Ink jet printer, and ink discharge velocity adjusting method and apparatus in the same

Abstract

An ink jet printer is provided with: an ink discharge device for discharging ink, having (i) a body prescribing an ink flow path through which the ink is supplied, a plurality of ink storing chambers each connected to the ink flow path in which the supplied ink is temporarily stored and a plurality of ink discharge holes connected to respective one of the ink storing chambers though which the temporarily stored ink is discharged, and (ii) a plurality of piezoelectric elements for selectively changing capacities of the ink storing chambers; a driving voltage generating device for generating a driving voltage having a pulse-like waveform, which causes the ink to be discharged from each of the ink discharge holes by deforming the respective one of the piezoelectric elements; a plurality of analog switching devices for selectively opening and closing each current-carrying path, through which the driving voltage is supplied to the respective one of the piezoelectric elements; a power source voltage supplying device for supplying a power source voltage to the analog switching devices; a driving voltage adjusting device for changing at least one of a slope and an amplitude of the waveform of the driving voltage; and a power source voltage adjusting device for changing the power source voltage.