Patents by Inventor Yasumasa Ohtsuka

Yasumasa Ohtsuka 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: 5697037
    Abstract: In a fixing device for heating and melting a toner image and fixing it onto a transfer material, the fixing device has a fixing member surface which comes in contact with a toner image. The fixing member surface has at least a resin and an ion-conductive electrical resistance value controlling material having a melting point higher than a maximum temperature in the fixing device.
    Type: Grant
    Filed: February 1, 1996
    Date of Patent: December 9, 1997
    Assignees: Canon Kabushiki Kaisha, I.S.T. Corporation
    Inventors: Hideyuki Yano, Yasumasa Ohtsuka, Mahito Yoshioka, Naoki Konishi, Masafumi Matsumura
  • Patent number: 5669039
    Abstract: An image heating apparatus includes a heater which is stationary in use; a film slidable on the heater; a backup member cooperable the heater to form a nip, with the film being interposed between them, an image carried on a recording material being heated through the film in the nip by heat from the heater; and a feeding interval controlling device for varying the recording material interval with which the recording materials are consecutively fed.
    Type: Grant
    Filed: September 30, 1996
    Date of Patent: September 16, 1997
    Assignee: Canon Kabushiki Kaisha
    Inventors: Yasumasa Ohtsuka, Kouichi Okuda, Yohji Tomoyuki, Akira Hayakawa, Daizo Fukuzawa
  • Patent number: 5659869
    Abstract: An image fixing apparatus includes a fixing roller contactable to an unfixed image, and a back-up roller cooperable with the fixing roller to fix the unfixed image, wherein the back-up roller contains a fluorine surface active agent having an antistatic effect substantially to reduce electrostatic offset and enable the back-up roller to remove toner deposited on the fixing roller.
    Type: Grant
    Filed: April 28, 1994
    Date of Patent: August 19, 1997
    Assignee: Canon Kabushiki Kaisha
    Inventors: Yasumasa Ohtsuka, Miho Aoki, Yukihiro Ohzeki, Masaharu Ohkubo, Koichi Okuda
  • Patent number: 5592276
    Abstract: A heater includes a base plate, and a resistor, extending in a longitudinal direction of the base plate, for generating heat when a power supply is applied thereto. A recess, such as a hole or groove, is formed in the base plate in a longitudinal portion of the resistor, to bias the base plate to break at the longitudinal portion and to open a circuit including the power supply and the resistor, to safely prevent overheating or smoking of the heater.
    Type: Grant
    Filed: June 3, 1994
    Date of Patent: January 7, 1997
    Assignee: Canon Kabushiki Kaisha
    Inventors: Yasumasa Ohtsuka, Shunji Nakamura, Kouichi Okuda, Yohji Tomoyuki, Akira Hayakawa, Daizo Fukuzawa
  • Patent number: 5568240
    Abstract: An image heating apparatus includes a movable member having an electrically conductive layer and movable with a recording material; an excitation coil for producing magnetic flux, which produces eddy current in said movable member to generate heat therein, and wherein an image on said recording material is heated by heat of said movable member; wherein said movable member has a low thermal conductivity material at a side nearer to said excitation coil than the conductive layer.
    Type: Grant
    Filed: October 17, 1994
    Date of Patent: October 22, 1996
    Assignee: Canon Kabushiki Kaisha
    Inventor: Yasumasa Ohtsuka
  • Patent number: 5552874
    Abstract: An image fixing apparatus includes a heating member for heating an unfixed image carried on a recording material; a fixing temperature controller for providing a variable fixing temperature of the heating member; wherein when the fixing temperature is lowered, an interval of recording material supply to the heating member is increased.
    Type: Grant
    Filed: April 28, 1994
    Date of Patent: September 3, 1996
    Assignee: Canon Kabushiki Kaisha
    Inventors: Yasumasa Ohtsuka, Yohji Tomoyuki, Akira Hayakawa, Manabu Takano, Daizo Fukuzawa, Atsuyoshi Abe
  • Patent number: 5552582
    Abstract: An image heating apparatus includes magnetic flux generating means, having an excitation coil and a core member therein, for generating magnetic flux; an electroconductive member, movable together with a recording material having and image, for generating heat by eddy current generated therein by the magnetic flux generated by the magnetic flux generating means, wherein the image is heated by the heat; wherein the core member is divided into first and second portions in a direction substantially perpendicular to a movement direction of the electroconductive member.
    Type: Grant
    Filed: June 22, 1995
    Date of Patent: September 3, 1996
    Assignee: Canon Kabushiki Kaisha
    Inventors: Atsuyoshi Abe, Yasumasa Ohtsuka, Yohji Tomoyuki, Manabu Takano, Daizo Fukuzawa, Kenichi Ogawa
  • Patent number: 5534987
    Abstract: A fixing apparatus includes a heating member; a temperature detecting member for detecting the temperature of the heating member; a power supply controller for controlling the power supply to the heating member so that the temperature detected by the temperature detecting element during a fixing operation is maintained substantially constant at a predetermined fixing temperature; and a temperature selecting device for selecting a fixing temperature in response to both the temperature of the heating member before beginning of the fixing temperature control and a rate of the temperature change of the heating member upon supplying a predetermined amount of power to the heating member or upon turning it off.
    Type: Grant
    Filed: July 28, 1995
    Date of Patent: July 9, 1996
    Assignee: Canon Kabushiki Kaisha
    Inventors: Yasumasa Ohtsuka, Shunji Nakamura, Takashi Soya, Kouichi Okuda, Yohji Tomoyuki, Akira Hayakawa, Manabu Takano, Daizo Fukuzawa, Hidenobu Suzuki, Atsuyoshi Abe
  • Patent number: 5471288
    Abstract: An image heating apparatus includes a heater; a movable film having a first surface in contact with the heater and a second surface contactable with a recording material supporting a toner image; heating a toner image on a recording material by heat from the heater; the film comprising an insulative base layer chargeable to a polarity opposite from the of the toner and an electrically conductive layer at a position closer to the insulative base layer.
    Type: Grant
    Filed: March 7, 1994
    Date of Patent: November 28, 1995
    Assignee: Canon Kabushiki Kaisha
    Inventors: Yasumasa Ohtsuka, Yohji Tomoyuki, Hideyuki Hatakeyama
  • Patent number: 5464964
    Abstract: An image heating apparatus includes a heater; temperature detector for detecting a temperature of the heater; electric power supply controller for controlling electric power supply to the heater during image heating, so that the temperature detector detects a predetermined set temperature; and a temperature determining device for determining the set temperature on the basis of a change of the temperature detected by the temperature detector when electric power supply to the heater is stopped.
    Type: Grant
    Filed: December 8, 1992
    Date of Patent: November 7, 1995
    Assignee: Canon Kabushiki Kaisha
    Inventors: Kouichi Okuda, Shunji Nakamura, Toshio Yoshimoto, Yasumasa Ohtsuka, Yohji Tomoyuki, Daizo Fukuzawa, Tomoko Nanbu, Hidenobu Suzuki
  • Patent number: 5444521
    Abstract: An image heating device which includes a heater; a temperature detecting element to detect a temperature of the heater; and a controller for controlling power supply to the heater, so that the temperature detected by the temperature detecting member is maintained at a predetermined temperature, and the controller controls the power supply to the heater, based on a rising speed of the temperature detected during a period from the time when the power supply to the heater is started till the time when the temperature reaches the predetermined temperature.
    Type: Grant
    Filed: July 13, 1992
    Date of Patent: August 22, 1995
    Assignee: Canon Kabushiki Kaisha
    Inventors: Yohji Tomoyuki, Shunji Nakamura, Yasumasa Ohtsuka, Kouichi Okuda, Eihiro Sakaki, Akira Hayakawa, Daizo Fukuzawa
  • Patent number: 5365314
    Abstract: An image heating apparatus includes a heater; a temperature detecting member for detecting a temperature of the heater; the controller for controlling electric power supplied to the heater so that the temperature detected by the temperature detecting member is maintained at a predetermined temperature; comparing device for comparing the temperature detected by the temperature detecting member to the reference temperature; wherein, when the detected temperature remains to be no less than the reference temperature for a predetermined period of time, the controller reduces a duty ratio of the electric power to be supplied to the heater.
    Type: Grant
    Filed: March 29, 1993
    Date of Patent: November 15, 1994
    Assignee: Canon Kabushiki Kaisha
    Inventors: Kouichi Okuda, Shunji Nakamura, Yasumasa Ohtsuka, Yohji Tomoyuki, Akira Hayakawa, Daizo Fukuzawa
  • Patent number: 5331385
    Abstract: An image fixing rotatable member and an image fixing apparatus using the rotatable member as a pressing rotatable member, having a fluorine resin tube over a rubber layer, wherein the volume resistivity of the rubber layer is lower than that of the fluorine resin tube so as to avoid charge build-up on the fluorine resin tube.
    Type: Grant
    Filed: May 15, 1991
    Date of Patent: July 19, 1994
    Assignee: Canon Kabushiki Kaisha
    Inventors: Yasumasa Ohtsuka, Akihiko Takeuchi, Koichi Tanigawa, Hideo Nanataki
  • Patent number: 5280155
    Abstract: An image heating apparatus includes a heater and a film movable together with a recording material carrying an image so that the image on the recording material is heated by heat from the heater through the film. A guiding member guides a surface of the film that contacts the heater, and the guiding member has a surface with projections effective to reduce a contact area between the guiding surface and the film. In addition, a lubricant is supplied between the guiding surface and the film so as to reduce frictional contact.
    Type: Grant
    Filed: July 17, 1992
    Date of Patent: January 18, 1994
    Assignee: Canon Kabushihi Kaisha
    Inventors: Yasumasa Ohtsuka, Shunji Nakamura, Kouichi Okuda, Yohji Tomoyuki, Akira Hayakawa, Daizo Fukuzawa
  • Patent number: 5253022
    Abstract: An image forming apparatus includes a movable image bearing member; an image forming device for forming a toner image on the image bearing member; an image transfer device for transferring the toner image onto a transfer material at a transfer position, the transfer device including a rotatable member contactable to such a side of the transfer material as is opposite from a side contactable to the image bearing member and an electric field forming device for forming an electric field between the image bearing member and the rotatable member; wherein the electric field forming device forms a first electric field effective to transfer the toner from the rotatable member to the image bearing member and a second electric field which is opposite in a direction from the first electric field during a period in which the transfer material is absent at the transfer position, wherein each of the first and second electric fields is formed at least for a period required for the entire surface of the rotatable member pass
    Type: Grant
    Filed: May 15, 1990
    Date of Patent: October 12, 1993
    Assignee: Canon Kabushiki Kaisha
    Inventors: Akihiko Takeuchi, Takayasu Yuminamochi, Hiroto Hasegawa, Koichi Tanigawa, Yasumasa Ohtsuka, Hiroki Kisu
  • Patent number: 5253024
    Abstract: The present invention relates to a fixing apparatus having a pair of rotary members for pinching and conveying a supporting material bearing a non-fixed toner image thereon, thereby fixing the non-fixed toner image on the supporting material and wherein a rectifier element is connected to at least one of the rotary members in a predetermined orientation, whereby the present invention prevent a toner offset that the toner on the supporting material is adhered to the rotary members.
    Type: Grant
    Filed: December 10, 1991
    Date of Patent: October 12, 1993
    Assignee: Canon Kabushiki Kaisha
    Inventors: Koichi Okuda, Yoji Tomoyuki, Toshio Miyamoto, Junji Araya, Yukihiro Ohzeki, Masanobu Saito, Shunji Nakamura, Yasumasa Ohtsuka, Tatsunori Ishiyama, Katsuhiko Nishimura, Akira Hayakawa, Yasushi Sato, Kimio Nakahata
  • Patent number: 5235386
    Abstract: A charging device including a movable member to be charged, and a charging member which is contactable to the member to be charged so as to charge the member to be charged, wherein the coefficient of dynamic friction between the member to be charged and a surface of the charging member contactable to the member to be charged is not lower than 0.4.
    Type: Grant
    Filed: February 21, 1992
    Date of Patent: August 10, 1993
    Assignee: Canon Kabushiki Kaisha
    Inventors: Hideyuki Yano, Koichi Tanigawa, Akihiko Takeuchi, Hiroshi Sasame, Yasumasa Ohtsuka, Takayasu Yuminamochi, Hiroto Hasegawa, Hideo Nanataki, Kazuaki Ono
  • Patent number: 5179397
    Abstract: An image forming apparatus includes a movable image bearing member; an image forming device for forming a toner image on the image bearing member; image transfer device for transferring the toner image from the image bearing member to a transfer material at an image transfer station, wherein the transfer device includes a charging member press-contacted or faced to the image bearing member and a device for applying a voltage to the charging member, wherein the voltage applying device applies a voltage to the charging member so that the charging member is constant-voltage-controlled when an image region of the image bearing member is in the transfer station, and the charging member is constant-current-controlled during at least a part of a period when it is not in the transfer station, wherein a voltage V2 applied during the constant voltage control is a voltage V1 appearing in the transfer device during the constant current control multiplied by a coefficient R, in which R is larger than 1.
    Type: Grant
    Filed: March 28, 1990
    Date of Patent: January 12, 1993
    Assignee: Canon Kabushiki Kaisha
    Inventors: Yukihiro Ohzeki, Tatsunori Ishiyama, Koichi Hiroshima, Junji Araya, Yasushi Sato, Kimio Nakahata, Akihiko Takeuchi, Takayasu Yuminamochi, Hiroto Hasegawa, Koichi Tanigawa, Yasumasa Ohtsuka
  • Patent number: 5177549
    Abstract: An image fixing apparatus for fixing a toner image on a recording material includes a pair of rotatable members for forming a nip through which the recording material is passed; and bias voltage applying source for applying a bias voltage to at least one of the rotatable members, wherein the bias voltage is automatically changed in accordance with change of an ambient condition.
    Type: Grant
    Filed: May 15, 1991
    Date of Patent: January 5, 1993
    Assignee: Canon Kabushiki Kaisha
    Inventors: Yasumasa Ohtsuka, Koichi Tanigawa, Akihiko Takeuchi, Hideo Nanataki, Hideyuki Yano, Takayasu Yuminamochi, Hiroshi Sasame, Hiroto Hasegawa, Tetsuo Saito, Kenji Nagata, Fumitaka Aoki, Hirokazu Ikenoue
  • Patent number: 5153654
    Abstract: An image forming apparatus includes a movable image bearing member; an image forming device for forming an image on the image bearing member; and a transfer device for transferring the image from the image bearing member onto a transfer material, the transfer device including a movable transfer member contacted to the image bearing member and for conveying the transfer material by the contact portion. The transfer member is disposed in such a direction that a surface friction in the direction of the movement of the transfer member relative to the image bearing member is large.
    Type: Grant
    Filed: August 5, 1991
    Date of Patent: October 6, 1992
    Assignee: Canon Kabushiki Kaisha
    Inventors: Takayasu Yuminamochi, Koichi Tanigawa, Akihiko Takeuchi, Hiroshi Sasame, Yasumasa Ohtsuka, Hiroto Hasegawa, Hideyuki Yano, Hideo Nanataki