Patents by Inventor Motoko Sakai

Motoko Sakai 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: 8507167
    Abstract: The invention provides a toner for developing an electrostatic image including toner particles having a shape factor SF1 of 110 or more and including a binder resin, and particles of an external additive that adhere to the toner particles, wherein the particles of the external additive including first particles, and second particles which are adhered to the first particles and have a primary particle size of 0.2 times to 0.5 times as large as that of the first particles, and in an image obtained by observing the particles of the external additive with a microscope, when the projection surface area of the first particle is defined as S1 and the total of the projection surface areas of the second particles which are not hidden by the first particle is defined as S2, S2 being from 0.1 times to 0.5 times as large as S1.
    Type: Grant
    Filed: August 9, 2010
    Date of Patent: August 13, 2013
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Yutaka Saito, Michio Take, Yoshifumi Iida, Sakon Takahashi, Motoko Sakai, Katsuyuki Kitajima
  • Patent number: 8227158
    Abstract: The invention provides a toner for electrostatic image development, containing a toner particle and external additive particles adhered to the surface of the toner particle, each of the external additive particles being constituted of plural irreversibly coalesced primary particles.
    Type: Grant
    Filed: August 11, 2009
    Date of Patent: July 24, 2012
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Tetsuya Taguchi, Motoko Sakai, Jun Igarashi, Masahiro Takagi
  • Publication number: 20120156601
    Abstract: A toner for developing an electrostatic image, including: toner particles containing at least a binder resin, a release agent, and a colorant; and an external additive having a volume average particle diameter (d) of from 70 nm to 400 nm, a ratio (d/?) of the volume average particle diameter (d) to a standard deviation (?) of a volumetric basis particle diameter of from 2.0 to 12, and an average circularity of from 0.5 to 0.9.
    Type: Application
    Filed: May 20, 2011
    Publication date: June 21, 2012
    Applicant: FUJI XEROX CO., LTD.
    Inventors: Katsuyuki KITAJIMA, Yutaka SAITO, Michio TAKE, Yoshifumi IIDA, Motoko SAKAI
  • Publication number: 20110229812
    Abstract: A two-component developer includes: a toner; a carrier having a surface energy of from about 23 dyne/cm to about 37 dyne/cm; and an external additive having a shape factor SF1 of from about 130 to about 150 and a number-average particle diameter of from about 80 nm to about 1 ?m; and an existence ratio A of the external additive on a surface of the toner and an existence ratio B of the external additive on a surface of the carrier satisfying the relationship of the following Expression 1: 0.04?B/A?0.4.
    Type: Application
    Filed: September 3, 2010
    Publication date: September 22, 2011
    Applicant: FUJI XEROX CO., LTD.
    Inventors: Sakon TAKAHASHI, Motoko Sakai, Yutaka Saito, Katsuyuki Kitajima
  • Publication number: 20110229811
    Abstract: The invention provides a toner for developing an electrostatic image including toner particles having a shape factor SF1 of 110 or more and including a binder resin, and particles of an external additive that adhere to the toner particles, wherein the particles of the external additive including first particles, and second particles which are adhered to the first particles and have a primary particle size of 0.2 times to 0.5 times as large as that of the first particles, and in an image obtained by observing the particles of the external additive with a microscope, when the projection surface area of the first particle is defined as S1 and the total of the projection surface areas of the second particles which are not hidden by the first particle is defined as S2, S2 being from 0.1 times to 0.5 times as large as S1.
    Type: Application
    Filed: August 9, 2010
    Publication date: September 22, 2011
    Applicant: FUJI XEROX CO., LTD.
    Inventors: Yutaka SAITO, Michio Take, Yoshifumi Iida, Sakon Takahashi, Motoko Sakai, Katsuyuki Kitajima
  • Patent number: 7955773
    Abstract: A toner for developing an electrostatic image includes a toner particle to which particles of an external additive A having a number average particle diameter of from 7 nm to 200 nm and particles of an external additive B having a number average particle diameter of from 30 nm to 4000 nm have been externally added. The ratio of the number average particle diameter of the particles of the external additive B to the number average particle diameter of the particles of the external additive A is in a range of from 2 to 20. The particles of one of the external additive A or the external additive B are particles having a core material covered with an organic material containing hydrogen and nitrogen. The particles of the other one of the external additive A or the external additive B are SiO2 particles.
    Type: Grant
    Filed: February 19, 2009
    Date of Patent: June 7, 2011
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Motoko Sakai, Masahiro Takagi, Jun Igarashi, Tetsuya Taguchi
  • Publication number: 20100248110
    Abstract: The invention provides a toner for electrostatic image development, containing a toner particle and external additive particles adhered to the surface of the toner particle, each of the external additive particles being constituted of plural irreversibly coalesced primary particles.
    Type: Application
    Filed: August 11, 2009
    Publication date: September 30, 2010
    Applicant: FUJI XEROX CO., LTD.
    Inventors: Tetsuya Taguchi, Motoko Sakai, Jun Igarashi, Masahiro Takagi
  • Publication number: 20100081074
    Abstract: A toner for developing an electrostatic image includes a toner particle to which particles of an external additive A having a number average particle diameter of from 7 nm to 200 nm and particles of an external additive B having a number average particle diameter of from 30 nm to 4000 nm have been externally added. The ratio of the number average particle diameter of the particles of the external additive B to the number average particle diameter of the particles of the external additive A is in a range of from 2 to 20. The particles of one of the external additive A or the external additive B are particles having a core material covered with an organic material containing hydrogen and nitrogen. The particles of the other one of the external additive A or the external additive B are SiO2 particles.
    Type: Application
    Filed: February 19, 2009
    Publication date: April 1, 2010
    Applicant: FUJI XEROX CO., LTD.
    Inventors: Motoko SAKAI, Masahiro TAKAGI, Jun IGARASHI, Tetsuya TAGUCHI
  • Patent number: 7160662
    Abstract: The present invention relates to an image forming method including: a charging step; an electrostatic latent image forming step; a developing step; a transfer step; a fixing step; and a cleaning step, wherein an electrostatic latent image developing agent comprises a toner and a carrier, wherein particles which have a volume resistivity of at least 1×1014 ?cm and an average primary particle diameter of 50 nm or less has a higher covering ratio than other particles on the toner particle surfaces, a shape factor SF1 of the toner is in the range of from 100 to 140, the carrier is a resin coated carrier, and at least a coating resin layer comprises a positively charging resin and a quaternary ammonium salt compound.
    Type: Grant
    Filed: December 11, 2003
    Date of Patent: January 9, 2007
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Susumu Yoshino, Yoshifumi Iida, Seki Yamaguchi, Motoko Sakai, Sueko Sakai
  • Patent number: 7095974
    Abstract: An image forming method including a charging step, a latent image forming step, a developing step, a transfer step, and a cleaning step, wherein remaining toner recovered in the cleaning step is used as recycled toner, and a ratio of the recycled toner to a total amount of supply toner supplied to a developer is 15% by weight or greater.
    Type: Grant
    Filed: December 12, 2003
    Date of Patent: August 22, 2006
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Susumu Yoshino, Motoko Sakai, Yoshifumi Iida, Sueko Sakai, Seki Yamaguchi
  • Patent number: 7026085
    Abstract: The invention provides an electrostatic latent image developing dry toner composition that is used for forming images on both sides of a recording material, in which the toner contains calcium compound particles, and the amount W of the calcium compound particles added and the size d of the calcium compound particles meet the requirement of 5<W/d<500 . . . (1) (W: ratio to the total amount of toner (% by weight), d: volume average particle size (?m)), a developer constituted by the toner composition and a carrier, and an image forming method using the toner composition.
    Type: Grant
    Filed: September 25, 2003
    Date of Patent: April 11, 2006
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Susumu Yoshino, Motoko Sakai
  • Patent number: 6929893
    Abstract: An electrostatic image dry toner composition comprising a binding resin, a colorant, a releasing agent, and two or more kinds of inorganic oxide powders having different volume average primary particle diameters. A surface of at least one kind of the inorganic oxide powders is covered with a coating material selected from the group of 1) a fatty acid metal salt, 2) a wax having a melting point of 40° C. or higher, and 3) a resin having a glass transition temperature of 40° C. or higher.
    Type: Grant
    Filed: April 9, 2003
    Date of Patent: August 16, 2005
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Susumu Yoshino, Motoko Sakai, Yoshifumi Iida, Seiichi Takagi
  • Publication number: 20040234877
    Abstract: The present invention relates to an image forming method including: a charging step; an electrostatic latent image forming step; a developing step; a transfer step; a fixing step; and a cleaning step, wherein an electrostatic latent image developing agent comprises a toner and a carrier, wherein particles which have a volume resistivity of at least 1×1014 &OHgr;cm and an average primary particle diameter of 50 nm or less has a higher covering ratio than other particles on the toner particle surfaces, a shape factor SF1 of the toner is in the range of from 100 to 140, the carrier is a resin coated carrier, and at least a coating resin layer comprises a positively charging resin and a quaternary ammonium salt compound.
    Type: Application
    Filed: December 11, 2003
    Publication date: November 25, 2004
    Applicant: FUJI XEROX CO., LTD.
    Inventors: Susumu Yoshino, Yoshifumi Iida, Seki Yamaguchi, Motoko Sakai, Sueko Sakai
  • Publication number: 20040234310
    Abstract: An image forming method including a charging step, a latent image forming step, a developing step, a transfer step, and a cleaning step, wherein remaining toner recovered in the cleaning step is used as recycled toner, and a ratio of the recycled toner to a total amount of supply toner supplied to a developer is 15% by weight or greater.
    Type: Application
    Filed: December 12, 2003
    Publication date: November 25, 2004
    Applicant: FUJI XEROX CO., LTD.
    Inventors: Susumu Yoshino, Motoko Sakai, Yoshifumi Iida, Sueko Sakai, Seki Yamaguchi
  • Publication number: 20040185361
    Abstract: The invention provides an electrostatic latent image developing dry toner composition that is used for forming images on both sides of a recording material, in which the toner contains calcium compound particles, and the amount W of the calcium compound particles added and the size d of the calcium compound particles meet the requirement of 5<W/d<500 . . . (1) (W: ratio to the total amount of toner (% by weight), d: volume average particle size (&mgr;m)), a developer constituted by the toner composition and a carrier, and an image forming method using the toner composition.
    Type: Application
    Filed: September 25, 2003
    Publication date: September 23, 2004
    Applicant: FUJI XEROX CO., LTD.
    Inventors: Susumu Yoshino, Motoko Sakai
  • Publication number: 20040058258
    Abstract: An electrostatic image dry toner composition comprising a binding resin, a colorant, a releasing agent, and two or more kinds of inorganic oxide powders having different volume average primary particle diameters. A surface of at least one kind of the inorganic oxide powders is covered with a coating material selected from the group of 1) a fatty acid metal salt, 2) a wax having a melting point of 40° C. or higher, and 3) a resin having a glass transition temperature of 40° C. or higher.
    Type: Application
    Filed: April 9, 2003
    Publication date: March 25, 2004
    Applicant: Fuji Xerox Co., Ltd.
    Inventors: Susumu Yoshino, Motoko Sakai, Yoshifumi Iida, Seiichi Takagi