In ink jet system printers of the charge amplitude controlling type, it is required, to ensure stable printing, that ink drop separation (drop formation) is timed to be in agreement with the application of charging signals. To this end, there are provided phase detecting signals having a period which...http://www.google.de/patents/US4025926?utm_source=gb-gplus-sharePatent US4025926 - Phase synchronization for ink jet system printer
