser is disposed downstream from an exit of the fixing nip in the rotation direction of the fixing belt. The presser brings the fixing belt into contact with the pressure rotator. A mover is coupled to the presser to move the presser between a contact position where the presser brings the fixing belt into contact with the pressure rotator and an isolation position where the presser isolates the fixing belt from the pressure rotator.
    Type: Application
    Filed: March 2, 2017
    Publication date: September 21, 2017
    Inventors: Masami OKAMOTO, Seiji SAITOH, Keisuke KUBOTA, Shuutaroh YUASA, Kensuke YAMAJI, Fumihiro HIROSE, Yuuta KANDA
  • Publication number: 20170269524
    Abstract: A fixing device includes a fixing belt that is endless and rotatable in a rotation direction and a nip former stretching the fixing belt and including an elastic layer as a surface layer. A pressure rotator presses against the nip former via the fixing belt to form a fixing nip between the fixing belt and the pressure rotator, through which a recording medium is conveyed. A presser is disposed downstream from an exit of the fixing nip in a recording medium conveyance direction. The presser brings the fixing belt into contact with the pressure rotator.
    Type: Application
    Filed: March 2, 2017
    Publication date: September 21, 2017
    Inventors: Kensuke YAMAJI, Keisuke KUBOTA, Seiji SAITOH, Masami OKAMOTO, Fumihiro HIROSE, Shuutaroh YUASA, Kenji NOZAWA, Kaori HEMMI, Jun OGINO, Yuuta KANDA
  • Patent number: 9733600
    Abstract: A fixing device includes a fixing belt looped over a first roller and a second roller and rotatable in a predetermined direction of rotation and a pressure rotator to press against the first roller via the fixing belt to form a fixing nip between the fixing belt and the pressure rotator. A separation aid, disposed downstream from the fixing nip in the direction of rotation of the fixing belt, contacts an inner circumferential surface of the fixing belt to decrease a radius of curvature of the fixing belt. A polishing roller, disposed downstream from the separation aid and upstream from the second roller in the direction of rotation of the fixing belt, contacts an outer circumferential surface of the fixing belt. An opposed roller, disposed opposite the polishing roller via the fixing belt, forms a polishing nip between the polishing roller and the fixing belt.
    Type: Grant
    Filed: March 14, 2016
    Date of Patent: August 15, 2017
    Assignee: Ricoh Company, Ltd.
    Inventors: Kenji Nozawa, Masami Okamoto, Yuuki Kikushima, Keisuke Kubota, Shuutaroh Yuasa, Kaori Hemmi
  • Patent number: 9519249
    Abstract: A fixing device includes a cylindrical heat roller; a plurality of heaters disposed inside the heat roller, extending along a longitudinal axis of the heat roller; and a heat adjuster, disposed among the plurality of heaters, to adjust heat from one to another of the plurality of heaters. An image forming apparatus includes an image forming section to form an image on a recording medium; and the fixing device as described above, to fix the image onto the recording medium.
    Type: Grant
    Filed: December 14, 2015
    Date of Patent: December 13, 2016
    Assignee: Ricoh Company, Ltd.
    Inventors: Fumihiro Hirose, Masami Okamoto, Kenji Nozawa, Yuuki Kikushima, Kensuke Yamaji, Keisuke Kubota, Shuutaroh Yuasa, Kaori Hemmi
  • Publication number: 20160306306
    Abstract: A fixing device includes a fixing belt looped over a first roller and a second roller and rotatable in a predetermined direction of rotation and a pressure rotator to press against the first roller via the fixing belt to form a fixing nip between the fixing belt and the pressure rotator. A separation aid, disposed downstream from the fixing nip in the direction of rotation of the fixing belt, contacts an inner circumferential surface of the fixing belt to decrease a radius of curvature of the fixing belt. A polishing roller, disposed downstream from the separation aid and upstream from the second roller in the direction of rotation of the fixing belt, contacts an outer circumferential surface of the fixing belt. An opposed roller, disposed opposite the polishing roller via the fixing belt, forms a polishing nip between the polishing roller and the fixing belt.
    Type: Application
    Filed: March 14, 2016
    Publication date: October 20, 2016
    Applicant: Ricoh Company, Ltd.
    Inventors: Kenji Nozawa, Masami OKAMOTO, Yuuki KIKUSHIMA, Keisuke KUBOTA, Shuutaroh YUASA, Kaori HEMM!