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.

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.

One example provides a fluidic die including a semiconductor substrate, and a nozzle layer disposed on the substrate, the nozzle layer having a top surface opposite the substrate and including a nozzle formed therein, the nozzle including a fluid chamber disposed below the top surface and a nozzle orifice extending through the nozzle layer from the top surface to the fluid chamber, the fluid chamber to hold fluid, and the nozzle to eject fluid drops from the fluid chamber via the nozzle orifice. An electrode is disposed in contact with the nozzle layer about a perimeter of the nozzle orifice, the electrode to carry an electrical charge to adjust movement of electrically charged components of the fluid.

One example provides a fluidic die including a semiconductor substrate, and a nozzle layer disposed on the substrate, the nozzle layer having a top surface opposite the substrate and including a nozzle formed therein, the nozzle including a fluid chamber disposed below the top surface and a nozzle orifice extending through the nozzle layer from the top surface to the fluid chamber, the fluid chamber to hold fluid, and the nozzle to eject fluid drops from the fluid chamber via the nozzle orifice. An electrode is disposed in contact with the nozzle layer about a perimeter of the nozzle orifice, the electrode to carry an electrical charge to adjust movement of electrically charged components of the fluid.

An inkjet recording device and a method for controlling an inkjet recording device are provided. A heating device that heats the ink to be supplied to a nozzle immediately ahead of the nozzle, a thermometer that detects a temperature of the ink inside the heating device or after heating, a viscometer that detects a viscosity of the ink in a main ink container are provided. The heating device is driven using a detection value of the thermometer to control the temperature of the ink such that the viscosity reaches an ink viscosity which enables normal printing, and when the viscosity of the ink is out of a range which enables printing, the solvent or the replenishment ink is supplied to the main ink container using a detection value of the viscometer such that the viscosity reaches the range which enables normal printing.

An inkjet recording device and a method for controlling an inkjet recording device are provided. A heating device that heats the ink to be supplied to a nozzle immediately ahead of the nozzle, a thermometer that detects a temperature of the ink inside the heating device or after heating, a viscometer that detects a viscosity of the ink in a main ink container are provided. The heating device is driven using a detection value of the thermometer to control the temperature of the ink such that the viscosity reaches an ink viscosity which enables normal printing, and when the viscosity of the ink is out of a range which enables printing, the solvent or the replenishment ink is supplied to the main ink container using a detection value of the viscometer such that the viscosity reaches the range which enables normal printing.

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.

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.

The print head cover (83) of an electrostatic deflection inkjet printer is made of a material having an electrical surface resistivity of no more than 10.sup.12 ohms per square or an electrical volume resistivity of no more than 10.sup.9 ohm metres and is electrically connected to an earth line (93, 97). This prevents build-up of electric charge on the cover (83). The resistance from the surface of the cover (83) to a place where a cover earth line (93) joins a signal earth line (97) or enters the umbilical (7) is at least 16000 times the resistance from that place to earth. This prevents an electrostatic discharge to the cover (83) disrupting the electronic circuits. The high resistance earth connection for the cover (83) avoids the need for an earthing wire braid in the umbilical (7). The cover (83) may be moulded from an antistatic or static dissipative material.