Patents by Inventor Kenneth L. Christensen

Kenneth L. Christensen 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).

  • Publication number: 20010012041
    Abstract: A three-color ink-jet cartridge has a conduit connecting an ink reservoir to a print head orifice. The conduit has a pair of internal longitudinal grooves to permit ink to flow past a trapped bubble in the conduit. This ink flow prevents ink leakage through the orifice when ambient pressure changes cause the trapped bubble to expand.
    Type: Application
    Filed: December 6, 1999
    Publication date: August 9, 2001
    Applicant: HEWLETT-PACKARD COMPANY
    Inventors: MELISSA D. BOYD, KENNETH L. CHRISTENSEN, JULIE JO BOSTATER
  • Patent number: 5969739
    Abstract: An ink-jet pen is disclosed that has a body of resilient felted polyurethane foam mounted in an ink chamber for ink retention and backpressure. A rectangular ink pipe extends from a bottom wall of the ink chamber between the walls of the ink chamber. A wire mesh filter is mounted to the ink pipe. The ink pipe and mesh filter extend into compressive contact with the foam to locally increase the capillarity of the foam. Any air that comes out of solution collects as a bubble in the rectangular ink pipe. This bubble does not block ink flow to the printhead, however, because the corners of the rectangular ink pipe provide a fluid capillary path. The bubble tends to form in a spheroid shape and does not extend into the corners of the ink pipe. In addition, rectangular filters are used, which reduces waste and expense compared to circular filters.
    Type: Grant
    Filed: February 19, 1997
    Date of Patent: October 19, 1999
    Assignee: Hewlett-Packard Company
    Inventors: John M. Altendorf, Joseph R. Elliot, Melissa D. Boyd, Kenneth L. Christensen, Julie Jo Bostater, Brian D. Gragg, James G. Salter
  • Patent number: 5812165
    Abstract: A three-color ink-jet cartridge has a conduit connecting an ink reservoir to a print head orifice. The conduit includes a standpipe which has a pair of internal longitudinal grooves to permit ink to flow past a trapped bubble in the standpipe thereby preventing ink leakage through the orifices when pressure changes cause the trapped bubble to expand. The conduit also includes a tube from the standpipe to the print head. Disposed longitudinally along the tube is a rib which enables capillary flow of ink around a bubble in the tube to prevent depriming of the print head.
    Type: Grant
    Filed: March 4, 1996
    Date of Patent: September 22, 1998
    Assignee: Hewlett-Packard Company
    Inventors: Melissa D. Boyd, Kenneth L. Christensen, Julie Jo Bostater, Naoto Kawamura
  • Patent number: 5151715
    Abstract: A printhead wiper for ink-jet printers molded from an elastomer and including a wiping beam having a wiping edge formed at one end of the beam. The other end of the beam is integral with a base. A hole through the beam near the base decreases beam stiffness. A higher durometer elastomer may thus be used without applying excessive wiping force to the printhead. In another embodiment the wiper includes a pair of wiping blades each of which have wiping edges for wiping a printhead traveling thereby. The first wipe removes pooled ink and debris and spreads viscous ink while the second wipe further the spread ink before it can retract to its former drop or pooled configuration.
    Type: Grant
    Filed: July 30, 1991
    Date of Patent: September 29, 1992
    Assignee: Hewlett-Packard Company
    Inventors: Jefferson P. Ward, J. P. Harmon, Kris M. English, Kenneth L. Christensen