Patents by Inventor Tamotsu Aruga

Tamotsu Aruga 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: 4620876
    Abstract: An aqueous ink for ink-jet printing comprising at least a water-soluble dye, a water-soluble organic solvent, a water-soluble preservative and anti-mold agent, and water, wherein(1) the water-soluble dye is a mixture of dye compounds I and II and/or III, the peak ratio of I/II and/or III of the water-soluble dye measured by liquid chromatography is in the range of 0.9 to 3.0; the total concentration of NaCl and Na.sub.2 SO.sub.4 contained in the water-soluble dye is 3.0 wt.
    Type: Grant
    Filed: October 24, 1985
    Date of Patent: November 4, 1986
    Assignee: Ricoh Company, Ltd.
    Inventors: Tadashi Fujii, Kakuji Murakami, Eiichi Akutsu, Tamotsu Aruga
  • Patent number: 4581071
    Abstract: An aqueous ink is disclosed, which comprises a first magenta dye having the formula (I), a second magenta dye having the formula (II), a water-soluble organic solvent having a boiling point of 100.degree. C. or higher, water and a preservative and anti-mold agent: ##STR1## wherein R.sup.1 and R.sup.2 each represent ##STR2## (in which R.sup.5, R.sup.6, R.sup.7 and R.sup.8 each represent a lower alkyl group, an amino group, a sulfonic acid group in the form of an alkali metal salt, or a carboxyl group in the form of an alkali metal salt); R.sup.3 and R.sup.4 each represent a lower alkyl group, an amino group, a sulfonic acid group in the form of an alkali metal salt, or a carboxyl group in the form of an alkali metal salt; and k, l, m and n each represent an integer of 0, 1 or 2.
    Type: Grant
    Filed: March 6, 1985
    Date of Patent: April 8, 1986
    Assignee: Ricoh Company, Ltd.
    Inventors: Eiichi Akutsu, Kakuji Murakami, Tamotsu Aruga
  • Patent number: 4554555
    Abstract: A recording method by use of an ink is disclosed, in which images are formed by an aqueous ink comprising at least one dye selected from the group consisting of a pyrazolone azo dye, a phthalocyanine sulfonate dye, a xanthene dye and an azo dye on a recording medium containing at least one component selected from the group consisting of a water-soluble metal salt whose metal has an ion valence of 2 or more, an alkyl amine and a quaternary ammonium salt.
    Type: Grant
    Filed: December 9, 1983
    Date of Patent: November 19, 1985
    Assignee: Ricoh Company, Ltd.
    Inventors: Tamotsu Aruga, Tadashi Fujii, Kakuji Murakami, Eiichi Akutsu