Patent ID: 6922203

Claim:
An ink jet printhead comprising: a substrate; an ink feed slot formed through the substrate; a thin film layer disposed on a surface of the substrate, the thin film layer defining a plurality of firing resistors, a plurality of ink feed openings formed through the thin film layer to provide respective ink paths through the thin film layer from the ink feed slot; a barrier/orifice structure disposed on the thin film layer, the structure defining an array of nozzles arranged in a plurality of nozzle columns and an array of firing chambers in correspondence with correspondence with the array of nozzles; the firing resistors being arranged in correspondence with the firing chambers; the barrier/orifice structure further comprising a continuous rib portion extending between adjacent first and second ones of the plurality of nozzle columns and over said ink feed slot to fluidically separate the first and second ones of the nozzle columns; wherein said plurality of ink feed openings are arranged in a first group on a first side of said rib portion for feeding nozzles of the first one of said plurality of columns, and a second group on a second side of said rib portion for feeding nozzles of the second one of said plurality of columns; and wherein the nozzles comprising the array are arranged in subgroups of nozzles, each subgroup comprising at least two nozzles, each subgroup fed with liquid ink through a corresponding ink flow path isolated from other nozzles of the array by the barrier layer/orifice structure, wherein the ink flow path for each nozzle subgroup includes an opening or set of openings through the thin film layer and through the substrate, and wherein each nozzle of a nozzle subgroup supplied with ink via said opening or set of openings.