Patent ID: 8529037

Claim:
An ink tank for being installed in an ink jet recording apparatus to supply an ink to the ink jet recording apparatus, the ink tank comprising: an ink storage portion for storing the ink; one side surface of a casing of the ink tank in which side surface an opening for supplying the ink to the ink jet recording apparatus is formed; and a one-piece joint member for joining the one side surface to the ink jet recording apparatus by engaging with a connection member of the ink jet recording apparatus, wherein the joint member has a welding portion for being welded to the one side surface along a peripheral portion of the opening, the welding portion corresponding to the peripheral portion; and a hollow portion forming a positioning hole for inserting therein and engaging therewith the connection member for positioning or determining a relative position of the ink jet recording apparatus and the one side surface which are to be joined to each other, and wherein the hollow portion is provided on the outside of the welding portion and abuts to the one side surface without being welded.