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).
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Patent number: 7099609Abstract: 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 saType: GrantFiled: July 1, 2005Date of Patent: August 29, 2006Assignee: Canon Kabushiki KaishaInventors: Fumitake Hirobe, Masaru Hibino, Tomoyuki Sakamaki
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Publication number: 20060127134Abstract: 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: ApplicationFiled: December 7, 2005Publication date: June 15, 2006Applicant: Canon Kabushiki KaishaInventors: Tomoyuki Sakamaki, Hiroyuki Kidaka
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Publication number: 20060083527Abstract: 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: ApplicationFiled: October 12, 2005Publication date: April 20, 2006Applicant: Canon Kabushiki KaishaInventor: Tomoyuki Sakamaki
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Patent number: 6978108Abstract: 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: GrantFiled: June 11, 2003Date of Patent: December 20, 2005Assignee: Canon Kabushiki KaishaInventor: Tomoyuki Sakamaki
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Patent number: 6975825Abstract: 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: GrantFiled: April 4, 2003Date of Patent: December 13, 2005Assignee: Canon Kabushiki KaishaInventors: Tomoyuki Sakamaki, Masaru Hibino, Fumitake Hirobe
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Patent number: 6973281Abstract: 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 saType: GrantFiled: April 23, 2003Date of Patent: December 6, 2005Assignee: Canon Kabushiki KaishaInventors: Fumitake Hirobe, Masaru Hibino, Tomoyuki Sakamaki
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Publication number: 20050244195Abstract: 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 saType: ApplicationFiled: July 1, 2005Publication date: November 3, 2005Applicant: Canon Kabushiki KaishaInventors: Fumitake Hirobe, Masaru Hibino, Tomoyuki Sakamaki
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Publication number: 20050214001Abstract: 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 hType: ApplicationFiled: March 24, 2005Publication date: September 29, 2005Applicant: Canon Kabushiki KaishaInventor: Tomoyuki Sakamaki
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Patent number: 6850722Abstract: 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: GrantFiled: October 8, 2002Date of Patent: February 1, 2005Assignee: Canon Kabushiki KaishaInventors: Yuji Sakemi, Koji Masuda, Keiko Igarashi, Tomoyuki Sakamaki, Kota Arimoto
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Publication number: 20040037594Abstract: 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: ApplicationFiled: April 4, 2003Publication date: February 26, 2004Applicant: Canon Kabushiki KaishaInventors: Tomoyuki Sakamaki, Masaru Hibino, Fumitake Hirobe
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Publication number: 20040022560Abstract: 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 saType: ApplicationFiled: April 23, 2003Publication date: February 5, 2004Applicant: Canon Kabushiki KaishaInventors: Fumitake Hirobe, Masaru Hibino, Tomoyuki Sakamaki
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Publication number: 20030235437Abstract: 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: ApplicationFiled: June 11, 2003Publication date: December 25, 2003Applicant: Canon Kabuishiki KaishaInventor: Tomoyuki Sakamaki
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Publication number: 20030072588Abstract: 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: ApplicationFiled: October 8, 2002Publication date: April 17, 2003Applicant: Canon Kabushiki KaishaInventors: Yuji Sakemi, Koji Masuda, Keiko Igarashi, Tomoyuki Sakamaki, Kota Arimoto
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Patent number: 6546222Abstract: 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: GrantFiled: June 6, 2001Date of Patent: April 8, 2003Assignee: Canon Kabushiki KaishaInventors: Yuji Sakemi, Keiko Igarashi, Tomoyuki Sakamaki
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Publication number: 20020028094Abstract: 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: ApplicationFiled: September 21, 2001Publication date: March 7, 2002Inventors: Yuji Sakemi, Keiko Igarashi, Tomoyuki Sakamaki