RECIRCULATION OF INK

摘要

An apparatus includes an inkjet assembly having inkjet nozzles through each of which ink flows at a nominal flow rate as it is ejected from the nozzle onto a substrate. Ink is held under a nominal negative pressure associated with a characteristic of a meniscus of the ink in the nozzle when ejection of ink from the nozzle is not occurring. The apparatus includes recirculation flow paths, each flow path having a nozzle end at which it opens into one of the nozzles and another location spaced from the nozzle end that is to be subjected to a recirculation pressure lower than the nominal negative pressure so that ink is recirculated from the nozzle through the flow path at a recirculation flow rate. Each recirculation flow path has a fluidic resistance between the nozzle end and the other location such that a recirculation pressure at the nozzle end of the flow path that results from the recirculation pressure applied at the other location of the flow path is small enough so that any reduction in flow rate below the nominal flow rate when ink is being ejected is less than a threshold, or a change in the nominal negative pressure when ink is not being ejected is less than a threshold, or both.