Patents by Inventor Hirohmi Tamura

Hirohmi Tamura 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: 9223261
    Abstract: An image forming apparatus including multiple imaging units and a fixing unit is provided. Each of the imaging units includes an image bearing member, a developing device containing a toner including a pressure-induced phase transition resin or a thermoplastic resin, a transfer device, and an image bearing member cleaner, and is adapted to form a toner image with the toner. The fixing unit includes a pressure fixing device adapted to fix the toner including the pressure-induced phase transition resin on the recording medium by applying a temperature Tb and a pressure Pb thereto in a pressure fixing nip, and a heat fixing device adapted to fix the toner including the thermoplastic resin on the recording medium by applying a temperature Ta and a pressure Pa thereto in a heat fixing nip. The image forming apparatus satisfies the following inequations: Tb<Ta and Pb>Pa.
    Type: Grant
    Filed: June 29, 2012
    Date of Patent: December 29, 2015
    Assignee: Ricoh Company, Ltd.
    Inventors: Hirohmi Tamura, Satoru Ishikake, Hirokatsu Suzuki, Ryuji Yoshida, Takashi Bisaiji
  • Patent number: 8422897
    Abstract: By using a black-image forming device, an abrasive pattern is formed on a sheet conveying belt so that toner is input to a contact section where a cleaning blade is in contact with the sheet conveying belt. After the toner is input to the contact section where the cleaning blade is in contact with the sheet conveying belt and then the sheet conveying belt makes one or more revolutions, a process control is performed in which Y, M, and C toner patterns and B toner pattern are transferred onto the sheet conveying belt.
    Type: Grant
    Filed: August 27, 2010
    Date of Patent: April 16, 2013
    Assignee: Ricoh Company, Limited
    Inventors: Hirokatsu Suzuki, Kazuhisa Sudo, Masanori Kawasumi, Shunichi Hashimoto, Mugijirou Uno, Akira Shinshi, Masaharu Furuya, Masahiko Satoh, Hirohmi Tamura, Kazuya Saitoh, Tomoko Takahashi, Takuya Suganuma
  • Patent number: 8385793
    Abstract: An image forming apparatus includes a first image carrier, a second image carrier, an intermediate transfer member disposed facing the second image carrier, a conveyance belt to transport a transfer sheet, disposed facing both the first image carrier and the intermediate transfer member, a first transfer member to transfer a first toner image formed on the first image carrier onto the transfer sheet, a second transfer member to transfer a second toner image formed on the second image carrier onto the intermediate transfer member, and a third transfer member disposed downstream from the second image carrier in a rotation direction of the intermediate transfer member, to transfer the second toner image from the intermediate transfer member onto the transfer sheet transported by the conveyance belt. The first image carrier and the intermediate transfer member inflect the conveyance belt at a first inflection angle and a second inflection angle, respectively.
    Type: Grant
    Filed: July 1, 2010
    Date of Patent: February 26, 2013
    Assignee: Ricoh Company, Limited
    Inventors: Masaharu Furuya, Masahiko Satoh, Masanori Kawasumi, Hirokatsu Suzuki, Hirohmi Tamura, Kazuya Saitoh, Takuya Suganuma, Mugijirou Uno, Shunichi Hashimoto, Akira Shinshi, Kazuhisa Sudo, Tomoko Takahashi
  • Publication number: 20130011171
    Abstract: An image forming apparatus including multiple imaging units and a fixing unit is provided. Each of the imaging units includes an image bearing member, a developing device containing a toner including a pressure-induced phase transition resin or a thermoplastic resin, a transfer device, and an image bearing member cleaner, and is adapted to form a toner image with the toner. The fixing unit includes a pressure fixing device adapted to fix the toner including the pressure-induced phase transition resin on the recording medium by applying a temperature Tb and a pressure Pb thereto in a pressure fixing nip, and a heat fixing device adapted to fix the toner including the thermoplastic resin on the recording medium by applying a temperature Ta and a pressure Pa thereto in a heat fixing nip. The image forming apparatus satisfies the following inequations: Tb<Ta and Pb>Pa.
    Type: Application
    Filed: June 29, 2012
    Publication date: January 10, 2013
    Applicant: RICOH COMPANY, LTD.
    Inventors: Hirohmi Tamura, Satoru Ishikake, Hirokatsu Suzuki, Ryuji Yoshida, Takashi Bisaiji
  • Patent number: 8200135
    Abstract: A transfer-fixing device includes a transfer-fixing member, a pressing member, a heating device, and a temperature equalizer. The transfer-fixing member carries the toner image. The pressing member presses against the transfer-fixing member to form a nip portion to which the recording medium is conveyed. The heating device heats the transfer-fixing surface of the recording medium conveyed toward the nip portion. The temperature equalizer equalizes a temperature distribution of a surface of the transfer-fixing member in a width direction of the transfer-fixing member after the surface of the transfer-fixing member passes through the nip portion.
    Type: Grant
    Filed: February 15, 2008
    Date of Patent: June 12, 2012
    Assignee: Ricoh Company, Ltd.
    Inventors: Takashi Fujita, Shin Kayahara, Hiromitsu Takagaki, Takashi Seto, Takeshi Takemoto, Hirohmi Tamura
  • Patent number: 8095042
    Abstract: An image forming apparatus includes a plurality of first image carriers on which different color toner images C are respectively formed, a transfer fixing member onto which a multicolor toner image A consisting of the toner images C is transferred, a heater located configured to fuse the toner image A on the transfer fixing member, a pressurizer pressing against the transfer fixing member, an image carrier located upstream of the transfer fixing member in a direction in which the recording medium is transported, on which a toner image B is formed, and a transferer facing the image carrier. The toner image A is transferred from the transfer fixing member and fixed on a recording medium in a nip formed between the transfer fixing member and the pressurizer. The toner image B is transferred from image carrier onto the recording medium before the toner image A is transferred thereonto and fixed thereon.
    Type: Grant
    Filed: June 6, 2008
    Date of Patent: January 10, 2012
    Assignee: Ricoh Company, Ltd.
    Inventor: Hirohmi Tamura
  • Patent number: 7912412
    Abstract: A transfer-fixing device transfers and fixes a toner image onto a transfer-fixing surface of a recording medium, and includes a transfer-fixing member, a pressing member, a heating member, and a temperature equalization member. The transfer-fixing member carries the toner image. The pressing member pressingly contacts the transfer-fixing member to form a nip between the pressing member and the transfer-fixing member through which the recording medium passes. The heating member heats the transfer-fixing surface of the recording medium conveyed toward the nip so that the recording medium reaches the nip before a temperature of a back surface opposite the transfer-fixing surface of the recording medium increases. The temperature equalization member equalizes temperature distribution on a surface of the transfer-fixing member in a width direction of the transfer-fixing member perpendicular to a conveyance direction of the recording medium, after the surface of the transfer-fixing member passes the nip.
    Type: Grant
    Filed: March 6, 2008
    Date of Patent: March 22, 2011
    Assignee: Ricoh Company, Ltd.
    Inventors: Takashi Fujita, Shin Kayahara, Takeshi Takemoto, Hiromitsu Takagaki, Takashi Seto, Hirohmi Tamura
  • Patent number: 7907881
    Abstract: The transfer-fixing device includes an image carrier, a pressing member, a heater, and an electrical field generator. The image carrier carries a toner image. The pressing member presses against the image carrier to form a transfer-fixing nip between the pressing member and the image carrier. The heater heats the toner image carried by the image carrier so that a temperature of the toner image is not higher than Tm +10 degrees centigrade when a toner softening point is Tm degrees centigrade. The electrical field generator forms a transfer electrical field at the transfer-fixing nip.
    Type: Grant
    Filed: March 4, 2008
    Date of Patent: March 15, 2011
    Assignee: Ricoh Company Limited
    Inventors: Shin Kayahara, Takashi Fujita, Takeshi Takemoto, Hiromitsu Takagaki, Takashi Seto, Hirohmi Tamura
  • Publication number: 20110058832
    Abstract: By using a black-image forming device, an abrasive pattern is formed on a sheet conveying belt so that toner is input to a contact section where a cleaning blade is in contact with the sheet conveying belt. After the toner is input to the contact section where the cleaning blade is in contact with the sheet conveying belt and then the sheet conveying belt makes one or more revolutions, a process control is performed in which Y, M, and C tone patterns and B tone pattern are transferred onto the sheet conveying belt.
    Type: Application
    Filed: August 27, 2010
    Publication date: March 10, 2011
    Inventors: Hirokatsu SUZUKI, Kazuhisa Sudo, Masanori Kawasumi, Shunichi Hashimoto, Mugijirou Uno, Akira Shinshi, Masaharu Furuya, Masahiko Satoh, Hirohmi Tamura, Kazuya Saitoh, Tomoko Takahashi, Takuya Suganuma
  • Publication number: 20110013950
    Abstract: An image forming apparatus includes a first image carrier, a second image carrier, an intermediate transfer member disposed facing the second image carrier, a conveyance belt to transport a transfer sheet, disposed facing both the first image carrier and the intermediate transfer member, a first transfer member to transfer a first toner image formed on the first image carrier onto the transfer sheet, a second transfer member to transfer a second toner image formed on the second image carrier onto the intermediate transfer member, and a third transfer member disposed downstream from the second image carrier in a rotation direction of the intermediate transfer member, to transfer the second toner image from the intermediate transfer member onto the transfer sheet transported by the conveyance belt. The first image carrier and the intermediate transfer member inflect the conveyance belt at a first inflection angle and a second inflection angle, respectively.
    Type: Application
    Filed: July 1, 2010
    Publication date: January 20, 2011
    Inventors: Masaharu FURUYA, Masahiko Satoh, Masanori Kawasumi, Hirokatsu Suzuki, Hirohmi Tamura, Kazuya Saitoh, Takuya Suganuma, Mugijirou Uno, Shunichi Hashimoto, Akira Shinshi, Kazuhisa Sudo, Tomoko Takahashi
  • Patent number: 7711300
    Abstract: An image forming apparatus includes an image carrier for bearing a visible image thereon, an endless transfer-fixing belt stretchedly disposed between a plurality of spanning members, a pressure member for pressing the transfer-fixing belt to the image carrier while contacting a backside of the transfer-fixing belt at the transfer nip, and a heater for heating the visible image. The visible image on the image carrier is transferred onto the front surface of the transfer-fixing belt at the transfer nip and is transported to the transfer-fixing nip while heated by the heater, where the visible image is transferred and fixed on a recording member. The transfer-fixing belt is stretchedly arranged such that the transfer-fixing belt travels in a direction substantially perpendicular to a pressure direction of the pressure member in the proximity of the transfer nip.
    Type: Grant
    Filed: September 19, 2007
    Date of Patent: May 4, 2010
    Assignee: Ricoh Company Ltd.
    Inventors: Atsushi Nakafuji, Takashi Fujita, Shin Kayahara, Hiromitsu Takagaki, Takashi Seto, Katsuaki Miyawaki, Kazumi Suzuki, Hirohmi Tamura
  • Patent number: 7711301
    Abstract: An image transfer device provided in an image forming apparatus in which, employing an endless belt as an intermediate transfer member, image transfer is performed at nip positions of a primary transfer portion and secondary transfer portion. Generation of warp in the transferred image resulting from transmission of fluctuations in load and torque of the endless belt generated at the nip position of one transfer portion nip to the nip position of the other transfer portion is prevented. The endless belt is turned between rollers and the endless belt is individually driven at the primary transfer portion and secondary transfer portion by drive sources to generate deflection between the primary transfer portion and the secondary transfer portion.
    Type: Grant
    Filed: March 7, 2007
    Date of Patent: May 4, 2010
    Assignee: Ricoh Company, Ltd.
    Inventors: Takeshi Takemoto, Takashi Seto, Katsuaki Miyawaki, Takashi Fujita, Hiromitsu Takagaki, Atsushi Nakafuji, Shin Kayahara, Hirohmi Tamura, Kazumi Suzuki
  • Patent number: 7551882
    Abstract: An image forming apparatus includes an image bearing member, a latent electrostatic image forming unit, a developing unit, an intermediate transferring unit which has an intermediate transfer belt and a plurality of rollers supporting the intermediate transfer belt, and a transfer fixing unit. The transfer fixing unit has a transfer fixing belt, a plurality of rollers supporting the transfer fixing belt, a heating member, and a pressurizing member forming a transfer fixing nip with the transfer fixing belt. A first roller, which is one of the plurality of rollers supporting the intermediate transferring belt, is opposite to a second roller, which is one of the plurality of rollers supporting the fixing transfer belt. The first roller and the second roller form a transfer nip between the intermediate transferring belt and the fixing transfer belt. The diameter of the first roller is smaller than the diameter of the second roller.
    Type: Grant
    Filed: June 1, 2007
    Date of Patent: June 23, 2009
    Assignee: Ricoh Company, Ltd.
    Inventors: Takashi Seto, Takashi Fujita, Katsuaki Miyawaki, Shin Kayahara, Atsushi Nakafuji, Kazumi Suzuki, Hirohmi Tamura, Hiromitsu Takagaki
  • Patent number: 7526242
    Abstract: A first guide member and a second guide member guide a recording medium into a nip between a transfer member and a nip-forming member. The first guide member and the second guide member are arranged so as to form a substantial V-shape with tip of the V-shape being toward the nip. A distance between the first guide member and the second guide member at the tip being equal to or less than 5 millimeters.
    Type: Grant
    Filed: September 15, 2006
    Date of Patent: April 28, 2009
    Assignee: Ricoh Company, Limited
    Inventors: Hiromitsu Takagaki, Takashi Fujita, Atsushi Nakafuji, Hirohmi Tamura, Hiroyuki Kunii, Kohji Ue
  • Publication number: 20080304879
    Abstract: An image forming apparatus includes a plurality of first image carriers on which different color toner images C are respectively formed, a transfer fixing member onto which a multicolor toner image A consisting of the toner images C is transferred, a heater located configured to fuse the toner image A on the transfer fixing member, a pressurizer pressing against the transfer fixing member, an image carrier located upstream of the transfer fixing member in a direction in which the recording medium is transported, on which a toner image B is formed, and a transferer facing the image carrier. The toner image A is transferred from the transfer fixing member and fixed on a recording medium in a nip formed between the transfer fixing member and the pressurizer. The toner image B is transferred from image carrier onto the recording medium before the toner image A is transferred thereonto and fixed thereon.
    Type: Application
    Filed: June 6, 2008
    Publication date: December 11, 2008
    Inventor: Hirohmi Tamura
  • Publication number: 20080219718
    Abstract: A transfer-fixing device transfers and fixes a toner image onto a transfer-fixing surface of a recording medium, and includes a transfer-fixing member, a pressing member, a heating member, and a temperature equalization member. The transfer-fixing member carries the toner image. The pressing member pressingly contacts the transfer-fixing member to form a nip between the pressing member and the transfer-fixing member through which the recording medium passes. The heating member heats the transfer-fixing surface of the recording medium conveyed toward the nip so that the recording medium reaches the nip before a temperature of a back surface opposite the transfer-fixing surface of the recording medium increases. The temperature equalization member equalizes temperature distribution on a surface of the transfer-fixing member in a width direction of the transfer-fixing member perpendicular to a conveyance direction of the recording medium, after the surface of the transfer-fixing member passes the nip.
    Type: Application
    Filed: March 6, 2008
    Publication date: September 11, 2008
    Inventors: Takashi Fujita, Shin Kayahara, Takeshi Takemoto, Hiromitsu Takagaki, Takashi Seto, Hirohmi Tamura
  • Publication number: 20080219717
    Abstract: The transfer-fixing device includes an image carrier, a pressing member, a heater, and an electrical field generator. The image carrier carries a toner image. The pressing member presses against the image carrier to form a transfer-fixing nip between the pressing member and the image carrier. The heater heats the toner image carried by the image carrier so that a temperature of the toner image is not higher than Tm +10 degrees centigrade when a toner softening point is Tm degrees centigrade. The electrical field generator forms a transfer electrical field at the transfer-fixing nip.
    Type: Application
    Filed: March 4, 2008
    Publication date: September 11, 2008
    Inventors: Shin KAYAHARA, Takashi FUJITA, Takeshi TAKEMOTO, Hiromitsu TAKAGAKI, Takashi SETO, Hirohmi TAMURA
  • Publication number: 20080199229
    Abstract: A transfer-fixing device includes a transfer-fixing member, a pressing member, a heating device, and a temperature equalizer. The transfer-fixing member carries the toner image. The pressing member presses against the transfer-fixing member to form a nip portion to which the recording medium is conveyed. The heating device heats the transfer-fixing surface of the recording medium conveyed toward the nip portion. The temperature equalizer equalizes a temperature distribution of a surface of the transfer-fixing member in a width direction of the transfer-fixing member after the surface of the transfer-fixing member passes through the nip portion.
    Type: Application
    Filed: February 15, 2008
    Publication date: August 21, 2008
    Inventors: Takashi Fujita, Shin Kayahara, Hiromitsu Takagaki, Takashi Seto, Takeshi Takemoto, Hirohmi Tamura
  • Publication number: 20080069610
    Abstract: An image forming apparatus includes an image carrier for bearing a visible image thereon, an endless transfer-fixing belt stretchedly disposed between a plurality of spanning members, a pressure member for pressing the transfer-fixing belt to the image carrier while contacting a backside of the transfer-fixing belt at the transfer nip, and a heater for heating the visible image. The visible image on the image carrier is transferred onto the front surface of the transfer-fixing belt at the transfer nip and is transported to the transfer-fixing nip while heated by the heater, where the visible image is transferred and fixed on a recording member. The transfer-fixing belt is stretchedly arranged such that the transfer-fixing belt travels in a direction substantially perpendicular to a pressure direction of the pressure member in the proximity of the transfer nip.
    Type: Application
    Filed: September 19, 2007
    Publication date: March 20, 2008
    Inventors: Atsushi NAKAFUJI, Takashi Fujita, Shin Kayahara, Hiromitsu Takagaki, Takashi Seto, Katsuaki Miyawaki, Kazumi Suzuki, Hirohmi Tamura
  • Publication number: 20080008505
    Abstract: An image forming apparatus includes an image bearing member, a latent electrostatic image forming unit, a developing unit, an intermediate transferring unit which has an intermediate transfer belt and a plurality of rollers supporting the intermediate transfer belt, and a transfer fixing unit. The transfer fixing unit has a transfer fixing belt, a plurality of rollers supporting the transfer fixing belt, a heating member, and a pressurizing member forming a transfer fixing nip with the transfer fixing belt. A first roller, which is one of the plurality of rollers supporting the intermediate transferring belt, is opposite to a second roller, which is one of the plurality of rollers supporting the fixing transfer belt. The first roller and the second roller form a transfer nip between the intermediate transferring belt and the fixing transfer belt. The diameter of the first roller is smaller than the diameter of the second roller.
    Type: Application
    Filed: June 1, 2007
    Publication date: January 10, 2008
    Inventors: Takashi SETO, Takashi Fujita, Katsuaki Miyawaki, Shin Kayahara, Atsushi Nakafuji, Kazumi Suzuki, Hirohmi Tamura, Hiromitsu Takagaki