An image forming apparatus including a first carriage having at least two first recording heads, a second carriage separatably dockable with the first carriage, a pattern forming unit to control the at least two first recording heads to form on a recording medium adjustment patterns for correcting a shift in landing positions of liquid droplets ejected from the at least two first recording heads, a pattern detector provided to the first carriage to read the adjustment patterns, and a landing position corrector to correct the shift in the landing positions of the liquid droplets based on a result obtained by the pattern detector. The at least two first recording heads form multiple rows of the adjustment patterns, and the pattern detector successively reads at least two rows of the multiple rows of the adjustment patterns without docking and separation of the first and second carriages.