Pressure enhancing formations in an ink jet printhead

Abstract

A printer has at least one ink jet printhead including a substrate that defines a plurality of ink inlet channels. A plurality of micro-electromechanical nozzle arrangements is positioned on the substrate. Each nozzle arrangement includes a nozzle chamber positioned on the substrate and having a fixed portion that is fast with the substrate and a movable portion that is displaceable with respect to the substrate and that defines an ink ejection port. The nozzle chamber is in fluid communication with a respective ink inlet channel and the movable portion is displaceable towards and away from the substrate respectively to eject ink from the ink ejection port. An actuator is anchored to the substrate and is operatively engaged with the movable portion to displace the movable portion towards the substrate upon receipt of an electrical signal. A restrictive formation is arranged on the substrate and defines an opening that has a cross-sectional area that is less than that of the ink inlet channel.

Dependencies are inferred from the claim text.