High Frequency Drop-on-Demand Ink Jet System (HIGH FREQUENCY DROP-ON DEMAND INK JET SYSTEM)

摘要

In the high frequency drop-on-demand ink jet system described in the specification, the variable impedance characteristic of the ink jet orifice is used to provide a maximum drop injection velocity that exceeds the maximum possible velocity with a fixed orifice impedance characteristic. In one embodiment, by applying successive negative 30, positive 31 and negative 32 pulses to eject each drop at a maximum ink drop ejection rate of 10-20 KHz to 150-200 KHz, In another embodiment, the ink jet orifice 38 is comprised of a bellmouth arranged to enhance the variable impedance characteristic.