Patent ID: 7500729

Claim:
A method for correcting an amount of ejected ink in a line head inkjet printer including an inkjet head having a plurality of nozzles, which are divided into blocks including at least one nozzle, a flow path unit in which the plurality of nozzles are formed, and a plurality of actuator units having a trapezoidal shape, the actuator units being arranged on the flow paths unit so that oblique sides of adjacent actuator units overlap each other when viewed in a conveyance direction, the method composing: measuring the amount of ink ejected from each of n of the blocks divided by n−1 virtual lines extending in the conveyance direction of a printing medium where n represents a natural number equal to or greater than 2, wherein the virtual lines each pass through a corresponding one of a plurality of structural change points in the inkjet head, each structural change point corresponding to a point where an oblique side of one of the actuator units intersects with a short side of the one of the actuator units, the structural change points extending in a direction perpendicular to the conveyance direction; and obtaining a correction factor for each block on a basis of the measured amount of ejected ink in each block, the correction factors making a difference among the blocks in an amount of ejected ink per nozzle becoming smaller than that without using the obtained correction factors.