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: 9383692
    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: Grant
    Filed: October 10, 2013
    Date of Patent: July 5, 2016
    Assignee: Ricoh Company, Ltd.
    Inventors: Satoshi Ueno, Jun Okamoto, Tetsuo Tokuda, Naoto Suzuki, Takashi Sakamaki, Fumihiro Hirose, Motoyoshi Yamano
  • Patent number: 9316977
    Abstract: A fixing device includes an exciting coil to generate a magnetic flux and a heat generation layer disposed opposite the exciting coil to generate heat by the magnetic flux from the exciting coil. A temperature sensitive magnetic body, disposed opposite the exciting coil via the heat generation layer, obtains and loses 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 made of a non-magnetic material having an electrical resistivity smaller than an electrical resistivity of the temperature sensitive magnetic body. The degausser is disposed opposite the exciting coil with an interval in a range of from about 4.2 mm to about 8.2 mm.
    Type: Grant
    Filed: March 11, 2014
    Date of Patent: April 19, 2016
    Assignee: Ricoh Company, Ltd.
    Inventors: Motoyoshi Yamano, Tetsuo Tokuda, Takashi Sakamaki, Naoto Suzuki, Satoshi Ueno, Kohichi Utsunomiya, Fumihiro Hirose
  • Patent number: 9310733
    Abstract: A fixing device includes a substantially cylindrical metal member, a heater, an endless, flexible fixing member, a rotary pressing member, and a stationary member. The heater heats the metal member. The fixing member is disposed rotatable around the metal member. An inner circumferential surface of the fixing member is heated by the metal member to heat and fix a toner image. The rotary pressing member is disposed opposite the metal member and pressed against an outer circumferential surface of the fixing member to form a nip between the rotary pressing member and the fixing member through which a recording medium bearing the toner image passes. The stationary member is disposed in pressure contact with the inner circumferential surface of the fixing member, and has an opposing face opposing the rotary pressing member and having a curvature smaller than a curvature of the rotary pressing member.
    Type: Grant
    Filed: February 4, 2011
    Date of Patent: April 12, 2016
    Assignee: Ricoh Company, LTD.
    Inventors: Hiroshi Yoshinaga, Masaaki Yoshikawa, Kenichi Hasegawa, Kenji Ishii, Akira Shinshi, Naoki Iwaya, Yutaka Ikebuchi, Ippei Fujimoto, Yoshiki Yamaguchi, Shuntaroh Tamaki, Tetsuo Tokuda, Takamasa Hase, Takahiro Imada, Toshihiko Shimokawa
  • Patent number: 9250581
    Abstract: A fixing device includes an excitation coil, a rotatable heater, and a support shaft. The excitation coil includes a turning end and an extended portion continuous with the turning end. The heater includes a heat generation layer and a thermosensitive magnetic body composed to switch between magnetized and demagnetized states at a Curie temperature to selectively create localized heating areas in the heat generation layer. The support shaft is made of a nonmagnetic material having a lower electrical resistivity than the thermosensitive magnetic body and supports opposed ends of the heater axially along the heater. The support shaft includes a body portion having a largest outer diameter of the support shaft and an end positioned outside the turning end of the excitation coil, and support portions having a smallest outer diameter of the support shaft and supporting the heater.
    Type: Grant
    Filed: October 31, 2014
    Date of Patent: February 2, 2016
    Assignee: Ricoh Company, Ltd.
    Inventor: Tetsuo Tokuda
  • Publication number: 20160004197
    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: September 11, 2015
    Publication date: January 7, 2016
    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
  • Patent number: 9207594
    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: Grant
    Filed: March 14, 2014
    Date of Patent: December 8, 2015
    Assignee: Ricoh Company, Ltd.
    Inventors: Tetsuo Tokuda, Naoto Suzuki, Kohichi Utsunomiya
  • Patent number: 9158250
    Abstract: 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: Grant
    Filed: January 9, 2012
    Date of Patent: October 13, 2015
    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: 9152099
    Abstract: A fixing device includes a pressing rotary body to press against a fixing rotary body. A pivotable pressure lever rotatably mounts the pressing rotary body. A pressurization cam assembly pivots the pressure lever to press the pressing rotary body against the fixing rotary body and release pressure between the pressing rotary body and the fixing rotary body. A pivotable cleaning unit includes a cleaning web separably contacting the pressing rotary body to clean the pressing rotary body, a pressure adjuster contacting the cleaning web to separably press the cleaning web against the pressing rotary body, a take-up reel to reel up the cleaning web, and a supply reel to reel out the cleaning web. A cleaning unit cam assembly contacts the cleaning unit to pivot the cleaning unit to press against and separate from the pressing rotary body.
    Type: Grant
    Filed: March 12, 2014
    Date of Patent: October 6, 2015
    Assignee: RICOH COMPANY, LTD.
    Inventors: Satoshi Ueno, Tetsuo Tokuda, Naoto Suzuki, Takashi Sakamaki, Kohichi Utsunomiya, Fumihiro Hirose, Motoyoshi Yamano
  • Patent number: 9116494
    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 having differing thicknesses is a load direction arranged in series from upstream to downstream in the conveyance direction.
    Type: Grant
    Filed: June 3, 2013
    Date of Patent: August 25, 2015
    Assignee: RICOH COMPANY, LTD.
    Inventor: Tetsuo Tokuda
  • Publication number: 20150227097
    Abstract: A fixing device includes an exciting coil to generate a magnetic flux and a heat generation layer disposed opposite the exciting coil to generate heat by the magnetic flux from the exciting coil. A temperature sensitive magnetic body, disposed opposite the exciting coil via the heat generation layer, obtains and loses 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 made of a non-magnetic material having an electrical resistivity smaller than an electrical resistivity of the temperature sensitive magnetic body. The degausser is disposed opposite the exciting coil with an interval in a range of from about 4.2 mm to about 8.2 mm.
    Type: Application
    Filed: March 11, 2014
    Publication date: August 13, 2015
    Inventors: Motoyoshi YAMANO, Tetsuo Tokuda, Takashi Sakamaki, Naoto Suzuki, Satoshi Ueno, Kohichi Utsunomiya, Fumihiro Hirose
  • Patent number: 9052650
    Abstract: A fixing device fixes a toner image on a recording medium by heating the recording medium, with a heating area and a non-heating area selected in accordance with a magnetic flux and a repulsive magnetic flux. The fixing device includes a heat generating layer, an exciting coil, and a demagnetizing member. The heat generating layer generates heat. The exciting coil generates the magnetic flux, and thereby inductively heats the heat generating layer. The demagnetizing member faces the heat generating layer in the non-heating area. The demagnetizing member generates the repulsive magnetic flux against the magnetic flux generated by the exciting coil, and thereby demagnetizes the magnetic flux and suppresses the heating. Further, the demagnetizing member has a demagnetization effect different between at least a portion of the non-heating area adjacent to the heating area and the remaining portion of the non-heating area.
    Type: Grant
    Filed: November 7, 2012
    Date of Patent: June 9, 2015
    Assignee: Ricoh Company, Ltd.
    Inventors: Motoyoshi Yamano, Jun Okamoto, Tetsuo Tokuda, Takashi Sakamaki, Satoshi Ueno, Naoto Suzuki, Fumihiro Hirose
  • Patent number: 9046837
    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: Grant
    Filed: January 4, 2012
    Date of Patent: June 2, 2015
    Assignee: 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: 20150125192
    Abstract: A fixing device includes an excitation coil, a rotatable heater, and a support shaft. The excitation coil includes a turning end and an extended portion continuous with the turning end. The heater includes a heat generation layer and a thermosensitive magnetic body composed to switch between magnetized and demagnetized states at a Curie temperature to selectively create localized heating areas in the heat generation layer. The support shaft is made of a nonmagnetic material having a lower electrical resistivity than the thermosensitive magnetic body and supports opposed ends of the heater axially along the heater. The support shaft includes a body portion having a largest outer diameter of the support shaft and an end positioned outside the turning end of the excitation coil, and support portions having a smallest outer diameter of the support shaft and supporting the heater.
    Type: Application
    Filed: October 31, 2014
    Publication date: May 7, 2015
    Inventor: Tetsuo TOKUDA
  • Patent number: 8983353
    Abstract: A fixing apparatus includes: a fixing belt; a pressurizing roller; a supporting member; a heating unit; a nip forming member; and a deform preventing unit. The fixing apparatus and an image forming apparatus including the fixing apparatus prevent a supporting member from deforming due to sliding of a fixing member, improving energy conservation and durability of parts and obtaining a good image.
    Type: Grant
    Filed: November 22, 2011
    Date of Patent: March 17, 2015
    Assignee: Ricoh Company, Ltd.
    Inventors: Arinobu Yoshiura, Masaaki Yoshikawa, Yuji Arai, Yoshiki Yamaguchi, Tetsuo Tokuda, Yutaka Ikebuchi, Toshihiko Shimokawa, Kenji Ishii, Hiroshi Yoshinaga, Hiromasa Takagi, Naoki Iwaya, Takuya Seshita, Takahiro Imada, Hajime Gotoh, Ippei Fujimoto
  • Patent number: 8953993
    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: Grant
    Filed: November 10, 2011
    Date of Patent: February 10, 2015
    Assignee: Ricoh Company, Ltd.
    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
  • Patent number: 8929789
    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: Grant
    Filed: March 6, 2012
    Date of Patent: January 6, 2015
    Assignee: 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
  • Patent number: 8903296
    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: Grant
    Filed: December 15, 2011
    Date of Patent: December 2, 2014
    Assignee: Ricoh Company, Ltd.
    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
  • 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
  • Publication number: 20140294456
    Abstract: A fixing device includes a pressing rotary body to press against a fixing rotary body. A pivotable pressure lever rotatably mounts the pressing rotary body. A pressurization cam assembly pivots the pressure lever to press the pressing rotary body against the fixing rotary body and release pressure between the pressing rotary body and the fixing rotary body. A pivotable cleaning unit includes a cleaning web separably contacting the pressing rotary body to clean the pressing rotary body, a pressure adjuster contacting the cleaning web to separably press the cleaning web against the pressing rotary body, a take-up reel to reel up the cleaning web, and a supply reel to reel out the cleaning web. A cleaning unit cam assembly contacts the cleaning unit to pivot the cleaning unit to press against and separate from the pressing rotary body.
    Type: Application
    Filed: March 12, 2014
    Publication date: October 2, 2014
    Applicant: RICOH COMPANY, LTD.
    Inventors: Satoshi UENO, Tetsuo TOKUDA, Naoto SUZUKI, Takashi SAKAMAKI, Kohichi UTSUNOMIYA, Fumihiro HIROSE, Motoyoshi YAMANO
  • 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