Patents by Inventor Robert W Sperry

Robert W Sperry 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: 6860588
    Abstract: A printhead for an inkjet printer having geometric features which reduce drop placement error of main and satellite drops ejected from the nozzles of the printhead. Nozzles that are tilted along an axis corresponding to the direction of scanning of the printhead while printing have reduced drop placement error in the orthogonal direction to the scanning, and create a breakoff velocity for the satellite drop that can cause the main and satellite drops to be placed in a coincident location on the medium in one of the directions of scanning, thus forming desireable round printed spots and reducing drop placement error in the scan direction. These improvements can be repeatably achieved for all nozzles. Nozzles with non-circular and asymmetric bores also reduce drop placement errors, particularly when these types of nozzles are also tilted.
    Type: Grant
    Filed: October 11, 2000
    Date of Patent: March 1, 2005
    Assignee: Hewlett-Packard Development Company, L.P.
    Inventors: Clayton L Holstun, Jeffrey Allen Nielsen, Matthew D Giere, Scott Norum, Stephen W Bauer, Mark D Lund, Robert W Sperry, Dustin W Blair
  • Publication number: 20030018120
    Abstract: Ink-jet treating solution having a water base and an imidized styrene maleic anhydride polymer. The polymer is insoluble in a neutral aqueous medium and it is present in a concentration by weight of between about 2% and 4%, with a preferred concentration of about 3%. The polymer imparts wet smudge resistance to ink-jet inks when printed.
    Type: Application
    Filed: February 12, 2001
    Publication date: January 23, 2003
    Inventors: Shirley Lee, Anne M. Kelly-Rowley, Robert W. Sperry