Patent ID: 7976143

Claim:
An ink pressure regulator for regulating a hydrostatic pressure of ink supplied to an inkjet printhead, said regulator comprising: an ink chamber having an ink outlet for fluid communication with the printhead via an ink line, wherein a roof of the ink chamber comprises: an air inlet; a regulator channel having a first end communicating with the air inlet and a second end communicating with a headspace of the chamber, said second end defining a bubble outlet; and a wetting system for maintaining at least some liquid in said regulator channel, thereby ensuring that air entering the headspace first passes through said liquid, wherein said regulator channel is dimensioned to control a Laplace pressure of air bubbles drawn from said bubble outlet as result of supplying ink to the printhead, thereby regulating a hydrostatic pressure of the ink, and wherein said wetting system comprises: a first wetting chamber connected to said first end; a second wetting chamber connected to said second end; and a liquid-retaining structure positioned in at least one of said wetting chambers, such that said regulator channel, said first wetting chamber, said second wetting chamber and said liquid-retaining structure are all in fluid communication with each other.