Patent ID: 8899708

Claim:
An image forming apparatus comprising: a carriage that includes at least one head and is moved for scanning in a main-scanning direction, the head including a black nozzle array in which a plurality of nozzles for ejecting black droplets are arranged and a color nozzle array in which a plurality of nozzles for ejecting color droplets are arranged, the black nozzle array being disposed at a position shifted in a sub-scanning direction downstream in a medium conveying direction with respect to the color nozzle array; a conveying unit configured to convey a recording medium in the sub-scanning direction; and a control unit configured to control forming a first line of an image by the color nozzle array in a first main scanning direction, moving the recording medium in the sub-scanning direction by an amount equivalent to the first line to a subsequent main-scanning position thereafter, and forming an image by only the black nozzle array on the first line of the image formed by the color nozzle array in a following main scanning in a second main-scanning direction so as to complete the first line of the image while simultaneously forming a second line of the image by the color nozzle array in the second main-scanning direction, wherein the first and second lines have a width substantially equivalent to a width of at least one of the color nozzle array and the black nozzle array.