Patent ID: 7954916

Claim:
An apparatus for ejecting droplets to form dots on a medium, the apparatus comprising: an ejection pressure applying section which is a piezoelectric actuator and which applies ejection pressure to a storage chamber which stores liquid; a first nozzle which communicates with the storage chamber and which ejects a first main droplet in a first trajectory together with a satellite droplet having a volume smaller than the first main droplet; a second nozzle which communicates with the storage chamber and which ejects a second main droplet in a second trajectory intersecting the first trajectory at a predetermined intersection point; a control device which controls the ejection pressure applying section, the control device providing a drive pulse signal to the ejection pressure applying section so that the first main droplet and the second main droplet collide with each other at the intersection point to form a united droplet, and the satellite droplet, which has been ejected from the first nozzle, lands on the medium, the piezoelectric actuator applying the ejection pressure to the storage chamber communicating with both of the first nozzle and the second nozzle and being commonly used for the ejections of the first main droplet and the satellite droplet from the first nozzle and the second main droplet from the second nozzle; a medium holding device which holds the medium; and a droplet catching section which catches the united droplet and which is disposed in a trajectory of the united droplet so that the united droplet does not land on the medium, wherein a following expression is held when the control device drives the ejection pressure applying section: L 1 /V 1 =L 2 /V 2 , wherein L 1 is a linear distance between an ejection port of the first nozzle and the intersection point; L 2 is a linear distance between an ejection port of the second nozzle and the intersection point; V 1 is an ejection speed of the first main droplet ejected from the first nozzle; and V 2 is an ejection speed of the second main droplet ejected from the second nozzle.