Patent ID: 7673977

Claim:
An ink cartridge comprising: a cylindrical member having an ink port at one axial end thereof; a piston which is fitted in the cylindrical member air-tightly and slidably, and partially defines an ink chamber within the cylindrical member, the ink chamber being in communication with the ink port; a piston rod which is connected to the piston on the side opposite to the ink chamber, and extends in the cylindrical member along an axial direction of the cylindrical member; and a thrusting portion at least partially positioned in the cylindrical member and configured to apply a thrust force to the piston rod and thereby move the piston along the axial direction, the thrusting portion comprising a driven portion drivable from the exterior of the cylindrical member, wherein the cylindrical member includes a slit which communicates the interior of the cylindrical member with the exterior of the cylindrical member, and the driven portion extends from the piston rod in a radial direction of the piston rod and includes an operable portion which protrudes onto the exterior of the cylindrical member through the slit.