Patent ID: 7360870

Claim:
A nozzle plate comprising: a plurality of nozzle groups of a trapezoid, each of the nozzle groups in which a plurality of nozzles for ejecting ink are arranged two dimensionally within the trapezoid on an ink ejection surface; and a plurality of dummy holes; wherein: each of the nozzle groups has a plurality of nozzle rows in which a plurality of nozzle holes are arranged in a direction of a long side of the trapezoid at predetermined intervals, the nozzle holes and the dummy holes passing through the nozzle plate; the nozzle groups are arranged so that the long sides thereof are parallel to each other; oblique sides of adjacent nozzle groups face each other to be parallel to each other; the oblique sides of the adjacent nozzle groups partially overlap each other when viewed from a direction, which is perpendicular to the long sides and is on the ink ejection surface; when the nozzle holes of the nozzle groups are projected from a predetermined direction onto a virtual line, which is on a plane including the ink ejection surface and is parallel to the long sides, projection points of the nozzle holes are arranged at even intervals on the virtual line; the predetermined direction is parallel to the plane including the ink ejection surface; and the dummy holes are arranged on an extension line of the nozzle rows and are located outside the trapezoids of the nozzle groups.