Droplet deposition apparatus comprises a plurality of fluid chambers (2), each fluid ejection chamber being defined in part by at least one wall (11) actuable by an electrical signal to effect droplet ejection from that chamber. The apparatus provides means (16) for cyclically supplying electrical signals to the walls (11) for actuation thereof, means (60) for measuring, within a period between the application of successive electrical signals to the walls, a temperature dependent electrical property of a wall of a fluid chamber to provide a signal having a magnitude dependant on the temperature of fluid in the fluid chambers, and means for adjusting the magnitude of the actuating electrical signals depending on the magnitude of the temperature dependant signal.

An actuator taking the form of a piezoelectric wall separating two chambers, which utilizes two actuation modes. Both actuation modes cause volume displacements in both chambers, but act to reinforce one another in one chamber and cancel one another in the other chamber. A fluid pump for droplet deposition having an array of channels separated by such actuators can be operated with each channel acting substantially independently of its neighbors.

Inkjet printhead with an array of ejection chambers spaced in an array direction, each communicating with an ink orifice, inlet and outlet plenum chambers communicating with the ejection chambers, and inlet and outlet manifolds extending in the array direction and communicating with the plenum chambers through a porous sheet. While there are substantial net ink flows in the array direction in the inlet and the outlet manifolds, there is substantially no net flow in the array direction in the inlet or outlet plenum chamber. Ink pressure is therefore constant over the array of ejection chambers.

A nozzle plate component manufactured by forming a layer of photoresist on a substrate and selectively exposing and removing material to define an array of distinct bodies. Nickel is then electroformed around the bodies to form a plate, with nozzles subsequently formed by ablation through the photoresist. The process can essentially be repeated to form a guard structure around each nozzle.

A nozzle in a nozzle plate for an inkjet printhead is formed by directing a laser beam at a nozzle plate. Accurate control of the divergence of the beam is achieved by splitting the beam into sub-beams, each sub-beam having divergence with an origin lying apart from the point at which the beam is created by splitting, and thereafter recombining the sub-beams. Greater accuracy in the taper and inlet shape of the manufactured nozzle is thereby obtained.