Patents by Inventor David Steven Waldrop

David Steven 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).

  • Apparatus for driving multiple ink jet printheads with a single set of drive outputs
    Patent number: 5867183
    Abstract: An ink jet printing apparatus includes a printhead controller including a printhead driver circuit having a set of ink jet nozzle control outputs and a printhead select circuit having a plurality of printhead select outputs. A plurality of printheads are provided, wherein each printhead includes a plurality of ink jet nozzles, a plurality of individually controllable ink jet nozzle firing circuits, and a printhead enable circuit, wherein the printhead enable circuit is electrically coupled between the plurality of individually controllable ink jet nozzle firing circuits and the set of ink jet nozzle control outputs, and wherein the printhead enable circuit is electrically coupled to one of the plurality of printhead select outputs and enables the electrical conduction of the plurality of controllable ink jet nozzle firing circuits upon receipt of a printhead select signal from one of the printhead select outputs of the printhead select circuits.
    Type: Grant
    Filed: January 11, 1996
    Date of Patent: February 2, 1999
    Assignee: Lexmark International, Inc.
    Inventors: Robert Wilson Cornell, George Keith Parish, Lawrence Russell Steward, David Steven Waldrop