Patent ID: 7241002

Claim:
An ink cartridge, comprising: an ink chamber comprising a wall; a translucent portion positioned at the wall, wherein the translucent portion has an inner space formed therein; and a movable member comprising: a first member disposed within the inner space of the translucent member; and a second member disposed within the ink chamber, wherein at least one of the first member and an interior surface of the translucent portion comprises at least one protrusion portion, and at least one of a surface of the first member and the interior surface of the translucent portion comprises a first surface portion and a second surface portion, wherein the second surface portion is raised with respect to the first surface portion, wherein the first surface portion comprises a first flat surface, the second surface portion comprises a second flat surface and a plurality of projecting portions which extend a predetermined distance from the second flat surface, wherein a distance between a first protrusion of the plurality of projecting portions and a second protrusion of the plurality of projecting portions is less than about 0.6 mm.