Patents by Inventor Toshihiko Shimokawa

Toshihiko Shimokawa 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: 11662678
    Abstract: A fixing device includes a fixing rotator over which a recording medium bearing an image is conveyed. A first heater heats the fixing rotator and generates heat evenly in a maximum conveyance span where the recording medium having a maximum width in a width direction of the recording medium is conveyed. The maximum width is available for the fixing rotator. A second heater heats the fixing rotator and generates heat in the maximum conveyance span. The second heater includes a first portion that generates heat in a first heat generation amount and a second portion that generates heat in a second heat generation amount that is greater than the first heat generation amount of the first portion.
    Type: Grant
    Filed: November 24, 2021
    Date of Patent: May 30, 2023
    Assignee: RICOH COMPANY, LTD.
    Inventors: Ryohei Matsuda, Ryuuichi Mimbu, Toshihiko Shimokawa, Satoshi Kuno, Kentaro Yamanaka
  • Patent number: 11474461
    Abstract: A disclosed fixing device includes a pressing member; an endless tubular fixing member disposed opposite to the pressing member; a heating source configured to heat the fixing member; a nip forming member disposed opposite to the pressing member via the fixing member to form a nip portion; and a supply unit configured to supply lubricant to a portion of an inner surface of the fixing member, the portion facing the nip forming member, wherein the nip forming member includes a contact portion that contacts the inner surface of the fixing member, the contact portion includes a guide portion for guiding lubricant, and the guide portion is formed by extending obliquely from opposite ends in a width direction toward a center of the fixing member as the contact portion moves from upstream to downstream in a rotational direction of the fixing member.
    Type: Grant
    Filed: March 7, 2019
    Date of Patent: October 18, 2022
    Assignee: RICOH COMPANY, LTD.
    Inventors: Ryuuichi Mimbu, Toshihiko Shimokawa, Kazuya Saito
  • Publication number: 20220171315
    Abstract: A fixing device includes a fixing rotator over which a recording medium bearing an image is conveyed. A first heater heats the fixing rotator and generates heat evenly in a maximum conveyance span where the recording medium having a maximum width in a width direction of the recording medium is conveyed. The maximum width is available for the fixing rotator. A second heater heats the fixing rotator and generates heat in the maximum conveyance span. The second heater includes a first portion that generates heat in a first heat generation amount and a second portion that generates heat in a second heat generation amount that is greater than the first heat generation amount of the first portion.
    Type: Application
    Filed: November 24, 2021
    Publication date: June 2, 2022
    Inventors: Ryohei MATSUDA, Ryuuichi MIMBU, Toshihiko SHIMOKAWA, Satoshi KUNO, Kentaro YAMANAKA
  • Patent number: 11320767
    Abstract: A heating device includes a tubular rotator that rotates and a heat source that heats the tubular rotator. A thermal conductor includes a first face that contacts the tubular rotator and a second face that is opposite the first face. A first thickness portion is disposed in a first span of the thermal conductor in a longitudinal direction of the thermal conductor. The first thickness portion has a first thickness. A second thickness portion is disposed in at least a part of a second span of the thermal conductor in the longitudinal direction of the thermal conductor. The second span is different from the first span. The second thickness portion has a second thickness that is greater than the first thickness of the first thickness portion. The second thickness portion includes a folded portion that is disposed on the second face.
    Type: Grant
    Filed: January 25, 2021
    Date of Patent: May 3, 2022
    Assignee: RICOH COMPANY, LTD.
    Inventors: Toshihiko Shimokawa, Ippei Fujimoto
  • Publication number: 20210294247
    Abstract: A heating device includes a tubular rotator that rotates and a heat source that heats the tubular rotator. A thermal conductor includes a first face that contacts the tubular rotator and a second face that is opposite the first face. A first thickness portion is disposed in a first span of the thermal conductor in a longitudinal direction of the thermal conductor. The first thickness portion has a first thickness. A second thickness portion is disposed in at least a part of a second span of the thermal conductor in the longitudinal direction of the thermal conductor. The second span is different from the first span. The second thickness portion has a second thickness that is greater than the first thickness of the first thickness portion. The second thickness portion includes a folded portion that is disposed on the second face.
    Type: Application
    Filed: January 25, 2021
    Publication date: September 23, 2021
    Applicant: Ricoh Company, Ltd.
    Inventors: Toshihiko SHIMOKAWA, Ippei FUJIMOTO
  • Patent number: 10935911
    Abstract: A fixing device includes an endless belt rotatable in a predetermined direction of rotation and a nip formation assembly disposed opposite an inner circumferential surface of the endless belt. An opposed rotary body is pressed against the nip formation assembly via the endless belt to form a fixing nip between the endless belt and the opposed rotary body through which a recording medium bearing a toner image is conveyed. A belt holder contacts and supports each lateral end of the endless belt in an axial direction thereof. The belt holder is isolated from the opposed rotary body with a first interval interposed therebetween in the axial direction of the endless belt.
    Type: Grant
    Filed: October 30, 2017
    Date of Patent: March 2, 2021
    Assignee: Ricoh Company, Ltd.
    Inventors: Teppei Kawata, Masahiko Satoh, Masaaki Yoshikawa, Kenji Ishii, Hiroshi Yoshinaga, Tadashi Ogawa, Takahiro Imada, Hiromasa Takagi, Kazuya Saito, Naoki Iwaya, Kensuke Yamaji, Takamasa Hase, Toshihiko Shimokawa, Shuutaroh Yuasa, Takuya Seshita, Takeshi Uchitani, Arinobu Yoshiura, Hajime Gotoh, Akira Suzuki
  • Publication number: 20210041812
    Abstract: A disclosed fixing device includes a pressing member; an endless tubular fixing member disposed opposite to the pressing member; a heating source configured to heat the fixing member; a nip forming member disposed opposite to the pressing member via the fixing member to form a nip portion; and a supply unit configured to supply lubricant to a portion of an inner surface of the fixing member, the portion facing the nip forming member, wherein the nip forming member includes a contact portion that contacts the inner surface of the fixing member, the contact portion includes a guide portion for guiding lubricant, and the guide portion is formed by extending obliquely from opposite ends in a width direction toward a center of the fixing member as the contact portion moves from upstream to downstream in a rotational direction of the fixing member.
    Type: Application
    Filed: March 7, 2019
    Publication date: February 11, 2021
    Inventors: Ryuuichi MIMBU, Toshihiko SHIMOKAWA, Kazuya SAITO
  • Patent number: 10678170
    Abstract: A fixing device includes a fixing rotator being rotatable and a heater to heat the fixing rotator. The heater includes a tube, a heat generator, disposed inside the tube, to generate heat, and a sealing portion, disposed at each lateral end of the tube in a longitudinal direction of the heater, to seal the tube. A reflector reflects heat radiated from the heater toward the fixing rotator. The reflector includes an outboard edge being disposed inboard from at least a part of the sealing portion in an axial direction of the fixing rotator.
    Type: Grant
    Filed: November 9, 2018
    Date of Patent: June 9, 2020
    Assignee: RICOH COMPANY, LTD.
    Inventors: Yasunori Ishigaya, Kazuya Saito, Keitaro Shoji, Toshihiko Shimokawa, Hiromasa Takagi
  • Publication number: 20190094764
    Abstract: A fixing device includes a fixing rotator being rotatable and a heater to heat the fixing rotator. The heater includes a tube, a heat generator, disposed inside the tube, to generate heat, and a sealing portion, disposed at each lateral end of the tube in a longitudinal direction of the heater, to seal the tube. A reflector reflects heat radiated from the heater toward the fixing rotator. The reflector includes an outboard edge being disposed inboard from at least a part of the sealing portion in an axial direction of the fixing rotator.
    Type: Application
    Filed: November 9, 2018
    Publication date: March 28, 2019
    Inventors: Yasunori ISHIGAYA, Kazuya SAITO, Keitaro SHOJI, Toshihiko SHIMOKAWA, Hiromasa TAKAGI
  • Patent number: 10156818
    Abstract: A fixing device includes a fixing rotator being rotatable and a heater to heat the fixing rotator. The heater includes a tube, a heat generator, disposed inside the tube, to generate heat, and a sealing portion, disposed at each lateral end of the tube in a longitudinal direction of the heater, to seal the tube. The sealing portion includes an inboard edge. A reflector reflects heat radiated from the heater toward the fixing rotator. The reflector includes an outboard edge being disposed inboard from the inboard edge of the sealing portion in an axial direction of the fixing rotator.
    Type: Grant
    Filed: January 19, 2017
    Date of Patent: December 18, 2018
    Assignee: Ricoh Company, Ltd.
    Inventors: Yasunori Ishigaya, Kazuya Saito, Keitaro Shoji, Toshihiko Shimokawa, Hiromasa Takagi
  • Patent number: 10152006
    Abstract: A fixing device includes a rotatable endless belt formed into a loop and a heater disposed opposite the endless belt to heat the endless belt. A nip formation pad is disposed inside the loop formed by the endless belt. The nip formation pad includes a metallic thermal equalizer extending in an axial direction of the endless belt. A rotatable pressure rotator presses against the nip formation pad via the endless belt to form a fixing nip between the endless belt and the pressure rotator, through which a recording medium bearing a toner image is conveyed. The pressure rotator includes an increased tackiness portion disposed at a lateral end of the pressure rotator in an axial direction of the pressure rotator to transmit a driving force to the endless belt. The increased tackiness portion is disposed opposite the thermal equalizer of the nip formation pad.
    Type: Grant
    Filed: May 20, 2016
    Date of Patent: December 11, 2018
    Assignee: Ricoh Company, Ltd.
    Inventors: Yasunori Ishigaya, Yutaka Ikebuchi, Kazuya Saito, Keitaro Shoji, Ryohei Matsuda, Hiromasa Takagi, Ryuuichi Mimbu, Toshihiko Shimokawa
  • Patent number: 10061235
    Abstract: A fixing device includes an endless fixing belt that is multilayered, an opposing rotator disposed opposite the fixing belt and pressed to the fixing belt to form a nip, a heater disposed inside the fixing belt, and a safety device including a contactless temperature sensor disposed outside the fixing belt and apart from an outer face of the fixing. The fixing belt is to rotate and thermally expand. The contactless temperature sensor detects a temperature of the fixing belt. The safety device stops heating by the heater when the temperature detected by the contactless temperature sensor is at or higher than a predetermined temperature. As the outer face of the fixing belt shifts outward in the radial direction due to thermal, a proportion of the outer face of the fixing belt in a viewing angle of the contactless temperature sensor increases.
    Type: Grant
    Filed: December 30, 2016
    Date of Patent: August 28, 2018
    Assignee: Ricoh Company, Ltd.
    Inventors: Keitaro Shoji, Yasunori Ishigaya, Kazuya Saito, Ryohei Matsuda, Hiromasa Takagi, Ryuuichi Mimbu, Toshihiko Shimokawa
  • Patent number: 10012932
    Abstract: An image forming apparatus includes a fixing device to fix a toner image onto a recording medium, a voltmeter to measure an input voltage from an external source, and a controller operatively connected to the fixing device and the voltmeter. The fixing device includes an endless, fixing rotator formed into a loop, a heater to heat the fixing rotator, a pressure pad disposed inside the loop, and a pressure rotator disposed opposite the pressure pad via the fixing rotator to press the fixing rotator against the pressure pad to form a fixing nip between the fixing rotator and the pressure rotator, through which the recording medium bearing the toner image is conveyed. The controller controls a heating operation of the heater and a fixing operation of the fixing device to fix the toner image onto the recording medium, based on the input voltage measured by the voltmeter.
    Type: Grant
    Filed: January 9, 2017
    Date of Patent: July 3, 2018
    Assignee: Ricoh Company, Ltd.
    Inventors: Yasunori Ishigaya, Ryuuichi Mimbu, Hiromasa Takagi, Toshihiko Shimokawa, Kazuya Saito, Keitaro Shoji
  • Patent number: 10001735
    Abstract: A fixing device may include an endless fixing member; a heater inside the fixing member; and a nip forming unit configured to form a nip through which a recording sheet is conveyed, the nip forming unit including a supporting member and a contact member supported by the supporting member, the supporting member including at least one contact surface and the contact member including a plurality of protrusions protruding towards the supporting member such that two or more of the plurality of protrusions are configured to contact one of the at least one contact surface of the supporting member, each of the plurality of protrusions having a height associated there with such that the height of the plurality of protrusions increases in a direction from ends of the contact member towards a center of the contact member.
    Type: Grant
    Filed: December 20, 2016
    Date of Patent: June 19, 2018
    Assignee: Ricoh Company, Limited
    Inventors: Takahiro Imada, Masaaki Yoshikawa, Kenji Ishii, Hiroshi Yoshinaga, Yuji Arai, Naoki Iwaya, Tetsuo Tokuda, Hiromasa Takagi, Yoshiki Yamaguchi, Ippei Fujimoto, Takuya Seshita, Yutaka Ikebuchi, Arinobu Yoshiura, Toshihiko Shimokawa, Hajime Gotoh
  • Patent number: 9983526
    Abstract: A fixing device includes a heat source; a fixing member looped into a generally cylindrical shape to rotate in a circumferential direction thereof and partially heated by the heat source and to heat a surface of a recording medium bearing an unfixed toner image to fix the unfixed toner image thereon in a fixing process; a rotary pressing member disposed facing the fixing member to form a nip therebetween, through which the recording medium is transported in a transport direction; and a rotation driver to rotate one of the fixing member and the pressing member. In a case in which the fixing member is halted for a reason other than the fixing process while power of the fixing device is on, electric power is not supplied to the heat source and the fixing member is rotated by a predetermined amount or more after the fixing member is halted.
    Type: Grant
    Filed: June 9, 2017
    Date of Patent: May 29, 2018
    Assignee: Ricoh Company, Ltd.
    Inventors: Takeshi Uchitani, Masahiko Satoh, Kenji Ishii, Tadashi Ogawa, Teppei Kawata, Arinobu Yoshiura, Toshihiko Shimokawa, Kensuke Yamaji, Takamasa Hase, Shuutaroh Yuasa, Masaaki Yoshikawa, Hiromasa Takagi, Takahiro Imada, Hajime Gotoh, Akira Suzuki, Takuya Seshita, Hiroshi Yoshinaga, Kazuya Saito, Shinichi Namekata, Takayuki Seki, Yuji Arai, Ryuuichi Mimbu, Yoshiki Yamaguchi, Shuntaroh Tamaki, Yutaka Ikebuchi
  • Patent number: 9971289
    Abstract: An image forming apparatus includes a fixing device. The fixing device includes a rotatable endless fixing member, a nip forming member arranged inside the fixing member, a pressing member in contact with the nip forming member via the fixing member, and a heating source configured to heat the fixing member. When an abnormality occurs in at least one of the fixing device and other devices included in the image forming apparatus, a rotation of the fixing member is stopped prior to stopping a rotation driving of a discharging unit and, after stopping, the fixing member is controlled to rotate.
    Type: Grant
    Filed: May 23, 2017
    Date of Patent: May 15, 2018
    Assignee: RICOH COMPANY, LTD.
    Inventors: Takamasa Hase, Masahiko Satoh, Shinichi Namekata, Kenji Ishii, Takeshi Uchitani, Tadashi Ogawa, Teppei Kawata, Arinobu Yoshiura, Kazuya Saito, Toshihiko Shimokawa, Shuutaroh Yuasa, Kensuke Yamaji, Masaaki Yoshikawa, Hiroshi Yoshinaga, Hiromasa Takagi, Naoki Iwaya, Takuya Seshita, Takahiro Imada, Hajime Gotoh, Akira Suzuki
  • Patent number: 9927748
    Abstract: A fixing device includes: a rotatable endless fixing belt; a nip forming member arranged inside the fixing belt; a facing rotating body that abuts the nip forming member via the fixing belt to form a nip portion with the fixing belt; a heat source that directly heats up the fixing belt at a portion other than the nip portion; and a supporting member that supports the nip forming member. The fixing device conveys a recording medium carrying an unfixed image to the nip portion to fix the unfixed image to the recording medium, and the supporting member includes a rising portion extending in an abutting direction of the facing rotating body against the fixing belt and having a tip close to an inner circumferential surface of the fixing belt, and is set to have a section modulus of 200 mm3 or higher.
    Type: Grant
    Filed: January 28, 2013
    Date of Patent: March 27, 2018
    Assignee: RICOH COMPANY, LTD.
    Inventors: Hiroshi Yoshinaga, Masahiko Satoh, Masaaki Yoshikawa, Kenji Ishii, Tadashi Ogawa, Hiromasa Takagi, Naoki Iwaya, Takuya Seshita, Takahiro Imada, Hajime Gotoh, Akira Suzuki, Teppei Kawata, Toshihiko Shimokawa, Arinobu Yoshiura, Takamasa Hase, Takeshi Uchitani, Shuutaroh Yuasa, Kensuke Yamaji
  • Patent number: 9904220
    Abstract: A fixing device includes a fixing belt and an opposed rotator to press against a nip formation pad via the fixing belt to form a fixing nip between the fixing belt and the opposed rotator. A primary heater and a secondary heater heat the fixing belt. The secondary heater includes a lateral end heat generator. The nip formation pad includes a base and at least one thermal conductor being interposed between the base and the fixing nip and having a thermal conductivity greater than a thermal conductivity of the base. The at least one thermal conductor includes an outboard edge disposed between an inboard edge and an outboard edge of the lateral end heat generator and disposed outboard from a conveyance span of the fixing belt in an axial direction of the fixing belt, where a recording medium is conveyed over the fixing belt.
    Type: Grant
    Filed: February 16, 2017
    Date of Patent: February 27, 2018
    Assignee: Ricoh Company, Ltd.
    Inventors: Kazuya Saito, Yasunori Ishigaya, Keitaro Shoji, Hiromasa Takagi, Toshihiko Shimokawa
  • Publication number: 20180046121
    Abstract: A fixing device includes an endless belt rotatable in a predetermined direction of rotation and a nip formation assembly disposed opposite an inner circumferential surface of the endless belt. An opposed rotary body is pressed against the nip formation assembly via the endless belt to form a fixing nip between the endless belt and the opposed rotary body through which a recording medium bearing a toner image is conveyed. A belt holder contacts and supports each lateral end of the endless belt in an axial direction thereof. The belt holder is isolated from the opposed rotary body with a first interval interposed therebetween in the axial direction of the endless belt.
    Type: Application
    Filed: October 30, 2017
    Publication date: February 15, 2018
    Inventors: Teppei KAWATA, Masahiko SATOH, Masaaki YOSHIKAWA, Kenji ISHll, Hiroshi YOSHINAGA, Tadashi OGAWA, Takahiro IMADA, Hiromasa TAKAGI, Kazuya SAITO, Naoki IWAYA, Kensuke YAMAJI, Takamasa HASE, Toshihiko SHIMOKAWA, Shuutaroh YUASA, Takuya SESHITA, Takeshi UCHITANI, Arinobu YOSHIURA, Hajime GOTOH, Akira SUZUKI
  • Patent number: 9811029
    Abstract: A fixing device has a flexible endless fixing member; a heater to heat the fixing member; a nip forming member to contact the fixing member directly or via a slide member; a pressure member, rotatably disposed opposite the fixing member and the nip forming member; and a back curl correction structure that includes a drive roller disposed on a side where a back curl appears in the recording sheet; a driven roller disposed opposite the drive roller; an auxiliary nip portion to feed the recording sheet; a guide member to guide the recording sheet fed out from the auxiliary nip portion to bend in a direction opposite a curled direction of the back curl of the recording sheet. A driving connection between the drive roller and the pressure member is performed by a connection between a drive roller side connection gear and a pressure member side connection gear.
    Type: Grant
    Filed: March 18, 2016
    Date of Patent: November 7, 2017
    Assignee: Ricoh Company, Ltd.
    Inventors: Haruyuki Honda, Ryuuichi Mimbu, Yoshio Hattori, Yoshiki Yamaguchi, Toshihiko Shimokawa