PURPOSE: To prevent variation in printing density, an unstable ink delivery, and a clog with ink from occurring by a method wherein a magnet for applying a magnetic field and electrodes for permitting an electric current to flow at right angles to the direction of the magnetic field generated by the magnet are provided on nozzles, and an ink drop is delivered by a force generated in ink per se.

CONSTITUTION: Nozzles 1 are provided between two magnetic poles of a permanent magnet having different polarties, i.e., a magnetic pole (N pole) 2 and a magnetic pole (S pole) 3. A magnetic field 6 is vertically applied to the nozzles 1. On the inner surface of each nozzle 1, a positive electrode 4 and a negative electrode 5 are disposed opposedly to each other. By passing an electric current between the electrodes, the current flows at right angles to the direction of the magnetic field 6. Therefore, a delivery force occurs in conductive ink contained in the nozzle 1 by Fleming's left-hand rule. The top part of the conductive ink in the nozzle 1 separates as an ink drop to be delivered toward the recording paper.