Videojet Systems International, Inc.

Jianming Tsai

James E Clark

Pietro C Lostumbo

Mairi Campbell MacLean

An anti-clogging nozzle system for a continuous jet ink jet printer is disclosed. A printing nozzle has both an ink inlet and an ink outlet permitting constant ink flow behind the nozzle orifice during printing. A pressure sensor monitors the ink flow and signals clogs to an automatic unclogging system. The unclogging system includes a control circuit to initiate an unclogging operating cycle when necessary. One of two unclogging modes is employed, both of which require the control system to operate an unclogging valve to vary pressure in the ink return line.

Cross flow nozzle system for an ink jet printer

An apparatus and method for producing a stream of ink drops in a continuous ink jet printer having a maximum allowable number of fast satellite drops. An ink, which may be a hot-melt ink in its liquid phase, is pressurized for continuous flow to a nozzle and a rectangular or triangular waveform is generated at a fixed frequency. The waveform is applied to a transducer coupled to the nozzle such that nozzle vibrates and the ink flow is perturbed and discharged from the nozzle as primary drops with satellite drops formed therewith. The harmonic content of the rectangular or triangular waveform is adjusted until the desired number of fast satellite drops suitable for desired image formation are formed in the stream of primary drops. In a preferred embodiment, the desired number of fast satellites is a maximum of three.

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Schaumburg, IL, United States of America

Jianming Tsai