Patent ID: 6203146
Filing Date: 2001-03-20
Classification: B41J

Abstract:
An inkjet printing system of the type having a replaceable ink supply for providing ink to a printhead, the inkjet printing system comprising:a semipermanent inkjet printhead having a fluid input for receiving ink and an ejection portion for selectively depositing ink in response to control signals, the inkjet printhead capable of printing a plurality of ink volumes;a replaceable ink supply for storing one of the plurality of ink volumes, the replaceable ink supply configured for providing ink to the inkjet printhead and having therein no more than a nominal quantity of free air; andan accumulator portion in fluid communication with the inkjet printhead, the accumulator portion compensates for air introduced into the inkjet printhead to maintain the printhead pressure range within an operating range allowing the printhead to print the plurality of ink volumes without purging air from the inkjet printhead, the accumulator portion is sized to provide a warehouse capacity for accommodating expansion and contraction of up to a warehouse volume of air in the printhead while maintaining the negative internal pressure, said warehouse volume of air including said no more than a nominal quantity of free air in said replaceable ink supply, and wherein said warehouse capacity of said accumulator portion is sufficiently large to accommodate said no more than a nominal quantity of free air of said replaceable ink supply and nominal quantities of air introduced from the printhead and from removal and replacement of the replaceable ink supply with other replaceable ink supplies to print the plurality of ink volumes.