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).

  • Publication number: 20140341624
    Abstract: A fixing device includes a fixing rotary body and a heater disposed opposite and heating the fixing rotary body. A nip formation assembly presses against an opposed body via the fixing rotary body to form a fixing nip between the fixing rotary body and the opposed body, through which a recording medium is conveyed. A movable heat shield movable in a circumferential direction of the fixing rotary body is interposed between the heater and the fixing rotary body to shield the fixing rotary body from the heater in a variable axial span of the fixing rotary body. A stationary heat shield, interposed between the heater and the fixing rotary body to shield the fixing rotary body from the heater, is disposed outboard from a lateral edge of a heat generator of the heater in an axial direction of the fixing rotary body.
    Type: Application
    Filed: May 1, 2014
    Publication date: November 20, 2014
    Inventors: Yuji ARAI, Masaaki Yoshikawa, Takayuki Seki, Takeshi Yamamoto, Ryuuichi Mimbu, Yutaka Ikebuchi, Takuya Seshita, Shuntaro Tamaki, Hajime Gotoh, Takahiro Imada, Kazuya Saito, Toshihiko Shimokawa, Shuutaroh Yuasa, Kensuke Yamaji, Akira Suzuki, Hiroshi Yoshinaga
  • Patent number: 8886103
    Abstract: A fixing device includes an endless belt and a belt holder contacting and rotatably supporting each lateral end of the endless belt in an axial direction thereof. A first protection ring and a second protection ring are interposed between the endless belt and the belt holder in the axial direction of the endless belt and rotatable in accordance with rotation of the endless belt to protect each lateral end of the endless belt as the endless belt is skewed in the axial direction thereof and brought into contact with the first protection ring. A friction coefficient between the first protection ring and the second protection ring is smaller than a friction coefficient between the first protection ring and the endless belt.
    Type: Grant
    Filed: January 22, 2013
    Date of Patent: November 11, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Kensuke Yamaji, Masahiko Satoh, Masaaki Yoshikawa, Hiroshi Yoshinaga, Kenji Ishii, Tadashi Ogawa, Takeshi Uchitani, Hiromasa Takagi, Naoki Iwaya, Teppei Kawata, Arinobu Yoshiura, Takahiro Imada, Hajime Gotoh, Takamasa Hase, Kazuya Saito, Toshihiko Shimokawa, Shuutaroh Yuasa, Akira Suzuki
  • Patent number: 8886090
    Abstract: A fixing device comprises a rotatable fixing member to heat a side of a recording medium bearing an unfixed image; a heat source to heat the rotatable fixing member; a rotatable pressing member disposed opposite the fixing member to press against an outer side of the fixing member; a housing to accommodate the fixing member and the pressing member; a conveyance path defined internally within the fixing device to convey a recording medium therethrough and between the fixing member and the pressing member, and a shutter actuator to move the shutter to open and close the conveyance path. The housing holds the shutter and the shutter actuator.
    Type: Grant
    Filed: December 11, 2012
    Date of Patent: November 11, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Teppei Kawata, Kenji Ishii, Tadashi Ogawa, Arinobu Yoshiura, Toshihiko Shimokawa, Kensuke Yamaji, Yuji Arai, Yoshiki Yamaguchi, Hiromasa Takagi, Naoki Iwaya, Takahiro Imada, Hajime Gotoh, Akira Suzuki, Masaaki Yoshikawa, Takayuki Seki, Shuntaroh Tamaki, Kazuya Saito, Yutaka Ikebuchi
  • Patent number: 8886101
    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: November 15, 2012
    Date of Patent: November 11, 2014
    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
  • Patent number: 8873984
    Abstract: A fixing device includes a fixing rotary body rotatable in a predetermined direction of rotation and a heater disposed opposite and heating a heating span of the fixing rotary body. A controller is operatively connected to a power supply that supplies power to the heater and a driver that rotates the fixing rotary body to control the power supply and the driver. The controller performs at least one of a rotation speed control that controls the driver to rotate the fixing rotary body at an increased rotation speed and a power supply control that controls the power supply to supply an increased amount of power to the heater.
    Type: Grant
    Filed: March 8, 2013
    Date of Patent: October 28, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Kenji Ishii, Yuji Arai, Yoshiki Yamaguchi, Arinobu Yoshiura, Toshihiko Shimokawa, Masaaki Yoshikawa, Hiromasa Takagi, Akira Suzuki, Naoki Iwaya, Takahiro Imada, Hajime Gotoh, Tadashi Ogawa, Kensuke Yamaji, Teppei Kawata
  • Patent number: 8867976
    Abstract: A fixing device includes a support member fixedly provided inside a loop formed by a fixing member to support a nip formation member provided inside the loop formed by the fixing member. A biasing member is provided between the support member and a heater support that supports a laminated heater that generates heat to be transmitted to the fixing member. The heater support thermally expands in a first direction due to heat generated by the laminated heater. The biasing member applies bias to the heater support in a second direction opposite the first direction and in which the heater support presses the laminated heater against an inner circumferential surface of the fixing member.
    Type: Grant
    Filed: February 16, 2011
    Date of Patent: October 21, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Ippei Fujimoto, Kenji Ishii, Masaaki Yoshikawa, Hiroshi Yoshinaga, Naoki Iwaya, Yoshiki Yamaguchi, Yutaka Ikebuchi, Tetsuo Tokuda, Takahiro Imada, Takamasa Hase, Toshihiko Shimokawa, Takuya Seshita
  • Patent number: 8855506
    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: February 8, 2013
    Date of Patent: October 7, 2014
    Assignee: Ricoh Company, Limited
    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: 8843043
    Abstract: A fixing device includes a flexible, endless belt-shaped fixing member that rotates in a predetermined direction of rotation, a substantially cylindrical metal heat conductor provided inside a loop formed by the fixing member and facing an inner circumferential surface of the fixing member, a pressing member that presses the fixing member against the metal heat conductor to form a nip between the fixing member and the pressing member through which a recording medium bearing a toner image passes, and a separator that presses the fixing member against the metal heat conductor, provided downstream from the nip in the direction of rotation of the fixing member and contacting the recording medium discharged from the nip to separate the recording medium from the fixing member and guide the recording medium out of the fixing device.
    Type: Grant
    Filed: December 9, 2010
    Date of Patent: September 23, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Naoki Iwaya, Masaaki Yoshikawa, Akira Shinshi, Kenji Ishii, Kenichi Hasegawa, Hiroshi Yoshinaga, Yoshiki Yamaguchi, Yutaka Ikebuchi, Ippei Fujimoto, Shuntaroh Tamaki, Toshihiko Shimokawa, Tetsuo Tokuda
  • Publication number: 20140270831
    Abstract: An image forming apparatus includes a fixing device including a fixing rotary body and a heater for heating the fixing rotary body. An opposed body contacts the fixing rotary body with releasable pressure therebetween to form a fixing nip therebetween through which a recording medium is conveyed. A heat shield is interposed between the heater and the fixing rotary body and movable in a circumferential direction of the fixing rotary body to shield the fixing rotary body from the heater in a variable circumferential direct heating span of the fixing rotary body where the heater is disposed opposite the fixing rotary body directly. A controller halts the heat shield instantly when a fault occurs during a print job.
    Type: Application
    Filed: December 30, 2013
    Publication date: September 18, 2014
    Inventors: Hiroshi YOSHINAGA, Takayuki SEKI, Yuji ARAI, Yutaka IKEBUCHI, Ryuuichi MIMBU, Yoshiki YAMAGUCHI, Shuntaro TAMAKI, Kazuya SAITO, Shuutaroh YUASA, Toshihiko SHIMOKAWA
  • Publication number: 20140270872
    Abstract: A fixing device includes a fixing rotary body rotatable in a predetermined direction of rotation and a heater disposed opposite and heating the fixing rotary body. An opposed body contacts the fixing rotary body to form a fixing nip therebetween through which a recording medium is conveyed. A heat shield is movable in a circumferential direction of the fixing rotary body and interposed between the heater and the fixing rotary body to shield the fixing rotary body from the heater. A driver is connected to the heat shield to drive and move the heat shield between a shield position where the heat shield is interposed between the heater and the fixing rotary body to shield the fixing rotary body from the heater and a retracted position where the heat shield is retracted from the shield position. A reinforcement is mounted on a long edge of the heat shield.
    Type: Application
    Filed: December 26, 2013
    Publication date: September 18, 2014
    Applicant: RICOH COMPANY, LTD.
    Inventors: Shuntaroh Tamaki, Takayuki Seki, Hiroshi Yoshinaga, Yuji Arai, Ryuuichi Mimbu, Yoshiki Yamaguchi, Yutaka Ikebuchi, Kazuya Saito, Toshihiko Shimokawa, Shuutaroh Yuasa
  • Publication number: 20140270832
    Abstract: A fixing device includes a fixing rotary body rotatable in a predetermined direction of rotation and a heater disposed opposite and heating the fixing rotary body. An opposed body contacts the fixing rotary body with releasable pressure therebetween to form a fixing nip therebetween through which a recording medium is conveyed. A heat shield is interposed between the heater and the fixing rotary body and movable in a circumferential direction of the fixing rotary body between a home position where the heat shield is disposed opposite the heater indirectly and a shield position where the heat shield is disposed opposite the heater directly to shield the fixing rotary body from the heater. A controller is operatively connected to the heat shield to move the heat shield to the home position when a print job is finished.
    Type: Application
    Filed: January 22, 2014
    Publication date: September 18, 2014
    Applicant: RICOH COMPANY, LTD.
    Inventors: Kazuya Saito, Takayuki Seki, Yuji Arai, Ryuuichi Mimbu, Yoshiki Yamaguchi, Shuntaro Tamaki, Toshihiko Shimokawa, Hiroshi Yoshinaga, Yutaka Ikebuchi, Shuutaroh Yuasa
  • Publication number: 20140270820
    Abstract: A fixing device includes a fixing rotary body rotatable in a predetermined direction of rotation and a heater disposed opposite and heating the fixing rotary body. A heat shield is movable in a circumferential direction of the fixing rotary body and interposed between the heater and the fixing rotary body to shield the fixing rotary body from the heater. A driver is connected to the heat shield to drive and move the heat shield within a circumferential moving span in the circumferential direction of the fixing rotary body. An abnormal temperature detector detects an abnormal temperature of the fixing rotary body that is not lower than a predetermined temperature. The abnormal temperature detector is disposed opposite a circumferential outboard span outboard from the circumferential moving span of the heat shield in the circumferential direction of the fixing rotary body.
    Type: Application
    Filed: December 26, 2013
    Publication date: September 18, 2014
    Applicant: RICOH COMPANY, LTD.
    Inventors: Kazuya Saito, Takayuki Seki, Hiroshi Yoshinaga, Yuji Arai, Ryuuichi Mimbu, Yutaka Ikebuchi, Yoshiki Yamaguchi, Shuntaroh Tamaki, Toshihiko Shimokawa, Shuutaroh Yuasa
  • Publication number: 20140270875
    Abstract: A pressure adjuster for changing pressure between a plurality of opposed bodies pressed against each other includes a cam rotatable in a given direction of rotation and having a top dead center on an outer circumferential surface thereof that is distanced farthest from a rotation axis of the cam. A driver is connected to the cam to drive and rotate the cam. A cam rest contacts the cam and is connected to one of the plurality of opposed bodies. A cam regulation assembly is connected to the cam to regulate rotation of the cam at least when the top dead center of the cam passes a contact position where the cam contacts the cam rest.
    Type: Application
    Filed: February 28, 2014
    Publication date: September 18, 2014
    Applicant: RICOH COMPANY, LTD.
    Inventors: Ryuuichi MIMBU, Takayuki SEKI, Hiroshi YOSHINAGA, Yuji ARAI, Yutaka IKEBUCHI, Yoshiki YAMAGUCHI, Kazuya SAITO, Shuutaroh YUASA, Shuntaro TAMAKI, Toshihiko SHIMOKAWA, Naoki IWAYA
  • Publication number: 20140270833
    Abstract: A fixing device includes a fixing rotary body and a heater for heating the fixing rotary body. An opposed body contacts the fixing rotary body with releasable pressure therebetween to form a fixing nip therebetween through which a recording medium is conveyed. A heat shield is interposed between the heater and the fixing rotary body and movable in a circumferential direction of the fixing rotary body to shield the fixing rotary body from the heater in a variable circumferential direct heating span of the fixing rotary body where the heater is disposed opposite the fixing rotary body directly. A controller is operatively connected to the heater and the heat shield to move the heat shield after the controller turns on the heater as a print job starts so as to change an area of the direct heating span of the fixing rotary body.
    Type: Application
    Filed: February 7, 2014
    Publication date: September 18, 2014
    Applicant: RICOH COMPANY, LTD.
    Inventors: Shuutaroh Yuasa, Shuntaro Tamaki, Takayuki Seki, Hiroshi Yoshinaga, Yuji Arai, Ryuuichi Mimbu, Yoshiki Yamaguchi, Toshihiko Shimokawa, Yutaka Ikebuchi, Kazuya Saito
  • Patent number: 8831494
    Abstract: A fixing device includes a substantially cylindrical metal member, a heater positioned to heat the metal member, an endless, flexible fixing member disposed rotatably around the metal member and heated by the metal member to heat and fix a toner image, a rotary pressing member disposed opposite the metal member and pressed against an outer circumferential surface of the fixing member to form a nip therebetween, and a stationary member disposed at an inner circumferential surface side of the fixing member and pressed by the pressing member via the fixing member to form the nip. At least when the fixing member is relatively moved toward the metal member during assembly of the fixing member with the metal member, the metal member includes at least one protruding portion protruding axially outward from an axial end of the metal member to guide the fixing member axially toward the metal member.
    Type: Grant
    Filed: February 15, 2011
    Date of Patent: September 9, 2014
    Assignee: Ricoh Company Limited
    Inventors: Yutaka Ikebuchi, Hiroshi Yoshinaga, Toshihiko Shimokawa, Masaaki Yoshikawa, Yoshiki Yamaguchi, Naoki Iwaya, Tetsuo Tokuda, Kenji Ishii, Ippei Fujimoto, Shuntaroh Tamaki, Akira Shinshi, Takahiro Imada, Takamasa Hase, Kenichi Hasegawa
  • Patent number: 8831498
    Abstract: A fixing device includes a rotatable, endless flexible belt, an elongated stationary pad, a rotatable pressure member, a rotary driver, a releasable biasing mechanism, a first guide member, and a second guide member. The endless flexible belt is looped into a generally cylindrical configuration. The elongated stationary pad is stationarily disposed inside the loop of the belt. The rotatable pressure member is disposed parallel to the stationary pad with the belt interposed between the pressure member and the stationary pad. The rotary driver is operatively connected with the pressure member to impart torque to the pressure member. The releasable biasing mechanism is operatively connected with the pressure member to apply a releasable pressure to the pressure member against the belt in a load direction. The first guide member defines a first elongated opening. The second guide member defines a second elongated opening.
    Type: Grant
    Filed: March 12, 2013
    Date of Patent: September 9, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Naoki Iwaya, Masahiko Satoh, Masaaki Yoshikawa, Hiroshi Yoshinaga, Kenji Ishii, Tadashi Ogawa, Hiromasa Takagi, Takeshi Uchitani, Takuya Seshita, Takahiro Imada, Hajime Gotoh, Akira Suzuki, Teppei Kawata, Toshihiko Shimokawa, Arinobu Yoshiura, Takamasa Hase, Shuutaroh Yuasa, Kensuke Yamaji
  • Publication number: 20140248072
    Abstract: A fixing device includes a support member disposed to support a nip formation member on an inner peripheral surface of a fixing belt. The support member includes a parallel portion that supports the nip formation member and extends parallel to a sheet transport direction in a nip portion, and a rise portion that extends from the parallel portion in a direction drawn apart from the nip portion. The rise portion is inclined to the parallel portion such that an inclination direction of the rise portion is substantially parallel to a virtual straight line connecting a center of rotation of the fixing belt and an inlet point of the nip portion or falls within a range of rotational angles of ±15° by which the virtual straight line is rotated around the center of rotation of the fixing belt.
    Type: Application
    Filed: February 25, 2014
    Publication date: September 4, 2014
    Applicant: RICOH COMPANY, LTD.
    Inventors: Hiroshi Yoshinaga, Takayuki Seki, Yuji Arai, Ryuuichi Mimbu, Yutaka Ikebuchi, Yoshiki Yamaguchi, Shuntaro Tamaki, Kazuya Saito, Shuutaroh Yuasa, Toshihiko Shimokawa
  • Patent number: 8811837
    Abstract: A fixing device includes a substantially cylindrical metal member, a heater, an endless, flexible fixing member, a rotary pressing member, a stationary member, a first temperature detector, and a second temperature detector. The first temperature detector is disposed upstream from a nip in a rotation direction of the fixing member to detect a surface temperature of the fixing member. The second temperature detector is disposed downstream from the nip in a rotation direction of the pressing member to detect a surface temperature of the pressing member. When a difference between a surface temperature of the fixing member detected by the first temperature detector and a surface temperature of the pressing member detected by the second temperature detector after a predetermined time has elapsed since the first temperature detector detects the surface temperature of the fixing member is greater than a predetermined threshold, the heater stops heating the metal member.
    Type: Grant
    Filed: February 28, 2011
    Date of Patent: August 19, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Hiroshi Yoshinaga, Kenichi Hasegawa, Masaaki Yoshikawa, Kenji Ishii, Akira Shinshi, Naoki Iwaya, Yutaka Ikebuchi, Tetsuo Tokuda, Ippei Fujimoto, Yoshiki Yamaguchi, Takahiro Imada, Takamasa Hase, Toshihiko Shimokawa
  • Patent number: 8811874
    Abstract: A belt device includes a flange assembly including a tube inserted into a loop formed by an endless belt at each lateral end of the endless belt in an axial direction thereof and a slip ring slidably contacting a groove mounted on the tube. An inner diameter ID 51 of the slip ring through a rotation axis of the slip ring is smaller than a minimum outer diameter OD50a of the tube through the rotation axis of the slip ring. The minimum outer diameter OD50a is smaller than a maximum outer diameter OD21 of a track of the endless belt rotating in a predetermined direction of rotation through the rotation axis of the slip ring. The maximum outer diameter OD21 is smaller than an outer diameter OD51 of the slip ring through the rotation axis of the slip ring.
    Type: Grant
    Filed: July 25, 2012
    Date of Patent: August 19, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Toshihiko Shimokawa, Kenji Ishii, Masaaki Yoshikawa, Hiroshi Yoshinaga, Naoki Iwaya, Yoshiki Yamaguchi, Yutaka Ikebuchi, Tetsuo Tokuda, Takahiro Imada, Takamasa Hase, Ippei Fujimoto, Takuya Seshita
  • Patent number: 8792797
    Abstract: A fixing device includes a fuser member, a heater, a thermometer, and a power supply controller. The fuser member is subjected to heating. The heater is adjacent to the fuser member to heat the fuser member. The thermometer is adjacent to the fuser member to detect an operational temperature of the fuser member. The power supply controller controls power supply to the heater by adjusting a duty cycle. The controller includes a duty cycle calculator, a driver circuit, and a duty cycle modifier. The duty cycle calculator is operatively connected to the thermometer to calculate a primary value of the duty cycle based on the operational temperature. The driver circuit is operatively connected to the duty cycle calculator to supply power to the heater according to the duty cycle. The duty cycle modifier is connected between the duty cycle calculator and the driver circuit to modify the duty cycle.
    Type: Grant
    Filed: March 2, 2012
    Date of Patent: July 29, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Yutaka Ikebuchi, Masaaki Yoshikawa, Kenji Ishii, Hiroshi Yoshinaga, Yuji Arai, Hiromasa Takagi, Naoki Iwaya, Tetsuo Tokuda, Yoshiki Yamaguchi, Ippei Fujimoto, Takuya Seshita, Arinobu Yoshiura, Takahiro Imada, Hajime Gotoh, Toshihiko Shimokawa