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:
Jun. 05, 1990
Filed:
Jan. 31, 1989
Bruce Cowger, Corvallis, OR (US);
Niels J Nielsen, Corvallis, OR (US);
John H Dion, Corvallis, OR (US);
Hewlett-Packard Company, Palo Alto, CA (US);
Abstract
An ink jet pen having a main ink reservoir therein connected to a thin film printhead by way of a large diameter standpipe, wherein the diameter of an air accumulating section of the standpipe is sufficiently large to enable ink to pass through the standpipe despite the presence of air in the air accumulating section when the printhead is in operation. The large diameter air bubbles which form in the air accumulating section are easily deformed by suction force from the printhead and thus allow ink to pass through the standpipe between the air bubbles and the walls of the standpipe. This action enables the ink jet pen to operated continuously without undue suction on the standpipe which leads to depriming.