Patent ID: 7824017

Claim:
A printhead comprising: a substrate including a nozzle; and a drop forming mechanism disposed on the substrate, the drop forming mechanism including a plurality of straight resistor segments made of a first material and a plurality of coupling segments made of a second material, the plurality of straight resistor segments being positioned on every side of the nozzle, one of the plurality of coupling segments being positioned between two of the plurality of straight resistor segments, each of the plurality of coupling segments including a short current path and a long current path, the short current path and the long current path being present throughout each of the plurality of coupling segments such that current crowding exists throughout each of the plurality of coupling segments, each of the plurality of straight resistor segments having an electrical resistivity, each of the plurality of the coupling segments having an electrical resistivity, wherein the ratio of the resistivity of each of the plurality of coupling segments to the resistivity of each of the plurality of straight resistor segments is selected such that little or no heat is generated within each of the plurality of coupling segments even though current crowding still exists within each of the plurality of coupling segments, and wherein the first material and the second material are of the same material, the first material having a first doping and the second material having a second doping, the first doping being different when compared to the second doping.