Patents by Inventor Tomoyuki Sakamaki

Tomoyuki Sakamaki 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: 7099609
    Abstract: A developing apparatus includes a developing container for containing a developer comprising toner and a carrier, said developing container is partitioned into a first chamber and a second chamber constituting a circulation path of the developer; a first developing rotatable member, provided in said first chamber, for developing an electrostatic image formed on the image bearing member with the developer in said first chamber; a regulating member for regulating a layer thickness of the developer on said first developing rotatable member; first magnetic pole and second magnetic pole, disposed in said first developing rotatable member in order named in a rotational direction of said first developing rotatable member, said first magnetic pole and second magnetic pole being defective to form a repelling magnetic field; a second developing rotatable member, disposed in said second chamber, for developing the the electrostatic image formed on the image bearing member with the developer magnetically received from sa
    Type: Grant
    Filed: July 1, 2005
    Date of Patent: August 29, 2006
    Assignee: Canon Kabushiki Kaisha
    Inventors: Fumitake Hirobe, Masaru Hibino, Tomoyuki Sakamaki
  • Publication number: 20060127134
    Abstract: An image forming apparatus includes a plurality of image forming stations and a transferring device. Each image forming station includes an image carrier for carrying an electrostatic image and a developing device for developing the electrostatic image with toner. The transferring device transfers toner images formed by the plurality of image forming stations to a transferring medium. The plurality of image forming stations include a transparent image forming station using transparent toner and color image forming stations using, for example, yellow, magenta, cyan, and black toners, respectively. The transparent image forming station includes a cleaning device that is in contact with the image carrier and picks up residual toner on the image carrier. The developing devices of the color image forming stations develop electrostatic images on the corresponding image carriers and simultaneously pick up residual toners on the corresponding image carriers.
    Type: Application
    Filed: December 7, 2005
    Publication date: June 15, 2006
    Applicant: Canon Kabushiki Kaisha
    Inventors: Tomoyuki Sakamaki, Hiroyuki Kidaka
  • Publication number: 20060083527
    Abstract: The image forming apparatus includes image forming parts, a developing device and a cleaner to clean at least the intermediate transfer material or the transfer device, wherein at the image forming operation starting time, in each image forming part, after starting the charging, the application of the developing bias is started before the top end of the charging portion of the image bearing member surface reaches a developing area in which the image bearing member and the developer bearing member are set against each other, and from among the areas on the image bearing member in which the charging is not yet performed in each image forming part, in case each area having passed the developing area when the developing bias is applied is brought into contact with the intermediate transfer member, the contact area with each area in the intermediate transfer member is controlled without superposing on the intermediate transfer member.
    Type: Application
    Filed: October 12, 2005
    Publication date: April 20, 2006
    Applicant: Canon Kabushiki Kaisha
    Inventor: Tomoyuki Sakamaki
  • Patent number: 6978108
    Abstract: To control bending of a magnetic field generation unit provided inside a developer carrying member, a developing apparatus for developing an electrostatic image formed on an image bearing member according to the present invention includes: a developer container which contains a magnetic developer; first and second developer carrying members which carry the developer in the developer container to the image bearing member; and first and second magnetic field generation units which are fixedly arranged in the first and second developer carrying members. In the developing apparatus, the first magnetic field generation unit and the second magnetic field generation unit form a magnetic field for delivering the developer from the first developer carrying member to the second developer carrying member, and the developing apparatus further includes a magnetic unit which exerts a magnetic force, which resists a magnetic force caused by the magnetic field, on the first and second magnetic field generation units.
    Type: Grant
    Filed: June 11, 2003
    Date of Patent: December 20, 2005
    Assignee: Canon Kabushiki Kaisha
    Inventor: Tomoyuki Sakamaki
  • Patent number: 6975825
    Abstract: A developing apparatus includes a developer container containing a magnetic developer including a toner and a wax contained in the toner. First and second developer carrying members are rotatably provided in the developer container, for carrying the magnetic developer. A regulation member regulates a thickness of a layer of the magnetic developer carried on the first developer carrying member. A first magnet has a first magnetic pole disposed opposite to the second developer carrying member and a second magnetic pole, which is a subsequent magnetic pole, dispose downstream from the first magnetic pole in a rotation direction of the first developer carrying member and having a polarity identical to a polarity of the first magnetic pole. A second magnet has a third magnetic pole, which has a polarity opposite to a polarity of the first magnetic pole, is disposed opposite to the first developer carrying member.
    Type: Grant
    Filed: April 4, 2003
    Date of Patent: December 13, 2005
    Assignee: Canon Kabushiki Kaisha
    Inventors: Tomoyuki Sakamaki, Masaru Hibino, Fumitake Hirobe
  • Patent number: 6973281
    Abstract: A developing apparatus includes a developing container for containing a developer comprising toner and a carrier, said developing container is partitioned into a first chamber and a second chamber constituting a circulation path of the developer; a first developing rotatable member, provided in said first chamber, for developing an electrostatic image formed on the image bearing member with the developer in said first chamber; a regulating member for regulating a layer thickness of the developer on said first developing rotatable member; first magnetic pole and second magnetic pole, disposed in said first developing rotatable member in order named in a rotational direction of said first developing rotatable member, said first magnetic pole and second magnetic pole being defective to form a repelling magnetic field; a second developing rotatable member, disposed in said second chamber, for developing the the electrostatic image formed on the image bearing member with the developer magnetically received from sa
    Type: Grant
    Filed: April 23, 2003
    Date of Patent: December 6, 2005
    Assignee: Canon Kabushiki Kaisha
    Inventors: Fumitake Hirobe, Masaru Hibino, Tomoyuki Sakamaki
  • Publication number: 20050244195
    Abstract: A developing apparatus includes a developing container for containing a developer comprising toner and a carrier, said developing container is partitioned into a first chamber and a second chamber constituting a circulation path of the developer; a first developing rotatable member, provided in said first chamber, for developing an electrostatic image formed on the image bearing member with the developer in said first chamber; a regulating member for regulating a layer thickness of the developer on said first developing rotatable member; first magnetic pole and second magnetic pole, disposed in said first developing rotatable member in order named in a rotational direction of said first developing rotatable member, said first magnetic pole and second magnetic pole being defective to form a repelling magnetic field; a second developing rotatable member, disposed in said second chamber, for developing the the electrostatic image formed on the image bearing member with the developer magnetically received from sa
    Type: Application
    Filed: July 1, 2005
    Publication date: November 3, 2005
    Applicant: Canon Kabushiki Kaisha
    Inventors: Fumitake Hirobe, Masaru Hibino, Tomoyuki Sakamaki
  • Publication number: 20050214001
    Abstract: A developing device for developing an electrostatic image formed on an image bearing drum, includes a developing container for accommodating a developer including toner and carrier; developer stirring means provided in the developing container; a developer carrying sleeve for carrying the developer to an opposing portion where the sleeve is opposed to the drum; supplying means for supplying a developer including toner and carrier into the developing container; discharging means for discharging the developer from the developing container; supply control means for controlling a supplying operation of the supplying means to control a toner content in the developer in the developing container, wherein an amount of the developer A (g) in the developing container when a difference between an amount of the carrier supplied by the supplying means per unit time and an amount of discharge of the carrier by the discharging means per unit time becomes not more than 5 (g/min) during development of an electrostatic image h
    Type: Application
    Filed: March 24, 2005
    Publication date: September 29, 2005
    Applicant: Canon Kabushiki Kaisha
    Inventor: Tomoyuki Sakamaki
  • Patent number: 6850722
    Abstract: An image forming apparatus includes an image bearing member; a plurality of first developing devices for developing an electrostatic latent image formed on the image bearing member at a developing position using a developer which includes a toner and a carrier; a rotatable member rotatable in a path including the first developing position, for supporting the plurality of first developing devices, wherein each of the plurality of first developing devices is effective to discharge excess developer produced by receiving the developer including the toner and the carrier to outside of each of the plurality of first developer devices using a rotation of the rotatable member; and a second developer container for developing an electrostatic latent image formed on the image bearing member at a second developing position using a developer including a toner, wherein the second developing device is disposed at a position so as to be non-rotatably adjacent to the image bearing member.
    Type: Grant
    Filed: October 8, 2002
    Date of Patent: February 1, 2005
    Assignee: Canon Kabushiki Kaisha
    Inventors: Yuji Sakemi, Koji Masuda, Keiko Igarashi, Tomoyuki Sakamaki, Kota Arimoto
  • Publication number: 20040037594
    Abstract: A developing apparatus includes a developer container containing a magnetic developer comprising a toner and a wax contained in the toner, first and second developer carrying member, rotatably provided in the developer container, for carrying the magnetic developer, a regulation member for regulating a thickness of a layer of the magnetic developer carried on the first developer carrying member, and magnetic field generation means for generating a magnetic field for transferring the magnetic developer from the first developer carrying member to the second developer carrying member. A common electrostatic latent image formed on an image bearing member is developed with the developer carried on the first developer carrying member and the developer carried on the developer carrying member in this order.
    Type: Application
    Filed: April 4, 2003
    Publication date: February 26, 2004
    Applicant: Canon Kabushiki Kaisha
    Inventors: Tomoyuki Sakamaki, Masaru Hibino, Fumitake Hirobe
  • Publication number: 20040022560
    Abstract: A developing apparatus includes a developing container for containing a developer comprising toner and a carrier, said developing container is partitioned into a first chamber and a second chamber constituting a circulation path of the developer; a first developing rotatable member, provided in said first chamber, for developing an electrostatic image formed on the image bearing member with the developer in said first chamber; a regulating member for regulating a layer thickness of the developer on said first developing rotatable member; first magnetic pole and second magnetic pole, disposed in said first developing rotatable member in order named in a rotational direction of said first developing rotatable member, said first magnetic pole and second magnetic pole being defective to form a repelling magnetic field; a second developing rotatable member, disposed in said second chamber, for developing the the electrostatic image formed on the image bearing member with the developer magnetically received from sa
    Type: Application
    Filed: April 23, 2003
    Publication date: February 5, 2004
    Applicant: Canon Kabushiki Kaisha
    Inventors: Fumitake Hirobe, Masaru Hibino, Tomoyuki Sakamaki
  • Publication number: 20030235437
    Abstract: To control bending of a magnetic field generation unit provided inside a developer carrying member, a developing apparatus for developing an electrostatic image formed on an image bearing member according to the present invention includes: a developer container which contains a magnetic developer; first and second developer carrying members which carry the developer in the developer container to the image bearing member; and first and second magnetic field generation units which are fixedly arranged in the first and second developer carrying members. In the developing apparatus, the first magnetic field generation unit and the second magnetic field generation unit form a magnetic field for delivering the developer from the first developer carrying member to the second developer carrying member, and the developing apparatus further includes a magnetic unit which exerts a magnetic force, which resists a magnetic force caused by the magnetic field, on the first and second magnetic field generation units.
    Type: Application
    Filed: June 11, 2003
    Publication date: December 25, 2003
    Applicant: Canon Kabuishiki Kaisha
    Inventor: Tomoyuki Sakamaki
  • Publication number: 20030072588
    Abstract: An image forming apparatus includes an image bearing member; a first developer container for containing toner and carrier particles and for developing an electrostatic latent image formed on the image bearing member at a developing station; a rotatable member for rotating the first developer container along a path extending through the developing station, wherein the first developer container is effective to discharge residual matter produced by receiving the toner and carrier particles to outside of the first developer container using a rotation of the rotatable member; a first stretch that the second developer container for containing toner particles and for developing an electrostatic latent image formed on the image bearing member, wherein the second developer container is disposed at a position different from that of the developing station.
    Type: Application
    Filed: October 8, 2002
    Publication date: April 17, 2003
    Applicant: Canon Kabushiki Kaisha
    Inventors: Yuji Sakemi, Koji Masuda, Keiko Igarashi, Tomoyuki Sakamaki, Kota Arimoto
  • Patent number: 6546222
    Abstract: A developing apparatus for an image forming apparatus forms an electrostatic latent image corresponding to an image information signal on an image bearing member. The developing apparatus includes a developer carrying member which bears and conveys a two-component developer containing a non-magnetic toner and a magnetic carrier for forming a toner image by developing the electrostatic latent image formed on the image bearing member. Convexities and concavities are formed on a surface of the developer carrying member. An average peak-to-peak spacing (Sm) of the convexities and concavities is set at ⅓ to 6 times of a weight-average particle diameter of the magnetic carrier (D) (D/3≦Sm≦6*D). An average roughness at ten points (Rz) on the surface of the developer carrying member is set at {fraction (1/10)} to ½ times of the weight-average particle diameter of the magnetic carrier. A number of concavities which are 1 &mgr;m to 10 &mgr;m wide and 0.
    Type: Grant
    Filed: June 6, 2001
    Date of Patent: April 8, 2003
    Assignee: Canon Kabushiki Kaisha
    Inventors: Yuji Sakemi, Keiko Igarashi, Tomoyuki Sakamaki
  • Publication number: 20020028094
    Abstract: A developing apparatus for an image forming apparatus has means for forming an electrostatic latent image corresponding to an image information signal on an image bearing member having: a developer carrying member which bears and conveys a two-component developer containing a non-magnetic toner and a magnetic carrier for forming a toner image by developing the electrostatic latent image on the image bearing member. The convexities and concavities are formed on a surface of the developer carrying member, and an average peak-to-peak spacing (Sm) of the convexities and concavities is set at ⅓ to 6 times of a weight-average particle diameter of said magnetic carrier (D) (D/3≦Sm≦6*D), average roughness at ten points (Rz) on the surface of the developer carrying member is set at {fraction (1/10)} to ½ times of the weight-average particle diameter of the magnetic carrier and a number of concavities which are 1 &mgr;m to 10 &mgr;m wide and 0.
    Type: Application
    Filed: September 21, 2001
    Publication date: March 7, 2002
    Inventors: Yuji Sakemi, Keiko Igarashi, Tomoyuki Sakamaki