Patents by Inventor Katsunori Kurose

Katsunori Kurose 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: 20110045401
    Abstract: An image forming apparatus, wherein a surface resistivity Rse[?] of a charger and a volume resistivity Rsw [?·cm] of the composition having a low softening point satisfy the following relationship: 0.8×10?1Rse<Rvw<1.5×10Rse is provided. The image forming apparatus contains a photoreceptor; a charger configured to charge the photoreceptor with a charger contacting thereto; an irradiator configured to irradiate the photoreceptor to form an electrostatic latent image thereon; an image developer configured to develop the electrostatic latent image with a toner to form a toner image on the photoreceptor; a transferer configured to transfer the toner image onto a recording material directly or through an intermediate transferer; and a fixer configured to fix the toner image on the recording material, wherein the toner comprises: a binder resin; a colorant; a composition having a low softening point; and an external additive.
    Type: Application
    Filed: October 26, 2010
    Publication date: February 24, 2011
    Inventors: Hiroyuki MURAKAMI, Masahide Inoue, Chiyoshi Nozaki, Tsuyoshi Nozaki, Atsushi Yamamoto, Takuya Kadota, Mitsuyo Matsumoto, Katsunori Kurose, Yoshimichi Ishikawa
  • Patent number: 7867685
    Abstract: An image forming method, including charging a photoreceptor with a charger contacting thereto; irradiating the photoreceptor to form an electrostatic latent image thereon; developing the electrostatic latent image with a toner to form a toner image on the photoreceptor; transferring the toner image onto a recording material directly or through an intermediate transferer; and fixing the toner image on the recording material, wherein the toner includes a binder resin; a colorant; a composition having a low softening point; and an external additive, and wherein a surface resistivity Rse [?] of the charger and a volume resistivity Rsw [?·cm] of the composition having a low softening point satisfy the following relationship: 0.8×10?1Rse<Rvw<1.5×10Rse.
    Type: Grant
    Filed: September 7, 2007
    Date of Patent: January 11, 2011
    Assignee: Ricoh Company, Limited
    Inventors: Hiroyuki Murakami, Masahide Inoue, Chiyoshi Nozaki, Tsuyoshi Nozaki, Atsushi Yamamoto, Takuya Kadota, Mitsuyo Matsumoto, Katsunori Kurose, Yoshimichi Ishikawa
  • Patent number: 7838193
    Abstract: A toner including toner particles including a binder resin, a colorant and a release agent, and an external additive including a first particulate inorganic material having a formula of MgxSiyOx+2y where each of x and y is an integer, and a number average secondary particle diameter of from 0.02 ?m to 2 ?m, wherein the first atomic ratio (Mg/Si)s in a surface portion of the first particulate inorganic material is not greater than (preferably less than) the second atomic ratio (Mg/Si)e in the entire first particulate inorganic material. Alternatively, a toner including toner particles including a binder resin and a colorant, and an external additive which includes a particulate inorganic material having a formula of MgxSiyOx+2y where each of x and y is an integer and which has a surface treated with a fatty acid.
    Type: Grant
    Filed: February 1, 2007
    Date of Patent: November 23, 2010
    Assignee: Ricoh Company Limited
    Inventors: Masayuki Hagi, Takuya Kadota, Hiroaki Katoh, Atsushi Yamamoto, Katsunori Kurose, Yoshihiro Mikuriya, Masahide Inoue, Hideaki Yasunaga, Minoru Nakamura, Yoshimichi Ishikawa, Hiroyuki Murakami
  • Patent number: 7833686
    Abstract: A toner kit containing at least a black toner, a yellow toner, a magenta toner and a cyan toner, wherein these toners have at least the binder resin, the colorant and the charge controlling agent having the molecular structure containing K+ as the counterion, when the K+ intensity detected by the fluorescent X ray on the surface of the black toner is Kk, the K+ intensity detected by the fluorescent X ray on the surface of the yellow toner is Ky, the K+ intensity detected by the fluorescent X ray on the surface of the magenta toner is Km and the K+ intensity detected by the fluorescent X ray on the surface of the cyan toner is Kc, the following formulae: Kk<Ky, Kk<Km and Kk<Kc are fulfilled is provided.
    Type: Grant
    Filed: December 26, 2006
    Date of Patent: November 16, 2010
    Assignee: Ricoh Company, Ltd.
    Inventors: Takuya Kadota, Minoru Nakamura, Masayuki Hagi, Yoshihiro Mikuriya, Katsunori Kurose, Hideaki Yasunaga, Hiroaki Kato, Yoshimichi Ishikawa, Atsushi Yamamoto, Masahide Inoue
  • Patent number: 7829254
    Abstract: The present invention aims at providing non-magnetic toner which is excellent in fixing property and charge property and capable of inhibiting occurrence of scumming, as well as an image forming apparatus and a process cartridge using the non-magnetic toner. A non-magnetic toner comprising: a toner base particle which comprises a binding resin, and a colorant; and external additives, wherein a surface of the toner base particle contains at least a resin having at least silanol group, and the external additives contain at least particles composed of silicon oxide.
    Type: Grant
    Filed: March 16, 2007
    Date of Patent: November 9, 2010
    Assignee: Ricoh Company, Ltd.
    Inventors: Katsunori Kurose, Chiyoshi Nozaki, Tsuyoshi Nozaki, Atsushi Yamamoto, Mitsuyo Matsumoto
  • Patent number: 7817946
    Abstract: The present invention provides a developing device that allows for maintaining the conveyance amount of a toner within a certain definite range. A developing device 12 of the present invention is provided with a toner conveying unit 13 configured to convey a first toner and a controlling member 15 configured to control the thickness of a toner layer formed with the first toner conveyed by the toner conveying unit 13, wherein a second toner provided with a charged amount per unit mass that differs from a charged amount per unit mass of the first toner is applied over the surface of the controlling member 15.
    Type: Grant
    Filed: September 6, 2007
    Date of Patent: October 19, 2010
    Assignee: Ricoh Company, Ltd.
    Inventors: Hiroyuki Murakami, Masahide Inoue, Masayuki Hagi, Takuya Kadota, Yoshihiro Mikuriya, Katsunori Kurose, Hideaki Yasunaga, Hiroaki Kato, Yoshimichi Ishikawa, Kazuoki Fuwa
  • Patent number: 7749671
    Abstract: To provide a toner containing at least a toner base containing a binder resin and a colorant, and an inorganic fine particle, wherein the inorganic fine particle contains a compound oxide expressed by the following Composition Formula (1): [M1]aSibOc??Composition Formula (1) where “M1” represents a metal element selected from Sr, Mg, Zn, Co, Mn and Ce, “a” and “b” each represents an integer of 1 to 9 and “c” represents an integer of 3 to 9, wherein an average primary particle diameter of the compound oxide is 0.02 ?m to 1.5 ?m, and an average secondary particle diameter of the compound oxide is 0.08 ?m to 3.5 ?m, where the secondary particle is an aggregate of the primary particles.
    Type: Grant
    Filed: September 15, 2006
    Date of Patent: July 6, 2010
    Assignee: Ricoh Company, Ltd.
    Inventors: Atsushi Yamamoto, Masahide Inoue, Chiyoshi Nozaki, Minoru Nakamura, Masayuki Hagi, Yoshihiro Mikuriya, Tsuyoshi Nozaki, Hiroaki Kato, Takuya Kadota, Katsunori Kurose, Hideaki Yasunaga, Yoshimichi Ishikawa
  • Patent number: 7709171
    Abstract: The present invention provides a charge control agent, adapted to control charging ability of resins or compositions containing resins, comprising a copolymer that comprises a polymer block A and a polymer block B, the polymer block A is prepared by copolymerizing a maleimide, which being unsubstituted or substituted for a hydrogen atom of an imide group by an electron-donating group, and styrene or a styrene derivative, and the polymer block B is formed of a polymer of styrene or a styrene derivative.
    Type: Grant
    Filed: July 18, 2007
    Date of Patent: May 4, 2010
    Assignee: Ricoh Company, Ltd.
    Inventors: Atsushi Yamamoto, Chiyoshi Nozaki, Tsuyoshi Nozaki, Mitsuyo Matsumoto, Katsunori Kurose
  • Patent number: 7695885
    Abstract: A negatively-chargeable non-magnetic one-component developer for developing an electrostatic latent image using a contact DC-bias development method, having a capacitance of 1.05×10?12 to 1.25×10?12 F, a volume resistivity of 5.0×1010 to 5.0×1012 ?·cm and a dielectric loss tangent of 1.0×10?3 to 2.0×10?2. In a contact DC-bias development method, the developer has a capacitance of 1.30×10?12 to 1.60×10?12 F, a resistivity of 5.0×109 to 5.0×1010 ?·cm and a dielectric loss tangent of 1.0×10?3 to 2.0×10?2. In a non-contact DC/AC-bias development method, the developer has a capacitance of 1.45×10?12 to 1.60×10?12 F, a resistivity of 5.0×109 to 1.0×1010 ?·cm and a dielectric loss tangent of 1.0×10?3 to 2.0×10?2.
    Type: Grant
    Filed: January 18, 2007
    Date of Patent: April 13, 2010
    Assignee: Ricoh Company Limited
    Inventors: Hideaki Yasunaga, Minoru Nakamura, Masayuki Hagi, Takuya Kadota, Hiroaki Katoh, Yoshihiro Mikuriya, Katsunori Kurose, Atsushi Yamamoto, Masahide Inoue
  • Patent number: 7632619
    Abstract: A toner including a binder resin, a wax, and a colorant, wherein particles of the wax having a particle diameter of less than 1.00 ?m are included in the toner in an amount of not less than 35% by number and less than 55% by number, and wherein the wax has a particle diameter distribution property such that when particle diameters of particles of the wax are classified into ranges having a width of 0.05 ?m, the wax has a particle diameter mode value that is not less than 0.75 ?m and less than 1.00 ?m; and a fixing method and an image forming method using the above toner.
    Type: Grant
    Filed: June 19, 2006
    Date of Patent: December 15, 2009
    Assignee: Ricoh Company Limited
    Inventors: Yoshihiro Mikuriya, Atsushi Yamamoto, Hiroaki Katoh, Takuya Kadota, Masayuki Hagi, Katsunori Kurose, Masahide Inoue
  • Publication number: 20090297975
    Abstract: A toner manufactured by a method including the steps of dissolving or dispersing toner components comprising a binder resin, a colorant, and an encapsulated plasticizer to prepare an oily toner components liquid, and emulsifying or dispersing the oily toner components liquid in an aqueous medium to prepare the toner.
    Type: Application
    Filed: June 1, 2009
    Publication date: December 3, 2009
    Inventors: Yoshimichi ISHIKAWA, Chiyoshi NOZAKI, Tsuyoshi NOZAKI, Takuya KADOTA, Katsunori KUROSE, Mitsuyo MATSUMOTO, Atsushi YAMAMOTO
  • Publication number: 20090220879
    Abstract: Provision of a toner for developing a latent electrostatic image, including a colorant, a binder resin, and a releasing agent, where molecular weight distribution of THF-soluble components of the toner measured by a GPC is in the range of Mw 4,000 to Mw 11,000, and a peak area of low molecular weight components having a molecular weight of 200 to 500 is 3.2% or less based on the whole peak area.
    Type: Application
    Filed: February 20, 2009
    Publication date: September 3, 2009
    Inventors: Mitsuyo MATSUMOTO, Chiyoshi Nozaki, Takuya Kadota, Katsunori Kurose, Tsuyoshi Nozaki, Atsushi Yamamoto, Yoshimichi Ishikawa
  • Patent number: 7556904
    Abstract: It is an object of the present invention to provide a toner containing toner particles and inorganic fine particles wherein the inorganic fine particles are externally added to the toner particles which contain a binder resin and a colorant and at least one type of the inorganic fine particles is a compound oxide having a relative permittivity measured at 1 MHz of 2 to 10 and a volume resistivity of 1011?·cm or more and an image forming method using the toner.
    Type: Grant
    Filed: April 26, 2006
    Date of Patent: July 7, 2009
    Assignee: Ricoh Company, Ltd.
    Inventors: Takuya Kadota, Masahide Inoue, Yoshihiro Mikuriya, Katsunori Kurose, Masayuki Hagi, Minoru Nakamura, Hiroaki Kato, Atsushi Yamamoto, Hideaki Yasunaga
  • Patent number: 7556906
    Abstract: A toner is provided including a colorant; a resin composition (A) comprising at least one binder resin and a hydrocarbon wax having a melting point of 70-90° C. in an amount of from 6 to 30% by weight based on total weight of resin composition (A), and having a softening point (T1/2(A)) of from 120 to 150° C.; and a resin composition (B) having a softening point (T1/2 (B)) of from 100 to 130° C., wherein a weight ratio of the resin composition (A) to the resin composition (B) is from 10/90 to 45/55, and the following relationship is satisfied: T1/2(A)?T1/2(B)+3; and the use of the toner in an image forming method, an image forming apparatus, and a process cartridge.
    Type: Grant
    Filed: November 28, 2006
    Date of Patent: July 7, 2009
    Assignee: Ricoh Company Limited
    Inventors: Hiroaki Katoh, Masayuki Hagi, Takuya Kadota, Yoshihiro Mikuriya, Katsunori Kurose, Atsushi Yamamoto, Masahide Inoue, Minoru Nakamura, Chiyoshi Nozaki, Tsuyoshi Nozaki, Hideaki Yasunaga
  • Publication number: 20090017391
    Abstract: A toner including a colorant, a polyester (I), and an urea-modified polyester is provided. The urea-modified polyester is a reaction product of an isocyanate-modified polyester with an amine. The isocyanate-modified polyester is obtained by modifying a polyester (II) with an isocyanate. The polyester (II) has specific number average molecular weight (Mn) and hydroxyl value [OHV]. The toner can be manufactured by dispersing or emulsifying a toner constituent liquid including the colorant, the polyester (I), and the isocyanate-modified polyester, in an aqueous medium. The toner can be used for a one-component developing device.
    Type: Application
    Filed: July 14, 2008
    Publication date: January 15, 2009
    Inventors: Atsushi Yamamoto, Chiyoshi Nozaki, Tsuyoshi Nozaki, Mitsuyo Matsumoto, Takuya Kadota, Katsunori Kurose, Yoshimichi Ishikawa
  • Publication number: 20080279591
    Abstract: The present invention is to provide a nonmagnetic one-component toner containing a colorant, and a binder resin, wherein metal oxide fine particles are fixed on a toner surface with an adhesion strength of 95% to 99%, the toner has a direct current resistance of 1E7 ?·cm to 1E9 ?·cm, and an electrostatic capacity of 1.0E-12F to 1.5E-11F.
    Type: Application
    Filed: August 23, 2007
    Publication date: November 13, 2008
    Inventors: Hideaki Yasunaga, Hiroaki Kato, Kazuoki Fuwa, Masayuki Hagi, Yoshihiro Mikuriya, Takuya Kadota, Hiroyuki Murakami, Yoshimichi Ishikawa, Katsunori Kurose
  • Publication number: 20080232857
    Abstract: An image forming apparatus having at least a latent electrostatic image bearing member, and a recharging unit configured to recharge a residual toner remaining on the latent electrostatic image bearing member, wherein after transfer, the residual toner is passed through the recharging unit and is then recovered in a developing device; a charging component of the recharging unit that comes into contact with the latent electrostatic image bearing member is a polymer sheet having a surface roughness (Ra) of 0.12 ?m to 0.51 ?m; the toner contains at least a pigment, a binder resin, and a releasing agent, and contains inorganic fine particles as an external additive, and the amount of the inorganic fine particles and the amount of the releasing agent satisfy three specific Expressions.
    Type: Application
    Filed: March 12, 2008
    Publication date: September 25, 2008
    Inventors: Mitsuyo Matsumoto, Chiyoshi Nozaki, Takuya Kadota, Katsunori Kurose, Tsuyoshi Nozaki, Atsushi Yamamoto, Yoshimichi Ishikawa
  • Publication number: 20080233510
    Abstract: Disclosed is a non-magnetic toner for use in developing electrostatic toner image, wherein the toner is produced by a toner production method that includes: dispersing in an aqueous medium an organic dispersion liquid that comprises in an organic solvent a pigment, a binder resin and/or a binder resin precursor, and a releasing agent; removing the organic solvent to prepare a dispersion slurry in which toner particles are dispersed in the aqueous medium; heating the dispersion slurry to a temperature equal to or higher than the melting point of the releasing agent; and washing the toner particles.
    Type: Application
    Filed: March 12, 2008
    Publication date: September 25, 2008
    Inventors: Tsuyoshi NOZAKI, Chiyoshi Nozaki, Atsushi Yamamoto, Mitsuyo Matsumoto, Takuya Kadota, Katsunori Kurose, Yoshimichi Ishikawa
  • Publication number: 20080233511
    Abstract: A toner including particles including a toner composition including a binder resin and a coloring material, wherein the toner composition includes a laminate compound A in which a cation between layers is modified by an organic cation, and a laminate compound B in which an anion between layers is modified by an organic anion, the laminate compound A is of negative charging property upon particulation of the laminate compound A by dispersion or internal addition in the binder resin and the laminate compound B is of positive charging property upon particulation of the laminate compound B by dispersion or internal addition in the binder resin, and the toner is of a positive charging property.
    Type: Application
    Filed: March 19, 2008
    Publication date: September 25, 2008
    Inventors: Yoshimichi ISHIKAWA, Chiyoshi Nozaki, Tsuyoshi Nozaki, Takuya Kadota, Hiroyuki Murakami, Mitsuyo Matsumoto, Atsushi Yamamoto, Katsunori Kurose
  • Publication number: 20080233497
    Abstract: A toner for developing a latent electrostatic image produced by suspension polymerizing a polymerizable monomer composition in an aqueous dispersion medium, wherein the polymerizable monomer composition contains a polymerizable monomer, a colorant, and a layered inorganic mineral in which at least a part of an interlayer ion is replaced with an organic ion, and a process cartridge and an image forming method using the toner.
    Type: Application
    Filed: March 17, 2008
    Publication date: September 25, 2008
    Inventors: Atsushi YAMAMOTO, Chiyoshi Nozaki, Tsuyoshi Nozaki, Takuya Kadota, Hiroyuki Murakami, Mitsuyo Matsumoto, Katsunori Kurose, Yoshimichi Ishikawa