PRINTHEAD NOZZLE ARRANGEMENT EMPLOYING VARIABLE VOLUME NOZZLE CHAMBER
A printhead has a plurality of nozzle arrangements. Each nozzle arrangement includes an ink inlet aperture for receiving ink into the nozzle arrangmenet; a wall portion bounding the ink inlet aperture; a crown portion arranged opposite the ink inlet aperture and defining a nozzle opening; a skirt portion depending from the crown portion to form part of a peripheral wall of the nozzle arrangement, the crown and skirt portions being displaceable with respect to the wall portion towards the substrate to alter a volume of a nozzle chamber defined by the wall, crown and skirt portions; and a thermal actuator interconnecting the crown portion with the substrate, the actuator for displacing the crown and skirt portions. The wall portion is angled inwardly with respect to the nozzle chamber defined by the wall, crown, and skirt portions. The wall portion defines a lip at a to free end thereof, the lip for facilitating the formation of a fluidic seal with the skirt portion.
1 . A printhead having a plurality of nozzle arrangements, each nozzle arrangement comprising:
an ink inlet aperture for receiving ink into the nozzle arrangmenet;
a wall portion bounding the ink inlet aperture;
a crown portion arranged opposite the ink inlet aperture and defining a nozzle opening;
a skirt portion depending from the crown portion to form part of a peripheral wall of the nozzle arrangement, the crown and skirt portions being displaceable with respect to the wall portion towards the substrate to alter a volume of a nozzle chamber defined by the wall, crown and skirt portions; and
a thermal actuator interconnecting the crown portion with the substrate, the actuator for displacing the crown and skirt portions, wherein
the wall portion is angled inwardly with respect to the nozzle chamber defined by the wall, crown, and skirt portions, and
the wall portion defines a lip at a free end thereof, the lip for facilitating the formation of a fluidic seal with the skirt portion.
2 . The printhead of claim 1 , wherein each nozzle arrangement further comprises a layer of micro-electromechanical drive circuitry for actuating the actuator.
3 . The printhead of claim 1 , wherein the actuator has a first active beam arranged above a second passive beam, the beams fabricated from a conductive ceramic material with an electrical connection between the active beam and the drive circuitry established via conductive pads.
4 . The printhead of claim 1 , wherein the skirt portion defines a first part of a peripheral wall of the nozzle chamber and the wall portion defines a second part of the peripheral wall of the nozzle chamber.
5 . The printhead of claim 1 , wherein the actuator is connected to an anchor extending upwardly from a substrate in which the ink inlet aperture is defined, said anchor mounted on the conductive pads to form an electrical connection with the actuator.
6 . The printhead of claim 1 , wherein the nozzle opening is arranged at an angle to the vertical so that ejection of ink deviates from the perpendicular.
7 . The printhead of claim 1 , further comprising a nozzle guard having a planar cover member positioned on a support structure extending from the substrate, the planar cover member defining a plurality of passages, each passage being in register with a respective nozzle opening.
8 . The printhead of claim 7 , wherein the support structure of the nozzle guard defines a number of openings for permitting the ingress of air into a region between the printhead and the cover member, whereby air is permitted to pass through the passages.