The invention describes a method and apparatus for characterising EHT tripping events and thus discriminating between false trip events and those that warrant the printer being shut down.

The invention describes a method and apparatus for characterising EHT tripping events and thus discriminating between false trip events and those that warrant the printer being shut down.

A method comprises: providing a first stream of discrete volumes (908b) of material, and directing a pulsed laser beam (912) at a first discrete volume (908b) of material in the first stream of discrete volumes of material so as to interact with the first discrete volume of material and thereby displace the first discrete volume away from the first stream. An apparatus and a system for achieving such steps are also disclosed.

A method comprises: providing a first stream of discrete volumes (908b) of material, and directing a pulsed laser beam (912) at a first discrete volume (908b) of material in the first stream of discrete volumes of material so as to interact with the first discrete volume of material and thereby displace the first discrete volume away from the first stream. An apparatus and a system for achieving such steps are also disclosed.

A print head of a continuous ink jet printer, including, in a cover: means for producing at least one ink jet; means for separating drops of jets intended for printing from those that do not serve for printing; a slot, enabling drops intended for printing to get out; a recovery gutter (7) for drops not intended for printing, the recovery gutter comprising an ink recovery volume (12); at least one detection conductor (20), arranged inside the head; means (16) for detecting a variation in impedance of at least one of the detection conductors when ink (21) is present in contact with the conductor or with a dielectric layer (22) in contact therewith.

A print head of a continuous ink jet printer, including, in a cover: means for producing at least one ink jet; means for separating drops of jets intended for printing from those that do not serve for printing; a slot, enabling drops intended for printing to get out; a recovery gutter (7) for drops not intended for printing, the recovery gutter comprising an ink recovery volume (12); at least one detection conductor (20), arranged inside the head; means (16) for detecting a variation in impedance of at least one of the detection conductors when ink (21) is present in contact with the conductor or with a dielectric layer (22) in contact therewith.

The invention firstly relates to a print head of a continuous ink jet printer, comprising a first reservoir (12) and a second reservoir (22), arranged on either side of least one jet ejection nozzle (30, 30.sub.1-30.sub.n) to which they are connected, and a first actuator (16, 16.sub.1-16.sub.n) for applying a 1.sup.st pressure to the ink of the, or coming from the, 1.sup.st reservoir, and a second actuator (26, 26.sub.1-26.sub.n) for applying a 2.sup.nd pressure to the ink of the, or coming from the, 2.sup.nd reservoir, and a controller for controlling these first and second actuators, said controller being programmed to apply a variable difference between these 2 pressures.

The invention firstly relates to a print head of a continuous ink jet printer, comprising a first reservoir (12) and a second reservoir (22), arranged on either side of least one jet ejection nozzle (30, 30.sub.1-30.sub.n) to which they are connected, and a first actuator (16, 16.sub.1-16.sub.n) for applying a 1.sup.st pressure to the ink of the, or coming from the, 1.sup.st reservoir, and a second actuator (26, 26.sub.1-26.sub.n) for applying a 2.sup.nd pressure to the ink of the, or coming from the, 2.sup.nd reservoir, and a controller for controlling these first and second actuators, said controller being programmed to apply a variable difference between these 2 pressures.

An inkjet printing apparatus comprises an inkjet head disposed above a stage and including nozzles through which ink including bipolar elements is discharged, the bipolar elements each having regions partially doped with different polarities. At least part of the nozzles is deflected from a direction in case that the nozzles are in a deflected state.

An inkjet printing apparatus comprises an inkjet head disposed above a stage and including nozzles through which ink including bipolar elements is discharged, the bipolar elements each having regions partially doped with different polarities. At least part of the nozzles is deflected from a direction in case that the nozzles are in a deflected state.