Patent ID: 6969161

Claim:
An ink supply system comprising: a first ink storage area having a first ink container to store ink, negative pressure generating means to generate negative pressure in the first ink container, and connecting means through which the ink is supplied; and a second ink storage area connected to the first ink storage area through said connecting means to introduce the ink from the first ink storage area for supply to a print head; and a means which, when the connecting means disconnects a connecting portion on the second ink storage area side from a connecting portion on the first ink storage area side, hermetically closes the connecting portion on the first ink storage area side; wherein the connecting means disconnectably connects the second ink storage area to the first ink storage area and, when the two ink storage areas are connected, forms a plurality of communication paths communicating the two ink storage areas with each other; wherein the second ink storage area, excluding the plurality of communication paths and a connecting portion with the print head, virtually forms a hermetically closed space; wherein, when the ink is refilled into the second ink storage area from the first ink storage area through at least one of the plurality of communication paths, a gas present in the second ink storage area can be transferred to the first ink storage area through at least one other communication path; wherein at least a part of the first ink storage area is situated higher in the gravity direction than the connecting means; wherein the first ink storage area is provided with a gas accommodating chamber which is installed higher than the connecting means and accommodates a gas transferred from the second ink storage area; and wherein said first ink storage area further comprises means to reduce an internal volume of the accommodating chamber.