Patents Examined by John E. Borlow, Jr.
  • Patent number: 6309052
    Abstract: This present invention is embodied in a low-cost printing system including a printhead and an ink composition that provides photographic-quality resolution. The printhead of the present invention includes a high-density array of drop generators that eject ink drops having a low drop weight and that operate at a high frequency. Further, high-resistance firing resistors are used to provide minimum energy dissipation and the firing resistors are preferably thin-film resistors to ensure that a minimal amount of energy is needed to eject ink drops. The stability of the ink drop volume is maintained by including an overdamped structure within the ink drop generators that allow the ink chambers to fill up with ink slowly. The ink composition of the present invention includes an ink additive that prevents decel from occurring during sustained high-frequency printing bursts.
    Type: Grant
    Filed: August 30, 1999
    Date of Patent: October 30, 2001
    Assignee: Hewlett-Packard Company
    Inventors: Rama Prasad, Todd A. Cleland, Robert C Maze, Dale R. Oughton