Method of cleaning nozzles in inkjet printhead

• Main Author: Dietl, Steven J
• Format: Patent
• Language: English
• Published: 14.09.2004

The invention generally relates to inkjet printers, and more particularly to a method of cleaning nozzles in an inkjet printhead. A method of cleaning spaced nozzles in a printhead of a drop-on-demand inkjet printer in which a slight negative pressure is desired in an ink reservoir in order to prevent ink drool from the nozzles, comprises: deforming a compliant pressure regulator membrane that covers an opening in an ink reservoir, inwardly at the opening, to decrease the ink holding volume of the reservoir; deforming a compliant valve membrane that covers an opening in the ink reservoir and caps an ink conduit projecting into the reservoir, outwardly at the opening and away from the ink conduit, to uncap the ink conduit in order that the ink conduit can provide ink delivery at a positive pressure into the reservoir and out through the nozzles to clean the nozzles; returning the compliant valve membrane inwardly towards the ink conduit to recap the ink conduit in order to terminate ink delivery into the reservoir; and returning the compliant pressure regulator membrane outwardly to increase the ink holding volume of the reservoir in order to reduce ink pressure in the reservoir. Also, the method can further comprise: ejecting some ink from the nozzles by activating thermal or piezoelectric activators for the nozzles, in order to ensure a slight negative pressure in the reservoir.