Patents by Inventor Kosaku Kawada

Kosaku Kawada 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).

  • Non-directional electret microphone with an air passage to balance pressures on opposite sides of the diaphragm
    Patent number: 4117275
    Abstract: A non-directional capacitive microphone assembly comprises an electrically conductive casing which is air-tight except at least one sound hole formed in front end of the casing and a capacitive diaphragm disposed behind the sound hole. The sound hole is communicated with a cavity formed behind the diaphragm through an air passage provided in the casing.
    Type: Grant
    Filed: June 13, 1977
    Date of Patent: September 26, 1978
    Assignee: Chemi-Con Onkyo Co., Ltd.
    Inventors: Kunio Miyanaga, Kosaku Kawada