Patents by Inventor Tadashi Tamiya

Tadashi Tamiya 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 element using a thickness shear hexagonal quartz blank and method for manufacturing the same
    Patent number: 6031319
    Abstract: A quartz crystal element in which unwanted response is suppressed, comprising a thickness shear quartz blank such as an AT-cut type. An area where an amplitude of unwanted response may be strong can be eliminated from the quartz blank by forming the quartz blank into a substantially hexagon. Preferably, each pair of three pairs of opposite sides are mutually parallel and one of the pairs is parallel to the longest diagonal line of the quartz blank. For an AT-cut type of quartz crystal element, the direction of the longest diagonal line of the quartz blank is within the range of 28.degree..+-.15.degree. or 118.degree..+-.15.degree. from the Z' axis direction of the quartz blank, and the quartz blank is held at the ends of the longest diagonal line.
    Type: Grant
    Filed: March 11, 1998
    Date of Patent: February 29, 2000
    Assignee: Nihon Dempa Kogyo Co., Ltd.
    Inventors: Mitsuaki Koyama, Shigenori Watanabe, Tadashi Tamiya, Keisuke Miyashita, Chiaki Kato, Shuzi Osawa