Patents by Inventor Tetsuo Tokuda

Tetsuo Tokuda 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: 8428501
    Abstract: In a fixing device, a nip formation member is provided inside a loop formed by a fixing member rotating in a predetermined direction of rotation. A pressing member is pressed against the nip formation member via the fixing member to form a nip between the fixing member and the pressing member through which a recording medium bearing a toner image passes. The fixing member and the pressing member rotate and convey the recording medium bearing the toner image through the nip. The heat conduction member faces an inner circumferential surface of the fixing member to guide the fixing member sliding over the heat conduction member and to transmit heat to the fixing member. The heat conduction member includes a plurality of convex portions provided on an outer circumferential surface of the heat conduction member and contacting the inner circumferential surface of the fixing member.
    Type: Grant
    Filed: September 2, 2010
    Date of Patent: April 23, 2013
    Assignee: Ricoh Company, Ltd.
    Inventors: Akira Shinshi, Yoshiki Yamaguchi, Kenichi Hasegawa, Masaaki Yoshikawa, Hiroshi Yoshinaga, Kenji Ishii, Tetsuo Tokuda, Ippei Fujimoto, Yutaka Ikebuchi, Shuntaroh Tamaki, Toshihiko Shimokawa, Naoki Iwaya
  • Patent number: 8428502
    Abstract: A fixing device includes an endless flexible fixing member, a supporting member having a pipe shape disposed inside a loop formed by the fixing member to support the fixing member, a pressing member disposed opposite the supporting member via the fixing member, and a nip formation member disposed opposite the pressing member via the fixing member to form a fixing nip between the fixing member and the pressing member. The fixing member contacts an outer circumferential face of the supporting member at a side opposite a side at which the fixing member contacts the nip formation member at the fixing nip. The fixing member has slack portions formed upstream and downstream from the fixing nip in a conveyance direction of a recording medium. The slack portions extend toward the pressing member over the fixing nip without contacting either the supporting member or the pressing member.
    Type: Grant
    Filed: September 10, 2010
    Date of Patent: April 23, 2013
    Assignee: Ricoh Company, Limited
    Inventors: Tetsuo Tokuda, Masaaki Yoshikawa, Akira Shinshi, Kenichi Hasegawa, Hiroshi Yoshinaga, Naoki Iwaya, Yoshiki Yamaguchi, Yutaka Ikebuchi, Shuntaroh Tamaki, Toshihiko Shimokawa, Ippei Fujimoto, Kenji Ishii
  • Patent number: 8401448
    Abstract: A fixing device includes a fixing member, a nip formation member, a pressing member, and a low-friction sheet. The nip formation member is provided inside a loop formed by the fixing member rotating in a predetermined direction of rotation. The pressing member is pressed against the nip formation member via the fixing member to form a nip between the fixing member and the pressing member through which a recording medium bearing a toner image passes. The fixing member and the pressing member rotate and convey the recording medium bearing the toner image through the nip. The low-friction sheet, over which the fixing member slides, covers the nip formation member. The nip formation member includes a first sandwiching member covered by the low-friction sheet, and a second sandwiching member sandwiching the low-friction sheet together with the first sandwiching member.
    Type: Grant
    Filed: September 23, 2010
    Date of Patent: March 19, 2013
    Assignee: Ricoh Company, Ltd.
    Inventors: Yoshiki Yamaguchi, Kenichi Hasegawa, Masaaki Yoshikawa, Hiroshi Yoshinaga, Kenji Ishii, Akira Shinshi, Naoki Iwaya, Tetsuo Tokuda, Ippei Fujimoto, Yutaka Ikebuchi, Shuntaroh Tamaki, Toshihiko Shimokawa
  • Patent number: 8401414
    Abstract: In a fixing device, a pressing member rotates in a predetermined direction of rotation. A flexible endless fixing member rotates in accordance with rotation of the pressing member. A nip formation member is provided inside a loop formed by the fixing member and pressed against the pressing member via the fixing member to form a nip between the fixing member and the pressing member through which a recording medium bearing a toner image passes. A first heat generator faces an inner circumferential surface of the fixing member at a position other than the nip to heat the fixing member. A second heat generator faces the inner circumferential surface of the fixing member at a position other than the nip to heat the fixing member, and is disposed adjacent to the first heat generator along the inner circumferential surface of the fixing member.
    Type: Grant
    Filed: August 17, 2010
    Date of Patent: March 19, 2013
    Assignee: Ricoh Company, Ltd.
    Inventors: Masaaki Yoshikawa, Yoshiki Yamaguchi, Toshihiko Shimokawa, Kenji Ishii, Naoki Iwaya, Takahiro Imada, Yutaka Ikebuchi, Takamasa Hase, Tetsuo Tokuda, Hiroshi Yoshinaga, Kenichi Hasegawa, Ippei Fujimoto, Akira Shinshi
  • Publication number: 20130045032
    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: Application
    Filed: July 25, 2012
    Publication date: February 21, 2013
    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: 8364052
    Abstract: A fixing device includes a hollow, stationary metal roller, a flexible fuser belt, a rotatable pressure member, a fuser pad, a reinforcing member, and a heating assembly. The metal roller has an outer circumference thereof subjected to heating. The flexible fuser belt is looped for rotation around the metal roller to transfer heat radially outward from the heated metal roller. The fuser pad is held stationary inside the loop of the fuser belt to press against the pressure member through the fuser belt to form a fixing nip. The reinforcing member is disposed stationary within the roller interior. The heating assembly is disposed stationary within the roller interior to heat the metal roller from inside, and includes a first heater and a second heater. The first and second heaters are arranged in juxtaposition with each other along the inner circumference of the metal roller.
    Type: Grant
    Filed: September 14, 2010
    Date of Patent: January 29, 2013
    Assignee: Ricoh Company, Ltd.
    Inventors: Naoki Iwaya, Akira Shinshi, Masaaki Yoshikawa, Kenji Ishii, Kenichi Hasegawa, Hiroshi Yoshinaga, Tetsuo Tokuda, Yoshiki Yamaguchi, Yutaka Ikebuchi, Ippei Fujimoto, Shuntaroh Tamaki, Takahiro Imada, Takamasa Hase, Toshihiko Shimokawa
  • Patent number: 8311469
    Abstract: In a fixing device, a stationary member is provided inside a belt member and pressed against a rotary pressing member via the belt member to form a nip between the rotary pressing member and the belt member through which a recording medium bearing a toner image passes. An expandable heating member is provided inside the belt member to face an inner circumferential surface of the belt member to heat the belt member. A regulator contacts a downstream portion of the heating member provided downstream from a center of the nip in a direction of rotation of the belt member to expand the downstream portion of the heating member.
    Type: Grant
    Filed: July 22, 2010
    Date of Patent: November 13, 2012
    Assignee: Ricoh Company, Ltd.
    Inventors: Masaaki Yoshikawa, Yoshiki Yamaguchi, Toshihiko Shimokawa, Kenji Ishii, Naoki Iwaya, Takahiro Imada, Takamasa Hase, Tetsuo Tokuda, Yutaka Ikebuchi, Hiroshi Yoshinaga, Ippei Fujimoto, Kenichi Hasegawa, Shuntaroh Tamaki, Akira Shinshi
  • Publication number: 20120237273
    Abstract: In a fixing device, a heating element is extended along a fixing member at a location other than a nip on an inner circumferential surface side of the fixing member to generate heat. The fixing member contacts the heating element either indirectly via a gap of a prescribed size or directly contacts the heating element by with a prescribed pressure when the fixing member is rotating, and continuously separates from the heating element by a prescribed distance greater than the size of the gap when the fixing member stops rotating.
    Type: Application
    Filed: March 6, 2012
    Publication date: September 20, 2012
    Applicant: RICOH COMPANY, LTD.
    Inventors: Hiroshi Yoshinaga, Masaaki Yoshikawa, Kenji Ishii, Yuji Arai, Hiromasa Takagi, Naoki Iwaya, Tetsuo Tokuda, Ippei Fujimoto, Yoshiki Yamaguchi, Yutaka Ikebuchi, Takuya Seshita, Arinobu Yoshiura, Takahiro Imada, Hajime Gotoh, Toshihiko Shimokawa
  • Publication number: 20120224878
    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: Application
    Filed: March 2, 2012
    Publication date: September 6, 2012
    Applicant: 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
  • Publication number: 20120177388
    Abstract: A fixing device comprises a rotatable endless flexible belt, a drive roller opposed to the rotatable endless flexible belt to contact and drive an outer circumferential surface of the rotatable endless flexible belt, and a nip formation device receiving pressure from the drive roller via the rotatable endless flexible belt to form a nip thereon to sandwich and convey a recording sheet. A heat source is provided to generate heat and heat the nip. Each of the end roller portions of the drive roller has a higher friction coefficient surface than a central roller portion of the drive roller sandwiching the recording sheet. These end roller portions are composed of separate bodies from the central roller portion and detachably attachable from and to the central roller portion.
    Type: Application
    Filed: January 9, 2012
    Publication date: July 12, 2012
    Applicant: RICOH COMPANY, LTD.
    Inventors: Takahiro Imada, Masaaki Yoshikawa, Kenji Ishii, Naoki Iwaya, Takuya Seshita, Takamasa Hase, Tetsuo Tokuda, Yoshiki Yamaguchi, Yutaka Ikebuchi, Toshihiko Shimokawa, Hiroshi Yoshinaga, Ippei Fujimoto
  • Publication number: 20120177393
    Abstract: A fixing device includes a heater to generate heat based on soft-start control. The heater is supplied with power using different power-turn-on-duty control patterns in accordance with power requirements and an operation mode of the fixing device.
    Type: Application
    Filed: January 4, 2012
    Publication date: July 12, 2012
    Applicant: RICOH COMPANY, LTD.
    Inventors: Yutaka Ikebuchi, Masaaki Yoshikawa, Kenji Ishii, Yuji Arai, Hiromasa Takagi, Naoki Iwaya, Tetsuo Tokuda, Yoshiki Yamaguchi, Takuya Seshita, Takahiro Imada, Ippei Fujimoto, Hiroshi Yoshinaga, Hajime Gotoh, Arinobu Yoshiura, Toshihiko Shimokawa
  • Publication number: 20120177423
    Abstract: According to an embodiments, a fixing device includes: an endless fixing member; a heating unit that is provided inside an inner peripheral surface of the fixing member; and a nip forming unit that comes into press-contact with a rotationally driven pressing member with the fixing member interposed therebetween to form a nip. The nip forming unit has a shape in which a center of a contact surface protrudes toward the pressing member compared to both ends. The nip forming unit has a protruding amount at a center toward the pressing member compared to both ends of the nip forming unit in no-load state is set to be less than a bent amount of the nip forming unit when the nip forming unit comes into press-contact with the pressing member with the fixing member interposed therebetween.
    Type: Application
    Filed: January 9, 2012
    Publication date: July 12, 2012
    Applicant: 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
  • Publication number: 20120177420
    Abstract: A fixing device includes a thermal conductor disposed inside a flexible endless fixing belt formed into a loop and configured to conduct heat from a heater to the fixing belt. The thermal conductor includes a center heating portion heated by the heater and disposed at a center of the thermal conductor in a longitudinal direction thereof orthogonal to a conveyance direction of a recording medium conveyed to the fixing belt and lateral end non-heating portions disposed at lateral ends of the thermal conductor in the longitudinal direction thereof and contiguous to the center heating portion. The center heating portion having a first diameter conducts heat from the heater to the fixing belt. The lateral end non-heating portions having a second diameter smaller than the first diameter of the center heating portion minimize conduction of heat from the heater to the fixing belt.
    Type: Application
    Filed: December 15, 2011
    Publication date: July 12, 2012
    Inventors: Toshihiko Shimokawa, Yuji Arai, Hiromasa Takagi, Yoshiki Yamaguchi, Arinobu Yoshiura, Tetsuo Tokuda, Yutaka Ikebuchi, Kenji Ishii, Naoki Iwaya, Takahiro Imada, Hiroshi Yoshinaga, Takuya Seshita, Hajime Gotoh, Ippei Fujimoto, Masaaki Yoshikawa
  • Publication number: 20120155935
    Abstract: A fixing device, including a fixing member; a pressure member; a nip forming member; a reinforcing member; a heating member; and a flange member including a cylinder inserted in an inner circumference at an edge of the fixing member in an axial direction thereof and a flange fixed on a frame of the fixing device, wherein the cylinder of the flange member includes a notch storing the nip forming member at a part on the circumference, has an arc-shaped outer circumferential cross-section at an area corresponding to an area where the fixing member is heated by the heating member, having a predetermined radius equivalent to a radius of the fixing member, and the arc has a center located at an upstream side in a recording medium feeding direction relative to a center line of the nip forming member in the recording medium feeding direction.
    Type: Application
    Filed: December 9, 2011
    Publication date: June 21, 2012
    Inventors: Masaaki YOSHIKAWA, Tetsuo TOKUDA, Yutaka IKEBUCHI, Takuya SESHITA, Hiroshi YOSHINAGA, Hajime GOTOH, Yoshiki YAMAGUCHI, Toshihiko SHIMOKAWA, Kenji ISHII, Takahiro IMADA, Naoki IWAYA, Yuji ARAI, Arinobu YOSHIURA, Hiromasa TAKAGI, Ippei FUJIMOTO
  • Publication number: 20120155936
    Abstract: A fixing device includes a tubular belt holder, a rotatable, flexible fuser belt, a heater, a fuser pad, a pressure member, and a reinforcing member. The fuser belt is looped for rotation around the belt holder. The heater is disposed adjacent to the belt holder to heat the belt holder. The fuser pad is accommodated in the belt holder inside the loop of the fuser belt, and extends in an axial direction of the belt holder. The pressure member is disposed opposite the belt holder with the fuser belt interposed between the fuser pad and the pressure member. The reinforcing member is disposed inside the loop of the fuser belt to reinforce the fuser pad under pressure from the pressure member. The fuser pad includes an elongated base, multiple longitudinally spaced protrusions, a perforated, anti-friction cover, and a fastener.
    Type: Application
    Filed: December 9, 2011
    Publication date: June 21, 2012
    Inventors: Yoshiki YAMAGUCHI, Masaaki Yoshikawa, Kenji Ishii, Hiroshi Yoshinaga, Yuji Arai, Hiromasa Takagi, Tetsuo Tokuda, Naoki Iwaya, Yutaka Ikebuchi, Takuya Seshita, Ippei Fujimoto, Takahiro Imada, Hajime Gotoh, Toshihiko Shimokawa, Arinobu Yoshiura
  • Publication number: 20120148303
    Abstract: A fixing device includes a frame, a tubular belt holder, a rotatable, flexible fuser belt, a heater, a fuser pad, a pressure member, and a mounting attachment. The tubular belt holder extends in an axial direction thereof. The fuser belt is looped into a generally cylindrical configuration around the belt holder to rotate in a circumferential direction of the belt holder. The heater is disposed adjacent to the belt holder to heat the belt holder. The fuser pad is accommodated in the belt holder inside the loop of the fuser belt, and extends in the axial direction. The pressure member is disposed opposite the belt holder with the fuser belt interposed between the fuser pad and the pressure member. The mounting attachment is provided to a longitudinal end of the tubular belt holder to allow retention and detachable attachment of the belt holder end to the frame.
    Type: Application
    Filed: December 5, 2011
    Publication date: June 14, 2012
    Inventors: Yoshiki YAMAGUCHI, Masaaki Yoshikawa, Kenji Ishii, Yuji Arai, Hiromasa Takagi, Naoki Iwaya, Tetsuo Tokuda, Yutaka Ikebuchi, Takuya Seshita, Takahiro Imada, Ippei Fujimoto, Hiroshi Yoshinaga, Hajime Gotoh, Arinobu Yoshiura, Toshihiko Shimokawa
  • Publication number: 20120121304
    Abstract: A fixing device includes a rotatable, flexible fuser belt, a heater, a fuser pad, and a pressure member. The fuser belt is looped into a generally cylindrical configuration. The heater is disposed adjacent to the fuser belt to heat the fuser belt. The fuser pad is disposed inside the loop of the fuser belt, and has an outer peripheral surface thereof formed in a generally concave configuration. The pressure member is disposed opposite the fuser pad with the fuser belt interposed between the fuser pad and the pressure member. The pressure member presses in a load direction against the outer peripheral surface of the fuser pad through the fuser belt to form a fixing nip therebetween. The fuser pad includes, along the outer peripheral surface thereof, a protruding portion and an inwardly curved portion adjoining the protruding portion to face an outer circumferential surface of the pressure member.
    Type: Application
    Filed: November 10, 2011
    Publication date: May 17, 2012
    Inventors: Tetsuo TOKUDA, Masaaki Yoshikawa, Kenji Ishii, Hiroshi Yoshinaga, Yuji Arai, Hiromasa Takagi, Naoki Iwaya, Yutaka Ikebuchi, Takuya Seshita, Ippei Fujimoto, Yoshiki Yamaguchi, Arinobu Yoshiura, Takahiro Imada, Hajime Gotoh, Toshihiko Shimokawa
  • Publication number: 20120121303
    Abstract: A fixing device includes a rotatable fixing member in a form of an endless belt; a pressing member pressing the fixing member; a contacting member in contact with the pressing member; a holding member holding the contacting member in a pressing direction of the pressing member; a heating unit heating the fixing member; and shape maintaining units maintaining a shape of the fixing member. Further, the heating unit is disposed on an upstream side of a horizontal line passing through the center of the pressing member and the holding member is disposed on a downstream side of a horizontal line passing through the arc axis of the shape maintaining units.
    Type: Application
    Filed: November 8, 2011
    Publication date: May 17, 2012
    Inventors: Hiromasa TAKAGI, Masaaki Yoshikawa, Kenji Ishii, Hiroshi Yoshinaga, Yuji Arai, Naoki Iwaya, Tetsuo Tokuda, Yoshiki Yamaguchi, Takahiro Imada, Ippei Fujimoto, Takuya Seshita, Yutaka Ikebuchi, Arinobu Yoshiura, Toshihiko Shimokawa, Hajime Gotoh
  • Publication number: 20120121305
    Abstract: A fixing device includes a tubular belt holder, a rotatable, flexible fuser belt, a heater, a fuser pad, and a pressure member. The belt holder extends in an axial direction. The fuser belt is looped around the belt holder to rotate in a circumferential direction of the belt holder. The heater is disposed adjacent to the belt holder to heat the belt holder. The fuser pad is accommodated in the belt holder inside the loop of the fuser belt. The pressure member is disposed opposite the belt holder with the fuser belt interposed between the fuser pad and the pressure member. The pressure member presses in a load direction against the fuser pad through the fuser belt to form a fixing nip therebetween. The belt holder includes, along a circumferential dimension thereof, an upstream, first circumferential portion, a downstream, second circumferential portion, and a midstream, third circumferential portion.
    Type: Application
    Filed: November 10, 2011
    Publication date: May 17, 2012
    Inventors: Masaaki YOSHIKAWA, Yuji ARAI, Hiromasa TAKAGI, Yoshiki YAMAGUCHI, Arinobu YOSHIURA, Toshihiko SHIMOKAWA, Tetsuo TOKUDA, Yutaka IKEBUCHI, Kenji ISHII, Naoki IWAYA, Takahiro IMADA, Hiroshi YOSHINAGA, Takuya SESHITA, Hajime GOTOH, Ippei FUJIMOTO
  • Publication number: 20120114345
    Abstract: A fixing device includes a fixing belt; a pressing rotary body disposed outside a loop formed by the fixing belt; a nip formation pad disposed inside the loop formed by the fixing belt and pressed against the pressing rotary body via the fixing belt to form a fixing nip between the pressing rotary body and the fixing belt through which a recording medium bearing a toner image is conveyed. The nip formation pad includes a protrusion disposed downstream from the fixing nip in a conveyance direction of the recording medium and protruding toward the pressing rotary body without contacting the pressing rotary body. The fixing device further includes a pressing rotary body mover to contact and move the pressing rotary body bidirectionally in the conveyance direction of the recording medium to move the fixing nip toward and away from the protrusion.
    Type: Application
    Filed: November 1, 2011
    Publication date: May 10, 2012
    Inventors: IPPEI FUJIMOTO, YUJI ARAI, HIROMASA TAKAGI, YOSHIKI YAMAGUCHI, NAOKI IWAYA, ARINOBU YOSHIURA, TOSHIHIKO SHIMOKAWA, TETSUO TOKUDA, YUTAKA IKEBUCHI, KENJI ISHII, TAKAHIRO IMADA, HIROSHI YOSHINAGA, TAKUYA SESHITA, HAJIME GOTOH, MASAAKI YOSHIKAWA