Patent ID: 8042925

Claim:
An ink cartridge, comprising: a case having at least a portion of an ink chamber defined therein, wherein the ink chamber is configured to store ink, and the case comprises an inner surface and an outer surface, wherein the outer surface has a front face and a rear face opposite the front face, and the ink chamber is positioned between the front face and the rear face; an ink supply portion positioned at the front face of the case, wherein the ink supply portion is configured to dispense ink from an interior of the ink chamber to an exterior of the ink chamber; a movable member configured to move relative to the case; and at least one resilient member having a first end which is coupled to the rear face of the case and a second end which is coupled to the movable member, wherein the at least one resilient member is configured to expand in an expansion direction and to contract in a contraction direction opposite the expansion direction to move the movable member relative to the case, and a size of the case in the expansion and contraction directions is unaltered when the at least one resilient member expands and contracts, wherein the entire moveable member is configured to substantially simultaneously move in a first direction relative to the case when the at least one resilient member expands, and the entire moveable member is configured to substantially simultaneously move in a second direction opposite the first direction when the at least one resilient member contracts.