Re-circulating fluid delivery system

A fluid delivery system, comprising:

• a print cartridge including:
• a housing structure;
• an air-fluid separator structure within the housing structure for separating air bubbles from a fluid and venting the air bubbles from the housing structure;
• a fluid ejector mounted to the housing structure;
• a fluid plenum within the housing structure in fluid communication with said fluid ejector;
• a free fluid reservoir in the housing structure in fluid communication with the plenum and the air-fluid separator for supplying fluid to the plenum under negative pressure;
• a fluid re-circulation path in said housing structure through said separator structure and said fluid plenum;
• a pump structure mounted to the housing structure for re-circulating fluid and air through said re-circulation path during a pump mode, wherein air bubbles may be separated from re-circulated fluid and vented from the housing structure;
• and
• a fluid supply fluidically coupled to said free fluid reservoir during fluid ejecting operations for supplying fluid under negative pressure to the free fluid reservoir.

A fluid delivery system, comprising:

• a print cartridge including:
• a housing structure;
• a fluid ejector mounted to the housing structure;
• an air-fluid separator structure within the housing structure for separating air bubbles from a fluid and venting the air bubbles from the housing structure;
• a fluid plenum within the housing structure in fluid communication with said fluid ejector;
• a free fluid reservoir in the housing structure in fluid communication with the plenum and the air-fluid separator for supplying fluid to the plenum under negative pressure;
• a fluid re-circulation path in said housing structure through said separator structure, said free fluid reservoir and said fluid plenum;
• a pump structure mounted to the housing structure for re-circulating fluid and air through said re-circulation path during a pump mode, wherein fluid is passed through said air separator, said free fluid reservoir and said plenum to purge air bubbles from the fluid and housing structure;
• and
• a fluid supply fluidically coupled to said free fluid reservoir during fluid ejecting operations for supplying fluid under negative pressure to the free fluid reservoir.