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).

  • Publication number: 20070140749
    Abstract: An improved developing device for developing latent images to toner images is provided for stabilizing the amount of the developer on the developing bearing member, in which the amount of toner particles consumed in one second for the development process “a” (mg/sec) and circumferential velocity of the surface of the developer bearing member “b” (m/sec) are arranged to satisfy the following relationships (1) and (2) at the condition in which the amount of the developer after 20 hours of rotation of the developer bearing member exceeds the amount of the developer before rotation: 45 mg/m<a/b??(1) a/b<110 mg/m??(2).
    Type: Application
    Filed: December 8, 2006
    Publication date: June 21, 2007
    Inventors: Satoru Miyamoto, Makoto Yasuda, Tomio Kondou, Shinichiro Yagi, Kousuke Suzuki, Hitoshi Iwatsuki
  • Patent number: 7232632
    Abstract: A method for forming a full color image including: forming at least yellow, magenta and cyan color toner images on a receiving material to form a full color image thereon; and fixing the full color image upon application of heat thereto while not contacting the full color image, wherein each of the yellow, magenta and cyan color toner images includes a binder resin and a pigment, wherein the yellow color toner includes a benzimidazolone pigment, the magenta color toner includes at least one of Naphthol Carmine F6B and a combination of Naphthol Carmine F6B and Naphthol Carmine FBB, and the cyan color toner includes ? copper phthalocyanine, and wherein the yellow color toner image has a position closer to the receiving material than any other color toner image when two or more of the color toner images including the yellow color toner image are overlaid.
    Type: Grant
    Filed: April 30, 2001
    Date of Patent: June 19, 2007
    Assignee: Ricoh Company, Ltd
    Inventors: Tomio Kondou, Shinichi Kuramoto, Hideki Sugiura
  • Patent number: 7226713
    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: January 30, 2004
    Date of Patent: June 5, 2007
    Assignee: Ricoh Company, Ltd.
    Inventors: Masahide Yamashita, Satoshi Mochizuki, Tomio Kondou, Kohsuke Suzuki
  • Publication number: 20070082286
    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: Application
    Filed: September 28, 2006
    Publication date: April 12, 2007
    Inventors: Masahide Yamashita, Satoshi Mochizuki, Tomio Kondou, Kohsuke Suzuki
  • Patent number: 7172846
    Abstract: A carrier including a manganese ferrite core material having a layer on its surface such that 0.1?K?30, where K=(S/M)×100, S and M represent the standard deviation and average of M2/(M1+M2), respectively, M ranging from 0.05 to 0.45, and M1 and M2 represent the content of iron and manganese, respectively, in a carrier particle. The carrier has a magnetization ranging from 45 to 75 emu/g at 1,000 Oe, a mass-averaged particle diameter, D4, ranging from 25 to 65 ?m and carrier particles having a particle diameter not greater than 12 ?m are included in an amount not greater than 0.3% by weight, and a ratio, D4/D1, ranging from 1 to 1.3, where D1 is a number-averaged particle diameter of the carrier.
    Type: Grant
    Filed: May 13, 2004
    Date of Patent: February 6, 2007
    Assignee: Ricoh Company, Ltd.
    Inventors: Masahide Yamashita, Tomio Kondou, Kohsuke Suzuki
  • Publication number: 20070015078
    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: Application
    Filed: November 10, 2005
    Publication date: January 18, 2007
    Inventors: Kousuke Suzuki, Tomio Kondou, Shinichiro Yagi, Hitoshi Iwatsuki
  • Publication number: 20060291911
    Abstract: A carrier including a manganese ferrite core material having a layer on its surface such that 0.1?K?30, where K=(S/M)×100, S and M represent the standard deviation and average of M2/(M1+M2), respectively, M ranging from 0.05 to 0.45, and M1 and M2 represent the content of iron and manganese, respectively, in a carrier particle. The carrier has a magnetization ranging from 45 to 75 emu/g at 1,000 Oe, a mass-averaged particle diameter, D4, ranging from 25 to 65 ?m and carrier particles having a particle diameter not greater than 12 ?m are included in an amount not greater than 0.3% by weight, and a ratio, D4/D1, ranging from 1 to 1.3, where D1 is a number-averaged particle diameter of the carrier.
    Type: Application
    Filed: September 1, 2006
    Publication date: December 28, 2006
    Inventors: Masahide Yamashita, Tomio Kondou, Kohsuke Suzuki
  • Patent number: 7144669
    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: March 12, 2004
    Date of Patent: December 5, 2006
    Assignee: Ricoh Company, Ltd.
    Inventors: Kousuke Suzuki, Tomio Kondou, Masahide Yamashita
  • Publication number: 20060251982
    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: Application
    Filed: April 6, 2006
    Publication date: November 9, 2006
    Inventors: Hitoshi Iwatsuki, Tomio Kondou, Shinichiro Yagi, Kousuke Suzuki
  • Publication number: 20060228641
    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: Application
    Filed: June 9, 2006
    Publication date: October 12, 2006
    Inventors: Kousuke Suzuki, Tomio Kondou, Masahide Yamashita
  • Publication number: 20050260516
    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: Application
    Filed: May 11, 2005
    Publication date: November 24, 2005
    Inventors: Masami Tomita, Tomio Kondou, Masahide Yamashita, Kousuke Suzuki
  • Publication number: 20050238980
    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: Application
    Filed: March 2, 2005
    Publication date: October 27, 2005
    Inventors: Masahide Yamashita, Tomio Kondou, Kousuke Suzuki
  • Publication number: 20050079434
    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: October 12, 2004
    Publication date: April 14, 2005
    Inventors: Kousuke Suzuki, Tomio Kondou, Masahide Yamashita
  • Publication number: 20050003292
    Abstract: A carrier including a manganese ferrite core material having a layer on its surface such that 0.1?K?30, where K=(S/M)×100, S and M represent the standard deviation and average of M2/(M1+M2), respectively, M ranging from 0.05 to 0.45, and M1 and M2 represent the content of iron and manganese, respectively, in a carrier particle. The carrier has a magnetization ranging from 45 to 75 emu/g at 1,000 Oe, a mass-averaged particle diameter, D4, ranging from 25 to 65 ?m and carrier particles having a particle diameter not greater than 12 ?m are included in an amount not greater than 0.3% by weight, and a ratio, D4/D1, ranging from 1 to 1.3, where D1 is a number-averaged particle diameter of the carrier.
    Type: Application
    Filed: May 13, 2004
    Publication date: January 6, 2005
    Inventors: Masahide Yamashita, Tomio Kondou, Kohsuke Suzuki
  • Publication number: 20040253528
    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≦(&sgr;a/&sgr;b)<1.00 (1); 200≦(&sgr;b·&rgr;c)≦400 (2); 10≦(&sgr;b/&rgr;c)≦20 (3), wherein &sgr;b represents a magnetization of the carrier at 1,000 Oe, &sgr;a represents a magnetization of the carrier after frictionized with a cylindrical sleeve under a specific condition and &rgr;c represents a true specific gravity of the carrier, wherein the carrier has a weight-average particle diameter of about 25 to about 65 &mgr;m and includes carrier particles having a weight-average particle diameter not greater than about 12 &mgr;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: Application
    Filed: January 30, 2004
    Publication date: December 16, 2004
    Inventors: Masahide Yamashita, Satoshi Mochizuki, Tomio Kondou, Kohsuke Suzuki
  • Publication number: 20040234876
    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: Application
    Filed: March 12, 2004
    Publication date: November 25, 2004
    Inventors: Kousuke Suzuki, Tomio Kondou, Masahide Yamashita
  • Patent number: 6821699
    Abstract: A toner having a half melting temperature not greater than 115° C. has good fixability without filming, even in an image forming method using a non-contact fixing method; has good fixability and color reproducibility, even in an image forming method reproducing multi-colored images by combining two or more toner layers of different color; has good heat resistance without impairing fixability and color reproducibility; and produces high quality images without impairing fixability and color reproducibility.
    Type: Grant
    Filed: September 25, 2002
    Date of Patent: November 23, 2004
    Assignee: Ricoh Company Limited
    Inventors: Tomio Kondou, Hachiro Tosaka, Hitoshi Ueda, Tomiaki Ito
  • Patent number: 6780556
    Abstract: An external additive for a toner, having an average primary particle diameter not greater than 100 nm and including at least inorganic fine particles and a hydrophobizing agent applied to the surface of the inorganic fine particles, wherein after the external additive is treated with chloroform, pyrolysates of the residual components include a compound having at least one structure selected from organopolysiloxane structures and ring siloxane structures.
    Type: Grant
    Filed: March 4, 2002
    Date of Patent: August 24, 2004
    Assignee: Ricoh Company Limited
    Inventors: Hideki Sugiura, Tomio Kondou
  • Patent number: 6641969
    Abstract: A magnetic toner with a negative polarity for developing latent electrostatic images is made of toner particles, each toner particle containing a binder resin, a magnetic powder, and a charge control agent, the surface of the magnetic toner satisfying the relationship of 2×10−7≦C/Sw≦10×10−7, provided C≦8×10−3, wherein C is an amount (g/g) of the charge control agent dissolved in a solvent comprising water and methanol, and Sw is a specific surface area (cm2/cm3) of the toner particles determined from a weight-average particle diameter of the toner particles. An image forming apparatus has an electrostatic image bearing member, and a unit for developing the electrostatic image with the above magnetic toner, the unit having a developer holding member provided with a magnet, and a developer container.
    Type: Grant
    Filed: September 20, 2002
    Date of Patent: November 4, 2003
    Assignee: Ricoh Company, Ltd.
    Inventors: Osamu Uchinokura, Tomio Kondou
  • Patent number: 6630276
    Abstract: An external additive for a toner, which has an average particle diameter not greater than 100 nm and includes an inorganic particulate material; and a hydrophobizing agent which is present on the inorganic particulate material in an amount of Ws by weight and present as a free hydrophobizing agent in an amount of Wf by weight, wherein a residual ratio defined as a ratio {Ws/(Ws+Wf)}×100 is from 40 to 98.5%, and wherein at least one of a compound having an organopolysiloxane structure and a compound having a ring siloxane structure is detected when the external additive is analyzed by a pyrolysis gas chromatography mass spectroscopy method after the external additive is washed with chloroform.
    Type: Grant
    Filed: November 6, 2001
    Date of Patent: October 7, 2003
    Assignee: Ricoh Company, Ltd.
    Inventors: Hideki Sugiura, Tomio Kondou