Patent ID: 7591520

Claim:
An ink jet printer, comprising: an ink jet head comprising a nozzle that discharges an ink droplet toward a print medium and an actuator that makes the nozzle discharge the ink droplet when a pulse signal is applied to the actuator; an applying device configured to apply at least two kinds of pulse signals to the actuator, wherein the pulse width of each kind of pulse signal mutually differs; a first storage that stores at least two kinds of base pulse widths, wherein each kind of base pulse width corresponds with a different kind of pulse signal, and each kind of base pulse width mutually differs; an inputting device that inputs a fixed predetermined value; and a second storage that stores the fixed predetermined value input by the inputting device, wherein the applying device determines a pulse width of each kind of pulse signal by multiplying the corresponding base pulse width stored in the first storage by the fixed predetermined value stored in the second storage, the applying device is configured to apply a first pulse signal to the actuator, the applying device is configured to apply a second pulse signal to the actuator, the first storage stores a first base pulse width corresponding to the first pulse signal, and a second base pulse width corresponding to the second pulse signal, the applying device determines a pulse width of the first pulse signal by multiplying the first base pulse width stored in the first storage by the fixed predetermined value stored in the second storage, the applying device determines a pulse width of the second pulse signal by multiplying the second base pulse width stored in the first storage by the fixed predetermined value stored in the second storage, and the fixed predetermined value is determined by dividing a pulse width of a pulse signal which is configured to obtain the largest ink droplet discharging speed by the first base pulse width.