Patents by Inventor Youhachi Yamashita

Youhachi Yamashita 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).

  • High dielectric constant type ceramic composition
    Patent number: 4544644
    Abstract: There is disclosed a high dielectric constant material which comprises a composite material comprising at least one of BaO and CaO; PbO; Fe.sub.2 O.sub.3 ; Nb.sub.2 O.sub.5 ; WO.sub.3 and CuO, said composite material being represented by the general formula:xPb(Fe.sub.1/2 Nb.sub.1/2 l )O.sub.3 -yM(Cu.sub.1/2 W.sub.1/2 )O.sub.3 -zPb(Fe.sub.2/3 W.sub.1/3 )O.sub.3wherein M is at least one of Ba and Ca, and x, y and z are defined in the specification.The disclosed dielectric material can also contain 0 to 1.0% by weight, relative to said composite material, of manganese oxide.
    Type: Grant
    Filed: March 26, 1984
    Date of Patent: October 1, 1985
    Assignee: Tokyo Shibaura Denki Kabushiki Kaisha
    Inventors: Youhachi Yamashita, Takashi Takahashi, Mituo Harata
  • Piezoelectric oxide material
    Patent number: 4321155
    Abstract: A piezoelectric oxide material suitable for an ultrasonic probe is provided. The piezoelectric material has the general formula ##EQU1## wherein 0.01.ltoreq.X.ltoreq.0.10 and 0.20.gtoreq.a.ltoreq.0.35, to which is added, as an additive, 0.05 to 2.0% by weight of at least one of MnO, NiO and Fe.sub.2 O.sub.3 based on the total content of the basic composition; the thickness coupling factor (Kt) is 50% or more; the ratio (Kt/Kp) of the thickness coupling factor (Kt) to the planar coupling factor (Kp) is 10 or more.
    Type: Grant
    Filed: February 18, 1981
    Date of Patent: March 23, 1982
    Assignee: Tokyo Shibaura Denki Kabushiki Kaisha
    Inventors: Youhachi Yamashita, Katsunori Yokoyama, Tadashi Ido, Seiichi Yoshida