Printing system with air accumulation control means enabling a semipermanent printhead without air purge

A printing system, comprising:

• a replaceable printhead capable of printing a plurality of ink volumes without purging air from the replaceable printhead, the printhead including an ejector portion for ejecting droplets of ink in response to control signals, the printhead including an internal plenum in communication with the ejector portion, the printhead including an accumulator that compensates for expansion of accumulated air in the plenum, the printhead including a fluid inlet that is fluidically coupled to the plenum for providing ink to the plenum;
• a fluid conduit having a self-sealing conduit outlet adapted to be fluidically coupled to the fluid inlet, the conduit outlet self-seals when it is uncoupled from the fluid inlet to prevent air from entering the conduit outlet, the fluid conduit including a self-sealing conduit inlet;
• and
• a replaceable ink supply having a fluid outlet adapted to be fluidically coupled to the conduit inlet, the conduit inlet self-seals when it is uncoupled from the fluid inlet to prevent air from entering the conduit inlet, the replaceable ink supply including a fluid reservoir in fluid communication with the fluid outlet for containing one of the plurality of ink volumes, the replaceable ink supply having therein no more than a nominal quantity of free air;
• the accumulator 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 said nominal quantity of free air in said replaceable ink supply, and wherein said warehouse capacity is sufficiently large to accommodate nominal quantities of air introduced from the printhead, said no more than said nominal quantity of free air from said replaceable ink supply, the fluid conduit and from removal and replacement of the replaceable ink supply to print the plurality of ink volumes.

An apparatus for providing ink to a printing system, the printing system including a semi-permanent printhead having an ejector portion for depositing ink in response to control signals, the printhead capable of printing a plurality of ink volumes, the printhead including an internal plenum in communication with the ejector portion, the internal plenum having a negative internal pressure to prevent printhead failure, the plenum including an accumulator portion sized to provide a warehouse capacity for accommodating expansion and contraction of up to a warehouse volume of air in the plenum while maintaining the negative internal pressure, the internal plenum fluidically coupled to a self-sealing fluid coupling device, the apparatus including:

• a reservoir for storing one of the plurality of ink volumes, the reservoir adapted to be releasably mounted to the printing system, the reservoir having no more than a nominal quantity of free air disposed therein;
• a fluid outlet in communication with the reservoir, the fluid outlet adapted to fluidically couple to the fluid coupling device when the reservoir is releasably mounted to the printing system;
• and
• wherein ink flows out of the reservoir, through the fluid outlet, and to the internal plenum when the reservoir is releasably mounted to the printing system, the ink carrying said no more than a nominal quantity of free air to the plenum, and wherein the reservoir, the fluid outlet, and the ink are adapted to provide less than the warehouse capacity of air during the life of the printhead including removal and replacement of the ink reservoir to print the plurality of volumes of ink without purging air from the printing system.

An ink delivery apparatus adapted to provide ink to a printing system, the printing system including a printhead having an ejector portion for depositing ink in response to control signals, the printhead including an internal plenum for providing ink to the ejector portion, the printing system including a fluid input associated with the printhead that is fluidically coupled to the internal plenum, the printhead capable of printing a plurality of ink volumes, the ink delivery apparatus comprising:

• a fluid outlet adapted to fluidically couple to the fluid input;
• and
• a fluid reservoir in fluid communication with the fluid outlet for containing one of the plurality of ink volumes, the fluid reservoir having therein no more than a nominal quantity of free air, the fluid reservoir and the internal plenum fluidically coupled to form an ink delivery system for the ejector portion when the fluid outlet is fluidically coupled to the fluid input, the ink delivery system including a fluid accumulator for accommodating air introduced to the ink delivery system to allow the printhead to print the plurality of ink volumes without purging air from the inkjet printhead, the accumulator sized to provide a warehouse capacity for accommodating expansion and contraction of up to a warehouse volume of air in the internal plenum while maintaining the negative internal pressure, and wherein said warehouse capacity is sufficiently large to accommodate nominal quantities of air introduced from the printhead, said no more than a nominal quantity of free air from said reservoir, the fluid conduit and from removal and replacement of the replaceable ink supply to print the plurality of ink volumes.

An ink delivery method for a printing system, the printing system including a semipermanent printhead, the printhead having a fluid input for receiving ink and an ejector portion for ejecting droplets of ink on media, the printhead including a plenum for providing ink to the ejector portion, the plenum having an initial volume of accumulated air, the printhead including an accumulator, the method comprising:

• (a) fluidically coupling a first volume of deliverable ink to the fluid input, a first volume of air added to the plenum while the first volume of ink is provided to the ejector portion;
• (b) compensating for expansion of the initial and the first volumes of accumulated air in the printhead to maintain the printhead at a negative pressure within an operating pressure range without purging air from the printhead, said compensating performed by said accumulator, wherein said accumulator is sized to provide a warehouse capacity for accommodating expansion and contraction of up to a warehouse volume of air;
• (c) fluidically coupling a second volume of deliverable ink to the fluid input, a second volume of air added to the plenum while the second volume of ink is provided to the ejector portion;
• and
• (d) compensating for expansion of the initial, first, and second volumes of air in the printhead to maintain the printhead at a negative pressure within an operating pressure range without purging air from the printhead.

An inkjet printing system, including 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 and including a plenum in which ink is held at a negative pressure relative to atmospheric pressure, a replaceable ink supply for storing a first one of the plurality of ink volumes, the replaceable ink supply having therein no more than a nominal quantity of free air, the replaceable ink supply configured for providing ink to the inkjet printhead and for ready removal and replacement when said first one of said ink volumes is exhausted, the printing system subject to introduction of air into the printhead over its life, the air tending to reduce the negative pressure, the inkjet printing system further comprising:

• an air warehousing apparatus in fluid communication with the inkjet printhead for compensating 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 warehousing apparatus 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 without purging air from the printhead, and wherein said warehouse capacity is sufficiently large to accommodate without purging air from the printhead nominal budgeted quantities of air introduced from the printhead, from the replaceable ink supply including said no more than a nominal quantity of free air, and from removal and replacement of the replaceable ink supply with other replaceable ink supplies to print the plurality of ink volumes.

A method for inkjet printing using a printing system, comprising:

• (a) providing 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 and including a plenum in which ink is held at a negative pressure relative to atmospheric pressure;
• (b) fluidically coupling to the printhead a replaceable ink supply holding one of the plurality of ink volumes, said replaceable ink supply having no more than a nominal quantity of free air;
• (c) providing an air warehousing apparatus in fluid communication with the inkjet printhead for compensating 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 warehousing apparatus 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, and wherein said warehouse capacity is sufficiently large to accommodate nominal budgeted quantities of air introduced from the printhead, from the replaceable ink supply including said no more than the nominal quantity of free air and from removal and replacement of the replaceable ink supply with other replaceable ink supplies to print the plurality of ink volumes;
• (d) operating the printing system during printing operations, using the printhead and the ink volume;
• (e) compensating for further introduction of air into the plenum using the air warehousing apparatus without purging air from the printhead to maintain the printhead at a negative pressure within an operating pressure range;
• (f) replacing the replaceable ink supply with another replaceable ink supply holding another volume of ink and no more than another quantity of free air;
• (g) operating the printing system to print, using the printhead and said another volume of ink;
• (h) compensating for further introduction of air into the plenum including said no more than another quantity of free air using the air warehousing apparatus without purging air from the printhead to maintain the printhead at a negative pressure within an operating pressure range;
• (i) repeating steps (f)-(h) until said plurality of volumes of ink have been printed by said printhead without purging air from said printhead.