| 摘要 |
PROBLEM TO BE SOLVED: To restrain the spread of toner particles ejected from a nozzle, and enable dots to be printed with clear peripheries in a toner printer employing electrostatic fields. SOLUTION: A screen electrode 110 is set at the side near the platen 100 of arrangement boards 28, and screen bias voltage Vs is applied thereto. A conductive rod 102 is passed through the platen 100 along the central axis of a nozzle opening 30, and platen bias voltage Vp is applied thereto. A conductive layer 104 is put on the surface of the platen opposite to the arrangement boards 28 by keeping an insulation with the conductive rod 102 to subsequently be grounded. Vs, Vp and the electric potentials Vc, Vr of column electrodes 52 and row electrodes 54 are made Vs<(Vc, Vr)<Vp, resulting in the generation of electric fields as shown in Figure. Even after toner particles with negative electric charge pass through the openings 30 to the platen 100 side, they receive forces toward the conductive rod 102 by the electric fields polarized, thereby decreasing the spread caused by repulsion among the toner particles. |
