Ink-jet apparatus

An ink-jet apparatus comprising:

• multiple nozzles for ejecting ink;
• pressure chambers, each of the pressure chambers communicating with each of the nozzles;
• piezoelectric elements A for applying a pressure to the pressure chambers;
• partition walls arranged between the pressure chambers;
• piezoelectric elements B, each of piezoelectric elements B supporting each of the partition walls;
• and a diaphragm arranged between the partition walls and the piezoelectric elements B, the diaphragm being in contact with the piezoelectric elements A;
• wherein:
• a relationship L4≧L3>L1 is satisfied when:
• L1 is a width of a part of each of the piezoelectric elements A in direction X along which the nozzles are arranged, the part being in contact with the diaphragm;
• L2 is a width of a part of each of the piezoelectric elements B in direction X, the part being in contact with the diaphragm;
• and L4 is a width of a part of each of the piezoelectric elements A and the piezoelectric elements B in direction X;
• and
• a relationship W2>W1 is satisfied when:
• W1 is a width of a part of each of the piezoelectric elements A and the piezoelectric elements B in direction Y perpendicular to direction X and along an axis of each of the nozzles;
• and W2 is a width of a part of each of the piezoelectric elements A or each of the piezoelectric elements B in direction Y, the part being in contact with the diaphragm.