Patents by Inventor Akira Tohama

Akira Tohama 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).

  • Ultrasonic wave generator
    Patent number: 3967143
    Abstract: The ultrasonic wave generator of the present invention always drives a transducer with the resonant frequency f.sub.o of the transducer. Although the resonant frequency f.sub.o changes due to the temperature change etc., the driving frequency automatically follows the change of the resonant frequency f.sub.o. The control of the driving frequency is performed by means of a feed-back loop including a voltage controlled oscillator and means for applying a control signal to said voltage controlled oscillator according to the amplitude and/or phase of the driving signal of the transducer.
    Type: Grant
    Filed: October 10, 1974
    Date of Patent: June 29, 1976
    Assignee: Oki Electric Industry Company, Ltd.
    Inventors: Akinori Watanabe, Katsuhide Tanoshima, Takao Ando, Akira Tohama, Akio Nagano