Methods of adjusting ink ejection characteristics of inkjet printing apparatus and driving the inkjet printing apparatus

A method of driving an inkjet printing apparatus, the method comprising:

• applying a first driving signal to a plurality of piezoelectric actuators to eject a first plurality of ink droplets onto a printing medium from a plurality of nozzles;
• determining a plurality of second driving signals for the plurality of piezoelectric actuators by adjusting at least one of a voltage and an application duration of the first driving signal so that volumes of a second plurality of ink droplets having a uniform volume are ejected from the plurality of nozzles;
• and
• displacing application starting times of the plurality of second driving signals and applying the second driving signals with the displaced application starting time to the plurality of piezoelectric actuators so that the second plurality of ink droplets ejected from the plurality of nozzles reach a printing medium at the same time.