Patent ID: 6402282
Filing Date: 2002-06-11
Classification: B41J

Abstract:
Method of operating an inkjet printhead for printing on a substrate; the printhead having a chamber communicating with a nozzle for ejection of ink droplets and with a supply of ink;the printhead further comprising electrically actuable means associated with the chamber and actuable in accordance with print tone data, thereby to eject ink droplets to form a printed dot of appropriate tone on the substrate; the method comprising the steps of: applying two or more successive electrical signals to the electrically actuable means in accordance with the print tone data to effect ejection of two or more successive corresponding droplets, each corresponding to one of the successive signals, a time delay between application of the successive signals being such that any variation in an average velocity at which the corresponding droplets travel to the substrate to form said printed dot remains below that which would lead to droplet placement errors in a printed image detectable by an individual viewing the printed image, regardless of how many of the corresponding droplets are ejected to form said printed dot.