Liquid ejection head, liquid ejection apparatus and image forming apparatus

A liquid ejection head comprising a nozzle surface in which a plurality of nozzles for ejecting droplets of liquid toward an ejection receiving medium are arranged two-dimensionally, wherein:

• a first direction is a direction in which the ejection receiving medium is moved relatively with respect to the liquid ejection head, and a second direction being substantially perpendicular to the first direction;
• second direction nozzle rows constituted by the nozzles arranged linearly on the nozzle surface in the second direction are formed in n rows at mutually different positions on the nozzle surface in terms of the first direction, where n is an integer not less than 4;
• m rows of the second direction nozzle rows are disposed within a distance in the first direction on the nozzle surface between a pair of the nozzles that eject the droplets to form dots that are aligned adjacently in the second direction on the ejection receiving medium, where m is an integer satisfying 1≦m≦n/2;
• the liquid ejection head is capable of forming a second direction dot line of dots aligned in the second direction on the ejection receiving medium by depositing the droplets ejected from the nozzles in each of the n rows onto the ejection receiving medium, while moving the ejection receiving medium relatively with respect to the liquid ejection head in the first direction;
• and
• a jagged line nozzle arrangement is adopted, in which, when the nozzles in the nozzle surface which correspond to the dots are tracked following an alignment sequence of the dots that are mutually adjacent in the second direction in respect of a continuous group of n dots formed of the droplets ejected from the nozzles in each of the n rows in the second direction dot line, then nozzle lines comprising nozzle groups in which the nozzle which ejects the droplet forming a next dot in the alignment sequence is positioned on an upstream side in terms of the first direction, and nozzle lines comprising nozzle groups in which the nozzle which ejects the droplet forming the next dot in the alignment sequence is positioned on a downstream side in terms of the first direction, are combined together in a form of a jagged line.