| 摘要 |
PURPOSE:To prevent defective printing from occurring by providing lift means for lifting an ink tank corresponding to discharge of ink from a nozzle. CONSTITUTION:When residual quantity of ink in an ink bag 15 decreases due to printing operation, the negative pressure in the ink bag 15 rises and the ink pressure to be supplied to a nozzle 5 from the ink bag 15 decreases. At this time, the ink discharge quantity is calculated based on the frequency of a piezoelectric device, a step motor 20 is driven based on this data, its torque is transferred to each gear 18 through a drive gear 19, screw rods 17 rotate, an ink cartridge 13 moves upward, so that a difference H in height between a nozzle face 5a of the nozzle 5 and the cartridge 13 becomes smaller. Accordingly, even if the residual quantity of the ink in the ink bag 15 decreases, defective printing caused by non-discharge of the ink from the nozzle face 5a and thinning in printing density can be prevented. |
