Patent ID: 7407271

Claim:
An ink jet printhead comprising: a plurality of nozzles; and at least one respective heater element corresponding to each nozzle, wherein the printhead is configured to receive ejectable liquid at an ambient temperature, and wherein each heater element is arranged for being in thermal contact with the ejectable liquid, each heater element is configured to receive energy as an electrical pulse with a duration less than 1 microsecond to heat at least part of the ejectable liquid to a temperature above its boiling point to form a gas bubble therein thereby to cause the ejection of a drop of the ejectable liquid through the corresponding nozzle; and each heater element is configured such that the energy required to be applied thereto to heat said part to cause the ejection of said drop is less than the energy required to heat a volume of said ejectable liquid equal to the volume of said drop, from a temperature equal to said ambient temperature to said boiling point.