Patents by Inventor Michiaki Tsurumi

Michiaki Tsurumi 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: 4968649
    Abstract: The present invention provides a dielectric ceramic composition for use in a high-frequency range represented by the general formula (1-x)Ba.sub.1- y(Zn.sub.1/3, Ta.sub.2/3)O.sub.3 +xBa.sub.1-y ZrO.sub.3. In the formula, y is 0.004.ltoreq.y.ltoreq.0.013 and x is the amount of substitution of Ba.sub.1-y ZrO.sub.3 and 0<x.ltoreq.0.06. This composition is prepared by weighing raw materials so that the mixing ratio of Ba is slightly smaller than that of the stoichiometric composition, calcining the resultant mixture to prepare a calcination product, grinding the calcination product through only dry process without conducting wet pulverization, molding the resultant powder, and sintering the molded product at 1600.degree. to 1700.degree. C. for 1 to 10 hr.
    Type: Grant
    Filed: December 8, 1989
    Date of Patent: November 6, 1990
    Assignee: Fuji Electrochemical Co., Ltd.
    Inventors: Michiaki Tsurumi, Kenji Fujimoto, Kazuaki Endo