US 6,273,559 B1 · Spraying process for an electrically conducting liquid and a continuous ink jet printing device using this process

Abstract

One or several jets (14) of an electrically conducting liquid such as ink, are emitted at a given speed Vj and are stimulated so as to form drops (22, 24) at a frequency F, at two break off points (C, L) separated by a distance ΔD less than the wavelength λ of the jet, defined by the relation λ=Vj/F. Two contiguous areas are created (20) in the vicinity of these two break off points (C, L), and the potential of these two areas is brought up to constant electrical potentials with opposite signs (V1, V2). Different quantities of electric charge are thus applied on the drops (22, 24), which are relatively constant even if the break off points should vary. A deflection device (30) then deviates the drops to be recycled (24) and the drops to be printed (22) depending on their charge, which depends on their break off point.

Claims11

Dependent claims

Process for projecting an electrically conducting liquid comprising the steps of:

emitting at least one continuous liquid jet at a constant speed Vj;
stimulating the jet on request, so as to break it at two predetermined distinct break off points to form liquid drops at a given emission frequency F;
applying different electric charge quantities to the drops, depending on their break off points;
and then
applying a same electric field on all drops, so as to only deviate drops formed at one of the first of the said break off points which is relatively distant;
and in which the jet is stimulated such that the two break off points are separated by a distance ΔD strictly less than a wavelength λ of the jet, defined by the relation λ=Vj/F, and approximately the same quantity of charge is applied to all drops formed within an area around the second of the said break off points, said area centered on the second break off point and having a length equal to approximately λ/4.

3 more elements

Continuous ink jet printing device comprising:

a pressurized reservoir equipped with several nozzles capable of simultaneously emitting several continuous ink jets parallel to each other, at a given speed Vj;
an individual means of binary stimulation of each jet, capable of fragmenting these jets on request, at two distinct predetermined break off points, to form ink drops at a given emission frequency F;
a charging means common to all ink jets, to apply different quantities of electric charge to the ink drops, depending on the break off points;
a deflection means common to the several ink jets, to apply a same electrical field to the drops, in order to deviate only the drops formed at the first of the break off points relatively far from the nozzle;
and
a recycling gutter for drops deviated towards the pressurized reservoir;
in which the individual binary stimulation means for each jet is controlled by predefined voltage levels such that the two break off points are separated by a distance strictly less than a wavelength λ of the jet defined by the relation λ=Vj/F, the charging means being capable of applying approximately the same quantity of charge on all drops formed within an area around the second of the said break off points, said area centered on the second break off point and having a length equal to approximately λ/4.

4 more elements

Dependencies are inferred from the claim text.

Spraying process for an electrically conducting liquid and a continuous ink jet printing device using this process

Life of this patent

Spraying process for an electrically conducting liquid and a continuous ink jet printing device using this process

Life of this patent

Abstract

Claims11