Patents by Inventor Noboru Kuroda

Noboru Kuroda 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: 8403149
    Abstract: A cyclone classifier for classifying a particulate material, including an outer cylinder having a waistless part and an inverted-cone part vertically connected to an underside of the waistless part, and an inner cylinder which includes an exhaust opening such that the inner cylinder has a position-adjustable bottom end.
    Type: Grant
    Filed: November 17, 2006
    Date of Patent: March 26, 2013
    Assignee: Ricoh Company, Ltd.
    Inventors: Takahiro Kadota, Kenichi Uehara, Noboru Kuroda, Masato Kobayashi
  • Patent number: 7585607
    Abstract: A method of manufacturing a toner including dissolving or dispersing a toner component containing a colorant and a resin in an organic solvent to obtain a liquid solution or dispersion, continuously emulsifying and dispersing the liquid solution or dispersion in an aqueous medium containing a particulate dispersant to obtain emulsified primary particles, controlling cohesion and agglomeration of the emulsified primary particles and removing the organic solvent, such that the ratio (T1/T2) of the arithmetic mean accumulation time (T1) of the emulsified primary particles obtained in the controlling step to the arithmetic mean accumulation time (T2) of the emulsified primary particles obtained in the continuously emulsifying and dispersing step is from 1 to 5.
    Type: Grant
    Filed: March 15, 2006
    Date of Patent: September 8, 2009
    Assignee: Ricoh Company, Ltd.
    Inventors: Masashi Miyakawa, Noboru Kuroda, Kazuyuki Matsui, Hiroshi Takahashi, Takahiro Kadota
  • Patent number: 7223510
    Abstract: A method for producing a toner including dissolving or dispersing a toner constituent mixture including a binder resin and a colorant in an organic solvent to prepare a toner constituent mixture liquid; dispersing the toner constituent mixture liquid in an aqueous medium including a particulate dispersant to prepare an emulsion; and removing the organic solvent from the emulsion while applying a shearing force to the emulsion. A toner manufactured by the method and having a spindle form while satisfying specific particle diameter relationships. An image forming apparatus using the toner. A toner packing method and device in which the toner is fluidized and pressurized to be fed from a fluidizing container to a toner container on which a gas-powder separation sieve is set to discharge air therefrom.
    Type: Grant
    Filed: May 21, 2004
    Date of Patent: May 29, 2007
    Assignee: Ricoh Company Limited
    Inventors: Kazuyuki Matsui, Noboru Kuroda, Kifuku Takagi, Masato Kobayashi
  • Publication number: 20070114159
    Abstract: A cyclone classifier for classifying a particulate material, including an outer cylinder having a waistless part and an inverted-cone part vertically connected to an underside of the waistless part, and an inner cylinder which includes an exhaust opening such that the inner cylinder has a position-adjustable bottom end.
    Type: Application
    Filed: November 17, 2006
    Publication date: May 24, 2007
    Inventors: Takahiro Kadota, Kenichi Uehara, Noboru Kuroda, Masato Kobayashi
  • Publication number: 20060216629
    Abstract: A method of manufacturing a toner including dissolving or dispersing a toner component containing a colorant and a resin in an organic solvent to obtain a liquid solution or dispersion, continuously emulsifying and dispersing the liquid solution or dispersion in an aqueous medium containing a particulate dispersant to obtain emulsified primary particles, controlling cohesion and agglomeration of the emulsified primary particles and removing the organic solvent, such that the ratio (T1/T2) of the arithmetic mean accumulation time (T1) of the emulsified primary particles obtained in the controlling step to the arithmetic mean accumulation time (T2) of the emulsified primary particles obtained in the continuously emulsifying and dispersing step is from 1 to 5.
    Type: Application
    Filed: March 15, 2006
    Publication date: September 28, 2006
    Inventors: Masashi Miyakawa, Noboru Kuroda, Kazuyuki Matsui, Hiroshi Takahashi, Takahiro Kadota
  • Publication number: 20040234882
    Abstract: A method for producing a toner including dissolving or dispersing a toner constituent mixture including a binder resin and a colorant in an organic solvent to prepare a toner constituent mixture liquid; dispersing the toner constituent mixture liquid in an aqueous medium including a particulate dispersant to prepare an emulsion; and removing the organic solvent from the emulsion while applying a shearing force to the emulsion. A toner manufactured by the method and having a spindle form while satisfying specific particle diameter relationships. An image forming apparatus using the toner. A toner packing method and device in which the toner is fluidized and pressurized to be fed from a fluidizing container to a toner container on which a gas-powder separation sieve is set to discharge air therefrom.
    Type: Application
    Filed: May 21, 2004
    Publication date: November 25, 2004
    Inventors: Kazuyuki Matsui, Noboru Kuroda, Kifuku Takagi, Masato Kobayashi
  • Patent number: 6569590
    Abstract: A method is provided for manufacturing a master batch pigment for a toner, including the steps of mixing a dry pigment powder, a binder resin and water to prepare a mixture thereof; and kneading the mixture upon application of heat to prepare the master batch pigment, wherein the master batch pigment has a weight loss of from 0.01 to 1.0% when heated at 110° C. for 2 hrs.
    Type: Grant
    Filed: August 24, 2001
    Date of Patent: May 27, 2003
    Assignee: Ricoh Company Limited
    Inventors: Noboru Kuroda, Shoichi Sugiyama
  • Patent number: 6432590
    Abstract: A toner including toner particles including at least a binder resin having a first melting point and a first solubility parameter, a colorant and a particulate release agent having a second melting point lower than the first melting point and a second solubility parameter different from the first solubility parameter, wherein the particulate release agent dispersed in the toner particles has an average needle-shape degree LD/SD of not less than 1.6, where LD is a diameter of a particle of the release agent dispersed in the toner in a major axis direction thereof and SD is a diameter of the particle in a minor axis direction.
    Type: Grant
    Filed: November 13, 2000
    Date of Patent: August 13, 2002
    Assignee: Ricoh Company, Ltd.
    Inventors: Hideyuki Ueda, Shohichi Sugimoto, Satoru Miyamoto, Osamu Uchinokura, Kumi Hasegawa, Tamotsu Kajihara, Yoshihiro Suguro, Noboru Kuroda
  • Patent number: 6395443
    Abstract: A toner for developing an electrostatic image, including a binder, a coloring agent and a charge controlling agent. When that portion of the toner which has a particle diameter of 5.04 &mgr;m or less accounts for 15-60% of the total number N of the toner, that portion of the toner which provides a number average particle diameter of 4.0 to 4.5 &mgr;m has such a content C1% by weight of the charge controlling agent that gives a ratio of C1/CT of 1.00 to 1.10, where CT is a total amount, in terms of % by weight, of the charge controlling agent in the toner. When that portion of the toner which has a particle diameter of 5.04 &mgr;m or less accounts for 15% or less of the total number N, that portion of the toner which provides a number average particle diameter of 4.2 to 4.8 &mgr;m has such a content C2% by weight of the charge controlling agent that gives a ratio of C2/CT of 1.02 to 1.15.
    Type: Grant
    Filed: November 29, 2000
    Date of Patent: May 28, 2002
    Assignee: Ricoh Company, Ltd.
    Inventors: Noboru Kuroda, Tomoyuki Satoh, Yasushi Nakamura, Nobutaka Kinoshita, Masahiro Kawamoto, Shigeru Emoto, Osamu Kouzu
  • Publication number: 20020048712
    Abstract: A method is provided for manufacturing a master batch pigment for a toner, including the steps of mixing a dry pigment powder, a binder resin and water to prepare a mixture thereof; and kneading the mixture upon application of heat to prepare the master batch pigment, wherein the master batch pigment has a weight loss of from 0.01 to 1.0% when heated at 110° C. for 2 hrs.
    Type: Application
    Filed: August 24, 2001
    Publication date: April 25, 2002
    Applicant: Ricoh Company Limited Ohta-ku, Japan
    Inventors: Noboru Kuroda, Shoichi Sugiyama
  • Publication number: 20010041298
    Abstract: A toner for developing an electrostatic image, including a binder, a coloring agent and a charge controlling agent. When that portion of the toner which has a particle diameter of 5.04 &mgr;m or less accounts for 15-60% of the total number N of the toner, that portion of the toner which provides a number average particle diameter of 4.0 to 4.5 &mgr;m has such a content C1% by weight of the charge controlling agent that gives a ratio of C1/CT of 1.00 to 1.10, where CT is a total amount, in terms of % by weight, of the charge controlling agent in the toner. When that portion of the toner which has a particle diameter of 5.04 &mgr;m or less accounts for 15% or less of the total number N, that portion of the toner which provides a number average particle diameter of 4.2 to 4.8 &mgr;m has such a content C2% by weight of the charge controlling agent that gives a ratio of C2/CT of 1.02 to 1.15.
    Type: Application
    Filed: November 29, 2000
    Publication date: November 15, 2001
    Inventors: Noboru Kuroda, Tomoyuki Satoh, Yasushi Nakamura, Nobutaka Kinoshita, Masahiro Kawamoto, Shigeru Emoto, Osamu Kouzu
  • Patent number: 6258502
    Abstract: A two-component developer includes a magnetic carrier including magnetic carrier particles with an average particle diameter of 35 &mgr;m to 100 &mgr;m, and a toner including toner particles with a weight-average particle diameter of 6.0 &mgr;m to 11.5 &mgr;m, to which at least one additive is externally added thereto in an amount of 0.3 to 1.5 wt. % to the toner, the toner particles including (a) toner particles with a particle diameter of 5 &mgr;m or less with a content ratio of 15% or less by number, and (b) toner particles with such a particle diameter that is two times or greater than the weight-average particle diameter of the toner particles with a content ratio of 5% or less by volume, the toner particles satisfying a relationship of 0.60≦D25/D75≦0.85 as defined in the specification. A container in which the two-component developer is contained, and an electrophotographic image formation apparatus in which the container is incorporated are proposed.
    Type: Grant
    Filed: May 30, 2000
    Date of Patent: July 10, 2001
    Assignee: Ricoh Company, Ltd.
    Inventors: Yasushi Nakamura, Noboru Kuroda, Ryoichi Ito, Yasuaki Iwamoto, Kohki Katoh, Yoshihiro Sugiyama, Kenichi Uehara, Tomio Kondou
  • Patent number: 6200719
    Abstract: A toner containing toner particles has a particular weight-average particle diameter, containing therein toner particles with another particle diameter in a predetermined number percentage of the number of the toner particles. A releasing agent contained in the toner particles has a particular endotherm ratio (Q/q), that is measured, using a differential scanning calorimeter (DSC), wherein q is the endotherm (&mgr;V·min/mg) of the releasing agent contained in predetermined classified and sampled toner particles, assessed per unit amount of the sampled toner particles, and Q is the endotherm (&mgr;V·min/mg) of the releasing agent contained in the toner particles of the toner in its entirety, assessed per unit amount of the toner particles. A method of producing the toner, and a method of forming images, using the toner, and a toner container or cartridge containing therein the toner are disclosed.
    Type: Grant
    Filed: April 7, 2000
    Date of Patent: March 13, 2001
    Assignee: Ricoh Company, Ltd.
    Inventor: Noboru Kuroda
  • Patent number: 6183926
    Abstract: A toner is made or toner particles which contains a binder resin and a coloring agent, wherein the toner particles have a weight-average particle size in a range of 6.0 to 11.5 &mgr;m, and contains toner particles (a) with a particle diameter of 5 &mgr;m or less in a content ratio of 1 to 15% by number, and toner particles (b) with a particle diameter of twice or more the weight-average particle size in a content ratio of 5 wt % or less, and the number-average particle size D25 and the number-average particle size D75 respectively obtained when the cumulative number of the toner particles reaches 25% and 75% at the measurement of a cumulative toner particle distribution by number thereof are in the relationship of 0.60≦D25/D75≦0.95. A two-component developer includes the above-mentioned toner and a carrier.
    Type: Grant
    Filed: October 25, 1999
    Date of Patent: February 6, 2001
    Assignee: Ricoh Company, Ltd.
    Inventors: Noboru Kuroda, Yasushi Nakamura, Ryoichi Ito, Yasuaki Iwamoto, Kohki Katoh, Tomio Kondou, Kenichi Uehara, Yoshihiro Sugiyama, Yasuyuki Sanui
  • Patent number: 6180298
    Abstract: A multi-color toner set includes a plurality of color toners with different colors, each color toner including toner particles, each toner particle including a binder resin, a pigment and a releasing agent, at least part of the releasing agent being present in the form of domains in the binder resin, with a difference between a maximum content and a minimum content of the releasing agent in the form of domains in the binder resin in each of the color toners being in a range of 20% or less. Multi-color images can be formed, using this multi-color toner set.
    Type: Grant
    Filed: April 16, 1999
    Date of Patent: January 30, 2001
    Assignee: Ricoh Company, Ltd.
    Inventors: Noboru Kuroda, Kohsuke Suzuki, Yohichiroh Watanabe, Keiko Shiraishi
  • Patent number: 6074795
    Abstract: A toner for developing electrostatic latent images which includes at least a binder resin, a colorant and a releasing agent, wherein the releasing agent includes a particulate material capable of absorbing the releasing agent. The particulate material preferably has an absorption rate not less than about 10% by weight in a combination with the releasing agent.
    Type: Grant
    Filed: July 1, 1999
    Date of Patent: June 13, 2000
    Assignee: Ricoh Company, Ltd.
    Inventors: Yohichiroh Watanabe, Keiko Shiraishi, Noboru Kuroda, Kohsuke Suzuki