Patents by Inventor Tomio Kondou

Tomio Kondou 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: 8213833
    Abstract: An image forming apparatus including at least an image bearer; a charger charging the image bearer; an irradiator irradiating the image bearer to form an electrostatic latent image thereon; an image developer developing the electrostatic latent image with a developer comprising a toner and a carrier to form a toner image on the image bearer; a developer feeder feeding a supplemental developer including the toner and the carrier into the image developer; and a developer collector collecting the developer in the image developer, wherein the developer feeder includes a cylindrical supplemental developer container containing the supplemental developer, including a spiral developer guide race on the inner circumferential surface thereof; and a sub-hopper configured to store the supplemental developer, and wherein the carrier includes a core material; and a layer coated on the core material, including a binder resin and non-black or a non-color inorganic particulate material.
    Type: Grant
    Filed: January 11, 2008
    Date of Patent: July 3, 2012
    Assignee: Ricoh Company, Ltd.
    Inventors: Shinichiro Yagi, Tomio Kondou, Masashi Nagayama, Hltoahi Iwatsuki
  • Patent number: 8086143
    Abstract: An image forming apparatus including an image bearing member; and a developing device including a developer bearing member, a developer containing portion, a developer supplying passage supplying the developer to the developer bearing member while feeding the developer in a direction, and a developer agitating passage feeding a mixture of the developer fed through the developer supplying passage without used for developing, and the developer used for developing, in the opposite direction. The developer supplying passage, and developer agitating passage are separated from each other except for at least both the end portions. The developer includes a toner and a carrier having a cover layer thereon, which includes a binder resin and a particulate material. The ratio of the volume average particle diameter of the particulate material to the average thickness of the resinous portion of the cover layer is greater than 1 and less than 10.
    Type: Grant
    Filed: September 12, 2008
    Date of Patent: December 27, 2011
    Assignee: Ricoh Company, Limited
    Inventors: Masashi Nagayama, Tomio Kondou, Shinichiro Yagi, Hitoshi Iwatsuki
  • Patent number: 8026032
    Abstract: A carrier for use in an image forming apparatus in which a toner and a carrier are fed to an image developer thereof and an extra developer including the toner and the carrier in the image developer is discharged therefrom, wherein at least one of the carrier fed to the image developer and a carrier readily contained therein includes a core material; and a coated film coating the core material, and wherein the coated film includes a binder resin and a particulate material having a ratio of an average particle diameter thereof to an average thickness of the coated film of from 0.01 to 1, and includes concavities and convexities having an average difference of elevation of from 0.02 to 3.0 ?m.
    Type: Grant
    Filed: October 11, 2007
    Date of Patent: September 27, 2011
    Assignee: Ricoh Company, Ltd.
    Inventors: Hitoshi Iwatsuki, Tomio Kondou, Shinichiro Yagi, Masashi Nagayama
  • Patent number: 7835677
    Abstract: Provided is a developing device containing a two-component developer including a magnetic carrier and a toner; a developer bearing member containing a nonmagnetic developing sleeve configured to bear the two-component developer on a surface thereof while rotating; a magnetic field generating unit fixed inside of the nonmagnetic developing sleeve; and a developer amount control member configured to control an amount of the two-component developer borne on the developer bearing member. The magnetic carrier contains a core material and a coating layer coated on the core material, and the coating layer containing a binder resin and conductive particles. The magnetic carrier satisfy a ratio D/h of 1.00<[D/h]?1.95, where D denotes an average primary particle diameter of the conductive fine particles, and h denotes a thickness of the coating layer, and a ratio Ra/D of 1.0<[Ra/D]<10.0, where Ra denotes a surface roughness of the developing sleeve.
    Type: Grant
    Filed: March 11, 2009
    Date of Patent: November 16, 2010
    Assignee: Ricoh Company, Ltd.
    Inventors: Koichi Sakata, Tomio Kondou, Shinichiro Yagi
  • Patent number: 7713670
    Abstract: A developer for an electrophotographic tandem image forming method is provided that contains a toner; and a carrier, wherein the toner has a shape factor SF-1 of from 120 to 160, an average circularity of form 0.93 to 0.98, a weight-average particle diameter (D4) of from 3.0 to 8.0 ?m, and a ratio (D4/Dn) of the weight-average particle diameter (D4) to a number-average particle diameter (Dn) of from 1.01 to 1.20, and wherein the carrier is almost a spherical ferrite coated with a resin wherein alumina is dispersed, which has an average particle diameter of from 20 to 45 ?m and the following formula: (MgO)x(MnO)y(Fe2O3)z wherein x is from 1 to 5 mol %, y is from 5 to 55 mol % and z is from 45 to 55 mol %.
    Type: Grant
    Filed: May 11, 2005
    Date of Patent: May 11, 2010
    Assignee: Ricoh Company, Ltd.
    Inventors: Masami Tomita, Tomio Kondou, Masahide Yamashita, Kousuke Suzuki
  • Patent number: 7592116
    Abstract: The object of the present invention is to provide a carrier for electrophotography which includes a core material and a coating layer comprising particles on a surface of the core material, in which the carrier for electrophotography comprises indium (In) in an amount of 0.0001% by mass to 0.5% by mass. The present invention also provides a developer using the carrier, a developer container, an image forming method, an image forming apparatus, and a process cartridge in each of which the carrier is used.
    Type: Grant
    Filed: November 10, 2005
    Date of Patent: September 22, 2009
    Assignee: Ricoh Company, Ltd.
    Inventors: Kousuke Suzuki, Tomio Kondou, Shinichiro Yagi, Hitoshi Iwatsuki
  • Publication number: 20090232532
    Abstract: Provided is a developing device containing a two-component developer including a magnetic carrier and a toner; a developer bearing member containing a nonmagnetic developing sleeve configured to bear the two-component developer on a surface thereof while rotating; a magnetic field generating unit fixed inside of the nonmagnetic developing sleeve; and a developer amount control member configured to control an amount of the two-component developer borne on the developer bearing member. The magnetic carrier contains a core material and a coating layer coated on the core material, and the coating layer containing a binder resin and conductive particles. The magnetic carrier satisfy a ratio D/h of 1.00<[D/h]?1.95, where D denotes an average primary particle diameter of the conductive fine particles, and h denotes a thickness of the coating layer, and a ratio Ra/D of 1.0<[Ra/D]?10.0, where Ra denotes a surface roughness of the developing sleeve.
    Type: Application
    Filed: March 11, 2009
    Publication date: September 17, 2009
    Inventors: Koichi Sakata, Tomio Kondou, Shinichiro Yagi
  • Patent number: 7527908
    Abstract: A carrier contains a core material; and a coated film containing a binder resin, and a particulate material, the coated film covering the core material, wherein a ratio (D/h) of an average particle diameter (D) of the particulate material to an average thickness (h) of the coated film is from 0.01 to 1, and wherein the carrier has concavities and convexities on the surface of the carrier, the concavities and convexities having a difference of elevation of from 0.05 to 2.0 ?m.
    Type: Grant
    Filed: April 6, 2006
    Date of Patent: May 5, 2009
    Assignee: Ricoh Company, Ltd.
    Inventors: Hitoshi Iwatsuki, Tomio Kondou, Shinichiro Yagi, Kousuke Suzuki
  • Publication number: 20090074450
    Abstract: An image forming apparatus including an image bearing member; and a developing device including a developer bearing member, a developer containing portion, a developer supplying passage supplying the developer to the developer bearing member while feeding the developer in a direction, and a developer agitating passage feeding a mixture of the developer fed through the developer supplying passage without used for developing, and the developer used for developing, in the opposite direction. The developer supplying passage, and developer agitating passage are separated from each other except for at least both the end portions. The developer includes a toner and a carrier having a cover layer thereon, which includes a binder resin and a particulate material. The ratio of the volume average particle diameter of the particulate material to the average thickness of the resinous portion of the cover layer is greater than 1 and less than 10.
    Type: Application
    Filed: September 12, 2008
    Publication date: March 19, 2009
    Inventors: Masashi NAGAYAMA, Tomio Kondou, Shinichiro Yagi, Hitoshi Iwatsuki
  • Publication number: 20090041510
    Abstract: An image forming apparatus is provided containing an image bearing member, a developer bearing member, and a developer control member being magnetic. The electrostatic latent image on the image bearing member is developed with a toner to form a toner image. The carrier includes magnetic core particles having a cover layer on the surfaces thereof, including fine particles having a weight average particle diameter of from 0.02 to 0.5 ?m. The carrier has a weight average particle diameter of from 22 to 32 ?m, and a ratio (E10/E100) of from 1.00 to 1.20. The ratio (E10/E100) is a ratio of a total energy (E10) to a total energy (E100) at a leading edge speed of the blade of 10 mm/s and 100 mm/s, respectively, measured using a power rheometer at an angle of approach of ?5°.
    Type: Application
    Filed: August 11, 2008
    Publication date: February 12, 2009
    Inventors: Naoki Imahashi, Tomio Kondou, Kimitoshi Yamaguchi, Hitoshi Iwatsuki
  • Publication number: 20080213684
    Abstract: To provide a carrier for electrophotographic developer including core particles and a cover layer covering the particles, wherein at least one of the carrier to be supplied in a developing apparatus and carrier contained in the developing apparatus has a weight average particle diameter Dw of 22 ?m or more and 32 ?m or less, a ratio Dw/Dp of the weight average particle diameter Dw to the number average particle diameter Dp that satisfies the relationship 1.00?Dw/Dp?1.20, particles whose particle diameter x (?m) is within a range of 0<x<20 in an amount of 7 wt % or less, and particles whose particle diameter y (?m) is within a range of 0<y<36 in an amount of 90 wt % or more and 100 wt % or less.
    Type: Application
    Filed: January 16, 2008
    Publication date: September 4, 2008
    Inventors: Masashi NAGAYAMA, Tomio Kondou, Shinichiro Yagi, Hitoshi Iwatsuki
  • Publication number: 20080213682
    Abstract: Provided is a toner for developing electrostatic image, comprising particles of oil phase containing at least a toner composition and/or toner composition precursor in an aqueous medium, wherein the toner composition and/or toner composition precursor comprises an organic-modified layered inorganic mineral prepared by modifying at least partially an ion of a layered inorganic mineral into an organic ion, and the organic ion-modification ratio X satisfies the relation of 100<X(%)<150 in the organic-modified layered inorganic mineral.
    Type: Application
    Filed: February 29, 2008
    Publication date: September 4, 2008
    Inventors: Akinori SAITOH, Masahide Yamada, Osamu Uchinokura, Junichi Awamura, Tomomi Suzuki, Shinichiro Yagi, Tomio Kondou, Masashi Nagayama, Hitoshi Iwatsuki
  • Publication number: 20080171274
    Abstract: An image forming apparatus including at least an image bearer; a charger charging the image bearer; an irradiator irradiating the image bearer to form an electrostatic latent image thereon; an image developer developing the electrostatic latent image with a developer comprising a toner and a carrier to form a toner image on the image bearer; a developer feeder feeding a supplemental developer including the toner and the carrier into the image developer; and a developer collector collecting the developer in the image developer, wherein the developer feeder includes a cylindrical supplemental developer container containing the supplemental developer, including a spiral developer guide race on the inner circumferential surface thereof; and a sub-hopper configured to store the supplemental developer, and wherein the carrier includes a core material; and a layer coated on the core material, including a binder resin and non-black or a non-color inorganic particulate material.
    Type: Application
    Filed: January 11, 2008
    Publication date: July 17, 2008
    Inventors: Shinichiro Yagi, Tomio Kondou, Masashi Nagayama, Hltoahi Iwatsuki
  • Publication number: 20080152393
    Abstract: A carrier for electrophotographic developer that comprises a particle of core material and a coating layer that coats the particle of core material, wherein a toner and a carrier are supplied into a developing device where a toner and a carrier being contained, and the surplus developer within the developing device is discharged, a coating layer on at least one of the supplied carrier and the carrier contained in the developing device comprises a white conductive fine particle that includes tin dioxide and indium oxide on a base material.
    Type: Application
    Filed: December 18, 2007
    Publication date: June 26, 2008
    Inventors: Masashi NAGAYAMA, Tomio Kondou, Shinichiro Yagi, Hitoshi Iwatsuki
  • Patent number: 7384719
    Abstract: A carrier composition, including a particulate magnetic material; and a layer located on a surface of the particulate magnetic material, wherein the layer is formed by heating a mixture containing a metal alkoxide; a resin having a hydroxyl group reacting with the metal alkoxide; and a particulate inorganic material.
    Type: Grant
    Filed: March 2, 2005
    Date of Patent: June 10, 2008
    Assignee: Ricoh Company Ltd.
    Inventors: Masahide Yamashita, Tomio Kondou, Kousuke Suzuki
  • Publication number: 20080096121
    Abstract: A carrier for use in an image forming apparatus in which a toner and a carrier are fed to an image developer thereof and an extra developer including the toner and the carrier in the image developer is discharged therefrom, wherein at least one of the carrier fed to the image developer and a carrier readily contained therein includes a core material; and a coated film coating the core material, and wherein the coated film includes a binder resin and a particulate material having a ratio of an average particle diameter thereof to an average thickness of the coated film of from 0.01 to 1, and includes concavities and convexities having an average difference of elevation of from 0.02 to 3.0 ?m.
    Type: Application
    Filed: October 11, 2007
    Publication date: April 24, 2008
    Inventors: Hitoshi IWATSUKI, Tomio Kondou, Shinichiro Yagi, Masashi Nagayama
  • Patent number: 7344812
    Abstract: A developer for developing an electrostatic latent image, including a carrier which includes core particles, and a surface layer surrounding each of the core particles and containing an acrylic resin binder; and a toner which includes toner particles and an external additive of inorganic or organic fine particles present on each of the toner particles. Each of the toner particles comprises a colorant, a matrix of a first resin, and a plurality of domains of a second resin dispersed in the matrix and containing a wax. The first resin is substantially free of tetrahydrofuran insoluble matters and has a weight average molecular weight of 3,000 to 90,000.
    Type: Grant
    Filed: March 20, 2003
    Date of Patent: March 18, 2008
    Assignee: Ricoh Company, Ltd.
    Inventors: Kohsuke Suzuki, Satoshi Mochizuki, Tomio Kondou, Masahide Yamashita, Tomomi Tamura, Takayuki Koike
  • Patent number: 7272347
    Abstract: A carrier including a magnetic core material and a layer located on a surface of the magnetic core material, wherein the carrier satisfies the following relationships (1) to (3): 0.90?(?a/?b)<1.00 (1); 200?(?b·?c)?400 (2); 10?(?b/?c)?20 (3), wherein ?b represents a magnetization of the carrier at 1,000 Oe, ?a represents a magnetization of the carrier after frictionized with a cylindrical sleeve under a specific condition and ?c represents a true specific gravity of the carrier, wherein the carrier has a weight-average particle diameter of about 25 to about 65 ?m and includes carrier particles having a weight-average particle diameter not greater than about 12 ?m in an amount of not greater than about 0.3% by weight, wherein a ratio between the weight-average particle diameter and a number-average particle diameter of the carrier is about 1 to about 1.3, and wherein an electric resistance is from about 1.0×109 to about 1.
    Type: Grant
    Filed: September 28, 2006
    Date of Patent: September 18, 2007
    Assignee: Ricoh Company, Ltd.
    Inventors: Masahide Yamashita, Satoshi Mochizuki, Tomio Kondou, Kohsuke Suzuki
  • Publication number: 20070202430
    Abstract: A carrier for a double component developer for developing latent electrostatic images at least contains a particulate core material having a weight average particle diameter (Dw) of from 25 to 45 ?m and a magnetic moment of from 65 to 90 Am2/Kg at 1 KOe and a resin layer located on the surface of the particulate core material. Further, the carrier has a breakdown voltage not less than 1,000 V.
    Type: Application
    Filed: May 3, 2007
    Publication date: August 30, 2007
    Inventors: Kousuke Suzuki, Tomio Kondou, Masahide Yamashita
  • Patent number: 7252919
    Abstract: A carrier for electrostatic development contains a core particle and a coating layer covering the core particle, and the core particle is a ferrite particle containing at least one of Zr in an amount of 0.005% by mass to 5% by mass and Bi in an amount of 0.001% by mass to 1% by mass. The carrier shows a sufficient resistance, is stably charged over a long period of time, can avoid roughness and irregular density in halftone images, prevents deposition of the carrier particles on a photoconductor, can satisfactorily reproduce character images and can produce high-quality images over a long period of time. The carrier is usable for constituting a developer, a container housing the developer, an image forming apparatus and process, and process cartridge using the developer.
    Type: Grant
    Filed: June 9, 2006
    Date of Patent: August 7, 2007
    Assignee: Ricoh Company, Ltd.
    Inventors: Kousuke Suzuki, Tomio Kondou, Masahide Yamashita