Air vent for an ink supply cartridge in a thermal ink-jet printer

摘要

A cartridge for supplying liquid ink to a thermal ink-jet printing apparatus includes a chamber having a ventilation port and an outlet port. A medium occupies at least a portion of the chamber, for retaining liquid ink therein at a predetermined back pressure. An open- ended conduit defines a passageway extending from the ventilation port to a portion of the chamber substantially devoid of liquid ink, to prevent leakage of liquid ink from the cartridge.