Patents by Inventor James M. Foster

James M. Foster 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).

  • Faulty ink ejector detection in an ink jet printer
    Patent number: 6375299
    Abstract: A system and method for detecting a faulty piezoelectrically actuated ink ejector includes the piezoelectric element with an input signal, and sensing a response of the piezoelectric element to the input signal. Phase relationships and frequency dependent impedances may be analyzed and used to detect faulty ink ejectors. The detection circuit may include processing in the digital domain.
    Type: Grant
    Filed: November 2, 1998
    Date of Patent: April 23, 2002
    Assignee: Encad, Inc.
    Inventors: James M. Foster, John C. Love