Patent attributes
An ink container for an ink jet printer adapted to supply ink via a tube to an ink jet cartridge. The cartridge includes a bottle, a cap engaging the bottle to form an ink containing cavity, an ink exit channel from the ink containing cavity through the cap, an air inlet channel through the cap into the ink containing cavity, and an air entrance opening from the air inlet channel into the ink containing cavity. The air entrance opening has a perimeter to area ratio that is greater than 2/R where R is the equivalent radius of the air entrance opening. This perimeter to area ratio (or shape factor) allows for easy formation and break off of bubbles at the air inlet channel. If such bubbles remain attached to the air inlet opening they can prevent some of the ink in the container from flowing therefrom for printing.
