METHOD AND DEVICE FOR RECOVERING OPERATION OF INK JET PRINTING NOZZLE

摘要

The operation restorer has blockages eliminated by a control circuit (118) which operates at a higher frequency than that used for printing, under control of a microprocessor (120), electronic selector switch (124) and frequency generator (122). Simultaneously suction is produced by a suction pump (38) connected to a resilient cup (34) fitted in front of the nozzles in a parking position of the head (12) beyond a platen. Before the cup is withdrawn from the nozzles the suction is nullified by opening a vent (89) to ensure the ink does not escape. A rubber disc adjacent to the platen roller cleans the printing elements as they wipe across its edge as the head moves back in front of the platen.