Tone reproducible ink jet printer

Abstract

An ink jet printer in which a plurality of ink jet generators are moved in unison with one another and relative to a record medium for recording. Each of the ink jet generators comprises a nozzle for continuously ejecting an ink, a charge electrode for applying a pulse voltage to the ink to selectively charge droplets of the ejected ink, a deflector electrode for producing a deflection electric field for deflecting a row of charged droplets and permitting a row of uncharged droplets to proceed straight, an oscillation controller, an oscillator for oscillating the nozzle to control ink droplet formation in response to clock pulses output by the oscillation controller, a pulsewidth modulator for controlling a pulsewidth of the pulse voltage to be applied to the charge electrode according to a dot size to be recorded, a delay circuit for delaying the pulse voltage from the pulsewidth modulator, and a phase synchronizing circuit for outputting the pulse voltage of the delay circuit to the charge electrode in phase with the clock pulses output by the oscillation controller. This construction is capable of adjusting dot position displacement among the nozzles over a wide range without injuring control of the ink to a row of ink droplets, thereby to record images with high resolution and high tone reproduction.