In an image forming device including a liquid discharge head in which nozzles for discharging liquid drops are arranged side by side, a drive waveform generating unit generates, within a single drive cycle, a first drive waveform containing a drive signal to discharge an amount of liquid drop used for image formation, and a second drive waveform containing a drive signal to discharge an amount of liquid drop smaller than a minimum discharge drop amount used for image formation. A head control unit causes the liquid discharge head to discharge the amount of liquid drop used for image formation in accordance with the first drive waveform for a region where an image is formed, and to discharge the amount of liquid drop smaller than the minimum discharge drop amount in accordance with the second drive waveform for a region where any image is not formed.