Liquid droplet jetting apparatus

A liquid droplet jetting apparatus which jets liquid droplets of a liquid, comprising:

• a liquid droplet jetting head having a cavity unit in which a pressure chamber extending in a predetermined direction and a nozzle communicating with the pressure chamber are formed, and a piezoelectric actuator which is joined to the cavity unit to cover the pressure chamber, which applies pressure to the liquid in the pressure chamber, and which has first active portion corresponding to a central portion of the pressure chamber, and a second active portion corresponding to outer peripheral portion, of the pressure chamber, outside the central portion;
• and
• a voltage applying mechanism which applies a voltage to the piezoelectric actuator in a liquid droplet jetting mode of jetting the liquid droplets from the nozzle and a warm-up mode of heating the liquid inside the pressure chamber without jetting the liquid as liquid droplets from the nozzle,
• wherein in the liquid droplet jetting mode, the voltage applying mechanism applies the voltage to the first active portion and does not apply the voltage to the second active portion to provide a first state in which the first active portion is deformed to project toward the pressure chamber, and then the voltage applying mechanism applies the voltage to the second active portion and does not apply the voltage to the first active portion to provide a second state in which the second active portion is deformed to project in a direction away from the pressure chamber, and then the first state is again provided;
• and
• in the warm-up mode, the voltage applying mechanism applies the voltage to both the first active portion and the second active portion to provide a third state in which the first active portion is deformed to project toward the pressure chamber and the second active portion is deformed to project in the direction away from the pressure chamber, and then the voltage applying mechanism does not apply any voltage to the first active portion and the second active portion to provide a fourth state in which both the first active portion and the second active portion are not deformed, such that the third state and the fourth state are repeated alternately.