Patent ID: 6130694
Filing Date: 2000-10-10
Classification: B41J

Abstract:
A method for controlling fluid pressure within an ink-jet printhead comprising the steps of:providing a printhead including an ink channel inside the printhead wherein the ink channel defines a volume through which ink flows, the ink channel in fluid communication with a firing chamber inside the printhead and having a nozzle through which ink droplets are ejected from the printhead;dividing the channel into two chambers that are joined by a passageway such that ink may flow through the passageway;affixing to the printhead a plunger that extends through the passageway such that said plunger is moveable between an open position and a closed position wherein the plunger occludes the passageway; andmoving the plunger to said open position in response to ambient pressure changes or to pressure changes in one of the chambers such that ink may flow through the passageway and to said closed position such that ink flow through the passageway is restricted.