| 摘要 |
<p>In an electrostatic ink jet printer, all nozzles (10, 11, 12, 13, 14) of a printhead (20) are spaced generally the same distance from a moving paper print substrate (15). Three voltage levels (VB, VS, VP) are selectively applied to each nozzle of the printhead. As the paper moves past the printhead, a bias voltage (VB) is applied to all nozzles which have a static protruding meniscus which shape is determined by a balance between the internal pressure, surface tension, and bias voltage. When the paper arrives at a print row, non-printing nozzles (11, 12) and field compensation electrodes each have a shadow pulse (VS) applied thereto, and printing nozzles have a higher magnitude print pulse (VP) applied thereto. The magnitude of the shadow pulse causes an additional excursion of the ink meniscus (50, 60) to form at each non-printing nozzle. The higher magnitude of the print pulse causes an ink filament (200, 213, 214) to move from a printing nozzle (10, 13, 14) to the paper. The time duration of each print pulse is varied in accordance with an ink density parameter up to a range that is determined by the duration of the shadow pulse. The electrostatic field difference between printing nozzles and each of non-printing nozzles and field compensation electrodes is of a low magnitude that inhibits ink filament deflection and ink volume differences due to crosstalk between nozzles.</p> |
