Patents by Inventor Toru Takatsuna

Toru Takatsuna 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: 20030027067
    Abstract: In a magnetic one-component toner containing at least a binder resin, a charge control resin, and a magnetic powder, the charge control resin has a weight-average molecular weight of 1.5×104 or less, contains 8 to 15% by weight of functional groups, and is added in 5 to 20 parts by weight to 100 parts by weight of the binder resin. This makes the toner highly safe for humans and the environment and excellent in fixability and electric chargeability.
    Type: Application
    Filed: January 31, 2002
    Publication date: February 6, 2003
    Inventors: Toru Takatsuna, Takashi Nagai, Hiroko Higuchi, Seiji Kikushima
  • Patent number: 5804347
    Abstract: This invention provides an electrophotographic toner comprising the polyester resin being fixing resin and the electric charge control resin having the functional group that endows positively charging property to the toner, in which the polyester resin has an acid value of not more than 10 mgKOH/g and a hydroxyl value of not more than 40 mgKOH/g, and the functional group is present in 2 to 5 mol % in the electric charge control resin. This electrophotographic toner has stable positively charging property, so that good image is obtainable.
    Type: Grant
    Filed: June 5, 1996
    Date of Patent: September 8, 1998
    Assignee: Mita Industrial Co., Ltd.
    Inventors: Kazushige Inoue, Toru Takatsuna, Yukihiro Mori, Etsuro Nakagawa, Hiroko Higuchi
  • Patent number: 5648192
    Abstract: There is disclosed a positive charging type electrophotographic toner comprising a fixing resin, and a colorant and an electric charge controlling material, which are contained in the fixing resin, the electric charge controlling material being an electric charge controlling resin comprising a polymer which is compatible with the fixing resin, a molecular-weight distribution of the polymer resembling a molecular-weight distribution of a weight-average molecular weight of not more than 20,000 in the molecular-weight distribution of the fixing resin, and a group corresponding to a quaternary ammonium salt being contained at the side chain of the polymer. This toner is superior in charging properties, fixing properties, offset resistance and strength, because a resin having a quaternary ammonium salt group is used as the electric charge controlling material.
    Type: Grant
    Filed: November 16, 1995
    Date of Patent: July 15, 1997
    Assignee: Mita Industrial Co., Ltd.
    Inventors: Yoshihisa Kuramae, Kazushige Inoue, Takashi Nagai, Toru Takatsuna
  • Patent number: 5614348
    Abstract: The present invention provides a toner 1 for non-magnetic one-components developments to be used for a method for non-magnetic one-component contact type development, wherein an apparent density is not less than 0.32 g/cc and when supplying to a developing roller 2 immediately after the consumption at the black solid part, a charged amount is not less than 7 .mu.C/g at an absolute value. This toner is suitable for using in combination with an organic photoconductor and can prevent that a residual image of the black solid part is remained at the half tone part immediately after the development of the black solid part.
    Type: Grant
    Filed: September 20, 1995
    Date of Patent: March 25, 1997
    Assignee: Mita Industrial Co., Ltd.
    Inventors: Kazushige Inoue, Yoshihisa Kuramae, Takashi Nagai, Toru Takatsuna