This invention is intended to provide a ink-jet printing device which can detect leak of ink or solvent without the exclusive sensor for leak detection and without increasing cost. An ink jet printing device for printing letter by ejecting ink, comprising, a liquid container for containing ink or solvent, a surface level sensor for detecting surface level arranged on the liquid container, a control unit and a display unit, wherein the display unit displays indication in the case where the surface level change time detected by the control unit using the surface level sensor is larger than the settled surface level change time in settled printing condition is provided for solving the problem.

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.

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.

This invention is intended to provide a ink-jet printing device which can detect leak of ink or solvent without the exclusive sensor for leak detection and without increasing cost. An ink jet printing device for printing letter by ejecting ink, comprising, a liquid container for containing ink or solvent, a surface level sensor for detecting surface level arranged on the liquid container, a control unit and a display unit, wherein the display unit displays indication in the case where the surface level change time detected by the control unit using the surface level sensor is larger than the settled surface level change time in settled printing condition is provided for solving the problem.

This disclosure relates to an ink composition (e.g., a hot melt ink composition or a radiation curable ink composition) that has a relatively low conductivity. This disclosure also relates to a continuous printing process using such a composition and a product containing such a composition.

This disclosure relates to an ink composition (e.g., a hot melt ink composition or a radiation curable ink composition) that has a relatively low conductivity. This disclosure also relates to a continuous printing process using such a composition and a product containing such a composition.

This disclosure relates to an ink composition (e.g., a hot melt ink composition or a radiation curable ink composition) that has a relatively low conductivity. This disclosure also relates to a continuous printing process using such a composition and a product containing such a composition.

This disclosure relates to an ink composition (e.g., a hot melt ink composition or a radiation curable ink composition) that has a relatively low conductivity. This disclosure also relates to a continuous printing process using such a composition and a product containing such a composition.

The invention relates to a method of printing a two-dimensional bit-mapped image having a number of pixels per row, the printhead having a row of ejection channels and each ejection channel having associated ejection electrodes to which voltages are applied in use. During printing, in order to cause volumes of fluid to be ejected from selected ejection channels of the printhead for printing, voltage pulses having values of predetermined amplitude and duration as determined by respective image pixel bit values generated by a raster image processor are applied, at a given pulse period, to the electrodes of the selected ejection channels. The part of the raster image corresponding to an ejection channel is scanned to determine the number of adjacent non-printing pixel periods prior to a pixel to be printed and, immediately prior to the printing of said pixel, a voltage pulse, having a value predetermined in accordance with the time, measured in units of the given pixel period, between the last pixel to be printed and said pixel to be printed, is applied to the ejection electrode.

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.