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: 10401766
    Abstract: An image forming apparatus includes a fixing rotator rotatable in a predetermined direction of rotation, over which a recording medium is conveyed, and a heater to heat the fixing rotator. A temperature detector detects a temperature of the fixing rotator. A controller performs a primary productivity control to define a primary productivity rate of printing per unit time based on the temperature of the fixing rotator that is detected by the temperature detector. The controller calculates an amount of power suppliable to the heater and performs a secondary productivity control simultaneously with and separately from the primary productivity control. The secondary productivity control defines a secondary productivity rate of printing per unit time based on the amount of power suppliable to the heater. The controller selects one of the primary productivity rate and the secondary productivity rate whichever is lower as a productivity rate of the image forming apparatus.
    Type: Grant
    Filed: October 14, 2016
    Date of Patent: September 3, 2019
    Assignee: Ricoh Company, Ltd.
    Inventors: Ryohhei Sugiyama, Hiroshi Ono, Hironori Yamaoka, Motoyoshi Yamano, Yoshikuni Sasaki, Tetsuo Tokuda
  • Patent number: 10191423
    Abstract: An image forming apparatus includes a fixing belt stretched across a first roller and a second roller including an elastic layer. A pressure rotator presses against the second roller via the fixing belt to form a fixing nip between the pressure rotator and the fixing belt. A recording medium bearing a toner image is conveyed through the fixing nip. A clearance detector detects a clearance between the first roller and the second roller. A mover moves the pressure rotator with respect to the second roller in a pressing direction in which the pressure rotator presses against the second roller via the fixing belt and a separation direction in which the pressure rotator separates from the second roller. A controller controls an amount of movement of the pressure rotator moved by the mover toward the second roller based on the clearance detected by the clearance detector.
    Type: Grant
    Filed: September 19, 2017
    Date of Patent: January 29, 2019
    Assignee: Ricoh Company, Ltd.
    Inventors: Ryohhei Sugiyama, Hironori Yamaoka, Takashi Sakamaki, Tetsuo Tokuda, Akiyasu Amita, Shinichi Namekata, Yohhei Watanabe, Fumihiro Hirose, Teppei Kawata, Masateru Ujiie
  • Patent number: 10001735
    Abstract: A fixing device may include an endless fixing member; a heater inside the fixing member; and a nip forming unit configured to form a nip through which a recording sheet is conveyed, the nip forming unit including a supporting member and a contact member supported by the supporting member, the supporting member including at least one contact surface and the contact member including a plurality of protrusions protruding towards the supporting member such that two or more of the plurality of protrusions are configured to contact one of the at least one contact surface of the supporting member, each of the plurality of protrusions having a height associated there with such that the height of the plurality of protrusions increases in a direction from ends of the contact member towards a center of the contact member.
    Type: Grant
    Filed: December 20, 2016
    Date of Patent: June 19, 2018
    Assignee: Ricoh Company, Limited
    Inventors: Takahiro Imada, Masaaki Yoshikawa, Kenji Ishii, Hiroshi Yoshinaga, Yuji Arai, Naoki Iwaya, Tetsuo Tokuda, Hiromasa Takagi, Yoshiki Yamaguchi, Ippei Fujimoto, Takuya Seshita, Yutaka Ikebuchi, Arinobu Yoshiura, Toshihiko Shimokawa, Hajime Gotoh
  • Publication number: 20180088502
    Abstract: An image forming apparatus includes a fixing belt stretched across a first roller and a second roller including an elastic layer. A pressure rotator presses against the second roller via the fixing belt to form a fixing nip between the pressure rotator and the fixing belt. A recording medium bearing a toner image is conveyed through the fixing nip. A clearance detector detects a clearance between the first roller and the second roller. A mover moves the pressure rotator with respect to the second roller in a pressing direction in which the pressure rotator presses against the second roller via the fixing belt and a separation direction in which the pressure rotator separates from the second roller. A controller controls an amount of movement of the pressure rotator moved by the mover toward the second roller based on the clearance detected by the clearance detector.
    Type: Application
    Filed: September 19, 2017
    Publication date: March 29, 2018
    Inventors: Ryohhei SUGIYAMA, Hironori YAMAOKA, Takashi SAKAMAKI, Tetsuo TOKUDA, Akiyasu AMITA, Shinichi NAMEKATA, Yohhei WATANABE, Fumihiro HIROSE, Teppei KAWATA, Masateru UJIIE
  • Patent number: 9817345
    Abstract: A fixing device includes a heater, a fixing rotator, a pressure rotator to press against the fixing rotator to form a fixing nip between the fixing rotator and the pressure rotator, through which a recording medium is conveyed, a moving device to move the pressure rotator in directions in which the pressure rotator comes into contact with and separates from the fixing rotator, a thermal expansion amount predictor to predict an amount of thermal expansion of the fixing rotator while the recording medium is conveyed, and a nip width adjuster to control a moving distance of the pressure rotator moved by the moving device toward the fixing rotator, depending on the amount of thermal expansion of the fixing rotator predicted by the thermal expansion amount predictor, so as to adjust a width of the fixing nip to maintain a substantially constant width of the fixing nip.
    Type: Grant
    Filed: November 16, 2016
    Date of Patent: November 14, 2017
    Assignee: RICOH COMPANY, LTD.
    Inventors: Motoyoshi Yamano, Tetsuo Tokuda, Yoshikuni Sasaki, Hiroshi Ono, Hironori Yamaoka, Ryohhei Sugiyama, Kohichi Utsunomiya, Arinobu Yoshiura, Hideo Nagafuji
  • Patent number: 9715201
    Abstract: A fixing device includes a fixing rotator rotatable in a predetermined direction of rotation and a pressure rotator to press against the fixing rotator to form a fixing nip therebetween, through which a recording medium bearing a toner image is conveyed. A rotation load applicator is coupled to one of the fixing rotator and the pressure rotator to apply a rotation load to the one of the fixing rotator and the pressure rotator. The rotation load is in a range of from 0.1 Nm to 0.6 Nm.
    Type: Grant
    Filed: June 14, 2016
    Date of Patent: July 25, 2017
    Assignee: Ricoh Company, Ltd.
    Inventors: Takamasa Hase, Takashi Fujita, Seiji Saitoh, Kenji Ishii, Akiyasu Amita, Kenichi Hasegawa, Takashi Seto, Tetsuo Tokuda, Hiroshi Seo, Hironori Yamaoka
  • Patent number: 9696672
    Abstract: A drive transmission unit transmits driving force to a driven unit including a driven rotator coupled to the drive transmission unit via a unit coupler. The drive transmission unit includes a driving source, a drive transmission member to transmit driving force from the driving source to the driven rotator by engaging the driven rotator, and a basal plate with a turning shaft portion at one end thereof. The basal plate supports the driving source and the drive transmission member thereon. The drive transmission unit is turned around the turning shaft portion together with the driven unit in a direction substantially orthogonal to a direction of a driving reaction force applied to the drive transmission member when the driven rotator receives the driving force from the drive transmission member.
    Type: Grant
    Filed: April 19, 2016
    Date of Patent: July 4, 2017
    Assignee: RICOH COMPANY, LTD.
    Inventors: Hiroshi Ono, Tetsuo Tokuda, Yoshikuni Sasaki, Hironori Yamaoka, Ryohhei Sugiyama, Yamano Motoyoshi
  • Publication number: 20170146933
    Abstract: A fixing device includes a heater, a fixing rotator, a pressure rotator to press against the fixing rotator to form a fixing nip between the fixing rotator and the pressure rotator, through which a recording medium is conveyed, a moving device to move the pressure rotator in directions in which the pressure rotator comes into contact with and separates from the fixing rotator, a thermal expansion amount predictor to predict an amount of thermal expansion of the fixing rotator while the recording medium is conveyed, and a nip width adjuster to control a moving distance of the pressure rotator moved by the moving device toward the fixing rotator, depending on the amount of thermal expansion of the fixing rotator predicted by the thermal expansion amount predictor, so as to adjust a width of the fixing nip to maintain a substantially constant width of the fixing nip.
    Type: Application
    Filed: November 16, 2016
    Publication date: May 25, 2017
    Applicant: Ricoh Company, Ltd.
    Inventors: Motoyoshi YAMANO, Tetsuo TOKUDA, Yoshikuni SASAKI, Hiroshi ONO, Hironori YAMAOKA, Ryohhei SUGIYAMA, Kohichi UTSUNOMIYA, Arinobu YOSHIURA, Hideo NAGAFUJI
  • Publication number: 20170131666
    Abstract: An image forming apparatus includes a fixing rotator rotatable in a predetermined direction of rotation, over which a recording medium is conveyed, and a heater to heat the fixing rotator. A temperature detector detects a temperature of the fixing rotator. A controller performs a primary productivity control to define a primary productivity rate of printing per unit time based on the temperature of the fixing rotator that is detected by the temperature detector. The controller calculates an amount of power suppliable to the heater and performs a secondary productivity control simultaneously with and separately from the primary productivity control. The secondary productivity control defines a secondary productivity rate of printing per unit time based on the amount of power suppliable to the heater. The controller selects one of the primary conductivity rate and the secondary productivity rate whichever is lower as a productivity rate of the image forming apparatus.
    Type: Application
    Filed: October 14, 2016
    Publication date: May 11, 2017
    Applicant: Ricoh Company, Ltd.
    Inventors: Ryohhei SUGIYAMA, Hiroshi ONO, Hironori YAMAOKA, Motoyoshi YAMANO, Yoshikuni SASAKI, Tetsuo TOKUDA
  • Publication number: 20170102652
    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: December 20, 2016
    Publication date: April 13, 2017
    Applicant: Ricoh Company, Ltd.
    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: 9557692
    Abstract: A fixing device may include 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: September 11, 2015
    Date of Patent: January 31, 2017
    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
  • Publication number: 20170003633
    Abstract: A fixing device includes a fixing rotator rotatable in a predetermined direction of rotation and a pressure rotator to press against the fixing rotator to form a fixing nip therebetween, through which a recording medium bearing a toner image is conveyed. A rotation load applicator is coupled to one of the fixing rotator and the pressure rotator to apply a rotation load to the one of the fixing rotator and the pressure rotator. The rotation load is in a range of from 0.1 Nm to 0.6 Nm.
    Type: Application
    Filed: June 14, 2016
    Publication date: January 5, 2017
    Inventors: Takamasa HASE, Takashi Fujita, Seiji Saitoh, Kenji Ishii, Akiyasu Amita, Kenichi Hasegawa, Takashi Seto, Tetsuo Tokuda, Hiroshi Seo, Hironori Yamaoka
  • Publication number: 20160306311
    Abstract: A drive transmission unit transmits driving force to a driven unit including a driven rotator coupled to the drive transmission unit via a unit coupler. The drive transmission unit includes a driving source, a drive transmission member to transmit driving force from the driving source to the driven rotator by engaging the driven rotator, and a basal plate with a turning shaft portion at one end thereof. The basal plate supports the driving source and the drive transmission member thereon. The drive transmission unit is turned around the turning shaft portion together with the driven unit in a direction substantially orthogonal to a direction of a driving reaction force applied to the drive transmission member when the driven rotator receives the driving force from the drive transmission member.
    Type: Application
    Filed: April 19, 2016
    Publication date: October 20, 2016
    Applicant: Ricoh Company, Ltd.
    Inventors: Hiroshi ONO, Tetsuo TOKUDA, Yoshikuni SASAKI, Hironori YAMAOKA, Ryohhei SUGIYAMA, Yamano MOTOYOSHI
  • 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: D855083
    Type: Grant
    Filed: February 5, 2018
    Date of Patent: July 30, 2019
    Assignee: Caterpillar SARL
    Inventors: Takashi Yoneda, Niladri Manna, Shuji Tokuda, Tetsuo Nishiguchi, Yuki Takemoto, Hidenori Furutani