Domino UK Limited

Justin Chase

Stuart Mark Walkington

Richard Thomas Calhoun Bridges

Colin Jon Partridge

Antonio Martin

A continuous inkjet printer () has an ink droplet generator () and a controller () that varies a modulating voltage applied to the ink droplet generator () and measures corresponding breakup times of a jet of ink into ink droplets to obtain a portion of a characteristic of breakup time against modulating voltage. The controller () obtains a variation range, varies the modulating voltage over the variation range to obtain the portion of the characteristic, calculates a gradient from the portion of the characteristic, compares the gradient with a predetermined gradient and, depending on whether the calculated gradient is less than or greater than the predetermined gradient, generates an adjusted variation range that is displaced in a first sense or a second, opposite sense, respectively, relative to the variation range.

Dynamic modulating voltage adjustment

The invention discloses various methods of controlling or monitoring the performance of a continuous inkjet printer based on monitoring vacuum levels and/or noise in the gutter line.

Continuous inkjet printers

The invention provides a method of adding solvent or make-up fluid into the gutter line of a continuous ink printer. During the addition of solvent, the vacuum level in the gutter line is monitored and maintained at a level sufficient to ensure that vacuum is maintained at the gutter. Vacuum level in the gutter line is preferably controlled by controlling the speed of a variable speed gutter pump. Noise in the gutter line is preferably used as a control over pump speed.

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Elsworth, United Kingdom

Justin Chase