Patent ID: 8727512

Claim:
An ink cartridge for storing ink, comprising: a reservoir portion configured to store ink; a housing configured to cover said reservoir portion; a moving member capable of executing, a display in accordance with an ink volume within said reservoir portion based on a rotational position achieved by contacting said reservoir portion and rotating in accordance with a change in a contact position with said reservoir portion; and a support device provided to said housing and comprising at a predetermined interval in a first direction as an axial direction of a plug of said reservoir portion two concave portions for rotatably supporting said moving member; wherein: said moving member has: two arm portions at least partially elastic, provided at a predetermined interval in said first direction and that extends along a second direction orthogonal to said first direction; and a convex portion of a shape engageable with said concave portion, provided protruding from each of two of said arm portions along said first direction, disposed linearly at an interval in said first direction; and at least one of said arm portions is capable of elastic deformation in which, upon receipt of an external force along said first direction toward a direction opposite a protruding direction of said convex portion, changes a position of the convex portion provided to said one of said arm portions to an extent that said concave portion and said convex portion do not engage, generates an elastic force near said predetermined interval along said first direction when said external force is removed from said one of said arm portions, and positions said convex portion in a position, that includes a rotation center of said arm portion when said concave portion and said convex, portion engage.