Patent ID: 7510254

Claim:
An image forming apparatus, comprising: a print head including a first nozzle line having a plurality of nozzles arranged with a predetermined pitch I; and a second nozzle line disposed at a predetermined distance D from the first nozzle line and having a plurality of nozzles arranged to be deviated from the nozzles of the first nozzle line with a predetermined pitch I; and a controller for controlling the print head to inject ink to form at least a portion of dots to be overlapped by ink injected from the nozzles of the first nozzle line, wherein the controller controls the print head to inject ink to form at least a portion of dots to be overlapped by ink injected from the nozzles of the second nozzle line and controls the nozzles to inject the ink to form dots having a diameter of approximately 3I/2, and wherein the controller selects every other one of the nozzles in the first nozzle line to inject ink on a first line (L 1 - 1 ) of a printing medium, and controls unselected nozzles in the first nozzle line to inject ink on a second line (L 1 - 2 ) after conveying the printing medium a predetermined distance D 1 from the first line (L 1 - 1 ).