Patent ID: 7971960

Claim:
A printhead integrated circuit comprising: a plurality of nozzles formed on a frontside of a monolithic wafer substrate, the nozzles being arranged in rows extending longitudinally along the substrate, each nozzle having a respective nozzle inlet extending partially through the monolithic wafer substrate; and a plurality of ink supply channels defined in a backside surface of the monolithic wafer substrate and extending longitudinally along the backside of the substrate, each ink supply channel being deep enough to meet the nozzle inlets such that ink fed to the backside surface of the substrate is supplied to the nozzles on the frontside, the nozzles supplied with ink from one of the ink supply channels being different to the nozzles supplied with ink by another of the ink supply channels such that different ink colors are simultaneously printed; wherein each ink supply channel is separated into channel sections by one or more transverse walls that structurally stiffen the monolithic wafer substrate.