Patents by Inventor Naoko KITADA

Naoko KITADA 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: 10754270
    Abstract: Provided is a toner including a binder resin, and a charge-controlling agent, wherein a volume average particle diameter X of the toner after a stress treatment satisfies Formula (1), and an amount Y of fine toner particles having particle diameters of 3 micrometers or smaller and circularity of 0.70 or less satisfies Formula (2).
    Type: Grant
    Filed: February 15, 2018
    Date of Patent: August 25, 2020
    Assignee: Ricoh Company, Ltd.
    Inventors: Naoko Kitada, Satoshi Ogawa, Yoshitaka Sekiguchi, Masayuki Ishii, Shohta Kobayashi
  • Publication number: 20200174390
    Abstract: Provided is a toner including a binder resin, and a charge-controlling agent, wherein a volume average particle diameter X of the toner after a stress treatment satisfies Formula (1), and an amount Y of fine toner particles having particle diameters of 3 micrometers or smaller and circularity of 0.70 or less satisfies Formula (2).
    Type: Application
    Filed: February 15, 2018
    Publication date: June 4, 2020
    Inventors: Naoko KITADA, Satoshi OGAWA, Yoshitaka SEKIGUCHI, Masayuki ISHII, Shohta KOBAYASHI
  • Publication number: 20200019076
    Abstract: Provided is a toner including a binder resin, a release agent, and a charge-controlling agent, wherein the toner includes toner particles having particle diameters of 3 micrometers or smaller, among the toner particles having particle diameters of 3 micrometers or smaller, a proportion of the toner particles having an average circularity of 0.70 or greater but 0.85 or less in all of the toner particles is 10% by number or greater but less than 20% by number and a proportion of the toner particles having an average circularity of less than 0.70 in all of the toner particles is 10% by number or less.
    Type: Application
    Filed: February 21, 2018
    Publication date: January 16, 2020
    Inventors: Shohta KOBAYASHI, Satoshi OGAWA, Yoshitaka SEKIGUCHI, Masayuki ISHII, Naoko KITADA
  • Patent number: 10025213
    Abstract: A toner including a binder resin, wherein the toner includes a tetrahydrofuran (THF)-insoluble component in a range of from 10% by mass through 40% by mass, wherein the toner has a main peak in a range of from 12,000 through 18,000 in a molecular weight distribution of a THF-soluble component as measured by gel permeation chromatography (GPC), wherein the main peak has a half value width in a range of from 20,000 to 50,000, and wherein the toner includes a component having a molecular weight of 2,000 or less in a range of from 10.0% by mass through 20.0% by mass and a component having a molecular weight of 100,000 or more of 8.0% by mass or less.
    Type: Grant
    Filed: February 29, 2016
    Date of Patent: July 17, 2018
    Assignee: Ricoh Company, Ltd.
    Inventors: Masahiro Seki, Yoshitaka Sekiguchi, Satoshi Ogawa, Naoko Kitada
  • Publication number: 20180031992
    Abstract: A toner including a binder resin, wherein the toner includes a tetrahydrofuran (THF)-insoluble component in a range of from 10% by mass through 40% by mass, wherein the toner has a main peak in a range of from 12,000 through 18,000 in a molecular weight distribution of a THF-soluble component as measured by gel permeation chromatography (GPC), wherein the main peak has a half value width in a range of from 20,000 to 50,000, and wherein the toner includes a component having a molecular weight of 2,000 or less in a range of from 10.0% by mass through 20.0% by mass and a component having a molecular weight of 100,000 or more of 8.0% by mass or less.
    Type: Application
    Filed: February 29, 2016
    Publication date: February 1, 2018
    Inventors: Masahiro SEKI, Yoshitaka SEKIGUCHI, Satoshi OGAWA, Naoko KITADA