Patent ID: 7934820

Claim:
An ink cartridge comprising: an ink storage chamber configured to store ink therein; an atmospheric communication portion configured to selectively allow fluid communication between the ink storage chamber and an outside of the ink cartridge; and an ink supply portion comprising: an ink supply chamber configured to communicate with the ink storage chamber via a communication hole formed at a first end of the ink supply chamber, and configured to communicate with the outside of the ink cartridge via an ink supply hole formed at a second end of the ink supply chamber, such that ink stored in the ink storage chamber is supplied to the outside of the ink cartridge via the ink supply chamber; a closing member configured to selectively open and close the ink supply hole; and a check valve configured to selectively open and close the communication hole depending on a pressure differential between a first pressure in the ink storage chamber and a second pressure in the ink supply chamber, wherein, when the ink storage chamber is filled with ink, and the ink supply hole and the atmospheric communication portion are closed, the first pressure is lower than an atmospheric pressure, and the second pressure is higher than the first pressure such that the check valve closes the communication hole.