Patents by Inventor Tomohiko Niikawa

Tomohiko Niikawa 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: 4927580
    Abstract: A method for manufacturing an electronic device having therein a lead frame and a vibration-generating element integrally provided on the lead frame. The lead frame and the element are first provided in a metallic mold assembly comprising an upper mold portion and a lower mold portion, the upper and lower mold portions respectively having recess portions so as to form a cavity when the upper and lower mold portions are assembled with each other. A first sealing material is injected into the cavity so that the element is covered by the injected first sealing material, the first sealing material having a shrinkage property and a low adhesion property. After solidification of the injected first sealing material, they are removed from the mold assembly and then immersed in a second sealing material at a vacuum state so that the second sealing material is impregnated between the first sealing material portion and the lead frame.
    Type: Grant
    Filed: December 14, 1988
    Date of Patent: May 22, 1990
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Kazuhiko Nasu, Kazuei Kenmochi, Tomohiko Niikawa, Atsushi Matsui
  • Patent number: 4019072
    Abstract: A piezoelectric pressure sensor for detecting the amount of oil in an engine oil pan of an automobile, and liquid level or the amount of liquid such as water level in a water bath, makes use of the phenomenon that an impedance of an excited piezoelectric element varies between in a gas and in a liquid. The pressure sensor is insensitive to surrounding temperature, and has high response and is of simple construction.
    Type: Grant
    Filed: March 17, 1975
    Date of Patent: April 19, 1977
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Hideo Mifune, Kenroku Tani, Tomohiko Niikawa