Abstract: To clean a print head of an ink jet printer comprising an ink gun (1), connected, by means of devices capable of being controlled, to an ink chamber (2), a solvent chamber (8), a vacuum source (16), and an ink collection gutter (22) capable of being connected in a controlled manner to a vacuum source (16), the following steps are performed: (1) an interruption of a hydraulic connection between the gun (1) and the ink chamber (2) is ordered, (2) the gun (1) is connected to the vacuum source (16), (3) the solvent chamber (8) is hydraulically connected to the vacuum source (16) via a circuit (12, 14, 20) comprising the ink gun (1).

Abstract: An ink jet printer is characterised in that a connection part (1) of an umbilical connected to a connection part of a print head of the printer, comprises: first (12, 13, 14, 15, 17, 18, 20–23, 25) and second means (12, 14, 15, 16, 25) for positioning the umbilical electrical terminations (13, 19) and hydraulic terminations (24) mechanically fixed to the connection part (1) of the umbilical; third (12, 28) positioning means mechanically connected to the umbilical, and fourth positioning means (31, 48) mechanically connected to the connection part (3) of the print head, the third (12, 28) positioning means and the fourth positioning means (31, 48) cooperating to position the connection part (1) of the umbilical with respect to the connection part (3) of the print head. A translation movement alone is necessary to connect the umbilical onto the print head.

Abstract: A printer head of an ink jet printer is provided with an internal stimulation system with which it is possible to create in an upstream breaking position of a jet, an upstream break-up forming in a zero potential area, drops which will be used for printing, and jet sections on the one hand and in a downstream breaking position, a break-up of the jet or of sections of the jet forming in a non-zero potential area, drops which are recovered on the other hand. A sorting system common to all the jets of the head provides simplification of the head and reduction of its bulkiness.

Abstract: A twin-nozzle print head for a continuous inkjet deflection printer comprises an ink drop generator assembly having two inkjet ejection nozzles, each of the nozzles having an ejection axis. Charge electrodes, deflection electrodes deflecting charged drops and a single ink drop recovery gutter for both nozzles are also provided. The ejection axes of nozzles converge at a point located on an axis of a single inlet orifice of the single recovery gutter in the vicinity of this orifice or upstream of this gutter. A printer equipped with this head prints swathes of large width with good juncture.

Abstract: A closed ink supply system wherein air is sealed outside the system and not allowed to flow into components of the system may include an ink source. A first ink sub-reservoir may also be included that comprises a first top fluid surface at a first sub-reservoir fluid height, a first sub-reservoir ink inlet fluidly connected to the ink source, and a first sub-reservoir outlet and a second sub-reservoir outlet that is above the first sub-reservoir outlet. A print head may also be included that comprises a first print head portion fluidly connected to the first sub-reservoir outlet, and a second print head portion fluidly connected to the second sub-reservoir outlet. The second print head portion may be above the first print head portion, whereby a first pressure at the first print head portion is substantially equal to a second pressure at the second print head portion.

Abstract: An ink composition for continuous deflected jet printing that is liquid at room temperature and that contains: a binder; one or more dyes and/or pigments; and a solvent; wherein the said solvent contains more than 70% by weight—relative to the total weight of the ink—of propylene carbonate, and less than 10% by weight, preferably less than 5%, more preferably less than 1% and best 0% by weight of water.

Abstract: A printer head (1) of an ink jet printer (10), is provided with an internal stimulation system (31) with which it is possible to create in an upstream breaking position (11) of a jet (30), an upstream break-up forming in a zero potential area, drops (33) which will be used for printing, and jet sections (38) on the one hand and in a downstream breaking position (12), a break-up of the jet (30) or of sections (38) of the jet forming in a non-zero potential area, drops (43) which are recovered on the other hand. A sorting system (35) common to all the jets (30) of the head provides simplification of the head and reduction of its bulkiness.

Abstract: An ink jet printer is characterised in that a connection part (1) of an umbilical connected to a connection part of a print head of the printer, comprises: first (12, 13, 14, 15, 17, 18, 20-23, 25) and second means (12, 14, 15, 16, 25) for positioning the umbilical electrical terminations (13, 19) and hydraulic terminations (24) mechanically fixed to the connection part (1) of the umbilical; third (12, 28) positioning means mechanically connected to the umbilical, and fourth positioning means (31, 48) mechanically connected to the connection part (3) of the print head, the third (12, 28) positioning means and the fourth positioning means (31, 48) cooperating to position the connection part (1) of the umbilical with respect to the connection part (3) of the print head. A translation movement alone is necessary to connect the umbilical onto the print head.

Abstract: An ink composition for continuous deflected jet printing that is liquid at room temperature and that contains: a binder; one or more dyes and/or pigments; and a solvent; wherein the said solvent contains more than 70% by weight—relative to the total weight of the ink—of propylene carbonate, and less than 10% by weight, preferably less than 5%, more preferably less than 1% and best 0% by weight of water.

Abstract: Ink composition, in particular for continuous deflected ink jet printing comprising: a binder one or several dyes and/or pigments, and a solvent in which the said solvent comprises at least 10% by weight—in relation to the total weight of the ink—of 1,3-dioxolane, at least 5% by weight of one or several other organic compounds that can dissociate the ionisable species in the ink, and less than 5% water.

Abstract: An ink-drop generator (33) of an ink-jet printer is characterized in that a resonating ink cavity (6) from which the ink is supplied via a nozzle plate (39) onto a printing substrate has its lateral walls (7, 8, 9, 10) perpendicular to the nozzle plate (39). The end-nozzles may thus be positioned adjacent to the walls (9, 10) of the cavity (6).

Abstract: In a printing head of a printer with deviated continuous jet, one of the electrodes (2) for deviating the ink drops is provided in a downstream part with a longitudinal slit (12) presenting a plane of symmetry relative to a plane containing the axis of the ink jet. Thus the inter-electrode spacing can be reduced and the voltage present between the electrodes (2, 3) can be lowered without reducing the deflection efficiency.

Abstract: Process and device for cleaning the nozzles of ink jet printers, and the print head incorporating such a device. A fixed cleaning jet (22) is installed on the print head, downstream of the ink nozzle to be cleaned (18) and offset to one side of it. When the ink jet stops, a given volume of solvent is sprayed by this cleaning jet, which hits the nozzle (18) at an angle. In this way the front face of the droplet generator is cleaned and scoured, and the ink residues are ejected towards the opposite side of the housing (36). Dry compressed air is then blown through the cleaning jet towards the ink nozzle (18) to dry the front of the nozzle and the ink residues deposited on the side of the housing (36).

Abstract: A spraying control system for an electrically conducting liquid (3) emitted in the form of a pressurized jet (4) through at least one nozzle (2). The system contains apparatus for separating the liquid into drops, apparatus for electrically charging the drops and apparatus for applying an electrical deflection field to the charged drops. The system includes a first (8) and a second (6) monolithic element each with a continuous surface, laid out such that the continuous surfaces are facing each other and define a space (5) between them in which the pressurized jet (4) is emitted through the nozzle (2). The elements (6,8) include apparatus for continuously setting up potentials on the continuous surfaces to obtain the electrical charge of the drops and the electrical deflection field. The system also includes electronic control (31 to 36) for the potentials and apparatus for checking the intensity of electrical currents that can circulate on the continuous surfaces.

Abstract: Process for modification of the position at which electrically-charged ink droplets arrive on a substrate (27), the droplets being charged by charge electrodes (20) connected to a voltage generator, the paths of the droplets being affected by the action of deviation electrodes (23, 24) that deviate the droplets depending on the value of their electrical charge, between N positions defining a frame obtained by a burst of droplets in the form of a straight segment approximately parallel to an X direction along which the substrate advances, process characterized in that an additional random voltage equal to a fraction less than 1 of the difference between the nominal voltages to be applied to the charge electrodes for each droplet and for one of the two immediately adjacent droplets in the frame, is applied in addition to a nominal voltage to be applied to each droplet charging means.

Abstract: Process for compensation of mechanical defects in an ink jet printer in which the ink viscosity, the jet velocity, the distance at which the ink jet is broken into droplets and the phase are independently servocontrolled to respect set values, process according to which the droplet arrival position is compared with a reference position, and mechanical defects are compensated by varying the electrical charge on the droplets. The invention also relates to a printer equipped with checking and servocontrol means so that compensation according to the process can be applied. The mechanical assembly of the printer will thus be simplified.

Abstract: This invention relates to an ink jet printer and a method of managing the ink quality of such a printer, wherein information on ink pressure P, temperature T, jet speed V, and the nominal ink characteristics (&rgr;n(T), &mgr;n(T)) is available. When the machine is started for the first time, the ink jet is varied at its nominal value and the resulting pressure is measured so as to determine the values a and b characteristic of the ink circuit, the characteristics of the utilized ink &rgr;(T), &mgr;(T), and the difference in level between the print head and the pressure transducer H. These values allow to set the desired pressure value and to take corrective action on ink quality.

Abstract: Process for compensation of a defect in the advance of a print substrate by modifying the arrival position of ink droplets with a variable electrical charge on the substrate (27), these droplets being charged in a variable and sequential manner, the paths of the droplets being affected by deviation electrodes (23, 24) deviating the droplets to one of N positions defined by their row j (1≦j≦N), the N positions defining a frame obtained by a burst of droplets in the form of a straight line segment parallel to an X direction along which the substrate advances.

Abstract: The present invention relates to an ink circuit comprising an ink cartridge (10), an additive cartridge (11), a recovery tank (12), a storage tank or accumulator 913), a main filter (24), solenoid valves (8), an ink transfer pump (14) equipped with a pressure/temperature sensor (53), an air pressure regulator (30), said ink circuit comprising a double face support unit with a hydropneumatic face and an electronic face making it possible to separate the hydraulic, pneumatic and electronic assemblies, all the functional components being fitted outside on one or other of the two faces.

Abstract: Process for compensation of mechanical defects in an ink jet printer in which the ink viscosity, the jet velocity, the distance at which the ink jet is broken into droplets and the phase are independently servocontrolled to respect set values, process according to which the droplet arrival position is compared with a reference position, and mechanical defects are compensated by varying the electrical charge on the droplets. The invention also relates to a printer equipped with checking and servocontrol means so that compensation according to the process can be applied. The mechanical assembly of the printer will thus be simplified.