Patent ID: 7591519

Claim:
A liquid droplet ejection apparatus, comprising: a plurality of ejection heads having an ejection surface in which nozzles for ejecting droplets of liquid towards an ejection receiving medium are arranged two-dimensionally; a conveying device which conveys at least one of the ejection heads and the ejection receiving medium in a fixed direction to cause relative movement of the ejection heads and the ejection receiving medium in a relative movement direction; and a droplet ejection control device which performs droplet ejection control whereby droplets of the liquid are ejected from the ejection heads towards the ejection receiving medium together with the relative movement caused by the conveying device, and a row of dots is formed by the droplets of the liquid landing on the ejection receiving medium in which at least some of the dots overlap in a main scanning direction substantially perpendicular to the relative movement direction, wherein when a position between nozzles at which a droplet ejection time difference between adjacent dots in the main scanning direction in one ejection head differs from a droplet ejection time difference between other adjacent dots is referred to as a specific time difference nozzle pair position in a corresponding ejection head, the ejection head is positioned so that the specific time difference nozzle pair position differs in the main scanning direction between at least two of the ejection heads.