Patents by Inventor Chikara Hiraoka

Chikara Hiraoka 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: 7477867
    Abstract: To accomplish high-speed fixing which requires high-precision temperature control, or fixing of high-quality color images on various kinds of paper without increasing the size and production cost of the temperature detecting means and contaminating the back sides of paper by toner that comes off from the temperature detecting element, an image forming device is equipped with a fixing device comprising a heating roller, a pressing belt which forcibly contacts the heating roller, and a temperature detecting means which touches the surface of the heating roller to sense the surface temperature of the heating roller, wherein a cleaning means to clean the belt surface is provided on a place which is corresponding to a place at which the contact-type thermistor touches the heating roller.
    Type: Grant
    Filed: August 11, 2005
    Date of Patent: January 13, 2009
    Assignee: Ricoh Printing Systems, Ltd.
    Inventors: Chikara Hiraoka, Toru Hanashima, Masahiko Saito, Shunichi Oohara, Toshio Ogiso
  • Publication number: 20080292374
    Abstract: According to an aspect of the present invention, there is provided a fixing device including: a heating roller that generates a heat and is formed to have a mold releasing property; a pressure belt that is brought into contact with the heating roller and is driven according to a rotation of the heating roller; an arm that presses the pressure belt toward the heating roller; and a belt regulating member that contacts an end face of the pressure belt to regulate a shift thereof and is configured to be swingable with respect to the arm.
    Type: Application
    Filed: May 23, 2008
    Publication date: November 27, 2008
    Applicant: RICOH PRINTING SYSTEMS, LTD.
    Inventors: Chikara Hiraoka, Kazuhiro Wakamatsu, Katsumi Kumada
  • Patent number: 7406287
    Abstract: A disclosed fixing device includes: a heat roller unit having a rotatable roller having an elastic body on a surface thereof and a heating unit heating the roller; a pad disposed along a circumference of the elastic body of the heat roller; a belt member disposed on a curved surface of the pad, the belt member rotating by following a rotation of the heat roller; and a pressure member pressing the belt member to the heat roller using the pad, the fixing device causing a conveyed recording medium carrying a visualized image to pass through a space between the heat roller and the pressure member so as to fix the visualized image on the recording medium, wherein a curvature of the curved surface of the pad is changed in a central portion and end portions in an axial direction of the heat roller.
    Type: Grant
    Filed: February 20, 2007
    Date of Patent: July 29, 2008
    Assignee: Ricoh Printing Systems, Ltd.
    Inventors: Hiroyoshi Matsumoto, Toshio Ogiso, Shigeru Obata, Masahiro Yagi, Chikara Hiraoka, Chiharu Kamoshida
  • Publication number: 20080145094
    Abstract: According to an aspect of the present invention, there is provided a developing device including: a roller that develops an electric latent image formed on an image holding body; a chamber that stores a toner; a case that houses the roller and the chamber; a concave portion that is inwardly concaved from the case and that includes: a sidewall, a bottom, and a filling port formed in the bottom; and a first lid that closes the filling port.
    Type: Application
    Filed: December 10, 2007
    Publication date: June 19, 2008
    Applicant: RICOH PRINTING SYSTEMS, LTD.
    Inventors: Kenji Nakamura, Yuichiro Suzuki, Katsumi Kumada, Shoji Takeya, Chikara Hiraoka
  • Patent number: 7298981
    Abstract: A fixing device includes a first fixing part having a heater disposed therein, a second fixing part, disposed to oppose to the first fixing part, for pinching a recording medium to form a first nip portion, a pair of transfer rollers, disposed at a downstream side of the recording medium, for forming a second nip portion, a guide for biasing the recording medium discharged from the transfer rollers towards the first fixing part side from one of the transfers rollers, and means part for biasing the guide towards the recording medium side.
    Type: Grant
    Filed: July 7, 2005
    Date of Patent: November 20, 2007
    Assignee: Ricoh Printing Systems, Ltd.
    Inventors: Shunichi Oohara, Hiroyuki Seki, Toshio Ogiso, Shigeru Obata, Chikara Hiraoka, Toru Hanashima, Kazuhiro Wakamatsu
  • Publication number: 20070196145
    Abstract: A disclosed fixing device includes: a heat roller unit having a rotatable roller having an elastic body on a surface thereof and a heating unit heating the roller; a pad disposed along a circumference of the elastic body of the heat roller; a belt member disposed on a curved surface of the pad, the belt member rotating by following a rotation of the heat roller; and a pressure member pressing the belt member to the heat roller using the pad, the fixing device causing a conveyed recording medium carrying a visualized image to pass through a space between the heat roller and the pressure member so as to fix the visualized image on the recording medium, wherein a curvature of the curved surface of the pad is changed in a central portion and end portions in an axial direction of the heat roller.
    Type: Application
    Filed: February 20, 2007
    Publication date: August 23, 2007
    Inventors: Hiroyoshi MATSUMOTO, Toshio OGISO, Shigeru OBATA, Masahiro YAGI, Chikara HIRAOKA, Chiharu KAMOSHIDA
  • Patent number: 7231158
    Abstract: An image forming apparatus includes a fixing device having a pressure roller. The surface of the pressure roller is coated with a PFA resin and has an average surface roughness Ra of 0.05 to 0.13 ?m. A thermister is provided to detect the surface temperature of the pressure roller. The thermister includes a metal plate, a resister element attached to the metal plate, and a pair of fluorocarbon-resin films sandwiching the metal plate and the resister element. The fluorocarbon-resin film has a thickness of 15 ?m to 80 ?m.
    Type: Grant
    Filed: December 14, 2004
    Date of Patent: June 12, 2007
    Assignee: Ricoh Printing Systems, Ltd.
    Inventors: Chikara Hiraoka, Toru Hanashima, Tetsuji Takegoshi, Goro Sato, Shogo Matsumoto
  • Publication number: 20070048045
    Abstract: A ratio of a radius of curvature of a pressure applying member with an elastic layer, which pushes an endless belt wound around an endless heating member with pressure, in a transferring direction to a radius of curvature of an outer diameter of the heating roller is set to 1.1 or more.
    Type: Application
    Filed: August 23, 2006
    Publication date: March 1, 2007
    Applicant: RICOH PRINTING SYSTEMS, LTD.
    Inventors: Masahiro Yagi, Toshio Ogiso, Shigeru Obata, Chikara Hiraoka, Toru Hanashima, Osamu Saito
  • Patent number: 7167670
    Abstract: An electro-photographic apparatus for conducting printing includes a fixing member fixing an unfixed toner image on a surface of a recording medium onto the recording medium. The fixing member includes a heating roller and a pressurizing member, and a mounting member on which the pressurizing member is mounted. The pressurizing member is supported by the mounting member in a substantially center part in a longitudinal direction of the pressurizing member.
    Type: Grant
    Filed: May 12, 2005
    Date of Patent: January 23, 2007
    Assignee: Ricoh Printing Systems, Ltd.
    Inventors: Shigeru Obata, Shunichi Oohara, Toshio Ogiso, Kenji Asuwa, Toru Hanashima, Chikara Hiraoka
  • Patent number: 7142803
    Abstract: A fixing device includes a roller; an endless belt which is in contact with the roller and rotates with a circulation of the roller in a follower manner; a heating source in at lease one of an inside of the roller and an inside of the endless belt; and a pressure-applying member which is inside the endless belt and presses the endless belt against the roller. A sliding layer is provided on a side on which the pressure-applying member is in contact with the endless belt, and the sliding layer comprises at least two layers and holds a lubricant.
    Type: Grant
    Filed: December 15, 2004
    Date of Patent: November 28, 2006
    Assignee: Ricoh Printing Systems, Ltd.
    Inventors: Tuyoshi Koyama, Toshio Ogiso, Chikara Hiraoka, Kazuo Kikuchi, Tetsuji Takegoshi, Toru Hanashima, Shoji Ukei
  • Publication number: 20060034646
    Abstract: To accomplish high-speed fixing which requires high-precision temperature control, or fixing of high-quality color images on various kinds of paper without increasing the size and production cost of the temperature detecting means and contaminating the back sides of paper by toner that comes off from the temperature detecting element, an image for ming device is equipped with a fixing device comprising a heating roller, a pressing belt which forcibly contacts the heating roller, and a temperature detecting means which touches the surface of the heating roller to sense the surface temperature of the heating roller, wherein a cleaning means to clean the belt surface is provided on a place which is corresponding to a place at which the contact-type thermistor touches the heating roller.
    Type: Application
    Filed: August 11, 2005
    Publication date: February 16, 2006
    Inventors: Chikara Hiraoka, Toru Hanashima, Masahiko Saito, Shunichi Oohara, Toshio Ogiso
  • Publication number: 20060008283
    Abstract: A fixing device comprising a first fixing means having a heating means disposed therein, a second fixing means, disposed to oppose to the first fixing means, for pinching a recording medium to form a first nip portion, a pair of transfer rollers, disposed at a downstream side of the recording medium, for forming a second nip portion, a guide for biasing the recording medium discharged from the transfer rollers towards the first fixing means side from one of the transfers, and means for biasing the guide towards the recording medium side.
    Type: Application
    Filed: July 7, 2005
    Publication date: January 12, 2006
    Inventors: Shunichi Oohara, Hiroyuki Seki, Toshio Ogiso, Shigeru Obata, Chikara Hiraoka, Toru Hanashima, Kazuhiro Wakamatsu
  • Publication number: 20050254866
    Abstract: An electro-photographic apparatus for conducting printing includes a fixing member fixing an unfixed toner image on a surface of a recording medium onto the recording medium. The fixing member includes a heating roller and a pressurizing member, and a mounting member on which the pressurizing member is mounted. The pressurizing member is supported by the mounting member in a substantially center part in a longitudinal direction of the pressurizing member.
    Type: Application
    Filed: May 12, 2005
    Publication date: November 17, 2005
    Applicant: Ricoh Printing Systems, Ltd.
    Inventors: Shigeru Obata, Shunichi Oohara, Toshio Ogiso, Kenji Asuwa, Toru Hanashima, Chikara Hiraoka
  • Patent number: 6928257
    Abstract: An image forming and recording apparatus, having a fixing apparatus for fixing unfixed toner image on a recording medium, wherein the fixing apparatus includes a fixing roller integrating a heater therein, an endless belt wound around the fixing roller, and three pressure members for pressing the endless belt onto the fixing roller. A pressure member located nearest to a side of entry of paper among the three pressure members is made up with a non-rotary type pressure member, and other two pressure members are made up with either one of a rotary type pressure member and the non-rotary type pressure member.
    Type: Grant
    Filed: June 27, 2003
    Date of Patent: August 9, 2005
    Assignee: Ricoh Printing Systems, Ltd.
    Inventors: Toshio Ogiso, Masaru Nakano, Hiromitsu Fukuda, Shigeru Obata, Toru Hanashima, Kazushige Oonishi, Chikara Hiraoka, Toru Ohashi, Akira Shimizu, Kazuo Kikuchi, Shogo Matsumoto, Shoji Ukei, Katsuyoshi Onose, Tsuyoshi Koyama
  • Publication number: 20050147436
    Abstract: A fixing device includes a roller; an endless belt which is in contact with the roller and rotates with a circulation of the roller in a follower manner; a heating source in at lease one of an inside of the roller and an inside of the endless belt; and a pressure-applying member which is inside the endless belt and presses the endless belt against the roller. A sliding layer is provided on a side on which the pressure-applying member is in contact with the endless belt, and the sliding layer comprises at least two layers and holds a lubricant.
    Type: Application
    Filed: December 15, 2004
    Publication date: July 7, 2005
    Applicant: Ricoh Printing Systems, Ltd.
    Inventors: Tuyoshi Koyama, Toshio Ogiso, Chikara Hiraoka, Kazuo Kikuchi, Tetsuji Takegoshi, Toru Hanashima, Shoji Ukei
  • Publication number: 20050141914
    Abstract: An image forming apparatus includes a fixing device having a pressure roller. The surface of the pressure roller is coated with a PFA resin and has an average surface roughness Ra of 0.05 to 0.13 ?m. A thermister is provided to detect the surface temperature of the pressure roller. The thermister includes a metal plate, a resister element attached to the metal plate, and a pair of fluorocarbon-resin films sandwiching the metal plate and the resister element. The fluorocarbon-resin film has a thickness of 15 ?m to 80 ?m.
    Type: Application
    Filed: December 14, 2004
    Publication date: June 30, 2005
    Inventors: Chikara Hiraoka, Toru Hanashima, Tetsuji Takegoshi, Goro Sato, Shogo Matsumoto
  • Publication number: 20040057759
    Abstract: An image forming and recording apparatus, having a fixing apparatus for fixing unfixed toner image on a recording medium, wherein said fixing apparatus comprises: a fixing roller integrating a heater therein; an endless belt wound around said fixing roller; and three (3) pressure members for pressing said endless belt onto said fixing roller, wherein second one from a side of entry of paper is made at maximum in pressure loading, among said three (3) pressure members, thereby achieving stable fixing of oil-less toner at high speed.
    Type: Application
    Filed: June 27, 2003
    Publication date: March 25, 2004
    Inventors: Toshio Ogiso, Masaru Nakano, Hiromitsu Fukuda, Shigeru Obata, Toru Hanashima, Kazushige Oonishi, Chikara Hiraoka, Toru Ohashi, Akira Shimizu, Kazuo Kikuchi, Shogo Matsumoto, Shoji Ukei, Katsuyoshi Onose, Tsuyoshi Koyama
  • Patent number: 6661994
    Abstract: An electrophotographic image forming system having a form cassette for storing forms, a transfer unit for forming an image, a feeder for feeding the forms to the transfer unit and a fusing device for fusing transferred image of the form. The electrophotographic image forming system provides in a path for feeding the form with unfused colored particles (toner) deposited thereon, a form guide so as to contact the non-printing area of the surface of the form with unfused colored particles (toner) deposited thereon.
    Type: Grant
    Filed: July 30, 2002
    Date of Patent: December 9, 2003
    Assignee: Hitachi, Ltd.
    Inventors: Yoshio Ohuchi, Kazuhiro Wakamatsu, Hisao Suka, Katsumi Kumada, Chikara Hiraoka, Shizuo Tsuruta, Yoshitaro Ishii, Akira Sasaki, Masahiko Saito, Seiji Okunomiya, Tetsunori Kaneko, Masashi Yamamoto
  • Publication number: 20020176726
    Abstract: An electrophotographic image forming system having a form cassette for storing forms, a transfer unit for forming an image, a feeder for feeding the forms to the transfer unit and a fusing device for fusing transferred image of the form. The electrophotographic image forming system provides in a path for feeding the form with unfused colored particles (toner) deposited thereon, a form guide so as to contact the non-printing area of the surface of the form with unfused colored particles (toner) deposited thereon.
    Type: Application
    Filed: July 30, 2002
    Publication date: November 28, 2002
    Inventors: Yoshio Ohuchi, Kazuhiro Wakamatsu, Hisao Suka, Katsumi Kumada, Chikara Hiraoka, Shizuo Tsuruta, Yoshitaro Ishii, Akira Sasaki, Masahiko Saito, Seiji Okunomiya, Tetsunori Kaneko, Masashi Yamamoto
  • Patent number: 6400923
    Abstract: A fixing device in an image formation apparatus has a heating roller and a backup roller. These rollers are each coated with single silicone rubber layers around the respective peripheries of their core bars. This silicone rubber has a volume resistance value of 1013 &OHgr;·cm or more. The heating roller is charged with electricity of the same polarity as the polarity of toner particles due to frictional electrification caused at the time of feeding of a recording medium. The heating and the backup roller are polarized reverse to the polarity of the recording medium. A quantity of charged electricity on the backup roller is made larger than that on the heating roller. This permits the image formation apparatus to prevent offset from occurring at the time of fixing a toner image onto the recording medium to cope with various types of recording media.
    Type: Grant
    Filed: July 26, 2000
    Date of Patent: June 4, 2002
    Assignee: Hitachi, Ltd.
    Inventors: Hiromitsu Fukuda, Toshio Ogiso, Masaru Nakano, Kazuo Kikuchi, Katsumi Kumada, Chikara Hiraoka, Katsuyoshi Onose, Hitoshi Furuyama, Takashi Kakuhashi