Patent ID: 7735972

Claim:
A method of ejecting drops of an ejectable liquid from a printhead, the printhead comprising: a plurality of nozzles; a bubble forming chamber corresponding to each of the nozzles respectively; a plurality of heater elements disposed in each of the bubble forming chambers respectively, each heater element configured for thermal contact with a bubble forming liquid; wherein, each heater element is an elongate strip suspended between corresponding electrodes on opposite sides of the bubble forming chamber, each strip having a cross section with a lateral dimension at least triple that of the thickness of that strip and different than a lateral dimension of each other strip of the corresponding bubble forming chamber, the thickness of each strip being less than 0.3 microns, and the heater elements and associated electrodes are arranged so that the electrodes are non-coincident with the electrodes of the other heater elements; the method comprising the steps of: heating the heater element to a temperature above the boiling point of the bubble forming liquid to form a gas bubble on an axis which extends through the center of the nozzle that causes the ejection of a drop of an ejectable liquid from the nozzle; and supplying the nozzle with a replacement volume of the ejectable liquid equivalent to the ejected drop.