Controlling PWA inkjet nozzle timing as a function of media speed

TLDR: In this article, a page-wide-array (PWA) inkjet printer includes a printer element defining a printhead with thousands of nozzles spanning a pagewidth, and a sensor positioned in fixed relation to a PWA printer element detects the media's actual velocity.

Abstract: A page-wide-array ("PWA") inkjet printer includes a printer element defining a printhead with thousands of nozzles spanning a pagewidth. A media sheet travels along a media path adjacent to the printhead to receive character or graphic markings. Typically, a media sheet accelerates from rest to a constant velocity. To optimize print speed nozzle timing is controlled to respond to changes in media velocity. Printing occurs while the media is accelerating and while traveling at a constant velocity. A sensor positioned in fixed relation to a PWA printer element detects the media's actual velocity. Actual velocity is fed back to a printhead controller which compares actual velocity to a rated constant velocity. If actual velocity is slower than the rated velocity, then nozzle timing is adjusted to be slower than a rated timing. If actual velocity is faster than rated velocity, then nozzle timing is adjusted to be faster than the rated timing.