Patents by Inventor David S. Waldrop

David S. Waldrop 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).

  • Patent number: 5480240
    Abstract: A print quality enhancement arrangement for a dot matrix printer such as a thermal ink jet printer. The arrangement includes a buffer for receiving 300 dots per inch (dpi) resolution data in the horizontal (print head movement) direction and creates 600 dpi resolution data using image enhancement techniques. The arrangement further includes correction of the higher resolution data to remove pels which are unprintable due to the frequency response of the print elements in the print head. The correction is performed using knowledge of the history of printed pels and the original 300 dpi data. The creation of the higher resolution data and its correction occur "on-the-fly" as data is being fed to the print head, rather than through the creation of a 300 by 600 dpi bitmap.
    Type: Grant
    Filed: December 1, 1993
    Date of Patent: January 2, 1996
    Assignee: Lexmark International, Inc.
    Inventors: John P. Bolash, Curt P. Breswick, Thomas J. Eade, David K. Lane, Randall D. Mayo, David S. Waldrop