Patents Examined by Michael Nghieu
  • Patent number: 6231174
    Abstract: An ink jet recording device includes an ink tank 21 and a print head 1 connected together by a circulation channel. The circulation channel is formed from the ink tank 21, ink supply tubes 13, 23, a manifold 11 of a print head, and ink collection tubes 16, 26. An ink circulation pump 22 is disposed along the ink supply tube 23 for performing a circulation purge, wherein ink is forcibly circulated ink through the circulation channel. During circulation purge, the rotational direction of the ink circulation pump 22 is reversed for a short period of time, so that ink flows in a direction opposite of the normal flow direction. As a result, air bubbles are loosened from where they cling on the side surfaces of the ink channel. Because the air bubbles are more easy to remove, the air bubbles are removed by flow of ink during the circulation purge. The air bubbles are transported to and collected in the ink tank, whereupon they separate from the ink due to their buoyancy.
    Type: Grant
    Filed: February 4, 1999
    Date of Patent: May 15, 2001
    Assignee: Brother Kogyo Kabushiki Kaisha
    Inventor: Hideaki Haigo