Patent ID: 7690760

Claim:
A printhead for a thermal ink jet printer, the printhead comprising: a substrate containing at least one ink feed edge and a plurality of heater resistors spaced a distance from the ink feed edge in a substantially linear array of adjacent heater resistors, each of the heater resistors having a resistance ranging from about 80 to about 200 ohms; and a nozzle plate adjacent to the substrate, the nozzle plate containing a plurality of nozzle holes ink chambers, and ink channels laser ablated in the nozzle plate corresponding to the plurality of heater resistors, wherein adjacent nozzle holes for the heater resistors are spaced apart with a pitch ranging from about 600 to about 1200 dpi wherein the distance from the ink feed edge to the heater resistors ranges from about 20 to about 90 microns and wherein the distance from the ink feed edge is substantially the same for each of the heater resistors and wherein each ink chamber has at least one chamber wall that is not perpendicular to the substrate and provides a predetermined distance between the top and bottom of the chamber wall, and wherein the at least one chamber wall that is not perpendicular to the substrate and provides a predetermined distance between the top and bottom of the chamber wall has an angle of inclination of about 6° to about 18°.