Patent ID: 7455398

Claim:
An ink cartridge comprising: an ink chamber storing ink; a valve seat having a valve hole; a communication chamber communicating the ink chamber with the exterior of the ink cartridge via the valve hole; a valve member disposed in the communication chamber such that the valve member is displaceable between a first position to separate away from the valve seat to allow communication between the ink chamber and the exterior via the valve hole, and a second position to be held in close contact with the valve seat to shut off the communication; a biasing member including (a) side wall portion surrounding the valve member, and (b) an engaging portion extending inward from an end of the side wall portion and engaging with the valve member; the biasing member normally holding the valve member at the second position but allowing the valve member to be placed at the first position by an elastic deformation of at least one of the side wall portion and the engaging portion, and generating a biasing force to restore the valve member to the second position; and a disengagement preventer which prevents the valve member from disengaging from the engaging portion when the valve member is abnormally operated toward the first position.