04831389 is referenced by 105 patents and cites 9 patents.

A system for supplying ink to an ink jet pen wherein an off board ink supply is provided remote from the pen, and ink is fed from this supply to the pen by capillary action created during an ink jet printing operation. The pen includes a porous storage medium which is initially filled with ink at a slightly negative head. However, this negative head increases during ink depletion from the storage medium and provides the capillary forces necessary to pull ink into the storage medium from the off board ink supply. The driving energy for this action is provided by current drive to a thin film printhead of the pen, thus rendering the printhead multi-functional in purpose and simplifying the ink supply apparatus therefor. The use of an intermediate porous storage medium enables the ink supply system to accommodate large rates of changes in ink demand from the pen while still affording the user with a large ink capacity system in which disposable pens may be readily and easily replaced in a user-friendly operation.

Title
Off board ink supply system and process for operating an ink jet printer
Application Number
7/136060
Publication Number
4831389
Application Date
December 21, 1987
Publication Date
May 16, 1989
Inventor
C S Chan
Boise
ID, US
Agent
William J Bethurum
Assignee
Hewlett Packard Company
CA, US
IPC
G01D 15/16
View Original Source