Patent ID: 8602515

Claim:
An image forming device comprising: a liquid discharge head including plural piezoelectric elements for generating pressure for discharging liquid droplets; a drive waveform generating unit configured to generate and output a drive waveform for driving plural of the piezoelectric elements; a selection unit configured to selectively apply the drive waveform from the drive waveform generating unit to plural of the piezoelectric elements in accordance with a print image; a resonant frequency adjusting circuit including at least one of an inductance component and a capacitance component, the resonant frequency adjusting circuit being disconnectably connected in parallel with plural of the piezoelectric elements; a switch unit configured to switch between connection and disconnection of the resonant frequency adjusting circuit; and a switching control unit configured to cause the switch unit to switch in accordance with a first number of simultaneously driven piezoelectric elements among plural of the piezoelectric elements, wherein, when the first number of the simultaneously driven piezoelectric elements is greater than or equal to a predetermined number, the switching control unit causes the switch unit to switch to a state where the resonant frequency adjusting circuit is connected, so that plural of the piezoelectric elements are connected in parallel with the at least one of the inductance component and the capacitance component, and so that a resonant frequency of a closed loop that starts from the drive waveform generating unit and ends at the drive waveform generating unit through the liquid discharge head becomes lower than a resonant frequency of the closed loop when the first number of the simultaneously driven piezoelectric elements is less than the predetermined number.