Abstract: In a magnetic ink jet printer a continuous stream of ferrofluid ink drops is projected toward a print medium. A magnetic selector located proximate the stream is operated in synchronism with the flight of the ink drops for deflecting individual unwanted ink drops into a drop catcher. Due to fringing effects produced by the selector when unwanted drops are selected, adjacent print drops are deflected a lesser amount from the initial stream trajectory. Print drops not affected by the fringe magnetic field produced to select unwanted drops are subjected to a compensation deflection depending on their position relative to the unwanted drops so that all print drops follow the same trajectory, after passing the magnetic selector in their travel through a vertical deflector and deposition onto the print medium.

Abstract: A dot matrix printer apparatus has a magnetic ink jet recording head which projects a continuous stream of ferro-fluid ink drops toward a print medium. The ink drops are rastered in the direction orthogonal to the direction of relative motion of the recording head and the print medium to form characters from columns of dots. The slant of the characters caused by the change in direction of relative motion is controlled by reversing the direction or sequence of rastering of ink drops when the direction of printing reverses.