Patents by Inventor Shigeru Hirasawa

Shigeru Hirasawa 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).

  • Piezoelectric oscillator having reduced radiation of higher harmonics
    Patent number: 5302921
    Abstract: A piezoelectric oscillator in which radiation of higher harmonic components is reduced. A piezoelectric vibrator and a semiconductor device are provided in an oscillation circuit for making the piezoelectric vibrator oscillate, as is a filter for cutting components in a predetermined frequency band or higher harmonic components of an oscillation signal outputted from the semiconductor device. The piezoelectric vibrator, the semiconductor device and the filter are packed in one package. Radiation of the higher harmonic components is reduced by placing the filter close to the oscillator, by providing a shielding or by operating portions of the oscillator output circuit with a reduced supply voltage.
    Type: Grant
    Filed: April 16, 1992
    Date of Patent: April 12, 1994
    Assignee: Seiko Epson Corporation
    Inventors: Mikio Shigemori, Toru Oida, Shigeru Hirasawa, Katsumi Yamamura