Patent ID: 7753505

Claim:
An ink cartridge, comprising: an ink chamber configured to store an ink; a wall comprising a first end and a second end opposite the first end; an ink supply portion which is positioned at the wall, wherein the ink supply portion has an end portion and an ink supply opening formed in the end portion, and the ink supply portion is configured to supply the ink from an interior of the ink chamber to an exterior of the ink cartridge through the ink supply opening; and a plurality of protrusions protruding from the wall, wherein each of the plurality of protrusions has an end portion, and a first distance between the end portion of each of the plurality of protrusions and the wall is greater than a second distance between the end portion of the ink supply portion and the wall, wherein the plurality of protrusions comprise a first protrusion and a second protrusion positioned adjacent to the first protrusion, and the first protrusion is separated from the second protrusion by a separation distance, such that the first protrusion and the second protrusion are configured to retain an ink droplet positioned therebetween by a capillary force.