Liquid container and liquid ejection system

1. A liquid container for supplying a liquid to a liquid ejection apparatus, comprising:

a liquid chamber provided to store the liquid; and

an air chamber connected with the liquid chamber to introduce the outside air into the liquid chamber with consumption of the liquid in the liquid chamber;

a connection path connecting the liquid chamber with the air chamber; wherein

the liquid chamber has walls,

at least one portion of the connection path is formed in the projection projected outwards from one wall of the liquid chamber; and

wherein the liquid chamber and the at least one portion of the connection path are formed as respective concaves having respective openings on the same side and sealed with a film common to the respective openings.

2. The liquid container according to claim 1 ,

wherein the liquid chamber has a liquid inlet to fill the liquid into the liquid chamber and wherein the at least one portion of the connection path is located at a lower position than the liquid inlet when the liquid container is installed in the liquid ejection apparatus.

3. The liquid container according to claim 1 , further comprising a liquid discharge port communicating with the liquid chamber, the liquid discharge port located at a lower position than the position of the at least one portion of the connection path when the liquid container is installed in the liquid ejection apparatus.