Patents by Inventor David R. McGrew

David R. McGrew 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).

  • Electromagnetic detection line digitizer
    Patent number: 4138592
    Abstract: A graphic curve digitizer is disclosed wherein the x-y coordinate values of a response curve (made electrically conductive) are obtained by a digitally controlled x-y conductive probe and electronic system sensing when the probe contacts the curve by the voltage signal existing in the conductive curve due to the antenna effect of the conductive curve in an environmental alternating current electromagnetic field.
    Type: Grant
    Filed: September 16, 1977
    Date of Patent: February 6, 1979
    Inventors: Jack D. Capehart, John F. Mazzae, David R. McGrew