Ink jet printer of the ink-on-demand type

摘要

An ink-on-demand type ink jet printer includes a printer head having at least one nozzle, pressure chamber and means for pressurizing an ink in the pressure chamber so as to effect ejection of an ink droplet from a nozzle to effect printing during a printing operation. The printer further includes a pump for pressurizing an ink in the printer head and a pump driver for driving the pump continuously for a predetermined period of time after the printing operation has ceased during which a small amount of ink is partially ejected from the nozzle. A nozzle cover is provided for selectively covering the nozzle, with the nozzle cover moving to cover the nozzle during the predetermined period of time when the pump driving means is operating while ink is partially ejected from the nozzle to prevent ink clogging during a no-print condition after the printing operation has ceased.