METHOD AND DEVICE FOR INCREASING NUMBER OF INK DROPS IN AN INK DROP JET OF A CONTINUOUSLY OPERATING INKJET PRINTER

Abstract

The invention concerns a method for increasing the number of ink drops in an ink drop jet of a continuously operating inkjet printer, in which the ink drops of at least two separately produced ink drop jets are combined into an ink drop jet. In one example embodiment this is done so that the combined ink drop jet includes the ink drops of the respective separate ink drop jets. The invention also concerns a device for production of an ink drop jet of a continuously operating inkjet printer, which includes at least two pressure chambers for generation of a separate ink drop jet with electrically charged ink drops and an electrode arrangement wherein the separate ink drop jets can be combined into a singe ink drop jet.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1: shows a print head according to the invention for combining two separate ink drop jets in an electrode arrangement;

FIG. 2: shows an example arrangement according to FIG. 1 with an electrode arrangement for stabilization connected afterwards;

FIG. 3: shows a print head according to one aspect of the invention for combining three separate ink drop jets in an electrode arrangement.

Claims

1. A method for increasing the number of ink drops in an ink drop jet of a continuously operating inkjet printer, comprising: combining the ink drops from at least two separately produced ink drop jets to an ink drop jet so that the combined ink drop jet includes the ink drops of the respective separate ink drop jets.

2. The method according to claim 1, further comprising: electrically charging the ink drops of the separately produced ink drop jets, andcombining the separately produced ink drop jets to a single ink drop jet by deflection in at least one electric field.

3. The method according to claim 2, wherein the at least one electric field is an electrostatic field.

4. The method according to claim 2, wherein the ink drops acquire the same charge in a separate ink drop jet.

5. The method according to claim 2, wherein the separate ink drop jets are arranged in an angle relative to each other before deflection.

6. The method according to claim 2, wherein the ink drops of the separate ink drop jets are combined phase-shifted relative to each other into an ink drop jet.

7. The method according to claim 6, wherein the ink drops of the separate ink drop jets are combined phase-shifted relative to each other into an ink drop jet at the same frequency.

8. The method according to claim 6, wherein the phase shift is produced by phase-shifted electronic control of separate ink drop generating pressure chambers in terms of time shifting of a pressure chamber along the direction of at least one separate ink drop jet.

9. The method according to claim 6, wherein the phase shift is produced by phase-shifted electronic control of separate ink drop generating pressure chambers in terms of spatial shifting of a pressure chamber along the direction of at least one separate ink drop jet.

10. The method according to claim 6, wherein the phase shift is produced by phase-shifted electronic control of separate ink drop generating pressure chambers in terms of time and spatial shifting of a pressure chamber along the direction of at least one separate ink drop jet.

11. The method according to claim 6, wherein the phase shift of the ink drops between two separate ink drop jets is chosen at 360°/n, where n is the number of separate ink drop jets.

12. The method according to claim 2, wherein the deflection of separate ink drop jets to a combined ink drop jet is carried out by means of an electrode arrangement, which acts by at least one electric field, on at least two separate ink drop jets and is field-free in the area of the combined ink drop jet.

13. The method according to claim 2, wherein the at least one electric field is an electrostatic field.

14. The method according to claim 2, wherein at least one of the separate ink drop jets is guided field-free through an electrode arrangement for deflection of at least one other separate ink drop jet.

15. The method according to claim 2, wherein at least one of the separate ink drop jets is guided field-free through an electrode arrangement for deflection of at least one other separate ink drop jet,wherein the at least one ink drop jet guided field-free is produced coaxial to the combined ink drop jet.

16. The method according to claim 2, wherein groups of separate ink drop jets are combined to an ink drop jet, which in turn are combined again.

17. A device for generating an ink drop jet of a continuously operating inkjet printer, comprising: at least two pressure chambers for generating a separate ink drop jet with electrically charged ink drops and an electrode arrangement structured to combine the separate ink drop jets into an ink drop jet.

18. The device according to claim 17, wherein the pressure chambers are aligned at an angle relative to each other so that the undeflected separate ink drop jets intersect each other at a common intersection point.

19. The device according to claim 17, wherein modulation elements of at least two pressure chambers are driven with the same frequency.

20. The device according to claim 17, wherein the ink drops emerging from the at least two pressure chambers can be produced phase-shifted relative to each other in time and space.

21. The device according to claim 17, wherein the ink drops emerging from the at least two pressure chambers can be produced phase-shifted relative to each other in time and space by adjustability of the excitation frequency of the modulation elements of the at least two pressure chambers.

22. The device according to claim 17, wherein the ink drops emerging from the at least two pressure chambers can be produced phase-shifted relative to each other in time and space by phase-shiftability of the excitation frequency of the modulation elements of the at least two pressure chambers.

23. The device according to claim 17, wherein the ink drops emerging from the at least two pressure chambers can be produced phase-shifted relative to each other in time and space by adjustability and phase-shiftability of the excitation frequency of the modulation elements of the at least two pressure chambers.

24. The device according to claim 17, wherein, in the drop flight direction after a pressure chamber a charging electrode arrangement is arranged in order to charge the ink drops with an electric charge.

25. The device according to claim 17, wherein, in the drop flight direction after a pressure chamber a charging electrode arrangement is arranged in order to charge the ink drops with an electric charge, wherein each ink drop is charged with the same charge.

26. The device according to claim 17, further comprising: at least one electrode arrangement wherein at least one separate ink drop jet can be deflected so that it is combined with at least one other separate ink drop jet into an ink drop jet.

27. The device according to claim 17wherein the at least one electrode arrangement is a plate capacitor arrangement.

28. The device according to claim 26, further comprising: an electrode arrangement for combining two separate ink drop jets formed by a first electrode and a second electrode between which a third electrode is arranged, in which a first separate ink drop jet runs between the first and third electrodes and a second ink drop jet runs between the second and third electrodes.

29. The device according to claim 28, wherein the first and second electrodes have the same electric potential.

30. The device according to claim 28, wherein the third electrode is arranged in the drop flight direction between the first and second electrode so that it is positioned in the flight direction.

31. The device according to claim 28, wherein a third separate ink drop jet runs through the third electrode, which runs field-free through the electrode and is arranged coaxial to the combined ink drop jet.

32. The device according to claim 26, wherein the electrode arrangement for combining the separate ink drop jets has an additional electrode arrangement positioned behind it to stabilize the flight paths of the individual ink drops of the combined ink drop jet.

33. The device according to claim 17wherein the device is a print head of a continuously operating ink jet printer.