Patent ID: 8029112
Filing Date: 2011-10-04
Classification: B41J

Abstract:
1. An inkjet printer comprising: an inkjet printhead; and an ink pressure regulator for regulating a hydrostatic pressure of ink supplied to the printhead, said regulator comprising: an ink chamber having an ink outlet in fluid communication with the printhead via an ink line; an air inlet open to atmosphere; a bubble outlet positioned for bubbling air bubbles directly into a headspace of said ink chamber at all operative ink levels, each air bubble comprising an air cavity trapped inside a film of ink; a capillary channel in fluid communication with ink contained in the ink chamber, said capillary channel supplying ink from the chamber to the bubble outlet by capillary action; and an air channel connecting the air inlet and the bubble outlet, wherein said bubble outlet is dimensioned to control a Laplace pressure of air bubbles drawn into said chamber as result of supplying ink to the printhead, thereby regulating a hydrostatic pressure of the ink.