Abstract: An ink-jet cartridge adapted to be used for a thermal ink-jet printer is disclosed. The ink-jet cartridge includes a housing for storing the ink in an interior thereof, a printhead having a plurality of orifices thereon for allowing the ink to be Jetted therethrough when the thermal ink-jet printer is printing, and a pressure-adjusting device disposed in the housing for regulating a back pressure of the interior of the housing, wherein the pressure-adjusting device includes a first opening fixed on an upper portion of the housing and exposed to an ambient atmosphere, and a second opening disposed at a bottom of the interior of the housing and having at least one regulating hole thereon. Each regulating hole has a cross-sectional area being smaller than that of the first opening for maintaining the back pressure when the ink-jet cartridge is inverted.

Abstract: An ink-jet cartridge adapted to be used for a thermal ink-jet printer is disclosed. The ink-jet cartridge includes a housing for storing the ink in an interior thereof, a printhead having a plurality of orifices thereon for allowing the ink to be jetted therethrough when the thermal ink-jet printer is printing, and a pressure-adjusting device disposed in the housing for regulating a back pressure of the interior of the housing, wherein the pressure-adjusting device includes a first opening fixed on an upper portion of the housing and exposed to an ambient atmosphere, and a second opening disposed at a bottom of the interior of the housing and having at least one regulating hole thereon. Each regulating hole has a cross-sectional area being smaller than that of the first opening for maintaining the back pressure when the ink-jet cartridge is inverted.

Abstract: A pressure adjustment device in an ink cartridge employs an elastic air bag in communication with the atmosphere through a ventilation hole in a connection body which is installed in a top wall of the cartridge housing. Response to pressure changes is increased by a spring connected between a bottom end of the air bag and a bottom wall of the cartridge housing which applies a pulling force to the bottom end of the air bag.