Abstract: In a continuous ink jet printer of the type in which drops can be deflected to a plurality of print positions, the path of undeflected drops is angled relative to the substrate 23 which is printed onto, so as to shorten the path of the most deflected drops. Since the most deflected drops are the least stable, this tends to increase print quality or allow greater printing speed. The plane of deflection of ink drops may be parallel to a circuit board 1 on which components of the print head are mounted, enabling a deflection electrode 15 and other electrodes to be formed directly on the circuit board, thereby reducing the number of components which have to be mounted separately onto the circuit board 1.
Abstract: To flush ink out of the ink gun 15 of an ink jet printer, it is connected to a suction source 23 (normally used for gutter suction) through a purge line 33, purge valve 35 and gutter valve 27, while the ink feed line 13 is connected to the solvent reservoir 17 through a feed valve 11 and a flush valve 37. This draws solvent from the solvent reservoir 29 into the feed line 13 and the ink gun 15. Then, the purge line 33 is isolated from the suction device 23, and the feed valve 11 connects the feed line 13 to a supply of ink pressurized by ink pump 5. The pressurized ink is driven into the feed line 13, driving some of the solvent already in the feed line and the ink gun 15 out through the nozzle of the ink gun 15. The ink flow is then stopped before fresh ink reaches the ink gun 15. This avoids ink drying in the ink gun 15, blocking the nozzle, while the jet is not running.