Patent ID: 7980664

Claim:
A pagewidth printhead comprising: a printhead controller; a wafer substrate defining a plurality of inlets; and a plurality of micro-electromechanical nozzle arrangements on the wafer substrate and under control of the controller, each nozzle arrangement comprising: side walls disposed on the wafer substrate with a roof portion attached to said side walls to define a printing fluid chamber in fluid communication with one inlet, the roof portion defining an ejection port; at least two heater elements suspended between the side walls in the fluid chamber for forming a vapour bubble in response to electrical actuation energy being applied thereto, whereby a pressure increase in the chamber is effected and fluid in the fluid chamber ejected therefrom via the ejection port, wherein the controller is configured to actuate the at least two heater elements individually to facilitate ejection of weighted ink drop volumes from the nozzle arrangement, and a size of a first of the at least two heater elements is different to a size of a second of the at least two heater elements.