Patents by Inventor Fumio Kohyama

Fumio Kohyama 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).

  • Quartz crystal vibrator using Ni-Ag or Cr-Ni-Ag electrode layers
    Patent number: 4259607
    Abstract: A structure of an electrode film deposited on a tuning fork-type quartz crystal vibrator in which an electrode film on a tuning fork-type quartz crystal vibrator has a laminated structure obtained by forming, in the order mentioned, three overlapping layers, namely layers of chrome, nickel and silver, or two overlapping layers, namely layers of nickel and silver, on the surface of a tuning fork-shaped quartz crystal from the side nearest thereto, and in which the thickness of each layer of the electrode film is less than 300 A for the chrome layer, less than 500 A for the nickel layer, and less than 2000 A for the silver layer.
    Type: Grant
    Filed: June 19, 1978
    Date of Patent: March 31, 1981
    Assignee: Citizen Watch Co., Ltd.
    Inventors: Kazuo Noguchi, Makoto Wakasugi, Fumio Kohyama