Patent ID: 7703890

Claim:
A printhead comprising: an array of ink ejection nozzles; an array of chambers adapted to store ink for ejection through each of the nozzles respectively; a plurality of ink inlet channels for feeding ink to the array of chambers; a plurality of actuators, one of the actuators being positioned in each of the chambers respectively for ejecting drops of ink through the nozzle; and, a plurality of elongate ink feed channels connected to the ink inlet channels; a silicon substrate for supporting the array of chambers and defining the elongate ink feed channels, the silicon substrate having a planar structure with one surface that supports the chambers and an opposing surface from which the elongate ink feed channels extend; and layers of CMOS drive circuitry supported on the silicon substrate; wherein, the ink inlet channels each extend through the layers of CMOS drive circuitry and each of the ink inlet channels being long and narrow relative to the dimensions of the chamber such that ink in said chamber is restricted from flowing out during ink drop ejection by viscous drag generated by the ink inlet channel.