04931811 is referenced by 80 patents and cites 5 patents.

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.

Title
Thermal ink jet pen having a feedtube with improved sizing and operational with a minimum of depriming
Application Number
7/304549
Publication Number
4931811
Application Date
January 31, 1989
Publication Date
June 5, 1990
Inventor
John H Dion
Corvallis
OR, US
Niels J Nielsen
Corvallis
OR, US
Bruce Cowger
Corvallis
OR, US
Assignee
Hewlett Packard Company
CA, US
IPC
B41J 2/19
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