A silicon nozzle plate includes nozzles each with a first nozzle portion having a circular cross-section and a second nozzle portion having a circular cross-section wherein the circular cross-section of the first nozzle portion is smaller than the circular cross-section of the second nozzle portion....http://www.google.com.au/patents/US6863375?utm_source=gb-gplus-sharePatent US6863375 - Ejection device and inkjet head with silicon nozzle plate
