The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 22, 1998
Filed:
Apr. 12, 1996
Norman E Pawlowski, Jr, Corvallis, OR (US);
Ronald W Hall, Corvallis, OR (US);
Hewlett-Packard Company, Palo Alto, CA (US);
Abstract
The present invention relates to free-ink type ink-jet pens and, more particularly, to a method and apparatus for purging air from an on-axis ink accumulator. A biased regulator mechanism is provided within the pen to allow ink from a pressurized ink reservoir to be fed to the pen while maintaining a predetermined set point back-pressure at the printhead as needed for appropriate pen operation. A mechanism in communication with the ambient atmosphere is used in conjunction with a substantially constant force biasing mechanism to maintain the balance between the countervailing forces. Back-pressure is maintained substantially constant regardless of the ink flow rate from the ink reservoir into the accumulator. By application of a positive pressure to the ambient atmosphere mechanism, the biased regulator mechanism is forced open and any gas bubbles trapped within the accumulator is forced out through the reservoir ink feed.