Ink cartridge with collapsible ink reservoir.

摘要

An ink cartridge for a thermal ink jet printer contains a collapsible ink reservoir (5) which is kept under negative pressure by a pressure regulator (30) to prevent ink leakage. The reservoir has a pair of flexible plastic membrane ink bag sidewalls (22,24) connected to form an ink bag, and an ink pressure regulator (30) in the bag. The pressure regulator comprises a pair of spaced parallel side plates (40,50) urged apart by a spring (60) toward the adjacent bag sidewalls (22,24) whereby the reservoir is collapsible against the spring pressure to an essentially flat shape to permit substantially complete dispensation of ink from the bag. Inadvertent puncture of the thin bag walls (22,24) by the regulator is prevented by a protective edge guard (41,51) in the form of a layer of tough plastic bonded to the outer surfaces of the sideplates.