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).

  • Publication number: 20140294461
    Abstract: A fixing device includes an exciting coil and a heat generator disposed opposite the exciting coil. The heat generator includes a heat generation layer disposed opposite the exciting coil to generate heat by a magnetic flux from the exciting coil and a temperature sensitive magnetic body disposed opposite the exciting coil via the heat generation layer to obtain and lose magnetism at a temperature defined by a Curie temperature by composition adjustment to selectively create a heating region and a non-heating region of the heat generation layer. A degausser is disposed opposite the heat generator and made of a non-magnetic material having an electrical resistivity smaller than that of the temperature sensitive magnetic body. A holder contacting and supporting the degausser is disposed inboard from a lateral edge of the degausser and outboard from a lateral end of the exciting coil in a longitudinal direction of the degausser.
    Type: Application
    Filed: March 14, 2014
    Publication date: October 2, 2014
    Inventors: Tetsuo TOKUDA, Naoto SUZUKI, Kohichi UTSUNOMIYA
  • 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
  • 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: 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
  • Patent number: 8761650
    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: Grant
    Filed: November 8, 2011
    Date of Patent: June 24, 2014
    Assignee: Ricoh Company, Ltd.
    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
  • Patent number: 8725038
    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: Grant
    Filed: December 5, 2011
    Date of Patent: May 13, 2014
    Assignee: Ricoh Company, Ltd.
    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: 20140112680
    Abstract: A fixing device includes a fixing rotary body to come into contact with a toner image on a recording medium and a pressing rotary body separably pressed against the fixing rotary body to press the recording medium against the fixing rotary body. A cooler, disposed opposite the pressing rotary body to cool the pressing rotary body, includes a fan to move air to the pressing rotary body and at least one inlet duct interposed between the fan and the pressing rotary body to supply air from the fan to the pressing rotary body. The at least one inlet duct selectively cools the pressing rotary body in a variable axial span in an axial direction thereof.
    Type: Application
    Filed: October 10, 2013
    Publication date: April 24, 2014
    Inventors: Satoshi UENO, Jun Okamoto, Tetsuo Tokuda, Naoto Suzuki, Takashi Sakamaki, Fumihiro Hirose, Motoyoshi Yamano
  • Patent number: 8682192
    Abstract: An image forming apparatus includes a fixing device including a fixing member; a pressure member to press against the fixing member; and a halogen lamp to heat the fixing member, and a controller to control the halogen lamp. The controller controls an ON duty of the halogen lamp according to a control cycle, and sets the ON duty including two thresholds consisting of a first ON duty and a second ON duty that is larger than the first ON duty. The controller calculates an ON duty of the halogen lamp, judges whether the calculated ON duty is equal to or more than the first duty and less then the second duty, and changes the calculated ON duty when the calculated ON duty is equal to or more than the first duty and less then the second duty.
    Type: Grant
    Filed: August 25, 2011
    Date of Patent: March 25, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Yutaka Ikebuchi, Yoshiki Yamaguchi, Toshihiko Shimokawa, Kenji Ishii, Naoki Iwaya, Takahiro Imada, Tetsuo Tokuda, Takamasa Hase, Hiroshi Yoshinaga, Ippei Fujimoto, Masaaki Yoshikawa
  • Patent number: 8682218
    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: Grant
    Filed: December 9, 2011
    Date of Patent: March 25, 2014
    Assignee: Ricoh Company, Ltd.
    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
  • Patent number: 8676104
    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: Grant
    Filed: December 9, 2011
    Date of Patent: March 18, 2014
    Assignee: Ricoh Company, Ltd.
    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
  • Patent number: 8676103
    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: Grant
    Filed: November 10, 2011
    Date of Patent: March 18, 2014
    Assignee: Ricoh Company, Ltd.
    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
  • Patent number: 8676101
    Abstract: A fixing device includes a tubular, stationary metal pipe, a flexible fuser belt, a rotatable pressure member, a fuser pad, and a lubricant. The metal pipe is subjected to heating. The flexible fuser belt is looped for rotation around the metal pipe to transfer heat radially outward from the heated metal pipe. The rotatable pressure member extends opposite the metal pipe with the fuser belt interposed between the metal pipe and the pressure member. 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 lubricant is of a given particle size and deposited between the metal pipe and the fuser belt. The surface of the metal pipe has a rough section which exhibits a surface roughness equal to or greater than the particle size of the lubricant.
    Type: Grant
    Filed: December 2, 2010
    Date of Patent: March 18, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Masaaki Yoshikawa, Akira Shinshi, Yoshiki Yamaguchi, Toshihiko Shimokawa, Tetsuo Tokuda, Yutaka Ikebuchi, Naoki Iwaya, Shuntaroh Tamaki, Hiroshi Yoshinaga, Ippei Fujimoto, Kenji Ishii
  • Patent number: 8655246
    Abstract: A fixing device includes a fixing member formed into a loop and rotatable in a predetermined direction of rotation. A heating assembly faces a first region on an inner circumferential surface of the fixing member to heat the fixing member. The heating assembly is thermally deformed to contact and move the fixing member. A first fixing member support and a second fixing member support face a second region on the inner circumferential surface of the fixing member other than the first region. The first fixing member support and the second fixing member support contact and support the rotating fixing member moved by the thermally deformed heating assembly.
    Type: Grant
    Filed: March 8, 2011
    Date of Patent: February 18, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Tetsuo Tokuda, Masaaki Yoshikawa, Kenji Ishii, Hiroshi Yoshinaga, Naoki Iwaya, Yoshiki Yamaguchi, Yutaka Ikebuchi, Ippei Fujimoto, Takuya Seshita, Takahiro Imada, Takamasa Hase, Toshihiko Shimokawa
  • Patent number: 8655211
    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: Grant
    Filed: November 1, 2011
    Date of Patent: February 18, 2014
    Assignee: Ricoh Company, Ltd.
    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
  • Patent number: 8655244
    Abstract: A fixing device includes a stationary at least partially tubular thermal member, a flexible fuser belt, a fuser pad, and a rotatable pressure member. The thermal member has a tubular portion thereof extending in an axial direction and defining a closed axial cross-section. A circumference of the thermal member is subjected to heating. The fuser belt is looped for rotation around the thermal member. An inner circumference of the fuser belt at least partially faces the thermal member. The fuser pad is held stationary inside the loop of the fuser belt. The pressure member extends opposite the thermal member in the axial direction with the fuser belt interposed between the fuser pad and the pressure member. The fuser pad is pressed against the pressure member through the fuser belt to form a fixing nip. The thermal member is spaced apart from the fuser pad.
    Type: Grant
    Filed: September 29, 2010
    Date of Patent: February 18, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Kenichi Hasegawa, Masaaki Yoshikawa, Akira Shinshi, Kenji Ishii, Hiroshi Yoshinaga, Yoshiki Yamaguchi, Naoki Iwaya, Tetsuo Tokuda, Yutaka Ikebuchi, Toshihiko Shimokawa, Shuntaroh Tamaki, Takamasa Hase, Ippei Fujimoto, Takahiro Imada
  • Patent number: 8630572
    Abstract: A fixing device includes a nip forming member disposed inside a fixing member and pressed against a pressing member via the fixing member to form a nip portion between the pressing member and the fixing member through which a recording medium bearing a toner image passes. A heat generator disposed inside the fixing member heats the fixing member outside the nip portion and has variable heat distribution over a width of the fixing member. A first temperature detector disposed inside the fixing member contacts an end portion of the heat generator in the width direction of the fixing member, opposite a surface facing the fixing member, to detect a temperature of the heat generator. A second temperature detector disposed inside the fixing member contacts a center of an inner circumferential surface of the fixing member in the width direction, to detect the temperature of the fixing member.
    Type: Grant
    Filed: February 15, 2011
    Date of Patent: January 14, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Ippei Fujimoto, Hiroshi Yoshinaga, Tetsuo Tokuda, Takamasa Hase, Toshihiko Shimokawa, Kenji Ishii, Yoshiki Yamaguchi, Masaaki Yoshikawa, Naoki Iwaya, Takahiro Imada, Yutaka Ikebuchi, Kenichi Hasegawa, Akira Shinshi
  • Patent number: 8615175
    Abstract: A fixing unit removably installable in an image forming apparatus includes an endless fixing member; a metal member disposed in proximity to an inner surface of the fixing member; a nip formation member supported by the metal member to slidably contact the fixing member or oppose the fixing member via a slide sheet; a heater to heat the metal member to heat the fixing member; a rotary pressing member to rotate the fixing member, disposed opposite the nip formation member via the fixing member to form a nip between the rotary pressing member and the fixing member; a rotation detector to detect a rotational state of the fixing member. Heating rotation of the fixing member is continuously performed until a predetermined rotational state of the fixing member is obtained, to spread lubricant substantially uniformly at least between the fixing member and the metal member.
    Type: Grant
    Filed: March 15, 2011
    Date of Patent: December 24, 2013
    Assignee: Ricoh Company, Ltd.
    Inventors: Takahiro Imada, Masaaki Yoshikawa, Kenji Ishii, Akira Shinshi, Hiroshi Yoshinaga, Kenichi Hasegawa, Naoki Iwaya, Yoshiki Yamaguchi, Tetsuo Tokuda, Yutaka Ikebuchi, Takamasa Hase, Ippei Fujimoto, Toshihiko Shimokawa
  • Publication number: 20130330111
    Abstract: A fixing device includes a rotatable, flexible fuser belt, a fuser pad, and a pressure member. The rotatable, flexible fuser belt is looped into a generally cylindrical configuration. The fuser pad extends in an axial, longitudinal direction thereof inside the loop of the fuser belt. The pressure member extends in the axial direction opposite the fuser pad with the fuser belt interposed between the fuser pad and the pressure member. The pressure member presses against the fuser pad through the fuser belt in a load direction to form a fixing nip therebetween, through which a recording medium is conveyed in a conveyance direction. The fuser pad includes an upstream section, a midstream section, and a downstream section arranged in series from upstream to downstream in the conveyance direction.
    Type: Application
    Filed: June 3, 2013
    Publication date: December 12, 2013
    Applicant: RICOH COMPANY, LTD.
    Inventor: Tetsuo TOKUDA