Liquid container for ink jet head

An ink container comprising:

• a first chamber accommodating a liquid absorbing material and having a liquid supply port for supplying liquid toward an ejection head for image formation and an air vent for fluid communication with ambient atmosphere;
• a second chamber for containing the liquid to be supplied to said first chamber, said second chamber being in fluid communication with said first chamber through a communicating portion provided adjacent a bottom portion, in use, of said ink container, said second chamber being substantially hermetically sealed except for said communicating portion;
• a partition wall for separating said first chamber and second chamber and defining a top end of said communicating portion, wherein said ink container has a substantially flat thin and rectangular parallelopiped configuration;
• and
• wherein a projected surface is projected toward an inside of said ink container at a part of an inner surface of each of maximum area lateral sides of said first chamber sandwiching a side having said liquid supply port, said projected surface adjacent said liquid supply port, and wherein said second chamber is provided with an ink introduction groove extending along substantially an entirety of an inner corner portion, in use, of a bottom wall of said second chamber to said communicating portion.