A single-pass inkjet image forming apparatus comprising: at least two dot formers (45, 45c, 45k, 45m, 45y) each including a plurality of dot forming elements arranged along an array direction for ejecting droplets (142, 144) to form dots (152, 154) in one color on a recording medium; and a dot formation controller for independently controlling the at least two dot formers (45, 45c, 45k, 45m, 45y) to form the dots (152, 154) successively at a plurality of times to generate image arrays while the at least two dot formers (45, 45c, 45k, 45m, 45y) and the recording medium are moved relatively to each other, wherein: the at least two dot formers (45, 45c, 45k, 45m, 45y) and the recording medium are moved relatively to each other only once in a predeterminated direction perpendicular to the array direction; the at least two dot formers (45, 45c, 45k, 45m, 45y) are provided for each of a plurality of colors; and the at least two dot formers, which form the dots (152, 154) in a particular one of the plurality of colors, are disposed at a greater interval along the direction perpendicular to the array direction than the intervals along the direction perpendicular to the array direction at which the at least two dot formers (45c, 45m, 45y), which form the dots (152, 154) in the remaining ones of the plurality of colors, are disposed. at least two dot formers (45, 45c, 45k, 45m, 45y) each including a plurality of dot forming elements arranged along an array direction for ejecting droplets (142, 144) to form dots (152, 154) in one color on a recording medium; and a dot formation controller for independently controlling the at least two dot formers (45, 45c, 45k, 45m, 45y) to form the dots (152, 154) successively at a plurality of times to generate image arrays while the at least two dot formers (45, 45c, 45k, 45m, 45y) and the recording medium are moved relatively to each other, wherein: the at least two dot formers (45, 45c, 45k, 45m, 45y) and the recording medium are moved relatively to each other only once in a predeterminated direction perpendicular to the array direction; the at least two dot formers (45, 45c, 45k, 45m, 45y) are provided for each of a plurality of colors; and the at least two dot formers, which form the dots (152, 154) in a particular one of the plurality of colors, are disposed at a greater interval along the direction perpendicular to the array direction than the intervals along the direction perpendicular to the array direction at which the at least two dot formers (45c, 45m, 45y), which form the dots (152, 154) in the remaining ones of the plurality of colors, are disposed. the at least two dot formers (45, 45c, 45k, 45m, 45y) and the recording medium are moved relatively to each other only once in a predeterminated direction perpendicular to the array direction; the at least two dot formers (45, 45c, 45k, 45m, 45y) are provided for each of a plurality of colors; and the at least two dot formers, which form the dots (152, 154) in a particular one of the plurality of colors, are disposed at a greater interval along the direction perpendicular to the array direction than the intervals along the direction perpendicular to the array direction at which the at least two dot formers (45c, 45m, 45y), which form the dots (152, 154) in the remaining ones of the plurality of colors, are disposed.