Patent ID: 7325911

Claim:
An ink cartridge comprising: an ink tank for reserving ink; and a joint connected to the ink tank, the joint including an outer frame having an ink channel formed to secure communication between the ink tank and the outside, and a sealing member made of an elastic material and received in the outer frame, the sealing member having a cylindrical portion and a valve portion integrally; wherein when an ink supply pipe having an ink inlet is inserted into the cylindrical portion, the cylindrical portion abuts against an outer circumference of the ink supply pipe on an ink flow downstream side of the ink supply pipe with respect to the ink inlet, so as to close the ink channel; and the valve portion abuts against the outer frame so as to close the ink channel when the ink supply pipe is not inserted into the cylindrical portion, and the valve portion leaves the outer frame so as to open the ink channel when the ink supply pipe is inserted into the cylindrical portion.