Patent ID: 8814331

Claim:
A method comprising: coupling a vacuum source to one or more ink reservoirs to establish sufficient backpressure on ink in said reservoirs to prevent ink from dripping out one or more inkjet printheads coupled to said reservoirs, and to a backpressure capacitor so that a capacitor interface between a liquid in said capacitor and a confined low-pressure gas in the backpressure capacitor rises to a first level; decoupling said vacuum source from said ink reservoirs and said back-pressure capacitor so that said capacitor interface falls to a second level so as to maintain sufficient backpressure on said ink to prevent it from dripping from said inkjet printheads; and limiting a drop in backpressure in said ink reservoirs during decoupling by a predetermined amount by providing a volume into which said confined low-pressure gas can expand within said backpressure capacitor.