Patents by Inventor Vernon W. Popham

Vernon W. Popham 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: 6390582
    Abstract: A method is provided for reducing thermal aging in an ink jet print head while avoiding significant warm-up times. The method selectively utilizes multiple print head standby temperatures to reduce the effects of thermal aging over time. The ink for the printer is a phase change ink. The ink jet printer has a print head, the print head printing at a first print temperature and the print head standing by a different second standby temperature lower than the first print temperature. The ink is ejected from the print head by applying a voltage to a transducer. This method further comprises monitoring the time the printhead is at the second standby temperature, calculating a thermal aging period for the print head at the standby temperature, and at a predetermined value for the thermal aging period, increasing the voltage applied to the transducer when ink is ejected, the voltage being increased at a predetermined rate.
    Type: Grant
    Filed: February 16, 1999
    Date of Patent: May 21, 2002
    Assignee: Xerox Corporation
    Inventors: Christopher J. Laharaty, Michele L. Fingerson, Vernon W. Popham, Ronald F. Burr