Patents by Inventor Ayumi Oikawa

Ayumi Oikawa 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: 9176402
    Abstract: A method for manufacturing a toner, including at least: dissolving or dispersing a toner material including at least any one of a binder resin and a precursor of a binder resin in an organic solvent which is dispersed in a dispersant-including aqueous medium; forming particles by removing the organic solvent; washing the particles; forming voids in the particles by heating to a temperature T while or after dispersing the particles in an aqueous medium; forming toner base particles by adding a charge controlling agent; and adding an external additive to the toner base particles to obtain toner particles, wherein the T is between a glass transition temperature Tg of the toner particles and Tg+25° C., and the toner has a cross-sectional void fraction Sp/St of 0.1% to 15.0%, where St is a cross-sectional area of the toner particles, and Sp is a cross-sectional area of the voids.
    Type: Grant
    Filed: September 12, 2012
    Date of Patent: November 3, 2015
    Assignee: Ricoh Company, Ltd.
    Inventors: Keisuke Tada, Kenichi Uehara, Daisuke Misawa, Ayumi Oikawa, Hiroshi Endoh
  • Publication number: 20140342282
    Abstract: A method for manufacturing a toner, including at least: dissolving or dispersing a toner material including at least any one of a binder resin and a precursor of a binder resin in an organic solvent which is dispersed in a dispersant-including aqueous medium; forming particles by removing the organic solvent; washing the particles; forming voids in the particles by heating to a temperature T while or after dispersing the particles in an aqueous medium; forming toner base particles by adding a charge controlling agent; and adding an external additive to the toner base particles to obtain toner particles, wherein the T is between a glass transition temperature Tg of the toner particles and Tg+25° C., and the toner has a cross-sectional void fraction Sp/St of 0.1% to 15.0%, where St is a cross-sectional area of the toner particles, and Sp is a cross-sectional area of the voids.
    Type: Application
    Filed: September 12, 2012
    Publication date: November 20, 2014
    Inventors: Keisuke Tada, Kenichi Uehara, Daisuke Misawa, Ayumi Oikawa, Hiroshi Endoh