Ink jet printer with cartridge having integral storage chamber

A printer into which an ink-jet head and an ink container are receivable, said ink-jet head for ejecting ink to perform printing on a printing medium and said ink container for storing the ink to be supplied to said ink-jet head, said printer comprising:

• an ink storage container for temporarily storing the ink to be supplied from said ink container to said ink-jet head, said ink storage container having a closable air communicating portion communicating with ambient air;
• a first ink path which connects said ink container to said ink storage container, and which defines a flow of ink from said ink container to said ink storage container, said first ink path being provided with a one-way flow restricting member for permitting only a flow of ink in a direction of discharge from said ink container;
• a second ink path which connects said ink storage container to said ink container, and which defines a flow of ink for returning an excess amount of ink over a predetermined liquid amount in said ink storage container to said ink container;
• opening/closing means for opening and closing said air communicating portion to ambient air;
• a buffer container provided at a portion of said first ink path between said one-way flow restricting member and said ink storage container, said buffer container being capable of maintaining a predetermined liquid amount;
• and
• transfer means for transferring ink from said buffer container, said transfer means being provided at a portion of said first ink path between said buffer container and said ink storage container.