Patents by Inventor Sakon Takahashi

Sakon Takahashi 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: 8394567
    Abstract: There is provided a toner for electrostatic latent image developing, which includes a binder resin; a carbon black-surface treated with an isocyanate compound including a plurality of isocyanate groups which include one or more isocyanate groups that are not bonded to the carbon black; and a release agent having an acid value of about 5 mgKOH/g or higher and/or a hydroxyl value of about 5 mgKOH/g or higher.
    Type: Grant
    Filed: March 17, 2010
    Date of Patent: March 12, 2013
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Satoshi Kamiwaki, Akira Matsumoto, Sakon Takahashi
  • Patent number: 8383308
    Abstract: A positively chargeable two-component developer, including at least a toner and a carrier, wherein the toner contains a binder resin, a colorant, a wax, and a charge control agent, the binder resin contains at least a polyester resin and an addition polymerization resin grafted with a polyolefin, the wax and the addition polymerization resin grafted with a polyolefin are contained at a wax:addition polymerization resin grafted with a polyolefin ratio of from about 40:60 to about 80:20, and the carrier is a magnetic powder having a coating layer containing a methyl-containing silicone resin.
    Type: Grant
    Filed: October 29, 2008
    Date of Patent: February 26, 2013
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Sakon Takahashi, Daisuke Ishizuka, Michio Take, Seijiro Ishimaru, Chiaki Suzuki
  • Patent number: 8318399
    Abstract: An electrostatic charge image development carrier includes magnetic core particles and a resin coating layer that contains titanium dioxide particles doped with niobium and coats each of the magnetic core particles.
    Type: Grant
    Filed: August 26, 2010
    Date of Patent: November 27, 2012
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Toshiaki Hasegawa, Takeshi Shoji, Sakon Takahashi, Fusako Kiyono
  • Publication number: 20120107739
    Abstract: The present invention provides an electrostatic latent image developer used in an image forming apparatus including: an image holding member; a charging unit; a latent image forming unit; a developing unit which stores the electrostatic latent image developer and includes a developer holding member, wherein the developing unit develops the electrostatic latent image formed on the image holding member by bringing a magnetic brush, which is formed on a surface of the developer holding member by the electrostatic latent image developer, into contact with the image holding member, to form a toner image; a transfer unit; a cleaning unit; and a lubricant applying unit, wherein the electrostatic latent image developer contains a toner having a 50% integrated volume particle diameter of from 3.0 to 6.0 ?m, and a carrier having a mean magnetization of 5.0×10?16 to 4.0×10?15 AM2/particle in an applied magnetic field of 1 kilo-oersted.
    Type: Application
    Filed: April 26, 2011
    Publication date: May 3, 2012
    Applicant: FUJI XEROX CO., LTD.
    Inventors: Takayuki YAMASHITA, Kazuhiko ARAI, Kunihiko SATO, Haruhide ISHIDA, Michio TAKE, Sakon TAKAHASHI, Fusako KIYONO, Yoshifumi IIDA, Mona TASAKI
  • Publication number: 20120093543
    Abstract: An electrostatic latent image developer contains a toner having a volume-average particle diameter of about 2.0 ?m to about 6.5 ?m, and a carrier whose average magnetization per carrier particle at an applied magnetic field of 1 kilooersted is about 3.0×10?16 Am2/particle to about 3.0×10?15 Am2/particle, wherein the electrostatic latent image developer is used in an image forming apparatus including an image-carrying member having a top surface layer composed of a cured film containing fluorocarbon resin particles, a developing unit that develops an electrostatic latent image formed on the image-carrying member to form a toner image by bringing a magnetic brush formed of the electrostatic latent image developer and having a brush roughness of about 300 ?m to about 850 ?m into contact with the image-carrying member, and a cleaning unit that includes a cleaning blade.
    Type: Application
    Filed: August 5, 2011
    Publication date: April 19, 2012
    Applicant: FUJI XEROX CO., LTD.
    Inventors: Miho IKEDA, Sakon TAKAHASHI, Kazuhiko ARAI, Haruhide ISHIDA, Michio TAKE, Kunihiko SATO, Yoshinori KUBO, Fusako KIYONO
  • Publication number: 20110236813
    Abstract: An electrophotographic developer is provided which includes: a toner that includes toner base particles and an external additive attached to a surface of the toner base particles and has an amount of Al on the surface of the toner base particles of from about 0.002 to about 0.02 atm %; and a carrier that includes magnetic particles and a coating resin layer that coats the magnetic particles, the coating resin layer including particles with a volume-average particle diameter of from about 80 to about 800 nm, such as organic particles or inorganic particles having an organic layer on a surface of the inorganic particles, the carrier satisfying any one of the following formulas, where SP1, SP2 and SP3 represent a solubility parameter of resin of the coating resin layer, the organic particles, and the organic layer respectively: about 10>|SP1?SP2|>about 4??(1); and about 10>|SP1?SP3|>about 4??(2).
    Type: Application
    Filed: August 24, 2010
    Publication date: September 29, 2011
    Applicant: FUJI XEROX CO., LTD.
    Inventors: Fusako Kiyono, Sakon Takahashi, Toshiaki Hasegawa, Takeshi Shoji
  • Publication number: 20110236820
    Abstract: An electrostatic charge image development carrier includes magnetic core particles and a resin coating layer that contains titanium dioxide particles doped with niobium and coats each of the magnetic core particles.
    Type: Application
    Filed: August 26, 2010
    Publication date: September 29, 2011
    Applicant: FUJI XEROX CO., LTD.
    Inventors: Toshiaki HASEGAWA, Takeshi SHOJI, Sakon TAKAHASHI, Fusako KIYONO
  • 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
  • Publication number: 20110076606
    Abstract: There is provided a toner for electrostatic latent image developing, which includes a binder resin; a carbon black-surface treated with an isocyanate compound including a plurality of isocyanate groups which include one or more isocyanate groups that are not bonded to the carbon black; and a release agent having an acid value of about 5 mgKOH/g or higher and/or a hydroxyl value of about 5 mgKOH/g or higher.
    Type: Application
    Filed: March 17, 2010
    Publication date: March 31, 2011
    Applicant: FUJI XEROX CO., LTD.
    Inventors: Satoshi KAMIWAKI, Akira MATSUMOTO, Sakon TAKAHASHI
  • Publication number: 20100233615
    Abstract: A method of producing a carrier for electrophotography includes: covering a surface of a core particle with a coating layer including resin particles and a crosslinking resin in an uncrosslinked state present in spaces between the resin particles; and applying a mechanical impact from the outer surface of the coating layer before crosslinking of the crosslinking resin.
    Type: Application
    Filed: September 11, 2009
    Publication date: September 16, 2010
    Applicant: FUJI XEROX CO., LTD.
    Inventors: Sakon TAKAHASHI, Norihito FUKUSHIMA, Shunsuke NOZAKI, Michio TAKE
  • Patent number: 7776502
    Abstract: A toner for developing an electrostatic charge image, includes: a binder resin formed by reacting a polymerizable aromatic monomer having an ethylenically unsaturated double bond conjugated to an aromatic ring thereof, a nitrogen-containing polymerizable aliphatic monomer having an ethylenically unsaturated double bond and a sulfur-containing aliphatic compound to each other; and a colorant, wherein a ratio (MN/MS) of an amount of nitrogen (MN) to an amount of sulfur (MS) is in a range of from 1.0 to 15.
    Type: Grant
    Filed: April 26, 2007
    Date of Patent: August 17, 2010
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Norihito Fukushima, Rieko Kataoka, Sakon Takahashi, Toshiyuki Yano
  • Publication number: 20090233211
    Abstract: A positively chargeable two-component developer, including at least a toner and a carrier, wherein the toner contains a binder resin, a colorant, a wax, and a charge control agent, the binder resin contains at least a polyester resin and an addition polymerization resin grafted with a polyolefin, the wax and the addition polymerization resin grafted with a polyolefin are contained at a wax:addition polymerization resin grafted with a polyolefin ratio of from about 40:60 to about 80:20, and the carrier is a magnetic powder having a coating layer containing a methyl-containing silicone resin.
    Type: Application
    Filed: October 29, 2008
    Publication date: September 17, 2009
    Applicant: Fuji Xerox Co., Ltd.
    Inventors: Sakon TAKAHASHI, Daisuke ISHIZUKA, Michio TAKE, Seijiro ISHIMARU, Chiaki SUZUKI
  • Publication number: 20080102396
    Abstract: A toner for developing an electrostatic charge image, includes: a binder resin formed by reacting a polymerizable aromatic monomer having an ethylenically unsaturated double bond conjugated to an aromatic ring thereof, a nitrogen-containing polymerizable aliphatic monomer having an ethylenically unsaturated double bond and a sulfur-containing aliphatic compound to each other; and a colorant, wherein a ratio (MN/MS) of an amount of nitrogen (MN) to an amount of sulfur (MS) is in a range of from 1.
    Type: Application
    Filed: April 26, 2007
    Publication date: May 1, 2008
    Applicant: FUJI XEROX CO., LTD.
    Inventors: Norihito Fukushima, Rieko Kataoka, Sakon Takahashi, Toshiyuki Yano
  • Patent number: 6746810
    Abstract: An image formation method which remarkably extends developer life while providing size reduction and high speed coloring. Also, a replenishing toner and a method of producing the same, and a toner cartridge. In the image formation method, conducting image formation by an image formation apparatus having a plurality of xerography units, the developer apparatus of at least one xerography unit has a developer recovering mechanism appropriately replenishing a replenishing toner composed of a toner and a carrier into the developer apparatus and recovering an excess portion of a developer from the equipment. The above-mentioned replenishing toner has a carrier content in the range of 5 to 40% by weight, the above-mentioned carrier is a carrier coated with a resin having a specific composition, and/or the above-mentioned toner is in a specific shape. The replenishing toner may be produced using the above-mentioned recovered developer.
    Type: Grant
    Filed: March 26, 2002
    Date of Patent: June 8, 2004
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Chiaki Suzuki, Masahiro Takagi, Atsuhiko Eguchi, Satoshi Inoue, Sakon Takahashi, Masahiro Uchida, Rieko Kataoka, Hiroyuki Fukuda, Fusako Kiyono, Eiji Iwasaki
  • Patent number: 6673502
    Abstract: A carrier for the development of an electrostatic latent image, comprising a core material and a resin coating the core material therewith, wherein the coating resin comprises a copolymer of at least four kinds of monomers including: (1) a monomer containing a carboxyl group; (2) an acrylic acid alkylester monomer or methacrylic acid alkylester monomer, containing a C1-C3 linear alkyl group; (3) an acrylic acid alkylester monomer or methacrylic acid alkylester monomer, containing a C4-C10 linear alkyl group or C3-C10 branched alkyl group; and (4) a monomer containing fluorine. Also disclosed is a two-component developer for the development of an electrostatic latent image, comprising a toner and the carrier.
    Type: Grant
    Filed: October 16, 2001
    Date of Patent: January 6, 2004
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Sakon Takahashi, Hiroshi Nakazawa, Tomohito Nakajima, Masahiro Takagi, Atsuhiko Eguchi
  • Publication number: 20030148203
    Abstract: An image formation method which remarkably extends developer life while providing size reduction and high speed coloring. Also, a replenishing toner and a method of producing the same, and a toner cartridge. In the image formation method, conducting image formation by an image formation apparatus having a plurality of xerography units, the developer apparatus of at least one xerography unit has a developer recovering mechanism appropriately replenishing a replenishing toner composed of a toner and a carrier into the developer apparatus and recovering an excess portion of a developer from the equipment. The above-mentioned replenishing toner has a carrier content in the range of 5 to 40% by weight, the above-mentioned carrier is a carrier coated with a resin having a specific composition, and/or the above-mentioned toner is in a specific shape. The replenishing toner may be produced using the above-mentioned recovered developer.
    Type: Application
    Filed: March 26, 2002
    Publication date: August 7, 2003
    Applicant: FUJI XEROX CO., LTD.
    Inventors: Chiaki Suzuki, Masahiro Takagi, Atsuhiko Eguchi, Satoshi Inoue, Sakon Takahashi, Masahiro Uchida, Rieko Kataoka, Hiroyuki Fukuda, Fusako Kiyono, Eiji Iwasaki
  • Patent number: 6489075
    Abstract: A toner for developing an electrostatic latent image, a process for producing the same, and a developer for developing an electrostatic latent image using the same are provided, in which the toner flowability, the charging property, the developing property, the transferring property and the fixing property are simultaneously satisfied in a long period of time. The toner for developing an electrostatic latent image comprising a colored particles containing a binder resin, a coloring agent and a releasing agent, and an external additive, the external additive containing a monodisperse spherical inorganic oxide having a true specific gravity of from 1.3 to 1.9 and a volume average particle diameter of from 80 to 300 nm. It is preferred that the inorganic oxide is silica, the colored particles have a shape coefficient of 125 or less, and the external additive further contains a reaction product of metatitanic acid and a coupling agent, which has an electric resistance of 1010 &OHgr;.cm or more.
    Type: Grant
    Filed: February 1, 2002
    Date of Patent: December 3, 2002
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Chiaki Suzuki, Masahiro Takagi, Satoshi Inoue, Yosuke Tsurumi, Kozo Ota, Sakon Takahashi, Tomohito Nakajima, Atsuhiko Eguchi
  • Patent number: 6479206
    Abstract: A toner for developing an electrostatic latent image, a process for producing the same, and a developer for developing an electrostatic latent image using the same are provided, in which the toner flowability, the charging property, the developing property, the transferring property and the fixing property are simultaneously satisfied in a long period of time. The toner for developing an electrostatic latent image comprising a colored particles containing a binder resin, a coloring agent and a releasing agent, and an external additive, the external additive containing a monodisperse spherical inorganic oxide having a true specific gravity of from 1.3 to 1.9 and a volume average particle diameter of from 80 to 300 nm. It is preferred that the inorganic oxide is silica, the colored particles have a shape coefficient of 125 or less, and the external additive further contains a reaction product of metatitanic acid and a coupling agent, which has an electric resistance of 1010 &OHgr;·cm or more.
    Type: Grant
    Filed: April 26, 2002
    Date of Patent: November 12, 2002
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Chiaki Suzuki, Masahiro Takagi, Satoshi Inoue, Yosuke Tsurumi, Kozo Ota, Sakon Takahashi, Tomohito Nakajima, Atsuhiko Eguchi
  • Publication number: 20020160293
    Abstract: A carrier for the development of an electrostatic latent image, comprising a core material and a resin coating the core material therewith, wherein the coating resin comprises a copolymer of at least four kinds of monomers including: (1) a monomer containing a carboxyl group; (2) an acrylic acid alkylester monomer or methacrylic acid alkylester monomer, containing a C1-C3 linear alkyl group; (3) an acrylic acid alkylester monomer or methacrylic acid alkylester monomer, containing a C4-C10 linear alkyl group or C3-C10 branched alkyl group; and (4) a monomer containing fluorine. Also disclosed is a two-component developer for the development of an electrostatic latent image, comprising a toner and the carrier.
    Type: Application
    Filed: October 16, 2001
    Publication date: October 31, 2002
    Applicant: FUJI XEROX CO., LTD
    Inventors: Sakon Takahashi, Hiroshi Nakazawa, Tomohito Nakajima, Masahiro Takagi, Atsuhiko Eguchi