A binary array ink jet printhead assembly includes a cavity for containing ink, nozzle orifices in fluid communication with the cavity for passing the ink from the cavity to form droplets, the nozzle orifices extending along a length of the cavity, and an electrode assembly. The electrode assembly includes a front face configured to be disposed generally parallel to a plurality of droplet paths of droplets from the nozzle orifices. A plurality of charge electrodes are disposed on the front face, each charge electrode corresponding to a droplet path and disposed parallel to the droplet path. Circuitry is disposed on the electrode assembly, wherein each electrode is electrically connected to the circuitry. The circuitry is further in electrical connection to a connector for connecting the electrode assembly to a controller for the printhead.

An ink-jet printer including a conveyor, a carriage, a recording head, a power supply, an ink receiver, a command receiver, and a controller, is provided. The controller executes the steps of: determining a discharge ink amount that should be discharged to the ink receiver; raising a drive voltage to a first voltage when the discharge ink amount is less than a first threshold value, and raising the drive voltage to a second voltage when the discharge ink amount is the first threshold value or more; performing a flushing process; based on the flushing process after having raised the drive voltage to the second voltage having finished in the case of having raised the drive voltage to the second voltage, stepping down the drive voltage from the second voltage to the first voltage; and based on the flushing process having finished and on the drive voltage being the first voltage, performing a printing process.

An ink-jet printer including a conveyor, a carriage, a recording head, a power supply, an ink receiver, a command receiver, and a controller, is provided. The controller executes the steps of: determining a discharge ink amount that should be discharged to the ink receiver; raising a drive voltage to a first voltage when the discharge ink amount is less than a first threshold value, and raising the drive voltage to a second voltage when the discharge ink amount is the first threshold value or more; performing a flushing process; based on the flushing process after having raised the drive voltage to the second voltage having finished in the case of having raised the drive voltage to the second voltage, stepping down the drive voltage from the second voltage to the first voltage; and based on the flushing process having finished and on the drive voltage being the first voltage, performing a printing process.

An apparatus and method configured to eject an electrically charged liquid. The apparatus and method include a liquid-ejecting apparatus including a reservoir for storing a liquid, an electrically conductive faceplate for ejecting the liquid, a plurality of channels connecting the reservoir to the electrically conductive faceplate, and a voltage source to change and maintain an electric potential difference between the liquid and the electrically conductive faceplate during ejection from the electrically conductive faceplate.

An apparatus and method configured to eject an electrically charged liquid. The apparatus and method include a liquid-ejecting apparatus including a reservoir for storing a liquid, an electrically conductive faceplate for ejecting the liquid, a plurality of channels connecting the reservoir to the electrically conductive faceplate, and a voltage source to change and maintain an electric potential difference between the liquid and the electrically conductive faceplate during ejection from the electrically conductive faceplate.

A drop generator for a printing head of a continuous inkjet printer includes at least one ink feed conduit for feeding ink into a stimulation chamber, which has a quality factor Q lower than 2 and at least one resonant frequency f.sub.r; an actuator for stimulating a wall of said stimulation chamber; and at least one nozzle for ejecting a jet.

A drop generator for a printing head of a continuous inkjet printer includes at least one ink feed conduit for feeding ink into a stimulation chamber, which has a quality factor Q lower than 2 and at least one resonant frequency f.sub.r; an actuator for stimulating a wall of said stimulation chamber; and at least one nozzle for ejecting a jet.

A method for operating a printhead of a continuous inkjet printer comprising: producing at least one ink jet in a cavity of the print head; electrostatically separating drops or sections of one or more of the jet intended for printing from drops or sections that do not serve for printing; exiting from the cavity drops or sections of ink intended for printing, through a slot open on the outside of the cavity; and circulating at least one flow of air along the outlet slot of the cavity in a direction essentially perpendicular to at least one jet of ink emitted by the printhead and intended for printing. The air having a water vapor pressure lower than the water vapor pressure defined by 100% relative humidity at the coldest temperature of the printer.

A method for operating a printhead of a continuous inkjet printer comprising: producing at least one ink jet in a cavity of the print head; electrostatically separating drops or sections of one or more of the jet intended for printing from drops or sections that do not serve for printing; exiting from the cavity drops or sections of ink intended for printing, through a slot open on the outside of the cavity; and circulating at least one flow of air along the outlet slot of the cavity in a direction essentially perpendicular to at least one jet of ink emitted by the printhead and intended for printing. The air having a water vapor pressure lower than the water vapor pressure defined by 100% relative humidity at the coldest temperature of the printer.

An electrohydrodynamic print head includes a plurality of nozzles and a common electrode. Separately controllable electrostatic fields between the common electrode and each nozzle are provided. The common electrode can also shield adjacent electrostatic fields from each other. Each nozzle can be associated with separately controllable gas flow fields and separately back pressures. The print head enables simultaneous e-jet printing of different printing fluids and/or different resolutions. The print head may be part of a printing system with interchangeable cartridges. Each cartridge has multiple nozzles, and printing fluid extraction parameters can be made separately controllable for each nozzle.